My research focus involves the application of modern genomics to unravel complex human diseases and promote health. By integrating large-scale human genetic association data with multi-omic profiling and functional models, my work seeks to better understand causal disease mechanisms. Recent efforts involve the discovery of regulatory variants associated with coronary artery disease (CAD) linked to changes in chromatin structure and gene expression in primary vascular cells and tissues. This work encompasses genomics, epigenomics, transcriptomics and the development and application of robust and integrative computational pipelines. We are currently mapping differential allele-specific chromatin states and gene expression in large cohorts using various statistical frameworks. Ultimately these approaches will shed light on the functions and interactions of common regulatory variants, as well as hierarchical patterns of transcription factor binding, chromatin accessibility, and nucleosome positions in different environments. We are applying site-specific genomic targeting in inducible pluripotent stem cells (iPSC) and animal models to further close the gap between associations and disease-relevant phenotypes. I currently maintain a unique biobank of vascular tissues from explanted donor hearts. I am also involved with developing specialized curricula in genomic medicine for both medical students and practicing physicians.

Academic Appointments

Honors & Awards

  • ATVB Young Investigator Travel Award, American Heart Association (2015)
  • Young Investigator Fellowship, European Atherosclerosis Society Congress (2015)
  • K99 Pathway to Independence Award, NIH (2014-Present)
  • CVI Postdoctoral Travel Award, Stanford University (2013)
  • CVI Young Investigator Award, Stanford University (2013)
  • TEDMED Front Line Full Scholar, TEDMED (2013)
  • T32 NRSA - Myocardial Biology, NIH (2011-2014)
  • Wallace O. Fenn Award for Best Thesis (Finalist), University of Rochester (2011)
  • Predoctoral Fellowship, American Heart Association (2008-2010)
  • Graduate Student Society Merit Award (First Place), University of Rochester (2008)
  • Dean's List, President's List, Semester Academic Honors, University of Maryland - Baltimore County (1999-2003)
  • Presidential Award - Full Scholarship, University of Maryland - Baltimore County (1999-2003)

Professional Education

  • Postdoc, Stanford University (2014)
  • PhD, University of Rochester, Pharmacology (2011)
  • MS, University of Rochester, Pharmacology (2007)
  • BS, University of Maryland - Baltimore County, Neuroscience (2003)


Graduate and Fellowship Programs


All Publications

  • Genetics and Genomics of Coronary Artery Disease. Current cardiology reports Pjanic, M., Miller, C. L., Wirka, R., Kim, J. B., Direnzo, D. M., Quertermous, T. 2016; 18 (10): 102-?


    Coronary artery disease (or coronary heart disease), is the leading cause of mortality in many of the developing as well as the developed countries of the world. Cholesterol-enriched plaques in the heart's blood vessels combined with inflammation lead to the lesion expansion, narrowing of blood vessels, reduced blood flow, and may subsequently cause lesion rupture and a heart attack. Even though several environmental risk factors have been established, such as high LDL-cholesterol, diabetes, and high blood pressure, the underlying genetic composition may substantially modify the disease risk; hence, genome composition and gene-environment interactions may be critical for disease progression. Ongoing scientific efforts have seen substantial advancements related to the fields of genetics and genomics, with the major breakthroughs yet to come. As genomics is the most rapidly advancing field in the life sciences, it is important to present a comprehensive overview of current efforts. Here, we present a summary of various genetic and genomics assays and approaches applied to coronary artery disease research.

    View details for DOI 10.1007/s11886-016-0777-y

    View details for PubMedID 27586139

  • Integrative functional genomics identifies regulatory mechanisms at coronary artery disease loci. Nature communications Miller, C. L., Pjanic, M., Wang, T., Nguyen, T., Cohain, A., Lee, J. D., Perisic, L., Hedin, U., Kundu, R. K., Majmudar, D., Kim, J. B., Wang, O., Betsholtz, C., Ruusalepp, A., Franzén, O., Assimes, T. L., Montgomery, S. B., Schadt, E. E., Björkegren, J. L., Quertermous, T. 2016; 7: 12092-?


    Coronary artery disease (CAD) is the leading cause of mortality and morbidity, driven by both genetic and environmental risk factors. Meta-analyses of genome-wide association studies have identified >150 loci associated with CAD and myocardial infarction susceptibility in humans. A majority of these variants reside in non-coding regions and are co-inherited with hundreds of candidate regulatory variants, presenting a challenge to elucidate their functions. Herein, we use integrative genomic, epigenomic and transcriptomic profiling of perturbed human coronary artery smooth muscle cells and tissues to begin to identify causal regulatory variation and mechanisms responsible for CAD associations. Using these genome-wide maps, we prioritize 64 candidate variants and perform allele-specific binding and expression analyses at seven top candidate loci: 9p21.3, SMAD3, PDGFD, IL6R, BMP1, CCDC97/TGFB1 and LMOD1. We validate our findings in expression quantitative trait loci cohorts, which together reveal new links between CAD associations and regulatory function in the appropriate disease context.

