1
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Flor LS, Anderson JA, Ahmad N, Aravkin A, Carr S, Dai X, Gil GF, Hay SI, Malloy MJ, McLaughlin SA, Mullany EC, Murray CJL, O'Connell EM, Okereke C, Sorensen RJD, Whisnant J, Zheng P, Gakidou E. Health effects associated with exposure to secondhand smoke: a Burden of Proof study. Nat Med 2024; 30:149-167. [PMID: 38195750 PMCID: PMC10803272 DOI: 10.1038/s41591-023-02743-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 11/28/2023] [Indexed: 01/11/2024]
Abstract
Despite a gradual decline in smoking rates over time, exposure to secondhand smoke (SHS) continues to cause harm to nonsmokers, who are disproportionately children and women living in low- and middle-income countries. We comprehensively reviewed the literature published by July 2022 concerning the adverse impacts of SHS exposure on nine health outcomes. Following, we quantified each exposure-response association accounting for various sources of uncertainty and evaluated the strength of the evidence supporting our analyses using the Burden of Proof Risk Function methodology. We found all nine health outcomes to be associated with SHS exposure. We conservatively estimated that SHS increases the risk of ischemic heart disease, stroke, type 2 diabetes and lung cancer by at least around 8%, 5%, 1% and 1%, respectively, with the evidence supporting these harmful associations rated as weak (two stars). The evidence supporting the harmful associations between SHS and otitis media, asthma, lower respiratory infections, breast cancer and chronic obstructive pulmonary disease was weaker (one star). Despite the weak underlying evidence for these associations, our results reinforce the harmful effects of SHS on health and the need to prioritize advancing efforts to reduce active and passive smoking through a combination of public health policies and education initiatives.
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Affiliation(s)
- Luisa S Flor
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, WA, USA.
| | - Jason A Anderson
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Noah Ahmad
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Aleksandr Aravkin
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, WA, USA
| | - Sinclair Carr
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Xiaochen Dai
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Gabriela F Gil
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- Department of Global Health, University of Washington, Seattle, WA, USA
| | - Simon I Hay
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, WA, USA
| | - Matthew J Malloy
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Susan A McLaughlin
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Erin C Mullany
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Christopher J L Murray
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, WA, USA
| | - Erin M O'Connell
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Chukwuma Okereke
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Reed J D Sorensen
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Joanna Whisnant
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Peng Zheng
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, WA, USA
| | - Emmanuela Gakidou
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, WA, USA
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Wolters AAB, Kersten ETG, Koppelman GH. Genetics of preschool wheeze and its progression to childhood asthma. Pediatr Allergy Immunol 2024; 35:e14067. [PMID: 38284918 DOI: 10.1111/pai.14067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 12/13/2023] [Indexed: 01/30/2024]
Abstract
Wheezing is a common and heterogeneous condition in preschool children. In some countries, the prevalence can be as high as 30% and up to 50% of all children experience wheezing before the age of 6. Asthma often starts with preschool wheeze, but not all wheezing children will develop asthma at school age. At this moment, it is not possible to accurately predict which wheezing children will develop asthma. Recently, studying the genetics of wheeze and the childhood-onset of asthma have grown in interest. Childhood-onset asthma has a stronger heritability in comparison with adult-onset asthma. In early childhood asthma exacerbations, CDHR3, which encodes the receptor for Rhinovirus C, was identified, as well as IL33, and the 17q locus that includes GSDMB and ORMDL3 genes. The 17q locus is the strongest wheeze and childhood-onset asthma locus, and was shown to interact with many environmental factors, including smoking and infections. Finally, ANXA1 was recently associated with early-onset, persistent wheeze. ANXA1 may help resolve eosinophilic inflammation. Overall, despite its complexities, genetic approaches to unravel the early-onset of wheeze and asthma are promising, since these shed more light on mechanisms of childhood asthma-onset. Implicated genes point toward airway epithelium and its response to external factors, such as viral infections. However, the heterogeneity of wheeze phenotypes complicates genetic studies. It is therefore important to define accurate wheezing phenotypes and forge larger international collaborations to gain a better understanding of the pathways underlying early-onset asthma.
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Affiliation(s)
- Alba A B Wolters
- Department of Pediatric Pulmonology and Pediatric Allergology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Elin T G Kersten
- Department of Pediatric Pulmonology and Pediatric Allergology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Gerard H Koppelman
- Department of Pediatric Pulmonology and Pediatric Allergology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Tutino M, Granell R, Curtin JA, Haider S, Fontanella S, Murray CS, Roberts G, Arshad SH, Turner S, Morris AP, Custovic A, Simpson A. Dog ownership in infancy is protective for persistent wheeze in 17q21 asthma-risk carriers. J Allergy Clin Immunol 2023; 151:423-430. [PMID: 36273658 DOI: 10.1016/j.jaci.2022.10.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 10/10/2022] [Accepted: 10/14/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND Asthma-associated single nucleotide polymorphisms from large genome-wide association studies only explain a fraction of genetic heritability. Likely causes of the missing heritability include broad phenotype definitions and gene-environment interactions (GxE). The mechanisms underlying GxE in asthma are poorly understood. Previous GxE studies on pet ownership showed discordant results. OBJECTIVES We sought to study the GxE between the 17q12-21 locus and pet ownership in infancy in relation to wheeze. METHODS Wheezing classes derived from 5 UK-based birth cohorts (latent class analysis) were used to study GxE between the 17q12-21 asthma-risk variant rs2305480 and dog and cat ownership in infancy, using multinomial logistic regression. A total of 9149 children had both pet ownership and genotype data available. Summary statistics from individual analyses were meta-analyzed. RESULTS rs2305480 G allele was associated with increased risk of persistent wheeze (additive model odds ratio, 1.37; 95% CI, 1.25-1.51). There was no evidence of an association between dog or cat ownership and wheeze. We found significant evidence of a GxE interaction between rs2305480 and dog ownership (P = 8.3 × 10-4) on persistent wheeze; among dog owners, the G allele was no longer associated with an increased risk of persistent wheeze (additive model odds ratio, 0.95; 95% CI, 0.73-1.24). For those without pets, G allele was associated with increased risk of persistent wheeze (odds ratio, 1.61; 95% CI, 1.40-1.86). Among cat owners, no such dampening of the genetic effect was observed. CONCLUSIONS Among dog owners, rs2305480 G was no longer associated with an increased risk of persistent wheeze (or asthma). Early-life environmental exposures may therefore attenuate likelihood of asthma in those carrying 17q12-21 risk alleles.
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Affiliation(s)
- Mauro Tutino
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, The University of Manchester, Manchester Academic Health Science Centre, and Manchester University NHS Foundation Trust, Manchester, United Kingdom.
| | - Raquel Granell
- MRC Integrative Epidemiology Unit, Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - John A Curtin
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, The University of Manchester, Manchester Academic Health Science Centre, and Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Sadia Haider
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Sara Fontanella
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Clare S Murray
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, The University of Manchester, Manchester Academic Health Science Centre, and Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Graham Roberts
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom; NIHR Southampton Biomedical Research Centre, University Hospitals Southampton NHS Foundation Trust, Southampton, United Kingdom; David Hide Asthma and Allergy Research Centre, Isle of Wight, United Kingdom
| | - S Hasan Arshad
- NIHR Southampton Biomedical Research Centre, University Hospitals Southampton NHS Foundation Trust, Southampton, United Kingdom; David Hide Asthma and Allergy Research Centre, Isle of Wight, United Kingdom; Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Stephen Turner
- Child Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Andrew P Morris
- Centre for Genetics and Genomics Versus Arthritis, Division of Musculoskeletal and Dermatological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Adnan Custovic
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Angela Simpson
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, The University of Manchester, Manchester Academic Health Science Centre, and Manchester University NHS Foundation Trust, Manchester, United Kingdom
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Schoettler N, Dissanayake E, Craven MW, Yee JS, Eliason J, Schauberger EM, Lemanske RF, Ober C, Gern JE. New Insights Relating Gasdermin B to the Onset of Childhood Asthma. Am J Respir Cell Mol Biol 2022; 67:430-437. [PMID: 35580164 PMCID: PMC9564923 DOI: 10.1165/rcmb.2022-0043ps] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/17/2022] [Indexed: 02/06/2023] Open
Abstract
Chromosome 17q12-q21 is the most replicated genetic locus for childhood-onset asthma. Polymorphisms in this locus containing ∼10 genes interact with a variety of environmental exposures in the home and outdoors to modify asthma risk. However, the functional basis for these associations and their linkages to the environment have remained enigmatic. Within this extended region, regulation of GSDMB (gasdermin B) expression in airway epithelial cells has emerged as the primary mechanism underlying the 17q12-q21 genome-wide association study signal. Asthma-associated SNPs influence the abundance of GSDMB transcripts as well as the functional properties of GSDMB protein in airway epithelial cells. GSDMB is a member of the gasdermin family of proteins, which regulate pyroptosis and inflammatory responses to microbial infections. The aims of this review are to synthesize recent studies on the relationship of 17q12-q21 SNPs to childhood asthma and the evidence pointing to GSDMB gene expression or protein function as the underlying mechanism and to explore the potential functions of GSDMB that may influence the risk of developing asthma during childhood.
