Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Rheumatol Ther ; 11(3): 501-521, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38430455

RESUMO

INTRODUCTION: This study assesses the accuracy of neutrophil activation markers, including neutrophil extracellular traps (NETs) and calprotectin, as biomarkers of disease activity in patients with established rheumatoid arthritis (RA). We also analyse the relationship between NETs and various types of therapies as well as their association with autoimmunity. METHODS: Observational cross-sectional study of patients with RA receiving treatment with biological disease-modifying antirheumatic drugs or Janus kinase inhibitors (JAK-inhibitors) for at least 3 months. Plasma calprotectin levels were measured using an enzyme-linked immunosorbent assay test kit and NETs by measuring their remnants in plasma (neutrophil elastase-DNA and histone-DNA complexes). We also assessed clinical disease activity, joint ultrasound findings and autoantibody status [reumatoid factor (RF), anti-citrullinated peptide/protein antibodies (ACPAs) and anti-carbamylated protein (anti-CarP)]. Associations between neutrophilic biomarkers and clinical or ultrasound scores were sought using correlation analysis. The discriminatory capacity of both neutrophilic biomarkers to detect ultrasound synovitis was analysed through receiver-operating characteristic (ROC) curves. RESULTS: One hundred fourteen patients were included. Two control groups were included to compare NET levels. The active control group consisted of 15 patients. The second control group consisted of 30 healthy subjects. Plasma NET levels did not correlate with clinical disease status, regardless of the clinic index analysed or the biological therapy administered. No significant correlation was observed between NET remnants and ultrasound synovitis. There was no correlation between plasma NET and autoantibodies. In contrast, plasma calprotectin positively correlated with clinical parameters (swollen joint count [SJC] rho = 0.49; P < 0.001, Clinical Disease Activity Index [CDAI] rho = 0.30; P < 0.001) and ultrasound parameters (rho > 0.50; P < 0.001). Notably, this correlation was stronger than that observed with acute phase reactants. CONCLUSION: While NET formation induced by neutrophils may play a role in RA pathogenesis, our study raises questions about the utility of NET remnants in peripheral circulation as a biomarker for inflammatory activity. In contrast, this study strongly supports the usefulness of calprotectin as a biomarker of inflammatory activity in patients with RA.

2.
Arthritis Res Ther ; 25(1): 192, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798800

RESUMO

BACKGROUND: Autoantibodies are critical elements in RA pathogenesis and clinical assessment. The anti-malondialdehyde-acetaldehyde (anti-MAA) antibodies are potentially useful because of their claimed high sensitivity for all RA patients, including those lacking RF and anti-CCP antibodies. Therefore, we aimed to replicate these findings. METHODS: We independently attempted replication in Santiago and Barcelona using sera from 517 and 178 RA patients and 272 and 120 healthy controls, respectively. ELISA protocols for anti-MAA antibodies included five antigens (human serum albumin in three formulations, fibrinogen, and a synthetic peptide) and assays for the IgG, IgM, and IgA isotypes. We integrated our results with information found by searching the Web of Science for reports of anti-MAA antibodies in RA. The available patients (4989 in 11 sets) were included in a meta-analysis aimed at heterogeneity between studies. Factors accounting for heterogeneity were assessed with meta-regression. RESULTS: The sensitivity of anti-MAA antibodies in our RA patients was low, even in seropositive patients, with the percentage of positives below 23% for all ELISA conditions. Our results and bibliographic research showed IgG anti-MAA positive patients ranging from 6 to 92%. The extreme between-studies heterogeneity could be explained (up to 43%) in univariate analysis by sex, African ethnicity, the site of study, or recruitment from the military. The best model, including African ancestry and smoking, explained a high heterogeneity fraction (74%). CONCLUSION: Anti-MAA antibody sensitivity is extremely variable between RA patient collections. A substantial fraction of this variability cannot be attributed to ELISA protocols. On the contrary, heterogeneity is determined by complex factors that include African ethnicity, smoking, and sex.


Assuntos
Acetaldeído , Artrite Reumatoide , Humanos , Malondialdeído , Autoanticorpos , Imunoglobulina G , Fator Reumatoide , Peptídeos Cíclicos
3.
Int J Pharm ; 639: 122982, 2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37116598

