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Rozendaal AM, van Essen AJ, te Meerman GJ, Bakker MK, van der Biezen JJ, Goorhuis-Brouwer SM, Vermeij-Keers C, de Walle HEK. Periconceptional folic acid associated with an increased risk of oral clefts relative to non-folate related malformations in the Northern Netherlands: a population based case-control study. Eur J Epidemiol 2013; 28:875-87. [PMID: 24092049 DOI: 10.1007/s10654-013-9849-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 09/02/2013] [Indexed: 11/28/2022]
Abstract
Periconceptional folic acid has been associated with a reduced risk of neural tube defects, but findings on its effect in oral clefts are largely inconclusive. This case-control study assesses the effects of periconceptional folic acid on cleft risk, using complementary data from the Dutch Oral Cleft Registry and a population-based birth defects registry (Eurocat) of children and foetuses born in the Northern Netherlands between 1997 and 2009. Cases were live-born infants with non-syndromic clefts (n = 367) and controls were infants or foetuses with chromosomal/syndromal (n = 924) or non-folate related anomalies (n = 2,021). We analyzed type/timing/duration of supplement use related to traditional cleft categories as well as to their timing (early/late embryonic periods) and underlying embryological processes (fusion/differentiation defects). Consistent supplement use during the aetiologically relevant period (weeks 0-12 postconception) was associated with an increased risk of clefts (adjusted odds ratio 1.72, 95% confidence interval 1.19-2.49), especially of cleft lip/alveolus (3.16, 1.69-5.91). Further analysis systematically showed twofold to threefold increased risks for late differentiation defects-mainly clefts of the lip/alveolus-with no significant associations for early/late fusion defects. Effects were attributable to folic acid and not to other multivitamin components, and inclusion of partial use (not covering the complete aetiologically relevant period) generally weakened associations. In conclusion, this study presents several lines of evidence indicating that periconceptional folic acid in the Northern Netherlands is associated with an increased risk of clefts, in particular of cleft lip/alveolus. This association is strengthened by the specificity, consistency, systematic pattern, and duration of exposure-response relationship of our findings, underlining the need to evaluate public health strategies regarding folic acid and to further investigate potential adverse effects.
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Affiliation(s)
- Anna M Rozendaal
- Department of Plastic and Reconstructive Surgery, Erasmus MC, University Medical Center Rotterdam, Room EE 1591, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands,
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52
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Imbard A, Benoist JF, Blom HJ. Neural tube defects, folic acid and methylation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:4352-89. [PMID: 24048206 PMCID: PMC3799525 DOI: 10.3390/ijerph10094352] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 12/17/2022]
Abstract
Neural tube defects (NTDs) are common complex congenital malformations resulting from failure of the neural tube closure during embryogenesis. It is established that folic acid supplementation decreases the prevalence of NTDs, which has led to national public health policies regarding folic acid. To date, animal studies have not provided sufficient information to establish the metabolic and/or genomic mechanism(s) underlying human folic acid responsiveness in NTDs. However, several lines of evidence suggest that not only folates but also choline, B12 and methylation metabolisms are involved in NTDs. Decreased B12 vitamin and increased total choline or homocysteine in maternal blood have been shown to be associated with increased NTDs risk. Several polymorphisms of genes involved in these pathways have also been implicated in risk of development of NTDs. This raises the question whether supplementation with B12 vitamin, betaine or other methylation donors in addition to folic acid periconceptional supplementation will further reduce NTD risk. The objective of this article is to review the role of methylation metabolism in the onset of neural tube defects.
