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Melo TP, Fortes MRS, Bresolin T, Mota LFM, Albuquerque LG, Carvalheiro R. Multitrait meta-analysis identified genomic regions associated with sexual precocity in tropical beef cattle. J Anim Sci 2018; 96:4087-4099. [PMID: 30053002 DOI: 10.1093/jas/sky289] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 07/20/2018] [Indexed: 12/31/2022] Open
Abstract
Multitrait meta-analyses are a strategy to produce more accurate genome-wide association studies, especially for complex phenotypes. We carried out a meta-analysis study for traits related to sexual precocity in tropical beef cattle (Nellore and Brahman) aiming to identify important genomic regions affecting these traits. The traits included in the analyses were age at first calving (AFC), early pregnancy (EP), age at first corpus luteum (AGECL), first postpartum anoestrus interval (PPAI), and scrotal circumference (SC). The traits AFC, EP, and SCN were measured in Nellore cattle, while AGECL, PPAI, and SCB were measured in Brahman cattle. Meta-analysis resulted in 108 significant single-nucleotide polymorphisms (SNPs), at an empirical threshold P-value of 1.39 × 10-5 (false discovery rate [FDR] < 0.05). Within 0.5 Mb of the significant SNP, candidate genes were annotated and analyzed for functional enrichment. Most of the closest genes to the SNP with higher significance in each chromosome have been associated with important roles in reproductive function. They are TSC22D2, KLF7, ARHGAP29, 7SK, MAP3K5, TLE3, WDR5, TAF3, TMEM68, PPP1R15B, NR2F2, GALR1, SUFU, and KCNU1. We did not observe any significant SNP in BTA5, BTA12, BTA17, BTA18, BTA19, BTA20, BTA22, BTA23, BTA25, and BTA28. Although the majority of significant SNPs are in BTA14, it was identified significant associations in multiple chromosomes (19 out of 29 autosomes), which is consistent with the postulation that reproductive traits are complex polygenic phenotypes. Five proposed association regions harbor the majority of the significant SNP (76%) and were distributed over four chromosomes (P < 1.39 × 10-5, FDR < 0.05): BTA2 (5.55%) from 95 to 96 Mb, BTA4 (5.55%) from 94.1 to 94.8 Mb, BTA14 (59.26%) from 24 to 25 Mb and 29 to 30 Mb, and BTA21 (5.55%) from 6.7 Mb to 11.4 Mb. These regions harbored key genes related to reproductive function. Moreover, these genes were enriched for functional groups associated with immune response, maternal-fetal tolerance, pregnancy maintenance, embryo development, fertility, and response to stress. Further studies including other breeds and precocity traits could confirm the importance of these regions and identify new candidate regions for sexual precocity in beef cattle.
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Affiliation(s)
- Thaise P Melo
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, FCAV/ UNESP - Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil
| | - Marina R S Fortes
- The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland, Australia.,The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, St Lucia, Queensland, Australia
| | - Tiago Bresolin
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, FCAV/ UNESP - Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil
| | - Lucio F M Mota
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, FCAV/ UNESP - Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil
| | - Lucia G Albuquerque
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, FCAV/ UNESP - Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil.,National Council for Scientific and Technological Development (CNPq), Brasília, Distrito Federal, Brazil
| | - Roberto Carvalheiro
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, FCAV/ UNESP - Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil.,National Council for Scientific and Technological Development (CNPq), Brasília, Distrito Federal, Brazil
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Bellingham M, Fowler PA, MacDonald ES, Mandon‐Pepin B, Cotinot C, Rhind S, Sharpe RM, Evans NP. Timing of Maternal Exposure and Foetal Sex Determine the Effects of Low-level Chemical Mixture Exposure on the Foetal Neuroendocrine System in Sheep. J Neuroendocrinol 2016; 28:10.1111/jne.12444. [PMID: 27870155 PMCID: PMC5621486 DOI: 10.1111/jne.12444] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/21/2016] [Accepted: 11/01/2016] [Indexed: 01/09/2023]
Abstract
We have shown that continuous maternal exposure to the complex mixture of environmental chemicals (ECs) found in human biosolids (sewage sludge), disrupts mRNA expression of genes crucial for development and long-term regulation of hypothalamic-pituitary gonadal (HPG) function in sheep. The present study investigated whether exposure to ECs only during preconceptional period or only during pregnancy perturbed key regulatory genes within the hypothalamus and pituitary gland and whether these effects were different from chronic (life-long) exposure to biosolid ECs. The findings demonstrate that the timing and duration of maternal EC exposure influences the subsequent effects on the foetal neuroendocrine system in a sex-specific manner. Maternal exposure prior to conception, or during pregnancy only, altered the expression of key foetal neuroendocrine regulatory systems such as gonadotrophin-releasing hormone and kisspeptin to a greater extent than when maternal exposure was 'life-long'. Furthermore, hypothalamic gene expression was affected to a greater extent in males than in females and, following EC exposure, male foetuses expressed more 'female-like' mRNA levels for some key neuroendocrine genes. This is the first study to show that 'real-life' maternal exposure to low levels of a complex cocktail of chemicals prior to conception can subsequently affect the developing foetal neuroendocrine system. These findings demonstrate that the developing neuroendocrine system is sensitive to EC mixtures in a sex-dimorphic manner likely to predispose to reproductive dysfunction in later life.