RESUMO

Licochalcone-A (Lico-A) PLGA NPs functionalized with cell penetrating peptides B6 and Tet-1 are proposed for the treatment of ocular anti-inflammatory diseases. In this work, we report the in vitro biocompatibility of cell penetrating peptides-functionalized Lico-A-loaded PLGA NPs in Caco-2 cell lines revealing a non-cytotoxic profile, and their anti-inflammatory activity against RAW 264.7 cell lines. Given the risk of hydrolysis of the liquid suspensions, freeze-drying was carried out testing different cryoprotectants (e.g., disaccharides, alcohols, and oligosaccharide-derived sugar alcohol) to prevent particle aggregation and mitigate physical stress. As the purpose is the topical eye instillation of the nanoparticles, to reduce precorneal wash-out, increase residence time and thus Lico-A bioavailability, an in-situ forming gel based on poloxamer 407 containing Lico-A loaded PLGA nanoparticles functionalized with B6 and Tet-1 for ocular administration has been developed. Developed formulations remain in a flowing semi-liquid state under non-physiological conditions and transformed into a semi-solid state under ocular temperature conditions (35 °C), which is beneficial for ocular administration. The pH, viscosity, texture parameters and gelation temperature results met the requirements for ophthalmic formulations. The gel has characteristics of viscoelasticity, suitable mechanical and mucoadhesive performance which facilitate its uniform distribution over the conjunctiva surface. In conclusion, we anticipate the potential clinical significance of our developed product provided that a synergistic effect is achieved by combining the high anti-inflammatory activity of Lico-A delivered by PLGA NPs with B6 and Tet-1 for site-specific targeting in the eye, using an in-situ forming gel.


Assuntos
Peptídeos Penetradores de Células , Nanopartículas , Humanos , Células CACO-2 , Anti-Inflamatórios , Nanopartículas/química , Olho
4.
Int J Mol Sci ; 23(24)2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36555449

RESUMO

Post-translational modifications (PTMs) influence cellular processes and consequently, their dysregulation is related to the etiologies of numerous diseases. It is widely known that a variety of autoimmune responses in human diseases depend on PTMs of self-proteins. In this review we summarize the latest findings about the role of PTMs in the generation of autoimmunity and, specifically, we address the most relevant PTMs in rheumatic diseases that occur in synovial tissue. Citrullination, homocitrullination (carbamylation) and acetylation are responsible for the generation of Anti-Modified Protein/Peptide Antibodies (AMPAs family), autoantibodies which have been implicated in the etiopathogenesis, diagnosis and prognosis of rheumatoid arthritis (RA). Synthetic peptides provide complete control over the exact epitopes presented as well as the specific positions in their sequence where post-translationally modified amino acids are located and are key to advancing the detection of serological RA biomarkers that could be useful to stratify RA patients in order to pursue a personalized rheumatology. In this review we specifically address the latest findings regarding synthetic peptides post-translationally modified for the specific detection of autoantibodies in RA patients.


Assuntos
Artrite Reumatoide , Autoimunidade , Humanos , Citrulinação , Acetilação , Processamento de Proteína Pós-Traducional , Autoanticorpos , Artrite Reumatoide/diagnóstico
5.
Int J Mol Sci ; 22(24)2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34948087

RESUMO

Rheumatoid arthritis (RA) is characterized by the presence of autoantibodies that are of paramount importance for the diagnosis and prognosis of the disease and have been implicated in its pathogenesis. Proteins resulting from post-translational modifications (PTMs) are capable of triggering autoimmune responses important for the development of RA. In this work, we investigate serum antibody reactivity in patients with an established RA against a panel of chimeric peptides derived from fibrin and filaggrin proteins and bearing from one to three PTMs (citrullination, carbamylation and acetylation) by home-designed ELISA tests (anti-AMPA autoantibodies). The role of anti-AMPAs as biomarkers linked to the presence of a more severe RA phenotype (erosive disease with radiological structural damage) and to the presence of interstitial lung disease (ILD), a severe extra-articular manifestation in RA patients entailing a high mortality, was also analyzed. In general, the association with the clinical phenotype of RA was confirmed with the different autoantibodies, and especially for IgA and IgM isotypes. The prevalence of severe joint damage was only statistically significant for the IgG isotype when working with the peptide bearing three PTMs. Furthermore, the median titers were significantly higher in patients with RA-ILD, a finding not observed for the IgG isotype when working with the single- and double-modified peptides.


Assuntos
Artrite Reumatoide/metabolismo , Autoanticorpos/sangue , Peptídeos/imunologia , Processamento de Proteína Pós-Traducional , Acetilação , Artrite Reumatoide/sangue , Artrite Reumatoide/complicações , Artrite Reumatoide/imunologia , Biomarcadores/sangue , Citrulinação , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Humanos , Doenças Pulmonares Intersticiais/complicações , Peptídeos/metabolismo , Carbamilação de Proteínas
6.
Bioconjug Chem ; 32(9): 1999-2013, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34254794

