Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 17(6): e0269390, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35653364

RESUMO

Polymorphisms in human leukocyte antigen (HLA) class I loci are known to have a great impact on disease progression in HIV-1 infection. Prevailing HIV-1 subtypes and HLA genotype distribution are different all over the world, and the HIV-1 and host HLA interaction could be specific to individual areas. Data on the HIV-1 and HLA interaction have been accumulated in HIV-1 subtype B- and C-predominant populations but not fully obtained in West Africa where HIV-1 subtype CRF02_AG is predominant. In the present study, to obtain accurate HLA typing data for analysis of HLA association with disease progression in HIV-1 infection in West African populations, HLA class I (HLA-A, -B, and -C) four-digit allele typing was performed in treatment-naïve HIV-1 infected individuals in Ghana (n = 324) by a super high-resolution single-molecule sequence-based typing (SS-SBT) using next-generation sequencing. Comparison of the SS-SBT-based data with those obtained by a conventional sequencing-based typing (SBT) revealed incorrect assignment of several alleles by SBT. Indeed, HLA-A*23:17, HLA-B*07:06, HLA-C*07:18, and HLA-C*18:02 whose allele frequencies were 2.5%, 0.9%, 4.3%, and 3.7%, respectively, were not determined by SBT. Several HLA alleles were associated with clinical markers, viral load and CD4+ T-cell count. Of note, the impact of HLA-B*57:03 and HLA-B*58:01, known as protective alleles against HIV-1 subtype B and C infection, on clinical markers was not observed in our cohort. This study for the first time presents SS-SBT-based four-digit typing data on HLA-A, -B, and -C alleles in Ghana, describing impact of HLA on viral load and CD4 count in HIV-1 infection. Accumulation of these data would facilitate high-resolution HLA genotyping, contributing to our understanding of the HIV-1 and host HLA interaction in Ghana, West Africa.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Alelos , Progressão da Doença , Gana , Soropositividade para HIV/genética , HIV-1/genética , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Antígenos de Histocompatibilidade Classe I/genética , Humanos
2.
Viruses ; 14(5)2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35632692

RESUMO

Viral infections are influenced by various microorganisms in the environment surrounding the target tissue, and the correlation between the type and balance of commensal microbiota is the key to establishment of the infection and pathogenicity. Some commensal microorganisms are known to resist or promote viral infection, while others are involved in pathogenicity. It is also becoming evident that the profile of the commensal microbiota under normal conditions influences the progression of viral diseases. Thus, to understand the pathogenesis underlying viral infections, it is important to elucidate the interactions among viruses, target tissues, and the surrounding environment, including the commensal microbiota, which should have different relationships with each virus. In this review, we outline the role of microorganisms in viral infections. Particularly, we focus on gaining an in-depth understanding of the correlations among viral infections, target tissues, and the surrounding environment, including the commensal microbiota and the gut virome, and discussing the impact of changes in the microbiota (dysbiosis) on the pathological progression of viral infections.


Assuntos
Microbioma Gastrointestinal , Microbiota , Viroses , Vírus , Disbiose , Humanos
3.
Microbiol Spectr ; 10(2): e0168921, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35254122

RESUMO

The role of the intestinal microbiota in coronavirus disease 2019 (COVID-19) is being elucidated. Here, we analyzed the temporal changes in microbiota composition and the correlation between inflammation biomarkers/cytokines and microbiota in hospitalized COVID-19 patients. We obtained stool specimens, blood samples, and patient records from 22 hospitalized COVID-19 patients and performed 16S rRNA metagenomic analysis of stool samples over the course of disease onset compared to 40 healthy individual stool samples. We analyzed the correlation between the changes in the gut microbiota and plasma proinflammatory cytokine levels. Immediately after admission, differences in the gut microbiota were observed between COVID-19 patients and healthy subjects, mainly including enrichment of the classes Bacilli and Coriobacteriia and decrease in abundance of the class Clostridia. The bacterial profile continued to change throughout the hospitalization, with a decrease in short-chain fatty acid-producing bacteria including Faecalibacterium and an increase in the facultatively anaerobic bacteria Escherichia-Shigella. A consistent increase in Eggerthella belonging to the class Coriobacteriia was observed. The abundance of the class Clostridia was inversely correlated with interferon-γ level and that of the phylum Actinobacteria, which was enriched in COVID-19, and was positively correlated with gp130/sIL-6Rb levels. Dysbiosis was continued even after 21 days from onset. The intestines tended to be an aerobic environment in hospitalized COVID-19 patients. Because the composition of the gut microbiota correlates with the levels of proinflammatory cytokines, this finding emphasizes the need to understand how pathology is related to the temporal changes in the specific gut microbiota observed in COVID-19 patients. IMPORTANCE There is growing evidence that the commensal microbiota of the gastrointestinal and respiratory tracts regulates local and systemic inflammation (gut-lung axis). COVID-19 is primarily a respiratory disease, but the involvement of microbiota changes in the pathogenesis of this disease remains unclear. The composition of the gut microbiota of patients with COVID-19 changed over time during hospitalization, and the intestines tended to be an aerobic environment in hospitalized COVID-19 patients. These changes in gut microbiota may induce increased intestinal permeability, called leaky gut, allowing bacteria and toxins to enter the circulatory system and further aggravate the systemic inflammatory response. Since gut microbiota composition correlates with levels of proinflammatory cytokines, this finding highlights the need to understand how pathology relates to the gut environment, including the temporal changes in specific gut microbiota observed in COVID-19 patients.


