RESUMO
Obesity is a surging public health risk and is often associated with fatal diseases, including diabetes, stroke, and myocardial infarction. Common methods for obesity treatment include diet control, weight-loss medicine, and bariatric surgery, but these methods are often ineffective or unsafe. Herein, we introduce a minimally invasive and effective approach to reduce excessive fat accumulation by utilizing red/near-infrared emissive and lipid droplet targeting aggregation-induced emissive luminogens (AIEgens), namely, TTMN and MeTTMN, for specific targeting and photoinduced peroxidation of large lipid droplets in adipocytes. The reported AIEgens can trace and monitor the formation process of adipocytes from pre-adipocytes with a high signal-to-noise ratio. In addition, the presented AIEgens act as Type I photosensitizer that generates highly reactive hydroxyl radicals and superoxides under white light to eliminate mature adipocytes through the chain reactions of lipid peroxidation, even under low oxygen supply. We also demonstrate the use of AIEgens for in vivo photodynamic therapy (PDT) for subcutaneous fat reduction treatment. This work demonstrates the use of AIEgen as a dual imaging and Type I photosensitizer for photodynamic therapeutics to induce adipocyte apoptosis, involving a simple fabrication and treatment process. The suggested in vivo photodynamic obesity treatment processes have negligible toxicity toward nontargeted normal tissues, providing an alternative approach for effective and relatively safer obesity treatment in the future.
Assuntos
Fotoquimioterapia , Fármacos Fotossensibilizantes , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Peroxidação de Lipídeos , Fotoquimioterapia/métodos , Luz , Diagnóstico por ImagemRESUMO
Fluorescence-guided photodynamic therapy (PDT) has been considered as an emerging strategy for precise cancer treatment by making use of photosensitizers (PSs) with reactive oxygen species (ROS) generation. Some efficient PSs have been reported in recent years, but multifunctional PSs that are responsive to cancer-specific biomarkers are rarely reported. In this study, we introduced a phosphate group as a cancer-specific biomarker of alkaline phosphatase (ALP) on a PS with the features of aggregation-induced emission (AIE) for cancer cell imaging and therapy. In cancer cells with high ALP expression, the phosphate group on the AIE probe is selectively hydrolyzed by ALP. Consequently, the hydrophobic probe residue is aggregated in aqueous media and gives a "turn on" fluorescent response. Moreover, fluorescence-guided PDT was realized by the aggregates of probe residue with strong ROS generation efficiency under white light irradiation. Overall, this work presents a strategy of applying ALP-responsive AIE PS for specific imaging cancer cells and succeeding with specific PDT upon the cancer biomarker stimulated responsive reactions.
Assuntos
Neoplasias , Fotoquimioterapia , Humanos , Fármacos Fotossensibilizantes/química , Fotoquimioterapia/métodos , Fosfatase Alcalina , Espécies Reativas de Oxigênio/metabolismo , Luz , Neoplasias/tratamento farmacológicoRESUMO
Biotechnologies that use plant viruses as plant enhancement tools have shown great potential to flexibly engineer crop traits, but field applications of these technologies are still limited by efficient dissemination methods. Potyviruses can be rapidly inoculated into plants by aphid vectors due to the presence of the potyviral helper component proteinase (HC-Pro), which binds to the DAG motif of the coat protein (CP) of the virion. Previously it was determined that a naturally occurring DAG motif in the non-aphid-transmissible potexvirus, potato aucuba mosaic virus (PAMV), is functional when a potyviral HC-Pro is provided to aphids in plants. The DAG motif of PAMV was successfully transferred to the CP of another non-aphid-transmissible potexvirus, potato virus X, to convey aphid transmission capabilities in the presence of HC-Pro. Here, we demonstrate that DAG-containing segments of the CP from two different potyviruses (sugarcane mosaic virus and turnip mosaic virus), and from the previously used potexvirus, PAMV, can make the potexvirus, foxtail mosaic virus (FoMV), aphid-transmissible when fused with the FoMV CP. We show that DAG-containing FoMVs are transmissible by aphids that have prior access to HC-Pro through potyvirus-infected plants or ectopic expression of HC-Pro. The transmission efficiency of the DAG-containing FoMVs varied from less than 10â% to over 70â% depending on the length and composition of the surrounding amino acid sequences of the DAG-containing segment, as well as due to the recipient plant species. Finally, we show that the engineered aphid-transmissible FoMV is still functional as a plant enhancement resource, as endogenous host target genes were silenced in FoMV-infected plants after aphid transmission. These results suggest that aphid transmission could be engineered into non-aphid-transmissible plant enhancement viral resources to facilitate their field applications.
