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Introduction: We have reported that high total homocysteine (tHCY), and the coexistence of inadequate thyroid hormones in maternal serum increase the risk of fetal neural tube defects (NTDs). Placental iodothyronine deiodinases (DIOs: DIO1, DIO2, and DIO3) play a role in regulate the conversions between different forms of maternal thyroid hormones. This study hypothesized that single nucleotide polymorphisms (SNPs) in placental DIOs genes could be related to NTDs. Methods: We performed a case-control study from 2007 to 2009 that included pregnant women from Lüliang, Shanxi Province, China. Nine distinct SNPs in DIOs genes were analyzed and placental samples were obtained from 83 pregnant women with NTDs fetuses and 90 pregnant women with normal fetuses. The nine SNPs were analyzed using the Cochran–Armitage test and the Fisher’s exact test. Results: There were no statistically significant differences between case and control in the nine SNPs of DIOs (P>0.05). Conclusions: The results of this study suggested that SNPs of DIOs genes in placenta among pregnant women has no statistically significant difference between the two groups, suggesting that other factors might be involved in metabolism of maternal thyroid hormone provided to fetuses, such as epigenetic modification of methylation and homocysteinylation and genomic imprinting in the placenta. Further those functional studies on placenta samples are necessary.

Neural tube defects are the most severe congenital malformations that result from failure of neural tube closure during early embryonic development, and the underlying molecular mechanisms remain elusive. Retinoic acid, an active derivative of vitamin A, is critical for neural system development, and retinoic acid receptor (RAR) signalling malfunctions have been observed in human neural tube defects. However, retinoic acid–retinoic acid receptor signalling regulation and mechanisms in neural tube defects are not fully understood. The mRNA expression of RARs and retinoid X receptors in the different human neural tube defect phenotypes, including 11 pairs of anencephaly foetuses, 10 pairs of hydrocephalus foetuses and nine pairs of encephalocele foetuses, was investigated by NanoString nCounter technology. Immunoprecipitation–mass spectrometry was performed to screen the potential interacting targets of retinoic acid receptor γ. The interactions between proteins were confirmed by co-immunoprecipitation and immunofluorescence laser confocal microscopy. Luciferase and chromatin immunoprecipitation with quantitative real-time polymerase chain reaction assays were used to clarify the underlying mechanism. Moreover, a neural tube defect animal model, constructed using excess retinoic acid, was used for further analysis with established molecular biology technologies. We report that level of retinoic acid receptor γ (RARγ) mRNA was significantly upregulated in the brain tissues of human foetuses with anencephaly. To further understand the actions of retinoic acid receptor γ in neural tube defects, methylenetetrahydrofolate dehydrogenase 1 was identified as a specific retinoic acid receptor γ target from IP–MS screening. Additionally, methylenetetrahydrofolate dehydrogenase 1 negatively regulated retinoic acid receptor γ transcription factor activity. Furthermore, low expression of methylenetetrahydrofolate dehydrogenase 1 and activation of retinoic acid receptor signalling were further determined in human anencephaly and a retinoic acid-induced neural tube defect mouse model. This study reveals that methylenetetrahydrofolate dehydrogenase 1, the rate-determining enzyme in the one-carbon cycle, might be a specific regulator of retinoic acid receptors; these findings provide new insights into the functional linkage between nuclear folate metabolism and retinoic acid receptor signalling in neural tube defect pathology.

Diabetes mellitus (DM) in early pregnancy increases the risk of neural tube defects (NTDs) in offspring. Enzyme-regulated histone acetylation has been reportedly linked to this pathological process. Few studies have focused on the intermediate acetyl-CoA, a substrate source of histone acetylation modification in maternal DM-induced NTDs. Here, we report that ATP citrate lyase (Acl), a metabolic enzyme of the glucose-related tricarboxylic acid cycle, has increased expression in DM-related NTDs of humans and mice, which induces acetyl-CoA accumulation and subsequently upregulates histone 3 lysine 27 acetylation (H3K27ac). Elevated H3K27ac reduces expression of genes for neural tube closure, Gadd45g and Ddit3. After inhibition of Acl, glucose-induced suppression of Gadd45g is alleviated by downregulation of H3K27ac both in vivo and in vitro, which is a possible mechanism of NTDs. Our results indicate that high glucose regulates NTD-related genes by increasing Acl and upregulating H3K27ac, which provide a novel pathological mechanism of DM-related NTDs.

