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1.
Clin Exp Allergy ; 42(6): 966-75, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22909168

RESUMO

BACKGROUND: The mould Alternaria alternata is a major elicitor of allergic asthma. Diagnosis and specific immunotherapy (SIT) of Alternaria allergy are often limited by the insufficient quality of natural mould extracts. OBJECTIVE: To investigate whether recombinant Alt a 1 can be used for reliable diagnosis of Alternaria alternata allergy and to develop a safe, non-allergenic vaccine for SIT of Alternaria allergy. METHODS: The qualitative sensitization profile of 80 Alternaria-allergic patients from Austria and Italy was investigated using an allergen micro-array and the amount of Alternaria-specific IgE directed to rAlt a 1 was quantified by ImmunoCAP measurements. Peptides spanning regions of predicted high surface accessibility of Alt a 1 were synthesized and tested for IgE reactivity and allergenic activity, using sera and basophils from allergic patients. Carrier-bound peptides were studied for their ability to induce IgG antibodies in rabbits which recognize Alt a 1 and inhibit allergic patients' IgE reactivity to Alt a 1. RESULTS: rAlt a 1 allowed diagnosis of Alternaria allergy in all tested patients, bound the vast majority (i.e. >95%) of Alternaria-specific IgE and elicited basophil activation already at a concentration of 0.1 ng/mL. Four non-allergenic peptides were synthesized which, after coupling to the carrier protein keyhole limpet hemocyanin, induced Alt a 1-specific IgG and inhibited allergic patients' IgE binding to Alt a 1. CONCLUSIONS AND CLINICAL RELEVANCE: rAlt a 1 is a highly allergenic molecule allowing sensitive diagnosis of Alternaria allergy. Carrier-bound non-allergenic Alt a 1 peptides are candidates for safe SIT of Alternaria allergy.


Assuntos
Alternaria/imunologia , Antígenos de Fungos/imunologia , Vacinas Fúngicas/imunologia , Hipersensibilidade/diagnóstico , Hipersensibilidade/prevenção & controle , Peptídeos/imunologia , Adolescente , Adulto , Animais , Anticorpos Antifúngicos/sangue , Anticorpos Antifúngicos/imunologia , Anticorpos Antifúngicos/metabolismo , Especificidade de Anticorpos/imunologia , Antígenos de Fungos/química , Criança , Feminino , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina E/metabolismo , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Ligação Proteica/imunologia , Dobramento de Proteína , Multimerização Proteica , Estrutura Secundária de Proteína , Coelhos , Adulto Jovem
2.
J Immunol ; 185(6): 3661-8, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20696862

RESUMO

The current vaccines for anthrax in the United States and United Kingdom are efficacious in the two most accepted animal models of inhalation anthrax, nonhuman primates and rabbits, but require extensive immunization protocols. We previously demonstrated that a linear determinant in domain 2 of Bacillus anthracis protective Ag (PA) is a potentially important target for an epitope-specific vaccine for anthrax, as Abs specific for this site, referred to as the loop-neutralizing determinant (LND), neutralize lethal toxin in vitro, yet are virtually absent in PA-immunized rabbits. In this study, we evaluated the immunogenicity and protective efficacy in rabbits of multiple antigenic peptides (MAPs) consisting of aa 304-319 from the LND of PA colinearly synthesized at the C terminus (T-B MAP) or N terminus (B-T MAP) with a heterologous T cell epitope from Plasmodium falciparum. Immunogenicity studies demonstrated that both MAPs elicited toxin-neutralizing Ab in rabbits. To evaluate the MAPs as potential anthrax vaccines, we immunized groups of rabbits (n = 7) with each MAP in Freund's adjuvant and then exposed all rabbits to a 200-LD(50) challenge with aerosolized spores of B. anthracis Ames strain. All seven rabbits immunized with the B-T MAP and 89% (six of seven) of rabbits immunized with the T-B MAP survived the spore challenge. Corollary studies with reference sera from human vaccinees immunized with rPA or anthrax vaccine absorbed and nonhuman primates immunized with PA revealed no detectable Ab with specificity for the LND. We conclude that a synthetic peptide vaccine targeting the LND would be a potentially efficacious vaccine for anthrax.


