levoleucovorin and Neural-Tube-Defects

The effect of periconceptional multivitamin/trace element supplementation on pregnancy outcomes was evaluated in a randomised controlled trial. The final data-base included 5,502 females with confirmed pregnancy. A multivitamin including 0.8 mg folic acid or a trace element were supplemented for at least 28 days before conception and continuing for at least until the second missed menstrual period. Number of pregnancies, terminations of pregnancies, four types of fetal deaths, livebirths including low birth weight, preterm birth and sex ratio were analysed. Periconceptional multivitamin supplementation increased fertility (higher rates of cumulative conceptions and multiple births), had no significant effect on the rate of different groups of fetal deaths, low birth weight and preterm birth in singletons. This primary preventive method can reduce the occurrence and recurrence of neural-tube defects and had no other significant effect on pregnancy outcomes except multiple births.

Topics: Adult; Female; Fetal Death; Humans; Hungary; Infant, Low Birth Weight; Infant, Newborn; Leucovorin; Male; Neural Tube Defects; Obstetric Labor, Premature; Pregnancy; Pregnancy Outcome; Premedication; Risk Factors; Sex Ratio; Trace Elements; Vitamins

The biogenesis of ribosomes in vivo is an essential process for cellular functions. Transcription of ribosomal RNA (rRNA) genes is the rate-limiting step in ribosome biogenesis controlled by environmental conditions. Here, we investigated the role of folate antagonist on changes of DNA double-strand breaks (DSBs) landscape in mouse embryonic stem cells. A significant DSB enhancement was detected in the genome of these cells and a large majority of these DSBs were found in rRNA genes. Furthermore, spontaneous DSBs in cells under folate deficiency conditions were located exclusively within the rRNA gene units, representing a H3K4me1 hallmark. Enrichment H3K4me1 at the hot spots of DSB regions enhanced the recruitment of upstream binding factor (UBF) to rRNA genes, resulting in the increment of rRNA genes transcription. Supplement of folate resulted in a restored UBF binding across DNA breakage sites of rRNA genes, and normal rRNA gene transcription. In samples from neural tube defects (NTDs) with low folate level, up-regulation of rRNA gene transcription was observed, along with aberrant UBF level. Our results present a new view by which alterations in folate levels affects DNA breakage through epigenetic control leading to the regulation of rRNA gene transcription during the early stage of development.

Topics: Animals; Cells, Cultured; DNA Breaks, Double-Stranded; Embryonic Stem Cells; Fetus; Folic Acid Antagonists; Folic Acid Deficiency; G1 Phase; Gene Expression Regulation, Developmental; Genes, rRNA; Histones; Leucovorin; Methotrexate; Mice; Neural Tube Defects; Pol1 Transcription Initiation Complex Proteins; Transcription, Genetic

Copy number variations (CNVs) are thought to act as an important genetic mechanism underlying phenotypic heterogeneity. Impaired folate metabolism can result in neural tube defects (NTDs). However, the precise nature of the relationship between low folate status and NTDs remains unclear. Using an array-comparative genomic hybridization (aCGH) assay, we investigated whether CNVs could be detected in the NTD embryonic neural tissues of methotrexate (MTX)-induced folate dysmetabolism pregnant C57BL/6 mice and confirmed the findings with quantitative real-time PCR (qPCR). The CNVs were then comprehensively investigated using bioinformatics methods to prioritize candidate genes. We measured dihydrofolate reductase (DHFR) activity and concentrations of folate and relevant metabolites in maternal serum using enzymologic method and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Three high confidence CNVs on XqA1.1, XqA1.1-qA2, and XqE3 were found in the NTD embryonic neural tissues. Twelve putative genes and three microRNAs were identified as potential susceptibility candidates in MTX-induced NTDs and possible roles in NTD pathogenesis. DHFR activity and 5-methyltetrahydrofolate (5-MeTHF), 5-formyltetrahydrofolate (5-FoTHF), and S-adenosylmethionine (SAM) concentrations of maternal serum decreased significantly after MTX injection. These findings suggest that CNVs caused by defects in folate metabolism lead to NTD, and further support the hypothesis that folate dysmetabolism is a direct cause for CNVs in MTX-induced NTDs.

