Epigenetic multi-omics reveals the molecular regulatory mechanism underlying liver cold resistance in Hezuo pigs

Abstract

Non-shivering thermogenesis is one of the adaptive modes of heat production in animals to maintain a constant core body temperature in cold environments, in which the liver plays a crucial role. However, the underlying molecular regulatory mechanisms of this process remain unclear. In this study, 36 healthy 75-day-old Hezuo pigs were subjected to cold (-15 ± 2 °C) and normal temperature (23 ± 2 °C) treatments for 12 h, 24 h, 48 h, 5 d, 10 d, and 15 d. Liver tissues were collected at the end of the experiment for histomorphological, lipid metabolism genes and enzyme activities, and it was found that hepatic lipid metabolism was the most active in Hezuo pigs with 24 h of cold exposure, and this group was subjected to RNA- Seq, ATAC-Seq, CUT&Tag sequencing was performed on this group. Transcriptome analysis identified differentially expressed genes mainly enriched in PPAR, AMPK and other signaling pathways. Secondly, cold exposure remodelled chromatin accessibility and histone H3K27ac and H3K4me3 modification profiles of Hezuo pig livers. Western Blot results confirmed the activation of the AMPK signaling pathway. Additionally, functional validation confirmed that Nr1H4 promotes PPARA transcriptional activity and inhibits SREBF1 transcriptional activity, while Twist2 promotes CPT1A transcriptional activity. This study revealed the molecular regulatory mechanism of liver cold resistance in Hezuo pigs, and the screened transcription factor (TF)-mRNA regulatory relationship pairs (e.g., Nr1H4-PPARA, etc.) and key genes (e.g., PPARA and SREBF1 , etc.) for cold resistance in Hezuo pigs could provide valuable molecular markers for subsequent research.