Chronic cold stress induced transcriptomic alterations in multi-metabolically active tissues of pigs.

Cold stress poses significant challenges to livestock production; however, the regulatory mechanisms underlying porcine responses to chronic cold stress remain inadequately understood. To address this gap, we characterized the transcriptional responses of five metabolism-related tissues to chronic cold stress via bulk RNA sequencing. Our findings revealed tissue-specific transcriptional responses to cold stress, with skeletal muscle-particularly the longissimus dorsi muscle (LDM)-exhibiting the most pronounced changes. Furthermore, single-nucleus RNA sequencing analysis revealed cellular heterogeneity and metabolic remodeling in the LDM, which were induced by chronic cold stress. Specifically, chronic cold stress alters the proportions of key cell types-especially myonuclei, fibroblasts, and immune cells-enhances metabolic processes such as glucose metabolism and oxidative phosphorylation, and reduces intercellular communication related to growth signaling, particularly within the IGF pathway. Notably, we identified a distinct subset of oxidative metabolizing fibroblasts in skeletal muscle, potentially regulated by transcription factors such as CREB3L1, EGR1, EGR2, BHLHE41, and KLF5, as well as the CXCL signaling pathway, in response to chronic cold stress. Moreover, increased energy intake enhances cold stress-induced metabolic strategies without allocating energy to growth, adipose storage, or immune responses. These findings elucidate the adaptive transcriptional and metabolic remodeling that occurs in pigs under prolonged cold stress, offering valuable insights into the cold adaptation mechanisms and energy allocation strategies.