SummaryMetals are vital for a huge number of physiological processes in the human body, but can also destroy health when the concentration is not within the physiologically favourable range. Cigarette smoking interferes with the carefully controlled metal homeostasis of the human body. This review focuses on the consequences of metal delivery to the human body by cigarette smoking and discusses the body's responses. The metal content of tobacco plants, smoke, the circulation, and various organs is discussed. Finally, we link individual cigarette smoke contained metals to the genesis of human diseases. IUBMB Life, 57: 805 -809, 2005
Smoking is a significant risk factor for development of atherosclerosis. However, the pathophysiology of smoking-mediated vessel wall damage is not understood. With tools ranging from analytical chemistry to cell biology, we show that cigarette smoke contains metals that catalyze the direct oxidation of cellular proteins by smoke oxidants. Oxidation of cellular proteins causes a loss of microtubule function, culminating in microtubule depolymerization and proteasome-dependent degradation of alpha-tubulin. As a consequence of the microtubule collapse, cytoskeletal structures as well as intermediate filaments break down, leading finally to a contraction of vascular endothelial cells. We observed a smoke extract-induced, calpain-dependent degradation of the intracellular form of platelet-endothelial cell adhesion molecule 1/CD31, as well as a release of P-selectin/CD62P, IL-6, and IL-8 from endothelial cells into the supernatant. Increased levels of soluble CD62P and IL-6 are well known to be associated with smoking in humans. Increased permeability of the vascular endothelium is a crucial event in atherogenesis. This work highlights the compounds and mechanisms by which cigarette smoke induces leakiness of the vascular endothelium.
Atherosclerosis is a multifactorial, chronic-inflammatory disease for which the underlying cause remains unknown. It is also well documented that T-cells are among the first cells to migrate into the arterial intimal vessel layer, but their function there is still unexplained. Clinical and experimental data have provided evidence that atherosclerosis starts as an autoimmune reaction based on humoral and cellular immunity against a phylogenetically highly conserved stress protein, heat shock protein 60 (HSP60). In the present study, we phenotypically characterized T-cells from endarterectomized specimens of the carotid artery, and tested their reactivity to human HSP60. In addition, the T-cell receptor repertoire of the T-cell lines was defined by immunoscope analysis. We found a mixed population of CD4(+) and CD8(+) intralesional T-cells, with a slight predominance of CD8(+) cells. IFN-gamma production prevailed over IL-4 production. The T-cell reaction against human HSP60 was significantly increased in intralesional cells compared to peripheral T-cells. The lesion-derived T-cells showed an oligoclonally-restricted repertoire, in contrast to the polyclonal pattern of PBMC. These results clearly show that HSP60 is a major antigenic candidate, and that an oligoclonal T-cell expansion takes place in advanced human atherosclerotic lesions.
Background and Purpose-Little research has been conducted into risk factors of atherosclerosis development in young women. Methods-This cross-sectional study enrolled 205 18-to 22-year-old female students from the Educational Centre for Allied Health Professions. A broad array of risk conditions and lifestyle behaviors was carefully assessed. Intima media thickness (IMT) was used as a well-established surrogate for atherosclerosis and a predictor of vascular risk. High IMT was defined as levels exceeding the 90th percentile in the common and/or internal carotid arteries. Results-In multivariable logistic regression analysis, systolic blood pressure, family history for hypertension, lipoprotein(a), homocysteine, T-cell immune reaction against human heat shock protein 60, and exposure to environmental tobacco smoke and exhaust gases emerged as independent predictors of high IMT. Obesity, metabolic syndrome, and classical risk factors other than high blood pressure were rare and unrelated to IMT. Findings were similar once focusing on IMT as a continuous variable. Conclusion-In female youngsters displaying initiating stages of vascular pathology, blood pressure level and numerous nontraditional risk conditions showed a significant relation to high IMT. Our study indicates that (auto)immune processes, high lipoprotein(a), and environmental exposure to tobacco smoke and traffic exhaust may play a role in early atherogenesis.
Objective-Metal constituents of tobacco have long been suspected to contribute to cardiovascular diseases. In this study, we determined the serum concentrations of aluminum, cadmium (Cd), cobalt, copper, iron, manganese, nickel, lead, strontium (Sr), and zinc of young nonsmokers, passive smokers, and smokers. Methods and Results-Cd and Sr were found to be significantly increased in smokers compared with nonsmokers. The effects of these metals on primary arterial endothelial cells were then assessed using microarray technology and real-time polymerase chain reaction (RT-PCR). The data showed that Sr does not interfere with endothelial cell transcription. In contrast, the effects of Cd in amounts delivered to the human body by smoking were dramatic. Conclusions-Arterial endothelial cells responded to Cd exposure by massively upregulating metal and oxidant defense genes (metallothioneins) and by downregulating a number of transcription factors. In addition, the mRNA of the intermediate filament protein vimentin, crucial for the maintenance of cellular shape, was reduced. Surprisingly, a number of pro-inflammatory genes were downregulated in response to Cd. The present data suggest that by delivering Cd to the human body, smoking deregulates transcription, exerts stress, and damages the structure of the vascular endothelium; furthermore, in contrast to the effects of cigarette smoke as a whole, Cd seems to possess antiinflammatory properties. Key Words: atherosclerosis Ⅲ cigarette smoking Ⅲ endothelial Ⅲ metals Ⅲ microarray Ⅲ osteoporosis C igarette smoking is a well-established risk factor for cardiovascular diseases. We have previously shown that among young males, smoking was the most important risk factor for early pro-atherogenic vessel wall changes (increased intima-media thickness). 1 However, the mechanisms by which cigarette smoke constituents contribute to atherogenesis are poorly understood. Therefore, we performed a number of in vitro analyses and could show that out of 4800 different compounds in cigarette smoke, the mixture of metals and oxidants constitutes the crucial endotheliumdamaging noxa. 2 This combination leads to a chain reaction of protein oxidation, functional impairment of the microtubule system, contraction of endothelial cells, endothelial dysfunction, and, finally, to denudation of the inner vascular surface. 2 According to the "response to injury" hypothesis of atherosclerosis, endothelial dysfunction and vessel denudation play the central role in the atherogenic process. 3 Cigarette smoke contains a number of different metals, including aluminum (Al), cadmium, chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), and zinc (Zn). 4 Smoking leads to an increase of serum Cd, Cr, and Pb, 5 and increased serum Cd levels have been shown to contribute to smoking-induced peripheral arterial disease. 6 Abu-Hayyeh et al (2001) reported that along with increased serum levels, Cd also accumulates in the aortic vessel walls of smokers at concentrations of up to 7 mol/L. 7 Furthermo...
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