RESUMO
Rabies virus (RABV) is a neurotropic virus that causes fatal neurological disease, raising serious public health issues and attracting extensive attention in society. To elucidate the molecular mechanism of RABV-induced neuronal damage, we used hematoxylin-eosin staining, transmission electron microscopy, transcriptomics analysis, and immune response factor testing to investigate RABV-infected neurons. We successfully isolated the neurons from murine brains. The specificity of the isolated neurons was identified by a monoclonal antibody, and the viability of the neurons was 83.53-95.0%. We confirmed that RABV infection induced serious damage to the neurons according to histochemistry and transmission electron microscope (TEM) scanning. In addition, the transcriptomics analysis suggested that multiple genes related to the pyroptosis pathway were significantly upregulated, including gasdermin D (Gsdmd), Nlrp3, caspase-1, and IL-1ß, as well as the chemokine genes Ccl2, Ccl3, Ccl4, Ccl5, Ccl7, Ccl12, and Cxcl10. We next verified this finding in the brains of mice infected with the rRC-HL, GX074, and challenge virus standard strain-24 (CVS-24) strains of RABV. Importantly, we found that the expression level of the Gsdmd protein was significantly upregulated in the neurons infected with different RABV strains and ranged from 691.1 to 5764.96 pg/mL, while the basal level of mock-infected neurons was less than 100 pg/mL. Taken together, our findings suggest that Gsdmd-induced pyroptosis is involved in the neuron damage caused by RABV infection.
Assuntos
Neurônios , Proteínas de Ligação a Fosfato , Piroptose , Vírus da Raiva , Raiva , Animais , Neurônios/virologia , Neurônios/metabolismo , Neurônios/patologia , Vírus da Raiva/patogenicidade , Vírus da Raiva/fisiologia , Raiva/virologia , Raiva/patologia , Raiva/metabolismo , Camundongos , Proteínas de Ligação a Fosfato/metabolismo , Proteínas de Ligação a Fosfato/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Encéfalo/virologia , Encéfalo/patologia , Encéfalo/metabolismo , GasderminasRESUMO
A proteomics analysis of purified rabies virus (RABV) revealed 47 entrapped host proteins within the viral particles. Out of these, 11 proteins were highly disordered. Our study was particularly focused on five of the RABV-entrapped mouse proteins with the highest levels of disorder: Neuromodulin, Chmp4b, DnaJB6, Vps37B, and Wasl. We extensively utilized bioinformatics tools, such as FuzDrop, D2P2, UniProt, RIDAO, STRING, AlphaFold, and ELM, for a comprehensive analysis of the intrinsic disorder propensity of these proteins. Our analysis suggested that these disordered host proteins might play a significant role in facilitating the rabies virus pathogenicity, immune system evasion, and the development of antiviral drug resistance. Our study highlighted the complex interaction of the virus with its host, with a focus on how the intrinsic disorder can play a crucial role in virus pathogenic processes, and suggested that these intrinsically disordered proteins (IDPs) and disorder-related host interactions can also be a potential target for therapeutic strategies.
Assuntos
Proteínas Intrinsicamente Desordenadas , Vírus da Raiva , Vírion , Vírus da Raiva/fisiologia , Animais , Camundongos , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Vírion/metabolismo , Proteômica , Interações Hospedeiro-Patógeno , Raiva/virologia , Biologia Computacional/métodos , Proteínas Virais/metabolismo , Proteínas Virais/genética , Proteínas Virais/químicaRESUMO
Rabies virus (RABV) causes a fatal neurological disease, consisting of unsegmented negative-strand RNA, which encodes five structural proteins (3'-N-P-M-G-L-5'). Apolipoprotein D (ApoD), a lipocalin, is upregulated in the nervous system after injury or pathological changes. Few studies have focused on the role of ApoD during virus infection so far. This study demonstrated that ApoD is upregulated in the mouse brain (in vivo) and C8-D1A cells (in vitro) after RABV infection. By upregulating ApoD expression in C8-D1A cells, we found that ApoD facilitated RABV replication. Additionally, Co-immunoprecipitation demonstrated that ApoD interacted with RABV glycoprotein (G protein). The interaction could promote RABV replication by upregulating the cholesterol level. These findings revealed a novel role of ApoD in promoting RABV replication and provided a potential therapeutic target for rabies.
