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1.
iScience ; 27(5): 109814, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38746669

RESUMO

2'3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) is the endogenous agonist of STING; as such, cGAMP has powerful immunostimulatory activity, due to its capacity to stimulate type I interferon-mediated immunity. Recent evidence indicates that cancer cells, under certain conditions, can release cGAMP extracellularly, a phenomenon currently considered important for therapeutic responses and tumor rejection. Nonetheless, the mechanisms that regulate cGAMP activity in the extracellular environment are still largely unexplored. In this work, we collected evidence demonstrating that CD38 glycohydrolase can inhibit extracellular cGAMP activity through its direct binding. We firstly used different cell lines and clinical samples to demonstrate a link between CD38 and extracellular cGAMP activity; we then performed extensive in silico molecular modeling and cell-free biochemical assays to show a direct interaction between the catalytic pocket of CD38 and cGAMP. Altogether, our findings expand the current knowledge about the regulation of cGAMP activity.

2.
Pharmaceuticals (Basel) ; 16(8)2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37631045

RESUMO

Drug development in recent years is increasingly focused on developing personalized treatments based on blocking molecules selective for therapeutic targets specifically present in individual patients. In this perspective, the specificity of therapeutic targets and blocking agents plays a crucial role. Monoclonal antibodies (mAbs) and their surrogates are increasingly used in this context thanks to their ability to bind therapeutic targets and to inhibit their activity or to transport bioactive molecules into the compartments in which the targets are expressed. Small antibody-like molecules, such as Fabs, are often used in certain clinical settings where small size and better tissue penetration are required. In the wake of this research trend, we developed a murine mAb (3D1) neutralizing the activity of Nodal, an oncofetal protein that is attracting an ever-increasing interest as a selective therapeutic target for several cancer types. Here, we report the preparation of a recombinant Fab of 3D1 that has been humanized through a computational approach starting from the sequence of the murine antibody. The Fab has been expressed in bacterial cells (1 mg/L bacterial culture), biochemically characterized in terms of stability and binding properties by circular dichroism and bio-layer interferometry techniques and tested in vitro on Nodal-positive cancer cells.

3.
Int J Mol Sci ; 24(10)2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37239905

RESUMO

CD59 is an abundant immuno-regulatory human protein that protects cells from damage by inhibiting the complement system. CD59 inhibits the assembly of the Membrane Attack Complex (MAC), the bactericidal pore-forming toxin of the innate immune system. In addition, several pathogenic viruses, including HIV-1, escape complement-mediated virolysis by incorporating this complement inhibitor in their own viral envelope. This makes human pathogenic viruses, such as HIV-1, not neutralised by the complement in human fluids. CD59 is also overexpressed in several cancer cells to resist the complement attack. Consistent with its importance as a therapeutical target, CD59-targeting antibodies have been proven to be successful in hindering HIV-1 growth and counteracting the effect of complement inhibition by specific cancer cells. In this work, we make use of bioinformatics and computational tools to identify CD59 interactions with blocking antibodies and to describe molecular details of the paratope-epitope interface. Based on this information, we design and produce paratope-mimicking bicyclic peptides able to target CD59. Our results set the basis for the development of antibody-mimicking small molecules targeting CD59 with potential therapeutic interest as complement activators.


Assuntos
Proteínas do Sistema Complemento , HIV-1 , Humanos , Sítios de Ligação de Anticorpos , Proteínas do Sistema Complemento/metabolismo , Antígenos CD59/metabolismo , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Inativadores do Complemento , HIV-1/fisiologia
4.
Rev Gastroenterol Peru ; 39(4): 367-369, 2019.
Artigo em Espanhol | MEDLINE | ID: mdl-32097399

RESUMO

Transarterial hepatic chemoembolization is one of the treatments of unresectable hepatocellular carcinoma in which associated ischemic lesions have been described infrequently. When unusual upper gastrointestinal symptoms or exceeding the so-called post-chemoembolization syndrome after the procedure, the performance of a gastroscopy should be assessed to rule out the occurrence of these complications. The anatomical variants with common origin of gastric and hepatic arteries can favor the migration of the microspheres into gastric territory, forcing the possible modification of the technique to prevent it.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/efeitos adversos , Neoplasias Hepáticas/terapia , Úlcera Péptica/etiologia , Idoso , Antibióticos Antineoplásicos/administração & dosagem , Quimioembolização Terapêutica/métodos , Doxorrubicina/administração & dosagem , Artéria Hepática , Humanos , Isquemia/complicações , Masculino
7.
Molecules ; 21(8)2016 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-27472308

