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1.
Death Stud ; 47(5): 531-540, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35855580

RESUMO

Gatekeeper training for university students is a promising suicide prevention approach. However, there is a lack of comparative studies with control groups and the effectiveness of online gatekeeper training programs is unclear. We investigated the effectiveness of brief online gatekeeper training for Japanese university students. Participants were divided into two groups (training or control) and answered surveys at three time points (pretest, posttest, follow-up). The gatekeeper training improved students' knowledge. Skills were also improved post-training but returned to baseline level at follow-up. A brief online program may improve knowledge, but the effect is limited.


Assuntos
População do Leste Asiático , Prevenção do Suicídio , Humanos , Universidades , Estudos de Viabilidade , Estudantes
2.
Omega (Westport) ; : 302228231194857, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37584392

RESUMO

With the rapid development of digital technology in recent years, virtual funerals and the reproduction of deceased persons in digital spaces have become possible. However, few empirical studies have been conducted on this topic. This study assessed the attitudes of bereaved people toward digital bonds with their deceased relatives, and explored related factors. A survey was administered to bereaved, middle-aged Japanese citizens who had lost a first-degree relative within the previous 10 years. The results showed that most respondents did not seek digital bonds, but nearly 20% wanted to be reunited with their deceased in a digital space. The desire to maintain digital bonds was significantly related to other variables, such as the deceased's age and years since their death. Regression analysis revealed that the desire for digital bonds predicted complicated grief 5 months later. The findings suggest that digital bonds may influence post-bereavement maladjustment.

3.
J Artif Organs ; 25(4): 305-313, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35254539

RESUMO

Two equations have been developed from multi-frequency measurements of blood impedance Zb for a simultaneous electrical online estimation of changes in blood hematocrit ΔH [%] and temperatures ΔT [K] in cardiopulmonary bypass (CPB). Zb of fixed blood volumes at varying H and T were measured by an impedance analyzer and changes in blood conductivity σb and relative permittivity εb computed. Correlation analysis were based on changes in σb with H or T at f = 1 MHz while H and T equations were developed by correlating changes in εb with H and T at dual frequencies of f = 1 MHz and f = 10 MHz which best capture blood plasma Zp and red blood cell cytoplasm Zcyt impedances respectively. Results show high correlations between σb and H (R2 = 0.987) or σb and T (R2 = 0.9959) indicating dependence of the electrical parameters of blood on its H and T. Based on computed εb, changes in blood hematocrit ΔH and temperature ΔT at a given time t are estimated as ΔH(t) = 1.7298Δεb (f = 1 MHz) - 1.0669Δεb (f = 10 MHz) and ΔT(t) = -2.186Δεb (f = 1 MHz) + 2.13Δεb (f = 10 MHz). When applied to a CPB during a canine mitral valve plasty, ΔH and ΔT had correlations of R2 = 0.9992 and R2 = 0.966 against H and T respectively as measured by conventional devices.


Assuntos
Ponte Cardiopulmonar , Animais , Cães , Ponte Cardiopulmonar/métodos , Hematócrito , Temperatura , Impedância Elétrica
4.
Death Stud ; 46(2): 425-433, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-32189580

RESUMO

The compassionate communities movement challenges the notion that death and dying should be housed within clinical and institutional contexts, and works to normalize conversations about death and dying by promoting death literacy and dialogue in public spaces. Community-based practices and conversations about grief remain marginal in this agenda. We aimed to theorize how grief could be better conceptualized and operationalized within the compassionate communities movement. We develop the concept of Grief Literacy and present vignettes to illustrate a grief literate society. Grief literacy augments the concept of death literacy, thereby further enhancing the potential of the compassionate communities approach.


Assuntos
Pesar , Alfabetização , Empatia , Humanos
5.
Omega (Westport) ; : 302228211051512, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35345933

RESUMO

Survivors' adaptation to a suicide loss is likely influenced by their attitudes toward suicide and their respective sociocultural contexts. Our study aimed to compare suicide attitudes and their association with depressive symptoms and sense of community safety in Japanese and American suicide loss survivors. A total of 193 Japanese survivors and 232 American survivors completed online surveys. The results show that Japanese survivors tended not to consider suicide as an illness or to recognize that others understood their experience but were more likely than American survivors to consider suicide as justifiable. Regression analyses indicated that taking suicide as a right was associated with depressive symptoms. Further, their sense of being understood by others was positively correlated with perceived community safety in both samples, but justifying suicide and considering it to be an illness was positively related to perceived community safety only among Japanese survivors.

