Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
Expert Rev Clin Immunol ; 20(6): 665-672, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38465507

RESUMO

BACKGROUND: Primary Raynaud's phenomenon (pRP) is difficult to distinguish from secondary (sRP). Although nailfold capillaroscopy (NFC) may detect early alterations, no universal criteria yet discriminate between pRP from sRP. OBJECTIVES: To create and validate two NFC scores that could distinguish pRP from sRP and that could predict systemic sclerosis (SSc), respectively. METHODS: We performed NFC on two separate cohorts with isolated RP, and recorded number of capillaries per field, enlarged/giant capillaries, crossed/bizarre patterns, microhemorrhages, neoangiogenesis, rarefaction, edema, blood flow velocity, stasis. By multivariate regression analysis, we evaluated the adjusted prognostic role of these features in a derivation cohort of 656 patients. Results were used to construct algorithm-based prognostic scores (A and B). These scores were then tested on a confirmation cohort of 219 patients. RESULTS: Score A was unable to discriminate sRP from pRP (low negative predictive values with high positive predictive values for any cut-point); score B was unable to discriminate progression to SSc or a SSc-spectrum disorder (low positive predictive values with high negative predictive values for lower cut-points). CONCLUSION: NFC patterns, believed as specific, showed low discriminatory power and on their own are unable to reliably discriminate sRP from pRP or predict evolution to SSc.


Assuntos
Angioscopia Microscópica , Doença de Raynaud , Escleroderma Sistêmico , Humanos , Doença de Raynaud/diagnóstico , Angioscopia Microscópica/métodos , Feminino , Escleroderma Sistêmico/diagnóstico , Pessoa de Meia-Idade , Masculino , Estudos Prospectivos , Adulto , Prognóstico , Estudos de Coortes , Idoso , Diagnóstico Diferencial , Capilares/diagnóstico por imagem , Capilares/patologia , Unhas/irrigação sanguínea , Unhas/patologia , Valor Preditivo dos Testes
2.
Environ Sci Pollut Res Int ; 30(13): 36405-36421, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36547826

RESUMO

This study characterized and investigated the toxicity of two multi-walled carbon nanotubes (MWCNT) NM-401 and NM-403 at 60 and 180 µg after four repeated intratracheal instillations; follow-up times were 3, 7, 30, and 90 days after the last instillation. NM-401 was needle-like, long, and thick, while NM-403 was entangled, short, and thin. Both MWCNT types induced transient pulmonary and systemic alterations in renal function and oxidative lipid damage markers in recent times. Animals showed general toxicity in the immediate times after exposures, in addition to increased pulmonary LDH release at day 3. In further times, decreased liver and kidney relative weights were noted at higher MWCNT doses. Lung histological damages included pulmonary fibrosis, for both MWCNT types, similarly to asbestos; single liver and kidney histological alterations were present. Repeated instillations led to persistent pulmonary damage at low doses, and possibly the extrapulmonary effects may be associated with the consecutive exposures.


Assuntos
Nanotubos de Carbono , Fibrose Pulmonar , Animais , Nanotubos de Carbono/toxicidade , Pulmão , Fibrose Pulmonar/patologia , Fatores de Tempo , Líquido da Lavagem Broncoalveolar
3.
Methods Mol Biol ; 2461: 19-41, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35727442

RESUMO

Protein engineering can enhance desirable features and improve performance outside of the natural context. Several strategies have been adopted over the years for gene diversification, and engineering of modular proteins in particular is most effective when a high-throughput, library-based approach is employed. Nondegenerate saturation mutagenesis plays a dynamic role in engineering proteins by targeting multiple codons to generate massively diverse gene libraries. Herein, we describe the nondegenerate saturation mutagenesis techniques that we have developed for contiguous (ProxiMAX) and noncontiguous (MAX) randomized codon generation to create precisely defined, diverse gene libraries, in the context of other fully nondegenerate strategies. ProxiMAX randomization comprises saturation cycling with repeated cycles of blunt-ended ligation, type IIS restriction, and PCR amplification, and is now a commercially automated process predominantly used for antibody library generation. MAX randomization encompasses a manual process of selective hybridisation between individual custom oligonucleotide mixes and a conventionally randomized template and is principally employed in the research laboratory setting, to engineer alpha helical proteins and active sites of enzymes. DNA libraries generated using either technology create high-throughput amino acid substitutions via codon randomization, to generate genetically diverse clones.


