Single-cell RNA-Seq reveals transcriptional heterogeneity in sepsis and down-regulation of SNHG5/miR-324-5p/CDK16 axis in T cells.

OBJECTIVE AND DESIGN: T lymphopenia is a common phenomenon in the sepsis patients, closely related with secondary infection and patients death, whereas its mechanism is still largely unelucidated. Hence, it is urgent to study the mechanism underlying sepsis induced T lymphopenia and lower morbidity and mortality of septic infection. MATERIAL AND METHODS: We performed Single-cell RNA-seq (scRNA-seq) and created an atlas of peripheral blood mononuclear cells (PBMCs) from sepsis patients and healthy volunteers (n = 3). To further illustrate mechanisms related to fundamental biological in sepsis, we investigated SNHG5 mediated T cell apoptosis. RESULTS: We collected blood samples of 3 sepsis patients and 3 healthy donors, separated PBMCs, and performed scRNA-seq to create a atlas of PBMCs. 7 cell clusters were identified and annotated, followed by differentially expressed genes and pathway analysis. Then, we systematically discussed the cellular heterogeneity, and generated gene expression patterns of 7 different cellular cluster in sepsis and healthy group. Further analysis DEG and further bioinformatics analysis of different cellular cluster indicated that SNHG5/miR-324-5p/CDK16 axis contributed to inflammatory T cell apoptosis in sepsis. And further inhibitory and functional experiments indicated that SNHG5/miR-324-5p/CDK16 axis contributed to inflammatory T cell apoptosis in sepsis. CONCLUSION: This study unveiled molecular mechanisms related to T lymphopenia in sepsis, such as cell fate decisions and modulation of SNHG5/miR-324-5p/CDK16 axis, making SNHG5 a promising therapeutic measurement for sepsis.