Unveiling the molecular mechanisms of hemorrhagic shock and acute lung injury: An integrative RNA-Seq and network analysis.

Acute lung injury (ALI), especially when resulting from trauma-associated hemorrhagic shock (THS), is a life-threatening condition with limited treatment options and high mortality. Understanding the molecular mechanisms driving ALI in this context is essential to identify reliable biomarkers and therapeutic targets. This study aimed to explore the transcriptomic alterations and protein interaction networks in a rat model of THS-induced ALI using RNA sequencing and bioinformatics tools. RNA-seq analysis was performed on lung tissues from five THS-induced and five normal rats. Analysis revealed 1003 differentially expressed genes, including 365 upregulated and 638 downregulated. Functional enrichment pointed to significant involvement of pathways related to oxidative stress, hypoxia response, neutrophil degranulation, ferroptosis, and immune activation. Protein-protein interaction network analysis identified four key gene modules, with Module 3 notably associated with iron metabolism and neutrophilic inflammation. Hub genes such as Cd163, Nqo1, Gclc, Lcn2, and Mmp8 were identified as central regulators and validated in independent samples (three THS-induced and three controls). Lcn2 and cathepsins (CTSS, CTSK, CTSL) emerged as particularly relevant for their multifaceted roles in inflammation, iron homeostasis, and matrix remodeling. These findings provide novel insights into the immunometabolic dysregulation underlying THS-induced ALI and suggest promising molecular targets for future therapeutic interventions aimed at mitigating lung injury in critically injured trauma patients.