BackgroundThe antiparasitic agent niclosamide has been demonstrated to inhibit the arthropod-borne Zika virus. Here, we investigated the antiviral capacity of niclosamide against dengue virus (DENV) serotype 2 infection in vitro and in vivo.Principle findingNiclosamide effectively retarded DENV-induced infection in vitro in human adenocarcinoma cells (A549), mouse neuroblastoma cells (Neuro-2a), and baby hamster kidney fibroblasts (BHK-21). Treatment with niclosamide did not retard the endocytosis of DENV while niclosamide was unable to enhance the antiviral type I interferon response. Furthermore, niclosamide did not cause a direct effect on viral replicon-based expression. Niclosamide has been reported to competitively inhibit the mTOR (mammalian target of rapamycin), STAT3 (signal transducer and activator of transcription 3), and NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) signaling pathways; however, selective inhibitors of those pathways did not reduce DENV infection. Similar to the vacuolar-type H+-ATPase inhibitor bafilomycin A1, both niclosamide and other protonophores, such as CCCP (carbonyl cyanide m-chlorophenyl hydrazone), and FCCP (carbonyl cyanide-p-trifluoromethoxyphenylhydrazone), effectively reduced endosomal acidification and viral dsRNA replication. Co-administration of a single dose of niclosamide partially decreased viral replication, viral encephalitis, and mortality in DENV-infected ICR suckling mice.SignificanceThese results demonstrate that niclosamide diminishes viral infection by hindering endosomal acidification.
Proinflammatory TNF-α facilitates dengue virus (DENV) infection in endovascular dysfunction and neurotoxicity. The introduction of TNF-α blocking therapy with Abs is performed to test its therapeutic effect in this study. In DENV-infected mice, TNF-α production in the brain accompanied the progression of neurotoxicity and encephalitis. DENV infection caused the loss of hippocampal neurons with TNF-α expression around damaged regions, and immunostaining showed the induction of apoptosis in hippocampal neurons. TNF-α was expressed in active microglia and astrocytes in DENV-infected mice. TNF-α facilitated DENV-induced neurotoxicity in vitro in murine Neuro-2a cells. Using a currently established encephalitic mouse model in which DENV infection causes progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality 7 days postinfection, we showed that TNF-α transgenic mice represented the progressive disease development and administration of neutralizing TNF-α Ab reduced dengue encephalitis and mortality. These results demonstrate an immunopathogenesis of TNF-α for mediating DENV-induced encephalitis-associated neurotoxicity and that targeting TNF-α can be used as a strategy against dengue encephalitis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.