Rat insulinoma-derived pancreatic beta-cells express a functional leptin receptor that mediates a proliferative response.
In addition to its interaction at hypothalamic sites to affect feeding and energy expenditure, leptin has been shown to exhibit a proliferative response in erythropoietic cells. The functional leptin receptor is also present in pancreatic islets and we now demonstrate that a commonly used clonal insulin secreting beta-cell line, RINm5F, expresses high levels of the Ob-Rb mRNA. Leptin causes an increase in tyrosine phosphorylation of a number of intracellular proteins and a dose related (10 nM-200 nM) increase in expression of the immediate-early gene, c-fos. This precedes a leptin induced proliferative response in serum-deprived RINm5F cells, which suggests that leptin might be involved in the complex regulation of proliferation of the pancreatic beta-cell.
Islam
M S
MS
The Rolf Luft Centre for Diabetes Research, Department of Molecular Medicine, Karolinska Institute, Stockholm, Sweden.
Morton
N M
NM
Hansson
A
A
Emilsson
V
V
D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D004261:DNA Replication / Q000187:drug effects; D007340:Insulinoma; D007515:Islets of Langerhans / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics; D051381:Rats; D011956:Receptors, Cell Surface; D018121:Receptors, Cytokine / Q000096:biosynthesis* / Q000502:physiology; D054411:Receptors, Leptin; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D016760:Proto-Oncogene Proteins c-fos; D011956:Receptors, Cell Surface; D018121:Receptors, Cytokine; D054411:Receptors, Leptin; D019000:Phosphotyrosine