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Affiliation(s)
- M. Bellingham
- Institute of BiodiversityAnimal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - P. A. Fowler
- Division of Applied MedicineCentre for Reproductive Endocrinology and MedicineInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - E. S. MacDonald
- Institute of BiodiversityAnimal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | | | - C. Cotinot
- UMR BDRUniversite Paris SaclayParisFrance
| | - S. Rhind
- James Hutton InstituteAberdeenUK
| | - R. M. Sharpe
- MRC Centre for Reproductive HealthUniversity of EdinburghEdinburghUK
| | - N. P. Evans
- Institute of BiodiversityAnimal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
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Kim E, Jeong I, Kim S, Kim HK, Lee DW, Kim B, Seong JY, Bae YK, Ryu JH, Park HC. Distribution of galanin receptor 2b neurons and interaction with galanin in the zebrafish central nervous system. Neurosci Lett 2016; 628:153-60. [DOI: 10.1016/j.neulet.2016.06.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/14/2016] [Accepted: 06/09/2016] [Indexed: 01/12/2023]
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Bu L, Chang X, Cheng X, Yao Q, Su B, Sheng C, Qu S. Activated central galanin type 1 receptor alleviated insulin resistance in diabetic rat muscle. J Neurosci Res 2016; 94:947-55. [PMID: 27410235 DOI: 10.1002/jnr.23775] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 04/27/2016] [Accepted: 05/02/2016] [Indexed: 01/14/2023]
Affiliation(s)
- Le Bu
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
| | - Xusheng Chang
- Department of General Surgery; Yancheng City First People's Hospital; Yancheng City Jiangsu People's Republic of China
| | - Xiaoyun Cheng
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
| | - Qian Yao
- Key Laboratory of Sichuan Province of Medicinal Chemistry; Chengdu University; Chengdu People's Republic of China
| | - Bin Su
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
| | - Chunjun Sheng
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
| | - Shen Qu
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai People's Republic of China
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Marakhonov A, Sadovskaya N, Antonov I, Baranova A, Skoblov M. Analysis of discordant Affymetrix probesets casts serious doubt on idea of microarray data reutilization. BMC Genomics 2014; 15 Suppl 12:S8. [PMID: 25563078 PMCID: PMC4303952 DOI: 10.1186/1471-2164-15-s12-s8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background Affymetrix microarray technology allows one to investigate expression of thousands of genes simultaneously upon a variety of conditions. In a popular U133A microarray platform, the expression of 37% of genes is measured by more than one probeset. The discordant expression observed for two different probesets that match the same gene is a widespread phenomenon which is usually underestimated, ignored or disregarded. Results Here we evaluate the prevalence of discordant expression in data collected using Affymetrix HG-U133A microarray platform. In U133A, about 30% of genes annotated by two different probesets demonstrate a substantial correlation between independently measured expression values. To our surprise, sorting the probesets according to the nature of the discrepancy in their expression levels allowed the classification of the respective genes according to their fundamental functional properties, including observed enrichment by tissue-specific transcripts and alternatively spliced variants. On another hand, an absence of discrepancies in probesets that simultaneously match several different genes allowed us to pinpoint non-expressed pseudogenes and gene groups with highly correlated expression patterns. Nevertheless, in many cases, the nature of discordant expression of two probesets that match the same transcript remains unexplained. It is possible that these probesets report differently regulated sets of transcripts, or, in best case scenario, two different sets of transcripts that represent the same gene. Conclusion The majority of absolute gene expression values collected using Affymetrix microarrays may not be suitable for typical interpretative downstream analysis.
