Genetic Variation in Choline-Metabolizing Enzymes Alters Choline Metabolism in Young Women Consuming Choline Intakes Meeting Current Recommendations

Role of one-carbon nutrient intake and diabetes during pregnancy in children's growth and neurodevelopment: A 2-year follow-up study of a prospective cohort

BACKGROUND & AIMS

Both maternal metabolic dysregulation, e.g., gestational diabetes mellitus (GDM), and maternal supply of nutrients that participate in one-carbon (1C) metabolism, e.g., folate, choline, betaine, and vitamin B12, have been demonstrated to influence epigenetic modification such as DNA methylation, thereby exerting long-lasting impacts on growth and development of offspring. This study aimed to determine how maternal 1C nutrient intake was associated with DNA methylation and further, development of children, as well as whether maternal GDM status modified the association in a prospective cohort.

METHODS

In this study, women with (n = 18) and without (n = 20) GDM were recruited at 25-33 weeks gestation. Detailed dietary intake data was collected by 3-day 24-h dietary recall and nutrient levels in maternal blood were also assessed at enrollment. The maternal-child dyads were invited to participate in a 2-year follow-up during which anthropometric measurement and the Bayley Scales of Infant and Toddler Development™ Screening Test (Third Edition) were conducted on children. The association between maternal 1C nutrients and children's developmental outcomes was analyzed with a generalized linear model controlling for maternal GDM status.

RESULTS

We found that children born to mothers with GDM had lower scores in the language domain of the Bayley test (p = 0.049). Higher maternal food folate and choline intakes were associated with better language scores in children (p = 0.01 and 0.025, respectively). Higher maternal food folate intakes were also associated with better cognitive scores in children (p = 0.002). Higher 1C nutrient intakes during pregnancy were associated with lower body weight of children at 2 years of age (p < 0.05). However, global DNA methylation of children's buccal cells was not associated with any maternal 1C nutrients.

CONCLUSIONS

In conclusion, higher 1C nutrient intake during pregnancy was associated with lower body weight and better neurodevelopmental outcomes of children. This may help overcome the lower language scores seen in GDM-affected children in this cohort. Studies in larger cohorts and with a longer follow-up duration are needed to further delineate the relationship between prenatal 1C nutrient exposure, especially in GDM-affected pregnancies, and offspring health outcomes.

Choline kinase alpha genotype is related to hippocampal brain volume and cognition in postmenopausal women

This study examined how single nucleotide polymorphisms (SNPs) related to choline synthesis and metabolism, processes largely regulated by estrogen, influenced hippocampal volume and neuropsychological function following menopause. We investigated the effect of choline kinase alpha (CHKA) genotype on brain volume and neuropsychological performance in postmenopausal women. The effect alleles of certain CHKA SNPs (rs6591331 T, rs10791957 A) are associated with varied responses to choline deficiency and delegation of choline to physiological pathways. The presence of these alleles was hypothesized to correlate with worse cognitive performance in women after menopause. Results from structural MRI scans revealed larger right hippocampal volumes in subjects with a T/T CHKA rs6591331 genotype compared to A/A subjects. Delayed memory scores from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were lower in subjects with T/T genotypes compared to those with the A/T genotype and the A/A genotype. Based on these findings, we proposed a CHKA-dependent mechanism present within the brain to compensate for the decreased estrogen and biosynthesized choline associated with menopause.

Polymorphisms in the choline transporter SLC44A1 are associated with reduced cognitive performance in normotypic but not prenatal alcohol-exposed children

BACKGROUND

Choline is essential for healthy cognitive development. Single nucleotide polymorphisms (SNPs; rs3199966(G), rs2771040(G)) within the choline transporter SLC44A1 increase risk for choline deficiency. In a choline intervention trial of children who experienced prenatal alcohol exposure (PAE), these alleles are associated with improved cognition.

OBJECTIVE

This study aimed to determine if SNPs within SLC44A1 are differentially associated with cognition in children with PAE compared with normotypic controls (genotype × exposure). A secondary objective tested for an association of these SNPs and cognition in controls (genotype-only).

DESIGN

This is a secondary analysis of data from the Collaborative Initiative on Fetal Alcohol Spectrum Disorders. Participants (163 normotypic controls, 162 PAE) underwent psychological assessments and were genotyped within SLC44A1. Choline status was not assessed. Association analysis between genotype × exposure was performed using an additive genetic model and linear regression to identify the allelic effect. The primary outcome was the interaction between SLC44A1 genotype × exposure status with respect to cognition. The secondary outcome was the cognitive-genotype association in normotypic controls.

RESULTS

Genotype × exposure analysis identified 7 SNPs in SLC44A1, including rs3199966(G) and rs2771040(G), and in strong linkage (D' ≥ 0.87), that were associated (adjusted P ≤ 0.05) with reduced performance in measures of general cognition, nonverbal and quantitative reasoning, memory, and executive function (β, 1.92-3.91). In controls, carriers of rs3199966(GT or GG) had worsened cognitive performance than rs3199966(TT) carriers (β, 0.46-0.83; P < 0.0001), whereas cognitive performance did not differ by rs3199966 genotype in those with PAE.

CONCLUSIONS

Two functional alleles that increase vulnerability to choline deficiency, rs3199966(G) (Ser644Ala) and rs2771040(G) (3' untranslated region), are associated with worsened cognition in otherwise normotypic children. These alleles were previously associated with greater cognitive improvement in children with PAE who received supplemental choline. The findings endorse that choline benefits cognitive development in normotypic children and those with PAE.

The distribution of dietary choline intake and serum choline levels in Australian women during pregnancy and associated early life factors

BACKGROUND

Maternal dietary choline has a central role in foetal brain development and may be associated with later cognitive function. However, many countries are reporting lower than recommended intake of choline during pregnancy.

METHODS

Dietary choline was estimated using food frequency questionnaires in pregnant women participating in population-derived birth cohort, the Barwon Infant Study (BIS). Dietary choline is reported as the sum of all choline-containing moieties. Serum total choline-containing compounds (choline-c), phosphatidylcholine and sphingomyelin were measured using nuclear magnetic resonance metabolomics in the third trimester. The main form of analysis was multivariable linear regression.

RESULTS

The mean daily dietary choline during pregnancy was 372 (standard deviation (SD) 104) mg/day. A total of 236 women (23%) had adequate choline intake (440 mg/day) based on the Australian and New Zealand guidelines, and 27 women (2.6%) took supplemental choline ([Formula: see text] 50 mg/dose) daily during pregnancy. The mean serum choline-c in pregnant women was 3.27 (SD 0.44) mmol/l. Ingested choline and serum choline-c were not correlated (R2) = - 0.005, p = 0.880. Maternal age, maternal weight gain in pregnancy, and a pregnancy with more than one infant were associated with higher serum choline-c, whereas gestational diabetes and environmental tobacco smoke during preconception and pregnancy were associated with lower serum choline-c. Nutrients or dietary patterns were not associated with variation in serum choline-c.

CONCLUSION

In this cohort, approximately one-quarter of women met daily choline recommendations during pregnancy. Future studies are needed to understand the potential impact of low dietary choline intake during pregnancy on infant cognition and metabolic intermediaries.

