LncRNA H19 promotes osteoclast differentiation by sponging miR-29c-3p to increase expression of cathepsin K

Osteoporosis is a prevalent metabolic bone disease. Osteoporotic fractures can lead to severe functional impairment and increased mortality. Long noncoding RNA H19 has emerged as a pivotal player in bone remodeling, serving both as a biomarker and a regulator. While previous research has elucidated H19's role in promoting osteogenic differentiation through diverse mechanisms, its involvement in osteoclast differentiation remains largely unknown. In this study, we used lentiviral vectors to stably overexpress or knockdown H19 in RAW264.7 cell lines. Quantitative reverse polymerase chain reaction, Western blot, tartrate resistant acid phosphatase staining and bone resorption assay were performed to assess the level of osteoclast differentiation and bone resorption capacity. And fluorescence in situ hybridization, dual-luciferase reporter and RNA immunoprecipitation were used to explore the specific mechanism of H19 regulating osteoclast differentiation in vitro. Then, ovariectomized osteoporosis models in wild type mice and H19 knockout mice were conducted. And micro-CT analysis, HE staining, and immunohistochemistry were performed to verify the mechanism of H19 regulating osteoclast differentiation in vivo. Bone marrow derived monocytes and bone mesenchymal stem cells were extracted from mice and assayed for osteoclastic and osteogenic-related assays, respectively. In vitro, H19 promoted osteoclast differentiation and bone resorption of RAW264.7 cells, while miR-29c-3p inhibited them. Both H19 and cathepsin K were the target genes of miR-29c-3p. In vivo, H19 knockout mice have increased femur bone mineral density, decreased osteoclast formation, and reduced cathepsin K expression. MiR-29c-3p agomir could increase bone mineral density in osteoporotic mice on the premise of H19 knockout. H19 upregulates cathepsin K expression through sponging miR-29c-3p, which promoting osteoclast differentiation and enhancing bone resorption. This underscores the potential of H19 and miR-29c-3p as promising biomarkers for osteoporosis. •H19 promotes osteoclast differentiation and enhances bone resorption.•H19 activates the processes of both osteogenesis and osteoclastogenesis.•H19/miR-29c-3p/CTSK axis may have valuable clinical implications in osteoporosis.