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1.  Up-Regulation and Profibrotic Role of Osteopontin in Human Idiopathic Pulmonary Fibrosis 
PLoS Medicine  2005;2(9):e251.
Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal disorder characterized by fibroproliferation and excessive accumulation of extracellular matrix in the lung.
Methods and Findings
Using oligonucleotide arrays, we identified osteopontin as one of the genes that significantly distinguishes IPF from normal lungs. Osteopontin was localized to alveolar epithelial cells in IPF lungs and was also significantly elevated in bronchoalveolar lavage from IPF patients. To study the fibrosis-relevant effects of osteopontin we stimulated primary human lung fibroblasts and alveolar epithelial cells (A549) with recombinant osteopontin. Osteopontin induced a significant increase of migration and proliferation in both fibroblasts and epithelial cells. Epithelial growth was inhibited by the pentapeptide Gly-Arg-Gly-Asp-Ser (GRGDS) and antibody to CD44, while fibroproliferation was inhibited by GRGDS and antibody to αvβ3 integrin. Fibroblast and epithelial cell migration were inhibited by GRGDS, anti-CD44, and anti-αvβ3. In fibroblasts, osteopontin up-regulated tissue inhibitor of metalloprotease-1 and type I collagen, and down-regulated matrix metalloprotease-1 (MMP-1) expression, while in A549 cells it caused up-regulation of MMP-7. In human IPF lungs, osteopontin colocalized with MMP-7 in alveolar epithelial cells, and application of weakest link statistical models to microarray data suggested a significant interaction between osteopontin and MMP-7.
Our results provide a potential mechanism by which osteopontin secreted from the alveolar epithelium may exert a profibrotic effect in IPF lungs and highlight osteopontin as a potential target for therapeutic intervention in this incurable disease.
Osteopontin may have a critical role in the pathogenesis of idiopathic pulmonary fibrosis, and be a target for therapeutic intervention in this disease.
PMCID: PMC1198037  PMID: 16128620
2.  Osteopontin Expression and Serum Levels in Metastatic Uveal Melanoma — A Pilot Study 
PURPOSE: This pilot study examined osteopontin expression in uveal melanoma and focused on the role of measuring serum osteopontin to detect metastatic uveal melanoma.
METHODS: Osteopontin mRNA was measured in 3 uveal melanoma cell lines of varying invasive potential by real time PCR.Tissue sections of primary and metastatic uveal melanomas were stained for osteopontin. Serum osteopontin levels were measured by ELISA assays in 15 patients with metastatic uveal melanoma and in 37 patients who were disease-free for at least 10 years after treatment of the primary tumor. Paired serum samples drawn from 8 patients before and after development of metastasis were analyzed.
RESULTS: By real time PCR, highly invasive primary and metastatic uveal melanoma cells expressed 6 and 250 fold excess osteopontin mRNA respectively compared with poorly invasive primary uveal melanoma cells. Tissue sections of primary uveal melanomas lacking looping vasculogenic mimicry patterns either did not stain for osteopontin or exhibited weak diffuse staining. In primary melanomas containing looping vasculogenic mimicry patterns, strong osteopontin staining was detected in the tumor periphery where patterns were located. Diffuse strong expression of osteopontin was detected in 8 samples of metastatic uveal melanomas to the liver. Serum osteopontin levels were significantly higher in patients with metastatic uveal melanoma compared with patients who were disease-free for at least 10 years after treatment (p=0.0001) or with age matched controls. Serum osteopontin levels were significantly higher (p=0.008) after metastasis than before the detection of metastasis in 8 patients. When a cut-off value of 10ng/ml was used, the sensitivity and specificity of serum osteopontin in detecting metastatic melanoma was 87.5% and the area under the receiver operator characteristic curve was 96%.
CONCLUSIONS: Osteopontin is expressed diffusely in tissue sections of hepatic metastases from uveal melanoma and increased serum osteopontin levels correlate with metastatic melanoma to the liver with high specificity and sensitivity.
PMCID: PMC1414783  PMID: 16505010
3.  Osteopontin and MMP9: Associations with VEGF Expression/Secretion and Angiogenesis in PC3 Prostate Cancer Cells 
Cancers  2013;5(2):617-638.
Osteopontin and MMP9 are implicated in angiogenesis and cancer progression. The objective of this study is to gain insight into the molecular mechanisms underlying angiogenesis, and to elucidate the role of osteopontin in this process. We report here that osteopontin/αvβ3 signaling pathway which involves ERK1/2 phosphorylation regulates the expression of VEGF. An inhibitor to MEK or curcumin significantly suppressed the phosphorylation of ERK1/2 and expression of VEGF. MMP9 knockdown reduces the secretion but not the expression of VEGF. Moreover, MMP9 knockdown increases the release of angiostatin, a key protein that suppresses angiogenesis. Conditioned media from PC3 cells treated with curcumin or MEK inhibitor inhibited tube formation in vitro in human microvascular endothelial cells. Similar inhibitory effect on tube formation was found with conditioned media collected from PC3 cells expressing mutant-osteopontin at integrin-binding site and knockdown of osteopontin or MMP9. We conclude that MMP9 activation is associated with angiogenesis via regulation of secretion of VEGF and angiostatin in PC3 cells. Curcumin is thus a potential drug for cancer treatment because it demonstrated anti-angiogenic and anti-invasive properties.
PMCID: PMC3730333  PMID: 24216994
osteopontin; integrin αvβ3; MMP9; VEGF; angiogenesis; curcumin
4.  Cigarette Smoke–Induced CXCR3 Receptor Up-Regulation Mediates Endothelial Apoptosis 
Endothelial monocyte–activating polypeptide II (EMAP II) and interferon-inducible protein (IP)–10 are proinflammatory mediators, which in addition to their chemokine activities, selectively induce apoptosis in endothelial cells and are up-regulated in the lungs of cigarette smoke–exposed humans. Previously, we showed that EMAP II is an essential mediator of cigarette smoke–induced lung emphysema in mice linking endothelial cell apoptosis with inflammation. Here we addressed the role of the CXCR3 receptor in EMAP II–induced and IP-10–induced apoptosis in endothelial cells and its regulation by cigarette smoke. We found that both neutralizing antibodies and small inhibitory RNA to CXCR3 abrogated EMAP II–induced and IP-10–induced endothelial caspase-3 activation and DNA fragmentation. CXCR3 receptor surface expression in human lung microvascular endothelial cells and in lung tissue endothelium was up-regulated by exposure to cigarette smoke. In tissue culture conditions, EMAP II–induced and IP-10–induced apoptosis was enhanced by preincubation with cigarette smoke extract. Interestingly, serum starvation also induced CXCR3 up-regulation and enhanced EMAP II–induced endothelial apoptosis. Signal transduction via p38 mitogen-activated protein kinase activation was essential for CXCR3-induced cell death, but not for CXCR3 receptor up-regulation by cigarette smoke. In turn, protein nitration was required for CXCR3 receptor up-regulation by cigarette smoke and consequently for subsequent CXCR3-induced cell death. In conclusion, the concerted up-regulation of proinflammatory EMAP II, IP-10, and CXCR3 by cigarette smoke could sustain a cascade of cell death that may promote the alveolar tissue loss noted in human emphysema.
PMCID: PMC3547093  PMID: 22936405
CXCR3; endothelial; apoptosis; lung; emphysema
5.  The Brazil SimSmoke Policy Simulation Model: The Effect of Strong Tobacco Control Policies on Smoking Prevalence and Smoking-Attributable Deaths in a Middle Income Nation 
PLoS Medicine  2012;9(11):e1001336.
David Levy and colleagues use the SimSmoke model to estimate the effect of Brazil's recent stronger tobacco control policies on smoking prevalence and associated premature mortality, and the effect that additional policies may have.
Brazil has reduced its smoking rate by about 50% in the last 20 y. During that time period, strong tobacco control policies were implemented. This paper estimates the effect of these stricter policies on smoking prevalence and associated premature mortality, and the effect that additional policies may have.
