The Protective Effects Of Intermittent Fasting On Hepatic Ischemia And Reperfusion And Its Mechanism

Background and objective:Currently liver ischemia and reperfusion injury is still one important reason for causing the high morbidity and mortality during liver surgery, trauma and liver transplantation.liver Ischemia and reperfusion injury is the most important determinant of liver tissue’s activity After the liver hepatectomy or liver tissue transplant.In order to more effectively reduce hepatic ischemia and reperfusion injury, the mechanisms that related to hepatic ischemia-reperfusion injury and the treatment needs to be studied in-depth.Intermittent fasting and calorie restriction can extend the life and reduce the development of age-related diseases.Intermittent fasting and calorie could inhibit oxidative stress and inflammation, and reduce the extent of damage after the liver surgery and liver transplantation, which has an important protective role in liver ischemia-reperfusion injury. short-term intermittent fasting Perhaps is a feasible strategy to reduce complications after liver surgery.In support of its clinical transformation, intermittent fasting on hepatic ischemia reperfusion injury needs further elucidation.Therefore, we use mice hepatic ischemia-reperfusion injury model to study the protective effect of intermittent fasting. Whether the protective effect of intermittent fasting on the liver is related to energy metabolism, inflammation or changes in the intestinal flora.Methods:1. The intermittent fasting mice as the experimental group and mice fed ad libitum with wild-type littermates mice were used as a control group, To Establish hepatic ischemia-reperfusion injury model. After 6h,12h and 24h charged two groups of mice’s liver, serum and fecal colon.2. Using automatic biochemical analyzer to detect the expression levels of liver transaminases, blood glucose, triglycerides, blood cholesterol and free fatty acids.3. Use a dedicated commercial kits to detect liver triglyceride and liver glycogen, β-hydroxybutyrate and liver β-hydroxybutyrate.4. using ELISA kits to detect the expression levels of serum inflammatory cytokine TNF-α, IL-1β, IL-6 and IL-10.5. Use the special commercial kits to detect the expression levels of glutathione (GSH), malondialdehyde (MDA), hydrogen peroxide (H2O2) and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx).6. TUNEL assay to detect hepatocyte apoptosis and necrosis.7.Using western blot method to Detected liver tissue’s NF-KB, MAPKs signal pathway protein, NLRP3 inflammatory protein complexes and LPS/TLR4 signal pathway related proteins.8. Using CTAB method to extract genomic DNA samples, sequences were amplified to sequence hypervariable region of 16S rDNA. using HiSeq PE250 platform to sequence V3-V4 region, for the identification of intestinal flora species.Results:1. intermittent fasting can reduce the body weight of mice.2.Intermittent Fasting on ischemia-reperfusion injury has an important protective effect of reducing serum ALT, AST levels.3.Intermittent fasting causes changes in hepatic energy source, glucose,blood cholesterol, blood triglycerides is decreased and the concentrations of serum β-hydroxybutyrate,free fatty acids (FFA) is gradually rise high, intermittent fasting causes Glycogen and liver triglyceride content decreased, and increased activity of fatty acid P oxidation, increased production of ketone bodies (β-hydroxybutyrate).4. intermittent fasting to reduce liver injury by inhibiting oxidative stress that induced by hepatic ischemia-reperfusion injury. Intermittent fasting (IF) group liver tissue’s he expression levels of glutathione (GSH), malondialdehyde (MDA), hydrogen peroxide (H2O2) and the activity of superoxide dismutase (SOD), glutathione peptide peroxidase(GPx),compared to ad libitum group,the difference was statistically significant.5. intermittent fasting suppresses hepatic ischemia-reperfusion injury in inflammatory activity, inhibiting the expression of Serum pro-inflammatory cytokines such as TNF-a, IL-1β, IL-6 and increasing the expression of serum anti-inflammatory cytokine IL-10. 6.intermittent fasting reduced expression of NF-KB, MAPKs and inhibition the activity of inflammatory NLRP3 composite that induced by hepatic ischemia-reperfusion injury.7.intermittent fasting suppresses the activity of reactive oxygen species, reducing apoptosis of the liver cells in liver ischemia-reperfusion injury.8.intermittent fasting reduced liver tissue expression TLR4 in hepatic ischemia-reperfusion injury.9.Intermittent fasting promotes the liver tissue expression of of SIRT3 in hepatic ischemia reperfusion injury.10.The intermittent fasting suppresses the regeneration of liver in ischemia and reperfusion injury.11. The intermittent fasting caused changes in the permeability of the intestinal wall and intestinal microflora composition, and promote the expression of intestinal epithelial tight junction protein, reducing the incidence of bacterial translocation. Intermittent fasting may reduce the hepatic ischemia-reperfusion injury, Though reducing the shift of intestinal flora and by reducing the number of intestinal Grand negative bacteria intestinal flora.Conclusion:1.Intermittent fasting has an important protective effect for hepatic ischemia-reperfusion, reduced the liver tissue necrotic.2. intermittent fasting caused hepatic energy metabolism changes in liver glycogen formation and enhance gluconeogenesis, fatty acids are not esterified by fatty acid β oxidation activity of liver mitochondria increased, generating large amounts of ketones. The ketone bodies as the liver and other tissues and organs outside the liver energy sources.3.Non-esterified fatty acids in the liver by increased the activity of the mitochondrial fatty acid β oxidation and generate large amounts of ketones. The ketone bodies as energy sources of the liver and other extrahepatic organ.4. intermittent fasting reducing damage liver tissue by inhibiting the inflammatory response.by inhibiting the activity of NF-κB, MAPKs and NLRP3 complex inflammatory signaling pathways reducing the cell inflammatory cytokines of IL-1β, IL-6, TNF-a, IL-18.5. intermittent fasting causes Changes in intestinal permeability and intestinal flora composed, intermittent fasting may reduce the number of intestinal Grand negative bacteria flora and intestinal shift, possibly through inhibition the activity of LPS/TLR4 pathway, reducing the liver ischemia-reperfusion injury.