6.
Omega (Westport) ; 83(3): 601-610, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31242067

RESUMO

This study explored end-of-life (EOL) activities among community-dwelling Japanese older adults and the relationships between EOL activities and related variables. One hundred twenty-three older adults (38 men, 87 women; mean age = 72.54 years) who attended EOL seminars were surveyed regarding EOL activities, attitudes toward death, and mental health status. Cluster analysis of EOL activities revealed three clusters: Planning (e.g., had planned own funeral arrangements), Preference (e.g., had talked about EOL care with their family), and Preparation (e.g., already written their will). The number of EOL-related events attended was positively correlated with Preparation, while fear of death was negatively associated with Preference. Older adults with bereavement experience had higher Planning and Preparation scores than those without such experience.


Assuntos
Cuidados Paliativos na Terminalidade da Vida , Assistência Terminal , Idoso , Morte , Feminino , Humanos , Vida Independente , Japão , Masculino
7.
Omega (Westport) ; 79(1): 34-51, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-28578637

RESUMO

Several reports have indicated that grief and mental health outcomes of people bereaved by suicide vary by their relationship to the deceased. Parents who have lost offspring experience higher levels of distress than those with other relationships to the deceased. However, there are limited studies investigating the experience of parental bereavement by suicide, and further research is needed. The present study aimed to clarify the differences in grief reactions between bereaved parents and those with other relationships to the deceased in Japan and explore a statistical model of adaptation to the loss. In total, 105 bereaved participants completed a questionnaire covering grief reaction, meaning reconstruction, mental health, social context, and demographic variables. Parents scored higher on several grief reaction items and lower in sense-making than those with other relationships. In addition, path analysis showed that sense-making acted as a moderator in the experience of loss of offspring and grief reaction.


Assuntos
Adaptação Psicológica , Pesar , Pais/psicologia , Suicídio/psicologia , Adolescente , Adulto , Criança , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
8.
Omega (Westport) ; 75(4): 360-375, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28792358

RESUMO

Although Japan has a high suicide rate, there is insufficient research on the experiences of suicide-bereaved individuals. We investigated the qualitative aspects of the meaning reconstruction process after a loss to suicide. We conducted a life-story interview using open-ended questions with one middle-aged Japanese woman who lost her son to suicide. We used a narrative approach to transcribe and code the participant's narratives for analysis. The analysis revealed three meaning groups that structured the participant's reactions to the suicide: making sense of her son's death and life, relationships with other people, and reconstruction of a bond with the deceased. The belief that death is not an eternal split and that there is a connection between the living and the deceased reduced the pain felt by our participant. Furthermore, the narratives worked as scaffolds in the meaning reconstruction process. We discuss our results in the light of cross-cultural differences in the grieving process.


Assuntos
Adaptação Psicológica , Luto , Transtornos de Estresse Pós-Traumáticos/psicologia , Suicídio/psicologia , Características Culturais , Relações Familiares , Feminino , Humanos , Entrevistas como Assunto , Japão , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
Omega (Westport) ; 75(3): 219-229, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28701115

RESUMO

A total of 56 Japanese and 59 American survivor of suicide support group facilitators were asked to rank the mutual aid objectives of their groups following Shulman's scheme in terms of their frequency and importance. Both American and Japanese facilitators showed an emphasis on personal adaptation goals (such as helping bereaved feel less isolated in their grief or encouraging bereaved to share their coping with loss experiences) over collective goals (such as raising monies for more research on mental illness or trying to combat societal suicide stigma in their local communities). Differences were also noted with American facilitators evaluating helping with problem solving, sharing different ways of coping, viewing personal issues as societal problems, and advocating for promoting social change as significantly higher than the Japanese did. We believe some of these contrasts reflect differences in American and Japanese cultural values.