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Evans NP, Bellingham M, Sharpe RM, Cotinot C, Rhind SM, Kyle C, Erhard H, Hombach-Klonisch S, Lind PM, Fowler PA. Reproduction Symposium: does grazing on biosolids-treated pasture pose a pathophysiological risk associated with increased exposure to endocrine disrupting compounds? J Anim Sci 2014; 92:3185-98. [PMID: 24948646 DOI: 10.2527/jas.2014-7763] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Biosolids (processed human sewage sludge), which contain low individual concentrations of an array of contaminants including heavy metals and organic pollutants such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), and polychlorinated dibenzodioxins/polychlorinated dibenzofurans known to cause physiological disturbances, are increasingly being used as an agricultural fertilizer. This could pose a health threat to both humans and domestic and wild animal species. This review summarizes results of a unique model, used to determine the effects of exposure to mixtures of environmentally relevant concentrations of pollutants, in sheep grazed on biosolids-treated pastures. Pasture treatment results in nonsignificant increases in environmental chemical (EC) concentrations in soil. Whereas EC concentrations were increased in some tissues of both ewes and their fetuses, concentrations were low and variable and deemed to pose little risk to consumer health. Investigation of the effects of gestational EC exposure on fetal development has highlighted a number of issues. The results indicate that gestational EC exposure can adversely affect gonadal development (males and females) and that these effects can impact testicular morphology, ovarian follicle numbers and health, and the transcriptome and proteome in adult animals. In addition, EC exposure can be associated with altered expression of GnRH, GnRH receptors, galanin receptors, and kisspeptin mRNA within the hypothalamus and pituitary gland, gonadotroph populations within the pituitary gland, and regional aberrations in thyroid morphology. In most cases, these anatomical and functional differences do not result in altered peripheral hormone concentrations or reproductive function (e.g., lambing rate), indicating physiological compensation under the conditions tested. Physiological compensation is also suggested from studies that indicate that EC effects may be greater when exposure occurs either before or during gestation compared with EC exposure throughout life. With regard to human and animal health, this body of work questions the concept of safe individual concentration of EC when EC exposure typically occurs as complex mixtures. It suggests that developmental EC exposure may affect many different physiological systems, with some sex-specific differences in EC sensitivity, and that EC effects may be masked under favorable physiological conditions.
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Affiliation(s)
- N P Evans
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH
| | - M Bellingham
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH
| | - R M Sharpe
- MRC Human Reproductive Sciences Unit, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - C Cotinot
- INRA, UMR 1198, Biologie du Développement et Reproduction F-78350, Jouy-en-Josas, France
| | - S M Rhind
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - C Kyle
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - H Erhard
- INRA, UMR791 MoSAR/AgroParis Tech, UMR MoSAR, F-75005 Paris, France
| | - S Hombach-Klonisch
- Dept Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada
| | - P M Lind
- Dept Medical Sciences, Occupational and Environmental medicine, Uppsala University, 751 85 Uppsala, Sweden
| | - P A Fowler
- Institute of Medical Sciences, Division of Applied Medicine, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
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Bu L, Liu Z, Zou J, Gao X, Bao Y, Qu S. Blocking central galanin receptors attenuates insulin sensitivity in myocytes of diabetic trained rats. J Neurosci Res 2013; 91:971-7. [PMID: 23653288 DOI: 10.1002/jnr.23228] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 02/23/2013] [Accepted: 03/05/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Le Bu
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai; China
| | - Zhimin Liu
