Differential transcriptomic changes in the central nervous system and urinary bladders of mice infected with a coronavirus

Z-DNA binding protein 1 orchestrates innate immunity and inflammatory cell death

Innate immunity is not only the first line of host defense against microbial infections but is also crucial for the host responses against a variety of noxious stimuli. Z-DNA binding protein 1 (ZBP1) is a cytosolic nucleic acid sensor that can induce inflammatory cell death in both immune and nonimmune cells upon sensing of incursive virus-derived Z-form nucleic acids and self-nucleic acids via its Zα domain. Mechanistically, aberrantly expressed or activated ZBP1 induced by pathogens or noxious stimuli enables recruitment of TANK binding kinase 1 (TBK1), interferon regulatory factor 3 (IRF3), receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and RIPK3 to drive type I interferon (IFN-I) responses and activation of nuclear factor kappa B (NF-κB) signaling. Meanwhile, ZBP1 promotes the assembly of ZBP1- and absent in melanoma 2 (AIM2)-PANoptosome, which ultimately triggers PANoptosis through caspase 3-mediated apoptosis, mixed lineage kinase domain like pseudokinase (MLKL)-mediated necroptosis, and gasdermin D (GSDMD)-mediated pyroptosis. In response to damaged mitochondrial DNA, ZBP1 can interact with cyclic GMP-AMP synthase to augment IFN-I responses but inhibits toll like receptor 9-mediated inflammatory responses. This review summarizes the structure and expression pattern of ZBP1, discusses its roles in human diseases through immune-dependent (e.g., the production of IFN-I and pro-inflammatory cytokines) and -independent (e.g., the activation of cell death) functions, and highlights the attractive prospect of manipulating ZBP1 as a promising therapeutic target in diseases.

Z-nucleic acid sensor ZBP1 in sterile inflammation

Z-DNA binding protein 1 (ZBP1), a cytosolic nucleic acid sensor for Z-form nucleic acids (Z-NA), can detect both exogenous and endogenous nucleic acids. Upon sensing of self Z-NA or exposure to diverse noxious stimuli, ZBP1 regulates inflammation by activating nuclear factor kappa B and interferon regulating factor 3 signaling pathways. In addition, ZBP1 promotes the assembly of ZBP1 PANoptosome, which initiates caspase 3-mediated apoptosis, mixed lineage kinase domain like pseudokinase (MLKL)-mediated necroptosis, and gasdermin D (GSDMD)-mediated pyroptosis (PANoptosis), leading to the release of various damage-associated molecular patterns. Thereby, ZBP1 is implicated in the development and progression of diverse sterile inflammatory diseases. This review outlines the expression, structure, and function of ZBP1, along with its dual roles in controlling inflammation and cell death to orchestrate innate immunity in sterile inflammation, especially autoimmune diseases, and cancers. ZBP1 has emerged as an attractive therapeutic target for various sterile inflammatory diseases.