    View details for DOI 10.1038/ncomms12092

    View details for PubMedID 27386823

  • From Locus Association to Mechanism of Gene Causality: The Devil Is in the Details. Arteriosclerosis, thrombosis, and vascular biology Miller, C. L., Pjanic, M., Quertermous, T. 2015; 35 (10): 2079-2080

    View details for DOI 10.1161/ATVBAHA.115.306366

    View details for PubMedID 26399919

  • CD47-blocking antibodies restore phagocytosis and prevent atherosclerosis. Nature Kojima, Y., Volkmer, J., McKenna, K., Civelek, M., Lusis, A. J., Miller, C. L., DiRenzo, D., Nanda, V., Ye, J., Connolly, A. J., Schadt, E. E., Quertermous, T., Betancur, P., Maegdefessel, L., Matic, L. P., Hedin, U., Weissman, I. L., Leeper, N. J. 2016; 536 (7614): 86-90


    Atherosclerosis is the disease process that underlies heart attack and stroke. Advanced lesions at risk of rupture are characterized by the pathological accumulation of diseased vascular cells and apoptotic cellular debris. Why these cells are not cleared remains unknown. Here we show that atherogenesis is associated with upregulation of CD47, a key anti-phagocytic molecule that is known to render malignant cells resistant to programmed cell removal, or 'efferocytosis'. We find that administration of CD47-blocking antibodies reverses this defect in efferocytosis, normalizes the clearance of diseased vascular tissue, and ameliorates atherosclerosis in multiple mouse models. Mechanistic studies implicate the pro-atherosclerotic factor TNF-α as a fundamental driver of impaired programmed cell removal, explaining why this process is compromised in vascular disease. Similar to recent observations in cancer, impaired efferocytosis appears to play a pathogenic role in cardiovascular disease, but is not a fixed defect and may represent a novel therapeutic target.

    View details for PubMedID 27437576

  • Phenotypic Modulation of Smooth Muscle Cells in Atherosclerosis Is Associated With Downregulation of LMOD1, SYNPO2, PDLIM7, PLN, and SYNM. Arteriosclerosis, thrombosis, and vascular biology Perisic Matic, L., Rykaczewska, U., Razuvaev, A., Sabater-Lleal, M., Lengquist, M., Miller, C. L., Ericsson, I., Röhl, S., Kronqvist, M., Aldi, S., Magné, J., Paloschi, V., Vesterlund, M., Li, Y., Jin, H., Diez, M. G., Roy, J., Baldassarre, D., Veglia, F., Humphries, S. E., de Faire, U., Tremoli, E., Odeberg, J., Vukojević, V., Lehtiö, J., Maegdefessel, L., Ehrenborg, E., Paulsson-Berne, G., Hansson, G. K., Lindeman, J. H., Eriksson, P., Quertermous, T., Hamsten, A., Hedin, U. 2016; 36 (9): 1947-61


    Key augmented processes in atherosclerosis have been identified, whereas less is known about downregulated pathways. Here, we applied a systems biology approach to examine suppressed molecular signatures, with the hypothesis that they may provide insight into mechanisms contributing to plaque stability.Muscle contraction, muscle development, and actin cytoskeleton were the most downregulated pathways (false discovery rate=6.99e-21, 1.66e-6, 2.54e-10, respectively) in microarrays from human carotid plaques (n=177) versus healthy arteries (n=15). In addition to typical smooth muscle cell (SMC) markers, these pathways also encompassed cytoskeleton-related genes previously not associated with atherosclerosis. SYNPO2, SYNM, LMOD1, PDLIM7, and PLN expression positively correlated to typical SMC markers in plaques (Pearson r>0.6, P<0.0001) and in rat intimal hyperplasia (r>0.8, P<0.0001). By immunohistochemistry, the proteins were expressed in SMCs in normal vessels, but largely absent in human plaques and intimal hyperplasia. Subcellularly, most proteins localized to the cytoskeleton in cultured SMCs and were regulated by active enhancer histone modification H3K27ac by chromatin immunoprecipitation-sequencing. Functionally, the genes were downregulated by PDGFB (platelet-derived growth factor beta) and IFNg (interferron gamma), exposure to shear flow stress, and oxLDL (oxidized low-density lipoprotein) loading. Genetic variants in PDLIM7, PLN, and SYNPO2 loci associated with progression of carotid intima-media thickness in high-risk subjects without symptoms of cardiovascular disease (n=3378). By eQTL (expression quantitative trait locus), rs11746443 also associated with PDLIM7 expression in plaques. Mechanistically, silencing of PDLIM7 in vitro led to downregulation of SMC markers and disruption of the actin cytoskeleton, decreased cell spreading, and increased proliferation.We identified a panel of genes that reflect the altered phenotype of SMCs in vascular disease and could be early sensitive markers of SMC dedifferentiation.