Assuntos
Afídeos , Vírus de Plantas , Potexvirus , Potyvirus , Animais , Potexvirus/metabolismo , Potyvirus/genética , Cisteína Endopeptidases/química , Plantas , Doenças das PlantasAssuntos
Anticorpos Monoclonais Humanizados , Benzodiazepinas , Linfoma Difuso de Grandes Células B , Recidiva Local de Neoplasia , Anticorpos Monoclonais Humanizados/uso terapêutico , Benzodiazepinas/uso terapêutico , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/patologia , Recidiva Local de Neoplasia/tratamento farmacológicoRESUMO
INTRODUCTION: Spastic paraplegia type 4 (SPG4), resulting from heterozygous mutations in the SPAST gene, is the most common form among the heterogeneous group of hereditary spastic paraplegias (HSPs). We aimed to study genetic and clinical characteristics of SPG4 across Canada. METHODS: The SPAST gene was analyzed in a total of 696 HSP patients from 431 families by either HSP-gene panel sequencing or whole exome sequencing (WES). We used Multiplex ligation-dependent probe amplification to analyze copy number variations (CNVs), and performed in silico structural analysis of selected mutations. Clinical characteristics of patients were assessed, and long-term follow-up was done to study genotype-phenotype correlations. RESULTS: We identified 157 SPG4 patients from 65 families who carried 41 different SPAST mutations, six of which are novel and six are CNVs. We report novel aspects of mutations occurring in Arg499, a case with homozygous mutation, a family with probable compound heterozygous mutations, three patients with de novo mutations, three cases with pathogenic synonymous mutation, co-occurrence of SPG4 and clinically isolated syndrome, and novel or rarely reported signs and symptoms seen in SPG4 patients. CONCLUSION: Our study demonstrates that SPG4 is a heterogeneous type of HSP, with diverse genetic features and clinical manifestations. In rare cases, biallelic inheritance, de novo mutation, pathogenic synonymous mutations and CNVs should be considered.
Assuntos
Paraplegia Espástica Hereditária , Espastina , Adenosina Trifosfatases/genética , Variações do Número de Cópias de DNA , Humanos , Mutação , Paraplegia/genética , Fenótipo , Paraplegia Espástica Hereditária/diagnóstico , Paraplegia Espástica Hereditária/genética , Espastina/genéticaRESUMO
OBJECTIVE: Prostate cancer is a common malignancy and patients may progress to castration-resistant prostate cancer (CRPC). Among patients with CRPC, fatigue is a common symptom associated with current treatments. The aim of this real-world study was to describe patient-reported fatigue in Japanese patients treated with androgen receptor-axis-targeted therapies for CRPC. METHODS: Data of this observational study were collected in a quantitative phase for the description of patient-reported fatigue, and a qualitative phase for elicitation of fatigue perception and barriers to reporting fatigue. RESULTS: In the quantitative phase (N = 22), fatigue was investigated in two formats: symptoms report and Brief Fatigue Inventory (BFI). In the report of the symptoms, 12 patients reported tiredness, and four moderate-to-severe tiredness during treatment. In the BFI, all patients reported fatigue; eight reported moderate-to-severe fatigue. The most affected BFI domain was mood: five patients reporting moderate-to-severe impact. In interviews (qualitative phase; N = 8), diverse patient experience on fatigue was observed, including apathetic feelings, affected speed and distance during the walk, negative impact on profession, housework, or driving, reduced outgoing activity, and difficulty in enjoying time with grandchildren or travel. Five out of eight patients communicated fatigue to their physicians but received diverse reactions. CONCLUSION: Patient interviews highlighted the impact of fatigue on patients' lives and difficulties in communicating fatigue to physicians. Fatigue frequency after medication may need to be monitored and its burden is considered to provide treatment that meets the needs, wishes, and circumstances of each patient. Further research is needed to elucidate how fatigue affects patients' lives, and underscore patient-physician communication difficulties.
