Financial agencies: This work was supported by a grant from the USDA/NIFA (2010-38903-20740) to MFM and SMN and by the Wolfe Innovation Fund (University of Toledo Foundation). The work was also supported by grants from the NIH; R01 DK054254, R01 DK083850, and R01 HL112248 to SMN.
Tight association between macrophages and adipocytes in obesity: Implications for adipocyte preparation
Version of Record online: 4 DEC 2013
Copyright © 2013 The Obesity Society
Volume 22, Issue 5, pages 1246–1255, May 2014
How to Cite
Ebke, L. A., Nestor-Kalinoski, A. L., Slotterbeck, B. D., Al-Dieri, A. G., Ghosh-Lester, S., Russo, L., Najjar, S. M., von Grafenstein, H. and McInerney, M. F. (2014), Tight association between macrophages and adipocytes in obesity: Implications for adipocyte preparation. Obesity, 22: 1246–1255. doi: 10.1002/oby.20634
Disclosure: The authors declare no conflict of interest.
Author contributions: L. A. Ebke, B. D. Slotterbeck, and A. G. Al-Dieri researched, analyzed data, and contributed to the drafting of the manuscript. A. Nestor-Kalinoski provided image collection and helped analyze LSCM images. S. Ghosh-Lester and Lucia Russo provided adipose tissue from 4.5 and 4-month-feeding experiments respectively. S. M. Najjar provided the use of CeDER facilities, breeding pairs of Cc1-/- mice, design of feeding experiments, contributed to scientific discussion, and edited/reviewed the manuscript. H. von Grafenstein contributed to scientific discussion, data interpretation, and manuscript writing/review. M. F. McInerney oversaw the work, including its conception and study design, analyzed data, led scientific discussions and wrote/reviewed/edited the manuscript. All authors have read and approved the manuscript.
- Issue online: 1 MAY 2014
- Version of Record online: 4 DEC 2013
- Accepted manuscript online: 8 OCT 2013 12:34PM EST
- Manuscript Accepted: 26 SEP 2013
- Manuscript Received: 10 MAY 2013
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.
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.
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.
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.