RESUMEN
Objective:To investigate the effect and potential mechanism of serum exosome-derived cirC_0009362 on the osteogenic differentiation of human bone marrow mesenchymalstem cells (hBMSCs) .Methods:Serum samples from patients with osteoporosis (OP) were collected and exosomes were isolated. The expression level of circ_0009362 in exosomes was detected by qRT-PCR. hBMSCs osteogenesis was induced and the expression of circ_0009362 and miR-29b-3p was detected. The interaction between circ_0009362 and miR-29b-3p was detected by dual luciferase reporter assay. Alkaline phosphatase (ALP) kit was used to detect ALP activity and alizarin red (ARS) staining was used to detect calcium deposition.Results:Compared with healthy control group, the expression of circ_0009362 in serum exosomes of OP patients was increased, and the expression of circ_0009362 was decreased after inducing hBMSCs osteogenesis (all P<0.05) . The ALP activity and the percentage of calcium deposition in hBMSCs were decreased by exosomes, and this effect was achieved by secreting circ_0009362. The effect of exosomes was partially offset by circ_0009362 expression in knockdown exosomes (all P<0.05) . The expression of miR-29b-3p was increased after inducing hBMSCs osteogenesis ( P<0.05) . Circ_0009362 had a targeting relationship with miR-29b-3p, and exosomes inhibited the expression of miR-29b-3p by secreting circ_0009362. The ALP activity and the percentage of calcium deposition in hBMSCs were promoted by overexpression of miR-29b-3p, which was partially offset by exosomes (all P<0.05) . Conclusion:Serum exosomes of OP patients inhibit the osteogenic differentiation of hBMSCs by secreting circ_0009362 to down-regulate the expression of miR-29b-3p.
RESUMEN
Objective:To investigate the effect of miR-204 on the proliferation and differentiation of osteoblasts in osteoporosis mice by Wnt signaling pathway and its mechanism.Methods:Female Kunming mice were divided into: control group, sham operation group and osteoporosis group. Ovariectomy mouse models were established and identified by bilateral ovariectomy; Mouse primary osteoblasts were extracted and identified; Cells was transfected and detected the miR-204 expression levels; MTT was used to detect the viability of each group of cells; Alkaline phosphatase (ALP) activity was detected in each cell group; Cell flowmetry was used to detect apoptosis in each group; Cell flowmetry was used to detect the activity of Caspase-3 in each group of cells; Interaction between miR-204, β-catenin and LRP-5 was detected by dual luciferase reporter gene. Western blot was used to detect the expression of Wnt signaling pathway-related proteins.Results:The bone mineral density of the osteoporosis group was significantly lower than that of the control group and the sham operation group ( P=0.007, P=0.057) , indicating that the osteoporosis mice were successfully modeled; The expression level of miR-204 was significantly increased in the miR-204 mimics group ( P=0.007) , and decreased in the miR-204 inhibitor group ( P=0.031) ; The activity of bone cell and ALP activity of miR-204 mimics increased ( P=0.007, P=0.043) , and the activity of bone cell and ALP decreased by miR-204 inhibitor ( P=0.007, P=0.035) ; The invasive ability of miR-204 mimics was significantly increased ( P=0.006) , and the invasive ability of miR-204 inhibitor was decreased ( P=0.036) ; The apoptosis ability and Caspase-3 activity of miR-204 mimics were decreased ( P=0.041, P=0.045) , and the apoptosis ability and Caspase-3 activity of bone cells were enhanced by miR-204 inhibitor ( P=0.005, P=0.039) ; There were targeting relationship between miR-204 and β-catenin, LRP-5. The expressions of β-catenin and LRP-5 protein in osteoblasts of miR-204 mimics were up-regulated ( P=0.043, P=0.009) , and the expression of β-catenin and LRP-5 protein in bone cells of miR-204 inhibitor was down-regulated ( P=0.041, P=0.032) . Conclusion:miR-204 maybe promote the proliferation and differentiation of osteoblasts, activate Wnt signaling pathway, and has certain protective effect on osteoporosis.