LncRNA RMST Promotes Progression of Calcification of Aortic Valve Via the miR-195-5p/Smad7 Axis

Abstract

Calcified aortic valve disease (CAVD) is a cardiovascular disease closely related to cardiovascular morbidity and mortality. Osteogenesis differentiation of valvular interstitial cells (VICs) is the key process of CAVD. In this study, we investigated whether the circulating exosomes participated in the pathogenesis and progression of CAVD and explored the underlying mechanism. We constructed the CAVD model in rats to perform in-vivo experiments, and isolated the VICs to perfume in-vitro studies. A series of methods were used including exosomes extraction and identification, RNA sequencing, ALP activity assay, alizarin red staining, qRT-PCR, western blot, and luciferase reporter assay. RNA sequencing showed that the circulating exosomes from CAVD patients and the normal people exhibited aberrant long non-coding RNA level, among which RMST was significantly upregulated in the CAVD-derived circulating exosomes and in the calcified aortic valve tissues. ALP activity assay and alizarin red staining showed that RMST promoted the VICs calcification. Luciferase reporter assay indicated that RMST acted as the miR-195-5p sponge, and miR-195-5p could target the 3’UTR of Smad7. Further functional experiments revealed that RMST was enriched in the circulating exosomes, leading to the upregulation of Smad7 in through sponging miR-195-5p to promote osteogenic differentiation in VICs. Moreover, adipose-derived exosomes showed the same effect as the CAVD-derived circulating exosomes. In conclusion, we found that circulating exosomes from CAVD patients promoted the VICs calcification through delivering the lncRNA RMST which acted as the miR-195-5p sponge to regulate the Smad7 expression. These results provided a new understanding of the molecular mechanism of the progression of CAVD. Funding: This work was supported by National Natural Science Foundation of China (grant no. 81974033). Declaration of Interest: None to declare. Ethical Approval: The present research program had been reviewed and approved by the Ethics Committee of The First Affiliated Hospital of Nanjing Medical University.