Oxidative Stress Mediates Renal Endothelial Cell Damage In Mice Induced By Trichloroethylene Sensitization

Background:Trichlorethylene is volatile organic solvent.workers who were exposed to TCE for long-term may suffer from ODMLT.It is generally believed that ODMLT is a delayed type hypersensitivity mediated by T lymphocytes,but it can not fully explain the pathogenetic process.some patients have severe kidney damage.It's one of the main causes of high fatality rate.It indicated that there may be other pathogenesis for ODMLT,especially the mechanism of renal injury.Studies have shown that human and mice have an increase in oxidative stress after exposure of low concentrations TCE for a long-term.It suggests that renal oxidative stress may be one of the main causes of kidney damage,some studies show that the oxidative stress is closely related to the expression of endothelial cell related adhesion molecule,high expression of adhesion molecule can aggravate the damage of organs.In this study,the oxidative stress of sensitized mice was regulated by intraperitoneal injection of Tempol,try to explain the role of oxidative stress in the renal endothelial injury of TCE-sensitized miceObjective: We want to discuss the role of oxidative stress in the renal endothelial injury of TCE-sensitized mice by detecting their expression levels in kidney of mice after intraperitoneal injection of Tempol.Methods: Forty female BALB/c mice(6-8weeks old)were randomly divided in to blank group(n=5),solvent group(n=5),TCE group(n=15),and TCE+Tempol group (n=15).We ues TCE to bulid the sensitized mice model,the mice in the TCE+Tempol group were given intraperitoneal injection of Tempol 30 min before last challenge treatment.After 24 h of last challenge,we separated mice into sensitized groups and non-sensitized groups by mice skin reactions score.We take blood in eyeball and kideny from killed mice after 72 h of last challenge.Then we detected the levels of Cre and BUN in serum.Histological damage of renal was observed by HE staining.The expressions of e NOS,VCAM-1,ICAM-1 and E-selectin were observed by immunohistochemistry,the levels of NOS,NO,SOD,MDA were detected by commercial kit.The expressions of protein VCAM-1,ICAM-1 and E-selectin in kidney were detected by Western Blot.The levels of transcription of gene ICAM-1,E-selectin and ICAM-1 were detected by RT-PCR.Results: 1 Sensitization : There was no skin erythema or edema in the blank group and the solvent group.The sensitization rate was 40%(6/15)in the TCE treatment group and 33.3%(5/15)in the TCE+Tempol treatment group,with no statistical differences(P>0.05).2 Detection of renal function: The serum levels of Cre and BUN had no statistical difference among blank group,solvent control group and non-sensitized group.Compared with solvent group,the serum levels of Cre and BUN in two sensitized group were increased(P<0.05).Compared with TCE+Tempol sensitized group,the serum levels of Cre and BUN in TCE sensitized group were higher(P < 0.05).3 Kidney pathology: There was no significant renal pathological change in the blank,solvent and non-sensitized groups.Large-area vacuole degeneration and epithelial cell dissolution were found in renal tubules in the TCE sensitized group.However,there were smaller area in TCE+Tempol sensitized group,Compared with TCE sensitized group,the injure in TCE+Tempol sensitized group was alleviated.4 Kidney NO/NOS/SOD levels: There was no statistical significant difference of the levels of NO,NOS and SOD among blank group,solvent group and non-sensitized group.Compared with solvent group,TCE and TCE+Tempol sensitized group had lower levels of NO,NOS and SOD.Compared with TCE+Tempol sensitized group,TCE sensitized group had lower levels of NO,NOS and SOD,the difference was statistically significant(P<0.05).5 Kidney MDA levels: There was no statistical significant difference of MDA levels among blank group,solvent group and non-sensitized group.Compared with solvent group,TCE and TCE+Tempol sensitized group had higher levels of MDA.Compared with TCE+Tempol sensitized group,TCE sensitized group had higher levels of MDA,the difference was statistically significant(P<0.05).6 Detection of renal e NOS deposition: The Renel immunohistochemical assay results showed the higher expression of e NOS of renal tubules in blank group,solvent group,and the non-sensitized group than in TCE-sensitized group;low expression of e NOS of renal tubules and glomerular in TCE+Tempol sensitized group.7 Kidney E-selectin/VCAM-1/ICAM-1 protein levels: The renel assay showed higher expression of E-selectin,VCAM-1 and ICAM-1 in TCE and TCE+Tempol sensitized group than in all non-sensitized group,and they were higher in the former than in the latter. 8 Kidney E-selectin/VCAM-1/ICAM-1 transcription level: There was no statistical difference in transcriptions of genes E-selectin,VCAM-1 and ICAM-1 among blank group,control group,and non-sensitized group.The transcriptions of genes E-selectin,VCAM-1 and ICAM-1 were higher in TCE sensitized group and TCE+Tempol sensitized group than in solvent group,and they were higher in the former than in the latter(P<0.05).There was no difference of transcriptions of VCAM-1 and ICAM-1 between TCE and TCE+Tempol sensitized group.Conclusions: 1 The levels of some oxidative stress related indictors are increase in TCE-sensitized kidney,TCE-mediated kidney injury is related to oxidative stress.2.Intraperitoneal injection of Tempol to relieve TCE-mediated renal injury by reducing oxidative stress in the kidneys.3 Compared with TCE sensitization group,the expression of adhesion molecule in TCE+Tempol sensitized group was decreased,oxidative stress can reduce renal endothelial cell damage.4 There was no difference of transcription of ICAM-1 and VCAM-1 between the two sensitized groups.It is suggests that Tempol decreases the expressions of both these proteins not by decreasing the transcriptions of ICAM-1 and VCAM-1.