CHDH, a key mitochondrial enzyme, plays a diagnostic role in metabolic disorders diseases and tumor progression

Human choline dehydrogenase (CHDH) is a transmembrane protein located in mitochondria. CHDH has been shown to be one of the important catalytic enzymes that catalyze the oxidation of choline to betaine and is involved in mitochondrial autophagy after mitochondrial damage. In recent years, an increasing number of studies have focused on CHDH and found a close association with the pathogenesis of various diseases, including tumor prognosis. Here we summarized the genomic localization, protein structure and basic functions of CHDH and discuss the progress of CHDH research in metabolic disorders and other diseases. Moreover, we described the regulatory role of CHDH on the progression of different types of malignant tumors. In addition, major pathogenic mechanisms of CHDH in multiple diseases may be associated with single nucleotide polymorphism (SNP). We look forward to providing new strategies and basis for clinical diagnosis and prognosis prediction of diseases by diagnosing SNP loci of CHDH genes. Our work evaluates the feasibility of CHDH as a molecular marker relevant to the diagnosis of some metabolic disorders diseases and tumors, which may provide new targets for the treatment of related diseases and tumors.

Basal forebrain cholinergic neurons are vulnerable in a mouse model of Down syndrome and their molecular fingerprint is rescued by maternal choline supplementation

Basal forebrain cholinergic neuron (BFCN) degeneration is a hallmark of Down syndrome (DS) and Alzheimer's disease (AD). Current therapeutics in these disorders have been unsuccessful in slowing disease progression, likely due to poorly understood complex pathological interactions and dysregulated pathways. The Ts65Dn trisomic mouse model recapitulates both cognitive and morphological deficits of DS and AD, including BFCN degeneration and has shown lifelong behavioral changes due to maternal choline supplementation (MCS). To test the impact of MCS on trisomic BFCNs, we performed laser capture microdissection to individually isolate choline acetyltransferase-immunopositive neurons in Ts65Dn and disomic littermates, in conjunction with MCS at the onset of BFCN degeneration. We utilized single population RNA sequencing (RNA-seq) to interrogate transcriptomic changes within medial septal nucleus (MSN) BFCNs. Leveraging multiple bioinformatic analysis programs on differentially expressed genes (DEGs) by genotype and diet, we identified key canonical pathways and altered physiological functions within Ts65Dn MSN BFCNs, which were attenuated by MCS in trisomic offspring, including the cholinergic, glutamatergic and GABAergic pathways. We linked differential gene expression bioinformatically to multiple neurological functions, including motor dysfunction/movement disorder, early onset neurological disease, ataxia and cognitive impairment via Ingenuity Pathway Analysis. DEGs within these identified pathways may underlie aberrant behavior in the DS mice, with MCS attenuating the underlying gene expression changes. We propose MCS ameliorates aberrant BFCN gene expression within the septohippocampal circuit of trisomic mice through normalization of principally the cholinergic, glutamatergic, and GABAergic signaling pathways, resulting in attenuation of underlying neurological disease functions.

The association between plasma choline, growth and neurodevelopment among Malawian children aged 6-15 months enroled in an egg intervention trial

Choline is an essential micronutrient that may influence growth and development; however, few studies have examined postnatal choline status and children's growth and development in low- and middle-income countries. The aim of this observational analysis was to examine associations of plasma choline with growth and development among Malawian children aged 6-15 months enrolled in an egg intervention trial. Plasma choline and related metabolites (betaine, dimethylglycine and trimethylamine N-oxide) were measured at baseline and 6-month follow-up, along with anthropometric (length, weight, head circumference) and developmental assessments (the Malawi Developmental Assessment Tool [MDAT], the Infant Orienting with Attention task [IOWA], a visual paired comparison [VPC] task and an elicited imitation [EI] task). In cross-sectional covariate-adjusted models, each 1 SD higher plasma choline was associated with lower length-for-age z-score (-0.09 SD [95% confidence interval, CI -0.17 to -0.01]), slower IOWA response time (8.84 ms [1.66-16.03]) and faster processing speed on the VPC task (-203.5 ms [-366.2 to -40.7]). In predictive models, baseline plasma choline was negatively associated with MDAT fine motor z-score at 6-month follow-up (-0.13 SD [-0.22 to -0.04]). There were no other significant associations of plasma choline with child measures. Similarly, associations of choline metabolites with growth and development were null except higher trimethylamine N-oxide was associated with slower information processing on the VPC task and higher memory scores on the EI task. In this cohort of children with low dietary choline intake, we conclude that there were no strong or consistent associations between plasma choline and growth and development.

Nutritional Genomics in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common chronic condition associated with genetic and environmental factors in which fat abnormally accumulates in the liver. NAFLD is epidemiologically associated with obesity, type 2 diabetes, and dyslipidemia. Environmental factors, such as physical inactivity and an unbalanced diet, interact with genetic factors, such as epigenetic mechanisms and polymorphisms for the genesis and development of the condition. Different genetic polymorphisms seem to be involved in this context, including variants in PNPLA3, TM6SF2, PEMT, and CHDH genes, playing a role in the disease's susceptibility, development, and severity. From carbohydrate intake and weight loss to omega-3 supplementation and caloric restriction, different dietary and nutritional factors appear to be involved in controlling the onset and progression of NAFLD conditions influencing metabolism, gene, and protein expression. The polygenic risk score represents a sum of trait-associated alleles carried by an individual and seems to be associated with NAFLD outcomes depending on the dietary context. Understanding the exact extent to which lifestyle interventions and genetic predispositions can play a role in the prevention and management of NAFLD can be crucial for the establishment of a personalized and integrative approach to patients.

Association of Maternal Betaine-Homocysteine Methyltransferase (BHMT) and BHMT2 Genes Polymorphisms with Congenital Heart Disease in Offspring

To systematically explore the association of single nucleotide polymorphisms (SNPs) of maternal BHMT and BHMT2 genes with the risk of congenital heart disease (CHD) and its three subtypes including atrial septal defect (ASD), ventricular septal defect (VSD), and patent ductus arteriosus (PDA) in offspring. A hospital-based case-control study involving 683 mothers of CHD children and 740 controls was performed. Necessary exposure information was captured through epidemiological investigation. Totally twelve SNPs of maternal BHMT and BHMT2 genes were detected and analyzed systematically. The study showed that maternal BHMT gene polymorphisms at rs1316753 (CG vs. CC: OR = 1.96 [95% CI 1.41-2.71]; GG vs. CC: OR = 1.99 [95% CI 1.32-3.00]; dominant model: OR = 1.97 [95% CI 1.44-2.68]) and rs1915706 (TC vs. TT: OR = 1.93 [95% CI 1.44-2.59]; CC vs. TT: OR = 2.55 [95% CI 1.38-4.72]; additive model: OR = 1.77 [95% CI 1.40-2.24]) were significantly associated with increased risk of total CHD in offspring. And two haplotypes were observed to be significantly associated with risk of total CHD, including C-C haplotype involving rs1915706 and rs3829809 in BHMT gene (OR = 1.30 [95% CI 1.07-1.58]) and C-A-A-C haplotype involving rs642431, rs592052, rs626105, and rs682985 in BHMT2 gene (OR = 0.71 [95% CI 0.58-0.88]). Besides, a three-locus model involving rs1316753 (BHMT), rs1915706 (BHMT), and rs642431 (BHMT2) was identified through gene-gene interaction analyses (P < 0.01). As for three subtypes including ASD, VSD, and PDA, significant SNPs and haplotypes were also identified. The results indicated that maternal BHMT gene polymorphisms at rs1316753 and rs1915706 are significantly associated with increased risk of total CHD and its three subtypes in offspring. Besides, significant interactions between different SNPs do exist on risk of CHD. Nevertheless, studies with larger sample size in different ethnic populations and involving more SNPs in more genes are expected to further define the genetic contribution underlying CHD and its subtypes.

