Typl-HGF对TNBS诱发的大鼠溃疡性结肠炎的治疗作用

Gene therapy of hepatocyte growth factor mediated by attenuated salmonella typhimurium for TNBS-induced ulcerative colitis in rats

目的:评价携带肝细胞生长因子基因的减毒沙门氏菌(Typl-HGF)对TNBS诱发大鼠溃疡性结肠炎模型的治疗效果.方法:40只Wistar大鼠经TNBS灌肠诱发溃疡性结肠炎模型,并随机分为减毒沙门氏菌株(Ty)治疗组、Typl-HGF治疗组、携带绿色荧光蛋白基因的减毒沙门氏菌株(Typl-GFP)观察组和模型对照组4组,每组10只;另设生理盐水灌肠正常对照组10只.3次和6次ig1wk后,分别观察各组大鼠的一般情况、结肠大体观及评分、结肠组织学变化及评分和目的基因表达.结果:Typl-HGF治疗组3次ig后体质量略有增加,但差异无统计学意义;6次Typl-HGF治疗后动物体质量较模型对照组平均增加9.75±2.07g,差异有统计学意义(P<0.05),Ty治疗组与模型对照组大鼠症状均无明显缓解.3次和6次Typl-HGF治疗组结肠大体标本积分明显低于同期Ty治疗组和模型对照组(2.20±0.90vs5.10±1.70,5.30±1.30;1.70±1.10vs4.00±1.50,4.30±1.20,均P<0.01),且3次和6次Typl-HGFig治疗相比较有统计学意义(P<0.05).3次ig后Typl-HGF治疗组组织学评分与Ty治疗组和模型对照组无明显差别;6次Typl-HGF治疗后组织学评分与同期模型组标本积分相比,二者之间差异有统计学意义(1.60±0.30vs3.50±0.70,P<0.05).Typl-GFPig后在结肠组织可见GFP强表达.结论:Typl-HGF能明显减轻TNBS诱发溃疡性结肠炎模型大鼠的症状及炎症,对已形成的黏膜损伤及溃疡有促修复作用.

AIM： To explore the therapeutic efficacy of attenuated salmonella typhimurium carrying human hepatocyte growth factor （Typl-HGF） gene in rats with ulcerative colitis （UC） induced by 2, 4, 6-trinitrobenzene sulfonic acid （TNBS）. METHODS： Forty ulcerative colitis model rats were induced by TNBS enema, and then randomly divided into 4 groups （n = 10）： simple attenuated salmonella typhimurium （Ty） control group, Typl-HGF group, attenuated salmonellatyphimurium carrying green fluorescent protein （Typl-GFP） gene group and model control group. Another 10 rats were intrarectally administered with normal saline, serving as normal control group. After 3-6 times of treatment, the colons were removed and scored by appearance, and then the specimens were subjected to HE staining for histological observation and scoring. The expression of target gene in colon tissues was observed under fluorescence microscope. RESULTS： The weights of rats treated 3 times with Typl-HGF had a little increase, but those of rats treated 6 times with Typl-HGF showed a significant increase （9.75 ± 2.07 g） （P 〈 0.05）. The common symptoms of colitis were not obviously ameliorated in Ty group and model control group. Grossly, mucosal hyperemia and thickening of colonic wall were evidently ameliorated, and the colon appearance scores of rats treated with Typl-HGF 3 or 6 times were significantly lower than those of rats in Ty group and model control group （2.20 ± 0.90 vs 5.10 ± 1.70, 5.30 ± 1.30; 1.70 ± 1.10 vs 4.00 ± 1.50, 4.30 ± 1.20; all P 〈 0.01）; there was a significant difference between rats treated with Typl-HGF 3 and 6 times （P 〈 0.05）. Histopathologically, in Typl-HGF-treated 3-time group, the score was not significantly different from that in Ty group or model control group, but the score in Typl-HGF-treated 6-time group was significantly higher than that in model control group （1.60 ± 0.30 vs 3.50 ± 0.70, P 〈 0.05）. GFP expression was observed in colon tissues after intragastric administration of Typl-GFP. CONCLUSION： Typl-HGF can dramatically ameliorate mucosal inflammation and symptoms of TNBS-induced colitis as well as promote the repair of mucosal damage and ulcer in rats.