Ghrelin induces abdominal obesity via GHS-R-dependent lipid retention

Jeffrey S. Davies, Pia Kotokorpi, Sinan R. Eccles, Sarah K. Barnes, Paweł F. Tokarczuk, Sophie K. Allen, Hilary S. Whitworth, Irina A. Guschina, Bronwen A J Evans, Agneta Mode, Jeffrey M. Zigman, Timothy Wells

Research output: Contribution to journalArticle

120 Scopus citations

Abstract

Circulating ghrelin elevates abdominal adiposity by a mechanism independent of its central orexigenic activity. In this study we tested the hypothesis that peripheral ghrelin induces a depot-specific increase in white adipose tissue (WAT) mass in vivo by GH secretagogue receptor (GHS-R1a)-mediated lipolysis. Chronic iv infusion of acylated ghrelin increased retroperitoneal and inguinal WAT volume in rats without elevating superficial sc fat, food intake, or circulating lipids and glucose. Increased retroperitoneal WAT mass resulted from adipocyte enlargement probably due to reduced lipid export (ATP-binding cassette transporter G1 mRNA expression and circulating free fatty acids were halved by ghrelin infusion). In contrast, ghrelin treatment did not upregulate biomarkers of adipogenesis (peroxisome proliferator-activated receptor-γ2 or CCAAT/enhancer binding protein-α) or substrate uptake (glucose transporter 4, lipoprotein lipase, or CD36) and although ghrelin elevated sterol-regulatory element-binding protein 1c expression, WAT-specific mediators of lipogenesis (liver X receptor-α and fatty acid synthase) were unchanged. Adiposity was unaffected by infusion of unacylated ghrelin, and the effects of acylated ghrelin were abolished by transcriptional blockade of GHS-R1a, but GHS-R1a mRNA expression was similar in responsive and unresponsive WAT. Microarray analysis suggested that depot-specific sensitivity to ghrelin may arise from differential fine tuning of signal transduction and/or lipid-handling mechanisms. Acylated ghrelin also induced hepatic steatosis, increasing lipid droplet number and triacylglycerol content by a GHS-R1a-dependent mechanism. Our data imply that, during periods of energy insufficiency, exposure to acylated ghrelin may limit energy utilization in specific WAT depots by GHS-R1a-dependent lipid retention.

Original languageEnglish (US)
Pages (from-to)914-924
Number of pages11
JournalMolecular Endocrinology
Volume23
Issue number6
DOIs
StatePublished - Jun 2009

ASJC Scopus subject areas

  • Molecular Biology
  • Endocrinology

Fingerprint Dive into the research topics of 'Ghrelin induces abdominal obesity via GHS-R-dependent lipid retention'. Together they form a unique fingerprint.

  • Cite this

    Davies, J. S., Kotokorpi, P., Eccles, S. R., Barnes, S. K., Tokarczuk, P. F., Allen, S. K., Whitworth, H. S., Guschina, I. A., Evans, B. A. J., Mode, A., Zigman, J. M., & Wells, T. (2009). Ghrelin induces abdominal obesity via GHS-R-dependent lipid retention. Molecular Endocrinology, 23(6), 914-924. https://doi.org/10.1210/me.2008-0432