Assuntos
Médicos , Neoplasias de Próstata Resistentes à Castração , Comunicação , Fadiga/epidemiologia , Fadiga/etiologia , Humanos , Japão , Masculino , Neoplasias de Próstata Resistentes à Castração/complicações , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológicoRESUMO
BACKGROUND: Postoperative outcome following deep brain stimulation (DBS) of the subthalamic nucleus is variable, particularly with respect to axial motor improvement. We hypothesized a genetic underpinning to the response to surgical intervention, termed "surgicogenomics". OBJECTIVE: We aimed to identify genetic variants associated with clinical heterogeneity in DBS outcome of Parkinson's disease (PD) patients that could then be applied clinically to target selection leading to improved surgical outcome. METHODS: Retrospective clinical data was extracted from 150 patient's charts. Each individual was genotyped using the genome-wide NeuroX array tailored to study neurologic diseases. Genetic data were clustered based on surgical outcome assessed by comparing pre- and post-operative scores of levodopa equivalent daily dose and axial impairment at one and five years post-surgery. Allele frequencies were compared between patients with excellent vs. moderate/poor outcomes grouped using a priori defined cut-offs. We analyzed common variants, burden of rare coding variants, and PD polygenic risk score. RESULTS: NeuroX identified 2,917 polymorphic markers at 113 genes mapped to known PD loci. The gene-burden analyses of 202 rare nonsynonymous variants suggested a nominal association of axial impairment with 14 genes (most consistent with CRHR1, IP6K2, and PRSS3). The strongest association with surgical outcome was detected between a reduction in levodopa equivalent daily dose and common variations tagging two linkage disequilibrium blocks with SH3GL2. CONCLUSION: Once validated in independent populations, our findings may be implemented to improve patient selection for DBS in PD.
Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson , Estimulação Encefálica Profunda/efeitos adversos , Estimulação Encefálica Profunda/métodos , Humanos , Levodopa , Doença de Parkinson/complicações , Doença de Parkinson/genética , Doença de Parkinson/terapia , Estudos Retrospectivos , Resultado do Tratamento , TripsinaRESUMO
BACKGROUND: Epidemiological data suggest that cancer patients have a reduced risk of subsequent Parkinson's disease (PD) development, but the prevalence of PD in melanoma patients is often reported to be increased. Causal relationships between cancers and PD have not been fully explored. OBJECTIVE: To study causal relationship between different cancers and PD. METHODS: We used GWAS summary statistics of 15 different types of cancers and two-sample Mendelian randomization to study the causal relationship with PD. RESULTS: There was no evidence to support a causal relationship between the studied cancers and PD. We also performed reverse analyses between PD and cancers with available full summary statistics (melanoma, breast, prostate, endometrial and keratinocyte cancers) and did not find evidence of causal relationship. CONCLUSION: We found no evidence to support a causal relationship between cancers and PD and the previously reported associations could be a result of genetic pleiotropy, shared biology or biases.
Assuntos
Doença de Parkinson , Causalidade , Estudo de Associação Genômica Ampla , Humanos , Masculino , Melanoma/epidemiologia , Melanoma/genética , Análise da Randomização Mendeliana , Doença de Parkinson/epidemiologia , Doença de Parkinson/genéticaRESUMO
BACKGROUND: Although the typical inheritance of spastic paraplegia 7 is recessive, several reports have suggested that SPG7 variants may also cause autosomal dominant hereditary spastic paraplegia (HSP). OBJECTIVES: We aimed to conduct an exome-wide genetic analysis on a large Canadian cohort of HSP patients and controls to examine the association of SPG7 and HSP. METHODS: We analyzed 585 HSP patients from 372 families and 1175 controls, including 580 unrelated individuals. Whole-exome sequencing was performed on 400 HSP patients (291 index cases) and all 1175 controls. RESULTS: The frequency of heterozygous pathogenic/likely pathogenic SPG7 variants (4.8%) among unrelated HSP patients was higher than among unrelated controls (1.7%; OR 2.88, 95% CI 1.24-6.66, P = 0.009). The heterozygous SPG7 p.(Ala510Val) variant was found in 3.7% of index patients versus 0.85% in unrelated controls (OR 4.42, 95% CI 1.49-13.07, P = 0.005). Similar results were obtained after including only genetically-undiagnosed patients. We identified four heterozygous SPG7 variant carriers with an additional pathogenic variant in known HSP genes, compared to zero in controls (OR 19.58, 95% CI 1.05-365.13, P = 0.0031), indicating potential digenic inheritance. We further identified four families with heterozygous variants in SPG7 and SPG7-interacting genes (CACNA1A, AFG3L2, and MORC2). Of these, there is especially compelling evidence for epistasis between SPG7 and AFG3L2. The p.(Ile705Thr) variant in AFG3L2 is located at the interface between hexamer subunits, in a hotspot of mutations associated with spinocerebellar ataxia type 28 that affect its proteolytic function. CONCLUSIONS: Our results provide evidence for complex inheritance in SPG7-associated HSP, which may include recessive and possibly dominant and digenic/epistasis forms of inheritance. © 2021 International Parkinson and Movement Disorder Society.
