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1.
Alzheimers Res Ther ; 15(1): 179, 2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37849016

RESUMO

BACKGROUND: Current treatments for Alzheimer's disease (AD) have largely failed to yield significant therapeutic benefits. Novel approaches are desperately needed to help address this immense public health issue. Data suggests that early intervention at the first stages of mild cognitive impairment may have a greater chance for success. The calcineurin (CN)-Pin1 signaling cascade can be selectively targeted with tacrolimus (FK506), a highly specific, FDA-approved CN inhibitor used safely for > 20 years in solid organ transplant recipients. AD prevalence was significantly reduced in solid organ recipients treated with FK506. METHODS: Time release pellets were used to deliver constant FK506 dosage to APP/PS1 mice without deleterious manipulation or handling. Immunofluorescence, histology, molecular biology, and behavior were used to evaluate changes in AD pathology. RESULTS: FK506 can be safely and consistently delivered into juvenile APP/PS1 mice via time-release pellets to levels roughly seen in transplant patients, leading to the normalization of CN activity and reduction or elimination of AD pathologies including synapse loss, neuroinflammation, and cognitive impairment. Pin1 activity and function were rescued despite the continuing presence of high levels of transgenic Aß42. Indicators of neuroinflammation including Iba1 positivity and IL-6 production were also reduced to normal levels. Peripheral blood mononuclear cells (PBMC) obtained during treatment or splenocytes isolated at euthanasia activated normally after mitogens. CONCLUSIONS: Low-dose, constant FK506 can normalize CNS CN and Pin1 activity, suppress neuroinflammation, and attenuate AD-associated pathology without blocking peripheral IL-2 responses making repurposed FK506 a viable option for early, therapeutic intervention in AD.


Assuntos
Doença de Alzheimer , Animais , Humanos , Camundongos , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Precursor de Proteína beta-Amiloide/genética , Calcineurina/metabolismo , Modelos Animais de Doenças , Interleucina-2/imunologia , Interleucina-2/metabolismo , Leucócitos Mononucleares/patologia , Camundongos Transgênicos , Doenças Neuroinflamatórias , Fenótipo , Presenilina-1/genética , Linfócitos T/patologia , Tacrolimo/farmacologia , Tacrolimo/uso terapêutico
2.
Transpl Infect Dis ; 25(4): e14095, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37378536

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) continues to impact immunocompromised populations including solid organ transplant recipients (SOTRs). Monoclonal antibodies (mAbs) have shown effectiveness in reducing COVID-19-related hospitalizations and emergency department (ED) visits in SOTRs at different time frames in the COVID-19 pandemic; however, less data exist on the impact of mAbs for SOTRs across variant waves and with the advent of available COVID-19 vaccines. METHODS: This retrospective study included SOTR outpatients who tested positive for SARS-CoV-2 and received mAbs from December 2020 to February 2022 (n = 233); using in-house sequencing of clinical samples, we monitored the emergence of Alpha, Delta, and Omicron variants. The primary outcome was a composite of 29-day COVID-19-related hospitalizations and ED visits. Prespecified secondary outcomes included individual components of the primary endpoint; for patients requiring hospitalization post-mAb administration, we describe their inpatient treatment. RESULTS: A low percentage of SOTRs treated with mAb required hospitalization or an ED visit (14.6% overall); this did not differ across COVID-19 variants (p = .152). Hospitalization and ED visits did not significantly differ between abdominal and cardiothoracic SOTRs. For hospitalized patients, the majority received treatment with corticosteroids and few required intensive care unit (ICU) care. CONCLUSION: Among SOTR outpatients with mild or moderate COVID-19 symptoms, early administration of mAb minimizes the need for hospital care. For patients requiring hospitalization, corticosteroids were common but patients experienced low rates of oxygen supplementation and ICU care. Use of mAbs in SOTRs should be considered early in the disease when therapy is available.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Transplante de Órgãos , Humanos , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Transplante de Órgãos/efeitos adversos , Pandemias , Estudos Retrospectivos , SARS-CoV-2 , Transplantados
3.
Case Rep Infect Dis ; 2022: 6422861, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35873406