Background: This study hypothesized that single nucleotide polymorphisms in placental iodothyronine deiodinase genes could be related to neural tube defects in pregnant women with high maternal serum homocysteine and low thyroid hormone levels. Methods: We performed a case-control study between 2007 and 2009 that included pregnant women from the Lüliang Mountains, Shanxi Province, China. Nine distinct single nucleotide polymorphisms in the iodothyronine deiodinase type 1, type 2, and type 3 genes were analyzed using placental samples obtained from 83 pregnant women with fetuses harboring neural tube defects (cases) and 90 pregnant women with fetuses without neural tube defects (controls). The nine single nucleotide polymorphisms were analyzed using the Cochran–Armitage test and the Chi-squared test (Fisher’s exact test). Results: There were no statistically significant associations between the nine placental single nucleotide polymorphisms and neural tube defects (P>0.05). Additionally, no statistically significant relationships were found between the single nucleotide polymorphisms in placental iodothyronine deiodinase genes and neural tube defects among pregnant women with high maternal serum homocysteine and low thyroid hormone levels. Conclusions: Our result in this study supports our previous report, which showed dysregulation of iodothyronine deiodinase type 3 transcription due to histone modifications of the promotor region in a mouse model of spina bifida. Our result also suggests that other factors such as histone modifications of the genes of deiodinases by a higher level of serum total homocysteine rather than single nucleotide polymorphisms of the genes contribute to neural tube defects in pregnant women with high maternal serum homocysteine and low thyroid hormone levels.

Wnt signaling plays a major role in early neural development. An aberrant activation in Wnt/β-catenin pathway causes defective anteroposterior patterning, which results in neural tube closure defects (NTDs). Changes in folate metabolism may participate in early embryo fate determination. We have identified that folate deficiency activated Wnt/β-catenin pathway by upregulating a chorion-specific transcription factor Gcm1. Specifically, folate deficiency promoted formation of the Gcm1/β-catenin/T-cell factor (TCF4) complex formation to regulate the Wnt targeted gene transactivation through Wnt-responsive elements. Moreover, the transcription factor Nanog upregulated Gcm1 transcription in mESCs under folate deficiency. Lastly, in NTDs mouse models and low-folate NTDs human brain samples, Gcm1 and Wnt/β-catenin targeted genes related to neural tube closure are specifically overexpressed. These results indicated that low-folate level promoted Wnt/β-catenin signaling via activating Gcm1, and thus leaded into aberrant vertebrate neural development.

Mouse homozygous mutants in Wnt/planar cell polarity (PCP) pathway genes have been shown to cause neural tube defects (NTDs) through the disruption of normal morphogenetic processes critical to neural tube closure (NTC). Knockout mice that are heterozygotes of single PCP genes likely fail to produce NTD phenotypes, yet damaging variants detected in human NTDs are almost always heterozygous, suggesting that other deleterious interacting variants are likely to be present. Nonetheless, the Wnt/PCP pathway remains a genetic hotspot. Addressing these issues is essential for understanding the genetic etiology of human NTDs.We performed targeted next-generation sequencing (NGS) on 30 NTD-predisposing Wnt/PCP pathway genes in 184 Chinese NTD cases. We subsequently replicated our findings for the CELSR1 gene in an independent cohort of 292 Caucasian NTD samples from the USA. Functional validations were confirmed using in vitro assays.CELSR1, CELSR2 and CELSR3 genes were significantly clustered with rare driver coding mutations (q-value 0.05) demonstrated by OncodriveCLUST. During the validation stage, the number of rare loss of function (LoF) variants in CELSR1 was significantly enriched in NTDs compared with the LoF counts in the ExAC database (p 0.001). Functional studies indicated compound heterozygote variants of CELSR2 p.Thr2026Met and DVL3 p.Asp403Asn result in down regulation of PCP signals.These data indicate rare damaging variants of the CELSR genes, identified in ~ 14% of NTD cases, are expected to be driver genes in the Wnt/PCP pathway. Compound damaging variants of CELSR genes and other Wnt/PCP genes, which were observed in 3.3% of the studied NTD cohort, are also expected to amplify these effects at the pathway level.

Traditional cameras are limited by sensors and cannot directly capture single-shot high dynamic range (HDR) images. We propose an improved single-shot HDR image reconstruction method that uses a single-exposure filtered low dynamic range (FLDR) image. First, by adding an optical filter in front of the camera lens, a FLDR image with different RGB channel exposure states and luminance ranges can be captured in a single-shot, unlike the traditional LDR image. Second, a deep inverse tone mapping network (DITMnet) with multibranch features extraction and multioutput images synthesis is designed to reconstruct an HDR image from a single FLDR image. Experimentally, under different exposure states and color spaces, our method outperforms similar algorithms.