Assuntos
Vacinas contra Antraz/administração & dosagem , Vacinas contra Antraz/imunologia , Antraz/prevenção & controle , Bacillus anthracis/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia , Administração por Inalação , Sequência de Aminoácidos , Animais , Antraz/imunologia , Vacinas contra Antraz/síntese química , Bacillus anthracis/patogenicidade , Linhagem Celular , Feminino , Humanos , Macaca fascicularis , Macaca mulatta , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Plasmodium falciparum/imunologia , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas de Protozoários/administração & dosagem , Proteínas de Protozoários/imunologia , Coelhos , Esporos Bacterianos/imunologia , Vacinas de Subunidades Antigênicas/síntese química , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
3.
Biochem Biophys Res Commun ; 394(2): 393-7, 2010 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-20214884

RESUMO

Alzheimer's disease (AD) is the most common cause of dementia affecting the elderly. Treatment for effective cure of this complex neurodegenerative disease does not yet exist. In AD, otherwise soluble, monomeric form of amyloid beta (Abeta) peptide converts into toxic, fibrillar form rich in beta-sheet content. Several immunological approaches that prevent this conversion of Abeta into pathological form or that accelerate its clearance are being actively pursued worldwide. As part of these attempts, we report here, the design and characterization of a non-amyloidogenic homologue of Abeta (Abeta-KEK). We demonstrate that this peptide is helical in nature and retains the immunoneutralizing epitopes of native Abeta. More importantly, Fab fragments of the polyclonal anti-Abeta-KEK antibodies interfere with formation of Abeta fibrils as well as dissociate the preformed Abeta aggregates in vitro. These results suggest that non-amyloidogenic Abeta-KEK may serve as a safer alternative vaccine for Alzheimer's disease.


Assuntos
Doença de Alzheimer/prevenção & controle , Vacinas contra Alzheimer/imunologia , Peptídeos beta-Amiloides/imunologia , Epitopos Imunodominantes/imunologia , Vacinas contra Alzheimer/química , Sequência de Aminoácidos , Peptídeos beta-Amiloides/química , Anticorpos/imunologia , Humanos , Epitopos Imunodominantes/química , Fragmentos Fab das Imunoglobulinas/imunologia , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/imunologia , Estrutura Secundária de Proteína
4.
Biochim Biophys Acta Bioenerg ; 1861(2): 148117, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31734197

RESUMO

The xanthophyll cycle is a regulatory mechanism operating in the photosynthetic apparatus of plants. It consists of the conversion of the xanthophyll pigment violaxanthin to zeaxanthin, and vice versa, in response to light intensity. According to the current understanding, one of the modes of regulatory activity of the cycle is associated with the influence on a molecular organization of pigment-protein complexes. In the present work, we analyzed the effect of violaxanthin and zeaxanthin on the molecular organization of the LHCII complex, in the environment of membranes formed with chloroplast lipids. Nanoscale imaging based on atomic force microscopy (AFM) showed that the presence of exogenous xanthophylls promotes the formation of the protein supramolecular structures. Nanoscale infrared (IR) absorption analysis based on AFM-IR nanospectroscopy suggests that zeaxanthin promotes the formation of LHCII supramolecular structures by forming inter-molecular ß-structures. Meanwhile, the molecules of violaxanthin act as "molecular spacers" preventing self-aggregation of the protein, potentially leading to uncontrolled dissipation of excitation energy in the complex. This latter mechanism was demonstrated with the application of fluorescence lifetime imaging microscopy. The intensity-averaged chlorophyll a fluorescence lifetime determined in the LHCII samples without exogenous xanthophylls at the level of 0.72 ns was longer in the samples containing exogenous violaxanthin (2.14 ns), but shorter under the presence of zeaxanthin (0.49 ns) thus suggesting a role of this xanthophyll in promotion of the formation of structures characterized by effective excitation quenching. This mechanism can be considered as a representation of the overall photoprotective activity of the xanthophyll cycle.


Assuntos
Membranas Intracelulares/enzimologia , Complexos de Proteínas Captadores de Luz/química , Narcissus/química , Spinacia oleracea/enzimologia , Zeaxantinas/química , Clorofila A/química , Estrutura Secundária de Proteína , Xantofilas/química
5.
J Med Chem ; 63(8): 4205-4214, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32227946

RESUMO

Influenza and dengue viruses present a growing global threat to public health. Both viruses depend on the host endoplasmic reticulum (ER) glycoprotein folding pathway. In 2014, Sadat et al. reported two siblings with a rare genetic defect in ER α-glucosidase I (ER Glu I) who showed resistance to viral infections, identifying ER Glu I as a key antiviral target. Here, we show that a single dose of UV-4B (the hydrochloride salt form of N-(9'-methoxynonyl)-1-deoxynojirimycin; MON-DNJ) capable of inhibiting Glu I in vivo is sufficient to prevent death in mice infected with lethal viral doses, even when treatment is started as late as 48 h post infection. The first crystal structure of mammalian ER Glu I will constitute the basis for the development of potent and selective inhibitors. Targeting ER Glu I with UV-4B-derived compounds may alter treatment paradigms for acute viral disease through development of a single-dose therapeutic regime.


