Dynamic Effect Of Intermittent Fasting On Cell Pyroptosis With NASH Induced By High Fat And High Cholesterol In Rats

Background:Liver damage is a typical manifestation of nonalcoholic steatohepatitis(NASH).It originates from excessive cholesterol and fat accumulation,leading to hepatocyte inflammation,fibrosis and death.Pyroptosis plays an important role in the development of NASH.Thus,it is important to elucidate the effect of cholesterol and lipid accumulation on pyroptosis.Intermittent Fasting(IF)is a form of eating that uses short-term fasting to control the diet and promote overall health.It can reduce lipid accumulation in the liver,however,the mechanisms underlying these effects are unknown.Objective:To investigate the dynamic effect of Intermittent Fasting on cell pyroptosis with NASH induced by high fat and high cholesterol in rats.Methods:One hundred and twenty SD rats were randomly divided into the control group(CON group),high-fat and high-cholesterol-fed NASH model group(HFC2 group and HFC5group),and Intermittent Fasting group,namely IFCON group(feeding normal diet for 12 hours and then fasting for 36 hours,this feeding cycle is repeated continuously),the IF HFC2(feeding HFC2 diet for 12 hours and fasting for 36 hours)group and the IF HFC5(feeding HFC5 diet for 12 hours and fasting for 36 hours)group.With 8,12 and 16 weeks passed,the body weight and liver coefficient of the rats were determined.Plasma and liver samples were collected to detect the activity of ALT,AST,TC and TG.HE and Masson staining were used to observe the pathological changes of liver.q RT-PCR and Western blot were used to detect the expression of pyroptosis-related genes and proteins such as caspase-1,GSDMD and IL-1β.Results:After 8 weeks,rats in the model group(HFC2 and HFC5)did not gain significant weight,while the Intermittent Fasting group lost weight(P<0.05).The difference of the liver coefficient between groups was almost negligible,and the morphology of rat liver and hepatocytes were normal.At the same time,no obvious difference was found in ALT,AST,TC and TG content.q RT-PCR and western blot showed that expression of Caspase-1,GSDMD and IL-1β from the NASH model group was increased compared with CON group(P<0.01).However,the contents of genes and proteins of Caspase-1,GSDMD and IL-1β in Intermittent Fasting group were lower than those in model group(P<0.01).After 12 weeks,the body weight and liver coefficient of the NASH group were increased(P<0.01)in comparison with the CON group,the IF CON group had a obvious dorp in body weight relative to the CON group(P<0.01),but there was no significant difference in the liver coefficient between these two groups.By contrast with the model group,the body weight and liver coefficient of the Intermittent Fasting group were fall(P<0.05).By contrast with CON group,liver edge of HFC2 group and HFC5 group was more round and blunt,liver of HFC5 group had a little fat,and liver shape of other groups was regular.HE and Masson staining showed that there were a few small lipid droplets in the HFC2 group,a few large lipid droplets and a few fibers in the liver of the HFC5 group,while the morphology of liver cells in the other groups was regular.The contents of ALT,AST,TC and TG in model group were multiplied in comparison with the CON(P<0.05).The contents of ALT,AST,TC and TG in Intermittent Fasting group were decreased compared with NASH model group(P<0.05).The contents of genes and proteins of Caspase-1,GSDMD and IL-1β in model group were increased(P<0.001).Compared with model group,the contents of genes and proteins of Caspase-1,GSDMD and IL-1β in Intermittent Fasting group were significantly decreased(P<0.05).After 16 weeks,compared with the control group,rats in the model group had higher body weight,higher liver coefficient,harder liver texture,and clumpy lipid accumulation.Compared with model group,all of the rats among Intermittent Fasting group had clearly lower body weight and liver coefficient,with softer liver,but no lipid accumulation(P<0.05).HE and Masson staining showed that hepatocyte steatosis and fiber deposition were observed in model group.Compared with the model group(P<0.05),hepatocytes steatosis and fibrous deposition were visibly reduced in the IF HFC2 group and IF HFC5 group(P<0.05).Different from the CON group,the contents of ALT,AST in plasma and TC and TG in liver of rats in HFC2 group and HFC5 group had grown obviously,while the contents of ALT,AST in plasma and TC and TG in liver in IF HFC2 group and IF HFC5 group were decreased(P<0.05).q RT-PCR and Western blot results showed that the contents of genes and proteins of Caspase-1,GSDMD and IL-1β in HFC2 and HFC5 groups were higher than those in normal group,and the contents of genes and proteins of Caspase-1,GSDMD and IL-1β in Intermittent Fasting group were lower than those in model group(P<0.05).Conclusion:(1)The high fat and high cholesterol diet can induce the occurrence of NASH,and the severity of NASH is positively correlated with the content and the intake time of cholesterol.(2)Intermittent Fasting can mitigate liver injury induced by high fat and high cholesterol,and can relieve NASH.(3)Intermittent Fasting can alleviate the occurrence and development of nonalcoholic steatohepatitis,and the mechanism is possibly related to the inhibition of hepatocyte pyroptosis.