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Affiliation(s)
| | | | - Mark W. Craven
- Department of Biostatistics and Medical Informatics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - Jeremiah S. Yee
- Department of Biostatistics and Medical Informatics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - Joshua Eliason
- Department of Biostatistics and Medical Informatics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | | | | | - Carole Ober
- Department of Human Genetics, University of Chicago, Chicago, Illinois; and
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Sunde RB, Thorsen J, Pedersen CET, Stokholm J, Bønnelykke K, Chawes B, Bisgaard H. Prenatal tobacco exposure and risk of asthma and allergy outcomes in childhood. Eur Respir J 2022; 59:2100453. [PMID: 34244319 DOI: 10.1183/13993003.00453-2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 06/21/2021] [Indexed: 11/05/2022]
Abstract
BACKGROUND Harmful effects of prenatal tobacco exposure and possible interaction with 17q12-21 genetic variants have been shown for some asthma outcomes in childhood, whereas findings related to allergy outcomes are more inconsistent. This study aimed to examine the effect of prenatal tobacco exposure and relation to 17q12-21 genotype on a wide array of asthma and allergy-related outcomes in early childhood. METHODS Prenatal tobacco exposure was determined by maternal smoking during the third trimester (yes/no) in 411 children from the phenotyped Copenhagen Prospective Studies on Asthma in Childhood 2000 (COPSAC2000) birth cohort with clinical follow-up to age 7 years. The rs7216389 single nucleotide polymorphism was used as main representative of the 17q12-21 locus. Asthma end-points included asthma diagnosis, exacerbations, episodes with troublesome lung symptoms and lower respiratory tract infections, spirometry, plethysmography, bronchial responsiveness to methacholine, exercise and cold dry air. Allergy-related endpoints included aeroallergen sensitisation, allergic rhinitis, fractional exhaled nitric oxide, blood eosinophil count and urine eosinophil protein X levels. Statistical analyses were done using Cox regression, linear regression, logistic regression and quasi-Poisson regression. RESULTS Prenatal tobacco exposure increased the risk of asthma (adjusted hazard ratio (aHR) 2.05, 95% CI 1.13-3.73; p=0.02), exacerbations (aHR 3.76, 95% CI 2.05-6.91; p<0.001), number of LRTIs (adjusted incidence rate ratio 1.87, 95% CI 1.34-2.55; p<0.001), and was associated with decreased spirometry indices (forced expiratory volume in 1 s (FEV1) adjusted mean difference (aMD) -0.07 L, 95% CI -0.13- -0.005 L, p=0.03; maximal mid-expiratory flow aMD -0.19 L·s-1, -0.34- -0.04 L·s-1, p=0.01) and increased bronchial responsiveness to methacholine (provocative dose of methacholine causing a 20% drop in FEV1 adjusted geometric mean ratio 0.55, 95% CI 0.31-0.96; p=0.04). In contrast, there was no association with any allergy-related end-points. The effect on asthma depended on 17q12-21 genotype with an increased risk only among children without risk alleles. CONCLUSION Prenatal tobacco exposure was associated with asthma dependent on 17q12-21 genotype and with exacerbations, lung function and bronchial responsiveness, but not with any allergy-related outcomes. This suggests that tobacco exposure in utero leads to adverse lung developmental/structural effects rather than susceptibility to develop allergy and type 2 inflammation.
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Affiliation(s)
- Rikke Bjersand Sunde
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
- Dept of Pediatrics, Slagelse Sygehus, Slagelse, Denmark
| | - Jonathan Thorsen
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Casper-Emil Tingskov Pedersen
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Stokholm
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
- Dept of Pediatrics, Slagelse Sygehus, Slagelse, Denmark
| | - Klaus Bønnelykke
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Bo Chawes
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Hans Bisgaard
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
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Koppelman GH, Kersten ETG. Understanding How Asthma Starts: Longitudinal Patterns of Wheeze and the Chromosome 17q Locus. Am J Respir Crit Care Med 2021; 203:793-795. [PMID: 33621469 PMCID: PMC8017592 DOI: 10.1164/rccm.202102-0443ed] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- Gerard H Koppelman
- Department of Pediatric Pulmonology and Pediatric Allergology University Medical Center Groningen Groningen, the Netherlands and
- Groningen Research Institute for Asthma and COPD University Medical Center Groningen Groningen, the Netherlands
| | - Elin T G Kersten
- Department of Pediatric Pulmonology and Pediatric Allergology University Medical Center Groningen Groningen, the Netherlands and
- Groningen Research Institute for Asthma and COPD University Medical Center Groningen Groningen, the Netherlands
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7
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The intersect of genetics, environment, and microbiota in asthma-perspectives and challenges. J Allergy Clin Immunol 2021; 147:781-793. [PMID: 33678251 DOI: 10.1016/j.jaci.2020.08.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/07/2020] [Accepted: 08/05/2020] [Indexed: 02/07/2023]
Abstract
In asthma, a significant portion of the interaction between genetics and environment occurs through microbiota. The proposed mechanisms behind this interaction are complex and at times contradictory. This review covers recent developments in our understanding of this interaction: the "microbial hypothesis" and the "farm effect"; the role of endotoxin and genetic variation in pattern recognition systems; the interaction with allergen exposure; the additional involvement of host gut and airway microbiota; the role of viral respiratory infections in interaction with the 17q21 and CDHR3 genetic loci; and the importance of in utero and early-life timing of exposures. We propose a unified framework for understanding how all these phenomena interact to drive asthma pathogenesis. Finally, we point out some future challenges for continued research in this field, in particular the need for multiomic integration, as well as the potential utility of asthma endotyping.
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Expression quantitative trait locus fine mapping of the 17q12-21 asthma locus in African American children: a genetic association and gene expression study. THE LANCET RESPIRATORY MEDICINE 2020; 8:482-492. [PMID: 32380068 DOI: 10.1016/s2213-2600(20)30011-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/08/2020] [Accepted: 01/13/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND African ancestry is associated with a higher prevalence and greater severity of asthma than European ancestries, yet genetic studies of the most common locus associated with childhood-onset asthma, 17q12-21, in African Americans have been inconclusive. The aim of this study was to leverage both the phenotyping of the Children's Respiratory and Environmental Workgroup (CREW) birth cohort consortium, and the reduced linkage disequilibrium in African Americans, to fine map the 17q12-21 locus. METHODS We first did a genetic association study and meta-analysis using 17q12-21 tag single-nucleotide polymorphisms (SNPs) for childhood-onset asthma in 1613 European American and 870 African American children from the CREW consortium. Nine tag SNPs were selected based on linkage disequilibrium patterns at 17q12-21 and their association with asthma, considering the effect allele under an additive model (0, 1, or 2 effect alleles). Results were meta-analysed with publicly available summary data from the EVE consortium (on 4303 European American and 3034 African American individuals) for seven of the nine SNPs of interest. Subsequently, we tested for expression quantitative trait loci (eQTLs) among the SNPs associated with childhood-onset asthma and the expression of 17q12-21 genes in resting peripheral blood mononuclear cells (PBMCs) from 85 African American CREW children and in upper airway epithelial cells from 246 African American CREW children; and in lower airway epithelial cells from 44 European American and 72 African American adults from a case-control study of asthma genetic risk in Chicago (IL, USA). FINDINGS 17q12-21 SNPs were broadly associated with asthma in European Americans. Only two SNPs (rs2305480 in gasdermin-B [GSDMB] and rs8076131 in ORMDL sphingolipid biosynthesis regulator 3 [ORMDL3]) were associated with asthma in African Americans, at a Bonferroni-corrected threshold of p<0·0055 (for rs2305480_G, odds ratio [OR] 1·36 [95% CI 1·12-1·65], p=0·0014; and for rs8076131_A, OR 1·37 [1·13-1·67], p=0·0010). In upper airway epithelial cells from African American children, genotype at rs2305480 was the most significant eQTL for GSDMB (eQTL effect size [β] 1·35 [95% CI 1·25-1·46], p<0·0001), and to a lesser extent showed an eQTL effect for post-GPI attachment to proteins phospholipase 3 (β 1·15 [1·08-1·22], p<0·0001). No SNPs were eQTLs for ORMDL3. By contrast, in PBMCs, the five core SNPs were associated only with expression of GSDMB and ORMDL3. Genotype at rs12936231 (in zona pellucida binding protein 2) showed the strongest associations across both genes (for GSDMB, eQTLβ 1·24 [1·15-1·32], p<0·0001; and for ORMDL3 (β 1·19 [1·12-1·24], p<0·0001). The eQTL effects of rs2305480 on GSDMB expression were replicated in lower airway cells from African American adults (β 1·29 [1·15-1·44], p<0·0001). INTERPRETATION Our study suggests that SNPs regulating GSDMB expression in airway epithelial cells have a major role in childhood-onset asthma, whereas SNPs regulating the expression levels of 17q12-21 genes in resting blood cells are not central to asthma risk. Our genetic and gene expression data in African Americans and European Americans indicated GSDMB to be the leading candidate gene at this important asthma locus. FUNDING National Institutes of Health, Office of the Director.
