Tight association between macrophages and adipocytes in obesity: Implications for adipocyte preparation. (4th December 2013)

• Record Type: Journal Article
• Authors: Ebke, Lindsey A.; Nestor‐Kalinoski, Andrea L.; Slotterbeck, Brandon D.; Al‐Dieri, Ali G.; Ghosh‐Lester, Sumona; Russo, Lucia; Najjar, Sonia M.; von, Hermann; McInerney, Marcia F.
• Is Part Of: Obesity. Volume 22:Number 5(2014:May)
• Page Start: 1246
• Page End: 1255
• Publication Date: 2013-12-04
• Subjects: Obesity -- Periodicals; 616.398005
• DOI: 10.1002/oby.20634
• Languages: English
• ISSNs: 1930-7381

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="oby20634-sec-0001" sec-type="section"> <title>Objective</title> <p>To determine the cellular architecture of the inflammatory infiltrate in adipose tissue from obese mice, and identify the source of inflammatory cytokines in adipose tissue at a single cell level.</p> </sec> <sec id="oby20634-sec-0002" sec-type="section"> <title>Methods</title> <p>Adipose tissue from diet‐induced obese mice was digested by collagenase treatment and fractionated by density centrifugation to obtain an adipocyte floating layer and a pellet of stromal vascular cells. The cellular architecture of the adipocyte‐macrophage interaction in both intact white adipose tissue (WAT) and the separated density gradient floating layer fraction was analyzed by confocal immunohistochemistry. Cytokine expression was detected by semi‐quantitative real time PCR and immunohistochemical analysis.</p> </sec> <sec id="oby20634-sec-0003" sec-type="section"> <title>Results</title> <p>Three dimensional image analysis of WAT and the separated "adipocyte" floating layer revealed lipid‐engorged macrophages, macrophages in contact with lipid droplets and sheath‐like assemblies of macrophages surrounding adipocytes. The macrophages immunostained for TNFα and to a lesser extent for the immunoregulatory cytokine IL‐10. TNFα staining was associated only with macrophages indicating that macrophages and not adipocytes are the source of TNFα expression in the adipocyte floating layer.</p> </sec> <sec id="oby20634-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Macrophages form assemblies that tightly adhere to and cover adipocytes and lipid droplets. TNFα found in low density adipocyte preparations is due to contamination with macrophages.</p> </sec> </abstract>