    View details for DOI 10.1161/ATVBAHA.116.307893

    View details for PubMedID 27470516

  • PDE1C deficiency antagonizes pathological cardiac remodeling and dysfunction. Proceedings of the National Academy of Sciences of the United States of America Knight, W. E., Chen, S., Zhang, Y., Oikawa, M., Wu, M., Zhou, Q., Miller, C. L., Cai, Y., Mickelsen, D. M., Moravec, C., Small, E. M., Abe, J., Yan, C. 2016


    Cyclic nucleotide phosphodiesterase 1C (PDE1C) represents a major phosphodiesterase activity in human myocardium, but its function in the heart remains unknown. Using genetic and pharmacological approaches, we studied the expression, regulation, function, and underlying mechanisms of PDE1C in the pathogenesis of cardiac remodeling and dysfunction. PDE1C expression is up-regulated in mouse and human failing hearts and is highly expressed in cardiac myocytes but not in fibroblasts. In adult mouse cardiac myocytes, PDE1C deficiency or inhibition attenuated myocyte death and apoptosis, which was largely dependent on cyclic AMP/PKA and PI3K/AKT signaling. PDE1C deficiency also attenuated cardiac myocyte hypertrophy in a PKA-dependent manner. Conditioned medium taken from PDE1C-deficient cardiac myocytes attenuated TGF-β-stimulated cardiac fibroblast activation through a mechanism involving the crosstalk between cardiac myocytes and fibroblasts. In vivo, cardiac remodeling and dysfunction induced by transverse aortic constriction, including myocardial hypertrophy, apoptosis, cardiac fibrosis, and loss of contractile function, were significantly attenuated in PDE1C-knockout mice relative to wild-type mice. These results indicate that PDE1C activation plays a causative role in pathological cardiac remodeling and dysfunction. Given the continued development of highly specific PDE1 inhibitors and the high expression level of PDE1C in the human heart, our findings could have considerable therapeutic significance.

    View details for DOI 10.1073/pnas.1607728113

    View details for PubMedID 27791092

  • Systems Genomics Identifies a Key Role for Hypocretin/Orexin Receptor-2 in Human Heart Failure JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Perez, M. V., Pavlovic, A., Shang, C., Wheeler, M. T., Miller, C. L., Liu, J., Dewey, F. E., Pan, S., Thanaporn, P. K., Absher, D., Brandimarto, J., Salisbury, H., Chan, K., Mukherjee, R., Konadhode, R. P., Myers, R. M., Sedehi, D., Scammell, T. E., Quertermous, T., Cappola, T., Ashley, E. A. 2015; 66 (22): 2522-2533


    The genetic determinants of heart failure (HF) and response to medical therapy remain unknown. We hypothesized that identifying genetic variants of HF that associate with response to medical therapy would elucidate the genetic basis of cardiac function.This study sought to identify genetic variations associated with response to HF therapy.This study compared extremes of response to medical therapy in 866 HF patients using a genome-wide approach that informed the systems-based design of a customized single nucleotide variant array. The effect of genotype on gene expression was measured using allele-specific luciferase reporter assays. Candidate gene transcription-deficient mice underwent echocardiography and treadmill exercise. The ability of the target gene agonist to rescue mice from chemically-induced HF was assessed with echocardiography.Of 866 HF patients, 136 had an ejection fraction improvement of 20% attributed to resynchronization (n = 83), revascularization (n = 7), tachycardia resolution (n = 2), alcohol cessation (n = 1), or medications (n = 43). Those with the minor allele for rs7767652, upstream of hypocretin (orexin) receptor-2 (HCRTR2), were less likely to have improved left ventricular function (odds ratio: 0.40 per minor allele; p = 3.29 × 10(-5)). In a replication cohort of 798 patients, those with a minor allele for rs7767652 had a lower prevalence of ejection fraction >35% (odds ratio: 0.769 per minor allele; p = 0.021). In an HF model, HCRTR2-deficient mice exhibited poorer cardiac function, worse treadmill exercise capacity, and greater myocardial scarring. Orexin, an HCRTR2 agonist, rescued function in this HF mouse model.A systems approach identified a novel genetic contribution to human HF and a promising therapeutic agent efficacious in an HF model.

    View details for DOI 10.1016/j.jacc.2015.09.061

    View details for Web of Science ID 000366094500009

  • Sequence to Medical Phenotypes: A Framework for Interpretation of Human Whole Genome DNA Sequence Data PLOS GENETICS Dewey, F. E., Grove, M. E., Priest, J. R., Waggott, D., Batra, P., Miller, C. L., Wheeler, M., Zia, A., Pan, C., Karzcewski, K. J., Miyake, C., Whirl-Carrillo, M., Klein, T. E., Datta, S., Altman, R. B., Snyder, M., Quertermous, T., Ashley, E. A. 2015; 11 (10)
  • Characterization of TCF21 Downstream Target Regions Identifies a Transcriptional Network Linking Multiple Independent Coronary Artery Disease Loci PLOS GENETICS Sazonova, O., Zhao, Y., Nuernberg, S., Miller, C., Pjanic, M., Castano, V. G., Kim, J. B., Salfati, E. L., Kundaje, A. B., Bejerano, G., Assimes, T., Yang, X., Quertermous, T. 2015; 11 (5)
  • Coronary Artery Disease Associated Transcription Factor TCF21 Regulates Smooth Muscle Precursor Cells That Contribute to the Fibrous Cap PLOS GENETICS Nurnberg, S. T., Cheng, K., Raiesdana, A., Kundu, R., Miller, C. L., Kim, J. B., Arora, K., Carcamo-Oribe, I., Xiong, Y., Tellakula, N., Nanda, V., Murthy, N., Boisvert, W. A., Hedin, U., Perisic, L., Aldi, S., Maegdefessel, L., Pjanic, M., Owens, G. K., Tallquist, M. D., Quertermous, T. 2015; 11 (5)
  • Dissecting the causal genetic mechanisms of coronary heart disease. Current atherosclerosis reports Miller, C. L., Assimes, T. L., Montgomery, S. B., Quertermous, T. 2014; 16 (5): 406-?