Assuntos
Adaptação Psicológica , Luto , Grupos de Autoajuda , Suicídio/psicologia , Sobreviventes/psicologia , Comparação Transcultural , Família/psicologia , Humanos , Japão , Estados Unidos
10.
J Biol Chem ; 288(33): 24189-99, 2013 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-23836915

RESUMO

The Epstein-Barr virus (EBV) genome is episomally maintained in latently infected cells. The viral protein EBNA1 is a bridging molecule that tethers EBV episomes to host mitotic chromosomes as well as to interphase chromatin. EBNA1 localizes to cellular chromosomes (chromatin) via its chromosome binding domains (CBDs), which are rich in glycine and arginine residues. However, the molecular mechanism by which the CBDs of EBNA1 attach to cellular chromatin is still under debate. Mutation analyses revealed that stepwise substitution of arginine residues within the CBD1 (amino acids 40-54) and CBD2 (amino acids 328-377) regions with alanines progressively impaired chromosome binding activity of EBNA1. The complete arginine-to-alanine substitutions within the CBD1 and -2 regions abolished the ability of EBNA1 to stably maintain EBV-derived oriP plasmids in dividing cells. Importantly, replacing the same arginines with lysines had minimal effect, if any, on chromosome binding of EBNA1 as well as on its ability to stably maintain oriP plasmids. Furthermore, a glycine-arginine-rich peptide derived from the CBD1 region bound to reconstituted nucleosome core particles in vitro, as did a glycine-lysine rich peptide, whereas a glycine-alanine rich peptide did not. These results support the idea that the chromosome binding of EBNA1 is mediated by electrostatic interactions between the basic amino acids within the CBDs and negatively charged cellular chromatin.


Assuntos
Aminoácidos Básicos/metabolismo , Cromatina/metabolismo , Antígenos Nucleares do Vírus Epstein-Barr/química , Antígenos Nucleares do Vírus Epstein-Barr/metabolismo , Herpesvirus Humano 4/metabolismo , Plasmídeos/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Cromossomos Humanos/metabolismo , Células HeLa , Humanos , Dados de Sequência Molecular , Proteínas Mutantes/metabolismo , Mutação/genética , Nucleossomos/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Transporte Proteico , Proteínas Recombinantes de Fusão/metabolismo
11.
J Virol ; 87(18): 10148-62, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23843637

RESUMO

Reactivation of Epstein-Barr virus (EBV) from latency is dependent on expression of the viral transactivator BZLF1 protein, whose promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical or biological inducers. Using a reporter assay system, we screened for factors that can activate Zp and isolated genes, including those encoding MEF2B, KLF4, and some cellular b-Zip family transcription factors. After confirming their importance and functional binding sites in reporter assays, we prepared recombinant EBV-BAC, in which the binding sites were mutated. Interestingly, the MEF2 mutant virus produced very low levels of BRLF1, another transactivator of EBV, in addition to BZLF1 in HEK293 cells. The virus failed to induce a subset of early genes, such as that encoding BALF5, upon lytic induction, and accordingly, could not replicate to produce progeny viruses in HEK293 cells, but this restriction could be completely lifted by exogenous supply of BRLF1, together with BZLF1. In B cells, induction of BZLF1 by chemical inducers was inhibited by point mutations in the ZII or the three SP1/KLF binding sites of EBV-BAC Zp, while leaky BZLF1 expression was less affected. Mutation of MEF2 sites severely impaired both spontaneous and induced expression of not only BZLF1, but also BRLF1 in comparison to wild-type or revertant virus cases. We also observed that MEF2 mutant EBV featured relatively high repressive histone methylation, such as H3K27me3, but CpG DNA methylation levels were comparable around Zp and the BRLF1 promoter (Rp). These findings shed light on BZLF1 expression and EBV reactivation from latency.