Assuntos
Dengue/prevenção & controle , Retículo Endoplasmático/efeitos dos fármacos , Inibidores de Glicosídeo Hidrolases/administração & dosagem , Influenza Humana/prevenção & controle , alfa-Glucosidases , Animais , Dengue/tratamento farmacológico , Dengue/enzimologia , Vírus da Dengue/efeitos dos fármacos , Vírus da Dengue/enzimologia , Relação Dose-Resposta a Droga , Retículo Endoplasmático/enzimologia , Humanos , Influenza Humana/tratamento farmacológico , Influenza Humana/enzimologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos BALB C , Estrutura Secundária de Proteína , alfa-Glucosidases/metabolismo
6.
J Med Chem ; 63(5): 1859-1881, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-31663735

RESUMO

Infections caused by resistant bacteria are nowadays too common, and some pathogens have even become resistant to multiple types of antibiotics, in which case few or even no treatments are available. In recent years, the most successful strategy in anti-infective drug discovery for the treatment of such problematic infections is the combination therapy "antibiotic + inhibitor of resistance". These inhibitors allow the repurposing of antibiotics that have already proven to be safe and effective for clinical use. Three main types of compounds have been developed to block the principal bacterial resistance mechanisms: (i) ß-lactamase inhibitors; (ii) outer membrane permeabilizers; (iii) efflux pump inhibitors. This Perspective is focused on ß-lactamase inhibitors that disable the most prevalent cause of antibiotic resistance in Gram-negative bacteria, i.e., the deactivation of the most widely used antibiotics, ß-lactams (penicillins, cephalosporines, carbapenems, and monobactams), by the production of ß-lactamases. An overview of the most recently identified ß-lactamase inhibitors and of combination therapy is provided. The article also covers the mechanism of action of the different types of ß-lactamase enzymes as a basis for inhibitor design and target inactivation.


Assuntos
Antibacterianos/metabolismo , Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Inibidores de beta-Lactamases/metabolismo , beta-Lactamases/metabolismo , Animais , Infecções Bacterianas/metabolismo , Resistência Microbiana a Medicamentos/fisiologia , Humanos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Resultado do Tratamento , Inibidores de beta-Lactamases/química , Inibidores de beta-Lactamases/uso terapêutico
7.
Hum Vaccin Immunother ; 16(12): 2921-2931, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931361

RESUMO

The sudden emergence of a highly transmissible and pathogenic coronavirus SARS-CoV-2 in December 2019 from China and its rapid global spread has posed an international health emergency. The rapid development of an effective vaccine is imperative to control the spread of SARS-CoV-2. A number of concurrent efforts to find an effective therapeutic agent or vaccine for COVID-19 (coronavirus disease 2019) are being undertaken globally. Oral and nasal mucosal surfaces serve as the primary portal of entry for pathogens like coronaviruses in the human body. As evidenced by studies on similar coronaviruses (SARS-CoV and MERS-CoV), mucosal vaccination can provide a safe and effective means for the induction of long-lasting systemic and mucosal immunity to confer protection against SARS-CoV-2. This article summarizes the approaches to an effective mucosal vaccine formulation which can be a rewarding approach to combat the unprecedented threat posed by this emerging global pandemic.


