High-dose folic acid supplementation alters the human sperm methylome and is influenced by the MTHFR C677T polymorphism
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Mahmoud Aarabi
PROVIDER: E-GEOD-72606 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Dietary folate is a major source of methyl groups required for DNA methylation, an epigenetic modification that is actively maintained and remodelled during spermatogenesis. While high dose folic acid supplementation (up to ten times the daily recommended dose) has been shown to improve sperm parameters in infertile men, the effects of supplementation on the sperm epigenome are unknown. To assess the impact of six months of high dose folic acid supplementation on the sperm epigenome, we studied 30 men with idiopathic infertility. Blood folate concentrations increased significantly after supplementation with no significant improvements in sperm parameters. Methylation levels of the differentially methylated regions of several imprinted loci (H19, DLK1/GTL2, MEST, SNRPN, PLAGL1, KCNQ1OT1) were normal both before and after supplementation. Reduced representation bisulfite sequencing (RRBS) revealed a significant global loss of methylation across different regions of the sperm genome. The most marked loss of DNA methylation was found in sperm from patients homozygous for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, a common polymorphism in a key enzyme required for folate metabolism. RRBS analysis also showed that most of the differentially methylated tiles were located in DNA repeats, low CpG density and intergenic regions. Ingenuity Pathway Analysis revealed that methylation of promoter regions was altered in several genes involved in cancer and neurobehavioral disorders including CBFA2T3, PTPN6, COL18A1, ALDH2, UBE4B, ERBB2, GABRB3, CNTNAP4 and NIPA1. Our data reveal alterations of the human sperm epigenome associated with high dose folic acid supplementation, effects that were exacerbated by a common polymorphism in MTHFR.
2015-09-10 | GSE72606 | GEO
Project description:Supplementation with high doses of folic acid, an important mediator of one-carbon transfers for DNA methylation, is used clinically to improve sperm parameters in infertile men. We recently detected an unexpected loss of DNA methylation in the sperm of idiopathic infertile men after 6 months of daily supplementation with 5mg folic acid (>10× the daily recommended intake-DRI), exacerbated in men homozygous for a common variant in the gene encoding an important enzyme in folate metabolism, methylenetetrahydrofolate reductase (MTHFR 677C>T). To investigate the epigenomic impact and mechanism underlying effects of folic acid on male germ cells, wildtype and heterozygote mice for a targeted inactivation of the Mthfr gene were fed high-dose folic acid (10× the DRI) or control diets for six months. No changes were detected in general health, sperm counts or methylation of imprinted genes. Reduced representation bisulfite sequencing revealed sperm DNA hypomethylation in Mthfr+/- mice on the 10× diets. Wildtype mice demonstrated sperm hypomethylation only with a very high dose (20×) of folic acid for 12 months. Testicular MTHFR protein levels decreased significantly in wildtype mice on the 20× diet but not in those on the 10× diet, suggesting a possible role for MTHFR deficiency in sperm DNA hypomethylation. In-depth analysis of the folic acid-exposed sperm DNA methylome suggested mouse/human susceptibility of sequences with potential importance to germ cell and embryo development. Our data provide evidence for a similar cross-species response to high dose folic acid supplementation, of sperm DNA hypomethylation, and implicate MTHFR downregulation as a possible mechanism.
