Elevated Serum Homocysteine Levels Impair Embryonic Neurodevelopment by Dysregulating the Heat Shock Proteins

Observational studies have found that elevated serum homocysteine (Hcy) levels during pregnancy may be associated with the occurrence of neural tube defects (NTDs). However, the effect of Hcy on fetal neural development and its underlying molecular mechanisms remains unclear. To uncover the molecular mechanism, we analyzed the serum Hcy concentration in pregnant women with normal and abnormal pregnancy outcomes and treated zebrafish model embryos with high Hcy. Our findings indicate that elevated serum Hcy levels during pregnancy are associated with adverse pregnancy outcomes. Using the zebrafish model and transcriptome analysis, we found that high Hcy levels led to developmental neural malformations in embryos and affected the expression of key genes at various stages of neural development. Interestingly, deep transcriptome analysis showed that dysregulated heat shock proteins (HSP) might play a key role in high Hcy-mediated alterations in neural development. Importantly, the inhibition of HSP significantly restored the embryonic neuroteratogenic effects induced by high Hcy levels in the zebrafish model. In summary, our findings provide a novel molecular pathogenic mechanism in which ectopic HSP is associated with neural development defects caused by high Hcy levels, suggesting potential prevention and targeted therapies for high Hcy level-related NTDs during pregnancy.