Publications

Stanford University Professor in Pulmonary and Critical Care Medicine

Publications

  • Airway hypoxia in lung transplantation CURRENT OPINION IN PHYSIOLOGY Pasupneti, S., Nicolls, M. R. 2019; 7: 21–26
  • Phenotypically-Silent Bone Morphogenetic Protein Receptor 2 (Bmpr2) Mutations Predispose Rats to Inflammation-Induced Pulmonary Arterial Hypertension by Enhancing The Risk for Neointimal Transformation. Circulation Tian, W., Jiang, X., Sung, Y. K., Shuffle, E., Wu, T. H., Kao, P. N., Tu, A. B., Dorfmüller, P., Cao, A., Wang, L., Peng, G., Kim, Y., Zhang, P., Chappell, J., Pasupneti, S., Dahms, P., Maguire, P., Chaib, H., Zamanian, R., Peters-Golden, M., Snyder, M. P., Voelkel, N. F., Humbert, M., Rabinovitch, M., Nicolls, M. R. 2019

    Abstract

    Bmpr2 mutations are critical risk factors for hereditary pulmonary arterial hypertension (hPAH) with approximately 20% of carriers developing disease. There is an unmet medical need to understand how environmental factors, such as inflammation, render Bmpr2 mutants susceptible to PAH. Overexpressing 5-lipoxygenase (5-LO) provokes lung inflammation and transient PAH in Bmpr2+/- mice. Accordingly, 5-LO and its metabolite, leukotriene B4 (LTB4), are candidates for the 'second hit'. The purpose of this study was to determine how 5-LO-mediated pulmonary inflammation synergized with phenotypically-silent Bmpr2 defects to elicit significant pulmonary vascular disease in rats.Monoallelic Bmpr2 mutant rats were generated and found phenotypically normal for up to one year of observation. To evaluate whether a second hit would elicit disease, animals were exposed to 5-LO-expressing adenovirus (AdAlox5), monocrotaline, SU5416, SU5416 with chronic hypoxia or chronic hypoxia alone. Bmpr2-mutant hPAH patient samples were assessed for neointimal 5-LO expression. Pulmonary artery endothelial cells (PAECs) with impaired BMPR2 signaling were exposed to increased 5-LO-mediated inflammation and were assessed for phenotypic and transcriptomic changes.Lung inflammation, induced by intratracheal delivery of AdAlox5, elicited severe PAH with intimal remodeling in Bmpr2+/- rats but not in their wild-type littermates. Neointimal lesions in the diseased Bmpr2+/- rats gained endogenous 5-LO expression associated with elevated LTB4 biosynthesis. Bmpr2-mutant hPAH patients similarly expressed 5-LO in the neointimal cells. In vitro, BMPR2 deficiency, compounded by 5-LO-mediated inflammation, generated apoptosis-resistant, and proliferative PAECs with mesenchymal characteristics. These transformed cells expressed nuclear envelope-localized 5-LO consistent with induced LTB4 production, as well as a transcriptomic signature similar to clinical disease, including upregulated NF-κB, IL-6, and TGF-β signaling pathways. The reversal of PAH and vasculopathy in Bmpr2 mutants by TGF-β antagonism suggests that TGF-β is critical for neointimal transformation.In a new 'two-hit' model of disease, lung inflammation induced severe PAH pathology in Bmpr2+/- rats. Endothelial transformation required the activation of canonical and noncanonical TGF-β signaling pathways and was characterized by 5-LO nuclear envelope translocation with enhanced LTB4 production. This study offers one explanation of how an environmental injury unleashes the destructive potential of an otherwise-silent genetic mutation.

    View details for DOI 10.1161/CIRCULATIONAHA.119.040629

    View details for PubMedID 31462075

  • Endothelial HIF-2alpha is Required for the Maintenance of Airway Microvasculature. Circulation Jiang, X., Tian, W., Tu, A. B., Pasupneti, S., Shuffle, E., Dahms, P., Zhang, P., Cai, H., Dinh, T. T., Liu, B., Cain, C., Giaccia, A. J., Butcher, E. C., Simon, C., Semenza, G. L., Nicolls, M. R. 2018

    Abstract

    BACKGROUND: Hypoxia-inducible factors (HIFs), especially HIF-1alpha and HIF-2alpha, are key mediators of the adaptive response to hypoxic stress and play essential roles in maintaining lung homeostasis. Human and animal genetics studies confirm that abnormal HIF correlates with pulmonary vascular pathology and chronic lung diseases, but it remains unclear whether endothelial cell (EC) HIF production is essential for microvascular health. The large airway has an ideal circulatory bed for evaluating histologic changes and physiology in genetically-modified rodents.METHODS: The tracheal microvasculature of mice, with conditionally-deleted or overexpressed HIF-1alpha or HIF-2alpha, was evaluated for anatomy, perfusion, and permeability. Angiogenic signaling studies assessed vascular changes attributable to dysregulated HIF expression. An orthotopic tracheal transplantation model further evaluated the contribution of individual HIF isoforms in airway ECs.RESULTS: The genetic deletion of Hif-2alpha, but not Hif-1alpha, caused tracheal EC apoptosis, diminished pericyte coverage, reduced vascular perfusion, defective barrier function, overlying epithelial abnormalities and subepithelial fibrotic remodeling. HIF-2alpha promoted microvascular integrity in airways through endothelial angiopoietin-1/TIE2 signaling and Notch activity. In functional tracheal transplants, HIF-2alpha deficiency in airway donors accelerated graft microvascular loss, whereas HIF-2alpha or angiopoietin-1 overexpression prolonged transplant microvascular perfusion. Augmented endothelial HIF-2alpha in transplant donors promoted airway microvascular integrity and diminished alloimmune inflammation.CONCLUSIONS: Our findings reveal that the constitutive expression of endothelial HIF-2alpha is required for airway microvascular health.

    View details for PubMedID 30586708

  • A Dominant Role for Regulatory T Cells in Protecting Females Against Pulmonary Hypertension. Circulation research Tamosiuniene, R., Manouvakhova, O., Mesange, P., Saito, T., Qian, J., Sanyal, M., Lin, Y. C., Nguyen, L. P., Luria, A., Tu, A. B., Sante, J. M., Rabinovitch, M., Fitzgerald, D. J., Graham, B. B., Habtezion, A., Voelkel, N. F., Aurelian, L., Nicolls, M. R. 2018

    Abstract

    Rationale: Pulmonary arterial hypertension (PH) is a life-threatening condition associated with immune dysregulation and abnormal regulatory T cell (Treg) activity, but it is currently unknown whether and how abnormal Treg function differentially affects males and females. Objective: To evaluate whether and how Treg-deficiency differentially affects male and female rats in experimental PH. Methods and Results: Male and female athymicrnu/rnurats, lacking Tregs, were treated with the vascular endothelial growth factor receptor-2 (VEGFR2) inhibitor SU5416 or chronic hypoxia and evaluated for PH; some animals underwent Treg immune reconstitution (IR) before SU5416 administration. Plasma prostacyclin (PGI2) levels were measured. Lung and right ventricles (RVs) were assessed for the expression of the vasoprotective proteins cyclooxygenase-2 (COX-2), prostacyclin synthase (PTGIS), programmed death ligand-1 (PDL-1), and heme oxygenase-1 (HO-1). Inhibitors of these pathways were administered to athymic rats undergoing Treg IR. Finally, human cardiac microvascular endothelial cells co-cultured with Tregs were evaluated for COX-2, PDL-1, HO-1, and estrogen receptor (ER) expression, and culture supernatants were assayed for PGI2 and IL-10. SU5416-treatment and chronic hypoxia produced more severe PH in female than male athymic rats. Females were distinguished by greater pulmonary inflammation, augmented RV fibrosis, lower plasma PGI2 levels, decreased lung COX-2, PTGIS, HO-1 and PDL-1 expression and reduced RV PDL-1 levels. In both sexes, Treg IR protected against PH development and raised levels of plasma PGI2 and cardiopulmonary COX-2, PTGIS, PDL-1, and HO-1. Inhibiting COX-2, HO-1, and programmed death-1 (PD1)/PDL1 pathways abrogated Treg protection. In vitro, human Tregs directly upregulated endothelial COX-2, PDL1, HO-1, ERs and increased supernatant levels of PGI2 and IL-10. Conclusions: In two animal models of PH based on Treg deficiency, females developed more severe PH than males. The data suggest that females are especially reliant on normal Treg function to counteract the effects of pulmonary vascular injury leading to PH.

    View details for PubMedID 29545367

  • Pilot studies demonstrate the potential benefits of antiinflammatory therapy in human lymphedema. JCI insight Rockson, S. G., Tian, W., Jiang, X., Kuznetsova, T., Haddad, F., Zampell, J., Mehrara, B., Sampson, J. P., Roche, L., Kim, J., Nicolls, M. R. 2018; 3 (20)

    Abstract

    Lymphedema is a common condition affecting millions around the world that still lacks approved medical therapy. Because ketoprofen, an NSAID, has been therapeutic in experimental lymphedema, we evaluated its efficacy in humans.We first performed an exploratory open-label trial. Patients with either primary or secondary lymphedema received ketoprofen 75 mg by mouth 3 times daily for 4 months. Subjects were evaluated for changes in histopathology, with skin thickness, limb volume, and tissue bioimpedance changes serving as secondary endpoints. Based on our encouraging findings, we next conducted a placebo-controlled trial, with the primary outcome defined as a change in skin thickness, as measured by skin calipers. Secondary endpoints for this second study included histopathology, limb volume, bioimpedance, and systemic inflammatory mediators.We enrolled 21 lymphedema patients in the open-label trial, from November 2010 to July 2011. Histopathology and skin thickness were significantly improved at 4 months compared with baseline. In the follow-up, double-blind, placebo-controlled trial, we enrolled 34 patients from August 2011 to October 2015, with 16 ketoprofen recipients and 18 placebo-treated subjects. No serious adverse events occurred. The ketoprofen recipients demonstrated reduced skin thickness, as well as improved composite measures of histopathology and decreased plasma granulocyte CSF (G-CSF) expression.These 2 exploratory studies together support the utility of targeted antiinflammatory therapy with ketoprofen in patients with lymphedema. Our results highlight the promise of such approaches to help restore a failing lymphatic circulation.ClinicalTrials.gov NCT02257970.

    View details for PubMedID 30333315

  • Microhemorrhage-associated tissue iron enhances the risk forAspergillus fumigatusinvasion in a mouse model of airway transplantation. Science translational medicine Hsu, J. L., Manouvakhova, O. V., Clemons, K. V., Inayathullah, M., Tu, A. B., Sobel, R. A., Tian, A., Nazik, H., Pothineni, V. R., Pasupneti, S., Jiang, X., Dhillon, G. S., Bedi, H., Rajadas, J., Haas, H., Aurelian, L., Stevens, D. A., Nicolls, M. R. 2018; 10 (429)

    Abstract

    Invasive pulmonary disease due to the moldAspergillus fumigatuscan be life-threatening in lung transplant recipients, but the risk factors remain poorly understood. To study this process, we used a tracheal allograft mouse model that recapitulates large airway changes observed in patients undergoing lung transplantation. We report that microhemorrhage-related iron content may be a major determinant ofA. fumigatusinvasion and, consequently, its virulence. Invasive growth was increased during progressive alloimmune-mediated graft rejection associated with high concentrations of ferric iron in the graft. The role of iron inA. fumigatusinvasive growth was further confirmed by showing that this invasive phenotype was increased in tracheal transplants from donor mice lacking the hemochromatosis gene (Hfe -/- ). The invasive phenotype was also increased in mouse syngrafts treated with topical iron solution and in allograft recipients receiving deferoxamine, a chelator that increases iron bioavailability to the mold. The invasive growth of the iron-intolerantA. fumigatusdouble-knockout mutant (ΔsreA/ΔcccA) was lower than that of the wild-type mold. Alloimmune-mediated microvascular damage and iron overload did not appear to impair the host's immune response. In human lung transplant recipients, positive staining for iron in lung transplant tissue was more commonly seen in endobronchial biopsy sections from transplanted airways than in biopsies from the patients' own airways. Collectively, these data identify iron as a major determinant ofA. fumigatusinvasive growth and a potential target to treat or preventA. fumigatusinfections in lung transplant patients.

    View details for PubMedID 29467298

  • The Roles of Immunity in the Prevention and Evolution of Pulmonary Arterial Hypertension AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Nicolls, M. R., Voelkel, N. F. 2017; 195 (10): 1292-1299

    Abstract

    This Perspective provides an in depth overview of the many aspects of inflammation which are associated with many forms of severe pulmonary hypertension.Details of the pathobiology of severe pulmonary hypertension are discussed in the context of the multicellular inflammatory vascular infiltrates which represent a lung vessel response to injury and and a localized immune response.The important question whether inflammation is cause or consequence of pulmonary hypertension should not distract from designing and conducting clinical pilot studies which examine the efficacy of existing immune system modulating drugs.

    View details for DOI 10.1164/rccm.201608-1630PP

    View details for Web of Science ID 000401501400008

  • Leukotriene B-4 antagonism ameliorates experimental lymphedema SCIENCE TRANSLATIONAL MEDICINE Tian, W., Rockson, S. G., Jiang, X., Kim, J., Begaye, A., Shuffle, E. M., Tu, A. B., Cribb, M., Nepiyushchikh, Z., Feroze, A. H., Zamanian, R. T., Dhillon, G. S., Voelkel, N. F., Peters-Golden, M., Kitajewski, J., Dixon, J. B., Nicolls, M. R. 2017; 9 (389)
  • Simultaneously Targeting Myofibroblast Contractility and Extracellular Matrix Cross-Linking as a Therapeutic Concept in Airway Fibrosis AMERICAN JOURNAL OF TRANSPLANTATION Lin, Y., Sung, Y. K., Jiang, X., Peters-Golden, M., Nicolls, M. R. 2017; 17 (5): 1229-1241

    Abstract

    Fibrosis after solid organ transplantation is considered an irreversible process and remains the major cause of graft dysfunction and death with limited therapies. This remodeling is characterized by aberrant accumulation of contractile myofibroblasts that deposit excessive extracellular matrix (ECM) and increase tissue stiffness. However, studies demonstrate that a stiff ECM, itself, promotes fibroblast-to-myofibroblast differentiation, stimulating further ECM production. This creates a positive feedback loop that perpetuates fibrosis. We hypothesized that simultaneously targeting myofibroblast contractility with relaxin and ECM stiffness with lysyl oxidase inhibitors could break the feedback loop, thereby, reversing established fibrosis. To test this, we used the orthotopic tracheal transplanted (OTT) mouse model, which develops robust fibrotic airway remodeling. Mice with established fibrosis were treated with saline, mono-, or combination therapies. While monotherapies had no effect, combining these agents decreased collagen deposition and promoted re-epithelialization of remodeled airways. Relaxin inhibited myofibroblast differentiation and contraction, in a matrix-stiffness-dependent manner through prostaglandin E2 (PGE2 ). Furthermore, the effect of combination therapy was lost in PGE2 receptor knockout and PGE2 inhibited OTT mice. This study reveals the important synergistic roles of cellular contractility and tissue stiffness in the maintenance of fibrotic tissue and suggests a new therapeutic principle for fibrosis. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/ajt.14103

    View details for Web of Science ID 000400382300012

  • Models of Lung Transplant Research: a consensus statement from the National Heart, Lung, and Blood Institute workshop. JCI insight Lama, V. N., Belperio, J. A., Christie, J. D., El-Chemaly, S., Fishbein, M. C., Gelman, A. E., Hancock, W. W., Keshavjee, S., Kreisel, D., Laubach, V. E., Looney, M. R., McDyer, J. F., Mohanakumar, T., Shilling, R. A., Panoskaltsis-Mortari, A., Wilkes, D. S., Eu, J. P., Nicolls, M. R. 2017; 2 (9)

    Abstract

    Lung transplantation, a cure for a number of end-stage lung diseases, continues to have the worst long-term outcomes when compared with other solid organ transplants. Preclinical modeling of the most common and serious lung transplantation complications are essential to better understand and mitigate the pathophysiological processes that lead to these complications. Various animal and in vitro models of lung transplant complications now exist and each of these models has unique strengths. However, significant issues, such as the required technical expertise as well as the robustness and clinical usefulness of these models, remain to be overcome or clarified. The National Heart, Lung, and Blood Institute (NHLBI) convened a workshop in March 2016 to review the state of preclinical science addressing the three most important complications of lung transplantation: primary graft dysfunction (PGD), acute rejection (AR), and chronic lung allograft dysfunction (CLAD). In addition, the participants of the workshop were tasked to make consensus recommendations on the best use of these complimentary models to close our knowledge gaps in PGD, AR, and CLAD. Their reviews and recommendations are summarized in this report. Furthermore, the participants outlined opportunities to collaborate and directions to accelerate research using these preclinical models.

