免疫抑制剂对大鼠慢性移植肾肾病中转化生长因子β_1/Smads通路的影响及意义

Effects of different immunosuppresants on CAN by affecting the TGF-β_1 and smads signal pathway

目的探讨不同免疫抑制剂对慢性移植肾肾病(CAN)中转化生长因子β1(TGF-β1)/Smads通路的影响及意义。方法采用SD大鼠到Wistar大鼠的强化CAN模型,然后将模型大鼠随机分为对照组(不行处理)、环孢素A组(给予环孢素A6mg·kg-1·d-1)、他克莫司组(给予他克莫司0.15mg·kg-1·d-1)、霉酚酸酯组(给予霉酚酸酯20mg·kg-1·d-1)和西罗莫司组(给予西罗莫司0.8mg·kg-1·d-1)。分别于术后4、8、12周处死动物,观察移植肾组织的病理变化,用免疫组织化学法和实时荧光定量聚合酶链反应测定肾组织中TGF-β1、Smad2和Smad7蛋白及其基因的表达。结果术后各组均呈现CAN的病理改变,环孢素A组和他克莫司组的病变程度较对照组重,而霉酚酸酯组和西罗莫司组的病变轻于对照组。术后各时间段,环孢素A组和他克莫司组TGF-β1和Smad2蛋白及其mRNA的表达明显高于对照组(P<0.05),而Smad7蛋白及其mRNA的表达明显低于对照组(P<0.05);霉酚酸酯组和西罗莫司组TGF-β1和Smad2蛋白及其mRNA的表达明显低于对照组(P<0.05),而Smad7蛋白及其mRNA的表达明显高于对照组(P<0.05)。结论发生CAN时,环孢素A和他克莫司可上调TGF-β1的表达,影响TGF-β1/Smads通路,加重其病理损害,而霉酚酸酯和西罗莫司的作用与之相反。

Objective To investigate the effect of different immunosuppresants on CAN by affecting TGF-β1 and Smads signal pathway. Methods The SD→Wistar rat accelerated kidney sclerosis model was made following the procedure of Kamada with our modification. The rats were divided into 6 groups （each group n = 8）： Group A, psudo-OP group; Group B, control group Group C, CsA 6 mg·kg^-1·d ^-1; Group D, FK506 0.15mg·kg^-1·d^-1; GroupE, MMF20mg·kg^-1·d^-1 GroupF, RPM 0. 8 mg·kg^-1·d^-1. After 4, 8, 12 weeks, the animals were killed. The immunohistochemistry and real-time fluorescence quantitative PCR were used to detect localization and expression of TGF-β1, Smad2 and smad7 in transplant kidney. Results CsA and FK506 simultaneously stimulated the gene expression and protein production of TGF-β1 and Smad2 and inhibited the expression of Smad7 in transplant kidney, whereas MMF and RPM could down-regulate the gene expression and protein production of TGF-β1 and smad2 and up-regulate the expression of smad7. There was no significant difference between CsA group and FK506 group, as well as MMF group and RPM group. Conclusion Different immunosuppresants can affect TGF-β1 and Smads signal pathway in kidney graft. CsA and FK506 can cause CAN, owning to up-regulate the expression of Smad2, and down-regulate the Smad7 expression. MMF and RPM can prevent the progression of CAN because of down-regulating the expression of Smad2 and increasing Smad7 production.