Methods and Findings
The model was developed using the SimSmoke tobacco control policy model. Using policy, population, and smoking data for Brazil, the model assesses the effect on premature deaths of cigarette taxes, smoke-free air laws, mass media campaigns, marketing restrictions, packaging requirements, cessation treatment programs, and youth access restrictions. We estimate the effect of past policies relative to a counterfactual of policies kept to 1989 levels, and the effect of stricter future policies. Male and female smoking prevalence in Brazil have fallen by about half since 1989, which represents a 46% (lower and upper bounds: 28%–66%) relative reduction compared to the 2010 prevalence under the counterfactual scenario of policies held to 1989 levels. Almost half of that 46% reduction is explained by price increases, 14% by smoke-free air laws, 14% by marketing restrictions, 8% by health warnings, 6% by mass media campaigns, and 10% by cessation treatment programs. As a result of the past policies, a total of almost 420,000 (260,000–715,000) deaths had been averted by 2010, increasing to almost 7 million (4.5 million–10.3 million) deaths projected by 2050. Comparing future implementation of a set of stricter policies to a scenario with 2010 policies held constant, smoking prevalence by 2050 could be reduced by another 39% (29%–54%), and 1.3 million (0.9 million–2.0 million) out of 9 million future premature deaths could be averted.
Brazil provides one of the outstanding public health success stories in reducing deaths due to smoking, and serves as a model for other low and middle income nations. However, a set of stricter policies could further reduce smoking and save many additional lives.
Please see later in the article for the Editors' Summary
Editors' Summary
Tobacco kills up to half its users—more than 5 million smokers die every year from tobacco-related causes. It also kills more than half a million non-smokers annually who have been exposed to second-hand smoke. If current trends continue, annual tobacco-related deaths could increase to more than 8 million by 2030. In response to this global tobacco epidemic, the World Health Organization has developed an international instrument for tobacco control called the Framework Convention on Tobacco Control (FCTC). Since it came into force in February 2005, 176 countries have become parties to the FCTC. As such, they agree to implement comprehensive bans on tobacco advertizing, promotion, and sponsorship; to ban misleading and deceptive terms on tobacco packaging; to protect people from exposure to cigarette smoke in public spaces and indoor workplaces; to implement tax policies aimed at reducing tobacco consumption; and to combat illicit trade in tobacco products.
Why Was This Study Done?
Brazil has played a pioneering role in providing support for tobacco control measures in low and middle income countries. It introduced its first cigarette-specific tax in 1990 and, in 1996, it placed the first warnings on cigarette packages and introduced smoke-free air laws. Many of these measures have subsequently been strengthened. Over the same period, the prevalence of smoking among adults (the proportion of the population that smokes) has halved in Brazil, falling from 34.8% in 1989 to 18.5% in 2008. But did the introduction of tobacco control policies contribute to this decline, and if so, which were the most effective policies? In this study, the researchers use a computational model called the SimSmoke tobacco control policy model to investigate this question and to examine the possible effect of introducing additional control policies consistent with the FCTC, which Brazil has been a party to since 2006.
What Did the Researchers Do and Find?
The researchers developed Brazil SimSmoke by incorporating policy, population, and smoking data for Brazil into the SimSmoke simulation model; Brazil SimSmoke estimates smoking prevalence and smoking-attributable deaths from 1989 forwards. They then compared smoking prevalences and smoking-attributable deaths estimated by Brazil SimSmoke for 2010 with and without the inclusion of the tobacco control policies that were introduced between 1989 and 2010. The model estimated that the smoking prevalence in Brazil in 2010 was reduced by 46% by the introduction of tobacco control measures. Almost half of this reduction was explained by price increases, 14% by smoke-free laws, 14% by marketing restrictions, 8% by health warnings, 6% by anti-smoking media campaigns, and 10% by cessation treatment programs. Moreover, as a result of past policies, the model estimated that almost 420,000 tobacco-related deaths had been averted by 2010 and that almost 7 million deaths will have been averted by 2050. Finally, using the model to compare the effects of a scenario that includes stricter policies (for example, an increase in tobacco tax) with a scenario that includes the 2010 policies only, indicated that stricter control policies would reduce the estimated smoking prevalence by an extra 39% between 2010 and 2050 and avert about 1.3 million additional premature deaths.
What Do These Findings Mean?
These findings indicate that the introduction of tobacco control policies has been a critical factor in the rapid decline in smoking prevalence in Brazil over the past 20 years. They also suggest that the introduction of stricter policies that are fully consistent with the FCTC has the potential to reduce the prevalence of smoking further and save many additional lives. Although the reduction in smoking prevalence in Brazil between 1989 and 2010 predicted by the Brazil SimSmoke model is close to the recorded reduction over that period, these findings need to be interpreted with caution because of the many assumptions incorporated in the model. Moreover, the accuracy of the model's predictions depends on the accuracy of the data fed into it, some of which was obtained from other countries and may not accurately reflect the situation in Brazil. Importantly, however, these findings show that, even for a middle income nation, reducing tobacco use is a “winnable battle” that carries huge dividends in terms of reducing illness and death without requiring unlimited resources.
Additional Information
Please access these websites via the online version of this summary at
The World Health Organization provides information about the dangers of tobacco (in several languages), about the Framework Convention on Tobacco Control, and about tobacco control in Brazil
The Framework Convention Alliance provides more information about the FCTC
The Brazilian National Cancer Institute (INCA) provides information on tobacco control policies in Brazil; additional information about tobacco control laws in Brazil is available on the Tobacco Control Laws interactive website, which provides information about tobacco control legislation worldwide
More information on the SimSmoke model of tobacco control policies is available in document or slideshow form
SmokeFree, a website provided by the UK National Health Service, offers advice on quitting smoking and includes personal stories from people who have stopped smoking
PMCID: PMC3491001  PMID: 23139643
6.  Interleukin 4, interleukin 6 and osteopontin-serological markers of head and neck malignancy in primary diagnostics: A pilot study 
Oncology Letters  2014;8(3):1112-1118.
The progression of head and neck squamous cell carcinoma (HNSCC) is stimulated by various angiogenic peptides and growth factors. A correlation between tumor progression and the secretion of various serological mediators in patients with malignant tumors of the head and neck is of major interest for tumor diagnostics, evaluation of the therapy response and it may predict prognosis by specifying the individual tumor biology. Established chemotherapeutic regimes for head and neck tumors usually consist of platinum-based chemotherapeutic drugs and 5-fluorouracil (5-FU). The present pilot study sought to assess the eligibility of seven serological factors as biomarkers for malignant tumors of the head and neck: Platelet-derived growth factor, vascular endothelial growth factor, epidermal growth factor receptor, osteopontin, granulocyte-colony stimulating factor, interleukin-4 (IL-4) and IL-6. The serum levels of each factor in 20 patients receiving concomitant radiochemotherapy with cisplatin or carboplatin and 5-FU with curative intent were determined prior and subsequent to chemotherapy and were compared with 40 healthy controls. Another aim of the pilot study was to investigate whether the serum of patients showed significant differences in the concentrations of the analyzed factors at the start of concomitant radiochemotherapy compared with the controls, whether those markers indicated a neoplastic process and whether concomitant radiochemotherapy with cisplatin or carboplatin and 5-FU induced significant alterations of concentration compared with pre-therapeutic levels. The included patients were histopathologically diagnosed with HNSCC and the average age was 62.3 years. The serum samples of the patients were obtained during the course of regular pre- and post-chemotherapeutic blood draws one week prior to the start of radiochemotherapy and one week following the completion of chemotherapy. The healthy controls were collected from patients of the Sleep Laboratory of the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital (Mannheim, Germany) without clinical evidence or laboratory signs of inflammation or history of a malignant disease. The average age was 50.3 years. The serological level of each factor was ascertained by enzyme-linked immunosorbent assay in duplicate. Serum levels of IL-4, IL-6 and osteopontin were significantly increased in patients with HNSCC compared with those in chemotherapy-naive healthy controls. IL-4 and osteopontin showed no significant therapy-associated alterations. Notably, IL-6 levels significantly increased post-therapeutically. Using logistic regression with osteopontin and IL-4, an individual risk-profile for random samples was calculated. IL-4, IL-6 and osteopontin appear to be suitable indicators of the neoplastic process as they are significantly increased in HNSCC patients compared with the control group. With the exception of IL-6, whose levels were in fact increased following therapy, a significant therapy-associated alteration of these factors was missing. Therefore, these serological markers failed to predict the therapy response, but they may be valuable as a screening instrument in primary diagnostics.
