HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 296/6/E1383    most recent 00025.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Fowler, J. D. Articles by Bernlohr, D. A. PubMed PubMed Citation Articles by Fowler, J. D. Articles by Bernlohr, D. A.

Regulated renin release from 3T3-L1 adipocytes

Departments of ¹Integrative Biology and Physiology and ²Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota

Submitted 12 January 2009 ; accepted in final form 13 March 2009

Whereas adipose tissue possesses a local renin-angiotensin system, the synthesis and regulated release of renin has not been addressed. To that end, we utilized differentiating 3T3-L1 cells and analyzed renin expression and secretion. Renin mRNA expression and protein enzymatic activity were not detectable in preadipocytes. However, upon differentiation, renin mRNA and both intracellular and extracellular renin activity were upregulated. In differentiated adipocytes, forskolin treatment resulted in a 28-fold increase in renin mRNA, whereas TNF treatment decreased renin mRNA fourfold. IL-6, insulin, and angiotensin (Ang) II were without effect. In contrast, forskolin and TNF each increased renin protein secretion 12- and sevenfold, respectively. Although both forskolin and TNF induce lipolysis in adipocytes, fatty acids, prostaglandin E₂, and lipopolysaccharide had no effect on renin mRNA or secretion. To evaluate the mechanism(s) by which forskolin and/or TNF are able to regulate renin secretion, a general lipase inhibitor (E600) and PKA inhibitor (H89) were used. Both inhibitors attenuated forskolin-induced renin release, whereas they had no effect on TNF-regulated secretion. In contrast, E600 potentiated forskolin-stimulated renin mRNA levels, whereas H89 had no effect. Neither inhibitor had any influence on TNF regulation of renin mRNA. Relative to lean controls, renin expression was reduced 78% in the epididymal adipose tissue of obese male C57Bl/6J mice, consistent with TNF-mediated downregulation of renin mRNA in the culture system. In conclusion, the expression and secretion of renin are regulated under a complex series of hormonal and metabolic determinants in mature 3T3-L1 adipocytes.

secretion; tumor necrosis factor-; forskolin; renin-angiotensin system; angiotensin II