SUMO protein tags may shape organ damage in sepsis, review finds

A review published in Cell Biology and Toxicology examines whether a molecular labelling system inside cells, known as SUMOylation and its reverse process deSUMOylation, contributes to organ injury in sepsis. The authors, led by Lihong Yang and colleagues, assess SUMO-related evidence according to disease relevance and mechanistic causality, distinguishing what is supported from what remains uncertain.

SUMOylation is a chemical modification of proteins. Small ubiquitin-like modifier proteins, or SUMOs, are chemically attached to target proteins, altering their stability, their location within the cell and their ability to interact with other molecules. DeSUMOylation removes those tags. The review explains that available evidence implicates this dynamic labelling system in inflammatory signalling, immunometabolic adaptation, barrier homeostasis, mitochondrial quality control and regulated cell death, suggesting potential links between immune dysfunction, cellular stress and organ injury.

What makes this review unusual is its insistence on evidence quality. The authors deliberately separate findings from actual patient samples and infection-based sepsis models from those obtained in endotoxemia, acute injury models and other nonsepsis systems. The review notes that many proposed mechanisms come from endotoxemia, acute injury models and other nonsepsis systems rather than from patient samples or infection-based sepsis models, a distinction relevant when translating laboratory findings to clinical care.

The review also warns against oversimplification. SUMO proteins come in different paralogues, chiefly SUMO1 and SUMO2/3, and their effects depend on which paralogue is involved, which regulatory enzyme acts, which substrate is modified, at which site, in which cell type, within which tissue compartment and under which infection context. Changes in bulk SUMO1 or SUMO2/3 conjugation therefore cannot be interpreted as uniformly protective or pathogenic, according to the review.

Despite the mechanistic promise, the translational picture is sobering. Direct human evidence remains limited, and causal evidence resolved by individual cell type in infection-based models is scarce. Many proposed mechanisms lack endogenous site mapping or rescue validation, meaning researchers have often inferred rather than demonstrated that a specific SUMO modification drives a specific injury process.

Pharmacological approaches fare no better in the current evidence base. Broad inhibition of the SUMO pathway has produced discordant results across experimental models, and the clinical safety and efficacy of any intervention targeting SUMO in sepsis remain entirely unestablished. The clinical safety and efficacy of interventions targeting SUMO in sepsis remain unestablished.

The authors close with a research roadmap. Future studies, they argue, should establish causal relationships between SUMO enzymes, substrates and modification sites in defined cell types, develop reproducible pharmacodynamic biomarkers, and evaluate targeted interventions in clinically relevant models only after infection has been established, mirroring the clinical reality in which sepsis is diagnosed and treated.

For clinicians and researchers alike, the review's message is one of caution. Available evidence suggests SUMOylation and deSUMOylation may link immune dysfunction, cellular stress and organ injury in sepsis, but the review concludes that future studies should establish causal relationships between SUMO enzymes, substrates and modification sites in defined cell types before targeted interventions can be evaluated.

Subject of Research: The roles of SUMOylation and deSUMOylation protein modifications in sepsis-associated organ injury and the translational challenges of targeting them.

Article Title: SUMOylation and deSUMOylation in sepsis-associated organ injury: cellular mechanisms and translational challenges

Article References: Yang, L., Tang, F., Hu, X., Pan, L., & Xiao, D. (2026). SUMOylation and deSUMOylation in sepsis-associated organ injury: cellular mechanisms and translational challenges. Cell Biology and Toxicology. https://doi.org/10.1007/s10565-026-10307-8

Image Credits: AI Generated

DOI: 10.1007/s10565-026-10307-8

Keywords: SUMOylation, deSUMOylation, sepsis, organ injury, inflammation, mitochondrial quality control, cell death, barrier homeostasis, immunometabolism, translational research, Cell Biology and Toxicology, sepsis-associated