Mechanistic insights into pancreatic beta-cell mass regulation by glucose and free fatty acids / 대한해부학회지

Pancreatic islets are responsible for blood glucose homeostasis. Reduced numbers of functional (insulin-secreting) beta-cells in pancreatic islets underlies diabetes. Restoration of the secretion of the proper amount of insulin is a goal. Beta-cell mass is increased by neogenesis, proliferation and cell hypertrophy, and is decreased by beta-cell death primarily through apoptosis. Many hormones and nutrients affect beta-cell mass, and glucose and free fatty acid are thought to be the most important determinants of beta-cell equilibrium. A number of molecular pathways have been implicated in beta-cell mass regulation and have been studied. This review will focus on the role of the principle metabolites, glucose and free fatty acid, and the downstream signaling pathways regulating beta-cell mass by these metabolites.

Therapeutic Approaches for Preserving or Restoring Pancreatic beta-Cell Function and Mass

The goal for the treatment of patients with diabetes has today shifted from merely reducing glucose concentrations to preventing the natural decline in beta-cell function and delay the progression of disease. Pancreatic beta-cell dysfunction and decreased beta-cell mass are crucial in the development of diabetes. The beta-cell defects are the main pathogenesis in patients with type 1 diabetes and are associated with type 2 diabetes as the disease progresses. Recent studies suggest that human pancreatic beta-cells have a capacity for increased proliferation according to increased demands for insulin. In humans, beta-cell mass has been shown to increase in patients showing insulin-resistance states such as obesity or in pregnancy. This capacity might be useful for identifying new therapeutic strategies to reestablish a functional beta-cell mass. In this context, therapeutic approaches designed to increase beta-cell mass might prove a significant way to manage diabetes and prevent its progression. This review describes the various beta-cell defects that appear in patients with diabetes and outline the mechanisms of beta-cell failure. We also review common methods for assessing beta-cell function and mass and methodological limitations in vivo. Finally, we discuss the current therapeutic approaches to improve beta-cell function and increase beta-cell mass.

Silk fibroin hydrolysate exerts an anti-diabetic effect by increasing pancreatic beta cell mass in C57BL/KsJ-db/db mice

Components of silk including silk fibroin have long been used as anti-diabetic remedies in oriental medicine. However, detailed mechanisms underlying these anti-diabetic effects remain unclear. In this study, we examined the anti-diabetic activity of silk fibroin hydrolysate (SFH) in C57BL/KsJ-db/db (db/db) mice, a well-known animal model of non-insulin dependent diabetes mellitus. When the db/db mice were administered SFH in drinking water for 6 weeks, hyperglycemia in the animals gradually disappeared and the level of glycosylated hemoglobin decreased, indicating that SFH plays important role in reducing the symptoms of diabetes. In addition, SFH-treated db/db mice exhibited improved glucose tolerance with increased plasma insulin levels. Immunohistochemical and morphological analyses showed that SFH up-regulated insulin production by increasing pancreatic beta cell mass in the mice. In summary, our results suggest that SFH exerts anti-diabetic effects by increasing pancreatic beta cell mass in a non-insulin dependent diabetes mellitus mouse model.

Insulin Deficiency is an Important Risk Factor for the Development of Type 2 Diabetes in Asia / 한양의대학술지

No abstract available.