Topics: Animals; Chromatography, Liquid; Comparative Genomic Hybridization; Disease Models, Animal; DNA Copy Number Variations; Folic Acid; Gene Expression Profiling; Genetic Predisposition to Disease; Leucovorin; Methotrexate; Mice, Inbred C57BL; MicroRNAs; Neural Tube Defects; Real-Time Polymerase Chain Reaction; S-Adenosylmethionine; Tandem Mass Spectrometry; Tetrahydrofolate Dehydrogenase; Tetrahydrofolates

Folate deficiency is considered a risk factor for many diseases such as cancer, congenital heart disease and neural tube defects (NTDs). There is a pressing need for more methods of detecting folate and its main metabolites in the human body. Here, we developed a simple, fast and sensitive ultraperformance liquid chromatography tandem mass spectrometry (UPLC/MS/MS) method for the simultaneous quantifications of folate metabolites including folic acid, 5-methyltetrahydrofolate (5-MeTHF), 5-formyltetrahydrofolate (5-FoTHF), homocysteine (Hcy), S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH). The method was validated by determining the linearity (r(2)>0.998), sensitivity (limit of detection ranged from 0.05 to 0.200ng/mL), intra- and inter-day precision (both CV<6%) and recovery (each analyte was >90%). The total analysis time was 7min. Serum samples of NTD-affected pregnancies and controls from a NTD high-risk area in China were analyzed by this method, the NTD serum samples showed lower concentrations of 5-MeTHF (P<0.05) and 5-FoTHF (P<0.05), and higher concentrations of Hcy (P<0.05) and SAH (P<0.05) compared with serum samples from controls, consistent with a previous study. These results showed that the method is sensitive and reliable for simultaneous determination of six metabolites, which might indicate potential risk factors for NTDs, aid early diagnosis and provide more insights into the pathogenesis of NTDs.

Topics: Chromatography, High Pressure Liquid; Female; Folic Acid; Homocysteine; Humans; Leucovorin; Limit of Detection; Neural Tube Defects; Pregnancy; S-Adenosylhomocysteine; S-Adenosylmethionine; Tandem Mass Spectrometry; Tetrahydrofolates

Bent tail is a mouse model for X-linked neural tube defects (NTDs) that is characterized by the presence of exencephaly, a delayed posterior neuropore closure, and a tail phenotype. In addition, Bent tail shows laterality defects and increased prenatal mortality. The congenital malformations of this mouse are caused by a submicroscopic deletion that completely encompasses the gene coding for the zinc finger transcription factor Zic3. In this study we investigated the sensitivity of the phenotype of Bent tail to the nutrients folinic acid, myo-inositol, and zinc. These nutrients are thought to be involved in the etiology of NTDs, in combination with a genetic predisposition.. The most penetrant phenotype of the Bent tail mouse, the tail malformation, was used as a marker for the nutrient sensitivity of the neural phenotype. The size of the litters and the survival of the offspring, subdivided according to genotype, were analyzed as markers for the nutrient sensitivity of other phenotypic features of Bent tail.. In confirmation of earlier studies, we observed the prenatal loss of a number of homozygous females and hemizygous males, as well as the effect of genotype on the tail phenotype of Bent tail. However, periconceptional supplementation of the maternal diet with folinic acid, myo-inositol, or zinc produced no significant effects on either the tail phenotype of the offspring or the size and genotypic composition of the litters.. Bent tail appears to be a folinic acid-, myo-inositol-, and zinc-insensitive mouse model for NTDs.

Topics: Animals; Diet; Disease Models, Animal; DNA; Embryo Loss; Female; Genotype; Inositol; Leucovorin; Litter Size; Male; Mice; Mice, Mutant Strains; Morphogenesis; Neural Tube Defects; Pregnancy; Tail; Zinc

The mycotoxin fumonisin B1 (FB1) inhibits sphingolipid synthesis, blocks folate transport, and has been associated with increased incidences of cancer and neural tube defects. Results from reproductive studies in animal models in vivo and in vitro have demonstrated toxicity in some cases, but no specific terata after fumonisin exposure. No information is available about folic acid's potential to protect against this toxicity.. Neurulating mouse embryos were exposed to fumonisin or folinic acid in whole embryo culture and assessed for effects on growth and development.. Fumonisin exposure inhibited sphingolipid synthesis, reduced growth, and caused cranial neural tube defects in a dose dependent manner. Supplemental folinic acid ameliorated the effects on growth and development, but not inhibition of sphingolipid synthesis.. Fumonisin has the potential to inhibit embryonic sphingolipid synthesis and to produce embryotoxicity and neural tube defects. Folic acid can reverse some of these effects, supporting results showing that fumonisin disrupts folate receptor function.