Assuntos
Herpesvirus Humano 4/fisiologia , Interações Hospedeiro-Patógeno , Fatores de Regulação Miogênica/metabolismo , Transativadores/biossíntese , Ativação Viral , Linhagem Celular , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição MEF2 , Replicação Viral
12.
J Virol ; 87(7): 4060-70, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23365429

RESUMO

Epstein-Barr virus (EBV), a human oncogenic herpesvirus that establishes a lifelong latent infection in the host, occasionally enters lytic infection to produce progeny viruses. The EBV oncogene latent membrane protein 1 (LMP1), which is expressed in both latent and lytic infection, constitutively activates the canonical NF-κB (p65) pathway. Such LMP1-mediated NF-κB activation is necessary for proliferation of latently infected cells and inhibition of viral lytic cycle progression. Actually, canonical NF-κB target gene expression was suppressed upon the onset of lytic infection. TRAF6, which is activated by conjugation of polyubiquitin chains, associates with LMP1 to mediate NF-κB signal transduction. We have found that EBV-encoded BPLF1 interacts with and deubiquitinates TRAF6 to inhibit NF-κB signaling during lytic infection. HEK293 cells with BPLF1-deficient recombinant EBV exhibited poor viral DNA replication compared with the wild type. Furthermore, exogenous expression of BPLF1 or p65 knockdown in cells restored DNA replication of BPLF1-deficient viruses, indicating that EBV BPLF1 deubiquitinates TRAF6 to inhibit NF-κB signal transduction, leading to promotion of viral lytic DNA replication.


Assuntos
Herpesvirus Humano 4/enzimologia , NF-kappa B/metabolismo , Transdução de Sinais/fisiologia , Fator 6 Associado a Receptor de TNF/metabolismo , Proteínas da Matriz Viral/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Replicação Viral/fisiologia , Análise de Variância , Cromossomos Artificiais Bacterianos , Primers do DNA/genética , Células HEK293 , Herpesvirus Humano 4/fisiologia , Humanos , Immunoblotting , Imunoprecipitação , Luciferases , Mutagênese , Reação em Cadeia da Polimerase em Tempo Real , Transfecção , Ubiquitinação
13.
J Virol ; 87(4): 2120-7, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23221557

RESUMO

Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) protein is known as a regulator which recognizes phosphorylated Ser/Thr-Pro motifs and increases the rate of cis and trans amide isomer interconversion, thereby altering the conformation of its substrates. We found that Pin1 knockdown using short hairpin RNA (shRNA) technology resulted in strong suppression of productive Epstein-Barr virus (EBV) DNA replication. We further identified the EBV DNA polymerase catalytic subunit, BALF5, as a Pin1 substrate in glutathione S-transferase (GST) pulldown and immunoprecipitation assays. Lambda protein phosphatase treatment abolished the binding of BALF5 to Pin1, and mutation analysis of BALF5 revealed that replacement of the Thr178 residue by Ala (BALF5 T178A) disrupted the interaction with Pin1. To further test the effects of Pin1 in the context of virus infection, we constructed a BALF5-deficient recombinant virus. Exogenous supply of wild-type BALF5 in HEK293 cells with knockout recombinant EBV allowed efficient synthesis of viral genome DNA, but BALF5 T178A could not provide support as efficiently as wild-type BALF5. In conclusion, we found that EBV DNA polymerase BALF5 subunit interacts with Pin1 through BALF5 Thr178 in a phosphorylation-dependent manner. Pin1 might modulate EBV DNA polymerase conformation for efficient, productive viral DNA replication.


Assuntos
DNA Viral/biossíntese , Proteínas de Ligação a DNA/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Herpesvirus Humano 4/fisiologia , Interações Hospedeiro-Patógeno , Peptidilprolil Isomerase/metabolismo , Proteínas Virais/metabolismo , Replicação Viral , Linhagem Celular , Centrifugação , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , DNA Polimerase Dirigida por DNA/genética , Técnicas de Silenciamento de Genes , Herpesvirus Humano 4/enzimologia , Herpesvirus Humano 4/genética , Humanos , Imunoprecipitação , Peptidilprolil Isomerase de Interação com NIMA , Peptidilprolil Isomerase/genética , Fosforilação , Mapeamento de Interação de Proteínas , Treonina/metabolismo , Proteínas Virais/genética
14.
J Virol ; 87(11): 6482-91, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23552409