Assuntos
Apolipoproteínas D , Colesterol , Vírus da Raiva , Raiva , Replicação Viral , Animais , Feminino , Humanos , Masculino , Camundongos , Apolipoproteínas D/metabolismo , Apolipoproteínas D/genética , Encéfalo/virologia , Encéfalo/metabolismo , Linhagem Celular , Colesterol/metabolismo , Células HEK293 , Raiva/metabolismo , Raiva/virologia , Vírus da Raiva/fisiologia , Regulação para CimaRESUMO
The rabies virus enters the nervous system by interacting with several molecular targets on host cells to modify behavior and trigger receptor-mediated endocytosis of the virion by poorly understood mechanisms. The rabies virus glycoprotein (RVG) interacts with the muscle acetylcholine receptor and the neuronal α4ß2 subtype of the nicotinic acetylcholine receptor (nAChR) family by the putative neurotoxin-like motif. Given that the neurotoxin-like motif is highly homologous to the α7 nAChR subtype selective snake toxin α-bungarotoxin (αBTX), other nAChR subtypes are likely involved. The purpose of this study is to determine the activity of the RVG neurotoxin-like motif on nAChR subtypes that are expressed in brain regions involved in rabid animal behavior. nAChRs were expressed in Xenopus laevis oocytes, and two-electrode voltage clamp electrophysiology was used to collect concentration-response data to measure the functional effects. The RVG peptide preferentially and completely inhibits α7 nAChR ACh-induced currents by a competitive antagonist mechanism. Tested heteromeric nAChRs are also inhibited, but to a lesser extent than the α7 subtype. Residues of the RVG peptide with high sequence homology to αBTX and other neurotoxins were substituted with alanine. Altered RVG neurotoxin-like peptides showed that residues phenylalanine 192, arginine 196, and arginine 199 are important determinants of RVG peptide apparent potency on α7 nAChRs, while serine 195 is not. The evaluation of the rabies ectodomain reaffirmed the observations made with the RVG peptide, illustrating a significant inhibitory impact on α7 nAChR with potency in the nanomolar range. In a mammalian cell culture model of neurons, we confirm that the RVG peptide binds preferentially to cells expressing the α7 nAChR. Defining the activity of the RVG peptide on nAChRs expands our understanding of basic mechanisms in host-pathogen interactions that result in neurological disorders.
Assuntos
Glicoproteínas , Vírus da Raiva , Xenopus laevis , Receptor Nicotínico de Acetilcolina alfa7 , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Vírus da Raiva/fisiologia , Vírus da Raiva/metabolismo , Humanos , Glicoproteínas/metabolismo , Glicoproteínas/genética , Oócitos/metabolismo , Proteínas Virais/metabolismo , Proteínas Virais/genética , Proteínas do Envelope Viral/metabolismo , Proteínas do Envelope Viral/genética , Interações Hospedeiro-Patógeno , Ligação Proteica , Raiva/metabolismo , Raiva/virologia , Acetilcolina/metabolismo , Acetilcolina/farmacologia , Neurotoxinas/metabolismo , Neurotoxinas/farmacologiaRESUMO
Rabies, caused by lyssavirus rabies (Rabies lyssavirus, RABV), is a fatal disease among humans and almost all warm-blooded animals. In this study, we found that RABV infection induces the up-regulation of receptor transporter protein 4 (RTP4) in mouse brains and different cells of nervous tissue. Over-expression of RTP4 reduces the viral titer of RABV in different neuronal cells. Furthermore, a recombinant RABV expressing RTP4, named rRABV-RTP4, was constructed and displayed a lower viral titer in different neuronal cells due to the expression of RTP4. Moreover, the survival rates of mice infected with rRABV-RTP4 were significantly higher than those of mice infected with parent virus rRABV or control virus rRABV-RTP4(-). In terms of mechanism, RTP4 could bind viral genomic RNA (vRNA) of RABV, and suppress the whole viral genome amplification. In addition, we found that the zinc finger domain (ZFD) of RTP4 exerts the antiviral function by truncation analysis, and an important amino acids site (C95) in the RTP4 3CxxC motif which is essential for its antiviral function was identified by mutation analysis. This study contributes to our understanding of how RTP4 or other RTP proteins play a role in defense against the invasion of RABV or other viruses.
