D Chan1, S McGraw2, K Klein3, L M Wallock4, C Konermann5, C Plass5, P Chan6, B Robaire7, R A Jacob8, C M T Greenwood3,9, J M Trasler10,7. 1. Departments of Pediatrics and of Human Genetics of McGill University, Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Glen Site, 1001 Décarie Boulevard Block E- Room EM0.2236 Montreal, QC H4A 3J1, Canada. 2. Department of Obstetrics and Gynaecology, Biochemistry and Molecular Medicine of Université de Montréal, Research Center of the Sainte-Justine University Hospital, Montreal, QC H3T 1C5, Canada. 3. Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC H3T 1E2, Canada. 4. Department of Biological Sciences, Diablo Valley College, Pleasant Hill, CA 94523, USA. 5. Department of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany. 6. Royal Victoria Hospital of the McGill University Health Centre and Department of Surgery, McGill University, Montréal, QC H4A 3J1, Canada. 7. Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3A 0G4, Canada. 8. USDA, Agricultural Research Service, Western Human Nutrition Research Center, Davis, CA 95616, USA. 9. Departments of Oncology, Epidemiology, Biostatistics and Occupational Health, and Human Genetics, McGill University, Montréal, QC H4A 3J1, Canada. 10. Departments of Pediatrics and of Human Genetics of McGill University, Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Glen Site, 1001 Décarie Boulevard Block E- Room EM0.2236 Montreal, QC H4A 3J1, Canada jacquetta.trasler@mcgill.ca.
Abstract
STUDY QUESTION: Do short-term and long-term exposures to low-dose folic acid supplementation alter DNA methylation in sperm? SUMMARY ANSWER: No alterations in sperm DNA methylation patterns were found following the administration of low-dose folic acid supplements of 400 μg/day for 90 days (short-term exposure) or when pre-fortification of food with folic acid and post-fortification sperm samples (long-term exposure) were compared. WHAT IS KNOWN ALREADY: Excess dietary folate may be detrimental to health and DNA methylation profiles due to folate's role in one-carbon metabolism and the formation of S-adenosyl methionine, the universal methyl donor. DNA methylation patterns are established in developing male germ cells and have been suggested to be affected by high-dose (5 mg/day) folic acid supplementation. STUDY DESIGN, SIZE, DURATION: This is a control versus treatment study where genome-wide sperm DNA methylation patterns were examined prior to fortification of food (1996-1997) in men with no history of infertility at baseline and following 90-day exposure toplacebo (n = 9) or supplement containing 400 μg folic acid/day (n = 10). Additionally, pre-fortification sperm DNA methylation profiles (n = 19) were compared with those of a group of post-fortification (post-2004) men (n = 8) who had been exposed for several years to dietary folic acid fortification. PARTICIPANTS/MATERIALS, SETTING, METHODS:Blood and seminal plasma folate levels were measured in participants before and following the 90-day treatment with placebo or supplement. Sperm DNA methylation was assessed using the whole-genome and genome-wide techniques, MassArray epityper, restriction landmark genomic scanning, methyl-CpG immunoprecipitation and Illumina HumanMethylation450 Bead Array. MAIN RESULTS AND THE ROLE OF CHANCE: Following treatment, supplemented individuals had significantly higher levels of blood and seminal plasma folates compared to placebo. Initial first-generation genome-wide analyses of sperm DNA methylation showed little evidence of changes when comparing pre- and post-treatment samples. With Illumina HumanMethylation450 BeadChip arrays, no significant changes were observed in individual probes following low-level supplementation; when compared with those of the post-fortification cohort, there were also few differences in methylation despite exposure to years of fortified foods. LARGE SCALE DATA: Illumina HumanMethylation450 BeadChip data from this study have been submitted to the NCBI Gene Expression Omnibus under the accession number GSE89781. LIMITATIONS, REASONS FOR CAUTION: This study was limited to the number of participants available in each cohort, in particular those who were not exposed to early (pre-1998) fortification of food with folic acid. While genome-wide DNA methylation was assessed with several techniques that targeted genic and CpG-rich regions, intergenic regions were less well interrogated. WIDER IMPLICATIONS OF THE FINDINGS: Overall, our findings provide evidence that short-term exposure to low-dose folic acid supplements of 400 μg/day, over a period of 3 months, a duration of time that might occur during infertility treatments, has no major impact on the sperm DNA methylome. STUDY FUNDING/COMPETING INTERESTS: This work was supported by a grant to J.M.T. from the Canadian Institutes of Health Research (CIHR: MOP-89944). The authors have no conflicts of interest to declare.
