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.