Disturbed Flow Increases UBE2C (Ubiquitin E2 Ligase C) via Loss of miR-483-3p, Inducing Aortic Valve Calcification by the pVHL (von Hippel-Lindau Protein) and HIF-1 (Hypoxia-Inducible Factor-1) Pathway in Endothelial Cells

• Authors: Joan Fernandez Esmerats, Georgia Institute of Technology; Nicolas Villa-Roel, Georgia Institute of Technology; Sandeep Kumar, Emory University; Lina Gu, Georgia Institute of Technology; Md Tausif Salim, Georgia Institute of Technology; Michael Ohh, University of Toronto; W. Robert Taylor, Emory University; Robert Nerem, Emory University; Ajit Yoganathan, Emory University; Hanjoong Jo, Emory University
• Journal Title: Arteriosclerosis, Thrombosis, and Vascular Biology
• Volume: Volume 39, Number 3
• Publisher: Lippincott, Williams & Wilkins | 2019-03-01, Pages 467-481
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1161/ATVBAHA.118.312233
• Subjects: Engineering, Biomedical; Chemistry, Biochemistry
• Keywords: Science & Technology; Life Sciences & Biomedicine; Hematology; Peripheral Vascular Disease; Cardiovascular System & Cardiology; aortic valve; aortic valve stenosis; endothelial cells; endothelial-to-mesenchymal transition; inflammation; microRNAs; ubiquitination; CONJUGATING ENZYME E2C; MESENCHYMAL TRANSFORMATION; ADHESION MOLECULES; TARGETING HYPOXIA; BLADDER-CANCER; EARLY LESION; SHEAR; DISEASE; STENOSIS; MATRIX

Abstract

Objective - Calcific aortic valve (AV) disease, characterized by AV sclerosis and calcification, is a major cause of death in the aging population; however, there are no effective medical therapies other than valve replacement. AV calcification preferentially occurs on the fibrosa side, exposed to disturbed flow (d-flow), whereas the ventricularis side exposed to predominantly stable flow remains protected by unclear mechanisms. Here, we tested the role of novel flow-sensitive UBE2C (ubiquitin E2 ligase C) and microRNA-483-3p (miR-483) in flow-dependent AV endothelial function and AV calcification. Approach and Results - Human AV endothelial cells and fresh porcine AV leaflets were exposed to stable flow or d-flow. We found that UBE2C was upregulated by d-flow in human AV endothelial cells in the miR-483-dependent manner. UBE2C mediated OS-induced endothelial inflammation and endothelial-mesenchymal transition by increasing the HIF-1α (hypoxia-inducible factor-1α) level. UBE2C increased HIF-1α by ubiquitinating and degrading its upstream regulator pVHL (von Hippel-Lindau protein). These in vitro findings were corroborated by immunostaining studies using diseased human AV leaflets. In addition, we found that reduction of miR-483 by d-flow led to increased UBE2C expression in human AV endothelial cells. The miR-483 mimic protected against endothelial inflammation and endothelial-mesenchymal transition in human AV endothelial cells and calcification of porcine AV leaflets by downregulating UBE2C. Moreover, treatment with the HIF-1α inhibitor (PX478) significantly reduced porcine AV calcification in static and d-flow conditions. Conclusions - These results suggest that miR-483 and UBE2C and pVHL are novel flow-sensitive anti- and pro-calcific AV disease molecules, respectively, that regulate the HIF-1α pathway in AV. The miR-483 mimic and HIF-1α pathway inhibitors may serve as potential therapeutics of calcific AV disease.