RNA-seq and LC-MS/MS analysis of antiviral effects mediated by cold stress and stress hormone corticosterone in chicken DF-1 cells

Cold stress in poultry is a global problem that causes huge economic losses and threatens the health and welfare of poultry. However, knowledge of chicken responses to virus infection under cold stress is limited. The purpose of this research was to investigate the effects of cold stress on gene expression and viral replication in chicken DF-1 cells in hypothermia. In addition, the characterization of circulating steroid hormone profiles in the plasma of chickens under cold stress was analyzed by liquid chromatography-tandem mass spectrometry. Herein, we performed RNA sequencing to obtain DF-1 cell transcriptional profiles under cold stress. A total of 9499 differentially expressed genes (DEGs) were identified in DF-1 cells. Overexpressed DEGs were related to the proteasome, cell cycle, spliceosome, ribosome biogenesis, and mammalian target of rapamycin (mTOR). Down-regulated DEGs were related to ribosomes, oxidative phosphorylation, apoptosis, and the p53 signaling pathway. Gene set enrichment analysis showed that the DEGs mainly affect host ribosome translation and mitochondrial respiratory electron transport. The principal steroid hormone alterations in chickens subjected to cold stress included dihydrotestosterone, testosterone, beta-sitosterol, androstenedione, 7a,27-dihydroxycholesterol,7-ketocho-lesterol, and desmosterol, which are associated with endocrine resistance, ovarian steroidogenesis, and steroid hormone biosynthesis. In addition, Infectious bronchitis virus (IBV), Newcastle disease virus (NDV), and Influ-enza A (H9N2) Virus replication in DF-1 cells is significantly inhibited by cold stress. Moreover, the plasma concentrations of corticosterone, an important stress hormone in poultry, were significantly elevated in chickens subjected to cold stress, and we found that IBV and vesicular stomatitis virus (VSV) replication were strongly inhibited in DF-1 cells pretreated with CORT, but NDV and H9N2 replication were unaffected. In conclusion, in response to cold stress, the translation efficiency and mitochondrial respiratory chain are temporarily weakened in DF-1 cells, which affects virus replication. Chickens may regulate aromatase deficiency, androstenedione metabolism, androgen and estrogen metabolism, and 17-beta hydroxysteroid dehydrogenase III deficiency through steroid hormones in response to cold stress. This study provides valuable insights into the molecular regulatory mechanisms of poultry under cold stress and may support further research on the intrinsic link be-tween steroid hormones and virus replication under stress.