2018-01-23 | GSE100849 | GEO
Project description:5,10-Methylenetetrahydrofolate reductase (MTHFR) is an enzyme that plays a key role in providing methyl groups for DNA methylation, including during spermatogenesis. A common genetic variant in humans (MTHFR 677C>T), results in reduced enzyme activity and has been linked to various disorders, including male infertility. A new animal model has been created by reproducing the human equivalent of the polymorphism in mice using CRISPR/Cas9. Biochemical parameters in the Mthfr 677TT mice recapitulate alterations found in MTHFR 677TT men. Our aims were to: 1) characterize the sperm DNA methylome of the Mthfr 677CC and TT mice on a control diet (2mg folic acid/kg diet) and 2) assess the effects of folic acid deficiency (0.3mg/kg diet) and supplementation (10 mg/kg diet) on the sperm DNA methylome. Body and reproductive organ weights, testicular sperm counts, and histology were examined. DNA methylation in sperm was assessed using bisulfite pyrosequencing, Illumina Mouse Methylation Array and whole genome bisulfite sequencing. Reproductive parameters and imprinted gene methylation were unaffected by genotype or diets. The largest effect was due to genotype, with sperm from 677TT mice showing more hypo- than hypermethylation. Folate-deficient diets resulted in sperm hyper- and hypomethylation in CC and TT mice. Folic acid supplementation caused mostly hypermethylation in sperm of males of both genotypes and was found to partially correct the DNA methylation alterations in sperm associated with the TT genotype. The new mouse model will be useful in understanding the role of MTHFR deficiency in male fertility and in designing folate supplementation regimens for the clinic.
2024-04-17 | GSE240712 | GEO
Project description: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. 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. 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.
2016-11-12 | GSE89781 | GEO
Project description:High-dose folic acid supplementation alters the human sperm methylome and is influenced by the MTHFR C677T polymorphism
| PRJNA294457 | ENA
Project description:Testicular MTHFR deficiency may explain sperm DNA hypomethylation associated with high dose folic acid supplementation
| PRJNA393260 | ENA
Project description:Background: We tested the hypothesis that short-term supplementation with a physiological dose of folate can alter global gene expression in the colon of subjects with colorectal adenoma using a randomised double blind placebo controlled trial design. Materials and Methods: Fourteen subjects with histologically confirmed colorectal adenoma, randomised to receive folic acid (400M-BM-5g/d, n=6) or placebo (n=8) for 10 weeks, had blood samples and colonic tissue biopsies collected before and after the intervention. Blood samples were used to determine serum and red cell folate, plasma homocysteine, and genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR C677T) and methionine synthase (MS A2756G). RNA extracted from normal-appearing colonic tissue samples was used to determine global gene expression in the colon using AffymetrixM-oM-^CM-^R Microarray GeneChips. Microarray results were confirmed by quantitative real time RT-PCR. Two methods were used to analyse the microarray data: (1) differences between pre- and post-intervention gene expression values in the folic acid and placebo groups separately using paired-sample t tests; (2) differences between the folic acid and placebo groups in the ratio of post-intervention to pre-intervention gene expression values using independent sample t-tests. Results: (1) Following intervention, sixty seven genes were up-regulated and 13 genes were down-regulated in the folic acid group, while 21 genes were up-regulated and none were down-regulated in the placebo group (P<0.05, adjusted for multiple testing). (2) Thirty six genes were up-regulated and 18 genes were down-regulated in the folic acid group when compared with placebo, but none of these were statistically significant after adjustment for multiple testing. These genes are involved in multiple pathways, including cell cycle, signal transduction, cell differentiation, transport, cell division, cell motility, protein transport and immune response. There were no genes involved in 1-carbon metabolism that were altered in expression, although several genes involved in neoplasia were up-regulated. Conclusions: These results indicate that while folic acid can modify gene expression, it is difficult to separate its effects from the natural variability in gene expression in the colon. Fourteen patients with colorectal adenoma were treated with either folate supplementation (6 subjects) or a placebo (8 subjects) for 10 weeks in a randomised double-blind trial. Colonic biopsies of normal tissue were taken before and after the intervention, and analysed for gene expression.
