Pentraxin 3 (PTX3) is an acute phase protein expressed in the advanced atherosclerotic lesions and produced by endothelial cells, macrophages and, in rodents also by adipocytes under tumour necrosis factor α (TNFα) exposure. We investigated if PTX3 is expressed in human adipose tissue and is associated with cardiometabolic risk factors.
Methods: Samples of subcutaneous (SAT) and omental visceral (VAT) adipose tissue were obtained from 21 obese (BMI 38.8±4.48 kg/m2, 37.4±8.15 years) and 10 normal weight subjects (BMI 23.8±1.69 kg/m2, 43.7±11.07yr) who underwent abdominal surgery and had normal leucocyte count. Real-time PCR was used to quantify specific mRNA for PTX3, CD68 (macrophage marker), TNFα and adiponectin. Fresh adipose tissue was cultured and PTX3 measured in the medium. Serum insulin, glucose, HDL and LDL cholesterol, triglycerides, C- reactive protein (CRP), fibrinogen, adiponectin, TNFα and PTX3 were measured.
Results: PTX3 was expressed by adipocytes at similar levels in obese and normal weight subjects and in the two fat compartments. CD68 and PTX3 expression were correlated each other in SAT but not in VAT. In the whole group of subjects, after adjustment for age and sex, VAT PTX3 expression and release were correlated with VAT TNFα expression (r 0.537 and r 0.773, P<0.01 for both) and with LDL/HDL ratio (r −0.471, P<0.01 and r 0.773, P<0.001). VAT-PTX3 expression was also correlated with BMI (r 0.365, P<0.05), triglycerides (r 0.420, P<0.05), CRP (r 0.475, P<0.05), fibrinogen (r 0.446, P<0.05) and adiponectin (r −0.390, P<0.05). In the multivariate analysis with VAT-PTX3 RNA levels as dependent variable, LDL/HDL ratio and fibrinogen remained independently associated with VAT-PTX3 expression (β 0.521, P<0.01 and β 0.616, P<0.01). These associations were not seen within SAT.
Conclusions: Human adipose tissue expresses and releases PTX3 possibly under TNFα control. VAT production of PTX3 seems to contribute to the mechanisms underlying the development of atherosclerosis.
03 - 07 May 2008
European Society of Endocrinology