Integrative transcriptomic analysis reveals cross-species conserved core genes and pathways in alveolar macrophages...

acute respiratory distress syndrome (ARDS) is a severe pulmonary condition characterized by alveolar-capillary damage and refractory hypoxemia. Alveolar macrophages (AMs) play a crucial role in regulating inflammation and repair processes during acute lung injury (ALI)/ARDS. However, the transcriptional and functional changes in AMs during ALI/ARDS remain poorly understood, especially when considering species-specific differences between murine models and human pathophysiology. This study aims to elucidate these changes in AMs during ALI/ARDS by integrating in vitro and cross-species transcriptomic analyses.

We conducted RNA sequencing on LPS-stimulated MH-S cells and integrated the data with publicly available murine (GSE225406) and human (GSE40885) AM datasets to identify conserved differentially expressed genes (DEGs). Functional enrichment analysis and protein-protein interaction (PPI) network analysis were performed to explore the underlying mechanisms. Core genes were identified and validated using qRT-PCR, Western blot, immunohistochemical staining, and immunofluorescence staining. Additionally, we analyzed the diagnostic potential of these core genes using clinical datasets (GSE121871 and GSE243066).

We identified 45 conserved upregulated genes and 4 downregulated genes across species, highlighting core transcriptional regulators of LPS-induced Macrophage activation. Functional enrichment analysis revealed significant involvement of immune-inflammatory pathways. PPI network analysis identified 10 core genes potentially central to AM-mediated ALI/ARDS pathogenesis. Experimental validation confirmed the upregulation of key genes and demonstrated that LPS treatment significantly impaired the efferocytosis capacity of AMs with dysregulated expression of stabilin-2, suggesting a potential association with this functional defect. Furthermore, the core gene set showed diagnostic potential in ARDS patient samples (AUC = 0.86).

This analysis identifies cross-species conserved core genes and inflammatory pathways in AMs during ALI/ARDS. Our findings provide insights into AM-mediated inflammatory mechanisms and highlight candidate genes for further functional studies to explore their potential as therapeutic targets.