补体C3a受体在尿路感染小鼠膀胱和肾脏中的表达及意义分析  

Analysis of expression and significance of C3aR in bladder and kidney of mice with urinary tract infections

作　　者：邵静 陈婉冰 曹博 赵淑娟[2] 韩锦[2] 李可[1] 武坤毅 SHAO Jing;CHEN Wanbing;CAO Bo;ZHAO Shujuan;HAN Jin;LI Ke;WU Kunyi(Core Research Laboratory,The Second Affiliated Hospital,Xi'an Jiaotong University,Xi'an 710004,China;Department of Nephrology,The Second Affiliated Hospital,Xi'an Jiaotong University,Xi'an 710004,China)

机构地区：[1]西安交通大学第二附属医院科研中心实验室,陕西西安710004 [2]西安交通大学第二附属医院肾病科,陕西西安710004

出　　处：《中国病理生理杂志》2023年第8期1383-1389,共7页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81900620);陕西省自然科学基础研究计划项目(No.2020JQ-536)。

摘　　要：目的:研究补体C3a受体(C3aR)在尿路感染模型小鼠膀胱和肾脏的表达与分布。方法:将雌性C57BL/6小鼠随机分为正常对照组,以及3、6、24和48 h感染组,每组8~10只。采用逆行推注人型大肠杆菌J96建立小鼠尿路感染模型。平板涂布计数法检测小鼠膀胱和肾脏细菌负荷量;HE染色评估膀胱和肾脏病理损伤程度;ELISA检测肾组织肾脏损伤分子1(KIM-1)和尿液中C3a水平;蛋白印迹和免疫荧光检测C3aR在膀胱和肾脏的表达与分布。结果:感染24 h时小鼠膀胱细菌负荷量达到峰值,48 h时细菌量下降;感染6 h时小鼠肾脏中细菌负荷量最高,随着感染时间延长逐渐减少。感染后,膀胱病理表现为移行上皮细胞脱落,黏膜和固有层炎症细胞浸润;肾脏病理表现为肾小球萎缩,肾小管上皮细胞损伤,肾小管间质炎症细胞浸润及肾盂处组织脱落。感染后肾脏KIM-1显著增加,尿液中C3a水平升高。蛋白印迹结果显示,感染后膀胱和肾脏C3aR蛋白水平升高。免疫荧光分析显示,C3aR在正常膀胱上皮细胞有少量表达,感染后在上皮细胞大量表达,在深层肌肉组织有少量表达;C3aR在正常肾皮质的肾小球和髓质的实质细胞有少量表达,感染后在肾小球、肾小管间质以及髓质的炎症浸润细胞中大量表达。结论:小鼠尿路感染过程中C3a-C3aR信号激活,C3a在尿液中表达升高,C3aR在膀胱和肾脏中表达上调,炎症细胞表达的C3aR参与小鼠尿路感染进程并发挥作用。AIM:To investigate the expression and distribution of C3a receptor(C3aR)in the bladder and kidney of mice with urinary tract infections(UTIs).METHODS:Female C57BL/6 mice were randomly divided into 5 groups,including normal group,and 3,6,24 and 48 h infection group,with 8 to 10 mice in each group.The model of UTIs in the female mice was established by bladder inoculation with uropathogenic Escherichia coli J96.Bacterial load in bladder and kidney tissues was measured by plate assay.Bladder and kidney histopathology were assessed by hematoxylineosin(HE)staining.Levels of kidney injury molecule-1(KIM-1)in the kidney supernatants and C3a in the urine were determined using ELISA kits.The expression and distribution of C3aR were assessed by Western blot and immunofluorescence.RESULTS:The maximum bacterial load in the bladder was achieved at 24 h and the bacterial load decreased at 48 h.Meanwhile,the bacterial load in the kidney peaked at 6 h and gradually declined from 24 to 48 h with the time extension.After infection,the histopathology of the bladder showed shedding of transitional epithelial cells and infiltration of inflammatory cells in mucosa/lamina propria.The histopathology of the kidney showed injury of renal tubule epithelial cells,infiltration of renal tubule interstitial cells and shedding of renal pelvis tissue.Expression of KIM-1 in kidney was significantly increased and C3a in urine was increased after infection.Western blot results revealed a significant increase in C3aR expression in infected bladder and kidney tissues compared with normal tissues.Immunofluorescence analysis revealed that the C3aR protein was observed in a limited quantity within normal bladder epithelial cells.However,there was a significant increase in C3aR expression after infection,which could be detected in numerous bladder epithelial cells as well as deep muscle tissue.Expression of C3aR was presented in a limited number of glomerular and medullary parenchymal cells in normal kidney.However,C3aR expression was up-regulated in a s

关 键 词：尿路感染 过敏毒素 C3a受体 炎症 

分 类 号：R691.3[医药卫生—泌尿科学] R392[医药卫生—外科学] R378.21[医药卫生—临床医学]