Modifying Levels of Maternal Dietary Folic Acid or Choline to Study the Impact of Deficiencies on Offspring Health Outcomes.

Maternal nutrition during pregnancy and lactation plays an important role in the neurodevelopment of offspring. One-carbon (1C) metabolism, which centers around folic acid and choline, as well as other B vitamins, plays a key role during the closure of the neural tube of the developing fetus. However, the impact of these maternal nutritional deficiencies during pregnancy on offspring health outcomes after birth remains relatively undefined. Furthermore, maternal dietary deficiencies in folic acid or choline may impact other health outcomes in offspring - making this a valuable model. This protocol aims to outline the procedure for inducing a deficiency in 1C metabolism in female mice through dietary modifications. Females are placed on diets at weaning, up to 2 months of age, for 4-6 weeks prior to mating and remain on diet throughout pregnancy and lactation. Offspring from these females can be evaluated for health outcomes. Females can be used multiple times to generate offspring, and tissues from females can be collected to measure for 1C metabolite measurements. This protocol provides an overview of how to induce maternal dietary deficiencies in folic acid or choline to study offspring health outcomes.

Deficiencies in one-carbon metabolism led to increased neurological disease risk and worse outcome: homocysteine is a marker of disease state.

Elevated plasma homocysteine levels have been identified as a significant, independent risk factor for the development of cognitive decline including Alzheimer's disease. While several studies have explored the link between homocysteine and disease risk, the associations have not been entirely clear. Elevated levels of homocysteine serve as a disease marker and understanding the underlying cause of these increased levels (e.g., dietary or genetic deficiency in one-carbon metabolism, 1C) will provide valuable insights into neurological disease risk and outcomes. Previous cell culture experiments investigating the mechanisms involved used ultra-high levels of homocysteine that are not observed in human patients. These studies have demonstrated the negative impacts of ultra-high levels of homocysteine can have on for example proliferation of neuroprogenitor cells in the adult hippocampus, as well as triggering neuronal apoptosis through a series of events, including DNA damage, PARP activation, NAD depletion, mitochondrial dysfunction, and oxidative stress. The aim of this mini-review article will summarize the literature on deficiencies in 1C and how they contribute to disease risk and outcomes and that homocysteine is a marker of disease.

Dietary vitamin B12 deficiency impairs motor function and changes neuronal survival and choline metabolism after ischemic stroke in middle-aged male and female mice.

Nutrition is a modifiable risk factor for ischemic stroke. As people age their ability to absorb some nutrients decreases, a primary example is vitamin B12. Older individuals with a vitamin B12 deficiency are at a higher risk for ischemic stroke and have worse stroke outcome. However, the mechanisms through which these occur remain unknown. The aim of the study was to investigate the role of vitamin B12 deficiency in ischemic stroke outcome and mechanistic changes in a mouse model. Ten-month-old male and female mice were put on control or vitamin B12 deficient diets for 4 weeks prior to and after ischemic stroke to the sensorimotor cortex. Motor function was measured, and tissues were collected to assess potential mechanisms. All deficient mice had increased levels of total homocysteine in plasma and liver tissues. After ischemic stroke, deficient mice had impaired motor function compared to control mice. There was no difference between groups in ischemic damage volume. However, within the ischemic damage region, there was an increase in total apoptosis of male deficient mice compared to controls. Furthermore, there was an increase in neuronal survival in ischemic brain tissue of the vitamin B12 deficient mice compared to controls. Additionally, there were changes in choline metabolites in ischemic brain tissue because of a vitamin B12 deficiency. The data presented in this study confirms that a vitamin B12 deficiency worsens stroke outcome in male and female mice. The mechanisms driving this change may be a result of neuronal survival and compensation in choline metabolism within the damaged brain tissue.

Impact of increasing one-carbon metabolites on traumatic brain injury outcome using pre-clinical models.