Assuntos
Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Mucosa Nasal/imunologia , SARS-CoV-2/imunologia , Administração Intranasal/métodos , Animais , COVID-19/epidemiologia , Humanos , Mucosa Nasal/efeitos dos fármacos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , SARS-CoV-2/química , SARS-CoV-2/efeitos dos fármacos
8.
J Agric Food Chem ; 66(41): 10855-10863, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30284821

RESUMO

The 2S albumin Ara h 6 is one of the most important peanut allergens. A post-translationally cleaved Ara h 6 (pAra h 6) was purified from Virginia type peanuts, and the cleavage site was mapped using high-resolution mass spectrometry. Compared to intact Ara h 6, pAra h 6 lacks a 5-amino acid stretch, resembling amino acids 43-47 (UniProt accession number Q647G9) in the nonstructured loop. Consequently, pAra h 6 consists of two chains: an N-terminal chain of approximately 5 kDa and a C-terminal chain of approximately 9 kDa, held together by disulfide bonds. Intermediate post-translationally cleaved products, in which this stretch is cleaved yet still attached to one of the subunits, are also present. The secondary structure and immunoglobulin E (IgE) binding of pAra h 6 resembles that of intact Ara h 6, indicating that the loss of the nonstructured loop is not critical for maintaining the protein structure. Commercially available monoclonal and polyclonal immunoglobulin G (IgG) antibodies directed to Ara h 6 react with both intact Ara h 6 and pAra h 6, suggesting that the involved epitopes are not located in the area that is post-translationally cleaved. No differences between intact Ara h 6 and pAra h 6 in terms of IgE binding were found, suggesting that the area that is post-translationally cleaved is not involved in IgE epitopes either. For all main cultivars Runner, Virginia, Valencia, and Spanish, intact Ara h 6 and pAra h 6 occur in peanut at similar levels, indicating that pAra h 6 is a consistent and important contributor to the allergenic potency of peanut.


Assuntos
Albuminas 2S de Plantas/química , Albuminas 2S de Plantas/isolamento & purificação , Antígenos de Plantas/química , Antígenos de Plantas/isolamento & purificação , Arachis/química , Albuminas 2S de Plantas/imunologia , Sequência de Aminoácidos , Aminoácidos/química , Antígenos de Plantas/imunologia , Epitopos/imunologia , Glicoproteínas/química , Glicoproteínas/imunologia , Glicoproteínas/isolamento & purificação , Humanos , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Hipersensibilidade a Amendoim/metabolismo , Hipersensibilidade a Amendoim/prevenção & controle , Proteínas de Plantas/química , Proteínas de Plantas/imunologia , Proteínas de Plantas/isolamento & purificação , Estrutura Secundária de Proteína
9.
Biomed Pharmacother ; 86: 221-231, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28006747

RESUMO

Cancer is the second cause of death in 2015, and it has been estimated to surpass heart diseases as the leading cause of death in the next few years. Several mechanisms are involved in cancer pathogenesis. Studies have indicated that proteases are also implicated in tumor growth and progression which is highly dependent on nutrient and oxygen supply. On the other hand, protease inhibitors could be considered as a potent strategy in cancer therapy. On the basis of the type of the key amino acid in the active site of the protease and the mechanism of peptide bond cleavage, proteases can be classified into six groups: cysteine, serine, threonine, glutamic acid, aspartate proteases, as well as matrix metalloproteases. In this review, we focus on the role of different types of proteases and protease inhibitors in cancer pathogenesis.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Peptídeo Hidrolases/metabolismo , Inibidores de Proteases/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Carcinogênese/patologia , Humanos , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Estrutura Secundária de Proteína , Resultado do Tratamento
10.
Neurochem Int ; 107: 33-42, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28153786

RESUMO

Studies in multiple experimental systems show that Ca2+-calmodulin stimulated protein kinase II (CaMKII) is a major mediator of ischaemia-induced cell death and suggest that CaMKII would be a good target for neuroprotective therapies in acute treatment of stroke. However, as CaMKII regulates many cellular processes in many tissues any clinical treatment involving the inhibition of CaMKII would need to be able to specifically target the functions of ischaemia-activated CaMKII. In this review we summarise new developments in our understanding of the molecular mechanisms involved in ischaemia-induced CaMKII-mediated cell death that have identified ways in which such specificity of CaMKII inhibition after stroke could be achieved. We also review the mechanisms and phases of tissue damage in ischaemic stroke to identify where and when CaMKII-mediated mechanisms may be involved.


