Study On Effects Of Perchlorate On Lipid Metabolism In Liver Of High-fat Diet Mice

Perchlorate is a persistent inorganic pollutants,which is not easy to degrade in the environment,and has high water-solubility,diffusivity and stability.This property leads to the widespread existence of perchlorate in the world and perchlorate pollution has become a global environmental problem.Some studies believe that the occurrence of disease needs to meet two conditions,the first is the body develops fatty denaturation,the second is the contact with the source of triggering oxidative stress.With the improvement of living standard and excessive intake of lipids in their diet,the problem of overweight and obesity is becoming more and more serious.Sub-healthy people are more susceptible to disease.Many studies have reported that low doses of perchlorate do no harm to the normal body,but what about when the body consumes too much lipid? Therefore,this study took the global excessive lipid intake as the research background,combined with LC-MS/MS technology to conduct targeted lipidomics approach,to explore the effects of perchlorate on liver lipid metabolism in mice under the condition of high lipid diet.Methods:(1)Forty-eight C57BL/6J male mice were divided into 4 groups with 12 mice in each group.They were fed a high-fat diet containing 10% fat and were fed with 0 mg/kg,0.1mg/kg,1 mg/kg and 10 mg/kg perchlorate,respectively.The effects of perchlorate on lipid metabolism in liver of high-fat mice were evaluated by comparing the body weight,organ coefficient,AST and ALT activities,TC,TG,HDL,LDL and MDA contents in serum,and glucose tolerance in different groups of mice.(2)The activities of CPT-1,ACC and Fas,the composition and relative content of fatty acids in liver of mice were determined.(3)LC-MS/MS was used to study the targeted lipidomics in the liver of high-fat mice exposed to perchlorate.After data processing,the substances with significant changes were found and their metabolic pathways were analyzed to explore the effects of perchlorate on lipid metabolism in the liver of high-fat mice from the perspective of lipidomics.Results:(1)By analyzing the liver organ coefficient,oil red O staining,HE staining and routine indexes in serum of experimental mice,it was found that there was no significant difference between the high-fat mice exposed to 0.1 mg/kg perchlorate and the control group,indicating that 0.1 mg/kg perchlorate had no effect on lipid metabolism of mice.Serum indexes and staining sections were observed.Compared with the control group,the contents of TC,TG,HDL,LDL and MDA in serum of mice fed with 1 mg/kg and 10 mg/kg perchlorate increased,and lipid accumulation in liver was obvious.When the dose of perchlorate is greater than 1mg/kg,it can cause liver damage in high fat mice,and 10 mg/kg perchlorate has more significant effect on the health of mice.(2)The composition and relative content of fatty acids in mouse liver were analyzed.By analyzing the activity levels of CPT-1,ACC and Fas,it was found that perchlorate may promote the synthesis of fat.With the increase of perchlorate concentration,the levels of C16:0,C17:0,C18:0,C20:4 and C22:6 showed a downward trend,while the levels of C16:1,C18:1 and C18:2 showed an upward trend.On the overall level,SFA showed a downward trend while UFA showed an upward trend.(3)LC-MS/MS was used to study the targeted lipidomics in the liver of hyperlipidemic mice.To establish a method for the simultaneous determination of PG,PC,LPC,PE,SM and TG lipids,and to verify the reliability of the method.Of the 35 lipid metabolites detected,25 of the target metabolites showed significant differences in the three experimental groups compared with the control group.The PG(16:0/16:0),PG(18:2/20:3),PG(16:0/18:2),PG(18:0/18:1),LPC(22:6/0:0),LPC(20:0/0:0),LPC(20:1/0:0),LPC(20:4/0:0),PC(18:1/14:1),PC(2:0/15:1),PC(18:0/14:0),PC(22:1/14:0),PC(3:0/16:0),PC(6:0/13:1),PC(14:0/14:0),PE(20:3/15:0),PE(18:0/18:2),SM(d18:1/16:0),SM(d18:1/19:0),SM(d18:1/16:0),SM(d15:3/24:0),SM(d18:1/24:2),TAG(54:4/FA18:1),TAG(50:2/FA16:0),TAG(54:4/FA18:2),TAG(54:5/FA18:1),TAG(54:5/FA20:4),TAG(54:5/FA18:2),TAG(52:5/FA18:3),TAG(52:4/FA16:0),TAG(52:4/FA16:1),TAG(54:3/FA18:1),TAG(52:2/FA16:0),TAG(52:2/FA18:1)and TAG(52:5/FA18:1).PG and TAG were up-regulated in the three experimental groups.Some PC and PE are upregulated,and some are down-regulated.LPC was down-regulated compared with control group.The results showed that perchlorate mainly affected the glycerolipid metabolism pathway in the liver of C57BL/6J high-fat mice.