Background: Neural tube defects are a group of severe neurological birth defects with one-carbon metabolism disturbance. The lack of information available on the distribution of one-carbon metabolites in lesion tissues precludes further elucidation of the pathogenesis of NTDs. Our aims were to develop and validate a simple and robust method for one-carbon related amino acid measurements in both intracellular and extracellular bio-samples and apply this method to NTD tissues for risk metabolite screening. Method: A simultaneous test for nine amino acids (homocysteine, S-adenosylhomocysteine, serine, histidine, methionine, cystathionine, cysteine, glycine, and tryptophan) in both intracellular and extracellular matrices was developed using liquid chromatography tandem mass spectrometry in a multiple reaction monitoring mode. Three kinds of tissues from folate deficient and NTD-affected embryos and controls in a NTD high-risk area were analyzed using this method. Results: Method recoveries ranged from 87.10% to 118.85% and accuracy (relative error, RE%) ranged from −14.96% to 13.96%. Calibration curves were linear (R2 > 0.99). The within-run and between-run precision were both lower than 15%. Reproducibility CV% ranged from 0.29% to 13.37% in low, medium and high concentration standard spiked plasma, HEK-293 cells, and brain, lung, heart tissues. NTD brain tissue showed significantly high concentration of homocysteine and cystathionine, and low concentration of histidine, glycine, methionine and tryptophan. Conclusion: This high-throughput method is reliable and accurate for simultaneous determination of one-carbon amino acid metabolites in both intracellular and extracellular bio-samples.

Background This study tested the hypothesis that abnormal maternal metabolism of both homocysteine and thyroid hormone network in pregnant women is associated with neural tube defects (NTDs) in a part of China with high NTD prevalence. Methods A case–control study was performed between 2007 and 2009 in Luliang Mountains, Shanxi Province. This study included 83 pregnant women who had fetuses with NTDs (cases) and 90 pregnant women with normal fetuses (controls). In addition, a cell model to illustrate the epidemiological findings was established. Results Fetuses of mother who had both high total homocysteine (tHcy) and inadequate free thyroxine were 3 times more at risk of developing NTDs (adjusted odds ratio = 3.5; 95 % confidence interval = 1.2–10.4; cases vs. controls) using multivariate logistic regression models. Furthermore, biological interaction between metabolisms of Hcy and thyroid hormones was demonstrated in vitro. In homocysteine thiolactone of a metabolite of Hcy-treated mouse embryonic neural stem NE4C cells, genes (Bmp7, Ctnnb1, Notch 1, Gli2, and Rxra) related to both neural tube closure and thyroid hormone network were shown to be regulated by H3K79 homocysteinylation, which increased their expression levels. Conclusions The effect of maternal serum high tHcy on risk of developing NTDs is depended on maternal serum level of thyroxine. Meanwhile, a higher level of tHcy might also affect both maternal metabolism of thyroid hormone and neural tube closure in embryogenesis through homocysteinylation of histones.

In this paper, a novel Deep HDR Merger network, which is called MergeNet, is proposed to reconstruct a HDR image from a single filtered LDR image. Filtered images are adopted as input since they contain more dynamic range than traditional ones. By learning the correlation between filtered LDR images and HDR images, the MergeNet successfully achieves HDR reconstruction of filtered images. We used five evaluation methods to make qualitative and quantitative comparisons to show that our method produced excellent results. Experimental results show that the proposed method performs favorably against state-of-the-art HDR image reconstruction methods.

Previous studies have suggested that different types of human-computer interactions (HCI) have different impact on use's emotional responses in virtual environment. In this study, we investigat the effects of two different types of HCI, including controller-based interaction and speech-based interaction, on user's emotion in a virtual counseling environment. To achieve this end, we first develop a virtual counseling environment which enable each participant acted as a counselor to help a depressed virtual woman. We then assess the emotional intensity of each participant after they experienced 20-30 minutes' consultation in either controller-based or speech-based interaction condition. Our results show that, although there is no significant difference in emotional intensity between two different interaction conditions, participants in speech-based condition show relatively stronger emotion than these in controller-based condition.