Efficacy and pharmacokinetics of betaine in CBS and cblC deficiencies: a cross-over randomized controlled trial

BACKGROUND

Betaine is an "alternate" methyl donor for homocysteine remethylation catalyzed by betaine homocysteine methyltransferase (BHMT), an enzyme mainly expressed in the liver and kidney. Betaine has been used for more than 30 years in pyridoxine non-responsive cystathionine beta-synthase (pnrCBS) and cobalamin C (cblC) deficiencies to lower the hyperhomocysteinemia, although little is known about the optimal therapeutic dosage and its pharmacokinetic in these patients.

AIMS

We compared 2 betaine doses (100 mg/kg/day vs. 250 mg/kg/day) in children affected by pnrCBS or cblC deficiencies. We also measured the pharmacokinetics parameters after a single dose of betaine (100 or 250 mg/kg) in these patients.

METHODS

We conducted a prospective, randomized, crossover clinical trial with blinded evaluation. The primary outcome was the equivalence of total plasma homocysteine (tHcy) concentrations upon one-month oral treatment with betaine at 100 versus 250 mg/kg/day.

RESULTS

Eleven patients completed the study (5 pnrCBS and 6 cblC). tHcy concentrations were equivalent after a one-month treatment period for the two betaine dosages. Multivariate analysis showed a significant effect of betaine dose on methionine (Met) (p = 0.01) and S-adenosylmethionine (SAM) concentrations (p = 0.006).

CONCLUSIONS

Our analysis shows that there is no overt benefit to increasing betaine dosage higher than 100 mg/kg/day to lower tHcy concentrations in pnrCBS and cblC deficiencies. However, increasing betaine up to 250 mg/kg/d could benefit cblC patients through the increase of methionine and SAM concentrations, as low Met and SAM concentrations are involved in the pathophysiology of this disease. In contrast, in pnrCBS deficiency, betaine doses higher than 100 mg/kg/day could be harmful to these patients with pre-existing hypermethioninemia.

TRIAL REGISTRATION

Clinical Trials, NCT02404337. Registered 23 May 2015-prospectively registered, https://clinicaltrials.gov .

Betaine consumption as a new clinical approach to treatment and prophylaxis of folate-related pathologies

The most important pathway in the development of folate-related pathologies is an increase in the level of homocysteine (HC). HC, a cytotoxic and neurotoxic amino acid (when its level is ≥12 μmol/L), is 1 of the most widely studied compounds in cardiology, neurobiology, oncology, and embryology for the last 20 years. Given its toxicity, the processes of endogenous detoxification of HC are of particular interest to medicine. To date, the most studied pathway is that of remethylation (the conversion of HC to methionine), with the participation of B12- and B9-dependent methionine synthase. Less studied is remethylation with the participation of the choline derivatives betaine and betaine-HC-S-methyltransferase (BHMT). Therefore, the aim of this review was to conduct a theoretical analysis of available information regarding the contribution of betaine metabolism, its enzyme, and its genetic polymorphism to folate metabolism disturbances, and the development of folate-related pathologies. This review emphasizes the potential clinical significance of 2 factors that can influence the remethylation reaction of HC: the use of betaine and identifying the BHMT gene variants and their impact on the risk for developing certain folate-related pathologies, and treatment options. Moreover, with a high level of methylation of the BHMT gene and in the presence of its low-function variants (eg, rs3733890), it is necessary to use betaine as an additional methyl donor, especially during folate therapy. More clinical research is needed to identify the effects of the different BHMT gene variants on the individual risk for folate-related pathologies to better assess the clinical significance, the need for genetic testing, and betaine consumption.

Genetic Variants in One-Carbon Metabolism and Their Effects on DHA Biomarkers in Pregnant Women: A Post-Hoc Analysis

The delivery of docosahexanoic acid (DHA) to the fetus is dependent on maternal one-carbon metabolism, as the latter supports the hepatic synthesis and export of a DHA-enriched phosphatidylcholine molecule via the phosphatidylethanolamine N-methyltransferase (PEMT) pathway. The following is a post-hoc analysis of a choline intervention study that sought to investigate whether common variants in one-carbon metabolizing genes associate with maternal and/or fetal blood biomarkers of DHA status. Pregnant women entering their second trimester were randomized to consume, until delivery, either 25 (n = 15) or 550 (n = 15) mg choline/d, and the effects of genetic variants in the PEMT, BHMT, MTHFD1, and MTHFR genes on DHA status were examined. Variant (vs. non-variant) maternal PEMT rs4646343 genotypes tended to have lower maternal RBC DHA (% total fatty acids) throughout gestation (6.9% vs. 7.4%; main effect, p = 0.08) and lower cord RBC DHA at delivery (7.6% vs. 8.4%; main effect, p = 0.09). Conversely, variant (vs. non-variant) maternal MTHFD1 rs2235226 genotypes exhibited higher cord RBC DHA (8.3% vs. 7.3%; main effect, p = 0.0003) and higher cord plasma DHA (55 vs. 41 μg/mL; main effect, p = 0.05). Genotype tended to interact with maternal choline intake (p < 0.1) to influence newborn DHA status for PEMT rs4646343 and PEMT rs7946. These data support the need to consider variants in one-carbon metabolic genes in studies assessing DHA status and requirements during pregnancy.

Metabolomics as a Crucial Tool to Develop New Therapeutic Strategies for Neurodegenerative Diseases

Neurodegenerative diseases (NDs), such as Alzheimer’s (AD), Parkinson’s (PD), and amyotrophic lateral sclerosis (ALS), share common pathological mechanisms, including metabolism alterations. However, their specific neuronal cell types affected and molecular biomarkers suggest that there are both common and specific alterations regarding metabolite levels. In this review, we were interested in identifying metabolite alterations that have been reported in preclinical models of NDs and that have also been documented as altered in NDs patients. Such alterations could represent interesting targets for the development of targeted therapy. Importantly, the translation of such findings from preclinical to clinical studies is primordial for the study of possible therapeutic agents. We found that N-acetyl-aspartate (NAA), myo-inositol, and glutamate are commonly altered in the three NDs investigated here. We also found other metabolites commonly altered in both AD and PD. In this review, we discuss the studies reporting such alterations and the possible pathological mechanism underlying them. Finally, we discuss clinical trials that have attempted to develop treatments targeting such alterations. We conclude that the treatment combination of both common and differential alterations would increase the chances of patients having access to efficient treatments for each ND.

Prenatal choline supplementation improves biomarkers of maternal docosahexaenoic acid (DHA) status among pregnant participants consuming supplemental DHA: a randomized controlled trial

BACKGROUND

Dietary methyl donors (e.g., choline) support the activity of the phosphatidylethanolamine N-methyltransferase (PEMT) pathway, which generates phosphatidylcholine (PC) molecules enriched in DHA that are exported from the liver and made available to extrahepatic tissues.