Assuntos
RNA Viral , Vírus da Raiva , Raiva , Animais , Humanos , Camundongos , Encéfalo/virologia , Linhagem Celular , Genoma Viral , Lyssavirus/genética , Neurônios/virologia , Raiva/virologia , Vírus da Raiva/genética , Vírus da Raiva/fisiologia , Vírus da Raiva/patogenicidade , RNA Viral/genética , Replicação ViralRESUMO
Rabies virus (RABV) is highly lethal and triggers severe neurological symptoms. The neuropathogenic mechanism remains poorly understood. Ras-related C3 botulinum toxin substrate 1 (Rac1) is a Rho-GTPase that is involved in actin remodeling and has been reported to be closely associated with neuronal dysfunction. In this study, by means of a combination of pharmacological inhibitors, small interfering RNA, and specific dominant-negatives, we characterize the crucial roles of dynamic actin and the regulatory function of Rac1 in RABV infection, dominantly in the viral entry phase. The data show that the RABV phosphoprotein interacts with Rac1. RABV phosphoprotein suppress Rac1 activity and impedes downstream Pak1-Limk1-Cofilin1 signaling, leading to the disruption of F-actin-based structure formation. In early viral infection, the EGFR-Rac1-signaling pathway undergoes a biphasic change, which is first upregulated and subsequently downregulated, corresponding to the RABV entry-induced remodeling pattern of F-actin. Taken together, our findings demonstrate for the first time the role played by the Rac1 signaling pathway in RABV infection and may provide a clue for an explanation for the etiology of rabies neurological pathogenesis.IMPORTANCEThough neuronal dysfunction is predominant in fatal rabies, the detailed mechanism by which rabies virus (RABV) infection causes neurological symptoms remains in question. The actin cytoskeleton is involved in numerous viruses infection and plays a crucial role in maintaining neurological function. The cytoskeletal disruption is closely associated with abnormal nervous symptoms and induces neurogenic diseases. In this study, we show that RABV infection led to the rearrangement of the cytoskeleton as well as the biphasic kinetics of the Rac1 signal transduction. These results help elucidate the mechanism that causes the aberrant neuronal processes by RABV infection and may shed light on therapeutic development aimed at ameliorating neurological disorders.
Assuntos
Citoesqueleto de Actina , Actinas , Vírus da Raiva , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/genética , Humanos , Citoesqueleto de Actina/metabolismo , Animais , Vírus da Raiva/fisiologia , Actinas/metabolismo , Receptores ErbB/metabolismo , Receptores ErbB/genética , Quinases Ativadas por p21/metabolismo , Quinases Ativadas por p21/genética , Quinases Lim/metabolismo , Quinases Lim/genética , Internalização do Vírus , Raiva/metabolismo , Raiva/virologia , Linhagem Celular , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Fatores de Despolimerização de Actina/metabolismoRESUMO
The innate immune response is a first-line defense mechanism triggered by rabies virus (RABV). Interferon (IFN) signaling and ISG products have been shown to confer resistance to RABV at various stages of the virus's life cycle. Human tetherin, also known as bone marrow stromal cell antigen 2 (hBST2), is a multifunctional transmembrane glycoprotein induced by IFN that has been shown to effectively counteract many viruses through diverse mechanisms. Here, we demonstrate that hBST2 inhibits RABV budding by tethering new virions to the cell surface. It was observed that release of virus-like particles (VLPs) formed by RABV G (RABV-G VLPs), but not RABV M (RABV-G VLPs), were suppressed by hBST2, indicating that RABV-G has a specific effect on the hBST2-mediated restriction of RABV. The ability of hBST2 to prevent the release of RABV-G VLPs and impede RABV growth kinetics is retained even when hBST2 has mutations at dimerization and/or glycosylation sites, making hBST2 an antagonist to RABV, with multiple mechanisms possibly contributing to the hBST2-mediated suppression of RABV. Our findings expand the knowledge of host antiviral mechanisms that control RABV infection.
Assuntos
Vírus da Raiva , Raiva , Humanos , Vírus da Raiva/fisiologia , Raiva/prevenção & controle , Glicosilação , Asparagina/metabolismo , Cisteína/metabolismo , Dimerização , Liberação de Vírus , Antígeno 2 do Estroma da Médula Óssea/genética , Antígenos CD/metabolismo , Proteínas Ligadas por GPI/metabolismoRESUMO
Manipulative neuroparasites are a fascinating group of organisms that possess the ability to hijack the nervous systems of their hosts, manipulating their behavior in order to enhance their own survival and reproductive success. This review provides an overview of the different strategies employed by manipulative neuroparasites, ranging from viruses to parasitic worms and fungi. By examining specific examples, such as Toxoplasma gondii, Leucochloridium paradoxum, and Ophiocordyceps unilateralis, we highlight the complex mechanisms employed by these parasites to manipulate their hosts' behavior. We explore the mechanisms through which these parasites alter the neural processes and behavior of their hosts, including the modulation of neurotransmitters, hormonal pathways, and neural circuits. This review focuses less on the diseases that neuroparasites induce and more on the process of their neurological manipulation. We also investigate the fundamental mechanisms of host manipulation in the developing field of neuroparasitology, which blends neuroscience and parasitology. Finally, understanding the complex interaction between manipulative neuroparasites and their hosts may help us to better understand the fundamentals of behavior, neurology, and host-parasite relationships.
