Effects of "second-hand" smoke on structure and function of fibroblasts, cells that are critical for tissue repair and remodeling

Multiplexed quantitative high content screening reveals that cigarette smoke condensate induces changes in cell structure and function through alterations in cell signaling pathways in human bronchial cells

Human bronchial cells are one of the first cell types exposed to environmental toxins. Toxins often activate nuclear factor-kappaB (NF-kappaB) and protein kinase C (PKC). We evaluated the hypothesis that cigarette smoke condensate (CSC), the particulate fraction of cigarette smoke, activates PKC-alpha and NF-kappaB, and concomitantly disrupts the F-actin cytoskeleton, induces apoptosis and alters cell function in BEAS-2B human bronchial epithelial cells. Compared to controls, exposure of BEAS-2B cells to doses of 30mug/ml CSC significantly activated PKC-alpha, while CSC doses above 20mug/ml CSC significantly activated NF-kappaB. As NF-kappaB was activated, cell number decreased. CSC treatment of BEAS-2B cells induced a decrease in cell size and an increase in cell surface extensions including filopodia and lamellipodia. CSC treatment of BEAS-2B cells induced F-actin rearrangement such that stress fibers were no longer prominent at the cell periphery and throughout the cells, but relocalized to perinuclear regions. Concurrently, CSC induced an increase in the focal adhesion protein vinculin at the cell periphery. CSC doses above 30mug/ml induced a significant increase in apoptosis in BEAS-2B cells evidenced by an increase in activated caspase 3, an increase in mitochondrial mass and a decrease in mitochondrial membrane potential. As caspase 3 increased, cell number decreased. CSC doses above 30mug/ml also induced significant concurrent changes in cell function including decreased cell spreading and motility. CSC initiates a signaling cascade in human bronchial epithelial cells involving PKC-alpha, NF-kappaB and caspase 3, and consequently decreases cell spreading and motility. These CSC-induced alterations in cell structure likely prevent cells from performing their normal function thereby contributing to smoke-induced diseases.

Ccn2/Ctgf overexpression induced by cigarette smoke during cutaneous wound healing is strain dependent

Cigarette smoke has been associated with poor healing in several studies, but the precise mechanisms involving this impairment are still not elucidated. The aim of this work was to investigate cigarette smoke exposure effects on initial phases of cutaneous healing in mice, focusing mainly on gene expression of two molecules involved in wound repair (Ccn2/Ctgf and Tgfb1) and to study if these effects are strain dependent. Mice were exposed to the smoke of nine cigarettes per day, three times per day, for ten days. In the eleventh day an excisional wound was made. The control group was sham-exposed. The cigarette smoke exposure protocol was performed until euthanasia, seven days after wounding. Wound contraction was evaluated. Sections were stained with hematoxylin-eosin, Sirius red, and toluidine blue, and also immunostained for alpha-smooth muscle actin. Gene expression of Ccn2/Ctgf and Tgfb1 was evaluated by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). Smoke-exposed animals presented delay in wound contraction; fibroblastic, inflammatory, and mast cell recruitment; re-epithelialization; myofibroblastic differentiation; and Ccn2/Ctgf and Tgfb1 gene expression. Those alterations were strain dependent. This work confirmed the deleterious effects of cigarette smoke exposure on mouse cutaneous healing depending on mouse strain and links these effects to an overexpression of Ccn2/Ctgf.

Cigarette smoke induces cellular senescence via Werner's syndrome protein down-regulation

RATIONALE

Werner's syndrome is a genetic disorder that causes premature aging due to loss-of-function mutations in a gene encoding a member of the RecQ helicase family. Both Werner's syndrome and cigarette smoking accelerate aging. No studies have examined the effect of cigarette smoke on Werner's syndrome protein.

OBJECTIVES

To investigate the role of Werner's syndrome protein in cigarette smoke-induced cellular senescence.

METHODS

Cellular senescence and amounts of Werner's syndrome protein were measured in fibroblasts isolated from patients with emphysema and compared with age-matched nonsmokers. The in vitro effects of cigarette smoke on amounts of Werner's syndrome protein, function, and senescence were also evaluated in primary human lung fibroblasts and epithelial cells.