RESUMO

In a previous work, we defined a novel HIV-1 fusion inhibitor peptide (E1P47) with a broad spectrum of activity against viruses from different clades, subtypes, and tropisms. With the aim to enhance its efficacy, in the present work we address the design and synthesis of several peptide amphiphiles (PAs) based on the E1P47 peptide sequence to target the lipid rafts of the cell membrane where the cell-cell fusion process takes place. We report the synthesis of novel PAs having a hydrophobic moiety covalently attached to the peptide sequence through a hydrophilic spacer of polyethylene glycol. Characterization of self-assembly in condensed phase and aqueous solution as well as their interaction with model membranes was analyzed by several biophysical methods. Our results demonstrated that the length of the spacer of polyethylene glycol, the position of the peptide conjugation as well as the type of the hydrophobic residue determine the antiviral activity of the construct. Peptide amphiphiles with one alkyl tail either in C-terminus (C-PAmonoalkyl) or in N-terminus (N-PAmonoalkyl) showed the highest anti-HIV-1 activities in the cellular model of TZM-bl cells or in a preclinical model of the human mucosal tissue explants.


Assuntos
HIV-1 , Peptídeos , Interações Hidrofóbicas e Hidrofílicas , Nanofibras
7.
Sci Rep ; 10(1): 14430, 2020 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-32879375

RESUMO

Based on the structure of an HIV-1 entry inhibitor peptide two stapled- and a retro-enantio peptides have been designed to provide novel prevention interventions against HIV transmission. The three peptides show greater inhibitory potencies in cellular and mucosal tissue pre-clinical models than the parent sequence and the retro-enantio shows a strengthened proteolytic stability. Since HIV-1 fusion inhibitor peptides need to be embedded in the membrane to properly interact with their viral target, the structural features were determined by NMR spectroscopy in micelles and solved by using restrained molecular dynamics calculations. Both parent and retro-enantio peptides demonstrate a topology compatible with a shared helix-turn-helix conformation and assemble similarly in the membrane maintaining the active conformation needed for its interaction with the viral target site. This study represents a straightforward approach to design new targeted peptides as HIV-1 fusion inhibitors and lead us to define a retro-enantio peptide as a good candidate for pre-exposure prophylaxis against HIV-1.


Assuntos
Fármacos Anti-HIV/química , HIV-1/efeitos dos fármacos , Oligopeptídeos/química , Proteínas Estruturais Virais/antagonistas & inibidores , Fármacos Anti-HIV/farmacologia , HIV-1/química , Humanos , Simulação de Acoplamento Molecular , Oligopeptídeos/farmacologia , Ligação Proteica , Proteínas Estruturais Virais/química , Proteínas Estruturais Virais/metabolismo
8.
Mol Ther Nucleic Acids ; 17: 891-906, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31476668

RESUMO

Autosomal dominantly inherited genetic disorders such as corneal dystrophies are amenable to allele-specific gene silencing with small interfering RNA (siRNA). siRNA delivered to the cornea by injection, although effective, is not suitable for a frequent long-term treatment regimen, whereas topical delivery of siRNA to the cornea is hampered by the eye surface's protective mechanisms. Herein we describe an attractive and innovative alternative for topical application using cell-penetrating peptide derivatives capable of complexing siRNA non-covalently and delivering them into the cornea. Through a rational design approach, we modified derivatives of a cell-penetrating peptide, peptide for ocular delivery (POD), already proved to diffuse into the corneal layers. These POD derivatives were able to form siRNA-peptide complexes (polyplexes) of size and ζ-potential similar to those reported able to undergo cellular internalization. Successful cytoplasmic release and gene silencing in vitro was obtained when an endosomal disruptor, chloroquine, was added. A palmitoylated-POD, displaying the best delivery properties, was covalently functionalized with trifluoromethylquinoline, an analog of chloroquine. This modified POD, named trifluoromethylquinoline-palmitoyl-POD (QN-Palm-POD), when complexed with siRNA and topically applied to the eye in vivo, resulted in up to 30% knockdown of luciferase reporter gene expression in the corneal epithelium. The methods developed within represent a valid standardized approach that is ideal for screening of a range of delivery formulations.

9.
Sci Rep ; 9(1): 3257, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30824796

RESUMO

Novel strategies in the design of HIV-1 fusion/entry inhibitors are based on the construction of dual-targeting fusion proteins and peptides with synergistic antiviral effects. In this work we describe the design of dual-targeting peptides composed of peptide domains of E2 and E1 envelope proteins from Human Pegivirus with the aim of targeting both the loop region and the fusion peptide domains of HIV-1 gp41. In a previous work, we described the inhibitory role of a highly conserved fragment of the E1 protein (domain 139-156) which interacts with the HIV-1 fusion peptide at the membrane level. Here, two different dual-targeting peptides, where this E1 peptide is located on the N- or the C-terminus respectively, have been chemically synthesized and their antiviral activities have been evaluated with HIV pseudotyped viruses from different clades. The study of the functional behaviour of peptides in a membranous environment attending to the peptide recognition of the target sites on gp41, the peptide conformation as well as the peptide affinity to the membrane, demonstrate that antiviral activity of the dual-targeting peptides is directly related to the peptide affinity and its subsequent assembly into the model membrane. The overall results point out to the necessity that fusion inhibitor peptides that specifically interfere with the N-terminal region of gp41 are embedded within the membrane in order to properly interact with their viral target.


