KGF和HIF-1α联合对大鼠肠缺血再灌注致肠黏膜氧化应激损伤的防护作用

Protective Effect of KGF Combined with HIF-1αon the Ischemia-reperfusion-induced Oxidative Stress Injury of Intestinal Mucosa in Rats

目的研究携带缺氧诱导因子-1α(HIF-1α)和角质细胞生长因子(KGF)的重组减毒沙门菌(TPHK)对大鼠肠黏膜氧化应激损伤的防护作用。方法雄性Wistar大鼠126只,随机分为NC组(6只)及TC、Ty21a、TPH、TPK、TPHK组,各实验组又分为2、6、12、24 h四个时间点,每个时间点6只。建模前给予相应基因药物10^(9) CFU/只,共4次,隔日1次,随后建立肠缺血再灌注(I/R)模型。检测各组小肠组织HIF-1α和KGF蛋白表达,并进行组织病理学观察,比较各组小肠组织和血浆超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量。结果与NC组比较,各实验组小肠组织HIF-1α表达水平在I/R后6 h时达峰值,且TPHK组HIF-1α表达水平在6、12、24 h高于TPK和TPH组(P<0.05,P<0.01);与NC组比较,TPK和TPHK组小肠组织KGF表达水平在I/R后6 h时达峰值,后开始下降,TPHK组小肠组织KGF表达水平在I/R后2、6、24 h高于TPK和TPH组(P<0.05)。I/R后24 h组织病理学观察显示,TPHK组较其他实验组黏膜和腺体结构完整,隐窝深度深,炎性细胞浸润少,黏膜固有层结构近似正常。与NC组比较,各实验组小肠组织和血浆SOD活力在I/R后6 h达峰值,TPHK组SOD活力在I/R后6、12、24 h高于TPK和TPH组(P<0.05);I/R后6 h时各实验组小肠组织和血浆MDA含量达峰值,TPHK组小肠组织和血浆MDA含量在I/R后6、12、24 h低于TPK和TPH组(P<0.01)。结论TPH、TPK和TPHK对大鼠肠I/R应激致肠黏膜氧化应激损伤有较好防护作用,其中TPHK抗氧化应激作用优于TPH与TPK,KGF和HIF-1α对氧化应激损伤有协同防护作用。

Objective To study protective effect of recombinant attenuated salmonella(TPHK)carrying hypoxia inducible factor 1α(HIF-1α)and keratinocyte growth factor(KGF)on oxidative stress injury(OSI)of intestinal mucosa in rats.Methods A total of 126 male Wistar rats were randomly divided into NC(n=6),TC,Ty21a,TPH,TPK and TPHK groups.Each group was divided into 4 time points(after I/R for 2 h,6 h,12 h,and 24 h)with 6 rats at each time point.The corresponding gene drug 10^(9) CFU was given to each rat before modeling once every other day for 4 times,and then animal models of intestinal ischemia-reperfusion(I/R)were established.Protein expressions of HIF-1αand KGF in small intestinal tissue were detected,and histopathological observation were carried out.Superoxide dismutase(SOD)activities and malondialdehyde(MDA)contents in the small intestine tissue and plasma of each group were compared.Results Compared with those in NC group,HIF-1αexpressions in the small intestine in each experimental group reached the peak after I/R for 6 h,and HIF-1αexpressions were significantly higher in TPHK group than those in TPK and TPH groups after I/R for 6 h,12 h,and 24 h(P<0.05,P<0.01).Compared with those in NC group,KGF expressions in the small intestine in TPK and TPHK groups reached the peak after I/R for 6 h,and then began to decline,and KGF expressions of TPHK group were significantly higher than those in TPK and TPH groups after I/R for 2 h,6 h,and 24 h(P<0.05).Histopathological observation after I/R for 24 h showed that the mucosa and glands were intact,deeper depth of crypts,a small amount of inflammatory cell infiltration and practically normal lamina propria structure in TPHK group compared with those in other groups.Compared with those in NC group,SOD activities in small intestine tissue and plasma in each experimental group reached a peak after I/R for 6 h,and the activities in TPHK group were significantly higher than those in TPK and TPH groups after I/R for 6 h,12 h,and 24 h(P<0.05).MDA contents of the small intestine tissue and plasma in each experimental group reached the peak after I/R for 6 h,and the MDA contents of small intestine tissue and plasma in TPHK group were significantly lower than those in TPK and TPH groups after I/R for 6 h,12 h and 24 h(P<0.01).Conclusion TPH,TPK and TPHK all have good protective effects on OSI of intestinal mucosa induced by intestinal I/R stress in rats,and the anti-oxidative stress effect of TPHK is superior to those by TPH and TPK,and KGF and HIF-1αmay have a synergistic protective effect on OSI.