2013-10-01 | E-GEOD-40928 | biostudies-arrayexpress
Project description:STUDY QUESTION: Could clinically-relevant moderate and/or high dose maternal folic acid supplementation prevent aberrant developmental and epigenetic outcomes associated with assisted reproductive technologies (ART)? SUMMARY ANSWER: Our results demonstrate dose-dependent and sex-specific effects of folic acid supplementation in ART and provide evidence that moderate dose supplements may be optimal for both sexes. WHAT IS KNOWN ALREADY: Children conceived using ART are at an increased risk for growth and genomic imprinting disorders, often associated with DNA methylation defects. Folic acid supplementation is recommended during pregnancy to prevent adverse offspring outcomes; however, the effects of folic acid supplementation in ART remain unclear. STUDY DESIGN, SIZE, DURATION: Outbred female mice were fed 3 folic-acid supplemented diets, control (rodent daily recommended intake or DRI; CD), moderate (4-fold DRI; 4FASD) or high (10-fold DRI; 10FASD) dose, for six weeks prior to ART and throughout gestation. Mouse ART involved a combination of superovulation, in vitro fertilization, embryo culture and embryo transfer. PARTICIPANTS/MATERIALS, SETTING, METHODS: Upon collection of midgestation embryos and placentas (n=74-99 embryos/group), all embryos were assessed for developmental delay and gross morphological abnormalities. Embryos and placentas were also examined at the epigenetic level. We assessed methylation at four imprinted genes (Snrpn, Kcnq1ot1, Peg1, and H19) in matched midgestation embryos and placentas (n=31-32/group) using bisulfite pyrosequencing. In addition, we examined genome-wide DNA methylation patterns in midgestation placentas (n=6 normal placentas per sex/group) and embryos (n=6 normal female embryos/group; n=3 delayed female embryos/group) using reduced representation bisulfite sequencing. MAIN RESULTS AND THE ROLE OF CHANCE: Moderate, but not high dose supplementation, was associated with a decrease in the proportion of developmentally delayed embryos. Although moderate dose folic acid supplementation reduced DNA methylation variance at certain imprinted genes in embryonic and placental tissues, high dose supplementation exacerbated the negative effects of ART at imprinted loci. Furthermore, folic acid supplements resolved female-biased aberrant imprinted gene methylation. Supplementation was more effective at correcting ART-induced genome-wide methylation defects in male versus female placentas; however, folic acid supplementation also led to additional methylation perturbations which were far more pronounced in males. LIMITATIONS, REASONS FOR CAUTION: Although the combination of mouse ARTs utilized in this study consisted of techniques commonly used in human fertility clinics, there may be species differences. Therefore, human studies, designed to determine the optimal levels of folic acid supplementation for ART pregnancies, and taking into account fetal sex, are warranted. WIDER IMPLICATIONS OF THE FINDINGS: Taken together, our findings support moderation in the dose of folic acid supplements taken during ART.
2019-05-15 | GSE123143 | GEO
Project description:Defects in homocysteine and folate metabolism are associated with increased risks for neural tube and congenital heart defects, cardiovascular disease and stroke, cancers, and neurodegeneration. In many but not all cases, dietary supplementation with folate significantly reduces the severity and incidence of these conditions. Common polymorphisms modulate these metabolic pathways and disease risks, but do not fully account for the particular birth defects and adult diseases that occur in at-risk individuals. To test whether other pathways contribute to disease pathogenesis, we analyzed global and pathway-specific changes in gene expression and levels of selected metabolites after depletion and repletion of dietary folate in two genetically distinct inbred strains of mice. Compared to the C57BL/6J strain, A/J showed greater homeostatic response to folate perturbation by retaining a higher serum folate level and minimizing global gene expression changes. Remarkably, folate perturbation led to systematic strain-specific differences only in the expression profile of the cholesterol biosynthesis pathway and translated to changes in levels of serum and liver total cholesterol. By genetically increasing serum and liver total cholesterol levels in APOE deficient mice, we modestly but significantly improved folate retention during folate depletion, suggesting an interplay between homocysteine and folate metabolism and cholesterol metabolism. Absence of measurable changes in global methylation patterns or amelioration of effects with supplementation with an alternative methyl donor suggest that dietary folate perturbations do not act through large-scale or general changes in methylation. These results suggest that homeostatic responses in cholesterol metabolism contribute to the beneficial effects of dietary folate supplementation. Keywords: time course, stress response, diet, genetic, homeostasis Six-week old female A/J and C57BL/6J mice were purchased from the Jackson Laboratory. All mice were raised on a control diet containing four ppm folic acid (Basal Diet 5755, TestDiet) for one week before the start of studies. Selected mice were then placed on folic acid deficient diet (58C3, TestDiet) containing 1% succinylsulfathiazole, a non-absorbable antibiotic commonly used to suppress folate production by bacteria in the intestine. We had nine different treatment plans per strain with eight replicate mice per treatment. There were four folic acid depletion treatment in which mice were placed on folic acid deficient diet for 1, 2, 7, or 14 days. There were two folic acid repletion treatment in which mice were placed on folic acid deficient diet for 14 days followed by 1 day on control diet and another set of mice on 14 days of folic acid deficient diet followed by 7 days of control diet. There were three control time points in which mice were placed on the control diet for 0, 9, or 22 days. Eight biological replicate liver tissue from each treatment was pooled and total RNA from each pool and total RNA from Universal Mouse Reference RNA (Stratagene) were aminoallyl labeled with Cy3 and Cy5 in duplicate, with reversing of dyes.