- Department of Endocrinology; Changzheng Hospital, Second Military Medical University; Shanghai; China
| | - Junjie Zou
- Department of Endocrinology; Changzheng Hospital, Second Military Medical University; Shanghai; China
| | - Xiang Gao
- Department of Nephrology; Changzheng Hospital, Second Military Medical University; Shanghai; China
| | - Yi Bao
- Department of Endocrinology; Changzheng Hospital, Second Military Medical University; Shanghai; China
| | - Shen Qu
- Department of Endocrinology; Shanghai 10th People's Hospital, Tongji University School of Medicine; Shanghai; China
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Li L, Wei S, Huang Q, Feng D, Zhang S, Liu Z. A novel galanin receptor 1a gene in zebrafish: Tissue distribution, developmental expression roles in nutrition regulation. Comp Biochem Physiol B Biochem Mol Biol 2013; 164:159-67. [DOI: 10.1016/j.cbpb.2012.12.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 12/12/2012] [Accepted: 12/13/2012] [Indexed: 01/10/2023]
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Tofighi R, Barde S, Palkovits M, Höög A, Hökfelt T, Ceccatelli S, Hulting AL. Galanin and its three receptors in human pituitary adenoma. Neuropeptides 2012; 46:195-201. [PMID: 22889491 DOI: 10.1016/j.npep.2012.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 06/26/2012] [Accepted: 07/04/2012] [Indexed: 11/21/2022]
Abstract
Galanin, a 29-aminoacid peptide (30 in humans), is widely distributed in the nervous and endocrine systems and exerts its actions via three G-protein-coupled receptors, GalR1-3. The galanin system has, among others, been associated with tumorigenesis. Our objective was to assess the expression of galanin and its receptors in pituitary tumors. Transcript levels of galanin and galanin receptors 1-3 (GalR1-3) were measured using quantitative real-time PCR (q-PCR) in pituitary tumors, surgically removed from thirteen patients, and twelve post mortem pituitaries. Galanin, GalR1 and GalR2 mRNA, but not GalR3 mRNA, were found in the twelve human post-mortem pituitaries. Expression of GalR1 was relatively increased in most, whereas GalR2 was decreased in some tumors. High levels of GalR3 were only found in tumors of five patients, who all relapsed shortly after surgical intervention. The results suggest that GalR3, a receptor for the neuroendocrine peptide galanin, is a potential marker for relapsing pituitary tumors. Thus, galanin receptors may play an important role in pituitary tumors, also for surgical outcome and prognosis, and may serve as a diagnostic tool. The association of GalR3 with tumor relapse suggests that antagonists to this receptor represent a potential therapeutic approach to treatment of pituitary tumors.
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Affiliation(s)
- Roshan Tofighi
- Department of Neuroscience, Karolinska Institutet and Karolinska Hospital, S-17177 Stockholm, Sweden.
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Zhang Z, Sheng S, Guo L, Li G, Zhang L, Zhang L, Shi M, Bo P, Zhu Y. Intracerebroventricular administration of galanin antagonist sustains insulin resistance in adipocytes of type 2 diabetic trained rats. Mol Cell Endocrinol 2012; 361:213-8. [PMID: 22564511 DOI: 10.1016/j.mce.2012.04.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 04/06/2012] [Accepted: 04/27/2012] [Indexed: 10/28/2022]
Abstract
The aim of this study is to investigate whether galanin (GAL) central receptors are involved in regulation of insulin resistance. To test it, a GAL antagonist, M35 was intracerebroventricularly administrated in trained type 2 diabetic rats. The euglycemic-hyperinsulinemic clamp test was conducted for an index of glucose infusion rates. The epididymal fat pads were processed for determination of glucose uptake and Glucose Transporter 4 (GLUT4) amounts. The Gal mRNA expression levels in hypothalamus were quantitatively assessed too. We found an inhibitory effect of M35 on glucose uptake into adipocytes, Gal mRNA expression levels in hypothalamus, glucose infusion rates in the clamp test and GLUT4 concentration in plasma membranes and total cell membranes of adipocytes. The ratios of GLUT4 contents of the former to the latter in M35 groups were lower. These results suggest a facilitating role for GAL on GLUT4 translocation and insulin sensitivity via its central receptors in rats.
