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1.
Nat Immunol ; 23(6): 916-926, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35618833

RESUMO

At steady state, the NOD-like receptor (NLR)-containing pyrin domain (PYD) (NLRP)1 inflammasome is maintained in an auto-inhibitory complex by dipeptidyl peptidases 8 and 9 (DPP8 and DPP9) and is activated by pathogen-encoded proteases after infection. Here, we showed that the open reading frame (ORF)45 protein of the Kaposi's sarcoma-associated herpesvirus activated the human NLRP1 (hNLRP1) inflammasome in a non-protease-dependent manner, and we additionally showed that the Linker1 region of hNLRP1, situated between the PYD and NACHT domains, was required for the auto-inhibition and non-protease-dependent activation of hNLRP1. At steady state, the interaction between Linker1 and the UPA subdomain silenced the activation of hNLRP1 in auto-inhibitory complexes either containing DPP9 or not in a manner independent of DPP9. ORF45 binding to Linker1 displaced UPA from the Linker1-UPA complex and induced the release of the C-terminal domain of hNLRP1 for inflammasome assembly. The ORF45-dependent activation of the NLRP1 inflammasome was conserved in primates but was not observed for murine NLRP1b inflammasomes.


Assuntos
Herpesvirus Humano 8 , Inflamassomos , Proteínas Virais/metabolismo , Animais , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Herpesvirus Humano 8/metabolismo , Humanos , Inflamassomos/metabolismo , Camundongos , Proteínas NLR/química , Proteínas NLR/metabolismo
2.
PLoS Pathog ; 18(4): e1010504, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35482828

RESUMO

RSK1, an essential cellular kinase for Kaposi's sarcoma-associated herpesvirus (KSHV) replication, is highly phosphorylated and SUMOylated during KSHV lytic cycle, which determine the substrate phosphorylation and specificity of RSK1, respectively. However, the SUMO E3 ligase responsible for attaching SUMO to RSK1 has not yet been identified. By genome-wide screening, we found that KSHV ORF45 is necessary and sufficient to enhance RSK1 SUMOylation. Mechanistically, KSHV ORF45 binds to SUMOs via two classic SUMO-interacting motifs (SIMs) and functions as a SIM-dependent SUMO E3 ligase for RSK1. Mutations on these ORF45 SIMs resulted in much lower lytic gene expressions, viral DNA replication, and mature progeny virus production. Interestingly, KSHV ORF45 controls RSK1 SUMOylation and phosphorylation via two separated functional regions: SIMs and amino acid 17-90, respectively, which do not affect each other. Similar to KSHV ORF45, ORF45 of Rhesus Macaque Rhadinovirus has only one SIM and also increases RSK1 SUMOylation in a SIM-dependent manner, while other ORF45 homologues do not have this function. Our work characterized ORF45 as a novel virus encoded SUMO E3 ligase, which is required for ORF45-RSK1 axis-mediated KSHV lytic gene expression.


Assuntos
Herpesvirus Humano 8 , Proteínas Imediatamente Precoces , Animais , Linhagem Celular , Replicação do DNA , DNA Viral , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/metabolismo , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Macaca mulatta/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Replicação Viral
3.
Clin Immunol ; 254: 109698, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37481013

RESUMO

Strengthened glycolysis is crucial for the macrophage pro-inflammatory response during sepsis. Activating transcription factor 4 (ATF4) plays an important role in regulating glucose and lipid metabolic homeostasis in hepatocytes and adipocytes. However, its immunometabolic role in macrophage during sepsis remains largely unknown. In the present study, we found that the expression of ATF4 in peripheral blood mononuclear cells (PBMCs) was increased and associated with glucose metabolism in septic patients. Atf4 knockdown specifically decreased LPS-induced spleen macrophages and serum pro-inflammatory cytokines levels in mice. Moreover, Atf4 knockdown partially blocked LPS-induced pro-inflammatory cytokines, lactate accumulation and glycolytic capacity in RAW264.7. Mechanically, ATF4 binds to the promoter region of hexokinase II (HK2), and interacts with hypoxia inducible factor-1α (HIF-1α) and stabilizes HIF-1α through ubiquitination modification in response to LPS. Furthermore, ATF4-HIF-1α-HK2-glycolysis axis launches pro-inflammatory response in macrophage depending on the activation of mammalian target of rapamycin (mTOR). Importantly, Atf4 overexpression improves the decreased level of pro-inflammatory cytokines and lactate secretion and HK2 expression in LPS-induced tolerant macrophages. In conclusion, we propose a novel function of ATF4 as a crucial glycolytic activator contributing to pro-inflammatory response and improving immune tolerant in macrophage involved in sepsis. So, ATF4 could be a potential new target for immunotherapy of sepsis.