RESUMO

Epstein-Barr virus (EBV) replication proteins are transported into the nucleus to synthesize viral genomes. We here report molecular mechanisms for nuclear transport of EBV DNA polymerase. The EBV DNA polymerase catalytic subunit BALF5 was found to accumulate in the cytoplasm when expressed alone, while the EBV DNA polymerase processivity factor BMRF1 moved into the nucleus by itself. Coexpression of both proteins, however, resulted in efficient nuclear transport of BALF5. Deletion of the nuclear localization signal of BMRF1 diminished the proteins' nuclear transport, although both proteins can still interact. These results suggest that BALF5 interacts with BMRF1 to effect transport into the nucleus. Interestingly, we found that Hsp90 inhibitors or knockdown of Hsp90ß with short hairpin RNA prevented the BALF5 nuclear transport, even in the presence of BMRF1, both in transfection assays and in the context of lytic replication. Immunoprecipitation analyses suggested that the molecular chaperone Hsp90 interacts with BALF5. Treatment with Hsp90 inhibitors blocked viral DNA replication almost completely during lytic infection, and knockdown of Hsp90ß reduced viral genome synthesis. Collectively, we speculate that Hsp90 interacts with BALF5 in the cytoplasm to assist complex formation with BMRF1, leading to nuclear transport. Hsp90 inhibitors may be useful for therapy for EBV-associated diseases in the future.


Assuntos
Antígenos Virais/metabolismo , Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Infecções por Vírus Epstein-Barr/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Herpesvirus Humano 4/enzimologia , Proteínas Virais/metabolismo , Transporte Ativo do Núcleo Celular , Antígenos Virais/genética , Núcleo Celular/genética , Núcleo Celular/virologia , Proteínas de Ligação a DNA/genética , DNA Polimerase Dirigida por DNA/genética , Infecções por Vírus Epstein-Barr/virologia , Proteínas de Choque Térmico HSP90/genética , Células HeLa , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Humanos , Ligação Proteica , Proteínas Virais/genética
15.
J Virol ; 87(12): 6693-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23552415

RESUMO

Productive replication of the Epstein-Barr virus (EBV) occurs in discrete sites in nuclei, called replication compartments, where viral genome DNA synthesis and transcription take place. The replication compartments include subnuclear domains, designated BMRF1 cores, which are highly enriched in the BMRF1 protein. During viral lytic replication, newly synthesized viral DNA genomes are organized around and then stored inside BMRF1 cores. Here, we examined spatial distribution of viral early and late gene mRNAs within replication compartments using confocal laser scanning microscopy and three-dimensional surface reconstruction imaging. EBV early mRNAs were mainly located outside the BMRF1 cores, while viral late mRNAs were identified inside, corresponding well with the fact that late gene transcription is dependent on viral DNA replication. From these results, we speculate that sites for viral early and late gene transcription are separated with reference to BMRF1 cores.


Assuntos
Núcleo Celular/ultraestrutura , Núcleo Celular/virologia , Herpesvirus Humano 4/metabolismo , Proteínas Virais/metabolismo , Replicação Viral , Animais , Antígenos Virais/genética , Antígenos Virais/metabolismo , Linhagem Celular , Replicação do DNA , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Imageamento Tridimensional , Hibridização in Situ Fluorescente , Microscopia Confocal , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Virais/genética
16.
Lab Chip ; 24(12): 3183-3190, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38828904

RESUMO

hERG channel screening has been achieved based on electrical impedance tomography and extracellular voltage activation (EIT-EVA) to improve the non-invasive aspect of drug discovery. EIT-EVA screens hERG channels by considering the change in extracellular ion concentration which modifies the extracellular resistance in cell suspension. The rate of ion passing in cell suspension is calculated from the extracellular resistance Rex, which is obtained from the EIT measurement at a frequency of 500 kHz. In the experiment, non-invasive screening is applied by a novel integrated EIT-EVA printed circuit board (PCB) sensor to human embryonic kidney (HEK) 293 cells transfected with the human ether-a-go-go-related gene (hERG) ion channel, while the E-4031 antiarrhythmic drug is used for hERG channel inhibition. The extracellular resistance Rex of the HEK 293 cells suspension is measured by EIT as the hERG channels are activated by EVA over time. The Rex is reconstructed into extracellular conductivity distribution change Δσ to reflect the extracellular K+ ion concentration change Δc resulting from the activated hERG channel. Δc is increased rapidly during the hERG channel non-inhibition state while Δc is increased slower with increasing drug concentration cd. In order to evaluate the EIT-EVA system, the inhibitory ratio index (IR) was calculated based on the rate of Δc over time. Half-maximal inhibitory concentration (IC50) of 2.7 nM is obtained from the cd and IR dose-response relationship. The IR from EIT-EVA is compared with the results from the patch-clamp method, which gives R2 of 0.85. In conclusion, EIT-EVA is successfully applied to non-invasive hERG channel screening.