MEASUREMENTS AND MAIN RESULTS

Cultured lung fibroblasts isolated from patients with emphysema exhibited a senescent phenotype accompanied by a decrease in Werner's syndrome protein. Cigarette smoke extract decreased Werner's syndrome protein in cultured fibroblasts and epithelial cells. Werner's syndrome protein-deficient fibroblasts were more susceptible to cigarette smoke-induced cellular senescence and cell migration impairment. In contrast, exogenous overexpression of Werner's syndrome protein attenuated the cigarette smoke effects.

CONCLUSIONS

Cigarette smoke induces cellular senescence and cell migration impairment via Werner's syndrome protein down-regulation. Rescue of Werner's syndrome protein down-regulation may represent a potential therapeutic target for smoking-related diseases.

The aryl hydrocarbon receptor attenuates tobacco smoke-induced cyclooxygenase-2 and prostaglandin production in lung fibroblasts through regulation of the NF-kappaB family member RelB

Diseases such as chronic obstructive pulmonary disease and lung cancer caused by cigarette smoke affect millions of people worldwide. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that influences responses to certain environmental pollutants such as tobacco smoke. However, the physiological function(s) of the AhR is unknown. Herein we propose that the physiologic role of the AhR is to limit inflammation. We show that lung fibroblasts from AhR(-/-) mice produce a heightened inflammatory response to cigarette smoke, typified by increased levels of cyclooxygenase-2 (COX-2) and prostaglandins (PGs), when compared with wild type (AhR(+/+)) fibroblasts. This response was dependent on AhR expression as transient transfection of an AhR expression plasmid into AhR(-/-) fibroblasts significantly attenuated the smoke-induced COX-2 and PG production, confirming the anti-inflammatory role of the AhR. The AhR can interact with NF-kappaB. However, the heightened inflammatory response observed in AhR(-/-) fibroblasts was not the result of NF-kappaB (p50/p65) activation. Instead it was coupled with a loss of the NF-kappaB family member RelB in AhR(-/-) fibroblasts. Taken together, these studies provide compelling evidence that AhR expression limits proinflammatory COX-2 and PG production by maintaining RelB expression. The association between RelB and AhR may represent a new therapeutic and more selective target with which to combat inflammation-associated diseases.

Toxicological Screening for the Effects of Short-Term Exposure of Sidestream Cigarette Smoke on Angiogenesis

Angiogenesis is a fundamental process that ensures adequate metabolic supply to tissues in numerous biological and pathological states, including tumorigenesis. Cigarette smoking causes numerous adverse effects, some of which are associated with disruption of the normal process of angiogenesis. It is believed that sidestream cigarette smoke severely affects different components that help in the normal process of angiogenesis. Sidestream cigarette smoke is composed primarily of smoke that emanates from the burning end of a cigarette, and contaminants that diffuse through the cigarette paper. The aim of the current study was to ascertain the toxicological effects of different sidestream cigarette smoke solutions (SSCSS) on angiogenesis by using chicken chorioallantoic membrane (CAM) assay. Decrease in total vascular area, diameter of secondary and tertiary blood vessels, cell proliferation, migration of blood vessels toward ectoderm, and number of capillary plexuses formation was observed by application of SSCSS. Scanning microscopy also revealed deviation in pattern formed by the major capillary plexuses and the fibrillar elements of the mesoderm SSCSS in treated CAMs. It is concluded that SSCSS may hinder the normal process of angiogenesis resulting in abnormal blood supply to tissues and decreased repair and remodeling, which are common problems among smoke-exposed individuals. Further study is required to delineate the effects of different chemicals in SSCSS on angiogenesis.

