TY - JOUR
T1 - Age-related impairment in insulin release
T2 - The essential role of β 2-adrenergic receptor
AU - Santulli, Gaetano
AU - Lombardi, Angela
AU - Sorriento, Daniela
AU - Anastasio, Antonio
AU - Del Giudice, Carmine
AU - Formisano, Pietro
AU - Béguinot, Francesco
AU - Trimarco, Bruno
AU - Miele, Claudia
AU - Iaccarino, Guido
PY - 2012/3
Y1 - 2012/3
N2 - In this study, we investigated the significance of β 2- adrenergic receptor (β 2AR) in age-related impaired insulin secretion and glucose homeostasis. We characterized the metabolic phenotype of β 2AR-null C57Bl/6N mice (β 2AR -/-) by performing in vivo and ex vivo experiments. In vitro assays in cultured INS-1E β-cells were carried out in order to clarify the mechanism by which β 2AR deficiency affects glucose metabolism. Adult β 2AR -/- mice featured glucose intolerance, and pancreatic islets isolated from these animals displayed impaired glucose-induced insulin release, accompanied by reduced expression of peroxisome proliferator-activated receptor (PPAR)γ, pancreatic duodenal homeobox-1 (PDX-1), and GLUT2. Adenovirus-mediated gene transfer of human β 2AR rescued these defects. Consistent effects were evoked in vitro both upon β 2AR knockdown and pharmacologic treatment. Interestingly, with aging, wild-type (β 2AR +/+) littermates developed impaired insulin secretion and glucose tolerance. Moreover, islets from 20-month-old β 2AR +/+ mice exhibited reduced density of β 2AR compared with those from younger animals, paralleled by decreased levels of PPARγ, PDX-1, and GLUT2. Overexpression of β 2AR in aged mice rescued glucose intolerance and insulin release both in vivo and ex vivo, restoring PPARγ/PDX-1/GLUT2 levels. Our data indicate that reduced β 2AR expression contributes to the age-related decline of glucose tolerance in mice.
AB - In this study, we investigated the significance of β 2- adrenergic receptor (β 2AR) in age-related impaired insulin secretion and glucose homeostasis. We characterized the metabolic phenotype of β 2AR-null C57Bl/6N mice (β 2AR -/-) by performing in vivo and ex vivo experiments. In vitro assays in cultured INS-1E β-cells were carried out in order to clarify the mechanism by which β 2AR deficiency affects glucose metabolism. Adult β 2AR -/- mice featured glucose intolerance, and pancreatic islets isolated from these animals displayed impaired glucose-induced insulin release, accompanied by reduced expression of peroxisome proliferator-activated receptor (PPAR)γ, pancreatic duodenal homeobox-1 (PDX-1), and GLUT2. Adenovirus-mediated gene transfer of human β 2AR rescued these defects. Consistent effects were evoked in vitro both upon β 2AR knockdown and pharmacologic treatment. Interestingly, with aging, wild-type (β 2AR +/+) littermates developed impaired insulin secretion and glucose tolerance. Moreover, islets from 20-month-old β 2AR +/+ mice exhibited reduced density of β 2AR compared with those from younger animals, paralleled by decreased levels of PPARγ, PDX-1, and GLUT2. Overexpression of β 2AR in aged mice rescued glucose intolerance and insulin release both in vivo and ex vivo, restoring PPARγ/PDX-1/GLUT2 levels. Our data indicate that reduced β 2AR expression contributes to the age-related decline of glucose tolerance in mice.
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U2 - 10.2337/db11-1027
DO - 10.2337/db11-1027
M3 - Article
C2 - 22315324
AN - SCOPUS:84857393446
SN - 0012-1797
VL - 61
SP - 692
EP - 701
JO - Diabetes
JF - Diabetes
IS - 3
ER -