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1.
Aging Ment Health ; 28(2): 319-329, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37650239

RESUMO

OBJECTIVES: Focusing on the nexus of race/ethnicity and nativity, this study examined profiles of adversity and their mental health implications in five groups of middle-aged and older adults: native-born whites, native-born blacks, native-born Hispanics, foreign-born whites, and foreign-born Hispanics. METHODS: Data were from the 2018 psychosocial assessment of the HRS (N = 5,223). Latent class analysis (LCA) was employed to identify patterns of eleven adversity indicators and to compare the latent structures and class prevalence across the race/ethnicity and nativity groups. Regressions were used to examine the associations between adversity profiles and depression and life satisfaction, respectively. RESULTS: Four adversity profiles emerged: low adversity (59.84%), low human capital (15.27%), socially marginalized (15.26%), and neighborhood adversity (9.63%). Regardless of nativity status, white older adults were most likely to have the low adversity profile (74 ∼ 75%). In contrast, all the racial/ethnic minority groups were more likely to have the other three adversity profiles. The adversity experienced by racial/ethnic minorities was further cofounded by their immigration status. Overall, having low adversity was associated with the best mental health outcomes and socially marginalized had the poorest outcomes. Even with the low adversity profile, native-born blacks had significantly more depressive symptoms than native-born whites. CONCLUSION: Findings revealed heterogeneity in adversity profiles and their mental health implications in disadvantaged aging populations. Tailored programs are needed to address unique needs of different minority populations.


Assuntos
Etnicidade , Saúde Mental , Grupos Minoritários , Grupos Raciais , Idoso , Humanos , Pessoa de Meia-Idade , Etnicidade/psicologia , Grupos Minoritários/psicologia , Grupos Raciais/psicologia , Estados Unidos , Depressão/epidemiologia , Satisfação Pessoal
2.
Antiviral Res ; 217: 105678, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37494979

RESUMO

The 36th International Conference on Antiviral Research (ICAR), sponsored by the International Society for Antiviral Research (ISAR), was held March 13-17, 2023, in Lyon, France, and concurrently through an interactive remote meeting platform. Here we provide a report summarizing the presentations at the 36th ICAR, including the ISAR speaker awards. We also detail special events, sessions, and additional awards conferred at the meeting. ICAR returned to in-person meetings in 2022, convening in Seattle, WA, USA. The 36th ICAR is the first in-person meeting of the society in Europe since the beginning of the COVID-19 pandemic, which restricted most events to virtual attendance to help mitigate the spread and subsequent public health impact of SARS-CoV-2. An exceptionally high number of registrants and record attendance at this year's ICAR, along with a vast array of demonstrable expertise in a variety of antiviral research-related fields, reflected a strong and growing antiviral research community committed to improving health outcomes from viral diseases, including SARS-CoV-2, and to future pandemic preparedness. This report highlights the breadth of expertise, quality of research, and notable advancements that were contributed by members of ISAR and other participants at the meeting. ICAR aims to continue to provide a platform for sharing information, fostering collaborations, and supporting trainees in the field of antiviral research. The 37th ICAR will be held in Gold Coast, Australia, May 20-24, 2024.


Assuntos
Antivirais , COVID-19 , Humanos , Antivirais/farmacologia , Antivirais/uso terapêutico , Complexo Ferro-Dextran , Pandemias , SARS-CoV-2
3.
Antiviral Res ; 211: 105521, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36596323

RESUMO

The 35th International Conference on Antiviral Research (ICAR), sponsored by the International Society for Antiviral Research (ISAR), was held in Seattle, Washington, USA, on March 21-25, 2022 and concurrently through an interactive remote meeting platform. This report gives an overview of the conference on behalf of the society. It provides a general review of the meeting and awardees, summarizing the presentations and their main conclusions from the perspective of researchers active in many different areas of antiviral research and development. Through ICAR, leaders in the field of antiviral research were able to showcase their efforts, as participants learned about key advances in the field. The impact of these efforts was exemplified by many presentations on SARS-CoV-2 demonstrating the remarkable response to the ongoing pandemic, as well as future pandemic preparedness, by members of the antiviral research community. As we address ongoing outbreaks and seek to mitigate those in the future, this meeting continues to support outstanding opportunities for the exchange of knowledge and expertise while fostering cross-disciplinary collaborations in therapeutic and vaccine development. The 36th ICAR will be held in Lyon, France, March 13-17, 2023.