Assuntos
Isquemia Encefálica/enzimologia , Isquemia Encefálica/prevenção & controle , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/antagonistas & inibidores , Fármacos Neuroprotetores/administração & dosagem , Acidente Vascular Cerebral/enzimologia , Acidente Vascular Cerebral/prevenção & controle , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/química , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Sistemas de Liberação de Medicamentos/tendências , Humanos , Neuroproteção/efeitos dos fármacos , Neuroproteção/fisiologia , Inibidores de Proteínas Quinases/administração & dosagem , Estrutura Secundária de Proteína
11.
Int J Biochem Cell Biol ; 37(2): 336-49, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15474979

RESUMO

Conserved, high-activity, red blood cell binding malaria peptide 6786, from the HRP-I protein, having a random 3D structure as determined by 1H-NMR, was non-immunogenic and non-protection inducing when used as an immunogen in Aotus monkeys. Modifications made in its amino acid sequence were thus performed to render it immunogenic and protection inducing. Non-immunogenic, non-protection inducing modified peptide 13852 presented A2-H8 and K14-L18 helix fragments. Immunogenic, non-protection inducing modified peptide 23428 presented a short, displaced helix in a different region, whilst immunogenic, protection inducing peptide 24224 had 2 displaced helical regions towards the central region giving more flexibility to its N- and C-terminals. Immunogenic and protection inducing peptides bound with high affinity to HLA-DRB1* 0301 whilst others did not bind to any HLA-DRB1* purified molecule. Structural modifications may thus lead to inducing immunogenicity and protection associated with their capacity to bind specifically to purified HLA-DRB1* molecules, suggesting a new way of developing multi-component, subunit-based malarial vaccines.


Assuntos
Antígenos de Protozoários/imunologia , Antígenos HLA-DR/imunologia , Vacinas Antimaláricas/imunologia , Malária Falciparum/imunologia , Oligopeptídeos/imunologia , Peptídeos/imunologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Protozoários/química , Aotidae/imunologia , Antígenos HLA-DR/metabolismo , Humanos , Malária Falciparum/prevenção & controle , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Plasmodium falciparum/química , Ligação Proteica/imunologia , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas de Protozoários/química
12.
Science ; 349(6254): 1301-6, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26303961

RESUMO

The identification of human broadly neutralizing antibodies (bnAbs) targeting the hemagglutinin (HA) stem revitalized hopes of developing a universal influenza vaccine. Using a rational design and library approach, we engineered stable HA stem antigens ("mini-HAs") based on an H1 subtype sequence. Our most advanced candidate exhibits structural and bnAb binding properties comparable to those of full-length HA, completely protects mice in lethal heterologous and heterosubtypic challenge models, and reduces fever after sublethal challenge in cynomolgus monkeys. Antibodies elicited by this mini-HA in mice and nonhuman primates bound a wide range of HAs, competed with human bnAbs for HA stem binding, neutralized H5N1 viruses, and mediated antibody-dependent effector activity. These results represent a proof of concept for the design of HA stem mimics that elicit bnAbs against influenza A group 1 viruses.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Humanos , Camundongos , Multimerização Proteica , Estrutura Secundária de Proteína
13.
Br J Pharmacol ; 172(17): 4391-405, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26076332

RESUMO

BACKGROUND AND PURPOSE: Myeloid differentiation 2 (MD-2) recognizes LPS, which is required for TLR4 activation, and represents an attractive therapeutic target for severe inflammatory disorders. We previously found that a chalcone derivative, L6H21, could inhibit LPS-induced overexpression of TNF-α and IL-6 in macrophages. Here, we performed a series of biochemical experiments to investigate whether L6H21 specifically targets MD-2 and inhibits the interaction and signalling transduction of LPS-TLR4/MD-2. EXPERIMENTAL APPROACH: The binding affinity of L6H21 to MD-2 protein was analysed using computer docking, surface plasmon resonance analysis, elisa, fluorescence measurements and flow cytometric analysis. The effects of L6H21 on MAPK and NF-κB signalling were determined using EMSA, fluorescence staining, Western blotting and immunoprecipitation. The anti-inflammatory effects of L6H21 were confirmed using elisa and RT-qPCR in vitro. The anti-inflammatory effects of L6H21 were also evaluated in septic C57BL/6 mice. KEY RESULTS: Compound L6H21 inserted into the hydrophobic region of the MD-2 pocket, forming hydrogen bonds with Arg(90) and Tyr(102) in the MD-2 pocket. In vitro, L6H21 subsequently suppressed MAPK phosphorylation, NF-κB activation and cytokine expression in macrophages stimulated by LPS. In vivo, L6H21 pretreatment improved survival, prevented lung injury, decreased serum and hepatic cytokine levels in mice subjected to LPS. In addition, mice with MD-2 gene knockout were universally protected from the effects of LPS-induced septic shock. CONCLUSIONS AND IMPLICATIONS: Overall, this work demonstrated that the new chalcone derivative, L6H21, is a potential candidate for the treatment of sepsis. More importantly, the data confirmed that MD-2 is an important therapeutic target for inflammatory disorders.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/toxicidade , Antígeno 96 de Linfócito/metabolismo , Sepse/metabolismo , Sepse/prevenção & controle , Animais , Linhagem Celular , Chalcona/administração & dosagem , Chalcona/química , Chalcona/metabolismo , Relação Dose-Resposta a Droga , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/prevenção & controle , Mediadores da Inflamação/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína
14.
Nat Rev Endocrinol ; 8(12): 728-42, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22945360

