Gabrielsson Britt G, Johansson Jenny M, Lönn Malin, Jernås Margareta, Olbers Torsten, Peltonen Markku, Larsson Ingrid, Lönn Lars, Sjöström Lars, Carlsson Björn, Carlsson Lena M S
Research Centre for Endocrinology and Metabolism, Sahlgrenska University Hospital, Göteborg University, Göteborg, Sweden.
Obes Res. 2003 Jun;11(6):699-708. doi: 10.1038/oby.2003.100.
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.
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.
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).
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.
内脏脂肪堆积被认为是肥胖相关代谢紊乱的一个预测指标。主要在该脂肪库中表达的因子可能介导内脏肥胖与相关疾病之间的联系。
从10名肥胖男性身上获取配对的皮下和网膜脂肪组织活检样本。通过DNA微阵列进行三次重复分析以及实时聚合酶链反应来分析基因表达。通过放射免疫扩散测定法对代表普通人群横断面的91名受试者的血清C3和C4进行分析。通过计算机断层扫描测量身体成分。
与皮下脂肪组织相比，网膜脂肪组织中补体成分C2、C3、C4、C7和因子B的表达更高（分别约为2倍、4倍、17倍、10倍和7倍）。此外，属于替代途径的脂肪酶以及经典途径成分C1QB、C1R和C1S在两个脂肪库中均有表达。组织分布分析显示，网膜脂肪组织中C2、C3和C4表达较高，只有肝脏中这些基因的表达更高。男性和女性的血清C3水平与内脏和皮下脂肪组织均相关（男性中r = 0.65，p < 0.001；r = 0.52，p < 0.001；女性中r = 0.34，p = 0.023；r = 0.49，p < 0.001），而C4水平在男性中仅与内脏脂肪相关（r = 0.36，p = 0.015），在女性中与两个脂肪库均相关（内脏：r = 0.58，p < 0.001；皮下：r = 0.51，p < 0.001）。
最近的研究表明，代谢综合征与几种免疫标志物的慢性升高水平相关，其中一些可能具有代谢作用。腹部脂肪组织中补体基因的高表达可能表明补体系统参与了内脏肥胖的发展和/或导致了与内脏脂肪量增加相关的代谢并发症。