OBJECTIVES

This study investigated the effect of prenatal choline supplementation on biomarkers of DHA status among pregnant participants consuming supplemental DHA.

METHODS

Pregnant participants (n = 30) were randomly assigned to receive supplemental choline intakes of 550 mg/d [500 mg/d d0-choline + 50 mg/d deuterium-labeled choline (d9-choline); intervention] or 25 mg/d (25 mg/d d9-choline; control) from gestational week (GW) 12-16 until delivery. All participants received a daily 200-mg DHA supplement and consumed self-selected diets. Fasting blood samples were obtained at baseline, GW 20-24, and GW 28-32; maternal/cord blood was obtained at delivery. Mixed-effects linear models were used to assess the impact of prenatal choline supplementation on maternal and newborn DHA status.

RESULTS

Choline supplementation (550 vs. 25 mg/d) did not achieve a statistically significant intervention × time interaction for RBC PC-DHA (P = 0.11); a significant interaction was observed for plasma PC-DHA and RBC total DHA, with choline supplementation yielding higher levels (+32-38% and +8-11%, respectively) at GW 28-32 (P < 0.05) and delivery (P < 0.005). A main effect of choline supplementation on plasma total DHA was also observed (P = 0.018); its interaction with time was not significant (P = 0.068). Compared with controls, the intervention group exhibited higher (P = 0.007; main effect) plasma enrichment of d3-PC (d3-PC/total PC). Moreover, the ratio of d3-PC to d9-PC was higher (+50-67%; P < 0.001) in the choline intervention arm (vs. control) at GW 20-24, GW 28-32, and delivery.

CONCLUSIONS

Prenatal choline supplementation improves hepatic DHA export and biomarkers of DHA status by bolstering methyl group supply for PEMT activity among pregnant participants consuming supplemental DHA. This trial is registered at www.clinicaltrials.gov as NCT03194659.

Genetic variants in choline metabolism pathway are associated with the risk of bladder cancer in the Chinese population

Choline metabolism alteration is considered as a metabolic hallmark in cancer, reflecting the complex interactions between carcinogenic signaling pathways and cancer metabolism, but little is known about whether genetic variants in the metabolism pathway contribute to the susceptibility of bladder cancer. Herein, a case-control study comprising 580 patients and 1,101 controls was carried out to analyze the association of bladder cancer with genetic variants on candidate genes involved in the choline metabolism pathway using unconditional logistic regression. Gene expression data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database were applied for differential gene expression analysis. Cox regression was also applied to estimate the role of candidate genes on bladder cancer prognosis. Our results demonstrated that C allele of rs6810830 in ENPP6 was a significant protective allele of bladder cancer, compared to the T allele [Odds ratio (OR) = 0.74, 95% confidence interval (CI) = 0.64-0.86, P = 7.14 × 10^-5 in additive model]. Besides, we also found that the expression of ENPP6 remarkably decreased in bladder tumors compared with normal tissues. Moreover, high expression of ENPP6 was associated with worse overall survival (OS) in bladder cancer patients [hazard ratio (HR) with their 95% CI 1.39 (1.02-1.90), P = 0.039]. In conclusion, our results suggested that SNP rs6810830 (T > C) in ENPP6 might be a potential susceptibility loci for bladder cancer, and these findings provided novel insights into the underlying mechanism of choline metabolism in cancers.

Utilizing Genomically Targeted Molecular Data to Improve Patient-Specific Outcomes in Autism Spectrum Disorder

Molecular biology combined with genomics can be a powerful tool for developing potential intervention strategies for improving outcomes in children with autism spectrum disorders (ASD). Monogenic etiologies rarely cause autism. Instead, ASD is more frequently due to many polygenic contributing factors interacting with each other, combined with the epigenetic effects of diet, lifestyle, and environment. One limitation of genomics has been identifying ways of responding to each identified gene variant to translate the information to something clinically useful. This paper will illustrate how understanding the function of a gene and the effects of a reported variant on a molecular level can be used to develop actionable and targeted potential interventions for a gene variant or combinations of variants. For illustrative purposes, this communication highlights a specific genomic variant, SHANK3. The steps involved in developing molecularly genomically targeted actionable interventions will be demonstrated. Cases will be shared to support the efficacy of this strategy and to show how clinicians utilized these targeted interventions to improve ASD-related symptoms significantly. The presented approach demonstrates the utility of genomics as a part of clinical decision-making.

Plasma Choline Concentration Was Not Increased After a 6-Month Egg Intervention in 6-9-Month-Old Malawian Children: Results from a Randomized Controlled Trial

BACKGROUND

Eggs are a rich source of choline, an essential nutrient important for child growth and development. In a randomized trial of 1 egg/d in young children in Ecuador, an egg intervention led to significant improvements in growth, which were partially mediated by increased plasma choline concentration. A similar trial in Malawi (clinicaltrials.gov: NCT03385252) found little improvement in child growth or development.

OBJECTIVES

We aimed to evaluate the effect of 1 egg/d for 6 mo on plasma choline concentrations in Malawian children enrolled in a randomized trial.

METHODS

Infants aged 6-9 mo in rural Malawi were randomly assigned to receive 1 egg/d (n = 331) or serve as a nonintervention control (n = 329) for 6 mo. Anthropometric, developmental, and dietary data were collected at baseline and 6-mo follow-up, along with a blood draw. Plasma choline, betaine, dimethylglycine, trimethylamine N-oxide (TMAO), and DHA were measured at both time points using ultrahigh performance liquid chromatography-tandem MS (n = 200 per group). Linear regression analysis was used to determine the difference in plasma choline and related metabolites between groups after 6 mo of intervention.

RESULTS

Plasma choline, betaine, dimethylglycine, and DHA concentrations did not differ between groups at 6-mo follow-up. Plasma TMAO was significantly (26%; 95% CI: 7%, 48%) higher in the egg intervention group in a fully adjusted model.

CONCLUSIONS

Provision of 1 egg/d for 6 mo did not result in increases in plasma choline or related metabolites, except TMAO. This could partially explain the lack of effect on growth and development. Additional interventions are needed to improve choline status, growth, and development in this population.

Endosomal-lysosomal dysfunctions in Alzheimer's disease: Pathogenesis and therapeutic interventions

The endosomal-lysosomal system mediates the process of protein degradation through endocytic pathway. This system consists of early endosomes, late endosomes, recycling endosomes and lysosomes. Each component in the endosomal-lysosomal system plays individual crucial role and they work concordantly to ensure protein degradation can be carried out functionally. Dysregulation in the endosomal-lysosomal system can contribute to the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD). In AD endosomal-lysosomal abnormalities are the earliest pathological features to note and hence it is important to understand the involvement of endosomal-lysosomal dysfunction in the pathogenesis of AD. In-depth understanding of this dysfunction can allow development of new therapeutic intervention to prevent and treat AD.

