重组人甲状旁腺激素1-34促进小鼠间充质干细胞增殖及骨向分化

Recombinant human parathyroid hormone 1-34 treatment promotes proliferation of bone marrow stromal cells in mice and their differentiation to osteoblasts

目的研究重组人甲状旁腺激素1-34[recombinant human parathyroid hormone1-34,rhPTH(1-34)]间断处理对小鼠骨髓间充质干细胞(bone marrow stromal cell,BMSC)增殖以及骨向分化的影响,进一步探讨rhPTH(1-34)促骨形成的机制。方法无菌条件下分离6～8周的C3H雄性小鼠BMSC,传代培养,10 nmol/L rhPTH(1-34)间断处理或者Vehicle处理,MTT检测细胞增殖;BMSC成骨诱导后,分别在3、6、9 d进行碱性磷酸酶(alkaline phosphatase,ALP)染色和活性测定;RT-PCR检测成骨细胞功能标志基因核心结合因子α1(core binding factorα1,Cbfα1)、骨桥蛋白(osteopontin,OP)、骨钙素蛋白(osteocalcin,OC)的表达水平;Western blot检测p-Erk1/2,p-P38信号通路。结果 rhPTH(1-34)间断处理促进BMSC增殖;诱导9 d时与对照组比较,显著增加ALP活性[D(405)/D(562):(0.625±0.049)vs(0.543±0.038),(P<0.05)];显著增加成骨功能相关基因Cbfα1(增加186.6%,P<0.01),OC(增加210.5%,P<0.01),OP mRNA(增加5.5%,P<0.05)的表达水平;p-Erk1/2,p-P38水平均增加。结论 rhPTH(1-34)间断处理通过激活下游的p-Erk1/2和p-P38通路,促进BMSC增殖,增强其向成骨细胞分化,使成骨细胞数量和活性增加,从而增加骨形成达到治疗骨质疏松的目的。

Objective To study the effect of recombinant human parathyroid hormone 1-34（rhPTH 1-34） intermittent treatment on proliferation of bone marrow stromal cells（BMSC） and their differentiation to osteoblasts as well as its mechanism underlying bone formation.Methods BMSC,isolated from C3H male mice at the age of 6-8 weeks,were subcultured and treated with 10 nmol/L rhPTH 1-34 intermittently or with vehicle.Proliferation of BMSC was detected by MTT assay.BMSC were stained with alkaline phophatase（ALP） and ALP activity was assayed on days 3,6 and 9 after they were differentiated to osteoblasts.Expressions of core binding factor α 1（Cbfα1）,osteocalcin（OC） and osteopontin（OP） were detected by RT-PCR.Erk1/2 and P38 signals were detected by Western blot analysis.Results rhPTH 1-34 intermittent treatment promoted the proliferation of BMSC,increased the ALP activity more significantly in treatment group than in control group on day 9 after BMSC were differentiated to osteoblasts（0.625±0.049 vs 0.543±0.038,P0.05）,and the expression levels of osteogenic markers including Cbfα1,OC and OP for 186.6%,210.5%,and 5.5%,respectively（P0.05）.The p-Erk1/2 and p-P38 signals were activated after rhPTH1-34 treatment.Conclusion rhPTH 1-34 intermittent treatment can increase the proliferation of BMSC,differentiation of BMSC to osteoblasts,and the number and activity of osteoblasts by activating the p-Erk1/2 and p-P38 signals.