    Large-scale genome-wide association studies (GWAS) have identified 46 loci that are associated with coronary heart disease (CHD). Additionally, 104 independent candidate variants (false discovery rate of 5 %) have been identified (Schunkert H, Konig IR, Kathiresan S, Reilly MP, Assimes TL, Holm H et al. Nat Genet 43:333-8, 2011; Deloukas P, Kanoni S, Willenborg C, Farrall M, Assimes TL, Thompson JR et al. Nat Genet 45:25-33, 2012; C4D Genetics Consortium. Nat Genet 43:339-44, 2011). The majority of the causal genes in these loci function independently of conventional risk factors. It is postulated that a number of the CHD-associated genes regulate basic processes in the vascular cells involved in atherosclerosis, and that study of the signaling pathways that are modulated in this cell type by causal regulatory variation will provide critical new insights for targeting the initiation and progression of disease. In this review, we will discuss the types of experimental approaches and data that are critical to understanding the molecular processes that underlie the disease risk at 9p21.3, TCF21, SORT1, and other CHD-associated loci.

    View details for DOI 10.1007/s11883-014-0406-4

    View details for PubMedID 24623178

  • Coronary heart disease-associated variation in TCF21 disrupts a miR-224 binding site and miRNA-mediated regulation. PLoS genetics Miller, C. L., Haas, U., Diaz, R., Leeper, N. J., Kundu, R. K., Patlolla, B., Assimes, T. L., Kaiser, F. J., Perisic, L., Hedin, U., Maegdefessel, L., Schunkert, H., Erdmann, J., Quertermous, T., Sczakiel, G. 2014; 10 (3)


    Genome-wide association studies (GWAS) have identified chromosomal loci that affect risk of coronary heart disease (CHD) independent of classical risk factors. One such association signal has been identified at 6q23.2 in both Caucasians and East Asians. The lead CHD-associated polymorphism in this region, rs12190287, resides in the 3' untranslated region (3'-UTR) of TCF21, a basic-helix-loop-helix transcription factor, and is predicted to alter the seed binding sequence for miR-224. Allelic imbalance studies in circulating leukocytes and human coronary artery smooth muscle cells (HCASMC) showed significant imbalance of the TCF21 transcript that correlated with genotype at rs12190287, consistent with this variant contributing to allele-specific expression differences. 3' UTR reporter gene transfection studies in HCASMC showed that the disease-associated C allele has reduced expression compared to the protective G allele. Kinetic analyses in vitro revealed faster RNA-RNA complex formation and greater binding of miR-224 with the TCF21 C allelic transcript. In addition, in vitro probing with Pb2+ and RNase T1 revealed structural differences between the TCF21 variants in proximity of the rs12190287 variant, which are predicted to provide greater access to the C allele for miR-224 binding. miR-224 and TCF21 expression levels were anti-correlated in HCASMC, and miR-224 modulates the transcriptional response of TCF21 to transforming growth factor-β (TGF-β) and platelet derived growth factor (PDGF) signaling in an allele-specific manner. Lastly, miR-224 and TCF21 were localized in human coronary artery lesions and anti-correlated during atherosclerosis. Together, these data suggest that miR-224 interaction with the TCF21 transcript contributes to allelic imbalance of this gene, thus partly explaining the genetic risk for coronary heart disease associated at 6q23.2. These studies implicating rs12190287 in the miRNA-dependent regulation of TCF21, in conjunction with previous studies showing that this variant modulates transcriptional regulation through activator protein 1 (AP-1), suggests a unique bimodal level of complexity previously unreported for disease-associated variants.

    View details for DOI 10.1371/journal.pgen.1004263

    View details for PubMedID 24676100

  • Cyclin-dependent kinase inhibitor 2B regulates efferocytosis and atherosclerosis JOURNAL OF CLINICAL INVESTIGATION Kojima, Y., Downing, K., Kundu, R., Miller, C., Dewey, F., Lancero, H., Raaz, U., Perisic, L., Hedin, U., Schadt, E., Maegdefessel, L., Quertermous, T., Leeper, N. J. 2014; 124 (3): 1083-1097


    Genetic variation at the chromosome 9p21 risk locus promotes cardiovascular disease; however, it is unclear how or which proteins encoded at this locus contribute to disease. We have previously demonstrated that loss of one candidate gene at this locus, cyclin-dependent kinase inhibitor 2B (Cdkn2b), in mice promotes vascular SMC apoptosis and aneurysm progression. Here, we investigated the role of Cdnk2b in atherogenesis and found that in a mouse model of atherosclerosis, deletion of Cdnk2b promoted advanced development of atherosclerotic plaques composed of large necrotic cores. Furthermore, human carriers of the 9p21 risk allele had reduced expression of CDKN2B in atherosclerotic plaques, which was associated with impaired expression of calreticulin, a ligand required for activation of engulfment receptors on phagocytic cells. As a result of decreased calreticulin, CDKN2B-deficient apoptotic bodies were resistant to efferocytosis and not efficiently cleared by neighboring macrophages. These uncleared SMCs elicited a series of proatherogenic juxtacrine responses associated with increased foam cell formation and inflammatory cytokine elaboration. The addition of exogenous calreticulin reversed defects associated with loss of Cdkn2b and normalized engulfment of Cdkn2b-deficient cells. Together, these data suggest that loss of CDKN2B promotes atherosclerosis by increasing the size and complexity of the lipid-laden necrotic core through impaired efferocytosis.

