Project description:Background: Endothelial progenitor cells play an important role in vascular wall repair. Patients with type 1 diabetes have reduced levels of endothelial progenitor cells of which their functional capacity is impaired. Reduced nitric oxide bioavailability and increased oxidative stress play a role in endothelial progenitor cell dysfunction in these patients. Folic acid, a B-vitamin with anti-oxidant properties, may be able to improve endothelial progenitor cell function. In this study, we investigated the gene expression profiles of endothelial progenitor cells from patients with type 1 diabetes compared to endothelial progenitor cells from healthy subjects. Furthermore, we studied the effect of folic acid on gene expression profiles of endothelial progenitor cells from patients with type 1 diabetes. Methods: We used microarray analysis to investigate the gene expression profiles of endothelial progenitor cells from type 1 diabetes patients before (n=11) and after a four week period of folic acid supplementation (n=10) compared to the gene expression profiles of endothelial progenitor cells from healthy subjects (n=11). The probability of genes being differentially expressed among the classes was computed using a random-variance t-test. A multivariate permutation test was used to identify genes that were differentially expressed among the two classes. Functional classification of differentially expressed genes was performed using the biological process ontology in the Gene Ontology database. Results: Type 1 diabetes significantly modulated the expression of 1591 genes compared to healthy controls. These genes were found to be involved in processes regulating development, cell communication, cell adhesion and localization. After folic acid treatment, endothelial progenitor cell gene expression profiles from diabetic patients were similar to those from healthy controls. Genes that were normalized by folic acid played a prominent role in development, such as the transcription factors ID1 and MAFF. Few oxidative-stress related genes were affected by folic acid. Conclusion: Folic acid normalizes endothelial progenitor cell gene expression profiles of patients with type 1 diabetes. Signaling pathways modulated by folic acid may be potential therapeutic targets to improve endothelial progenitor cell function.
Project description:We determined the effects of excess folic acid supplementation (5x recommendation) on maternal and fetal offspring metabolic health. Using a mouse (female C57BL/6J) model of gestational dibetes (GDM; 45% kcal fat diet) and control mice (10% kcal diet) we show that folic acid supplementation increased weight gain and fat mass in both GDM and control mice but improved insulin sensitivity in GDM mice and worsened insulin sensitivity in control mice. We found no unmetabolized folic acid in liver from supplemented mice suggesting the metabolic effects of folic acid supplementation may not be due to unmetabolized folic acid. Male fetal (gestational day 18.5) offspring from folic acid supplemented dams (GDM and control) had greater beta cell mass and density than those from unsupplemented dams; this was not observed in female offspring. Differential sex-specific hepatic gene expression profiles were observed in the offspring from supplemented dams but this differed between GDM and controls. Our findings suggest that folic acid supplementation affects insulin sensitivity in female mice, but is dependent on their metabolic phenotype, and has sex-specific effects on offspring pancreas and liver.
Project description:Folic acid deficiency is common worldwide and is linked to intestinal flora imbalance. The intestinal microbial utilization of folic acid based on model animals faces the challenges of repeatability and individual variability. In this study, we built an in vitro fecal slurry culture model deficient in folic acid. We examined the effects of supplementation with different forms of folic acid (5-methyltetrahydrofolate and non-reduced folic acid) on the modulation of intestinal flora. 16S rDNA gene sequencing showed alpha diversity increased after folic acid supplementation compared to fermentation samples with folic acid deficiency. In the non-reduced folic acid (FA) group, the relative abundance of the Firmicutes phylum dropped to 56.7%, whereas in the 5-methyltetrahydrofolate (MTHF) supplementation group, it grew to 64.9%. Lactobacillus genera became more prevalent, reaching 22.8% and 30.8%, respectively. Additionally, Bifidobacterium and Pedioccus, two common probiotic bacteria, were in higher abundance. Short-chain fatty acids (SCFAs) analysis showed that supplementation with folic acid (non-reduced folic acid, 5-methyltetrahydrofolate) decreased acetic acid and increased the fermentation yield of isobutyric acid. The in vitro fecal slurry culture model developed in this study can be utilized as a human folic acid deficiency model for studying intestinal microbiota and demonstrated that both 5-methyltetrahydrofolate and non-reduced folic acid have effects on the regulation of intestinal microecology.
Project description:DNA methylation profiles from saliva collected from 89 mothers and 179 adolescent children who received or did not receive perinatal folic acid supplementation Periconceptional folic acid supplementation and DNA methylation patterns in adolescents
Project description:Folic acid supplements prior to and during gestation are recommended and necessary to prevent neural tube defects in developing embryos. But there are also studies suggesting possible adverse effects of high-dose folic acid supplementation. Here, we address whether maternal dietary folic acid supplementation at 40 mg/kg chow (FD), restricted to a period prior to conception, affects gene expression in the offspring generation.
Project description:Folic acid supplementation (8 mg/kg diet) promotes colon tumor formation in mice with established colitis induced by carcinogen azoxymethane (AOM) and dextran sulfate sodium sulfate (DSS). This induction of colon tumors was associated with hypomethylation of DNA cased by folic acid supplementation.
Project description:Folic acid supplementation (8 mg/kg diet) promotes colon tumor formation in mice with established colitis induced by carcinogen azoxymethane (AOM) and dextran sulfate sodium sulfate (DSS). This induction of colon tumors was associated with hypomethylation of DNA cased by folic acid supplementation.
Project description:Folic acid is present in pre-natal vitamins, fortified cereal grains and multi-vitamin supplements. High intake of folic acid through these sources has resulted in populations with increased levels of serum folate and unmetabolized folic acid. Although the benefits of folic acid in the prevention of neural tube defects are undeniable, the impact of long-term consumption of folic acid on the prostate is not fully understood. In this study, we used a rodent model to test whether dietary folic acid (FA) supplementation changes prostate homeostasis and response to androgen deprivation. Although intact prostate weights do not differ between diet groups, we made the surprising observation that dietary folic acid supplementation confers partial resistance to castration-mediated prostate involution. More specifically, male mice that were fed a folic acid supplemented diet and then castrated had greater prostate wet weights, greater prostatic luminal epithelial cell heights, and more abundant RNAs encoding prostate secretory proteins compared to mice that were fed a control diet and castrated. We used RNA-seq to identify signaling pathways enriched in the castrated prostates from folic acid supplemented diet fed mice compared to control mice. We observed differential expression of genes involved in several metabolic pathways in the FA supplemented mice. Together, our results show that dietary FA supplementation can impact metabolism in the prostate and attenuate the prostate’s response to androgen deprivation. This has important implications for androgen deprivation therapies used in the treatment of prostate disease, as consumption of high levels of folic acid could reduce the efficacy of these treatments.
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. Reduced representation bisulfite sequencing of 28 human sperm samples before and after 6 month of high dose folic acid supplementation.
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.