Down-regulation of placental folate transporters in intrauterine growth restriction

Diet-induced hyperhomocysteinemia causes sex-dependent deficiencies in offspring musculature and brain function

Hyperhomocysteinemia (HHcy), characterized by elevated homocysteine (Hcy) levels, is a known risk factor for cardiovascular, renal, and neurological diseases, as well as pregnancy complications. Our study aimed to investigate whether HHcy induced by a high-methionine (high-Met) diet exacerbates cognitive and behavioral deficits in offspring and leads to other breeding problems. Dietary HHcy was induced four weeks before mating and continued throughout gestation and post-delivery. A battery of behavioral tests was conducted on offspring between postnatal days (PNDs) 5 and 30 to assess motor function/activity and cognition. The results were correlated with brain morphometric measurements and quantitative analysis of mammalian target of rapamycin (mTOR)/autophagy markers. The high-Met diet significantly increased parental and offspring urinary tHcy levels and influenced offspring behavior in a sex-dependent manner. Female offspring exhibited impaired cognition, potentially related to morphometric changes observed exclusively in HHcy females. Male HHcy pups demonstrated muscle weakness, evidenced by slower surface righting, reduced hind limb suspension (HLS) hanging time, weaker grip strength, and decreased activity in the beaker test. Western blot analyses indicated the downregulation of autophagy and the upregulation of mTOR activity in HHcy cortexes. HHcy also led to breeding impairments, including reduced breeding rate, in-utero fetal death, lower pups' body weight, and increased mortality, likely attributed to placental dysfunction associated with HHcy. In conclusion, a high-Met diet impairs memory and cognition in female juveniles and weakens muscle strength in male pups. These effects may stem from abnormal placental function affecting early neurogenesis, the dysregulation of autophagy-related pathways in the cortex, or epigenetic mechanisms of gene regulation triggered by HHcy during embryonic development.

Altered placental immune cell composition and gene expression with isolated fetal spina bifida

PROBLEM

Fetal spina bifida (SB) is more common in pregnant people with folate deficiency or anomalies of folate metabolism. It is also known that fetuses with SB have a higher risk of low birthweight, a condition that is typically placental-mediated. We therefore hypothesized that fetal SB would associate with altered expression of key placental folate transporters and an increase in Hofbauer cells (HBCs), which are folate-dependent placental macrophages.

METHOD OF STUDY

Folate receptor-α (FRα), proton coupled folate receptor (PCFT), and reduced folate carrier (RFC) protein localization and expression (immunohistochemistry) and HBC phenotypes (HBC abundance and folate receptor-β [FRβ] expression; RNA in situ hybridization) were assessed in placentae from fetuses with SB (cases; n = 12) and in term (n = 10) and gestational age (GA) - and maternal body mass index - matched (n = 12) controls without congenital anomalies.

RESULTS

Cases had a higher proportion of placental villous cells that were HBCs (6.9% vs. 2.4%, p = .0001) and higher average HBC FRβ expression (3.2 mRNA molecules per HBC vs. 2.3, p = .03) than GA-matched controls. HBCs in cases were largely polarized to a regulatory phenotype (median 92.1% of HBCs). In sex-stratified analyses, only male cases had higher HBC levels and HBC FRβ expression than GA-matched controls. There were no differences between groups in the total percent of syncytium and stromal cells that were positive for FRα, PCFT, or RFC protein immunolabeling.

CONCLUSIONS

HBC abundance and FRβ expression by HBCs are increased in placentae of fetuses with SB, suggesting immune-mediated dysregulation in placental phenotype, and could contribute to SB-associated comorbidities.

The effect of possible mediators on the association between chewing khat during pregnancy and fetal growth and newborn size at birth in Eastern Ethiopia

INTRODUCTION

Restriction in the growth of the fetus is a leading cause of stillbirth, neonatal mortality, and short- and long-term morbidity. Documented existing scientific evidence have shown the effects of maternal drugs use, alcohol drinking, tobacco smoking, cocaine use and heroin use on fetal growth restriction. However, data is lacking on the effects of khat chewing during pregnancy on fetal growth status and newborn size at birth. Therefore, the aim of the present study was to measure the effect of chewing khat during pregnancy on fetal growth and size at birth in eastern Ethiopia.

