上调Smad7表达对腹膜纤维化大鼠腹膜炎症细胞浸润及促炎症因子表达的影响

Impact of overexpressive Smad7 on the infiltration of inflammatory cells and the expression of proinflammatory factors in peritoneum of rat peritoneal fibrotic model

目的研究基因转染上调Smad7表达对大鼠腹膜纤维化模型腹膜炎症细胞浸润及促炎症因子表达的影响。方法 48只SD大鼠随机分为(1)正常对照组(n=12);(2)模型组(n= 12):每日给予腹腔注射4．25％葡萄糖腹膜透析液(100 ml／kg),同时于第8、10、12、22、24、26天腹腔注射脂多糖(LPS,0．6 mg／kg);(3)空白载体对照组(n=12):仅转入不含Smad7的Tet-on／ vector空白载体:(4)Smad7基因转染组(n=12):在造模后第0、14天分别转染Smad7。第28天时杀检,分别应用免疫荧光染色及RT-PCR检测脏层腹膜泛白细胞标志性抗原(OX-1)、单核巨噬细胞抗原(ED-1)、白介素1(IL-1)、肿瘤坏死因子α(TNF-α)蛋白和mRNA的表达水平。Smad7 基因转染采用超声介导的微泡基因转染技术。结果与模型组及空白载体转染组比较,Smad7转基因组脏层腹膜OX-1、ED-1阳性细胞以及IL-1、TNF-α表达水平有明显的减少,但均高于正常对照组。结论高糖腹膜透析液联合LPS可刺激腹膜炎症细胞的浸润及腹膜间皮细胞IL-1、 TNF-α表达上调。基因转染上调Smad7表达可明显抑制大鼠腹膜纤维化模型腹膜炎症细胞浸润及促炎症因子的表达上调。

Objective To observe the effects of overexpressive Smad7 on the infiltration of inflammatory cells and the expression proinflammatory factors in peritoneum of rat peritoneal fibrotic model. Methods Forth-eight male SD rats were divided into four groups： normal control group; peritoneal fibrotic model group;empty vector group;Smad7 gene transfer group. All the rats with peritoneal fibrosis received daily intraperitoneal injection with 4.25% glucose dialysate （100 mg/kg BW） for 4 weeks and LPS（0.6 mg/kg BW）at day 8,10,12,22,24,26. Empty vector and Smad7 were transferred respectively with Tet-on/vector and Smad7 gene at day 0 and day 14 in empty vector group and Smad7 gene transfer group. All the rats were sacrificod at day 28 after peritoneal fibrosis model were induced.OX-1 ,ED-1 positive cells and IL-1 and TNF-α protein expression were measured by indirect immunoflurence.IL-1 and TNF-α mRNA expression were examined with RT- PCR. Smad7 gene transfer with ultrasound microbubble induced optimal gene transfection method. Results Comparing with the rats in peritoneal fibrotic and empty vector group, the infiltration of OX- 1 and ED-1 positive cells in peritoneum was markedly improved in smad7 gene transfer group. IL-1 and TNF-α expression,including mRNA and protein, were also down regulated. Conclusion Overexpression of Smad7 with ultrasound microbubble induced gene therapy can successfully suppresse the infdtration of inflammatory cells and higher expression of IL-1 and TNF-α in rats with peritoneal fibrosis induced by high glucose and LPS.