LncRNA NEAT1 sponges miR-214-3p to promote osteoblast differentiation through regulating the PI3K/AKT/mTOR pathway in aortic valve calcification

Calcific aortic valve disease (CAVD) is the common valvular disease associated with significant morbidity and mortality. Dysregulation of long non-coding RNA (lncRNA) has been implicated in the pathogenesis of CAVD. This study aims to investigate the role of NEAT1 in CAVD pathogenesis. NEAT1, miR-214-3p and mRNA expressions were determined by qRT-PCR. Protein expressions were detected by Western blotting. Mineralized bone matrix formation was assessed by Alizarin Red staining. The osteogenic phenotype was evaluated by the alkaline phosphatase activity assay. Dual-luciferase assays were employed to confirm the binding interactions between NEAT1 and miR-214-3p, miR-214-3p and PTEN. NEAT1 was up-regulated in calcific aortic valves and after osteogenic induction of valve interstitial cells (VICs). NEAT1 could act as a positive regulator of osteogenic differentiation by repressing miR-214-3p and thereby promote expression of osteoblast-specific markers. Mechanistically, we identified PTEN as a direct target of miR-214-3p. PTEN could regulate the PI3K/AKT/mTOR pathway and participate in osteogenic differentiation. Importantly, NEAT1 could directly interact with miR-214-3p and change of miR-214-3p expression could efficiently reverse PTEN expression and osteogenic differentiation induced by NEAT1. Thus, NEAT1 positively regulated PTEN expression and activated autophagy through sponging miR-214-3p, and promoted osteogenic differentiation through the PI3K/AKT/mTOR pathway. In conclusion, we elucidates the vital function of NEAT1 as a miRNA sponge in CAVD pathogenesis, and sheds new light on lncRNA-directed diagnostic and therapeutic strategies for CAVD.