The effects of second-hand smoke on biological processes important in atherogenesis

BACKGROUND: Atherosclerosis is the leading cause of death in western societies and cigarette smoke is among the factors that strongly contribute to the development of this disease. The early events in atherogenesis are stimulated on the one hand by cytokines that chemoattract leukocytes and on the other hand by decrease in circulating molecules that protect endothelial cells (ECs) from injury. Here we focus our studies on the effects of "second-hand" smoke on atherogenesis. METHODS: To perform these studies, a smoking system that closely simulates exposure of humans to second-hand smoke was developed and a mouse model system transgenic for human apoB(100 )was used. These mice have moderate lipid levels that closely mimic human conditions that lead to atherosclerotic plaque formation. RESULTS: "Second-hand" cigarette smoke decreases plasma high density lipoprotein levels in the blood and also decreases the ratios between high density lipoprotein and low density lipoprotein, high density lipoprotein and triglyceride, and high density lipoprotein and total cholesterol. This change in lipid profiles causes not only more lipid accumulation in the aorta but also lipid deposition in many of the smaller vessels of the heart and in hepatocytes. In addition, mice exposed to smoke have increased levels of Monocyte Chemoattractant Protein–1 in circulation and in the heart/aorta tissue, have increased macrophages in the arterial walls, and have decreased levels of adiponectin, an EC-protective protein. Also, cytokine arrays revealed that mice exposed to smoke do not undergo the switch from the pro-inflammatory cytokine profile (that develops when the mice are initially exposed to second-hand smoke) to the adaptive response. Furthermore, triglyceride levels increase significantly in the liver of smoke-exposed mice. CONCLUSION: Long-term exposure to "second-hand" smoke creates a state of permanent inflammation and an imbalance in the lipid profile that leads to lipid accumulation in the liver and in the blood vessels of the heart and aorta. The former potentially can lead to non-alcoholic fatty liver disease and the latter to heart attacks

Martins-Green M. Reversal of second-hand cigarette smoke-induced impairment of corneal wound healing by thymosin beta 4 combined with anti-inflammatory agents. Invest Ophthalmol Vis Sci. 2010; 51: 2424–2435. doi

PURPOSE. Abnormalities in corneal reepithelialization caused by second-hand cigarette smoke (CS) are less known than the effects of CS on other tissues. The effects of CS on corneal epithelial cell migration and associated signaling mechanisms were examined, to determine the mechanisms by which CS delays corneal wound healing. METHODS. Corneal epithelial cells in two-dimensional or organ culture were exposed to sidestream whole (SSW) smoke, a major component of second-hand CS. Thymosin beta 4 (T␤4), a molecule thought to promote wound healing in the cornea, was tested to determine whether it can reverse the adverse effects of SSW smoke on corneal healing. RESULTS. Cell migration, actin reorganization, and phosphorylation of focal adhesion kinase (FAK) and paxillin were all inhibited by exposure to SSW smoke, and the distribution of phospho-src in the cells was disrupted. Activation of RhoA, an important regulator of the cytoskeleton during cell migration, was also inhibited. T␤4 stimulated corneal epithelial cell migration in the presence of SSW smoke in culture and in vivo, and it partially reversed the inhibition of corneal healing by SSW smoke. However, T␤4 plus dexamethasone, an inhibitor of inflammation, together, reversed the effects of SSW smoke on corneal healing. CONCLUSIONS. These findings suggest that SSW smoke exerts its effects on cell migration during corneal epithelial healing through inhibition of actin reorganization, activation of focal adhesion molecules, formation of the focal adhesion complex, and activation of Rho-GTPases. Furthermore, they strongly suggest that corneal injury induced by toxicants can be treated using anti-inflammatory agents coupled with T␤4. (Invest Ophthalmol Vis Sci

The effects of second-hand smoke on biological processes important in atherogenesis.

BackgroundAtherosclerosis is the leading cause of death in western societies and cigarette smoke is among the factors that strongly contribute to the development of this disease. The early events in atherogenesis are stimulated on the one hand by cytokines that chemoattract leukocytes and on the other hand by decrease in circulating molecules that protect endothelial cells (ECs) from injury. Here we focus our studies on the effects of "second-hand" smoke on atherogenesis.MethodsTo perform these studies, a smoking system that closely simulates exposure of humans to second-hand smoke was developed and a mouse model system transgenic for human apoB100 was used. These mice have moderate lipid levels that closely mimic human conditions that lead to atherosclerotic plaque formation.Results"Second-hand" cigarette smoke decreases plasma high density lipoprotein levels in the blood and also decreases the ratios between high density lipoprotein and low density lipoprotein, high density lipoprotein and triglyceride, and high density lipoprotein and total cholesterol. This change in lipid profiles causes not only more lipid accumulation in the aorta but also lipid deposition in many of the smaller vessels of the heart and in hepatocytes. In addition, mice exposed to smoke have increased levels of Monocyte Chemoattractant Protein-1 in circulation and in the heart/aorta tissue, have increased macrophages in the arterial walls, and have decreased levels of adiponectin, an EC-protective protein. Also, cytokine arrays revealed that mice exposed to smoke do not undergo the switch from the pro-inflammatory cytokine profile (that develops when the mice are initially exposed to second-hand smoke) to the adaptive response. Furthermore, triglyceride levels increase significantly in the liver of smoke-exposed mice.ConclusionLong-term exposure to "second-hand" smoke creates a state of permanent inflammation and an imbalance in the lipid profile that leads to lipid accumulation in the liver and in the blood vessels of the heart and aorta. The former potentially can lead to non-alcoholic fatty liver disease and the latter to heart attacks