Folate contributes to the accumulation of DNA strand breaks (DSBs) in the genome. Kdm6a plays a critical role in early embryogenesis but it is unknown whether Kdm6a is involved in the DNA damage response under folate deficiency. Here, we established a low folate environment for mouse embryonic cells using a folate antagonist (methotrexate, MTX). We found increased enrichment of DSBs in Kdm6a in MTX-treated cells, resulting in reduced Kdm6a expression. MTX treatment enriched KDM6A in the nonhomologous end-joining (NHEJ) repair pathway and controlled the expression of the Ku heterodimer (Ku70/80) and XRCC4. The activation of NHEJ repair pathway-associated genes under folate deficiency relied on the specific interaction between KDM6A and p53. p53 silencing increased Ku heterodimer expression. In addition, in a neural tube defect (NTD) mouse model and low folate neural tube defect human brain samples, KDM6A levels were also decreased and accompanied by over-expression of Ku80. Our findings highlight how alterations in folate levels affect KDM6A with respect to DNA breakage and DNA repair, offering a new insight into the molecular function of KDM6A.Summary statementOur study demonstrates for the first time that in mammals, Kdm6a and p53 have synergistic effects during DNA fragmentation repair.

To analysis the associations between the polymorphisms of TMPRSS6 and the levels of serum ferritin( SF) and soluble transferrin receptor( s TfR) in pregnant women.A total of 807 pregnant women were recruited by using cluster random sampling method from Lüliang in Shanxi Province in 2014. Roche Tinaquant immunoturbidimetric assay was used to measure the level of SF and s TfR, then iron deficiency( ID) was identified by the criteria of SF25 ng/m L and s TfR4. 4 mg/L, respectively. Sequenom MassArray was used to genotype the 7 targeted single-nucleotide polymorphisms( SNPs)( rs11704654, rs1421312, rs2111833, rs2235321, rs2543519, rs4820268 and rs855791) of the subjects. The t test and ANOVA analysis were used to test the different levels of SF and s TfR among SNPs, and chi-square test and Logistic regression were conducted to detect the associations between genotypes of each locus and ID.The differences of the levels of Ln SF between genotypes in rs2111833 were significant( F = 3. 57, P = 0. 0287), and the Ln SF level of T allele carrier group was lower than CC group( t = 2. 03, P = 0. 0429). The Ln SF level of A allele carrier group was lower than GG carrier group in rs855791( t = 1. 97, P = 0. 0490). For rs11704654, the ratio of SF25 ng/m L of T allele carriers was higher than CC carriers( χ~2= 4. 5456, P = 0. 0330). For rs211183, the ratio of SF25 ng/m L of T allele carriers was higher than CC carriers( χ~2= 4. 6431, P = 0. 0312). For rs855791, the ratio of SF25 ng/m L of GG carriers was lower than A allele carriers( χ~2= 5. 0134, P = 0. 0263). rs11704654( T) and rs855791( A) were still shown the association with SF25 ng/m L status in logistic analysis adjusted by age and gestational weeks. The Ln s TfR level of T allele carrier group in rs11704654 was higher than CC carrier group( t =-2. 012, P = 0. 024), and the Ln s TfR level of G allele carrier group in rs2543519 was higher than AA carrier group( t =-1. 954, P = 0. 011).The associations between polymorphisms of TMPRSS6 and the levels of SF and s TfR are observed in pregnant women.

Folate deficiency in early development leads to disturbance in multiple processes, including neurogenesis during which fibroblast growth factor (FGF) pathway is one of the crucial pathways. Whether folic acid (FA) directly affects FGF pathways to influence neurodevelopment and the possible mechanism remains unclear. In this study, we presented evidence that in human FA-insufficient encephalocele, the FGF pathway was interfered. Furthermore, in Brachyury knockout mice devoid of such T-box transcription factors regulating embryonic neuromesodermal bipotency and a key component of FGF pathway, change in expression of Brachyury downstream targets, activator Fgf8 and suppressor dual specificity phosphatase 6 was detected, along with the reduction in expression of other key FGF pathway genes. By using a FA-deficient cell model, we further demonstrated that decrease in Brachyury expression was through alteration in hypermethylation at the Brachyury promoter region under FA deficiency conditions, and suppression of Brachyury promoted the inactivation of the FGF pathway. Correspondingly, FA supplementation partially reverses the effects seen in FA-deficient embryoid bodies. Lastly, in mice with maternal folate-deficient diets, aberrant FGF pathway activity was found in fetal brain dysplasia. Taken together, our findings highlight the effect of FA on FGF pathways during neurogenesis, and the mechanism may be due to the low expression of Brachyury gene via hypermethylation under FA-insufficient conditions.-Chang, S., Lu, X., Wang, S., Wang, Z., Huo, J., Huang, J., Shangguan, S., Li, S., Zou, J., Bao, Y., Guo, J., Wang, F., Niu, B., Zhang, T., Qiu, Z., Wu, J., Wang, L. The effect of folic acid deficiency on FGF pathway via Brachyury regulation in neural tube defects.