Traumatic brain injury is a major cause of death and disability worldwide, affecting over 69 million individuals yearly. One-carbon metabolism has been shown to have beneficial effects after brain damage, such as ischemic stroke. However, whether increasing one-carbon metabolite vitamins impacts traumatic brain injury outcomes in patients requires more investigation. The aim of this review is to evaluate how one-carbon metabolites impact outcomes after the onset of traumatic brain injury. PubMed, Web of Science, and Google Scholar databases were searched for studies that examined the impact of B-vitamin supplementation on traumatic brain injury outcomes. The search terms included combinations of the following words: traumatic brain injury, dietary supplementation, one-carbon metabolism, and B-vitamins. The focus of each literature search was basic science data. The year of publication in the literature searches was not limited. Our analysis of the literature has shown that dietary supplementation of B-vitamins has significantly improved the functional and behavioral recovery of animals with traumatic brain injury compared to controls. However, this improvement is dosage-dependent and is contingent upon the onset of supplementation and whether there is a sustained or continuous delivery of vitamin supplementation post-traumatic brain injury. The details of supplementation post-traumatic brain injury need to be further investigated. Overall, we conclude that B-vitamin supplementation improves behavioral outcomes and reduces cognitive impairment post-traumatic brain injury in animal model systems. Further investigation in a clinical setting should be strongly considered in conjunction with current medical treatments for traumatic brain injury-affected individuals.

Impact of maternal dietary folic acid or choline dietary deficiencies on vascular function in young and middle-aged female mouse offspring after ischemic stroke.

Adequate maternal dietary levels of one-carbon metabolites, such as folic acid and choline, play an important role in the closure of the neural tube in utero; however, the impact of deficiencies in one-carbon (1C) metabolism on offspring neurological function after birth remain undefined. Stroke is one of the leading causes of death and disability globally. The aim of our study was to determine the impact of maternal 1C nutritional deficiencies on cerebral and peripheral blood flow after ischemic stroke in adult female offspring. In this study, female mice were placed on either control (CD)-, folic acid (FADD)-, or choline (ChDD)-deficient diets before pregnancy. Female offspring were weaned onto a CD for the duration of the study. Ischemic stroke was induced in offspring and after 6 wk cerebral and peripheral blood flow velocity was measured using ultrasound imaging. Our data showed that 11.5-mo-old female offspring from ChDD mothers had reduced blood flow in the posterior cerebral artery compared with controls. In peripheral blood flow velocity measurements, we report an aging effect. These results emphasize the importance of maternal 1C diet in early life neuro-programming on long-term vasculature health.NEW & NOTEWORTHY We demonstrate that a maternal dietary deficiency in one-carbon (1C) metabolites result in reduced cerebral blood flow in adult female offspring after ischemic stroke, but the long-term effects are not present. This result points to the key role of the maternal diet in early life neuroprogramming, while emphasizing its effects on both fetal development and long-term cerebrovascular health.

The Role of One-Carbon Metabolism in Healthy Brain Aging.

Aging results in more health challenges, including neurodegeneration. Healthy aging is possible through nutrition as well as other lifestyle changes. One-carbon (1C) metabolism is a key metabolic network that integrates nutritional signals with several processes in the human body. Dietary supplementation of 1C components, such as folic acid, vitamin B12, and choline are reported to have beneficial effects on normal and diseased brain function. The aim of this review is to summarize the current clinical studies investigating dietary supplementation of 1C, specifically folic acid, choline, and vitamin B12, and its effects on healthy aging. Preclinical studies using model systems have been included to discuss supplementation mechanisms of action. This article will also discuss future steps to consider for supplementation. Dietary supplementation of folic acid, vitamin B12, or choline has positive effects on normal and diseased brain function. Considerations for dietary supplementation to promote healthy aging include using precision medicine for individualized plans, avoiding over-supplementation, and combining therapies.

Maternal dietary deficiencies in folic acid or choline worsen stroke outcomes in adult male and female mouse offspring.

Maternal one-carbon metabolism plays an important role in early life programming. There is a well-established connection between the fetal environment and the health status of the offspring. However, there is a knowledge gap on how maternal nutrition impacts stroke outcomes in offspring. The aim of our study was to investigate the role of maternal dietary deficiencies in folic acid or choline on stroke outcomes in 3-month-old offspring. Adult female mice were fed a folic acid-deficient diet, choline-deficient diet, or control diet 4 weeks before pregnancy. They were continued on diets during pregnancy and lactation. Male and female offspring were weaned onto a control diet and at 2 months of age were subjected to ischemic stroke within the sensorimotor cortex via photothrombotic damage. Mothers maintained on either a folic acid-deficient diet or choline-deficient diet had reduced levels of S-adenosylmethionine in the liver and S-adenosylhomocysteine in the plasma. After ischemic stroke, motor function was impaired in 3-month-old offspring from mothers receiving either a folic acid-deficient diet or choline-deficient diet compared to the animals receiving a control diet. In brain tissue, there was no difference in ischemic damage volume. When protein levels were assessed in ischemic brain tissue, there were lower levels of active caspase-3 and hypoxia-inducible factor 1α in males compared to females and betaine levels were reduced in offspring from the mothers receiving a choline-deficient diet. Our results demonstrate that a deficient maternal diet at critical time points in neurodevelopment results in worse stroke outcomes. This study emphasizes the importance of maternal diet and the impact it can have on offspring health.

