Folic acid ameliorates high glucose–induced neurotoxicity in human forebrain organoids: Insights from proteomics

Pregestational diabetes (PGDM) has been associated with an elevated risk of congenital abnormalities, particularly those affecting the nervous system. The efficacy of folic acid (FA) supplementation in reducing the incidence of neurodevelopmental damage caused by PGDM has been well documented. However, the exact mechanism is unclear. Here, a human forebrain organoid model, which replicates the three-dimensional structure of the early fetal neural tissue, was employed to study the neuroprotective effects of FA in PGDM. In this study, the forebrain organoids were cultured at high glucose (HG) concentrations from Days 20 to 40 with or without FA. Immunostaining revealed that the supplementation of FA significantly decreased HG-induced neuron apoptosis. The proteomics examination suggested HG caused an increase in glial fibrillary acidic protein expression, a marker of astrocytes, leading to the upregulation of metallothionein expression and perturbation of mineral absorption, whereas FA reversed this effect. Proteomics analysis further showed that FA reduced HG-induced cell migration. Moreover, Western blot analysis verified that FA mitigated HG-induced apoptosis and cell migration via AMPK/FOXO pathway. Overall, current findings indicate that FA, as a functional food ingredient, has a protective effect on HG-induced abnormal fetal neurodevelopment.