METHOD

A cohort study was conducted in selected health institutions in eastern Ethiopia. All pregnant women fulfilled the eligibility criteria in the selected health institutions was the source population. The calculated sample size of exposed and unexposed groups included in the study, in total, was 344. Data collection was performed prospectively by interviewers administered questionnaires, and anthropometric, clinical and ultrasound measurements. Data was analyzed using SPSS version 27 and STATA version 16 software. The survival analysis (cox proportional hazards model) and generalized linear model (GLM) for the binomial family analysis were performed to estimate the crude and adjusted relative risk and attributable risk (AR) with corresponding 95% CI of chewing khat on fetal growth restriction. The mediation effect has been examined through Generalized Structural Equation Modeling (GSEM) analysis using the Stata 'gsem' command. Statistically significant association was declared at p-value less than 5%.

RESULTS

In the present study, the incidence of fetal growth restriction (FGR) among the study cohorts was 95 (29.7%); of this, 81 (85.3%) were among khat chewer cohorts. The relative risk of fetal growth restriction among khat chewer cohort mothers was significantly higher (aRR = 4.32; 95%CI 2.62-7.12). Moreover, the incidence of small for gestational age at birth among the present study cohorts was 100 (31.3%); 84 (84%) were from khat chewer cohorts' deliveries. More importantly, in the present study, 98.95% of the ultrasound-identified fetuses with FGR were found to be SGA at birth. Hence, in the current study, FGR was highly associated with SGA at birth. In additional analysis, the regression coefficient of khat chewing during pregnancy on fetal growth restriction has been decreased in size from path o, β = 0.43, p < 0.001 to path o', β = 0.32, p < 0.001, after adjusting for gestational hypertension and maternal anemia.

CONCLUSION

In sum, the present study showed khat chewing during pregnancy is not simply affected the mothers, but it also affected the unborn fetuses. Therefore, the health workers as well as the local community and religious leaders should give high emphasis on provision of health education regarding the damage of chewing khat by pregnant mothers, with especial focus of the effects on their fetuses.

Folate-depletion alters mouse trophoblast stem cell regulation in vitro

Maternal folate deficiency increases risk of congenital malformations, yet its effect on placenta development is unclear. Here, we investigated how folate-depleted culture medium affects the developmental potential of mouse trophoblast stem cells (TSCs). When cultured in stem cell conditions, TSC viability was unaffected by folate depletion, but ectopic differentiation of trophoblast cell subtypes occurred. When cultured in conditions that promote differentiation, folate-depleted TSCs were driven towards a syncytiotrophoblast cell fate potentially at the expense of other lineages. Additionally, trophoblast giant cell nuclei were small implicating folate in the regulation of endoreduplication. Therefore, dietary folate intake likely promotes trophoblast development.

Therapeutic strategies targeting folate receptor α for ovarian cancer

Epithelial ovarian cancer (EOC) is the deadliest gynecological cancer, and presents a major clinical challenge due to limited treatment options. Folate receptor alpha (FRα), encoded by the FOLR1 gene, is an attractive therapeutically target due to its prevalent and high expression in EOC cells. Recent basic and translational studies have explored several modalities, such as antibody-drug conjugate (ADC), monoclonal antibodies, small molecules, and folate-drug conjugate, to exploit FRα for EOC treatment. In this review, we summarize the function of FRα, and clinical efficacies of various FRα-based therapeutics. We highlight mirvetuximab soravtansine (MIRV), or Elahere (ImmunoGen), the first FRα-targeting ADC approved by the FDA to treat platinum-resistant ovarian cancer. We discuss potential mechanisms and management of ocular adverse events associated with MIRV administration.

Associations of solar activity and related exposures with fetal growth

BACKGROUND

Solar and geomagnetic activity have been shown to suppress melatonin and to degrade folate levels, important hormones for fetal development. We examined whether solar and geomagnetic activity were associated with fetal growth.

METHODS

We included 9573 singleton births with 26,879 routine ultrasounds at an academic medical center in Eastern Massachusetts from 2011 through 2016. Sunspot number and Kp index were obtained from the NASA Goddard Space Flight Center. Three exposure windows were considered, including the first 16 weeks of pregnancy, one month prior to fetal growth measurement, and conception until fetal growth measurement (cumulative). Ultrasound scans from which we extracted biparietal diameter, head circumference, femur length, and abdominal circumference measurements were categorized as anatomic (<24 weeks' gestation) or growth scans (≥24 weeks' gestation) based on clinical practice. Ultrasound parameters and birth weight were standardized, and linear mixed models adjusted for long-term trends were fitted.

