ICAM-1 expression in adipose tissue: effects of diet-induced obesity in mice.
Obesity has been linked to cardiovascular disease, hypertension, diabetes and the metabolic syndrome, with elevated markers of systemic inflammation. Intercellular adhesion molecule-1 (ICAM-1) is a transmembrane adhesion molecule involved in leukocyte migration to sites of inflammation. In human obesity, elevated expression of the soluble form of ICAM-1 (sICAM-1) is positively correlated with abdominal fat deposition. Increases in adiposity have also been correlated with macrophage infiltration into adipose tissue. Here we investigate adipose tissue production and transcriptional regulation of ICAM-1 in a mouse model of dietary obesity. After feeding mice a high-fat diet, ICAM-1 expression in serum and adipose tissue was analyzed by ELISA, Northern blotting, real-time quantitative PCR, and flow cytometry. After 6 mo on the high-fat diet, sICAM-1 levels significantly correlated with body weight and abdominal fat mass. ICAM-1 mRNA was expressed in adipose tissue of mice, with significantly higher levels in males than females. After only 3 wk, there were adipose tissue-specific increases in mRNAs for ICAM-1, IL-6, and monocyte chemoattractant protein-1 (MCP-1) in male mice. Analysis of the stromal-vascular fraction of male adipose tissue revealed CD11b-negative cells with increased surface ICAM-1 and CD34. We also found two populations of F4/80+, CD11b+, ICAM-1+ cells, one of which also expressed CD14 and CD11c and was increased in response to a high-fat diet. These results indicate that within 3 wk on a high-fat diet, male mice exhibited significant increases in pro-inflammatory factors and immune cell infiltration in adipose tissue that may represent links between obesity and its associated inflammatory complications.
Brake
Danett K
DK
Section of Leukocyte Biology, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030-2600, USA.
Smith
E O'Brian
EO
Mersmann
Harry
H
Smith
C Wayne
CW
Robker
Rebecca L
RL
D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D000943:Antigens, Differentiation / Q000378:metabolism; D001835:Body Weight; D016207:Cytokines / Q000378:metabolism; D004032:Diet; D004041:Dietary Fats; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000276:immunology / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D015703:Antigens, CD; D000943:Antigens, Differentiation; D016207:Cytokines; D004041:Dietary Fats; D020033:Protein Isoforms; C036763:monocyte-macrophage differentiation antigen; D018799:Intercellular Adhesion Molecule-1