Effects And Mechanisms Of Subchronic Exposure To Nano-copper On Renal Cytochrome P450s In Rats

Cu Nanoparticles?Cu NPs?has gradually been used as a feed additive.The toxic target organs of Cu NPs are mainly liver,kidney and spleen,and Cu NPs enters into the body,resulting in stress reaction,inflammatory reaction and tissue damage.However,there are few reports on the changes and mechanisms of cytochrome P450 enzymes?CYP450s?in tissues caused by chronic Cu NPs poisoning.This topic focused on the interaction and mechanism of Cu NPs-renal CYP450s.By studying the dynamic characteristics of Cu NPs with different particle sizes,it was found that the kidney was the accumulating organ and the target organ of toxic action of Cu NPs.In order to further explore whether Cu NPs affects the expression and activity of renal CYP450s through its toxic effects.The 28 d subchronic exposure model was established by continuous perfusion of 80-100 nm Cu NPs,study on the effect of Cu NPs subchronic exposure on rat kidney function,tissue pathology,oxidation/nitriding factors and cytokines,Finally,the mRNA expression,protein expression,in vitro activity of CYP450s and signal pathway related protein expression in kidney were detected by quantitative real-time PCR?RT-PCR?,Western Blot,“Cocktail”probe drug and luminex technology multiplex assay,respectively.To further analyze the mechanism of Cu NPs affecting the expression and activity of CYP450s in the kidney.The results are as follows:1.The pharmacokinetics of Cu NPs in ratsThere was no significant difference in the distribution of Cu NPs and Cu²⁺in the organs,organs of Cu NPs reached no delayed effect,and determine the liver and kidney are the main organs of Cu NPs that is most distributed and may accumulate.2.Study on the toxicity of Cu NPs on rat kidney?1?Effects on kidney:Cu NPs 200 mg/kg subchronic exposure could significantly increase urea?UREA?and creatinine?CREA?level?p<0.05?,weight significantly decreased,kidney and kidney index increased significantly?p<0.01?,and had significant pathological damage effect?p<0.05?.?2?Effect of stress responses:Cu NPs 200 mg/kg could increase the glutathione peroxidase?GSH-Px?,superoxide dismutase?SOD?,total antioxidant capacity?T-AOC?and malondialdehyde?MDA?levels?p<0.01?,also significantly increased nitric oxide?NO?and inducible nitric oxide synthase?iNOS?expressions,and there are dose dependent?p<0.01?.?3?Effects of cytokines:Cu NPs 200 mg/kg could significantly increase the expression levels of inflammatory cytokines such as IL-2,interferon?IFN?-gamma,tumor necrosis factor?TNF?-A and chemokines?MIP?-1 alpha?p<0.01?.3.The effect of Cu NPs on renal CYP450sCu NPs could significantly reduce the mRNA expression and protein expression of CYP2C11,CYP2D6 and CYP3A1?p<0.01?,and inhibit the activity of all the subtypes of renal CYP450s in vitro?p<0.01?.4.The study of the mechanism of Cu NPs on renal CYP450sCu NPs could significantly decrease the aryl hydrocarbon receptor?AhR?,constitutive androstane receptor?CAR?and pregnane X receptor?PXR?protein expression levels?p<0.05?;Cu NPs significantly increased total protein and phosphorylation levels of CREB,p70S6K,JNK,Akt and STAT3?p<0.05?,and significantly increased NF-?B,P38,and STAT5 phosphorylation levels?p<0.05?.Showed that Cu NPs can activate the signaling pathways associated with inflammation.In conclusion,Cu NPs had strong toxic effects on rat kidney,could significantly affect the expression and activity of renal CYP450s.It is speculated that Cu NPs can cause stress and inflammatory reaction after entering the body,through the cascading of signal pathways and the network of intracellular active molecules,thereby affecting the normal expression and function of CYP450s.