Figure 7
Model of folate dose-dependent regulation on zebrafish heart development. ER: Endoplasmic reticulum; FR: Folate receptor; SAM: S-adenosylmethionine; Folic acid enters the cell through the folate receptor and undergoes the metabolic cycle. MTX specifically antagonizes MTRR, and knockout of the mthfr gene inhibits the endoplasmic reticulum synthesis MTHFR enzyme. These factors cause the conversion of folic acid to 5-methyl THF to be blocked, which reduces the efficiency of the conversion of homocysteine to methionine in the cell. Decreasing the content of methionine leads to a decrease in the content of DNA methylation donor SAM, which in turn affects the methylation of the hand2 promoter. This can lead to abnormal embryonic heart development.