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Affiliation(s)
- Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, PR China
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Bell JT, Tsai PC, Yang TP, Pidsley R, Nisbet J, Glass D, Mangino M, Zhai G, Zhang F, Valdes A, Shin SY, Dempster EL, Murray RM, Grundberg E, Hedman AK, Nica A, Small KS, Dermitzakis ET, McCarthy MI, Mill J, Spector TD, Deloukas P. Epigenome-wide scans identify differentially methylated regions for age and age-related phenotypes in a healthy ageing population. PLoS Genet 2012; 8:e1002629. [PMID: 22532803 PMCID: PMC3330116 DOI: 10.1371/journal.pgen.1002629] [Citation(s) in RCA: 491] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 02/22/2012] [Indexed: 12/18/2022] Open
Abstract
Age-related changes in DNA methylation have been implicated in cellular senescence and longevity, yet the causes and functional consequences of these variants remain unclear. To elucidate the role of age-related epigenetic changes in healthy ageing and potential longevity, we tested for association between whole-blood DNA methylation patterns in 172 female twins aged 32 to 80 with age and age-related phenotypes. Twin-based DNA methylation levels at 26,690 CpG-sites showed evidence for mean genome-wide heritability of 18%, which was supported by the identification of 1,537 CpG-sites with methylation QTLs in cis at FDR 5%. We performed genome-wide analyses to discover differentially methylated regions (DMRs) for sixteen age-related phenotypes (ap-DMRs) and chronological age (a-DMRs). Epigenome-wide association scans (EWAS) identified age-related phenotype DMRs (ap-DMRs) associated with LDL (STAT5A), lung function (WT1), and maternal longevity (ARL4A, TBX20). In contrast, EWAS for chronological age identified hundreds of predominantly hyper-methylated age DMRs (490 a-DMRs at FDR 5%), of which only one (TBX20) was also associated with an age-related phenotype. Therefore, the majority of age-related changes in DNA methylation are not associated with phenotypic measures of healthy ageing in later life. We replicated a large proportion of a-DMRs in a sample of 44 younger adult MZ twins aged 20 to 61, suggesting that a-DMRs may initiate at an earlier age. We next explored potential genetic and environmental mechanisms underlying a-DMRs and ap-DMRs. Genome-wide overlap across cis-meQTLs, genotype-phenotype associations, and EWAS ap-DMRs identified CpG-sites that had cis-meQTLs with evidence for genotype–phenotype association, where the CpG-site was also an ap-DMR for the same phenotype. Monozygotic twin methylation difference analyses identified one potential environmentally-mediated ap-DMR associated with total cholesterol and LDL (CSMD1). Our results suggest that in a small set of genes DNA methylation may be a candidate mechanism of mediating not only environmental, but also genetic effects on age-related phenotypes. Epigenetic patterns vary during healthy ageing and development. Age-related DNA methylation changes have been implicated in cellular senescence and longevity, yet the causes and functional consequences of these variants remain unclear. To understand the biological mechanisms involved in potential longevity and rate of healthy ageing, we performed genome-wide association of epigenetic and genetic variation with both chronological age and age-related phenotypes. We identified hundreds of DNA methylation variants significantly associated with age and replicated these in an independent sample of young adult twins. Only a small proportion of these variants were also associated with age-related phenotypes. Therefore, the majority of age-related epigenetic changes do not contribute to rate of healthy ageing at later stages in life. Our results suggest that age-related changes in methylation occur throughout an individual's lifespan and that a proportion of these may be initiated from an early age. Intriguingly, a fraction of the age differentially methylated regions also associated with genetic variants in our sample, suggesting that DNA methylation may be a candidate mechanism of mediating not only environmental but also genetic effects on age-related phenotypes.
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Affiliation(s)
- Jordana T. Bell
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
- * E-mail: (JTB); (TDS); (PD)
| | - Pei-Chien Tsai
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Tsun-Po Yang
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Ruth Pidsley
- MRC Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, United Kingdom
| | - James Nisbet
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Daniel Glass
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Massimo Mangino
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Guangju Zhai
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada
| | - Feng Zhang
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Ana Valdes
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - So-Youn Shin
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Emma L. Dempster
- MRC Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, United Kingdom
| | - Robin M. Murray
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, United Kingdom
| | - Elin Grundberg
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Asa K. Hedman
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Alexandra Nica
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland
| | - Kerrin S. Small
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | | | | | - Mark I. McCarthy
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
- Oxford National Institute for Health Research Biomedical Research Centre, Churchill Hospital, Oxford, United Kingdom
| | - Jonathan Mill
- MRC Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, United Kingdom
| | - Tim D. Spector
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
- * E-mail: (JTB); (TDS); (PD)
| | - Panos Deloukas
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
- * E-mail: (JTB); (TDS); (PD)
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Whitelaw CM, Robinson JE, Hastie PM, Padmanabhan V, Evans NP. Effects of cycle stage on regionalised galanin, galanin receptors 1-3, GNRH and GNRH receptor mRNA expression in the ovine hypothalamus. J Endocrinol 2012; 212:353-61. [PMID: 22159505 DOI: 10.1530/joe-11-0352] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The neurotransmitter galanin has been implicated in the steroidogenic regulation of reproduction based on work mainly conducted in rodents. This study investigated the temporal changes in the expression of galanin and its three receptor isoforms and GNRH and GNRHR mRNA in specific hypothalamic nuclei known to be involved in the regulation of reproductive cyclicity, namely the medial pre-optic area (mPOA), the rostral mPOA/organum vasculosum of the lamina terminalis, the paraventricular nucleus and the arcuate nucleus using an ovine model. Following synchronisation of their oestrous cycles, tissues were collected from ewes at five time points: the early follicular, mid follicular (MF) and late follicular phases and the early luteal and mid luteal phases. The results indicated significant differences in regional expression of most of the genes studied, with galanin mRNA expression being highest during the MF phase at the start of the GNRH/LH surge and the expression of the three galanin receptor (GalR) isoforms and GNRH and its receptor highest during the luteal phase. These findings are consistent with a role for galanin in the positive feedback effects of oestradiol (E(2)) on GNRH secretion and a role for progesterone induced changes in the pattern of expression of GalRs in the regulation of the timing of E(2)'s positive feedback through increased sensitivity of galanin-sensitive systems to secreted galanin.