Assuntos
Engenharia de Proteínas , Proteínas , Códon/genética , Biblioteca Gênica , Mutagênese , Engenharia de Proteínas/métodos , Proteínas/química , Distribuição Aleatória
4.
Rheumatol Int ; 42(8): 1393-1402, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34480254

RESUMO

This study aimed at analysing the causes and predictors of acute hospitalization and mortality in a cohort of SSc. Retrospective analysis of all acute hospital admissions of SSc patients fulfilling the 2013 EULAR/ACR Classification Criteria, from a single-centre cohort of 95 patients, between 2010 and 2020. The total number of SSc patients registered in our hospital, in this period, was 123. Clinical data were collected from medical files of our institution and from the National Healthcare Registry platform. 53 patients needed acute hospitalization, in a total of 164 admissions. The most frequent causes for admission were: infectious diseases [27%; 70% due to pneumoniae, of which 74% had SSc-associated interstitial lung disease (ILD)], cardiac disease (16.5%), peripheral vascular disease [12.8%; all due to digital ulcers], pulmonary hypertension (PH) (9.8%) and ILD (9.1%). There was an increase in admissions due to cardiac disease over the 10 years of follow-up, and a decrease of ILD over the last 5 years. Fourteen patients died (in-hospital mortality of 9%) mainly due to pneumoniae (36%), heart failure (21%), neoplastic diseases (21%), PH (14%) and ILD (7%). From all the admissions due to infection 70.5% were under immunosuppression at the time of the hospitalization. The frequency of acute admissions superior to 1 was associated with infection (OR 2.29, 95%CI 1.11-4.71). There were several factors associated with both acute admissions and mortality, including: gender, race, digital ulcers, cardiac dysfunction, ILD and PH. Infection was the principal cause of acute hospitalization and mortality, mainly due to pneumoniae. Although a high percentage of those had ILD, it has been decreasing in the last years in our cohort, as a direct cause of hospital admission and mortality, possibly reflecting the advances in its management.


Assuntos
Cardiopatias , Hipertensão Pulmonar , Doenças Pulmonares Intersticiais , Escleroderma Sistêmico , Estudos de Coortes , Hospitalização , Humanos , Hipertensão Pulmonar/epidemiologia , Hipertensão Pulmonar/etiologia , Doenças Pulmonares Intersticiais/etiologia , Estudos Retrospectivos , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/epidemiologia , Úlcera/complicações
5.
Cureus ; 13(3): e14075, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33903837