Assuntos
Hexoquinase , Sepse , Animais , Camundongos , Fator 4 Ativador da Transcrição/metabolismo , Citocinas/metabolismo , Glicólise , Hexoquinase/genética , Hexoquinase/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Tolerância Imunológica , Ácido Láctico , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos , Macrófagos/metabolismo , Mamíferos/metabolismo , Sepse/genética , Sepse/metabolismo , Ubiquitinação
4.
PLoS Pathog ; 17(12): e1010123, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34871326

RESUMO

RSK1, a downstream kinase of the MAPK pathway, has been shown to regulate multiple cellular processes and is essential for lytic replication of a variety of viruses, including Kaposi's sarcoma-associated herpesvirus (KSHV). Besides phosphorylation, it is not known whether other post-translational modifications play an important role in regulating RSK1 function. We demonstrate that RSK1 undergoes robust SUMOylation during KSHV lytic replication at lysine residues K110, K335, and K421. SUMO modification does not alter RSK1 activation and kinase activity upon KSHV ORF45 co-expression, but affects RSK1 downstream substrate phosphorylation. Compared to wild-type RSK1, the overall phosphorylation level of RxRxxS*/T* motif is significantly declined in RSK1K110/335/421R expressing cells. Specifically, SUMOylation deficient RSK1 cannot efficiently phosphorylate eIF4B. Sequence analysis showed that eIF4B has one SUMO-interacting motif (SIM) between the amino acid position 166 and 170 (166IRVDV170), which mediates the association between eIF4B and RSK1 through SUMO-SIM interaction. These results indicate that SUMOylation regulates the phosphorylation of RSK1 downstream substrates, which is required for efficient KSHV lytic replication.


Assuntos
Herpesvirus Humano 8/fisiologia , Interações Hospedeiro-Patógeno/fisiologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Sumoilação/fisiologia , Replicação Viral/fisiologia , Linhagem Celular , Humanos
5.
J Med Virol ; 95(3): e28659, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36905218

RESUMO

Kaposi sarcoma-associated herpesvirus (KSHV) is the etiological agent of several human diseases, including Kaposi sarcoma, primary effusion lymphoma, and a subset of multicentric Castleman's disease. KSHV uses its gene products to manipulate many aspects of the host responses during its life cycles. Among KSHV-encoded proteins, ORF45 is unique in both temporal and spatial expression: it is expressed as an immediate-early gene product and is an abundant tegument protein contained in the virion. ORF45 is specific to the gammaherpesvirinae subfamily but the homologs share only very limited homology and differ dramatically in protein length. In the past two decades, we and others have shown that ORF45 plays critical roles in immune evasion, viral replication, and virion assembly by targeting various host and viral factors. Herein, we summarize our current knowledge of ORF45 throughout the KSHV life cycle. We discuss the cellular processes targeted by ORF45 with emphasis on the modulation of host innate immune responses and rewiring the host signaling through impacting three major posttranslational modifications: phosphorylation, SUMOylation, and ubiquitination.


Assuntos
Herpesvirus Humano 8 , Proteínas Imediatamente Precoces , Sarcoma de Kaposi , Humanos , Linhagem Celular , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Replicação Viral/fisiologia
6.
J Med Virol ; 95(1): e28243, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36262094

RESUMO

The strain of Zika virus (ZIKV) that circulated during the 2015 epidemic in Brazil has been associated with more than 2000 cases of microcephaly from September 2015 through November 2016. The viral genome determines the biology and pathogenesis of a virus and the virus employs its own gene products to evade host immune surveillance, manipulate cellular machineries, and establish efficient replication. Therefore, understanding the functions of virus-encoded protein not only aids the knowledge of ZIKV biology but also guides the development of anti-ZIKV drugs. In this review, we focus on 10 proteins encoded by ZIKV and summarize their functions in ZIKV replication and pathogenesis according to studies published in the past 6 years.