PMCID: PMC4114600  PMID: 25120668
vascular endothelial growth factor; granulocyte-colony stimulating factor; platelet-derived growth factor; osteopontin; epidermal growth factor receptor; interleukin-4; serological markers; interleukin-6; head and neck squamous cell carcinoma
7.  Cigarette Smoking Blocks the Protective Expression of Nrf2/ARE Pathway in Peripheral Mononuclear Cells of Young Heavy Smokers Favouring Inflammation 
PLoS ONE  2009;4(12):e8225.
Cigarette smoking is an important risk factor for atherosclerosis, a chronic inflammatory disease. However the underlying factors of this effect are unclear. It has been hypothesized that water-soluble components of cigarette smoke can directly promote oxidative stress in vasculature and blood cells. Aim of this study was to study the relationship between oxidative stress and inflammation in a group of young smokers. To do this we evaluated: 1) the oxidation products of phospholipids (oxPAPC) in peripheral blood mononuclear cells (PBMC); 2) their role in causing PBMC reactive oxygen species (ROS) generation and changes in GSH; 3) the expression of the transcription factor NF-E2-related factor 2 (Nrf2) and of related antioxidant genes (ARE); 4) the activation of NF-kB and C-reactive protein (CRP) values. We studied 90 healthy volunteers: 32 non-smokers, 32 moderate smokers (5–10 cigarettes/day) and 26 heavy smokers (25–40 cigarettes/day). OxPAPC and p47phox expression, that reasonably reflects NADPH oxidase activity, were higher in moderate smokers and heavy smokers than in non-smokers (p<0.01), the highest values being in heavy smokers (p<0.01). In in vitro studies oxPAPC increased ROS generation via NADPH oxidase activation. GSH in PBMC and plasma was lower in moderate smokers and heavy smokers than in non-smokers (p<0.01), the lowest values being in heavy smokers (p<0.01). Nrf2 expression in PBMC was higher in moderate smokers than in non-smokers (p<0.01), but not in heavy smokers, who had the highest levels of NF-kB and CRP (p<0.01). In in vitro studies oxPAPC dose-dependently increased NF-kB activation, whereas at the highest concentrations Nrf2 expression was repressed. The small interference (si) RNA-mediated knockdown of NF-κB/p65 increased about three times the expression of Nrf2 stimulated with oxPAPC. Cigarette smoke promotes oxPAPC formation and oxidative stress in PBMC. This may cause the activation of NF-kB that in turn may participate in the negative regulation of Nrf2/ARE pathway favouring inflammation.
PMCID: PMC2784946  PMID: 20011043
8.  FLJ10540 is associated with tumor progression in nasopharyngeal carcinomas and contributes to nasopharyngeal cell proliferation, and metastasis via osteopontin/CD44 pathway 
Nasopharyngeal carcinoma (NPC) is well-known for its highly metastatic characteristics, but little is known of its molecular mechanisms. New biomarkers that predict clinical outcome, in particular the ability of the primary tumor to develop metastatic tumors are urgently needed. The aim of this study is to investigate the role of FLJ10540 in human NPC development.
A bioinformatics approach was used to explore the potentially important regulatory genes involved in the growth/metastasis control of NPC. FLJ10540 was chosen for this study. Two co-expression strategies from NPC microarray were employed to identify the relationship between FLJ10540 and osteopontin. Quantitative-RT-PCR, immunoblotting, and immunohistochemistry analysis were used to investigate the mRNA and protein expression profiles of FLJ10540 and osteopontin in the normal and NPC tissues to confirm microarray results. TW01 and Hone1 NPC cells with overexpression FLJ10540 or siRNA to repress endogenous FLJ10540 were generated by stable transfection to further elucidate the molecular mechanisms of FLJ10540-elicited cell growth and metastasis under osteopontin stimulation.
We found that osteopontin expression exhibited a positive correlation with FLJ10540 in NPC microarray. We also demonstrated comprehensively that FLJ10540 and osteopontin were not only overexpressed in NPC specimens, but also significantly correlated with advanced tumor and lymph node-metastasis stages, and had a poor 5-year survival rate, respectively. Stimulation of NPC parental cells with osteopontin results in an increase in FLJ10540 mRNA and protein expressions. Functionally, FLJ10540 transfectant alone, or stimulated with osteopontin, exhibited fast growth and increased metastasis as compared to vehicle control with or without osteopontin stimulation. Conversely, knockdown of FLJ10540 by siRNA results in the suppression of NPC cell growth and motility. Treatment with anti-CD44 antibodies in NPC parental cells not only resulted in a decrease of FLJ10540 protein, but also affected the abilities of FLJ10540-elicited cell growth and motility in osteopontin stimulated-NPC cells.
These findings suggest that FLJ10540 may be critical regulator of disease progression in NPC, and the underlying mechanism may involve in the osteopontin/CD44 pathway.
PMCID: PMC3419101  PMID: 22591637
Nasopharyngeal carcinoma; FLJ10540; Osteopontin; CD44
9.  Current and Former Smoking and Risk for Venous Thromboembolism: A Systematic Review and Meta-Analysis 
PLoS Medicine  2013;10(9):e1001515.
In a meta-analysis of 32 observational studies involving 3,966,184 participants and 35,151 events, Suhua Wu and colleagues found that current, ever, and former smoking was associated with risk of venous thromboembolism.
Please see later in the article for the Editors' Summary
Smoking is a well-established risk factor for atherosclerotic disease, but its role as an independent risk factor for venous thromboembolism (VTE) remains controversial. We conducted a meta-analysis to summarize all published prospective studies and case-control studies to update the risk for VTE in smokers and determine whether a dose–response relationship exists.
Methods and Findings
We performed a literature search using MEDLINE (source PubMed, January 1, 1966 to June 15, 2013) and EMBASE (January 1, 1980 to June 15, 2013) with no restrictions. Pooled effect estimates were obtained by using random-effects meta-analysis. Thirty-two observational studies involving 3,966,184 participants and 35,151 VTE events were identified. Compared with never smokers, the overall combined relative risks (RRs) for developing VTE were 1.17 (95% CI 1.09–1.25) for ever smokers, 1.23 (95% CI 1.14–1.33) for current smokers, and 1.10 (95% CI 1.03–1.17) for former smokers, respectively. The risk increased by 10.2% (95% CI 8.6%–11.8%) for every additional ten cigarettes per day smoked or by 6.1% (95% CI 3.8%–8.5%) for every additional ten pack-years. Analysis of 13 studies adjusted for body mass index (BMI) yielded a relatively higher RR (1.30; 95% CI 1.24–1.37) for current smokers. The population attributable fractions of VTE were 8.7% (95% CI 4.8%–12.3%) for ever smoking, 5.8% (95% CI 3.6%–8.2%) for current smoking, and 2.7% (95% CI 0.8%–4.5%) for former smoking. Smoking was associated with an absolute risk increase of 24.3 (95% CI 15.4–26.7) cases per 100,000 person-years.
Cigarette smoking is associated with a slightly increased risk for VTE. BMI appears to be a confounding factor in the risk estimates. The relationship between VTE and smoking has clinical relevance with respect to individual screening, risk factor modification, and the primary and secondary prevention of VTE.
Please see later in the article for the Editors' Summary
Editors' Summary
Blood normally flows throughout the human body, supplying its organs and tissues with oxygen and nutrients. But, when an injury occurs, proteins called clotting factors make the blood gel (coagulate) at the injury site. The resultant clot (thrombus) plugs the wound and prevents blood loss. Occasionally, a thrombus forms inside an uninjured blood vessel and partly or completely blocks the blood flow. Clot formation inside one of the veins deep within the body, usually in a leg, is called deep vein thrombosis (DVT) and can cause pain, swelling, and redness in the affected limb. DVT can be treated with drugs that stop the blood clot from getting larger (anticoagulants) but, if left untreated, part of the clot can break off and travel to the lungs, where it can cause a life-threatening pulmonary embolism. DVT and pulmonary embolism are collectively known as venous thromboembolism (VTE). Risk factors for VTE include having an inherited blood clotting disorder, oral contraceptive use, prolonged inactivity (for example, during a long-haul plane flight), and having surgery. VTEs are present in about a third of all people who die in hospital and, in non-bedridden populations, about 10% of people die within 28 days of a first VTE event.