RESUMO

Background Autoimmune inner ear disease (AIED) represents less than 1% of all cases of sensorineural hearing loss (SNHL) but its frequency may be underestimated due to lack of specific clinical and laboratory criteria. AIED can be associated with a systemic autoimmune disease (SAID) in 15%-30% of the cases. The objective of the present study was to characterize the clinical and prognostic factors of a cohort of patients with AIED. Materials and methods The authors conducted a retrospective descriptive analysis of a cohort of patients with AIED referred from the otorhinolaryngology department to a systemic immune-mediated diseases unit between March 2013 and November 2020. A consecutive sample of 39 patients with suspected AIED was referred. SNHL was defined as a fall of the hearing threshold of at least 30 decibels in three consecutive frequencies. Eight patients were excluded for not meeting the audiometric criteria or having confounding factors. The remaining 31 patients were included with a total of 50 affected ears. To classify the intensity of hearing loss, an arithmetic mean of pure tone was calculated. Normal hearing or mild hearing loss at the last pure tone audiometry of the follow-up were an indicator of good prognosis and were considered the outcome of interest. Results Thirty-two percent of the patients had an associated SAID. There were no differences regarding demographic and clinical characteristics when comparing patients with AIED alone and patients with AIED and a SAID, except for the positivity of antinuclear antibodies (ANA). ANA positivity was superior in patients with the association of AIED and a SAID when compared with patients with AIED alone (90% vs 50%; p=0.037). The SAID was diagnosed after the AIED in 70% of the patients, in which diagnosis of the SAID occurred a median of 4,2 (IQR 0.8-5.1) years after the diagnosis of the AIED. Normal audiometric evaluation or a mild hearing loss was achieved in 31% of the ears at the last audiometric evaluation. A normal audiometry or a mild hearing loss at the time of diagnosis was independently associated with a better outcome (31%, 14%, CI 1.71-273.69; p=0.018). Bilateral hearing loss was independently associated with a worse outcome (54%, 79%, CI 0.01-0.84; p=0.035). The use of systemic corticosteroids (p=0.941), transtympanic corticosteroids (p=0.700) and non-steroid immunomodulator drugs (p=0.986) did not affect prognosis. The presence of a SIAD did not affect the prognosis (p=0.986). Conclusions In this cohort, SAID was present in one-third of the patients with AIED. A good prognosis was achieved in one-third of the patients. A normal audiometry or mild disease at presentation was associated with a good outcome, whilst bilateral involvement was associated with a bad one. Association of a SAID did not seem to influence the hearing-related prognosis. Positivity of ANA antibodies may justify performing a complementary investigation to determine the presence of a SAID.

6.
Clin Case Rep ; 9(3): 1405-1407, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33768855

RESUMO

GCA is not always a linear diagnosis. Rarely reported as a paraneoplastic condition when associated with solid tumors, the available cases are associated with poor response to corticosteroids.

7.
Cell Chem Biol ; 28(5): 686-698.e7, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33497606

RESUMO

There is increasing evidence of a significant correlation between prolonged drug-target residence time and increased drug efficacy. Here, we report a structural rationale for kinetic selectivity between two closely related kinases: focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK2). We found that slowly dissociating FAK inhibitors induce helical structure at the DFG motif of FAK but not PYK2. Binding kinetic data, high-resolution structures and mutagenesis data support the role of hydrophobic interactions of inhibitors with the DFG-helical region, providing a structural rationale for slow dissociation rates from FAK and kinetic selectivity over PYK2. Our experimental data correlate well with computed relative residence times from molecular simulations, supporting a feasible strategy for rationally optimizing ligand residence times. We suggest that the interplay between the protein structural mobility and ligand-induced effects is a key regulator of the kinetic selectivity of inhibitors of FAK versus PYK2.


Assuntos
Quinase 1 de Adesão Focal/antagonistas & inibidores , Indóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Sulfonamidas/farmacologia , Células Cultivadas , Feminino , Quinase 1 de Adesão Focal/metabolismo , Células HEK293 , Humanos , Indóis/síntese química , Indóis/química , Cinética , Ligantes , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Sulfonamidas/síntese química , Sulfonamidas/química
8.
Microb Pathog ; 141: 103975, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31931114

RESUMO

Leptospirosis is a widespread zoonotic disease caused by pathogenic spirochetes of the genus Leptospira. The commercially available vaccines are bacterins that offer limited protection, short-term effect, and serovar-specific immunity. The development of novel immunization strategies is crucial to control the infection and decrease the chances of new outbreaks. In this study, purified monoclonal antibodies (mAbs) anti-LipL32 (1D9 and mAb3) were evaluated by their capacity to bind and neutralize the pathogen improving host survival. For that, an in vitro growth inhibition assay, and in vivo passive immunization were performed in animal model. Syrian hamsters were passively immunized by three different strategies. Hamsters immunized with mAb3 6 h prior to the lethal challenge showed a significantly higher survival rate of 61.1%, and a significant reduction in tissue damage in the lungs. Cumulatively, our results showed that anti-LipL32 mAbs inhibited the growth of L. interrogans in vitro, and that passive immunization offered significant protection in animal model when administered prior to infection.


Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Leptospira interrogans/imunologia , Leptospirose/prevenção & controle , Lipoproteínas/imunologia , Animais , Anticorpos Antibacterianos/farmacologia , Anticorpos Monoclonais/farmacologia , Cricetinae , Modelos Animais de Doenças , Feminino , Imunização , Leptospirose/microbiologia , Leptospirose/mortalidade , Leptospirose/patologia , Resultado do Tratamento
9.
J Chem Inf Model ; 59(12): 5135-5147, 2019 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-31697501

RESUMO

We here report on nonequilibrium targeted molecular dynamics simulations as a tool for the estimation of protein-ligand unbinding kinetics. Correlating simulations with experimental data from SPR kinetics measurements and X-ray crystallography on two small molecule compound libraries bound to the N-terminal domain of the chaperone Hsp90, we show that the mean nonequilibrium work computed in an ensemble of trajectories of enforced ligand unbinding is a promising predictor for ligand unbinding rates. We furthermore investigate the molecular basis determining unbinding rates within the compound libraries. We propose ligand conformational changes and protein-ligand nonbonded interactions to impact on unbinding rates. Ligands may remain longer at the protein if they exhibit strong electrostatic and/or van der Waals interactions with the target. In the case of ligands with a rigid chemical scaffold that exhibit longer residence times, transient electrostatic interactions with the protein appear to facilitate unbinding. Our results imply that understanding the unbinding pathway and the protein-ligand interactions along this path is crucial for the prediction of small molecule ligands with defined unbinding kinetics.


Assuntos
Simulação de Dinâmica Molecular , Proteínas/metabolismo , Cinética , Ligantes , Ligação Proteica , Conformação Proteica , Proteínas/química , Eletricidade Estática
10.
Vaccine ; 37(13): 1844-1852, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30826147

RESUMO

Leptospirosis is a zoonosis of worldwide distribution, caused by infection with pathogenic Leptospira species. The vaccines that are currently available are bacterins, with limited human use, that confer short-term, serovar-specific immunity. Lig proteins are considered to be the best vaccine candidates to date. Here, we aimed to construct a recombinant Lig chimera (LC) comprised of LigAni and LigBrep fragments, and to evaluate it as subunit or DNA vaccine using different administration strategies. Vaccines were formulated with 50 µg of recombinant LC associated with different adjuvants or with 100 µg of pTARGET/LC. Four-week-old hamsters received two doses of vaccine with different strategies and were challenged with 5 × DL50Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130. The immune response generated by Lig chimera conferred 100% protection to hamsters treated with at least one dose of recombinant LC. Despite the high levels of antibodies that vaccinated animals produced, a sterilizing immunity was not achieved. The lack of a sterilizing immunity could indicate the importance of a mixed humoral and cellular immune response. The present study generated insights that will be useful in the future development of improved subunit vaccines against leptospirosis.


Assuntos
Antígenos de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Leptospira/imunologia , Leptospirose/prevenção & controle , Proteínas Recombinantes de Fusão/imunologia , Vacinas de Subunidades Antigênicas/imunologia , Adjuvantes Imunológicos , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/genética , Vacinas Bacterianas/genética , Células CHO , Cricetinae , Cricetulus , Expressão Gênica , Humanos , Leptospira/genética , Leptospirose/imunologia , Leptospirose/microbiologia , Leptospirose/mortalidade , Proteínas Recombinantes de Fusão/genética , Vacinas de DNA , Vacinas de Subunidades Antigênicas/genética
11.
Vaccine ; 37(6): 776-782, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30630695

