Identification of differentially expressed genes associated with tracheal injury recovery in a rabbit model of septic shock

BACKGROUND: Sepsis is a syndrome caused by the host's inflammatory response to an infection with an unknown mechanism. This study aimed to identify differentially expressed genes (DEGs) potentially involved in the development and recovery of tracheal injury from septic shock. METHODS: Nine New Zealand white rabbits were randomized to control (CON), septic shock model (SS), and septic shock norepinephrine treatment (SSNE) groups (each group n = 3). The SS and SSNE groups were injected with lipopolysaccharide to induce septic shock. The SSNE group was administered Ringer lactate with norepinephrine to maintain normal blood pressure. All animals underwent cuffed endotracheal intubation for 2 h. The injured tracheal segment was harvested. RNA sequencing was performed to identify the DEGs, followed by bioinformatics analysis, and pathological staining (both HE and Masson) was performed for pathological evaluation. Bioinformatics analysis included principal component analysis (PCA), gene set enrichment analysis (GSEA), and protein-protein interaction (PPI) network construction. Key findings were validated by qRT-PCR and immunohistochemistry. RESULTS: We obtained 124 upregulated and 28 downregulated DEGs in SS vs. CON groups, along with 60 upregulated and 178 downregulated DEGs in SSNE vs. SS groups. The pathological score showed that trachea tissue in the SS group had the highest score. The protein-protein interaction (PPI) prediction identified APOB and CD36 as the hub genes. The molecular experiments further confirmed that at mRNA and protein levels, APOB was significantly upregulated, while CD36 was significantly downregulated. Subsequent qRT-PCR and immunohistochemical analyses confirmed that APOB expression was significantly upregulated while CD36 was downregulated in the septic shock group, a trend partially reversed by norepinephrine treatment. CONCLUSIONS: Our study results suggest that APOB and CD36 may be involved in the pathogenesis of tracheal injury recovery in septic shock patients treated with NE. CLINICAL TRIAL NUMBER: Not applicable.