Consequences of BMPR2 Deficiency in the Pulmonary Vasculature and Beyond: Contributions to Pulmonary Arterial Hypertension.
International journal of molecular sciences
2018; 19 (9)
Since its association with familial pulmonary arterial hypertension (PAH) in 2000, Bone Morphogenetic Protein Receptor II (BMPR2) and its related signaling pathway have become recognized as a key regulator of pulmonary vascular homeostasis. Herein, we define BMPR2 deficiency as either an inactivation of the receptor, decreased receptor expression, or an impairment of the receptor's downstream signaling pathway. Although traditionally the phenotypic consequences of BMPR2 deficiency in PAH have been thought to be limited to the pulmonary vasculature, there is evidence that abnormalities in BMPR2 signaling may have consequences in many other organ systems and cellular compartments. Revisiting how BMPR2 functions throughout health and disease in cells and organs beyond the lung vasculature may provide insight into the contribution of these organ systems to PAH pathogenesis as well as the potential systemic manifestation of PAH. Here we review our knowledge of the consequences of BMPR2 deficiency across multiple organ systems.
View details for DOI 10.3390/ijms19092499
View details for PubMedID 30149506
Fragile Histidine Triad (FHIT), a Novel Modifier Gene in Pulmonary Arterial Hypertension.
American journal of respiratory and critical care medicine
RATIONALE: Pulmonary arterial hypertension (PAH) is characterized by progressive narrowing of pulmonary arteries resulting in right heart failure and death. Bone Morphogenetic Protein Receptor type-2 (BMPR2) mutations account for most familial PAH (FPAH) forms while reduced BMPR2 is present in many idiopathic PAH (IPAH) forms, suggesting dysfunctional BMPR2 signaling to be a key feature of PAH. Modulating BMPR2 signaling is therapeutically promising, yet how BMPR2 is downregulated in PAH is unclear.OBJECTIVES: We intended to identify and pharmaceutically target BMPR2 modifier genes to improve PAH.METHODS: We combined siRNA High Throughput Screening (HTS) of >20,000 genes with a multi-cohort analysis of publicly available PAH RNA expression data to identify clinically relevant BMPR2-modifiers. After confirming gene dysregulation in PAH patient tissue, we determined the functional roles of BMPR2-modifiers in vitro and tested the repurposed drug Enzastaurin for its propensity to improve experimental PH.MEASUREMENTS AND MAIN RESULTS: We discovered Fragile Histidine Triad (FHIT) as a novel BMPR2-modifier. BMPR2 and FHIT expression were reduced in PAH patients. FHIT reductions were associated with endothelial and smooth muscle cell dysfunction, rescued by Enzastaurin through a dual mechanism: upregulation of FHIT as well as miR17-5 repression. Fhit-/- mice had exaggerated hypoxic PH and failed to recover in normoxia. Enzastaurin reversed PH in the Sugen5416/Hypoxia/Normoxia rat model, by improving Right Ventricular Systolic Pressure (RVSP), RV hypertrophy, cardiac fibrosis and vascular remodeling.CONCLUSIONS: This study highlights the importance of the novel BMPR2 modifier FHIT in PH and the clinical value of the repurposed drug Enzastaurin as a potential novel therapeutic strategy to improve PAH.
View details for DOI 10.1164/rccm.201712-2553OC
View details for PubMedID 30107138
Pneumonia Pathogen Characterization Is an Independent Determinant of Hospital Readmission
2015; 148 (1): 103?11
Hospital readmissions for pneumonia occur often and are difficult to predict. For fiscal year 2013, the Centers for Medicare & Medicaid Services readmission penalties have been applied to acute myocardial infarction, heart failure, and pneumonia. However, the overall impact of pneumonia pathogen characterization on hospital readmission is undefined.This was a retrospective 6-year cohort study (August 2007 to September 2013).We evaluated 9,624 patients with a discharge diagnosis of pneumonia. Among these patients, 4,432 (46.1%) were classified as having culture-negative pneumonia, 1,940 (20.2%) as having pneumonia caused by antibiotic-susceptible bacteria, 2,991 (31.1%) as having pneumonia caused by potentially antibiotic-resistant bacteria, and 261 (2.7%) as having viral pneumonia. The 90-day hospital readmission rate for survivors (n = 7,637, 79.4%) was greatest for patients with pneumonia attributed to potentially antibiotic-resistant bacteria (11.4%) followed by viral pneumonia (8.3%), pneumonia attributed to antibiotic-susceptible bacteria (6.6%), and culture-negative pneumonia (5.8%) (P < .001). Multiple logistic regression analysis identified pneumonia attributed to potentially antibiotic-resistant bacteria to be independently associated with 90-day readmission (OR, 1.75; 95% CI, 1.56-1.97; P < .001). Other independent predictors of 90-day readmission were Charlson comorbidity score > 4, cirrhosis, and chronic kidney disease. Culture-negative pneumonia was independently associated with lower risk for 90-day readmission.Readmission after hospitalization for pneumonia is relatively common and is related to pneumonia pathogen characterization. Pneumonia attributed to potentially antibiotic-resistant bacteria is associated with an increased risk for 90-day readmission, whereas culture-negative pneumonia is associated with lower risk for 90-day readmission.
View details for DOI 10.1378/chest.14-2129
View details for Web of Science ID 000359003000031
View details for PubMedID 25429607