RESULTS

Prenatal exposures were positively associated with larger head parameters measured <24 weeks' gestation, negatively associated with smaller fetal parameters measured ≥24 weeks' gestation, and not associated with birth weight. The strongest associations were observed for cumulative exposure in growth scans, where an interquartile range increase in sunspot number (32.87 sunspots) was associated with a -0.17 (95 % CI: -0.26, -0.08), -0.25 (-0.36, -0.15), and -0.13 (95 % CI: -0.23, -0.03) difference in mean biparietal diameter, head circumference, and femur length z-score, respectively. An interquartile range increase in cumulative Kp index (0.49) was associated with a -0.11 (95 % CI: -0.22, -0.01) and -0.11 (95 % CI: -0.20, -0.02) difference in mean head circumference and abdominal circumference z-score, respectively, in growth scans.

CONCLUSIONS

Solar and geomagnetic activity were associated with fetal growth. Future studies are needed to better understand the impact of these natural phenomena on clinical endpoints.

The influence of early environment and micronutrient availability on developmental epigenetic programming: lessons from the placenta

DNA methylation is the most commonly studied epigenetic mark in humans, as it is well recognised as a stable, heritable mark that can affect genome function and influence gene expression. Somatic DNA methylation patterns that can persist throughout life are established shortly after fertilisation when the majority of epigenetic marks, including DNA methylation, are erased from the pre-implantation embryo. Therefore, the period around conception is potentially critical for influencing DNA methylation, including methylation at imprinted alleles and metastable epialleles (MEs), loci where methylation varies between individuals but is correlated across tissues. Exposures before and during conception can affect pregnancy outcomes and health throughout life. Retrospective studies of the survivors of famines, such as those exposed to the Dutch Hunger Winter of 1944-45, have linked exposures around conception to later disease outcomes, some of which correlate with DNA methylation changes at certain genes. Animal models have shown more directly that DNA methylation can be affected by dietary supplements that act as cofactors in one-carbon metabolism, and in humans, methylation at birth has been associated with peri-conceptional micronutrient supplementation. However, directly showing a role of micronutrients in shaping the epigenome has proven difficult. Recently, the placenta, a tissue with a unique hypomethylated methylome, has been shown to possess great inter-individual variability, which we highlight as a promising target tissue for studying MEs and mixed environmental exposures. The placenta has a critical role shaping the health of the fetus. Placenta-associated pregnancy complications, such as preeclampsia and intrauterine growth restriction, are all associated with aberrant patterns of DNA methylation and expression which are only now being linked to disease risk later in life.

One-carbon metabolism is required for epigenetic stability in the mouse placenta

One-carbon metabolism, including the folate cycle, has a crucial role in fetal development though its molecular function is complex and unclear. The hypomorphic Mtrr ^gt allele is known to disrupt one-carbon metabolism, and thus methyl group availability, leading to several developmental phenotypes (e.g., neural tube closure defects, fetal growth anomalies). Remarkably, previous studies showed that some of the phenotypes were transgenerationally inherited. Here, we explored the genome-wide epigenetic impact of one-carbon metabolism in placentas associated with fetal growth phenotypes and determined whether specific DNA methylation changes were inherited. Firstly, methylome analysis of Mtrr ^gt/gt homozygous placentas revealed genome-wide epigenetic instability. Several differentially methylated regions (DMRs) were identified including at the Cxcl1 gene promoter and at the En2 gene locus, which may have phenotypic implications. Importantly, we discovered hypomethylation and ectopic expression of a subset of ERV elements throughout the genome of Mtrr ^gt/gt placentas with broad implications for genomic stability. Next, we determined that known spermatozoan DMRs in Mtrr ^gt/gt males were reprogrammed in the placenta with little evidence of direct or transgenerational germline DMR inheritance. However, some spermatozoan DMRs were associated with placental gene misexpression despite normalisation of DNA methylation, suggesting the inheritance of an alternative epigenetic mechanism. Integration of published wildtype histone ChIP-seq datasets with Mtrr ^gt/gt spermatozoan methylome and placental transcriptome datasets point towards H3K4me3 deposition at key loci. These data suggest that histone modifications might play a role in epigenetic inheritance in this context. Overall, this study sheds light on the mechanistic complexities of one-carbon metabolism in development and epigenetic inheritance.

