Article Impact Level: HIGH Data Quality: STRONG Summary of Nature. https://doi.org/10.1038/s41586-025-09536-4 Dr. Konstantinos Kelepouras et al.
Points
- The loss of Caspase-8 in keratinocytes results in the accumulation of cytosolic DNA, which activates the cGAS/STING pathway and leads to a lethal necroptosis-driven inflammatory dermatitis in preclinical models.
- Activated STING upregulates Z-DNA binding protein-1 and MLKL, triggering a ZBP1–RIPK1–RIPK3 necroptotic complex that functions independently of the canonical FADD pathway.
- This mechanism is central to STING-Associated Vasculopathy with onset in Infancy, where chronic STING activation in patients orchestrates an abnormal necroptotic transcriptional program leading to severe pathology.
- Genetically co-deleting RIPK3 in a preclinical N153S-SAVI mouse model remarkably rescued immune cell–driven pathology and lethality, confirming the crucial role of necroptosis in disease progression.
- These findings establish a new therapeutic paradigm, suggesting that targeting the ZBP1-RIPK3-MLKL necroptosis axis could be a promising strategy for SAVI and other intractable interferonopathies.
Summary
A recent study has identified a novel molecular pathway linking the immune sensor STING directly to necroptotic cell death, independent of the canonical TNFR1/FADD signaling axis. Researchers found that in a model of lethal dermatitis caused by conditional deletion of Caspase-8 in epidermal keratinocytes (Casp8E-KO), the resulting accumulation of cytosolic DNA activates a cGAS/STING-mediated transcriptional program. This activation of STING was shown to directly upregulate both Z-DNA binding protein-1 (ZBP1) and the necroptosis effector mixed lineage kinase domain-like (MLKL). This process enables the assembly of a distinct ZBP1–RIPK1–RIPK3 complex, which triggers necroptosis without requiring the FADD-dependent complex, thereby uncovering a new etiology for necroptotic inflammation.
The clinical relevance of this pathway was investigated in STING-Associated Vasculopathy with onset in Infancy (SAVI), a severe interferonopathy driven by gain-of-function mutations in the human STING protein. Analysis of patient samples confirmed the presence of a necroptotic transcriptional program. This finding was further validated in a preclinical N153S-SAVI mouse model, where the characteristic immune cell–driven pathology and associated lethality were significantly rescued by the co-deletion of RIPK3. This genetic evidence confirms that STING-induced pathology in this context is mechanistically dependent on the execution of necroptosis.
These findings establish STING-driven, ZBP1-mediated necroptosis as a central pathogenic mechanism in both Casp8-deficient inflammation and in the genetic disorder SAVI. The study concludes that the ZBP1-RIPK3-MLKL signaling axis represents a critical and previously unrecognized driver of inflammation in these conditions. This work suggests that therapeutic strategies targeting the specific necroptosis pathway hold significant potential for treating SAVI and other STING-related autoinflammatory syndromes, which are currently incurable and characterized by excessive inflammatory cell death.
Link to the article: https://www.nature.com/articles/s41586-025-09536-4
References Kelepouras, K., Saggau, J., Bonasera, D., Kiefer, C., Locci, F., Rakhsh-Khorshid, H., Grauvogel, L., Varanda, A. B., Peifer, M., Loricchio, E., Montinaro, A., Croon, M., Trifunovic, A., Prencipe, G., Insalaco, A., De Benedetti, F., Walczak, H., & Liccardi, G. (2025). STING induces ZBP1-mediated necroptosis independently of TNFR1 and FADD. Nature. https://doi.org/10.1038/s41586-025-09536-4
