OSTEOBLAST-SPECIFIC MICRORNA-29A AMELIORATES OESTROGEN LOSS-INDUCED OSTEOPOROSIS

BackgroundMicroRNAs are non-coding small RNAs that reportedly regulate mRNA targets or protein translation of various tissues in physiological and pathological contexts. This study was undertaken to characterise the contributions of microRNA-29a (miR-29a) to the progression of estrogen deficiency-mediated excessive osteoclast resorption and bone loss.MethodsOsteoblast-specific transgenic mice overexpressing miR-29a driven by osteocalcin promoter (C57BL/6JNarl-TgOCN-mir29a) or wild-type mice were subjected to bilateral ovariectomy. Bone mineral density, trabecular microarchitecture and osteoclast distribution was quantified by μCT and histomorphometry. Primary CD11b+CSF-1R+ preosteoclasts were isolated for detecting ex vivo osteoclast differentiation. Gene expression and transcription factor-promoter interaction were quantified by RT-PCR and chromatin immunoprecipitation.ResultsEstrogen depletion deteriorated bone integrity in concomitant with decrement of miR-29a expression. Transgenic mice had increased ...