Maternal Dietary Deficiencies in Folic Acid and Choline Result in Larger Damage Volume, Reduced Neuro-Degeneration and -Inflammation and Changes in Choline Metabolites after Ischemic Stroke in Middle-Aged Offspring.

Maternal dietary levels of one-carbon (1C) metabolites (folic acid and choline) during pregnancy play a vital role in neurodevelopment. However, the impact of maternal dietary deficiencies on offspring stroke outcomes later in life remains undefined. The aim of this study was to investigate the role of maternal dietary deficiencies in folic acid and choline on ischemic stroke outcomes in middle-aged offspring. Female mice were maintained on either a control or deficient diet prior to and during pregnancy and lactation. At 10 months of age ischemic stroke was induced in male and female offspring. Stroke outcome was assessed by measuring motor function and brain tissue. There was no difference in offspring motor function; however, sex differences were present. In brain tissue, maternal dietary deficiency increased ischemic damage volume and offspring from deficient mothers had reduced neurodegeneration and neuroinflammation within the ischemic region. Furthermore, there were changes in plasma 1C metabolites as a result of maternal diet and sex. Our data indicate that maternal dietary deficiencies do not impact offspring behavior after ischemic stroke but do play a role in brain histology and one-carbon metabolite levels in plasma. Additionally, this study demonstrates that the sex of mice plays an important role in stroke outcomes.

The Impact of Maternal Folates on Brain Development and Function after Birth.

Folate is vital for biological processes within the body, including DNA synthesis, DNA repair, and methylation reactions that metabolize homocysteine. The role of folate is particularly important in pregnancy, where there is rapid cellular and tissue growth. Maternal folate deficiencies secondary to inadequate dietary supplementation are known to produce defects in the neural tube and spinal cord, yet the exact mechanism of folate in neurodevelopment is unknown. The consequences of maternal folate deficiency on offspring brain development and function beyond gestation are not well defined. The objective of this review is to investigate the role of folate deficiency in offspring neurodevelopment, and the complications that arise post-gestation. This was accomplished through a comprehensive review of the data presented in both clinical and preclinical studies. Evidence supports that folate deficiency is associated with altered offspring neurodevelopment, including smaller total brain volume, altered cortical thickness and cerebral white matter, altered neurogenesis, and neuronal apoptosis. Some of these changes have been associated with altered brain function in offspring with memory, motor function, language skills, and psychological issues. This review of literature also presents potential mechanisms of folate deficiency in neurodevelopment with altered metabolism, neuroinflammation, epigenetic modification through DNA methylation, and a genetic deficiency in one-carbon metabolism.

Ischemic Stroke and Dietary Vitamin B12 Deficiency in Old-Aged Females: Impaired Motor Function, Increased Ischemic Damage Size, and Changed Metabolite Profiles in Brain and Cecum Tissue.

A vitamin B12 deficiency (vit. B12 def.) is common in the elderly, because of changes in metabolism. Clinical studies have reported that a vit. B12 def. results in worse outcome after stroke, and the mechanisms through which a vit. B12 def. changes the brain requires further investigation. This study investigated the role of vit. B12 def. on stroke outcome and mechanisms using aged female mice. Eighteen-month-old females were put on a control or vit. B12 def. diet for 4 weeks, after which an ischemic stroke was induced in the sensorimotor cortex. After damage, motor function was measured, the animals were euthanized, and tissues were collected for analysis. Vit. B12 def. animals had increased levels of total homocysteine in plasma and liver, and choline levels were also increased in the liver. Vit. B12 def. animals had larger damage volume in brain tissue and more apoptosis. The cecum tissue pathway analysis showed dysfunction in B12 transport. The analysis of mitochondrial metabolomics in brain tissue showed reduced levels of metabolites involved in the TCA cycle in vit. B12 def. animals. Motor function after stroke was impaired in vit. B12 def. animals. A dietary vit. B12 def. impairs motor function through increased apoptosis and changes in mitochondrial metabolism in brain tissue.