Assuntos
Antivirais , COVID-19 , Humanos , Antivirais/uso terapêutico , Washington , Complexo Ferro-Dextran , SARS-CoV-2
4.
Antivir Chem Chemother ; 30: 20402066221130853, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36305015

RESUMO

As a result of the multiple gathering and travels restrictions during the SARS-CoV-2 pandemic, the annual meeting of the International Society for Antiviral Research (ISAR), the International Conference on Antiviral Research (ICAR), could not be held in person in 2021. Nonetheless, ISAR successfully organized a remote conference, retaining the most critical aspects of all ICARs, a collegiate gathering of researchers in academia, industry, government and non-governmental institutions working to develop, identify, and evaluate effective antiviral therapy for the benefit of all human beings. This article highlights the 2021 remote meeting, which presented the advances and objectives of antiviral and vaccine discovery, research, and development. The meeting resulted in a dynamic and effective exchange of ideas and information, positively impacting the prompt progress towards new and effective prophylaxis and therapeutics.


Assuntos
Antivirais , Tratamento Farmacológico da COVID-19 , Humanos , Antivirais/farmacologia , Antivirais/uso terapêutico , SARS-CoV-2 , Pandemias
5.
Gerontologist ; 62(9): 1278-1288, 2022 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-35583246

RESUMO

BACKGROUND AND OBJECTIVES: Studies have shown that neighborhood environment shapes older Americans' aging experience and health. However, it remains largely unknown whether and how neighborhood environment influences the well-being of older Asian Immigrants. Guided by the neighborhood stress process model, this study aims to investigate (a) the associations between neighborhood environmental stressors and depression among Chinese older immigrants and (b) the potential mediation effects of intrapersonal (sense of mastery and sense of hopefulness) and interpersonal coping (social engagement) resources in such associations. RESEARCH DESIGN AND METHODS: This study analyzed data collected from 2,801 Chinese older immigrants in the greater Chicago area. Structural equation modeling with bootstrap resampling was used to fit path models on neighborhood environmental stressor, intra- and interpersonal coping resources, and depression. RESULTS: Findings showed that neighborhood social disintegration and physical disorder were associated with more depressive symptoms directly and indirectly via lower intra- and interpersonal coping resources. Specifically, older immigrants living in neighborhoods with greater social disintegration reported lower sense of mastery and social engagement, which in turn were associated with more depressive symptoms (partial mediation). Older immigrants living in neighborhoods with greater physical disorder reported lower sense of hopefulness and mastery, which subsequently were associated with more depressive symptoms (full mediation). DISCUSSION AND IMPLICATIONS: The findings showed that neighborhood environmental stressors are risk factors for mental health of Chinese older immigrants, and coping resources may serve as pathways of the associations. The implications for future research and practice were discussed.


Assuntos
Depressão , Emigrantes e Imigrantes , Humanos , Estados Unidos/epidemiologia , Idoso , Depressão/epidemiologia , Apoio Social , Características de Residência , Adaptação Psicológica , China/epidemiologia
6.
mBio ; 13(2): e0288821, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35389262

