Dihydromyricetin Enhances Insulin Sensitivity Of Adipocytes Through PLC-CaMKK2-AMPK

With the continuous changes in people’s diet structure and the continuous improvement of living standards,more and more people are obese,and obesity has become a global "epidemic".Obesity is often accompanied by low-level inflammatory responses throughout the body and induces insulin resistance in the body.Insulin resistance is an important morbidity factor in the development and development of type 2 diabetes.Insulin resistance and islet β cell dysfunction are two major pathophysiological features of type 2 diabetes.When the body’s tissues(fat,liver,muscle,etc.)develop insulin resistance,the cells’ ability to take up and use glucose declines,causing diabetes.Dihydromyricetin(DHM)is a dihydroflavone alcohol plant extract.Previous studies have confirmed that dihydromyricetin exerts antioxidant,anti-inflammatory and enhances insulin by regulating signaling pathways such as AMPK,NRF2 and NF-κB Sensitivity and other functions,but the molecular mechanism of how DHM enhances insulin sensitivity is still unclear.In this study,the C57 B / L6 mice were fed on a high-fat diet at a living level to build an obese mouse model,and DHM was administered for 12 weeks to observe the treatment effect.By measuring body weight and body composition analysis of mice,staining of tissue sections,oral glucose tolerance test and blood routine detection of inflammation levels in mice,explore the effect of DHM on improving insulin resistance caused by inflammatory response in obese individuals.At the cellular level,the inflammatory factor TNFα induces mature 3T3-L1 to produce insulin resistance,using DHM,AMPK inhibitors,CaMKK2 blockers,calcium probes,glucose uptake,qPCR and WB and other analytical methods to explore DHM resistance to inflammation The molecular mechanism of insulin resistance.The research results obtained are as follows:1.1.DHM reduces high fat diet-induced fat accumulation in mice and reduces obesity-induced insulin resistanceAt the living level,ELISA test results showed that DHM can significantly reduce the levels of inflammatory factors(IL-1,IL-6 and TNFα)in serum and adipose tissue,and glucose tolerance test results showed that DHM significantly enhanced insulin sensitivity in obese mice.This shows that DHM can effectively reduce obesity-induced insulin resistance.2.DHM inhibits TNFα-induced insulin resistance in 3T3-L1 cellsAt the cellular level,mature adipocytes were treated with 50 ng / m L TNFα,and glucose uptake,quantitative PCR,and WB detection were found to cause insulin resistance.After treatment with DHM,it can inhibit TNFα-induced insulin resistance in 3T3-L1 cells.3.DHM enhances insulin sensitivity in 3T3-L1 cells dependent on AMPKAfter co-treatment with AMPK inhibitor and DHM,it was found that DHM’s ability to inhibit cellular insulin resistance also disappeared.This indicates that DHM inhibits insulin resistance in 3T3-L1 cells dependent on AMPK.4.DHM enhances insulin sensitivity of 3T3-L1 cells dependent on CaMKK2-AMPKSimilarly,after co-treatment with CaMKK2 inhibitors and DHM,it was found that DHM’s ability to inhibit cellular insulin resistance also disappeared.This indicates that DHM inhibits the insulin resistance of 3T3-L1 cells dependent on CaMKK2-AMPK.5.DHM raises intracellular calcium to activate CaMKK2-AMPK through IP3 receptorThrough the calcium ion probe experiment,it was found that in the absence of calcium ions in the external environment,DHM can increase the intracellular calcium ion concentration.After the use of phospholipase C inhibitors and lannie base inhibitors,it was found that DHM generates IP3 by activating the hydrolysis of phospholipase C and then acts on the endoplasmic reticulum IP3 receptor,thereby releasing calcium ions and increasing the intracellular calcium ion concentration.Activate CaMKK2-AMPK signaling pathway.In conclusion,this study proved through cell and living experiments that DHM can increase the intracellular calcium ion level,activate the CaMKK2-AMPK signaling pathway,and improve insulin resistance caused by obesity and inflammation.The body’s inflammatory response caused by obesity is the main cause of insulin resistance and diabetes.Increasing insulin sensitivity and glucose uptake of fat cells is one of the means to treat type 2 diabetes.The innovation of this study is to explain the molecular mechanism of DHM to alleviate obese body’s insulin resistance,and provide experimental data for the development of new drugs to treat insulin resistance and solve the problem of type 2 diabetes.It has important social value and scientific significance.