The Effect Of Amylin On The Gene Expression Of Human Hepatocyte Glucose-6-phosphatase

Objective:Glucose-6-phosphatase(G-6-Pase)is an important enzyme in glucose metabolism.As a rate-limiting enzyme of the last reaction of glyconeogenesis and glycogenolysis,the change of G-6-Pase in gene expression will affect the output of endogenic glucose directly.In fact, insulin resistance in liver contributes to the excessive hepatic output of glucose,which is highly correlated with hyperglycemia in type 2 diabetes. So,G-6-Pase is a potent therapeutic molecular target of diabetes.Amylin,as the important hormone of pancreaticβcell,is associated with the blood regulation closely.The current study shows that the abnormal secretion of amylin involves in insulin resistance.The purpose of this experiment is to study the effect of amylin on G-6-Pase gene expression and to further explore the relationship of amylin and hepatic insulin resistance.Methods:1 To culture human hepatocytes in vitro.2 The cultured human hepatocytes were incubated in high D-glucose and insulin and different concentration of amylin for 24 hours,then the expression of G-6-Pase were measured through SQ-RT-PCR (semi-quantitative reverse transcription-polymerase chain reaction).Results:1 The human hepatocytes grew well in vitro.2 After cultured with 15mM glucose and 100IU/L insulin for 24 hours,the mRNA of G-6-Pase of human hepatocytes increased.(P＜0.05).3 Afrer incubated in medium cantaining different concentration of amylin and high glucose and insulin,the mRNA of G-6-Pase in 0.1μM,1μM amylin-group had no significant change,while the mRNA of G-6-Pase in 10μM amylin-group increased significantly(P＜0.01). Conclusion:1 The human hepatocytes grew well in vitro.2 After cultured with 15mM glucose and 100IU/L insulin for 24 hours,the mRNA of G-6-Pase of human hepatocytes increased,which suggested the influence of high glucose on the mRNA of G-6-Pase was over of that insulin. In the different concentrations of the amylin,the mRNA of G-6-Pase in 0.1μM, 1μM amylin-group had no change while 10μM arnylin made the mRNA of G-6-Pase significantly increased.That suggested that in high concentrations of amylin and glucose conditions,the influence of insulin on G-6-PasemRNA further reduced.It showed that amylin of abnormal secretion on diabetic patients interfered hepatic output of glucose and participated in insulin resistance.