    View details for PubMedID 28469087

  • Lymphatic Dysfunction, Leukotrienes, and Lymphedema. Annual review of physiology Jiang, X., Nicolls, M. R., Tian, W., Rockson, S. G. 2017

    Abstract

    The lymphatic system is essential for the maintenance of tissue fluid homeostasis, gastrointestinal lipid absorption, and immune trafficking. Whereas lymphatic regeneration occurs physiologically in wound healing and tissue repair, pathological lymphangiogenesis has been implicated in a number of chronic diseases such as lymphedema, atherosclerosis, and cancer. Insight into the regulatory mechanisms of lymphangiogenesis and the manner in which uncontrolled inflammation promotes lymphatic dysfunction is urgently needed to guide the development of novel therapeutics: These would be designed to reverse lymphatic dysfunction, either primary or acquired. Recent investigation has demonstrated the mechanistic role of leukotriene B4 (LTB4) in the molecular pathogenesis of lymphedema. LTB4, a product of the innate immune response, is a constituent of the eicosanoid inflammatory mediator family of molecules that promote both physiological and pathological inflammation. Here we provide an overview of lymphatic development, the pathophysiology of lymphedema, and the role of leukotrienes in lymphedema pathogenesis. Expected final online publication date for the Annual Review of Physiology Volume 80 is February 10, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

    View details for PubMedID 29029593

  • Simultaneously Targeting Myofibroblast Contractility and Extracellular Matrix Cross-Linking as a Therapeutic Concept in Airway Fibrosis. American journal of transplantation Lin, Y., Sung, Y. K., Jiang, X., Peters-Golden, M., Nicolls, M. R. 2016

    Abstract

    Fibrosis after solid organ transplantation is considered an irreversible process and remains the major cause of graft dysfunction and death with limited therapies. This remodeling is characterized by aberrant accumulation of contractile myofibroblasts that deposit excessive extracellular matrix (ECM) and increase tissue stiffness. However, studies demonstrate that a stiff ECM, itself, promotes fibroblast-to-myofibroblast differentiation, stimulating further ECM production. This creates a positive feedback loop that perpetuates fibrosis. We hypothesized that simultaneously targeting myofibroblast contractility with relaxin and ECM stiffness with lysyl oxidase inhibitors could break the feedback loop, thereby, reversing established fibrosis. To test this, we used the orthotopic tracheal transplanted (OTT) mouse model, which develops robust fibrotic airway remodeling. Mice with established fibrosis were treated with saline, mono-, or combination therapies. While monotherapies had no effect, combining these agents decreased collagen deposition and promoted re-epithelialization of remodeled airways. Relaxin inhibited myofibroblast differentiation and contraction, in a matrix-stiffness-dependent manner through prostaglandin E2 (PGE2 ). Furthermore, the effect of combination therapy was lost in PGE2 receptor knockout and PGE2 inhibited OTT mice. This study reveals the important synergistic roles of cellular contractility and tissue stiffness in the maintenance of fibrotic tissue and suggests a new therapeutic principle for fibrosis. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/ajt.14103

    View details for PubMedID 27804215

  • Enhanced Electrochemical Sensing with Carbon Nanotubes Modified with Bismuth and Magnetic Nanoparticles in a Lab-on-a-Chip. ChemNanoMat : chemistry of nanomaterials for energy, biology and more Jothimuthu, P., Hsu, J. L., Chen, R., Inayathullah, M., Pothineni, V. R., Jan, A., Gurtner, G. C., Rajadas, J., Nicolls, M. R. 2016; 2 (9): 904–10

    Abstract

    Iron plays an especially important role in human physiological functions and pathological impairments. The superior properties of carbon nanotubes (CNTs) and their modification with bismuth and magnetic nanoparticles as developed in this work have led to an extraordinary and novel material to facilitate ultrasensitive detection in the nanomolar range. Here, we present the development of an electrochemical sensor for detection of ferrous (Fe(2+)) and ferric (Fe(3+)) iron by means of CNTs modified with bismuth and magnetic nanoparticles for higher sensitivity of detection. The sensor fabrication includes microfabrication methodologies, soft lithography, and electrodeposition. Cyclic voltammetry and differential pulse voltammetry are used for the electroanalytical studies and detection of the ions in samples. The sensor has a dynamic range of detection from 0.01 nm to 10 mm. The performance of the sensor with modified CNTs was explored for sensitivity and specificity. CNTs, modified with bismuth and magnetic nanoparticles by means of electrodeposition, enhanced the detection limit significantly down to 0.01 nm.

    View details for PubMedID 27857882

  • Leukotriene B-4 Activates Pulmonary Artery Adventitial Fibroblasts in Pulmonary Hypertension HYPERTENSION Qian, J., Tian, W., Jiang, X., Tamosiuniene, R., Sung, Y. K., Shuffle, E. M., Tu, A. B., Valenzuela, A., Jiang, S., Zamanian, R. T., Fiorentino, D. F., Voelkel, N. F., Peters-Golden, M., Stenmark, K. R., Chung, L., Rabinovitch, M., Nicolls, M. R. 2015; 66 (6): 1227-1239

    Abstract

    A recent study demonstrated a significant role for leukotriene B4 (LTB4) causing pulmonary vascular remodeling in pulmonary arterial hypertension. LTB4 was found to directly injure luminal endothelial cells and promote growth of the smooth muscle cell layer of pulmonary arterioles. The purpose of this study was to determine the effects of LTB4 on the pulmonary adventitial layer, largely composed of fibroblasts. Here, we demonstrate that LTB4 enhanced human pulmonary artery adventitial fibroblast proliferation, migration, and differentiation in a dose-dependent manner through its cognate G-protein-coupled receptor, BLT1. LTB4 activated human pulmonary artery adventitial fibroblast by upregulating p38 mitogen-activated protein kinase as well as Nox4-signaling pathways. In an autoimmune model of pulmonary hypertension, inhibition of these pathways blocked perivascular inflammation, decreased Nox4 expression, reduced reactive oxygen species production, reversed arteriolar adventitial fibroblast activation, and attenuated pulmonary hypertension development. This study uncovers a novel mechanism by which LTB4 further promotes pulmonary arterial hypertension pathogenesis, beyond its established effects on endothelial and smooth muscle cells, by activating adventitial fibroblasts.

    View details for DOI 10.1161/HYPERTENSIONAHA.115.06370

    View details for PubMedID 26558820

  • Noninvasive monitoring of infection and rejection after lung transplantation. Proceedings of the National Academy of Sciences of the United States of America De Vlaminck, I., Martin, L., Kertesz, M., Patel, K., Kowarsky, M., Strehl, C., Cohen, G., Luikart, H., Neff, N. F., Okamoto, J., Nicolls, M. R., Cornfield, D., Weill, D., Valantine, H., Khush, K. K., Quake, S. R. 2015; 112 (43): 13336-13341

    Abstract

    The survival rate following lung transplantation is among the lowest of all solid-organ transplants, and current diagnostic tests often fail to distinguish between infection and rejection, the two primary posttransplant clinical complications. We describe a diagnostic assay that simultaneously monitors for rejection and infection in lung transplant recipients by sequencing of cell-free DNA (cfDNA) in plasma. We determined that the levels of donor-derived cfDNA directly correlate with the results of invasive tests of rejection (area under the curve 0.9). We also analyzed the nonhuman cfDNA as a hypothesis-free approach to test for infections. Cytomegalovirus is most frequently assayed clinically, and the levels of CMV-derived sequences in cfDNA are consistent with clinical results. We furthermore show that hypothesis-free monitoring for pathogens using cfDNA reveals undiagnosed cases of infection, and that certain infectious pathogens such as human herpesvirus (HHV) 6, HHV-7, and adenovirus, which are not often tested clinically, occur with high frequency in this cohort.

    View details for DOI 10.1073/pnas.1517494112

    View details for PubMedID 26460048

  • Cyclosporine Does Not Prevent Microvascular Loss in Transplantation but Can Synergize With a Neutrophil Elastase Inhibitor, Elafin, to Maintain Graft Perfusion During Acute Rejection AMERICAN JOURNAL OF TRANSPLANTATION Jiang, X., Nguyen, T. T., Tian, W., Sung, Y. K., Yuan, K., Qian, J., Rajadas, J., Sallenave, J., Nickel, N. P., Perez, V. d., RABINOVITCH, M., Nicolls, M. R. 2015; 15 (7): 1768-1781

    Abstract

    The loss of a functional microvascular bed in rejecting solid organ transplants is correlated with fibrotic remodeling and chronic rejection; in lung allografts, this pathology is predicted by bronchoalveolar fluid neutrophilia which suggests a role for polymorphonuclear cells in microcirculatory injury. In a mouse orthotopic tracheal transplant model, cyclosporine, which primarily inhibits T cells, failed as a monotherapy for preventing microvessel rejection and graft ischemia. To target neutrophil action that may be contributing to vascular injury, we examined the effect of a neutrophil elastase inhibitor, elafin, on the microvascular health of transplant tissue. We showed that elafin monotherapy prolonged microvascular perfusion and enhanced tissue oxygenation while diminishing the infiltration of neutrophils and macrophages and decreasing tissue deposition of complement C3 and the membrane attack complex, C5b-9. Elafin was also found to promote angiogenesis through activation of the extracellular signal-regulated kinase (ERK) signaling pathway but was insufficient as a single agent to completely prevent tissue ischemia during acute rejection episodes. However, when combined with cyclosporine, elafin effectively preserved airway microvascular perfusion and oxygenation. The therapeutic strategy of targeting neutrophil elastase activity alongside standard immunosuppression during acute rejection episodes may be an effective approach for preventing the development of irreversible fibrotic remodeling.

    View details for DOI 10.1111/ajt.13189

    View details for Web of Science ID 000356494300013

    View details for PubMedID 25727073

  • Elafin Reverses Pulmonary Hypertension via Caveolin-1-Dependent Bone Morphogenetic Protein Signaling AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Nickel, N. P., Spiekerkoetter, E., Gu, M., Li, C. G., Li, H., Kaschwich, M., Diebold, I., Hennigs, J. K., Kim, K., Miyagawa, K., Wang, L., Cao, A., Sa, S., Jiang, X., Stockstill, R. W., Nicolls, M. R., Zamanian, R. T., Bland, R. D., Rabinovitch, M. 2015; 191 (11): 1273-1286

    Abstract

    Pulmonary arterial hypertension is characterized by endothelial cell dysfunction, impaired BMPR2 signaling, and increased elastase activity. Synthetic elastase inhibitors reverse experimental pulmonary hypertension but cause hepatotoxicity in clinical studies. The endogenous elastase inhibitor elafin attenuates the development of hypoxic pulmonary hypertension in mice, but its potential to improve endothelial cell function and BMPR2 signaling, and to reverse severe experimental pulmonary hypertension or vascular pathology in the human disease was unknown.To assess elafin-mediated regression of pulmonary vascular pathology in rats with pulmonary hypertension induced by VEGF receptor blockade and hypoxia (Sugen/Hypoxia), and in lung explants from pulmonary hypertension patients. To determine if elafin amplifies BMPR2 signaling in pulmonary artery endothelial cells from controls and patients, and to elucidate the underlying mechanism. Methods, Measurements and Main Results: In Sugen/Hypoxia rats, elafin reduced elastase activity and reversed pulmonary hypertension, judged by regression of right ventricular systolic pressure and hypertrophy and pulmonary artery occlusive changes. Elafin improved endothelial function by increasing apelin, a product of BMPR2 signaling. Elafin induced apoptosis in human pulmonary arterial smooth muscle cells and in lung organ culture elafin decreased neointimal lesions. In normal and patient pulmonary artery endothelial cells, elafin enhanced survival and promoted angiogenesis by increasing pSMAD dependent and independent BMPR2 signaling. This was linked mechanistically to augmented interaction of BMPR2 with caveolin-1 via elafin-mediated stabilization of caveolin-1 on endothelial surfaces.Elafin reverses obliterative changes in rat and human pulmonary arteries via elastase inhibition and caveolin-1 dependent amplification of BMPR2 signaling.

    View details for DOI 10.1164/rccm.201412-2291OC

    View details for Web of Science ID 000356105000014

    View details for PubMedID 25853696

  • Inflammation and Immunity in the Pathogenesis of Pulmonary Arterial Hypertension CIRCULATION RESEARCH Rabinovitch, M., Guignabert, C., Humbert, M., Nicolls, M. R. 2014; 115 (1): 165-175

    Abstract

    This review summarizes an expanding body of knowledge indicating that failure to resolve inflammation and altered immune processes underlie the development of pulmonary arterial hypertension. The chemokines and cytokines implicated in pulmonary arterial hypertension that could form a biomarker platform are discussed. Pre-clinical studies that provide the basis for dysregulated immunity in animal models of the disease are reviewed. In addition, we present therapies that target inflammatory/immune mechanisms that are currently enrolling patients, and discuss others in development. We show how genetic and metabolic abnormalities are inextricably linked to dysregulated immunity and adverse remodeling in the pulmonary arteries.

    View details for DOI 10.1161/CIRCRESAHA.113.301141

    View details for Web of Science ID 000337738900018

    View details for PubMedID 24951765

  • Working toward immune tolerance in lung transplantation. The Journal of clinical investigation Jiang, X., Nicolls, M. R. 2014: 1–4

    Abstract

    Long-term allograft survival is a major challenge facing solid organ transplantation. Recent studies have shown a negative correlation between infiltration of memory T cells and allograft survival. Furthermore, blockade of leukocyte activation increases acceptance of transplanted organs, including heart, liver, and kidney. Lung allografts are associated with high rates of rejection, and therapies that increase acceptance of other transplanted organs have not translated into the lung. In this issue of the JCI, Krupnick and colleagues demonstrate in a murine model that lung allograft acceptance requires infiltration of a specific T cell population into the graft. This study highlights the unique immunobiology of the lung and the complexity of lung transplant tolerance.

