Expression data from monozygotic twins discordant for nicotine metabolism
Ontology highlight
ABSTRACT: The Nicotine Metabolic Ratio (NMR), the ratio of two stable metabolites of nicotine, cotinine and trans-3’hydroxycotinin, is a determinant of the number of cigarettes smoked per day (CPD), of smoking topography, responsiveness to treatment via transdermal nicotine for smoking cessation, and carcinogen activation and level. The predominant gene involved in nicotine metabolism is CYP2A6, a highly polymorphic locus located in a cluster of P450 cytochrome protein loci on chr19q13. A recent study comprehensively modeling CYP2A6 genetic variation at seven polymorphisms and a related Nicotine Metabolic Ratio, the cotinine: cotinine+nicotine ratio, explains 72% of NMRC/C+N variation. These results suggest that additional genes may be contributing to nicotine and cotinine metabolism directly or via interaction with CYP2A6 or other genes. To identify additional genes that may influence the NMR, we conducted a genome-wide gene expression analysis of lymphoblastoid cell line (LCL) gene expression in a sample of monozygotic twins discordant for the NMR.
Project description:<p>A genome-wide association study on smoking behavior and nicotine dependence in Icelandic smokers, assessed by the number of cigarettes smoked per day, smoking initiation and degree of dependence on nicotine.</p> <p>The number of cigarettes smoked per day was ascertained through questionnaires given to individuals participating in multiple disease projects at deCODE Genetics (n=16,483). Smoking initiation was analyzed by comparing those that have ever smoked (n=16,483) versus those that have never smoked (n=21,667). The nicotine dependence analysis included 3,435 nicotine dependent cases (score 4 or higher on Fagerstrom Test for Nicotine Dependence (FTND) or endorsement of at least three of the seven Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) criteria) and 3,344 low-quantity smokers as controls.</p>
Project description:We used microarrays to determine the transcriptional profiles of placental tissue obtained from women who smoked during pregnancy and from women who did not smoke during pregnancy. Fetal growth restriction is a frequent complication in mothers who smoke cigarettes during pregnancy. To evaluate novel pathways that regulate fetal growth affected by mothers who smoke, we isolated placental mRNA from smoking mothers with severe fetal growth restriction and compared them by microarray analysis to non-smoking mothers with appropriately grown fetuses. Bioinformatics analysis revealed distinct transcriptional patterns in the placentas of smoking mothers when compared to placentas from control non-smoking women. Analyses of the top upregulated and downregulated genes revealed several gene products such as secreted frizzled related protein 1 that was markedly upregulated in the placentas from women who smoked cigarettes during pregnancy.
Project description:Cigarette smoke is a major risk factor for the development and progression of chronic obstructive pulmonary disease. Tobacco smoking is also the main cause of lung cancer and the main preventable cause of other lung and heart disease. Strategies to eliminate cigarette smoking have led to the emergence of new tobacco-related products as alternatives for cigarette smoking or tools for smoking cessation. Electronic cigarettes (E-cigarettes) have been introduced to the market in recent years as an alternative to smoking conventional cigarettes. E-cigarettes are nicotine delivery devices by heating and converting to aerosol a liquid mixture composed of propylene glycol, vegetable glycerine, flavouring chemicals, and nicotine. Despite the lack of appropriate studies, e-cigarettes are nowadays widely used and advertised as safe cigarette replacements and the number of users is rapidly growing. Unlike cigarette smoke, where the determinant effects are well studied and documented, very limited amount of research has been done on the health effects and public health of e-cigarettes. The study aims to investigate the effects of e-cigarette vapour extract on gene expression in different primary isolated mouse lung cells [pulmonary arterial smooth muscle cells (PASMC) and alveolar epithelial type two cells (AECII)]. The cells will be exposed to e-cigarette vapour extract (ECVE).
Project description:We used microarrays to determine the transcriptional profiles of placental tissue obtained from women who smoked during pregnancy and from women who did not smoke during pregnancy. Fetal growth restriction is a frequent complication in mothers who smoke cigarettes during pregnancy. To evaluate novel pathways that regulate fetal growth affected by mothers who smoke, we isolated placental mRNA from smoking mothers with severe fetal growth restriction and compared them by microarray analysis to non-smoking mothers with appropriately grown fetuses. Bioinformatics analysis revealed distinct transcriptional patterns in the placentas of smoking mothers when compared to placentas from control non-smoking women. Analyses of the top upregulated and downregulated genes revealed several gene products such as secreted frizzled related protein 1 that was markedly upregulated in the placentas from women who smoked cigarettes during pregnancy. Total RNA was isolated from placental specimens obtained at time of delivery. RNA was hybridized to Affymetrix arrays, and analyzed.