Assuntos
COVID-19 , Microbioma Gastrointestinal , Bactérias/genética , Citocinas , Disbiose/microbiologia , Fezes/microbiologia , Microbioma Gastrointestinal/fisiologia , Hospitalização , Humanos , Inflamação , RNA Ribossômico 16S/genética
4.
Hepatol Res ; 52(3): 227-234, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34825436

RESUMO

AIM: After the hepatitis A virus (HAV) outbreak among men who have sex with men (MSM) around 2018, the importance of HAV vaccination was emphasized, especially for MSM-living with human immunodeficiency virus (MSM-LWHIV). Aimmugen® is licensed and distributed exclusively in Japan. While administration of three doses is recommended, 85% of recipients in the general population were reported to acquire seroprotection after the second dose. In this study, we evaluated the efficacy of two or three vaccine doses along with predictors associated with the response to Aimmugen® in MSM-LWHIV. METHODS: We retrospectively examined anti-HA-IgG titers of MSM-LWHIV vaccinated with Aimmugen® in our hospital. Patients' data were collected from medical records. RESULTS: Between January 2018 and October 2019, 141 subjects whose median age was 46 years old, were examined. All the subjects were on antiretroviral therapy (ART) and the median CD4 count was 615/µL. The acquisition rate of protectable anti-HA-IgG titers after the second and third dose was 71.1% and 98.6%, respectively. In 114 subjects whose anti-HA-IgG titers were tested after the second-dose, factors significantly associated with better response were prolonged ART duration and higher CD4 count. The titers of anti-HA-IgG after the third dose were higher in those who became seropositive after the second-dose than those who did not. CONCLUSIONS: Three-dose of Aimmugen® for MSM-LWHIV was effective while two-dose was less effective compared to non-HIV-infected people. People-LWHIV with shorter duration of ART and lesser CD4 cell count achieved lower titers of anti-HA-IgG and might require an additional vaccination.

5.
Viruses ; 13(10)2021 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-34696531

RESUMO

Hepatitis A virus (HAV) causes transient acute infection, and little is known of viral shedding via the duodenum and into the intestinal environment, including the gut microbiome, from the period of infection until after the recovery of symptoms. Therefore, in this study, we aimed to comprehensively observe the amount of virus excreted into the intestinal tract, the changes in the intestinal microbiome, and the level of inflammation during the healing process. We used blood and stool specimens from patients with human immunodeficiency virus who were infected with HAV during the HAV outbreak in Japan in 2018. Moreover, we observed changes in fecal HAV RNA and quantified the plasma cytokine level and gut microbiome by 16S rRNA analysis from clinical onset to at least 6 months after healing. HAV was detected from clinical onset up to a period of more than 150 days. Immediately after infection, many pro-inflammatory cytokines were elicited, and some cytokines showed different behaviors. The intestinal microbiome changed significantly after infection (dysbiosis), and the dysbiosis continued for a long time after healing. These observations suggest that the immunocompromised state is associated with prolonged viral shedding into the intestinal tract and delayed recovery of the intestinal environment.


Assuntos
Disbiose/virologia , Fezes/virologia , Hepatite A/complicações , Adulto , Disbiose/microbiologia , Microbioma Gastrointestinal/fisiologia , Infecções por HIV/fisiopatologia , Infecções por HIV/virologia , HIV-1/patogenicidade , Hepatite A/fisiopatologia , Hepatite A/virologia , Vírus da Hepatite A/patogenicidade , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética , Carga Viral , Eliminação de Partículas Virais
6.
Microbiol Spectr ; 9(1): e0070821, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34378948