Effect of nicotine on in vitro maturation of bovine oocytes

The putative effect of nicotine on maturation and the chromosomal complement of bovine oocytes were investigated in the present study. Cumulus-enclosed oocytes were incubated in maturation medium with 0, 0.5, 1.0, 2.5, 5.0, and 10.0 mmol concentrations of nicotine. The results indicated that: (1) nicotine affected cumulus cell expansion in a dose-dependent manner and the perivitelline space failed to form when concentrations were equal to or greater than 5.0 mmol; (2) oocytes treated with 0.5 and 1.0 mmol nicotine concentrations resulted in maturation rates (83.3% and 85.9%, respectively) which was similar to the control (86.2%), whereas treatment with 2.5 and 5.0 mmol concentrations significantly decreased maturation rates to 70.2% and 26.7%, respectively; (3) nicotine at or over 2.5 mmol caused extremely irregular meiotic spindles and interrupted microfilament organization; (4) chromosomal analyses of oocytes with PB1 showed that oocytes derived from 0.5 and 1.0 mmol nicotine groups had haploid complements similar to the control (87-90%), but when the concentrations were increased to 2.5 and 5.0 mmol the haploid state was significantly reduced to around 70%; (5) oocytes at GVBD (germinal vesicle breakdown) and metaphase I stages were less affected by nicotine at 5.0 and 10.0 mmol concentrations than GV-stage oocytes; (6) maturation rates of the short-term nicotine-treated oocytes could be improved when subsequently incubated in normal maturation medium. Prolonged culture of nicotine-pretreated oocytes resulted in self-activation and some oocytes formed 1 or 2 pronuclei. In conclusion, nicotine affects bovine oocyte cumulus cell expansion, maturation rate, and chromosomal complement in a dose-dependent and an oocyte-stage-dependent manner.

Effects of cigarette smoke in mice wound healing is strain dependent

It has been clinically and experimentally shown that cigarette smokers suffer from impaired wound healing, but the mechanisms that lead to the alterations are not well understood. The aim of this study was to investigate if the effects of cigarette smoke exposure on excisional cutaneous wound healing are different depending on the strain (Swiss, BALB/c and C57BL/6 mice) studied. Male mice were exposed to smoke of nine whole cigarettes per day, 3 times/day, daily, for 10 days. In the 11th day a full-thickness excisional wound was performed. Control group was sham-exposed and also had a full-thickness excisional wound. The cigarette smoke exposure protocol was performed until euthanasia. Animals were euthanatized 14 days after wounding. Wound contraction was evaluated 7 and 14 days after lesion. Sections were stained with hematoxylin-eosin, Sirius red or toluidine blue and immunostained for alpha-smooth muscle actin. Smoke exposed animals presented delay in wound contraction, in fibroblastic and inflammatory cells recruitment and in myofibroblastic differentiation; those alterations were strain dependent. Cigarette smoke exposure also affected mast cells recruitment and neoepidermis thickness. In conclusion, the present study demonstrated that the effects of cigarette smoke in mice cutaneous wound healing are related to mice strain studied.

Cytotoxicity and gene expression profiles in cell cultures exposed to whole smoke from three types of cigarettes

The purpose of this study was to evaluate and compare the cytotoxicity and gene expression profiles in cell cultures exposed to whole smoke generated from a full flavor cigarette (Test 1), a low tar cigarette (Test 2), and an ultra-low tar cigarette (Test 3). In addition, a reference cigarette 2R4F was evaluated for cytotoxicity. Neutral red (NR) cytotoxicity assay was performed to determine relative cell death at each exposure concentration (n = 6). LC(50) was generated using wet total particular matter (WTPM), cigarette number, or nicotine concentrations. The overall order of cytotoxicity was Test 1 >> 2R4F approximately Test 2 > Test 3. Cell culture samples were collected for RNA extraction at WTPM concentrations of each cigarette that gave similar nicotine concentrations. Affymetrix mouse whole genome 430 2.0 array was used to characterize the gene expression profiles for each cigarette. A total of 598 genes in Test 1, 176 genes in Test 2, and 234 genes in Test 3 samples were differentially expressed compared to the concurrent sham controls. The major biological processes associated with the changed genes in Test 1 samples were down-regulated DNA replication and cell proliferation; the same biological processes were much less affected in Test 2 and Test 3 samples. The common findings in all three cigarettes types were increased glutathione biosynthesis/consumption and inflammatory response, which are known biological effects caused by smoke exposure. The most significantly up-regulated genes were CYP1A1, GSTs, Hmox1, and Procr in smoke-exposed samples, which are either related to well-studied mechanisms of smoke exposure-related diseases or potential new biomarkers for assessing and monitoring biological effects of cigarette smoke exposure in vivo and in smokers. In summary, both the NR cytotoxicity assay and gene expression profiling were able to differentiate the three types of test cigarettes, and the results demonstrated reduced biological effects for the Test 2 and Test 3 cigarettes compared to the Test 1 cigarette in BALB/c-3T3 Cells.

