Relative suppression of pyroptosis- and necroptosis-related transcriptional programs and enrichment of ferroptosis-related signatures are associated with fatal sepsis: multi-cohort bulk and single-cell transcriptomic evidence

Abstract

Sepsis is a life-threatening syndrome caused by a dysregulated host response to infection and remains a major cause of mortality in critically ill patients. Multiple forms of programmed cell death (PCD) may contribute to immune dysregulation and organ injury, but their transcriptional patterns across disease severity and outcome remain incompletely defined. We performed an integrative transcriptomic analysis of five public sepsis cohorts, including single-cell RNA sequencing datasets GSE167363 and GSE151263 and three bulk transcriptomic cohorts. Primary outcome analyses focused on cohort-defined fatal sepsis (28-day non-survivors in GSE65682 and the deposited sepsis-death group in GSE63042), whereas pneumonia/ARDS comparisons were treated as secondary exploratory analyses. PCD-related transcriptional programs were evaluated across clinical groups and immune-cell populations. Six candidate genes were further assessed by RT-qPCR in LPS-stimulated RAW264.7 and THP-1 cells as targeted in vitro transcriptional validation. In GSE65682, 28-day non-survivors showed lower pyroptosis, necroptosis and apoptosis program scores but higher ferroptosis scores than survivors, and higher pyroptosis scores were associated with better 28-day survival. GSE154918 instead showed broader increases in PCD-related program scores from healthy controls to infection/sepsis groups, reflecting a disease-versus-control contrast rather than an outcome contrast. In the LPS model, CASP1, RIPK3 and NLRP3 were upregulated, whereas SIRT1, BCL2 and HIF1A were downregulated. These cell experiments assessed acute inflammatory transcriptional responsiveness and were not intended to reproduce the mortality-associated direction observed in patient cohorts. Multi-cohort analyses identified outcome-associated PCD transcriptional patterns in sepsis, including relative suppression of pyroptosis- and necroptosis-related programs and enrichment of ferroptosis-related signatures in non-survivors. The LPS experiments provide complementary mRNA-level evidence that selected PCD genes are transcriptionally responsive to inflammatory stimulation, but they do not constitute directional or functional validation of the fatal-sepsis signature. Functional and prospective clinical validation remains required.