High expression of complement components in omental adipose tissue in obese men.
Journal article, 2003
OBJECTIVE: Accumulation of visceral fat is recognized as a predictor of obesity-related metabolic disturbances. Factors that are predominantly expressed in this depot could mediate the link between visceral obesity and associated diseases. RESEARCH METHODS AND PROCEDURES: Paired subcutaneous and omental adipose tissue biopsies were obtained from 10 obese men. Gene expression was analyzed by DNA microarrays in triplicate and by real-time polymerase chain reaction. Serum C3 and C4 were analyzed by radial immunodiffusion assays in 91 subjects representing a cross section of the general population. Body composition was measured by computerized tomography. RESULTS: Complement components C2, C3, C4, C7, and Factor B had higher expression in omental compared with subcutaneous adipose tissue ( approximately 2-, 4-, 17-, 10-, and 7-fold, respectively). In addition, adipsin, which belongs to the alternative pathway, and the classical pathway components C1QB, C1R, and C1S were expressed in both depots. Analysis of tissue distribution showed high expression of C2, C3, and C4 in omental adipose tissue, and only liver had higher expression of these genes. Serum C3 levels correlated with both visceral and subcutaneous adipose tissue in both men (r = 0.65 and p < 0.001 and r = 0.52 and p < 0.001, respectively) and women (r = 0.34 and p = 0.023 and r = 0.49 and p < 0.001, respectively), whereas C4 levels correlated with only visceral fat in men (r = 0.36, p = 0.015) and with both depots in women (visceral: r = 0.58, p < 0.001; and subcutaneous: r = 0.51, p < 0.001). DISCUSSION: Recent studies show that the metabolic syndrome is associated with chronically elevated levels of several immune markers, some of which may have metabolic effects. The high expression of complement genes in intra-abdominal adipose tissue might suggest that the complement system is involved in the development of visceral adiposity and/or contributes to the metabolic complications associated with increased visceral fat mass.
genetics
Complement C2
Gene Expression
Male
Complement Factor B
Complement C3
Oligonucleotide Array Sequence Analysis
genetics
Complement C1q
Serine Endopeptidases
Polymerase Chain Reaction
Adipose Tissue
metabolism
genetics
Humans
Obesity
genetics
chemistry
genetics
Complement C7
Complement Factor D
Complement C1s
Complement C1r
Complement System Proteins
genetics
Complement C4
Omentum
genetics
Adult
genetics
genetics
Middle Aged
genetics
Author
Britt Gabrielsson
University of Gothenburg
Jenny Palming
University of Gothenburg
Malin Lönn
University of Gothenburg
Margareta Jernås
University of Gothenburg
Torsten Olbers
University of Gothenburg
Markku Peltonen
University of Gothenburg
Ingrid Larsson
University of Gothenburg
Lars Lönn
University of Gothenburg
Lars Sjöström
University of Gothenburg
Björn Carlsson
University of Gothenburg
Lena M S Carlsson
University of Gothenburg
Obesity Research
1071-7323 (ISSN) 1550-8528 (eISSN)
Vol. 11 6 699-708Subject Categories
Dermatology and Venereal Diseases
Medical Genetics
DOI
10.1038/oby.2003.100
PubMed
12805391