Polymorphisms in GNMT and DNMT3b are associated with methotrexate treatment outcome in plaque psoriasis

Methotrexate is used as first-line treatment of moderate to severe psoriasis. Despite the marked variability in treatment outcomes, no pharmacogenetic markers are currently used for personalised management of therapy. In this retrospective study, we investigated the effects of genetic predisposition on efficacy and toxicity of low-dose methotrexate in a cohort of 137 patients with moderate to severe plaque psoriasis. We genotyped 16 polymorphisms in genes for enzymes involved in the folate-methionine pathway and in methotrexate transport, and analysed their association with treatment efficacy and toxicity using classification and regression tree analysis and logistic regression. The most pronounced effect observed in this study was for GNMT rs10948059, which was identified as a risk factor for inadequate efficacy leading to treatment discontinuation. Patients carrying at least one variant allele had ~7-fold increased risk of treatment failure compared to patients with the wild-type genotype, as shown by the classification and regression tree analysis and logistic regression (odds ratio [OR], 6.94; p = 0.0004). Another risk factor associated with insufficient treatment responses was DNMT3b rs2424913, where patients carrying at least one variant allele had a 4-fold increased risk of treatment failure compared to patients with the wild-type genotype (OR, 4.10; p = 0.005). Using classification and regression tree analysis, we show that DNMT3b rs2424913 has a more pronounced role in patients with the variant GNMT genotype, and hence we suggest an interaction between these two genes. Further, we show that patients with the BHMT rs3733890 variant allele had increased risk of hepatotoxicity (OR, 3.17; p = 0.022), which is the most prominent reason for methotrexate discontinuation. We also show that variants in the genes for methotrexate transporters OATP1B1 (rs2306283/rs4149056 SLCO1B1 haplotypes) and ABCC2 (rs717620) are associated with increased risk of treatment failure. The associations identified have not been reported previously. These data suggest that polymorphisms in genes for enzymes of the methionine cycle (which affect cell methylation potential) might have significant roles in treatment responses to methotrexate of patients with psoriasis. Further studies are warranted to validate the potential of the pharmacogenetic markers identified.

Polymorphisms in SLC44A1 are associated with cognitive improvement in children diagnosed with fetal alcohol spectrum disorder: an exploratory study of oral choline supplementation

BACKGROUND

The essential nutrient choline provides one-carbon units for metabolite synthesis and epigenetic regulation in tissues including brain. Dietary choline intake is often inadequate, and higher intakes are associated with improved cognitive function.

OBJECTIVE

Choline supplements confer cognitive improvement for those diagnosed with fetal alcohol spectrum disorder (FASD), a common set of neurodevelopmental impairments; however, the effect sizes have been modest. In this retrospective analysis, we report that genetic polymorphisms affecting choline utilization are associated with cognitive improvement following choline intervention.

METHODS

Fifty-two children from the upper midwestern United States and diagnosed with FASD, ages 2-5 y, were randomly assigned to receive choline (500 mg/d; n = 26) or placebo (n = 26) for 9 mo, and were genotyped for 384 choline-related single nucleotide polymorphisms (SNPs). Memory and cognition were assessed at enrollment, study terminus, and at 4-y follow-up for a subset.

RESULTS

When stratified by intervention (choline vs. placebo), 14-16 SNPs within the cellular choline transporter gene solute carrier family 44 member 1 (SLC44A1) were significantly associated with performance in an elicited imitation sequential memory task, wherein the effect alleles were associated with the greatest pre-/postintervention improvement. Of these, rs3199966 is a structural variant (S644A) and rs2771040 is a single-nucleotide variant within the 3' untranslated region of the plasma membrane isoform. An additive genetic model best explained the genotype associations. Lesser associations were observed for cognitive outcome and polymorphisms in flavin monooxygenase-3 (FMO3), methylenetetrahydrofolate dehydrogenase-1 (MTHFD1), fatty acid desaturase-2 (FADS2), and adiponectin receptor 1 (ADIPOR1).

CONCLUSIONS

These SLC44A1 variants were previously associated with greater vulnerability to choline deficiency. Our data potentially support the use of choline supplements to improve cognitive function in individuals diagnosed with FASD who carry these effect alleles. Although these findings require replication in both retrospective and prospective confirmatory trials, they emphasize the need to incorporate similar genetic analyses of choline-related polymorphisms in other FASD-choline trials, and to test for similar associations within the general FASD population. This trial was registered at www.clinicaltrials.gov as NCT01149538.

Nutrition, genetic variation and male fertility

Infertility affects nearly 50 million couples worldwide, with 40-50% of cases having a male factor component. It is well established that nutritional status impacts reproductive development, health and function, although the exact mechanisms have not been fully elucidated. Genetic variation that affects nutrient metabolism may impact fertility through nutrigenetic mechanisms. This review summarizes current knowledge on the role of several dietary components (vitamins A, B₁₂, C, D, E, folate, betaine, choline, calcium, iron, caffeine, fiber, sugar, dietary fat, and gluten) in male reproductive health. Evidence of gene-nutrient interactions and their potential effect on fertility is also examined. Understanding the relationship between genetic variation, nutrition and male fertility is key to developing personalized, DNA-based dietary recommendations to enhance the fertility of men who have difficulty conceiving.

Dietary Choline Intake during Pregnancy and PEMT rs7946 Polymorphism on Risk of Preterm Birth: A Case-Control Study

INTRODUCTION AND AIMS

Choline-metabolizing genetic variation may interact with choline intake on fetal programming and pregnancy outcome. This case-control study aims to explore the association of maternal choline consumption and phosphatidylethanolamine N-methyltransferase (PEMT) gene polymorphism rs7946 with preterm birth risk.

METHODS

145 Han Chinese women with preterm delivery and 157 Han Chinese women with term delivery were recruited in Shanghai. Dietary choline intake during pregnancy was assessed using a validated food frequency questionnaire. Additionally, DNA samples were genotyped for PEMT rs7946 (G5465A) with plasma homocysteine (Hcy) levels measured.

RESULTS

Compared with the lowest quartile of choline intake, women within the highest consumption quartile had adjusted odds ratio (aOR) for preterm birth of 0.48 (95% confidence interval, CI [0.24, 0.95]). There was a significant interaction between maternal choline intake and PEMT rs7946 (p for interaction = 0.04), where the AA genotype carriers who consumed the energy-adjusted choline <255.01 mg/day had aOR for preterm birth of 3.75 (95% CI [1.24, 11.35]), compared to those with GG genotype and choline intake >255.01 mg/day during pregnancy. Additionally, the greatest elevated plasma Hcy was found in the cases with AA genotype and choline consumption <255.01 mg/day (p < 0.001).

CONCLUSION

The AA genotype of PEMT rs7946 may be associated with increased preterm birth in these Han Chinese women with low choline intake during pregnancy.

Associations between Plasma Choline Metabolites and Genetic Polymorphisms in One-Carbon Metabolism in Postmenopausal Women: The Women's Health Initiative Observational Study

BACKGROUND

Choline plays an integral role in one-carbon metabolism in the body, but it is unclear whether genetic polymorphisms are associated with variations in plasma choline and its metabolites.

OBJECTIVES

This study aimed to evaluate the association of genetic variants in choline and one-carbon metabolism with plasma choline and its metabolites.