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Affiliation(s)
- Apolline Imbard
- Biochemistry-Hormonology Laboratory, Robert Debré Hospital, APHP, 48 bd Serrurier, Paris 75019, France; E-Mail:
- Metabolic Unit, Department of Clinical Chemistry, VU Free University Medical Center, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands; E-Mail:
| | - Jean-François Benoist
- Biochemistry-Hormonology Laboratory, Robert Debré Hospital, APHP, 48 bd Serrurier, Paris 75019, France; E-Mail:
| | - Henk J. Blom
- Metabolic Unit, Department of Clinical Chemistry, VU Free University Medical Center, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands; E-Mail:
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53
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Strickland KC, Krupenko NI, Krupenko SA. Molecular mechanisms underlying the potentially adverse effects of folate. Clin Chem Lab Med 2013; 51:607-16. [PMID: 23241610 DOI: 10.1515/cclm-2012-0561] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 11/09/2012] [Indexed: 12/20/2022]
Abstract
The importance of proper consumption of dietary folate for human health has been highlighted by an extensive number of publications over several decades. Fortification of grain products with folic acid was initiated with the specific intent to prevent neural tube defects, and the scope of this endeavor is unique in that its target population (women of the periconceptional period) is many times smaller than the population it affects (everyone who ingests fortified grain products). Folate fortification has been wildly successful in terms of its goal; since its inception, the incidence of neural tube defects has markedly decreased. In the wake of this public health triumph, it is important to catalog both the serendipitous benefits and potential side effects of folic acid supplementation. The vitamin is generally regarded as a harmless nutrient based on studies evaluating the safe upper limits of folate intake. In recent years, however, a concern has been raised with respect to a potential downside to folate supplementation; namely, its proposed ability to enhance proliferation of malignant tumors. The current review summarizes the available literature on the effects of folate supplementation and the molecular mechanisms by which high doses of folate may have negative consequences on human health, especially with regard to cancer.
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Affiliation(s)
- Kyle C Strickland
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
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54
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Copp AJ, Stanier P, Greene NDE. Neural tube defects: recent advances, unsolved questions, and controversies. Lancet Neurol 2013; 12:799-810. [PMID: 23790957 DOI: 10.1016/s1474-4422(13)70110-8] [Citation(s) in RCA: 372] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neural tube defects are severe congenital malformations affecting around one in every 1000 pregnancies. An innovation in clinical management has come from the finding that closure of open spina bifida lesions in utero can diminish neurological dysfunction in children. Primary prevention with folic acid has been enhanced through introduction of mandatory food fortification in some countries, although not yet in the UK. Genetic predisposition accounts for most of the risk of neural tube defects, and genes that regulate folate one-carbon metabolism and planar cell polarity have been strongly implicated. The sequence of human neural tube closure events remains controversial, but studies of mouse models of neural tube defects show that anencephaly, open spina bifida, and craniorachischisis result from failure of primary neurulation, whereas skin-covered spinal dysraphism results from defective secondary neurulation. Other malformations, such as encephalocele, are likely to be postneurulation disorders.
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Affiliation(s)
- Andrew J Copp
- Neural Development Unit and Newlife Birth Defects Research Centre, UCL Institute of Child Health, London, UK.
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55
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Massarwa R, Ray HJ, Niswander L. Morphogenetic movements in the neural plate and neural tube: mouse. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2013; 3:59-68. [DOI: 10.1002/wdev.120] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- R'ada Massarwa
- Department of Molecular Genetics; The Weizmann Institute of Science; Rehovot Israel
| | - Heather J. Ray
- Department of Pediatrics, Cell Biology Stem Cells and Development Graduate Program; University of Colorado School of Medicine and Children's Hospital Colorado; Aurora CO USA
| | - Lee Niswander
- Department of Pediatrics, Cell Biology Stem Cells and Development Graduate Program; University of Colorado School of Medicine and Children's Hospital Colorado; Aurora CO USA
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Salbaum JM, Kruger C, Kappen C. Mutation at the folate receptor 4 locus modulates gene expression profiles in the mouse uterus in response to periconceptional folate supplementation. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1653-61. [PMID: 23651732 DOI: 10.1016/j.bbadis.2013.04.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 04/25/2013] [Accepted: 04/29/2013] [Indexed: 11/28/2022]
Abstract
Periconceptional supplementation of folic acid to the diet of women is considered a great success for a public health intervention. Higher folate status, either by supplementation, or via the mandatory fortification of grain products in the United States, has led to significant reduction in the incidence of neural tube defects. Besides birth defects, folate deficiency has been linked to a variety of morbidities, most notably to increased risk for cancer. However, recent evidence suggests that excess folate may be detrimental - for birth defect incidence or in the progression of cancer. How folate mediates beneficial or detrimental effects is not well understood. It is also unknown what molecular responses are elicited in women taking folate supplements, and thus experience a bolus of folate on top of the status achieved by fortification. To characterize the response to a periconceptional regimen of supplementation with folinic acid, we performed gene expression profiling experiments on uterus tissue of pregnant mice with either wildtype alleles or targeted disruption at the folate receptor 4 locus. We observed that, depending on the genetic background, folinic acid supplementation affects expression of genes that contribute to lipid metabolism, protein synthesis, mitochondrial function, cell cycle, and cell activation. The extent of the response is strongly modulated by the genetic background. Finally, we provide evidence that folinic acid supplementation in the mutant paradigm affects histone methylation status, a potential mechanism of gene regulation in this model.