RESUMO

Chronic hepatitis B virus (HBV) infection persists due to the lack of therapies that effectively target the HBV covalently closed circular DNA (cccDNA). We used HBV-specific guide RNAs (gRNAs) and CRISPR-Cas9 and determined the fate of cccDNA after gene editing. We set up a ribonucleoprotein (RNP) delivery system in HBV-infected HepG2-NTCP cells. HBV parameters after Cas9 editing were analyzed. Southern blot (SB) analysis and DNA/RNA sequencing (DNA/RNA-seq) were performed to determine the consequences of cccDNA editing and transcriptional activity of mutated cccDNA. Treatment of infected cells with HBV-specific gRNAs showed that CRISPR-Cas9 can efficiently affect HBV replication. The appearance of episomal HBV DNA variants after dual gRNA treatment was observed by PCR, SB analysis, and DNA/RNA-seq. These transcriptionally active variants are the products of simultaneous Cas9-induced double-strand breaks in two target sites, followed by repair and religation of both short and long fragments. Following suppression of HBV DNA replicative intermediates by nucleoside analogs, mutations and formation of smaller transcriptionally active HBV variants were still observed, suggesting that established cccDNA is accessible to CRISPR-Cas9 editing. Targeting HBV DNA with CRISPR-Cas9 leads to cleavage followed by appearance of episomal HBV DNA variants. Effects induced by Cas9 were sustainable after RNP degradation/loss of detection, suggesting permanent changes in the HBV genome instead of transient effects due to transcriptional interference. IMPORTANCE Hepatitis B virus infection can develop into chronic infection, cirrhosis, and hepatocellular carcinoma. Treatment of chronic hepatitis B requires novel approaches to directly target the viral minichromosome, which is responsible for the persistence of the disease. Designer nuclease approaches represent a promising strategy to treat chronic infectious diseases; however, comprehensive knowledge about the fate of the HBV minichromosome is needed before this potent tool can be used as a potential therapeutic approach. This study provides an in-depth analysis of CRISPR-Cas9 targeting of HBV minichromosome.


Assuntos
Vírus da Hepatite B , Hepatite B Crônica , Sistemas CRISPR-Cas , DNA Circular/genética , DNA Viral/genética , Vírus da Hepatite B/genética , Hepatite B Crônica/tratamento farmacológico , Humanos , RNA Guia de Cinetoplastídeos/genética
7.
Antiviral Res ; 202: 105295, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35339583

RESUMO

Chikungunya virus (CHIKV) has re-emerged as a significant human pathogen in the 21st century, causing periodic, and sometimes widespread, outbreaks over the past 15 years. Although mortality is very rare, a debilitating arthralgia is very common and may persist for months or years. There are no antivirals that are approved for the treatment of CHIKV infection, and current treatment options consist of supportive care only. Herein, we demonstrate the efficacy of a CHIKV-specific antibody in the prophylactic and therapeutic treatment of CHIKV in mouse models of disease. The fully human anti-CHIKV monoclonal Ab SVIR023 demonstrated broad in vitro activity against representative strains from the three major CHIKV clades. Therapeutic treatment with SVIR023 administered 1- or 3-days post-infection resulted in reduced virus in various tissues in a dose- and time-dependent manner. Prophylactic treatment up to 4 weeks prior to virus challenge was also effective in preventing disease in mice. Mice treated with SVIR023 and infected with CHIKV were resistant to secondary challenge and no evidence of antibody enhancement of disease was observed. Treatment with SVIR023 was effective in mouse models of CHIKV infection and disease and further evaluation towards clinical development is warranted.


Assuntos
Febre de Chikungunya , Vírus Chikungunya , Animais , Anticorpos Antivirais/uso terapêutico , Antivirais/farmacologia , Antivirais/uso terapêutico , Febre de Chikungunya/tratamento farmacológico , Febre de Chikungunya/prevenção & controle , Vírus de DNA , Modelos Animais de Doenças , Camundongos , Roedores
9.
J Infect Dis ; 224(Supplement_1): S1-S21, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34111271

RESUMO

The NIH Virtual SARS-CoV-2 Antiviral Summit, held on 6 November 2020, was organized to provide an overview on the status and challenges in developing antiviral therapeutics for coronavirus disease 2019 (COVID-19), including combinations of antivirals. Scientific experts from the public and private sectors convened virtually during a live videocast to discuss severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) targets for drug discovery as well as the preclinical tools needed to develop and evaluate effective small-molecule antivirals. The goals of the Summit were to review the current state of the science, identify unmet research needs, share insights and lessons learned from treating other infectious diseases, identify opportunities for public-private partnerships, and assist the research community in designing and developing antiviral therapeutics. This report includes an overview of therapeutic approaches, individual panel summaries, and a summary of the discussions and perspectives on the challenges ahead for antiviral development.


