Neuropeptide Y is produced in visceral adipose tissue and promotes proliferation of adipocyte precursor cells via the Y1 receptor.
Neuropeptide Y (NPY) is synthesized in neural tissue of the central and peripheral nervous systems and has a number of important functions besides regulating appetite and energy homeostasis. Here we identify a novel site of NPY biosynthesis and a role for NPY in promoting proliferation of adipocyte precursor cells. We show that NPY mRNA is not only expressed in visceral adipose tissue (VAT) but that its levels are up-regulated 6-fold in our early-life programmed rat model of increased visceral adiposity. This is accompanied by a parallel rise in NPY protein, demonstrating that VAT is a novel peripheral site of NPY biosynthesis. Furthermore, NPY mRNA expression is also elevated >2-fold in VAT of obese Zucker rats. Importantly, NPY stimulates proliferation of primary rat preadipocytes as well as 3T3-L1 preadipocytes in vitro. This mitogenic effect appears to be mediated by the Y1 receptor and involves the activation of extracellular related kinase 1/2. In addition, insulin and glucocorticoid up-regulate VAT NPY expression in lean but not obese Zucker rats. Taken together, these results suggest that an enhanced local expression of NPY within VAT may be a common feature of and contribute to the molecular mechanisms underlying increased visceral adiposity.
Yang
Kaiping
K
Children's Health Research Institute, Rm. A5-132, Victoria Research Laboratories,Westminster Campus, 800 Commissioners Rd. East, London, Ontario, Canada N6A 4G5. kyang@uwo.ca
Guan
Haiyan
H
Arany
Edith
E
Hill
David J
DJ
Cao
Xiang
X
D017667:Adipocytes / Q000737:chemistry*; D000273:Adipose Tissue / Q000502:physiology*; D000818:Animals; D002455:Cell Division; D005260:Female; D008098:Litter Size; D008297:Male; D023421:Models, Animal; D009478:Neuropeptide Y / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D011924:Rats, Zucker; D017476:Receptors, Neuropeptide Y / Q000502:physiology*; D014781:Viscera
D009478:Neuropeptide Y; D017476:Receptors, Neuropeptide Y; C097212:neuropeptide Y-Y1 receptor