NFATc1-ERK5通路介导流体剪切力促进成骨细胞BMP7表达

摘要

目的:探讨成骨细胞中NFATc1与ERK5调控关系,并研究流体剪切力(FSS)调节BMP7表达的信号通路.方法:实验分为6组,即空白组、FSS组、CsA(Cyclosporin,NFATc1抑制剂)组、XMD8-92(ERK5抑制剂)组、FSS+CsA组、FSS+XMD8-92组.用Western Blot方法检测不同干预条件下NFATc1、ERK5、p-ERK5以及BMP7蛋白表达水平并进行比较.结果:12 dyn/cm2FSS作用45 min能够显著提高NFATc1、p-ERK5在成骨细胞内水平,400 nmol/L CsA干预30 min能够有效抑制NFATc1表达量升高以及ERK5磷酸化,但5 μmol/L XMD8-92作用1 h仅能够抑制ERK5磷酸化,而对NFATc1没有作用.此外,FSS促进MC3T3-E1细胞中BMP7表达量升高,CsA和XMD8-92任何一种抑制剂均能显著阻止BMP7表达.结论:FSS在成骨细胞中通过NFATc1来调控ERK5磷酸化,BMP7为ERK5下游靶点受NFATc1-ERK5通路调控.%Objective To discuss the interrelation between nuclear factor of activated T cells c1(NFATc1)and extracellular-regulated protein kinase 5(ERK5),and explore the fluid shear stress(FSS)-induced signal pathway that regulates the expression of bone morphogenetic protein 7(BMP7).Methods The experiment was divided into 6 groups,namely control group,FSS group, CsA(Cyclosporin,NFATc1 inhibitor)group,XMD8-92(ERK5 inhibitor)group,FSS+CsA group,and FSS+XMD8-92 group. Western Blot was applied to access the expression level of NFATc1,ERK5,p-ERK5 and BMP7.Results 12 dyn/cm2FSS for 45 min well promoted the level of NFATc1 and p-ERK5 in osteoblasts.400 nmol/L CsA for 30 min effectively inhibited the expression of NFATc1 and the phosphorylation of ERK5,but 5 μmol/L XMD8-92 for 1 h only blocked the phosphorylation of ERK5,without causing effects on NFATc1.The expression level of BMP7 in MC3T3-E1 cell was promoted by FSS,and either CsA or XMD8-92 significantly inhibited the expression of BMP7.Conclusion FSS mediates the phosphorylation of ERK5 in osteoblasts by NFATc1,and BMP7 regarded as downstream target of ERK5 was regulated by NFATc1-ERK5 pathway.