Mechanism of FoxO1 in the Metabolic Shift of Fetal Rat Heart

Cardiovascular diseases remain a leading cause of morbidity and mortality worldwide, underscoring the need to better understand cardiovascular physiology. A key aspect involves identifying regulatory molecules that govern metabolic shifts. Forkhead box protein O1 (FoxO1) has emerged as a potential regulator; however, its role and underlying mechanisms remain unclear. This study investigated FoxO1 in metabolic adaptation using Wistar rats divided into age groups (fetal, postnatal day 1, postnatal day 7, adult) and treatment groups (control, hypoxia, FoxO1 inhibitor, combination). Hypoxia (12-14% O₂) and FoxO1 inhibitor (AS1842856, 10 mg/kgBW/day) were administered accordingly. Parameters assessed included hypoxia inducible factor 1 α (HIF-1α), FoxO1 mRNA and protein, glucose transporter type 1 (GLUT1), glucose transporter type 4 (GLUT4), cluster of differentiation 36 (CD36), hexokinase, pyruvate dehydrogenase kinase isoform 4 (PDK4), phosphoenolpyruvate carboxykinase (PEPCK), lactic acid, malonyl-CoA, carnitine palmitoyltransferase 1 (CPT1), citrate synthase, cytochrome c, and adenosine triphosphate (ATP). ATP production increased with age, associated with higher FoxO1 expression and metabolic shifts. Hypoxia in fetal hearts reduced HIF-1α and FoxO1. FoxO1 inhibition elevated glycolytic and oxidative markers. In conclusion, FoxO1 regulates glycolysis and lipid metabolism, offering insights into cardiac adaptation to hypoxia and potential therapeutic strategies.