MicroRNA‐638 inhibits human aortic valve interstitial cell calcification by targeting Sp7

Calcific aortic valve disease (CAVD) is a complex heart valve disease involving a wide range of pathological changes. Emerging evidence indicates that osteogenic differentiation of human aortic valve interstitial cells (hAVICs) plays a key role in valve calcification. In this study, we aimed to investigate the function of miR‐638 in hAVICs osteogenesis. Both miRNA microarray assay and qRT‐PCR results demonstrating miR‐638 was obviously up‐regulated in calcific aortic valves compared with non‐calcific valves. We also proved that miR‐638 was significantly up‐regulated during hAVICs osteogenic differentiation. Overexpression of miR‐638 suppressed osteogenic differentiation of hAVICs in vitro, whereas down‐regulation of miR‐638 enhance the process. Target prediction analysis and dual‐luciferase reporter assay confirmed that Sp7 transcription factor (Sp7) was a direct target of miR‐638. Furthermore, knockdown of Sp7 inhibited osteogenic differentiation of hAVICs, which is similar to the results observed in up‐regulation miR‐638. Our data indicated that miR‐638 plays an inhibitory role in hAVICs osteogenic differentiation, which may act by targeting Sp7. MiR‐638 may be a potential therapeutic target for CAVD.