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1.
BMC Geriatr ; 23(1): 16, 2023 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-36631767

RESUMO

BACKGROUND: Nurse care managers (NCM) operate through care management programs to provide care for persons living with dementia (PLWD) and interact regularly with their family caregivers; however, most do not receive formal instruction in dementia care or caregiver support. CRESCENT (CaReEcoSystem primary Care Embedded demeNtia Treatment) is a telephone-based dementia care intervention adapted from the Care EcoSystem model designed to equip NCMs with these tools. For this study, we aimed to measure intervention fidelity and understand how dementia care training impacted NCMs' provision of dementia care management services during interactions with caregivers of PLWD. METHODS: We recruited 30 active NCMs; 15 were randomly assigned to receive training. For each nurse, we randomly selected 1-3 patients with a diagnosis of dementia in each nurse's care during January-June 2021 for a total of 54 medical charts. To assess training uptake and fidelity, we identified documentation by NCMs of CRESCENT protocol implementation in the medical records. To understand how the training impacted the amount and types of dementia care management services provided in interactions with family caregivers, we compared attention to key dementia topic areas between trained NCMs (intervention) and untrained NCMs (control). RESULTS: Within the trained group only, community resources for PLWD, followed by safety, medication reconciliation, and advanced care planning topic areas were addressed most frequently (> 30%), while behavior management was addressed least frequently (12%). Trained NCMs were more likely to document addressing aspects of caregiver wellbeing (p = 0.03), community resources (p = 0.002), and identification of behavior (p = 0.03) and safety issues (p = 0.02) compared to those without training. There was no difference between groups in the amount of care coordination provided (p = 0.64). CONCLUSION: Results from this study demonstrate that focused dementia care training enriches care conversations in important topic areas for PLWD and family caregivers. Future research will clarify how best to sustain and optimize high quality dementia care in care management programs with special attention to the NCM-family caregiver relationship. TRIAL NUMBER: NCT04556097.


Assuntos
Demência , Educação em Enfermagem , Humanos , Cuidadores/educação , Demência/diagnóstico , Demência/terapia , Ecossistema , Serviços de Saúde
3.
Proc Natl Acad Sci U S A ; 112(32): E4354-63, 2015 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-26195743

RESUMO

Recent advances in biosensing technologies present great potential for medical diagnostics, thus improving clinical decisions. However, creating a label-free general sensing platform capable of detecting multiple biotargets in various clinical specimens over a wide dynamic range, without lengthy sample-processing steps, remains a considerable challenge. In practice, these barriers prevent broad applications in clinics and at patients' homes. Here, we demonstrate the nanoplasmonic electrical field-enhanced resonating device (NE(2)RD), which addresses all these impediments on a single platform. The NE(2)RD employs an immunodetection assay to capture biotargets, and precisely measures spectral color changes by their wavelength and extinction intensity shifts in nanoparticles without prior sample labeling or preprocessing. We present through multiple examples, a label-free, quantitative, portable, multitarget platform by rapidly detecting various protein biomarkers, drugs, protein allergens, bacteria, eukaryotic cells, and distinct viruses. The linear dynamic range of NE(2)RD is five orders of magnitude broader than ELISA, with a sensitivity down to 400 fg/mL This range and sensitivity are achieved by self-assembling gold nanoparticles to generate hot spots on a 3D-oriented substrate for ultrasensitive measurements. We demonstrate that this precise platform handles multiple clinical samples such as whole blood, serum, and saliva without sample preprocessing under diverse conditions of temperature, pH, and ionic strength. The NE(2)RD's broad dynamic range, detection limit, and portability integrated with a disposable fluidic chip have broad applications, potentially enabling the transition toward precision medicine at the point-of-care or primary care settings and at patients' homes.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas e Procedimentos Diagnósticos/instrumentação , Eletricidade , Nanoestruturas/química , Linhagem Celular Tumoral , Coinfecção/diagnóstico , Meio Ambiente , Ensaio de Imunoadsorção Enzimática , Desenho de Equipamento , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Microfluídica , Concentração Osmolar , Reprodutibilidade dos Testes , Temperatura
4.
Chembiochem ; 15(9): 1317-24, 2014 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-24828915

