scholarly journals Methylenetetrahydrofolate Reductase Deficiency Reduces Brain Microglia in Zebrafish During Embryonic Development and Is Not Corrected by Folic Acid

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 925-925
Author(s):  
Rebecca Simonian ◽  
Emanuela Pannia ◽  
Rola Hammoud ◽  
Xiucheng Cui ◽  
Ruslan Kubant ◽  
...  
Keyword(s):  
Folic Acid ◽  
Embryonic Development ◽  
Methylenetetrahydrofolate Reductase ◽  
Fetal Brain ◽  
Neutral Red ◽  
High Dose ◽  
Head Region ◽  
Zebrafish Model ◽  
Mthfr Deficiency

Abstract Objectives Neuronal development and function is dependent on the interaction between the central nervous system and immune system. Microglia are resident macrophages of the brain critical for regulating neuronal activity during embryonic development. 5-methyltetrahydrofolate (5MTHF), the bioactive folate form, is essential for fetal brain development and immune function. Common variants in methylenetetrahydrofolate reductase (MTHFR), required for conversion of folic acid (FA) to 5-MTHF, limits its production. High dose FA supplementation is recommended but high FA may have the converse effect of reducing MTHFR activity. The objective of this study was to determine the effects of mthfr deficiency and its interaction with FA during embryonic development on microglia in a zebrafish model. Methods The mthfr gene in zebrafish was disrupted using two CRISPR mutagenesis methods. A set of 4 guide RNAs (gRNAs) + cas9 protein or cas9 alone (control) were injected to assay F0 zebrafish, or 2 gRNAs + cas9 mRNA were used to induce a germline mutation. To visualize macrophages at 4 days post fertilization (dpf) in live zebrafish, the transgenic mpeg1: mcherry line was used. In a subset of embryos, FA was added at 0, 50, 75, or 100- μM from 0–4dpf. At 4dpf, live neutral red staining for microglia was performed and the number in the optic tectum was quantified. 5MTHF, s-adenosylmethionine (SAM) and s-adenosylhomocysteine (SAH) were assayed in whole zebrafish at 5dpf. Results In vivo imaging revealed a reduction in macrophage number (∼30%, P < 0.001) in the head region of mthfr disrupted zebrafish, but not in the periphery. mthfr zebrafish also had less microglia compared to controls (15%, P < 0.001). These changes were associated with lower 5MTHF (90%, P < 0.0001) and SAM: SAH (∼50%, P < 0.001) at 5dpf indicative of lower methylation potential. Exposure with FA did not correct the phenotype and at 100µM FA, control zebrafish also showed a decrease in microglia similar to mthfr zebrafish, confirming inhibitory effects of the high FA dose. Conclusions mthfr deficiency reduces microglia in zebrafish but supplementation with FA does not prevent and may exacerbate the negative effects. The 5MTHF form of folate may be a better alternative to FA for brain health in patients with underlying genetic conditions. Funding Sources Supported by CIHR-INMD.

scholarly journals Testicular MTHFR deficiency may explain sperm DNA hypomethylation associated with high dose folic acid supplementation

2018 ◽  
Vol 27 (7) ◽  
pp. 1123-1135 ◽  
Author(s):  
Mahmoud Aarabi ◽  
Karen E Christensen ◽  
Donovan Chan ◽  
Daniel Leclerc ◽  
Mylène Landry ◽  
...  
Keyword(s):  
Folic Acid ◽  
Folic Acid Supplementation ◽  
High Dose ◽  
Dna Hypomethylation ◽  
Acid Supplementation ◽  
Sperm Dna ◽  
Mthfr Deficiency

Oxidative stress and platelet activation in subjects with moderate hyperhomocysteinaemia due to MTHFR 677 C→T polymorphism

