Effects of altered parental folate and one-carbon nutrient status on offspring growth and metabolism

RBC Folate and Serum Folate, Vitamin B-12, and Homocysteine in Chinese Couples Prepregnancy in the Shanghai Preconception Cohort

BACKGROUND

The protective effects of maternal folate on neural tube defects are well-established. Emerging evidence has shown paternal folate also is related to pregnancy outcome and offspring health.

OBJECTIVES

This study aimed to assess the status of red blood cell (RBC) folate and serum folate, vitamin B-12, and homocysteine (Hcy) and their associated factors in a cohort of pregnancy-preparing couples.

METHODS

This was a cross-sectional study involving 14,178 participants from the extension of the Shanghai Preconception Cohort conducted in 2018-2021. Circulating biomarker concentrations were measured, and the prevalence of abnormal status was reported. Linear and logistic regression analyses were conducted to examine associations of demographic factors (age, education, and income), lifestyle factors (smoking, drinking, and folic acid supplement use), and BMI with concentrations of the folate-related biomarkers, abnormal status of folate (deficiency and insufficiency) and vitamin B-12 (deficiency and marginal deficiency), and hyperhomocysteinemia.

RESULTS

The geometric mean (95% CI) concentrations of RBC folate, serum folate, vitamin B-12, and Hcy were 490 nmol/L (485, 496 nmol/L), 20.1 nmol/L (19.8, 20.3 nmol/L), 353 pmol/L (350, 357 pmol/L), and 7.54 μmol/L (7.48, 7.60 μmol/L) in females, respectively, and 405 nmol/L (401, 409 nmol/L), 13.5 nmol/L (13.4, 13.7 nmol/L), 277 pmol/L (274, 279 pmol/L), and 12.0 μmol/L (11.9, 12.2 μmol/L) in males, respectively. Prevalence of abnormal status was higher in males than females for the 4 folate-related biomarkers: RBC folate deficiency (<340 nmol/L, 32.2% compared with 18.9%), serum folate deficiency (<10.0 nmol/L, 26.5% compared with 7.3%), RBC folate insufficiency (<906 nmol/L, 96.6% compared with 90.1%), serum folate insufficiency (<15.9 nmol/L, 65.5% compared with 31.4%), vitamin B-12 marginal deficiency (148-221 pmol/L, 21.4% compared with 8.8%), and hyperhomocysteinemia (>15.0 μmol/L, 22.1% compared with 2.5%).

CONCLUSIONS

Most pregnancy-preparing couples failed to achieve the optimal RBC folate status (>906 nmol/L) as recommended by the WHO. These findings call for attention to the insufficiency status of folate and promising strategies to improve the folate status of the pregnancy-preparing population not exposed to folic acid fortification.

Early supplementation of folate and vitamin B12 improves insulin resistance in intrauterine growth retardation rats

BACKGROUND

Insulin sensitivity is changed during the neonatal period in small for gestational age (SGA) infants. Yet, the interventional strategies are still limited. We aimed to investigate the effects of supplementation with high folate and vitamin B12 diets in the early postnatal period on the changes in insulin sensitivity in an intrauterine growth retardation (IUGR) rat model.

METHODS

IUGR rat model was established by both low-protein diet feeding and daily diet restriction. High folate and vitamin B12 diet was supplied in IUGR as nutritional interventional group (IUGR-I), otherwise, the non-intervened IUGR group (IUGR-NI). In this study, male rats were studied in order to avoid hormonal and gender influence. At 21, 60 and 120 days, fasting plasma glucose, insulin, triglyceride, cholesterol, and homocysteine levels were measured among the control, IUGR-I, and IUGR-NI groups. Pearson analysis was used to evaluate the correlation between homocysteine and fasting blood glucose, insulin, HOMA-IR, triglyceride, and cholesterol levels.

