Expressions of SOCS-1 and SOCS-3 in the myocardium of patients with sudden cardiac death.

BACKGROUND As the regulators of cytokines, suppressors of cytokine signaling (SOCS) play an important role in the inflammation reaction. Some studies found that SOCS-1 and SOCS-3 were involved in the pathogenesis of some inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease. But the expressions of SOCS in coronary heart disease have not yet been reported. This study aimed to investigate the expression and clinical significance of SOCS-1 and SOCS-3 in the myocardium of patients with sudden cardiac death (SCD). METHODS Myocardial autopsy specimens were collected from 24 patients at the Forensic Medicine Department of Sun Yat-Sen University, Guangzhou, China between 2005 and 2006. Of them, 9 patients had autopsy findings consistent with coronary atherosclerosis (non-myocardial infarction) leading to SCD (non-MI group), 7 died of acute myocardial infaction (MI group), and 8 died from traffic accidents and trauma (control group). The expressions of SOCS-1 mRNA and SOCS-3 mRNA in the myocardium of the non-MI, MI and control groups were detected using RT-PCR. The levels of SOCS-1 and SOCS-3 proteins were detected using immunohistochemistry. Statistical analyses were performed using SPSS version 13.0 software and the data were analyzed by ANOVA. RESULTS The expressions of SOCS-1 mRNA and SOCS-3 mRNA in the non-MI and MI groups were significantly higher than those in the control group[(0.788±0.101), (0.741±0.111) vs. (0.436±0.044), (P<0.01); (0.841±0.092), (0.776±0.070) vs. (0.454±0.076), (P<0.01)] respectively. The antibody-positive cells of SOCS-1 protein in the myocardium of the non-MI and MI groups were significantly higher than those in the myocardium of the control group[(320.00±48.48), (347.14±70.88) vs. (42.50±10.35), (P<0.01)] respectively. The antibody-positive cells of SOCS-3 protein in the myocardium of the non-MI and MI groups were significantly higher than those in the myocardium of the control group[(381.11±59.25) vs. (40.00±10.69), (P<0.01)] and[(332.86±111.91) vs. (40.00±10.69), (P=0.001)]. CONCLUSION The expressions of SOCS-1 and SOCS-3 in the myocardium of patients with SCD from coronary heart disease are significantly increased and contribute to the pathogenesis of SCD.