Matrix-Degrading and Pro-Inflammatory Changes in Human Vascular Endothelial Cells Exposed to Cigarette Smoke Condensate

Abstract

Cigarette smoking has been associated with an increase in the severity and prevalence of atherosclerosis in the abdominal aorta. To begin our investigation of this finding, we used an integrated approach combining gene expression profiling, protein analysis, cytokine measurements, and cytotoxicity determinations to examine molecular responses of cultured human aortic and coronary endothelial cells exposed to cigarette smoke condensate (CSC) and nicotine. Exposure of endothelial cells to CSC (30 and 60 microg/mL TPM) for 24 h resulted in minimal cytotoxicity, and the upregulation of genes involved in matrix degradation (MMP-1, MMP-8, and MMP-9), xenobiotic metabolism (HO-1 and CYP1A2), and downregulation of genes involved in cell cycle regulation (including TOP2A, CCNB1, CCNA, CDKN3). Exposure of cells to a high physiological concentration of nicotine resulted in few differentially expressed genes. Immunoblot analysis of proteins selected from genes shown to be differentially regulated by microarray analysis revealed similar responses. Finally, a number of inflammatory cytokines measured in culture media were elevated in response to CSC. Together, these results describe a complex proinflammatory response, possibly mediating the recruitment of leukocytes through cytokine signaling. Additionally, fibrous cap destabilization may be facilitated by matrix metalloproteinase upregulation.

Smoking, Metalloproteinases, and Vascular Disease

“…Exposure of endothelial cells to cigarette smoke condensate induces expression of MMP-1, MMP-8, and MMP-9. 107 Carotid endarterectomy specimens from cigarette smokers have higher MMP-12 and lower TIMP-1 expression than those from nonsmokers, and this is associated with decreased elastin content. 108 Variation in the stromeolysin-1 gene and smoking status demonstrated synergy in conferring risk for myocardial infarction.…”

Drug Treatment of Hypertension: Focus on Vascular Health

“…Smoking also increases vascular smooth muscle cell proliferation and migration through activation of the platelet-derived growth factor-protein kinase C signalling cascade and alterations in the extracellular matrix and tissue remodelling through increased expression of matrix metalloproteinases (MMP-1/8/9) 199,[209][210][211] . Overall, smoking contributes to endothelial damage and dysfunction, with a shift towards a pro-oxidative and pro-inflammatory state that accelerates atherogenesis and increases the risk of atherosclerotic cardiovascular events 199 .…”

Effect of Smoking on Metalloproteinases (MMPs) Activity in Patients with Acute Myocardial Infarction (AMI)

“…Studies have also shown the increased expression of MMP9 along with other MMPs in endothelial cells exposed to cigarette smoke condensate [27]. Activity of MMP is regulated at the levels of gene transcription, proenzyme activation and endogenous inhibitors of MMPs.…”