Long non-coding RNA MEG3 silencing and microRNA-214 restoration elevate osteoprotegerin expression to ameliorate osteoporosis by limiting TXNIP

Abstract

BackgroundLong non-coding RNAs (LncRNAs) have been found to regulate innumerable diseases, yet the role of lncRNA MEG3 in osteoporosis (OP) has rarely been discussed. Here, we intend to probe into the mechanism of MEG3 on OP development by modulating microRNA-214 (miR-214) and thioredoxin-interacting protein (TXNIP)MethodsRat models of OP were established. MEG3, miR-214, and TXNIP mRNA expression in rat femoral tissues was detected, along with TXNIP, PCNA, cyclin D1, OCN, RUNX2, Osteolix, OPG, and PANKL protein expression. Ca, P and ALP contents in rat blood samples were also determined. Primary osteoblasts were isolated and cultured. Viability, COL-I, COL-II and COL-Χ contents, ALP content and activity, and mineralized nodule area of rat osteoblasts in each group were further detected.ResultsMEG3 and TXNIP were overexpressed while miR-214 was underexpressed in femoral tissues of OP rats. MEG3 silencing and miR-214 overexpression increased BMD, BV/TV, Tb.N, Tb.Th, the number of osteoblasts, collagen area and OPG expression, and downregulated PANKL of femoral tissues in OP rats. MEG3 silencing and miR-214 overexpression elevated Ca and P contents and reduced ALP content in OP rats’ blood, elevated viability, differentiation ability, COL-I and COL-Χ contents and ALP activity, and abated COL-II content of osteoblasts. MEG3 specifically bound to miR-214 to regulate TXNIP.ConclusionCollectively, we demonstrated that MEG3 silencing and miR-214 overexpression promote proliferation and differentiation of osteoblasts in OP by downregulating TXNIP, which further improves OP.