    View details for DOI 10.1172/JCI74701

    View details for PubMedID 24569371

  • Promotion of airway anastomotic microvascular regeneration and alleviation of airway ischemia by deferoxamine nanoparticles. Biomaterials Jiang, X., Malkovskiy, A. V., Tian, W., Sung, Y. K., Sun, W., Hsu, J. L., Manickam, S., Wagh, D., Joubert, L., Semenza, G. L., Rajadas, J., Nicolls, M. R. 2014; 35 (2): 803-813

    Abstract

    Airway tissue ischemia and hypoxia in human lung transplantation is a consequence of the sacrifice of the bronchial circulation during the surgical procedure and is a major risk factor for the development of airway anastomotic complications. Augmented expression of hypoxia-inducible factor (HIF)-1α promotes microvascular repair and alleviates allograft ischemia and hypoxia. Deferoxamine mesylate (DFO) is an FDA-approved iron chelator which has been shown to upregulate cellular HIF-1α. Here, we developed a nanoparticle formulation of DFO that can be topically applied to airway transplants at the time of surgery. In a mouse orthotopic tracheal transplant (OTT) model, the DFO nanoparticle was highly effective in enhancing airway microvascular perfusion following transplantation through the production of the angiogenic factors, placental growth factor (PLGF) and stromal cell-derived factor (SDF)-1. The endothelial cells in DFO treated airways displayed higher levels of p-eNOS and Ki67, less apoptosis, and decreased production of perivascular reactive oxygen species (ROS) compared to vehicle-treated airways. In summary, a DFO formulation topically-applied at the time of surgery successfully augmented airway anastomotic microvascular regeneration and the repair of alloimmune-injured microvasculature. This approach may be an effective topical transplant-conditioning therapy for preventing airway complications following clinical lung transplantation.

    View details for DOI 10.1016/j.biomaterials.2013.09.092

    View details for PubMedID 24161166

  • Temporal response of the human virome to immunosuppression and antiviral therapy. Cell De Vlaminck, I., Khush, K. K., Strehl, C., Kohli, B., Luikart, H., Neff, N. F., Okamoto, J., Snyder, T. M., Cornfield, D. N., Nicolls, M. R., Weill, D., Bernstein, D., Valantine, H. A., Quake, S. R. 2013; 155 (5): 1178-1187

    Abstract

    There are few substantive methods to measure the health of the immune system, and the connection between immune strength and the viral component of the microbiome is poorly understood. Organ transplant recipients are treated with posttransplant therapies that combine immunosuppressive and antiviral drugs, offering a window into the effects of immune modulation on the virome. We used sequencing of cell-free DNA in plasma to investigate drug-virome interactions in a cohort of organ transplant recipients (656 samples, 96 patients) and find that antivirals and immunosuppressants strongly affect the structure of the virome in plasma. We observe marked virome compositional dynamics at the onset of the therapy and find that the total viral load increases with immunosuppression, whereas the bacterial component of the microbiome remains largely unaffected. The data provide insight into the relationship between the human virome, the state of the immune system, and the effects of pharmacological treatment and offer a potential application of the virome state to predict immunocompetence.

    View details for DOI 10.1016/j.cell.2013.10.034

    View details for PubMedID 24267896

  • Blocking Macrophage Leukotriene B-4 Prevents Endothelial Injury and Reverses Pulmonary Hypertension SCIENCE TRANSLATIONAL MEDICINE Tian, W., Jiang, X., Tamosiuniene, R., Sung, Y. K., Qian, J., Dhillon, G., Gera, L., Farkas, L., Rabinovitch, M., Zamanian, R. T., Inayathullah, M., Fridlib, M., Rajadas, J., Peters-Golden, M., Voelkel, N. F., Nicolls, M. R. 2013; 5 (200)

    Abstract

    Pulmonary hypertension (PH) is a serious condition that affects mainly young and middle-aged women, and its etiology is poorly understood. A prominent pathological feature of PH is accumulation of macrophages near the arterioles of the lung. In both clinical tissue and the SU5416 (SU)/athymic rat model of severe PH, we found that the accumulated macrophages expressed high levels of leukotriene A4 hydrolase (LTA4H), the biosynthetic enzyme for leukotriene B4 (LTB4). Moreover, macrophage-derived LTB4 directly induced apoptosis in pulmonary artery endothelial cells (PAECs). Further, LTB4 induced proliferation and hypertrophy of human pulmonary artery smooth muscle cells. We found that LTB4 acted through its receptor, BLT1, to induce PAEC apoptosis by inhibiting the protective endothelial sphingosine kinase 1 (Sphk1)-endothelial nitric oxide synthase (eNOS) pathway. Blocking LTA4H decreased in vivo LTB4 levels, prevented PAEC apoptosis, restored Sphk1-eNOS signaling, and reversed fulminant PH in the SU/athymic rat model of PH. Antagonizing BLT1 similarly reversed established PH. Inhibition of LTB4 biosynthesis or signal transduction in SU-treated athymic rats with established disease also improved cardiac function and reopened obstructed arterioles; this approach was also effective in the monocrotaline model of severe PH. Human plexiform lesions, one hallmark of PH, showed increased numbers of macrophages, which expressed LTA4H, and patients with connective tissue disease-associated pulmonary arterial hypertension exhibited significantly higher LTB4 concentrations in the systemic circulation than did healthy subjects. These results uncover a possible role for macrophage-derived LTB4 in PH pathogenesis and identify a pathway that may be amenable to therapeutic targeting.

    View details for Web of Science ID 000323705100010

  • Targeting complement component 5a promotes vascular integrity and limits airway remodeling. Proceedings of the National Academy of Sciences of the United States of America Khan, M. A., Maasch, C., Vater, A., Klussmann, S., Morser, J., Leung, L. L., Atkinson, C., Tomlinson, S., Heeger, P. S., Nicolls, M. R. 2013; 110 (15): 6061-6066

    Abstract

    Increased microvascular dilatation and permeability is observed during allograft rejection. Because vascular integrity is an important indicator of transplant health, we have sought to limit injury to blood vessels by blocking complement activation. Although complement component 3 (C3) inhibition is known to be vasculoprotective in transplantation studies, we recently demonstrated the paradoxical finding that, early in rejection, C3(-/-) transplant recipients actually exhibit worse microvascular injury than controls. In the genetic absence of C3, thrombin-mediated complement component 5 (C5) convertase activity leads to the generation of C5a (anaphylatoxin), a promoter of vasodilatation and permeability. In the current study, we demonstrated that microvessel thrombin deposition is significantly increased in C3(-/-) recipients during acute rejection. Thrombin colocalization with microvessels is closely associated with remarkably elevated plasma levels of C5a, vasodilatation, and increased vascular permeability. Administration of NOX-D19, a specific C5a inhibitor, to C3(-/-) recipients of airway transplants significantly improved tissue oxygenation, limited microvascular leakiness, and prevented airway ischemia, even in the absence of conventional T-cell-directed immunosuppression. As C3 inhibitors enter the clinics, the simultaneous targeting of this thrombin-mediated complement activation pathway and/or C5a itself may confer significant clinical benefit.

    View details for DOI 10.1073/pnas.1217991110

    View details for PubMedID 23530212

    View details for PubMedCentralID PMC3625314

  • Tie2-dependent VHL knockdown promotes airway microvascular regeneration and attenuates invasive growth of Aspergillus fumigatus. Journal of molecular medicine (Berlin, Germany) Jiang, X., Hsu, J. L., Tian, W., Yuan, K., Olcholski, M., de Jesus Perez, V., Semenza, G. L., Nicolls, M. R. 2013

    Abstract

    Microvascular ischemia and infections are associated with the development of chronic rejection following lung transplantation. The von Hippel-Lindau protein (VHL) controls protein levels of hypoxia-inducible factors (HIFs), regulates vascular repair, and improves tissue perfusion. Here, we studied the role of VHL in microvascular repair by orthotopically transplanting tracheas into mice with VHL haplodeficiency in Tie2 lineage cells. We showed that VHL haplodeficiency prolonged airway microvascular perfusion and promoted tissue blood flow through the production of the angiogenic factors, SDF-1 and angiopoietin 1. VHL-haplodeficient pulmonary endothelial cells exhibited increased angiogenic activity, resistance to serum deprivation-induced cell death, and enhanced microvascular repair. By contrast, in recipient mice with HIF-1α deficiency in Tie2 lineage cells, microvascular repair was significantly diminished and suggested that recipient-derived HIF-1α normally participates in the repair of alloimmune-mediated microvascular damage. To evaluate the translational impact of our findings, we compared VHL-haplodeficient mice with wild-type controls using a model of Aspergillus airway infection. In 83 % of the VHL-haplodeficient recipients, Aspergillus fumigatus was noninvasive in contrast to 75 % of wild-type mice in which the mold was deeply invasive. Our study demonstrated that stabilization of HIF-1α in angiogenic cells, through Tie2 cell VHL haplodeficiency, promoted airway microvascular regeneration and vascular normalization and thereby minimized tissue ischemia and hypoxia. By also mitigating the virulence of A. fumigatus, a common pathogen and itself a risk factor for the development of lung transplant rejection, the selective enhancement of HIF-1α expression has the prospect of offering several novel therapeutic effects to transplant recipients.Microvascular loss and prolonged ischemia occurs with acute rejection. Von Hippel-Lindau (VHL) protein controls hypoxia inducible factors (HIFs). In tracheal allografts, VHL haplodeficient Tie2 cells promote neovascularization. Reduced transplant ischemia limits Aspergillus invasion.

    View details for DOI 10.1007/s00109-013-1063-8

    View details for PubMedID 23797537

  • CD4(+) T Cells and Complement Independently Mediate Graft Ischemia in the Rejection of Mouse Orthotopic Tracheal Transplants CIRCULATION RESEARCH Khan, M. A., Jiang, X., Dhillon, G., Beilke, J., Holers, V. M., Atkinson, C., Tomlinson, S., Nicolls, M. R. 2011; 109 (11): 1290-U256

    Abstract

    While microvascular injury is associated with chronic rejection, the cause of tissue ischemia during alloimmune injury is not yet elucidated.We investigated the contribution of T lymphocytes and complement to microvascular injury-associated ischemia during acute rejection of mouse tracheal transplants.Using novel techniques to assess microvascular integrity and function, we evaluated how lymphocyte subsets and complement specifically affect microvascular perfusion and tissue oxygenation in MHC-mismatched transplants. To characterize T cell effects on microvessel loss and recovery, we transplanted functional airway grafts in the presence and absence of CD4(+) and CD8(+) T cells. To establish the contribution of complement-mediated injury to the allograft microcirculation, we transplanted C3-deficient and C3-inhibited recipients. We demonstrated that CD4(+) T cells and complement are independently sufficient to cause graft ischemia. CD8(+) T cells were required for airway neovascularization to occur following CD4-mediated rejection. Activation of antibody-dependent complement pathways mediated tissue ischemia even in the absence of cellular rejection. Complement inhibition by CR2-Crry attenuated graft hypoxia, complement/antibody deposition on vascular endothelium and promoted vascular perfusion by enhanced angiogenesis. Finally, there was a clear relationship between the burden of tissue hypoxia (ischemia×time duration) and the development of subsequent airway remodeling.These studies demonstrated that CD4(+) T cells and complement operate independently to cause transplant ischemia during acute rejection and that sustained ischemia is a precursor to chronic rejection.

    View details for DOI 10.1161/CIRCRESAHA.111.250167

    View details for PubMedID 21998328

  • Regulatory T Cells Limit Vascular Endothelial Injury and Prevent Pulmonary Hypertension CIRCULATION RESEARCH Tamosiuniene, R., Tian, W., Dhillon, G., Wang, L., Sung, Y. K., Gera, L., Patterson, A. J., Agrawal, R., Rabinovitch, M., Ambler, K., Long, C. S., Voelkel, N. F., Nicolls, M. R. 2011; 109 (8): 867-U120

    Abstract

    Pulmonary arterial hypertension (PAH) is an incurable disease associated with viral infections and connective tissue diseases. The relationship between inflammation and disease pathogenesis in these disorders remains poorly understood.To determine whether immune dysregulation due to absent T-cell populations directly contributes to the development of PAH.Vascular endothelial growth factor receptor 2 (VEGFR2) blockade induced significant pulmonary endothelial apoptosis in T-cell-deficient rats but not in immune-reconstituted (IR) rats. T cell-lymphopenia in association with VEGFR2 blockade resulted in periarteriolar inflammation with macrophages, and B cells even prior to vascular remodeling and elevated pulmonary pressures. IR prevented early inflammation and attenuated PAH development. IR with either CD8 T cells alone or with CD4-depleted spleen cells was ineffective in preventing PAH, whereas CD4-depleting immunocompetent euthymic animals increased PAH susceptibility. IR with either CD4(+)CD25(hi) or CD4(+)CD25(-) T cell subsets prior to vascular injury attenuated the development of PAH. IR limited perivascular inflammation and endothelial apoptosis in rat lungs in association with increased FoxP3(+), IL-10- and TGF-β-expressing CD4 cells, and upregulation of pulmonary bone morphogenetic protein receptor type 2 (BMPR2)-expressing cells, a receptor that activates endothelial cell survival pathways.PAH may arise when regulatory T-cell (Treg) activity fails to control endothelial injury. These studies suggest that regulatory T cells normally function to limit vascular injury and may protect against the development of PAH.

    View details for DOI 10.1161/CIRCRESAHA.110.236927

    View details for PubMedID 21868697

  • Regulatory T Cells and Pulmonary Hypertension TRENDS IN CARDIOVASCULAR MEDICINE Tamosiuniene, R., Nicolls, M. R. 2011; 21 (6): 166-171

    Abstract

    Pulmonary hypertension (PH) is a disease of high lethality arising from numerous causes. For a significant subset of PH patients, autoimmune biomarkers or frank autoimmune disease are simultaneously present, but the extent to which lung inflammation contributes to PH is unknown. However, emerging experimental and clinical evidence suggests that immune dysregulation may lead to the propagation of vascular injury and PH. A recent preclinical study demonstrated that regulatory T cells are important mediators normally enlisted to control inflammation and that, if absent or dysfunctional, may predispose to the development of PH.

    View details for Web of Science ID 000306942700003

    View details for PubMedID 22814424

  • Adenovirus-mediated HIF-1 alpha gene transfer promotes repair of mouse airway allograft microvasculature and attenuates chronic rejection JOURNAL OF CLINICAL INVESTIGATION Jiang, X., Khan, M. A., Tian, W., Beilke, J., Natarajan, R., Kosek, J., Yoder, M. C., Semenza, G. L., Nicolls, M. R. 2011; 121 (6): 2336-2349

    Abstract

    Chronic rejection, manifested as small airway fibrosis (obliterative bronchiolitis [OB]), is the main obstacle to long-term survival in lung transplantation. Recent studies demonstrate that the airways involved in a lung transplant are relatively hypoxic at baseline and that OB pathogenesis may be linked to ischemia induced by a transient loss of airway microvasculature. Here, we show that HIF-1α mediates airway microvascular repair in a model of orthotopic tracheal transplantation. Grafts with a conditional knockout of Hif1a demonstrated diminished recruitment of recipient-derived Tie2⁺ angiogenic cells to the allograft, impaired repair of damaged microvasculature, accelerated loss of microvascular perfusion, and hastened denudation of epithelial cells. In contrast, graft HIF-1α overexpression induced via an adenoviral vector prolonged airway microvascular perfusion, preserved epithelial integrity, extended the time window for the graft to be rescued from chronic rejection, and attenuated airway fibrotic remodeling. HIF-1α overexpression induced the expression of proangiogenic factors such as Sdf1, Plgf, and Vegf, and promoted the recruitment of vasoreparative Tie2⁺ cells. This study demonstrates that a therapy that enhances vascular integrity during acute rejection may promote graft health and prevent chronic rejection.

