Enterovirus D68 Infection Induces TDP-43 Cleavage, Aggregation, and Neurotoxicity

• Published in: Journal of virology 2023-04, Vol.97 (4), p.e0042523-e0042523
• Main Authors: Zhang, Lili, Yang, Jiaxin, Li, Huili, Zhang, Zhe, Ji, Zhilin, Zhao, Lirong, Wei, Wei
• Format: Article
• Language: English
• Subjects: 3C Viral Proteases - metabolism; Cell Line, Tumor; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; DNA-Binding Proteins - pharmacology; Enterovirus D, Human; Enterovirus Infections - physiopathology; Enterovirus Infections - virology; Gene Silencing; Humans; Lopinavir - pharmacology; Protease Inhibitors - pharmacology; Protein Aggregation, Pathological - genetics; Proteolysis - drug effects; Virology; Virus-Cell Interactions
• ISSN: 0022-538X; 1098-5514
• DOI: 10.1128/jvi.00425-23

Enterovirus D68 (EV-D68), which causes severe respiratory diseases and irreversible central nervous system damage, has become a serious public health problem worldwide. However, the mechanisms by which EV-D68 exerts neurotoxicity remain unclear. Thus, we aimed to analyze the effects of EV-D68 infection on the cleavage, subcellular translocation, and pathogenic aggregation of TAR DNA-binding protein 43 kDa (TDP-43) in respiratory or neural cells. The results showed that EV-D68-encoded proteases 2A and 3C induced TDP-43 translocation and cleavage, respectively. Specifically, 3C cleaved residue 327Q of TDP-43. The 3C-mediated cleaved TDP-43 fragments had substantially decreased protein solubility compared with the wild-type TDP-43. Hence, 3C activity promoted TDP-43 aggregation, which exerted cytotoxicity to diverse human cells, including glioblastoma T98G cells. The effects of commercially available antiviral drugs on 3C-mediated TDP-43 cleavage were screened, and the results revealed lopinavir as a potent inhibitor of EV-D68 3C protease. Overall, these results suggested TDP-43 as a conserved host target of EV-D68 3C. This study is the first to provide evidence on the involvement of TDP-43 dysregulation in EV-D68 pathogenesis. Over the past decade, the incidence of enterovirus D68 (EV-D68) infection has increased worldwide. EV-D68 infection can cause different respiratory symptoms and severe neurological complications, including acute flaccid myelitis. Thus, elucidating the mechanisms underlying EV-D68 toxicity is important to develop novel methods to prevent EV-D68 infection-associated diseases. This study shows that EV-D68 infection triggers the translocalization, cleavage, and aggregation of TDP-43, an intracellular protein closely related to degenerative neurological disorders. The viral protease 3C decreased TDP-43 solubility, thereby exerting cytotoxicity to host cells, including human glioblastoma cells. Thus, counteracting 3C activity is an effective strategy to relieve EV-D68-triggered cell death. Cytoplasmic aggregation of TDP-43 is a hallmark of degenerative diseases, contributing to neural cell damage and central nervous system (CNS) disorders. The findings of this study on EV-D68-induced TDP-43 formation extend our understanding of virus-mediated cytotoxicity and the potential risks of TDP-43 dysfunction-related cognitive impairment and neurological symptoms in infected patients.