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Braun M, Klingelhöfer D, Oremek GM, Quarcoo D, Groneberg DA. Influence of Second-Hand Smoke and Prenatal Tobacco Smoke Exposure on Biomarkers, Genetics and Physiological Processes in Children-An Overview in Research Insights of the Last Few Years. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E3212. [PMID: 32380770 PMCID: PMC7246681 DOI: 10.3390/ijerph17093212] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/16/2020] [Accepted: 04/29/2020] [Indexed: 02/07/2023]
Abstract
Children are commonly exposed to second-hand smoke (SHS) in the domestic environment or inside vehicles of smokers. Unfortunately, prenatal tobacco smoke (PTS) exposure is still common, too. SHS is hazardous to the health of smokers and non-smokers, but especially to that of children. SHS and PTS increase the risk for children to develop cancers and can trigger or worsen asthma and allergies, modulate the immune status, and is harmful to lung, heart and blood vessels. Smoking during pregnancy can cause pregnancy complications and poor birth outcomes as well as changes in the development of the foetus. Lately, some of the molecular and genetic mechanisms that cause adverse health effects in children have been identified. In this review, some of the current insights are discussed. In this regard, it has been found in children that SHS and PTS exposure is associated with changes in levels of enzymes, hormones, and expression of genes, micro RNAs, and proteins. PTS and SHS exposure are major elicitors of mechanisms of oxidative stress. Genetic predisposition can compound the health effects of PTS and SHS exposure. Epigenetic effects might influence in utero gene expression and disease susceptibility. Hence, the limitation of domestic and public exposure to SHS as well as PTS exposure has to be in the focus of policymakers and the public in order to save the health of children at an early age. Global substantial smoke-free policies, health communication campaigns, and behavioural interventions are useful and should be mandatory.
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Affiliation(s)
- Markus Braun
- Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe University Frankfurt, D-60590 Frankfurt, Germany; (D.K.); (G.M.O.); (D.Q.); (D.A.G.)
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Willis-Owen SAG, Cookson WOC, Moffatt MF. The Genetics and Genomics of Asthma. Annu Rev Genomics Hum Genet 2019; 19:223-246. [PMID: 30169121 DOI: 10.1146/annurev-genom-083117-021651] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Asthma is a common, clinically heterogeneous disease with strong evidence of heritability. Progress in defining the genetic underpinnings of asthma, however, has been slow and hampered by issues of inconsistency. Recent advances in the tools available for analysis-assaying transcription, sequence variation, and epigenetic marks on a genome-wide scale-have substantially altered this landscape. Applications of such approaches are consistent with heterogeneity at the level of causation and specify patterns of commonality with a wide range of alternative disease traits. Looking beyond the individual as the unit of study, advances in technology have also fostered comprehensive analysis of the human microbiome and its varied roles in health and disease. In this article, we consider the implications of these technological advances for our current understanding of the genetics and genomics of asthma.
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Affiliation(s)
- Saffron A G Willis-Owen
- National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom; , ,
| | - William O C Cookson
- National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom; , ,
| | - Miriam F Moffatt
- National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom; , ,
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11
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Hammoudeh S, Gadelhak W, Janahi IA. Asthma and obesity in the Middle East region: An overview. Ann Thorac Med 2019; 14:116-121. [PMID: 31007762 PMCID: PMC6467016 DOI: 10.4103/atm.atm_115_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/07/2018] [Indexed: 01/03/2023] Open
Abstract
This paper aims to cover the current status of asthma and obesity in the Middle East, as well as to introduce the various studies tying the two diseases; further expanding on the proposed mechanisms. Finally, the paper covers recent literature related to sphingolipids and its role in asthma, followed by recommendations and future directions. In preparation of this paper, we searched PubMed and Google Scholar, with no restrictions, using the following terms; asthma, obesity, Middle East, sphingolipids. We also used the reference list of retrieved articles to further expand on the pool of articles that were used for this review.
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Affiliation(s)
- Samer Hammoudeh
- Medical Research Center, Research Affairs, Hamad Medical Corporation, Doha, Qatar
| | - Wessam Gadelhak
- Medical Research Center, Research Affairs, Hamad Medical Corporation, Doha, Qatar
| | - Ibrahim A. Janahi
- Medical Research Center, Research Affairs, Hamad Medical Corporation, Doha, Qatar
- Pediatric Pulmonology, Hamad Medical Corporation, Doha, Qatar
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Morales E, Duffy D. Genetics and Gene-Environment Interactions in Childhood and Adult Onset Asthma. Front Pediatr 2019; 7:499. [PMID: 31921716 PMCID: PMC6918916 DOI: 10.3389/fped.2019.00499] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 11/18/2019] [Indexed: 11/13/2022] Open
Abstract
Asthma is a heterogeneous disease that results from the complex interaction between genetic factors and environmental exposures that occur at critical periods throughout life. It seems plausible to regard childhood-onset and adult-onset asthma as different entities, each with a different pathophysiology, trajectory, and outcome. This review provides an overview about the role of genetics and gene-environment interactions in these two conditions. Looking at the genetic overlap between childhood and adult onset disease gives one window into whether there is a correlation, as well as to mechanism. A second window is offered by the genetics of the relationship between each type of asthma and other phenotypes e.g., obesity, chronic obstructive pulmonary disease (COPD), atopy, vitamin D levels, and inflammatory and immune status; and third, the genetic-specific responses to the many environmental exposures that influence risk throughout life, and particularly those that occur during early-life development. These represent a large number of possible combinations of genetic and environmental factors, at least 150 known genetic loci vs. tobacco smoke, outdoor air pollutants, indoor exposures, farming environment, and microbial exposures. Considering time of asthma onset extends the two-dimensional problem of gene-environment interactions to a three-dimensional problem, since identified gene-environment interactions seldom replicate for childhood and adult asthma, which suggests that asthma susceptibility to environmental exposures may biologically differ from early life to adulthood as a result of different pathways and mechanisms of the disease.
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Affiliation(s)
- Eva Morales
- Biomedical Research Institute of Murcia (IMIB-Arrixaca), University of Murcia, Murcia, Spain.,CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - David Duffy
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
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A decade of research on the 17q12-21 asthma locus: Piecing together the puzzle. J Allergy Clin Immunol 2018; 142:749-764.e3. [PMID: 29307657 PMCID: PMC6172038 DOI: 10.1016/j.jaci.2017.12.974] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/13/2017] [Accepted: 12/16/2017] [Indexed: 12/20/2022]
Abstract
Chromosome 17q12–21 remains the most highly replicated and significant asthma locus. Genotypes in the core region defined by the first genome-wide association study correlate with expression of 2 genes, ORM1-like 3 (ORMDL3) and gasdermin B (GSDMB), making these prime candidate asthma genes, although recent studies have implicated gasdermin A (GSDMA) distal to and post-GPI attachment to proteins 3 (PGAP3) proximal to the core region as independent loci. We review 10 years of studies on the 17q12–21 locus and suggest that genotype-specific risks for asthma at the proximal and distal loci are not specific to early-onset asthma and mediated by PGAP3, ORMDL3, and/or GSDMA expression. We propose that the weak and inconsistent associations of 17q single nucleotide polymorphisms with asthma in African Americans is due to the high frequency of some 17q alleles, the breakdown of linkage disequilibrium on African-derived chromosomes, and possibly different early-life asthma endotypes in these children. Finally, the inconsistent association between asthma and gene expression levels in blood or lung cells from older children and adults suggests that genotype effects may mediate asthma risk or protection during critical developmental windows and/or in response to relevant exposures in early life. Thus studies of young children and ethnically diverse populations are required to fully understand the relationship between genotype and asthma phenotype and the gene regulatory architecture at this locus. (J Allergy Clin Immunol 2018;142:749–64.)
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Schwantes EA, Evans MD, Cuskey A, Burford A, Smith JA, Lemanske RF, Jarjour NN, Mathur SK. Elevated fractional exhaled nitric oxide and blood eosinophil counts are associated with a 17q21 asthma risk allele in adult subjects. J Asthma Allergy 2017; 11:1-9. [PMID: 29296089 PMCID: PMC5741070 DOI: 10.2147/jaa.s149183] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Background and objectives Genome-wide association studies identified single-nucleotide polymorphisms (SNPs) at the 17q21 locus conferring increased risk for childhood-onset asthma. Little is known about how these SNPs impact adult asthma patients. We sought to examine an adult population for associations between rs7216389 (17q21-associated SNP) and features of asthma including fractional exhaled nitric oxide (FeNO), eosinophil counts, and age of asthma onset. Methods Subjects were genotyped at SNP rs7216389. The geometric mean of FeNO measurements and peripheral blood eosinophil counts from 2008 to 2015 were collected. Demographics and medical history were collected including self-reported allergy diagnoses and age of asthma onset. Eosinophils, monocytes, and peripheral blood mononuclear cells (PBMCs) were isolated for the examination of ORMDL3 expression. Results FeNO levels from 157 genotyped subjects (31CC, 72CT, and 54TT) and peripheral eosinophil counts from 252 genotyped subjects (46CC, 122CT, and 84TT) were analyzed. In a sub-group analysis of asthma subjects, the number of attributable T alleles was associated with significantly lower age of asthma onset (P=0.03) and greater FeNO levels (geometric mean 30.0 ppb TT, 20.0 ppb CT, 20.0 ppb CC, P=0.02). In the total cohort of subjects, the T allele was associated with a higher percentage of individual eosinophil counts >200/mm3 (45% TT, 26% CT, 24% CC, P=0.005). Eosinophils expressed ORMDL3 mRNA and protein. Conclusion In adult subjects, the number of T alleles at SNP rs7216389 corresponds to significantly greater FeNO levels and peripheral eosinophil counts. The expression of ORMDL3 in eosinophils suggests that they may participate in mediating the asthma risk associated with the 17q21 locus.
