| Aryl hydrocarbon receptors are ligand-dependent transcription factors of the basic helix-loop-helix family,and generally act as sensors in response to environmental changes.Some literatures have pointed out that the level of AHR is increased in the serum of patients with nonalcoholic fatty liver disease.In addition,some literatures have pointed out that AHR also regulates the metabolic activating enzyme cytochrome P4501A1(cytochrome P4501A1)and tumor necrosis factor-?(tumor necrosis factor-?)expression.CYP1A1 is a key enzyme for oxidative stress,TNF-? is a key enzyme for insulin resistance.Oxidative stress and insulin resistance are two key causes of NAFLD formation and are known as "two hits".Therefore,AHR plays an important role in the formation of NAFLD.alpha-naphthoflavone can inhibit the expression of AHR.Therefore,this study will explore the relationship between AHR and NAFLD through in vivo and in vitro experiments and whether inhibition of AHR can treat NAFLD.Objective By reviewing relevant literature published in the last decade,this study will verify the relationship between AHR and NAFLD through in vivo and in vitro experiments.Method In order to study the role of AHR in the formation of NAFLD,this study will investigate the expression changes of AHR,CYP1A1,TNF-? during the development of NAFLD through in vivo and in vitro experiments.In the in vivo experiments,the NAFLD model of C57 BL mice fed with high-fat diet was used as the research object in this experiment.In the in vitro experiments,this experiment will use oleic acid to induce human liver cancer cells(Hep G2 cells)as a model of cell lipid accumulation.1.AHR,CYP1A1,TNF-? expression changes in vivo experiments24 clean-age C57 BL male mice aged 4 weeks were purchased,weighing 20-22 g.In the experimental study of the mechanism of action of aryl hydrocarbon receptors in the formation of non-alcoholic fatty liver disease,mice fed with high-fat diet for 4 weeks were used as the NAFLD model group,mice fed with normal diet were used as the normal group,mice fed with AHR inhibitor(resveratrol)plus high-fat diet were used as inhibitor group,and AHR agonist(Benzopyrene)plus high fat diet as agonist group.In the experimental study on the therapeutic effect of non-alcoholic fatty liver disease targeting aryl hydrocarbon receptors,the normal group and the model group are the same as the above experiment,and ANF with different dosages are used as different inhibitor groups.All mice were administered by gavage.The high-fat diet was fed for four weeks and administered for four weeks.Mice were euthanized after the administration,blood was taken,and livers were taken.2.Changes of AHR,CYP1A1,TNF-? expression in vitro experimentsIn the experimental study of the mechanism of action of aryl hydrocarbon receptors in the formation of NAFLD,human liver cancer cells(Hep G2 cells)induced by oleic acid(OA)for 24 hours were used as the model group of cell lipid accumulation,and normal cells were used as the normal group.AHR inhibitor(resveratrol)was used in the experiment of aromatic receptor Add OA as inhibitor group and AHR agonist(benzopyrene)plus OA as agonist group.In the experimental study on the therapeutic effect of non-alcoholic fatty liver disease targeting aryl hydrocarbon receptors,the normal group and the model group are the same as the above experiment,ANF was selected as inhibitors of AHR,and different concentrations of ANF were used as different inhibitor groups.During the experiment,the OA stimulation time was 24 hours,and the drug stimulation time was 24 hours.In the AHR silencing experiment,normal cells were used as the control group,blank RNA was transfected into the normal group,blank RNA plus OA was used as the model group,AHR interfering RNA plus oleic acid was used as the si-RNA group,and OA stimulation time was 24 h.After the experiment,cell proteins and cell supernatants were extracted and used.Results In the experimental study of the mechanism of action of aryl hydrocarbon receptors in the formation of non-alcoholic fatty liver disease,the AST,ALT,TC,and TG contents in the serum and cells of mice were detected.The levels of AST,ALT,TC,and TG were: agonist group,model group,Inhibitor group and normal group.The protein expression results showed that the protein expression levels of CYP1A1 and TNF-? were: agonist group,model group,inhibitor group,and normal group.HE staining of mouse liver and oil red staining of cells showed the degree of fat accumulation.In turn: agonist group,model group,inhibitor group,normal group.This shows that increasing the expression of AHR aggravates liver injury,and decreasing the expression of AHR reduces liver injury.In the experimental study on the therapeutic effect of non-alcoholic fatty liver disease targeting aryl hydrocarbon receptors,the AST,ALT,TC and TG in mouse serum and cells were detected,and the content of AST,ALT,TC and TG in the model group was the highest.With the increase of drug concentration,The contents of AST,ALT,TC and TG gradually decreased.The protein expression results showed that AHR,CYP1A1 and TNF-? protein expression were highest in the model group,and the protein expression gradually decreased with the increase of drug concentration.Liver and cell staining results showed that the model group had the most fat accumulation,which gradually decreased with increasing drug concentration.In the AHR cell silencing experiment,the contents of AST,ALT,TC and TG in the model group were higher than those in the siRNA group.The protein expression results showed that the expressions of AHR,CYP1A1 and TNF-? proteins in the model group were higher than those in the si-RNA group.Oil red staining results showed that the lipid accumulation in the model group was higher than that in the si-RNA group.Therefore,it can be said that inhibition of AHR expression can reduce liver damage.Conclusion This study indicates that AHR affects the development of NAFLD by regulating the expression of CYP1A1 and TNF-?.Explain that AHR plays a key role in the formation of NAFLD. |
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