Assuntos
Paraplegia Espástica Hereditária , Proteases Dependentes de ATP , ATPases Associadas a Diversas Atividades Celulares/genética , Canadá , Humanos , Metaloendopeptidases/genética , Mutação/genética , Paraplegia , Paraplegia Espástica Hereditária/genética , Fatores de TranscriçãoRESUMO
OBJECTIVE: To examine the role of genes identified through genome-wide association studies (GWASs) of Parkinson disease (PD) in the risk of isolated REM sleep behavior disorder (iRBD). METHODS: We fully sequenced 25 genes previously identified in GWASs of PD in a total of 1,039 patients with iRBD and 1,852 controls. The role of rare heterozygous variants in these genes was examined with burden tests. The contribution of biallelic variants was further tested. To examine the potential effect of rare nonsynonymous BST1 variants on the protein structure, we performed in silico structural analysis. Finally, we examined the association of common variants using logistic regression adjusted for age and sex. RESULTS: We found an association between rare heterozygous nonsynonymous variants in BST1 and iRBD (p = 0.0003 at coverage >50× and 0.0004 at >30×), driven mainly by 3 nonsynonymous variants (p.V85M, p.I101V, and p.V272M) found in 22 (1.2%) controls vs 2 (0.2%) patients. All 3 variants seem to be loss-of-function variants with a potential effect on the protein structure and stability. Rare noncoding heterozygous variants in LAMP3 were also associated with iRBD (p = 0.0006 at >30×). We found no association between rare heterozygous variants in the rest of genes and iRBD. Several carriers of biallelic variants were identified, yet there was no overrepresentation in iRBD. CONCLUSION: Our results suggest that rare coding variants in BST1 and rare noncoding variants in LAMP3 are associated with iRBD. Additional studies are required to replicate these results and to examine whether loss of function of BST1 could be a therapeutic target.
Assuntos
ADP-Ribosil Ciclase/genética , Antígenos CD/genética , Proteínas de Membrana Lisossomal/genética , Proteínas de Neoplasias/genética , Transtorno do Comportamento do Sono REM/genética , Idoso , Simulação por Computador , Bases de Dados Genéticas , Feminino , Proteínas Ligadas por GPI/genética , Variação Genética , Estudo de Associação Genômica Ampla , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Estrutura Secundária de Proteína , Transtorno do Comportamento do Sono REM/epidemiologiaRESUMO
ABSTRACT: Huge variations exist in cardiology training programs across the world. In developing (middle-income) countries, such as Brazil, to find the right balance between training improvements and social and economic conditions of the country may be a difficult task. Adding more training years or different mandatory rotations, for instance, may be costly and not have an immediate direct impact on enhancing patient care or public health. In this text, we compare the Brazilian cardiology training system with other proposals implemented in developed countries from North America and Europe, aiming to point out issues worth of future discussion. Factors such as training rotations and competencies, and program duration and distribution across the countries are presented. The number of first year cardiology trainees per inhabitants is similar between Brazil and the United States (0.24 medical residents/100,000 inhabitants in Brazil and 0.26 medical residents/100,000 inhabitants in the USA). These numbers should be analyzed considering the inequality in training program distribution across Brazil, since most centers are located in the Southeast and South regions. Having more residency programs in distant areas could improve cardiovascular care in these areas. Duration of cardiology Residency Training is shorter in Brazil (two years) in comparison with developed countries (> 3 years). Brazilian residency programs give less emphasis to scientific research and diagnostic methods. Unifying minimum training requirements across the globe would facilitate the development of international learning opportunities and even professional exchange around the world.