    View details for DOI 10.1172/JCI46192

    View details for Web of Science ID 000291234300032

    View details for PubMedID 21606594

    View details for PubMedCentralID PMC3104770

  • Lung Transplant Airway Hypoxia A Diathesis to Fibrosis? AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Dhillon, G. S., Zamora, M. R., Roos, J. E., Sheahan, D., Sista, R. R., van der Starre, P., Weill, D., Nicolls, M. R. 2010; 182 (2): 230-236

    Abstract

    Chronic rejection, manifested pathologically as airway fibrosis, is the major problem limiting long-term survival in lung transplant recipients. Airway hypoxia and ischemia, resulting from a failure to restore the bronchial artery (BA) circulation at the time of transplantation, may predispose patients to chronic rejection. To address this possibility, clinical information is needed describing the status of lung perfusion and airway oxygenation after transplantation.To determine the relative pulmonary arterial blood flow, airway tissue oxygenation and BA anatomy in the transplanted lung was compared with the contralateral native lung in lung allograft recipients.Routine perfusion scans were evaluated at 3 and 12 months after transplantation in 15 single transplant recipients. Next, airway tissue oximetry was performed in 12 patients during surveillance bronchoscopies in the first year after transplant and in 4 control subjects. Finally, computed tomography (CT)-angiography studies on 11 recipients were reconstructed to evaluate the post-transplant anatomy of the BAs.By 3 months after transplantation, deoxygenated pulmonary arterial blood is shunted away from the native lung to the transplanted lung. In the first year, healthy lung transplant recipients exhibit significant airway hypoxia distal to the graft anastomosis. CT-angiography studies demonstrate that BAs are abbreviated, generally stopping at or before the anastomosis, in transplant airways.Despite pulmonary artery blood being shunted to transplanted lungs after transplantation, grafts are hypoxic compared with both native (diseased) and control airways. Airway hypoxia may be due to the lack of radiologically demonstrable BAs after lung transplantation.

    View details for DOI 10.1164/rccm.200910-1573OC

    View details for Web of Science ID 000280206700014

    View details for PubMedID 20339145

    View details for PubMedCentralID PMC3269232

  • Microvascular destruction identifies murine allografts that cannot be rescued from airway fibrosis JOURNAL OF CLINICAL INVESTIGATION Babu, A. N., Murakawa, T., Thurman, J. M., Miller, E. J., Henson, P. M., Zamora, M. R., Voelkel, N. F., Nicolls, M. R. 2007; 117 (12): 3774-3785

    Abstract

    Small airway fibrosis (bronchiolitis obliterans syndrome) is the primary obstacle to long-term survival following lung transplantation. Here, we show the importance of functional microvasculature in the prevention of epithelial loss and fibrosis due to rejection and for the first time, relate allograft microvascular injury and loss of tissue perfusion to immunotherapy-resistant rejection. To explore the role of alloimmune rejection and airway ischemia in the development of fibroproliferation, we used a murine orthotopic tracheal transplant model. We determined that transplants were reperfused by connection of recipient vessels to donor vessels at the surgical anastomosis site. Microcirculation through the newly formed vascular anastomoses appeared partially dependent on VEGFR2 and CXCR2 pathways. In the absence of immunosuppression, the microvasculature in rejecting allografts exhibited vascular complement deposition, diminished endothelial CD31 expression, and absent perfusion prior to the onset of fibroproliferation. Rejecting grafts with extensive endothelial cell injury were refractory to immunotherapy. After early microvascular loss, neovascularization was eventually observed in the membranous trachea, indicating a reestablishment of graft perfusion in established fibrosis. One implication of this study is that bronchial artery revascularization at the time of lung transplantation may decrease the risk of subsequent airway fibrosis.

    View details for DOI 10.1172/JCI32311

    View details for Web of Science ID 000251396600026

    View details for PubMedID 18060031

  • Absence of T cells confers increased pulmonary arterial hypertension and vascular remodeling. Am J Respir Crit Care Med Nicolls MR*, Taraseviciene-Stewart L, Kraskauskas D, Scerbavicius R, Burns N, Cool C, Wood K, Parr JE, Boackle SA, Voelkel NF (*co-1st author) 2007; 175 (12): 1280-9
  • LFA-1 (CD11a) as a therapeutic target AMERICAN JOURNAL OF TRANSPLANTATION Nicolls, M. R., Gill, R. G. 2006; 6 (1): 27-36

    Abstract

    Leukocyte function associated antigen-1 (LFA-1) was one of the earliest of cell-surface molecules identified by monoclonal antibodies generated against leukocyte immunogens. This integrin heterodimer is perhaps best known as a classic adhesion molecule facilitating the interaction between T cells and antigen-presenting cells. However, varied studies indicate that LFA-1 has multi-faceted roles in the immune response including adhesion, activation and trafficking of leukocyte populations. While there has been long-standing interest in LFA-1 as a therapeutic target for regulating immunity, anti-LFA-1 therapy is still not a first-line indication for any clinical condition. Antagonism of LFA-1 with monoclonal antibodies, either alone or in combination with other agents, can result in regulatory tolerance in vivo. Furthermore, new generation humanized anti-LFA-1 monoclonal antibodies (Efalizumab) show at least modest promise for continued application in clinical trials. Thus, anti-LFA-1 forms a potential, but still largely unexploited, immunotherapy which may find its greatest application as an agent which augments other therapies.

    View details for DOI 10.1111/j.1600-6143.2005.01158.x

    View details for Web of Science ID 000234344900008

    View details for PubMedID 16433753

  • Autoimmunity and pulmonary hypertension: a perspective EUROPEAN RESPIRATORY JOURNAL Nicolls, M. R., Taraseviciene-Stewart, L., Rai, P. R., Badesch, D. B., Voelkel, N. F. 2005; 26 (6): 1110-1118

    Abstract

    The association between autoimmunity and pulmonary arterial hypertension (PAH) has been appreciated for >40 yrs, but how autoimmune injury might contribute to the pathogenesis of this disease has only been examined in a case-specific manner. It is becoming increasingly clear that a variety of diverse clinical diseases, ranging from viral infections to connective tissue disorders, can culminate in pulmonary vascular pathology that is indistinguishable. Is there a hitherto unappreciated biology that unites these seemingly unrelated conditions? The answer to this question may come from the increasing body of evidence concerned with the central importance of regulatory T-cells in preventing inappropriate B-cell activity. Two striking similarities between conditions associated with severe angioproliferative pulmonary hypertension are a defect in the CD4 T-cell compartment and auto-antibody production. Pathogenic auto-antibodies targeting endothelial cells are capable of inducing vascular endothelial apoptosis and may initiate the development of PAH. The present review will focus on what is known about autoimmune phenomena in pulmonary arterial hypertension patients, in order to better consider whether an early loss of self-tolerance followed by autoimmune injury could influence the early development of severe angioproliferative pulmonary hypertension.

    View details for DOI 10.1183/09031936.05.00045705

    View details for Web of Science ID 000234203100023

    View details for PubMedID 16319344

  • Chemokine-mediated angiogenesis: an essential link in the evolution of airway fibroses? JOURNAL OF CLINICAL INVESTIGATION Douglas, I. S., Nicolls, T. R. 2005; 115 (5): 1133-1136

    Abstract

    Angiogenesis may be an important factor in the development of fibrotic lung disease. Prior studies have strongly suggested a role for angiogenic vascular remodeling in pulmonary fibrosis, and emerging evidence indicates that new vessel formation is critical in airway fibrosis. Bronchiolitis obliterans syndrome is a fibrotic occlusion of distal airways that is largely responsible for the morbidity and mortality of patients after lung transplantation. In this issue, Belperio et al. demonstrate a role for CXC chemokine receptor 2 in the regulation of angiogenesis-mediated airway fibroproliferation. By integrating an understanding of neovascularization into the study of events that occur between inflammation and fibrosis, it becomes increasingly possible to rationally design therapies that can halt conditions of maladaptive fibrosis.

    View details for DOI 10.1172/JCI200525193

    View details for Web of Science ID 000228908300010

    View details for PubMedID 15864341

    View details for PubMedCentralID PMC1087192

  • Simultaneous LFA-1 and CD40 ligand antagonism prevents airway remodeling in orthotopic airway transplantation: Implications for the role of respiratory epithelium as a modulator of fibrosis JOURNAL OF IMMUNOLOGY Murakawa, T., Kerklo, M. M., Zamora, M. R., Wei, Y., Gill, R. G., Henson, P. M., Grover, F. L., Nicolls, M. R. 2005; 174 (7): 3869-3879

    Abstract

    Airway remodeling is a prominent feature of certain immune-mediated lung diseases such as asthma and chronic lung transplant rejection. Under conditions of airway inflammation, the respiratory epithelium may serve an important role in this remodeling process. Given the proposed role of respiratory epithelium in nonspecific injury models, we investigated the respiratory epithelium in an immune-specific orthotopic airway transplant model. MHC-mismatched tracheal transplants in mice were used to generate alloimmune-mediated airway lesions. Attenuation of this immune injury and alteration of antidonor reactivity were achieved by the administration of combined anti-LFA-1/anti-CD40L mAbs. By contrast, without immunotherapy, transplanted airways remodeled with a flattening of respiratory epithelium and significant subepithelial fibrosis. Unopposed alloimmune injury for 10 days was associated with subsequent epithelial transformation and subepithelial fibrosis that could not be reversed with immunotherapy. The relining of donor airways with recipient-derived epithelium was delayed with immunotherapy resulting in partially chimeric airways by 28 days. Partial chimerism was sufficient to prevent luminal fibrosis. However, epithelial chimerism was also associated with airway remodeling. Therefore, there appears to be an intimate relationship between the morphology and level of chimerism of the respiratory epithelium and the degree of airway remodeling following alloimmune injury.

    View details for Web of Science ID 000228000100010

    View details for PubMedID 15778341

  • Proteomics as a tool for discovery: Proteins implicated in Alzheimer's disease are highly expressed in normal pancreatic islets JOURNAL OF PROTEOME RESEARCH Nicolls, M. R., D'Antonio, J. M., Hutton, J. C., Gill, R. G., Czwornog, J. L., Duncan, M. W. 2003; 2 (2): 199-205

    Abstract

    A proteomic analysis of islets was undertaken to determine the protein constituents of normal adult mouse islets. Unexpectedly, we identified several islet proteins that are associated with the pathogenesis of Alzheimer's disease. Some of these proteins had chaperone activity that is integral to proper protein folding. This group includes GRP78, valosin-containing protein, calreticulin, protein disulfide isomerase, DnaK, HSP70, HSP60, and TCP-1. Additionally, neuronal proteins key to coordinated neuronal guidance and survival were also identified in islets. This group includes proprotein convertase subtilisin, collapsin response mediator protein 2, ubiquinol-cytochrome c reductase core protein, L-3-hydroxyacyl-Coenzyme A dehydrogenase, glutamine synthetase, peroxiredoxin, and secretogogin. An important subset of the proteins identified here has not been reported previously in pancreatic islets. Abnormal activity of these proteins in brain may contribute to the pathogenesis of Alzheimer's disease, a neurodegenerative condition characterized by focal amyloid deposits with neurofibrillary tangles. The putative role of these proteins in Alzheimer's pathogenesis is intriguing given the possible clinical relationship and pathological similarity of Alzheimer's disease to type 2 diabetes. These findings have therefore led to the hypothesis that these proteins may also play a role in type 2 diabetes.

    View details for DOI 10.1021/pr025576x

    View details for Web of Science ID 000182143500010

    View details for PubMedID 12716134

  • CD4-dependent generation of dominant transplantation tolerance induced by simultaneous perturbation of CD154 and LFA-1 pathways JOURNAL OF IMMUNOLOGY Nicolls, M. R., Coulombe, M., Beilke, J., Gelhuas, H. C., Gill, R. G. 2002; 169 (9): 4831-4839

    Abstract

    CD154 and LFA-1 (CD11a) represent conceptually distinct pathways of receptor/ligand interactions (costimulation and adhesion/homing, respectively) that have been effectively targeted to induce long-term allograft acceptance and tolerance. In the current study, we determined the relative efficacy and nature of tolerance induced by mAbs specific for these pathways. In vitro analysis indicated that simultaneous targeting of CD154 and LFA-1 resulted in profound inhibition of alloreactivity, suggesting that combined anti-CD154/anti-LFA-1 therapy could be highly effective in vivo. Thus, we evaluated combining mAb therapies targeting CD154 and LFA-1 for inducing transplantation tolerance to pancreatic islet allografts. Monotherapy with either anti-CD154 or anti-LFA-1 was partially effective for inducing long-term allograft survival, whereas the combination resulted in uniform allograft acceptance in high-responder C57BL/6 recipients. This combined therapy was not lymphocyte depleting and did not require the long-term deletion of donor-reactive T lymphocytes to maintain allograft survival. Importantly, combined anti-CD154/anti-LFA therapy uniquely resulted in "dominant" transplantation tolerance. Therefore, simultaneous perturbation of CD154 and LFA-1 molecules can result in profound tolerance induction not accomplished through individual monotherapy approaches. Furthermore, results show that such regulatory tolerance can coexist with the presence of robust anti-donor reactivity, suggesting that active tolerance does not require a corresponding deletion of donor-reactive T cells. Interestingly, although the induction of this regulatory state was highly CD4 dependent, the adoptive transfer of tolerance was less CD4 dependent in vivo.

    View details for Web of Science ID 000178777400019

    View details for PubMedID 12391193

  • Anti-LFA-1 therapy induces long-term islet allograft acceptance in the absence of IFN-gamma or IL-4 JOURNAL OF IMMUNOLOGY Nicolls, M. R., Coulombe, M., Yang, H., Bolwerk, A., Gill, R. G. 2000; 164 (7): 3627-3634

    Abstract

    mAb therapy directed against a variety of cell surface accessory molecules has been effectively utilized to prolong allograft acceptance in various models of tissue and organ transplantation. The purpose of this study was to determine whether transient therapy directed against the adhesion molecule LFA-1 (CD11a) was sufficient to induce donor-specific tolerance to pancreatic islet allografts. Anti-LFA-1 monotherapy was found to be efficacious in inducing long-term islet allograft acceptance in multiple donor-recipient strain combinations. Graft acceptance following anti-LFA-1 therapy was not simply due to clonal ignorance of donor Ags in that the majority of recipients bearing established islet allografts resisted rejection induced by immunization with donor-type APCs. Furthermore, donor-specific tolerance from anti-LFA-1-treated animals could be transferred to secondary immune-deficient animals. Taken together, these results indicated that transient anti-LFA-1 monotherapy resulted in donor-specific tolerance. In vitro, functionally tolerant animals retained normal anti-donor reactivity as assessed by proliferative, cytotoxic, and cytokine release assays that demonstrated that tolerance was not secondary to general clonal deletion or anergy of donor-reactive T cells. Finally, anti-LFA-1 treatment was effective in both IL-4-deficient and IFN-gamma-deficient recipients, indicating that neither of these cytokines are universally required for allograft acceptance. These results suggest that anti-adhesion-based therapy can induce a nondeletional form of tolerance that is not overtly dependent on the prototypic Th1 and Th2 cytokines, IFN-gamma and IL-4, respectively, in contrast to results in other transplantation models.