2012 ◽  
Vol 108 (09) ◽  
pp. 533-542 ◽  
Author(s):  
Alfredo Dragani ◽  
Angela Falco ◽  
Francesca Santilli ◽  
Stefania Basili ◽  
Giancarlo Rolandi ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Folic Acid ◽  
Platelet Activation ◽  
Methylenetetrahydrofolate Reductase ◽  
Folic Acid Supplementation ◽  
Control Group ◽  
Loading Test ◽  
Study Objective ◽  
Acid Supplementation

SummaryThe methylenetetrahydrofolate reductase (MTHFR) 677 C→T polymorphism may be associated with elevated total homocysteine (tHcy) levels, an independent risk factor for cardiovascular disease. It was the study objective to evaluate in vivo lipid peroxidation and platelet activation in carriers of the MTHFR 677 C→T polymorphism and in non-carriers, in relation to tHcy and folate levels. A cross-sectional comparison of urinary 8-iso-prostaglandin (PG)F2α and 11-dehydro-thromboxane (TX)B2 (markers of in vivo lipid peroxidation and platelet activation, respectively) was performed in 100 carriers and 100 non-carriers of the polymorphism. A methionine-loading test and folic acid supplementation were performed to investigate the causal relationship of the observed associations. Urinary 8-iso-PGF2α and 11-dehydro-TXB2 were higher in carriers with hyperhomocysteinaemia than in those without hyperhomocysteinaemia (p<0.0001). Hyperhomocysteinaemic carriers had lower folate levels (p=0.0006), higher urinary 8-iso-PGF2α (p<0.0001) and 11-dehydro-TXB2 (p<0.0001) than hyperhomocysteinaemic non-carriers. On multiple regression analysis, high tHcy (p<0.0001), low folate (p<0.04) and MTHFR 677 C→T polymorphism (p<0.001) independently predicted high rates of 8-iso-PGF2α excretion. Methionine loading increased plasma tHcy (p=0.002), and both urinary prostanoid metabolites (p=0.002). Folic acid supplementation was associated with decreased urinary 8-iso-PGF2α and 11-dehydro-TXB2 excretion (p<0.0003) in the hyperhomocysteinaemic group, but not in the control group, with substantial inter-individual variability related to baseline tHcy level and the extent of its reduction. In conclusion, hyperhomocysteinaemia due to the MTHFR 677 C→T polymorphism is associated with enhanced in vivo lipid peroxidation and platelet activation that are reversible, at least in part, following folic acid supplementation. An integrated biomarker approach may help identifying appropriate candidates for effective folate supplementation.

scholarly journals Development of a Zebrafish Model for Studies of the Interaction of Methylenetetrahydrofolate Reductase Deficiency and Dietary Folates on Metabolic Regulation

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 947-947
Author(s):  
Emanuela Pannia ◽  
Rebecca Simonian ◽  
Rola Hammoud ◽  
Xiucheng Cui ◽  
Ruslan Kubant ◽  
...  
Keyword(s):  
High Throughput ◽  
Lipid Accumulation ◽  
Metabolic Regulation ◽  
Methylenetetrahydrofolate Reductase ◽  
Transcriptional Start Site ◽  
Whole Body ◽  
High Cholesterol Diet ◽  
Zebrafish Model ◽  
Metabolic Dysregulation ◽  
Mthfr Deficiency

