黄芪多糖联合TPHK对低氧水浸复合应激致大鼠胃肠道损伤的防护作用

Protective effect of astragalus polysaccharide combined with TPHK on the gastrointestinal injury of rats that induced by hypoxic and water immersion combined stress

目的:研究黄芪多糖联合携带HIF-1α和KGF双基因重组减毒沙门菌(TPHK)对应激损伤的氧化应激和炎症的防护作用。方法:通过服用TPHK和黄芪多糖,在低氧舱内模拟高原低氧水浸复合应激方法制造大鼠应激性模型,实验分为空白组(N组)、模型组(M组)、TPHK组(T组)、黄芪组(H组)、TPHK+黄芪组(L组),在造模后3 d、5 d、7 d分别取大鼠血液,胃肠组织,粪便进行检测;RT-PCR检测结肠组织中HIF-1α及KGF基因表达;检测血清超氧化物歧化酶(superoxide dismutase,SOD)和丙二醛(malondialdehyde,MDA)含量;ELISA方法检测结肠组织中IL-17的表达水平。结果:T组、H组及L组HIF-1α表达量在应激3 d后均明显升高;T组和L组KGF相对表达量较M组均明显升高(P<0.05),且在应激5 d、7 d后继续保持上升趋势。低氧应激5 d、7 d时H组、T组及L组SOD不同程度上升(P<0.05);M组血清MDA含量在低氧应激3 d、5 d、7 d时显著升高(P<0.05),7 d后H组、T组MDA显著上升(P<0.05)。低氧应激3 d、5 d时,H、T、L组IL-17表达显著低于M组(P<0.05或P<0.01),应激7 d时,H、T组较M组表达无差异,而L组IL-17表达显著低于M、H、T组(P<0.01),且L组较H、T组IL-17表达均显著降低(P<0.05或P<0.01)。结论:TPHK在应激损伤的肠道能够高效表达目的蛋白KGF和HIF-1α,TPHK和黄芪多糖单独和联合使用均可显著提高SOD活性,降低MDA、IL-17水平,发挥抗氧化应激和抑制炎症反应的保护作用,且以两者联合应用效果更好。

Objective:To study the protective effect that astragalus polysaccharides combined with HIF-1αand KGF double gene recombinant attenuated salmonella(TPHK)on oxidative stress and inflammation caused by stress injury.Methods:By taking TPHK and astragalus polysaccharides,in a hypoxic cabin,simulated high altitude hypoxia water immersion combined stress method to create a rat stress model,the experiment was divided into blank group(N group),model group(M group),TPHK group(T group),Astragalus group(H group),TPHK+Astragalus group(L group),blood,gastrointestinal tissue,and feces were taken from rats 3 days,5 days,and 7 days after modeling.RT-PCR detection of HIF-1αand KGF gene expression in colon tissue,detection of serum superoxide dismutase(SOD)and malondialdehyde(MDA)content.ELISA method to detect expression level of IL-17 in colon tissue.Results:The expression of HIF-1αin the T,H,and L groups all increased significantly after stress for 3 days,the relative expression that KGF in the M,T and L groups all increased significantly(P<0.05).After 5 d and 7 d of stress,it continued to increase.The SOD activity increased to varying degrees in the H,T,and L groups at 5 and 7 days of hypoxic stress(P<0.05),serum MDA levels increased significantly in the M group at 3,5,and 7 days of hypoxic stress(P<0.05).MDA in group H and T increased significantly after 7 days(P<0.05).Intestinal tissue IL-17 expression was significantly lower than that of M group on the 3 d and 5 d in H,T,and L groups(P<0.05 or P<0.01).On the 7 d of stress,the H,T group was higher than that of M group.There was no difference in expression,while the expression of IL-17 in the L group was significantly lower than that in the M,H,and T groups(P<0.01),and the IL-17 expression in the L group was significantly lower than that in the H and T groups(P<0.05 or P<0.01).Conclusion:TPHK can efficiently express the target protein KGF and HIF-1αin the intestines damaged by stress.TPHK and Astragalus polysaccharide can significantly increase the activity of SOD,reduce the levels of MDA and IL-17,and exert anti-oxidative stress and inhibition.The protective effect of inflammatory response,and the combined application of the two has a better effect.