Assuntos
Epidemias , Microcefalia , Infecção por Zika virus , Zika virus , Humanos , Infecção por Zika virus/epidemiologia , Replicação Viral
7.
J Med Virol ; 95(7): e28967, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37496184

RESUMO

As an intracellular parasite, the virus usurps cellular machinery and modulates cellular metabolism pathways to replicate itself in cells. Lipid droplets (LDs) are universally conserved energy storage organelles that not only play vital roles in maintaining lipid homeostasis but are also involved in viral replication. Increasing evidence has demonstrated that viruses take advantage of cellular lipid metabolism by targeting the biogenesis, hydrolysis, and lipophagy of LD during viral infection. In this review, we summarize the current knowledge about the modulation of cellular LD by different viruses, with a special emphasis on the Hepatitis C virus, Dengue virus, and SARS-CoV-2.


Assuntos
COVID-19 , Gotículas Lipídicas , Humanos , Gotículas Lipídicas/metabolismo , COVID-19/metabolismo , SARS-CoV-2 , Metabolismo dos Lipídeos , Hepacivirus
8.
J Med Virol ; 95(3): e28630, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36861654

RESUMO

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection leads to the accumulation of lipid droplets (LD), the central hubs of the lipid metabolism, in vitro or in type II pneumocytes and monocytes from coronavirus disease 19 (COVID-19) patients and blockage of LD formation by specific inhibitors impedes SARS-CoV-2 replication. Here, we showed that ORF3a is necessary and sufficient to trigger LD accumulation during SARS-CoV-2 infection, leading to efficient virus replication. Although highly mutated during evolution, ORF3a-mediated LD modulation is conserved in most SARS-CoV-2 variants except the Beta strain and is a major difference between SARS-CoV and SARS-CoV-2 that depends on the genetic variations on the amino acid position 171, 193, and 219 of ORF3a. Importantly, T223I substitution in recent Omicron strains (BA.2-BF.8) impairs ORF3a-Vps39 association and LD accumulation, leading to less efficient replication and potentially contributing to lower pathogenesis of the Omicron strains. Our work characterized how SARS-CoV-2 modulates cellular lipid homeostasis to benefit its replication during virus evolution, making ORF3a-LD axis a promising drug target for the treatment of COVID-19.


Assuntos
COVID-19 , SARS-CoV-2 , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Humanos , Gotículas Lipídicas , SARS-CoV-2/genética , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética
9.
J Med Virol ; 95(7): e28932, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37403923

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is undergoing continuous evolution and convergent mutation. These new subvariants are raising concerns that they may evade neutralizing monoclonal antibodies (mAbs). We investigated the serum neutralization efficacy of Evusheld (cilgavimab and tixagevimab) against SARS-CoV-2 Omicron BA.2, BA.2.75, BA.2.76, BA.5, BF.7, BQ.1.1, and XBB.1.5. A total of 90 serum samples from healthy individuals were collected in Shanghai. Anti-RBD antibodies were measured and symptoms of infection with COVID-19 were compared among those individuals. The neutralizing activity of serum against Omicron variants was analyzed by pseudovirus neutralization assays in 22 samples. Evusheld retained neutralizing activity against BA.2, BA.2.75, and BA.5, albeit with somewhat reduced titers. However, the neutralizing activity of Evusheld against BA.2.76, BF.7, BQ.1.1, and XBB.1.5 significantly decreased, with XBB.1.5 showing the greatest escape activity among the subvariants. We also observed that Evusheld recipients displayed elevated antibody levels in their serum, which efficiently neutralized the original variant, and exhibited different characteristics of infection than those who did not receive Evusheld. The mAb has partial neutralization activity against Omicron sublineages. However, the increasing doses of mAb and a larger size of population should be further investigated.