RESUMO: Existe enorme variação nos programas de residência em cardiologia no mundo. Em países em desenvolvimento, tal como o Brasil, encontrar o equilíbrio correto entre melhorias nos programas de residência e condições socioeconômicas do país pode ser uma tarefa difícil. Aumentar a duração dos programas ou o número de estágios obrigatórios, por exemplo, pode ter um custo elevado e não ter um impacto imediato na melhoria do cuidado do paciente ou na saúde pública. Neste texto, comparamos o sistema de residência em cardiologia brasileiro com outras propostas implementadas em países desenvolvidos da América do Norte e Europa, com objetivo de indicar questões para discussões futuras. Apresentamos fatores como rodízios por estágios e competências, duração e distribuição dos programas pelos países. O número de alunos no primeiro ano de Residência em cardiologia por número de habitantes é similar entre o Brasil e os Estados Unidos (0,24 médicos residentes/100 mil habitantes no Brasil e 0,26 médicos residentes/100 mil habitantes nos EUA). Esses números devem ser analisados considerando a desigualdade na distribuição dos programas pelo país, uma vez que a maioria dos centros localiza-se nas regiões sul e sudeste do país. A existência de mais programas de residência em áreas distantes melhoraria o cuidado cardiovascular nessas áreas. O período de treinamento é menor no Brasil (dois anos) em comparação a países desenvolvidos (>3 anos). Os programas de residência no Brasil dão menos ênfase em pesquisa científica e métodos diagnósticos. O estabelecimento de exigências mínimas que sejam padronizadas a todos os países facilitaria o desenvolvimento de oportunidades de aprendizagem e mesmo o intercâmbio de profissionais pelo mundo.
Assuntos
Cardiologia , Educação Médica , Internato e Residência , Brasil , Acreditação de ProgramasRESUMO
Ribosomal proteins (RP) regulate specific gene expression by selectively translating subsets of mRNAs. Indeed, in Diamond-Blackfan anemia and 5q- syndrome, mutations in RP genes lead to a specific defect in erythroid gene translation and cause anemia. Little is known about the molecular mechanisms of selective mRNA translation and involvement of ribosomal-associated factors in this process. Ribonuclease inhibitor 1 (RNH1) is a ubiquitously expressed protein that binds to and inhibits pancreatic-type ribonucleases. Here, we report that RNH1 binds to ribosomes and regulates erythropoiesis by controlling translation of the erythroid transcription factor GATA1. Rnh1-deficient mice die between embryonic days E8.5 and E10 due to impaired production of mature erythroid cells from progenitor cells. In Rnh1-deficient embryos, mRNA levels of Gata1 are normal, but GATA1 protein levels are decreased. At the molecular level, we found that RNH1 binds to the 40S subunit of ribosomes and facilitates polysome formation on Gata1 mRNA to confer transcript-specific translation. Further, RNH1 knockdown in human CD34+ progenitor cells decreased erythroid differentiation without affecting myelopoiesis. Our results reveal an unsuspected role for RNH1 in the control of GATA1 mRNA translation and erythropoiesis.
Assuntos
Embrião de Mamíferos/metabolismo , Eritropoese , Fator de Transcrição GATA1/biossíntese , Células-Tronco Hematopoéticas/metabolismo , Biossíntese de Proteínas , Proteínas/metabolismo , Animais , Embrião de Mamíferos/citologia , Fator de Transcrição GATA1/genética , Células-Tronco Hematopoéticas/citologia , Humanos , Células K562 , Camundongos , Camundongos Knockout , Proteínas/genética , Subunidades Ribossômicas Maiores/genética , Subunidades Ribossômicas Maiores/metabolismoRESUMO
BACKGROUND: Childhood cancer survivors treated with anthracycline chemotherapy are at an increased risk of long-term cardiac toxicity, and guidelines recommend that exposed survivors undergo echocardiography every 1-5 years. However, it is unclear whether survivors should undergo echocardiographic screening indefinitely, or if a period of echocardiographic stability indicates that screening is no longer necessary. The objective of this study was to evaluate the outcomes of echocardiographic screening to aid in the refinement of existing guidelines. METHODS: We retrospectively analyzed the results of echocardiographic screening in a cohort of adult survivors of childhood cancer treated with anthracyclines and/or cardiac radiation therapy. Interval regression analysis was performed to identify predictors of single-episode or sustained abnormal echocardiograms. RESULTS: The cohort constituted 333 survivors, with median follow-up time of 15.8 years post-treatment (range: 5.0-47.9), and median age at treatment of 8 years (range: 1.5-18). Forty-nine survivors had an abnormal echocardiogram (14.7%), and 29 (8.7%) had reproducible abnormal findings. An ongoing continual increase in the incidence of sustained echocardiographic abnormality was seen among patients treated with >250 mg/m(2) doxorubicin at age <5 years, reaching 43% by 20 years of therapy. In contrast, no sustained abnormal echocardiographic findings arose after 10 years of therapy in survivors treated with <250 mg/m(2) at age ≥5 years. CONCLUSIONS: Single-episode echocardiographic abnormalities are often not reproduced in subsequent evaluations. The duration of echocardiographic screening for childhood cancer survivors should be reassessed for patients who received lower doses of anthracycline after age 5.