Project description:Little is known about the health risks to humans associated with smoking or “vaping” electronic cigarettes (EC). Based on the knowledge that the adverse effects of cigarette smoking are observed in the dysregulation of lung biology long before clinical abnormalities manifest, we assessed the hypothesis that acute exposure to EC vapors, with or without nicotine, modifies the biology of the lung of healthy never smokers. No significant changes in clinical parameters were observed following this brief exposure to EC vapors. However, marked changes were observed in the transcriptome of small airway epithelium and alveolar macrophage compared to baseline for both exposure groups with and without nicotine, and the group inhaling the nicotine containing vapors had elevated plasma endothelial microparticle levels. While additional studies are needed to ascertain long-term health risks of EC, this study provides preliminary in vivo data suggesting that EC vapors likely dysregulates normal human lung homeostasis, at least at the biologic level.
Project description:Background: Healthy individuals exposed to low levels of cigarette smoke have a decrement in lung function and higher risk for lung disease compared to unexposed individuals. We hypothesized that healthy individuals exposed to low levels of tobacco smoke must have biologic changes in the small airway epithelium compared to healthy unexposed individuals. Methods: Small airway epithelium was obtained by bronchoscopy from 121 individuals; microarrays assessed genome wide gene expression, and urine nicotine and cotinine were used to categorized subjects as “nonsmokers,” “active smokers,” and “low exposure.” The gene expression data was used to determine the threshold and ID50 of urine nicotine and cotinine at which the small airway epithelium showed abnormal responses. Results: There was no threshold of urine nicotine without an abnormal small airway epithelial response, and only a slightly above detectable threshold abnormal response for cotinine. The nicotine ID50 for nicotine was 25 ng/ml and cotinine 104 ng/ml. Conclusions: The small airway epithelium detects and responds to low levels of tobacco smoke with transcriptome modifications. This provides biologic correlates of epidemiologic studies linking low level tobacco smoke exposure to lung health risk, health, identifies genes in the lung cells most sensitive to tobacco smoke and defines thresholds at the lung epithelium responds to inhaled tobacco smoke. Affymetrix arrays were used to assess the gene expression data of smoking-responsive genes in the in small airway epithelium obtained by fiberoptic bronchoscopy of 48 healthy non-smokers (non-smoker or Nsaets), 65 healthy smokers (smoker), 7 symptomatic smokers (SYMs) and a healthy occasional smoker (OcSs). YSB and LO contributed equally to the study.
Project description:<p>Ascertainment: Families were ascertained through panels of adult Australian twins, and a sample of spouses of Australian twins. Families with at least one offspring who was identified as a current or former smoker in an earlier survey. Screening telephone interviews were conducted with index cases to provide confirmation of a history of heavy cigarette smoking, to obtain confirmation of a history of heavy cigarette smoking, and to obtain additional information on the history of cigarette use and the survival status of other family members, and their full siblings and parents. Index cases were the affected spouse of a twin, or the affected twin from pairs discordant for a history of heavy smoking, or a randomly chosen twin from pairs where both have a history of regular smoking (i.e., has smoked at least 100 cigarettes lifetime), and at least one live biological parent to identify sibships with at least one affected sib pair (ASP) concordant for heavy smoking, and at least one living parent. If permission was granted by the index case, eligible family members were contacted and invited to provide a blood sample and to complete a telephone diagnostic interview. In families with just one available biological parent, and additional unaffected sibling who had never smoked on a regular basis (i.e., has smoked fewer than 100 cigarette lifetime, but has experimented with cigarettes once or twice) was included (when available) to help compensate for the loss of information due to missing parental phenotypes. (Target N=400 Australian families with approximately 600 ASPs; and 600 TDT trios comprised of a nicotine dependent index case and both biological parents). <b>Diagnostic Assessment</b>: The telephone diagnostic interview assessed DSM-IV and modified DSM-IIIR diagnoses (i.e., without time clustering) for nicotine dependence, alcohol and other drug dependence and abuse, major depression, and childhood conduct disorder. Most diagnostic assessments were based on the SSAGA/SSAGA-II, developed for the multi-site gene-mapping alcoholism study (the Collaborative Study on the Genetics of Alcohol. An exception was the tobacco section, which was developed directly from the CIDI and DIS (as the original SSAGA did not include a diagnostic section on nicotine dependence).</p>
Project description:Smoking cigarettes is harmful to the cardiovascular system. Considerable attention has been paid to the reduced harm potential of alternative nicotine-containing inhalable products such as e-cigarettes. We investigated the effects of E-vapor aerosols or cigarette smoke (CS) on atherosclerosis progression, cardiovascular function, and molecular changes in the heart and aorta of female ApoE−/− mice. The mice were exposed to aerosols from three different E-vapor formulations: (1) carrier (propylene glycol and vegetable glycerol), (2) base (carrier and nicotine) or (3) test (base and flavor) or to CS from 3R4F reference cigarettes for up to 6 months. Concentrations of CS and base or test aerosols were matched at 35 µg nicotine/L. Exposure to CS, compared with sham-exposed fresh air controls, accelerated atherosclerotic plaque formation, while no such effect was seen for any of the three E-vapor aerosols. Molecular changes indicated disease mechanisms related to oxidative stress and inflammation in general, plus changes in calcium regulation, and altered cytoskeletal organization and microtubule dynamics in the left ventricle. While ejection fraction, fractional shortening, cardiac output, and isovolumic contraction time remained unchanged following E-vapor aerosols exposure, the nicotine-containing base and test aerosols caused an increase in isovolumic relaxation time similar to CS. A nicotine-related increase in pulse wave velocity and arterial stiffness was also observed, but it was significantly lower for base and test aerosols than for CS. These results demonstrate that in comparison with CS, E-vapor aerosols induce substantially lower biological responses associated with smoking-related cardiovascular diseases.