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MESH Headings
- Animals
- Arcuate Nucleus of Hypothalamus/metabolism
- Estradiol/physiology
- Estrous Cycle/metabolism
- Estrus Synchronization
- Feedback, Physiological
- Female
- Follicular Phase/metabolism
- Galanin/genetics
- Gene Expression
- Gonadotropin-Releasing Hormone/genetics
- Hypothalamus/chemistry
- Hypothalamus/metabolism
- Luteal Phase/metabolism
- Paraventricular Hypothalamic Nucleus/metabolism
- Preoptic Area/metabolism
- Progesterone/physiology
- RNA, Messenger/analysis
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 3/metabolism
- Receptors, Galanin/genetics
- Receptors, LHRH/genetics
- Sheep/metabolism
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Affiliation(s)
- Christine Margaret Whitelaw
- College of Medical, Veterinary and Life Sciences, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G61 1QH, UK
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13
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Tillet Y, Tourlet S, Picard S, Sizaret PY, Caraty A. Morphofunctional interactions between galanin and GnRH-containing neurones in the diencephalon of the ewe. The effect of oestradiol. J Chem Neuroanat 2012; 43:14-9. [DOI: 10.1016/j.jchemneu.2011.09.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 08/17/2011] [Accepted: 09/16/2011] [Indexed: 11/28/2022]
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14
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Lawrence C, Fraley GS. Galanin-like peptide (GALP) is a hypothalamic regulator of energy homeostasis and reproduction. Front Neuroendocrinol 2011; 32:1-9. [PMID: 20558195 PMCID: PMC2950899 DOI: 10.1016/j.yfrne.2010.06.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 04/26/2010] [Accepted: 06/09/2010] [Indexed: 12/30/2022]
Abstract
Galanin-like peptide (GALP) was discovered in 1999 in the porcine hypothalamus and was found to be a 60 amino acid neuropeptide. GALP shares sequence homology to galanin (1-13) in position 9-21 and can bind to, as well as activate, the three galanin receptor subtypes (GalR1-3). GALP-expressing cells are limited, and are mainly found in the arcuate nucleus of the hypothalamus (ARC) and the posterior pituitary. GALP-positive neurons in the ARC project to several brain regions where they appear to make contact with multiple neuromodulators. These neuromodulators are involved in the regulation of energy homeostasis and reproduction, anatomical evidence that suggests a role for GALP in these physiological functions. In support of this idea, GALP gene expression is regulated by several factors that reflect metabolic state including the metabolic hormones leptin and insulin, thyroid hormones, and blood glucose. Considerable evidence now exists to support the hypothesis that GALP has a role in the regulation of energy homeostasis and reproduction; and, that GALP's role may be independent of the known galanin receptors. In this review, we (1) provide an overview of the distribution of GALP, and discuss the potential relationship between GALP and other neuromodulators of energy homeostasis and reproduction, (2) discuss the metabolic factors that regulate GALP expression, (3) review the evidence for the role of GALP in energy homeostasis and reproduction, (4) discuss the potential downstream mediators and mechanisms underlying GALP's effects, and (5) discuss the possibility that GALP may mediate its effects via an as yet unidentified GALP-specific receptor.