RESUMO

Leptospirosis is a zoonosis that is responsible for one million human cases per year. Fusing multiple immunogenic antigens represents a promising approach to delivering an effective vaccine against leptospirosis. Mycobacterium bovis bacillus Calmette-Guérin (BCG) is a potential vaccine vector due to its adjuvant properties and safety. Two chimeric genes based on genic sequences of ligANI, ligBrep, lipL32, and lemA, were individually cloned into five BioBrick vectors with different promoters (pAN, Hsp60, 18 kDa, Ag85B and Ag85B plus signal sequence) for antigen expression in BCG. Groups of ten hamsters were vaccinated with recombinant BCG (rBCG) strains in two doses of 106 CFU and challenged with 5 × LD50 of L. interrogans serovar Copenhageni. All rBCG vaccines expressing chimera 1, based on antigens LipL32, LigANI, and LemA, under the control of any promoter, protected 80-100% of the hamsters from challenge (P < 0.05) and four of them also protected from renal carrier status; for chimera 2, based on LigANI and LigBrep antigens, the only vaccine that afforded survival rates statistically different from the control was the vaccine that incorporated the pAN promoter (60% of survival). A single vaccine dose was sufficient to induce significant IgG levels by all vaccine compositions evaluated; however, humoral response was not related to protection. These findings suggest that the combination of potential vaccine candidates in chimeric antigens and the use of BCG as a live vector are promising strategies by which it is possible to obtain an effective and sterilizing vaccine against leptospirosis.


Assuntos
Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Leptospira/imunologia , Leptospirose/prevenção & controle , Mycobacterium bovis , Animais , Proteínas de Bactérias/genética , Vacinas Bacterianas/genética , Cricetinae , Feminino , Imunoglobulina G/sangue , Leptospira/genética , Masculino , Proteínas Recombinantes de Fusão/imunologia , Vacinas Sintéticas/imunologia
12.
J Clin Rheumatol ; 25(3): e12-e15, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29782426

RESUMO

OBJECTIVE: The aim of this study was to evaluate the association of nailfold videocapillaroscopy (NVC) changes and the presence and severity of interstitial lung disease (ILD) in systemic sclerosis. METHODS: This was a cross-sectional analysis of 48 systemic sclerosis patients (21 patients with ILD). The NVC characteristics considered were capillary organization, capillary loss (CL), avascular areas, enlarged and giant capillaries, hemorrhages, abnormally shaped capillaries, edema, and intermittent flux.We analyzed the association between NVC findings and (1) presence and extension of ILD and (2) percent predicted of forced vital capacity (FVC) and the carbon monoxide diffusing capacity (DLCO). RESULTS: Capillary loss and avascular areas showed a significant association with the presence of ILD (odds ratio, 18.57; 95% confidence interval [CI], 2.17-158.72 [p = 0.008]; and odds ratio, 4.64; 95% CI, 1.35-15.91 [p = 0.015], respectively). Receiver operating characteristic (ROC) curve analysis confirmed the association between CL and ILD (area under the ROC curve, 90.1%; 95% CI, 81.8-91.4). Avascular areas and CL were associated with a worse pulmonary function (FVC -18.1% [p = 0.034], DLCO -14.0% [p = 0.013]; and FVC -15.3% [p = 0.086], DLCO -12.3% [p = 0.049], respectively). No association was found between other NVC findings and ILD or lung function. CONCLUSIONS: Capillary loss and avascular area showed a significant association with the presence of ILD, supported by ROC curve analysis. These results may reinforce a prognostic role for NVC and a physiopathology mechanism for ILD based on vascular damage.


Assuntos
Capilares , Doenças Pulmonares Intersticiais , Angioscopia Microscópica/métodos , Escleroderma Sistêmico , Adulto , Idoso , Capilares/diagnóstico por imagem , Capilares/fisiopatologia , Monóxido de Carbono/análise , Feminino , Humanos , Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Capacidade de Difusão Pulmonar , Curva ROC , Reprodutibilidade dos Testes , Testes de Função Respiratória/métodos , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/diagnóstico , Escleroderma Sistêmico/fisiopatologia , Índice de Gravidade de Doença , Capacidade Vital
13.
Free Radic Res ; 52(10): 1063-1082, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30226391

RESUMO

Systemic sclerosis (SSc) is a multisystem autoimmune disease: characterised from the clinical side by progressive vasculopathy and fibrosis of the skin and different organs and from the biochemical side by fibroblast deregulation with excessive production of collagen and increased expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). The latter contributes to an overproduction of reactive oxygen species that through an autocrine loop maintains NOX4 in a state of activation. Reactive oxygen and nitrogen species are implicated in the origin and perpetuation of several clinical manifestations of SSc having vascular damage in common; attempts to dampen oxidative and nitrative stress through different agents with antioxidant properties have not translated into a sustained clinical benefit. Objective of this narrative review is to describe the origin and clinical implications of oxidative and nitrative stress in SSc, with particular focus on the central role of NOX4 and its interactions, to re-evaluate the antioxidant approaches so far used to limit disease progression, to appraise the complexity of antioxidant treatment and to touch on novel pathways elements of which may represent specific treatment targets in the not so distant future.


