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This Article Full Text Full Text (PDF) All Versions of this Article: fj.07-100735v1 fj.07-100735v2 22/7/2452    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Yang, K. Articles by Cao, X. PubMed PubMed Citation Articles by Yang, K. Articles by Cao, X.

Neuropeptide Y is produced in visceral adipose tissue and promotes proliferation of adipocyte precursor cells via the Y1 receptor

Kaiping Yang^*,,,1, Haiyan Guan^*,,, Edith Arany^,, David J. Hill^, and Xiang Cao^*,,

^* Children’s Health Research Institute; and

Department of Obstetrics and Gynecology,

Department of Physiology and Pharmacology, and

Department of Medicine, Lawson Health Research Institute; University of Western Ontario, London, Ontario, Canada

¹Correspondence: Children’s Health Research Institute, Rm. A5–132, Victoria Research Laboratories,Westminster Campus, 800 Commissioners Rd. East, London, Ontario, Canada N6A 4G5. E-mail: kyang{at}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.—Yang, K., Guan, H., Arany, E., Hill, D. J., Cao, X. Neuropeptide Y is produced in visceral adipose tissue and promotes proliferation of adipocyte precursor cells via the Y1 receptor.

Key Words: obesity • Zucker rat • adipogenesis • 3T3-L1 cells