Imbalance of Angiogenic and Growth Factors in Placenta in Maternal Hyperhomocysteinemia

Numerous studies have shown that various adverse factors of different nature and action mechanisms have similar negative influence on placental angiogenesis, resulting in insufficiency of placental blood supply. One of the risk factors for pregnancy complications with placental etiology is an increased level of homocysteine in the blood of pregnant women. However, the effect of hyperhomocysteinemia (HHcy) on the development of the placenta and, in particular, on the formation of its vascular network is at present poorly understood. The aim of this work was to study the effect of maternal HHcy on the expression of angiogenic and growth factors (VEGF-A, MMP-2, VEGF-B, BDNF, NGF), as well as their receptors (VEGFR-2, TrkB, p75NTR), in the rat placenta. The effects of HHcy were studied in the morphologically and functionally different maternal and fetal parts of the placenta on the 14th and 20th day of pregnancy. The maternal HHcy caused increase in the levels of oxidative stress and apoptosis markers accompanied by an imbalance of the studied angiogenic and growth factors in the maternal and/or fetal part of the placenta. The influence of maternal HHcy in most cases manifested in a decrease in the protein content (VEGF-A), enzymatic activity (MMP-2), gene expression (VEGFB, NGF, TRKB), and accumulation of precursor form (proBDNF) of the investigated factors. In some cases, the effects of HHcy differed depending on the placental part and stage of development. The influence of maternal HHcy on signaling pathways and processes controlled by the studied angiogenic and growth factors could lead to incomplete development of the placental vasculature and decrease in the placental transport, resulting in fetal growth restriction and impaired fetal brain development.

Epigenome-wide association study of serum folate in maternal peripheral blood leukocytes

Aim: To perform an epigenome-wide association study (EWAS) of serum folate in maternal blood. Methods: Cross-ancestry (Europeans = 302, South Asians = 161) and ancestry-specific EWAS in the EPIPREG cohort were performed, followed by methyl quantitative trait loci analysis and association with cardiometabolic phenotypes. Replication was attempted using maternal folate intake and blood methylation data from the MoBa study and verified if the findings were significant in a previous EWAS of maternal serum folate in cord blood. Results & conclusion: cg19888088 (cross-ancestry) in EBF3, cg01952260 (Europeans) and cg07077240 (South Asians) in HERC3 were associated with serum folate. cg19888088 and cg01952260 were associated with diastolic blood pressure. cg07077240 was associated with variants in CASC15. The findings were not replicated and were not significant in cord blood.

Effect of levetiracetam on the gene expression of placental transporters in a murine model

OBJECTIVE

Levetiracetam (LEV) is an antiseizure medication prescribed to women during childbearing age. The impact of LEV on placental transporters is poorly understood. This study aimed to assess the effect of LEV exposure on the messenger RNA (mRNA) expression of placental transporters for hormones and nutrients and to correlate their expression with the drug's serum concentration in pregnant mice.

METHODS

Studies were conducted on gestational days (GD) 13 and 18, following oral treatment with 100 mg/kg LEV or the vehicle every 24 h after weaning. Serum LEV measurements were performed by High-performance liquid chromatography with a UV detector (HPLC-UV). The weight, height, and width of the fetuses were also analyzed. In addition, the placental expression of transporters xCt, Lat1, Oatp4a1, Fr-α, Rfc, and Snat4 was evaluated through semi-quantitative real-time polymerase chain reaction (qPCR). The Kruskal-Wallis and the Mann-Whitney U tests were used to determine the statistical significance (p < .05). The correlation between serum LEV concentration and placental gene expression was evaluated using the Spearman test.

RESULTS

The weight, height, and width were lower in the fetuses exposed to LEV compared with the control group (p < .05). The number of fetuses was lower in the LEV-exposed group than in the control GD 13 group (p < .001). No significant differences were detected in the mRNA expression level at GD 13. At GD 18, the expression of Lat1, Oatp4a1, xCT, and Snat4 was higher in the group treated with LEV compared with the control group (p < .05), whereas the expression of Rfc was lower (p < .05). No correlation was identified between serum LEV concentrations and gene expression levels.