RESUMO

Chronic inflammation is a hallmark of human immunodeficiency virus (HIV) infection and a risk factor for the development and progression of age-related comorbidities. Although HIV-associated gut dysbiosis has been suggested to be involved in sustained chronic inflammation, there remains a limited understanding of the association between gut dysbiosis and chronic inflammation during HIV infection. Here, we investigated compositional changes in the gut microbiome and its role in chronic inflammation in patients infected with HIV. We observed that the gut microbiomes of patients with low CD4 counts had reduced alpha diversity compared to those in uninfected controls. Following CD4 recovery, alpha diversity was restored, but intergroup dissimilarity of bacterial composition remained unchanged between patients and uninfected controls. Patients with HIV had higher abundance of the classes Negativicutes, Bacilli, and Coriobacteriia, as well as depletion of the class Clostridia. These relative abundances positively correlated with inflammatory cytokines and negatively correlated with anti-inflammatory cytokines. We found that gut dysbiosis accompanying HIV infection was characterized by a depletion of obligate anaerobic Clostridia and enrichment of facultative anaerobic bacteria, reflecting increased intestinal oxygen levels and intestinal permeability. Furthermore, it is likely that HIV-associated dysbiosis shifts the immunological balance toward inflammatory Th1 responses and encourages proinflammatory cytokine production. Our results suggest that gut dysbiosis contributes to sustaining chronic inflammation in patients with HIV infection despite effective antiretroviral therapy and that correcting gut dysbiosis will be effective in improving long-term outcomes in patients. IMPORTANCE Chronic inflammation is a hallmark of HIV infection and is associated with the development and progression of age-related comorbidities. Although the gastrointestinal tract is a major site of HIV replication and CD4+ T-cell depletion, the role of HIV-associated imbalance of gut microbiome in chronic inflammation is unclear. Here, we aimed to understand the causal relationship between abnormalities in the gut microbiome and chronic inflammation in patients with HIV. Our results suggest HIV-associated gut dysbiosis presents a more aerobic environment than that of healthy individuals, despite prolonged viral suppression. This dysbiosis likely results from a sustained increase in intestinal permeability, which supports sustained bacterial translocation in HIV patients, despite effective therapy. Additionally, we observed that several bacterial taxa enriched in HIV patients were associated with increased expression of inflammatory cytokines. Collectively, these results suggest that gut dysbiosis plays an important role in chronic inflammation in HIV patients.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Microbioma Gastrointestinal , Infecções por HIV/tratamento farmacológico , Infecções por HIV/microbiologia , Adulto , Fármacos Anti-HIV/efeitos adversos , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Linfócitos T CD4-Positivos/imunologia , Doença Crônica/terapia , Disbiose/etiologia , Disbiose/microbiologia , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Infecções por HIV/imunologia , Humanos , Masculino , Pessoa de Meia-Idade
7.
Sci Rep ; 11(1): 13945, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34230563

RESUMO

Acute gastroenteritis associated with diarrhea is considered a serious disease in Africa and South Asia. In this study, we examined the trends in the causative pathogens of diarrhea and the corresponding gut microbiota in Ghana using microbiome analysis performed on diarrheic stools via 16S rRNA sequencing. In total, 80 patients with diarrhea and 34 healthy adults as controls, from 2017 to 2018, were enrolled in the study. Among the patients with diarrhea, 39 were norovirus-positive and 18 were rotavirus-positive. The analysis of species richness (Chao1) was lower in patients with diarrhea than that in controls. Beta-diversity analysis revealed significant differences between the two groups. Several diarrhea-related pathogens (e.g., Escherichia-Shigella, Klebsiella and Campylobacter) were detected in patients with diarrhea. Furthermore, co-infection with these pathogens and enteroviruses (e.g., norovirus and rotavirus) was observed in several cases. Levels of both Erysipelotrichaceae and Staphylococcaceae family markedly differed between norovirus-positive and -negative diarrheic stools, and the 10 predicted metabolic pathways, including the carbohydrate metabolism pathway, showed significant differences between rotavirus-positive patients with diarrhea and controls. This comparative study of diarrheal pathogens in Ghana revealed specific trends in the gut microbiota signature associated with diarrhea and that pathogen-dependent dysbiosis occurred in viral gastroenteritis.