Assuntos
COVID-19 , Humanos , SARS-CoV-2/genética , China , Anticorpos Neutralizantes , Anticorpos Antivirais
10.
Proc Natl Acad Sci U S A ; 117(44): 27509-27515, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33077598

RESUMO

Immune checkpoint-blocking antibodies that attenuate immune tolerance have been used to effectively treat cancer, but they can also trigger severe immune-related adverse events. Previously, we found that Bifidobacterium could mitigate intestinal immunopathology in the context of CTLA-4 blockade in mice. Here we examined the mechanism underlying this process. We found that Bifidobacterium altered the composition of the gut microbiota systematically in a regulatory T cell (Treg)-dependent manner. Moreover, this altered commensal community enhanced both the mitochondrial fitness and the IL-10-mediated suppressive functions of intestinal Tregs, contributing to the amelioration of colitis during immune checkpoint blockade.


Assuntos
Doenças Autoimunes/prevenção & controle , Bifidobacterium/imunologia , Microbioma Gastrointestinal/imunologia , Probióticos/administração & dosagem , Linfócitos T Reguladores/imunologia , Animais , Doenças Autoimunes/induzido quimicamente , Doenças Autoimunes/imunologia , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Tolerância Imunológica , Interleucina-10/genética , Interleucina-10/metabolismo , Camundongos , Camundongos Knockout , Linfócitos T Reguladores/metabolismo
11.
Br J Neurosurg ; 37(4): 682-684, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30693794

RESUMO

Simultaneous spontaneous bilateral external capsule hemorrhage is a rare clinical entity with extremely poor outcome. However, knowledge on the effective management of this fatal disease is limited. Herein,we described a case of a 42-year-old man with acute coma and quadriplegia as well as respiratory failure related to the disease. The patient underwent minimally invasive surgery plus local thrombolysis. Consequently, he recovered with satisfactory neurological function recovery on the 180th day of follow-up.


Assuntos
Hemorragia dos Gânglios da Base , Coma , Masculino , Humanos , Adulto , Coma/etiologia , Cápsula Externa , Resultado do Tratamento , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia dos Gânglios da Base/complicações , Hemorragia dos Gânglios da Base/diagnóstico por imagem , Hemorragia dos Gânglios da Base/cirurgia
12.
Br J Neurosurg ; 37(5): 1082-1087, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35475398

RESUMO

PURPOSE: Spontaneous intracerebral haemorrhage (ICH) is the main presentation in adults with moyamoya disease (MMD), an unusual clinical entity with a poor prognosis. However, optimal management in the acute stage of ICH in patients with MMD remains a challenge. Since minimally invasive surgery (MIS) plus local thrombolysis has emerged as a promising strategy for ICH, we aimed to describe our experience of performing this procedure in this special population in the acute phase, while focusing on its efficacy and safety. MATERIALS AND METHODS: The medical data of patients with ICH treated with MIS and local thrombolysis between November 2013 and December 2017 were retrospectively reviewed at our institution. MMD was identified based on the angiographic images. The primary outcome was postoperative intracranial rebleeding. The secondary outcomes were 30-day mortality and 6-month outcome graded using the modified Rankin scale (mRS). Logistic regression was applied to explore independent risk factors for the above outcomes. RESULTS: A cohort of consecutive 337 ICH patients was analysed, of whom 14 (4.15%) were diagnosed with MMD. In total, 36 (11.46%) patients experienced postoperative intracranial rehaemorrhage, of which one patient had MMD. No significant difference was found between the patients with and without MMD regarding postoperative rebleeding (9.09% vs. 11.55%, p = 1.000). Additionally, the 30-day mortality of patients with MMD was 21.42% (3/14), which was not significantly different from that of non-MMD patients (10.83%; p = 0.201). Moreover, 53.8% of patients had poor outcomes at the 6-month follow-up among MMD patients, similar to 43.9% of patients without MMD (p = 0.573). The coexistence of MMD failed to show a significant association with postoperative intracranial rebleeding (p = 0.348), 30-day mortality (p = 0.211), or poor outcome at the 6-month follow-up (p = 0.450). CONCLUSION: Our findings suggest that coexistent MMD is not associated with an increased risk of postoperative rebleeding or poor outcome after local thrombolysis for ICH.