Abstract Objectives Methylenetetrahydrofolate reductase (MTHFR) is required for 5-methyltetrahydrofolate (5MTHF) synthesis, and common variants reduces its efficiency and associate with metabolic disorders. High folic acid (FA) intakes, commonly consumed by pregnant women in North America, may further inhibit MTHFR enzyme; programming long-term metabolic dysregulation in offspring. The zebrafish (Danio rerio) is a valuable model for study of embryonic development and high-throughput nutrient × gene interactions. The objective of this study was to characterize a zebrafish model of mthfr deficiency and assess the interaction between mthfr and FA intakes on early-life metabolic dysregulation. Methods Zebrafish were co-injected with a set of 4 guide RNAs (gRNAs) or cas9 protein alone and F0 embryos were assayed for a high-throughput phenotypic screen. Germline F1 knock-out homozygous mutants (mthfr −/−) were made by co-injecting cas9 mRNA with 2 gRNAs targeting the transcriptional start site of the mthfr gene. Embryos were raised up to 5 days post-fertilization (dpf) and folate and 1-carbon metabolites measured by LC-MS/MS. Lipid accumulation was assessed at 5dpf and after feeding a high cholesterol diet (HDC) with cholesteryl-ester (CE)-BoDipy-C12® from 5–15dpf. A subset of embryos were exposed to no (0µM) or high (100µM) FA from 0–5dpf and whole-body lipids measured. Results mthfr disruption in zebrafish reduced (80%) mthfr mRNA and 5MTHF levels (90%) compared to controls (P &lt; 0.0001). They had lower 1-carbon metabolites including betaine, methionine, s-adenosylmethionine, and higher choline, s-adenosylhomocysteine, cystathionine and homocysteine (P &lt; 0.01). As well, neutral lipid accumulation was higher in liver, heart and vasculature at 5 and 15 dpf along with higher CE altered cholesterol transport/metabolism. High FA exposure ameliorated lipid accumulation in mthfr mutants at 5 dpf (P = 0.06), but increased lipids accumulation in controls compared to no exposure (P = 0.03). Conclusions The zebrafish mthfr deficient model exhibits a similar alteration to 1-carbon metabolites as in humans with severe MTHFR deficiency. This zebrafish model has potential for understanding the interaction of mthfr deficiency and dietary folates on metabolism. Funding Sources CIHR-INMD, EP by NSERC-CGS

scholarly journals C1 metabolism and CVD outcomes in older adults

2011 ◽  
Vol 71 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Helene McNulty ◽  
J. J. Strain ◽  
Kristina Pentieva ◽  
Mary Ward
Keyword(s):  
Folic Acid ◽  
Methylenetetrahydrofolate Reductase ◽  
Epidemiological Studies ◽  
Plasma Homocysteine ◽  
Convincing Evidence ◽  
B Vitamins ◽  
Current Evidence ◽  
High Dose ◽  
C1 Metabolism ◽  
Meta Analyses

CVD is the most common cause of death in people over 65 years. This review considers the latest evidence for a potential protective effect of C1 donors (folate and the metabolically related B-vitamins) in CVD. Such an effect may or may not be mediated via the role of these nutrients in maintaining plasma homocysteine concentrations within a desirable range. Despite predictions from epidemiological studies that lowering plasma homocysteine would reduce cardiovascular risk, several secondary prevention trials in at-risk patients published since 2004 have failed to demonstrate a benefit of homocysteine-lowering therapy with B-vitamins on CVD events generally. All these trials were performed in CVD patients with advanced disease; thus current evidence suggests that intervention with high-dose folic acid is of no benefit in preventing another event, at least in the case of heart disease. The evidence at this time, however, is stronger for stroke, with meta-analyses of randomised trials showing that folic acid reduces the risk of stroke, particularly in people with no history of stroke. Genetic studies provide convincing evidence to support a causal relationship between sub-optimal B-vitamin status and CVD. People homozygous for the common C677T variant in the gene encoding the folate-metabolising enzyme, methylenetetrahydrofolate reductase (MTHFR), typically have a 14–21% higher risk of CVD. Apart from folate, riboflavin is required as a co-factor for MTHFR. New evidence shows that riboflavin intervention results in marked lowering of blood pressure, specifically in patients with the MTHFR 677TT genotype. This novel gene–nutrient interaction may provide insights as to the mechanism that links C1 metabolism with CVD outcomes.

scholarly journals Effect of High Dose Folic Acid Therapy on Hyperhomocysteinemia in Hemodialysis Patients