    View details for Web of Science ID 000086020700025

    View details for PubMedID 10725719

  • Diffuse alveolar hemorrhage with underlying pulmonary capillaritis in the retinoic acid syndrome AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Nicolls, M. R., Terada, L. S., Tuder, R. M., Prindiville, S. A., Schwarz, M. I. 1998; 158 (4): 1302-1305

    Abstract

    All-trans-retinoic acid (ATRA) can induce a clinical remission in patients with acute promyelocytic leukemia. An adverse condition called "retinoic acid syndrome" limits this therapy. It is characterized by fever and respiratory distress, along with weight gain, pleural or pericardial effusions, peripheral edema, thromboembolic events, and intermittent hypotension. The lung disease has been previously ascribed to an infiltration of leukemic or maturing myeloid cells into lung parenchyma, which is sometimes associated with pleural effusions and diffuse alveolar hemorrhage. We report a case of retinoic acid syndrome in an 18-yr-old woman who developed diffuse alveolar hemorrhage while being treated with ATRA for acute promyelocytic leukemia. An open lung biopsy revealed pulmonary capillaritis.

    View details for Web of Science ID 000076453300044

    View details for PubMedID 9769296

  • INDUCTION OF LONG-TERM SPECIFIC TOLERANCE TO ALLOGRAFTS IN RATS BY THERAPY WITH AN ANTI-CD3-LIKE MONOCLONAL-ANTIBODY TRANSPLANTATION Nicolls, M. R., AVERSA, G. G., Pearce, N. W., Spinelli, A., Berger, M. F., Gurley, K. E., Hall, B. M. 1993; 55 (3): 459-468

    Abstract

    Monoclonal antibodies to CD3 have been shown to activate T cells in vivo and in vitro but have also been shown to render T cells anergic in vitro. In this study G4.18, a mouse IgG3 mAb, was produced that appeared to recognize CD3 by its binding to all peripheral T cells, including a population not recognized by mAb to TCR-alpha/beta that was presumed to be TCR-gamma/delta cells. It precipitated molecules in the 24-26 kd region consistent with the CD3 complex as well as molecules approximately 45 and approximately 49 kd that corresponded to TCR alpha and beta chains and a 92-kd complex. Incubating T cells for 24 hr with saturating concentrations of G4.18 caused modulation of the TCR complex. In vitro, it activated T cells but only if prebound to plastic. In solution it inhibited MLC and CML, but not PHA or Con A activation. In vivo, G4.18 was not toxic even in high doses, and this was thought to be due to the inability of this mAb to activate T cells in vitro because the rat lacks Fc receptors for mouse IgG3. Therapy with G4.18 resulted in transient modulation of TCR/CD3 on T cells and depletion of these cells from blood. G4.18 had no depleting effects by lymph node or spleen cells but caused marked, transient thymic involution. Therapy with G4.18 also induced indefinite survival (> 100 days) of PVG (RTIc) heart grafts but not skin grafts in DA (RTIa) hosts. These hosts with long-surviving cardiac transplants, when grafted from PVG skin, accepted these grafts but rejected third-party skin in first-set. Thus G4.18 was shown to induce long-term specific tolerance to an organ allograft.

    View details for Web of Science ID A1993KT96100001

    View details for PubMedID 8456460

  • Preservation of Microvascular Integrity in Murine Orthotopic Tracheal Allografts by Clopidogrel TRANSPLANTATION Heim, C., Khan, M., von Silva-Tarouca, B., Kuckhahn, A., Stamminger, T., Ramsperger-Gleixner, M., Nicolls, M. R., Weyand, M., Ensminger, S. M. 2019; 103 (5): 899–908
  • Inducible expression of immediate early genes is regulated through dynamic chromatin association by NF45/ILF2 and NF90/NF110/ILF3 PLOS ONE Wu, T., Shi, L., Lowe, A. W., Nicolls, M. R., Kao, P. N. 2019; 14 (4)
  • Loss of Endothelium-Derived Wnt5a Is Associated With Reduced Pericyte Recruitment and Small Vessel Loss in Pulmonary Arterial Hypertension CIRCULATION Yuan, K., Shamskhou, E. A., Orcholski, M. E., Nathan, A., Reddy, S., Honda, H., Mani, V., Zeng, Y., Ozen, M. O., Wang, L., Demirci, U., Tian, W., Nicolls, M. R., Perez, V. 2019; 139 (14): 1710–24
  • Discovery of Distinct Immune Phenotypes Using Machine Learning in Pulmonary Arterial Hypertension CIRCULATION RESEARCH Sweatt, A. J., Hedlin, H. K., Balasubramanian, V., Hsi, A., Blum, L. K., Robinson, W. H., Haddad, F., Hickey, P. M., Condliffe, R., Lawrie, A., Nicolls, M. R., Rabinovitch, M., Khatri, P., Zamanian, R. T. 2019; 124 (6): 904–19
  • Preservation of microvascular integrity in murine orthotopic tracheal allografts by clopidogrel. Transplantation Heim, C., Khan, M. A., Silva-Tarouca, B. v., Kuckhahn, A., Stamminger, T., Ramsperger-Gleixner, M., Nicolls, M. R., Weyand, M., Ensminger, S. M. 2019

    Abstract

    BACKGROUND: Survival after lung transplantation is mainly limited by the development of chronic lung allograft dysfunction (CLAD). The aim of this study was to investigate if platelet inhibition by clopidogrel has a functionally relevant influence on the microvascular integrity of orthotopic tracheal allografts as an anatomic basis for the development of CLAD.METHODS: We orthotopically transplanted C57Bl/6 (H-2) tracheas into CBA.J (H-2) recipients which afterwards received clopidogrel (1mg/kg). Morphometric analysis was performed by measuring epithelial height in proportion to thickness of the lamina propria (ELR). Tissue oxygenation was determined using a fluorescence quenching technique and graft perfusion monitoring was performed by Laser Doppler Flowmetry and lectin-binding assay. Immunohistochemistry was used for detection of CD31 and iNOS while iron deposition was shown with Prussian blue reaction. Quantitative RT-PCR analysis was used for gene expression analysis.RESULTS: Isografts maintained good oxygenation and perfusion throughout the experiment, while both were drastically reduced in allografts. Treatment with clopidogrel attenuated graft hypoxia and reduced loss of perfusion. Additionally, clopidogrel led to increased ELR while iron deposition was impaired. Gene expression analysis revealed elevated levels of angiogenic VEGF in the clopidogrel group. Improved endothelial function shown by immunohistochemistry (CD31, iNOS).CONCLUSIONS: Continuous administration of clopidogrel significantly improved tissue oxygenation, limited microvascular leakiness, and prevented airway ischemia. These data demonstrate that clopidogrel ameliorates microvascular injury during acute airway rejection which is a known predisposing factor for the development of CLAD.

    View details for PubMedID 30801550

  • Anti-hyperlipidaemic effects of synthetic analogues of nordihydroguaiaretic acid in dyslipidaemic rats BRITISH JOURNAL OF PHARMACOLOGY Singh, M., Bittner, S., Li, Y., Bittner, A., Han, L., Cortez, Y., Inayathullah, M., Arif, Z., Parthasarathi, R., Rajadas, J., Shen, W., Nicolls, M. R., Kraemer, F. B., Azhar, S. 2019; 176 (3): 369–85

    View details for DOI 10.1111/bph.14528

    View details for Web of Science ID 000455517100003

  • Discovery of Distinct Immune Phenotypes Using Machine Learning in Pulmonary Arterial Hypertension. Circulation research Sweatt, A. J., Hedlin, H. K., Balasubramanian, V., Hsi, A., Blum, L. K., Robinson, W. H., Haddad, F., Hickey, P. M., Condliffe, R. A., Lawrie, A., Nicolls, M. R., Rabinovitch, M., Khatri, P., Zamanian, R. T. 2019

    Abstract

    Accumulating evidence implicates inflammation in pulmonary arterial hypertension (PAH) and therapies targeting immunity are under investigation, though it remains unknown if distinct immune phenotypes exist.Identify PAH immune phenotypes based on unsupervised analysis of blood proteomic profiles.In a prospective observational study of Group 1 PAH patients evaluated at Stanford University (discovery cohort, n=281) and University of Sheffield (validation cohort, n=104) between 2008-2014, we measured a circulating proteomic panel of 48 cytokines, chemokines, and factors using multiplex immunoassay. Unsupervised machine learning (consensus clustering) was applied in both cohorts independently to classify patients into proteomic immune clusters, without guidance from clinical features. To identify central proteins in each cluster, we performed partial correlation network analysis. Clinical characteristics and outcomes were subsequently compared across clusters. Four PAH clusters with distinct proteomic immune profiles were identified in the discovery cohort. Cluster 2 (n=109) had low cytokine levels similar to controls. Other clusters had unique sets of upregulated proteins central to immune networks- cluster 1 (n=58)(TRAIL, CCL5, CCL7, CCL4, MIF), cluster 3 (n=77)(IL-12, IL-17, IL-10, IL-7, VEGF), and cluster 4 (n=37)(IL-8, IL-4, PDGF-β, IL-6, CCL11). Demographics, PAH etiologies, comorbidities, and medications were similar across clusters. Non-invasive and hemodynamic surrogates of clinical risk identified cluster 1 as high-risk and cluster 3 as low-risk groups. Five-year transplant-free survival rates were unfavorable for cluster 1 (47.6%, CI 35.4-64.1%) and favorable for cluster 3 (82.4%, CI 72.0-94.3%)(across-cluster p<0.001). Findings were replicated in the validation cohort, where machine learning classified four immune clusters with comparable proteomic, clinical, and prognostic features.Blood cytokine profiles distinguish PAH immune phenotypes with differing clinical risk that are independent of World Health Organization Group 1 subtypes. These phenotypes could inform mechanistic studies of disease pathobiology and provide a framework to examine patient responses to emerging therapies targeting immunity.

    View details for PubMedID 30661465

  • High Dose Ubenimex Interferes with the Efficacy of Sildenafil in Experimental Pulmonary Hypertension Dahms, P., Tian, A., Zhang, P., Tu, A. B., Jiang, X., Pasupneti, S., Peng, G., Nicolls, M. R. AMER THORACIC SOC. 2019
  • The Role of Iron-Induced Macrophage Dysregulation in Aspergillus Fumigatus Invasion in Airway Transplantation Matthaiou, E., Manouvakhova, O. M., Sinha, M., Tu, A. B., Clemons, K. V., Stevens, D. A., Nicolls, M. R., Hsu, J. L. AMER THORACIC SOC. 2019
  • HIF1 alpha-Mediated Lymphangiogenesis Influences Airway Transplant Rejection Tu, A. B., Jiang, X., Tian, A., Dahms, P., Zhang, P., Pasupneti, S., Nicolls, M. R. AMER THORACIC SOC. 2019
  • Inducible expression of immediate early genes is regulated through dynamic chromatin association by NF45/ILF2 and NF90/NF110/ILF3. PloS one Wu, T. H., Shi, L., Lowe, A. W., Nicolls, M. R., Kao, P. N. 2019; 14 (4): e0216042

    Abstract

    Immediate early gene (IEG) transcription is rapidly activated by diverse stimuli. This transcriptional regulation is assumed to involve constitutively expressed nuclear factors that are targets of signaling cascades initiated at the cell membrane. NF45 (encoded by ILF2) and its heterodimeric partner NF90/NF110 (encoded by ILF3) are chromatin-interacting proteins that are constitutively expressed and localized predominantly in the nucleus. Previously, NF90/NF110 chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) in K562 erythroleukemia cells revealed its enriched association with chromatin at active promoters and strong enhancers. NF90/NF110 specifically occupied the promoters of IEGs. Here, ChIP in serum-starved HEK293 cells demonstrated that NF45 and NF90/NF110 pre-exist and specifically occupy the promoters of IEG transcription factors EGR1, FOS and JUN. Cellular stimulation with phorbol myristyl acetate increased NF90/NF110 chromatin association, while decreasing NF45 chromatin association at promoters of EGR1, FOS and JUN. In HEK293 cells stably transfected with doxycycline-inducible shRNA vectors targeting NF90/NF110 or NF45, doxycycline-mediated knockdown of NF90/NF110 or NF45 attenuated the inducible expression of EGR1, FOS, and JUN at the levels of transcription, RNA and protein. Dynamic chromatin association of NF45 and NF90/NF110 at IEG promoters are observed upon stimulation, and NF45 and NF90/NF110 contribute to inducible transcription of IEGs. NF45 and NF90/NF110 operate as chromatin regulators of the immediate early response.

    View details for PubMedID 31022259

  • Circulating plasmablasts are elevated and produce pathogenic anti-endothelial cell autoantibodies in idiopathic pulmonary arterial hypertension. European journal of immunology Blum, L. K., Cao, R. R., Sweatt, A. J., Bill, M., Lahey, L. J., Hsi, A. C., Lee, C. S., Kongpachith, S., Ju, C. H., Mao, R., Wong, H. H., Nicolls, M. R., Zamanian, R. T., Robinson, W. H. 2018

    Abstract

    Idiopathic pulmonary arterial hypertension (IPAH) is a devastating pulmonary vascular disease in which autoimmune and inflammatory phenomena are implicated. B cells and autoantibodies have been associated with IPAH and identified as potential therapeutic targets. However, the specific populations of B cells involved and their roles in disease pathogenesis are not clearly defined. We aimed to assess the levels of activated B cells (plasmablasts) in IPAH, and to characterize recombinant antibodies derived from these plasmablasts. Blood plasmablasts are elevated in IPAH, remain elevated over time, and produce IgA autoantibodies. Single-cell sequencing of plasmablasts in IPAH revealed repertoires of affinity-matured antibodies with small clonal expansions, consistent with an ongoing autoimmune response. Recombinant antibodies representative of these clonal lineages bound known autoantigen targets and displayed an unexpectedly high degree of polyreactivity. Representative IPAH plasmablast recombinant antibodies stimulated human umbilical vein endothelial cells to produce cytokines and overexpress the adhesion molecule ICAM-1. Together, our results demonstrate an ongoing adaptive autoimmune response involving IgA plasmablasts that produce anti-endothelial cell autoantibodies in IPAH. These antibodies stimulate endothelial cell production of cytokines and adhesion molecules, which may contribute to disease pathogenesis. These findings suggest a role for mucosally-driven autoimmunity and autoimmune injury in the pathogenesis of IPAH. This article is protected by copyright. All rights reserved.

