Alveolar Epithelial Cell Dysfunction in Acute Respiratory Distress Syndrome: Mechanistic Insights and Targeted Interventions

Acute respiratory distress syndrome (ARDS) is a life-threatening condition with high mortality. A central driver in its pathogenesis is alveolar epithelial cell (AEC) dysfunction, which leads to disruption of the epithelial barrier, impaired fluid clearance, and dysregulated inflammatory responses. This review summarizes the key mechanisms underlying AEC injury, including programmed cell death (apoptosis, pyroptosis, necroptosis, ferroptosis), oxidative stress, mitochondrial dysfunction, epigenetic reprogramming (DNA methylation, histone modifications), metabolic rewiring (succinate accumulation), and spatiotemporal heterogeneity revealed by single-cell sequencing and spatial transcriptomics. Multicellular crosstalk involving epithelial–immune–endothelial networks and the gut-lung axis further shapes disease progression. Building on these mechanistic foundations, we evaluate emerging AEC-targeted interventions such as pharmacologic agents (antioxidants, anti-inflammatories), biologics (mesenchymal stem cells and engineered exosomes), and gene-based approaches (adeno-associated virus and CRISPR-Cas9 systems delivered via smart nanocarriers). Complementary strategies include microbiome modulation through probiotics, short-chain fatty acids, or fecal microbiota transplantation, and biomarker-guided precision medicine (e.g., sRAGE, exosomal miRNAs) to enable promise individualized regimens. We also discuss translational hurdles, including nanotoxicity, mesenchymal stem cell (MSC) heterogeneity, and gene-editing safety, and highlight future opportunities involving AI-driven multi-omics, lung-on-chip platforms, and epithelium-centered regenerative therapies. By integrating mechanistic insights with innovative therapeutic strategies, this review aims to outline a roadmap toward epithelium-targeted, precision-guided therapies for ARDS.