Nicotine at a low concentration promotes wound healing

BACKGROUND

The adverse effects of smoking on wound healing of the skin are known clinically. Recently, an endogenous cholinergic pathway for angiogenesis mediated by endothelial nicotinic acetylcholine receptors was discovered. The objective of this study was to investigate the appropriate concentration of nicotine at which angiogenesis and wound healing are accelerated in a murine excisional wound model.

MATERIALS AND METHODS

Full-thickness skin defects (8 mm) were created on the dorsum of C57BL mice and a silicone sheet (8 mm) was sutured. PBS (10 microL), bFGF (1 microg), nicotine (10(-1) M, 10(-3) M, 10(-4) M, 10(-7) M, and 10(-10)M), and both bFGF and 10(-4) M nicotine were topically injected for 7 days. Mice were sacrificed on day 8, and the wound area, the neoepithelium length, and the area of newly formed capillaries were assessed.

RESULTS

The wound area was significantly decreased in the wound treated with bFGF, with 10(-4) M nicotine, and with both bFGF and 10(-4) M nicotine. The length of the epithelium was significantly longer and the area of capillaries was also increased significantly in these three groups. The wound area, the length of the epithelium, and the area of capillaries in the group treated with both bFGF and 10(-4) M nicotine were significantly different from those in the 10(-4) M nicotine-treated group.

CONCLUSIONS

In this study, nicotine at a low concentration accelerated angiogenesis and promoted wound healing; these effects of nicotine were synergistic with bFGF.

Effect of smoking on abdominal aortic aneurysms: novel insights through murine models

Abdominal aortic aneurysm is a poorly understood and fatal disease. The etiology of the disease is believed to be multifactorial. Of all the recognized clinical associations, none has a greater impact on the incidence and progression of the disease than exposure to tobacco smoke. Novel murine models developed over the past several years present the opportunity to investigate the mechanism of this critical clinical relationship.

Cigarette smoke exposure inhibits extracellular MMP-2 (gelatinase A) activity in human lung fibroblasts

Background

Exposure to cigarette smoke is considered a major risk factor for the development of lung diseases, since its causative role has been assessed in the induction and maintenance of an inflamed state in the airways. Lung fibroblasts can contribute to these processes, due to their ability to produce proinflammatory chemotactic molecules and extracellular matrix remodelling proteinases. Among proteolytic enzymes, gelatinases A and B have been studied for their role in tissue breakdown and mobilisation of matrix-derived signalling molecules. Multiple reports linked gelatinase deregulation and overexpression to the development of inflammatory chronic lung diseases such as COPD.

Methods

In this study we aimed to determine variations in the gelatinolytic pattern of human lung fibroblasts (HFL-1 cell line) exposed to cigarette smoke extract (CSE). Gelatinolytic activity levels were determined by using gelatin zymography for the in-gel detection of the enzymes (proenzyme and activated forms), and the subsequent semi-quantitative densitometric evaluation of lytic bands. Expression of gelatinases was evaluated also by RT-PCR, zymography of the cell lysates and by western blotting.