METHODS

We analyzed data from 1423 postmenopausal women in a case-control study nested within the Women's Health Initiative Observational Study. Plasma concentrations of choline, betaine, dimethylglycine (DMG), and trimethylamine N-oxide were determined in 12-h fasting blood samples collected at baseline (1993-1998). Candidate and tagging single-nucleotide polymorphisms (SNPs) were genotyped in betaine-homocysteine S-methyltransferase (BHMT), BHMT2, 5,10-methylenetetrahydrofolate reductase (MTHFR), methylenetetrahydrofolate dehydrogenase (NADP+ dependent 1) (MTHFD1), 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR), and 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR). Linear regression was used to derive percentage difference in plasma concentrations per variant allele, adjusting for confounders, including B-vitamin biomarkers. Potential effect modification by plasma vitamin B-12, vitamin B-6, and folate concentrations and folic-acid fortification periods was examined.

RESULTS

The candidate SNP BHMT R239Q (rs3733890) was associated with lower concentrations of plasma betaine and DMG concentrations (-4.00% and -6.75% per variant allele, respectively; both nominal P < 0.05). Another candidate SNP, BHMT2 rs626105 A>G, was associated with higher plasma DMG concentration (13.0%; P < 0.0001). Several tagSNPs in these 2 genes were associated with plasma concentrations after correction for multiple comparisons. Vitamin B-12 status was a significant effect modifier of the association between the genetic variant BHMT2 rs626105 A>G and plasma DMG concentration.

CONCLUSIONS

Genetic variations in metabolic enzymes were associated with plasma concentrations of choline and its metabolites. Our findings contribute to the knowledge on the variation in blood nutrient concentrations in postmenopausal women.

Choline in cystic fibrosis: relations to pancreas insufficiency, enterohepatic cycle, PEMT and intestinal microbiota

BACKGROUND

Cystic Fibrosis (CF) is an autosomal recessive disorder with life-threatening organ manifestations. 87% of CF patients develop exocrine pancreas insufficiency, frequently starting in utero and requiring lifelong pancreatic enzyme substitution. 99% develop progressive lung disease, and 20-60% CF-related liver disease, from mild steatosis to cirrhosis. Characteristically, pancreas, liver and lung are linked by choline metabolism, a critical nutrient in CF. Choline is a tightly regulated tissue component in the form of phosphatidylcholine (Ptd'Cho) and sphingomyelin (SPH) in all membranes and many secretions, particularly of liver (bile, lipoproteins) and lung (surfactant, lipoproteins). Via its downstream metabolites, betaine, dimethylglycine and sarcosine, choline is the major one-carbon donor for methionine regeneration from homocysteine. Methionine is primarily used for essential methylation processes via S-adenosyl-methionine.

CLINICAL IMPACT

CF patients with exocrine pancreas insufficiency frequently develop choline deficiency, due to loss of bile Ptd'Cho via feces. ~ 50% (11-12 g) of hepatic Ptd'Cho is daily secreted into the duodenum. Its re-uptake requires cleavage to lyso-Ptd'Cho by pancreatic and small intestinal phospholipases requiring alkaline environment. Impaired CFTR-dependent bicarbonate secretion, however, results in low duodenal pH, impaired phospholipase activity, fecal Ptd'Cho loss and choline deficiency. Low plasma choline causes decreased availability for parenchymal Ptd'Cho metabolism, impacting on organ functions. Choline deficiency results in hepatic choline/Ptd'Cho accretion from lung tissue via high density lipoproteins, explaining the link between choline deficiency and lung function. Hepatic Ptd'Cho synthesis from phosphatidylethanolamine by phosphatidylethanolamine-N-methyltransferase (PEMT) partly compensates for choline deficiency, but frequent single nucleotide polymorphisms enhance choline requirement. Additionally, small intestinal bacterial overgrowth (SIBO) frequently causes intraluminal choline degradation in CF patients prior to its absorption. As adequate choline supplementation was clinically effective and adult as well as pediatric CF patients suffer from choline deficiency, choline supplementation in CF patients of all ages should be evaluated.

Choline, Neurological Development and Brain Function: A Systematic Review Focusing on the First 1000 Days

The foundations of neurodevelopment across an individual's lifespan are established in the first 1000 days of life (2 years). During this period an adequate supply of nutrients are essential for proper neurodevelopment and lifelong brain function. Of these, evidence for choline has been building but has not been widely collated using systematic approaches. Therefore, a systematic review was performed to identify the animal and human studies looking at inter-relationships between choline, neurological development, and brain function during the first 1000 days of life. The database PubMed was used, and reference lists were searched. In total, 813 publications were subject to the title/abstract review, and 38 animal and 16 human studies were included after evaluation. Findings suggest that supplementing the maternal or child's diet with choline over the first 1000 days of life could subsequently: (1) support normal brain development (animal and human evidence), (2) protect against neural and metabolic insults, particularly when the fetus is exposed to alcohol (animal and human evidence), and (3) improve neural and cognitive functioning (animal evidence). Overall, most offspring would benefit from increased choline supply during the first 1000 days of life, particularly in relation to helping facilitate normal brain development. Health policies and guidelines should consider re-evaluation to help communicate and impart potential choline benefits through diet and/or supplementation approaches across this critical life stage.

Associations of choline-related nutrients with cardiometabolic and all-cause mortality: results from 3 prospective cohort studies of blacks, whites, and Chinese

BACKGROUND

Choline-related nutrients are dietary precursors of a gut microbial metabolite, trimethylamine-N-oxide, which has been linked to cardiometabolic diseases and related death. However, epidemiologic evidence on dietary choline and mortality remains limited, particularly among nonwhite populations.

OBJECTIVES

This study aimed to investigate the associations of choline-related nutrients with cardiometabolic and all-cause mortality among black and white Americans and Chinese adults.

METHODS

Included were 49,858 blacks, 23,766 whites, and 134,001 Chinese, aged 40-79 y, who participated in 3 prospective cohorts and lived ≥1 y after enrollment. Cox regression models were used to estimate HRs and 95% CIs for cardiometabolic [e.g., ischemic heart disease (IHD), stroke, and diabetes] and all-cause deaths. To account for multiple testing, P values < 0.003 were considered significant.

RESULTS

Mean choline intake among blacks, whites, and Chinese was 404.1 mg/d, 362.0 mg/d, and 296.8 mg/d, respectively. During a median follow-up of 11.7 y, 28,673 deaths were identified, including 11,141 cardiometabolic deaths. After comprehensive adjustments, including for overall diet quality and disease history, total choline intake was associated with increased cardiometabolic mortality among blacks and Chinese (HR for highest compared with lowest quintile: 1.26; 95% CI: 1.13, 1.40 and HR: 1.23; 95% CI: 1.11, 1.38, respectively; both P-trend < 0.001); among whites, the association was weaker (HR: 1.12; 95% CI: 0.95, 1.33; P-trend = 0.02). Total choline intake was also associated with diabetes and all-cause mortality in blacks (HR: 1.66; 95% CI: 1.26, 2.19 and HR: 1.20; 95% CI: 1.12, 1.29, respectively), with diabetes mortality in Chinese (HR: 2.24; 95% CI: 1.68, 2.97), and with IHD mortality in whites (HR: 1.31; 95% CI: 1.02, 1.69) (all P-trend < 0.001). The choline-mortality association was modified by alcohol consumption and appeared stronger among individuals with existing cardiometabolic disease. Betaine intake was associated with increased cardiometabolic mortality in Chinese only (HR: 1.16; 95% CI: 1.08, 1.25; P-trend < 0.001).

