miR-181a/b-5p regulates human umbilical vein endothelial cell angiogenesis by targeting PDGFRA

Abstract

Type 2 diabetes mellitus (T2DM) is a growing burden in low-and middle-income countries. Changing lifestyles and lack of physical activity are some of the reasons contributing to this epidemic increase. Co-morbidities associated with T2DM are largely due to the complications which arise as a consequence of endothelial dysfunction. Platelet derived growth factor-alpha (PDGFRA) is a protein responsible for cell proliferation, angiogenesis, migration and invasion. Increased levels of PDGFRA have been reported in T2DM. This study assessed the epigenetic regulation of PDGFRA through microRNAs (miR-181a/b-5p).Using a bioinformatics-based approach, we assessed the binding of miR-181a/b-5p to PDGFRA. Experimentally, this binding was confirmed using a dual luciferase reporter assay. Further, we overexpressed miR-181a/b-5p in Human umbilical vein endothelial cells (HUVECs) and the influence of over-expression on cell proliferation, migration and angiogenesis was assessed using in-vitro approaches. The influence of miR-181a/b-5p over expression on cellular apoptosis was ascertained using a TUNEL assay with concomitant changes being observed in the levels of Bcl-2 and cleaved Caspase-3.In HUVECs, PDGFRA is a direct target for miR-181a/b-5p. Over expression of miR-181a/b-5p decreased cellular proliferation, migration, invasion, and tube formation-a surrogate marker for angiogenesis. miR-181a/b-5p may be used as a therapeutic intervention to restrict uncontrolled levels of PDGFRA and thereby rescue the phenotypes of increased cell proliferation, migration, invasion and tube formation. miR-181a/b negatively regulates PDGFRA levels. Significance of the study: T2DM and its associated complications emerge from endothelial dysfunction. The associated phenotypes are regulated by a number of proteins, one such member being, PDGFRA. PDGFRA is in turn regulated by miR-181a/b-5p. Complementation with miR-181a/b-5p resulted in reversion of phenotypes. Thus, miR-181a/b-5p-mediated suppression of PDGFRA may be used as a therapeutic intervention in the management of type 2 diabetes.

Keywords: miR-181a-5p; HUVECs; PDGFRA; angiogenesis; miR-181b-5p.