Assuntos
Impedância Elétrica , Canais de Potássio Éter-A-Go-Go , Humanos , Células HEK293 , Canais de Potássio Éter-A-Go-Go/metabolismo , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Tomografia/instrumentação , Canal de Potássio ERG1/metabolismo , Canal de Potássio ERG1/antagonistas & inibidores , Piperidinas/farmacologia , Piperidinas/química , Piridinas/farmacologia , Piridinas/química
17.
J Virol ; 86(9): 4752-61, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22357272

RESUMO

The Epstein-Barr virus (EBV) predominantly establishes latent infection in B cells, and the reactivation of the virus from latency is dependent on the expression of the viral BZLF1 protein. The BZLF1 promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical or biological inducers, such as 12-O-tetradecanoylphorbol-13-acetate (TPA), calcium ionophores, or histone deacetylase (HDAC) inhibitors. In some cell lines latently infected with EBV, an HDAC inhibitor alone can induce BZLF1 transcription, while the treatment does not enhance expression in other cell lines, such as B95-8 or Raji cells, suggesting unknown suppressive mechanisms besides histone deacetylation in those cells. Here, we found the epigenetic modification of the BZLF1 promoter in latent Raji cells by histone H3 lysine 27 trimethylation (H3K27me3), H3K9me2/me3, and H4K20me3. Levels of active markers such as histone acetylation and H3K4me3 were low in latent cells but increased upon reactivation. Treatment with 3-deazaneplanocin A (DZNep), an inhibitor of H3K27me3 and H4K20me3, significantly enhanced the BZLF1 transcription in Raji cells when in combination with an HDAC inhibitor, trichostatin A (TSA). The knockdown of Ezh2 or Suv420h1, histone methyltransferases for H3K27me3 or H4K20me3, respectively, further proved the suppression of Zp by the methylations. Taken together, the results indicate that H3K27 methylation and H4K20 methylation are involved, at least partly, in the maintenance of latency, and histone acetylation and H3K4 methylation correlate with the reactivation of the virus in Raji cells.


Assuntos
Epigênese Genética , Herpesvirus Humano 4/genética , Histonas/metabolismo , Regiões Promotoras Genéticas , Transativadores/genética , Latência Viral/genética , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Linhagem Celular , Metilases de Modificação do DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Decitabina , Proteína Potenciadora do Homólogo 2 de Zeste , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Inibidores de Histona Desacetilases/farmacologia , Histona-Lisina N-Metiltransferase/genética , Humanos , Complexo Repressor Polycomb 2 , Regiões Promotoras Genéticas/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
18.
Biomed Phys Eng Express ; 9(6)2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37659392

RESUMO

Image reconstruction in electrical impedance tomography (EIT) is a typical ill-posed inverse problem, from which the stability of conductivity reconstruction affects the reliability of physiological parameters evaluation. In order to improve the stability, the effect of boundary voltage noise on conductivity reconstruction should be controlled. A noise-controlling method based on hybrid current-stimulation and voltage-measurement for EIT (HCSVM-EIT) is proposed for stable conductivity reconstruction. In HCSVM-EIT, the boundary voltage is measured by one current-stimulation and voltage-measurement pattern (high-SNRpattern) with a higher signal-to-noise ratio (SNR); the sensitivity matrix is calculated by another current-stimulation and voltage-measurement pattern (low-condpattern) with a lower condition number; the boundary voltage is then transformed from thehigh-SNRpattern into thelow-condpattern by multiplying by an optimized transformation matrix for image reconstruction. The stability of conductivity reconstruction is improved by combining the advantages of thehigh-SNRpattern for boundary voltage measurement and thelow-condpattern for sensitivity matrix calculation. The simulation results show that the HCSVM-EIT increases the correlation coefficient (CC) of conductivity reconstruction. The experiment results show that theCCof conductivity reconstruction of the human lower limb is increased from 0.3424 to 0.5580 by 62.97% compared to the quasi-adjacent pattern, and from 0.4942 to 0.5580 by 12.91% compared to the adjacent pattern. In conclusion, the stable conductivity reconstruction with higherCCin HCSVM-EIT improves the reliability of physiological parameters evaluation for disease detection.