Assuntos
Antioxidantes/farmacologia , Estresse Nitrosativo , Estresse Oxidativo , Escleroderma Sistêmico/tratamento farmacológico , Escleroderma Sistêmico/metabolismo , Animais , Antioxidantes/metabolismo , Antioxidantes/uso terapêutico , Humanos , NADPH Oxidase 4/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/imunologia
14.
Angew Chem Int Ed Engl ; 57(31): 9955-9960, 2018 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-29772085

RESUMO

Investigation of protein-ligand interactions is crucial during early drug-discovery processes. ATR-FTIR spectroscopy can detect label-free protein-ligand interactions with high spatiotemporal resolution. Here we immobilized, as an example, the heat shock protein HSP90 on an ATR crystal. This protein is an important molecular target for drugs against several diseases including cancer. With our novel approach we investigated a ligand-induced secondary structural change. Two specific binding modes of 19 drug-like compounds were analyzed. Different binding modes can lead to different efficacy and specificity of different drugs. In addition, the kobs values of ligand dissociation were obtained. The results were validated by X-ray crystallography for the structural change and by SPR experiments for the dissociation kinetics, but our method yields all data in a single and simple experiment.


Assuntos
Descoberta de Drogas , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Pirazóis/farmacologia , Triazóis/farmacologia , Cristalografia por Raios X , Proteínas de Choque Térmico HSP90/química , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Ligantes , Modelos Moleculares , Conformação Molecular , Pirazóis/química , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Triazóis/química
15.
Thromb Haemost ; 118(6): 1088-1100, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29723873

RESUMO

Quantitative and qualitative defects of high-density lipoprotein (HDL) are important in atherogenesis. In this study, we investigated whether antibodies against HDL components had additional value to conventional cardiovascular risk factors for the diagnosis of ischaemic stroke (IS) and coronary artery disease (CAD). Cross-sectional study was conducted on 53 patients with IS, 51 with CAD and 55 healthy controls, and in vitro studies to validate findings of the clinical study. We determined serum immunoglobulin G (IgG) antibodies against HDL (aHDL), apolipoproteins (aApoA-I, aApoA-II and aApoC-I) and paraoxonase-1 (aPON1) as well as PON1 activity (PON1a), total antioxidant capacity and biomarkers of endothelial activation (serum nitric oxide metabolites, 3-nitrotyrosine, VCAM-1 and ICAM-1); in vitro assays tested the capacity of IgG aHDL purified from high titer patients to inhibit PON1a and to reverse protective effect of HDL on endothelial cells. IgG aHDL, aApoA-I and aPON1 were higher in IS and CAD than controls (p < 0.001), predicted negatively PON1a and positively VCAM-1 and ICAM-1. By adding IgG aHDL and aApoA-I to a traditional cardiovascular risk factors model for IS and by adding IgG aHDL in a similar model for CAD, we obtained better discrimination of IS and CAD from healthy controls. IgG aHDL purified from IS and CAD inhibited PON1a by 38% (p < 0.01) and abrogated the protective effect of HDL on VCAM-1 expression by 126% compared with non-specific human IgG (p < 0.001). IgG against HDL components interfere with the antioxidant and anti-inflammatory properties of HDL and may represent novel biomarkers for vascular disease that need to be investigated in prospective studies.