    View details for PubMedID 29369345

  • Pathology and pathobiology of pulmonary hypertension: state of the art and research perspectives. The European respiratory journal Humbert, M., Guignabert, C., Bonnet, S., Dorfmüller, P., Klinger, J. R., Nicolls, M. R., Olschewski, A. J., Pullamsetti, S. S., Schermuly, R. T., Stenmark, K. R., Rabinovitch, M. 2018

    Abstract

    Clinical and translational research has played a major role in advancing our understanding of pulmonary hypertension (PH), including pulmonary arterial hypertension and other forms of PH with severe vascular remodelling (e.g. chronic thromboembolic PH and pulmonary veno-occlusive disease). However, PH remains an incurable condition with a high mortality rate, underscoring the need for a better transfer of novel scientific knowledge into healthcare interventions. Herein, we review recent findings in pathology (with the questioning of the strict morphological categorisation of various forms of PH into pre- or post-capillary involvement of pulmonary vessels) and cellular mechanisms contributing to the onset and progression of pulmonary vascular remodelling associated with various forms of PH. We also discuss ways to improve management and to support and optimise drug development in this research field.

    View details for PubMedID 30545970

  • Loss of Endothelial Derived WNT5A is Associated with Reduced Pericyte Recruitment and Small Vessel Loss in Pulmonary Arterial Hypertension. Circulation Yuan, K., Shamskhou, E. A., Orcholski, M. E., Nathan, A., Reddy, S., Honda, H., Mani, V., Zeng, Y., Ozen, M. O., Wang, L., Demirci, U., Tian, W., Nicolls, M. R., de Jesus Perez, V. A. 2018

    Abstract

    Pulmonary arterial hypertension (PAH) is a life-threatening disorder of the pulmonary circulation associated with loss and impaired regeneration of microvessels. Reduced pericyte coverage of pulmonary microvessels is a pathological feature of PAH and is partly due to the inability of pericytes to respond to signaling cues from neighboring pulmonary microvascular endothelial cells (PMVECs). We have shown that activation of the Wnt/PCP pathway is required for pericyte recruitment but whether production and release of specific Wnt ligands by PMVECs is responsible for Wnt/PCP activation in pericytes is unknown.Isolation of pericytes and PMVECs from healthy donor and PAH lungs was carried out using 3G5 or CD31 antibody conjugated magnetic beads. Wnt expression profile of PMVECs was documented via qPCR using a Wnt primer library. Exosome purification from PMVEC media was carried out using the ExoTIC device. Hemodynamic profile, right ventricular function and pulmonary vascular morphometry were obtained in a conditional endothelial specific Wnt5a knockout ( Wnt5aECKO) mouse model under normoxia, chronic hypoxia and hypoxia recovery.Quantification of Wnt ligand expression in healthy PMVECs co-cultured with pericytes demonstrated a 35-fold increase in Wnt5a, a known Wnt/PCP ligand. This Wnt5a spike was not seen in PAH PMVECs, which correlated with inability to recruit pericytes in matrigel co-culture assays. Exosomes purified from media demonstrated an increase in Wnt5a content when healthy PMVECs were co-cultured with pericytes, a finding that was not observed in exosomes of PAH PMVECs. Furthermore, the addition of either recombinant Wnt5a or purified healthy PMVEC exosomes increased pericyte recruitment to PAH PMVECs in co-culture studies. While no differences were noted in normoxia and chronic hypoxia, Wnt5aECKO mice demonstrated persistent pulmonary hypertension and right ventricular failure four weeks after recovery from chronic hypoxia, which correlated with significant reduction, muscularization and decreased pericyte coverage of microvessels.We identify Wnt5a as a key mediator for the establishment of pulmonary endothelial-pericyte interactions and its loss could contribute to PAH by reducing the viability of newly formed vessels. We speculate that therapies that mimic or restore Wnt5a production could help prevent loss of small vessels in PAH.

    View details for PubMedID 30586764

  • Increased Lymphangiogenesis in Animal Models of Pulmonary Arterial Hypertension Zhang, P., Tian, A. W., Tu, A. B., Jiang, X., Nicolls, M. R. AMER THORACIC SOC. 2018
  • Endothelial HIF-2 alpha Maintains Airway Microvasculature Through Angiopoietin-1/TIE2 Signaling Tu, A., Jiang, X., Tian, W., Nicolls, M. R. AMER THORACIC SOC. 2018
  • The Role of Hypoxia Inducible Factors in Maintenance of Airway Epithelial Health Pasupneti, S., Tian, A., Jiang, X., Nicolls, M. R. AMER THORACIC SOC. 2018
  • A Pro - Con debate: Current Controversies in PAH Pathogenesis at the American Thoracic Society International Meeting in 2017. American journal of physiology. Lung cellular and molecular physiology Kuebler, W. M., Nicolls, M. R., Olschewski, A., Abe, K., Rabinovitch, M., Stewart, D. J., Chan, S. Y., Morrell, N. W., Archer, S. L., Spiekerkoetter, E. 2018

    Abstract

    The following review summarizes the pro-con debate about current controversies regarding the pathogenesis of pulmonary arterial hypertension (PAH) that took place at the American Thoracic Society Conference in May 2017. Leaders in the field of PAH research discussed the importance of the immune system, the role of hemodynamic stress and endothelial apoptosis as well as bone morphogenetic protein receptor 2 (BMPR2) signaling in PAH pathogenesis. While this summary does not intend to resolve obvious conflicts in opinion, we hope that the presented arguments entice further discussions and draw a new generation of enthusiastic researchers into this vibrant field of science to bridge existing gaps for a better understanding and therapy of this fatal disease.

    View details for PubMedID 29877097

  • Nordihydroguaiaretic acid, a lignan from Larrea tridentata (Creosote bush) protects against ALIOS diet-induced metabolic dysfunction in mice. The Journal of pharmacology and experimental therapeutics Chan, J. K., Bittner, S., Bittner, A., Atwal, S., Shen, W. J., Inayathullah, M., Rajada, J., Nicolls, M. R., Kraemer, F. B., Azhar, S. 2018

    Abstract

    To determine the effects of NDGA on metabolic and molecular changes in response to feeding mice typical American fast food or Western diet, mice were fed with ALIOS diet and subjected to metabolic analysis. Male C57BL/6J mice were randomly assigned to: ALIOS, ALIOS + NDGA, or control diet and maintained on the specific diet for 8 weeks. Mice fed ALIOS diet, showed increased body, liver and epididymal fat pad weight, plasma ALT and AST levels (a measure of liver injury), and liver triglyceride (TG) content. Co-administration of NDGA normalized body and epididymal fat pad weight, ALT and AST levels, and liver TG. NDGA treatment also improved insulin sensitivity but not glucose intolerance in ALIOS diet fed mice. In ALIOS diet fed mice, NDGA supplementation induced PPARα (the master regulator of fatty acid oxidation) and mRNA levels of Cpt1c and Cpt2, key genes involved in fatty acid oxidation as compared to ALIOS diet. NDGA significantly reduced liver ER stress response CHOP protein, as compared to chow or ALIOS diet and also ameliorated ALIOS diet-induced elevation of apoptosis signaling protein, CASP3. Likewise, NDGA downregulated the ALIOS-diet induced mRNA levels of Pparg, Fasn, and Dgat2. NDGA treatment of ALIOS fed mice upregulated the hepatic expression of antioxidant enzymes, GPX4 and PRDX3 proteins. In conclusion, we provide evidence that NDGA improves metabolic dysregulation by simultaneously modulating PPARα transcription factor and key genes involved in fatty acid oxidation, key antioxidant and lipogenic enzymes, and apoptosis and ER stress signaling pathways.

    View details for PubMedID 29472517

  • Dynamics of the human antibody repertoire after B cell depletion in systemic sclerosis SCIENCE IMMUNOLOGY de Bourcy, C. A., Dekker, C. L., Davis, M. M., Nicolls, M. R., Quake, S. R. 2017; 2 (15)
  • Microvascular Integrity Can Be Preserved by Anti-Platelet Therapy and in Combination with mTOR Inhibitor Heim, C., Khan, M. A., Motsch, B., Gocht, A., Ramsperger-Gleixner, M., Stamminger, T., Nicolls, M. R., Weyand, M., Ensminger, S. M. ELSEVIER SCIENCE INC. 2017: S376
  • Donor-Derived Cell-Free DNA Associates with Rejection in Lung Transplantation Using Clinical-Grade Targeted Next-Generation Sequencing Khush, K. K., Beausang, J. F., Woodward, R. N., Lew, D., Sninsky, J., De Vlaminck, I., Strehl, C., Luikart, H., Nicolls, M., Weill, D. ELSEVIER SCIENCE INC. 2017: S146
  • Translating Research into Improved Patient Care in Pulmonary Arterial Hypertension AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Bonnet, S., Provencher, S., Guignabert, C., Perros, F., Boucherat, O., Schermuly, R. T., Hassoun, P. M., Rabinovitch, M., Nicolls, M. R., Humbert, M. 2017; 195 (5): 583-595

    Abstract

    Despite important advances in its therapeutic management, pulmonary arterial hypertension (PAH) remains an incurable disease. Although numerous drugs exhibited beneficial effects in preclinical settings, only few have reached clinical trial phases, highlighting the challenges of translating preclinical investigations into clinical trials. Potential reasons for delayed PAH drug development may include the inherent limitations of the currently available animal and in vitro models, potential lack of appropriate standardization of the experimental design, regulatory agencies requirements, competing clinical trials and insufficient funding. Although this is not unique to PAH, there is urgency for reducing the number of false positive signals in preclinical studies and optimizing the development of innovative therapeutic targets through performance of clinical trials based on more robust experimental data. The current review discusses the challenges and opportunities in preclinical research to foster drug development in PAH.

    View details for DOI 10.1164/rccm.201607-1515PP

    View details for Web of Science ID 000395357400008

  • Discovery Of Proteomic Immune Signatures In Pulmonary Arterial Hypertension By Unsupervised Consensus Clustering Sweatt, A., Hedlin, H., Balasubramanian, V., Hsi, A., Blum, L., Robinson, W., Nicolls, M. R., Rabinovitch, M., Khatri, P., Zamanian, R. T. AMER THORACIC SOC. 2017
  • Introduction to the 59th Annual Thomas L. Petty Aspen Lung Conference. Lung Transplantation: Opportunities for Repair and Regeneration. Annals of the American Thoracic Society Zamora, M. R., Martinu, T., Nicolls, M. R. 2017; 14 (Supplement_3): S209

    View details for PubMedID 28945478

  • Hypoxia Inducible Factor-1 alpha Increases Bone Morphogenetic Protein Receptor 2 Signaling In Pulmonary Artery Endothelial Cells (paecs) Kuang, J., Tian, X., Prosseda, S., Tian, A., Cornfield, D., Nicolls, M. R., Spiekerkoetter, E. F. AMER THORACIC SOC. 2017
  • Dynamics of the human antibody repertoire after B cell depletion in systemic sclerosis Dynamics of the human antibody repertoire after B cell depletion in systemic sclerosis de Bourcy, C. F., Dekker, C. L., Davis, M. M., Nicolls, M. R., Quake, S. R. 2017; 2 (15)
  • Upregulation of HERV-K is Linked to Immunity and Inflammation in Pulmonary Arterial Hypertension. Circulation Saito, T., Miyagawa, K., Chen, S. Y., Tamosiuniene, R., Wang, L., Sharp, O., Samayoa, E., Harada, D., Moonen, J. A., Cao, A., Chen, P. I., Hennigs, J. K., Gu, M., Li, C. G., Leib, R. D., Li, D., Adams, C. M., Del Rosario, P. A., Bill, M. A., Haddad, F., Montoya, J. G., Robinson, W., Fantl, W. J., Nolan, G. P., Zamanian, R. T., Nicolls, M. R., Chiu, C. Y., Ariza, M. E., Rabinovitch, M. 2017

    Abstract

    Background -Immune dysregulation has been linked to occlusive vascular remodeling in pulmonary arterial hypertension (PAH) that is hereditary, idiopathic or associated with other conditions. Circulating autoantibodies, lung perivascular lymphoid tissue and elevated cytokines have been related to PAH pathogenesis but without clear understanding of how these abnormalities are initiated, perpetuated and connected in the progression of disease. We therefore set out to identify specific target antigens in PAH lung immune complexes as a starting point toward resolving these issues to better inform future application of immunomodulatory therapies. Methods -Lung immune complexes were isolated and PAH target antigens were identified by liquid chromatography tandem mass spectrometry (LCMS), confirmed by ELISA, and localized by confocal microscopy. One PAH antigen linked to immunity and inflammation was pursued and a link to PAH pathophysiology was investigated by next generation sequencing, functional studies in cultured monocytes and endothelial cells (EC) and hemodynamic and lung studies in a rat. Results -SAM domain and HD1 domain-containing protein (SAMHD1), an innate immune factor that suppresses HIV replication was identified and confirmed as highly expressed in immune complexes from 16 hereditary and idiopathic PAH vs. 12 control lungs. Elevated SAMHD1 was localized to endothelial cells (EC), perivascular dendritic cells and macrophages and SAMHD1 antibodies were prevalent in tertiary lymphoid tissue. An unbiased screen using metagenomic sequencing related SAMHD1 to increased expression of human endogenous retrovirus K (HERV-K) in PAH vs. control lungs (n=4 each). HERV-K envelope and deoxyuridine triphosphate nucleotidohydrolase (dUTPase) mRNAs were elevated in PAH vs. control lungs (n=10) and proteins were localized to macrophages. HERV-K dUTPase induced SAMHD1 and pro-inflammatory cytokines (e.g., IL6, IL1β and TNFα) in circulating monocytes and pulmonary arterial (PA) EC, and activated B cells. Vulnerability of PAEC to apoptosis was increased by HERV-K dUTPase in an IL6 independent manner. Furthermore, three weekly injections of HERV-K dUTPase induced hemodynamic and vascular changes of pulmonary hypertension in rats (n=8), and elevated IL6. Conclusions -Our study reveals that upregulation of the endogenous retrovirus HERV-K could both initiate and sustain activation of the immune system and cause vascular changes associated with PAH.

    View details for PubMedID 28935667

  • Dynamics of the human antibody repertoire after B cell depletion in systemic sclerosis. Science immunology de Bourcy, C. F., Dekker, C. L., Davis, M. M., Nicolls, M. R., Quake, S. R. 2017; 2 (15)

    Abstract

    Systemic sclerosis with pulmonary arterial hypertension (SSc-PAH) is a debilitating and frequently lethal disease of unknown cause lacking effective treatment options. Lymphocyte anomalies and autoantibodies observed in systemic sclerosis have suggested an autoimmune character. We study the clonal structure of the B cell repertoire in SSc-PAH using immunoglobulin heavy chain (IGH) sequencing before and after B cell depletion. We found SSc-PAH to be associated with anomalies in B cell development, namely, altered VDJ rearrangement frequencies (reduced IGHV2-5 segment usage) and an increased somatic mutation-fixation probability in expanded B cell lineages. SSc-PAH was also characterized by anomalies in B cell homeostasis, namely, an expanded immunoglobulin D-positive (IgD(+)) proportion with reduced mutation loads and an expanded proportion of highly antibody-secreting cells. Disease signatures pertaining to IGHV2-5 segment usage, IgD proportions, and mutation loads were temporarily reversed after B cell depletion. Analyzing the time course of B cell depletion, we find that the kinetics of naïve replenishment are predictable from baseline measurements alone, that release of plasma cells into the periphery can precede naïve replenishment, and that modes of B cell receptor diversity are highly elastic. Our findings reveal humoral immune signatures of SSc-PAH and uncover determinism in the effects of B cell depletion on the antibody repertoire.

