Monocyte chemoattractant protein-1 is produced in isolated adipocytes, associated with adiposity and reduced after weight loss in morbid obese subjects.

Abstract

Obesity is associated with insulin resistance and premature atherosclerosis. The human adipose tissue produce several adipokines including monocyte chemoattractant protein (MCP)-1, associated with cardiovascular disease and found to be involved in the pathogenesis of atherosclerosis in vitro. (1) To compare mRNA levels of MCP-1, leptin and a macrophage-specific marker (CD68) in isolated adipocytes vs stromal-vascular (SV) cells, (2) to compare mRNA levels of MCP-1 in human adipose tissue to circulating MCP-1 and adiposity (eg BMI: kg/m2) and (3) investigate the effect of weight loss in obese subjects on circulating MCP-1 and leptin. (1) MCP-1 and CD68 mRNA levels in isolated adipocytes vs SV cells were 17% (P<0.01) and approximately 2% (P<0.001), respectively. Leptin mRNA levels in SV cells were approximately 1% of that in isolated adipocytes (P<0.01). (2) MCP-1 mRNA levels correlated with circulating MCP-1 (P<0.05) and BMI (P<0.05). (3) A 12% weight loss (P<0.001) was associated with a 25% decrease in insulin levels (P<0.01). Circulating MCP-1 and leptin decreased by 20% (P<0.001) and by 24% (P<0.001), respectively. The findings demonstrate that MCP-1 is produced in isolated human adipocytes. In addition, the findings suggest that MCP-1 may be involved in obesity-related health complications and support the hypothesis that weight loss is beneficial by improving the low-grade inflammation observed in obesity.