Ghrelin but not obestatin regulates insulin secretion from INS1 beta cell line via UCP2-dependent mechanism.
The mitochondrial UCP2 mediates glucose-stimulated insulin secretion by decreasing intracellular ATP/ADP ratio. Insulin secretion is a tightly regulated process. Ghrelin, as well as obestatin, were intensively studied to determine their ability to modify insulin secretion. Ghrelin is considered to be an inhibitor of insulin release from pancreatic islets, however little is known about the effects of obestatin. In our study we demonstrate the stimulating effects of both peptides on insulin secretion in INS1 cells. Furthermore, we investigate the potential role of UCP2 in mediating the effects of both peptides on insulin secretion. UCP2 mRNA expression was down-regulated by ghrelin in the presence of 26.4 mM glucose, however it was unchanged after obestatin treatment. Our results confirm that UCP2 could be involved in the stimulating effect of ghrelin on insulin release from INS1 cells.
Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland.
J
J
Chmielewska
D
D
Szczepankiewicz
M
M
Skrzypski
D
D
Kregielska
M Z
MZ
Strowski
K W
KW
Nowak
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D054439:Ghrelin / Q000494:pharmacology* / Q000502:physiology; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism*; D007473:Ion Channels / Q000235:genetics / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000502:physiology*; D036361:Peptide Hormones / Q000494:pharmacology* / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D000071246:Uncoupling Protein 2
D017931:DNA Primers; D054439:Ghrelin; D007328:Insulin; D007473:Ion Channels; D024101:Mitochondrial Proteins; D036361:Peptide Hormones; D012333:RNA, Messenger; C000604391:Ucp2 protein, rat; D000071246:Uncoupling Protein 2; C505798:obestatin, rat