RESUMO

Many biological experiments are not compatible with the use of immunofluorescence, genetically encoded fluorescent tags, or FRET-based reporters. Conjugation of existing kinase inhibitors to cell-permeable fluorophores can provide a generalized approach to develop fluorescent probes of intracellular kinases. Here, we report the development of a small molecule probe of Src through conjugation of BODIPY to two well-established dual Src-Abl kinase inhibitors, dasatinib and saracatinib. We show that this approach is not successful for saracatinib but that dasatinib-BODIPY largely retains the biological activity of its parent compound and can be used to monitor the presence of Src kinase in individual cells by flow cytometry. It can also be used to track the localization of Src by fixed and live-cell fluorescence microscopy. This strategy could enable generation of additional kinase-specific probes useful in systems not amenable to genetic manipulation or could be used together with fluorescent proteins to enable a multiplexed assay readout.


Assuntos
Compostos de Boro/química , Fluorescência , Sondas Moleculares/química , Quinases da Família src/química , Animais , Benzodioxóis/química , Benzodioxóis/farmacologia , Compostos de Boro/metabolismo , Compostos de Boro/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dasatinibe , Relação Dose-Resposta a Droga , Humanos , Camundongos , Microscopia de Fluorescência , Sondas Moleculares/metabolismo , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Quinazolinas/química , Quinazolinas/farmacologia , Relação Estrutura-Atividade , Tiazóis/química , Tiazóis/farmacologia , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismo
5.
J Eval Clin Pract ; 29(8): 1243-1246, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37593781

RESUMO

RATIONALE: The informal caregivers who provide unpaid support for persons living with dementia (PLWD) are often unprepared to appropriately manage symptoms and navigate health services to support themselves or the PLWD. AIM: To understand informal caregivers' perceived capabilities of handling dementia symptomology and perceived support from providers. METHODS: We identified and surveyed caregivers of primary care patients in the Mass General Brigham health system. We included a self-efficacy questionnaire to assess caregivers' ability and confidence in access to dementia care, symptom management, and provider support. RESULTS: Respondents indicated that although their provider had knowledge of dementia and memory care, they were least likely to agree (39.2%) that their provider helped them with these challenging symptoms. Those who live with the care recipient were least likely to receive advice about common symptoms (43.6%) and to access community services (63.8%), and in general felt moderately knowledgeable about the progression of the disease (47.9%). CONCLUSIONS: The findings imply that caregivers are aware of disease progression, dementia symptoms, and do not feel supported by their providers in managing care or accessing support services. There is opportunity to support informal caregivers in a primary care setting by appropriately uptraining providers in dementia care.


Assuntos
Cuidadores , Demência , Humanos , Demência/terapia , Serviços de Saúde , Atenção Primária à Saúde
6.
Health Aff (Millwood) ; 41(10): 1505-1512, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36190876

RESUMO

Pandemic-related disruptions in access to medical care services, along with elevated rates of comorbidity, increase the risk for severe illness and death from COVID-19 for people with disabilities. Analyzing data from the 2020 National Health Interview Survey, we examined the impact of the COVID-19 pandemic on adults' access to medical care services by presence and type of disability. Adults with disabilities, including in each disability category, experienced significant disparities in delayed and unmet need for medical care during the first year of the COVID-19 pandemic. Improving data collection on disabled Americans according to disability status and type of disability, designating people with disabilities as a Special Medically Underserved Population under the Public Health Services Act, and incorporating standardized disability data in electronic health record systems would inform policies, programs, and interventions to achieve equitable access to high-quality medical care services that meet the needs of all people with disabilities during the COVID-19 pandemic and beyond.