RESUMO

The bacterial genus Myroides, like other members of the Flavobacteriaceae family, consists of aerobic, non-motile, Gram-negative bacilli. Myroides spp. is considered predominantly opportunistic pathogens as, historically, most documented infections have been in immunocompromised individuals. Along with advancements in molecular assay testing, there are growing reports of clinically relevant Myroides spp. infections in immunocompetent individuals. These organisms display broad antimicrobial resistance, and while research into their mechanisms of resistance is progressing, genetic testing has revealed metallo-ß-lactamases present in their genome. The sporadic identification of Myroides spp. and ongoing clarification of resistance patterns make empiric treatment difficult. This report documents two cases of extensively drug-resistant Myroides odoratus isolated from critically ill but otherwise immunocompetent patients followed by a review of available literature on Myroides spp. antibiotic sensitivities. Our findings indicate that minocycline and moxifloxacin have the highest documented in vitro activity against Myroides spp.

4.
Occup Ther Int ; 2022: 2941655, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35241995

RESUMO

OBJECTIVE: The purpose of this study is to assess the effectiveness of the use of sensory garments for improving sleep in children with autism spectrum disorder. METHOD: Using a single-subject ABAB reversal design, the researchers evaluated the effectiveness of a sensory garment on sleep duration, sleep latency, and parental stress related to a child's sleep. Four children aged 4-10 participated. We measured sleep duration and sleep latency using the Garmin watches and parent-report sleep logs, parent stress using the Parenting Stress Index Short Form, and sleep behaviors using the Children's Sleep Habits Questionnaire. Results/Discussion. Data showed variable effects on sleep duration and latency across children. The oldest child with the hyposensitive sensory patterns experienced the greatest sleep improvements. All parents experienced stress from daily life, and some reported increased stress due to study participation. Future research is recommended to further investigate the effectiveness of sensory garments on sleep for children with ASD. Therapists are encouraged to evaluate children's development and sensory preferences prior to recommending sensory garments for sleep.


Assuntos
Transtorno do Espectro Autista , Terapia Ocupacional , Transtorno do Espectro Autista/terapia , Criança , Pré-Escolar , Vestuário , Humanos , Pais , Sono , Inquéritos e Questionários
5.
Case Rep Transplant ; 2021: 8667589, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34912585

RESUMO

Mucormycosis is caused by ubiquitous fungi and encompasses a variety of different opportunistic syndromes in humans that disproportionately affect immunocompromised patients. Mortality has been documented to range between 50 and 100%; however, location of infection greatly dictates likelihood of survival. Treatment of mucormycosis involves aggressive surgical intervention and combination therapy of antifungal agents. In solid organ transplant recipients, immunosuppressive agents used to prevent rejection of the transplanted organ pose additional obstacles in the treatment of invasive fungal infections. We report on 3 high models for end-stage liver disease (MELD-Na) score orthotopic liver transplant (OLT) recipients who all were diagnosed with Rhizopus spp. infections with positive, 1-year outcomes after aggressive, individualized treatment.

6.
Cells ; 10(2)2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33494375

RESUMO

Eosinophils become polarized in response to cytokines such IL-5 or eotaxin prior to directional migration. Polarization is preceded by F-actin assembly, but the mechanisms that regulate these events and how the shape change influences cell migration from the peripheral blood into the lung remain unclear. In this study, we show that the prolyl isomerase, Pin1, is required for IL-5-induced Eos polarization and migration. Co-immunoprecipitation and immunofluorescence analysis revealed that Pin1 directly interacts with members of Rho GTPase family. Mouse eosinophils lacking Pin1 or human cells treated with Pin1 inhibitors showed significantly reduced IL-5-induced GTPase activity and cofilin phosphorylation, resulting in reduced F-actin polymerization, cell polarization, and directional migration to chemokines. Our result suggests that Pin1 regulates cytoskeletal re-organization, eosinophil morphology, and cell migration through the modulation of Rho GTPase activity. Targeting Pin1 along with GTPases could provide a new approach to reduce pulmonary Eos accumulation during asthmatic exacerbations.