Assuntos
Hypocreales , Sistema Nervoso , Toxoplasma , Trematódeos , Toxoplasma/crescimento & desenvolvimento , Toxoplasma/fisiologia , Trematódeos/crescimento & desenvolvimento , Trematódeos/fisiologia , Hypocreales/crescimento & desenvolvimento , Hypocreales/fisiologia , Vírus da Raiva/fisiologia , Animais , Sistema Nervoso/microbiologia , Sistema Nervoso/parasitologia , Humanos , Interações Hospedeiro-PatógenoRESUMO
Retrograde tracing is an important method for dissecting neuronal connections and mapping neural circuits. Over the past decades, several virus-based retrograde tracers have been developed and have contributed to display multiple neural circuits in the brain. However, most of the previously widely used viral tools have focused on mono-transsynaptic neural tracing within the central nervous system, with very limited options for achieving polysynaptic tracing between the central and peripheral nervous systems. In this study, we generated a novel mouse line, GT mice, in which both glycoprotein (G) and ASLV-A receptor (TVA) were expressed throughout the body. Using this mouse model, in combination with the well-developed rabies virus tools (RABV-EnvA-ΔG) for monosynaptic retrograde tracing, polysynaptic retrograde tracing can be achieved. This allows functional forward mapping and long-term tracing. Furthermore, since the G-deleted rabies virus can travel upstream against the nervous system as the original strain, this mouse model can also be used for rabies pathological studies. Schematic illustrations about the application principles of GT mice in polysynaptic retrograde tracing and rabies pathological research.
Assuntos
Vírus da Raiva , Raiva , Animais , Camundongos , Vírus da Raiva/fisiologia , Neurônios/fisiologia , Encéfalo , Rede NervosaRESUMO
Rabies is a zoonotic disease caused by rabies virus of the genus Lyssa virus and family Rhabdoviridae. It affects all mammals and is prevalent throughout the world and endemic in many countries except in Islands like Australia and Antarctica. It is highly fatal, but preventable. Disease causes threat to public health because rabid dogs bite humans, resulting in thousands of deaths every year. Around 59,000 people die every year from rabies in the world. Dogs play a vital role in most of the human exposure in rabies endemic areas. Transmission of virus occurs through the bite of an infected dog. Disease is manifested by fatal nervous symptoms leading to paralysis and death. Direct fluorescent antibody technique is the gold standard for the diagnosis of the disease in animals and humans. Prevention of rabies involves the vaccination of dogs and humans before or after an exposure. This review describes the etiology, pathogenesis, diagnosis, its prevention and control strategies.
Assuntos
Mordeduras e Picadas , Doenças do Cão , Vacina Antirrábica , Vírus da Raiva , Raiva , Animais , Cães , Humanos , Raiva/diagnóstico , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/veterinária , Saúde Pública , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Zoonoses , Vírus da Raiva/fisiologia , Mamíferos , Mordeduras e Picadas/veterináriaRESUMO
Neurotropic viruses severely damage the central nervous system (CNS) and human health. Common neurotropic viruses include rabies virus (RABV), Zika virus, and poliovirus. When treating neurotropic virus infection, obstruction of the blood-brain barrier (BBB) reduces the efficiency of drug delivery to the CNS. An efficient intracerebral delivery system can significantly increase intracerebral delivery efficiency and facilitate antiviral therapy. In this study, a rabies virus glycopeptide (RVG) functionalized mesoporous silica nanoparticle (MSN) packaging favipiravir (T-705) was developed to generate T-705@MSN-RVG. It was further evaluated for drug delivery and antiviral treatment in a VSV-infected mouse model. The RVG, a polypeptide consisting of 29 amino acids, was conjugated on the nanoparticle to enhance CNS delivery. The T-705@MSN-RVG caused a significant decrease in virus titers and virus proliferation without inducing substantial cell damage in vitro. By releasing T-705, the nanoparticle promoted viral inhibition in the brain during infection. At 21 days post-infection (dpi), a significantly enhanced survival ratio (77%) was observed in the group inoculated with nanoparticle compared with the non-treated group (23%). The viral RNA levels were also decreased in the therapy group at 4 and 6 dpi compared with that of the control group. The T-705@MSN-RVG could be considered a promising system for CNS delivery for treating neurotropic virus infection.
