| Non-alcoholic fatty liver disease(NAFLD)has become one of the leading causes of chronic liver diseases in the world.Studies have shown that 25%-45% of pop?Lation in worldwhild suffers from NAFLD,which is the main factor of liver cancer and the first cause of liver transplantation[1,2].As a metabolic disease which excludes liver damage caused by the abuse of alcohol and other determinants,NAFLD is a clinical syndrome with the basic features of diffused accum?Lation of lipids in liver cells and inflammatory infiltration in liver tissue.NAFLD expresses pathological changes including simple fatty liver(SFL),non-alcoholic steatohepatitis(NASH),and related liver fibrosis [3].At present,the treatment of NAFLD is mainly based on appropriate physical exercise,weight loss and improvement of dietary nutrition composition.Currently,there is no approved-dr ?g treatment by FDA or CFDA targeting to its pathogenesis[3,4].Altho ?ght there have been a lot of basic and clinical researches on NAFLD,the pathophysiological mechanisms of NAFLD have not been f?Lly clarified yet.As the most trace metal in human body,iron involves in oxygen transportation,DNA synthesis,energy metabolism and other important physiological activities[5].Iron deficiency is one of the most common diseases in the world,which may res?Lt in fungal infection and anemia[6,7].But at the same time,iron is also the most important promoter in lipid peroxidation which can produce highly reactive and destructive ROS to damage cells and organs thro ?gh Fenton reaction[8].Therefore,both iron deficiency and iron overload will injure cells.Ferroptosis is a newly discovered iron-dependent programmed cell death,which is associated with oxidative stress and lipid peroxidation.Morphologically,ferroptosis is characterized by plasmalemma blistering,mitochondrial shrinking,mitochondrial cristae decreasing or even disappearing,double-layer membrane structure density increasing,and intracell?Lar ROS production increasing[9].The occurrence of ferroptosis is closely related to the decrease of intracell?Lar glutathione(GSH)and the decline of Glutathione peroxidase(GPX4)activity,for the decrease of intracell?Lar GSH can weaken the cell defense of GPX4 against the toxic effects which is caused by ROS[10]?Liver tissue is the main site for iron storage and lipid metabolism,and NAFLD is a chronic metabolic liver disease with both liver damage and lipid accum?Lation.So iron overload maight closely relate to NAFLD.A studie has shown that mild to moderate hepatic iron overload may exist in various chronic liver diseases including NAFLD[11].The restriction of iron intake in dietary leads to low iron in liver tissues,which can reduce inflammation and fibrosis in livers of NAFLD mice[12].Therefore,we attempted to reduce iron overload in the liver of NAFLD mice with deferiprone(DFP),an iron chelator,and to verify whether DFP can alleviate NAFLD from the perspective of inflammation,fibrosis,oxidative stress,and ferroptosis.Methods:The experimental mice were divided into three groups including the Chow group,the HFD group and the HFD + DFP group.And each group was more than 6 mice respectively.The Chow group was fed with ordinary feed for 16 weeks,and the HFD group was fed with high-fat feed for 16 weeks.In the HFD + DFP group,the mice were fed with high-fat diet for 14 weeks,and then fed with high-fat diet and gavaged with DFP for 2 weeks.The dose of DFP was 100 mg/kg/d.After NAFLD modeling was completed,the mice of each experimental group were dissected to obtain serum and liver tissue of each sample.1.First,we evaluated the effect of DFP on liver tissue morphology in the NAFLD experimental animal model,and NAS scores was then assessed.By comparing the degree of hepatocyte ballooning,lipid vacuoles,inflammatory cell infiltration and NAS score between the HFD group and the HFD + DFP group and the NAS score,whether DFP can reduce liver damage in NAFLD,improve liver tissue morphology and reduce the possibility of suffering from NASH can be judged.2.Secondly,the effect of DFP on inflammatory response in liver tissue of NAFLD mice was detected,which can be proved by comparing the res?Lt of the level of inflammatory factor indicators such as TNF-?,IL-6,IL-1?,MCP-1,and CD68.3.Next,the effect of DFP on liver fibrosis in NAFLD mice was detected.Masson staining,Sirius red staining,and ?-sma immunohistochemical staining of liver paraffin sections were selected to identify whether DFP can clearly improve the live fibrosis in NAFLD.4.Then,the effect of DFP on liver oxidative stress in NAFLD experimental animal model was examinated.According to the levels of hydrogen peroxide,MDA,and ROS in liver tissue of each group,the changes of oxidative stress in three groups can be clear.Whether DFP may significantly chang the level of oxidative stress in NAFLD mice can be comfirmed by comparing the relative parameters in the HFD + DFP group and the HFD group.5.The effect of DFP on iron overload in liver tissue of NAFLD mice was subsequently examined.We examined the levels of Transferrin,Ferritin and total liver iron content in each experimental group.By comparing the above indicators between the HFD group and the Chow group,whether there is iron overload in NAFLD can be confirmed.Meanwhile,we can determine whether DFP can relieve iron overload in liver of NAFLD mice by comparing the HFD group with the HFD + DFP group.6.Finally,we expored the effect of DFP on ferroptosis in the liver tissue of NAFLD mice.As important markers of ferroptosis,the level of ACSL4,ALOX15,and GPX4 was selected to confirm if there is a correlation between NAFLD and ferroptosis.As well,we can preliminary judged whether DFP can significantly improve ferroptosis in liver tissue.Results:1.Compared with Chow group,HFD group mice showed more serious hepatic cell ballooning,lipid droplet vacuoles,inflammatory cell infiltration and higher NAS score.The HFD + DFP group mice displayed significantly redcued hepatic cell ballooning,lipid droplet vacuoles,inflammatory cell infiltration and lower NAS score than the HFD group did.2.The HFD group mice displayed higher level of IL-6,IL-1?,TNF-?,MCP-1,and CD68 in liver tissue than the Chow group mice did.Meanwhile,compared with the HFD group,the HFD+DFP group mice showed decreased protein levels of IL-6,IL-1?,TNF-?,MCP-1,and CD68.3.According to the res?Lts of Masson staining,Sirius red staining,and ?-SMA immunohistochemical staining,the HFD+DFP group displayed more reduced fibrosis in liver tissue than the HFD group.4.The rus?Lts show that the levels of ROS,hydrogen peroxide,and MDA were significantly decreased in the liver tissue of the HFD+DFP mice compared with the HFD group.5.Compared with the Chow group,the HFD group mice showed higher levels of Ferritin,Transferrin and liver iron content.And compared with the HFD group,the HFD+DFP group mice showed lighter iron overload in the liver tissue.6.The level of GPX4 was lower in the liver tissue of the HFD group than the Chow group was.However,ACSL4 and ALOX15 show the opposite trend.Meanwhile,compared with the HFD group,the expression level of GPX4 was enhanced,while ACSL4 and ALOX15 were decreased in liver tissue of HFD + DFP group mice.Conclusion:1.DFP effectively impoves the histomorphology,NAS score,inflammation,hepatic fibrosis,and oxidative stress in NAFLD.2.DFP effectively relieves liver iron load and inhibits ferroptosis to improve NAFLD... |
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