Assuntos
Disbiose/microbiologia , Disbiose/virologia , Gastroenterite/microbiologia , Gastroenterite/virologia , Microbioma Gastrointestinal , Adolescente , Adulto , Bactérias/classificação , Biodiversidade , Estudos de Casos e Controles , Criança , Pré-Escolar , Diarreia/microbiologia , Diarreia/virologia , Fezes/microbiologia , Feminino , Gana , Humanos , Masculino , Filogenia , Rotavirus/fisiologia
8.
Front Cell Infect Microbiol ; 11: 646467, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34084754

RESUMO

HIV-1 infected individuals under antiretroviral therapy can control viremia but often develop non-AIDS diseases such as cardiovascular and metabolic disorders. Gut microbiome dysbiosis has been indicated to be associated with progression of these diseases. Analyses of gut/fecal microbiome in individual regions are important for our understanding of pathogenesis in HIV-1 infections. However, data on gut/fecal microbiome has not yet been accumulated in West Africa. In the present study, we examined fecal microbiome compositions in HIV-1 infected adults in Ghana, where approximately two-thirds of infected adults are females. In a cross-sectional case-control study, age- and gender-matched HIV-1 infected adults (HIV+; n = 55) and seronegative controls (HIV-; n = 55) were enrolled. Alpha diversity of fecal microbiome in HIV+ was significantly reduced compared to HIV- and associated with CD4 counts. HIV+ showed reduction in varieties of bacteria including Faecalibacterium, the most abundant in seronegative controls, but enrichment of Proteobacteria. Ghanaian HIV+ exhibited enrichment of Dorea and Blautia; bacteria groups whose depletion has been reported in HIV-1 infected individuals in several other cohorts. Furthermore, HIV+ in our cohort exhibited a depletion of Prevotella, a genus whose enrichment has recently been shown in men having sex with men (MSM) regardless of HIV-1 status. The present study revealed the characteristics of dysbiotic fecal microbiome in HIV-1 infected adults in Ghana, a representative of West African populations.


Assuntos
Infecções por HIV , HIV-1 , Microbiota , Adulto , Estudos de Casos e Controles , Estudos Transversais , Disbiose , Feminino , Gana , Humanos , Masculino
9.
Jpn J Infect Dis ; 74(1): 42-47, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-32611986

RESUMO

Recent studies have indicated an association between gut microbiome composition and various disorders, including infectious diseases. The composition of the microbiome differs among ethnicities and countries, possibly resulting in diversified interactions between host immunity and the gut microbiome. Characterization of baseline microbiome composition in healthy people is an essential step for better understanding of the biological interactions associated with individual populations. However, data on the gut/fecal microbiome have not been accumulated for individuals in West Africa. In the present study, we examined the fecal microbiome composition in healthy adults in Ghana. Toward this, 16S rRNA gene libraries were prepared using bacterial fractions derived from 55 Ghanaian adults, which were then subjected to next-generation sequencing. The fecal microbiome of the Ghanaian adults was dominated by Firmicutes (Faecalibacterium, Subdoligranulum, and Ruminococcaceae UCG-014), Proteobacteria (Escherichia-Shigella and Klebsiella), and Bacteroidetes (Prevotella 9 and Bacteroides), consistent with previous observations in African cohorts. Further, our analysis revealed differences in microbiome composition and a lower diversity of the fecal microbiome in the Ghanaian cohort compared with those reported in non-African countries. This is the first study to describe substantial fecal microbiome data obtained using high-throughput metagenomic tools on samples derived from a cohort in Ghana. The data may provide a valuable basis for determining the association between the fecal microbiome and progression of various diseases in West African populations.


Assuntos
Fezes/microbiologia , Microbioma Gastrointestinal/genética , Adulto , Bacteroidetes/genética , Estudos Transversais , Feminino , Firmicutes/genética , Gana , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Metagenômica , Microbiota , Pessoa de Meia-Idade , Proteobactérias/genética , RNA Bacteriano/isolamento & purificação , RNA Ribossômico 16S/genética
10.
Jpn J Infect Dis ; 72(6): 374-380, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31257246

RESUMO

In human immunodeficiency virus type-1 (HIV-1) infections, cytotoxic T-lymphocyte (CTL) responses targeting human leukocyte antigen (HLA)-restricted viral epitopes exert strong suppressive pressure on viral replication and frequently select for mutations resulting in viral escape from CTL recognition. Numerous data on these HLA-associated mutations in HIV-1 subtypes B and C have been amassed with few reports described in other subtypes. In the present study, we investigated the HLA-associated mutations in HIV-1 subtype CRF02_AG prevailing in Ghana, Western Africa. We determined viral gag sequences in 246 out of 324 HIV-1-infected Ghanaians. Phylogeny analysis revealed that 200 (81.3%) individuals were infected with HIV-1 CRF02_AG. Full gag and vif sequences were obtained from 199 and 138, respectively, out of the 200 individuals infected with CRF02_AG and subjected to determination of HLA-associated mutations. The analysis found HLA-associated HIV-1 CRF02_AG non-synonymous polymorphisms at 19 sites; 13 in gag and six in vif, including those that were newly determined. Generation of this data is an important contribution to our understanding of HIV-1 CRF02_AG and host T cell interaction.