Assuntos
Nanopartículas , Vírus da Raiva , Viroses , Infecção por Zika virus , Zika virus , Humanos , Animais , Camundongos , Vírus da Raiva/fisiologia , Glicopeptídeos , Peptídeos/farmacologia , Antivirais/farmacologia , Antivirais/uso terapêuticoRESUMO
Identification of bona fide functional receptors and elucidation of the mechanism of receptor-mediated virus entry are important to reveal targets for developing therapeutics against rabies virus (RABV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Our previous studies suggest that metabotropic glutamate receptor subtype 2 (mGluR2) functions as an entry receptor for RABV in vitro, and is an important internalization factor for SARS-CoV-2 in vitro and in vivo. Here, we demonstrate that mGluR2 facilitates RABV internalization in vitro and infection in vivo. We found that transferrin receptor 1 (TfR1) interacts with mGluR2 and internalizes with mGluR2 and RABV in the same clathrin-coated pit. Knockdown of TfR1 blocks agonist-triggered internalization of mGluR2. Importantly, TfR1 also interacts with the SARS-CoV-2 spike protein and is important for SARS-CoV-2 internalization. Our findings identify a novel axis (mGluR2-TfR1 axis) used by RABV and SARS-CoV-2 for entry, and reveal TfR1 as a potential target for therapeutics against RABV and SARS-CoV-2. IMPORTANCE We previously found that metabotropic glutamate receptor subtype 2 (mGluR2) is an entry receptor for RABV in vitro, and an important internalization factor for SARS-CoV-2 in vitro and in vivo. However, whether mGluR2 is required for RABV infection in vivo was unknown. In addition, how mGluR2 mediates the internalization of RABV and SARS-CoV-2 needed to be resolved. Here, we found that mGluR2 gene knockout mice survived a lethal challenge with RABV. To our knowledge, mGluR2 is the first host factor to be definitively shown to play an important role in RABV street virus infection in vivo. We further found that transferrin receptor protein 1 (TfR1) directly interacts and cooperates with mGluR2 to regulate the endocytosis of RABV and SARS-CoV-2. Our study identifies a novel axis (mGluR2-TfR1 axis) used by RABV and SARS-CoV-2 for entry and opens a new door for the development of therapeutics against RABV and SARS-CoV-2.
Assuntos
COVID-19 , Vírus da Raiva , Receptores de Glutamato Metabotrópico , Receptores da Transferrina , SARS-CoV-2 , Internalização do Vírus , Animais , Humanos , Camundongos , Raiva/metabolismo , Vírus da Raiva/fisiologia , Receptores de Glutamato Metabotrópico/metabolismo , Receptores da Transferrina/metabolismo , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/metabolismoRESUMO
Rabies is a fatal neurological zoonotic disease caused by the rabies virus (RABV), and the approved post-exposure prophylaxis (PEP) procedure remains unavailable in areas with inadequate medical systems. Although strategies have been proposed for PEP and postinfection treatment (PIT), because of the complexity of the treatment procedures and the limited curative outcome, developing an effective treatment strategy remains a holy grail in rabies research. Herein, a facile approach is proposed involving photothermal therapy (PTT) and photothermally triggered immunological effects to realize effective PEP and PIT simultaneously. The designed photothermal agent (N+ TT-mCB nanoparticles) featured positively charged functional groups and high photo-to-heat efficiency, which are favorable for virus targeting and inactivation. The level of the virus at the site of infection in mice is significantly decreased upon treatment with orthotopic PTT, and the transfer of the virus to the brain is significantly inhibited. Furthermore, the survival ratio of the mice three days postinfection is increased by intracranial injection of N+ TT-mCB and laser irradiation. Overall, this work provides a platform for the effective treatment of RABV and opens a new avenue for future antiviral studies.
