Role Of MiR-128 In The Pathogenesis Of Osteoporosis

Part 1 Regulatory effects of miR-128 on osteogenic differentiation and adipogenesis differentiation of human mesenchymal stem cellsObjective: To observe the role of miR-128 in adipogenic differentiation and osteogenic differentiation of human mesenchymal stem cellsMaterial and Methods: Morphology of h MSCs,lipid droplets and calcium nodules were observed and photographed by LSM microscopy after over-expression or down-regulation of miR-128.The m RNA level of miR-128,CCAAT/enhancer binding protein-?(C/EBP?),peroxisome proliferator-activated receptor-?(PPAR?),osteocalcin(OCN)and Runt-related transcription factor 2(RUNX2)was determined by RNA preparation and reverse transcription polymerase chain reaction(RT-PCR)after over-expression or down-regulation of miR-128.Results: It was suggested that miR-128 expression showed a 4.56-fold induction by adipogenic treatment and a 58.8% reduction by osteogenic treatment.Over-expression of miR-128,promoted adipogenic differentiation while inhibited osteogenic differentiation.In contrast,adipocyte formation was inhibited and osteogenesis was enhanced in cells sliencing miR-128.Conclusions: MiR-128 regulated the adipogenic and osteogenic differentiation of h MSCs.Part 2 The role of VEGF signaling pathway in the process of osteogenic differentiation and adipogenesis differentiation of h MSCs regulated by miR-128Objective: To observe the role of vascular endothelial growth factor(VEGF)signaling pathway in adipogenic differentiation and osteogenic differentiation of human mesenchymal stem cells regulated by miR-128.Material and Methods: Protein expression of VEGF was analyzed by Western blot after over-expression or down-regulation of miR-128.The h MSCs was transiently transfected with small interfering RNA(si RNA)of VEGF,and the effect of VEGF on adipogenesis and osteogenic differentiation regulated by miR-128 was observed.Results: Over-expression of miR-128 significantly down-regulated VEGF expression in adipogenically and osteogenically differentiated cells.We further identified whether VEGF was a key regulator in miR-128-induced adipogenic and osteogenic differentiation.Results showed that over-expression of miR-128 significantly increased m RNA level of PPAR? and C / EBP?,and reduced m RNA level of RUNX2 and OCN.Following VEGF silence,the effects of over-expression of miR-128 on adipogenic and osteogenic differentiation of h MSCs were partly eliminated.Conclusions: It was indicated that miR-128 regulated adipogenic and osteogenic differentiation of h MSCs through the suppression of VEGF pathway.