Assuntos
Antraciclinas/efeitos adversos , Ecocardiografia , Cardiopatias , Neoplasias , Sobreviventes , Adolescente , Adulto , Antraciclinas/administração & dosagem , Criança , Pré-Escolar , Feminino , Seguimentos , Cardiopatias/induzido quimicamente , Cardiopatias/diagnóstico por imagem , Cardiopatias/fisiopatologia , Humanos , Lactente , Masculino , Neoplasias/tratamento farmacológico , Neoplasias/fisiopatologia , Estudos RetrospectivosRESUMO
A current paradigm proposes that mitochondrial damage is a critical determinant of NLRP3 inflammasome activation. Here, we genetically assess whether mitochondrial signalling represents a unified mechanism to explain how NLRP3 is activated by divergent stimuli. Neither co-deletion of the essential executioners of mitochondrial apoptosis BAK and BAX, nor removal of the mitochondrial permeability transition pore component cyclophilin D, nor loss of the mitophagy regulator Parkin, nor deficiency in MAVS affects NLRP3 inflammasome function. In contrast, caspase-8, a caspase essential for death-receptor-mediated apoptosis, is required for efficient Toll-like-receptor-induced inflammasome priming and cytokine production. Collectively, these results demonstrate that mitochondrial apoptosis is not required for NLRP3 activation, and highlight an important non-apoptotic role for caspase-8 in regulating inflammasome activation and pro-inflammatory cytokine levels.
Assuntos
Proteínas de Transporte/biossíntese , Caspase 8/biossíntese , Inflamassomos/metabolismo , Mitocôndrias/metabolismo , Apoptose/genética , Autofagia/genética , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Proteínas de Transporte/genética , Caspase 8/genética , Células Cultivadas , Peptidil-Prolil Isomerase F , Ciclofilinas/antagonistas & inibidores , Ciclofilinas/genética , Humanos , Interleucina-1beta/biossíntese , Mitocôndrias/patologia , Mitofagia/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR , Receptores Toll-Like/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Host innate immune responses to DNA viruses involve members of the nucleotide-binding domain, leucine-rich repeat and pyrin domain containing protein (NLRP) family, which form "inflammasomes" that activate caspase-1, resulting in proteolytic activation of cytokines interleukin (IL)-1ß and IL-18. We hypothesized that DNA viruses would target inflammasomes to overcome host defense. A Vaccinia virus (VACV) B-cell CLL/lymphoma 2 (Bcl-2) homolog, F1L, was demonstrated to bind and inhibit the NLR family member NLRP1 in vitro. Moreover, infection of macrophages in culture with virus lacking F1L (ΔF1L) caused increased caspase-1 activation and IL-1ß secretion compared with wild-type virus. Virulence of ΔF1L virus was attenuated in vivo, causing altered febrile responses, increased proteolytic processing of caspase-1, and more rapid inflammation in lungs of infected mice without affecting cell death or virus replication. Furthermore, we found that a hexapeptide from F1L is necessary and sufficient for inhibiting the NLRP1 inflammasome in vitro, thus identifying a peptidyl motif required for binding and inhibiting NLRP1. The functional importance of this NLRP1-binding motif was further confirmed by studies of recombinant ΔF1L viruses reconstituted either with the wild-type F1L or a F1L mutant that fails to bind NLRP1. Cellular infection with wild-type F1L reconstituted virus-suppressed IL-1ß production, whereas mutant F1L did not. In contrast, both wild-type and mutant versions of F1L equally suppressed apoptosis. In vivo, the NLR nonbinding F1L mutant virus exhibited an attenuated phenotype similar to ΔF1L virus, thus confirming the importance of F1L interactions with NLRP1 for viral pathogenicity in mice. Altogether, these findings reveal a unique viral mechanism for evading host innate immune responses.