Assuntos
Infecções por HIV/virologia , HIV-1/genética , Antígenos HLA/imunologia , Polimorfismo Genético , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene vif do Vírus da Imunodeficiência Humana/genética , Adolescente , Adulto , Idoso , Criança , Feminino , Genótipo , Gana/epidemiologia , Infecções por HIV/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Adulto Jovem
11.
J Virol ; 90(12): 5665-5676, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-27030274

RESUMO

UNLABELLED: HIV-1 patients continue to remain at an abnormal immune status despite prolonged combination antiretroviral therapy (cART), which results in an increased risk of non-AIDS-related diseases. Given the growing recognition of the importance of understanding and controlling the residual virus in patients, additional virological markers to monitor infected cells are required. However, viral replication in circulating cells is much poorer than that in lymph nodes, which results in the absence of markers to distinguish these cells from uninfected cells in the blood. In this study, we identified prematurely terminated short HIV-1 transcripts (STs) in peripheral blood mononuclear cells (PBMCs) as an efficient intracellular biomarker to monitor viral activation and immune status in patients with cART-mediated full viral suppression in plasma. STs were detected in PBMCs obtained from both treated and untreated patients. ST levels in untreated patients generally increased with disease progression and decreased after treatment initiation. However, some patients exhibited sustained high levels of ST and low CD4(+) cell counts despite full viral suppression by treatment. The levels of STs strongly reflected chronic immune activation defined by coexpression of HLA-DR and CD38 on CD8(+) T cells, rather than circulating proviral load. These observations represent evidence for a relationship between viral persistence and host immune activation, which in turn results in the suboptimal increase in CD4(+) cells despite suppressive antiretroviral therapy. This cell-based measurement of viral persistence contributes to an improved understanding of the dynamics of viral persistence in cART patients and will guide therapeutic approaches targeting viral reservoirs. IMPORTANCE: Combination antiretroviral therapy (cART) suppresses HIV-1 load to below the detectable limit in plasma. However, the virus persists, and patients remain at an abnormal immune status, which results in an increased risk of non-AIDS-related complications. To achieve a functional cure for HIV-1 infection, activities of viral reservoirs must be quantified and monitored. However, latently infected cells are difficult to be monitored. Here, we identified prematurely terminated short HIV-1 transcripts (STs) as an efficient biomarker for monitoring viral activation and immune status in patients with cART-mediated full viral suppression in plasma. This cell-based measurement of viral persistence will contribute to our understanding of the impact of residual virus on chronic immune activation in HIV-1 patients during cART.


Assuntos
Terapia Antirretroviral de Alta Atividade , Infecções por HIV/virologia , HIV-1/genética , Leucócitos Mononucleares/virologia , RNA Viral/genética , ADP-Ribosil Ciclase 1/genética , Adulto , Biomarcadores/sangue , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Progressão da Doença , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Antígenos HLA-DR/genética , Humanos , Masculino , Glicoproteínas de Membrana/genética , Provírus/genética , Provírus/isolamento & purificação , RNA Viral/sangue , Reação em Cadeia da Polimerase em Tempo Real , Carga Viral
12.
J Biol Chem ; 291(6): 2829-36, 2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26637351

RESUMO

As a possible route for invasion of the CNS, circulating poliovirus (PV) in the blood is believed to traverse the blood-brain barrier (BBB), resulting in paralytic poliomyelitis. However, the underlying mechanism is poorly understood. In this study, we demonstrated that mouse transferrin receptor 1 (mTfR1) is responsible for PV attachment to the cell surface, allowing invasion into the CNS via the BBB. PV interacts with the apical domain of mTfR1 on mouse brain capillary endothelial cells (MBEC4) in a dose-dependent manner via its capsid protein (VP1). We found that F-G, G-H, and H-I loops in VP1 are important for this binding. However, C-D, D-E, and E-F loops in VP1-fused Venus proteins efficiently penetrate MBEC4 cells. These results imply that the VP1 functional domain responsible for cell attachment is different from that involved in viral permeation of the brain capillary endothelium. We observed that co-treatment of MBEC4 cells with excess PV particles but not dextran resulted in blockage of transferrin transport into cells. Using the Transwell in vitro BBB model, transferrin co-treatment inhibited permeation of PV into MBEC4 cells and delayed further viral permeation via mTfR1 knockdown. With mTfR1 as a positive mediator of PV-host cell attachment and PV permeation of MBEC4 cells, our results indicate a novel role of TfR1 as a cellular receptor for human PV receptor/CD155-independent PV invasion of the CNS.