Why Was This Study Done?
Some but not all studies have reported that smoking is also a risk factor for VTE. A clear demonstration of a significant association (a relationship unlikely to have occurred by chance) between smoking and VTE might help to reduce the burden of VTE because smoking can potentially be reduced by encouraging individuals to quit smoking and through taxation policies and other measures designed to reduce tobacco consumption. In this systematic review and meta-analysis, the researchers examine the link between smoking and the risk of VTE in the general population and investigate whether heavy smokers have a higher risk of VTE than light smokers. A systematic review uses predefined criteria to identify all the research on a given topic; meta-analysis is a statistical method for combining the results of several studies.
What Did the Researchers Do and Find?
The researchers identified 32 observational studies (investigations that record a population's baseline characteristics and subsequent disease development) that provided data on smoking and VTE. Together, the studies involved nearly 4 million participants and recorded 35,151 VTE events. Compared with never smokers, ever smokers (current and former smokers combined) had a relative risk (RR) of developing VTE of 1.17. That is, ever smokers were 17% more likely to develop VTE than never smokers. For current smokers and former smokers, RRs were 1.23 and 1.10, respectively. Analysis of only studies that adjusted for body mass index (a measure of body fat and a known risk factor for conditions that affect the heart and circulation) yielded a slightly higher RR (1.30) for current smokers compared with never smokers. For ever smokers, the population attributable fraction (the proportional reduction in VTE that would accrue in the population if no one smoked) was 8.7%. Notably, the risk of VTE increased by 10.2% for every additional ten cigarettes smoked per day and by 6.1% for every additional ten pack-years. Thus, an individual who smoked one pack of cigarettes per day for 40 years had a 26.7% higher risk of developing VTE than someone who had never smoked. Finally, smoking was associated with an absolute risk increase of 24.3 cases of VTE per 100,000 person-years.
What Do These Findings Mean?
These findings indicate that cigarette smoking is associated with a statistically significant, slightly increased risk for VTE among the general population and reveal a dose-relationship between smoking and VTE risk. They cannot prove that smoking causes VTE—people who smoke may share other unknown characteristics (confounding factors) that are actually responsible for their increased risk of VTE. Indeed, these findings identify body mass index as a potential confounding factor that might affect the accuracy of estimates of the association between smoking and VTE risk. Although the risk of VTE associated with smoking is smaller than the risk associated with some well-established VTE risk factors, smoking is more common (globally, there are 1.1 billion smokers) and may act synergistically with some of these risk factors. Thus, smoking behavior should be considered when screening individuals for VTE and in the prevention of first and subsequent VTE events.
Additional Information
Please access these Web sites via the online version of this summary at
The US National Heart Lung and Blood Institute provides information on deep vein thrombosis (including an animation about how DVT causes pulmonary embolism), and information on pulmonary embolism
The UK National Health Service Choices website has information on deep vein thrombosis, including personal stories, and on pulmonary embolism; SmokeFree is a website provided by the UK National Health Service that offers advice on quitting smoking
The non-profit organization US National Blood Clot Alliance provides detailed information about deep vein thrombosis and pulmonary embolism for patients and professionals and includes a selection of personal stories about these conditions
The World Health Organization provides information about the dangers of tobacco (in several languages), from the US National Cancer Institute, offers online tools and resources to help people quit smoking
MedlinePlus has links to further information about deep vein thrombosis, pulmonary embolism, and the dangers of smoking (in English and Spanish)
PMCID: PMC3775725  PMID: 24068896
10.  Osteopontin is elevated during neointima formation in rat arteries and is a novel component of human atherosclerotic plaques. 
Journal of Clinical Investigation  1993;92(4):1686-1696.
In an earlier report, we used differential cloning to identify genes that might be critical in controlling arterial neointima formation (Giachelli, C., N. Bae, D. Lombardi, M. Majesky, and S. Schwartz. 1991. Biochem. Biophys. Res. Commun. 177:867-873). In this study, we sequenced the complete cDNA and conclusively identified one of these genes, 2B7, as rat osteopontin. Using immunochemistry and in situ hybridization, we found that medial smooth muscle cells (SMC) in uninjured arteries contained very low levels of osteopontin protein and mRNA. Injury to either the adult rat aorta or carotid artery using a balloon catheter initiated a qualitatively similar time-dependent increase in both osteopontin protein and mRNA in arterial SMC. Expression was transient and highly localized to neointimal SMC during the proliferative and migratory phases of arterial injury, suggesting a possible role for osteopontin in these processes. In vitro, basic fibroblast growth factor (bFGF), transforming growth factor-beta (TGF-beta), and angiotensin II (AII), all proteins implicated in the rat arterial injury response, elevated osteopontin expression in confluent vascular SMC. Finally, we found that osteopontin was a novel component of the human atherosclerotic plaque found most strikingly associated with calcified deposits. These data implicate osteopontin as a potentially important mediator of arterial neointima formation as well as dystrophic calcification that often accompanies this process.
PMCID: PMC288328  PMID: 8408622
11.  Nicotine and oxidative cigarette smoke constituents induce immune-modulatory and pro-inflammatory dendritic cell responses1 
Molecular immunology  2008;45(12):3321-3329.
Chronic airway inflammation is a cardinal feature of chronic obstructive pulmonary disease (COPD), a destructive cigarette smoke-induced lung disease. Although it is apparent that dendritic cells (DCs) are an important constituent of the chronic inflammatory cell influx found in airways of COPD patients, the functional roles of DCs in the pathogenesis of smoking-induced emphysema are unknown. We postulated that DCs activated by cigarette smoke constituents directly participate in the chronic inflammation that characterizes COPD airways. Concordant with this hypothesis, we observed that incubation of DCs with cigarette smoke extract (CSE), and chronic exposure of mice to cigarette smoke, both augmented the generation of neutrophilic chemokines by immature and lipopolysaccharide (LPS) or CD40L-matured DCs. The generation of interleukin-8 (CXCL8/IL-8) by human DCs conditioned with CSE was suppressed by the anti-oxidant n-acetyl cysteine (NAC), implying the involvement of oxidant sensitive pathways as a primary mechanism involved in the enhanced CXCL8/IL-8 generation. Cigarette smoke extract and nicotine also augment the production of secreted prostaglandin E2 and intracellular cyclo-oxygenase-2 (COX-2) in maturing DCs. Whereas NAC suppressed production of CXCL8 by CSE-conditioned DCs, it augmented production of PGE2 and cellular COX-2 levels in maturing DCs. These studies indicate that the stimulation of DCs by cigarette smoke-induced oxidative stress and nicotine promote the generation of pro-inflammatory responses that promote chronic inflammation in smokers. Certain pharmacologic strategies such as anti-oxidant therapy may be only partially effective in mitigating cigarette smoke-induced pro-inflammatory DC-mediated responses in smokers.
PMCID: PMC2857673  PMID: 18533267
Smoking; dendritic cell; oxidative stress; neutrophil; chemokines; prostaglandins
12.  Induction of the unfolded protein response by cigarette smoke is primarily an activating transcription factor 4-C/EBP homologous protein mediated process 
Cigarette smoke is the major risk factor associated with the development of chronic obstructive pulmonary disease (COPD). Recent studies propose a link between endoplasmic reticulum (ER) stress and emphysema, demonstrated by increased ER stress markers under smoking conditions. Here, we investigate whether cigarette smoke-induced ER stress is cell specific and correlates with acute and chronic cigarette smoke exposure.
Gene and protein expression changes in human primary lung cell cultures following cigarette smoke extract (CSE) exposure were monitored by qPCR and Western blot analysis. Mice and guinea pigs were exposed to cigarette smoke and ER stress markers examined in whole lung homogenates. Inflammatory cells from the bronchoalveolar lavage fluid of 10 days smoke exposed mice were also examined.
