Precise Dose of Folic Acid Supplementation Is Essential for Embryonic Heart Development in Zebrafish

Abstract

Folic acid, one of the 13 essential vitamins, plays an important role in cardiovascular development. Mutations in folic acid synthesis gene 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with the occurrence of congenital heart disease. However, the mechanisms underlying the regulation of cardiac development by mthfr gene are poorly understood. Here, we exposed zebrafish embryos to excessive folate or folate metabolism inhibitors. Moreover, we established a knock-out mutant of mthfr gene in zebrafish by using CRISPR/Cas9. The zebrafish embryos of insufficient or excessive folic acid and mthfr−/− mutant all gave rise to early pericardial edema and cardiac defect at 3 days post fertilization (dpf). Furthermore, the folic acid treated embryos showed abnormal movement at 5 dpf. The expression levels of cardiac marker genes hand2, gata4, and nppa changed in the abnormality of folate metabolism embryos and mthfr−/− mutant, and there is evidence that they are related to the change of methylation level caused by the change of folate metabolism. In conclusion, our study provides a novel model for the in-depth study of MTHFR gene and folate metabolism. Furthermore, our results reveal that folic acid has a dose-dependent effect on early cardiac development. Precise dosage of folic acid supplementation is crucial for the embryonic development of organisms.

Evaluation of the association between maternal folic acid supplementation and the risk of congenital heart disease: a systematic review and meta-analysis

“…It is interesting that we found a positive association between FA supplementation within 1 month before and after pregnancy and CHD, and high-dose FA intake is positively associated with ASD. FA supplementation may have a negative effect on heart development in high doses or specific time windows, the precise biological mechanisms of FA on heart development remain to be elucidated [ 40 ]. At present, little is known about the effects of dosage of FA supplementation on infant birth outcome.…”

hoxa1a-Null Zebrafish as a Model for Studying HOXA1-Associated Heart Malformation in Bosley–Salih–Alorainy Syndrome

“…The lateral view of zebrafish adults was also imaged after anesthesia by camera. Calculation of heart rate, stroke volume, cardiac output (CO) and fractional area change (FAC) were carried out as previously described [22,23].…”

Somatic GATA4 mutation contributes to tetralogy of Fallot

“…Environmental precipitating factors may contribute to ~10% of congenital heart disease cases, although their underlying mechanisms are largely unclear ( 2 ). Non-inheritable factors predisposing congenital heart disease encompass maternal viral infection, folate deficiency, early-onset pre-eclampsia, obesity, diabetes mellitus, autoimmune imbalance and maternal consumption of alcohol, tobacco and medications as well as exposure to toxicants and air pollutants during gestation ( 47 , 52 , 53 ). However, ever-mounting evidence demonstrates that heritable pathogenic determinants are the leading cause of congenital heart disease ( 2 , 51 ).…”