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Affiliation(s)
- J Michael Salbaum
- Department of Regulation of Gene Expression, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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57
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Solomon LR. Advanced age as a risk factor for folate-associated functional cobalamin deficiency. J Am Geriatr Soc 2013; 61:577-82. [PMID: 23521545 DOI: 10.1111/jgs.12155] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To determine whether high serum folate levels contribute to metabolite changes in elderly subjects with normal cobalamin levels. DESIGN Case series. SETTING Outpatient clinic at a university-based staff model health maintenance organization. PARTICIPANTS Two hundred thirty-three ambulatory individuals without diabetes mellitus with normal renal function and normal cobalamin levels evaluated for cobalamin deficiency. MEASUREMENTS Cobalamin, serum folate, methylmalonic acid (MMA), and homocysteine. RESULTS Older individuals (≥60) with low-normal cobalamin levels (201-300 pg/mL) had higher MMA and lower homocysteine levels when serum folate levels were high (>20 ng/mL) than when serum folate levels were normal (P < .02), but serum folate levels within the normal range were not a determinant of either metabolite. In younger subjects with low-normal cobalamin levels, high serum folate levels were not associated with significant differences in either metabolite. At mid-normal cobalamin levels (301-600 pg/mL), high serum folate levels were associated with lower homocysteine levels in older adults (P < .001) but not with differences in MMA in either age group. Cobalamin therapy decreased or normalized MMA and homocysteine in 89% or more of participants even at pretherapy cobalamin levels greater than 600 pg/mL. CONCLUSION High serum folate levels are associated with higher MMA levels when cobalamin levels are low-normal, and this effect is age dependent, not progressive within the normal serum folate range (suggesting a threshold effect), and reversed by cobalamin therapy. Because MMA may be neurotoxic, these findings suggest caution in the use of folic acid supplements in elderly adults.
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Affiliation(s)
- Lawrence R Solomon
- Section of Palliative Care, Department of Medicine, School of Medicine, Yale University, New Haven, CT 06520, USA.
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Wallingford JB, Niswander LA, Shaw GM, Finnell RH. The continuing challenge of understanding, preventing, and treating neural tube defects. Science 2013; 339:1222002. [PMID: 23449594 DOI: 10.1126/science.1222002] [Citation(s) in RCA: 318] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Human birth defects are a major public health burden: The Center for Disease Control estimates that 1 of every 33 United States newborns presents with a birth defect, and worldwide the estimate approaches 6% of all births. Among the most common and debilitating of human birth defects are those affecting the formation of the neural tube, the precursor to the central nervous system. Neural tube defects (NTDs) arise from a complex combination of genetic and environmental interactions. Although substantial advances have been made in the prevention and treatment of these malformations, NTDs remain a substantial public health problem, and we are only now beginning to understand their etiology. Here, we review the process of neural tube development and how defects in this process lead to NTDs, both in humans and in the animal models that serve to inform our understanding of these processes. The insights we are gaining will help generate new intervention strategies to tackle the clinical challenges and to alleviate the personal and societal burdens that accompany these defects.
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Affiliation(s)
- John B Wallingford
- Howard Hughes Medical Institute, The University of Texas at Austin, Austin, TX 78712, USA.
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60
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Yamaguchi Y, Miura M. How to form and close the brain: insight into the mechanism of cranial neural tube closure in mammals. Cell Mol Life Sci 2012; 70:3171-86. [PMID: 23242429 PMCID: PMC3742426 DOI: 10.1007/s00018-012-1227-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 11/07/2012] [Accepted: 11/27/2012] [Indexed: 12/18/2022]
Abstract
The development of the embryonic brain critically depends on successfully completing cranial neural tube closure (NTC). Failure to properly close the neural tube results in significant and potentially lethal neural tube defects (NTDs). We believe these malformations are caused by disruptions in normal developmental programs such as those involved in neural plate morphogenesis and patterning, tissue fusion, and coordinated cell behaviors. Cranial NTDs include anencephaly and craniorachischisis, both lethal human birth defects. Newly emerging methods for molecular and cellular analysis offer a deeper understanding of not only the developmental NTC program itself but also mechanical and kinetic aspects of closure that may contribute to cranial NTDs. Clarifying the underlying mechanisms involved in NTC and how they relate to the onset of specific NTDs in various experimental models may help us develop novel intervention strategies to prevent NTDs.