Cigarette smoke induced a trend increase in the ER stress response through an activating transcription factor 4 (ATF4) mediated induction of C/EBP homologous protein (CHOP) in primary small airway epithelial cells. Bronchial epithelial cells and macrophages responded similarly to CSE. Wild-type mice and guinea pigs exposed to acute levels of cigarette smoke exhibited increased levels of CHOP but not at significant levels. However, after long-term chronic cigarette smoke exposure, CHOP expression was reduced. Interestingly, inflammatory cells from smoke exposed mice had a significant increase in CHOP/ATF4 expression.
A trend increase in CHOP levels appear in multiple human lung cell types following acute cigarette smoke exposure in vitro. In vivo, inflammatory cells, predominately macrophages, demonstrate significant cigarette smoke-induced ER stress. Early induction of CHOP in cigarette smoke may play a pivotal role in early induction of lung disease, however in vivo long-term cigarette smoke exposure exhibited a reduction in the ER stress response.
PMCID: PMC3119106  PMID: 21697995
COPD; ER stress; cigarette smoke; CHOP
13.  Osteopontin and integrin are involved in cholesterol gallstone formation 
This study aimed to investigate the role of osteopontin and its receptor, integrin αv, in gallstone formation using human tissue specimens and a guinea pig lithogenic model.
The nucleation role of osteopontin was determined in patients’ and normal gallbladder bile samples in vitro. Normal gallbladder was the control, and gallstone gallbladders were divided into group I (with normal epithelia) and group II (with degenerated epithelia) based on pathology change. Immunostaining, mRNA and protein expressions of osteopontin and integrin αv were analyzed. The animals were randomly divided into a lithogenic diet group and a normal diet group; the osteopontin mRNA expression in gallbladder and liver and osteopontin concentrations were determined.
Osteopontin prolonged nucleation time and inhibited the pro-nucleating role induced by calcium in human bile in vitro. Immunostaining for osteopontin and integrin αv in human gallbladder tissues showed a higher reactivity in Group I than control group and Group II. The immunostaining in Group II was weaker than control group; similar results were observed for mRNA and protein expression of osteopontin and integrin αv. In the animal assay, the mRNA expression and concentration of osteopontin in gallbladder and liver gradually increased at initial stages and decreased in later stages. The concentrations of osteopontin in bile and serum of guinea pig showed similar trends.
Our results suggest that osteopontin is involved in cholesterol gallstone formation, and the role of osteopontin might correlate with integrin αv and calcium.
PMCID: PMC3560682  PMID: 22207105
osteopontin; cholesterol gallstone formation; bile; lithogenic model
14.  Paracrine Potential of Fibroblasts Exposed to Cigarette Smoke Extract With Vascular Growth Factor Induction 
The Laryngoscope  2013;123(9):2228-2236.
Nicotine, a major constituent of cigarette smoke, can activate the cholinergic anti-inflammatory pathway by binding to α7-nicotinic acetylcholine receptor (α7nAChR) expressed on the surface of certain cells. Here, we ask whether cigarette smoke extract induced different paracrine factors compared to the in vivo regulator of inflammation, tumor necrosis factor-α, in human vocal fold fibroblasts (hVFFs) shown to express low levels of α7nAChR.
Study Design
In vitro.
α7nAChR was detected by nested polymerase chain reaction and immunohistochemistry. γH2AX, a marker for DNA double-stand breaks, was measured by immunofluorescence. Cigarette smoke extract was prepared in accordance with investigators studying effects of cigarette smoke. hVFFs treated for 3 hours had media replaced for an additional 24 hours. Cytokine, chemokine, and growth factor levels in media were assessed by multiplex analysis.
α7nAChR expression levels decreased with the passage number of fibroblasts. Tumor necrosis factor-α induced a significantly different profile of cytokines, chemokines, and growth factor compared to cigarette smoke extract exposure. Cigarette smoke extract at a concentration not associated with induction of γH2AX nuclear foci significantly increased vascular endothelial growth factor.
Cigarette smoke extract elicited a response important for regulation of angiogenesis and vascular permeability during inflammation, without evidence of DNA double-stand breaks associated with carcinogenesis. hVFFs are capable of participating in paracrine regulation of pathological blood vessel formation associated with cigarette smoking–related diseases (ie, Reinke edema). These cells express α7nAChR, an essential component of the cholinergic anti-inflammatory pathway regulated by the vagus nerve in certain tissues and a target of therapeutic agents.
PMCID: PMC4113205  PMID: 23494588
Vocal fold fibroblasts; cigarette smoke extract; γH2AX foci; vascular endothelial growth factor
15.  Osteopontin mediates obesity-induced adipose tissue macrophage infiltration and insulin resistance in mice 
The Journal of Clinical Investigation  2007;117(10):2877-2888.
Obesity is associated with a state of chronic, low-grade inflammation characterized by abnormal cytokine production and macrophage infiltration into adipose tissue, which may contribute to the development of insulin resistance. During immune responses, tissue infiltration by macrophages is dependent on the expression of osteopontin, an extracellular matrix protein and proinflammatory cytokine that promotes monocyte chemotaxis and cell motility. In the present study, we used a murine model of diet-induced obesity to examine the role of osteopontin in the accumulation of adipose tissue macrophages and the development of insulin resistance during obesity. Mice exposed to a high-fat diet exhibited increased plasma osteopontin levels, with elevated expression in macrophages recruited into adipose tissue. Obese mice lacking osteopontin displayed improved insulin sensitivity in the absence of an effect on diet-induced obesity, body composition, or energy expenditure. These mice further demonstrated decreased macrophage infiltration into adipose tissue, which may reflect both impaired macrophage motility and attenuated monocyte recruitment by stromal vascular cells. Finally, obese osteopontin-deficient mice exhibited decreased markers of inflammation, both in adipose tissue and systemically. Taken together, these results suggest that osteopontin may play a key role in linking obesity to the development of insulin resistance by promoting inflammation and the accumulation of macrophages in adipose tissue.
PMCID: PMC1964510  PMID: 17823662
16.  Osteopontin Enhances the Expression and Activity of MMP-2 via the SDF-1/CXCR4 Axis in Hepatocellular Carcinoma Cell Lines 
PLoS ONE  2011;6(8):e23831.
Background and Aims
Osteopontin, SDF-1α, and MMP-2 are important secreted molecules involved in the pathophysiology of human hepatocellular carcinoma (HCC). This study investigates the effect of the SDF-1α/CXCR4 axis on expression and activity of MMP-2 induced by osteopontin.
The expression of CXCR4, SDF-1α, MMP-2 and their associated cellular signaling cascades, involving Akt and MAP Kinases, were determined by Western blotting. The activities of MMP-2 and MMP-9 were assayed by gel zymography. The role of the osteopontin receptors integrin αvβ3 and CD44v6 was evaluated using neutralizing antibodies. We also established CXCR4-deficient SMMC7721 cell lines by transfection with miRNA-CXCR4 plasmids and determined cell invasion activity in a transwell assay.
In comparison with untreated cells, recombinant human osteopontin (rhOPN) up-regulated CXCR4, SDF-1α, and MMP-2 expression about 5-, 4-, and 6-fold on the protein levels through binding to integrin αvβ3 and CD44v6 in hepatocellular carcinoma cells (SMMC7721 and HepG2). Inhibition of the SDF-1α/CXCR4 axis down-regulated the rhOPN-induced MMP-2 expression and activity. rhOPN also activated Akt, p38 and JNK. Down-regulation of CXCR4 decreased the rhOPN-induced invasion in SMMC7721 cells.
These results indicate that rhOPN up-regulates MMP-2 through the SDF-1α/CXCR4 axis, mediated by binding to integrin αvβ3 and CD44v6 and activating the PI-3K/Akt and JNK pathways in HepG2 and SMMC7721 cells. Therefore, the osteopontin-SDF-1α/CXCR4-MMP-2 system may be a new therapeutic target for treating HCC progression.
