不同免疫抑制剂对大鼠血管平滑肌细胞转化生长因子-β1和Smads信号通路的影响及意义

Role of different immunosuppressants in VSMC by affecting the TGF-β1 and smads signal pathway

目的研究不同免疫抑制剂对大鼠血管平滑肌细胞(VSMC)转化生长因子(TGF)-β1和Smads信号通路的影响,探讨其在慢性移植肾肾病发生、发展中的作用。方法应用大鼠胸主动脉平滑肌细胞体外原代培养技术,分别用CsA(3mg/L)、FK506(1 mg/L)、MMF(0．3mg/L)与RPM (10 mg/L)处理6、12h。用免疫组织化学和实时荧光定量聚合酶链反应检测TGF-β1、Smads蛋白和mRNA在平滑肌细胞中的表达及定位。结果CsA组和FK506组TGF-β1、Smad2的蛋白和mRNA表达水平高于对照组、MMF组和RPM组(P＜0．01),Smad7蛋白和mRNA表达低于对照组、MMF组和RPM组(P＜0．01)；MMF组和RAPA组TGF-β1、Smad2蛋白和mRNA表达低于对照组(P＜0．01),而Smad7的表达高于对照组(P＜0．01)。CsA组和FK506组,以及MMF组和RPM组的组间差异无统计学意义(P＞0．05)。结论不同免疫抑制剂可能通过影响血管平滑肌细胞TGF-β1和Smads信号通路,导致移植物动脉硬化,从而影响慢性移植肾功能丧失的进程。

Objective To investigate the effect of different immunosuppressants on vascular smooth muscle cells （VSMC） by affecting TGF-β1 and smads signal pathway. Methods VMSC from rat aorta were incubated with different immunosuppressants （CsA 3 mg/L, FK506 1 mg/L, MMF 0.3 mg/ L, RPM 10 mg/L）, respectively for 6 or 12 h, as control without anything. The immunohistochemistry and real-time fluorescence quantitative polymerase chain reaction were used to detect the expression of TGF-β1 and Smad2, 7 in VMSC. Results As compared with control groups, CsA and FK506 increased the expression of TGF-β1 and Smad2 and inhibited the expression of Smad7, whereas MMF and RPM could down-regulate the expression of TGF-β1 and Smad2. and up-regulate the expression of Smad7. The increased TGF-β1 was associated with overexpression of Smad2 and down-expression of Smad7 in VSMC. There was no significant difference between CsA group and FK506 group, as well as MMF group and RPM group. CsA and FK506 affected TGF-β1, Smad2 and Smad7 in VSMC in a time-dependent manner. Conclusion Different immunosuppressants can affect TGF-β1/Smads signal pathway in VSMC, and CsA and FK506 may cause atherosclerosis. However, MMF and RPM have a opposite role in VSMC compared with CsA and FK506.