Sex-Specific Effects of Early-Life Iron Deficiency and Prenatal Choline Treatment on Adult Rat Hippocampal Transcriptome

BackgroundFetal-neonatal iron deficiency (ID) causes long-term neurocognitive and affective dysfunctions. Clinical and preclinical studies have shown that early-life ID produces sex-specific effects. However, little is known about the molecular mechanisms underlying these early-life ID-induced sex-specific effects on neural gene regulation. ObjectiveTo illustrate sex-specific transcriptome alteration in adult rat hippocampus induced by fetal-neonatal ID and prenatal choline treatment. MethodsPregnant rats were fed an iron-deficient (4 mg/kg Fe) or iron-sufficient (200 mg/kg Fe) diet from gestational day (G) 2 to postnatal day (P) 7 with or without choline supplementation (5 g/kg choline) from G11-18. Hippocampi were collected from P65 offspring of both sexes and analyzed for changes in gene expression. ResultsBoth early-life ID and choline treatment induced transcriptional changes in adult female and male rat hippocampus. Both sexes showed ID-induced alterations in gene networks leading to enhanced neuroinflammation. In females, ID-induced changes indicating enhanced activity of oxidative phosphorylation and fatty acid metabolism, which are contrary to the ID effect in males. Prenatal choline supplementation induced the most robust changes in gene expression, particularly in the iron-deficient animals where it partially rescued ID-induced dysregulations. Choline supplementation also altered hippocampal transcriptome in the iron-sufficient rats with indications for both beneficial and adverse effects. ConclusionsThis study provided unbiased global assessments of gene expression regulated by iron and choline status in a sex-specific manner, with greater effects in female than male rats. Our new findings highlight potential sex-specific gene networks regulated by iron and choline status for further investigation.