LINC01013 reverses bisphosphonate-impaired osteogenic differentiation of JBMMSCs by regulating intracellular translocation of ILF3.

Background: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious complication associated with bisphosphonate (BP) therapy. Enhancement of the osteogenic differentiation of human jaw bone marrow mesenchymal stem cells (JBMMSCs) is a key issue in the treatment of BRONJ. In this study, we investigated the role and mechanism of LINC01013 in regulating osteogenic differentiation of JBMMSCs.

Methods: Osteogenic differentiation of JBMMSCs was assessed in vitro using alkaline phosphatase (ALP), alizarin red staining (ARS), and western blotting. JBMMSCs transplanted into the backs of nude mice were used to detect JBMMSCs osteogenesis in vivo. Molecular mechanisms involved in JBMMSCs osteogenesis were evaluated using real-time fluorescence quantitative polymerase chain reaction, western blotting, fluorescence in situ hybridization, RNA pull-down, and RNA-seq.

Results: Homeobox C8 (HOXC8) knockdown enhanced ALP activity, ARS, and expression of bone sialoprotein and osteocalcin in JBMMSCs under normal and BP stimulation conditions. HOXC8 negatively regulated LINC01013 expression. LINC01013 enhanced JBMMSCs osteogenic differentiation impaired by BP stimulation. Furthermore, LINC01013 regulated the expression of inflammation-related genes in JBMMSCs under BP conditions. LINC01013 formed a complex with ILF3. Two isoforms of ILF3 (NF90 and NF110) promoted the osteogenic differentiation of JBMMSCs under normal and BP conditions, depending on their nuclear localization. Additionally, NF90, which is located in the nucleus, inhibited the expression of NLR family pyrin domain containing 3 (NLRP3).

Conclusions: In summary, HOXC8 negatively regulates LINC01013 to inhibit osteogenic differentiation of JBMMSCs under BP conditions. We also further clarified that LINC01013 binding to ILF3 affects ILF3 nuclear localization to regulate JBMMSCs osteogenic differentiation and regulates NLRP3/Caspase-1 pathway to affect JBMMSCs function under BP stimulation.