dongSpace is a wide area multiplayer interactive game system based on mixed reality technology. The system uses a head-mounted display to track user's posture, allowing user to perform a wide range of movement in more than 2,000 square meters of outdoor environments. The laptop that the user carries with him will render the game screen in real time. The computer performs computational rendering to provide high-definition, large-angle-of-view content display. The system also provides users with a hand-held simulation gun with tracking that can be used to shoot or interact with virtual environment objects. The system integrates display devices, tracking devices, interactive devices, computers and other devices, which breaks through the limitations of traditional MR systems.

Neural tube defects (NTDs) are severe malformations of the central nervous system caused by complex genetic and environmental factors. Among genes involved in NTD, cilia-related genes have been well defined and found to be essential for the completion of neural tube closure (NTC). We have carried out next-generation sequencing on target genes in 373 NTDs and 222 healthy controls, and discovered eight disease-specific rare mutations in cilia-related gene DNAAF1. DNAAF1 plays a central role in cytoplasmic preassembly of distinct dynein-arm complexes, and is expressed in some key tissues involved in neural system development, such as neural tube, floor plate, embryonic node, and brain ependyma epithelial cells in zebrafish and mouse. Therefore, we evaluated the expression and functions of mutations in DNAAF1 in transfected cells to analyze the potential correlation of these mutants to NTDs in humans. One rare frameshift mutation (p.Gln341Argfs*10) resulted in significantly diminished DNAAF1 protein expression, compared to the wild type. Another mutation, p.Lys231Gln, disrupted cytoplasmic preassembly of the dynein-arm complexes in cellular assay. Furthermore, results from NanoString assay on mRNA from NTD samples indicated that DNAAF1 mutants altered the expression level of NTC-related genes. Altogether, these findings suggest that the rare mutations in DNAAF1 may contribute to the susceptibility for NTDs in humans.

BackgroundThe polymorphism of genes involved in folate-mediated one-carbon metabolism may be a risk factor for neural tube defects (NTDs). In the present study, we aimed to investigate the single nucleotide polymorphisms (SNPs) of the genes BHMT, CUBN, FTCD, GAMT, GART, SARDH, SHMT1, and MUT, and their effect on NTDs in the Chinese Han population.

We investigated single-nucleotide polymorphisms (SNPs) in the aldehyde dehydrogenase family1 L1 gene (ALDH1L1) and their association with neural tube defects (NTDs) in the Chinese population. A total of 271 NTDs cases and 192 healthy controls were used in this study. A total of 112 selected SNPs in the ALDH1L1 gene were analyzed using the next-generation sequencing method. Statistical analysis was carried out to investigate the correlation between SNPs and patient susceptibility to NTDs. Statistical analysis revealed a significant correlation between the SNP sites rs4646733, rs2305225, and rs2276731 in the ALDH1L1 gene and NTDs. The TT genotype and T allele of rs4646733 in ALDH1L1 were associated with a significantly increased incidence of NTDs [odds ratio (OR) = 2.16, 95 % confidence interval (CI) 1.199-3.896 for genotype; and OR = 1.46, 95 % CI 1.092-1.971 for allele]. The AA genotype and A allele of rs2305225 in ALDH1L1 were associated with a significantly increased incidence of NTDs (OR = 2.03, 95 % CI 1.202-3.646 for genotype, and OR = 1.44, 95 % CI 1.096-1.905 for allele). The CT genotype and C allele of rs2276731 in ALDH1L1 significantly were associated with an increased incidence of NTDs (OR = 1.67, 95 % CI 1.129-2.491 with genotype, and OR = 1.32, 95 % CI 0.956-1.816 with allele).The polymorphic loci rs4646733, rs2305225, and rs2276731 in the ALDH1L1 gene maybe potential risk factors for NTDs in the Chinese population.

We designed a within-subject experiment to compare visual discomfort to preteen users caused by using head-mounted displays (HMD) and tablet computers for an hour. 18 participants younger than 13 years old were recruited to fulfill a series of similar painting tasks under both display conditions. Visual fatigue was measured with visual analog scale before and after experiment and during the break of experiment. The results indicated that HMD had a trend to bring higher visual fatigue than tablet computer during the exposure of 1 hour. Although the symptoms of visual discomfort disappeared after resting, there is need for preteen-specific head-mounted displays.