RCT Entities:
STUDY QUESTION: Do short-term and long-term exposures to low-dose folic acid supplementation alter DNA methylation in sperm? SUMMARY ANSWER: No alterations in sperm DNA methylation patterns were found following the administration of low-dose folic acid supplements of 400 μg/day for 90 days (short-term exposure) or when pre-fortification of food with folic acid and post-fortification sperm samples (long-term exposure) were compared. WHAT IS KNOWN ALREADY: Excess dietary folate may be detrimental to health and DNA methylation profiles due to folate's role in one-carbon metabolism and the formation of S-adenosyl methionine, the universal methyl donor. DNA methylation patterns are established in developing male germ cells and have been suggested to be affected by high-dose (5 mg/day) folic acid supplementation. STUDY DESIGN, SIZE, DURATION: This is a control versus treatment study where genome-wide sperm DNA methylation patterns were examined prior to fortification of food (1996-1997) in men with no history of infertility at baseline and following 90-day exposure to placebo (n = 9) or supplement containing 400 μg folic acid/day (n = 10). Additionally, pre-fortification sperm DNA methylation profiles (n = 19) were compared with those of a group of post-fortification (post-2004) men (n = 8) who had been exposed for several years to dietary folic acid fortification. PARTICIPANTS/MATERIALS, SETTING, METHODS: Blood and seminal plasma folate levels were measured in participants before and following the 90-day treatment with placebo or supplement. Sperm DNA methylation was assessed using the whole-genome and genome-wide techniques, MassArray epityper, restriction landmark genomic scanning, methyl-CpG immunoprecipitation and Illumina HumanMethylation450 Bead Array. MAIN RESULTS AND THE ROLE OF CHANCE: Following treatment, supplemented individuals had significantly higher levels of blood and seminal plasma folates compared to placebo. Initial first-generation genome-wide analyses of sperm DNA methylation showed little evidence of changes when comparing pre- and post-treatment samples. With Illumina HumanMethylation450 BeadChip arrays, no significant changes were observed in individual probes following low-level supplementation; when compared with those of the post-fortification cohort, there were also few differences in methylation despite exposure to years of fortified foods. LARGE SCALE DATA: Illumina HumanMethylation450 BeadChip data from this study have been submitted to the NCBI Gene Expression Omnibus under the accession number GSE89781. LIMITATIONS, REASONS FOR CAUTION: This study was limited to the number of participants available in each cohort, in particular those who were not exposed to early (pre-1998) fortification of food with folic acid. While genome-wide DNA methylation was assessed with several techniques that targeted genic and CpG-rich regions, intergenic regions were less well interrogated. WIDER IMPLICATIONS OF THE FINDINGS: Overall, our findings provide evidence that short-term exposure to low-dose folic acid supplements of 400 μg/day, over a period of 3 months, a duration of time that might occur during infertility treatments, has no major impact on the sperm DNA methylome. STUDY FUNDING/COMPETING INTERESTS: This work was supported by a grant to J.M.T. from the Canadian Institutes of Health Research (CIHR: MOP-89944). The authors have no conflicts of interest to declare.
Authors: Donovan Chan; Duncan W Cushnie; Oana R Neaga; Andrea K Lawrance; Rima Rozen; Jacquetta M Trasler Journal: Endocrinology Date: 2010-05-05 Impact factor: 4.736
Authors: Mathias Ehrich; Matthew R Nelson; Patrick Stanssens; Marc Zabeau; Triantafillos Liloglou; George Xinarianos; Charles R Cantor; John K Field; Dirk van den Boom Journal: Proc Natl Acad Sci U S A Date: 2005-10-21 Impact factor: 11.205
Authors: Kathryn Blaschke; Kevin T Ebata; Mohammad M Karimi; Jorge A Zepeda-Martínez; Preeti Goyal; Sahasransu Mahapatra; Angela Tam; Diana J Laird; Martin Hirst; Anjana Rao; Matthew C Lorincz; Miguel Ramalho-Santos Journal: Nature Date: 2013-06-30 Impact factor: 49.962
Authors: Haotian Wu; Molly S Estill; Alexander Shershebnev; Alexander Suvorov; Stephen A Krawetz; Brian W Whitcomb; Holly Dinnie; Tayyab Rahil; Cynthia K Sites; J Richard Pilsner Journal: Hum Reprod Date: 2017-11-01 Impact factor: 6.918
Authors: Jeffrey Hoek; Régine P M Steegers-Theunissen; Sten P Willemsen; Sam Schoenmakers Journal: Mol Nutr Food Res Date: 2020-02-20 Impact factor: 5.914
Authors: Donovan Chan; Xiaojian Shao; Marie-Charlotte Dumargne; Mahmoud Aarabi; Marie-Michelle Simon; Tony Kwan; Janice L Bailey; Bernard Robaire; Sarah Kimmins; Maria C San Gabriel; Armand Zini; Clifford Librach; Sergey Moskovtsev; Elin Grundberg; Guillaume Bourque; Tomi Pastinen; Jacquetta M Trasler Journal: Environ Health Perspect Date: 2019-08-08 Impact factor: 9.031
Authors: Christopher P Morgan; Amol C Shetty; Jennifer C Chan; Dara S Berger; Seth A Ament; C Neill Epperson; Tracy L Bale Journal: Sci Rep Date: 2020-10-15 Impact factor: 4.379