RESUMO

In healthy humans, the incretin glucagon-like peptide 1 (GLP-1) is secreted after eating and lowers glucose concentrations by augmenting insulin secretion and suppressing glucagon release. Additional effects of GLP-1 include retardation of gastric emptying, suppression of appetite and, potentially, inhibition of ß-cell apoptosis. Native GLP-1 is degraded within ~2-3 min in the circulation; various GLP-1 receptor agonists have, therefore, been developed to provide prolonged in vivo actions. These GLP-1 receptor agonists can be categorized as either short-acting compounds, which provide short-lived receptor activation (such as exenatide and lixisenatide) or as long-acting compounds (for example albiglutide, dulaglutide, exenatide long-acting release, and liraglutide), which activate the GLP-1 receptor continuously at their recommended dose. The pharmacokinetic differences between these drugs lead to important differences in their pharmacodynamic profiles. The short-acting GLP-1 receptor agonists primarily lower postprandial blood glucose levels through inhibition of gastric emptying, whereas the long-acting compounds have a stronger effect on fasting glucose levels, which is mediated predominantly through their insulinotropic and glucagonostatic actions. The adverse effect profiles of these compounds also differ. The individual properties of the various GLP-1 receptor agonists might enable incretin-based treatment of type 2 diabetes mellitus to be tailored to the needs of each patient.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Peptídeo 1 Semelhante ao Glucagon/agonistas , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hipoglicemiantes/uso terapêutico , Medicina de Precisão/métodos , Sequência de Aminoácidos , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Exenatida , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Peptídeo 1 Semelhante ao Glucagon/uso terapêutico , Humanos , Hipoglicemiantes/farmacologia , Liraglutida , Dados de Sequência Molecular , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Estrutura Secundária de Proteína , Resultado do Tratamento , Peçonhas/farmacologia , Peçonhas/uso terapêutico
15.
Curr Opin Endocrinol Diabetes Obes ; 17(2): 171-6, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20125002

RESUMO

PURPOSE OF REVIEW: Synthetic high-density lipoprotein (HDL) and apolipoprotein (apo) A-I mimetic peptides emulate many of the atheroprotective biological functions attributed to HDL and can modify atherosclerotic disease processes. Administration of these agents as HDL replacement or modifying therapy has tremendous potential of providing new treatments for cardiovascular disease. Progress in the understanding of these agents is discussed in this review. RECENT FINDINGS: Prospective, observational, and interventional studies have convincingly demonstrated that elevated serum levels of high-density lipoprotein-cholesterol (HDL-C) are associated with reduced risk for coronary heart disease (CHD). Although traditional pharmacological agents have shown modest utility in raising HDL levels and reducing CHD risk, use of HDL and apo A-I mimetics provides novel therapies to not only increase HDL levels, but to also influence HDL functionality. Evidence developed over the last several years has identified a number of pathways affected by synthetic HDL and apoA-I mimetic peptides, including enhancing reverse cholesterol transport and reducing oxidation and inflammation that directly influence the progression and regression of atherosclerotic disease. SUMMARY: Clinical trials of relatively short-term synthetic HDL infusion into patients with CHD demonstrate beneficial effects. Use of apo A-I mimetic peptides could potentially overcome some of the limitations associated with use of the intact apo. Studies to establish the most efficacious peptides, optimal dosing regimens, and routes of administration are needed. Use of apo A-I mimetic peptides shows great promise as a therapeutic modality for HDL replacement and enhancing HDL function in treatment of patients with CHD.


