Effects And Mechanism Of CuO Nanoparticles On Energy Metabolism Of Human Hepatocellular Cells HepG2 And Zebrafish

In recent years,nanomaterials have a good development prospect.Because of their superior performance compared with traditional materials,they are widely used in various industries such as medical treatment,environmental protection,science and technology,cosmetics,etc.Therefore,in this paper,human hepatoma cell HepG2cells and zebrafish were used as experimental models for in vitro and in vivo experiments,to systematically study the effects of nano copper oxide(CuO NPS)on energy metabolism and its mechanism,and the following conclusions were obtained:1.In order to explore the effect of CuO NPs on energy metabolism of HepG2cells,HepG2 cells were exposed to different concentrations of CuO NPs.The results showed that(1)the glucose consumption in the culture medium decreased significantly after exposure to CuO NPs,and the intracellular glycogen also decreased significantly.Further real-time quantitative PCR(RT-q PCR)experimental results showed that the expression of glucose transporter(GLUT1)was down-regulated,but the expression increased at 4 mg·L^-1and 8 mg·L^-1;the key to glycolysis is the rate-limiting enzymes pyruvate kinase(PKM)and phosphofructokinase(PFK2)have similar expressions.Compared with the control group,the gene expression after exposure was down-regulated,but PFK2 increased significantly at high concentrations;The expression of the gluconeogenesis pathway related gene fructose-6-phosphate kinase(g6pc)decreased significantly;while the rate-limiting enzyme isocitrate dehydrogenase(IDH2)during the citric acid cycle was significantly increased at 8 mg·L^-1,compared with the control group Up-regulated about 3 times;the expression of glycogen synthase kinase 3?(gsk3?),a gene related to glycogen synthesis,increased,and the expression of glycogen synthase 2(gys2)increased significantly at 1 mg·L^-1;The expression of glycogen phosphorylase(PYGL),a gene related to proteolysis,was significantly down-regulated.In short,CuO NPs exposure reduced the absorption of extracellular glucose by HepG2 cells,interfered with the synthesis and decomposition of intracellular glycogen,and inhibited glycolysis and gluconeogenesis.(2)After exposure to CuO NPs,the content of triglyceride(TG)in HepG2 cells was significantly reduced,liver lipase(LIPC),carnitine palmitoyltransferase 1?(CPT1?),acyl-Co A oxidase(ACOX),fatty acid synthase(FASN)expression was significantly up-regulated.In short,CuO NPs inhibited lipid metabolism in HepG2 cells.(3)After exposure to CuO NPs,the intracellular ATP content decreased significantly,the mitochondrial membrane potential gradually decreased,and the expression of related primers changed,causing mitochondrial dysfunction and affecting the energy metabolism of HepG2 cells.2.The adult zebrafish were exposed to different concentrations of CuO NPs(CK,10,50,100 mg·L^-1),and the exposure time was divided into 15 d and 30 d.At the end of the experiment,samples were collected to determine the relevant indicators.The study found that the results at the two time points were consistent.Exposure of CuO NPs to zebrafish liver caused varying degrees of damage,including inflammation and cell vacuolation.After exposure,insulin and glucagon in each treatment group increased,inhibiting glycolysis.At the same time,zebrafish liver glycogen and pyruvate content decreased,glycolysis-related genes pyruvate kinase(pklr),glycogen synthesis gene(gys2)expression was significantly down-regulated,and gluconeogenesis-related gene glucose-6-phosphatase(g6pc)was significantly down-regulated Up.In short,zebrafish liver is damaged after CuO NPs exposure,and glucose metabolism is significantly affected.3.Lipid metabolism is also an important part of energy metabolism.Based on the above experiments,the effect of CuO NPs on zebrafish lipid metabolism was studied.The results showed that the content of triglycerides(TG)in the liver decreased significantly,which was consistent with the results of oil red O stained sections;the expression of liver lipase(LIPC),which catalyzes the decomposition of TG,decreased significantly,and the glycerol-3-phosphate acyltransferase(gpat3)expression is first down-regulated and then up.In short,CuO NPs exposure will affect liver lipid metabolism.In summary,this study found that CuO NPs can disrupt the energy metabolism of HepG2 cells;damaged the liver of zebrafish and caused disorders of glucose and lipid metabolism.This study verified the metabolic toxicity of CuO NPs and provided data for the development of environmental pollutant emission standards.