Dietary folic acid deficiency impacts hippocampal morphology and cortical acetylcholine metabolism in adult male and female mice.

OBJECTIVE: One-carbon (1C) metabolism is a metabolic network that integrates nutritional signals with biosynthesis, redox homeostasis, and epigenetics. There are sex differences in hepatic 1C metabolism, however, it is unclear whether sex differences in 1C impact the brain. The aim of this study was to investigate if sex modulates the effects of dietary folic acid deficiency, the main component of 1C, in brain tissue using a mouse model. METHODS: Male and female C57Bl/6J mice were placed on a folic acid deficient (FD) or control diet (CD) at six weeks until six months of aged. After which brain tissue and serum were collected for analysis. In brain tissue, hippocampal volume, morphology, and apoptosis as well as cortical acetylcholine metabolism were measured. RESULTS: Male and female FD mice had reduced serum levels of folate. Both males and females maintained on a FD showed a decrease in the thickness of the hippocampal CA1-CA3 region. Interestingly, there was a sex difference in the levels of active caspase-3 within the CA3 region of the hippocampus. In cortical tissue, there were increased levels of neuronal ChAT and reduced levels of AChE in FD females and male mice. CONCLUSIONS: The results indicated that FD impacts hippocampal morphology and cortical neuronal acetylcholine metabolism. The data from our study indicate that there was only one sex difference and that was in hippocampal apoptosis. Our study provides little evidence that sex modulates the effects of dietary folate deficiency on hippocampal morphology and cortical neuronal acetylcholine metabolism.

Methylenetetrahydrofolate reductase deficiency alters cellular response after ischemic stroke in male mice.

Objective: Elevated homocysteine concentrations are a risk factor for stroke. A common genetic polymorphism in methylenetetrahydrofolate reductase (MTHFR 677 C→T) results in elevated levels of homocysteine. MTHFR plays a critical role in the synthesis of S-adenosylmethionine (SAM), a global methyl donor. Our previous work has demonstrated that Mthfr+/- mice, which model the MTHFR polymorphism in humans, are more vulnerable to ischemic damage. The aim of this study was to investigate the cellular mechanisms by which the MTHFR-deficiency changes the brain in the context of ischemic stroke injury.Methods: In the present study, three-month-old male Mthfr+/- and wild-type littermate mice were subjected to photothrombosis (PT) damage. Four weeks after PT damage, animals were tested on behavioral tasks, in vivo imaging was performed using T2-weighted MRI, and brain tissue was collected for histological analysis.Results: Mthfr+/- animals used their non-impaired forepaw more to explore the cylinder and had a larger damage volume compared to wild-type littermates. In brain tissue of Mthfr+/- mice methionine adenosyltransferase II alpha (MAT2A) protein levels were decreased within the damage hemisphere and increased levels in hypoxia-induced factor 1 alpha (HIF-1α) in non-damage hemisphere. There was an increased antioxidant response in the damage site as indicated by higher levels of nuclear factor erythroid 2-related factor 2 (Nrf2) in neurons and astrocytes and neuronal superoxide dismutase 2 (SOD2) levels.Conclusions: Our results suggest that Mthfr+/- mice are more vulnerable to PT-induced stroke damage through the regulation of the cellular response. The increased antioxidant response we observed may be compensatory to the damage amount.

Writing an effective and supportive recommendation letter.

Writing recommendation letters on behalf of students and other early-career researchers is an important mentoring task within academia. An effective recommendation letter describes key candidate qualities such as academic achievements, extracurricular activities, outstanding personality traits, participation in and dedication to a particular discipline, and the mentor's confidence in the candidate's abilities. In this Words of Advice, we provide guidance to researchers on composing constructive and supportive recommendation letters, including tips for structuring and providing specific and effective examples, while maintaining a balance in language and avoiding potential biases.

Building and sustaining mentor interactions as a mentee.

Mentorship is experience and/or knowledge-based guidance. Mentors support, sponsor and advocate for mentees. Having one or more mentors when you seek advice can significantly influence and improve your research endeavours, well-being and career development. Positive mentee-mentor relationships are vital for maintaining work-life balance and success in careers. Early-career researchers (ECRs), in particular, can benefit from mentorship to navigate challenges in academic and nonacademic life and careers. Yet, strategies for selecting mentors and maintaining interactions with them are often underdiscussed within research environments. In this Words of Advice, we provide recommendations for ECRs to seek and manage mentorship interactions. Our article draws from our experiences as ECRs and published work, to provide suggestions for mentees to proactively promote beneficial mentorship interactions. The recommended practices highlight the importance of identifying mentorship needs, planning and selecting multiple and diverse mentors, setting goals, and maintaining constructive, and mutually beneficial working relationships with mentors.