RESULTS

We established IUGR rat model by both low protein and restricted diet feeding during pregnancy and the incidence of IUGR pups was 93.33%. There was no difference in fasting glucose, insulin, HOMA-IR, triglyceride and cholesterol levels between the control, the IUGR-NI and the IUGR-I group at day 21. At day 60, insulin, HOMA-IR and triglyceride levels in the IUGR-I group were remarkably lower than those in the IUGR-NI group, but still higher than those in the control group (F=38.34, P=0.02; F=49.48, P=0.02; F=17.93, P<0.001, respectively). At day 120, glucose, insulin, HOMA-IR and Hcy levels in the IUGR-I group were obviously lower than those in the IUGR-NI group, although still higher than those in the control group (F=21.60, P<0.001; F=164.46, P<0.001; F=75.15, P<0.001; F=35.46, P<0.001, respectively). There were no significant differences in triglyceride and cholesterol levels between the IUGR-I group and the control group at day 120. At 120-day, homocysteine in IUGR-I group was highly positively correlated with fasting glucose and HOMA-IR (r=0.863, P=0.006; r=0.725, P=0.042, respectively); Only homocysteine was positively correlated with fasting glucose in IUGR-NI group (r=0.721, P=0.044).

CONCLUSIONS

Early supplementation of folate and vitamin B12 improved insulin resistance and lipid levels in IUGR rats to some extent, along with decreasing homocysteine levels, but not enough to completely repair glucose and lipid metabolism.

Altered dietary ratio of folic acid and vitamin B12 during pregnancy influences the expression of imprinted H19/IGF2 locus in C57BL/6 mice

Maternal folic acid and vitamin B12 (B12) status during pregnancy influence fetal growth. This study elucidated the effect of altered dietary ratio of folic acid and B12 on the regulation of H19/IGF2 locus in C57BL/6 mice. Female mice were fed diets with 9 combinations of folic acid and B12 for 4 weeks. They were mated and the offspring born (F1) were continued on the same diet for 6 weeks post-weaning and were allowed to mate. The placenta and fetal (F2) tissues were collected at day 20 of gestation. H19 overexpression observed under dietary deficiency of folate combined with normal B12 (BNFD) was associated with an increased expression of miR-675 in maternal and fetal tissues. Insulin-like growth factor 2 (IGF2), expression was decreased under folic acid deficient conditions combined with normal, deficient or over-supplemented state of B12 (BNFD, BDFD, BOFD) in fetal tissues along with B12 deficiency combined with normal folic acid (BDFN) in the placenta. The altered expression of imprinted genes under folic acid deficient conditions was related to decreased serum levels of folate and body weight (F1). Hypermethylation observed at the H19 differentially methylated region (DMR) (in BNFD) might be responsible for the decreased expression of IGF2 in female fetal tissues. IGF2 DMR2 was found to be hypomethylated and associated with low serum B12 levels with B12 deficiency in fetal tissues. Results suggest that the altered dietary ratio of folic acid and B12 affects the in-utero development of the fetus in association with altered epigenetic regulation of H19/IGF2 locus.

Consequences of Paternal Nutrition on Offspring Health and Disease

It is well established that the maternal diet during the periconceptional period affects the progeny’s health. A growing body of evidence suggests that the paternal diet also influences disease onset in offspring. For many years, sperm was considered only to contribute half of the progeny’s genome. It now appears that it also plays a crucial role in health and disease in offspring’s adult life. The nutritional status and environmental exposure of fathers during their childhood and/or the periconceptional period have significant transgenerational consequences. This review aims to describe the effects of various human and rodent paternal feeding patterns on progeny’s metabolism and health, including fasting or intermittent fasting, low-protein and folic acid deficient food, and overnutrition in high-fat and high-sugar diets. The impact on pregnancy outcome, metabolic pathways, and chronic disease onset will be described. The biological and epigenetic mechanisms underlying the transmission from fathers to their progeny will be discussed. All these data provide evidence of the impact of paternal nutrition on progeny health which could lead to preventive diet recommendations for future fathers.