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Affiliation(s)
| | | | - Alex Cuskey
- Division of Allergy, Pulmonary and Critical Care, Department of Medicine
| | - Alex Burford
- Division of Allergy, Pulmonary and Critical Care, Department of Medicine
| | - Judith A Smith
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Robert F Lemanske
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Nizar N Jarjour
- Division of Allergy, Pulmonary and Critical Care, Department of Medicine
| | - Sameer K Mathur
- Division of Allergy, Pulmonary and Critical Care, Department of Medicine
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Ober C, Sperling AI, von Mutius E, Vercelli D. Immune development and environment: lessons from Amish and Hutterite children. Curr Opin Immunol 2017; 48:51-60. [PMID: 28843541 DOI: 10.1016/j.coi.2017.08.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/06/2017] [Accepted: 08/08/2017] [Indexed: 12/20/2022]
Abstract
Children who grow up in traditional farm environments are protected from developing asthma and allergy. This 'farm effect' can be largely explained by the child's early life contact with farm animals, in particular cows, and their microbes. Our studies in Amish and Hutterite school children living on farms in the U.S. have further demonstrated that this protection is mediated through innate immune pathways. Although very similar with respect to ancestry and many lifestyle factors that are associated with asthma risk, Amish and Hutterites follow farming practices that are associated with profound differences in the levels of house dust endotoxin, in the prevalence of asthma and atopy among school children, and in the proportions, phenotypes, and functions of immune cells from these children. In this review, we will consider our studies in Amish and Hutterites children in the context of the many previous studies in European farm children and discuss how these studies have advanced our understanding of the asthma-protective 'farm effect'.
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Affiliation(s)
- Carole Ober
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA.
| | - Anne I Sperling
- Section of Pulmonary and Critical Care Medicine, Department of Medicine and the Committee on Immunology, University of Chicago, Chicago, IL 60637, USA
| | - Erika von Mutius
- Dr. von Hauner Children's Hospital, Ludwig Maximilians University Munich, Germany; Comprehensive Pneumology Center, Munich, Germany; German Center for Lung Research, Germany
| | - Donata Vercelli
- Department of Cellular and Molecular Medicine, Asthma and Airway Disease Research Center, and Bio5 Institute, The University of Arizona, Tucson, AZ 85724, USA
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Abdullah B, Muadz B, Norizal MN, Ismail N, Kornain NK, Kutty M. Pregnancy outcome and cord blood cotinine level: A cross-sectional comparative study between secondhand smokers and non-secondhand smokers. Eur J Obstet Gynecol Reprod Biol 2017; 214:86-90. [PMID: 28494268 DOI: 10.1016/j.ejogrb.2017.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 02/12/2017] [Accepted: 05/02/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE To compare the pregnancy outcome and cord blood cotinine levels between secondhand smokers and non-secondhand smokers. STUDY DESIGN This was a cross-sectional comparative study in a Malaysian tertiary obstetric hospital involving 200 non-smoking pregnant women at term, of whom 100 were secondhand smokers and 100 were non-secondhand smokers. Those with multiple pregnancies, with a body mass index (BMI) of more than 30kg/m2 or who delivered by Caesarean section were excluded. The participants' basic demographic details, delivery details, neonatal outcome and placental weight were recorded. Umbilical cord blood samples were obtained, and cord blood cotinine levels were measured with a Cotinine ELISA kit. The primary outcomes were baby's birth weight, length, and head circumference, Apgar score at 5min and placental weight. The secondary outcome was difference in cord blood cotinine levels between the two groups and the correlation of these differences with the neonatal outcome. RESULTS The secondhand smoker group had significantly lower baby weight (2.94±0.31kg vs 3.05±0.40kg), head circumference (30.87±2.35cm vs 37.13±2.36cm), length (46.58±1.95cm vs 51.53±2.05cm) and placental weight (520±73.5g vs 596±61.3g) and significantly higher cord blood cotinine levels (16.35±12.84ng/mL vs 0.56±0.22ng/mL). Cord blood cotinine levels had significant negative correlations with placental weight (r=-0.461), baby's weight (r=-0.297), baby's head circumference (r=-0.501) and baby's length (r=-0.374). CONCLUSION Secondhand smoke increases the incidence of adverse pregnancy outcomes (newborns'anthropometric measurements and placental weight) and causes higher cord blood cotinine levels.
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Affiliation(s)
- B Abdullah
- Discipline of Obstetrics and Gynaecology, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor Darul Ehsan, Malaysia; Maternofetal and Embryology (MatE) Research Group, Health and Wellbeing CoRe, Faculty of Medicine, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia.
| | - B Muadz
- Pathology and Laboratory Medicine, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor Darul Ehsan, Malaysia
| | - M N Norizal
- Pathology and Laboratory Medicine, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor Darul Ehsan, Malaysia
| | - N Ismail
- Population Health and Preventive Medicine, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor Darul Ehsan, Malaysia
| | - N K Kornain
- Pathology and Laboratory Medicine, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor Darul Ehsan, Malaysia
| | - M Kutty
- Pathology and Laboratory Medicine, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, 47000, Sungai Buloh, Selangor Darul Ehsan, Malaysia
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Abstract
Genome-wide association studies (GWAS) of asthma have yielded exciting results and identified novel risk alleles and loci. But, like other common complex diseases, asthma-associated alleles have small effect sizes and account for little of the prevalence of asthma. In this review, I discuss the limitations of GWAS approaches and the major challenges facing geneticists in the post-GWAS era and propose alternative strategies to address these challenges. In particular, I propose that focusing on genetic variations that influences gene expression and using cell models of gene-environment interactions in cell types that are relevant to asthma will allow us to more completely characterize the genetic architecture of asthma.
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18
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Paulenda T, Draber P. The role of ORMDL proteins, guardians of cellular sphingolipids, in asthma. Allergy 2016; 71:918-30. [PMID: 26969910 DOI: 10.1111/all.12877] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2016] [Indexed: 12/29/2022]
Abstract
A family of widely expressed ORM-like (ORMDL) proteins has been recently linked to asthma in genomewide association studies in humans and extensively explored in in vivo studies in mice. ORMDL proteins are key regulators of serine palmitoyltransferase, an enzyme catalyzing the initial step of sphingolipid biosynthesis. Sphingolipids play prominent roles in cell signaling and response to stress, and they affect the mechanistic properties of cellular membranes. Deregulation of sphingolipid biosynthesis and their recycling has been proven to support and even cause several diseases including allergy, inflammation, and asthma. ORMDL3, the most extensively studied member of the ORMDL family, has been shown to be important for endoplasmic reticulum homeostasis by regulating the unfolded protein response and calcium response. In immune cells, ORMDL3 is involved in migration and in the production of proinflammatory cytokines. Furthermore, changes in the expression level of ORMDL3 are important in allergen-induced asthma pathologies. This review focuses on functional aspects of the ORMDL family proteins, which may serve as new therapeutic targets for the treatment of asthma and some other life-threatening diseases.
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Affiliation(s)
- T. Paulenda
- Laboratory of Signal Transduction; Institute of Molecular Genetics; Academy of Sciences of the Czech Republic; Prague Czech Republic
| | - P. Draber
- Laboratory of Signal Transduction; Institute of Molecular Genetics; Academy of Sciences of the Czech Republic; Prague Czech Republic
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Chogtu B, Bhattacharjee D, Magazine R. Epigenetics: The New Frontier in the Landscape of Asthma. SCIENTIFICA 2016; 2016:4638949. [PMID: 27293973 PMCID: PMC4879257 DOI: 10.1155/2016/4638949] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 04/19/2016] [Indexed: 06/06/2023]
Abstract
Over the years, on a global scale, asthma has continued to remain one of the leading causes of morbidity, irrespective of age, sex, or social bearings. This is despite the prevalence of varied therapeutic options to counter the pathogenesis of asthma. Asthma, as a disease per se, is a very complex one. Scientists all over the world have been trying to obtain a lucid understanding of the machinations behind asthma. This has led to many theories and conjectures. However, none of the scientific disciplines have been able to provide the missing links in the chain of asthma pathogenesis. This was until epigenetics stepped into the picture. Though epigenetic research in asthma is in its nascent stages, it has led to very exciting results, especially with regard to explaining the massive influence of environment on development of asthma and its varied phenotypes. However, there remains a lot of work to be done, especially with regard to understanding how the interactions between immune system, epigenome, and environment lead to asthma. But introduction of epigenetics has infused a fresh lease of life in research into asthma and the mood among the scientific community is that of cautious optimism.