2000 ◽  
Vol 11 (6) ◽  
pp. 1106-1116 ◽  
Author(s):  
GERE SUNDER-PLASSMANN ◽  
MANUELA FÖDINGER ◽  
HEIDI BUCHMAYER ◽  
MENELAOS PAPAGIANNOPOULOS ◽  
JADWIGA WOJCIK ◽  
...  
Keyword(s):  
Folic Acid ◽  
Treatment Period ◽  
Plasma Levels ◽  
Methylenetetrahydrofolate Reductase ◽  
Plasma Concentrations ◽  
Hemodialysis Patients ◽  
High Dose ◽  
Acid Therapy ◽  
Total Homocysteine

Abstract. Homocysteine is associated with atherosclerosis and enhanced cardiovascular risk. In previous studies, treatment with folic acid up to 15 mg/d failed to correct hyperhomocysteinemia in the majority of end-stage renal disease patients. A dose of 30 or 60 mg of folic acid per day was compared with 15 mg/d in an attempt to normalize hyperhomocysteinemia in 150 hemodialysis patients. In a randomized, double-blind, multicenter study, 144 patients completed the 4-wk treatment period and 121 patients completed the 6-mo follow-up. Total homocysteine plasma levels were reduced by 32.1% (15 mg/d), 29.9% (30 mg/d), or 37.8% (60 mg/d) with no significant differences found between the three treatment groups. Baseline total homocysteine plasma concentration was an independent predictor of the response to folic acid therapy (P= 0.0001), whereas the 5,10-methylenetetrahydrofolate reductase polymorphisms (MTHFR677C → T and 1298A → C) had no influence. Nevertheless, patients with theMTHFR677TT genotype more frequently attained normal total homocysteine plasma levels than patients with the CC or CT genotype (P= 0.025). In response to 60 mg of folic acid per day, TT genotype patients had lower folate plasma levels compared to CC or CT genotype patients (P= 0.016). After completion of the 4-wk treatment period with 30 or 60 mg of folic acid per day, there was a marked rebound of total homocysteine plasma levels at the end of the follow-up in patients with theMTHFR677TT genotype, which even exceeded baseline values in several patients (P= 0.0001). This study clearly demonstrates that doses of 30 or 60 mg of folic acid per day are not more effective than 15 mg/d in reducing hyperhomocysteinemia in regular hemodialysis patients. Patients with theMTHFR677TT genotype are more likely to realize normal total homocysteine plasma levels. Folic acid at 30 or 60 mg/d but not 15 mg/d results in a rebound of total homocysteine plasma concentrations when treatment is stopped.

scholarly journals Genetically encoded thiol redox-sensors in the zebrafish model: lessons for embryonic development and regeneration

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Oksana Breus ◽  
Thomas Dickmeis
Keyword(s):  
Embryonic Development ◽  
Tissue Injury ◽  
Zebrafish Model ◽  
Research Fields ◽  
Open Questions ◽  
Downstream Effects ◽  
Imaging Results ◽  
Redox Sensors ◽  
Thiol Redox

AbstractImportant roles for reactive oxygen species (ROS) and redox signaling in embryonic development and regenerative processes are increasingly recognized. However, it is difficult to obtain information on spatiotemporal dynamics of ROS production and signaling in vivo. The zebrafish is an excellent model for in vivo bioimaging and possesses a remarkable regenerative capacity upon tissue injury. Here, we review data obtained in this model system with genetically encoded redox-sensors targeting H2O2 and glutathione redox potential. We describe how such observations have prompted insight into regulation and downstream effects of redox alterations during tissue differentiation, morphogenesis and regeneration. We also discuss the properties of the different sensors and their consequences for the interpretation of in vivo imaging results. Finally, we highlight open questions and additional research fields that may benefit from further application of such sensor systems in zebrafish models of development, regeneration and disease.

