[*QUOTE*]
--------------------------------------------------------------------------
Published online before print March 7, 2008 as
doi: 10.1096/fj.07-100735.
Neuropeptide Y is produced in visceral adipose tissue and promotes
proliferation of adipocyte precursor cells via the Y1 receptorKaiping Yang, Haiyan Guan, Edith Arany, David J. Hill, and Xiang Cao
E-mail contact: kyang [bat] uwo.ca
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.
Neuropeptide Y is produced in visceral adipose tissue and promotes
proliferation of adipocyte precursor cells
via the Y1 receptor.
Copyright © 2008
by The Federation of American Societies for Experimental Biology.
--------------------------------------------------------------------------
[*/QUOTE*]
source:
http://www.fasebj.org/cgi/content/abstract/fj.07-100735v2full text
http://www.fasebj.org/cgi/rapidpdf/fj.07-100735v2(requires registration)
.