木通皂苷D促进糖皮质激素环境下小鼠骨髓间充质干细胞成骨分化

目的观察木通皂苷D(ASD)对糖皮质激素(GC)环境下小鼠骨髓间充质干细胞(BMSCs)成骨分化的影响及其机制。方法体外培养小鼠BMSCs,实验分为三组,分别用成骨诱导培养基(OBI)、OBI+地塞米松(DEXA,0.1μmol/L)、OBI+DEXA(0.1μmol/L)+ASD(10μmol/L)干预。ALP试剂盒检测ALP活性,茜素红染色检测矿化情况,qRT-PCR检测成骨因子Runx2、骨钙素(OCN)及Smad1、Smad5 mRNA表达,Western blot检测Smad1/5磷酸化水平及Smad1/5/8总蛋白表达。结果OBI+DEXA组ALP活性明显较OBI组低(P<0.001),OBI+DEXA+ASD组ALP活性明显较OBI+DEXA升高(P<0.01)。OBI+DEXA干预组成骨相关因子Runx2、OCN、Smad1和Smad5 mRNA表达较OBI组均明显下调(P<0.01),OBI+DEXA+ASD组Runx2、OCN、Smad1和Smad5 mRNA表达较OBI+DEXA干预组明显上调(P<0.01和P<0.05)。三组Smad1/5/8总蛋白表达差异无统计学意义,OBI+DEXA干预组pSmad1/5较OBI干预组表达降低,OBI+DEXA+ASD干预组pSmad1/5表达较OBI+DEXA干预组增加。结论ASD可促进GC环境下小鼠BMSCs成骨分化,其机制可能与激活BMP/Smad信号通路有关。

Akebia saponin D promotes osteogenic differentiation of bone marrow mesenchymal stem cells under glucocorticoid condition in mice

Objective To investigate the effect of akebia saponin D(ASD)on osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)under glucocorticoid(GC)condition in mice.Methods Mice BMSCs were cultured in vitro.BMSCs were divided into three groups,and were induced by osteoblastic differentiation induction(OBI),OBI+DEXA(0.1μmol/L),and OBI+DEXA(0.1μmol/L)+ASD(10μmol/L),respectively.ALP activity was examined with ALP kit.Alizarin red staining was performed to determine the status of mineralization.qRT-PCR was performed to examine the mRNA expression of osteogenic factors Runx2,osteocalcin(OCN),Smad1,and Smad5.The phosphorylation level of Smad1/5 and expression of total Smad1/5/8 protein were examined using Western blotting.Results Compared to that in OBI group,ALP activity decreased in OBI+DEXA group(P<0.001),but increased in OBI+DEXA(0.1μmol/L)+ASD group(P<0.01).Relative expression of osteogenesis related factors Runx2,OCN,Smad1,and Smad5 mRNAs were down-regulated in OBI+DEXA group versus OBI,but were up-regulated in OBI+DEXA+ASD group compared to OBI+DEXA group(P<0.01 and P<0.05).There was no obvious difference in level of Smad1/5/8 total protein between any two groups.pSmad1/5 level was obviously lower in OBI+DEXA(0.1μmol/L)group than in OBI group.It was strikingly higher in OBI+DEXA+ASD group than in OBI+DEXA group.Conclusion ASD promotes osteogenic differentiation of mice BMSCs under GC condition probably through activating BMP/Smad signaling pathway.