Assuntos
Regulação Viral da Expressão Gênica , Imunidade Inata , Inflamassomos/metabolismo , Vaccinia virus/metabolismo , Proteínas Virais/metabolismo , Motivos de Aminoácidos , Animais , Caspases/metabolismo , Chlorocebus aethiops , Citocinas/metabolismo , Células HEK293 , Células HeLa , Humanos , Interleucina-1beta/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Fenótipo , Proteínas Recombinantes/metabolismo , Células Vero , VirulênciaRESUMO
In multicellular organisms, apoptosis is a powerful method of host defense against viral infection. Apoptosis is mediated by a cascade of caspase-family proteases that commit infected cells to a form of programmed cell death. Therefore, to replicate within host cells, viruses have developed various strategies to inhibit caspase activation. In the mitochondrial cell-death pathway, release of cytochrome c from mitochondria into the cytosol triggers assembly of the oligomeric apoptosome, resulting in dimerization and activation of the apical caspase-9 (C9), and in turn its downstream effector caspases, leading to apoptosis. We previously showed that the vaccinia virus-encoded Bcl-2-like protein, F1L, which suppresses cytochrome c release by binding Bcl-2 family proteins, is also a C9 inhibitor. Here, we identify a novel motif within the flexible N-terminal region of F1L that is necessary and sufficient for interaction with and inhibition of C9. Based on functional studies and mutagenesis, we developed an atomic model of the complex in which F1L inhibits C9 by engaging the active site in the reverse orientation with respect to substrate peptides, in a manner analogous to that of XIAP-mediated inhibition of caspases-3 and -7. These studies offer new insights into the mechanism of apoptosome inhibition by F1L as well as novel probes to understand the molecular bases of apoptosome regulation and turnover. They also suggest how the two distinct functionalities of F1L (inhibition of C9 and suppression of pro-apoptotic Bcl-2 family proteins) may operate in a cellular setting.
Assuntos
Caspase 9/metabolismo , Vaccinia virus/metabolismo , Proteínas Virais/química , Sequência de Aminoácidos , Apoptose , Morte Celular , Células HEK293 , Humanos , Imunidade Inata , Modelos Biológicos , Dados de Sequência Molecular , Peptídeos/química , Plasmídeos/metabolismo , Ligação Proteica , Homologia de Sequência de Aminoácidos , Proteínas Virais/metabolismoRESUMO
The risk of cardiac hospitalization (CH) in Hodgkin lymphoma (HL) patients with preexisting heart disease was evaluated. Patients with HL were identified from a population-based registry (N = 3964). Data were abstracted from records of a randomly selected subcohort (N = 1096). A population-based registry was used to identify CH. Factors associated with CH and the incidence of CH after HL were estimated with competing risk models. Preexisting heart disease was the strongest predictor of posttreatment CH (hazard ratio = 3.98, P < .001) and significantly modified (P = .01) the effect of treatment on the risk of CH. Among patients with preexisting heart disease, treatment with mediastinal radiation therapy plus doxorubicin-based chemotherapy was associated with a 10-year incidence of CH more than 20% higher than treatment with chemotherapy alone. There is a high risk of CH after mediastinal radiation therapy plus doxorubicin-based chemotherapy among patients with preexisting heart disease; this is an important consideration when weighing treatment options, and in the follow-up of these patients.
Assuntos
Cardiopatias/complicações , Doença de Hodgkin/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibióticos Antineoplásicos/efeitos adversos , Estudos de Coortes , Doxorrubicina/efeitos adversos , Feminino , Cardiopatias/etiologia , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/radioterapia , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Mediastino/efeitos da radiação , Pessoa de Meia-Idade , Ontário , Sistema de Registros , Fatores de Risco , Adulto JovemRESUMO
The 14 kDa homodimeric N1L protein is a potent vaccinia and variola (smallpox) virulence factor. It is not essential for viral replication, but it causes a strong attenuation of viral production in culture when deleted. The N1L protein is predicted to contain the BH3-like binding domain characteristic of Bcl-2 family proteins, and it is able to bind the BH3 peptides. Its overexpression has been reported to prevent infected cells from committing apoptosis. Therefore, interfering with the N1L apoptotic blockade may be a legitimate therapeutic strategy affecting the viral growth. By using in silico ligand docking and an array of in vitro assays, we have identified submicromolar (600 nM) N1L antagonists belonging to the family of polyphenols. Their affinity is comparable to that of the BH3 peptides (70-1000 nM). We have also identified the natural polyphenol resveratrol as a moderate N1L inhibitor. Finally, we show that our ligands efficiently inhibit growth of vaccinia virus.
