Defined Diets Link Iron and α-Linolenic Acid to Cyp1b1 Regulation of Neonatal Liver Development Through Srebp Forms...

Area of Science:

• Developmental biology
• Nutritional science
• Molecular toxicology

Background:

• Cytochrome P450 1B1 (Cyp1b1) plays a role in hepatic vascular and stellate cell (HSC) function, impacting liver fibrosis.
• While hepatocyte expression is minimal, Cyp1b1 deletion significantly alters neonatal liver gene expression.
• Embryonic mesenchyme is a likely source of Cyp1b1 during early organogenesis.

Purpose of the Study:

• To investigate the interconnected effects of dietary alpha-linolenic acid (ALA), vitamin A deficiency (VAD), and suboptimal iron on neonatal liver gene expression in Cyp1b1-deficient mice.
• To elucidate the role of Cyp1b1 in regulating HSC activation, iron homeostasis, and metabolic pathways during early development.

Main Methods:

• Utilized Cyp1b1-deficient mice fed defined breeder diets varying in ALA, VAD, and iron.
• Analyzed neonatal liver gene expression at birth and weaning.
• Assessed HSC activation, hepcidin expression, and pathways related to fatty acid and cholesterol biosynthesis.

Main Results:

• Cyp1b1 deletion and VAD independently activated perinatal HSC and suppressed hepcidin, impacting iron control.
• Cyp1b1 deficiency altered iron regulation gene expression and suppressed Srebp-regulated fatty acid/cholesterol biosynthesis pathways.
• Alpha-linolenic acid (ALA) countered Cyp1b1 deletion's inhibitory effects on hepcidin expression, suggesting oxylipin mediation.

Conclusions:

• Neonatal liver development is significantly influenced by Cyp1b1, particularly in its interaction with maternal diet (ALA, VAD, iron).
• Cyp1b1 deficiency impacts HSC activation, iron metabolism, and lipid biosynthesis, with VAD partially reversing these effects.
• Dietary ALA may mitigate adverse effects of Cyp1b1 deficiency on iron homeostasis, potentially via oxylipin metabolites.