Assuntos
Doença de Moyamoya , Adulto , Humanos , Doença de Moyamoya/complicações , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/cirurgia , Estudos Retrospectivos , Resultado do Tratamento , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/cirurgia , Terapia Trombolítica/efeitos adversos , Hematoma/cirurgia
13.
Sens Actuators B Chem ; 345: 130411, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34248284

RESUMO

The outbreak of corona virus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a global pandemic. The high infectivity of SARS-CoV-2 highlights the need for sensitive, rapid and on-site diagnostic assays of SARS-CoV-2 with high-throughput testing capability for large-scale population screening. The current detection methods in clinical application need to operate in centralized labs. Though some on-site detection methods have been developed, few tests could be performed for high-throughput analysis. We here developed a gold nanoparticle-based visual assay that combines with CRISPR/Cas12a-assisted RT-LAMP, which is called Cas12a-assisted RT-LAMP/AuNP (CLAP) assay for rapid and sensitive detection of SARS-CoV-2. In optimal condition, we could detect down to 4 copies/µL of SARS-CoV-2 RNA in 40 min. by naked eye. The sequence-specific recognition character of CRISPR/Cas12a enables CLAP a superior specificity. More importantly, the CLAP is easy for operation that can be extended to high-throughput test by using a common microplate reader. The CLAP assay holds a great potential to be applied in airports, railway stations, or low-resource settings for screening of suspected people. To the best of our knowledge, this is the first AuNP-based colorimetric assay coupled with Cas12 and RT-LAMP for on-site diagnosis of COVID-19. We expect CLAP assay will improve the current COVID-19 screening efforts, and make contribution for control and mitigation of the pandemic.

14.
J Virol ; 92(4)2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29167347

RESUMO

The viral Bcl-2 homolog (vBcl2) of Kaposi's sarcoma-associated herpesvirus (KSHV) displays efficient antiapoptotic and antiautophagic activity through its central BH3 domain, which functions to prolong the life span of virus-infected cells and ultimately enhances virus replication and latency. Independent of its antiapoptotic and antiautophagic activity, vBcl2 also plays an essential role in KSHV lytic replication through its amino-terminal amino acids (aa) 11 to 20. Here, we report a novel molecular mechanism of vBcl2-mediated regulation of KSHV lytic replication. vBcl2 specifically bound the tegument protein open reading frame 55 (ORF55) through its amino-terminal aa 11 to 20, allowing their association with virions. Consequently, the vBcl2 peptide derived from vBcl2 aa 11 to 20 effectively disrupted the interaction between vBcl2 and ORF55, inhibiting the incorporation of the ORF55 tegument protein into virions. This study provides new insight into vBcl2's function in KSHV virion assembly that is separable from its inhibitory role in host apoptosis and autophagy.IMPORTANCE KSHV, an important human pathogen accounting for a large percentage of virally caused cancers worldwide, has evolved a variety of stratagems for evading host immune responses to establish lifelong persistent infection. Upon viral infection, infected cells can go through programmed cell death, including apoptosis and autophagy, which plays an effective role in antiviral responses. To counter the host response, KSHV vBcl2 efficiently blocks apoptosis and autophagy to persist for the life span of virus-infected cells. Besides its anti-programmed-cell-death activity, vBcl2 also interacts with the ORF55 tegument protein for virion assembly in infected cells. Interestingly, the vBcl2 peptide disrupts the vBcl2-ORF55 interaction and effectively inhibits KSHV virion assembly. This study indicates that KSHV vBcl2 harbors at least three genetically separable functions to modulate both host cell death signaling and virion production and that the vBcl2 peptide can be developed as an anti-KSHV therapeutic application.


Assuntos
Herpesvirus Humano 8/fisiologia , Proteínas Oncogênicas/fisiologia , Fases de Leitura Aberta , Proteínas Virais/fisiologia , Montagem de Vírus , Apoptose , Autofagia , Sequência de Bases , Replicação do DNA , DNA Viral/genética , Expressão Gênica , Técnicas de Inativação de Genes , Genoma Viral , Células HEK293 , Herpesvirus Humano 8/genética , Humanos , Proteínas Oncogênicas/genética , Proteínas Virais/genética
15.
PLoS Pathog ; 12(5): e1005648, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27187079