PMCID: PMC3166084  PMID: 21909361
17.  Circulating osteopontin: a dual marker of bone destruction and angiogenesis in patients with multiple myeloma 
The matrix protein osteopontin has been shown to be a marker of osteoclastic activity in multiple myeloma patients, as well as a regulator of angiogenesis. We measured serum levels of osteopontin in 50 untreated multiple myeloma patients (in 25, also after treatment) and examined the relation to markers of osteolytic and angiogenic activity. The median (range) of serum osteopontin was 85 (5-232) in the patient group vs. 36 (2-190) ng/ml in the control group. Serum osteopontin levels were significantly higher in patients with advanced stage or grade of myeloma disease. All patients with serum osteopontin levels >100 ng/ml had advanced stage (II or III) or high grade bone disease, whereas stage I or low grade patients had serum osteopontin levels <100ng/ml. Serum osteopontin levels significantly decreased after treatment. There was a positive correlation of osteopontin with the bone turnover marker N-terminal propeptide of procollagen type I (NTx) and the angiogenic markers vascular endothelial growth factor (VEGF) and bone marrow microvessel density (r: 0.35, 0.47 and 0.30 respectively, p < 0.05). These results support osteopontin as a dual marker of bone destruction and angiogenic activity in myeloma patients. Osteopontin represents a useful biomarker for monitoring myeloma disease activity.
PMCID: PMC3102033  PMID: 21548993
18.  Protein Phosphatase 2A Regulates Innate Immune and Proteolytic Responses to Cigarette Smoke Exposure in the Lung 
Toxicological Sciences  2012;126(2):589-599.
Protein phosphatase 2A (PP2A) is the primary serine-threonine phosphatase of eukaryotic cells, and changes in its activity have been linked to neoplastic and neurodegenerative diseases. However, the role of PP2A in noncancerous lung diseases such as chronic obstructive pulmonary disease (COPD) has not been previously examined. This study determined that PP2A activity was significantly increased in the lungs of advanced emphysema subjects compared with age-matched controls. Furthermore, we found that cigarette smoke exposure increases PP2A activity in mouse lung in vivo and in primary human small airway epithelial (SAE) cells in vitro. In mice, intratracheal transfection of PP2A protein prior to cigarette smoke exposure prevented acute smoke–induced lung inflammation. Conversely, inhibiting PP2A activity during smoke exposure exacerbated inflammatory responses in the lung. To further determine how PP2A modulates the responses to cigarette smoke in the lung, enzyme levels were manipulated in SAE cells using protein transfection and short hairpin RNA (shRNA) techniques. Increasing PP2A activity in SAE cells via PP2A protein transfection downregulated cytokine expression and prevented the induction of proteases following cigarette smoke extract (CSE) treatment. Conversely, decreasing enzymatic activity by stably transfecting SAE cells with shRNA for the A subunit of PP2A exacerbated these smoke-mediated responses. This study establishes that PP2A induction by cigarette smoke modulates immune and proteolytic responses to cigarette smoke exposure. Together, these findings suggest that manipulation of PP2A activity may be a plausible means to treat COPD and other inflammatory diseases.
PMCID: PMC3307605  PMID: 22223484
phosphatase; inflammation; emphysema
19.  Dynamics of heat shock protein 60 in endothelial cells exposed to cigarette smoke extract 
Heat shock protein 60 (HSP60), expressed on the surface of endothelial cells (ECs) stressed by e.g. oxidized LDL or mechanical shear, was shown to function as an auto-antigen and thus as a pro-atherosclerotic molecule. The aim of this study was to determine whether cigarette smoke chemicals can lead to the activation of the “HSP60 pathway.” It was also our aim to elucidate the dynamics of HSP60 from gene expression to endothelial surface expression and secretion. Here we show for the first time that the exposure of human umbilical vein endothelial cells (HUVECs) to cigarette smoke extract (CSE) results in an up-regulation of HSP60 mRNA. Live cell imaging analysis of a HSP60-EYFP fusion protein construct transfected into ECs revealed that mitochondrial structures collapse in response to CSE exposure. As a result, HSP60 is released from the mitochondria, transported to the cell surface, and released into the cell culture supernatant. Analysis of HSP60 in the sera of healthy young individuals exposed to secondhand smoke revealed significantly elevated levels of HSP60. Cigarette smoking is one of the most relevant risk factors for atherosclerosis. Herein, we provide evidence that cigarette smoke may initiate atherosclerosis in the sense of the “auto-immune hypothesis of atherosclerosis.”
► Cigarette smoke alters the structure and function of mitochondria. ► Cigarette smoke potently induces HSP60 expression and translocation. ► Secondhand smokers are particularly prone to cigarette smoke-induced atherosclerosis.
PMCID: PMC3190135  PMID: 21798264
Cigarette smoking; Heat shock protein 60; Atherosclerosis; Autoimmunity; Live cell imaging
Surgery  2010;148(2):298-309.
Cigarette smoke and nicotine are among the leading environmental risk factors for developing pancreatic ductal adenocarcinoma (PDA). We showed recently that nicotine induces osteopontin (OPN), a protein that plays critical roles in inflammation and tumor metastasis. We identified an OPN isoform, OPNc, that is selectively inducible by nicotine and highly expressed in PDA tissue from smokers. In this study, we explored the potential proinflammatory role of nicotine in PDA through studying its effect on the expression of monocyte chemoattractant protein- (MCP)-1 and evaluated the role of OPN in mediating these effects.
MCP-1 mRNA and protein in PDA cells treated with or without nicotine (3–300 nM) or OPN (0.15–15 nM) were analyzed by real time PCR and ELISA. Luciferase-labeled promoter studies evaluated the effects of nicotine and OPN on MCP-1 transcription. Intracellular and tissue colocalization of OPN and MCP-1 were examined by immunofluorescence and immunohistochemistry.
Nicotine treatment significantly increased MCP-1 expression in PDA cells. Interestingly, blocking OPN with siRNA or OPN antibody abolished these effects. Transient transfection of the OPNc gene in PDA cells or their treatment with recombinant OPN protein significantly (P<0.05) increased MCP-1 mRNA and protein and induced its promoter activity. MCP-1 was found in 60% of invasive PDA lesions, of which 66% were smokers. MCP-1 colocalized with OPN in PDA cells and in the malignant ducts, and correlated well with higher expression levels of OPN in the tissue from patients with invasive PDA.
Our data suggest that cigarette smoking and nicotine may contribute to PDA inflammation through inducing MCP-1 and provide a novel insight into a unique role for OPN in mediating these effects.
PMCID: PMC2908036  PMID: 20579680
pancreatic cancer; nicotine; osteopontin; monocyte chemoattractant protein-1
21.  Agonistic induction of PPARγ reverses cigarette smoke–induced emphysema 
The Journal of Clinical Investigation  2014;124(3):1371-1381.
The development of emphysema in humans and mice exposed to cigarette smoke is promoted by activation of an adaptive immune response. Lung myeloid dendritic cells (mDCs) derived from cigarette smokers activate autoreactive Th1 and Th17 cells. mDC-dependent activation of T cell subsets requires expression of the SPP1 gene, which encodes osteopontin (OPN), a pleiotropic cytokine implicated in autoimmune responses. The upstream molecular events that promote SPP1 expression and activate mDCs in response to smoke remain unknown. Here, we show that peroxisome proliferator–activated receptor γ (PPARG/Pparg) expression was downregulated in mDCs of smokers with emphysema and mice exposed to chronic smoke. Conditional knockout of PPARγ in APCs using Cd11c-Cre Ppargflox/flox mice led to spontaneous lung inflammation and emphysema that resembled the phenotype of smoke-exposed mice. The inflammatory phenotype of Cd11c-Cre Ppargflox/flox mice required OPN, suggesting an antiinflammatory mechanism in which PPARγ negatively regulates Spp1 expression in the lung. A 2-month treatment with a PPARγ agonist reversed emphysema in WT mice despite continual smoke exposure. Furthermore, endogenous PPARγ agonists were reduced in the plasma of smokers with emphysema. These findings reveal a proinflammatory pathway, in which reduced PPARγ activity promotes emphysema, and suggest that targeting this pathway in smokers could prevent and reverse emphysema.
PMCID: PMC3934169  PMID: 24569375
22.  Characterization of osteopontin expression and function after status epilepticus 
Epilepsia  2008;49(10):1675-1685.
Osteopontin is a cytokine found in many tissues and plays a role in tissue injury and repair. This study had two goals: to characterize osteopontin expression after status epilepticus (SE), and to test the hypotheses that osteopontin affects the susceptibility to seizures or alters cell death and inflammation after SE.
