MicroRNA-204 Targets Runx2 to Attenuate BMP-2-induced Osteoblast Differentiation of Human Aortic Valve Interstitial Cells

Abstract

Osteoblast differentiation of valve interstitial cells (VICs) is a key step in valve calcification, but the molecular mechanisms involved are not fully understood. In this study, we aimed to investigate whether microRNA (miR)-204-regulated VICs differentiation through modulation of runt-related transcription factor 2 (Runx2), a key transcription factor for osteogenesis. Our data demonstrated that miR-204 was markedly downregulated in both human calcified aortic valves and bone morphogenetic protein (BMP)-2-stimulated aortic VICs. In vitro experiments showed that miR-204 acted as a negative regulator of osteogenic differentiation by repressing Runx2 and thereby inhibiting expression of osteoblast-related genes, including alkaline phosphatase and osteocalcin, which were all induced by BMP-2. Luciferase reporter assays validated Runx2 as the direct target of miR-204. Furthermore, increased alkaline phosphatase activity and osteocalcin expression after miR-204 inhibition were abolished by small interfering RNA-mediated silencing of Runx2. Overall, these data suggested miR-204 as a possible molecular switch inhibiting osteoblastic transdifferentiation of human aortic VICs and targeting miR-204 may have therapeutic potential for human aortic valve calcification.

Circulating microRNAs signature correlates with positive [18F]fluorodeoxyglucose-positron emission tomography in patients with abdominal aortic aneurysm

“…Modifications of miR-125b-5p level have been involved in arterial calcification by smooth muscle cells 37 by regulating their transdifferentiation into osteoblast-like cells through the regulation of SP7 and RUNX2, 36 a marker of osteogenesis also found to be involved in arterial calcification. 38,39 MiR-204-5p also directly targets RUNX2. Five other target genes were found to be common between both miRNAs, including HAPLN1, an extracellular matrix protein interacting with proteoglycans and involved in cartilage development.…”

In vitro 3D model and miRNA drug delivery to target calcific aortic valve disease

“…Using the broad parameters “aortic | valve”, Abcam Firefly Discovery Engine identified 30 publications on 41 miRNAs related to various biological processes, including fibrosis ( miR-21 [62]), inflammation ( miR-125b [63]; miR-148a [64]), differentiation ( miR-204 [65]), and calcification ( miR-141 [66]; miR-204 [65]; miR-30b [67]; miR-214 [68]). Tables 1 and 2 provide an overview of the profiling and functional studies that have been conducted to highlight the roles of these miRNAs in their respective target pathways.…”

“…Multiple studies demonstrated that miR-30b is functionally involved in the prevention of osteogenesis and apoptosis by direct targeting of Runx2, Smad1, and caspase-3 [67,69]. Similarly, miR-26a down-regulates multiple genes related to calcification [69], miR-141 blocks TGF- β -triggered BMP-2 signaling, and miR-204 represses Runx2 [66], consequently inhibiting osteogenic differentiation [65]. Thus, valve calcification could be caused by negative regulation of these miRs, which would abrogate various protective mechanisms.…”

Role of Osterix and MicroRNAs in Bone Formation and Tooth Development

“…An in vivo experiment also showed that miR-138 negatively regulates osteoblast differentiation and bone formation [20]. Other miRNAs, such as miRNA-194, miRNA-210, miRNA-204, miRNA-24, miRNA-23, miRNA-145, miRNA-375, and miRNA-150, have also been confirmed to participate in this process [21–26]. Zhou et al showed that miR-17-92 cluster critically regulates bone metabolism, mostly through its function in osteoblasts [27].…”