RESUMO

Aerobic glycolysis is essential for supporting the fast growth of a variety of cancers. However, its role in the survival of cancer cells under stress conditions is unclear. We have previously reported an efficient model of gammaherpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV)-induced cellular transformation of rat primary mesenchymal stem cells. KSHV-transformed cells efficiently induce tumors in nude mice with pathological features reminiscent of Kaposi's sarcoma tumors. Here, we report that KSHV promotes cell survival and cellular transformation by suppressing aerobic glycolysis and oxidative phosphorylation under nutrient stress. Specifically, KSHV microRNAs and vFLIP suppress glycolysis by activating the NF-κB pathway to downregulate glucose transporters GLUT1 and GLUT3. While overexpression of the transporters rescues the glycolytic activity, it induces apoptosis and reduces colony formation efficiency in softagar under glucose deprivation. Mechanistically, GLUT1 and GLUT3 inhibit constitutive activation of the AKT and NF-κB pro-survival pathways. Strikingly, GLUT1 and GLUT3 are significantly downregulated in KSHV-infected cells in human KS tumors. Furthermore, we have detected reduced levels of aerobic glycolysis in several KSHV-infected primary effusion lymphoma cell lines compared to a Burkitt's lymphoma cell line BJAB, and KSHV infection of BJAB cells reduced aerobic glycolysis. These results reveal a novel mechanism by which an oncogenic virus regulates a key metabolic pathway to adapt to stress in tumor microenvironment, and illustrate the importance of fine-tuning the metabolic pathways for sustaining the proliferation and survival of cancer cells, particularly under stress conditions.


Assuntos
Adaptação Fisiológica/fisiologia , Transformação Celular Viral/fisiologia , Infecções por Herpesviridae/metabolismo , Animais , Western Blotting , Linhagem Celular Tumoral , Sobrevivência Celular , Modelos Animais de Doenças , Citometria de Fluxo , Imunofluorescência , Técnicas de Silenciamento de Genes , Glicólise/fisiologia , Herpesvirus Humano 8/metabolismo , Humanos , Linfoma de Efusão Primária/metabolismo , Linfoma de Efusão Primária/virologia , Microscopia Confocal , Reação em Cadeia da Polimerase , Ratos
16.
Biochim Biophys Acta ; 1862(10): 1883-90, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27425033

RESUMO

Parkinson's disease (PD) is a progressive neurodegenerative disease. α-Synuclein (α-syn) oligomers play a critical role in the progression of PD. Baicalein, a typical flavonoid compound, can inhibit the formation of the α-syn oligomers, and disaggregate existing α-syn oligomers in vitro. However, whether baicalein could inhibit or disaggregate α-syn oligomers in vivo has not been investigated. Therefore, this study was designed to investigate the inhibitory effects of baicalein on α-syn oligomers in vivo and to explore the possible mechanisms of such inhibition. A chronic PD mouse model was created by continuous intragastric administration of rotenone (5mg/kg, 12weeks). Baicalein (100mg/kg) was intraperitoneally injected from 7week to 12week. Our result showed that the amount of α-syn, changes in the levels of the striatal neurotransmitters, and the behavioral changes found in the chronic PD mouse model were prevented after the baicalein injections. Although baicalein did not decrease α-syn mRNA expression, α-syn oligomers were significantly decreased in the ileum, thoracic spinal cord, and midbrain. Furthermore, transmission electron microscopy analysis showed that baicalein could prevent α-syn monomers from the oligomer formation in vitro. Taken together, these results suggest that baicalein could prevent the progression of α-syn accumulation in PD mouse model partly by inhibiting formation of the α-syn oligomers.


Assuntos
Flavanonas/farmacologia , Mesencéfalo/metabolismo , Doença de Parkinson Secundária/metabolismo , Multimerização Proteica/efeitos dos fármacos , Rotenona/efeitos adversos , Medula Espinal/metabolismo , alfa-Sinucleína/metabolismo , Animais , Masculino , Mesencéfalo/patologia , Camundongos , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/patologia , Rotenona/farmacologia , Medula Espinal/patologia
17.
J Virol ; 89(9): 4918-31, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25694600