Assuntos
Vírus da Raiva , Raiva , Animais , Camundongos , Vírus da Raiva/fisiologia , Raiva/prevenção & controle , Raiva/tratamento farmacológico , Inativação de Vírus , Temperatura Alta , Antivirais/farmacologiaRESUMO
Rabies is a fatal encephalitis caused by the Rabies lyssavirus (RABV). The presence of minimal neuropathological changes observed in rabies indicates that neuronal dysfunction, rather than neuronal death contributes to the fatal outcome. The role of mitochondrial changes has been suggested as a possible mechanism for neuronal dysfunction in rabies. However, these findings are mostly based on studies that have employed experimental models and laboratory-adapted virus. Studies on brain tissues from naturally infected human and animal hosts are lacking. The current study investigated the role of mitochondrial changes in rabies by morphological, biochemical and proteomic analysis of RABV-infected human and canine brains. Morphological analysis showed minimal inflammation with preserved neuronal and disrupted mitochondrial structure in both human and canine brains. Proteomic analysis revealed involvement of mitochondrial processes (oxidative phosphorylation, cristae formation, homeostasis and transport), synaptic proteins and autophagic pathways, with over-expression of subunits of mitochondrial respiratory complexes. Consistent with these findings, human and canine brains displayed elevated activities of complexes I (p < 0.05), IV (p < 0.05) and V (p < 0.05). However, this did not result in elevated ATP production (p < 0.0001), probably due to lowered mitochondrial membrane potential as noted in RABV-infected cells in culture. These could lead to mitochondrial dysfunction and mitophagy as indicated by expression of FKBP8 (p < 0.05) and PINK1 (p < 0.001)/PARKIN (p > 0.05) and ensuing autophagy, as shown by the status of LCIII (p < 0.05), LAMP1 (p < 0.001) and pertinent ultrastructural markers. We propose that altered mitochondrial bioenergetics and cristae architecture probably induce mitophagy, leading to autophagy and consequent neuronal dysfunction in rabies.
Assuntos
Vírus da Raiva , Raiva , Animais , Encéfalo/metabolismo , Cães , Humanos , Mitocôndrias/metabolismo , Proteômica , Raiva/metabolismo , Raiva/patologia , Vírus da Raiva/fisiologiaRESUMO
Rabies, caused by rabies virus (RABV), is an ancient zoonotic disease that significantly affects human and animal health throughout the world. RABV causes acute encephalitis in mammals with a high fatality rate in developing countries. G protein-coupled receptor 17 (GPR17) is a vital gene in the central nervous system (CNS) that plays important roles in demyelinating diseases and ischemia brain. However, it is still unclear whether GPR17 participates in the regulation of RABV infection. Here, we found that upregulation or activation of GPR17 can reduce the virus titer; conversely, the inactivation or silence of GPR17 led to increased RABV replication in N2a cells. The recombinant RABV expressing GPR17 (rRABV-GPR17) showed reduced replication capacity compared to the parent virus rRABV. Moreover, overexpression of GPR17 can attenuate RABV pathogenicity in mice. Further study demonstrated that GPR17 suppressed RABV replication via BAK-mediated apoptosis. Our findings uncover an unappreciated role of GPR17 in suppressing RABV infection, where GPR17 mediates cell apoptosis to limit RABV replication and may be an attractive candidate for new therapeutic interventions in the treatment of rabies.
Assuntos
Proteínas do Tecido Nervoso , Vírus da Raiva , Raiva , Receptores Acoplados a Proteínas G , Replicação Viral , Proteína Killer-Antagonista Homóloga a bcl-2 , Animais , Apoptose , Mamíferos , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Raiva/metabolismo , Raiva/virologia , Vírus da Raiva/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismoRESUMO
Rabies is a fatal zoonotic disease caused by rabies virus (RABV). Despite the existence of control measures, dog-transmitted human rabies accounts for Ë95% reported cases due to unavailability of sensitive diagnostic methods, inadequate understanding of disease progression and absence of therapeutics. In addition, host factors and their role in RABV infection are poorly understood. In this study, we used 8-plex iTRAQ coupled with HRMS approach to identify differentially abundant proteins (DAPs) of dog brain associated with furious rabies virus infection. Total 40 DAPs including 26 down-regulated and 14 up-regulated proteins were statistically significant in infected samples. GO annotation and IPA showed that calcium signaling and calcium transport, efficient neuronal function, metabolic pathway associated proteins were mostly altered during this infection. Total 34 proteins including 10 down-regulated proteins pertaining to calcium signaling and calcium transport pathways were successfully verified by qRT-PCR and two proteins were verified by western blot, thereby suggesting these pathways may play an important role in this infection. This study provides the map of altered brain proteins and some insights into the molecular pathophysiology associated with furious rabies virus infection. However, further investigations are required to understand their role in disease mechanism. SIGNIFICANCE: Transmission of rabies by dogs poses the greatest hazard world-wide and the rare survival of post-symptomatic patients as well as severe neurological and immunological problems pose a question to understand the molecular mechanism involved in rabies pathogenesis. However, information regarding host factors and their function in RABV infection is still inadequate. Our study has used an advanced quantitative proteomics approach i.e. 8-plex iTRAQ coupled with HRMS and identified 40 DAPs in furious rabies infected dog brain tissues compared to the controls. Further analysis showed that calcium signaling and transport pathway, efficient neuronal functions and metabolic pathway associated brain proteins were most altered during furious rabies virus infection. This data provides a map of altered brain proteins which may have role in furious rabies virus infection. Hence, this will improve our understanding of the molecular pathogenesis of RABV infection.