Assuntos
Membrana Celular/metabolismo , Inibidores da Fusão de HIV/farmacologia , HIV-1/efeitos dos fármacos , Peptídeos/metabolismo , Peptídeos/farmacologia , Sequência de Aminoácidos , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/metabolismo , Humanos , Micelas , Peptídeos/química , Domínios Proteicos , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Triptofano/metabolismo
10.
Mol Pharm ; 15(11): 5005-5018, 2018 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-30226777

RESUMO

New therapeutic alternatives to fight against the spread of HIV-1 are based on peptides designed to inhibit the early steps of HIV-1 fusion in target cells. However, drawbacks, such as bioavailability, short half-life, rapid clearance, and poor ability to cross the physiological barriers, make such peptides unattractive for the pharmaceutical industry. Here we developed, optimized, and characterized polymeric nanoparticles (NPs) coated with glycol chitosan to incorporate and release an HIV-1 fusion inhibitor peptide (E1) inside the vaginal mucosa. The NPs were prepared by a modified double emulsion method, and optimization was carried out by a factorial design. In vitro, ex vivo, and in vivo studies were carried out to evaluate the optimized formulation. The results indicate that the physicochemical features of these NPs enable them to incorporate and release HIV fusion inhibitor peptides to the vaginal mucosa before the fusion step takes place.


Assuntos
Portadores de Fármacos/química , HIV-1/efeitos dos fármacos , Peptídeos/administração & dosagem , Inibidores de Proteínas Virais de Fusão/administração & dosagem , Administração Intravaginal , Animais , Quitosana/química , Desenho de Fármacos , Feminino , Proteína gp41 do Envelope de HIV/antagonistas & inibidores , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , HIV-1/fisiologia , Modelos Animais , Mucosa/efeitos dos fármacos , Mucosa/metabolismo , Mucosa/virologia , Nanopartículas/química , Tamanho da Partícula , Peptídeos/química , Peptídeos/farmacocinética , Suínos , Vagina/efeitos dos fármacos , Vagina/metabolismo , Vagina/virologia , Proteínas do Envelope Viral/química , Inibidores de Proteínas Virais de Fusão/química , Inibidores de Proteínas Virais de Fusão/farmacocinética , Internalização do Vírus/efeitos dos fármacos
11.
Clin Chem Lab Med ; 56(2): 285-293, 2018 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-28850543

RESUMO

BACKGROUND: The objective of the study was to compare the diagnostic yield of home-made ELISA tests based on synthetic chimeric fibrin/filaggrin citrullinated peptides (CFFCPs) with CCP3 and CCP3.1 commercial tests to detect anti-citrullinated protein/peptide antibodies (ACPAs) in rheumatoid arthritis (RA) patients. The prognostic value is also studied in a cohort of patients with early RA. Moreover, we transfer immunological assays from microtiter plates to microarray formats to allow the simultaneous analysis of several peptide sequences and reduce the volume of serum from patients. METHODS: The diagnostic study includes: 100 RA patients who fulfilled the 1987 ACR criteria; 100 healthy blood donors; 35 patients with SLE according ACR criteria; 35 patients with PsA fulfilling the Wright and Moll criteria and 30 patients with HCV infection. The prognostic value study includes 50 patients with early RA with follow-up data available. All samples are from outpatients attending the Rheumatology Department of the Hospital Clinic of Barcelona. RESULTS: Similar sensitivity, specificity and predictive values for the diagnosis of RA of CCFCPs compared to CCP3/CCP3.1 were obtained. Although a high concordance is observed between anti-CFFCPs and anti-CCP3/CCP3.1 in the early patients that rendered Larsen radiographic progression, CFFCPs could be a better marker of radiographic outcome. Strong correlations between the microarray and ELISA results were found for individual CFFCPs peptides. CONCLUSIONS: The development of multiplexing techniques combining a different spectrum of markers in a single analysis, including CFFCP peptides, could allow a more detailed analysis of the autoantibodies reactivity found in the sera of patients suffering of this heterogeneous disease.