Identification and Development of Therapeutics for COVID-19.

After emerging in China in late 2019, the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread worldwide, and as of mid-2021, it remains a significant threat globally. Only a few coronaviruses are known to infect humans, and only two cause infections similar in severity to SARS-CoV-2: Severe acute respiratory syndrome-related coronavirus, a species closely related to SARS-CoV-2 that emerged in 2002, and Middle East respiratory syndrome-related coronavirus, which emerged in 2012. Unlike the current pandemic, previous epidemics were controlled rapidly through public health measures, but the body of research investigating severe acute respiratory syndrome and Middle East respiratory syndrome has proven valuable for identifying approaches to treating and preventing novel coronavirus disease 2019 (COVID-19). Building on this research, the medical and scientific communities have responded rapidly to the COVID-19 crisis and identified many candidate therapeutics. The approaches used to identify candidates fall into four main categories: adaptation of clinical approaches to diseases with related pathologies, adaptation based on virological properties, adaptation based on host response, and data-driven identification (ID) of candidates based on physical properties or on pharmacological compendia. To date, a small number of therapeutics have already been authorized by regulatory agencies such as the Food and Drug Administration (FDA), while most remain under investigation. The scale of the COVID-19 crisis offers a rare opportunity to collect data on the effects of candidate therapeutics. This information provides insight not only into the management of coronavirus diseases but also into the relative success of different approaches to identifying candidate therapeutics against an emerging disease. IMPORTANCE The COVID-19 pandemic is a rapidly evolving crisis. With the worldwide scientific community shifting focus onto the SARS-CoV-2 virus and COVID-19, a large number of possible pharmaceutical approaches for treatment and prevention have been proposed. What was known about each of these potential interventions evolved rapidly throughout 2020 and 2021. This fast-paced area of research provides important insight into how the ongoing pandemic can be managed and also demonstrates the power of interdisciplinary collaboration to rapidly understand a virus and match its characteristics with existing or novel pharmaceuticals. As illustrated by the continued threat of viral epidemics during the current millennium, a rapid and strategic response to emerging viral threats can save lives. In this review, we explore how different modes of identifying candidate therapeutics have borne out during COVID-19.

A community-led initiative for training in reproducible research.

Open and reproducible research practices increase the reusability and impact of scientific research. The reproducibility of research results is influenced by many factors, most of which can be addressed by improved education and training. Here we describe how workshops developed by the Reproducibility for Everyone (R4E) initiative can be customized to provide researchers at all career stages and across most disciplines with education and training in reproducible research practices. The R4E initiative, which is led by volunteers, has reached more than 3000 researchers worldwide to date, and all workshop materials, including accompanying resources, are available under a CC-BY 4.0 license at https://www.repro4everyone.org/.

Identification and Development of Therapeutics for COVID-19.

After emerging in China in late 2019, the novel coronavirus SARS-CoV-2 spread worldwide and as of mid-2021 remains a significant threat globally. Only a few coronaviruses are known to infect humans, and only two cause infections similar in severity to SARS-CoV-2: Severe acute respiratory syndrome-related coronavirus, a closely related species of SARS-CoV-2 that emerged in 2002, and Middle East respiratory syndrome-related coronavirus, which emerged in 2012. Unlike the current pandemic, previous epidemics were controlled rapidly through public health measures, but the body of research investigating severe acute respiratory syndrome and Middle East respiratory syndrome has proven valuable for identifying approaches to treating and preventing novel coronavirus disease 2019 (COVID-19). Building on this research, the medical and scientific communities have responded rapidly to the COVID-19 crisis to identify many candidate therapeutics. The approaches used to identify candidates fall into four main categories: adaptation of clinical approaches to diseases with related pathologies, adaptation based on virological properties, adaptation based on host response, and data-driven identification of candidates based on physical properties or on pharmacological compendia. To date, a small number of therapeutics have already been authorized by regulatory agencies such as the Food and Drug Administration (FDA), while most remain under investigation. The scale of the COVID-19 crisis offers a rare opportunity to collect data on the effects of candidate therapeutics. This information provides insight not only into the management of coronavirus diseases, but also into the relative success of different approaches to identifying candidate therapeutics against an emerging disease.