Assuntos
COVID-19 , Pessoas com Deficiência , Adulto , COVID-19/epidemiologia , Acessibilidade aos Serviços de Saúde , Humanos , Pandemias , Assistência ao Paciente , Estados Unidos/epidemiologia
7.
PLoS Pathog ; 5(2): e1000292, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19197360

RESUMO

The cytidine deaminases APOBEC3G and APOBEC3F exert anti-HIV-1 activity that is countered by the HIV-1 vif protein. Based on potential transcription factor binding sites in their putative promoters, we hypothesized that expression of APOBEC3G and APOBEC3F would vary with T helper lymphocyte differentiation. Naive CD4+ T lymphocytes were differentiated to T helper type 1 (Th1) and 2 (Th2) effector cells by expression of transcription factors Tbet and GATA3, respectively, as well as by cytokine polarization. APOBEC3G and APOBEC3F RNA levels, and APOBEC3G protein levels, were higher in Th1 than in Th2 cells. T cell receptor stimulation further increased APOBEC3G and APOBEC3F expression in Tbet- and control-transduced, but not in GATA3-transduced, cells. Neutralizing anti-interferon-gamma antibodies reduced both basal and T cell receptor-stimulated APOBEC3G and APOBEC3F expression in Tbet- and control-transduced cells. HIV-1 produced from Th1 cells had more virion APOBEC3G, and decreased infectivity, compared to virions produced from Th2 cells. These differences between Th1- and Th2-produced virions were greater for viruses lacking functional vif, but also seen with vif-positive viruses. Over-expression of APOBEC3G in Th2 cells decreased the infectivity of virions produced from Th2 cells, and reduction of APOBEC3G in Th1 cells increased infectivity of virions produced from Th1 cells, consistent with a causal role for APOBEC3G in the infectivity difference. These results indicate that APOBEC3G and APOBEC3F levels vary physiologically during CD4+ T lymphocyte differentiation, that interferon-gamma contributes to this modulation, and that this physiological regulation can cause changes in infectivity of progeny virions, even in the presence of HIV-1 vif.


Assuntos
Citidina Desaminase/genética , Regulação da Expressão Gênica , HIV-1/fisiologia , Células Th1/metabolismo , Células Th2/metabolismo , Desaminase APOBEC-3G , Citidina Desaminase/metabolismo , Citosina Desaminase/genética , Citosina Desaminase/metabolismo , Citometria de Fluxo , Fator de Transcrição GATA3/metabolismo , Humanos , Interferon gama/metabolismo , Células Th1/imunologia , Células Th1/virologia , Células Th2/imunologia , Células Th2/virologia , Fatores de Transcrição/metabolismo , Vírion/metabolismo , Produtos do Gene vif do Vírus da Imunodeficiência Humana/metabolismo
8.
J Virol ; 83(17): 8646-54, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19535442

RESUMO

Cytoplasmic APOBEC3G has been reported to block wild-type human immunodeficiency virus type 1 (HIV-1) infection in some primary cells. It is not known whether cytoplasmic APOBEC3G has residual activity in activated T cells, even though virion-packaged APOBEC3G does restrict HIV-1 in activated T cells. Because we found that APOBEC3G expression is greater in activated CD4(+) T-helper type 1 (Th1) lymphocytes than in T-helper type 2 (Th2) lymphocytes, we hypothesized that residual target cell restriction of incoming Vif-positive virions that lack APOBEC3G, if present, would be greater in Th1 than Th2 lymphocytes. Infection of activated Th1 cells with APOBEC3-negative virions did result in decreased amounts of early and late reverse transcription products and integrated virus relative to infection of activated Th2 cells. Two-long terminal repeat (2-LTR) circles, which are formed in the nucleus when reverse transcripts do not integrate, were increased after APOBEC3-negative virus infection of activated Th1 cells relative to infection of activated Th2 cells. In contrast, 2-LTR circle forms were decreased after infection of APOBEC3G-negative cells with APOBEC3G-containing virions relative to APOBEC3G-negative virions and with Th1 cell-produced virions relative to Th2 cell-produced virions. Increasing APOBEC3G in Th2 cells and decreasing APOBEC3G in Th1 cells modulated the target cell phenotypes, indicating causation by APOBEC3G. The comparison between activated Th1 and Th2 cells indicates that cytoplasmic APOBEC3G in activated Th1 cells partially restricts reverse transcription and integration of incoming Vif-positive, APOBEC3G-negative HIV-1. The differing effects of cytoplasmic and virion-packaged APOBEC3G on 2-LTR circle formation indicate a difference in their antiviral mechanisms.