Assuntos
Vírus da Raiva , Raiva , Animais , Encéfalo/metabolismo , Cães , Humanos , Neurônios/patologia , Proteômica , Raiva/veterinária , Vírus da Raiva/fisiologiaRESUMO
Rabies is an old zoonotic disease caused by rabies virus (RABV), but the pathogenic mechanism of RABV is still not completely understood. Lipid droplets (LDs) have been reported to play a role in pathogenesis of several viruses. However, their role in RABV infection remains unclear. Here, we initially found that RABV infection upregulated LD production in multiple cells and mouse brains. After treatment with atorvastatin, a specific inhibitor of LDs, RABV replication in N2a cells decreased. Then we found that RABV infection could upregulate N-myc downstream regulated gene-1 (NDRG1), which in turn enhanced the expression of diacylglycerol acyltransferase 1/2 (DGAT1/2). DGAT1/2 could elevate cellular triglyceride synthesis and ultimately promote intracellular LD formation. Furthermore, we found that RABV-M and RABV-G, which were mainly involved in the viral budding process, could colocalize with LDs, indicating that RABV might utilize LDs as a carrier to facilitate viral budding and eventually increase virus production. Taken together, our study reveals that lipid droplets are beneficial for RABV replication, and their biogenesis is regulated via the NDRG1-DGAT1/2 pathway, which provides novel potential targets for developing anti-RABV drugs. IMPORTANCE Lipid droplets have been proven to play an important role in viral infections, but their role in RABV infection has not yet been elaborated. Here, we find that RABV infection upregulates the generation of LDs by enhancing the expression of N-myc downstream regulated gene-1 (NDRG1). Then NDRG1 elevated cellular triglycerides synthesis by increasing the activity of diacylglycerol acyltransferase 1/2 (DGAT1/2), which promotes the biogenesis of LDs. RABV-M and RABV-G, which are the major proteins involved in viral budding, could utilize LDs as a carrier for transport to cell membrane, resulting in enhanced virus budding. Our findings will extend the knowledge of lipid metabolism in RABV infection and help to explore potential therapeutic targets for RABV.
Assuntos
Gotículas Lipídicas/metabolismo , Vírus da Raiva/fisiologia , Raiva/virologia , Liberação de Vírus , Replicação Viral , Animais , Anticolesterolemiantes/farmacologia , Atorvastatina/farmacologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diacilglicerol O-Aciltransferase/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Gotículas Lipídicas/efeitos dos fármacos , Camundongos , Neurônios/metabolismo , Neurônios/virologia , Raiva/metabolismo , Vírus da Raiva/efeitos dos fármacos , Triglicerídeos/metabolismo , Proteínas Estruturais Virais/metabolismo , Liberação de Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacosRESUMO
BACKGROUND: An evaluation of postexposure prophylaxis (PEP) surveillance has not been conducted in over 10 years in the United States. An accurate assessment would be important to understand current rabies trends and inform public health preparedness and response to human rabies. METHODOLOGY/PRINCIPLE FINDINGS: To understand PEP surveillance, we sent a survey to public health leads for rabies in 50 U.S. states, Puerto Rico, Washington DC, Philadelphia, and New York City. Of leads from 54 jurisdictions, 39 (72%) responded to the survey; 12 reported having PEP-specific surveillance, five had animal bite surveillance that included data about PEP, four had animal bite surveillance without data about PEP, and 18 (46%) had neither. Although 12 jurisdictions provided data about PEP use, poor data quality and lack of national representativeness prevented use of this data to derive a national-level PEP estimate. We used national-level and state specific data from the Healthcare Cost & Utilization Project (HCUP) to estimate the number of people who received PEP based on emergency department (ED) visits. The estimated annual average of initial ED visits for PEP administration during 2012-2017 in the United States was 46,814 (SE: 1,697), costing upwards of 165 million USD. State-level ED data for initial visits for administration of PEP for rabies exposure using HCUP data was compared to state-level surveillance data from Maryland, Vermont, and Georgia between 2012-2017. In all states, state-level surveillance data was consistently lower than estimates of initial ED visits, suggesting even states with robust PEP surveillance may not adequately capture individuals who receive PEP. CONCLUSIONS: Our findings suggest that making PEP a nationally reportable condition may not be feasible. Other methods of tracking administration of PEP such as syndromic surveillance or identification of sentinel states should be considered to obtain an accurate assessment.