CONCLUSIONS

High choline intake was associated with increased cardiometabolic mortality in racially diverse populations.

Dysregulation of multiple metabolic networks related to brain transmethylation and polyamine pathways in Alzheimer disease: A targeted metabolomic and transcriptomic study

BACKGROUND

There is growing evidence that Alzheimer disease (AD) is a pervasive metabolic disorder with dysregulation in multiple biochemical pathways underlying its pathogenesis. Understanding how perturbations in metabolism are related to AD is critical to identifying novel targets for disease-modifying therapies. In this study, we test whether AD pathogenesis is associated with dysregulation in brain transmethylation and polyamine pathways.

METHODS AND FINDINGS

We first performed targeted and quantitative metabolomics assays using capillary electrophoresis-mass spectrometry (CE-MS) on brain samples from three groups in the Baltimore Longitudinal Study of Aging (BLSA) (AD: n = 17; Asymptomatic AD [ASY]: n = 13; Control [CN]: n = 13) (overall 37.2% female; mean age at death 86.118 ± 9.842 years) in regions both vulnerable and resistant to AD pathology. Using linear mixed-effects models within two primary brain regions (inferior temporal gyrus [ITG] and middle frontal gyrus [MFG]), we tested associations between brain tissue concentrations of 26 metabolites and the following primary outcomes: group differences, Consortium to Establish a Registry for Alzheimer's Disease (CERAD) (neuritic plaque burden), and Braak (neurofibrillary pathology) scores. We found significant alterations in concentrations of metabolites in AD relative to CN samples, as well as associations with severity of both CERAD and Braak, mainly in the ITG. These metabolites represented biochemical reactions in the (1) methionine cycle (choline: lower in AD, p = 0.003; S-adenosyl methionine: higher in AD, p = 0.005); (2) transsulfuration and glutathione synthesis (cysteine: higher in AD, p < 0.001; reduced glutathione [GSH]: higher in AD, p < 0.001); (3) polyamine synthesis/catabolism (spermidine: higher in AD, p = 0.004); (4) urea cycle (N-acetyl glutamate: lower in AD, p < 0.001); (5) glutamate-aspartate metabolism (N-acetyl aspartate: lower in AD, p = 0.002); and (6) neurotransmitter metabolism (gamma-amino-butyric acid: lower in AD, p < 0.001). Utilizing three Gene Expression Omnibus (GEO) datasets, we then examined mRNA expression levels of 71 genes encoding enzymes regulating key reactions within these pathways in the entorhinal cortex (ERC; AD: n = 25; CN: n = 52) and hippocampus (AD: n = 29; CN: n = 56). Complementing our metabolomics results, our transcriptomics analyses also revealed significant alterations in gene expression levels of key enzymatic regulators of biochemical reactions linked to transmethylation and polyamine metabolism. Our study has limitations: our metabolomics assays measured only a small proportion of all metabolites participating in the pathways we examined. Our study is also cross-sectional, limiting our ability to directly test how AD progression may impact changes in metabolite concentrations or differential-gene expression. Additionally, the relatively small number of brain tissue samples may have limited our power to detect alterations in all pathway-specific metabolites and their genetic regulators.

CONCLUSIONS

In this study, we observed broad dysregulation of transmethylation and polyamine synthesis/catabolism, including abnormalities in neurotransmitter signaling, urea cycle, aspartate-glutamate metabolism, and glutathione synthesis. Our results implicate alterations in cellular methylation potential and increased flux in the transmethylation pathways, increased demand on antioxidant defense mechanisms, perturbations in intermediate metabolism in the urea cycle and aspartate-glutamate pathways disrupting mitochondrial bioenergetics, increased polyamine biosynthesis and breakdown, as well as abnormalities in neurotransmitter metabolism that are related to AD.

Choline: Exploring the Growing Science on Its Benefits for Moms and Babies

The importance of ensuring adequate choline intakes during pregnancy is increasingly recognized. Choline is critical for a number of physiological processes during the prenatal period with roles in membrane biosynthesis and tissue expansion, neurotransmission and brain development, and methyl group donation and gene expression. Studies in animals and humans have shown that supplementing the maternal diet with additional choline improves several pregnancy outcomes and protects against certain neural and metabolic insults. Most pregnant women in the U.S. are not achieving choline intake recommendations of 450 mg/day and would likely benefit from boosting their choline intakes through dietary and/or supplemental approaches.

Maternal choline supplementation alters vitamin B-12 status in human and murine pregnancy

Despite participation in overlapping metabolic pathways, the relationship between choline and vitamin B-12 has not been well characterized especially during pregnancy. We sought to determine the effects of maternal choline supplementation on vitamin B-12 status biomarkers in human and mouse pregnancy, hypothesizing that increased choline intake would improve vitamin B-12 status. Associations between common genetic variants in choline-metabolizing genes and vitamin B-12 status biomarkers were also explored in humans. Healthy third-trimester pregnant women (n=26) consumed either 480 or 930 mg choline/day as part of a 12-week controlled feeding study. Wild-type NSA and Dlx3 heterozygous (Dlx3+/-) mice, which display placental insufficiency, consumed a 1×, 2× or 4× choline diet and were sacrificed at gestational days 15.5 and 18.5. Serum vitamin B-12, methylmalonic acid (MMA) and homocysteine were measured in all samples; holotranscobalamin (in humans) and hepatic vitamin B-12 (in mice) were also measured. The 2× choline supplementation for 12 weeks in pregnant women yielded higher serum concentrations of holotranscobalamin, the bioactive form of vitamin B-12 (~24%, P=.01). Women with genetic variants in choline dehydrogenase (CHDH) and betaine-homocysteine S-methyltransferase (BHMT) had higher serum MMA concentrations (~31%, P=.03) and lower serum holotranscobalamin concentrations (~34%, P=.03), respectively. The 4× choline dose decreased serum homocysteine concentrations in both NSA and Dlx3+/- mice (~36% and~43% respectively, P≤.015). In conclusion, differences in choline supply due to supplementation or genetic variation modulate vitamin B-12 status during pregnancy, supporting a functional relationship between these nutrients.

Long-term effects of maternal choline supplementation on CA1 pyramidal neuron gene expression in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease

Choline is critical for normative function of 3 major pathways in the brain, including acetylcholine biosynthesis, being a key mediator of epigenetic regulation, and serving as the primary substrate for the phosphatidylethanolamine N-methyltransferase pathway. Sufficient intake of dietary choline is critical for proper brain function and neurodevelopment. This is especially important for brain development during the perinatal period. Current dietary recommendations for choline intake were undertaken without critical evaluation of maternal choline levels. As such, recommended levels may be insufficient for both mother and fetus. Herein, we examined the impact of perinatal maternal choline supplementation (MCS) in a mouse model of Down syndrome and Alzheimer's disease, the Ts65Dn mouse relative to normal disomic littermates, to examine the effects on gene expression within adult offspring at ∼6 and 11 mo of age. We found MCS produces significant changes in offspring gene expression levels that supersede age-related and genotypic gene expression changes. Alterations due to MCS impact every gene ontology category queried, including GABAergic neurotransmission, the endosomal-lysosomal pathway and autophagy, and neurotrophins, highlighting the importance of proper choline intake during the perinatal period, especially when the fetus is known to have a neurodevelopmental disorder such as trisomy.-Alldred, M. J., Chao, H. M., Lee, S. H., Beilin, J., Powers, B. E., Petkova, E., Strupp, B. J., Ginsberg, S. D. Long-term effects of maternal choline supplementation on CA1 pyramidal neuron gene expression in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.