Background Mouse homozygous mutants in Wnt/planar cell polarity (PCP) pathway genes have been shown to cause neural tube defects (NTDs) through the disruption of normal morphogenetic processes critical to neural tube closure (NTC). Knockout mice that are heterozygotes of single PCP genes likely fail to produce NTD phenotypes, yet damaging variants detected in human NTDs are almost always heterozygous, suggesting that other deleterious interacting variants are likely to be present. Nonetheless, the Wnt/PCP pathway remains a genetic hotspot. Addressing these issues is essential for understanding the genetic etiology of human NTDs. Methods We performed targeted next-generation sequencing (NGS) on 30 NTD-predisposing Wnt/PCP pathway genes in 184 Chinese NTD cases. We subsequently replicated our findings for the CELSR1 gene in an independent cohort of 292 Caucasian NTD samples from the USA. Functional validations were confirmed using in vitro assays. Results CELSR1, CELSR2 and CELSR3 genes were significantly clustered with rare driver coding mutations (q-valueCELSR1 was significantly enriched in NTDs compared with the LoF counts in the ExAC database (p CELSR2 p.Thr2026Met and DVL3 p.Asp403Asn result in down regulation of PCP signals. Conclusions These data indicate rare damaging variants of the CELSR genes, identified in ~ 14% of NTD cases, are expected to be driver genes in the Wnt/PCP pathway. Compound damaging variants of CELSR genes and other Wnt/PCP genes, which were observed in 3.3% of the studied NTD cohort, are also expected to amplify these effects at the pathway level.

Optical tracking has become the most commonly used virtual reality (VR) tracking technology because of its high precision and non-contact characteristics. The optical tracking system represented by HTC VIVE has the problem that signals of base stations interfere with each other, and the number of base stations cannot be extended by cascades, thereby limiting the scope of its work. In this paper, an extensible optical tracking system is proposed, which can distinguish the signals from different base stations and support the simultaneous operation of multiple base stations. Furthermore, we designed an encoding scheme to generate independent code for up to 32 base stations and proposed a highspeed decoding method. Experiments demonstrate that the system has high tracking accuracy and low system latency. Users can adjust the number and layout of base stations according to the actual demand, which greatly improves the flexibility of the system, and benefits promoting the development of large scale optical tracking equipment with low cost and high precision.

Table S1. Demographic characteristics in NTD cohorts. (DOCX 17Â kb)

Background The polymorphism of methylenetetrahydrofolate dehydrogenase (MTHFD1) has been reported as a risk factor for neural tube defects (NTDs). In the present study, we aimed to investigate whether the single-nucleotide polymorphisms (SNPs) of MTHFD1 gene are associated with NTDs in a Chinese population and to determine their mechanism of action. Material/Methods MTHFD1 gene was scanned in a total of 270 NTDs cases and 192 healthy controls by using next-generation sequencing (NGS) method. After quality control procedures, 208 selected SNP sites in MTHFD1 gene were enrolled for follow-up statistical association analyses. Functional analyses were also performed for significant SNPs through bioinformatics analysis. Folic acid levels of brain tissue in available NTDs cases and healthy controls (113 and 123, respectively) were measured. Statistical and bioinformatics analyses were performed to investigate the relationship between SNPs in MTHFD1 and susceptibility to NTDs. Results Statistical analysis showed that 2 independent SNPs, rs1956545 and rs56811449, confer the risk of NTDs (P value=0.0195, OR (odds ratio)=1.41, 95% CI (confidence interval)=1.06–1.88; P value=0.0107, OR=0.56, 95% CI=0.36–0.87). The haplotype GGGG, which consists of 4 SNPs (rs2236225, rs2236224, rs1256146, and rs6573559), is also associated with risk of NTDs (P value=0.0438, OR=0.7180, 95% CI=0.5214–0.9888). The risk allele C of rs1956545 is also associated with decreased folic acid levels in the brain (P value=0.0222, standard beta=−0.2238, 95% CI=−0.4128 – −0.0349) according to analysis in the subset of NTDs cases and healthy controls. Bioinformatics analysis indicates that rs1956545 and rs56811449 are within ENCODE regulatory regions, the open chromatin regions of blastula Trophoblast cell line, and histone-marked region of brain astrocyte cell line. Conclusions The polymorphism of SNP loci rs1956545 and rs56811449 as well as a haplotype in MTHFD1 gene could serve as an indicator for the occurrence of NTDs in Chinese population and some specific genotypes of the loci may have lower risk of developing NTDs.