Assuntos
Citidina Desaminase/imunologia , DNA Circular/genética , HIV-1/imunologia , HIV-1/fisiologia , Transcrição Reversa , Sequências Repetidas Terminais/genética , Células Th1/virologia , Células Th2/virologia , Replicação Viral , Desaminase APOBEC-3G , Núcleo Celular/virologia , HIV-1/genética , Humanos , Integração Viral
9.
Antiviral Res ; 139: 171-179, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28034743

RESUMO

We report here on an approach targeting the host reactive cysteinome to identify inhibitors of host factors required for the infectious cycle of Flaviviruses and other viruses. We used two parallel cellular phenotypic screens to identify a series of covalent inhibitors, exemplified by QL-XII-47, that are active against dengue virus. We show that the compounds effectively block viral protein expression and that this inhibition is associated with repression of downstream processes of the infectious cycle, and thus significantly contributes to the potent antiviral activity of these compounds. We demonstrate that QL-XII-47's antiviral activity requires selective, covalent modification of a host target by showing that the compound's antiviral activity is recapitulated when cells are preincubated with QL-XII-47 and then washed prior to viral infection and by showing that QL-XII-47R, a non-reactive analog, lacks antiviral activity at concentrations more than 20-fold higher than QL-XII-47's IC90. QL-XII-47's inhibition of Zika virus, West Nile virus, hepatitis C virus, and poliovirus further suggests that it acts via a target mediating inhibition of these other medically relevant viruses. These results demonstrate the utility of screens targeting the host reactive cysteinome for rapid identification of compounds with potent antiviral activity.


Assuntos
Antivirais/química , Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Descoberta de Drogas , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Antivirais/isolamento & purificação , Dengue/tratamento farmacológico , Dengue/virologia , Flavivirus/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Humanos , Replicação Viral/efeitos dos fármacos , Vírus do Nilo Ocidental/efeitos dos fármacos , Zika virus/efeitos dos fármacos
10.
J Pharm Pharmacol ; 57(1): 111-6, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15638999

RESUMO

NAD(P)H oxidase contributes to the pathogenesis of cancer and cardiovascular diseases such as hypertension, atherosclerosis, restenosis, cardiac hypertrophy and heart failure. Plumbagin, a plant-derived naphthoquinone, has been shown to exert anticarcinogenic and anti-atherosclerosis effects in animals. However, the molecular mechanisms underlying these effects remain unknown. It is possible that the beneficial effect of plumbagin is due to the inhibition of NAD(P)H oxidase. Human embryonic kidney 293 (HEK293) and brain tumour LN229 cells express mainly Nox-4, a renal NAD(P)H oxidase. We have examined the effect of plumbagin on Nox-4 activity in HEK293 and LN229 cells using lucigenin-dependent chemiluminescence assay. Plumbagin inhibited the activity of Nox-4 in a time- and dose-dependent manner in HEK293 and LN229 cells. Production of superoxide in HEK293 cells was inhibited by diphenyleneiodonium (DPI), a NAD(P)H oxidase inhibitor. The superoxide production in HEK293 cells was NADPH- and NADH-dependent indicating that the superoxide was generated by a NAD(P)H oxidase in HEK293 cells, but not by the redox-cycling of lucigenin. Furthermore, plumbagin inhibited the superoxide production in Nox-4 transfected COS-7 cells. These results indicated that plumbagin directly interacted with Nox-4 and inhibited its activity.