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Affiliation(s)
- Yoshifumi Yamaguchi
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, and CREST, JST, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
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61
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Massarwa R, Niswander L. In toto live imaging of mouse morphogenesis and new insights into neural tube closure. Development 2012; 140:226-36. [PMID: 23175632 DOI: 10.1242/dev.085001] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In the field of developmental biology, live imaging is a powerful tool for studying, in real time, the dynamic behaviors of tissues and cells during organ formation. Mammals, which develop in utero, have presented a challenge for live imaging. Here, we offer a novel, prolonged and robust live imaging system for visualizing the development of a variety of embryonic tissues in the midgestation mouse embryo. We demonstrate the advantages of this imaging system by following the dynamics of neural tube closure during mouse embryogenesis and reveal extensive movements of the cranial neural tissue that are independent of neural fold zipping.
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Affiliation(s)
- R'ada Massarwa
- Howard Hughes Medical Institute, Department of Pediatrics, University of Colorado Anschutz Medical Campus and Children's Hospital Colorado, Aurora, CO 80045, USA.
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Mikael LG, Deng L, Paul L, Selhub J, Rozen R. Moderately high intake of folic acid has a negative impact on mouse embryonic development. ACTA ACUST UNITED AC 2012; 97:47-52. [PMID: 23125102 DOI: 10.1002/bdra.23092] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 09/25/2012] [Accepted: 09/25/2012] [Indexed: 01/21/2023]
Abstract
BACKGROUND The incidence of neural tube defects has diminished considerably since the implementation of food fortification with folic acid (FA). However, the impact of excess FA intake, particularly during pregnancy, requires investigation. In a recent study, we reported that a diet supplemented with 20-fold higher FA than the recommended intake for rodents had adverse effects on embryonic mouse development at embryonic days (E)10.5 and 14.5. In this report, we examined developmental outcomes in E14.5 embryos after administering a diet supplemented with 10-fold higher FA than recommended to pregnant mice with and without a mild deficiency of methylenetetrahydrofolate reductase (MTHFR). METHODS Pregnant mice with or without a deficiency in MTHFR were fed a control diet (recommended FA intake of 2 mg/kg diet for rodents) or an FA-supplemented diet (FASD; 10-fold higher than the recommended intake [20 mg/kg diet]). At E14.5, mice were examined for embryonic loss and growth retardation, and hearts were assessed for defects and for ventricular wall thickness. RESULTS Maternal FA supplementation was associated with embryonic loss, embryonic delays, a higher incidence of ventricular septal defects, and thinner left and right ventricular walls, compared to mothers fed control diet. CONCLUSIONS Our work suggests that even moderately high levels of FA supplementation may adversely affect fetal mouse development. Additional studies are warranted to evaluate the impact of high folate intake in pregnant women. Birth Defects Research (Part A), 2013. © 2012 Wiley Periodicals, Inc.
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Affiliation(s)
- Leonie G Mikael
- Departments of Human Genetics and Pediatrics, McGill University, Montreal Children's Hospital Research Institute, Montreal, Quebec, Canada
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63
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Wallingford JB. Planar cell polarity and the developmental control of cell behavior in vertebrate embryos. Annu Rev Cell Dev Biol 2012; 28:627-53. [PMID: 22905955 DOI: 10.1146/annurev-cellbio-092910-154208] [Citation(s) in RCA: 186] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Planar cell polarity (PCP), the orientation and alignment of cells within a sheet, is a ubiquitous cellular property that is commonly governed by the conserved set of proteins encoded by so-called PCP genes. The PCP proteins coordinate developmental signaling cues with individual cell behaviors in a wildly diverse array of tissues. Consequently, disruptions of PCP protein functions are linked to defects in axis elongation, inner ear patterning, neural tube closure, directed ciliary beating, and left/right patterning, to name only a few. This review attempts to synthesize what is known about PCP and the PCP proteins in vertebrate animals, with a particular focus on the mechanisms by which individual cells respond to PCP cues in order to execute specific cellular behaviors.
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Affiliation(s)
- John B Wallingford
- Howard Hughes Medical Institute, Section of Molecular, Cell and Developmental Biology, University of Texas, Austin, Texas 78712, USA.
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