RESUMO

Capsaicinoids are plant secondary metabolites, capsaicin being the principal responsible for the pungency of chili peppers. It is biosynthesized through two pathways involved in phenylpropanoid and fatty acid metabolism. Plant capsaicin concentration is mainly affected by genetic, environmental and crop management factors. However, its synthesis can be enhanced by the use of elicitors. Capsaicin is employed as food additive and in pharmaceutical applications. Additionally, it has been found that capsaicin can act as a cancer preventive agent and shows wide applications against various types of cancer. This review is an approach in contextualizing the use of controlled stress on the plant to increase the content of capsaicin, highlighting its synthesis and its potential use as anticancer agent.


Assuntos
Antineoplásicos Fitogênicos/metabolismo , Capsaicina/metabolismo , Capsicum/química , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Vias Biossintéticas , Capsaicina/administração & dosagem , Capsaicina/química , Capsaicina/farmacologia , Capsicum/metabolismo , Linhagem Celular Tumoral , Aditivos Alimentares/química , Aditivos Alimentares/metabolismo , Humanos , Estrutura Molecular
8.
Alzheimers Res Ther ; 7(1): 50, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26203303

RESUMO

INTRODUCTION: Because of its genetic underpinnings and consistent age of onset within families, autosomal dominant Alzheimer's disease (ADAD) provides a unique opportunity to conduct clinical trials of investigational agents as preventative or symptom-delaying treatments. The design of such trials may be complicated by low rates of genetic testing and disclosure among persons at risk of inheriting disease-causing mutations. METHODS: To better understand the attitudes toward genetic testing and clinical trials of persons at risk for ADAD, we surveyed participants in the Dominantly Inherited Alzheimer's Network (DIAN), a multisite longitudinal study of clinical and biomarker outcomes in ADAD that does not require learning genetic status to participate. RESULTS: Eighty participants completed a brief anonymous survey by mail or on-line; 40 % reported knowing if they carried a gene mutation, 15 % did not know but expressed a desire to learn their genetic status, and 45 % did not know and did not desire to know their genetic status. Among participants who knew or wished to know their genetic status, 86 % were interested in participating in a clinical trial. Seventy-two percent of participants who did not wish to learn their genetic status reported that they would change their mind, if learning that they carried a mutation gave them the opportunity to participate in a clinical trial. Nearly all participants responded that they would be interested if an open-label extension were offered. CONCLUSIONS: These results suggest that the availability of clinical trials to prevent ADAD can affect persons' desire to undergo genetic testing and that consideration can be given to performing studies in which such testing is required.

9.
JAMA Neurol ; 72(3): 325-32, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25622095

RESUMO

IMPORTANCE: This study assesses factors associated with the most common adverse event following lumbar puncture. OBJECTIVE: To identify factors associated with the risk, onset, and persistence of post-dural puncture headache (PDPH). DESIGN, SETTING, AND PARTICIPANTS: We performed univariate and multivariable analyses of 338 lumbar punctures in the Dominantly Inherited Alzheimer Network observational study using linear mixed models, adjusting for participant-level and family-level random effects. MAIN OUTCOMES AND MEASURES: We directly evaluated associations of 3 post-lumbar puncture outcomes (immediate postprocedural headache, PDPH at 24-hour follow-up, and PDPH receiving a therapeutic blood patch) with participant age and sex, positioning, collection method, needle size, needle insertion site, and cerebrospinal fluid (CSF) volume collected. RESULTS: The incidence of adverse events included 73 immediate postprocedural headaches (21.6%), 59 PDPHs at 24-hour follow-up (17.5%), and 15 PDPHs receiving a therapeutic blood patch (4.4%). Greater volume of CSF collected was associated with increased risk of immediate postprocedural headache, largely owing to a nonlinear increase in risk on collection of volumes above 30 mL (odds ratio, 3.73 for >30 mL and 0.98 for <17 mL). In contrast, collection of higher volumes showed a protective effect in decreasing rates of PDPH at 24-hour follow-up and rates of PDPH receiving a therapeutic blood patch (odds ratio, 0.35 per 10 mL). Although differences in needle size did not reach statistical significance, no participant in the 24G needle group received a therapeutic blood patch compared to 8 of 253 for the larger 22G needles. CONCLUSIONS AND RELEVANCE: Factors that acutely lower CSF pressure (eg, seated positioning or extracting very high volumes of CSF) may be associated with transient post-lumbar puncture headache, without increasing rates of persistent PDPH or therapeutic blood patch. Collection of up to 30 mL of CSF appears to be well tolerated and safe.