Assuntos
Antivirais/uso terapêutico , Tratamento Farmacológico da COVID-19 , SARS-CoV-2/efeitos dos fármacos , Antivirais/farmacologia , COVID-19/virologia , Desenvolvimento de Medicamentos , Humanos , National Institutes of Health (U.S.) , Peptídeo Hidrolases/metabolismo , Inibidores de Proteases/farmacologia , Inibidores de Proteases/uso terapêutico , Estados Unidos , Replicação Viral/efeitos dos fármacos
10.
Cell Host Microbe ; 28(5): 638-645, 2020 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-33152278

RESUMO

When SARS-CoV-2 emerged at the end of 2019, no approved therapeutics or vaccines were available. An urgent need for countermeasures during this crisis challenges the current paradigm of traditional drug discovery and development, which usually takes years from start to finish. Approaches that accelerate this process need to be considered. Here we propose the minimum data package required to move a compound into clinical development safely. We further define the additional data that should be collected in parallel without impacting the rapid path to clinical development. Accelerated paths for antivirals, immunomodulators, anticoagulants, and other agents have been developed and can serve as "roadmaps" to support prioritization of compounds for clinical testing. These accelerated paths are fueled by a skewed risk-benefit ratio and are necessary to advance therapeutic agents into human trials rapidly and safely for COVID-19. Such paths are adaptable to other potential future pandemics.


Assuntos
Antivirais , Betacoronavirus , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Vacinas , Antivirais/uso terapêutico , COVID-19 , Humanos , SARS-CoV-2
11.
J Hepatol ; 73(1): 40-51, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32087349

RESUMO

BACKGROUND & AIMS: Covalently closed circular DNA (cccDNA) is the episomal form of the HBV genome that stably resides in the nucleus of infected hepatocytes. cccDNA is the template for the transcription of 6 major viral RNAs, i.e. preC, pg, preS1/2, S and HBx RNA. All viral transcripts share the same 3' end and are all to various degrees subsets of each other. Especially under infection conditions, it has been difficult to study in depth the transcription of the different viral transcripts. We thus wanted to develop a method with which we could easily detect the full spectrum of viral RNAs in any lab. METHODS: We set up an HBV full-length 5'RACE (rapid amplification of cDNA ends) method with which we measured and characterized the full spectrum of viral RNAs in cell culture and in chronically infected patients. RESULTS: In addition to canonical HBx transcripts coding for full-length X, we identified shorter HBx transcripts potentially coding for short X proteins. We showed that interferon-ß treatment leads to a strong reduction of preC and pgRNAs but has only a moderate effect on the other viral transcripts. We found pgRNA, 1 spliced pgRNA variant and a variety of HBx transcripts associated with viral particles generated by HepAD38 cells. The different HBx RNAs are both capped and uncapped. Lastly, we identified 3 major categories of circulating RNA species in patients with chronic HBV infection: pgRNA, spliced pgRNA variants and HBx. CONCLUSIONS: This HBV full-length 5'RACE method should significantly contribute to the understanding of HBV transcription during the course of infection and therapy and may guide the development of novel therapies aimed at targeting cccDNA. LAY SUMMARY: Especially under infection conditions, it has been difficult to study the different hepatitis B virus transcripts in depth. This study introduces a new method that can be used in any standard lab to discriminate all hepatitis B viral transcripts in cell culture and in the serum of patients.