Assuntos
Tomografia , Humanos , Impedância Elétrica , Reprodutibilidade dos Testes , Simulação por Computador , Condutividade Elétrica
19.
J Biol Chem ; 286(25): 22007-16, 2011 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-21525011

RESUMO

Reactivation of the Epstein-Barr virus from latency is dependent on expression of the BZLF1 viral immediate-early protein. The BZLF1 promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical inducers such as 12-O-tetradecanoylphorbol-13-acetate and calcium ionophore. We found that Jun dimerization protein 2 (JDP2) plays a significant role in suppressing Zp activity. Reporter, EMSA, and ChIP assays of a Zp mutant virus revealed JDP2 association with Zp at the ZII cis-element, a binding site for CREB/ATF/AP-1. Suppression of Zp activity by JDP2 correlated with HDAC3 association and reduced levels of histone acetylation. Although introduction of point mutations into the ZII element of the viral genome did not increase the level of BZLF1 production, silencing of endogenous JDP2 gene expression by RNA interference increased the levels of viral early gene products and viral DNA replication. These results indicate that JDP2 plays a role as a repressor of Zp and that its replacement by CREB/ATF/AP-1 at ZII is crucial to triggering reactivation from latency to lytic replication.


Assuntos
Herpesvirus Humano 4/fisiologia , Proteínas Repressoras/metabolismo , Latência Viral , Inativação Gênica , Células HEK293 , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Histona Desacetilases/metabolismo , Humanos , Regiões Promotoras Genéticas/genética , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Transativadores/genética , Transcrição Gênica , Ativação Viral
20.
J Biol Chem ; 286(49): 42524-42533, 2011 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-22013073

RESUMO

Epstein-Barr virus LMP1, a major oncoprotein expressed in latent infection, is critical for primary B cell transformation, functioning as a TNFR family member by aggregation in the plasma membrane resulting in constitutive activation of cellular signals, such as NF-κB, MAPK, JAK/STAT, and AKT. Although transcription of LMP1 in latent type III cells is generally under the control of the viral coactivator EBNA2, little is known about EBNA2-independent LMP1 expression in type II latency. We thus screened a cDNA library for factors that can activate the LMP1 promoter in an EBNA2-independent manner, using a reporter assay system. So far, we have screened >20,000 clones, and here identified C/EBPε as a new transcriptional activator. Exogenous expression of C/EBPα, -ß, or -ε efficiently augmented LMP1 mRNA and protein levels in EBV-positive cell lines, whereas other members of the C/EBP family exhibited modest or little activity. It has been demonstrated that LMP1 gene transcription depends on two promoter regions: proximal (ED-L1) and distal (TR-L1). Interestingly, although we first used the proximal promoter for screening, we found that C/EBP increased transcription from both promoters in latent EBV-positive cells. Mutagenesis in reporter assays and EMSA identified only one functional C/EBP binding site, through which activation of both proximal and distal promoters is mediated. Introduction of point mutations into the identified C/EBP site in EBV-BAC caused reduced LMP1 transcription from both LMP1 promoters in epithelial cells. In conclusion, C/EBP is a newly identified transcriptional activator of the LMP1 gene, independent of the EBNA2 coactivator.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Regulação da Expressão Gênica , Ativação Transcricional , Proteínas da Matriz Viral/genética , Motivos de Aminoácidos , Sítios de Ligação , Linhagem Celular , Biblioteca Gênica , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Células HeLa , Humanos , Modelos Genéticos , Oncogenes , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Transcrição Gênica
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