Effect of imbalance in folate and vitamin B12 in maternal/parental diet on global methylation and regulatory miRNAs

DNA methylation, a central component of the epigenetic network is altered in response to nutritional influences. In one-carbon cycle, folate acts as a one-carbon carrier and vitamin B12 acts as co-factor for the enzyme methionine synthase. Both folate and vitamin B12 are the important regulators of DNA methylation which play an important role in development in early life. Previous studies carried out in this regard have shown the individual effects of these vitamins but recently the focus has been to study the combined effects of both the vitamins during pregnancy. Therefore, this study was planned to elucidate the effect of the altered dietary ratio of folate and B12 on the expression of transporters, related miRNAs and DNA methylation in C57BL/6 mice. Female mice were fed diets with 9 combinations of folate and B12 for 4 weeks. They were mated and off-springs born (F1) were continued on the same diet for 6 weeks post-weaning. Maternal and fetal (F2) tissues were collected at day 20 of gestation. Deficient state of folate led to an increase in the expression of folate transporters in both F1 and F2 generations, however, B12 deficiency (BDFN) also led to an increase in the expression in both the generations. B12 transporters/proteins were found to be increased with B12 deficiency in F1 and F2 generations except for TC-II in the kidney which was found to be decreased in the F1 generation. miR-483 was found to be increased with all conditions of folate and B12 in both F1 and F2 generations, however, deficient conditions of B12 led to an increase in the expression of miR-221 in both F1 and F2 generations. The level of miR-133 was found to be increased in BDFN group in F1 generation however; in F2 generation the change in expression was tissue and sex-specific. Global DNA methylation was decreased with deficiency of both folate and B12 in maternal tissues (F1) but increased with folate deficiency in placenta (F1) and under all conditions in fetal tissues (F2). DNA methyltransferases were overall found to be increased with deficiency of folate and B12 in both F1 and F2 generations. Results suggest that the dietary ratio of folate and B12 resulted in altered expression of transporters, miRNAs, and genomic DNA methylation in association with DNMTs.

The effect of GNAQ methylation on GnRH secretion in sheep hypothalamic neurons

Kazakh sheep are seasonal estrous animals, and gonadotropin-releasing hormone (GnRH) is the key to fertility regulation. The nutritional level has a certain regulatory effect on estrous, and vitamin B folate plays a role in DNA methylation, directly participating in the process. The goal of this study was to determine whether folate is involved in GnAQ methylation and its effect on GnRH secretion. The hypothalamic neurons of Kazakh fetal sheep were treated with folate at concentrations of 0 mg/mL, 4 mg/mL, 40 mg/mL, and 80 mg/mL. GnAQ promoter methylation, DNMT1, GnAQ expression, and GnRH secretion following treatment with different concentrations of folate were analyzed. One CpG site was methylated in the GNAQ promoter with 40 mg/mL folic acid, and no CpG methylation was found in the other groups. GnAQ expression was related to folate concentration and showed a trend of increasing first and then decreasing. The GnRH expression level in the 40 mg/mL folate group was significantly higher than in the other three groups ( P < .05). These results demonstrate that the appropriate folate concentration promoted GANQ promoter methylation, which in turn affected GnRH secretion.

Early Disruption of the Microbiome Leading to Decreased Antioxidant Capacity and Epigenetic Changes: Implications for the Rise in Autism

Currently, 1 out of every 59 children in the United States is diagnosed with autism. While initial research to find the possible causes for autism were mostly focused on the genome, more recent studies indicate a significant role for epigenetic regulation of gene expression and the microbiome. In this review article, we examine the connections between early disruption of the developing microbiome and gastrointestinal tract function, with particular regard to susceptibility to autism. The biological mechanisms that accompany individuals with autism are reviewed in this manuscript including immune system dysregulation, inflammation, oxidative stress, metabolic and methylation abnormalities as well as gastrointestinal distress. We propose that these autism-associated biological mechanisms may be caused and/or sustained by dysbiosis, an alteration to the composition of resident commensal communities relative to the community found in healthy individuals and its redox and epigenetic consequences, changes that in part can be due to early use and over-use of antibiotics across generations. Further studies are warranted to clarify the contribution of oxidative stress and gut microbiome in the pathophysiology of autism. A better understanding of the microbiome and gastrointestinal tract in relation to autism will provide promising new opportunities to develop novel treatment modalities.