RESUMO

UNLABELLED: The ORF45 protein of Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus-specific immediate-early tegument protein. Our previous studies have revealed its crucial roles in both early and late stages of KSHV infection. In this study, we surveyed the interactome of ORF45 using a panel of monoclonal antibodies. In addition to the previously identified extracellular regulated kinase (ERK) and p90 ribosomal S6 kinase (RSK) proteins, we found several other copurified proteins, including prominent ones of ∼38 kDa and ∼130 kDa. Mass spectrometry revealed that the 38-kDa protein is viral ORF33 and the 130-kDa protein is cellular USP7 (ubiquitin-specific protease 7). We mapped the ORF33-binding domain to the highly conserved carboxyl-terminal 19 amino acids (aa) of ORF45 and the USP7-binding domain to the reported consensus motif in the central region of ORF45. Using immunofluorescence staining, we observed colocalization of ORF45 with ORF33 or USP7 both under transfected conditions and in KSHV-infected cells. Moreover, we noticed ORF45-dependent relocalization of a portion of ORF33/USP7 from the nucleus to the cytoplasm. We found that ORF45 caused an increase in ORF33 protein accumulation that was abolished if either the ORF33- or USP7-binding domain in ORF45 was deleted. Furthermore, deletion of the conserved carboxyl terminus of ORF45 in the KSHV genome drastically reduced the level of ORF33 protein in KSHV-infected cells and abolished production of progeny virions. Collectively, our results not only reveal new components of the ORF45 interactome, but also demonstrate that the interactions among these proteins are crucial for KSHV lytic replication. IMPORTANCE: Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of several human cancers. KSHV ORF45 is a multifunctional protein that is required for KSHV lytic replication, but the exact mechanisms by which ORF45 performs its critical functions are unclear. Our previous studies revealed that all ORF45 protein in cells exists in high-molecular-weight complexes. We therefore sought to characterize the interactome of ORF45 to provide insights into its roles during lytic replication. Using a panel of monoclonal antibodies, we surveyed the ORF45 interactome in KSHV-infected cells. We identified two new binding partners of ORF45: the viral protein ORF33 and cellular ubiquitin-specific protease 7 (USP7). We further demonstrate that the interaction between ORF45 and ORF33 is crucial for the efficient production of KSHV viral particles, suggesting that the targeted interference with this interaction may represent a novel strategy to inhibit KSHV lytic replication.


Assuntos
Proteínas do Capsídeo/metabolismo , Herpesvirus Humano 8/fisiologia , Proteínas Imediatamente Precoces/metabolismo , Mapeamento de Interação de Proteínas , Ubiquitina Tiolesterase/metabolismo , Replicação Viral , Proteínas do Capsídeo/química , Linhagem Celular , Humanos , Espectrometria de Massas , Peso Molecular , Ubiquitina Tiolesterase/química , Peptidase 7 Específica de Ubiquitina
18.
J Virol ; 89(10): 5308-17, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25740994

RESUMO

UNLABELLED: Kaposi's sarcoma-associated herpesvirus (KSHV) evades host defenses through tight suppression of autophagy by targeting each step of its signal transduction: by viral Bcl-2 (vBcl-2) in vesicle nucleation, by viral FLIP (vFLIP) in vesicle elongation, and by K7 in vesicle maturation. By exploring the roles of KSHV autophagy-modulating genes, we found, surprisingly, that vBcl-2 is essential for KSHV lytic replication, whereas vFLIP and K7 are dispensable. Knocking out vBcl-2 from the KSHV genome resulted in decreased lytic gene expression at the mRNA and protein levels, a lower viral DNA copy number, and, consequently, a dramatic reduction in the amount of progeny infectious viruses, as also described in the accompanying article (A. Gelgor, I. Kalt, S. Bergson, K. F. Brulois, J. U. Jung, and R. Sarid, J Virol 89:5298-5307, 2015). More importantly, the antiapoptotic and antiautophagic functions of vBcl-2 were not required for KSHV lytic replication. Using a comprehensive mutagenesis analysis, we identified that glutamic acid 14 (E14) of vBcl-2 is critical for KSHV lytic replication. Mutating E14 to alanine totally blocked KSHV lytic replication but showed little or no effect on the antiapoptotic and antiautophagic functions of vBcl-2. Our study indicates that vBcl-2 harbors at least three important and genetically separable functions to modulate both cellular signaling and the virus life cycle. IMPORTANCE: The present study shows for the first time that vBcl-2 is essential for KSHV lytic replication. Removal of the vBcl-2 gene results in a lower level of KSHV lytic gene expression, impaired viral DNA replication, and consequently, a dramatic reduction in the level of progeny production. More importantly, the role of vBcl-2 in KSHV lytic replication is genetically separated from its antiapoptotic and antiautophagic functions, suggesting that the KSHV Bcl-2 carries a novel function in viral lytic replication.


