Regulatory role of lncRNA DANCR in osteogenic differentiation of bone marrow mesenchymal stem cells through targeting the miR-19a-3p/PTEN/AKT/mTOR pathway.

Given the involvement of long non-coding RNA-differentiation antagonizing non-protein coding RNA (lncRNA DANCR) in osteoporosis (OP), this study aimed to investigate its role in osteogenic differentiation (OD) of bone marrow mesenchymal stem cells (BMSCs) and underlying mechanisms. BMSCs were intervened with sh-DANCR, oe-DANCR, sh-phosphatase and tensin homolog (PTEN) lentivirus, miR-19a-3p agomir, or MK-2206 dihydrochlorode. The number of mature osteoblasts, osteogenic ability, and alkaline phosphatase (ALP) activity were assessed by ALP staining, alizarin red staining, and kit assay. Bioinformatics prediction, dual-luciferase assay, and RNA pull-down assay were conducted to assess the binding between lncRNA DANCR and miR-19a-3p and that between PTEN and miR-19a-3p. The levels of lncRNA DANCR, osteogenesis-related proteins (osteocalcin (OCN), runt-related transcription factor 2 (RUNX2), osteopontin (OPN)), PTEN, phosphorylated-protein kinase B (p-AKT), AKT, phosphorylated-mammalian target of rapamycin (p-mTOR), and mTOR were determined by RNA quantitation and western blot techniques. Silencing of lncRNA DANCR potentiated the OD capability of BMSCs, as evidenced by increased ALP activity, calcium nodule formation, and elevated expression of OPN, RUNX2, and OCN. In contrast, lncRNA DANCR overexpression inhibited the OD function by downregulating miR-19a-3p. Mechanistically, lncRNA DANCR regulated PTEN expression by competitively binding to miR-19a-3p. Additionally, PTEN silencing partially reversed the anti-OD effect of lncRNA DANCR. LncRNA DANCR knockdown activated the AKT/mTOR pathway, whereas lncRNA DANCR overexpression or MK-2206 treatment disrupted this activation. Silencing of lncRNA DANCR facilitates BMSC OD by binding to miR-19a-3p and further regulating the PTEN/AKT/mTOR pathway.