Assuntos
NADPH Oxidases/antagonistas & inibidores , Naftoquinonas/farmacologia , Plumbaginaceae/química , Animais , Neoplasias Encefálicas/metabolismo , Células COS , Linhagem Celular Tumoral , Chlorocebus aethiops , Inibidores Enzimáticos/farmacologia , Humanos , Neoplasias Renais/metabolismo , NAD/farmacologia , NADP/farmacologia , NADPH Oxidase 4 , NADPH Oxidases/biossíntese , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Oniocompostos/farmacologia , Transfecção
11.
Cancer Lett ; 177(2): 181-7, 2002 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-11825665

RESUMO

The activation of soluble guanylate cyclase by bradykinin and sodium nitroprusside (SNP), a direct activator of soluble guanylate cyclase, was evaluated in androgen-sensitive LNCaP and androgen-independent PC3 and DU145 prostate cancer cells. Bradykinin and SNP activated soluble guanylate cyclase in LNCaP cells, but not in PC3 and DU145 cells. Western blot analysis revealed that the bradykinin B2 receptor, Gqalpha, phospholipase Cgamma and endothelial nitric oxide synthase were expressed in LNCaP, PC3 and DU145 cells. However, both Western blotting and reverse transcriptase--polymerase chain reaction indicated that soluble guanylate cyclase was only expressed in LNCaP cells. These results demonstrate that the impaired bradykinin-soluble guanylate cyclase pathway in PC3 and DU145 cells is likely due to lack of expression of soluble guanylate cyclase.


Assuntos
Bradicinina/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Transdução de Sinais , Androgênios/metabolismo , Guanilato Ciclase/metabolismo , Humanos , Masculino , Neoplasias Hormônio-Dependentes/metabolismo , Guanilil Ciclase Solúvel , Células Tumorais Cultivadas
12.
J Pharm Pharmacol ; 55(11): 1539-45, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14713365

RESUMO

Oestrogen is known to exert both genomic and non-genomic effects on target tissues. Unlike the genomic effects, the identity of receptors mediating the non-genomic effects of oestrogen remains controversial. 17beta-estradiol has been shown to activate membrane-bound guanylate cyclase GC-A in PC12 cells in a non-genomic manner. To examine whether 17beta-estradiol exerts a similar effect in other cell types, we measured the effect of 17beta-estradiol and tamoxifen, an anti-oestrogen, on guanylate cyclase activity in porcine kidney proximal tubular LLC-PK1 cells. 17beta-estradiol increased cGMP levels in LLC-PK1 cells. Interestingly, addition of tamoxifen also increased cGMP levels in a concentration-dependent manner in LLC-PK1 cells. The effects of both 17beta-estradiol and tamoxifen on guanylate cyclase activity were not additive, suggesting that oestrogen and tamoxifen activate the same enzyme. Similar phenomena were also observed in LLC-PK1 cell membrane preparation. LLC-PK1 cells do not express membrane-bound guanylate cyclase GC-B and express low levels of membrane-bound guanylate cyclase GC-C. Tamoxifen inhibited the activation of GC-A by atrial natriuretic factor (ANF). However, it did not affect membrane-bound guanylate cyclase GC-C stimulated by guanylin or Escherichia coli heat-stable toxin STa. These results indicate that 17beta-estradiol and tamoxifen activate GC-A in LLC-PK1 cells. Thus, tamoxifen functions as an agonist rather than an antagonist for the membrane oestrogen receptor coupled to the activation of GC-A.