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Affiliation(s)
- Bharti Chogtu
- Department of Pharmacology, Kasturba Medical College, Manipal University, Karnataka 576104, India
| | - Dipanjan Bhattacharjee
- Department of Pharmacology, Kasturba Medical College, Manipal University, Karnataka 576104, India
| | - Rahul Magazine
- Department of Pulmonary Medicine, Kasturba Medical College, Manipal University, Karnataka 576104, India
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20
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Dizier MH, Nadif R, Margaritte-Jeannin P, Barton SJ, Sarnowski C, Gagné-Ouellet V, Brossard M, Lavielle N, Just J, Lathrop M, Holloway JW, Laprise C, Bouzigon E, Demenais F. Interaction between the DNAH9 gene and early smoke exposure in bronchial hyperresponsiveness. Eur Respir J 2016; 47:1072-81. [PMID: 26797031 DOI: 10.1183/13993003.00849-2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 11/18/2015] [Indexed: 12/21/2022]
Abstract
A previous genome-wide linkage scan of bronchial hyperresponsiveness (BHR) in the French Epidemiological study on the Genetics and Environment of Asthma (EGEA) families, performed in the presence of a gene×early-life environmental tobacco smoke (ETS) exposure interaction, showed the strongest interaction in the 17p11 region where linkage was detected only among unexposed siblings. Our goal was to conduct fine-scale mapping of 17p11 to identify single nucleotide polymorphisms (SNPs) interacting with ETS that influence BHR.Analyses were performed in 388 French EGEA asthmatic families, using a two-step strategy: 1) selection of SNPs displaying family-based association test (FBAT) association signals (p≤0.01) with BHR in unexposed siblings, and 2) a FBAT homogeneity test between exposed and unexposed siblings plus a robust log-linear interaction test.A single SNP reached the threshold (p≤3×10(-3)) for significant interaction with ETS using both interaction tests, after accounting for multiple testing. Results were replicated in 253 French-Canadian families, but not in 341 UK families, probably due in part to differences in phenotypic features between datasets.The SNP showing significant interaction with ETS belongs toDNAH9(dynein, axonemal, heavy chain 9), a promising candidate gene involved in respiratory cilia mobility and associated with primary ciliary dyskinesia, a disease associated with abnormalities of pulmonary function.
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Affiliation(s)
- Marie-Hélène Dizier
- INSERM, UMR 946, Genetic Variation and Human Diseases Unit, Paris, France Université Paris Diderot, Sorbonne Paris Cité, Institut Universitaire d'Hématologie, Paris, France
| | - Rachel Nadif
- INSERM, U1168, Aging and Chronic Diseases, Epidemiological and Public Health Approaches (VIMA), Villejuif, France Université Versailles Saint-Quentin-en-Yvelines, UMR_S 1168, Paris, France These authors contributed equally to this work
| | - Patricia Margaritte-Jeannin
- INSERM, UMR 946, Genetic Variation and Human Diseases Unit, Paris, France Université Paris Diderot, Sorbonne Paris Cité, Institut Universitaire d'Hématologie, Paris, France These authors contributed equally to this work
| | - Sheila J Barton
- MRC Lifecourse Epidemiology Unit, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Chloé Sarnowski
- INSERM, UMR 946, Genetic Variation and Human Diseases Unit, Paris, France Université Paris Diderot, Sorbonne Paris Cité, Institut Universitaire d'Hématologie, Paris, France Université Paris-Sud, UMR_S 1018, Villejuif, France
| | | | - Myriam Brossard
- INSERM, UMR 946, Genetic Variation and Human Diseases Unit, Paris, France Université Paris Diderot, Sorbonne Paris Cité, Institut Universitaire d'Hématologie, Paris, France Université Paris-Sud, UMR_S 1018, Villejuif, France
| | - Nolwenn Lavielle
- INSERM, UMR 946, Genetic Variation and Human Diseases Unit, Paris, France Université Paris Diderot, Sorbonne Paris Cité, Institut Universitaire d'Hématologie, Paris, France Université Paris-Sud, UMR_S 1018, Villejuif, France
| | - Jocelyne Just
- Service d'Allergologie Pédiatrique, Centre de l'Asthme et des Allergies, Hôpital d'Enfants Armand-Trousseau (APHP) - Sorbonne Universités, UPMC Université Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Equipe EPAR, Paris, France
| | - Mark Lathrop
- McGill University and Genome Quebec's Innovation Centre, Montréal, Canada
| | - John W Holloway
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Catherine Laprise
- Université du Québec, Chicoutimi, Canada These authors contributed equally to this work
| | - Emmanuelle Bouzigon
- INSERM, UMR 946, Genetic Variation and Human Diseases Unit, Paris, France Université Paris Diderot, Sorbonne Paris Cité, Institut Universitaire d'Hématologie, Paris, France These authors contributed equally to this work
| | - Florence Demenais
- INSERM, UMR 946, Genetic Variation and Human Diseases Unit, Paris, France Université Paris Diderot, Sorbonne Paris Cité, Institut Universitaire d'Hématologie, Paris, France
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Abstract
Over the past three decades, a large number of genetic studies have been aimed at finding genetic variants associated with the risk of asthma, applying various genetic and genomic approaches including linkage analysis, candidate gene polymorphism studies, and genome-wide association studies (GWAS). However, contrary to general expectation, even single nucleotide polymorphisms (SNPs) discovered by GWAS failed to fully explain the heritability of asthma. Thus, application of rare allele polymorphisms in well defined phenotypes and clarification of environmental factors have been suggested to overcome the problem of 'missing' heritability. Such factors include allergens, cigarette smoke, air pollutants, and infectious agents during pre- and post-natal periods. The first and simplest interaction between a gene and the environment is a candidate interaction of both a well known gene and environmental factor in a direct physical or chemical interaction such as between CD14 and endotoxin or between HLA and allergens. Several GWAS have found environmental interactions with occupational asthma, aspirin exacerbated respiratory disease, tobacco smoke-related airway dysfunction, and farm-related atopic diseases. As one of the mechanisms behind gene-environment interaction is epigenetics, a few studies on DNA CpG methylation have been reported on subphenotypes of asthma, pitching the exciting idea that it may be possible to intervene at the junction between the genome and the environment. Epigenetic studies are starting to include data from clinical samples, which will make them another powerful tool for re-search on gene-environment interactions in asthma.
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Affiliation(s)
- Jong-Uk Lee
- Department of Interdisciplinary Program in Biomedical Science Major, Soonchunhyang Graduate School, Bucheon, Korea
| | - Jeong Dong Kim
- Department of Interdisciplinary Program in Biomedical Science Major, Soonchunhyang Graduate School, Bucheon, Korea
| | - Choon-Sik Park
- Genome Research Center and Division of Allergy and Respiratory Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
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22
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[Genetic and environmental factors of asthma and allergy: Results of the EGEA study]. Rev Mal Respir 2015; 32:822-40. [PMID: 25794998 DOI: 10.1016/j.rmr.2014.12.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 12/12/2014] [Indexed: 12/26/2022]
Abstract
INTRODUCTION AND METHODS The EGEA study (epidemiological study on the genetics and environment of asthma, bronchial hyperresponsiveness and atopy), which combines a case-control and a family-based study of asthma case (n=2120 subjects) with three surveys over 20 years, aims to identify environmental and genetic factors associated with asthma and asthma-related phenotypes. We summarize the results of the phenotypic characterization and the investigation of environmental and genetic factors of asthma and asthma-related phenotypes obtained since 2007 in the EGEA study (42 articles). RESULTS Both epidemiological and genetic results confirm the heterogeneity of asthma. These results strengthen the role of the age of disease onset, the allergic status and the level of disease activity in the identification of the different phenotypes of asthma. The deleterious role of active smoking, exposure to air pollution, occupational asthmogenic agents and cleaning products on the prevalence and/or activity of asthma has been confirmed. Accounting for gene-environment interactions allowed the identification of new genetic factors underlying asthma and asthma-related traits and better understanding of their mode of action. CONCLUSION The EGEA study is contributing to the advances in respiratory research at the international level. The new phenotypic, environmental and biological data available in EGEA study will help characterizing the long-term evolution of asthma and the factors associated to this evolution.
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Challenges in conducting genome-wide association studies in highly admixed multi-ethnic populations: the Generation R Study. Eur J Epidemiol 2015; 30:317-30. [PMID: 25762173 PMCID: PMC4385148 DOI: 10.1007/s10654-015-9998-4] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 02/12/2015] [Indexed: 12/16/2022]
Abstract
Genome-wide association studies (GWAS) have been successful in identifying loci associated with a wide range of complex human traits and diseases. Up to now, the majority of GWAS have focused on European populations. However, the inclusion of other ethnic groups as well as admixed populations in GWAS studies is rapidly rising following the pressing need to extrapolate findings to non-European populations and to increase statistical power. In this paper, we describe the methodological steps surrounding genetic data generation, quality control, study design and analytical procedures needed to run GWAS in the multiethnic and highly admixed Generation R Study, a large prospective birth cohort in Rotterdam, the Netherlands. Furthermore, we highlight a number of practical considerations and alternatives pertinent to the quality control and analysis of admixed GWAS data.
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Magnus MC, Stigum H, Håberg SE, Nafstad P, London SJ, Nystad W. Peak weight and height velocity to age 36 months and asthma development: the Norwegian Mother and Child Cohort Study. PLoS One 2015; 10:e0116362. [PMID: 25635872 PMCID: PMC4312021 DOI: 10.1371/journal.pone.0116362] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 12/08/2014] [Indexed: 12/04/2022] Open
Abstract
Background The immediate postnatal period is the period of the fastest growth in the entire life span and a critical period for lung development. Therefore, it is interesting to examine the association between growth during this period and childhood respiratory disorders. Methods We examined the association of peak weight and height velocity to age 36 months with maternal report of current asthma at 36 months (n = 50,311), recurrent lower respiratory tract infections (LRTIs) by 36 months (n = 47,905) and current asthma at 7 years (n = 24,827) in the Norwegian Mother and Child Cohort Study. Peak weight and height velocity was calculated using the Reed1 model through multilevel mixed-effects linear regression. Multivariable log-binomial regression was used to calculate adjusted relative risks (adj.RR) and 95% confidence intervals (CI). We also conducted a sibling pair analysis using conditional logistic regression. Results Peak weight velocity was positively associated with current asthma at 36 months [adj.RR 1.22 (95%CI: 1.18, 1.26) per standard deviation (SD) increase], recurrent LRTIs by 36 months [adj.RR 1.14 (1.10, 1.19) per SD increase] and current asthma at 7 years [adj.RR 1.13 (95%CI: 1.07, 1.19) per SD increase]. Peak height velocity was not associated with any of the respiratory disorders. The positive association of peak weight velocity and asthma at 36 months remained in the sibling pair analysis. Conclusions Higher peak weight velocity, achieved during the immediate postnatal period, increased the risk of respiratory disorders. This might be explained by an influence on neonatal lung development, shared genetic/epigenetic mechanisms and/or environmental factors.
