ORIGINAL ARTICLE Dietary intervention-induced weight loss decreases macrophage content in adipose tissue of obese women M Kova ´c ˇikova ´ 1,2 , C Sengenes 3,4 , Z Kova ´c ˇova ´ 1,2 ,MS ˇ iklova ´-Vı ´tkova ´ 1,2 , E Klimc ˇa ´kova ´ 1,2 , J Pola ´k 2,5 , L Rossmeislova ´ 1,2,3 , M Bajzova ´ 1,2 , J Hejnova ´ 1,2 , Z Hne ˇvkovska ´ 1,2,5 , A Bouloumie ´ 3,4 , D Langin 1,3,4,6 and V S ˇ tich 1,2 1 Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague, Czech Republic and INSERM, Toulouse, France; 2 Department of Sports Medicine, Third Faculty of Medicine, Charles University, Prague, Czech Republic; 3 Inserm, U858, Obesity Research Laboratory, Rangueil Institute of Molecular Medicine, Toulouse, France; 4 Universite´de Toulouse, UPS, IFR150, Toulouse, France; 5 Second Internal Medicine Department, Vinohrady Teaching Hospital, Prague, Czech Republic and 6 CHU de Toulouse, Laboratory of Biochemistry, IFB, Toulouse, France Objective: Accumulation of adipose tissue macrophages (ATMs) is observed in obesity and may participate in the development of insulin resistance and obesity-related complications. The aim of our study was to investigate the effect of long-term dietary intervention on ATM content in human adipose tissue. Design: We performed a multi-phase longitudinal study. Subjects and measurements: A total of 27 obese pre-menopausal women (age 39±2 years, body mass index 33.7±0.5 kg m –2 ) underwent a 6-month dietary intervention consisting of two periods: 4 weeks of very low-calorie diet (VLCD) followed by weight stabilization composed of 2 months of low-calorie diet and 3to 4 months of weight maintenance diet. At baseline and at the end of each dietary period, samples of subcutaneous adipose tissue (SAT) were obtained by needle biopsy and blood samples were drawn. ATMs were determined by flow cytometry using combinations of cell surface markers. Selected cytokine and chemokine plasma levels were measured using enzyme-linked immunosorbent assay. In addition, in a subgroup of 16 subjects, gene expression profiling of macrophage markers in SAT was performed using real-time PCR. Results: Dietary intervention led to a significant decrease in body weight, plasma insulin and C-reactive protein levels. After VLCD, ATM content defined by CD45 þ /14 þ /206 þ did not change, whereas it decreased at the end of the intervention. This decrease was associated with a downregulation of macrophage marker mRNA levels (CD14, CD163, CD68 and LYVE-1 (lymphatic vessel endothelial hyaluronan receptor-1)) and plasma levels of monocyte-chemoattractant protein-1 (MCP-1) and CXCL5 (chemokine (C-X-C motif) ligand 5). During the whole dietary intervention, the proportion of two ATM subpopulations distinguished by the CD16 marker was not changed. Conclusion: A 6-month weight-reducing dietary intervention, but not VLCD, promotes a decrease in the number of the whole ATM population with no change in the relative distribution of ATM subsets. International Journal of Obesity (2011) 35, 91–98; doi:10.1038/ijo.2010.112; published online 8 June 2010 Keywords: subcutaneous adipose tissue; macrophages; dietary intervention; weight maintenance; obese women Introduction Obesity is a major health problem of the twenty-first century, characterized by increased metabolic and cardio- vascular complications. Its prevalence is reaching epidemic rate. During the past decade, systemic low-grade inflamma- tion and increased accumulation of immune cells into adipose tissue (AT) have been associated with an excess of fat mass. 1–6 Inflammation results in changes in the secretory pattern of AT. The excess fat mass is accompanied by elevated levels of pro-inflammatory cytokines (for example, tumor necrosis factor-a (TNFa) and interleukin-6), chemokines (for example, interleukin-8 and monocyte-chemoattractant protein-1 (MCP-1)) and acute-phase proteins (for example, Received 9 January 2010; revised 19 April 2010; accepted 3 May 2010; published online 8 June 2010 Correspondence: M Kovacikova, Department of Sports Medicine, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague 10, Czech Republic. E-mail: Michaela.Kovacikova@lf3.cuni.cz International Journal of Obesity (2011) 35, 91–98 & 2011 Macmillan Publishers Limited All rights reserved 0307-0565/11 www.nature.com/ijo