Assuntos
Anticorpos Antiproteína Citrulinada/sangue , Artrite Reumatoide/diagnóstico , Biomarcadores/sangue , Citrulina/imunologia , Peptídeos Cíclicos/imunologia , Anticorpos Antiproteína Citrulinada/imunologia , Citrulina/química , Ensaio de Imunoadsorção Enzimática/métodos , Fibrina/química , Fibrina/imunologia , Proteínas Filagrinas , Humanos , Proteínas de Filamentos Intermediários/química , Proteínas de Filamentos Intermediários/imunologia , Peptídeos Cíclicos/química , Prognóstico , Análise Serial de Proteínas/métodos , Domínios Proteicos
12.
Int J Nanomedicine ; 10: 609-31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25670897

RESUMO

In this work, a peptide for ocular delivery (POD) and human immunodeficiency virus transactivator were conjugated with biodegradable poly(lactic-co-glycolic acid) (PGLA)-polyethylene glycol (PEG)-nanoparticles (NPs) in an attempt to improve ocular drug bioavailability. The NPs were prepared by the solvent displacement method following two different pathways. One involved preparation of PLGA NPs followed by PEG and peptide conjugation (PLGA-NPs-PEG-peptide); the other involved self-assembly of PLGA-PEG and the PLGA-PEG-peptide copolymer followed by NP formulation. The conjugation of the PEG and the peptide was confirmed by a colorimetric test and proton nuclear magnetic resonance spectroscopy. Flurbiprofen was used as an example of an anti-inflammatory drug. The physicochemical properties of the resulting NPs (morphology, in vitro release, cell viability, and ocular tolerance) were studied. In vivo anti-inflammatory efficacy was assessed in rabbit eyes after topical instillation of sodium arachidonate. Of the formulations developed, the PLGA-PEG-POD NPs were the smaller particles and exhibited greater entrapment efficiency and more sustained release. The positive charge on the surface of these NPs, due to the conjugation with the positively charged peptide, facilitated penetration into the corneal epithelium, resulting in more effective prevention of ocular inflammation. The in vitro toxicity of the NPs developed was very low; no ocular irritation in vitro (hen's egg test-chorioallantoic membrane assay) or in vivo (Draize test) was detected. Taken together, these data demonstrate that PLGA-PEG-POD NPs are promising vehicles for ocular drug delivery.


Assuntos
Anti-Inflamatórios/farmacologia , Peptídeos Penetradores de Células/farmacologia , Sistemas de Liberação de Medicamentos , Epitélio Corneano/efeitos dos fármacos , Glicolatos/química , Ácido Láctico/química , Nanopartículas/química , Ácido Poliglicólico/química , Animais , Proteínas Reguladoras de Apoptose/química , Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , Sobrevivência Celular/efeitos dos fármacos , Galinhas , Membrana Corioalantoide/química , Portadores de Fármacos/química , Epitélio Corneano/citologia , Feminino , Células HeLa , Células Hep G2 , Humanos , Microscopia Confocal , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Coelhos , Proteínas Recombinantes de Fusão/química , Survivina , Produtos do Gene tat do Vírus da Imunodeficiência Humana/química
13.
Curr Top Med Chem ; 14(23): 2729-33, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25515746

RESUMO

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes joint inflammation and extra-articular manifestations. To prevent progressive and irreversible structural damage, early diagnosis of RA is of paramount importance. Antibodies directed against citrullinated proteins and peptides (ACPAs) are the most specific serological markers available for diagnosing RA. ACPAs may be detected several years before symptoms appear, and their presence at disease onset is a good predictor of the development of erosive joint lesions. Synthetic peptides can replace cognate proteins in solid-phase assays for specific autoantibody recognition in RA patients. The use of synthetic peptides instead of proteins represents an advantage in terms of the reproducibility of such immunoassays. They give absolute control over the exact epitopes presented. Furthermore, it is difficult to prepare sufficient amounts of high-quality antigenic proteins with a well-defined degree of citrullination. Synthetic citrullinated peptides, in contrast, are easily obtained in a pure form with a well-defined chemical structure and the epitopes can be precisely oriented in the plate by covalent binding of the peptides. We have recently obtained and highlighted the application of chimeric peptides bearing different citrullinated protein domains for the design of RA diagnosis systems. Our results indicate that more than one serological test is required to classify RA patients based on the presence or absence of ACPAs. Each of the target molecules reported (fibrin, vimentin and filaggrin) helps to identify a particular subset of RA patients.