Assuntos
Vírus da Hepatite B , Hepatite B , Hepatócitos/virologia , Técnicas de Amplificação de Ácido Nucleico/métodos , DNA Viral/análise , Perfilação da Expressão Gênica/métodos , Hepatite B/sangue , Hepatite B/patologia , Hepatite B/virologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Humanos , Transcriptoma
12.
Antiviral Res ; 171: 104592, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31473342

RESUMO

Filoviridae currently includes five official and one proposed genera. Genus Ebolavirus includes five established and one proposed ebolavirus species for Bombali virus (BOMV), Bundibugyo virus (BDBV), Ebola virus (EBOV), Reston virus (RESTV), Sudan virus (SUDV) and Taï Forest virus (TAFV), and genus Marburgvirus includes a single species for Marburg virus (MARV) and Ravn virus (RAVV). Ebola virus (EBOV) has emerged as a significant public health concern since the 2013-2016 Ebola Virus Disease outbreak in Western Africa. Currently, there are no therapeutics approved and the need for Ebola-specific therapeutics remains a gap. In search for anti-Ebola therapies we tested the idea of using inhibitory properties of peptides corresponding to the C-terminal heptad-repeat (HR2) domains of class I fusion proteins against EBOV infection. The fusion protein GP2 of EBOV belongs to class I, suggesting that a similar strategy to HIV may be applied to inhibit EBOV infection. The serum half-life of peptides was expanded by cholesterol conjugation to allow daily dosing. The peptides were further constrained to stabilize a helical structure to increase the potency of inhibition. The EC50s of lead peptides were in low micromolar range, as determined by a high-content imaging test of EBOV-infected cells. Lead peptides were tested in an EBOV lethal mouse model and efficacy of the peptides were determined following twice-daily administration of peptides for 9 days. The most potent peptide was able to protect mice from lethal challenge of mouse-adapted Ebola virus. These data show that engineered peptides coupled with cholesterol can inhibit viral production, protect mice against lethal EBOV infection, and may be used to build novel therapeutics against EBOV.


Assuntos
Antivirais/farmacologia , Ebolavirus/efeitos dos fármacos , Marburgvirus/efeitos dos fármacos , Peptídeos/farmacologia , Sequência de Aminoácidos , Animais , Antivirais/química , Linhagem Celular , Colesterol/química , Modelos Animais de Doenças , Doença pelo Vírus Ebola/virologia , Doença do Vírus de Marburg/virologia , Camundongos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Peptídeos/química , Conformação Proteica , Relação Estrutura-Atividade
13.
Antiviral Res ; 158: 88-102, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30086336

RESUMO

The 31st International Conference on Antiviral Research (ICAR) was held in Porto, Portugal from June 11-15, 2018. In this report, volunteer rapporteurs provide their summaries of scientific presentations, hoping to effectively convey the speakers' goals and the results and conclusions of their talks. This report provides an overview of the invited keynote and award lectures and highlights of short oral presentations, from the perspective of experts in antiviral research. Of note, a session on human cytomegalovirus included an update on the introduction to the clinic of letermovir for the prevention of CMV infection and disease. The 31st ICAR successfully promoted new discoveries in antiviral research and drug development. The 32nd ICAR will be held in Baltimore, Maryland, USA, May 6-10, 2019.


Assuntos
Antivirais/uso terapêutico , Antivirais/farmacologia , Distinções e Prêmios , Descoberta de Drogas , Humanos , Portugal , Pesquisa
14.
Antiviral Res ; 145: 184-196, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28774800

RESUMO

The 30th International Conference on Antiviral Research (ICAR) was held in Atlanta, GA, USA from May 18 to 21, 2017. This report provides an account of award lectures, invited keynote addresses and oral presentations during the meeting. The 2017 Gertrude Elion Memorial Lecture Award by Michael Sofia highlighted one of the most important accomplishments in recent drug discovery in antiviral research, the identification of the hepatitis C virus direct-acting antiviral sofosbuvir and new alternatives to combat hepatitis B virus (HBV) infection. The Antonín Holý Lecture Award by David Chu on medicinal chemistry provided an overview of early developments of nucleoside analogs for the treatment of HIV and varicella zoster virus infection and how this knowledge serves to develop new drugs targeting HBV. Priscilla Yang gave the first ISAR Women in Science lecture. She reported on pharmacological validation of new antiviral targets for dengue, Zika and other flaviviruses. The William Prusoff Young Investigator Lecture Award by Maaike Everts described the Alabama Drug Discovery Alliance and the Antiviral Drug Discovery and Development Consortium, and how they are helping to accelerate the development of new antivirals. The 30th ICAR was a success in promoting new discoveries in antiviral drug development and research. The 31st ICAR will be held in Porto, Portugal, June 11-15, 2018.