    View details for PubMedID 28963118

  • Aspergillus-related pulmonary diseases in lung transplantation MEDICAL MYCOLOGY Pasupneti, S., Manouvakhova, O., Nicolls, M. R., Hsu, J. L. 2017; 55 (1): 96-102

    Abstract

    While lung transplantation is an attractive treatment option for many end stage lung diseases, the relatively high 5-year mortality continues to be a significant limiting factor. Among the foremost reasons for this is the eventual development of obstructive chronic lung allograft dysfunction. Infections, which the lung allograft is especially prone to, are a major risk factor. Specifically, the Aspergillus species cause a higher burden of disease among lung transplant recipients, due to unique risk factors, such as relative hypoxemia. However, these risk factors also provide unique opportunities for treatment and preventative strategies, as outlined in this review.

    View details for DOI 10.1093/mmy/myw121

    View details for Web of Science ID 000393896500013

  • Leukotriene B4 Potentiates Bmpr2 Deficiency And Causes Paec Endmt In Pah Tian, A., Jiang, X., Shuffle, E., Tu, A., Jin, Q., Zamanian, R. T., Voelkel, N., Peters-Golden, M., Tuder, R., Rabinovitch, M., Nicolls, M. AMER THORACIC SOC. 2017
  • Delivery Of Il-10 Using A Novel High Molecular Weight Hyaluronan Vehicle Reduces Lung Fibrosis In A Bleomycin Mouse Model Of Lung Injury Shamskhou, E., Orcholski, M., Kaber, G., Yuan, K., Danielson, B., Chapman, H., Nicolls, M., Bollyky, P., Perez, V. AMER THORACIC SOC. 2017
  • Clinical Heterogeneity Across Proteomic Immunophenotypes In Pulmonary Arterial Hypertension Sweatt, A., Hedlin, H., Balasubramanian, V., Hsi, A., Blum, L., Robinson, W., Nicolls, M., Rabinovitch, M., Khatri, P., Zamanian, R. T. AMER THORACIC SOC. 2017
  • Enhanced Electrochemical Sensing with Carbon Nanotubes Modified with Bismuth and Magnetic Nanoparticles in a Lab-on-a-Chip CHEMNANOMAT Jothimuthu, P., Hsu, J. L., Chen, R., Inayathullah, M., Pothineni, V. R., Jan, A., Gurtner, G. C., Rajadas, J., Nicolls, M. R. 2016; 2 (9): 904-910

    Abstract

    Iron plays an especially important role in human physiological functions and pathological impairments. The superior properties of carbon nanotubes (CNTs) and their modification with bismuth and magnetic nanoparticles as developed in this work have led to an extraordinary and novel material to facilitate ultrasensitive detection in the nanomolar range. Here, we present the development of an electrochemical sensor for detection of ferrous (Fe(2+)) and ferric (Fe(3+)) iron by means of CNTs modified with bismuth and magnetic nanoparticles for higher sensitivity of detection. The sensor fabrication includes microfabrication methodologies, soft lithography, and electrodeposition. Cyclic voltammetry and differential pulse voltammetry are used for the electroanalytical studies and detection of the ions in samples. The sensor has a dynamic range of detection from 0.01 nm to 10 mm. The performance of the sensor with modified CNTs was explored for sensitivity and specificity. CNTs, modified with bismuth and magnetic nanoparticles by means of electrodeposition, enhanced the detection limit significantly down to 0.01 nm.

    View details for DOI 10.1002/cnma.201600174

    View details for Web of Science ID 000383766800009

    View details for PubMedCentralID PMC5110256

  • Challenges and opportunities in treating inflammation associated with pulmonary hypertension. Expert review of cardiovascular therapy Voelkel, N. F., Tamosiuniene, R., Nicolls, M. R. 2016; 14 (8): 939-951

    Abstract

    Inflammatory cells are present in the lungs from patients with many, if not all, forms of severe pulmonary hypertension. Historically the first inflammatory cell identified in the pulmonary vascular lesions was the mast cell. T and B lymphocytes, as well as macrophages, are present in and around the pulmonary arterioles and many patients have elevated blood levels of interleukin 1 and 6; some patients show elevated levels of leukotriene B4. An overlap between collagen-vascular disease-associated pulmonary arterial hypertension (PAH) and idiopathic PAH exists, yet only a few studies have been designed that evaluate the effect of anti-inflammatory treatments. Here we review the pertinent data that connect PAH and inflammation/immune dysregulation and evaluate experimental models of severe PAH with an emphasis on the Sugen/athymic rat model of severe PAH. We postulate that there are more than one inflammatory phenotype and predict that there will be several anti-inflammatory treatment strategies for severe PAH.

    View details for DOI 10.1080/14779072.2016.1180976

    View details for PubMedID 27096622

  • Effect of Transplant Center Volume on Cost and Readmissions in Medicare Lung Transplant Recipients. Annals of the American Thoracic Society Mooney, J. J., Weill, D., Boyd, J. H., Nicolls, M. R., Bhattacharya, J., Dhillon, G. S. 2016; 13 (7): 1034-1041

    Abstract

    While lung transplant recipient survival is better at higher volume centers, the effect of center volume on admission cost and early hospital readmission is unknown.To understand the association between transplant center volume and recipient risk-adjusted transplant admission cost, in-hospital mortality, and early hospital readmission in lung transplant recipients.Medicare lung transplant recipients from May 4, 2005 to December 31, 2011 were identified through linkage of transplant registry and Medicare administrative claims. Transplant admission cost was extracted, adjusted for regional price variation, and compared across low, intermediate, and high volume centers. A multivariable hierarchical generalized linear regression model was used to assess the effect of transplant center volume on recipient adjusted cost. Modified Poisson regression models were used to assess adjusted in-hospital mortality and early hospital readmission by transplant center volume.There were 3,128 Medicare lung transplant recipients identified. Unadjusted transplant cost was lower at high volume centers (mean

  • Microvascular injury after lung transplantation CURRENT OPINION IN ORGAN TRANSPLANTATION Nicolls, M. R., Hsu, J. L., Jiang, X. 2016; 21 (3): 279-284

    Abstract

    Airway microvessel injury following transplantation has been implicated in the development of chronic rejection. This review focuses on the most recent developments in the field describing preclinical and clinical findings that further implicate the loss of microvascular integrity as an important pathological event in the evolution of irreversible fibrotic remodeling.When lungs are transplanted, the airways appear vulnerable from the perspective of perfusion. Two vascular systems are lost, the bronchial artery and the lymphatic circulations, and the remaining vasculature in the airways expresses donor antigens susceptible to alloimmune-mediated injury via innate and adaptive immune mechanisms. Preclinical studies indicate the importance of hypoxia-inducible factor-1α in mediating microvascular repair and that hypoxia-inducible factor-1α can be upregulated to bolster endogenous repair.Airway microvascular injury is a feature of lung transplantation that limits short-term and long-term organ health. Although some problems are attributable to a missing bronchial artery circulation, another significant issue involves alloimmune-mediated injury to transplant airway microvessels. For a variety of reasons, bronchial artery revascularization surgery at the time of transplantation has not been widely adopted, and the current best hope for this era may be new medical approaches that offer protection against immune-mediated vascular injury or that promote microvascular repair.

    View details for DOI 10.1097/MOT.0000000000000307

    View details for Web of Science ID 000376015500007

    View details for PubMedID 26967995

  • Lung Quality and Utilization in Controlled Donation After Circulatory Determination of Death Within the United States AMERICAN JOURNAL OF TRANSPLANTATION Mooney, J. J., Hedlin, H., Mohabir, P. K., Vazquez, R., Nguyen, J., Ha, R., Chiu, P., Patel, K., Zamora, M. R., Weill, D., Nicolls, M. R., Dhillon, G. S. 2016; 16 (4): 1207-1215

    Abstract

    Although controlled donation after circulatory determination of death (cDCDD) could increase the supply of donor lungs within the United States, the yield of lungs from cDCDD donors remains low compared with donation after neurologic determination of death (DNDD). To explore the reason for low lung yield from cDCDD donors, Scientific Registry of Transplant Recipient data were used to assess the impact of donor lung quality on cDCDD lung utilization by fitting a logistic regression model. The relationship between center volume and cDCDD use was assessed, and the distance between center and donor hospital was calculated by cDCDD status. Recipient survival was compared using a multivariable Cox regression model. Lung utilization was 2.1% for cDCDD donors and 21.4% for DNDD donors. Being a cDCDD donor decreased lung donation (adjusted odds ratio 0.101, 95% confidence interval [CI] 0.085-0.120). A minority of centers have performed cDCDD transplant, with higher volume centers generally performing more cDCDD transplants. There was no difference in center-to-donor distance or recipient survival (adjusted hazard ratio 1.03, 95% CI 0.78-1.37) between cDCDD and DNDD transplants. cDCDD lungs are underutilized compared with DNDD lungs after adjusting for lung quality. Increasing transplant center expertise and commitment to cDCDD lung procurement is needed to improve utilization.

    View details for DOI 10.1111/ajt.13599

    View details for Web of Science ID 000373075400021

  • A Critical Role for Airway Microvessels in Lung Transplantation. American journal of respiratory and critical care medicine Nicolls, M. R., Dhillon, G. S., Daddi, N. 2016; 193 (5): 479-481

    View details for DOI 10.1164/rccm.201511-2117ED

    View details for PubMedID 26930430

  • Limitations Of Pulmonary Vascular Resistance As A Primary Endpoint For Therapeutic Trials Of Systemic Sclerosis Associated Pulmonary Arterial Hypertension Zamanian, R. T., Rhee, R., Pinckney, A., Goldmuntz, E., Welch, B., D'Aveta, C., Badesch, D., Nicolls, M., Kawut, S. M., Spychala, M., Autoimmunity Ctr Excellence ASC01 AMER THORACIC SOC. 2016
  • Circulating Elastase Confers A High Risk For The Development Of Bronchiolitis Obliterans Syndrome Milla, C. E., Zirbes, J. M., Yacob, A., Tian, L., Zamanian, R. T., Bental-Roof, M., Bland, R., Rabinovitch, M., Dhillon, G., Nicolls, M. AMER THORACIC SOC. 2016
  • Lung Quality and Utilization in Controlled Donation After Circulatory Determination of Death Within the United States. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons Mooney, J. J., Hedlin, H., Mohabir, P. K., Vazquez, R., Nguyen, J., Ha, R., Chiu, P., Patel, K., Zamora, M. R., Weill, D., Nicolls, M. R., Dhillon, G. S. 2016

    Abstract

    Although controlled donation after circulatory determination of death (cDCDD) could increase the supply of donor lungs within the United States, the yield of lungs from cDCDD donors remains low compared with donation after neurologic determination of death (DNDD). To explore the reason for low lung yield from cDCDD donors, Scientific Registry of Transplant Recipient data were used to assess the impact of donor lung quality on cDCDD lung utilization by fitting a logistic regression model. The relationship between center volume and cDCDD use was assessed, and the distance between center and donor hospital was calculated by cDCDD status. Recipient survival was compared using a multivariable Cox regression model. Lung utilization was 2.1% for cDCDD donors and 21.4% for DNDD donors. Being a cDCDD donor decreased lung donation (adjusted odds ratio 0.101, 95% confidence interval [CI] 0.085-0.120). A minority of centers have performed cDCDD transplant, with higher volume centers generally performing more cDCDD transplants. There was no difference in center-to-donor distance or recipient survival (adjusted hazard ratio 1.03, 95% CI 0.78-1.37) between cDCDD and DNDD transplants. cDCDD lungs are underutilized compared with DNDD lungs after adjusting for lung quality. Increasing transplant center expertise and commitment to cDCDD lung procurement is needed to improve utilization.

    View details for PubMedID 26844673

  • Bmpr2 Deficiency Potentiates The Ltb4 Mediated Paec Transformation In Pah Tian, W., Jiang, X., Qian, J., Tu, A., Shuffle, E., Mesange, P., Nicolls, M. AMER THORACIC SOC. 2016
  • Inhibition Of Connective Tissue Growth Factor Promotes Healthy Revascularization And Ameliorates Fibrosis In Orthotopic Tracheal Transplantation Lin, Y., Jiang, X., Nicolls, M. AMER THORACIC SOC. 2016
  • Acute Microvascular Rejection Increases Graft Iron, Promoting Aspergillus Fumigatus Allograft Invasion Hsu, J. L., Inayathulla, M., Tu, A. B., Clemons, K. V., Rajadas, J., Stevens, D. A., Nicolls, M. AMER THORACIC SOC. 2016
  • Endothelial Hif-2a Deficiency Disrupts Airway Microvascular Structure And Impairs The Repair Of Vessels Of Transplanted Airways Jiang, X., Tian, W., Tu, A., Nicolls, M. AMER THORACIC SOC. 2016
  • Non-Invasive Monitoring of Infection and Rejection After Lung Transplantation Vlaminck, I. D., Martin, L., Kertesz, M., Patel, K. N., Kowarsky, M., Strehl, C., Cohen, G., Luikart, H., Neff, N., Okamoto, J., Nicolls, M. N., Cornfield, D. N., Weill, D., Valantine, H. A., Khush, K. K., Quake, S. R. ELSEVIER SCIENCE INC. 2015: S137
  • Increased Resource Use in Lung Transplant Admissions in the Lung Allocation Score Era AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE Maxwelll, B. G., Mooney, J. J., Lee, P. H., Levitt, J. E., Chhatwani, L., Nicolls, M. R., Zamora, M. R., Valentine, V., Weill, D., Dhillon, G. S. 2015; 191 (3): 302-308

    Abstract

    Rationale: In 2005, the lung allocation score (LAS) was implemented to prioritize organ allocation to minimize waiting-list mortality and maximize one-year survival. It resulted in transplantation of older and sicker patients without changing one-year survival. Its effect on resource utilization is unknown. Objective: To determine changes in resource utilization over time in lung transplant admissions Methods: Solid organ transplant recipients were identified within the Nationwide Inpatient Sample (NIS) data from 2000 to 2011. Joinpoint regression methodology was performed to identify a time point of change in mean total hospital charges amongst lung transplant and other solid organ transplant recipients. Two temporal lung transplant recipient cohorts identified by joinpoint regression were compared for baseline characteristics and resource utilization, including total charges for index hospitalization, charges per day, length of stay, discharge disposition, tracheostomy, and need for extracorporeal membrane oxygenation (ECMO). Measurements and Main Results: A significant point of increased total hospital charges occurred for lung transplant recipients in 2005, corresponding to LAS implementation, that was not seen in other solid organ transplant recipients. Total transplant hospital charges increased by 40% in the post-LAS cohort [

  • Activation of the Wnt/Planar Cell Polarity Pathway Is Required for Pericyte Recruitment during Pulmonary Angiogenesis. American journal of pathology Yuan, K., Orcholski, M. E., Panaroni, C., Shuffle, E. M., Huang, N. F., Jiang, X., Tian, W., Vladar, E. K., Wang, L., Nicolls, M. R., Wu, J. Y., de Jesus Perez, V. A. 2015; 185 (1): 69-84

    Abstract

    Pericytes are perivascular cells localized to capillaries that promote vessel maturation, and their absence can contribute to vessel loss. Whether impaired endothelial-pericyte interaction contributes to small vessel loss in pulmonary arterial hypertension (PAH) is unclear. Using 3G5-specific, immunoglobulin G-coated magnetic beads, we isolated pericytes from the lungs of healthy subjects and PAH patients, followed by lineage validation. PAH pericytes seeded with healthy pulmonary microvascular endothelial cells failed to associate with endothelial tubes, resulting in smaller vascular networks compared to those with healthy pericytes. After the demonstration of abnormal polarization toward endothelium via live-imaging and wound-healing studies, we screened PAH pericytes for abnormalities in the Wnt/planar cell polarity (PCP) pathway, which has been shown to regulate cell motility and polarity in the pulmonary vasculature. PAH pericytes had reduced expression of frizzled 7 (Fzd7) and cdc42, genes crucial for Wnt/PCP activation. With simultaneous knockdown of Fzd7 and cdc42 in healthy pericytes in vitro and in a murine model of angiogenesis, motility and polarization toward pulmonary microvascular endothelial cells were reduced, whereas with restoration of both genes in PAH pericytes, endothelial-pericyte association was improved, with larger vascular networks. These studies suggest that the motility and polarity of pericytes during pulmonary angiogenesis are regulated by Wnt/PCP activation, which can be targeted to prevent vessel loss in PAH.