    View details for DOI 10.1172/JCI70391

    View details for Web of Science ID 000332347700028

  • Cyclic nucleotide phosphodiesterase 3A1 protects the heart against ischemia-reperfusion injury JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY Oikawa, M., Wu, M., Lim, S., Knight, W. E., Miller, C. L., Cai, Y., Lu, Y., Blaxall, B. C., Takeishi, Y., Abe, J., Yan, C. 2013; 64: 11-19


    Phosphodiesterase 3A (PDE3A) is a major regulator of cAMP in cardiomyocytes. PDE3 inhibitors are used for acute treatment of congestive heart failure, but are associated with increased incidence of arrhythmias and sudden death with long-term use. We previously reported that chronic PDE3A downregulation or inhibition induced myocyte apoptosis in vitro. However, the cardiac protective effect of PDE3A has not been demonstrated in vivo in disease models. In this study, we examined the role of PDE3A in regulating myocardial function and survival in vivo using genetically engineered transgenic mice with myocardial overexpression of the PDE3A1 isozyme (TG). TG mice have reduced cardiac function characterized by reduced heart rate and ejection fraction (52.5±7.8% vs. 83.9±4.7%) as well as compensatory expansion of left ventricular diameter (4.19±0.19mm vs. 3.10±0.18mm). However, there was no maladaptive increase of fibrosis and apoptosis in TG hearts compared to wild type (WT) hearts, and the survival rates also remained the same. The diminution of cardiac contractile function is very likely attributed to a decrease in beta-adrenergic receptor (β-AR) response in TG mice. Importantly, the myocardial infarct size (4.0±1.8% vs. 24.6±3.8%) and apoptotic cell number (1.3±1.0% vs. 5.6±1.5%) induced by ischemia/reperfusion (I/R) injury were significantly attenuated in TG mice. This was associated with decreased expression of inducible cAMP early repressor (ICER) and increased expression of anti-apoptotic protein BCL-2. To further verify the anti-apoptotic effects of PDE3A1, we performed in vitro apoptosis study in isolated adult TG and WT cardiomyocytes. We found that the apoptotic rates stimulated by hypoxia/reoxygenation or H2O2 were indeed significantly reduced in TG myocytes, and the differences between TG and WT myocytes were completely reversed in the presence of the PDE3 inhibitor milrinone. These together indicate that PDE3A1 negatively regulates β-AR signaling and protects against I/R injury by inhibiting cardiomyocyte apoptosis.

    View details for DOI 10.1016/j.yjmcc.2013.08.003

    View details for Web of Science ID 000326064400002

    View details for PubMedID 23988739

  • Disease-Related Growth Factor and Embryonic Signaling Pathways Modulate an Enhancer of TCF21 Expression at the 6q23.2 Coronary Heart Disease Locus PLOS GENETICS Miller, C. L., Anderson, D. R., Kundu, R. K., Raiesdana, A., Nuernberg, S. T., Diaz, R., Cheng, K., Leeper, N. J., Chen, C., Chang, I., Schadt, E. E., Hsiung, C. A., Assimes, T. L., Quertermous, T. 2013; 9 (7)
  • Loss of CDKN2B promotes p53-dependent smooth muscle cell apoptosis and aneurysm formation. Arteriosclerosis, thrombosis, and vascular biology Leeper, N. J., Raiesdana, A., Kojima, Y., Kundu, R. K., Cheng, H., Maegdefessel, L., Toh, R., Ahn, G., Ali, Z. A., Anderson, D. R., Miller, C. L., Roberts, S. C., Spin, J. M., de Almeida, P. E., Wu, J. C., Xu, B., Cheng, K., Quertermous, M., Kundu, S., Kortekaas, K. E., Berzin, E., Downing, K. P., Dalman, R. L., Tsao, P. S., Schadt, E. E., Owens, G. K., Quertermous, T. 2013; 33 (1): e1-e10


    Genomewide association studies have implicated allelic variation at 9p21.3 in multiple forms of vascular disease, including atherosclerotic coronary heart disease and abdominal aortic aneurysm. As for other genes at 9p21.3, human expression quantitative trait locus studies have associated expression of the tumor suppressor gene CDKN2B with the risk haplotype, but its potential role in vascular pathobiology remains unclear.Here we used vascular injury models and found that Cdkn2b knockout mice displayed the expected increase in proliferation after injury, but developed reduced neointimal lesions and larger aortic aneurysms. In situ and in vitro studies suggested that these effects were attributable to increased smooth muscle cell apoptosis. Adoptive bone marrow transplant studies confirmed that the observed effects of Cdkn2b were mediated through intrinsic vascular cells and were not dependent on bone marrow-derived inflammatory cells. Mechanistic studies suggested that the observed increase in apoptosis was attributable to a reduction in MDM2 and an increase in p53 signaling, possibly due in part to compensation by other genes at the 9p21.3 locus. Dual inhibition of both Cdkn2b and p53 led to a reversal of the vascular phenotype in each model.These results suggest that reduced CDKN2B expression and increased smooth muscle cell apoptosis may be one mechanism underlying the 9p21.3 association with aneurysmal disease.