Assuntos
Encéfalo/metabolismo , Capilares/metabolismo , Células Endoteliais/metabolismo , Poliovirus/metabolismo , Receptores da Transferrina/metabolismo , Ligação Viral , Internalização do Vírus , Animais , Encéfalo/patologia , Encéfalo/virologia , Capilares/patologia , Capilares/virologia , Proteínas do Capsídeo/metabolismo , Linhagem Celular Transformada , Células Endoteliais/patologia , Células Endoteliais/virologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Poliovirus/genética , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Receptores da Transferrina/genética
13.
J Biol Chem ; 290(30): 18391-9, 2015 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-26037922

RESUMO

The Werner syndrome helicase (WRN) plays a role in maintaining genomic stability. The lack of WRN results in Werner syndrome, a rare autosomal recessive genetic disorder, which causes premature aging accompanied by many complications such as rare forms of cancer and type 2 diabetes. However, the underlying mechanisms of these complications, arising due to the loss of WRN, are poorly understood. In this study, we demonstrated the function of WRN in transcriptional regulation of NF-κB targets. WRN physically interacts via its RecQ C-terminal (RQC) domain with the Rel homology domain of both the RelA (p65) and the p50 subunits of NF-κB. In the steady state, WRN is recruited to HIV-1 long terminal repeat (LTR), a typical NF-κB-responsive promoter, as well as the p50/p50 homodimer, in an NF-κB site-dependent manner. The amount of WRN on LTR increased along with the transactivating RelA/p50 heterodimer in response to TNF-α stimulation. Further, a knockdown of WRN reduced the transactivation of LTR in exogenous RelA/p50-introduced or TNF-α-stimulated cells. Additionally, knockdown of WRN reduced TNF-α stimulation-induced activation of the endogenous promoter of IL-8, an NF-κB-responsive gene, and WRN increased its association with the IL-8 promoter region together with RelA/p50 after TNF-α stimulation. In conjunction with studies that have shown NF-κB to be a key regulator of aging and inflammation, our results indicate a novel role of WRN in transcriptional regulation. Along with NF-κB, the loss of WRN is expected to result in incorrect regulation of downstream targets and leads to immune abnormalities and homeostatic disruption.


Assuntos
Exodesoxirribonucleases/genética , Interleucina-8/genética , Subunidade p50 de NF-kappa B/biossíntese , RecQ Helicases/genética , Fator de Transcrição RelA/biossíntese , Síndrome de Werner/genética , Envelhecimento/genética , Envelhecimento/patologia , Exodesoxirribonucleases/metabolismo , HIV-1/genética , Células HeLa , Humanos , Interleucina-8/biossíntese , Subunidade p50 de NF-kappa B/genética , Regiões Promotoras Genéticas , RecQ Helicases/metabolismo , Fator de Transcrição RelA/genética , Transcrição Genética , Fator de Necrose Tumoral alfa/farmacologia , Síndrome de Werner/patologia , Helicase da Síndrome de Werner
14.
Sci Rep ; 5: 8428, 2015 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-25673149

RESUMO

In epithelial cells, miRNA-199a-5p/-3p and Brm, a catalytic subunit of the SWI/SNF complex were previously shown to form a double-negative feedback loop through EGR1, by which human cancer cell lines tend to fall into either of the steady states, types 1 [miR-199a(-)/Brm(+)/EGR1(-)] and 2 [miR-199a(+)/Brm (-)/EGR1(+)]. We show here, that type 2 cells, unlike type 1, failed to form colonies in soft agar, and that CD44, MET, CAV1 and CAV2 (miR-199a targets), all of which function as plasma membrane sensors and can co-localize in caveolae, are expressed specifically in type 1 cells. Single knockdown of any of them suppressed anchorage-independent growth of type 1 cells, indicating that the miR-199a/Brm/EGR1 axis is a determinant of anchorage-independent growth. Importantly, two coherent feedforward loops are integrated into this axis, supporting the robustness of type 1-specific gene expression and exemplifying how the miRNA-target gene relationship can be stably sustained in a variety of epithelial tumors.


Assuntos
Carcinoma/genética , Proteína 1 de Resposta de Crescimento Precoce/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Fatores de Transcrição/genética , Carcinoma/metabolismo , Carcinoma/patologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Caveolina 1/genética , Caveolina 1/metabolismo , Caveolina 2/genética , Caveolina 2/metabolismo , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/metabolismo , Modelos Biológicos , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo
15.
FEBS Lett ; 588(9): 1630-6, 2014 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-24607481

RESUMO

In this study, we demonstrate that the 7SK small nuclear ribonucleoprotein (snRNP) complex is recruited to the HIV-1 promoter via newly-synthesized HIV-1 nascent transcripts (short transcripts) in an hnRNP A1-dependent manner and negatively regulates viral transcript elongation. Our deep-sequence analysis showed these short transcripts were mainly arrested at approximately +50 to +70 nucleotides from the transcriptional start site in the U1 cells, an HIV-1 latent model. TNF-α treatment promptly disrupted the 7SK snRNP complex on the nascent transcripts and viral elongated transcripts were increased. This report provides insight into how 7SK snRNP complex is recruited to HIV-1 promoter in the absence of Tat.