Results

CSE exposure at the doses used (1–10%) did not exert any significant cytotoxic effects on fibroblasts. Zymographic analysis showed that CSE exposure resulted in a linear decrease of the activity of gelatinase A. Control experiments allowed excluding a direct inhibitory effect of CSE on gelatinases. Zymography of cell lysates confirmed the expression of MMP-2 in all conditions. Semi-quantitative evaluation of mRNA expression allowed assessing a reduced transcription of the enzyme, as well as an increase in the expression of TIMP-2. Statistical analyses showed that the decrease of MMP-2 activity in conditioned media reached the statistical significance (p = 0.0031 for 24 h and p = 0.0012 for 48 h), while correlation analysis showed that this result was independent from CSE cytotoxicity (p = 0.7833 for both exposures).

Conclusion

Present work describes for the first time that, apart well characterized proinflammatory responses, human lung fibroblasts may react to CSE with a significant reduction of extracellular MMP-2 lytic activity. Therefore, fibroblasts may actively participate to the alteration of the proteolysis/antiproteolysis balance, which reflects the defective repair of the extracellular matrix. Such event should provide a further contribution to the maintenance of the inflamed state in the lungs.

The potential association between smoking and endodontic disease

The aim of this review was to analyse the literature to assess the possibility of an association between smoking and endodontic disease and the prognosis of endodontically treated teeth. The review of the prognosis of endodontically treated teeth involved taking account of any potential associations with smoking and endodontic disease and marginal periodontitis, and smoking and prosthodontic outcomes. In addition, the role of smoking in implant failure and surgical wound healing was analysed with a view to drawing parallels regarding the possible implications of smoking on the outcome of surgical endodontics. A MEDLINE and Cochrane library search including smoking and various endodontic keyword searches identified three papers which discussed the variables, and did not just mention them separately in the text. The literature demonstrates a paucity of evidence relating smoking with endodontic disease and prognosis, but nevertheless presents evidence of a possible influence on the prognosis of endodontically treated teeth in smokers and a likely increase in surgical complications. The possible merits of a smoking cessation protocol prior to surgical endodontics are also discussed.

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 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.

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.

Differential induction of apoptosis by cigarette smoke extract in primary human lung fibroblast strains: implications for emphysema

Cigarette smoke is the principal cause of emphysema. Recent attention has focused on the loss of alveolar fibroblasts in the development of emphysema. Fibroblasts may become damaged by oxidative stress and undergo apoptosis as a result of cigarette smoke exposure. Not all smokers develop lung diseases associated with tobacco smoke, a fact that may reflect individual variation among human fibroblast strains. We hypothesize that fibroblasts from different human beings vary in their ability to undergo apoptosis after cigarette smoke exposure. This could account for emphysematous changes that occur in the lungs of some but not all smokers. Primary human lung fibroblast strains were exposed to cigarette smoke extract (CSE) and assessed for viability, morphological changes, and mitochondrial transmembrane potential as indicators of apoptosis. We also examined the generation of intracellular reactive oxygen species (ROS), 4-hydroxy-2-nonenal, and changes in glutathione (GSH) and glutathione disulfide (GSSG) levels. Each human lung fibroblast strain exhibited a differential sensitivity to CSE as judged by changes in mitochondrial membrane potential, viability, ROS generation, and glutathione production. Interestingly, the thiol antioxidants N-acetyl-L-cysteine and GSH eliminated CSE-induced changes in fibroblast morphology such as membrane blebbing, nuclear condensation, and cell size and prevented alterations in mitochondrial membrane potential and the generation of ROS. These findings support the concept that oxidative stress and apoptosis are responsible for fibroblast death associated with exposure to tobacco smoke. Variations in the sensitivity of fibroblasts to cigarette smoke may account for the fact that only some smokers develop emphysema.