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Affiliation(s)
- Maria C. Magnus
- Department of Chronic Diseases, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
- * E-mail:
| | - Hein Stigum
- Department of Chronic Diseases, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
- Department of Community Medicine, Medical Faculty, University of Oslo, Oslo, Norway
| | - Siri E. Håberg
- Institute Management and Staff, Norwegian Institute of Public Health, Oslo, Norway
| | - Per Nafstad
- Department of Chronic Diseases, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
- Department of Community Medicine, Medical Faculty, University of Oslo, Oslo, Norway
| | - Stephanie J. London
- Epidemiology Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, United States of America
| | - Wenche Nystad
- Department of Chronic Diseases, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
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Kreiner-Møller E, Strachan DP, Linneberg A, Husemoen LLN, Bisgaard H, Bønnelykke K. 17q21 gene variation is not associated with asthma in adulthood. Allergy 2015; 70:107-14. [PMID: 25331618 DOI: 10.1111/all.12537] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND 17q21 gene variants are the strongest known genetic determinants for childhood asthma and have been reported to interact with environmental tobacco smoke exposure in childhood. It remains unclear whether individuals with 17q21 risk variants have increased risk of asthma or reduced lung function in adulthood. The aim was to examine the association between the 17q21 region and current adult asthma and lung function, and interaction with active smoking. METHODS We investigated the single nucleotide polymorphism rs7216389 at the 17q21 locus in 3471 adults from the Health2006 cross-sectional study and in 7008 adults from The British 1958 Birth Cohort and examined the association with current asthma, spirometry measures, and related atopic traits. Analyses were performed for interaction with active smoking. RESULTS We found no association between rs7216389[T] and asthma when meta-analyzed (OR = 1.02 [0.92-1.13], P = 0.81). The risk variant was associated with reduced FEV1 as compared to normal FEV1 (OR = 1.10 [1.01-1.12], P = 0.033) and with allergic sensitization (OR = 1.10 [1.03-1.17], P = 0.003). Individuals with rs7216389 risk variants smoked as frequently as individuals without risk variants, and there was no evidence that smoking modified the association between rs7216389 and asthma. CONCLUSION Our study suggests that the 17q21 rs7216389 locus variant does not substantially influence asthma risk in adulthood or susceptibility to detrimental effects of active smoking. This contrasts the findings in children and suggests that this locus is associated with a childhood-specific asthma endotype.
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Affiliation(s)
- E. Kreiner-Møller
- COPSAC; The Copenhagen Prospective Studies on Asthma in Childhood; Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- The Danish Pediatric Asthma Center; Copenhagen University Hospital; Gentofte Denmark
| | - D. P. Strachan
- Division of Population Health Sciences and Education; St George's University of London; London UK
| | - A. Linneberg
- Research Centre for Prevention and Health; Glostrup University Hospital; Glostrup Denmark
| | - L. L. N. Husemoen
- Research Centre for Prevention and Health; Glostrup University Hospital; Glostrup Denmark
| | - H. Bisgaard
- COPSAC; The Copenhagen Prospective Studies on Asthma in Childhood; Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- The Danish Pediatric Asthma Center; Copenhagen University Hospital; Gentofte Denmark
| | - K. Bønnelykke
- COPSAC; The Copenhagen Prospective Studies on Asthma in Childhood; Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- The Danish Pediatric Asthma Center; Copenhagen University Hospital; Gentofte Denmark
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Early origins of chronic obstructive lung diseases across the life course. Eur J Epidemiol 2014; 29:871-85. [PMID: 25537319 DOI: 10.1007/s10654-014-9981-5] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/06/2014] [Indexed: 12/12/2022]
Abstract
Chronic obstructive lung diseases, like asthma and chronic obstructive pulmonary disease, have high prevalences and are a major public health concern. Chronic obstructive lung diseases have at least part of their origins in early life. Exposure to an adverse environment during critical periods in early life might lead to permanent developmental adaptations which results in impaired lung growth with smaller airways and lower lung volume, altered immunological responses and related inflammation, and subsequently to increased risks of chronic obstructive lung diseases throughout the life course. Various pathways leading from early life factors to respiratory health outcomes in later life have been studied, including fetal and early infant growth patterns, preterm birth, maternal obesity, diet and smoking, children's diet, allergen exposure and respiratory tract infections, and genetic susceptibility. Data on potential adverse factors in the embryonic and preconception period and respiratory health outcomes are scarce. Also, the underlying mechanisms how specific adverse exposures in the fetal and early postnatal period lead to chronic obstructive lung diseases in later life are not yet fully understood. Current studies suggest that interactions between early environmental exposures and genetic factors such as changes in DNA-methylation and RNA expression patterns may explain the early development of chronic obstructive lung diseases. New well-designed epidemiological studies are needed to identify specific critical periods and to elucidate the mechanisms underlying the development of chronic obstructive lung disease throughout the life course.
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The Generation R Study: Biobank update 2015. Eur J Epidemiol 2014; 29:911-27. [PMID: 25527369 DOI: 10.1007/s10654-014-9980-6] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Accepted: 12/06/2014] [Indexed: 12/14/2022]
Abstract
The Generation R Study is a population-based prospective cohort study from fetal life until adulthood. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health from fetal life, childhood and young adulthood. In total, 9,778 mothers were enrolled in the study. Data collection in children and their parents include questionnaires, interviews, detailed physical and ultrasound examinations, behavioural observations, Magnetic Resonance Imaging and biological samples. Efforts have been conducted for collecting biological samples including blood, hair, faeces, nasal swabs, saliva and urine samples and generating genomics data on DNA, RNA and microbiome. In this paper, we give an update of the collection, processing and storage of these biological samples and available measures. Together with detailed phenotype measurements, these biological samples provide a unique resource for epidemiological studies focused on environmental exposures, genetic and genomic determinants and their interactions in relation to growth, health and development from fetal life onwards.
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Underner M, Perriot J, Peiffer G, Meurice JC. [Influence of tobacco smoking on the risk of developing asthma]. Rev Mal Respir 2014; 32:110-37. [PMID: 25765119 DOI: 10.1016/j.rmr.2014.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 07/25/2014] [Indexed: 02/05/2023]
Abstract
The aim of this general review is to investigate the influence of active and passive smoking on the development of asthma in children and adults. Passive smoking during and after pregnancy facilitates the onset of childhood asthma and wheezing. In particular, smoking during pregnancy is associated with the occurrence of wheezing prior to the age of 4 years. In contrast, the results of studies on the relationship between parental smoking in the post-natal period and the onset of asthma or wheezing are discordant. Exposure to passive smoking during childhood facilitates the occurrence of asthma in adulthood. In adults and adolescents, active smoking appears to be a factor favoring the development of asthma. On the other hand, non-smoking adult subjects without history of asthma exposed to passive smoking have a risk of asthma. The pathophysiological mechanisms by which tobacco smoke is the cause of asthma are still poorly known. Smoking cessation is an essential component in the management of asthmatic subjects who smoke, facilitating the control of the disease.
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Affiliation(s)
- M Underner
- Unité de tabacologie, service de pneumologie, centre de lutte antituberculeuse (CLAT 86), CHU de Poitiers, 86000 Poitiers, France.
| | - J Perriot
- Dispensaire Émile-Roux, centre de lutte antituberculeuse (CLAT 63), 63100 Clermont-Ferrand, France
| | - G Peiffer
- Service de pneumologie, CHR Metz-Thionville, 57038 Metz, France
| | - J-C Meurice
- Unité de tabacologie, service de pneumologie, centre de lutte antituberculeuse (CLAT 86), CHU de Poitiers, 86000 Poitiers, France
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29
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Acevedo N, Reinius LE, Greco D, Gref A, Orsmark-Pietras C, Persson H, Pershagen G, Hedlin G, Melén E, Scheynius A, Kere J, Söderhäll C. Risk of childhood asthma is associated with CpG-site polymorphisms, regional DNA methylation and mRNA levels at the GSDMB/ORMDL3 locus. Hum Mol Genet 2014; 24:875-90. [PMID: 25256354 PMCID: PMC4291244 DOI: 10.1093/hmg/ddu479] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Single-nucleotide polymorphisms (SNPs) in GSDMB (Gasdermin B) and ORMDL3 (ORMDL sphingolipid biosynthesis regulator 3) are strongly associated with childhood asthma, but the molecular alterations contributing to disease remain unknown. We investigated the effects of asthma-associated SNPs on DNA methylation and mRNA levels of GSDMB and ORMDL3. Genetic association between GSDMB/ORMDL3 and physician-diagnosed childhood asthma was confirmed in the Swedish birth-cohort BAMSE. CpG-site SNPs (rs7216389 and rs4065275) showed differences in DNA methylation depending on carrier status of the risk alleles, and were significantly associated with methylation levels in two CpG sites in the 5′ UTR (untranslated region) of ORMDL3. In the Swedish Search study, we found significant differences in DNA methylation between asthmatics and controls in five CpG sites; after adjusting for lymphocyte and neutrophil cell counts, three remained significant: one in IKZF3 [IKAROS family zinc finger 3 (Aiolos); cg16293631] and two in the CpG island (CGI) of ORMDL3 (cg02305874 and cg16638648). Also, cg16293631 and cg02305874 correlated with mRNA levels of ORMDL3. The association between methylation and asthma was independent of the genotype in rs7216389, rs4065275 and rs12603332. Both SNPs and CpG sites showed significant associations with ORMDL3 mRNA levels. SNPs influenced expression independently of methylation, and the residual association between methylation and expression was not mediated by these SNPs. We found a differentially methylated region in the CGI shore of ORMDL3 with six CpG sites less methylated in CD8+ T-cells. In summary, this study supports that there are differences in DNA methylation at this locus between asthmatics and controls; and both SNPs and CpG sites are independently associated with ORMDL3 expression.