Assuntos
Profilaxia Pós-Exposição/estatística & dados numéricos , Raiva/prevenção & controle , Raiva/veterinária , Animais , Anticorpos Antivirais/administração & dosagem , Humanos , Raiva/epidemiologia , Raiva/virologia , Vacina Antirrábica/administração & dosagem , Vírus da Raiva/imunologia , Vírus da Raiva/fisiologia , Vigilância de Evento Sentinela , Estados Unidos/epidemiologiaRESUMO
Rabies virus is a highly neurophilic negative-strand RNA virus with high lethality and remains a huge public health problem in developing countries to date. The double-stranded RNA-binding protein Staufen1 (STAU1) has multiple functions in RNA virus replication, transcription, and translation. However, its function in RABV infection and its mechanism of action are not clear. In this study, we investigated the role of host factor STAU1 in RABV infection of SH-SY-5Y cells. Immunofluorescence, TCID50 titers, confocal microscopy, quantitative real-time PCR and Western blotting were carried out to determine the molecular function and subcellular distribution of STAU1 in these cell lines. Expression of STAU1 in SH-SY-5Y cells was down-regulated by RNA interference or up-regulated by transfection of eukaryotic expression vectors. The results showed that N proficiently colocalized with STAU1 in SH-SY-5Y at 36 h post-infection, and the expression level of STAU1 was also proportional to the time of infection. Down-regulation of STAU1 expression increased the number of Negri body-like structures, enhanced viral replication, and a caused 10-fold increase in viral titers. Meanwhile, N protein and G protein mRNA levels also accumulated gradually with increasing infection time, which implied that STAU1 inhibited rabies virus infection of SH-SY-5Y cells in vitro. In conclusion, our results provide important clues for the detailed replication mechanism of rabies virus and the discovery of therapeutic targets.
Assuntos
Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a RNA/metabolismo , Vírus da Raiva/fisiologia , Replicação Viral , Linhagem Celular Tumoral , Proteínas do Citoesqueleto/genética , Interações Hospedeiro-Patógeno , Humanos , Corpos de Inclusão Viral/metabolismo , Proteínas do Nucleocapsídeo/genética , Proteínas do Nucleocapsídeo/metabolismo , Interferência de RNA , Proteínas de Ligação a RNA/genética , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismoRESUMO
Rabies virus (RABV) induces acute, fatal encephalitis in mammals including humans. The circRNAs are important in virus infection process, but whether circRNAs regulated RABV infection remains largely unknown. Here, mice brain with or without the RABV CVS-11 strain were subjected to RNA sequencing and a total of 30,985 circRNAs were obtained. Among these, 9021 candidates were shared in both groups, and 14,610 and 7354 circRNAs were expressed specifically to the control and experimental groups, indicating that certain circRNAs were specifically inhibited or induced on RABV infection. The circRNAs mainly derived from coding exons. In total, 636 circRNAs were differentially expressed in RABV infection, of which 426 significantly upregulated and 210 significantly downregulated (p < 0.05 and fold change ≥2). The expression of randomly selected 6 upregulated and 6 downregulated circRNAs was tested by RT-qPCR, and the expression trend of the 11 out of 12 circRNAs was consistent in RT- qPCR and RNA-seq analysis. Rnase R-resistant assay and Sanger sequencing were conducted to verify the circularity of circRNAs. GO analysis demonstrated that source genes of all differentially regulated circRNAs were mainly related to cell plasticity and synapse function. Both KEGG and GSEA analysis revealed that these source genes were engaged in the cGMP-PKG and MAPK signaling pathway, and HTLV-I infection. Also, pathways related to glucose metabolism and synaptic functions were enriched in KEGG analysis. The circRNA-miRNA-mRNA network was built with 25 of 636 differentially expressed circRNAs, 264 mRNAs involved in RABV infection, and 29 miRNAs. Several miRNAs and many mRNAs in the network were reported to be related to viral infection and the immune response, suggesting that circRNAs could regulate RABV infection via interacting with miRNAs and mRNAs. Taken together, this study first characterized the transcriptomic pattern of circRNAs, and signaling pathways and function that circRNAs are involved in, which may indicate directions for further research to understand mechanisms of RABV pathogenesis.