Macaque trophoblast migration toward RANTES is inhibited by cigarette smoke-conditioned medium

Trophoblast migration within the endometrium and uterine vasculature is essential for normal placental and fetal development. We previously demonstrated that macaque trophoblasts express the chemokine receptor CCR5 and that this receptor mediates trophoblast migration toward RANTES (regulated upon activation normal T-cell expressed and secreted). In the present paper we have used primary cultures of early gestation macaque trophoblasts to test the hypothesis that tobacco smoke inhibits trophoblast migration as the result of dysregulation of the RANTES/CCR5 chemotactic axis. Early gestation macaque trophoblasts were incubated in the absence or presence of cigarette smoke-conditioned medium (CSM). Cell migration was quantified using migration chambers. CCR5 and G protein receptor kinase 2 (GRK2) expression was measured by immunofluorescence microscopy and Western blotting. cAMP levels were measured by enzyme-linked immunosorbent assay. Trophoblast migration toward RANTES was reduced when cells were incubated in CSM. Trophoblasts also showed reduced expression of CCR5, increased levels of cAMP, and increased expression of GRK2. Finally, the secretion of RANTES by uterine endothelial cells was reduced by exposing the cells to CSM. These results support the idea that cigarette smoke constituents inhibit directional trophoblast migration by causing increased desensitization of trophoblast CCR5 and inhibiting the secretion of RANTES by endothelial cells.

Clusterin decreases oxidative stress in lung fibroblasts exposed to cigarette smoke

RATIONALE

Cigarette smoke causes injury to lung fibroblasts, partly by means of oxidative stress, and oxidative stress can lead to various lung diseases, such as chronic obstructive pulmonary disease. Clusterin is a widely distributed protein with many functions, including cellular protection in response to oxidative stress.

OBJECTIVES

To determine whether clusterin is involved in the defense of the lung against cigarette smoke, we investigated the effects of cigarette smoke extract on clusterin expression and its protective effect, if any, against oxidative stress.

METHODS

Fibroblasts were coincubated with conditioned medium and cigarette smoke extract, and bronchial biopsy specimens obtained from nonsmokers, smokers, and ex-smokers were analyzed by immunohistochemistry.

MEASUREMENTS AND MAIN RESULTS

At concentrations of 2.5 and 5.0%, cigarette smoke extract induced oxidative stress. It also markedly increased the expression of two clusterin isoforms (60 and 76-80 kD) and the 76-80-kD isoform was secreted in the incubation medium. Coincubation of fibroblasts with conditioned medium significantly decreased the cellular oxidation caused by the cigarette smoke extract. Immunohistochemical analysis of clusterin on bronchial biopsy specimens obtained from smokers and ex-smokers showed localization of clusterin mainly in the submucosa.

CONCLUSIONS

We conclude that clusterin may have a protective effect against cigarette smoke-induced oxidative stress in lung fibroblasts.

Impact of sidestream whole smoke solutions on the outcome of wound repair and related angiogenesis

Wound angiogenesis is essential to support the regenerating tissue and any setback in angiogenesis may result in retarded wound repair. Cigarette smoking causes numerous adverse effects, some of which are associated with poor healing. The current experiment was carried out to elucidate the possible detrimental effects of sidestream whole smoke solutions (SSWSS) on wound healing and related angiogenesis, using a well-defined chicken dorsum excision wound assay. Gross, histopathologic, SEM and computer based 3D image-probing modalities were utilized to quantify different detrimental effects of SSWSS on the fundamental processes of wound healing. A total of 160 chicks, aged 1 week, divided in eight groups were topically exposed for 8 days to SSWSS with different nicotine concentrations. At day 6 and day 8 post-wounding, very highly significant reduction (P<0.001) in wound closure was observed among all SSWSS treated groups. Histological and SEM evaluation of SSWSS treated wounds unveiled deteriorated dermal matrix, delayed re-epithelialization and retarded neovascularization. Moreover, image-probing exploration of SSWSS treated wounds also divulge a very highly significant decrease (P<0.001) in angular spectrum, Sa, Sy and Sci, at day 6 post-wounding. Our study suggests that the cumulative effect of different components of SSWSS has a negative impact on wound healing and related angiogenesis. Furthermore, our study demonstrates the effects that can contribute to abnormal healing and may explain why people who are consistently exposed to sidestream smoke suffer from slow healing and excessive scarring of wounds, much like the smokers themselves.