    View details for DOI 10.1016/j.ajpath.2014.09.013

    View details for PubMedID 25447046

  • Hypoxia Inducible Factor-1 alpha Increases Bone Morphogenetic Protein Signaling In Pulmonary Artery Endothelial Cells Kuang, J., Tian, X., Tian, A., Semenza, G., Nicolls, M. R., Spiekerkoetter, E. AMER THORACIC SOC. 2015
  • Activation of the Wnt/Planar Cell Polarity Pathway Is Required for Pericyte Recruitment during Pulmonary Angiogenesis AMERICAN JOURNAL OF PATHOLOGY Yuan, K., Orcholski, M. E., Panaroni, C., Shuffle, E. M., Huang, N. F., Jiang, X., Tian, W., Vladar, E. K., Wang, L., Nicolls, M. R., Wu, J. Y., Perez, V. A. 2015; 185 (1): 69-84

    Abstract

    Pericytes are perivascular cells localized to capillaries that promote vessel maturation, and their absence can contribute to vessel loss. Whether impaired endothelial-pericyte interaction contributes to small vessel loss in pulmonary arterial hypertension (PAH) is unclear. Using 3G5-specific, immunoglobulin G-coated magnetic beads, we isolated pericytes from the lungs of healthy subjects and PAH patients, followed by lineage validation. PAH pericytes seeded with healthy pulmonary microvascular endothelial cells failed to associate with endothelial tubes, resulting in smaller vascular networks compared to those with healthy pericytes. After the demonstration of abnormal polarization toward endothelium via live-imaging and wound-healing studies, we screened PAH pericytes for abnormalities in the Wnt/planar cell polarity (PCP) pathway, which has been shown to regulate cell motility and polarity in the pulmonary vasculature. PAH pericytes had reduced expression of frizzled 7 (Fzd7) and cdc42, genes crucial for Wnt/PCP activation. With simultaneous knockdown of Fzd7 and cdc42 in healthy pericytes in vitro and in a murine model of angiogenesis, motility and polarization toward pulmonary microvascular endothelial cells were reduced, whereas with restoration of both genes in PAH pericytes, endothelial-pericyte association was improved, with larger vascular networks. These studies suggest that the motility and polarity of pericytes during pulmonary angiogenesis are regulated by Wnt/PCP activation, which can be targeted to prevent vessel loss in PAH.

    View details for DOI 10.1016/j.ajpath.2014.09.013

    View details for Web of Science ID 000346887200008

  • Unique predictors of mortality in patients with pulmonary arterial hypertension associated with systemic sclerosis in the REVEAL registry. Chest Chung, L., Farber, H. W., Benza, R., Miller, D. P., Parsons, L., Hassoun, P. M., McGoon, M., Nicolls, M. R., Zamanian, R. T. 2014; 146 (6): 1494-1504

    Abstract

    Background:Patients with pulmonary arterial hypertension associated with systemic sclerosis (SSc-APAH) experience higher mortality rates than patients with idiopathic disease and those with other connective tissue diseases (CTD-APAH). We sought to identify unique predictors of mortality associated with SSc-APAH in the CTD-APAH population. Methods:The Registry to Evaluate Early and Long-Term PAH Management (REVEAL) is a multicenter, prospective US-based registry of patients with previously and newly diagnosed (enrollment within 90 days of diagnostic right heart catheterization) PAH. Cox regression models evaluated all previously identified candidate predictors of mortality in the overall REVEAL population to identify significant predictors of mortality in the SSc-APAH (n=500) versus non-SSc-CTD-APAH (n=304) populations. Results:Three-year survival in the previously diagnosed and newly diagnosed SSc-APAH group was 61.4±2.7% and 51.2±4.0%, respectively, compared with 80.9±2.7% and 76.4±4.6%, respectively, in the non-SSc-CTD-APAH group (P<.001). In multivariate analyses, males aged >60 years, systolic blood pressure (SBP) ≤110 mmHg, 6-minute walk distance (6MWD) <165 m, mean right atrial pressure (mRAP) >20 mmHg within 1 year, and pulmonary vascular resistance (PVR) >32 WU remained unique predictors of mortality in the SSc-APAH group; 6MWD ≥440 m was protective in the non-SSc-CTD-APAH group, but not the SSc-APAH group. Conclusions:Patients with SSc-APAH have higher mortality rates than non-SSc-CTD-APAH patients. Identifying SSc-APAH patients who are at particularly high risk of death, including elderly males and patients with low baseline SBP or 6MWD, or markedly elevated mRAP or PVR, will enable clinicians to identify patients who may benefit from closer monitoring and more aggressive treatment. Registered at:www.clinicaltrials.gov #NCT00370214.Patients with pulmonary arterial hypertension associated with systemic sclerosis (SSc-APAH) experience higher mortality rates than patients with idiopathic disease and those with other connective tissue diseases (CTD-APAH). We sought to identify unique predictors of mortality associated with SSc-APAH in the CTD-APAH population.The Registry to Evaluate Early and Long-Term PAH Management (REVEAL) is a multicenter, prospective US-based registry of patients with previously and newly diagnosed (enrollment within 90 days of diagnostic right heart catheterization) PAH. Cox regression models evaluated all previously identified candidate predictors of mortality in the overall REVEAL population to identify significant predictors of mortality in the SSc-APAH (n=500) versus non-SSc-CTD-APAH (n=304) populations.Three-year survival in the previously diagnosed and newly diagnosed SSc-APAH group was 61.4±2.7% and 51.2±4.0%, respectively, compared with 80.9±2.7% and 76.4±4.6%, respectively, in the non-SSc-CTD-APAH group (P<.001). In multivariate analyses, males aged >60 years, systolic blood pressure (SBP) ≤110 mmHg, 6-minute walk distance (6MWD) <165 m, mean right atrial pressure (mRAP) >20 mmHg within 1 year, and pulmonary vascular resistance (PVR) >32 WU remained unique predictors of mortality in the SSc-APAH group; 6MWD ≥440 m was protective in the non-SSc-CTD-APAH group, but not the SSc-APAH group.Patients with SSc-APAH have higher mortality rates than non-SSc-CTD-APAH patients. Identifying SSc-APAH patients who are at particularly high risk of death, including elderly males and patients with low baseline SBP or 6MWD, or markedly elevated mRAP or PVR, will enable clinicians to identify patients who may benefit from closer monitoring and more aggressive treatment.www.clinicaltrials.gov #NCT00370214.

    View details for DOI 10.1378/chest.13-3014

    View details for PubMedID 24992469

  • Impact of the lung allocation score on survival beyond 1 year. American journal of transplantation Maxwell, B. G., Levitt, J. E., Goldstein, B. A., Mooney, J. J., Nicolls, M. R., Zamora, M., Valentine, V., Weill, D., Dhillon, G. S. 2014; 14 (10): 2288-2294

    Abstract

    Implementation of the lung allocation score (LAS) in 2005 led to transplantation of older and sicker patients without altering 1-year survival. However, long-term survival has not been assessed and emphasizing the 1-year survival metric may actually sustain 1-year survival while not reflecting worsening longer-term survival. Therefore, we assessed overall and conditional 1-year survival; and the effect of crossing the 1-year threshold on hazard of death in three temporal cohorts: historical (1995-2000), pre-LAS (2001-2005) and post-LAS (2005-2010). One-year survival post-LAS remained similar to pre-LAS (83.1% vs. 82.1%) and better than historical controls (75%). Overall survival in the pre- and post-LAS cohorts was also similar. However, long-term survival among patients surviving beyond 1 year was worse than pre-LAS and similar to historical controls. Also, the hazard of death increased significantly in months 13 (1.44, 95% CI 1.10-1.87) and 14 (1.43, 95% CI 1.09-1.87) post-LAS but not in the other cohorts. While implementation of the LAS has not reduced overall survival, decreased survival among patients surviving beyond 1 year in the post-LAS cohort and the increased mortality occurring immediately after 1 year suggest a potential negative long-term effect of the LAS and an unintended consequence of increased emphasis on the 1-year survival metric.

    View details for DOI 10.1111/ajt.12903

    View details for PubMedID 25208599

  • Impact of the Lung Allocation Score on Survival Beyond 1 Year AMERICAN JOURNAL OF TRANSPLANTATION Maxwell, B. G., Levitt, J. E., Goldstein, B. A., Mooney, J. J., Nicolls, M. R., Zamora, M., Valentine, V., Weill, D., Dhillon, G. S. 2014; 14 (10): 2288-2294

    Abstract

    Implementation of the lung allocation score (LAS) in 2005 led to transplantation of older and sicker patients without altering 1-year survival. However, long-term survival has not been assessed and emphasizing the 1-year survival metric may actually sustain 1-year survival while not reflecting worsening longer-term survival. Therefore, we assessed overall and conditional 1-year survival; and the effect of crossing the 1-year threshold on hazard of death in three temporal cohorts: historical (1995-2000), pre-LAS (2001-2005) and post-LAS (2005-2010). One-year survival post-LAS remained similar to pre-LAS (83.1% vs. 82.1%) and better than historical controls (75%). Overall survival in the pre- and post-LAS cohorts was also similar. However, long-term survival among patients surviving beyond 1 year was worse than pre-LAS and similar to historical controls. Also, the hazard of death increased significantly in months 13 (1.44, 95% CI 1.10-1.87) and 14 (1.43, 95% CI 1.09-1.87) post-LAS but not in the other cohorts. While implementation of the LAS has not reduced overall survival, decreased survival among patients surviving beyond 1 year in the post-LAS cohort and the increased mortality occurring immediately after 1 year suggest a potential negative long-term effect of the LAS and an unintended consequence of increased emphasis on the 1-year survival metric.

    View details for DOI 10.1111/ajt.12903

    View details for Web of Science ID 000342663300014

  • CLOPIDOGREL PRESERVES MICROVASCULAR VASCULAR INTEGRITY IN ORTHOTOPIC TRACHEAL TRANSPLANTS AFFECTED BY OBLITERATIVE BRONCHIOLITIS Heim, C., Khan, M. A., Motsch, B., Mueller, S., Stamminger, T., Nicolls, M. R., Weyand, M., Ensminger, S. WILEY-BLACKWELL. 2014: 11
  • Nuclear Factor ?B Inhibition Reduces Lung Vascular Lumen Obliteration in Severe Pulmonary Hypertension in Rats. American journal of respiratory cell and molecular biology Farkas, D., Alhussaini, A. A., Kraskauskas, D., Kraskauskiene, V., Cool, C. D., Nicolls, M. R., Natarajan, R., Farkas, L. 2014; 51 (3): 413-425

    Abstract

    Nuclear factor-κB (NF-κB) and interleukin-6 (IL-6), a NF-κB downstream mediator, play a central role in the inflammatory response of tissues. We aimed to determine the role of the classical NF-κB pathway in severe pulmonary arterial hypertension (PAH) induced by SU5416 and chronic hypoxia (SuHx) in rats. Tissue samples from patients with idiopathic PAH (iPAH) and control subjects were investigated. SuHx rats were treated from days 1-3, 1-21 and 29-42 with the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) and/or from days 1-21 with anti-IL-6 antibody. Nuclear staining for NF-κB, an indicator of the activation of the classical NF-κB pathway, was detected in pulmonary arterial lesions of iPAH patients and SuHx rats. NF-κB inhibition with PDTC prevented and reduced pulmonary arterial obliteration without reducing muscularization. However, the elevated lung levels of IL-6 were not reduced in PDTC-treated SuHx animals. PDTC treatment prevented or reduced apoptosis of pulmonary artery wall cells and pulmonary arterial obliteration. IL-6 inhibition had only a partial effect on apoptosis and obliteration. Pulmonary arterial media wall thickness was not affected by any of these treatments. Preventive and therapeutic PDTC treatment promoted immune regulation by increasing the number of perivascular CD4+ T cells, in particular regulatory T cells (early treatment) and by reducing the number of perivascular CD8+ T lymphocytes and CD45RA+ B lymphocytes. Therapeutic PDTC treatment further preserved right ventricular function in SuHx animals. Inhibition of NF-κB may represent a therapeutic option for pulmonary arterial obliteration via reduced vessel wall cell apoptosis and improved regulation of the immune system.

    View details for DOI 10.1165/rcmb.2013-0355OC

    View details for PubMedID 24684441

  • Graft microvascular disease in solid organ transplantation. Journal of molecular medicine (Berlin, Germany) Jiang, X., Sung, Y. K., Tian, W., Qian, J., Semenza, G. L., Nicolls, M. R. 2014; 92 (8): 797-810

    Abstract

    Alloimmune inflammation damages the microvasculature of solid organ transplants during acute rejection. Although immunosuppressive drugs diminish the inflammatory response, they do not directly promote vascular repair. Repetitive microvascular injury with insufficient regeneration results in prolonged tissue hypoxia and fibrotic remodeling. While clinical studies show that a loss of the microvascular circulation precedes and may act as an initiating factor for the development of chronic rejection, preclinical studies demonstrate that improved microvascular perfusion during acute rejection delays and attenuates tissue fibrosis. Therefore, preservation of a functional microvasculature may represent an effective therapeutic strategy for preventing chronic rejection. Here, we review recent advances in our understanding of the role of the microvasculature in the long-term survival of transplanted solid organs. We also highlight microvessel-centered therapeutic strategies for prolonging the survival of solid organ transplants.

    View details for DOI 10.1007/s00109-014-1173-y

    View details for PubMedID 24880953

  • Relaxin Increases Cellular Softening Which Synergizes With ECM-Softening LOX Inhibitor to Attenuates Airway Fibrosis in Mouse Orthotopic Tracheal Transplantation Lin, Y., Jiang, X., Nicolls, M. LIPPINCOTT WILLIAMS & WILKINS. 2014: 400
  • Clopidogrel Preserves Microvascular Integrity in Orthotopic Tracheal Transplants Affected By Obliterative Bronchiolitis. Heim, C., Khan, M., Motsch, B., Mueller, S., Stamminger, T., Nicolls, M., Weyand, M., Ensminger, S. LIPPINCOTT WILLIAMS & WILKINS. 2014: 327
  • Hypoxia Inducible Factor-1 alpha Limits Aspergillus fumigatus Invasion in the Rejecting Airway Allograft. Hsu, J., Jiang, X., Clemons, K., Stevens, D., Nicolls, M. LIPPINCOTT WILLIAMS & WILKINS. 2014: 270