    View details for DOI 10.1161/ATVBAHA.112.300399

    View details for PubMedID 23162013

  • Cyclic nucleotide phosphodiesterase 1A: a key regulator of cardiac fibroblast activation and extracellular matrix remodeling in the heart BASIC RESEARCH IN CARDIOLOGY Miller, C. L., Cai, Y., Oikawa, M., Thomas, T., Dostmann, W. R., Zaccolo, M., Fujiwara, K., Yan, C. 2011; 106 (6): 1023-1039


    Cardiac fibroblasts become activated and differentiate to smooth muscle-like myofibroblasts in response to hypertension and myocardial infarction (MI), resulting in extracellular matrix (ECM) remodeling, scar formation and impaired cardiac function. cAMP and cGMP-dependent signaling have been implicated in cardiac fibroblast activation and ECM synthesis. Dysregulation of cyclic nucleotide phosphodiesterase (PDE) activity/expression is also associated with various diseases and several PDE inhibitors are currently available or in development for treating these pathological conditions. The objective of this study is to define and characterize the specific PDE isoform that is altered during cardiac fibroblast activation and functionally important for regulating myofibroblast activation and ECM synthesis. We have found that Ca(2+)/calmodulin-stimulated PDE1A isoform is specifically induced in activated cardiac myofibroblasts stimulated by Ang II and TGF-? in vitro as well as in vivo within fibrotic regions of mouse, rat, and human diseased hearts. Inhibition of PDE1A function via PDE1-selective inhibitor or PDE1A shRNA significantly reduced Ang II or TGF-?-induced myofibroblast activation, ECM synthesis, and pro-fibrotic gene expression in rat cardiac fibroblasts. Moreover, the PDE1 inhibitor attenuated isoproterenol-induced interstitial fibrosis in mice. Mechanistic studies revealed that PDE1A modulates unique pools of cAMP and cGMP, predominantly in perinuclear and nuclear regions of cardiac fibroblasts. Further, both cAMP-Epac-Rap1 and cGMP-PKG signaling was involved in PDE1A-mediated regulation of collagen synthesis. These results suggest that induction of PDE1A plays a critical role in cardiac fibroblast activation and cardiac fibrosis, and targeting PDE1A may lead to regression of the adverse cardiac remodeling associated with various cardiac diseases.

    View details for DOI 10.1007/s00395-011-0228-2

    View details for Web of Science ID 000297708200009

    View details for PubMedID 22012077

  • Cyclic Nucleotide Phosphodiesterase 1 Regulates Lysosome-Dependent Type I Collagen Protein Degradation in Vascular Smooth Muscle Cells ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY Cai, Y., Miller, C. L., Nagel, D. J., Jeon, K., Lim, S., Gao, P., Knight, P. A., Yan, C. 2011; 31 (3): 616-U299


    The phenotypic modulation of vascular smooth muscle cells (VSMCs) to a synthetic phenotype is vital during pathological vascular remodeling and the development of various vascular diseases. An increase in type I collagen (collagen I) has been implicated in synthetic VSMCs, and cyclic nucleotide signaling is critical in collagen I regulation. Herein, we investigate the role and underlying mechanism of cyclic nucleotide phosphodiesterase 1 (PDE1) in regulating collagen I in synthetic VSMCs.The PDE1 inhibitor IC86340 significantly reduced collagen I in human saphenous vein explants undergoing spontaneous remodeling via ex vivo culture. In synthetic VSMCs, high basal levels of intracellular and extracellular collagen I protein were markedly decreased by IC86340. This attenuation was due to diminished protein but not mRNA. Inhibition of lysosome function abolished the effect of IC86340 on collagen I protein expression. PDE1C but not PDE1A is the major isoform responsible for mediating the effects of IC86340. Bicarbonate-sensitive soluble adenylyl cyclase/cAMP signaling was modulated by PDE1C, which is critical in collagen I degradation in VSMCs.These data demonstrate that PDE1C regulates soluble adenylyl cyclase/cAMP signaling and lysosome-mediated collagen I protein degradation, and they suggest that PDE1C plays a critical role in regulating collagen homeostasis during pathological vascular remodeling.

