The Effect Of AMPK?2 And Clostridium Butyricum C.B 337239 On HFD-induced Metabolic Syndrome

Aims Diabetes is a disorder of glucose and lipid metabolism caused by islet cell dysfunction and insulin resistance.More than 90% of diabetes cases are type 2diabetes(T2DM).There are many reasons for the prevalence of diabetes,including population aging,economic development,urbanization,unhealthy eating habits and sedentary lifestyles.Nonalcoholic fatty liver disease(NAFLD)is closely related to metabolic disorders such as obesity,insulin resistance and T2 DM.AMPK plays an important role in the regulation of energy balance.However,the role of AMPK subunit ?2 in the development of NAFLD is still unclear.In addition,there is a causal relationship between the gut microbiota and the development of NAFLD.This study investigated whether Clostridium butyricum is related to obesity and the role of short chain fatty acids(SCFAs)in the development of inflammation that is associated with obesity.Methods and results In the first part,AMPK?2 knockout mice and C57 BL/6 wild-type mice were fed with normal diet or high-fat diet containing 60% lipid for 12 weeks to construct a non-alcoholic fatty liver model.Liver tissue and plasma were collected after 6 hours fasting.Lipid deposition in the liver was detected by Oil red O staining.Inflammation-related genes expressions were measured by real-time quantitive PCR.Liver inflammation and infiltratio were detected by immunofluorescence and immunohistochemistr.The proteins related with insulin resistance and inflammation were measured by Western blot.Compared with wild-type mice,fatty acid oxidation rate significantly decreased,whereas diglyceride,triglyceride content,lipid deposition,liver inflammation and CD68 level significantly increased in AMPK?2knockout mice under high fat feeding.The phosphorylation of IKK?/? significantly increased,resulting in increased NF-?B translocation to the nucleus.Injection of adenovirus over-expressing AMPK?2 to tail vein or injected with PDTC at a dose of 40 mg/Kg body weight of mice,relieved liver inflammation,lipid deposition and fibrosis induced by high fat diet.In the second part,male C57BL/6 mice were fed with high fat diet for 20 weeks following with 8 weeks Clostridium Butyricum or sodium chloride,respectively.The systemic inflammation was evaluated by immunohistochemistry and flow cytometry.16 S r RNA gene sequencing was used to detect the bacterial community.Western blot was carried out to explore the effects of Clostridium Butyricu and SCFAs on insulin signal,inflammmation and GPR41/43.After administration of Clostridium butyricum,the GPR41/43 signal was significantly activated.Systemic inflammation,glucose metabolism disorder,insulin resistance and intestinal flora imbalance caused by high-fat diet were obviously alleviated.Clostridium Butyricum significantly improved the intestinal microbiota richness accompanied by improvements of barrier function and intestinal inflammation.Conclusion Intervention of AMPK?2 or the composition of the flora by intragastric administration of Clostridium Butyricum can relieve glucose and lipid metabolism disorders,insulin resistance and systemic inflammation caused by high-fat diet.Activation of GPR43 in insulin target tissues or inhibition of NF-?B signaling pathway may be useful for the treatment of obesity-related metabolic syndromes.