Assuntos
Artrite Reumatoide/sangue , Artrite Reumatoide/diagnóstico , Autoanticorpos/sangue , Peptídeos , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Estudos de Casos e Controles , Citrulina/metabolismo , Diagnóstico Precoce , Epitopos/química , Epitopos/imunologia , Fibrina/química , Fibrina/imunologia , Fibrina/metabolismo , Proteínas Filagrinas , Humanos , Proteínas de Filamentos Intermediários/sangue , Proteínas de Filamentos Intermediários/química , Proteínas de Filamentos Intermediários/imunologia , Articulações/imunologia , Articulações/metabolismo , Articulações/patologia , Dados de Sequência Molecular , Peptídeos/síntese química , Prognóstico , Estrutura Terciária de Proteína , Técnicas de Síntese em Fase Sólida , Vimentina/sangue , Vimentina/química , Vimentina/imunologia
14.
Eur J Med Chem ; 86: 589-604, 2014 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-25218908

RESUMO

The development of peptide fusion inhibitors based on short synthetic peptides represents a promising option in the fight against HIV-1 infection, especially in individuals infected with multiresistant HIV-1 strains. GBV-C has the beneficial effect of retarding the progression of AIDS in people who are co-infected with both the GBV-C and HIV viruses. In previous works, the E1(22-39) GBV-C sequence (E1P8lin) was found to be capable of inhibiting the interaction of HIV-1 FP with bilayers and its cyclic analogue (E1P8cyc) showed a higher anti-HIV-1 activity. In the present work, in an attempt to gain a better understanding of the interaction of E1P8 peptides with HIV-1 FP, we analyzed direct interactions between peptides at the molecular level. Our results support that E1P8cyc might be more potent at blocking HIV-1 entry than E1P8lin as a consequence of the structure induced in the complex formed with HIV-1 FP, which is able to modify the conformation adopted by this functional domain of the HIV-1 gp41 protein in target cell membranes.


Assuntos
Fármacos Anti-HIV/farmacologia , Vírus GB C/química , Inibidores da Fusão de HIV/farmacologia , HIV-1/efeitos dos fármacos , HIV-1/metabolismo , Fragmentos de Peptídeos/farmacologia , Fármacos Anti-HIV/química , Relação Dose-Resposta a Droga , Inibidores da Fusão de HIV/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Fragmentos de Peptídeos/química , Relação Estrutura-Atividade
15.
Curr Med Chem ; 21(2): 238-50, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24083612

RESUMO

Following the report of beneficial effects of co-infection by GB virus C (GBV-C) for HIV-infected patients, we have studied synthetic GBV-C peptides and their relationship with HIV type-1. This paper reports the design and synthesis of new forms of presentation of two peptide inhibitors corresponding to the envelope proteins E1 and E2 of GBV-C, together with a study of their anti-HIV-1 activity. Homogeneous and heterogeneous multiple antigenic peptides (MAPs), lipophilic derivatizations, cyclization and peptide-gold conjugations are the chemical design strategies adopted. Our aim is to enhance the anti-viral potency of the GBV-C peptide domains. Of all the GBV-C peptide derivatives studied, peptide-gold complexes derived from the (22-39) sequence of the GBV-C E1 protein were the most active entry inhibitors. These results support the putative modulation of HIV-1 infection by the GBV-C E1 protein and open new perspectives for the development of novel peptide-derived HIV-1 entry inhibitors.


Assuntos
Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Vírus GB C/química , Compostos de Ouro/química , HIV-1/efeitos dos fármacos , Peptídeos/química , Peptídeos/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade
16.
Int J Mol Sci ; 14(6): 12313-28, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-23749115

RESUMO

Plantaricin149a (Pln149a) is a cationic antimicrobial peptide, which was suggested to cause membrane destabilization via the carpet mechanism. The mode of action proposed to this antimicrobial peptide describes the induction of an amphipathic α-helix from Ala7 to Lys20, while the N-terminus residues remain in a coil conformation after binding. To better investigate this assumption, the purpose of this study was to determine the contributions of the Tyr1 in Pln149a in the binding to model membranes to promote its destabilization. The Tyr to Ser substitution increased the dissociation constant (KD) of the antimicrobial peptide from the liposomes (approximately three-fold higher), and decreased the enthalpy of binding to anionic vesicles from -17.2 kcal/mol to -10.2 kcal/mol. The peptide adsorption/incorporation into the negatively charged lipid vesicles was less effective with the Tyr1 substitution and peptide Pln149a perturbed the liposome integrity more than the analog, Pln149S. Taken together, the peptide-lipid interactions that govern the Pln149a antimicrobial activity are found not only in the amphipathic helix, but also in the N-terminus residues, which take part in enthalpic contributions due to the allocation at a lipid-aqueous interface.