Topics: Animals; Dose-Response Relationship, Drug; Folic Acid; Fumonisins; Leucovorin; Mice; Microscopy, Electron, Scanning; Neural Crest; Neural Tube Defects; Organ Culture Techniques; Teratogens; Time Factors

Neural tube defects (NTDs) are among the most common human congenital malformations. Although clinical investigations have reported that periconceptional folic acid supplementation can reduce the occurrence of these defects, its mechanism remains unknown. Therefore, the murine mutant Splotch, which has a high incidence of spontaneous NTDs, along with the inbred strains SWV and LM/Bc, were used to investigate the relationship between folate and NTDs.. To investigate whether folates could reduce spontaneous NTDs, heterozygous Splotch dams (+/Sp) were treated with either folate or folinic acid throughout neurulation, gestational day (GD) 6.5 to 10.5. On GD 18.5 the dams were sacrificed and the fetuses examined for any neural tube defects. Subsequently, Sp/+ dams were treated with arsenic while receiving either a folate or folinic acid supplementation. Similar experiments were performed in the LM/Bc and SWV strains.. Neither folate nor folinic acid supplements reduced the frequency of spontaneous NTDs in the embryos from Splotch heterozygote crosses. Arsenic increased the frequency of NTDs and embryonic death in the Splotch, LM/Bc and SWV litters and folinic acid failed to ameliorate the teratogenic effect of this metal. A folate supplement given to arsenic-treated dams proved to be maternally lethal in all three strains.. Splotch embryos were not protected from either spontaneous or arsenic-induced NTDs by folinic or folic acid supplementation. Furthermore, folinic acid supplements did not reduce the incidence of arsenic-induced NTDs in either the LM/Bc or SWV litters.

Topics: Animals; Arsenates; DNA-Binding Proteins; Embryo Loss; Female; Fetal Resorption; Folic Acid; Genotype; Leucovorin; Male; Mice; Mice, Inbred C57BL; Neural Tube Defects; Paired Box Transcription Factors; PAX3 Transcription Factor; Teratogens; Transcription Factors

Topics: Fetal Diseases; Folic Acid; Humans; Leucovorin; Neural Tube Defects

Increases in total plasmatic homocysteine (tHcy) represents a risk factor for neural tube defects. We studied the effects of levofolinic acid (l,5-formyl-tetrahydrofolic) on the plasmatic tHcylevels in women of child-bearing age.. Healthy women aged 18-35 years (n = 30) received levofolinic acid, 5 mg/day,orally for 30 days. Both tHcy and intraerythrocytic folate levels were measured before treatment (day 0), on days 2, 5, 10 and 30 within the treatment period and on days 30 (day 60) and 60 (day 90) after the treatment was finished. Plasmatic tHcy was measured by fluorescence polarisation immunoassay and intraerythrocyticfolates by chemiluminescent immunoassay.. Plasmatic tHcy decreased from the second day of treatment onwards (day 0 vs. 2: mean of difference: -1.24 micromol/l; CI 95% = -0.84 to -1.63; p < 0.001). The maximum decline (32.3%) was observed after 30 days (mean of difference = -2.72 micromol/l; CI 95% = -2.20 to -3.24; p < 0.001).After finishing the treatment, the hypohomocysteinic effect persisted up to days 60 (mean of difference = -2.67 micromol/l; CI 95% = -2.07 to -3.26; p < 0.001)and 90 (mean of difference = -1.49 micromol/l; CI 95% = -0.94 to -2.03; p < 0.001). The response was greater when the plasmatic tHcy concentration was >= 9 micromol/l.. Levofolinic acid leads to a earlier, intense and persistent drop of the plasmatictHcy levels.

Topics: Adult; Female; Homocysteine; Humans; Leucovorin; Neural Tube Defects; Preconception Care

Topics: Abnormalities, Drug-Induced; Animals; Anticonvulsants; Bone and Bones; Female; Fetus; Leucovorin; Liver; Methionine; Methylation; Neural Tube Defects; Pregnancy; Rats; Rats, Wistar; S-Adenosylmethionine; Valproic Acid

The antiepileptic drug valproic acid (2-propylpentanoic acid; [VPA]) is teratogenic in humans and a number of animal species. Using a murine model, we studied the mechanism of VPA-induced teratogenesis during a period of organogenesis sensitive to interference with closure of the neural tube (days 8 to 9). Teratogenic doses of valproic acid altered the pattern of folate metabolites in the embryo: Levels of 5-formyl- and 10-formyl-tetrahydrofolates decreased, and the level of tetrahydrofolate increased. These changes could be explained by VPA-mediated inhibition of transfer of the formyl group via glutamate formyltransferase. Neural-tube defects, alteration of embryonic folate metabolism, and inhibition of the specific enzyme are all produced by comparable doses and levels of the drug. A closely related structural analog of VPA (2-en-VPA, 2-propyl-2-pentenoic acid), which exhibits antiepileptic activity but not teratogenicity, did not influence the embryonic folate metabolism. Our results suggest that interference with embryonic folate metabolism might be an important aspect of the induction of neural-tube defects by VPA. The novel techniques described also should prove useful in studying the teratogenic mechanisms of other drugs.