Project description:<p>This study includes samples from two projects: Collaborative Genetic Study of Nicotine Dependence (COGEND; PI: Laura Bierut) and Genetic Study of Nicotine Dependence in African Americans (AAND; PI: Laura Bierut and Eric Johnson).</p> <p>The majority of the COGEND subjects included in the current study overlap with the two datasets already available on dbGaP. GWAS data are available for COGEND subjects through the Study of Addiction: Genetics and Environment (SAGE), dbGaP study accession phs000092. It should be noted that the case definition in the SAGE study is DSM-IV alcohol dependence. GWAS data are available for additional COGEND subjects through The Genetic Architecture of Smoking and Smoking Cessation, dbGaP study accession phs000404.</p> <p>The overall goal of this project is to apply deep sequencing to key genomic regions associated with nicotine dependence in order to accelerate the discovery of variation in molecular pathways that govern the development of nicotine dependence. The sample includes unrelated cases and controls of European American and African American descent. Cases are defined by a commonly used definition of nicotine dependence, a current score of 4 or more (maximum score of 10) on the Fagerstrom Test for Nicotine Dependence (FTND). Control status is defined as an individual who smoked at least 100 cigarettes during their lifetime, yet never became dependent (lifetime FTND<2). By selecting controls who smoked cigarettes, we focus on those genetic effects that are specific to the development of nicotine dependence.</p> <p><b><u>COGEND:</u></b> COGEND was initiated in 2001 as a three-part program project grant funded through the National Cancer Institute (NCI; PI: Laura Bierut). The three projects included a study of the familial transmission of nicotine dependence, a genetic study of nicotine dependence, and a study of the relationship of nicotine dependence with nicotine metabolism. The primary goal was to detect, localize, and characterize genes that predispose or protect an individual with respect to heavy tobacco consumption, nicotine dependence, and related phenotypes and to integrate these findings with the family transmission and nicotine metabolism findings. The primary design was a community based case-control study. Nicotine dependent cases and non-dependent, smoking controls were identified and recruited from Detroit and St. Louis. More than 54,000 subjects aged 25-44 years were screened by telephone; more than 3,100 subjects were personally interviewed; and more than 2,900 subjects donated blood samples for genetic studies. </p> <p><b><u>AAND:</u></b> AAND was initiated in 2009 to identify and characterize genetic determinants of nicotine dependence in a large African American population. Community-based recruitment of approximately 100,000 people was conducted to ascertain 1,000 African American nicotine dependent cases and 1,000 African American non-dependent, smoking controls. All subjects were between the ages of 25-44. Subjects were screened by telephone; if they qualified as a case or control, they completed the same interview that was used in COGEND and donated a blood sample.</p> <p>Both studies (COGEND and AAND) included measures of basic socio-demographic variables, including age, sex, race/ethnicity, family income, and educational attainment using the Semi-Structured Assessment for the Genetics of Nicotine Dependence. Information on nicotine dependence, as assessed by the Fagerstrom Test for Nicotine Dependence (FTND) is available for all subjects. In addition, participants also completed the Nicotine Dependence Syndrome Scale (NDSS; Shiffman et al., 2004) and the Wisconsin Inventory of Smoking Dependence Motives (WISDM-68; Piper et al, 2004). All subjects were assessed in person by trained research assistants.</p>
Project description:Background: Healthy individuals exposed to low levels of cigarette smoke have a decrement in lung function and higher risk for lung disease compared to unexposed individuals. We hypothesized that healthy individuals exposed to low levels of tobacco smoke must have biologic changes in the small airway epithelium compared to healthy unexposed individuals. Methods: Small airway epithelium was obtained by bronchoscopy from 121 individuals; microarrays assessed genome wide gene expression, and urine nicotine and cotinine were used to categorized subjects as “nonsmokers,” “active smokers,” and “low exposure.” The gene expression data was used to determine the threshold and ID50 of urine nicotine and cotinine at which the small airway epithelium showed abnormal responses. Results: There was no threshold of urine nicotine without an abnormal small airway epithelial response, and only a slightly above detectable threshold abnormal response for cotinine. The nicotine ID50 for nicotine was 25 ng/ml and cotinine 104 ng/ml. Conclusions: The small airway epithelium detects and responds to low levels of tobacco smoke with transcriptome modifications. This provides biologic correlates of epidemiologic studies linking low level tobacco smoke exposure to lung health risk, health, identifies genes in the lung cells most sensitive to tobacco smoke and defines thresholds at the lung epithelium responds to inhaled tobacco smoke.