Assuntos
Apolipoproteína A-I/química , Materiais Biomiméticos/uso terapêutico , Hipolipemiantes/uso terapêutico , Sequência de Aminoácidos , Animais , Apolipoproteína A-I/uso terapêutico , Aterosclerose/tratamento farmacológico , Aterosclerose/prevenção & controle , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/química , Biomimética/tendências , Humanos , Hipolipemiantes/síntese química , Hipolipemiantes/química , Dados de Sequência Molecular , Fragmentos de Peptídeos/farmacologia , Fragmentos de Peptídeos/uso terapêutico , Estrutura Secundária de Proteína
16.
J. appl. oral sci ; 23(2): 135-144, Mar-Apr/2015. tab, graf
Artigo em Inglês | LILACS, BBO - odontologia (Brasil) | ID: lil-746539

RESUMO

The mandible condylar process cartilage (CP) of Wistar rats is a secondary cartilage and acts as a mandibular growth site. This phenomenon depends on adequate proteins intake and hormone actions, including insulin. Objectives The present study evaluated the morphological aspects and the expression of the insulin receptor (IR) in the cartilage of the condylar process (CP) of rats subjected to protein undernourishment. Material and Methods The nourished group received a 20% casein diet, while the undernourished group (U) received a 5% casein diet. The re-nourished groups, R and RR, were used to assess the effects of re-nutrition during puberty and adulthood, respectively. CPs were processed and stained with picro-sirius red, safranin-O and azocarmine. Scanning electron microscopy and immunohistochemistry were also performed. Results The area of the CP cartilage and the number of cells in the chondroblastic layer decreased in the U group, as did the thickness of the CP layer in the joint and hypertrophic layer. Renourishment during the pubertal stage, but not during the adult phase, restored these parameters. The cell number was restored when re-nutrition occurred in the pubertal stage, but not in the adult phase. The extracellular matrix also decreased in the U group, but was restored by re-nutrition during the pubertal stage and further increased in the adult phase. IR expression was observed in all CPs, being higher in the chondroblastic and hypertrophic cartilage layers. The lowest expression was found in the U and RR groups. Conclusions Protein malnutrition altered the cellularity, the area, and the fibrous cartilage complex, as well as the expression of the IRs. .


Assuntos
Animais , Camundongos , Anti-Inflamatórios não Esteroides/metabolismo , Ciclo-Oxigenase 1/metabolismo , /metabolismo , Inibidores de Ciclo-Oxigenase/metabolismo , Piroxicam/análogos & derivados , Tiazinas/metabolismo , Tiazóis/metabolismo , Substituição de Aminoácidos , Anti-Inflamatórios não Esteroides/química , Arginina/química , Arginina/genética , Arginina/metabolismo , Sítios de Ligação , Domínio Catalítico , Ciclo-Oxigenase 1/química , Ciclo-Oxigenase 1/genética , /química , /genética , Inibidores de Ciclo-Oxigenase/química , Ligação de Hidrogênio , Leucina/química , Leucina/genética , Leucina/metabolismo , Mutação , Piroxicam/química , Piroxicam/metabolismo , Estrutura Secundária de Proteína , Serina/química , Serina/genética , Serina/metabolismo , Tiazinas/química , Tiazóis/química , Tirosina/química , Tirosina/genética , Tirosina/metabolismo , Água
17.
Rev. bras. enferm ; 68(2): 219-227, Mar-Apr/2015. tab
Artigo em Espanhol | LILACS, BDENF - enfermagem (Brasil) | ID: lil-752507

RESUMO

RESUMEN Objetivo: estudio cualitativo que siguió los principios de la teoría fundamentada con el fin de analizar la identidad profesional de docentes de enfermería por medio del análisis de incidentes críticos que más las desestabilizaban. Método: entrevistas semi-estructuradas fueron realizadas a siete enfermeras que actúan como docentes e investigadoras en una universidad privada de Barcelona. Resultados: el material empírico resultante fue organizado en dos categorías: caracterización de los incidentes críticos y reacción de las enfermeras frente a ellos. Conclusión: se concluye que la identidad profesional de estas enfermeras en el campo académico está aún en construcción y que la inexperiencia es el mayor obstáculo que enfrentan para gestionar los incidentes críticos en el trabajo docente. .


RESUMO Objetivo: estudo qualitativo que seguiu os princípios da teoria fundamentada em dados com o objetivo de analisar a identidade profissional de docentes de enfermagem por meio da análise de incidentes críticos que mais as desestabilizaram. Método: entrevistas semiestruturadas foram realizadas com sete enfermeiras que atuam como docentes e pesquisadoras em uma universidade privada de Barcelona. Resultados: o material empírico resultante foi organizado em duas categorias: caracterização dos incidentes críticos e reação das enfermeiras frente a eles. Conclusão: concluiu-se que identidade profissional dessas enfermeiras no campo acadêmico está ainda em construção e a que inexperiência é o maior obstáculo que enfrentam para gerenciar incidentes críticos no trabalho docente. .


