Journal
AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM
Volume 292, Issue 5, Pages E1433-E1440Publisher
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/ajpendo.00664.2006
Keywords
C1 complement; gene expression
Categories
Funding
- NIDDK NIH HHS [R01 DK080743, R01 DK080743-01, DK-053189] Funding Source: Medline
Ask authors/readers for more resources
Adipose tissue inflammation has recently been linked to the pathogenesis of obesity and insulin resistance. C1 complex comprising three distinct proteins, C1q, C1r, and C1s, involves the key initial activation of the classic pathway of complement and plays an important role in the initiation of inflammatory process. In this study, we investigated adipose expression and regulation of C1 complement subcomponents and C1 activation regulator decorin in obesity and insulin resistance. Expression of C1q in epididymal adipose tissue was increased consistently in ob/ob mice, Zucker obese rats, and high fat-diet-induced obese (HF-DIO) mice. Decorin was found to increase in expression in Zucker obese rats and HF-DIO mice but decrease in ob/ob mice. After TZD administration, C1q and decorin expression was reversed in Zucker obese rats and HF-DIO mice. Increased expression of C1 complement and decorin was observed in both primary adipose and stromal vascular cells isolated from Zucker obese rats. Upregulation of C1r and C1s expression was also perceived in adipose cells from insulin-resistant humans. Furthermore, expression of C1 complement and decorin is dysregulated in TNF-alpha-induced insulin resistance in 3T3-L1 adipocytes and cultured rat adipose cells as they become insulin resistant after 24-h culture. These data suggests that both adipose and immune cells are the sources for abnormal adipose tissue production of C1 complement and decorin in obesity. Our findings also demonstrate that excessive activation of the classic pathway of complement commonly occurs in obesity, suggesting its possible role in adipose tissue inflammation and insulin resistance.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available