Assuntos
Bacteriocinas/química , Lipossomos/química , Fosfolipídeos/química , Tirosina/metabolismo , Sequência de Aminoácidos , Anti-Infecciosos/farmacologia , Calorimetria , Dicroísmo Circular , Hemólise/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Naftalenos/metabolismo , Peptídeos/síntese química , Peptídeos/química , Peptídeos/isolamento & purificação , Fosfatidilgliceróis/química , Compostos de Piridínio/metabolismo , Espectrometria de Fluorescência , Relação Estrutura-Atividade , Triptofano
17.
Curr Top Med Chem ; 13(6): 743-51, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23574523

RESUMO

Antibodies directed against citrullinated proteins and peptides (ACPAs) are the most specific serological markers available for diagnosing rheumatoid arthritis (RA). ACPAs may be detected several years before symptoms of RA appear, and their presence at disease onset is a good predictor of the development of erosive joint lesions. RA patients can be classified into two major groups: those who have ACPAs and those who do not. The presence of ACPAs at early stages of RA predicts the development of earlier and more widespread joint erosions, and low remission rates.Synthetic peptides can replace cognate proteins in solid-phase assays for specific autoantibody recognition in RA patients. The use of synthetic peptides instead of proteins represents an advantage in terms of the reproducibility of such immunoassays. Proteins also contain non-citrullinated epitopes that are recognized by non-RA sera and this could reduce the specificity of the test. The use of synthetic citrullinated peptides gives absolute control over the exact epitopes presented. Furthermore, it is difficult to prepare sufficient amounts of high-quality antigenic proteins with a well-defined degree of citrullination. Synthetic citrullinated peptides, in contrast, are easily obtained in a pure form with a well-defined chemical structure and the epitopes can be precisely oriented in the plate by covalent binding of the peptides.Chimeric peptides bearing different citrullinated protein domains have recently been used in the design of RA diagnosis systems. The results of the application of those systems indicate that more than one serological test is required to classify RA patients based on the presence or absence of ACPAs. Each of the target molecules reported (fibrin, vimentin and filaggrin) helps to identify a particular subset of RA patients.


Assuntos
Artrite Reumatoide/sangue , Artrite Reumatoide/diagnóstico , Peptídeos Cíclicos/sangue , Proteínas Filagrinas , Humanos
18.
J Pept Sci ; 18(5): 326-35, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22438139

RESUMO

Synthetic peptides derived from GB virus C (GBV-C) have previously been studied in our group for the development of new systems capable of diagnosing diseases caused by this humanotropic virus. We also recently described specific peptide domains of the E2 envelop protein of GBV-C that have the capacity to interfere with the HIV-1 fusion peptide, produce a notable decrease in cellular membrane fusion, and perturb HIV-1 infectivity in a dose-dependent manner. The present work discloses the design and synthesis of both linear and cyclic branched peptides based on a previously reported N-terminal sequence of the GBV-C E2 protein. Immunoassays and cell-cell fusion assays were performed to evaluate their diagnostic value to detect anti-GBV-C antibodies in HIV-1 patients, as well as their putative anti-HIV-1 activity as entry inhibitors. Our results showed that chemical modifications of the selected E2(7-26) linear peptide to afford cyclic architecture do not result in an enhanced inhibition of gp41 HIV-1-mediated cell-cell fusion nor improved sensitivity in the detection of GBV-C antibodies in HIV-1 co-infected patients. Thus, the ELISA data reinforce the potential utility of linear versions of the E2(7-26) region for the development of new peptide-based immunosensor devices for the detection of anti-GBV-C antibodies in HIV-1 co-infected patients.


Assuntos
Vírus GB C/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Peptídeos/farmacologia , Proteínas Virais/química , Linhagem Celular Tumoral , Coinfecção , Humanos , Imunoensaio , Peptídeos/síntese química , Peptídeos/química
19.
Rev. neurol. (Ed. impr.) ; 54(5): 277-283, 1 mar., 2012. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-99545

RESUMO

Introducción. La flunaricina, con nivel de evidencia A, y el nadolol, con nivel de evidencia C, estarían indicados como tratamiento preventivo de la migraña. No existen estudios previos que comparen la efectividad de ambos fármacos. Objetivo. Comparar parámetros de efectividad en grupos independientes de pacientes tratados preventivamente con uno de los fármacos del estudio a los que se aplicó el mismo protocolo. Pacientes y métodos. Se seleccionó a pacientes con migraña episódica (criterios de la Sociedad Internacional de Cefaleas del 2004) que se habían sometido a tratamiento preventivo por primera vez, con flunaricina (5 mg/día) o nadolol (20-40 mg/día). Se analizaron las variables principales de efectividad (reducción del número de crisis al cuarto mes de tratamiento y tasa de respondedores). Resultados. Se incluyó a 227 pacientes con intención de recibir tratamiento: 155 con flunaricina (80,5% mujeres; edad media: 38,3 ± 12,1 años) y 72 con nadolol (63,8% mujeres; edad media: 37,1 ± 12,0 años). La media de crisis en el mes previo al tratamiento fue de 6,09 ± 2,6 en el grupo de la flunaricina y de 5,1 ± 1,7 en el grupo del nadolol (p = 0,0079); la media de crisis al cuarto mes de tratamiento fue de 2,61 ± 2,4 en el grupo de la flunaricina y de 2,77 ± 2,4 en el grupo del nadolol (p = NS). Porcentaje de reducción de migrañas: 55,2% con flunaricina y 50,4% con nadolol (p = NS). La tasa de respondedores fue del 69% con flunaricina y del 67% con nadolol (p = NS). La tasa de respuesta excelente (reducción mayor o igual al 75% de las crisis) fue del 52,2% con flunaricina y del 36,1% con nadolol (p = 0,0077). Porcentaje de efectos adversos: 48,3% con flunaricina frente a 25% con nadolol (p = 0,0009). La tasa de satisfacción fue del 68%, similar en ambos grupos. Conclusión. Tanto la flunaricina como el nadolol mostraron ser efectivos en el tratamiento preventivo de la migraña episódica. La flunaricina se utilizó con mayor frecuencia en nuestro medio y fue peor tolerada (AU)