Pilocarpine was used to induce SE in OPN−/− and OPN+/+ mice to compare seizure susceptibility, neuropathological markers including real time PCR for inflammatory genes, and osteopontin immunohistochemistry. The effect of added osteopontin on excitotoxicity by N-methyl-d-aspartate in neuronal cultures of ONP−/− mice was determined.
Neurons undergoing degeneration showed osteopontin immunoreactivity 2–3 days after SE. After 10 to 31 days degenerating axons in the thalamus were osteopontin-positive. The susceptibility to seizures of OPN−/− and OPN+/+ mice in the pilocarpine, fluorothyl, and maximal electroshock models was similar. There were no significant differences in the extent of neuronal damage after pilocarpine-induced SE, the expression of several neuropathological markers or the RNA levels of selected inflammatory genes. Recombinant and natural bovine osteopontin did not affect the extent of NMDA-induced cell death in OPN−/− mouse neuronal cultures.
We demonstrated that osteopontin is up-regulated in response to SE in distinct temporal sequences in the hippocampus, specifically in degenerating neurons and axons. However, osteopontin did not appear to regulate neurodegeneration or inflammation within the first 3 days after SE.
PMCID: PMC4090704  PMID: 18522644
Seizure; Pilocarpine; Inflammation; Axonal degeneration; Neuronal degeneration
23.  “Efforts to Reprioritise the Agenda” in China: British American Tobacco's Efforts to Influence Public Policy on Secondhand Smoke in China 
PLoS Medicine  2008;5(12):e251.
Each year, 540 million Chinese are exposed to secondhand smoke (SHS), resulting in more than 100,000 deaths. Smoke-free policies have been demonstrated to decrease overall cigarette consumption, encourage smokers to quit, and protect the health of nonsmokers. However, restrictions on smoking in China remain limited and ineffective. Internal tobacco industry documents show that transnational tobacco companies (TTCs) have pursued a multifaceted strategy for undermining the adoption of restrictions on smoking in many countries.
Methods and Findings
To understand company activities in China related to SHS, we analyzed British American Tobacco's (BAT's) internal corporate documents produced in response to litigation against the major cigarette manufacturers to understand company activities in China related to SHS. BAT has carried out an extensive strategy to undermine the health policy agenda on SHS in China by attempting to divert public attention from SHS issues towards liver disease prevention, pushing the so-called “resocialisation of smoking” accommodation principles, and providing “training” for industry, public officials, and the media based on BAT's corporate agenda that SHS is an insignificant contributor to the larger issue of air pollution.
The public health community in China should be aware of the tactics previously used by TTCs, including efforts by the tobacco industry to co-opt prominent Chinese benevolent organizations, when seeking to enact stronger restrictions on smoking in public places.
Monique Muggli and colleagues study British American Tobacco (BAT) internal documents and find that from the mid 1990s BAT pursued a strategy aimed at influencing the public debate on secondhand smoke in China.
Editors' Summary
Each year, about one million people die in China from tobacco-caused diseases, including cancer, heart disease, and lung disease. Although most of these deaths occur among smokers—300 million people smoke in China, accounting for one-third of the global “consumption” of cigarettes—more than 100,000 deaths from tobacco-related causes occur annually among the 540 million Chinese people who are exposed to secondhand smoke. Tobacco smoke contains 4,000 known chemicals, 69 of which are known or probable carcinogens, and, when it is produced in enclosed spaces, both smokers and nonsmokers are exposed to its harmful effects. The only effective way to reduce tobacco smoke exposure indoors to acceptable levels is to implement 100% smoke-free environments—ventilation, filtration, and the provision of segregated areas for smokers and nonsmokers are insufficient. Importantly, as well as protecting nonsmokers from secondhand smoke, the implementation of smoke-free public places also reduces the number of cigarettes smoked among continuing smokers, increases the likelihood of smokers quitting, and reduces the chances of young people taking up smoking.
Why Was This Study Done?
Article 8 of the World Health Organization's Framework Convention on Tobacco Control (FCTC; an international public-health treaty that seeks to reduce tobacco-caused death and disease) calls on countries party to the treaty to protect their citizens from secondhand smoke exposure. China became a party to the FCTC in 2005 but restrictions on smoking in public places in China remain limited and ineffective. Previous analyses of internal tobacco industry documents have revealed that transnational tobacco companies (TTCs) have used a multifaceted approach to undermine the adoption of restrictions on smoking in many countries. TTCs have been shown to influence media coverage of secondhand smoke issues and to promote ineffective ventilation and separate smoking and nonsmoking areas in restaurants, bars, and hotels (so-called “resocalization of smoking” accommodation principles) with the aim of undermining smoke-free legislation. In addition, TTCs have created organizations interested in non-tobacco-related diseases to draw attention away from the public-health implications of secondhand smoke. In this study, the researchers ask whether TTCs have used a similar approach to undermine the adoption of restrictions on smoking in China, one of the most coveted cigarette markets in the world by the major TTCs.
What Did the Researchers Do and Find?
The researchers analyzed internal corporate documents produced by British American Tobacco (BAT; the predominant TTC in China) in response to litigation against major cigarette manufacturers stored in document depositories in Minnesota, USA and Guildford, UK. Among these documents, they found evidence that BAT had attempted to divert attention from secondhand smoke issues toward liver disease prevention by funding the Beijing Liver Foundation (BFL) from its inception in 1997 until at least 2002 (the most recent year that BAT's corporate records are available for public review). The researchers also found evidence that BAT had promoted “resocialization of smoking” accommodation principles as a “route to avoid smoking bans” and pushed ventilation and air filtration in airports and in establishments serving food and drink. Finally, the researchers found evidence that BAT had sought to “present the message that ‘tobacco smoke is just one of the sources of air polution [sic] and a very insignificant one compared with other pollutants'” through presentations given to the Chinese tobacco industry and media seminars aimed at Chinese journalists.
What Do These Findings Mean?
These findings indicate that, beginning in the mid 1990s and continuing until at least 2002, BAT has followed an intensive, multi-pronged strategy designed to undermine the health policy agenda on secondhand smoke in China. Given their findings, the researchers suggest that BFL and other charitable organizations in China must be wary of accepting tobacco money and that measures must be taken to improve the transparency and accountability of these and other public organizations. To meet FCTC obligations under Article 5.3 (industry interference), policy makers in China, they suggest, must be made aware of how BAT and other TTCs have repeatedly sought to influence health policy in China by focusing attention toward the adoption of ineffective air filtration and ventilation systems in hospitality venues rather than the implementation of 100% smoke-free environments. Finally, Chinese policy makers and the media need to be better informed about BAT's long-standing attempts to communicate misleading messages to them about the health effects of secondhand smoke.
Additional Information.
Please access these Web sites via the online version of this summary at
The World Health Organization's Regional Office for the Western Pacific provides smoking statistics for China and other countries in the region
The World Health Organization provides information on the health problems associated with secondhand smoke, about its Tobacco Free Initiative (available in several languages), and about the Framework Convention on Tobacco Control (also available in several languages)
MedlinePlus provides links to information about the dangers of secondhand smoke (available in English and Spanish)
The UK National Health Service Smokefree Web site provides information about the advantages of giving up smoking, how to give up smoking, and the dangers associated with secondhand smoke
British American Tobacco documents stored in the Minnesota and Guildford Depositories, including those analyzed in this study, can be searched through the British American Tobacco Documents Archive
PMCID: PMC2605899  PMID: 19108603
24.  The Effect of Tobacco Control Measures during a Period of Rising Cardiovascular Disease Risk in India: A Mathematical Model of Myocardial Infarction and Stroke 
PLoS Medicine  2013;10(7):e1001480.
In this paper from Basu and colleagues, a simulation of tobacco control and pharmacological interventions to prevent cardiovascular disease mortality in India predicted that Smokefree laws and increased tobacco taxation are likely to be the most effective measures to avert future cardiovascular deaths in India.
Please see later in the article for the Editors' Summary
We simulated tobacco control and pharmacological strategies for preventing cardiovascular deaths in India, the country that is expected to experience more cardiovascular deaths than any other over the next decade.