Assuntos
Herpesvirus Humano 8/fisiologia , Proteínas Oncogênicas/fisiologia , Proteínas Virais/fisiologia , Replicação Viral/fisiologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Apoptose , Autofagia , Sequência de Bases , Linhagem Celular , Replicação do DNA , DNA Viral/genética , Expressão Gênica , Técnicas de Inativação de Genes , Genoma Viral , Células HEK293 , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/fisiologia , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteínas Oncogênicas/antagonistas & inibidores , Proteínas Oncogênicas/genética , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/genética , Replicação Viral/genética
19.
Br J Neurosurg ; 30(4): 401-6, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27008453

RESUMO

OBJECTIVES: Single-target puncture plus catheter insertion into the clot is a routine step in hematoma aspiration and local thrombolysis for spontaneous intracerebral haemorrhage (ICH). However, multiple-target puncture of this procedure may imply faster hematoma reduction for large-area ICH. We retrospectively examined the outcomes after clot aspiration plus local thrombolysis with single-/double-target and conservative therapy for extensive basal ganglic hematomas. METHODS: A case note review was conducted on a consecutive series of ICH patients in a single centre with huge basal ganglia hematomas who underwent clots aspiration and thrombolysis or pure medical therapy. We analysed the clinical presentation, radiological features and treatment outcomes of ICH patients in single-target group, double-target group and conservative group. RESULTS: A total of 92 ICH cases were included in this study. At the post-treatment assessment, the average level by hematoma size in single-target and double-group was respectively smaller than that in the conservative group (20.61 ml vs. 15.75 ml vs 60.53 ml, p < 0.01). The 30-day case fatality rate in conservative group was respectively significantly higher than that in single-target and double-target groups (50% vs. 14.70% vs. 20.59%, p < 0.01). At the time of 6-month follow-up, the proportion of good survival in conservative group was respectively remarkably less than that in single- and double-target group (29.17% vs.64.71% vs. 67.65%, p < 0.01). But no difference was detected with respect to 30-day mortality or long-time outcome between the two micro-invasive groups (p = 0.53 and 0.798, respectively). CONCLUSION: Our data suggested for the massive basal ganglia hematomas, clot aspiration and thrombolysis can improve the short- and long-term prognosis compared with the pure conservative therapy. But, no evidence was found to demonstrate double-target of this procedure to be more effective than single-target to improve the outcome.


Assuntos
Hemorragia dos Gânglios da Base/tratamento farmacológico , Hemorragia dos Gânglios da Base/cirurgia , Hemorragia Cerebral/tratamento farmacológico , Fibrinolíticos/uso terapêutico , Ativador de Plasminogênio Tecidual/uso terapêutico , Adolescente , Adulto , Idoso , Hemorragia Cerebral/cirurgia , Tratamento Conservador/métodos , Feminino , Fibrinolíticos/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tecidual/administração & dosagem , Resultado do Tratamento , Adulto Jovem
20.
J Virol ; 87(22): 12499-503, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24027317

RESUMO

Autophagy is an important innate safeguard mechanism for protecting an organism against invasion by pathogens. We have previously discovered that Kaposi's sarcoma-associated herpesvirus (KSHV) evades this host defense through tight suppression of autophagy by targeting multiple steps of autophagy signal transduction. Here, we report that KSHV K7 protein interacts with Rubicon autophagy protein and inhibits the autophagosome maturation step by blocking Vps34 enzymatic activity, further highlighting how KSHV deregulates autophagy-mediated host immunity for its life cycle.


Assuntos
Autofagia , Herpesvirus Humano 8/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Mitocondriais/metabolismo , Fagossomos/metabolismo , Sarcoma de Kaposi/patologia , Proteínas Virais/metabolismo , Proteínas Relacionadas à Autofagia , Células HeLa , Humanos , Immunoblotting , Sarcoma de Kaposi/metabolismo , Sarcoma de Kaposi/virologia , Transdução de Sinais
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