Assuntos
Movimento Celular , Polaridade Celular , Eosinófilos/citologia , Eosinófilos/metabolismo , Interleucina-5/metabolismo , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Fatores de Despolimerização de Actina/metabolismo , Actinas/metabolismo , Animais , Humanos , Camundongos Endogâmicos C57BL , Polimerização , Ligação Proteica , Transdução de Sinais , Proteínas rho de Ligação ao GTP/metabolismo
7.
Ther Adv Infect Dis ; 7: 2049936120959561, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33014363

RESUMO

OBJECTIVE: This single-center, retrospective, observational cohort study evaluates the appropriateness of the BioFire® FilmArray® Gastrointestinal (GI) multiplex PCR panel testing at a community-teaching hospital. METHODS: All adult, hospitalized patients at Prisma Health Richland Hospital with a documented GI multiplex PCR panel from 1 April 2015 through 28 February 2018 were included in the analysis. Inappropriate use of the GI panel was defined as a test obtained without documented diarrhea, greater than 2 days of hospitalization, redundant use with other diagnostic tests (e.g. Clostridioides difficile PCR), or laxative use in the preceding 48 h. Antibiotic use and host variables were compared between groups with positive and negative results. RESULTS: During the study period, 442 GI panels were obtained, among which 268 (61%) were deemed inappropriate. Primary reasons for inappropriate testing were lack of documented diarrhea (n = 92), greater than 2 days of hospitalization (n = 116), having a duplicate C. difficile PCR test ordered (n = 118), or laxative use in the 48 h before testing (n = 36). A total of 141 (32%) GI panels were positive. The most frequently identified pathogens were C. difficile (51.1%, n = 72), Enteropathogenic Escherichia coli (17.7%, n = 25), and Norovirus GI/GII (12.1%, n = 17). Patients with negative GI panel results were initiated on antibiotics significantly less frequently than those with positive GI panels (62.5% versus 80.2%, p < 0.00001). CONCLUSION: Stewardship opportunities exist to optimize the diagnostic application of the GI multiplex PCR panel.

8.
Int J Antimicrob Agents ; 56(5): 106158, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32919007

RESUMO

Ceftolozane/tazobactam (C/T), a novel antipseudomonal cephalosporin plus ß-lactamase inhibitor, is used in multidrug-resistant Gram-negative infections. Continuous infusion (CI) of C/T is an attractive concept for aiding in transitions of care and maximising the pharmacodynamics of cephalosporins (T>MIC). This was a single-centre retrospective analysis of CI C/T use in adults from December 2016 to June 2019 in the inpatient or outpatient setting. Safety and effectiveness were assessed. When therapeutic drug monitoring (TDM) was performed, area under the concentration-time curve (AUC) and target attainment were calculated. Summary statistics were used to describe the data. CI C/T was used in seven unique regimens over the 31-month evaluation period. Patient age ranged from 23-70 years and the indication was primarily for treatment of deep-seated infections caused by multidrug-resistant Pseudomonas aeruginosa. Four regimens (57%) were used for outpatient transitions of care. The typical dose was 6 g every 24 h, although a renally adjusted dose was used in two instances (29%). TDM was performed in four uses (57%) and target attainment was confirmed in each. Ceftolozane AUC ranged from 365.7-818.2 µg•(h/mL). All patients had positive outcomes with no significant adverse events. One patient developed acute gout flares. One patient had recurrent infection with C/T-resistant P. aeruginosa after ~3 months of reduced dose for suppression. CI C/T was successfully utilised for deep-seated infections in inpatient and outpatient settings. TDM confirmed that CI C/T achieved pharmacodynamic targets for the entire dosing interval, suggesting an effective alternative dosing regimen applicable across the continuum of care.


