EGCG Improves Insulin Resistance Caused By Insulin Receptor Mutation

At present,diabetes has become a common disease and one of the causes of morbidity and mortality worldwide.Type 2 diabetes is the most common type.Insulin resistance is the main cause and important sign of type 2 diabetes,characterized by decreased sensitivity and function of insulin.Insulin receptor gene mutation is an important cause of severe insulin resistance,which can even lead to embryonic lethality.Epigallocatechin gallate(EGCG),as the main component of catechin,found in the previous research of our research group that EGCG can improve the binding of insulin and insulin receptor.So,whether EGCG can improve insulin resistance caused by insulin receptor gene mutation is rarely reported.Further study on EGCG improving insulin resistance caused by insulin receptor gene mutation can provide scientific basis for prevention and treatment of type 2diabetes.In this study,we first screened the action time and concentration of EGCG on CHO-K1 cell line,then constructed insulin resistance cell models with different insulin receptor gene mutations by plasmid construction and transfection,identified the mutations of target gene sites by gene sequencing technology,and detected the plasmid transfection by cell flow cytometry,Then,Western Blot was used to detect the changes in the influence of EGCG on insulin signaling pathway related protein levels in different insulin resistance models,and the glucose uptake and utilization of EGCG in different insulin resistance models were detected using a 2-deoxyglucose fluorescent analogue(2-NBDG)kit.The main research findings are as follows:1.Western Blot results show that the optimal action concentration of EGCG is 20 μg/m L,the optimal action time is 30 minutes;2.In the constructed cell model,gene sequencing results showed that in the 9 different types of mutations constructed in this study,including 15,59,62,86,89,233,323,460,and 735,the corresponding base substitutions were consistent with literature reports,indicating the successful construction of the mutation model;The flow cytometry results showed that compared with the peak values measured in CHO-K1 cells,the various mutations mentioned above,including the peak values measured in the INSR wild-type,showed a certain deviation,indicating successful plasmid transfection;In the Western Blot results,under the cell insulin resistance model established by different insulin receptor gene mutations,under the optimal conditions,compared with the insulin alone group,EGCG combined with insulin can phosphorylate the tyrosine 1150/1151 site of the insulin receptor(P<0.05),thus fully activating the insulin receptor,and promoting the phosphorylation of the downstream key protein serine/threonine kinase(AKT),However,the EGCG group alone did not have this effect,indicating that EGCG has a synergistic effect on insulin;In the glucose uptake experiment,under the insulin resistance model established by different insulin receptor gene mutations,the combination group of EGCG and insulin could significantly increase the level of glucose absorption compared with the single insulin group(P<0.05).To sum up,in the state of insulin resistance caused by insulin receptor gene mutation,EGCG can increase the role of insulin,increase the phosphorylation level of insulin signaling pathway related proteins,enhance the absorption and utilization of glucose,increase insulin sensitivity,and thus improve insulin resistance.These studies reveal the important role of insulin receptor in the role of insulin in maintaining blood glucose balance in the body;On the other hand,we continue to develop the application value of EGCG,which may become a potential drug for clinical treatment of diabetes and provide new ideas for the treatment of diabetes.