BACKGROUND Animal models of neural tube defects (NTDs) have indicated roles for the Fzd3 gene and the planar cell polarity signaling pathway in convergent extension. We investigated the involvement of FZD3 in genetic and epigenetic mechanisms associated with human NTDs, especially spina bifida. We explored the effects of variants spanning the FZD3 gene in NTDs and examined the role of aberrant methylation of the FZD3 promoter on gene expression in brain tissue in spina bifida. METHODS Six FZD3 single nucleotide polymorphisms were genotyped using a MassARRAY system in tissue from 165 NTD fetuses and 152 controls. DNA methylation aberrations in the FZD3 promoter region were detected using a MassARRAY EpiTYPER (17 CpG units from −500 to −2400 bp from the transcription start site) in brain tissue from 77 spina bifida and 74 control fetuses. RESULTS None of the six single nucleotide polymorphisms evaluated were significantly associated with spina bifida, but the mean methylation level was significantly higher in spina bifida samples (13.70%) compared with control samples (10.91%) (p = 0.001). In terms of specific sites, DNA methylation levels were significantly higher in the spina bifida samples at 14 of the 17 CpG units, which mostly included in R2 region. FZD3 mRNA expression was negatively correlated with methylation of the FZD3 promoter region, especially the R2 region (R = 0.970; p = 0.001) in HeLa cells. CONCLUSION The results of this study suggest that DNA methylation plays an important role in FZD3 gene expression regulation and may be associated with an increased risk of spina bifida. Birth Defects Research (Part A) 103:37–44, 2015. © 2014 Wiley Periodicals, Inc.

Neural tube defects (NTDs) in mammals are rooted in aberrant neural tube closure during early embryogenesis, which is caused by multiple environmental and genetic factors. The Sonic Hedgehog pathway is involved in the induction of the floor plate and participates in formation of the neural tube. Mutation of the suppressor of fused gene (SUFU), an essential repressor of Sonic Hedgehog signaling pathway, can result in NTDs. A case-control study was designed to compare the frequencies of the polymorphism at four sites in the SUFU gene in control and NTDs group, as well as in subtype groups, including anencephaly, spina bifida and encephalocele. We also explored the association between polymorphism and NTDs risk in a high prevalence population in China. Rs10786691, but not the other three SNPs, had an association between polymorphisms and NTDs. The heterozygous AG allele of rs10786691 was significantly related with NTDs and encephalocele (OR = 1.60, 95% CI: 1.04-2.48, p = 0.034; OR = 2.83, 95% CI: 1.07-7.47, p = 0.036). In female but not male fetuses, the AG genotype of rs10786691 increased the risk of NTDs (OR = 1.88, 95% CI: 1.03-3.41, p = 0.040). The SUFU rs10786691 A>G polymorphism may be a potential risk factor for NTDs and encephalocele in this high-risk population, but the association between the polymorphism and NTDs was probably influenced by gender.

The PCMT1 gene encodes the protein repair enzyme protein-L-isoaspartate (D-aspartate) O-methyltransferase, which is known to protect certain neural cells against Bax-induced apoptosis. Previous studies have produced inconsistent results regarding the effects of PCMT1 (rs4816 and rs4552) polymorphisms on neural tube defects (NTDs). Reduced maternal plasma folate levels and/or elevated homocysteine (Hcy) levels are considered to be risk factors for NTDs. In order to clarify the key factors contributing to the apparent discrepancy and investigate gene-environment interaction, we conducted a case-control study including 121 cases and 146 matched controls to investigate the association between the two PCMT1 polymorphisms in fetuses and the risk of NTDs in the Chinese population of Lvliang, which has low folate intake. Maternal plasma folate and Hcy levels were also measured, and the interaction between fetal PCMT1 gene status and maternal folate metabolites was assessed. Maternal plasma folate concentrations in the NTD group were lower than in controls (10.23 vs. 13.08 nmol/L, adjusted P = 0.059), and Hcy concentrations were significantly higher (14.46 vs. 11.65 μmol/L, adjusted P = 0.026). Fetuses carrying the rs4816 AG + GG genotype, combined with higher maternal plasma Hcy, had a 6.46-fold (95 % CI 1.15-36.46) increased risk of anencephaly. The results of this study imply that the fetal PCMT1 rs4816 polymorphism may play only a weak role in NTD formation and that gene-environment interactions might be more significant.