SIGNIFICANCE

The repression of the Rfc transcript by LEV at GD 18 suggests that the protein expression would be abolished contributing to the observed intrauterine growth restriction (IUGR). Furthermore, the significant increase in mRNA of xCt, Snat4, Oatp4a1, and Lat1 might be a compensatory mechanism for fetal survival at GD 18.

Prenatal Stress in Maternal Hyperhomocysteinemia: Impairments in the Fetal Nervous System Development and Placental Function

The article presents current views on maternal hyperhomocysteinemia (HHcy) as an important factor causing prenatal stress and impaired nervous system development in fetuses and newborns in early ontogenesis, as well as complications in adulthood. Experimental data demonstrate that prenatal HHcy (PHHcy) affects the morphological maturation of the brain and activity of its neurotransmitter systems. Cognitive deficit observed in the offspring subjected to PHHcy in experimental studies can presumably cause the predisposition to various neurodegenerative diseases, as the role of maternal HHcy in the pathogenesis such diseases has been proven in clinical studies. The review also discusses molecular mechanisms of the HHcy neurotoxic action on the nervous system development in the prenatal and early postnatal periods, which include oxidative stress, apoptosis activation, changes in the DNA methylation patterns and microRNA levels, altered expression and processing of neurotrophins, and neuroinflammation induced by an increased production of pro-inflammatory cytokines. Special attention is given to the maternal HHcy impact on the placenta function and its possible contribution to the brain function impairments in the offspring. Published data suggest that some effects of PHHcy on the developing fetal brain can be due to the disturbances in the transport functions of the placenta resulting in an insufficient supply of nutrients necessary for the proper formation and functioning of brain structures.

Periconceptional Folate Supplementation in Women after Bariatric Surgery-A Narrative Review

The prevalence of obesity is increasing globally, and along with it, there is a growing number of patients opting to undergo bariatric surgery to treat this condition. Whilst it has many advantages, bariatric surgery is known to induce micronutrient deficiency, with possible deleterious effects on overall health. This topic becomes even more relevant during pregnancy, where deficiencies can also affect the developing fetus, possibly being the cause of an increase in congenital anomalies. Most notably amongst these micronutrients is folate, or vitamin B9, which plays an essential role in development, gene expression and genomic stability. As insufficient levels of folate are associated with neural tube defects in the fetus, preventing and treating folate deficiencies during pregnancies after bariatric surgery is a relevant issue. Unfortunately, folate supplementation recommendations for bariatric patients who wish to become pregnant are not clear. In this narrative review, we discuss whether the recommendations for the general population are still valid for bariatric patients. Furthermore, we discuss the role of folate in the human body, folate status in both non-bariatric and bariatric patients, the various types of folate that are available for substitution and the risk associated with over-supplementation.

Developmental origins of metabolic diseases

Almost 2 billion adults in the world are overweight, and more than half of them are classified as obese, while nearly one-third of children globally experience poor growth and development. Given the vast amount of knowledge that has been gleaned from decades of research on growth and development, a number of questions remain as to why the world is now in the midst of a global epidemic of obesity accompanied by the "double burden of malnutrition," where overweight coexists with underweight and micronutrient deficiencies. This challenge to the human condition can be attributed to nutritional and environmental exposures during pregnancy that may program a fetus to have a higher risk of chronic diseases in adulthood. To explore this concept, frequently called the developmental origins of health and disease (DOHaD), this review considers a host of factors and physiological mechanisms that drive a fetus or child toward a higher risk of obesity, fatty liver disease, hypertension, and/or type 2 diabetes (T2D). To that end, this review explores the epidemiology of DOHaD with discussions focused on adaptations to human energetics, placental development, dysmetabolism, and key environmental exposures that act to promote chronic diseases in adulthood. These areas are complementary and additive in understanding how providing the best conditions for optimal growth can create the best possible conditions for lifelong health. Moreover, understanding both physiological as well as epigenetic and molecular mechanisms for DOHaD is vital to most fully address the global issues of obesity and other chronic diseases.