Assuntos
Antivirais/química , Fenóis/química , Proteínas Virais/antagonistas & inibidores , Fatores de Virulência/antagonistas & inibidores , Antivirais/síntese química , Antivirais/farmacologia , Proteínas Reguladoras de Apoptose/química , Proteína 11 Semelhante a Bcl-2 , Sítios de Ligação , Varredura Diferencial de Calorimetria , Linhagem Celular , Bases de Dados Factuais , Humanos , Ligantes , Proteínas de Membrana/química , Modelos Moleculares , Mutação , Fragmentos de Peptídeos/química , Fenóis/síntese química , Fenóis/farmacologia , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas/química , Resveratrol , Estilbenos/farmacologia , Relação Estrutura-Atividade , Termodinâmica , Ultracentrifugação , Vaccinia virus/efeitos dos fármacos , Vaccinia virus/crescimento & desenvolvimento , Proteínas Virais/genética , Fatores de Virulência/genéticaRESUMO
Apoptosis plays important roles in host defense, including the elimination of virus-infected cells. The executioners of apoptosis are caspase family proteases. We report that vaccinia virus-encoded F1L protein, previously recognized as anti-apoptotic viral Bcl-2 family protein, is a caspase-9 inhibitor. F1L binds to and specifically inhibits caspase-9, the apical protease in the mitochondrial cell death pathway while failing to inhibit other caspases. In cells, F1L inhibits apoptosis and proteolytic processing of caspases induced by overexpression of caspase-9 but not caspase-8. An N-terminal region of F1L preceding the Bcl-2-like fold accounts for caspase-9 inhibition and significantly contributes to the anti-apoptotic activity of F1L. Viral F1L thus provides the first example of caspase inhibition by a Bcl-2 family member; it functions both as a suppressor of proapoptotic Bcl-2 family proteins and as an inhibitor of caspase-9, thereby neutralizing two sequential steps in the mitochondrial cell death pathway.
Assuntos
Inibidores de Caspase , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Vaccinia virus/metabolismo , Proteínas Virais/metabolismo , Animais , Apoptose/genética , Caspase 8/química , Caspase 8/genética , Caspase 8/metabolismo , Caspase 9/química , Caspase 9/genética , Caspase 9/metabolismo , Bovinos , Células HeLa , Humanos , Mitocôndrias/química , Mitocôndrias/genética , Mitocôndrias/metabolismo , Ligação Proteica/fisiologia , Estrutura Terciária de Proteína/genética , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Vaccinia virus/química , Vaccinia virus/genética , Proteínas Virais/química , Proteínas Virais/genéticaRESUMO
CONCLUSION: The pathology of chronic otitis media (COM) could delay and reduce the energy transfer of sound to the inner ear. The significant improvement of postoperative vestibular evoked myogenic potential (VEMP) response rate and p13 latencies in the group of patients with no or negative postoperative ABG gain provided evidence that the sound energy inducing a VEMP might be different from the energy producing the auditory perception. OBJECTIVE: To evaluate the VEMP in patients with COM before and after surgery. SUBJECTS AND METHODS: Twenty-four subjects with unilateral COM were enrolled. A pure tone audiogram and VEMP using 500 Hz unilateral short tone-burst stimulations were recorded before and 3 months after surgery. The postoperative VEMP responses were compared with the responses before surgery and the healthy controls. RESULTS: After surgery, the 500 Hz air-bone gap (ABG) decreased significantly and the VEMP response rate increased significantly from 41.7% to 66.7% (p<0.05, bi-test). However, both the preoperative and postoperative p13 latencies were significantly longer than those of the healthy controls (p<0.05, Wilcoxon rank-sum test). In the 18 patients whose 500 Hz ABG did not improve with surgery, the p13 latencies were significantly shorter postoperatively (p<0.05, sign test), and the response rate also improved significantly from 44.4% (8/18) to 77.8% (14/18) (p<0.05, bi-test).