Effect Of Pancreatic ? Cell-specific Knockout Of OGA On Glucose Metabolism

Background and Objectives: Diabetes is a complex metabolic disorder,but the overall clinical efficacy of diabetes is still not ideal,diabetes morbidity and mortality are still high.Therefore,it is of far-reaching significance to find effective drugs.Traditional Chinese medicine contains a variety of effective ingredients that can effectively protect Pancreatic ? cells regulate glucose and lipid metabolism and signaling pathways,lower blood sugar,improve insulin resistance,and have a significant effect on diabetes and its complications.Recent studies have found that abnormal glycosylation of O-GlcNAc is closely related to disorders of glucose and lipid metabolism.Recent studies have found that abnormal O-GlcNAcylation is closely related to dysregulation of glucose and lipid metabolism.This subject established a pancreatic beta cell OGA specific knockout mice model to observe the effect of glucose metabolism under normal chow diet and high-glucose diet,to make a more accurate research basis for the evaluation of the efficacy of traditional Chinese medicine and traditional Chinese medicine monomer on diabetes in the future,to provide a suitable animal model for the in-depth study of the hypoglycemic effect of Chinese medicine and the development of new hypoglycemic drugs,and to make a more accurate research basis for the future evaluation of the efficacy of Chinese medicine and Chinese medicine monomers on diabetes.Methods: 1.The Cre-Lox P recombinase system was used to establish a pancreatic beta cell OGA specific knockout mice model,and the knockout efficiency was verified by agarose gel electrophoresis and immunohistochemical staining.2.To observe the glucose metabolism homeostasis and insulin sensitivity in pancreatic beta cell OGA deficiency,we performed several experiments including monitoration of fasting blood glucose,and weight,intraperitoneal glucose tolerance test(IPGTT)and intraperitoneal insulin tolerance test(IPITT),within conditions of chow diet and high-glucose diet.3.Serum multi-factor detection kit was used to detect the levels of various endocrine-regulating hormones,such as insulin and glucagon and etc.4.Metabolic cages were used to monitor the alteration of metabolic characteristics indicators in mice,including respiratory exchange rate,activity,food intake,and water intake.5.The alterations of intestinal microecology in mice were observed through 16 S r DNA sequencing.Results: 1.The results of agarose gel electrophoresis and immunohistochemistry showed that OGA protein expression was significantly reduced,and O-GlcNAcylation level was increased in pancreatic beta cell OGA knockout mice,compared with wild type(WT)mice.TUNEL staining found that the proportion of apoptotic cells increased greatly in islets of KO mice.2.Monitoration of blood glucose and weight of chow diet mice showed that the blood glucose of KO young mice was not significantly different with WT group,while in old age mice,the blood glucose of KO group was much higher than WT group(P < 0.05).The weight of KO young mice was less than WT group,while the weight of old group is the opposite(P < 0.05).The area under the glucose tolerance curve of the KO group was significantly larger than that of the WT group(P = 0.012),suggesting that glucose tolerance of KO mice was impaired,but insulin sensitivity was not significant between KO and WT group.Detection of endocrine regulating hormones invloved in serum metabolism showed that the average insulin value in the KO group was 1899.8 ng/m L,and that of WT group was 4274.0 ng/m L,which was significantly in statistics(P = 0.017).Dectection of leptin showed that the average leptin in the KO group was 1014.7 ng/m L,and the mean value in WT group was 375.5 ng/m L,which was significantly in statistics(P = 0.045).But there were no significant differences between the two groups in glucagon,resistin and other 6 metabolic-related endocrine regulating hormones(P > 0.05).Further monitoration of the metabolic cages showed that the oxygen consumption,carbon dioxide production,heat production,food intake and water intake in KO group were significantly higher than WT group(P <0.05).3.The tendency of blood glucose and weight of high-glucose diet mice are consistent with the chow diet mice,and the blood glucose and body weight of the KO group increased more rapidly.The area under the insulin tolerance curve of the KO group was significantly larger than that of the WT group(P = 0.005)after 24 weeks of high-glucose diet,suggesting that insulin sensitivity of KO group was impaired.Detection of endocrine regulating hormones invloved in serum metabolism showed that the average insulin value in the KO group was 3158.5 ng/m L,and that of WT group was 6956.5 ng/m L,which was significantly in statistics(P = 0.040).Dectection of leptin showed that the average leptin in the KO group was 1119.0 ng/m L,and the mean value in WT group was 534.9 ng/m L,which was significantly in statistics(P = 0.018).Besides,the serum glucagon in KO group was significantly lower than WT group(P = 0.0148),and resistin was significantly higher than that in WT group(P = 0.041).Monitoration of the metabolic cages showed that the food and water intake in KO group were significantly higher than WT group(P <0.05)after 4 weeks for high-sugar drinking water.4.16 S r DNA sequencing results showed that the mice in the WT group were more evenly distributed than those in the KO group.Compared with the conventionally fed mice,the bacterial community of the mice became more complicated high-glucose diet.At the same time,in the classification analysis,the Bacteroidetes/Firmicutes(F/B)in the KO group were higher at the door level,the Bacteroidetes decreased,and the Firmicutes increased.Conclusion: 1.In pancreatic beta cell OGA specific knockout mice,the O-GlcNAcylation was increased,pancreatic beta cell function was impaired,insulin secretion was reduced,and glucose tolerance is abnormal.2.Under the condition of high-glucose diet induction,the glucose metabolism became more disorder after pancreatic beta cell OGA specific knockout.3.high-glucose diet,pancreatic beta cell OGA knockout mice aggravated the disorder of glucose metabolism,which made the bacterial community more complicated.Some abundance changes in the expression of certain bacterial floras related to metabolic disorders suggest that the intestinal flora of mice the dysregulation may be closely related to the glucose metabolism disorder in pancreatic beta cell OGA knockout mice.