Abstract 16942: Effects of BMPR2 Mutations on Global MicroRNA Expression Profiles in Blood Outgrowth Endothelial Cells from Patients with Pulmonary Arterial Hypertension
Background: Mutations of the bone morphogenetic protein receptor 2 gene (BMPR2) are found in patients with heritable (H) or idiopathic (I) pulmonary arterial hypertension (PAH). However, their role in abnormalities of endothelial cell (EC) growth and survival in PAH is unclear. Therefore, blood-outgrowth endothelial cells (BOECs), which closely resemble mature endothelial cells, were used to study patient-specific effects of BMPR2 mutations on endothelial microRNAs (miRNA), which are recognized to be key regulators of gene expression.
Hypothesis: Disease-specific alterations in miRNA expression profiles in BOECs from patients with HPAH or IPAH, with and without BMPR2 mutations, contribute to the previously reported abnormalities in EC growth and survival in this disease.
Methods: BOECs were derived from the peripheral blood mononuclear cell fraction isolated from 7 patients (4 HPAH with BMPR2 mutations, and 3 IPAH) and 5 healthy controls (including 1 unaffected BMPR2 mutation carrier). Cells were characterized by cobblestone morphology and surface marker profile (cd31+/cd45-/cd14-/cd34+/KDR+). 1066 miRNAs were measured using an (RT)-qPCR array platform (Qiagen), and normalized with a mean-centering restricted method.
Results: 767 ± 30 miRNAs were detected in BOECs from the 12 participants (PCR Cq cutoff <35). 17 miRNAs were differentially expressed (-2.8 to 2 fold change) in HPAH with BMPR2 mutations vs. controls (p<0.05): 8 were downregulated in HPAH, including miR-124 and -129*; and 9 were upregulated, including miR-15a*. Only 4 miRNAs were found to be co-regulated in both HPAH and IPAH cells, which included miR-34c-3p and -196b; whereas, a number exhibited mutation-specific expression, notably miR-33a*, -3934, -670 and -3139 in HPAH patients and the unaffected BMPR2 mutation carrier.
Conclusion: A global analysis of miRNAs in BOECs revealed distinct profiles in IPAH and HPAH patients, with both disease- and BMPR2 mutation-specific patterns of expression. These data suggest that unique miRNAs may contribute to alterations in endothelial gene expression that underlie abnormalities in EC growth and survival, and may be novel targets for therapeutic and biomarker development.
- © 2012 by American Heart Association, Inc.