Inflammatory cytokines and cardiovascular disease.

The designation of atherosclerosis as a chronic inflammatory process represents an interesting paradigmatic shift for cardiologists. The plasma concentrations of interleukin-6 and its hepatic byproduct, C-reactive protein, may reflect the intensity of occult plaque inflammation and the vulnerability to rupture. Monocyte chemoattractant protein-1 and interleukin-8 play a crucial role in initiating atherosclerosis by recruiting monocytes/macrophages to the vessel wall, which promotes atherosclerotic lesions and plaque vulnerability. In addition, circulating levels of these proinflammatory cytokines increase in patients with acute myocardial infarction and unstable angina, but not in those with stable angina. Also, the plasma concentrations of these cytokines increase after percutaneous coronary intervention, causing late restenosis after the procedure. Angiotensin II and other atherogenic factors induce these cytokines in the cardiovascular tissues through the activation of transcription factors, such as nuclear factor-kappaB or peroxisome proliferator-activated receptors. Conversely, HMG-CoA reductase inhibitors (statins) can potently inhibit these proinflammatory factors in the vessels. A small GTP-binding protein, Rho, may be a key molecule to explain the anti-inflammatory effects of statins. Interleukin-10 also exerts anti-inflammatory effects on the cardiovascular tissues, possibly by deactivating proinflammatory cytokines and inducible nitric oxide synthase. Gene therapy using interleukin-10 may be a promising means for untreatable or complicated cases of cardiovascular diseases. Thus, therapeutic modulations of these inflammatory cytokines may be useful in the prevention of atherosclerosis and future cardiovascular events.