Assuntos
Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Tazobactam/uso terapêutico , Inibidores de beta-Lactamases/uso terapêutico , Adulto , Idoso , Área Sob a Curva , Combinação de Medicamentos , Monitoramento de Medicamentos , Humanos , Infusões Intravenosas , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
9.
ACS Chem Neurosci ; 9(6): 1233-1234, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29757603

RESUMO

Therapeutics to effectively treat Alzheimer's disease (AD) are lacking. In vitro, animal and human studies have implicated the excessive activation of the protein phosphatase calcineurin (CN) as an early step in the pathogenesis of AD. We discuss recent data showing that the prolyl isomerase Pin1 is suppressed by CN-mediated dephosphorylation induced by Aß42 signaling. Pin1 loss directly leads to the reductions in dendritic spines and synapses characteristic of early AD pathology. Pin1 activity, and synapse and dendritic spine numbers are rescued by FK506, a highly specific and United States Food and Drug Administration approved CN inhibitor. Solid organ transplant recipients chronically treated with FK506 showed much lower AD incidence than expected. As such, we suggest prospective clinical trials to determine if systemic FK506 can normalize CN activity in the brain, preserve Pin1 function and support synaptic health in early AD.


Assuntos
Doença de Alzheimer/terapia , Encéfalo/efeitos dos fármacos , Inibidores de Calcineurina/farmacologia , Espinhas Dendríticas/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Doença de Alzheimer/metabolismo , Animais , Encéfalo/metabolismo , Humanos , Tacrolimo/farmacologia
10.
Sci Signal ; 11(522)2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29559586

RESUMO

Early-stage Alzheimer's disease is characterized by the loss of dendritic spines in the neocortex of the brain. This phenomenon precedes tau pathology, plaque formation, and neurodegeneration and likely contributes to synaptic loss, memory impairment, and behavioral changes in patients. Studies suggest that dendritic spine loss is induced by soluble, multimeric amyloid-ß (Aß42), which, through postsynaptic signaling, activates the protein phosphatase calcineurin. We investigated how calcineurin caused spine pathology and found that the cis-trans prolyl isomerase Pin1 was a critical downstream target of Aß42-calcineurin signaling. In dendritic spines, Pin1 interacted with and was dephosphorylated by calcineurin, which rapidly suppressed its isomerase activity. Knockout of Pin1 or exposure to Aß42 induced the loss of mature dendritic spines, which was prevented by exogenous Pin1. The calcineurin inhibitor FK506 blocked dendritic spine loss in Aß42-treated wild-type cells but had no effect on Pin1-null neurons. These data implicate Pin1 in dendritic spine maintenance and synaptic loss in early Alzheimer's disease.


Assuntos
Peptídeos beta-Amiloides/farmacologia , Calcineurina/metabolismo , Espinhas Dendríticas/efeitos dos fármacos , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Inibidores de Calcineurina/farmacologia , Células Cultivadas , Espinhas Dendríticas/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peptidilprolil Isomerase de Interação com NIMA/genética , Fosforilação , Tacrolimo/farmacologia
11.
J Med Chem ; 61(8): 3516-3540, 2018 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-29526098

RESUMO

Dysregulated translation of mRNA plays a major role in tumorigenesis. Mitogen-activated protein kinase interacting kinases (MNK)1/2 are key regulators of mRNA translation integrating signals from oncogenic and immune signaling pathways through phosphorylation of eIF4E and other mRNA binding proteins. Modulation of these key effector proteins regulates mRNA, which controls tumor/stromal cell signaling. Compound 23 (eFT508), an exquisitely selective, potent dual MNK1/2 inhibitor, was designed to assess the potential for control of oncogene signaling at the level of mRNA translation. The crystal structure-guided design leverages stereoelectronic interactions unique to MNK culminating in a novel pyridone-aminal structure described for the first time in the kinase literature. Compound 23 has potent in vivo antitumor activity in models of diffuse large cell B-cell lymphoma and solid tumors, suggesting that controlling dysregulated translation has real therapeutic potential. Compound 23 is currently being evaluated in Phase 2 clinical trials in solid tumors and lymphoma. Compound 23 is the first highly selective dual MNK inhibitor targeting dysregulated translation being assessed clinically.