Assuntos
Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Guanilato Ciclase/efeitos dos fármacos , Tamoxifeno/farmacologia , Animais , Membrana Celular/efeitos dos fármacos , Células Cultivadas , GMP Cíclico/metabolismo , Ativação Enzimática/efeitos dos fármacos , Hormônios Gastrointestinais/farmacologia , Guanilato Ciclase/metabolismo , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/enzimologia , Peptídeos Natriuréticos , Peptídeos/farmacologia , Suínos
13.
J Pharm Pharmacol ; 55(3): 353-8, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12724041

RESUMO

Accumulated evidence suggests that quercetin, a dietary flavonoid, has beneficial effects in protection against cardiovascular diseases and in the inhibition of tumour growth. We have recently shown that antioxidants such as 17beta-estradiol, resveratrol, dithiothreitol and vitamin C activate membrane-bound guanylate cyclase GC-A, a receptor for atrial natriuretic factor (ANF). Since quercetin is a phytoestrogen and potent antioxidant, it is possible that it may activate GC-A or other guanylate cyclase isoforms. We examined whether quercetin activates GC-A or GC-B (the receptor for C-type natriuretic peptide, CNP) in PC12 and porcine kidney proximal tubular LLC-PK1 cells. The results showed that quercetin activated a guanylate cyclase isoform in both cell types. Quercetin inhibited CNP-stimulated GC-B activity, but had little effect on ANF-stimulated GC-A activity in PC12 cells, suggesting that quercetin mainly activates GC-B in PC12 cells. In contrast, CNP had no effect on guanylate cyclase activity in LLC-PK1 cells, indicating that GC-B is not expressed in LLC-PK1 cells. Furthermore, quercetin had a small effect on ANF-stimulated GC-A activity and had no effect on soluble guanylate cyclase activity in LLC-PK1 cells, suggesting that quercetin does not activate GC-A, GC-B or soluble guanylate cyclase in LLC-PK1 cells. However, quercetin did stimulate membrane-bound guanylate cyclase activity in LLC-PK1 cell membranes. These results indicate that quercetin activates the GC-B isoform in PC12 cells, but activates an unknown membrane-bound guanylate cyclase isoform in LLC-PK1 cells.


Assuntos
Estrogênios não Esteroides/farmacologia , Flavonoides/farmacologia , Guanilato Ciclase/metabolismo , Isoflavonas , Quercetina/farmacologia , Animais , Fator Natriurético Atrial/farmacologia , GMP Cíclico/biossíntese , Ativação Enzimática/efeitos dos fármacos , Isomerismo , Células LLC-PK1 , Membranas/efeitos dos fármacos , Membranas/enzimologia , Peptídeo Natriurético Tipo C/farmacologia , Células PC12 , Fitoestrógenos , Preparações de Plantas , Ratos , Suínos
14.
Cancers (Basel) ; 5(1): 281-95, 2013 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-24216708

RESUMO

The t(7;12)(q36;p13) translocation is a recurrent chromosome abnormality that involves the ETV6 gene on chromosome 12 and has been identified in 20-30% of infant patients with acute myeloid leukaemia (AML). The detection of t(7;12) rearrangements relies on the use of fluorescence in situ hybridization (FISH) because this translocation is hardly visible by chromosome banding methods. Furthermore, a fusion transcript HLXB9-ETV6 is found in approximately 50% of t(7;12) cases, making the reverse transcription PCR approach not an ideal screening method. Considering the report of few cases of variant translocations harbouring a cryptic t(7;12) rearrangement, we believe that the actual incidence of this abnormality is higher than reported to date. The clinical outcome of t(7;12) patients is believed to be poor, therefore an early and accurate diagnosis is important in the clinical management and treatment. In this study, we have designed and tested a novel three-colour FISH approach that enabled us not only to confirm the presence of the t(7;12) in a number of patients studied previously, but also to identify a cryptic t(7;12) as part of a complex rearrangement. This new approach has proven to be an efficient and reliable method to be used in the diagnostic setting.

