Pro-inflammatory gene expression in adipose tissue of patients with atherosclerosis

Inflammatory changes, both in the arterial wall and adipose tissue, play a crucial role in the development of atherosclerosis. We measured the gene expression of tumor necrosis factor-alpha (TNFalpha), monocyte chemoattractant protein-1 (MCP-1), and interleukin 6 (IL-6) in adipose tissue (AT) of living kidney donors (LKD) and patients with peripheral arterial disease (PAD). Quantitative polymerase chain reaction (qPCR) and flow cytometry analyses were performed in subcutaneous (SAT), visceral (VAT), and perivascular adipose tissue (PVAT). Data of PAD patients showed significantly higher expression in VAT in all three genes (TNFalpha 5-fold, p<0.05; MCP-1 3.6-fold, p<0.05; IL-6 18.8-fold, p<0.001). The differences in PVAT and SAT were less significant. Total body pro-inflammatory status was documented by higher TNFalpha concentration in patients (4.86+/-1.4 pg/ml) compared to LKDs (2.14+/-0.9 pg/ml; p<0.001), as was hsCRP (11.8+/-7.0 in PAD; 1.5+/-0.48 in LKDs; p=0.017). We found no age-dependent relationship between gene expression vs. TNFalpha and hsCRP concentrations in both compared groups. No effect of the atherosclerosis score on gene expression and circulating inflammatory markers within the PAD group was observed. Our results suggest that the AT of PAD patients infiltrated with macrophages produces more cytokines involved in the development of inflammation and atherosclerosis.