    View details for DOI 10.1161/ATVBAHA.110.212621

    View details for Web of Science ID 000287409900022

    View details for PubMedID 21148428

  • Ca2+/calmodulin-stimulated PDE1 regulates the beta-catenin/TCF signaling through PP2A B56 gamma subunit in proliferating vascular smooth muscle cells FEBS JOURNAL Jeon, K., Jono, H., Miller, C. L., Cai, Y., Lim, S., Liu, X., Gao, P., Abe, J., Li, J., Yan, C. 2010; 277 (24): 5026-5039


    The phenotypic change of vascular smooth muscle cells (VSMCs), from a 'contractile' phenotype to a 'synthetic' phenotype, is crucial for pathogenic vascular remodeling in vascular diseases such as atherosclerosis and restenosis. Ca(2+)/calmodulin-stimulated phosphodiesterase 1 (PDE1) isozymes, including PDE1A and PDE1C, play integral roles in regulating the proliferation of synthetic VSMCs. However, the underlying molecular mechanism(s) remain unknown. In this study, we explore the role and mechanism of PDE1 isoforms in regulating ?-catenin/T-cell factor (TCF) signaling in VSMCs, a pathway important for vascular remodeling through promoting VSMC growth and survival. We found that inhibition of PDE1 activity markedly attenuated ?-catenin/TCF signaling by downregulating ?-catenin protein. The effect of PDE1 inhibition on ?-catenin protein reduction is exerted via promoting glycogen synthase kinase 3 (GSK3)? activation, ?-catenin phosphorylation and subsequent ?-catenin protein degradation. Moreover, PDE1 inhibition specifically upregulated phosphatase protein phosphatase 2A (PP2A) B56? subunit gene expression, which is responsible for the effects of PDE1 inhibition on GSK3? and ?-catenin/TCF signaling. Furthermore, the effect of PDE1 inhibition on ?-catenin was specifically mediated by PDE1A but not PDE1C isozyme. Interestingly, in synthetic VSMCs, PP2A B56?, phospho-GSK3? and phospho-?-catenin were all found in the nucleus, suggesting that PDE1A regulates nuclear ?-catenin protein stability through the nuclear PP2A-GSK3?-?-catenin signaling axis. Taken together, these findings provide direct evidence for the first time that PP2A B56? is a critical mediator for PDE1A in the regulation of ?-catenin signaling in proliferating VSMCs.

    View details for DOI 10.1111/j.1742-4658.2010.07908.x

    View details for Web of Science ID 000284892300006

    View details for PubMedID 21078118

  • Targeting Cyclic Nucleotide Phosphodiesterase in the Heart: Therapeutic Implications JOURNAL OF CARDIOVASCULAR TRANSLATIONAL RESEARCH Miller, C. L., Yan, C. 2010; 3 (5): 507-515


    The second messengers, cAMP and cGMP, regulate a number of physiological processes in the myocardium, from acute contraction/relaxation to chronic gene expression and cardiac structural remodeling. Emerging evidence suggests that multiple spatiotemporally distinct pools of cyclic nucleotides can discriminate specific cellular functions from a given cyclic nucleotide-mediated signal. Cyclic nucleotide phosphodiesterases (PDEs), by hydrolyzing intracellular cyclic AMP and/or cyclic GMP, control the amplitude, duration, and compartmentation of cyclic nucleotide signaling. To date, more than 60 different isoforms have been described and grouped into 11 broad families (PDE1-PDE11) based on differences in their structure, kinetic and regulatory properties, as well as sensitivity to chemical inhibitors. In the heart, PDE isozymes from at least six families have been investigated. Studies using selective PDE inhibitors and/or genetically manipulated animals have demonstrated that individual PDE isozymes play distinct roles in the heart by regulating unique cyclic nucleotide signaling microdomains. Alterations of PDE activity and/or expression have also been observed in various cardiac disease models, which may contribute to disease progression. Several family-selective PDE inhibitors have been used clinically or pre-clinically for the treatment of cardiac or vascular-related diseases. In this review, we will highlight both recent advances and discrepancies relevant to cardiovascular PDE expression, pathophysiological function, and regulation. In particular, we will emphasize how these properties influence current and future development of PDE inhibitors for the treatment of pathological cardiac remodeling and dysfunction.

    View details for DOI 10.1007/s12265-010-9203-9

    View details for Web of Science ID 000284694700011

    View details for PubMedID 20632220

  • Role of Ca2+/Calmodulin-Stimulated Cyclic Nucleotide Phosphodiesterase 1 in Mediating Cardiomyocyte Hypertrophy CIRCULATION RESEARCH Miller, C. L., Oikawa, M., Cai, Y., Wojtovich, A. P., Nagel, D. J., Xu, X., Xu, H., Florio, V., Rybalkin, S. D., Beavo, J. A., Chen, Y., Li, J., Blaxall, B. C., Abe, J., Yan, C. 2009; 105 (10): 956-U59


