Globular adiponectin augments insulin secretion from pancreatic islet beta cells at high glucose concentrations.
Adiponectin plays an important role in improving insulin resistance and preventing atherosclerosis. However it has been rarely reported that adiponectin influences insulin secretion because its receptor was identified in human islet beta cells. In order to investigate the direct effect of adiponectin on pancreatic islet beta cells, we performed an insulin secretion test in purified rat islets, which were incubated with adiponectin (100 ng/mL) at low (3.3 mM) and high (16.7 mM) glucose concentrations. Furthermore, cell lysates were extracted from the adiponectin-treated islets for p-AMPKalpha assay. RTPCR and immunohistochemical examination showed both adiponectin receptor 1 (AdipoR1) and receptor 2 (AdipoR2) were expressed in islet cells and AdipoR1 was predominantly expressed. Insulin secretion was significantly increased in the presence of adiponectin for 6 h at high glucose concentration. Meanwhile, the levels of phosphorylated AMPK increased with adiponectin treatment at high glucose concentrations. It is concluded that adiponectin augments insulin secretion from pancreatic islet beta cells at high glucose concentration through AMPK activation.
Gu
Weiqiong
W
Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Rui-Jin Hospital, Shanghai Jiaotong University School of Medicine, PR China.
Li
Xiaoying
X
Liu
Changqin
C
Yang
Jun
J
Ye
Lei
L
Tang
Jingfen
J
Gu
Yuanjun
Y
Yang
Yisheng
Y
Hong
Jie
J
Zhang
Yifei
Y
Chen
Mingdao
M
Ning
Guang
G
D055372:AMP-Activated Protein Kinases; D052242:Adiponectin / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D005947:Glucose / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009097:Multienzyme Complexes / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D054419:Receptors, Adiponectin; D011956:Receptors, Cell Surface / Q000378:metabolism
D052242:Adiponectin; C499920:Adipoq protein, rat; D007328:Insulin; D009097:Multienzyme Complexes; D054419:Receptors, Adiponectin; D011956:Receptors, Cell Surface; C504339:adiponectin receptor 1, rat; C506573:adiponectin receptor 2, rat; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D005947:Glucose