“扶正清热通淋”汤通过调节NLRP3炎症小体通路对大鼠复杂性尿路感染作用的研究

Effect of"Fuzheng Qingretonglin"decoction on complex urinary tract infection in rats by regulating NLRP3 inflammasome pathway

目的:探讨“扶正清热通淋”汤能否通过调节NOD样受体蛋白3(Nod‑like receptor pyrin domain3,NLRP3)炎症小体改善耐药大肠杆菌所致大鼠复杂性尿路感染对泌尿系的损害,并探讨该汤剂联合左氧氟沙星治疗耐药菌所致复杂尿路感染的可行性。方法:将SD大鼠分为5组:空白对照组、模型组、左氧氟沙星组(西药组)、左氧氟沙星+扶正清热通淋汤组(中西组)、扶正清热通淋汤组(中药组)。实验完成后,取尿液做细菌培养以判断各组大鼠尿路感染情况;HE染色观察大鼠肾脏及膀胱组织病理改变情况;免疫组化检测NLRP3在肾脏及膀胱组织中表达情况;ELISA检测大鼠血清中IL‑1β及IL‑18表达情况;Western blotting检测NLRP3、ASC、Caspase‑1表达情况。结果:空白组尿液细菌培养阳性率为0%,模型组尿液细菌培养阳性率为100%;中西组尿液细菌培养阳性率为37.50%,与模型组比较差异有统计学意义(P<0.05)。模型组肾脏及膀胱组织HE染色可见大量炎症细胞,西药组及中药组肾脏及膀胱组织与模型组比较炎症细胞数量明显减少;中西组中肾脏及膀胱组织中炎症细胞数量及组织结构变化与空白组接近。中西组和中药组的肾脏及膀胱组织的NLRP3免疫组化与模型组比较差异均有统计学意义(P<0.001)。ELISA检测西药组、中药组和中西组血清中的IL‑1β和IL‑18水平较模型组明显降低(P<0.001)。其中中西组的IL‑1β和IL‑18较西药组和中药组明显降低,且差异有统计学意义(P<0.05)。Western blotting检测西药组、中药组和中西组的NLRP3、ASC、Caspase‑1蛋白表达较模型组明显降低(P<0.001)。中西组的NLRP3、ASC、Caspase‑1蛋白表达较西药组和中药组明显降低,且与两组比较差异均有统计学意义(P<0.05)。结论:“扶正清热通淋”汤可能通过抑制NLRP3炎症小体的活化对耐药大肠杆菌所致复杂性尿路感染大鼠的肾脏和膀胱起保护作用,中药联合左氧氟沙星比单独使用中药或左氧氟沙星治疗疗效更佳。

OBJECTIVE:To investigate whether"Fuzheng Qingretonglin"decoction can reduce urinary tract damage caused by complex urinary tract infection caused by drug resistant Escherichia coli by regulating Nod‑like receptor pyrin domain3 inflammasome,and to explore the feasibility of this decoction combined with levofloxacin in the treatment of complex urinary tract infection caused by drug resistant bacteria.Methods:SD rats were divided into five groups:sham group,model group,levofloxacin group(Lev group),levofloxacin+Fuzheng Qingre Tonglin decoction group(FZ+lev group),and Fuzheng Qingre Tonglin decoction group(FZQRTL group).After the experiment,urine was taken for bacterial culture to determine the urinary tract infection of rats in each group;HE staining was used to observe the pathological changes of kidney and bladder tissues in rats;The expression of NLRP3 in kidney and bladder tissues was detected by immunohistochemistry;The expression of IL‑1βand IL‑18 in serum of rats was detected by ELISA;The expressions of NLRP3,ASC and Caspase‑1 were detected by Western blotting.Results:The positive rate of urine bacteria culture in the sham group was 0%,the positive rate of urine bacteria culture in the model group was 100%;and the positive rate of urine bacteria culture in the FZ+lev group was 37.50%,which was statistically different from that in the model group(P<0.05).A large number of inflammatory cells were observed in the kidney and bladder tissues of the model group by HE staining,while the number of inflammatory cells in the kidney and bladder tissues of the Lev group and FZQRTL group was significantly reduced compared with that of the model group.The FZ+lev group in the number and structure of inflammatory cells in kidney and bladder were similar to the sham group.The NLRP3 immunohistochemistry of kidney and bladder tissue in FZ+lev groups and FZQRTL groups was significantly different from that in model group(P<0.001).The levels of IL‑1βand IL‑18 in serum of Lev group,FZQRTL group and FZ+lev group were significantly decreased by ELISA compared with model group(P<0.001).The levels of IL‑1βand IL‑18 in the FZ+lev groups were significantly lower than in the Lev group and FZQRTL group,and the differences were statistically significant(P<0.05).The protein expressions of NLRP3,ASC and Caspase‑1 in the Lev group,FZQRTL group and FZ+lev group were significantly lower than those in the model group(P<0.001).The protein expressions of NLRP3,ASC and Caspase‑1 in the FZ+lev groups were significantly lower than in the Lev group and FZQRTL group,and the differences were statistically significant(P<0.05).Conclusions:"Fuzheng Qingretonglin"decoction may have a protective effect on the kidney and bladder of rats with complex urinary tract infection caused by drug‑resistant Escherichia coli by inhibiting the activation of NLRP3 inflammatory bodies,and TCM combined with levofloxacin has a better therapeutic effect than TCM or levofloxacin alone.