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15
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Abstract
Endocrine pituitary cells are neuronlike; they express numerous voltage-gated sodium, calcium, potassium, and chloride channels and fire action potentials spontaneously, accompanied by a rise in intracellular calcium. In some cells, spontaneous electrical activity is sufficient to drive the intracellular calcium concentration above the threshold for stimulus-secretion and stimulus-transcription coupling. In others, the function of these action potentials is to maintain the cells in a responsive state with cytosolic calcium near, but below, the threshold level. Some pituitary cells also express gap junction channels, which could be used for intercellular Ca(2+) signaling in these cells. Endocrine cells also express extracellular ligand-gated ion channels, and their activation by hypothalamic and intrapituitary hormones leads to amplification of the pacemaking activity and facilitation of calcium influx and hormone release. These cells also express numerous G protein-coupled receptors, which can stimulate or silence electrical activity and action potential-dependent calcium influx and hormone release. Other members of this receptor family can activate calcium channels in the endoplasmic reticulum, leading to a cell type-specific modulation of electrical activity. This review summarizes recent findings in this field and our current understanding of the complex relationship between voltage-gated ion channels, ligand-gated ion channels, gap junction channels, and G protein-coupled receptors in pituitary cells.
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Affiliation(s)
- Stanko S Stojilkovic
- Program in Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Building 49, Room 6A-36, 49 Convent Drive, Bethesda, Maryland 20892-4510, USA.
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16
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Bellingham M, Fowler PA, Amezaga MR, Whitelaw CM, Rhind SM, Cotinot C, Mandon-Pepin B, Sharpe RM, Evans NP. Foetal hypothalamic and pituitary expression of gonadotrophin-releasing hormone and galanin systems is disturbed by exposure to sewage sludge chemicals via maternal ingestion. J Neuroendocrinol 2010; 22:527-33. [PMID: 20236231 PMCID: PMC4959564 DOI: 10.1111/j.1365-2826.2010.01974.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Animals and humans are chronically exposed to endocrine disrupting chemicals (EDCs) that are ubiquitous in the environment. There are strong circumstantial links between environmental EDC exposure and both declining human/wildlife reproductive health and the increasing incidence of reproductive system abnormalities. The verification of such links, however, is difficult and requires animal models exposed to 'real life', environmentally relevant concentrations/mixtures of environmental contaminants (ECs), particularly in utero, when sensitivity to EC exposure is high. The present study aimed to determine whether the foetal sheep reproductive neuroendocrine axis, particularly gondotrophin-releasing hormone (GnRH) and galaninergic systems, were affected by maternal exposure to a complex mixture of chemicals, applied to pasture, in the form of sewage sludge. Sewage sludge contains high concentrations of a spectrum of EDCs and other pollutants, relative to environmental concentrations, but is frequently recycled to land as a fertiliser. We found that foetuses exposed to the EDC mixture in utero through their mothers had lower GnRH mRNA expression in the hypothalamus and lower GnRH receptor (GnRHR) and galanin receptor (GALR) mRNA expression in the hypothalamus and pituitary gland. Strikingly, this, treatment had no significant effect on maternal GnRH or GnRHR mRNA expression, although GALR mRNA expression within the maternal hypothalamus and pituitary gland was reduced. The present study clearly demonstrates that the developing foetal neuroendocrine axis is sensitive to real-world mixtures of environmental chemicals. Given the important role of GnRH and GnRHR in the regulation of reproductive function, its known role programming role in utero, and the role of galanin in the regulation of many physiological/neuroendocrine systems, in utero changes in the activity of these systems are likely to have long-term consequences in adulthood and represent a novel pathway through which EC mixtures could perturb normal reproductive function.
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Affiliation(s)
- M Bellingham
- Division of Cell Sciences, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, UK
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17
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Mensah ET, Volkoff H, Unniappan S. Galanin systems in non-mammalian vertebrates with special focus on fishes. EXPERIENTIA SUPPLEMENTUM (2012) 2010; 102:243-62. [PMID: 21299073 DOI: 10.1007/978-3-0346-0228-0_17] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Galanin is a well characterized multifunctional neuropeptide in mammals. Galanin has been identified from several fishes, amphibians, reptiles and birds. A large set of data is available on galanin-like protein distribution and peptide and/or mRNA sequences in non-mammalian vertebrates. Galanin receptor sequences from fishes and birds are known, but its distribution and mechanisms of actions are poorly understood. While some biological actions of galanin are known in non-mammals, the functional role of galanin in lower vertebrates is limited. For example, galanin has been shown to regulate feeding, pituitary hormone secretion and gut motility in fishes. Several aspects of galanin biology remain unknown, yet, there is enough evidence to implicate galanin as an important physiological modulator in lower vertebrates. Majority of the research articles on galanin in non-mammals arise from studies that used fishes. The objective of this chapter is to provide a summarized discussion of current knowledge on galanin peptide and gene sequences and organization, distribution of galanin gene and protein, and physiological functions of galanin in non-mammalian vertebrates with a special focus on fishes.