Folic acid administration and antibodies against homocysteinylated proteins in subjects with hyperhomocysteinemia

2006 ◽  
Vol 96 (09) ◽  
pp. 342-347 ◽  
Author(s):  
Anetta Undas ◽  
Ewa Stïpień ◽  
Rafal Glowacki ◽  
Joanna Tisończyk ◽  
Wieslawa Tracz ◽  
...  
Keyword(s):  
Folic Acid ◽  
Healthy Subjects ◽  
Methylenetetrahydrofolate Reductase ◽  
Autoimmune Response ◽  
Serum Folate ◽  
Significant Difference ◽  
Artery Disease ◽  
Folate And Vitamin B12 ◽  
Acid Administration

SummaryGrowing evidence indicates that elevated total homocysteine (tHcy) levels can elicit autoimmune response in vivo. Antibodies against Nε-Hcy-proteins have been shown to be associated with stroke and premature myocardial infarction. The aim of the current study was to investigate the effect of treatment with folic acid on anti-Nε-Hcy-albumin and -hemoglobin antibodies. We recruited 20 apparently healthy men and 12 male patients with documented coronary artery disease (CAD). All participants had plasma fasting tHcy levels >15 µM. At baseline, and after three and six months of treatment with folic acid 1 mg daily, we determined tHcy, serum folate and vitamin B12 levels, along with serum anti-Nε-Hcy-albumin and -hemoglobin IgG antibodies using the home-made immunoenzymatic assays. Both groups did not differ with regard to age, tHcy, folate, lipid profile, and CRP. The only significant difference between healthy subjects and CAD patients was levels of antibodies against Nε-Hcy-albumin. As expected, folic acid administration led to significant decreases in tHcy and increases in folate levels in both groups. Levels of both anti-Nε-Hcy-albumin and -hemoglobin antibodies fell markedly following a three-month folic acid administration in healthy subjects, but not in CAD patients, without any changes at six months in either group. Folic acid administration resulted in a loss of significant correlations between tHcy and antibodies both following three and six months of the therapy in healthy subjects, in contrast to CAD patients. Carriers of the methylenetetrahydrofolate reductase (MTHFR) 677T allele with CAD had significantly higher levels of anti-Nε-Hcy-albumin before and during folic acid administration as compared to healthy subjects. In conclusion, our findings suggest that Hcy-related autoimmune response is resistant to folic acid administration in CAD patients, while in healthy subjects reduced tHcy levels are associated with suppressed production of antibodies against Nε-Hcyproteins. These observations might explain at least in part the failure of vitamin therapy to reduce the risk of cardiovascular events as recently reported.

scholarly journals FOLIC ACID;

2017 ◽  
Vol 24 (12) ◽  
pp. 1884-1888
Author(s):  
Haleema Yasmin ◽  
Shireen Bhutta ◽  
Hasina -
Keyword(s):  
Folic Acid ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Methylenetetrahydrofolate Reductase ◽  
T Test ◽  
Test Results ◽  
Inclusion Criteria ◽  
Folate Status ◽  
Significant Difference ◽  
Mthfr Deficiency

Objectives: The objective of our study was to assess the effectiveness offolic acid in optimizing the red blood cells folate levels and to observe the frequency of folateresistance among Pakistani female patients. Setting: Outpatient Department of Obstetrics &Gynaecology, Jinnah Post graduate Medical Centre (JPMC), Karachi. Period: January–July2016. Methodology: Participants fulfilling the inclusion criteria were included after informedconsent. Detail history and physical examination was done in each participant. All studyparticipants received 5mg (400 μg) folic acid as a daily supplement for 24 weeks. Red bloodcell folate concentrations were measured at baseline and after 24 weeks of therapy. Pairedsample t-test was used to find out significant difference between folate levels. Results: A totalof 44 women (23 pregnant while 21 non pregnant) were included in the study. Mean age of theparticipants was 27.6 ± 5.9years and mean BMI was 23.9 ± 4.1kg/m2 respectively. The meanvalues of Red blood cells folate at baseline and at 24 weeks were 623.6 ± 406.6 and 861.9 ±432.4respectively. Paired sample t-test results showed that there was no significant difference.Thirty-two (70.4%) women showed an increase in RBC folate status while 13 (29.6%) womenhad steady or decreased levels of folate after taking folic acid for 24 weekswhich may be dueto RBS enzyme methylenetetrahydrofolate reductase (MTHFR) deficiency. Conclusion: Simplefolic acid supplementation is not very helpful in improving folate status in female Pakistanipatients. Resistant to improvement may be due to MTHFR deficiency in our study subjects.