    Cyclic nucleotide phosphodiesterases (PDEs) through the degradation of cGMP play critical roles in maintaining cardiomyocyte homeostasis. Ca(2+)/calmodulin (CaM)-activated cGMP-hydrolyzing PDE1 family may play a pivotal role in balancing intracellular Ca(2+)/CaM and cGMP signaling; however, its function in cardiomyocytes is unknown.Herein, we investigate the role of Ca(2+)/CaM-stimulated PDE1 in regulating pathological cardiomyocyte hypertrophy in neonatal and adult rat ventricular myocytes and in the heart in vivo.Inhibition of PDE1 activity using a PDE1-selective inhibitor, IC86340, or downregulation of PDE1A using siRNA prevented phenylephrine induced pathological myocyte hypertrophy and hypertrophic marker expression in neonatal and adult rat ventricular myocytes. Importantly, administration of the PDE1 inhibitor IC86340 attenuated cardiac hypertrophy induced by chronic isoproterenol infusion in vivo. Both PDE1A and PDE1C mRNA and protein were detected in human hearts; however, PDE1A expression was conserved in rodent hearts. Moreover, PDE1A expression was significantly upregulated in vivo in the heart and myocytes from various pathological hypertrophy animal models and in vitro in isolated neonatal and adult rat ventricular myocytes treated with neurohumoral stimuli such as angiotensin II (Ang II) and isoproterenol. Furthermore, PDE1A plays a critical role in phenylephrine-induced reduction of intracellular cGMP- and cGMP-dependent protein kinase (PKG) activity and thereby cardiomyocyte hypertrophy in vitro.These results elucidate a novel role for Ca(2+)/CaM-stimulated PDE1, particularly PDE1A, in regulating pathological cardiomyocyte hypertrophy via a cGMP/PKG-dependent mechanism, thereby demonstrating Ca(2+) and cGMP signaling cross-talk during cardiac hypertrophy.

    View details for DOI 10.1161/CIRCRESAHA.109.198515

    View details for Web of Science ID 000271505400004

    View details for PubMedID 19797176

  • Regulation of phosphodiesterase 3 and inducible cAMP early repressor in the heart CIRCULATION RESEARCH Yan, C., Miller, C. L., Abe, J. 2007; 100 (4): 489-501


    Growing evidence suggests that multiple spatially, temporally, and functionally distinct pools of cyclic nucleotides exist and regulate cardiac performance, from acute myocardial contractility to chronic gene expression and cardiac structural remodeling. Cyclic nucleotide phosphodiesterases (PDEs), by hydrolyzing cAMP and cyclic GMP, regulate the amplitude, duration, and compartmentation of cyclic nucleotide-mediated signaling. In particular, PDE3 enzymes play a major role in regulating cAMP metabolism in the cardiovascular system. PDE3 inhibitors, by raising cAMP content, have acute inotropic and vasodilatory effects in treating congestive heart failure but have increased mortality in long-term therapy. PDE3A expression is downregulated in human and animal failing hearts. In vitro, inhibition of PDE3A function is associated with myocyte apoptosis through sustained induction of a transcriptional repressor ICER (inducible cAMP early repressor) and thereby inhibition of antiapoptotic molecule Bcl-2 expression. Sustained induction of ICER may also cause the change of other protein expression implicated in human and animal failing hearts. These data suggest that the downregulation of PDE3A observed in failing hearts may play a causative role in the progression of heart failure, in part, by inducing ICER and promoting cardiac myocyte dysfunction. Hence, strategies that maintain PDE3A function may represent an attractive approach to circumvent myocyte apoptosis and cardiac dysfunction.

    View details for DOI 10.1161/01.RES.0000258451.44949.d7

    View details for Web of Science ID 000244571600008

    View details for PubMedID 17332439

  • Collateral sprouting of human epidermal nerve fibers following intracutaneous axotomy JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM Hahn, K., Sirdofsky, M., Brown, A., Ebenezer, G., Hauer, P., Miller, C., Polydefkis, M. 2006; 11 (2): 142-147


    Despite the clinical need, there are no therapeutic compounds available to promote peripheral nerve regeneration. In part, this may be due to a lack of sensitive measures of nerve growth. Here, we describe a novel approach of measuring collateral sprouting of epidermal nerve fibers (ENF) in human subjects and describe the effect of the neuroimmunophilin ligand timcodar dimesylate on collateral nerve sprouting. The objective of this study was to describe a model of intracutaneous axotomy and evaluate the ability of timcodar dimesylate to accelerate human cutaneous nerve regeneration through collateral sprouting. Subjects were randomized to receive placebo, 12.5 or 50 mg/day timcodar dimesylate in a prospective, two-center, double-blind, placebo-controlled trial. A 3-mm distal thigh punch skin biopsy was performed at baseline, and a 4-mm overlapping concentric biopsy was taken after 56 days of treatment. Biopsies were processed to visualize ENF, and the collateral sprouting distance (CSD) was measured. Sixty-two subjects completed the trial, and the CSD was measurable in 52. The CSD (mean +/- SEM) was 474.5 microm +/- 38.3, 473.4 microm +/- 28.4, and 450.8 microm +/- 26.5 for the placebo, low and high dose groups, respectively (p = 0.84). The baseline ENF density was associated with the CSD (p = 0.02). Collateral sprouting was efficiently measured using an intracutaneous axotomy model and suggests a collateral sprouting rate of 8.5 microm/day in healthy subjects. The model was consistent across treatment groups and had a low coefficient of variation. Timcodar dimesylate treatment was safe over an 8-week period but did not improve collateral sprouting among healthy subjects.

    View details for Web of Science ID 000238289900006

    View details for PubMedID 16787512