Assuntos
HIV-1/genética , RNA Viral/genética , Ribonucleoproteínas/metabolismo , Sequência de Bases , Regulação Viral da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HEK293 , Ribonucleoproteína Nuclear Heterogênea A1 , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/genética , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/metabolismo , Humanos , Sequências Repetidas Invertidas , Dados de Sequência Molecular , Regiões Promotoras Genéticas , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas/genética , Fatores de Transcrição , Fator de Necrose Tumoral alfa/fisiologia
16.
J Biol Chem ; 287(15): 11924-33, 2012 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-22334708

RESUMO

We have previously shown that DPF2 (requiem/REQ) functions as a linker protein between the SWI/SNF complex and RelB/p52 NF-κB heterodimer and plays important roles in NF-κB transactivation via its noncanonical pathway. Using sensitive 293FT reporter cell clones that had integrated a SWI/SNF-dependent NF-κB reporter gene, we find in this study that the overexpression of DPF1, DPF2, DPF3a, DPF3b, and PHF10 significantly potentiates the transactivating activity of typical NF-κB dimers. Knockdown analysis using 293FT reporter cells that endogenously express these five proteins at low levels clearly showed that DPF3a and DPF3b, which are produced from the DPF3 gene by alternative splicing, are the most critical for the RelA/p50 NF-κB heterodimer transactivation induced by TNF-α stimulation. Our data further show that this transactivation requires the SWI/SNF complex. DPF3a and DPF3b are additionally shown to interact directly with RelA, p50, and several subunits of the SWI/SNF complex in vitro and to be co-immunoprecipitated with RelA/p50 and the SWI/SNF complex from the nuclear fractions of cells treated with TNF-α. In ChIP experiments, we further found that endogenous DPF3a/b and the SWI/SNF complex are continuously present on HIV-1 LTR, whereas the kinetics of RelA/p50 recruitment after TNF-α treatment correlate well with the viral transcriptional activation levels. Additionally, re-ChIP experiments showed DPF3a/b and the SWI/SNF complex associate with RelA on the endogenous IL-6 promoter after TNF-α treatment. In conclusion, our present data indicate that by linking RelA/p50 to the SWI/SNF complex, DPF3a/b induces the transactivation of NF-κB target gene promoters in relatively inactive chromatin contexts.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Regulação da Expressão Gênica , Subunidade p50 de NF-kappa B/metabolismo , Fator de Transcrição RelA/metabolismo , Fatores de Transcrição/fisiologia , Ativação Transcricional , Sítios de Ligação , Linhagem Celular , Núcleo Celular/metabolismo , Montagem e Desmontagem da Cromatina , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/metabolismo , Genes Reporter , Humanos , Cinética , Luciferases/biossíntese , Luciferases/genética , Complexos Multiproteicos/metabolismo , Ligação Proteica , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiologia , Estrutura Terciária de Proteína , Transporte Proteico , Elementos de Resposta , Fatores de Transcrição/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/fisiologia
17.
J Biol Chem ; 285(29): 21951-60, 2010 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-20460684

RESUMO

The SWI/SNF chromatin remodeling complex plays pivotal roles in mammalian transcriptional regulation. In this study, we identify the human requiem protein (REQ/DPF2) as an adaptor molecule that links the NF-kappaB and SWI/SNF chromatin remodeling factor. Through in vitro binding experiments, REQ was found to bind to several SWI/SNF complex subunits and also to the p52 NF-kappaB subunit through its nuclear localization signal containing the N-terminal region. REQ, together with Brm, a catalytic subunit of the SWI/SNF complex, enhances the NF-kappaB-dependent transcriptional activation that principally involves the RelB/p52 dimer. Both REQ and Brm were further found to be required for the induction of the endogenous BLC (CXCL13) gene in response to lymphotoxin stimulation, an inducer of the noncanonical NF-kappaB pathway. Upon lymphotoxin treatment, REQ and Brm form a larger complex with RelB/p52 and are recruited to the BLC promoter in a ligand-dependent manner. Moreover, a REQ knockdown efficiently suppresses anchorage-independent growth in several cell lines in which the noncanonical NF-kappaB pathway was constitutively activated. From these results, we conclude that REQ functions as an efficient adaptor protein between the SWI/SNF complex and RelB/p52 and plays important roles in noncanonical NF-kappaB transcriptional activation and its associated oncogenic activity.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Transdução de Sinais , Fator de Transcrição RelB/metabolismo , Fatores de Transcrição/metabolismo , Linhagem Celular , Quimiocina CXCL13/genética , Quimiocina CXCL13/metabolismo , DNA Helicases/metabolismo , Proteínas de Ligação a DNA/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Linfotoxina-alfa/farmacologia , Neoplasias/metabolismo , Neoplasias/patologia , Proteínas Nucleares/metabolismo , Ligação Proteica/efeitos dos fármacos , Subunidades Proteicas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética
18.
J Virol ; 83(22): 11569-80, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19726504