15.
ACS Chem Biol ; 7(12): 2019-26, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-22999307

RESUMO

Many cellular factors are regulated via mechanisms affecting protein conformation, localization, and function that may be undetected by most commonly used RNA- and protein-based profiling methods that monitor steady-state gene expression. Mass-spectrometry-based chemoproteomic profiling provides alternatives for interrogating changes in the functional properties of proteins that occur in response to biological stimuli, such as viral infection. Taking dengue virus 2 (DV2) infection as a model system, we utilized reactive ATP- and ADP-acyl phosphates as chemical proteomic probes to detect changes in host kinase function that occur within the first hour of infection. The DNA-dependent protein kinase (DNA-PK) was discovered as a host enzyme with significantly elevated probe labeling within 60 min of DV2 infection. Increased probe labeling was associated with increased DNA-PK activity in nuclear lysates and localization of DNA-PK in nucleoli. These effects on DNA-PK were found to require a postfusion step of DV2 entry and were recapitulated by transfection of cells with RNA corresponding to stem loop B of the DV2 5' untranslated region. Upon investigation of the potential downstream consequences of these phenomena, we detected a modest but significant reduction in the interferon response induced by DV2 in cells partially depleted of the Ku80 subunit of DNA-PK. These findings identify changes in DNA-PK localization and activity as very early markers of DV2 infection. More broadly, these results highlight the utility of chemoproteomic profiling as a tool to detect changes in protein function associated with different cell states and that may occur on very short time scales.


Assuntos
Biomarcadores/metabolismo , Proteína Quinase Ativada por DNA/metabolismo , Dengue/enzimologia , Proteômica , Regiões 5' não Traduzidas , Western Blotting , Linhagem Celular , Humanos , Transdução de Sinais
17.
Virology ; 377(1): 49-53, 2008 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-18499212

RESUMO

The HIV-1 virion infectivity factor (Vif) is required during viral replication to inactivate the host cell anti-viral factor, APOBEC3G (A3G). Vif binds A3G and a Cullin5-ElonginBC E3 ubiquitin ligase complex which results in the proteasomal degradation of A3G. The Vif PPLP motif (amino acids 161-164) is essential for normal Vif function because mutations in this motif reduce the infectivity of virions produced in T-cells. In this report, we demonstrate that mutation of the Vif PPLP motif reduces Vif binding to A3G without affecting its interaction with ElonginC and Cullin5. We demonstrate that the failure of the Vif mutant to bind A3G resulted in A3G incorporation into assembling virions with loss of viral infectivity.


Assuntos
Citidina Desaminase/metabolismo , HIV-1/fisiologia , Produtos do Gene vif do Vírus da Imunodeficiência Humana/metabolismo , Desaminase APOBEC-3G , Motivos de Aminoácidos , Sequência de Aminoácidos , Sítios de Ligação/genética , Linhagem Celular , Proteínas Culina/química , Proteínas Culina/metabolismo , Citidina Desaminase/antagonistas & inibidores , Elonguina , Teste de Complementação Genética , HIV-1/genética , HIV-1/patogenicidade , Humanos , Complexos Multiproteicos , Mutação , Complexo de Endopeptidases do Proteassoma/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Virulência , Replicação Viral , Produtos do Gene vif do Vírus da Imunodeficiência Humana/química , Produtos do Gene vif do Vírus da Imunodeficiência Humana/genética
18.
Hypertension ; 41(5): 1136-42, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12695417

RESUMO

Cyclosporin A (CsA) is used to reduce transplant rejection rates. Chronic use, however, has a destructive toxic effect on the kidney, resulting in hypertension. In this study, we investigated the effects of CsA treatment on the bradykinin/soluble guanylate cyclase signaling cascade and the involvement of superoxide in LLC-PK1 porcine kidney proximal tubule cells. Treatment with 1 micromol/L CsA for 24 hours increased basal cGMP levels by 41%, whereas CsA inhibited bradykinin-stimulated cGMP production by 26%. Western blotting showed increased expression of eNOS, but no other protein in the bradykinin/soluble guanylate cyclase (sGC) pathway was affected. Using lucigenin-dependent chemiluminescence, we found that CsA treatment significantly increased superoxide production. Production of O2- was not significantly reduced by 10 micromol/L oxypurinol or 30 micromol/L ketoconazole. However, it was inhibited by the NADPH oxidase inhibitor diphenyleneiodonium chloride (10 micromol/L) as well as the O2- scavenger superoxide dismutase (SOD) (100 U). On treatment with 50 micromol/L quercetin, 10 mmol/L N-acetyl-cysteine, both antioxidants, as well as the O2- scavenger Tiron (10 mmol/L), concomitant with 1 micromol/L CsA for 24 hours the activation of cGMP production, was restored in combination with a reduction in O2-. Incubation with 100 micromol/L menadione, a reactive oxygen generator, and 10 nmol/L bradykinin showed similar effects on the level of cGMP as with CsA. CsA treatment was found to increase nitrotyrosine levels. These findings suggest that CsA activates a NADPH oxidase that releases O2- and disrupts the bradykinin/soluble guanylate cyclase pathway, probably by binding with NO to form peroxynitrite (ONOO-).