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Affiliation(s)
- Nathalie Acevedo
- Department of Biosciences and Nutrition, and Center for Innovative Medicine (CIMED), Karolinska Institutet, Stockholm 141 83, Sweden Department of Medicine Solna, Translational Immunology Unit, Karolinska Institutet and University Hospital, Stockholm 171 77, Sweden
| | - Lovisa E Reinius
- Department of Biosciences and Nutrition, and Center for Innovative Medicine (CIMED), Karolinska Institutet, Stockholm 141 83, Sweden
| | - Dario Greco
- Systems Toxicology Team, Finnish Institute of Occupational Health, Helsinki 00250, Finland
| | | | - Christina Orsmark-Pietras
- Department of Biosciences and Nutrition, and Center for Innovative Medicine (CIMED), Karolinska Institutet, Stockholm 141 83, Sweden
| | - Helena Persson
- Department of Biosciences and Nutrition, and Center for Innovative Medicine (CIMED), Karolinska Institutet, Stockholm 141 83, Sweden
| | | | - Gunilla Hedlin
- Department of Women's and Children's Health Centre of Allergy Research, Karolinska Institutet, Stockholm 171 77, Sweden Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm 171 64, Sweden
| | - Erik Melén
- Institute of Environmental Medicine Centre of Allergy Research, Karolinska Institutet, Stockholm 171 77, Sweden Sachs' Children's Hospital, Södersjukhuset, Stockholm 118 83, Sweden and
| | - Annika Scheynius
- Department of Medicine Solna, Translational Immunology Unit, Karolinska Institutet and University Hospital, Stockholm 171 77, Sweden
| | - Juha Kere
- Department of Biosciences and Nutrition, and Center for Innovative Medicine (CIMED), Karolinska Institutet, Stockholm 141 83, Sweden Folkhälsan Institute of Genetics, Helsinki, and Research Programs Unit, University of Helsinki, Helsinki 00014, Finland
| | - Cilla Söderhäll
- Department of Biosciences and Nutrition, and Center for Innovative Medicine (CIMED), Karolinska Institutet, Stockholm 141 83, Sweden Centre of Allergy Research, Karolinska Institutet, Stockholm 171 77, Sweden
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30
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Abstract
This thesis explores the contribution of twin studies, particularly those studies originating from the Danish Twin Registry, to the understanding of the aetiology of asthma. First, it is explored how twin studies have established the contribution of genetic and environmental factors to the variation in the susceptibility to asthma, and to the variation in several aspects of the clinical expression of the disease such as its age at onset, its symptomatology, its intermediate phenotypes, and its relationship with other atopic diseases. Next, it is explored how twin studies have corroborated theories explaining asthma's recent increase in prevalence, and last, how these fit with the explanations of the epidemiological trends in other common chronic diseases of modernity.
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Abstract
PURPOSE OF REVIEW Most asthma starts early in life. Defining phenotypes of asthma at this age is difficult as many preschool children have asthma-like respiratory symptoms. This review discusses progress in defining early wheezing phenotypes and describes genetic factors associated with the age of onset of asthma. RECENT FINDINGS Latent class analyses confirmed transient and persistent wheezing phenotypes, and identified a novel intermediate-onset wheezing phenotype that was strongly associated with atopy and asthma at age 8 years. However, no single cross-sectional or longitudinal definition of respiratory symptoms in childhood strongly predicts asthma later in life. Genome-wide association (GWA) studies have identified a locus on chromosome 17q12-21 (encoding ORMDL3 and GSDMB) as a risk factor for predominantly childhood-onset asthma, but not for atopy, and overall not for adult-onset asthma. Other loci found by GWA studies appear to increase asthma risk both in children and adults. Atopy genes do not explain early-onset asthma. SUMMARY Although most asthma starts early in life, no valid test is able to identify asthma at that age period. GWA studies have provided more insight into the unique and common genetic origins of adult-onset and childhood-onset asthma. The 17q12-21 locus is predominantly associated with childhood-onset asthma.
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van der Valk RJP, Kiefte-de Jong JC, Sonnenschein-van der Voort AMM, Duijts L, Hafkamp-de Groen E, Moll HA, Tiemeier H, Steegers EAP, Hofman A, Jaddoe VWV, de Jongste JC. Neonatal folate, homocysteine, vitamin B12 levels and methylenetetrahydrofolate reductase variants in childhood asthma and eczema. Allergy 2013; 68:788-95. [PMID: 23692062 DOI: 10.1111/all.12146] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/11/2013] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To assess the associations of folate, homocysteine and vitamin B12 levels of children at birth and their methylenetetrahydrofolate reductase (MTHFR) variants with asthma and eczema in childhood. METHODS This study was embedded in a population-based prospective cohort study (n = 2,001). Neonatal cord blood folate, homocysteine and vitamin B12 levels were measured, and MTHFR C677T and A1298C genotyped. Wheezing and physician-diagnosed eczema were annually obtained by questionnaire until 4 years. At 6 years, we collected information on physician-diagnosed asthma ever and self-reported eczema ever, measured fractional exhaled nitric oxide (FeNO), and interrupter resistance (Rint). Data were analysed with generalized estimating equations or logistic regression: continuous outcomes with linear regression models. RESULTS Folate, homocysteine and vitamin B12 levels of children at birth were not associated with wheezing or eczema until 4 years, asthma and eczema ever, or FeNO or Rint at 6 years. In children carrying C677T mutations in MTHFR, higher folate levels were associated with an increased risk of eczema (repeated eczema until 4 years: OR 1.40 (95% CI 1.09-1.80) (SD change) P-interaction = 0.003, eczema ever at 6 years: OR 1.41 (0.97-2.03) P-interaction = 0.011). No interactions between MTHFR and child folate and homocysteine levels were observed for wheezing and asthma. CONCLUSIONS Folate, homocysteine and vitamin B12 levels of children at birth did not affect asthma- and eczema-related outcomes up to the age of 6 years. Further studies are warranted to establish the role of MTHFR variants in these associations.
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Affiliation(s)
| | | | | | | | | | | | | | | | - A. Hofman
- Department of Epidemiology; Erasmus MC; Rotterdam; The Netherlands
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Holgate ST. Immune circuits in asthma. Curr Opin Pharmacol 2013; 13:345-50. [PMID: 23639506 DOI: 10.1016/j.coph.2013.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 01/29/2013] [Accepted: 03/22/2013] [Indexed: 11/28/2022]
Abstract
Asthma is an inflammatory disorder of the conducting airways that has traditionally been classified according to severity. While this has been helpful in guiding treatment with drugs that are currently available such as β2-adrenoceptor agonists and corticosteroids, it takes little account of disease heterogeneity and causal pathways. This review draws attention to subphenotypes of asthma involving different mechanisms and moves the focus away from the adaptive immune response more towards innate immune mechanisms. This mandates a new view of the disease in which causal pathways linked to biomarkers are found and treatments targeted to these pathways as described in a more personalised approach to medicine.
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Affiliation(s)
- Stephen T Holgate
- Clinical and Experimental Sciences, Mail Point 810, Level F South Block, Southampton General Hospital, Southampton SO16 6YD, UK.
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34
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Calışkan M, Bochkov YA, Kreiner-Møller E, Bønnelykke K, Stein MM, Du G, Bisgaard H, Jackson DJ, Gern JE, Lemanske RF, Nicolae DL, Ober C. Rhinovirus wheezing illness and genetic risk of childhood-onset asthma. N Engl J Med 2013; 368:1398-407. [PMID: 23534543 PMCID: PMC3755952 DOI: 10.1056/nejmoa1211592] [Citation(s) in RCA: 393] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Both genetic variation at the 17q21 locus and virus-induced respiratory wheezing illnesses are associated with the development of asthma. Our aim was to determine the effects of these two factors on the risk of asthma in the Childhood Origins of Asthma (COAST) and the Copenhagen Prospective Study on Asthma in Childhood (COPSAC) birth cohorts. METHODS We tested genotypes at the 17q21 locus for associations with asthma and with human rhinovirus (HRV) and respiratory syncytial virus (RSV) wheezing illnesses and tested for interactions between 17q21 genotypes and HRV and RSV wheezing illnesses with respect to the risk of asthma. Finally, we examined genotype-specific expression of 17q21 genes in unstimulated and HRV-stimulated peripheral-blood mononuclear cells (PBMCs). RESULTS The 17q21 variants were associated with HRV wheezing illnesses in early life, but not with RSV wheezing illnesses. The associations of 17q21 variants with asthma were restricted to children who had had HRV wheezing illnesses, resulting in a significant interaction effect with respect to the risk of asthma. Moreover, the expression levels of ORMDL3 and of GSDMB were significantly increased in HRV-stimulated PBMCs, as compared with unstimulated PBMCs. The expression of these genes was associated with 17q21 variants in both conditions, although the increase with exposure to HRV was not genotype-specific. CONCLUSIONS Variants at the 17q21 locus were associated with asthma in children who had had HRV wheezing illnesses and with expression of two genes at this locus. The expression levels of both genes increased in response to HRV stimulation, although the relative increase was not associated with the 17q21 genotypes. (Funded by the National Institutes of Health.).