Assuntos
Biomarcadores/sangue , Doença da Artéria Coronariana/imunologia , Endotélio/fisiologia , Imunoglobulina G/sangue , Isquemia/imunologia , Lipoproteínas HDL/metabolismo , Acidente Vascular Cerebral/imunologia , Idoso , Apolipoproteínas/imunologia , Arildialquilfosfatase/imunologia , Arildialquilfosfatase/metabolismo , Estudos de Casos e Controles , Doença da Artéria Coronariana/diagnóstico , Estudos Transversais , Feminino , Humanos , Isquemia/diagnóstico , Lipoproteínas HDL/imunologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Risco , Acidente Vascular Cerebral/diagnóstico , Molécula 1 de Adesão de Célula Vascular/metabolismo
16.
J Chem Theory Comput ; 14(7): 3859-3869, 2018 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-29768913

RESUMO

Drug-target residence time (τ), one of the main determinants of drug efficacy, remains highly challenging to predict computationally and, therefore, is usually not considered in the early stages of drug design. Here, we present an efficient computational method, τ-random acceleration molecular dynamics (τRAMD), for the ranking of drug candidates by their residence time and obtaining insights into ligand-target dissociation mechanisms. We assessed τRAMD on a data set of 70 diverse drug-like ligands of the N-terminal domain of HSP90α, a pharmaceutically important target with a highly flexible binding site, obtaining computed relative residence times with an accuracy of about 2.3τ for 78% of the compounds and less than 2.0τ within congeneric series. Analysis of dissociation trajectories reveals features that affect ligand unbinding rates, including transient polar interactions and steric hindrance. These results suggest that τRAMD will be widely applicable as a computationally efficient aid to improving drug residence times during lead optimization.


Assuntos
Proteínas de Choque Térmico HSP90/metabolismo , Sítios de Ligação , Descoberta de Drogas , Proteínas de Choque Térmico HSP90/química , Humanos , Cinética , Ligantes , Simulação de Dinâmica Molecular , Ligação Proteica , Domínios Proteicos
17.
J Med Chem ; 61(10): 4397-4411, 2018 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-29701469

RESUMO

Residence time and more recently the association rate constant kon are increasingly acknowledged as important parameters for in vivo efficacy and safety of drugs. However, their broader consideration in drug development is limited by a lack of knowledge of how to optimize these parameters. In this study on a set of 176 heat shock protein 90 inhibitors, structure-kinetic relationships, X-ray crystallography, and molecular dynamics simulations were combined to retrieve a concrete scheme of how to rationally slow down on-rates. We discovered that an increased ligand desolvation barrier by introducing polar substituents resulted in a significant kon decrease. The slowdown was accomplished by introducing polar moieties to those parts of the ligand that point toward a hydrophobic cavity. We validated this scheme by increasing polarity of three Hsp90 inhibitors and observed a 9-, 13-, and 45-fold slowdown of on-rates and a 9-fold prolongation in residence time. This prolongation was driven by transition state destabilization rather than ground state stabilization.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Resistencia a Medicamentos Antineoplásicos , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Simulação de Dinâmica Molecular , Sítios de Ligação , Cristalografia por Raios X , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Ligantes , Modelos Moleculares , Estrutura Molecular , Ligação Proteica , Conformação Proteica
18.
Vaccine ; 36(19): 2574-2580, 2018 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-29625765

RESUMO

BACKGROUND: Recombinant subunit vaccines have been extensively evaluated as promising alternatives against leptospirosis. Here, we evaluated two proteins in formulations containing the adjuvant AddaVax™ as vaccine candidates for prevention and control of leptospirosis. METHODS: Recombinant proteins rErp Y-like and rLemA were characterized by ELISA to assess their ability to bind extracellular matrix (ECM) components and fibrinogen. Groups of eight hamsters were immunized intramuscularly with rErp Y-like or rLemA mixed with a squalene-based adjuvant (AddaVax), and then vaccine efficacy was determined in terms of protection against a lethal challenge. The humoral immune response was determined by ELISA, and the evidence of sub-lethal infection was evaluated by histopathology and kidney culture. RESULTS: rLemA protein binds laminin, fibrinogen, and collagen type IV, while rErp Y-like interacts with fibrinogen. Significant protection was achieved for rLemA and rErp Y-like vaccines, which showed 87.5% and 62.5% survivals, respectively. On day 28, the humoral immune response was significantly greater in the vaccine groups as compared to that in the control group, and the response was predominantly based on IgG2/3. The surviving animals showed negative results in culture isolation but presented with tissue lesions in the lungs and kidneys. CONCLUSION: Cumulatively, our findings suggest that LemA and Erp Y-like proteins act as adhesins and are able to protect against mortality, but not against tissue lesions. Moreover, AddaVax is a novel adjuvant with potential for improving the immunogenicity of leptospiral vaccines.