ABSTRACT Objective: a qualitative study that followed the principles of the grounded theory in order to analyze the professional identity of nursing academics through the analysis of the most disturbing critical incidents. Method: semi-structured interviews were conducted with seven nurses who worked as professors and researchers in a private university in Barcelona. Results: the resulting empirical material was organized into two categories: characterization of critical incidents and responsiveness to the incident. Conclusion: the professional identity of nurses regarding the academic area is still under construction and inexperience is the major obstacle in the management of critical incidents in the teaching career. .


Assuntos
Humanos , DNA , Receptores de Glucocorticoides/química , Receptores de Mineralocorticoides/química , Sequência de Aminoácidos , Cristalografia por Raios X , DNA , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Dados de Sequência Molecular , Mutação , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Pseudo-Hipoaldosteronismo/genética , Pseudo-Hipoaldosteronismo/metabolismo , Pseudo-Hipoaldosteronismo/patologia , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Receptores de Mineralocorticoides/genética , Receptores de Mineralocorticoides/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia Estrutural de Proteína
18.
J Mol Biol ; 389(2): 227-9, 2009 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-19376131

RESUMO

A subset of protein misfolding diseases, including, for example, Alzheimer's disease, is associated with the formation of highly insoluble amyloid fibrils with a beta-sheet structure. The amyloidogenic human lung surfactant protein C (SP-C) is generated from SP-C precursor, which has a C-terminal domain (CTC) that prevents SP-C amyloid fibril formation. Analysis of the substrate specificity of CTC reveals that it binds to all amino acid residues that promote membrane insertion, provided that they are in a nonhelical conformation. In line with this unexpectedly general substrate specificity, the anti-amyloid function of CTC extends to a transmembrane segment other than that of (pro)SP-C, namely, the amyloid beta-peptide associated with Alzheimer's disease. These findings indicate that CTC is the first known chaperone to be directed towards nonhelical transmembrane segments and that it may be employed for the development of new diagnostics or anti-amyloid therapies.


Assuntos
Amiloide/química , Dobramento de Proteína , Proteína C Associada a Surfactante Pulmonar/química , Amiloidose/prevenção & controle , Humanos , Proteínas de Membrana/química , Chaperonas Moleculares/química , Estrutura Secundária de Proteína , Especificidade por Substrato
19.
Int J Data Min Bioinform ; 1(4): 352-71, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18402047

RESUMO

The paper describes a novel framework, constructed using Constraint Logic Programming (CLP) and parallelism, to determine the association between parts of the primary sequence of a protein and alpha-helices extracted from 3D low-resolution descriptions of large protein complexes. The association is determined by extracting constraints from the 3D information, regarding length, relative position and connectivity of helices, and solving these constraints with the guidance of a secondary structure prediction algorithm. Parallelism is employed to enhance performance on large proteins. The framework provides a fast, inexpensive alternative to determine the exact tertiary structure of unknown proteins.


Assuntos
Algoritmos , Complexos Multiproteicos/química , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína
20.
Org Biomol Chem ; 3(21): 3843-50, 2005 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-16239998

RESUMO

An ageing society faces an increasing number of neurodegenerative diseases such as Alzheimer's, Parkinson's, and Creutzfeld-Jacob disease. The deposition of amyloid fibrils is a pathogenic factor causing the destruction of neuronal tissue. Amyloid-forming proteins are mainly alpha-helical in their native conformation, but undergo an alpha-helix to beta-strand conversion before or during fibril formation. Partially unfolded or misfolded beta-sheet fragments are discussed as direct precursors of amyloids. To potentially cure neurodegenerative diseases we need to understand the complex folding mechanisms that shift the equilibrium from the functional to the pathological isoform of the proteins involved. This paper describes a novel approach that allows us to study the interplay between peptide primary structure and environmental conditions for peptide and protein folding in its whole complexity on a molecular level. This de novo designed peptide system may achieve selective inhibition of fibril formation.


Assuntos
Amiloide/química , Peptídeos/química , Humanos , Metais , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/prevenção & controle , Estrutura Secundária de Proteína
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