Assuntos
Bradicinina/farmacologia , Ciclosporina/farmacologia , Superóxidos/metabolismo , Tirosina/análogos & derivados , Sal Dissódico do Ácido 1,2-Di-Hidroxibenzeno-3,5 Dissulfônico/farmacologia , Acetilcisteína/farmacologia , Animais , Antioxidantes/farmacologia , Western Blotting , GMP Cíclico/metabolismo , Ativação Enzimática/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Proteínas de Ligação ao GTP/metabolismo , Guanilato Ciclase/metabolismo , Células LLC-PK1/efeitos dos fármacos , Células LLC-PK1/metabolismo , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/metabolismo , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo III , Oniocompostos/farmacologia , Fosfolipases/metabolismo , Quercetina/farmacologia , Receptor B2 da Bradicinina , Receptores da Bradicinina/metabolismo , Transdução de Sinais , Solubilidade , Superóxidos/antagonistas & inibidores , Suínos , Tirosina/metabolismo , Vitamina K 3/farmacologia
19.
Hypertension ; 44(6): 963-8, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15466660

RESUMO

Cyclophilin A (CypA), a receptor for the immunosuppressive agent cyclosporin A, is a cis-trans-peptidyl-prolyl isomerase (PPIase). It accelerates the cis-trans isomerization of prolyl-peptide bonds. CypA binds and regulates the activity of a variety of proteins. Atrial natriuretic factor (ANF) and its receptor membrane-bound guanylate cyclase-A (GC-A) are involved in the regulation of blood pressure. We examined whether CypA affects the activation of GC-A by ANF. The results showed that CypA associated with GC-A. Interestingly, binding of ANF to GC-A released CypA. Transfection of CypA inhibited ANF-stimulated GC-A activity, indicating that CypA functions as an endogenous inhibitor for GC-A activation. CypA also inhibits the activity of guanylate cyclase-C (GC-c), the catalytic domain of GC-A, indicating that CypA interacts with the catalytic domain of GC-A. In contrast, transfection of CypA R55A, a CypA mutant expressing low PPIase activity, did not significantly attenuate the activity of GC-c and the activation of GC-A. Inhibition of PPIase activity of CypA with cyclosporin A also blocks the inhibitory effect of CypA on GC-c activity. These results demonstrate that PPIase activity is required for CypA to inhibit GC-c activity and GC-A activation by ANF. Furthermore, mutation of Pro 822, 902, or 958 in GC-c abolished its activity. Therefore, it is likely that CypA binds to GC-A and catalyzes the cis-trans isomerization of Pro 822, 902, or 958, which keeps GC-A in the inactive state, and that binding of ANF to GC-A alters the conformation of the catalytic domain that releases CypA from GC-A leading to enzyme activation.


Assuntos
Fator Natriurético Atrial/fisiologia , Ciclofilina A/fisiologia , Guanilato Ciclase/antagonistas & inibidores , Receptores do Fator Natriurético Atrial/antagonistas & inibidores , Animais , Células COS , Domínio Catalítico , Chlorocebus aethiops , Ativação Enzimática , Guanilato Ciclase/fisiologia , Células LLC-PK1 , Peptidilprolil Isomerase/fisiologia , Prolina/metabolismo , Receptores do Fator Natriurético Atrial/fisiologia , Suínos , Transfecção
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