Assuntos
Placa de Sangue Epidural/tendências , Cefaleia Pós-Punção Dural/diagnóstico , Cefaleia Pós-Punção Dural/terapia , Punção Espinal/efeitos adversos , Punção Espinal/tendências , Adulto , Feminino , Seguimentos , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Cefaleia Pós-Punção Dural/etiologia , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
11.
JAMA Neurol ; 71(9): 1111-22, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25069482

RESUMO

IMPORTANCE: Autosomal dominant Alzheimer disease (ADAD) is caused by rare genetic mutations in 3 specific genes in contrast to late-onset Alzheimer disease (LOAD), which has a more polygenetic risk profile. OBJECTIVE: To assess the similarities and differences in functional connectivity changes owing to ADAD and LOAD. DESIGN, SETTING, AND PARTICIPANTS: We analyzed functional connectivity in multiple brain resting state networks (RSNs) in a cross-sectional cohort of participants with ADAD (n = 79) and LOAD (n = 444), using resting-state functional connectivity magnetic resonance imaging at multiple international academic sites. MAIN OUTCOMES AND MEASURES: For both types of AD, we quantified and compared functional connectivity changes in RSNs as a function of dementia severity measured by the Clinical Dementia Rating Scale. In ADAD, we qualitatively investigated functional connectivity changes with respect to estimated years from onset of symptoms within 5 RSNs. RESULTS: A decrease in functional connectivity with increasing Clinical Dementia Rating scores were similar for both LOAD and ADAD in multiple RSNs. Ordinal logistic regression models constructed in one type of Alzheimer disease accurately predicted clinical dementia rating scores in the other, further demonstrating the similarity of functional connectivity loss in each disease type. Among participants with ADAD, functional connectivity in multiple RSNs appeared qualitatively lower in asymptomatic mutation carriers near their anticipated age of symptom onset compared with asymptomatic mutation noncarriers. CONCLUSIONS AND RELEVANCE: Resting-state functional connectivity magnetic resonance imaging changes with progressing AD severity are similar between ADAD and LOAD. Resting-state functional connectivity magnetic resonance imaging may be a useful end point for LOAD and ADAD therapy trials. Moreover, the disease process of ADAD may be an effective model for the LOAD disease process.


Assuntos
Doença de Alzheimer/fisiopatologia , Conectoma/métodos , Rede Nervosa/fisiopatologia , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/classificação , Doença de Alzheimer/genética , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
12.
Int J Mol Sci ; 14(5): 10178-96, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23676352

RESUMO

Hydrogen peroxide (H2O2) is an important ROS molecule (Reactive oxygen species) that serves as a signal of oxidative stress and activation of signaling cascades as a result of the early response of the plant to biotic stress. This response can also be generated with the application of elicitors, stable molecules that induce the activation of transduction cascades and hormonal pathways, which trigger induced resistance to environmental stress. In this work, we evaluated the endogenous H2O2 production caused by salicylic acid (SA), chitosan (QN), and H2O2 elicitors in Capsicum annuum L. Hydrogen peroxide production after elicitation, catalase (CAT) and phenylalanine ammonia lyase (PAL) activities, as well as gene expression analysis of cat1, pal, and pathogenesis-related protein 1 (pr1) were determined. Our results displayed that 6.7 and 10 mM SA concentrations, and, 14 and 18 mM H2O2 concentrations, induced an endogenous H2O2 and gene expression. QN treatments induced the same responses in lesser proportion than the other two elicitors. Endogenous H2O2 production monitored during several days, showed results that could be an indicator for determining application opportunity uses in agriculture for maintaining plant alert systems against a stress.