Methods and Findings
A microsimulation model was developed to quantify the differential effects of various tobacco control measures and pharmacological therapies on myocardial infarction and stroke deaths stratified by age, gender, and urban/rural status for 2013 to 2022. The model incorporated population-representative data from India on multiple risk factors that affect myocardial infarction and stroke mortality, including hypertension, hyperlipidemia, diabetes, coronary heart disease, and cerebrovascular disease. We also included data from India on cigarette smoking, bidi smoking, chewing tobacco, and secondhand smoke. According to the model's results, smoke-free legislation and tobacco taxation would likely be the most effective strategy among a menu of tobacco control strategies (including, as well, brief cessation advice by health care providers, mass media campaigns, and an advertising ban) for reducing myocardial infarction and stroke deaths over the next decade, while cessation advice would be expected to be the least effective strategy at the population level. In combination, these tobacco control interventions could avert 25% of myocardial infarctions and strokes (95% CI: 17%–34%) if the effects of the interventions are additive. These effects are substantially larger than would be achieved through aspirin, antihypertensive, and statin therapy under most scenarios, because of limited treatment access and adherence; nevertheless, the impacts of tobacco control policies and pharmacological interventions appear to be markedly synergistic, averting up to one-third of deaths from myocardial infarction and stroke among 20- to 79-y-olds over the next 10 y. Pharmacological therapies could also be considerably more potent with further health system improvements.
Smoke-free laws and substantially increased tobacco taxation appear to be markedly potent population measures to avert future cardiovascular deaths in India. Despite the rise in co-morbid cardiovascular disease risk factors like hyperlipidemia and hypertension in low- and middle-income countries, tobacco control is likely to remain a highly effective strategy to reduce cardiovascular deaths.
Please see later in the article for the Editors' Summary
Editors' Summary
Cardiovascular diseases (CVDs) are conditions that affect the heart and/or the circulation. In coronary heart disease, for example, narrowing of the heart's blood vessels by fatty deposits slows the blood supply to the heart and may eventually cause a heart attack (myocardial infarction). Stroke, by contrast, is a CVD in which the blood supply to the brain is interrupted. CVD has been a major cause of illness and death in high-income countries for many years, but the burden of CVD is now rapidly rising in low- and middle-income countries. Indeed, worldwide, three-quarters of all deaths from heart disease and stroke occur in low- and middle-income countries. Smoking, high blood pressure (hypertension), high blood cholesterol (hyperlipidemia), diabetes, obesity, and physical inactivity all increase an individual's risk of developing CVD. Prevention strategies and treatments for CVD include lifestyle changes (for example, smoking cessation) and taking drugs that lower blood pressure (antihypertensive drugs) or blood cholesterol levels (statins) or thin the blood (aspirin).
Why Was This Study Done?
Because tobacco use is a key risk factor for CVD and for several other noncommunicable diseases, the World Health Organization has developed an international instrument for tobacco control called the Framework Convention on Tobacco Control (FCTC). Parties to the FCTC (currently 176 countries) agree to implement a set of core tobacco control provisions including legislation to ban tobacco advertising and to increase tobacco taxes. But will tobacco control measures reduce the burden of CVD effectively in low- and middle-income countries as other risk factors for CVD are becoming more common? In this mathematical modeling study, the researchers investigated this question by simulating the effects of tobacco control measures and pharmacological strategies for preventing CVD on CVD deaths in India. Notably, many of the core FCTC provisions remain poorly implemented or unenforced in India even though it became a party to the convention in 2005. Moreover, experts predict that, over the next decade, this middle-income country will contribute more than any other nation to the global increase in CVD deaths.
What Did the Researchers Do and Find?
The researchers developed a microsimulation model (a computer model that operates at the level of individuals) to quantify the likely effects of various tobacco control measures and pharmacological therapies on deaths from myocardial infarction and stroke in India between 2013 and 2022. They incorporated population-representative data from India on risk factors that affect myocardial infarction and stroke mortality and on tobacco use and exposure to secondhand smoke into their model. They then simulated the effects of five tobacco control measures—smoke-free legislation, tobacco taxation, provision of brief cessation advice by health care providers, mass media campaigns, and advertising bans—and increased access to aspirin, antihypertensive drugs, and statins on deaths from myocardial infarction and stroke. Smoke-free legislation and tobacco taxation are likely to be the most effective strategies for reducing myocardial infarction and stroke deaths over the next decade, according to the model, and the effects of these strategies are likely to be substantially larger than those achieved by drug therapies under current health system conditions. If the effects of smoke-free legislation and tobacco taxation are additive, the model predicts that these two measures alone could avert about 9 million deaths, that is, a quarter of the expected deaths from myocardial infarction and stroke in India over the next 10 years, and that a combination of tobacco control policies and pharmacological interventions could avert up to a third of these deaths.
What Do These Findings Mean?
These findings suggest that the implementation of smoke-free laws and the introduction of increased tobacco taxes in India would yield substantial and rapid health benefits by averting future CVD deaths. The accuracy of these findings is likely to be affected by the many assumptions included in the mathematical model and by the quality of the data fed into it. Importantly, however, these finding suggest that, despite the rise in other CVD risk factors such as hypertension and hyperlipidemia, tobacco control is likely to be a highly effective strategy for the reduction of CVD deaths over the next decade in India and probably in other low- and middle-income countries. Policymakers in these countries should, therefore, work towards fuller and faster implementation of the core FCTC provisions to boost their efforts to reduce deaths from CVD.
Additional Information
Please access these websites via the online version of this summary at
The American Heart Association provides information on all aspects of cardiovascular disease; its website includes personal stories about heart attacks and stroke
The US Centers for Disease Control and Prevention has information on heart disease and on stroke (in English and Spanish
The UK National Health Service Choices website provides information about cardiovascular disease and stroke
MedlinePlus provides links to other sources of information on heart diseases, vascular diseases, and stroke (in English and Spanish)
The World Health Organization provides information (in several languages) about the dangers of tobacco, about the Framework Convention on Tobacco Control, and about noncommunicable diseases; its Global Noncommunicable Disease Network (NCDnet) aims to help low- and middle- income countries reduce illness and death caused by CVD and other noncommunicable diseases
SmokeFree, a website provided by the UK National Health Service, offers advice on quitting smoking and includes personal stories from people who have stopped smoking, supported by the US National Cancer Institute and other US agencies, offers online tools and resources to help people quit smoking
PMCID: PMC3706364  PMID: 23874160
25.  Molecular and Cellular Mechanisms of Cigarette Smoke-Induced Myocardial Injury: Prevention by Vitamin C 
PLoS ONE  2012;7(9):e44151.
Cardiovascular disease (CVD) remains one of the major killers in modern society. One strong risk factor of CVD is cigarette smoking that causes myocardial injury and leads to the genesis of pathological cardiovascular events. However, the exact toxic component(s) of cigarette smoke (CS) and its molecular and cellular mechanisms for causing myocardial injury leading to heart damage and its prevention are largely unknown.
Methodology/Principal Findings
Using a guinea pig model, here we show that chronic exposure to CS produces myocardial injury that is prevented by vitamin C. Male guinea pigs were fed either vitamin C-deficient (0.5 mg/day) or vitamin C-sufficient (15 mg/day) diet and subjected to CS exposure from 5 Kentucky Research cigarettes (3R4F)/day (6 days/week) in a smoke chamber up to 8 weeks. Pair-fed sham controls were subjected to air exposure instead of CS exposure under similar conditions. Myocardial injury was produced in CS-exposed marginal vitamin C-deficient guinea pigs as evidenced by release of cardiac Troponin-T and I in the serum, oxidative stress, inflammation, apoptosis, thrombosis and collagen deposition in the myocardium. Treatment of rat cardiomyocyte cells (H9c2) in vitro and guinea pigs in vivo with p-benzoquinone (p-BQ) in amounts derived from CS revealed that p-BQ was a major factor responsible for CS-induced myocardial damage. A moderately large dose of vitamin C (15 mg/day) prevented CS/p-BQ-induced myocardial injury. Population based studies indicated that plasma vitamin C levels of smokers without disease were significantly lower (p = 0,0000) than that of non-smokers. Vitamin C levels of CS-related cardiovascular patients were further lower (p = 0.0000) than that of smokers without disease.
The results indicate that dietary supplementation of vitamin C may be a novel and simple therapy for the prevention of pathological cardiovascular events in habitual smokers.
PMCID: PMC3435405  PMID: 22970172

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