[Effect of complement C5a on the expression of MCP-1 and NGAL in immune kidney injury of trichloroethylene sensitized mice].

Objective: To explore the possible role of C5a in the pathogenesis of renal injury in TCE- sensitized mice, to analyze the impact of expression of neutrophil gelatinase-associated lipocalin (NGAL) and monocyte chemotactic protein-1 (MCP-1) in the presence or absence of C5a receptor antagonist (C5aRA) pretreatment. Methods: A total of 50 female specific pathogens free(SPF) BALB/c mice were randomly divided into blank control group (n=5) , solvent control group (n=5) , TCE group (n=20) , and TCE+C5aRA group (n= 20) . After one week for adaptive feeding, a mouse model of TCE-induced skin sensitization was established by treating with 50% TCE and 30% TCE in turn. The mice in solvent control group accept same reagents without TCE and the mice in blank control group underwent nothing. In TCE +C5aRA group, except for the TCE solution treatment, mice were intraperitoneally injected with 0.5 mg/kg C5aRA solution at the time of challenge. And the skin erythema and edema reaction were scored 24 h after the last challenge. The mice were divided into sensitization positive group and sensitization negative group according to the scoring result. The mice were aseptically sacrificed 72 h after the last challenge to obtain the kidneys. The structural damage of kidney was observed after histopathological staining. The levels of NGAL and MCP-1 mRNA and proteins were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) , respectively. Results: The sensitization rate of mice in TCE group and TCE+C5aRA group was 45.0% (9/20) and 40.0% (8/20) , respectively. No skin lesions was found in the mice of blank control group and solvent control group. The results of histopathological staining showed that the TCE sensitization positive mice showed renal tubular dilatation, vacuolar degeneration of renal tubular epithelial cells, and infiltration of interstitial cells. The pathological damage of the kidney in TCE sensitization positive group was mild, and no inflammatory cell infiltration was seen. The data of qRT-PCR showed that the expression levels of NGAL and MCP-1 mRNA in the TCE sensitization positive group were significantly increased than in solvent control group and TCE sensitization negative group (P<0.05) , while the levels of NGAL and MCP-1 mRNA in TCE+C5aRA sensitization positive group were decreased than TCE sensitization positive group (P <0.05) . The results of IHC showed that the expression levels of NGAL and MCP-1 in TCE protein sensitization positive group were significantly higher than those in solvent control group and TCE sensitization negative group (P<0.05) . After C5aRA pretreatment, the expression levels of NGAL and MCP-1 protein were decreased than the mice in TCE sensitization positive group (P<0.05) . Conclusion: The regulation of C5a on the expression of MCP-1 and NGAL may participate in TCE- induced mice kidney damage, and pharmacological inhibition of C5a seems to be an effective way to protect the kidney injury in TCE-sensitized mice.目的： 分析补体片段5a(C5a）信号阻断对三氯乙烯（TCE）致敏小鼠肾脏损伤过程中中性粒细胞明胶酶相关脂质运载蛋白（NGAL）和单核细胞趋化蛋白-1(MCP-1）表达的影响，探讨C5a在TCE致敏小鼠免疫性肾脏损伤过程中的可能作用。 方法： 无特定病原体（SPF）级雌性BALB/c小鼠共50只，随机分为空白对照组（n=5）、溶剂对照组（n=5）、TCE处理组（n=20）、TCE+C5aRA联合处理组（n= 20）。依次用体积分数为50%和30% TCE溶液处理小鼠，建立TCE经皮致敏BALB/c小鼠模型为TCE处理组；溶剂对照组使用除TCE以外的其他试剂处理；空白对照组不做任何处理；TCE+C5aRA联合处理组小鼠在激发前2h腹腔注射0.5 mg/kg C5aRA溶液，其他处理同TCE处理组。于末次激发后24 h根据小鼠皮肤红斑和水肿反应评分结果将小鼠分为致敏阳性组和致敏阴性组。于末次激发后72 h无菌处死动物，分离小鼠肾脏，通过组织病理学染色观察小鼠肾脏结构损伤，分别采用实时荧光定量反转录聚合酶链反应（qRT-PCR）和免疫组化（IHC）的方法检测NGAL和MCP-1 mRNA及蛋白水平的改变。 结果： TCE处理组和TCE+C5aRA联合处理组小鼠致敏率分别为45.0%（9/20）和40.0%（8/20），空白对照组和溶剂对照组小鼠未见明显皮肤损害。组织病理学染色结果显示，TCE致敏阳性组小鼠可见明显的肾小管扩张，肾小管上皮细胞空泡变性，部分有间质炎细胞浸润；联合处理致敏阳性组小鼠上述病理损伤较轻，未见炎细胞浸润。qRT-PCR结果显示，TCE致敏阳性组小鼠肾脏中NGAL和MCP-1 mRNA表达水平均明显高于溶剂对照组和TCE致敏阴性组（P<0.05）；联合处理致敏阳性组小鼠肾脏中NGAL和MCP-1 mRNA表达水平均明显低于TCE致敏阳性组（P<0.05）。IHC结果显示，TCE致敏阳性组小鼠肾脏中NGAL和MCP-1蛋白表达水平均明显高于溶剂对照组和TCE致敏阴性组（P<0.05），联合处理致敏阳性组小鼠肾脏中NGAL和MCP-1蛋白表达水平均明显低于TCE致敏阳性组（P<0.05）。 结论： C5a可能通过影响NGAL和MCP-1的表达参与TCE致敏小鼠肾脏损伤，抑制C5a可能是保护TCE所致的免疫性肾脏损伤的有效手段。.