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Affiliation(s)
- Minal Calışkan
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA.
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Sex- and age-dependent DNA methylation at the 17q12-q21 locus associated with childhood asthma. Hum Genet 2013; 132:811-22. [PMID: 23546690 DOI: 10.1007/s00439-013-1298-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 03/18/2013] [Indexed: 12/31/2022]
Abstract
Chromosomal region 17q12-q21 is one of the best-replicated genome-wide association study (GWAS) hits and associated with childhood-onset asthma. However, the mechanism by which the genetic association is restricted to childhood-onset disease is unclear. During childhood, more boys than girls develop asthma. Therefore, we tested the hypothesis that the 17q12-q21 genetic association was sex-specific. Indeed, a TDT test showed that in the Saguenay-Lac-Saint-Jean familial collection, the 17q12-q21 association was significant among male, but not among female asthmatic subjects. We next hypothesized that the bias in the genetic association resulted from sex-specific and/or age-dependent DNA methylation at regulatory regions and determined the methylation profiles of five 17q12-q21 gene promoters using the bisulfite sequencing methylation assay. We identified a single regulatory region within the zona pellucida binding protein 2 (ZPBP2) gene, which showed statistically significant differences between males and females with respect to DNA methylation. DNA methylation also varied with age and was higher in adult males compared to boys. We have recently identified two functionally important polymorphisms, both within the ZPBP2 gene that influence expression levels of neighboring genes. Combined with the results of the present work, these data converge pointing to the same 5 kb region within the ZPBP2 gene as a critical region for both gene expression regulation and predisposition to asthma. Our data show that sex- and age-dependent DNA methylation may act as a modifier of genetic effects and influence the results of genetic association studies.
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Blekic M, Kljaic Bukvic B, Aberle N, Marinho S, Hankinson J, Custovic A, Simpson A. 17q12-21 and asthma: interactions with early-life environmental exposures. Ann Allergy Asthma Immunol 2013; 110:347-353.e2. [PMID: 23622005 DOI: 10.1016/j.anai.2013.01.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 01/28/2013] [Accepted: 01/28/2013] [Indexed: 10/27/2022]
Abstract
BACKGROUND 17q12-21 polymorphisms are associated with asthma presence and severity across different populations. OBJECTIVE To extensively investigate the genes in this region among Croatian schoolchildren in a case-control study, taking account of early-life environmental exposures. METHODS We included 423 children with asthma and 414 controls aged 5 to 18 years. Fifty-one haplotype tagging single-nucleotide polymorphisms (SNPs) were genotyped (GSDMA, GSDMB, ORMDL3, IKZF3, ZPBP2, and TOP2). Data on exposure to smoking and furry pet ownership were collected using a validated questionnaire. Information on severe asthma exacerbations with hospital admission were retrieved from hospital notes. All patients underwent spirometry. RESULTS We found 2 SNPs (1 novel rs9635726 in IKZF3) to be associated with asthma. Among children with asthma, 4 SNPs (in ZPBP2, GSDMB, and GSDMA) were associated with hospital admissions and 8 SNPs with lung function. One SNP (rs9635726) remained significantly associated with a predicted forced expiratory volume in 1 second after false discovery rate correction. Nine markers across 5 genes showed interaction with early-life environmental tobacco smoke (ETS) exposure in relation to asthma and 2 with furry pet ownership. Among children with asthma, we observed significant interactions between early-life ETS exposure and 3 SNPs for lung function and among early-life ETS exposure, 3 SNPs (in ORMDL3 and GSDMA), and hospital admission with asthma exacerbation. Three SNPs (in ORMDL3) interacted with current furry pet ownership in relation to hospital admissions for asthma exacerbation. CONCLUSION Our results indicate that several genes in the 17q12-21 region may be associated with asthma. This study confirms that environmental exposures may need to be included into the genetic association studies.
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Affiliation(s)
- Mario Blekic
- General Hospital Dr Josip Bencevic Slavonski Brod, University of Osijek, Osijek, Croatia
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37
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Kauffmann F, Demenais F. Gene-environment interactions in asthma and allergic diseases: challenges and perspectives. J Allergy Clin Immunol 2013. [PMID: 23195523 DOI: 10.1016/j.jaci.2012.10.038] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The concept of gene-environment (GxE) interactions has dramatically evolved in the last century and has now become a central theme in studies that assess the causes of human disease. Despite the numerous efforts to discover genes associated in asthma and allergy through various approaches, including the recent genome-wide association studies, investigation of GxE interactions has been mainly limited to candidate genes, candidate environmental exposures, or both. This review discusses the various strategies from hypothesis-driven strategies to the full agnostic search of GxE interactions with an illustration from recently published articles. Challenges raised by each piece of the puzzle (ie, phenotype, environment, gene, and analysis of GxE interaction) are put forward, and tentative solutions are proposed. New perspectives to integrate various types of data generated by new sequencing technologies and to progress toward a systems biology approach of disease are outlined. The future of a molecular network-based approach of disease to which GxE interactions are related requires space for innovative and multidisciplinary research. Assembling the various parts of a puzzle in a complex system could well occur in a way that might not necessarily follow the rules of logic.
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Affiliation(s)
- Francine Kauffmann
- INSERM, CESP Centre for research in Epidemiology and Population Health, U1018, Respiratory and Environmental Epidemiology Team, Villejuif, France
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Al-Saleh I, Alsabbahen A, Shinwari N, Billedo G, Mashhour A, Al-Sarraj Y, Mohamed GED, Rabbah A. Polycyclic aromatic hydrocarbons (PAHs) as determinants of various anthropometric measures of birth outcome. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 444:565-78. [PMID: 23314068 DOI: 10.1016/j.scitotenv.2012.12.021] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 12/08/2012] [Accepted: 12/09/2012] [Indexed: 05/25/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that are known to induce oxidative stress. There have been several reports about the link between PAH exposure and complications in pregnancy. This cross-sectional study was conducted to: (1) measure the levels of benzo(a)anthracene (BaA), chrysene (Ch), benzo(b)fluoranthene (BbF), benzo(a)pyrene (BaP), and dibenzo(a,h)anthracene (DBahA) in placentas and maternal and -umbilical cord blood obtained at delivery from 1578 women between June 2005 and 2006 in the area of Al-Kharj, Saudi Arabia; (2) assess their influence on various anthropometric measures of birth outcome taking into consideration the carcinogenic properties of these PAHs; and (3) determine the degree of PAH-related oxidative DNA damage and birth outcome. Among the five tested PAHs, only BaP was carcinogenic; therefore, the levels of the other four probable or possible carcinogenic PAHs (BaA, Ch, BaF, and DBahA) were summed as ∑4-PAHs. Levels of 1-hydroxypyrene (1-HP) were determined in maternal urine samples as a biomarker of PAH internal dose. Urinary cotinine (COT) was measured as an index of smoking. The following markers of oxidative stress were selected: malondialdehyde (MDA) in cord (C-MDA) and maternal (M-MDA) serum and 8-hydroxy-2-deoxyguanosine (8-OHdG) in maternal urine. None of the tested PAHs was found in maternal or cord blood. However, all five PAH compounds were detected in placentas; Ch was the highest (6.582 μg/kg dry wt.), and BaA was the lowest (0.236 μg/kg dry wt.). The mean concentration of urinary 1-HP found in this study was 0.216 ± 0.856 μg/g Cr. After adjusting for gestational age and other confounding variables, regression models revealed an inverse relationship between placental weight, cord length and placental BaP. A similar trend was observed between cord length and ∑4-PAHs in placental tissues. Urinary 1-HP, though, cannot be used as an unequivocal biomarker of PAH exposure, but it can be an appropriate indicator of exposure to environmental tobacco smoke (ETS). The data demonstrate that ETS exposure (as measured by urinary COT) may adversely affect birth outcome as shown by reduced head circumference, birth weight, and birth length, as well as increased cephalization index. The positive relationship between 8-OHdG levels and 1-HP in urine provides evidence of an oxidative stress mechanism. Although this study provides no direct evidence of an association between PAH exposure and DNA damage, increased oxidative stress in the form of lipid peroxidation significantly affected various birth measures. Therefore, there is a need for studies regarding PAH exposure and its associated biological effects to determine the extent of potential fetal damage as well as possible long-term effects, such as cancer.
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Affiliation(s)
- Iman Al-Saleh
- Environmental Health Section, Biological & Medical Research Department, King Faisal Specialist Hospital & Research Centre, PO Box: 3354, Riyadh, Saudi Arabia.
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