PFMG1 promotes osteoblast differentiation and prevents osteoporotic bone loss

OBJECTIVE To investigate the effect of Pinctadafucata mantle gene 1(pfmg1)on osteoporotic bone lossand the role in osteoblast differentiation and matrix mineralization,and to explore the molecular mechanismof how PFMG1 functions through both animal and cellular experiments.METHODS For animal experiments,female BALB/c mice were subjected to sham-operation(sham)or ovariectomy(ovx)at 5weeks of age,control and pfmg1 lentiviral particles were packaged and injected through tail vein to ovx mice(2×107TU/mouse),respectively.Bone mineral density(BMD)was detected 2 months after the surgery,and the proximal tibia was scanned in three dimensions byμCT.For cellular experiments,GST-PFMG1 protein was expressed and purified,then added to MC3T3E1 cell culture medium.MTT,ALP activity and the level of matrix mineralization were detected after the treatment.RESULTSEctopic expression of pfmg1 gene enhanced the BMD level of ovx mice.μCT images revealed that PFMG1 improvedthe osteoporotic characteristics caused by ovariectomy,including the decreases in trabecular number(Tb.N),trabecular thickness(Tb.Th),and in trabecular bone volume as a percentage of total bone volume(BV/TV);and the increases in trabecular spacing(Tb.Sp)and trabecular bone pattern factor(TBPf).The alkaline phosphatase(ALP)activity and the level of matrix mineralization increased,while the MTT activity decreased after treated with PFMG1 in the osteoblast cell line MC3T3E1.CONCLUSION PFMG1 from the mental of P.fucatacould promote osteoblast differentiation and matrix mineralization in vitro,and couldprevent bone loss caused by ovariectomy in vivo.These findings showed the potential of PFMG1 from nacre as a therapeutic drug for osteoporosis.