Assuntos
Adjuvantes Imunológicos/farmacologia , Vacinas Bacterianas/farmacologia , Leptospira interrogans/genética , Leptospirose/prevenção & controle , Polissorbatos/farmacologia , Esqualeno/farmacologia , Animais , Proteínas de Bactérias/genética , Vacinas Bacterianas/genética , Vacinas Bacterianas/imunologia , Cricetinae , Feminino , Leptospira interrogans/patogenicidade , Leptospirose/imunologia , Masculino , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/farmacologia , Fatores de Transcrição/genética , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/farmacologia
19.
Drug Discov Today ; 22(6): 896-911, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28412474

RESUMO

A considerable number of approved drugs show non-equilibrium binding characteristics, emphasizing the potential role of drug residence times for in vivo efficacy. Therefore, a detailed understanding of the kinetics of association and dissociation of a target-ligand complex might provide crucial insight into the molecular mechanism-of-action of a compound. This deeper understanding will help to improve decision making in drug discovery, thus leading to a better selection of interesting compounds to be profiled further. In this review, we highlight the contributions of the Kinetics for Drug Discovery (K4DD) Consortium, which targets major open questions related to binding kinetics in an industry-driven public-private partnership.


Assuntos
Descoberta de Drogas , Preparações Farmacêuticas/metabolismo , Animais , Indústria Farmacêutica , Humanos , Cinética , Farmacocinética
20.
Theriogenology ; 90: 101-108, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28166954

RESUMO

The present study was conducted to analyze the adverse effects of the anabolic steroids boldenone (BOL) and stanazolol (ST) in the reproductive function of male rats. These molecules were administered using three different protocols. In Protocol I, BOL and ST were administered in a higher dose than what is recommended but for a short period. In Protocol II, a moderate dose of these compounds was applied for an intermediate period, whereas in Protocol III a reduced dose was administered but for an extended period. Notably, Protocol I and III resulted in increased levels of reactive oxygen specimens (ROS [I, p < 0.01] [III, p < 0.001)]) and nitrite plus nitrate (NOx [I, p < 0.01] [II, p < 0.01] [III,p < 0.05]), respectively, whereas non-protein thiols (NPSH) levels were decreased only after Protocol III (p < 0.01). Myeloperoxidase activity was significantly increased after treatment with BOL in protocol II (p < 0.01) and III (p < 0.05) than with ST in protocol III (p < 0.05). Boldenone and ST also caused a significant up-regulation in the levels of serum testosterone when protocols I (p < 0.01) and II (p < 0.05) were performed. There were also visible histopathological alterations in the testes induced by treatment with BOL, namely degenerative changes primarily characterized by a decrease in the germinal epithelium. Together, these results suggest that the administration of BOL or ST exerts a significantly harmful effect in the testes of male rats. Moreover, all the treatment protocols used in this study induced deleterious effects on the testes, as indicated by the different biochemical parameters investigated. However, only the protocols of longer exposure time (II and III) induced morphological changes compatible with infertility.


Assuntos
Anabolizantes/efeitos adversos , Estanozolol/efeitos adversos , Testículo/efeitos dos fármacos , Testosterona/análogos & derivados , Animais , Relação Dose-Resposta a Droga , Masculino , Nitrosação , Estresse Oxidativo/efeitos dos fármacos , Peroxidase/metabolismo , Ratos Wistar , Espécies Reativas de Oxigênio/análise , Testículo/química , Testículo/patologia , Testosterona/efeitos adversos , Testosterona/sangue , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...