ABSTRACT
Objective To explore the association of expression between the longevity gene SIRT1 and the forkhead transcription factor FOXO1 in the beta cell of islet in rat,and provide the basic prevention and cure rationale for the type 2 diabetes mellitus.Methods Eleven male SD rats of 18 months old were randomized into two groups:6 in calorie restriction(CR)group and 5 in the control group.After 6 months' breeding,the caudal end of islet was collected.The expression and location of SIRT1,FOXO1 and insulin were detected by immunohistochemistry;sections of pancreas were stained for senescence-associated ?-galactosidase(SA-?-Gal)to identify cell senescence of pancreatic islets.Results SIRT1 and FOXO1 were expressed in both the kytoplasm and nucleus,while insulin and ?-Gal were located in the kytoplasm.Compared with the control group rats,there was higher SIRT1 expression(P0.05)expression was detected in the beta cells of CR group rats.The lower positive rate of FOXO1 located in the nucleus the higher expression of SIRT1 in the rat beta cell of islet.Conclusion Calorie restriction could induce the high expression of SIRT1 in the rat beta cell of islet,and we think SIRT1 may delay the senescence process of rat beta cell through the repression of transcription factor FOXO1;it's beneficial to the prevention and cure for type 2 diabetes mellitus.