scholarly journals Moxifloxacin efficacy against Mycobacterium abscessus in vivo using zebrafish model

2019 ◽  
Author(s):  
Wenjuan Nie ◽  
Shan Gao ◽  
Tianlu Teng ◽  
Wenqiang Zhou ◽  
Yuanyuan Shang ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Mycobacterium Abscessus ◽  
High Dose ◽  
Good Activity ◽  
Zebrafish Model ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Significant Difference

AbstractMoxifloxacin (MFX) showed good activity in vitro against Mycobacterium abscessus (M. abscessus) and was suggested as one of the antibiotic regimens for adults with M. abscessus disease. However, some other studies showed that MFX showed less or none activity against M. abscessus. In our study we aim to evaluate MFX activity against M. abscessus using zebrafish (ZF) model in vivo. MIC of each drugs were determined by broth microdilution method. M. abscessus labeled by CM-DiI, were micro-injected into ZF. Survival curves were determined by recording dead ZF every day. After 4 days of incubation ZF were lysed. Colony-forming unit (CFU) were enumerated and results are expressed as mean log10 CFU per ZF. Bacteria dissemination and fluorescence intensity in ZF were observed and analyzed. Inhibition rate was also calculated. In our study MFX showed good activity in vitro. But in vivo MFX showed limited restriction to M. abscessus. The association between increased survival and high dose of MFX is not significant. Same results were observed in bacterial fluorescence intensity and inhibition rates, with no significant difference when compared with no drug group (P > 0.05). However, significant difference was observed in azithromycin (AZM) group. MFX showed limited efficacy on Mycobacterium abscessus in vivo using ZF model. MFX’s activity in vivo need to be confirmed.

Reproductive and Developmental Toxicity of Arsenic in Rodents: A Review

2006 ◽  
Vol 25 (5) ◽  
pp. 319-331 ◽  
Author(s):  
Amy Wang ◽  
Steven D. Holladay ◽  
Douglas C. Wolf ◽  
S. Ansar Ahmed ◽  
John L. Robertson
Keyword(s):  
Drinking Water ◽  
Developmental Toxicity ◽  
Fetal Brain ◽  
Inorganic Arsenic ◽  
In Vivo Studies ◽  
Laboratory Animals ◽  
Population Exposure ◽  
High Dose ◽  
Oral Gavage

Arsenic is a recognized reproductive toxicant in humans and induces malformations, especially neural tube defects, in laboratory animals. Early studies showed that murine malformations occurred only when a high dose of inorganic arsenic was given by intravenous or intraperitoneal injection in early gestation. Oral gavage of inorganic arsenic at maternally toxic doses caused reduced fetal body weight and increased resorptions. Recently, arsenic reproductive and developmental toxicity has been studied in situations more similar to human exposures and using broader endpoints, such as behavioral changes and gene expression. For the general population, exposure to arsenic is mostly oral, particularly via drinking water, repeated and prolonged over time. In mice and rats, methylated or inorganic arsenic via drinking water or by repeated oral gavage induced male and female reproductive and developmental toxicities. Furthermore, at nonmaternally toxic levels, inorganic arsenic given to pregnant dams via drinking water affected fetal brain development and postnatal behaviors. However, arsenic given by repeated oral gavage to pregnant mice and rats was not morphologically teratogenic. In this review of arsenic reproductive and developmental toxicity in rats and mice, the authors summarize recent in vivo studies and discuss possible underlying mechanisms. The influences of folate, selenium, zinc, and arsenic methylation on arsenic reproductive and developmental toxicity are also discussed.

Sign in / Sign up

Export Citation Format

Share Document