Reduction of Macrophage Infiltration and Chemoattractant Gene Expression Changes in White Adipose Tissue of Morbidly Obese Subjects After Surgery-Induced Weight Loss.

Cancello, Raffaella; Henegar, Corneliu; Viguerie, Nathalie; Taleb, Soraya; Poitou, Christine; Rouault, Christine; Coupaye, Muriel; Pelloux, Veronique; Hugol, Danielle; Bouillot, Jean-Luc; Bouloumié, Anne; Barbatelli, Giorgio; Cinti, Saverio; Svensson, Per-Arne; Barsh, Gregory S.; Zucker, Jean-Daniel; Basdevant, Arnaud; Langin, Dominique; Clément, Karine

In human obesity, the stroma vascular fraction (SVF) of white adipose tissue (WAT) is enriched in macrophages. These cells may contribute to low-grade inflammation and to its metabolic complications. Little is known about the effect of weight loss on macrophages and genes involved in macrophage attraction. We examined subcutaneous WAT (scWAT) of 7 lean and 17 morbidly obese subjects before and 3 months after bypass surgery. Immunomorphological changes of the number of scWAT-infiltrating macrophages were evaluated, along with concomitant changes in expression of SVF-overexpressed genes. The number of scWAT-infiltrating macrophages before surgery was higher in obese than in lean subjects (HAM56+/CD68+; 22.6 ± 4.3 vs. 1.4 ± 0.6%, P < 0.001). Typical "crowns" of macrophages were observed around adipocytes. Drastic weight loss resulted in a significant decrease in macrophage number (-11.63 ± 2.3%, P < 0.001), and remaining macrophages stained positive for the anti-inflammatory protein interleukin 10. Genes involved in macrophage attraction (monocyte chemotactic protein [MCP]-1, plasminogen activator urokinase receptor [PLAUR], and colony-stimulating factor [CSF]-3) and hypoxia (hypoxia-inducible factor-1α [HIF-1α]), expression of which increases in obesity and decreases after surgery, were predominantly expressed in the SVF. We show that improvement of the inflammatory profile after weight loss is related to a reduced number of macrophages in scWAT. MCP-1, PLAUR, CSF-3, and HIF-1α may play roles in the attraction of macrophages in scWAT. Diabetes 54:2277-2286, 2005

OBESITY; MACROPHAGES; WEIGHT loss; ADIPOSE tissues; PREOPERATIVE care

Diabetes, 2005, Vol 54, Issue 8, p2277

0012-1797

Academic Journal

10.2337/diabetes.54.8.2277