Topics: Animals; Circadian Rhythm; Fatty Acids, Monounsaturated; Female; Fetus; Folic Acid; Leucovorin; Mice; Neural Tube Defects; Pregnancy; Valproic Acid

The diurnal variation of folate concentrations in mouse plasma and embryo between day 8.5 and day 9.5 of gestation (light cycle = 0900-2100) were determined by high-performance liquid chromatography. Folate concentrations in the embryo were high during the evening hours, decreased during the night, reached their lowest levels at 0500, and then increased again during the day. High levels of folates may be related to increased food intake by the pregnant mice. Small changes of the two major maternal plasma folate metabolites were observed. The relative amount of each folate metabolite in the embryo, as compared to the total folate concentration, remained in a narrow range. The main metabolites were tetrahydrofolic acid (THF) (32.4% +/- 2.1% of total folates), 5-CHO-THF (24.2% +/- 2.3%), and 10-CHO-THF (17.0% +/- 1.9%). A dramatic alteration of these ratios occurred only between 1100 and 1400. The relative content of THF increased (52.7% +/- 2.5%), whereas the relative concentration of 5-CHO-THF in the embryo decreased (6.5% +/- 1.9%). Before 1000 when the ratios of folate metabolites were stable, the rate of valproic acid-induced neural tube defects was reduced from 49% of living fetuses to 12% by coapplication of folinic acid via subcutaneously implanted minipumps. During the period in which dramatic changes in ratios between the folate metabolites in the embryo occurred, no protective effect of folinic acid on valproic acid-induced exencephaly could be observed. Our results indicate that the diurnal variation of folate metabolism in the embryo is important in regard to valproic acid teratogenesis and its protection by folate supplementation.

Topics: Abnormalities, Drug-Induced; Animals; Chromatography, High Pressure Liquid; Circadian Rhythm; Decidua; Embryo, Mammalian; Female; Fetal Resorption; Folic Acid; Leucovorin; Mice; Mice, Inbred Strains; Neural Tube Defects; Pregnancy; Valproic Acid

The anticonvulsant drug valproic acid (VPA) is suspected to be a developmental toxicant in humans, inducing primarily neural tube defects. The mechanism for this effect is unknown, but it has been suggested that the drug may act via a deficiency of the vitamin folic acid. We examined this possibility by concurrent treatment of rat embryos in a whole embryo culture system with VPA and folinic acid (FA), a folic acid derivative. Groups of CD rat embryos were treated with various concentrations of VPA, various concentrations of FA, or a combination of a teratogenic dose of VPA plus various levels of FA. At the end of the 44 hour culture period, each embryo was evaluated for viability (presence of a heartbeat), yolk sac circulation, presence of any malformations, morphological score, crown-rump and head lengths, as well as DNA and protein contents. The anticonvulsant did not decrease viability but did decrease yolk sac circulation and all growth and developmental endpoints in a dose-responsive manner. There was also a dose-related increase in the incidence of open neural tubes. The addition of FA alone had no significant effect on growth and development. When various concentrations of FA were added simultaneously with a teratogenic dose of VPA, there was no decrease in the incidence of open neural tubes. Growth and developmental endpoints were altered in a somewhat random fashion but were never increased to the control level. The lack of attenuation by FA was not due to instability of the compound in the culture system, nor was there a difference in the amount of FA present in the exocoelomic fluid of VPA-treated and control embryos.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Dose-Response Relationship, Drug; Embryo, Mammalian; Female; Fetal Death; In Vitro Techniques; Leucovorin; Neural Tube Defects; Pregnancy; Rats; Valproic Acid

Neural tube defects were induced dose-dependently by single injections of the anticonvulsant drug valproic acid (VPA) as sodium salt in mice on gestational day 8. Folinic acid (5-CHO-THF) coadministration by i.p. injection or by a constant rate infusion via osmotic minipumps, implanted s.c., significantly reduced the exencephaly rates using a randomized double-blind experimental procedure. 5-CHO-THF supplementation cut the exencephaly rates into half even at high maternal plasma levels of VPA (p less than 0.005, chi 2-test); resorption rates were not affected. The VPA plasma kinetics were not changed by any of the application regimens of 5-CHO-THF. The investigation of the folate metabolite pattern (determined by HPLC) showed that 5-CHO-THF and 5-methyl-tetrahydrofolic acid (5-CH3-THF) were the main metabolites in untreated mice. After supplementation with 5-CHO-THF, only the concentrations of this folate vitamer were increased in the plasma from 0.3 microgram/ml (normal) to 0.6 or 1.9 micrograms/ml (after injection of 3 x 1 mg/kg or 3 X 4 mg/kg) and to 4.2 micrograms/ml (after infusion via osmotic minipumps). Our results indicate that VPA-induced exencephaly in mice combined with the investigation of the plasma levels of VPA and the different folate metabolites could be an appropriate animal model to study protective effects of folates on the occurrence of neural tube defects.

Topics: Animals; Female; Leucovorin; Mice; Neural Tube Defects; Pregnancy; Teratogens; Valproic Acid