Assuntos
Antivirais , Química Farmacêutica , Descoberta de Drogas , Dengue/tratamento farmacológico , Hepatite B/tratamento farmacológico , Humanos , Infecção por Zika virus/tratamento farmacológico
15.
PLoS Negl Trop Dis ; 11(6): e0005637, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28628616

RESUMO

Chikungunya virus (CHIKV) is a mosquito-borne virus that causes a febrile syndrome in humans associated with acute and chronic debilitating joint and muscle pain. Currently no licensed vaccines or therapeutics are available to prevent or treat CHIKV infections. We recently isolated a panel of potently neutralizing human monoclonal antibodies (mAbs), one (4N12) of which exhibited prophylactic and post-exposure therapeutic activity against CHIKV in immunocompromised mice. Here, we describe the development of an engineered CHIKV mAb, designated SVIR001, that has similar antigen binding and neutralization profiles to its parent, 4N12. Because therapeutic administration of SVIR001 in immunocompetent mice significantly reduced viral load in joint tissues, we evaluated its efficacy in a rhesus macaque model of CHIKV infection. Rhesus macaques that were treated after infection with SVIR001 showed rapid elimination of viremia and less severe joint infiltration and disease compared to animals treated with SVIR002, an isotype control mAb. SVIR001 reduced viral burden at the site of infection and at distant sites and also diminished the numbers of activated innate immune cells and levels of pro-inflammatory cytokines and chemokines. SVIR001 therapy; however, did not substantively reduce the induction of CHIKV-specific B or T cell responses. Collectively, these results show promising therapeutic activity of a human anti-CHIKV mAb in rhesus macaques and provide proof-of-principle for its possible use in humans to treat active CHIKV infections.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Antivirais/administração & dosagem , Febre de Chikungunya/terapia , Fatores Imunológicos/administração & dosagem , Animais , Linfócitos B/imunologia , Febre de Chikungunya/patologia , Vírus Chikungunya/imunologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Macaca mulatta , Linfócitos T/imunologia , Resultado do Tratamento
16.
PLoS One ; 7(3): e33823, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22457791

RESUMO

Increased metabolism is a requirement for tumor cell proliferation. To understand the dependence of tumor cells on fatty acid metabolism, we evaluated various nodes of the fatty acid synthesis pathway. Using RNAi we have demonstrated that depletion of fatty-acid synthesis pathway enzymes SCD1, FASN, or ACC1 in HCT116 colon cancer cells results in cytotoxicity that is reversible by addition of exogenous fatty acids. This conditional phenotype is most pronounced when SCD1 is depleted. We used this fatty-acid rescue strategy to characterize several small-molecule inhibitors of fatty acid synthesis, including identification of TOFA as a potent SCD1 inhibitor, representing a previously undescribed activity for this compound. Reference FASN and ACC inhibitors show cytotoxicity that is less pronounced than that of TOFA, and fatty-acid rescue profiles consistent with their proposed enzyme targets. Two reference SCD1 inhibitors show low-nanomolar cytotoxicity that is offset by at least two orders of magnitude by exogenous oleate. One of these inhibitors slows growth of HCT116 xenograft tumors. Our data outline an effective strategy for interrogation of on-mechanism potency and pathway-node-specificity of fatty acid synthesis inhibitors, establish an unambiguous link between fatty acid synthesis and cancer cell survival, and point toward SCD1 as a key target in this pathway.