Assuntos
Antineoplásicos/uso terapêutico , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Piridinas/uso terapêutico , Piridonas/uso terapêutico , Pirimidinas/uso terapêutico , Compostos de Espiro/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Domínio Catalítico , Linhagem Celular Tumoral , Desenho de Fármacos , Fator de Iniciação 4E em Eucariotos/química , Fator de Iniciação 4E em Eucariotos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Estrutura Molecular , Fosforilação , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Piridinas/síntese química , Piridinas/química , Piridinas/farmacologia , Piridonas/síntese química , Piridonas/química , Piridonas/farmacologia , Pirimidinas/síntese química , Pirimidinas/química , Pirimidinas/farmacologia , Ratos , Serina/química , Transdução de Sinais/efeitos dos fármacos , Compostos de Espiro/síntese química , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Genes Dev ; 27(22): 2433-8, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24240233

RESUMO

We examined how a p53 enhancer transmits regulatory information in vivo. Using genetic ablation together with digital chromosome conformation capture and fluorescent in situ hybridization, we found that a Drosophila p53 enhancer region (referred to as the p53 response element [p53RE]) physically contacts targets in cis and across the centromere to control stress-responsive transcription at these sites. Furthermore, when placed at ectopic genomic positions, fragments spanning this element re-established chromatin contacts and partially restored target gene regulation to mutants lacking the native p53RE. Therefore, a defined p53 enhancer region is sufficient for long-range chromatin interactions that enable multigenic regulation.


Assuntos
Cromatina/química , Cromatina/metabolismo , Drosophila/genética , Drosophila/metabolismo , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica , Proteína Supressora de Tumor p53/genética , Animais , Centrômero/metabolismo , Ligação Proteica , Estresse Fisiológico/genética , Proteína Supressora de Tumor p53/metabolismo
13.
J Biomol Screen ; 18(6): 688-94, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23407365

RESUMO

Pesticides currently in widespread use often lack species specificity and also become less effective as resistance emerges. Consequently, there is a pressing need to develop novel agents that are narrowly targeted and safe to humans. A cell-based screening platform was designed to discover compounds that are lethal to mosquito (Anopheles and Aedes) cells but show little or no activity against other insect (Drosophila) or human cell lines. Mosquito-specific, aqueous-stable cytotoxins were recovered at rare frequencies. Three of these were profiled for structure-activity relationships and also assessed in whole-animal toxicity assays. In at least one test case, species-specific cytotoxicity seen in culture effectively translated to the whole-animal level, with potent toxicity against Anopheles yet none against Drosophila. Therefore, this initiative has the potential to advance novel mosquitocidal agents and, in a broader sense, could establish a versatile platform for developing customized pesticides that selectively target other disease vectors as well.


Assuntos
Aedes/efeitos dos fármacos , Anopheles/efeitos dos fármacos , Citotoxinas/farmacologia , Praguicidas/farmacologia , Aedes/metabolismo , Animais , Anopheles/metabolismo , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos/métodos , Insetos Vetores/efeitos dos fármacos , Insetos Vetores/metabolismo , Especificidade da Espécie , Relação Estrutura-Atividade
14.
Environ Entomol ; 38(5): 1373-8, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19825291

RESUMO

Several sibling species of the leaf beetle Diorhabda elongata (Brullé) have been introduced into North America for the biocontrol of saltcedars (Tamarix spp.), but only one, D. carinulata (Desbrochers), has been extensively used in the field. The first open releases took place in 2001, and widespread defoliation occurred at sites infested by Tamarix ramosissima, T. chinensis, and their hybrid forms. The beetles failed, however, to establish at sites where other Tamarix species are targeted for control. In this study, we compared the preference and performance of three Diorhabda sibling species using adult choice and larval performance experiments on the two formally targeted Tamarix species: T. ramosissima and T. parviflora. In the adult choice experiment, a greater proportion of D. carinulata was found on T. ramosissima than on T. parviflora. For the other two sibling species, D. elongata (Brullé) and D. carinata (Faldermann), adults were found in similar proportions on the two host plants. In the larval performance experiment, larval growth and survival did not differ between Tamarix species for any Diorhabda type; however, D. carinata larval biomass was 35-50% greater than the other beetles regardless of host species. Based on the few adults of D. carinulata found on T. parviflora in the adult choice experiment, we do not recommend introducing this beetle at sites where T. parviflora is targeted for biological control. The species D. carinata seems especially promising for future release because its larvae gained substantially more biomass than the other beetles during the same time period on both Tamarix species.


