谷氨酰胺对内毒素血症肠组织TLR2、4表达的影响

Effects of glutamine on Toll-like receptor 2 and 4 expression in rats with intestinal endotoxemia

目的:探讨谷氨酰胺对TLR2、4表达的调节与肠组织损伤的关系.方法:将24只10日龄Wistar幼鼠随机分为对照组(n=8),ip生理盐水,1 mL/kg;LPS组(n=8),ip LPS,5 mg/kg;谷氨酰胺组(n=8),ip LPS 5 mg/kg+谷氨酰胺10 mL/kg,3 h后取肠组织,HE染色观察病理改变,RT-PCR检测肠组织TLR2、4 mRNA的表达.Western blot检测TLR蛋白表达.结果:对照组TLR2、4 mRNA均较LPS组弱(TLR2 mRNA:1.386±0.04 vs 4.093±0.90.TLR4 mRNA:9.872±0.36 vs 16.706±1.28.TLR2蛋白:22.28±0.96 vs 79.27±3.16.TLR4蛋白:35.07±0.17 vs 65.18±0.46):与LPS组相比,谷氨酰胺组TLR2、4mRNA和蛋白表达明显下调(TLR2 mRNA:3.055±0.51.TLR4 mRNA:3.920±0.5.TLR2蛋白:51.15±1.84.TLR4蛋白:43.25±0.27),肠组织损伤明显减轻.结论:谷氨酰胺通过抑制TLR2、4 mRNA的表达,减轻肠组织的损伤.

AIM： To determine the effect of glutamine （Gin） on Toll-like receptor （TLR） 2 and 4 expression in rats with intestinal endotoxemia. METHODS： Twenty-four Wistar rat pups aged 10 d were randomly divided into three groups： control （normal saline 1 mL/kg ip, n = 8）, lipopolysaccharide （LPS） （LPS 5 mg/kg ip, n = 8）, and Gin group （LPS 5 mg/kg ＋ Gin 10 mL/kg ip, n = 8）. The rats were sacrificed at 3 h after treatment. The small intestine was dissected for histological analysis, and expression of TLR2 and TLR4 mRNA was detected by reverse transcription-polymerase chain reaction. TLR2 and TLR4 protein expression was measured by Western blotting. RESULTS： TLR2 and TLR4 mRNA and protein were detected at a low level in the intestine of the control group （TLR2 mRNA 1.386 ± 0.04, TLR4 mRNA 9.872 ± 0.36, TLR2 protein 22.28 ± 0.96, TLR4 protein 35.07 ± 0.17）, but they were markedly increased at 3 h in the LPS group （TLR2 mRNA 4.093 ± 0.90, TLR4 mRNA 16.706 ± 1.28, TLR2 protein 79.27 ± 3.16, TLR4 protein 65.18 ± 0.46）. In the Gin group, TLR2 and TLR4 mRNA and protein expressions were significantly decreased （TLR2 mRNA 3.055 ± 0.51, TLR4 mRNA 3.920 ± 0.5, TLR2 protein 51.15 ± 1.84, TLR4 prorein 43.25 ± 0.27）. The intestinal injury was obviously relieved. CONCLUSION： TLR2 and TLR4 mRNA and protein expressions in the intestine of rats with endotoxemia are markedly inhibited by Gln, which led to relief of intestinal damage.