USP4 modulates ZBP1 ubiquitination to regulate microglial PANoptosis and functional outcomes following traumatic brain injury
摘要
Secondary damage in traumatic brain injury (TBI) is characterized by the abnormal release of damage-associated molecular patterns and excessive production of pro-inflammatory cytokines. Neuroinflammation is a hallmark of TBI. However, the mechanisms through which immune cells contribute to cognitive deficits and secondary inflammatory pathology remain poorly understood. In this study, we found that ZBP1-mediated microglial PANoptosis, which is a distinct form of innate immune-driven inflammatory cell death, is triggered following TBI. We further determined that microglial PANoptosis is induced by the synergistic action of heme and TNF-α. Mechanistically, we identified USP4 as a critical deubiquitinase for ZBP1 in microglia. USP4 was found to interact with, deubiquitinate, and stabilize ZBP1. Notably, AKT-mediated phosphorylation was found to be essential for maintaining USP4 protein stability. Pharmacological inhibition of USP4 using Vialinin A led to ZBP1 degradation, reduced microglial PANoptosis, and the amelioration of TBI-related functional deficits. Moreover, USP4 expression levels were found to be negatively correlated with prognosis patients with severe TBI. Collectively, our findings highlight a crucial role for USP4 in facilitating ZBP1-mediated inflammasome activation, microglial death, and cognitive impairment post-TBI, underscoring its potential as a therapeutic target.