2008-08-27 | E-GEOD-9242 | biostudies-arrayexpress
Project description:Vitamin B-6, folate and homocysteine may play a critical role in the colorectal cancer progression. This is a 4-y study and the specific aims are: 1) to compare vitamin B-6, folate and homocysteine status, oxidative stress, antioxidant activities and DNA methylation between subjects with colorectal polyps and colorectal cancer; 2) to study the effects of vitamin B-6, folate and homocysteine status on oxidative stress, antioxidant activities and DNA methylation in colorectal cancer patients; 3) to evaluate whether folic acid and/or pyridoxine supplementation had a beneficial effect on oxidative stress, antioxidant activities and DNA methylation in patients with colorectal; 4) to compare vitamin B-6, folate and homocysteine status, oxidative stress, antioxidant activities and DNA methylation between colorectal cancer patients and age-, sex-matched healthy subjects; 5) to evaluate the effect of vitamin B-6, folate and homocysteine status, oxidative stress, antioxidant activities and DNA methylation on the risk of colorectal cancer (odds ratio); 6) to follow the effects of vitamin B-6, folate and homocysteine status, oxidative stress, antioxidant activities and DNA methylation on the occurrence of colorectal cancer; 7) to follow the effects of pyridoxine and/or folic acid supplementation on the occurrence of colorectal cancer.
This protocol is designed as a hospital-based cross-sectional, case-control, double blinded randomized placebo-controlled intervention and follow-up trial. Three hundred colorectal cancer patients and 300 age-, sex-matched controls who meet the inclusion criteria will be recruited from Taichung General Veterans Hospital. If cancer patients’ plasma pyridoxal 5’-phosphate (PLP) level less than 30 nmol/L will be asked to participate the intervention study and will be blinded and randomly assigned to either the 1) control (vitamin C, 100 mg/d); 2) 50 mg vitamin B-6; 3) 400 microgram/d folic acid; or 4) vitamin B-6 (50 mg/d) plus folic acid (400 microgram/d) for 1 year. Data on demography, anthropometry, medical history, food frequency questionnaire and 24-h diet recall will be collected. Cancer patients will have fasting blood drawn before surgery or receiving chemotherapy. Additionally, fasting blood samples will be obtained at month 0, 3, 6, 9 and 12 during intervention period and at month 6, 12, 18, 24, 30, 36, 42 and 48 during follow-up. Hematological, plasma and erythrocyte PLP, plasma pyridoxal and 4-pyridoxic acid, serum and erythrocyte folate, serum vitamin B-12, homocysteine, SAM, SAH, lipid peroxidation indicators (TBARS, oxidized LDL), glutathione, antioxidant enzymatic activities and DNA methylation and MTHFR 677C>T polymorphism will be measured.
| 2112226 | ecrin-mdr-crc