黄芪多糖对肾盂肾炎大鼠肾脏TLR4表达的影响

Effects of Astragalus on the Expression of TLR4 in Rat Kidney with Acute Pyelonephritis

目的:探讨toll样蛋白4(TLR4)在正常及急性肾盂肾炎大鼠肾脏中的表达及其与炎症的关系,并观察黄芪多糖对TLR4表达的影响。方法:24只SPF级成年雄性SD大鼠随机分为4组:正常组、假手术组、急性肾盂肾炎组和急性肾盂肾炎+黄芪多糖治疗组。膀胱内注射大肠杆菌法制作急性肾盂肾炎动物模型。HE染色观察和评价炎症程度。免疫组化SP法检测肾组织TLR4的表达部位和强度并分析其与炎症程度的关系。逆转录聚合酶链反应法(RT-PCR)检测各组TLR4 mRNA的表达。结果:正常组未见炎症改变,假手术组炎症浸润不明显,两者无统计学差异,肾盂肾炎组炎症显著高于正常组(P<0.05),治疗组较肾盂肾炎组炎症减轻。各组肾组织均表达TLR4,正常组和假手术组主要表达于远曲小管上皮细胞,肾盂肾炎组TLR4表达程度显著高于正常组和假手术组(P<0.05),除远曲小管外,也表达于部分近曲小管上皮细胞。治疗组TLR4表达较肾盂肾炎组增强。TLR4 mR-NA表达变化与TLR4蛋白表达变化一致。结论:本实验证实了肾组织TLR4主要表达于小管上皮细胞,TLR4在急性肾炎肾炎发病过程中起着重要作用,黄芪多糖可能通过增加TLR4表达而减轻肾盂肾炎的炎症反应。

Objective： To investigate the expression of TLR4 in normal kidney and Escherichia coli induced pyelonephritic kidney, and to investigate the effects of Astragalus on TLR4 expression. Methods. Twenty-four rats were randomly assigned into four groups： normal, sham operation, pyelonephritic and Astragalus-treated group. HE staining was used to observe inflammation changes. Immunohistochemistry and reverse transcription polymerase chain reaction （RT-PCR） were performed to evaluate the expression of TLR4 protein and mRNA respectively. Results： TLR4 labeling was observed in the renal tubular epithelial cells in rat kidney of all groups. In pyelonephritic group, the expression of TLR4 protein was significantly increased compared to that in normal and sham operative groups. Moreover, astragalus-treated animals had shown a further increase in the expression of TLR4 compared to pyelonephritic rats. Expression of TLR4 mRNA was corresponding to its protein expression. Conclusion： TLR4 expression was significantly increased in the experimental pyelonephritis, which might play an important role in the inflammation process and astragalus could up-regulate TLR4 expression.