Assuntos
Besouros/fisiologia , Tamaricaceae/fisiologia , Animais , Biomassa , Besouros/crescimento & desenvolvimento , Comportamento Alimentar , Larva/crescimento & desenvolvimento , Larva/fisiologia , Controle Biológico de Vetores , Especificidade da Espécie
15.
Proc Natl Acad Sci U S A ; 106(26): 10666-71, 2009 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-19541645

RESUMO

The incidence of brain metastasis is rising and poses a severe clinical problem, as we lack effective therapies and knowledge of mechanisms that control metastatic growth in the brain. Here we demonstrate a crucial role for high-affinity tumor cell integrin alpha(v)beta(3) in brain metastatic growth and recruitment of blood vessels. Although alpha(v)beta(3) is frequently up-regulated in primary brain tumors and metastatic lesions of brain homing cancers, we show that it is the alpha(v)beta(3) activation state that is critical for brain lesion growth. Activated, but not non-activated, tumor cell alpha(v)beta(3) supports efficient brain metastatic growth through continuous up-regulation of vascular endothelial growth factor (VEGF) protein under normoxic conditions. In metastatic brain lesions carrying activated alpha(v)beta(3), VEGF expression is controlled at the post-transcriptional level and involves phosphorylation and inhibition of translational respressor 4E-binding protein (4E-BP1). In contrast, tumor cells with non-activated alpha(v)beta(3) depend on hypoxia for VEGF induction, resulting in reduced angiogenesis, tumor cell apoptosis, and inefficient intracranial growth. Importantly, the microenvironment critically influences the effects that activated tumor cell alpha(v)beta(3) exerts on tumor cell growth. Although it strongly promoted intracranial growth, the activation state of the receptor did not influence tumor growth in the mammary fat pad as a primary site. Thus, we identified a mechanism by which metastatic cells thrive in the brain microenvironment and use the high-affinity form of an adhesion receptor to grow and secure host support for proliferation. Targeting this molecular mechanism could prove valuable for the inhibition of brain metastasis.


Assuntos
Neoplasias Encefálicas/secundário , Integrina alfaVbeta3/metabolismo , Neoplasias Mamárias Experimentais/patologia , Neovascularização Patológica/patologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apoptose , Western Blotting , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Hipóxia , Marcação In Situ das Extremidades Cortadas , Integrina alfaVbeta3/genética , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/metabolismo , Camundongos , Camundongos SCID , Mutação , Transplante de Neoplasias , Fosfoproteínas/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Heterólogo , Carga Tumoral , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
16.
Mol Biosyst ; 4(11): 1116-25, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18931787

RESUMO

Recent analysis of a Gal4 mutant (Gap71) carrying three point mutations (S22D, K23Q and K25F) in its DNA-binding domain (DBD), has demonstrated that it cannot occupy GAL promoters efficiently in cells and that it is not mono-ubiquitylated, suggesting a functional link between this modification and stable DNA binding in cells. The mechanistic underpinning of this phenotype is that this protein is hypersensitive to a newly discovered activity of the proteasomal ATPases--their ability to actively dissociate transcription factor-DNA complexes after direct interaction with the activation domain. In this paper, we examine the roles of each of the three point mutations contained in Gap71 individually. These experiments have revealed that serine 22 is a site of phosphorylation in the Gal4 DBD and that lysine 23 is essential for S22 phosphorylation, possibly acting as part of the kinase recognition site. Mutation of either residue blocks Gal4 DBD phosphorylation, its subsequent ubiquitylation and compromises the ability of the activator to bind promoter DNA in vivo. These data represent the first report of an essential phosphorylation event that is critical for the activity of this paradigmatic transcription factor.


Assuntos
DNA/metabolismo , Regiões Promotoras Genéticas , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo , Sítios de Ligação , Proteínas de Ligação a DNA , Células HeLa , Humanos , Lisina/genética , Lisina/metabolismo , Modelos Moleculares , Fosforilação , Mutação Puntual , Estrutura Terciária de Proteína , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Serina/genética , Serina/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/genética , Ubiquitinação
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