Assuntos
Capsicum/efeitos dos fármacos , Quitosana/farmacologia , Peróxido de Hidrogênio/farmacologia , Folhas de Planta/efeitos dos fármacos , Ácido Salicílico/farmacologia , Capsicum/genética , Capsicum/metabolismo , Catalase/genética , Catalase/metabolismo , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Oxidantes/metabolismo , Oxidantes/farmacologia , Estresse Oxidativo , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
13.
Viruses ; 4(9): 1792-801, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23170183

RESUMO

The Geminiviruses genome is a small, single strand DNA that replicates in the plant cell nucleus. Analogous to animal DNA viruses, Geminiviruses depend on the host replication machinery to amplify their genomes and only supply the factors required to initiate their replication. Consequently, Geminiviruses remove the cell-cycle arrest and induce the host replication machinery using an endocycle process. They encode proteins, such as the conserved replication-associated proteins (Rep) that interact with retinoblastoma-like proteins in plants and alter the cell division cycle in yeasts. Therefore, the aim of this work is to analyze the impact of Pepper Golden Mosaic Virus (PepGMV) Rep protein in mammalian cells. Results indicate that the pTracer-SV40:Rep construction obtained in this work can be used to analyze the Rep protein effect in mammalian cells in order to compare the cell cycle regulation mechanisms in plants and animals.


Assuntos
Begomovirus/patogenicidade , Proteínas Virais/metabolismo , Replicação Viral , Animais , Ciclo Celular , Linhagem Celular , Fibroblastos/virologia , Camundongos , Proteínas Virais/genética
14.
Clin Investig (Lond) ; 2(10): 975-984, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23139856

RESUMO

The Dominantly Inherited Alzheimer Network (DIAN) is a collaborative effort of international Alzheimer disease (AD) centers that are conducting a multifaceted prospective biomarker study in individuals at-risk for autosomal dominant AD (ADAD). DIAN collects comprehensive information and tissue in accordance with standard protocols from asymptomatic and symptomatic ADAD mutation carriers and their non-carrier family members to determine the pathochronology of clinical, cognitive, neuroimaging, and fluid biomarkers of AD. This article describes the structure, implementation, and underlying principles of DIAN, as well as the demographic features of the initial DIAN cohort.

15.
N Engl J Med ; 367(9): 795-804, 2012 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-22784036

RESUMO

BACKGROUND: The order and magnitude of pathologic processes in Alzheimer's disease are not well understood, partly because the disease develops over many years. Autosomal dominant Alzheimer's disease has a predictable age at onset and provides an opportunity to determine the sequence and magnitude of pathologic changes that culminate in symptomatic disease. METHODS: In this prospective, longitudinal study, we analyzed data from 128 participants who underwent baseline clinical and cognitive assessments, brain imaging, and cerebrospinal fluid (CSF) and blood tests. We used the participant's age at baseline assessment and the parent's age at the onset of symptoms of Alzheimer's disease to calculate the estimated years from expected symptom onset (age of the participant minus parent's age at symptom onset). We conducted cross-sectional analyses of baseline data in relation to estimated years from expected symptom onset in order to determine the relative order and magnitude of pathophysiological changes. RESULTS: Concentrations of amyloid-beta (Aß)(42) in the CSF appeared to decline 25 years before expected symptom onset. Aß deposition, as measured by positron-emission tomography with the use of Pittsburgh compound B, was detected 15 years before expected symptom onset. Increased concentrations of tau protein in the CSF and an increase in brain atrophy were detected 15 years before expected symptom onset. Cerebral hypometabolism and impaired episodic memory were observed 10 years before expected symptom onset. Global cognitive impairment, as measured by the Mini-Mental State Examination and the Clinical Dementia Rating scale, was detected 5 years before expected symptom onset, and patients met diagnostic criteria for dementia at an average of 3 years after expected symptom onset. CONCLUSIONS: We found that autosomal dominant Alzheimer's disease was associated with a series of pathophysiological changes over decades in CSF biochemical markers of Alzheimer's disease, brain amyloid deposition, and brain metabolism as well as progressive cognitive impairment. Our results require confirmation with the use of longitudinal data and may not apply to patients with sporadic Alzheimer's disease. (Funded by the National Institute on Aging and others; DIAN ClinicalTrials.gov number, NCT00869817.).


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Líquido Cefalorraquidiano/metabolismo , Idade de Início , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Biomarcadores/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Estudos Transversais , Feminino , Genes Dominantes , Glucose/metabolismo , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mutação , Testes Neuropsicológicos
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