Assuntos
Apoptose/fisiologia , Ácidos Graxos Monoinsaturados/metabolismo , Neoplasias/patologia , Estearoil-CoA Dessaturase/antagonistas & inibidores , Linhagem Celular Tumoral , Humanos , Estearoil-CoA Dessaturase/fisiologia
17.
Int J Oncol ; 38(3): 701-11, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21186402

RESUMO

Glucosylceramide synthase (GCS) is a key enzyme engaged in the biosynthesis of glycosphingolipids and in regulating ceramide metabolism. Studies exploring alterations in GCS activity suggest that the glycolase may have a role in chemosensitizing tumor cells to various cancer drugs. The chemosensitizing effect of inhibitors of GCS (e.g. PDMP and selected analogues) has been observed with a variety of tumor cells leading to the proposal that the sensitizing activity of GCS inhibitors is primarily through increases in intracellular ceramide leading to induction of apoptosis. The current study examined the chemosensitizing activity of the novel GCS inhibitor, Genz-123346 in cell culture. Exposure of cells to Genz-123346 and to other GCS inhibitors at non-toxic concentrations can enhance the killing of tumor cells by cytotoxic anti-cancer agents. This activity was unrelated to lowering intracellular glycosphingolipid levels. Genz-123346 and a few other GCS inhibitors are substrates for multi-drug resistance efflux pumps such as P-gp (ABCB1, gP-170). In cell lines selected to over-express P-gp or which endogenously express P-gp, chemosensitization by Genz-123346 was primarily due to the effects on P-gp function. RNA interference studies using siRNA or shRNA confirmed that lowering GCS expression in tumor cells did not affect their responsiveness to commonly used cytotoxic drugs.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dioxanos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glucosiltransferases/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Pirrolidinas/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Dioxanos/administração & dosagem , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacologia , Avaliação Pré-Clínica de Medicamentos , Resistencia a Medicamentos Antineoplásicos/genética , Sinergismo Farmacológico , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Pirrolidinas/administração & dosagem , RNA Interferente Pequeno/farmacologia , Células Tumorais Cultivadas
18.
Exp Cell Res ; 316(2): 258-71, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19732767

RESUMO

The PSMD14 (POH1, also known as Rpn11/MPR1/S13/CepP1) protein within the 19S complex (19S cap; PA700) is responsible for substrate deubiquitination during proteasomal degradation. The role of PSMD14 in cell proliferation and senescence was explored using siRNA knockdown in carcinoma cell lines. Our results reveal that down-regulation of PSMD14 by siRNA transfection had a considerable impact on cell viability causing cell arrest in the G0-G1 phase, ultimately leading to senescence. The molecular events associated with decreased cell proliferation, cell cycle arrest and senescence include down-regulation of cyclin B1-CDK1-CDC25C, down-regulation of cyclin D1 and up-regulation of p21(/Cip) and p27(/Kip1). Most notably, phosphorylation of the retinoblastoma protein was markedly reduced in PSMD14 knockdown cells. A comparative study with PSMB5, a subunit of the 20S proteasome, revealed that PSMB5 and PSMD14 have different effects on cell cycle, senescence and associated molecular events. These data support the view that the 19S and 20S subunits of the proteasome have distinct biological functions and imply that targeting 19S and 20S would have distinct molecular consequences on tumor cells.


Assuntos
Ciclo Celular/genética , Senescência Celular/genética , Complexo de Endopeptidases do Proteassoma/deficiência , Transativadores/deficiência , Proteína Quinase CDC2/genética , Proteína Quinase CDC2/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/genética , Ciclina B1/genética , Ciclina B1/metabolismo , Ciclina D1/genética , Ciclina D1/metabolismo , Proteínas Inibidoras de Quinase Dependente de Ciclina/genética , Proteínas Inibidoras de Quinase Dependente de Ciclina/metabolismo , DNA/análise , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Fase G1/genética , Expressão Gênica/genética , Células HeLa , Humanos , Fosforilação/genética , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , RNA Interferente Pequeno/genética , Fase de Repouso do Ciclo Celular/genética , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Sulfotransferases/metabolismo , Transativadores/genética , Transativadores/metabolismo , Transfecção , Proteínas Ubiquitinadas/metabolismo , Regulação para Cima/genética , beta-Galactosidase/metabolismo , Fosfatases cdc25/genética , Fosfatases cdc25/metabolismo
19.
Virology ; 333(2): 201-6, 2005 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-15721354