Introduction. Flunarizine, with level of evidence A, and nadolol, with evidence level C, would be indicated as preventive treatment of migraine. Yet, no previous studies have been conducted to compare the effectiveness of the two drugs. Aim. To compare the effectiveness parameters in independent groups of patients treated preventively with one of the pharmaceuticals from the study, the same protocol being applied in both cases. Patients and methods. The subjects selected for the study were patients with episodic migraine (according to 2004 International Headache Society criteria) who had undergone preventive treatment for the first time, with flunarizine (5 mg/day) or nadolol (20-40 mg/day). The main effectiveness variables (reduction in the number of seizures at four months of treatment and responder rates) were analysed. Results. The study included 227 patients who intended to receive treatment: 155 with flunarizine (80.5% females; mean age: 38.3 ± 12.1 years) and 72 with nadolol (63.8% females; mean age: 37.1 ± 12.0 years). The mean number of seizures prior to treatment was 6.09 ± 2.6 in the flunarizine group and 5.1 ± 1.7 in the nadolol group (p = 0.0079); at four months of treatment it was 2.61 ± 2.4 in the flunarizine group and 2.77 ± 2.4 in the nadolol group (p = NS). Percentage of reduction of migraines: 55.2% with flunarizine and 50.4% with nadolol (p = NS). The responder rate was 69% with flunarizine and 67% with nadolol (p = NS). The excellent response rate (reduction in the number of seizures by 75% or more) was 52.2% with flunarizine and 36.1% with nadolol (p = 0.0077). Percentage of adverse side effects: 48.3% with flunarizine and 25% with nadolol (p = 0.0009). The satisfaction rate was similar in both groups, 68%. Conclusions. Both flunarizine and nadolol proved to be effective in the preventive treatment of episodic migraine. Flunarizine is used more often in our milieu and was less well tolerated (AU)


Assuntos
Humanos , Nadolol/farmacocinética , Flunarizina/farmacocinética , Transtornos de Enxaqueca/prevenção & controle , Satisfação do Paciente , Avaliação de Resultado de Ações Preventivas , Anti-Inflamatórios não Esteroides/farmacocinética
20.
J Med Chem ; 54(21): 7486-92, 2011 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-21981664

RESUMO

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation and, in many cases, destruction of the joints. To prevent progressive and irreversible structural damage, early diagnosis of RA is of paramount importance. The present study addresses the search of new RA citrullinated antigens that could supplement or complement diagnostic/prognostic existing tests. With this aim, the epitope anticitrullinated vimentin antibody response was mapped using synthetic peptides. To improve the sensitivity/specificity balance, a vimentin peptide that was selected, and its cyclic analogue, were combined with fibrin- and filaggrin-related peptides to render chimeric peptides. Our findings highlight the putative application of these chimeric peptides for the design of RA diagnosis systems and imply that more than one serological test is required to classify RA patients based on the presence or absence of ACPAs. Each of the target molecules reported here (fibrin, vimentin, filaggrin) has a specific utility in the identification of a particular subset of RA patients.


Assuntos
Artrite Reumatoide/diagnóstico , Citrulina/metabolismo , Peptídeos , Vimentina/metabolismo , Idoso , Sequência de Aminoácidos , Artrite Reumatoide/sangue , Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Citrulina/química , Citrulina/imunologia , Ensaio de Imunoadsorção Enzimática , Epitopos , Feminino , Fibrina/química , Fibrina/imunologia , Proteínas Filagrinas , Humanos , Proteínas de Filamentos Intermediários/química , Proteínas de Filamentos Intermediários/imunologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Biblioteca de Peptídeos , Peptídeos/síntese química , Peptídeos/imunologia , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/imunologia , Sensibilidade e Especificidade , Técnicas de Síntese em Fase Sólida , Vimentina/química , Vimentina/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...