Choline and DHA in Maternal and Infant Nutrition: Synergistic Implications in Brain and Eye Health

The aim of this review is to highlight current insights into the roles of choline and docosahexaenoic acid (DHA) in maternal and infant nutrition, with special emphasis on dietary recommendations, gaps in dietary intake, and synergistic implications of both nutrients in infant brain and eye development. Adequate choline and DHA intakes are not being met by the vast majority of US adults, and even more so by women of child-bearing age. Choline and DHA play a significant role in infant brain and eye development, with inadequate intakes leading to visual and neurocognitive deficits. Emerging findings illustrate synergistic interactions between choline and DHA, indicating that insufficient intakes of one or both could have lifelong deleterious impacts on both maternal and infant health.

Prenatal Nutritional Intervention Reduces Autistic-Like Behavior Rates Among Mthfr-Deficient Mice

The causes and contributing factors of autism spectrum disorders (ASD) are poorly understood. One gene associated with increased risk for ASD is methylenetetrahydrofolate-reductase (MTHFR), which encodes a key enzyme in one carbon (C1) metabolism. The MTHFR 677C > T polymorphism reduces the efficiency of methyl group production with possible adverse downstream effects on gene expression. In this study, the effects of prenatal and/or postnatal diets enriched in C1 nutrients on ASD-like behavior were evaluated in Mthfr-deficient mice. Differences in intermediate pathways between the mice with and without ASD-like behaviors were tested. The findings indicate that maternal and offspring Mthfr deficiency increased the risk for an ASD-like phenotype in the offspring. The risk of ASD-like behavior was reduced in Mthfr-deficient mice supplemented with C1 nutrients prenatally. Specifically, among offspring of Mthfr+/- dams, prenatal diet supplementation was protective against ASD-like symptomatic behavior compared to the control diet with an odds ratio of 0.18 (CI:0.035, 0.970). Changes in major C1 metabolites, such as the ratios between betaine/choline and SAM/SAH in the cerebral-cortex, were associated with ASD-like behavior. Symptomatic mice presenting ASD-like behavior showed decreased levels of GABA pathway proteins such as GAD65/67 and VGAT and altered ratios of the glutamate receptor subunits GluR1/GluR2 in males and NR2A/NR2B in females. The altered ratios, in turn, favor receptor subunits with higher sensitivity to neuronal activity. Our study suggests that MTHFR deficiency can increase the risk of ASD-like behavior in mice and that prenatal dietary intervention focused on MTHFR genotypes can reduce the risk of ASD-like behavior.

Choline transport for phospholipid synthesis: An emerging role of choline transporter-like protein 1

IMPACT STATEMENT

This review will provide a summary of recent advances in choline transport research and highlight important novel areas of focus in the field.

Choline and choline-related nutrients in regular and preterm infant growth

BACKGROUND

Choline is an essential nutrient, with increased requirements during development. It forms the headgroup of phosphatidylcholine and sphingomyelin in all membranes and many secretions. Phosphatidylcholine is linked to cell signaling as a phosphocholine donor to synthesize sphingomyelin from ceramide, a trigger of apoptosis, and is the major carrier of arachidonic and docosahexaenoic acid in plasma. Acetylcholine is important for neurodevelopment and the placental storage form for fetal choline supply. Betaine, a choline metabolite, functions as osmolyte and methyl donor. Their concentrations are all tightly regulated in tissues.

CLINCAL IMPACT

During the fetal growth spurt at 24-34-week postmenstrual age, plasma choline is higher than beyond 34 weeks, and threefold higher than in pregnant women [45 (36-60) µmol/L vs. 14 (10-17) µmol/L]. The rapid decrease in plasma choline after premature birth suggests an untimely reduction in choline supply, as cellular uptake is proportional to plasma concentration. Supply via breast milk, with phosphocholine and α-glycerophosphocholine as its major choline components, does not prevent such postnatal decrease. Moreover, high amounts of liver PC are secreted via bile, causing rapid hepatic choline turnover via the enterohepatic cycle, and deficiency in case of pancreatic phospholipase A2 deficiency or intestinal resection. Choline deficiency causes hepatic damage and choline accretion at the expense of the lungs and other tissues.

CONCLUSION

Choline deficiency may contribute to the impaired lean body mass growth and pulmonary and neurocognitive development of preterm infants despite adequate macronutrient supply and weight gain. In this context, a reconsideration of current recommendations for choline supply to preterm infants is required.

Betaine and Choline Improve Lipid Homeostasis in Obesity by Participation in Mitochondrial Oxidative Demethylation

We investigated the metabolic effects of betaine (Bet) supplementation on CTP:phosphoethanolamine cytidylyltransferase/Pcyt2 heterozygous mice (HET). HET received either no treatment or were allowed access to 1% Bet supplemented water for 8 weeks. As we previously showed with choline (Cho), Bet improved hypertriglyceridemia, and hepatic steatosis in HET. The protection from obesity associated with reduced hepatic steatosis and increased lipid breakdown in adipocytes was attributed to increased energy requirements for metabolism and elimination of supplemented Bet and Cho. ¹H-NMR-based profiling revealed metabolic changes caused by Bet and Cho supplementation. Cho increased the citric acid cycle intermediate succinic acid while reducing isoleucine, valine, threonine, and lysine. Bet increased α-ketoglutaric acid and did not stimulate catabolism of amino acids. Increased histidine and alanine are specific biomarkers for Bet treatment. Cho and Bet caused glycerol accumulation and reduced sarcosine, taurine, acetate, and β-hydroxybutyrate levels. These data provide new insights on how Cho and Bet supplementation can aid in treatment of obesity related disorders due to their positive effects on lipolysis, the citric acid cycle, and mitochondrial oxidative demethylation.

Common Genetic Variants Alter Metabolism and Influence Dietary Choline Requirements

Nutrient needs, including those of the essential nutrient choline, are a population wide distribution. Adequate Intake (AI) recommendations for dietary choline (put forth by the National Academies of Medicine to aid individuals and groups in dietary assessment and planning) are grouped to account for the recognized unique needs associated with age, biological sex, and reproductive status (i.e., pregnancy or lactation). Established and emerging evidence supports the notion that common genetic variants are additional factors that substantially influence nutrient requirements. This review summarizes the genetic factors that influence choline requirements and metabolism in conditions of nutrient deprivation, as well as conditions of nutrient adequacy, across biological sexes and reproductive states. Overall, consistent and strong associative evidence demonstrates that common genetic variants in choline and folate pathway enzymes impact the metabolic handling of choline and the risk of nutrient inadequacy across varied dietary contexts. The studies characterized in this review also highlight the substantial promise of incorporating common genetic variants into choline intake recommendations to more precisely target the unique nutrient needs of these subgroups within the broader population. Additional studies are warranted to facilitate the translation of this evidence to nutrigenetics-based dietary approaches.