Expression Profiles of α1nAChR, ERK1/2, c-FOS and Matrix Metalloproteinases Among Male Smokers with Acute Coronary Syndrome

Acute Coronary Syndrome (ACS) is a severe manifestation of Coronary Artery Disease (CAD) caused by the rupture of unstable atherosclerotic plaques, resulting in reduced myocardial blood flow. Smoking is a major risk factor for ACS and has been associated with increased matrix metalloproteinase (MMP) activity, which contributes to the degradation of the plaque fibrous cap. However, the molecular alterations associated with smoking in ACS remain incompletely understood. This study aimed to investigate the expression of α1nAChR, ERK1/2, and c-FOS genes, together with MMP protein levels in atherosclerotic plaque tissues and peripheral blood mononuclear cells (PBMCs) of CAD patients. A total of 41 atherosclerotic plaque samples (26 smokers, 15 non-smokers) and 180 clinical subjects [n = 30 per group: ACS, chronic coronary syndrome (CCS), and controls; smokers and non-smokers] were included. Gene expression of ⍺1nAChR, ERK 1/2, and c-FOS was analyzed by RT-qPCR, while protein levels of MMP-2, MMP-9, and TIMP 3 were measured using ELISA. The expression of ERK 1/2 and c-FOS were significantly higher in plaque tissues of smokers compared with non-smokers (1.671- and 1.327-fold; p < 0.05). In PBMCs, α1nAChR expression was higher in CCS smokers (1.383-fold), while ERK 1/2 expression was higher in ACS smokers (1.355-fold). MMP-9 levels were significantly elevated in ACS and CCS compared with controls (p < 0.001). In conclusion, smoking CAD patients demonstrated increased expression of α1nAChR, ERK and MMP-9, indicating smoking-associated alterations in ⍺1nAChR-ERK signaling-related biomarkers in ACS.