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Affiliation(s)
- Elsie Tachie Mensah
- Laboratory of Integrative Neuroendocrinology, Department of Biology, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
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18
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Galanin-Like Peptide: Neural Regulator of Energy Homeostasis and Reproduction. EXPERIENTIA SUPPLEMENTUM 2010; 102:263-80. [DOI: 10.1007/978-3-0346-0228-0_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Bellingham M, Fowler PA, Amezaga MR, Rhind SM, Cotinot C, Mandon-Pepin B, Sharpe RM, Evans NP. Exposure to a complex cocktail of environmental endocrine-disrupting compounds disturbs the kisspeptin/GPR54 system in ovine hypothalamus and pituitary gland. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:1556-62. [PMID: 20019906 PMCID: PMC2790510 DOI: 10.1289/ehp.0900699] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Accepted: 06/05/2009] [Indexed: 05/09/2023]
Abstract
BACKGROUND Ubiquitous environmental chemicals, including endocrine-disrupting chemicals (EDCs), are associated with declining human reproductive health, as well as an increasing incidence of cancers of the reproductive system. Verifying such links requires animal models exposed to "real-life," environmentally relevant concentrations/mixtures of EDC, particularly in utero, when sensitivity to EDC exposure is maximal. OBJECTIVES We evaluated the effects of maternal exposure to a pollutant cocktail (sewage sludge) on the ovine fetal reproductive neuroendocrine axes, particularly the kisspeptin (KiSS-1)/GPR54 (G-protein-coupled receptor 54) system. METHODS KiSS-1, GPR54, and ERalpha (estrogen receptor alpha) mRNA expression was quantified in control (C) and treated (T) maternal and fetal (110-day) hypothalami and pituitary glands using semiquantitative reverse transcription polymerase chain reaction, and colocalization of kisspeptin with LHbeta (luteinizing hormone beta) and ERalpha in C and T fetal pituitary glands quantified using dual-labeling immunohistochemistry. RESULTS Fetuses exposed in utero to the EDC mixture showed reduced KiSS-1 mRNA expression across three hypothalamic regions examined (rostral, mid, and caudal) and had fewer kisspetin immunopositive cells colocalized with both LHbeta and ERalpha in the pituitary gland. In contrast, treatment had no effect on parameters measured in the adult ewe hypothalamus or pituitary. CONCLUSIONS This study demonstrates that the developing fetus is sensitive to real-world mixtures of environmental chemicals, which cause significant neuroendocrine alterations. The important role of kisspeptin/GPR54 in regulating puberty and adult reproduction means that in utero disruption of this system is likely to have long-term consequences in adulthood and represents a novel, additional pathway through which environmental chemicals perturb human reproduction.
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Affiliation(s)
- Michelle Bellingham
- Division of Cell Sciences, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Paul A. Fowler
- Centre for Reproductive Endocrinology and Medicine, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Maria R. Amezaga
- Centre for Reproductive Endocrinology and Medicine, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Corinne Cotinot
- Unité de Biologie du Dévelopement et Reproduction, Institut National de la Recherche Agronomique (INRA), Jouy en Josas, France
| | - Beatrice Mandon-Pepin
- Unité de Biologie du Dévelopement et Reproduction, Institut National de la Recherche Agronomique (INRA), Jouy en Josas, France
| | - Richard M. Sharpe
- Centre for Reproductive Biology, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Neil P. Evans
- Division of Cell Sciences, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
- Address correspondence to N. Evans, Division of Cell Sciences, Faculty of Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH UK. Telephone: 0141-330-5795. Fax: 0141-330-5797. E-mail:
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20
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Lawrence CB. Galanin-like peptide modulates energy balance by affecting inflammatory mediators? Physiol Behav 2009; 97:515-9. [DOI: 10.1016/j.physbeh.2009.02.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 02/16/2009] [Accepted: 02/18/2009] [Indexed: 12/25/2022]
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