[Potential role of the early response gene c-Myc in the loss of differentiation and function of pancreatic beta cells submitted to chronic hyperglycemia].
Chronic hyperglycemia exerts deleterious effects on glucose-induced insulin secretion by pancreatic beta cells. In 90% pancreatectomized rats, chronic hyperglycemia induces beta cell hypertrophy and loss of differentiation associated with increased expression of the early response gene c-Myc. Hyperglycemia also stimulates c-Myc expression in vivo in islets from glucose-infused rats and in vitro in cultured rat islets. This effect requires the elevation of cytosolic Ca2+ concentration produced by glucose. Our results suggest that overstimulation of c-Myc expression by chronic hyperglycemia may be the cause of beta cell hypertrophy and loss of differentiation and function observed in animal models of type 2 diabetes.
Jonas
J C
JC
Unité d'Endocrinologie et Métabolisme, Département de Physiologie et Pharmacologie, Faculté de Médecine, UCL.
D000818:Animals; D002454:Cell Differentiation; D017781:Genes, Immediate-Early / Q000502:physiology*; D016259:Genes, myc / Q000502:physiology*; D006943:Hyperglycemia; D007515:Islets of Langerhans / Q000166:cytology*; D051381:Rats
Rôle possible du gène de réponse précoce c-Myc dans la perte de différenciation et de fonction des cellules beta pancréatiques soumises à une hyperglycémie chronique.