Dynamic activation of lytic cell death-related programs identifies CD14 as a candidate hub gene associated with secondary injury after spinal cord injury

Background: Secondary spinal cord injury (SCI) involves persistent inflammation, oxidative stress, and multiple forms of programmed cell death. However, the dynamic activation of lytic cell death-related programs and their key regulatory nodes during SCI progression remain unclear. Methods: Public transcriptomic datasets were analyzed using single-sample gene set enrichment analysis (ssGSEA) to assess pyroptosis-, necroptosis-, and ferroptosis-related transcriptional activities, and integrated lytic cell death-related indices were constructed. Differential expression analysis, weighted gene co-expression network analysis, functional enrichment, and multiple machine learning models were combined to identify candidate hub genes associated with lytic cell death-related signatures. Key findings were further evaluated using an external human SCI-related cohort, RT-qPCR and immunofluorescence validation in a rat SCI model, and published single-cell RNA-seq data. Results: Pyroptosis-, necroptosis-, and ferroptosis-related transcriptional activities were all increased after SCI, with activation beginning in the acute phase and persisting over time. Enrichment analyses showed that lytic cell death-associated genes were mainly involved in inflammatory responses, immune regulation, myeloid activation, and related signaling pathways. Integrated multi-model analysis identified CD14 as the most robust candidate hub gene associated with the lytic cell death index. External validation in a human SCI-related peripheral blood cohort, RT-qPCR and immunofluorescence validation in a rat SCI model, and single-cell reanalysis further supported the upregulation of CD14 and its association with myeloid inflammatory activation and pyroptosis-, necroptosis-, and ferroptosis-related signatures. Conclusions: Lytic cell death-related programs are dynamically and persistently activated after SCI and are closely associated with immune-inflammatory responses during secondary injury. CD14 was identified as a candidate hub gene associated with myeloid inflammatory activation and lytic cell death-related signatures. However, the current findings are primarily associative, and further functional studies are required to determine whether CD14 directly modulates lytic cell death-related pathways and contributes to secondary injury progression after SCI.