Hypothyroidism drives hepatic ferroptosis via disrupting THRβ/RXRβ–AMPKα1–GPX4 axis

Congenital hypothyroidism (CH), the most common endocrine disorder in neonates, has a worldwide incidence of 1/1400–1/2800. CH has been reported to be associated with liver injury, including hepatitis, metabolic dysfunction-associated steatotic liver disease, and fibrosis, but the underlying mechanisms remain unclear. Using a previously generated CH pig model, this study aimed to elucidate the pathogenesis of hypothyroidism-induced liver injury (HILI) and explore potential therapeutic strategies. An integrated morphological, serological, and multiomics analysis was performed to characterize HILI in CH pigs. Serum iron content was also examined in human CH neonates. Triiodothyronine (T3) treatment and modulation of the thyroid hormone receptor/retinoid X receptor (THR/RXR) pathway were applied to hepatocytes from multiple species to elucidate the effect of T3 on ferroptosis. CH pigs spontaneously developed liver disease with hepatic inflammation and mild fibrosis. Surprisingly, RNA-sequencing of liver samples revealed the enrichment of the ferroptosis pathway in CH pigs. Hepatocyte ferroptosis was further confirmed by the severe iron overload, impaired glutathione metabolism, and excessive lipid peroxidation. Notably, both CH piglets and human neonates with CH showed marked elevations in serum iron, suggesting the clinical significance of iron dyshomeostasis in this condition. Molecularly, T3 deficiency in liver of CH pigs leads to the impairment of the AMPKα–GSK3β–NRF2–GPX4 antioxidant axis. Furthermore, we found that T3 treatment effectively resisted RAS-selective lethal 3 (RSL3)-induced ferroptosis in hepatic cell lines derived from humans, pigs, and mice. Mechanistically, T3 acts through the THRβ/RXRβ heterodimer to transcriptionally upregulate PRKAA1 , which activates the GSK3β–NRF2–GPX4 signaling cascade, ultimately suppressing lipid peroxidation and ferroptosis. Our study establishes the relationship between CH condition and iron dysregulation. We also identify the T3–THRβ/RXRβ–AMPKα1–GPX4 pathway as an anti-ferroptotic axis, and its impairment may contribute to hepatic ferroptosis and liver injury in CH pigs. Our study not only provides a new insight into the pathogenesis of HILI but also the potential therapeutic targets for this condition and other ferroptosis-related liver diseases.