Novel roles of mechanistic target of rapamycin signaling in regulating fetal growth†

Mechanistic target of rapamycin (mTOR) signaling functions as a central regulator of cellular metabolism, growth, and survival in response to hormones, growth factors, nutrients, energy, and stress signals. Mechanistic TOR is therefore critical for the growth of most fetal organs, and global mTOR deletion is embryonic lethal. This review discusses emerging evidence suggesting that mTOR signaling also has a role as a critical hub in the overall homeostatic control of fetal growth, adjusting the fetal growth trajectory according to the ability of the maternal supply line to support fetal growth. In the fetus, liver mTOR governs the secretion and phosphorylation of insulin-like growth factor binding protein 1 (IGFBP-1) thereby controlling the bioavailability of insulin-like growth factors (IGF-I and IGF-II), which function as important growth hormones during fetal life. In the placenta, mTOR responds to a large number of growth-related signals, including amino acids, glucose, oxygen, folate, and growth factors, to regulate trophoblast mitochondrial respiration, nutrient transport, and protein synthesis, thereby influencing fetal growth. In the maternal compartment, mTOR is an integral part of a decidual nutrient sensor which links oxygen and nutrient availability to the phosphorylation of IGFBP-1 with preferential effects on the bioavailability of IGF-I in the maternal-fetal interface and in the maternal circulation. These new roles of mTOR signaling in the regulation fetal growth will help us better understand the molecular underpinnings of abnormal fetal growth, such as intrauterine growth restriction and fetal overgrowth, and may represent novel avenues for diagnostics and intervention in important pregnancy complications.

Immune Cells in the Uterine Remodeling: Are They the Target of Endocrine Disrupting Chemicals?

Sufficient uterine remodeling is essential for fetal survival and development. Pathologies related to poor remodeling have a negative impact on maternal and fetal health even years after birth. Research of the last decades yielded excellent studies demonstrating the key role of immune cells in the remodeling processes. This review summarizes the current knowledge about the relevance of immune cells for uterine remodeling during pregnancy and further discusses immunomodulatory effects of man-made endocrine disrupting chemicals on immune cells.

Fetal Growth Restriction

Fetal growth restriction (FGR) is a failure of fetus to reach its expected biological growth, based on its genetically predetermined potential. Whenever effective fetal weight is less than, 10th percentile or 2 standard deviation of population-specific growth curve, it is considered small for gestational age (SGA). The FGR is associated with poor somatic growth with concomitant changes in placental and cerebral blood flow and/or biochemical markers along with EBW < 3rd percentile. It is an important cause of perinatal mortalities and morbidities. Ultrasound plays a definitive role in diagnosis and its management. This article is aimed to mini review the published guidelines on FGR and SGA and summarize the areas of consensus.

Knowledge Gaps and Emerging Research Areas in Intrauterine Growth Restriction-Associated Brain Injury

Intrauterine growth restriction (IUGR) is a complex global healthcare issue. Concerted research and clinical efforts have improved our knowledge of the neurodevelopmental sequelae of IUGR which has raised the profile of this complex problem. Nevertheless, there is still a lack of therapies to prevent the substantial rates of fetal demise or the constellation of permanent neurological deficits that arise from IUGR. The purpose of this article is to highlight the clinical and translational gaps in our knowledge that hamper our collective efforts to improve the neurological sequelae of IUGR. Also, we draw attention to cutting-edge tools and techniques that can provide novel insights into this disorder, and technologies that offer the potential for better drug design and delivery. We cover topics including: how we can improve our use of crib-side monitoring options, what we still need to know about inflammation in IUGR, the necessity for more human post-mortem studies, lessons from improved integrated histology-imaging analyses regarding the cell-specific nature of magnetic resonance imaging (MRI) signals, options to improve risk stratification with genomic analysis, and treatments mediated by nanoparticle delivery which are designed to modify specific cell functions.

Folate and choline absorption and uptake: Their role in fetal development

SCOPE

In this review, we attempt to assess how choline and folate transporters affect fetal development. We focus on how the expression of these transporters in response to choline and folate intake affects transport effectiveness. We additionally describe allelic variants of the genes encoding these transporters and their phenotypic effects.

METHODS AND RESULTS

We made an extensive review of recent articles describing role of choline and folate - with particularly emphasize on their transporters - in fetal development. Folate and choline are necessary for the proper functioning of the cell and body. During pregnancy, the requirements of these nutrients increase because of elevated maternal demand and the rapid division of fetal cells. The concentrations of folate and choline in cells depend on food intake, the absorption of nutrients, and the cellular transport system, which is tissue-specific and developmentally regulated. Relatively few studies have investigated the role of choline transporters in fetal development.

CONCLUSIONS

In this review we show relations between functioning of folate and choline transporters and fetal development.