RESUMO

To elucidate the epigenetic regulation of Tat-independent human immunodeficiency virus (HIV) transcription following proviral integration, we constructed an HIV type 1 (HIV-1)-based replication-defective viral vector that expresses a reporter green fluorescent protein (GFP) product from its intact long terminal repeat (LTR). We transduced this construct into human tumor cell lines that were either deficient in or competent for the Brm-type SWI/SNF complex. One day after transduction, single cells that expressed GFP were sorted, and the GFP expression profiles originating from each of these clones were analyzed. Unlike clones of the SWI/SNF-competent cell line, which exhibited clear unimodal expression patterns in all cases, many clones originating from Brm-deficient cell lines either showed a broad-range distribution of GFP expression or were fully silenced. The resorting of GFP-negative populations of these isolated clones showed that GFP silencing is either reversible or irreversible depending upon the proviral integration sites. We further observed that even in these silenced clones, proviral gene transcription initiates to accumulate short transcripts of around 60 bases in length, but no elongation occurs. We found that this termination is caused by tightly closed nucleosome-1 (nuc-1) at the 5' LTR. Also, nuc-1 is remodeled by exogenous Brm in some integrants. From these results, we propose that Brm is required for the occasional transcriptional elongation of the HIV-1 provirus in the absence of Tat. Since the Brm-type SWI/SNF complex is expressed at marginal levels in resting CD4+ T cells and is drastically induced upon CD4+ T-cell activation, we speculate that it plays crucial roles in the early Tat-independent phase of HIV transcription in affected patients.


Assuntos
Montagem e Desmontagem da Cromatina/genética , HIV-1/genética , Fatores de Elongação da Transcrição/genética , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genética , Linhagem Celular Tumoral , Vetores Genéticos/genética , HIV-1/fisiologia , Humanos , RNA Viral/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia , Transcrição Genética/genética , Fatores de Elongação da Transcrição/fisiologia , Transdução Genética , Replicação Viral/genética , Produtos do Gene tat do Vírus da Imunodeficiência Humana/fisiologia
19.
Exp Cell Res ; 315(10): 1779-89, 2009 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-19371634

RESUMO

In our recent study showing a correlation between Brm-deficiency and undifferentiated status of gastric cancer, we found that the Brm-type SWI/SNF complex is required for villin expression. To elucidate intestinal villin regulation more precisely, we here analyzed structure and function of the promoter of human villin. About 1.1 kb upstream of the determined major transcription start site, we identified a highly conserved region (HCR-Cdx) among mammals, which contains two binding sites for Cdx. Expression analyses of 30 human gastrointestinal cell lines suggested that villin is regulated by Cdx2. Introduction of Cdx family genes into colorectal SW480 cells revealed that villin is strongly induced strongly by Cdx2, moderately by Cdx1, and marginally by Cdx4. Knockdown of Cdx2 in SW480 cells caused a clear downregulation of villin, and reporter assays showed that HCR-Cdx is crucial for Cdx2-dependent and Brm-dependent villin expression. Immunohistochemical analyses of gastric intestinal metaplasia and cancer revealed that villin and Cdx2 expression are tightly coupled. GST pull-down assays demonstrated a direct interaction between Cdx2 and several SWI/SNF subunits. Chromatin immunoprecipitation analyses showed the recruitment of Cdx2 and Brm around HCR-Cdx. From these results, we concluded that Cdx2 regulates intestinal villin expression through recruiting Brm-type SWI/SNF complex to the villin promoter.


Assuntos
Trato Gastrointestinal/citologia , Trato Gastrointestinal/metabolismo , Regulação da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Proteínas dos Microfilamentos/genética , Fatores de Transcrição/metabolismo , Sequência de Bases , Sítios de Ligação , Western Blotting , Fator de Transcrição CDX2 , Linhagem Celular Tumoral , Montagem e Desmontagem da Cromatina , Sequência Conservada , Genes Reporter , Proteínas de Homeodomínio/genética , Humanos , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Ligação Proteica , Subunidades Proteicas/metabolismo , Sítio de Iniciação de Transcrição
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...