转化生长因子β1-结缔组织生长因子途径在FTY720干预大鼠抗Thy-1系膜增生性肾炎中的作用

FTY720 attenuates rat anti-Thy-1 mesangial proliferative glomerulonephritis by inhibition of transforming growth factor β1-connective tissue growth factor pathway

目的 观察并探讨FTY720是否通过抑制转化生长因子β1-结缔组织生长因子（TGFβ1-CTGF）途径在体内发挥抑制大鼠系膜增生和系膜基质扩张的作用.方法 制备大鼠抗Thy-1系膜增生性肾炎模型,同时给予FTY720干预,观察3组大鼠24 h尿蛋白定量、肾小球系膜增生程度,并分离肾小球进行培养,检测培养上清细胞外基质纤维连接蛋白、层黏蛋白和Ⅳ型胶原蛋白分泌水平变化,即时定量聚合酶链反应（RT-PCR）检测肾小球TGFβ1和CTGF基因表达,Western blot检测肾小球TGFβ1和CTGF蛋白表达.结果 在注射抗体后第1、3、7天,模型组尿蛋白[（27.9±7.3）、（63.5±18.8）、（52.4±15.4） mg/d]较对照组[（8.4±2.4）、（8.4±2.1）、（10.4±3.2）mg/d]明显增多,差异均有统计学意义（均P＜0.01）.FTY720干预组第3、7天尿蛋白[（31.4±7.0）、（25.5±7.7）mg/d]与模型组相比明显减少,但仍显著高于对照组,各组间差异有统计学意义（均P＜0.01）.注射后第3、7天,FTY720可以显著减少TGFβ1和CTGF基因以及蛋白表达,减低肾小球细胞外基质蛋白分泌,减轻肾小球系膜增生程度.结论 FTY720可以通过抑制TGFβl-CTGF途径显著减轻模型大鼠系膜增生和系膜基质扩张,干预抗Thy-1系膜增生性肾炎的发生.

Objective To investigate whether FTY720 inhibits rat mesangial proliferation and extracellular matrix expansion through suppression of transforming growth factor β1-connective tissue growth factor （TGFβ1-CTGF） pathway,and to explore experimental evidence for its effect on mesangial proliferative glomerulonephritis.Methods A rat model of anti-Thy-1 mesangial proliferative glomerulonephritis was established and FTY720 intervention was performed. Periphery blood lymphocyte count,urine protein excretion,glomerular mesangial proliferation,protein and gene expression of TGFβ1 and CTGF and extracellular matrix protein including fibronectin,laminin and collagen IV in isolated glomeruli were documented at 1,3 and 7 days after injection of anti-Thy-1 antibody.Results The model group developed proteinuria at 1,3 and 7 days after injection of anti-Thy-1 antibody,which were significantly higher [（27.9 ± 7.3 ）,（63.5 ± 18.8 ） and （ 52.4 ± 15.4 ） mg/d,respectively] than those in the control group [（ 8.4 ± 2.4）,（ 8.4 ± 2.1 ） and （ 10.4 ± 3.2） mg/d ; respectively,P 〈 0.01].FTY720 intervention group showed significantly decreased proteinuria at 3 and 7 days after injection [（ 31.4 ± 7.0）,（ 25.5 ± 7.7 ）mg/d,respectively] than model group （P 〈 0.01 ）,although higher than the control group （P 〈 0.01 ）.After intervention for 3 and 7 days,FTY720 significantly down-regulated both TGFβ1 and CTGF gene and protein expression in cultured glomeruli,and suppressed the production of glomerular extracellular matrix protein secretion,leading to attenuated mesangial cell proliferation and extracellular matrix expansion in rat anti-Thy-1 mesangial proliferative glonerulonephritis. Conclusion FTY720 significantly attenuates mesangial proliferation and extracellular matrix expansion through inhibition of TGFβ1 -CTGF pathway in rat,and thus ameliorates the development of anti-Thy-1 mesangial proliferative glomerulonephritis.