Dishevelled (DVL/Dvl) genes play roles in canonical and noncanonical Wnt signaling, both of which are essential in neural tube closing and are involved in balancing neural progenitor growth and differentiation, or neuroepithelial cell polarity, respectively. In mouse Dvl haploinsufficiency leads to neural tube defects (NTDs), which represent the second most common birth defects. However, DVL genes’ genetic contributions in human NTDs are modest. We sought to explore the molecular impact on such genes in human NTDs in a Han Chinese cohort. In 47 cases with NTDs and 61 matched controls, in brain tissues, the DVL1/2 mRNA levels were correlated with the levels of a serine/threonine protein kinase MARK2, and in 20 cases with lumbosacral spina bifida, the mRNA levels of DVL1 and MARK2 were significantly decreased; by contrast, only an intronic rare variant was found. Moreover, in an extended population, we found merely three novel rare missense variants in 1 % of individuals with NTDs. In cell-based assays, Mark2 depletion indeed reduces Dvl gene expression and interrupts neural stem cell (NSCs) growth and differentiation, which are likely to be mediated through a decrease in class IIa HDAC phosphorylation and reduced H3K4ac and H3K27ac occupancies at the Dvl1/2 promoters. Finally, the detections of folate concentration in human brain tissue and NSCs and MEF cells indicates that folate deficiency contributes to the observed decreases in Mark2 and Dvl1 expression. Our present study raises a potential common pathogenicity mechanism in human lumbosacral spina bifida about DVL genes rather than their genetic pathogenic role.

Increasing evidence that mutation of planar cell polarity (PCP) genes contributes to human cranial neural tube defect (NTD) susceptibility prompted us to hypothesize that rare variants of genes in the core apical-basal polarity (ABP) pathway are risk factors for cranial NTDs. In this study, we screened for rare genomic variation of PARD3 in 138 cranial NTD cases and 274 controls. Overall, the rare deleterious variants of PARD3 were significantly associated with increased risk for cranial NTDs (11/138 vs.7/274, P

Folate hydrolase 1 (FOLH1) gene encodes intestinal folate hydrolase, which regulates intestinal absorption of dietary folate. Previous studies on the association between polymorphisms rs202676 and rs61886492 and the risk of neural tube defects (NTDs) were inconclusive. A case–control study of women with NTD-affected pregnancies (n = 160) and controls (n = 320) was conducted in the Chinese population of Lvliang, a high-risk area for NTDs. We genotyped the polymorphic sites rs202676 and rs61886492 and assessed maternal plasma folate and total homocysteine (tHcy). Our results showed that in case group, plasma folate concentrations were 18 % lower compared with those of control group (8.32 vs. 6.79 nmol/L, p = 0.033) and tHcy concentrations were 17 % higher (10.47 vs. 12.65 μmol/L, p = 0.047). Almost all samples had the rs61886492 GG genotype (99.78 %). The result showed that the frequency of GG genotype in rs202676 was significantly higher in group with multiple NTDs than in controls (p = 0.030, OR = 2.157, 95 % CI, 1.06–4.38). The multiple-NTD group showed higher maternal plasma concentrations of tHcy (10.47 vs. 13.96 μmol/L, p = 0.024). The GG genotype of rs202676 had a lower maternal folate and higher tHcy concentrations than other genotypes with no significant differences. The result of structural prediction indicated that this variation might change the spatial structure of the protein. These results suggested that the maternal polymorphism rs202676 was a potential risk factor for multiple NTDs in this Chinese population. The allele G might affect maternal plasma folate and tHcy concentration.

Partitioning defective 3 homolog (PARD3) is an attractive candidate gene for screening neural tube defect (NTD) risk. To investigate the role of genetic variants in PARD3 on NTD risk, a case–control study was performed in a region of China with a high prevalence of NTDs. Total 53 single-nucleotide polymorphisms (SNPs) in PARD3 were genotyped in 224 fetuses with NTDs and in 253 normal fetuses. We found that 6 SNPs (rs2496720, rs2252655, rs3851068, rs118153230, rs10827337, and rs12218196) were statistically associated with NTDs (P < .05). After stratifying participants by NTD phenotypes, the significant association only existed in cases with anencephaly rather than spina bifida. Further haplotype analysis confirmed the association between PARD3 polymorphisms and NTD risk (global test P = 3.41e-008). Our results suggested that genetic variants in PARD3 were associated with susceptibility to NTDs in a Chinese Han population, and this association was affected by NTD phenotypes.