Increased TNF-α and Decreased TGF-β Expression in Peripheral Blood Leukocytes after Acute Myocardial Infarction

Abstract

Inflammation contributes to the development of atherosclerosis and cardiovascular events. Counteracting pro- and anti-inflammatory responses of serum cytokines have been reported, but the relevance of TNF-α, TGF-β and IL-6 gene expression in peripheral blood leukocytes and their contribution to systemic inflammation in atherosclerosis, especially after acute myocardial infarction (AMI), has not been investigated yet. Using quantitative RT-PCR, we determined temporal cytokine mRNA expression alterations in blood cells from patients with AMI (n = 51). Serum cytokine concentrations were analyzed in parallel using the ELISA technique. TNF-α mRNA expression rates and serum concentrations were significantly elevated in AMI patients compared to controls (n = 77), while mRNA expression and serum content of TGF-β were decreased. Interestingly, we found no statistically significant correlation between transcript and protein levels, indicating that gene expression in leukocytes may be an independent sign for systemic inflammation. While IL-6 was significantly increased in serum from AMI patients with positive correlation to left ventricular dysfunction and negative correlation to ejection fraction, IL-6 mRNA levels did not differ between patients and controls. Gene expression alterations indicate a sophisticated regulation of counteracting TNF-α and TGF-β cytokine expression in peripheral blood leukocytes after AMI with bias towards a pro-inflammatory situation.

Key words

Atherosclerosis - cytokines - gene expression - quantitative RT-PCR - blood cells - inflammation

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1 These authors contributed equally to the work.