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Journal of Immunology Research
Volume 2014, Article ID 309548, 10 pages
http://dx.doi.org/10.1155/2014/309548
Research Article

Human Adipose Tissue Macrophages Are Enhanced but Changed to an Anti-Inflammatory Profile in Obesity

1Department of Medicine and Endocrinology, MEA, Aarhus University Hospital, 8000 Aarhus, Denmark
2Department of Clinical Biochemistry, Aarhus University Hospital, 8000 Aarhus, Denmark

Received 11 November 2013; Revised 20 January 2014; Accepted 5 February 2014; Published 11 March 2014

Academic Editor: Joseph Fomusi Ndisang

Copyright © 2014 Karen Fjeldborg et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective. Adipose tissue (AT) macrophages are increased in obesity and associated with low grade inflammation. We aimed to characterize the phenotype of AT macrophages in humans in relation to obesity and insulin resistance. Design. Gene-expression levels of general macrophage markers (CD68 and CD14), proinflammatory markers/M1 (TNF-α, MCP-1, and IL-6), and anti-inflammatory markers/M2 (CD163, CD206, and IL-10) were determined by RT-PCR in subcutaneous AT samples from lean and obese subjects. Insulin resistance was determined by HOMA-IR. Results. All the macrophage markers were elevated in the AT from obese compared to lean subjects ( ). To determine the phenotype of the macrophages the level of CD14 was used to adjust the total number of macrophages. The relative expression of CD163 and IL-10 was elevated, and TNF-α and IL-6 were reduced in AT from obese subjects (all ). In a multivariate regression analysis CD163 was the only macrophage marker significantly associated with HOMA-IR (β: 0.57; ). Conclusion. Obesity is associated with elevated numbers of macrophages in the AT. Unexpectedly, the macrophages change phenotype by obesity, with a preponderance of M2 and a decrement of M1 markers in AT from obese subjects. Moreover, CD163 was the only macrophage marker associated with HOMA-IR after multiple adjustments.