Porcine coronary arteries: immunohistochemical profile of TNF-alpha, IL-1beta, TGF-beta1 and ICAM-1

In our study we used immunohistochemical technique to demonstrate the presence of the cytokines tumour necrosis factor alpha (TNF-α), interleukin 1beta (IL-1β), transforming growth factor beta1 (TGF-β1) and intercellular adhesion molecule-1 (ICAM-1) in porcine coronaries even in physiological conditions.

Inflammatory cytokines are polypeptide mediators which act as a communication signal between immune system cells and other types of cellsin different organs and tissues, both in human and pig coronary circulation.

Our results show that pro-inflammatory cytokines TNF-α, IL-1β, TGF-β1 and ICAM-1 are also present in the medium tunica of the coronary arteries under physiological conditions. These results may be compared with those found in coronary atherosclerosis, where the increase in TNF-α has a dramatic effect on the function of the left ventricle, and the high value of IL-1 correlates directly with the extent of myocardial necrosis. In our study we observe the damage and activation of endothelial cells; this induces endothelial dysfunction by accumulation and oxidation of low density lipoproteins (LDL). The formation of oxidized LDL could play a central role in the amplification of the inflammatory response causing an increased expression of pro-inflammatory cytokines which promotes leukocyte recruitment in the intimal layer. These leukocytes, after the adhesion to the endothelium, penetrate the intimate tunic.

Therefore inflammatory processes promote the onset and evolution of atheroma and the development of thrombotic complications.