摘要目的 观察重组组织因子途径抑制物(rTFPI)对大鼠肾脏系膜细胞(MsC)凋亡的影响,并探讨其可能相关的凋亡机制.方法 免疫组织化学(ABC)法检测人肾穿组织中TFPI表达;免疫荧光法检测培养正常大鼠MsC中TFPI表达;将rTFPI及其不同结构域蛋白分别作用于大鼠MsC,Hoechst 33258染色观察MsC细胞核形态变化;流式细胞仪定量检测MsC细胞凋亡率;DNA片段凝胶电泳分析MsC凋亡情况;Western blot检测凋亡相关激酶半胱氨酸蛋白酶3(caspase-3)、bel-2以及Fas蛋白的表达.结果 系膜增生型肾小球肾炎肾小球内TFPI表达高于轻微病变者;正常大鼠MsC中有TFPI表达;rTFPI及其C末端能诱导大鼠MsC发生凋亡,并具有剂量和时间依赖性劝口入rTFPI后,MsC的凋亡率分别为对照组的2.1、3.0及4.9倍(P<0.05).活性形式的caspase-3和Fas蛋白表达明显高于对照组,bcl-2表达无明显变化.结论 rTFPI能诱导正常大鼠MsC发生凋亡,并且其主要功能区位于C末端,死亡受体Fas/FasL信号通路可能参与了rTFPI诱导MsC凋亡的过程.

abstractsObjective To study the biological impact and mechanism of recombinant tissue factor pathway inhibitor (rTFPI) on apoptosis of rat kidney mesangial cells (MsC). Methods TFPI expression in human glomerular minor lesion (GML), mesangial proliferative glomerulonephritis (MPGN) and cultured rat MsC was detected using immunohistochemistry and immunofluorescence, respectively. Rat MsC were incubated with rTFPI and its variant peptides. Morphological changes of apoptosis were investigated by Hoechst 33258 and the apoptotic rate was assessed by flow cytometry. DNA fragmentation and effect of rTFPI on expression of caspase-3, Fas and bcl-2 were studied using gel electrophoresis and Western blot respectively. Results The expression of TFPI in MPGN was higher than that in GML. TFPI was expressed in cultured rat mesangial cells. Apoptosis of MsC was induced by rTFPI, especially by its C-termianl, in a dose- and time-dependent manner. Apoptosis ratios of MsC treated with rTFPI were 2.1,3.0 and 4.9 times more than control, respectively. Expression of gene caspase-3 and Fas was up-regulated in a dose-dependent manner wherease bcl-2 expression did not show any changes. Conclusion rTFPI induces apoptosis in cultured rat mesangial cells by its C-terminal possibly via Fas/FasL pathway.