A novel model of image acquisition and processing for holistic quantification of angiogenesis disrupted by application of mainstream and sidestream cigarette smoke solutions

Angiogenesis is a vital process in the growth of new blood vessels from pre-existing vasculature. Among several approaches being used for studies related to angiogenesis, chicken chorioallantoic membrane assay (CAM) is an excellent model system. However, its utility has been limited due to difficulty in quantifying putative angiogenic and anti-angiogenic response to an experimental compound in an objective and quantifiable manner. Herein, we report a novel approach of image acquisition and processing for better evaluation of neovascularization. The effects of mainstream cigarette smoke solutions (MSCSS) and sidestream cigarette smoke solutions (SSCSS) from different commercially available cigarettes on angiogenesis were quantified, using CAM assay. Different gross and nanometer scale topographies of CAMs were quantified, which are vital for 3D image scrutiny and can precisely enumerate angiogenesis. Pattern formation of blood vessels, diameter, area and 3D surface roughness of CAMs were substantially disrupted by application of cigarette-smoke extracts. An important point revealed in our study that SSCSS appeared to be significantly more toxic than MSCSS with respect to their effects on angiogenesis. This new imaging technique combined with other modalities, will provide a robust platform to optimize trial design and more patent studies in angiogenesis.

Cutaneous Effects of Smoking

BACKGROUND

Cigarette smoking is the single biggest preventable cause of death and disability in developed countries and is a significant public health concern. While known to be strongly associated with a number of cardiovascular and pulmonary diseases and cancers, smoking also leads to a variety of cutaneous manifestations.

OBJECTIVE

This article reviews the effects of cigarette smoking on the skin and its appendages.

METHODS

A literature review was based on a MEDLINE search (1966-2004) for English-language articles using the MeSH terms cutaneous, dermatology, tobacco, skin, and smoking. An additional search was subsequently undertaken for articles related to smoking and associated mucocutanous diseases, with the focus on pathogenesis and epidemiologic data. Articles presenting the highest level of evidence and latest reports were preferentially selected.

RESULTS

Smoking is strongly associated with numerous dermatologic conditions including poor wound healing, wrinkling and premature skin aging, squamous cell carcinoma, psoriasis, hidradenitis suppurativa, hair loss, oral cancers, and other oral conditions. In addition, it has an impact on the skin lesions observed in diabetes, lupus, and AIDS. The evidence linking smoking and melanoma, eczema, and acne is inconclusive. Anecdotal data exist on the possible protective effects of smoking in oral/genital aphthosis of Behçet's disease, herpes labialis, pyoderma gangrenosum, acral melanoma, and Kaposi's sarcoma in AIDS patients.

CONCLUSIONS

An appreciation of the adverse cutaneous consequences of smoking is important. Dermatologists can play an integral role in promoting smoking cessation by providing expert opinion and educating the public on the deleterious effects of smoking on the skin.

Automated migration analysis based on cell texture: method & reliability

Background

In this paper, we present and validate a way to measure automatically the extent of cell migration based on automated examination of a series of digital photographs. It was designed specifically to identify the impact of Second Hand Smoke (SHS) on endothelial cell migration but has broader applications. The analysis has two stages: (1) preprocessing of image texture, and (2) migration analysis.

Results

The output is a graphic overlay that indicates the front lines of cell migration superimposed on each original image, with automated reporting of the distance traversed vs. time. Expert preference compares to manual placement of leading edge shows complete equivalence of automated vs. manual leading edge definition for cell migration measurement.

Conclusion

Our method is indistinguishable from careful manual determinations of cell front lines, with the advantages of full automation, objectivity, and speed.

Nicotine effects on skin: Are they positive or negative?

The adverse effects of tobacco on the skin are well known but the role of nicotine is more controversial. Nicotinic receptors are expressed in the skin, on keratinocytes, fibroblasts and blood vessels. Nicotine induces vasoconstriction associated with local hyperaemia. It inhibits inflammation through effects on central and peripheral nervous system and through direct effect on immune cells. It delays wound healing and accelerates skin aging. The role of nicotine on skin diseases remains unclear. Therapeutic effects of nicotine could be possible and this a new stimulating field of research.