RESUMO

Latent Epstein-Barr virus (EBV) infection is strongly associated with B-cell proliferative diseases such as Burkitt's lymphoma. Here we show that the oncogenic serine/threonine kinases Pim-1 and Pim-2 enhance the activity of the viral transcriptional activator EBNA2. During EBV infection of primary B-lymphocytes, the mRNA expression levels of pim genes, especially of pim-2, are upregulated and remain elevated in latently infected B-cell lines. Thus, EBV-induced upregulation of Pim kinases and Pim-stimulated EBNA2 transcriptional activity may contribute to the ability of EBV to immortalize B-cells and predispose them to malignant growth.


Assuntos
Infecções por Vírus Epstein-Barr/enzimologia , Infecções por Vírus Epstein-Barr/genética , Antígenos Nucleares do Vírus Epstein-Barr/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Linfócitos B/enzimologia , Linfócitos B/virologia , Sequência de Bases , Linhagem Celular , DNA/genética , Endonucleases , Infecções por Vírus Epstein-Barr/etiologia , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Herpesvirus Humano 4/patogenicidade , Humanos , Proteínas Nucleares/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-pim-1 , Ativação Transcricional , Regulação para Cima , Proteínas Virais
20.
J Virol ; 78(8): 4108-19, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15047827

RESUMO

Epstein-Barr virus (EBV) latency III infection converts B lymphocytes into lymphoblastoid cell lines (LCLs) by expressing EBV nuclear and membrane proteins, EBNAs, and latent membrane proteins (LMPs), which regulate transcription through Notch and tumor necrosis factor receptor pathways. The role of NF-kappa B in LMP1 and overall EBV latency III transcriptional effects was investigated by treating LCLs with BAY11-7082 (BAY11). BAY11 rapidly and irreversibly inhibited NF-kappa B, decreased mitochondrial membrane potential, induced apoptosis, and altered LCL gene expression. BAY11 effects were similar to those of an NF-kappa B inhibitor, Delta N-I kappa B alpha, in effecting decreased JNK1 expression and in microarray analyses. More than 80% of array elements that decreased with Delta N-I kappa B alpha expression decreased with BAY11 treatment. Newly identified NF-kappa B-induced, LMP1-induced, and EBV-induced genes included pleckstrin, Jun-B, c-FLIP, CIP4, and I kappa B epsilon. Of 776 significantly changed array elements, 134 were fourfold upregulated in EBV latency III, and 74 were fourfold upregulated with LMP1 expression alone, whereas only 28 were more than fourfold downregulated by EBV latency III. EBV latency III-regulated gene products mediate cell migration (EBI2, CCR7, RGS1, RANTES, MIP1 alpha, MIP1 beta, CXCR5, and RGS13), antigen presentation (major histocompatibility complex proteins and JAW1), mitogen-activated protein kinase pathway (DUSP5 and p62Dok), and interferon (IFN) signaling (IFN-gamma R alpha, IRF-4, and STAT1). Comparison of EBV latency III LCL gene expression to immunoglobulin M (IgM)-stimulated B cells, germinal-center B cells, and germinal-center-derived lymphomas clustered LCLs with IgM-stimulated B cells separately from germinal-center cells or germinal-center lymphoma cells. Expression of IRF-2, AIM1, ASK1, SNF2L2, and components of IFN signaling pathways further distinguished EBV latency III-infected B cells from IgM-stimulated or germinal-center B cells.


Assuntos
Herpesvirus Humano 4/patogenicidade , NF-kappa B/fisiologia , Nitrilas , Sulfonas , Proteínas da Matriz Viral/genética , Apoptose/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Linfócitos B/virologia , Linhagem Celular , Sobrevivência Celular/fisiologia , Perfilação da Expressão Gênica , Genes Virais , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Humanos , Proteína Quinase 8 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/antagonistas & inibidores , Compostos Orgânicos/farmacologia , Transcrição Gênica , Latência Viral , Proteínas Quinases p38 Ativadas por Mitógeno
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