RESUMO
Ustekinumab (UST), a human anti-IL12/23p40 monoclonal antibody, was approved by FDA and EMA for the treatment of moderate to severe Crohn's disease (CD). Whether UST is effective in inducing deep remission, including mucosal healing and transmural healing, in patients with CD in a real life setting is not completely clear. This study was performed on 92 subjects with confirmed diagnosis of moderate to severe Crohn's disease and no neoplasia. Before inclusion, all patients had been exposed and had failed to respond to conventional and/or at least one biological therapy. All patients underwent endoscopic examination and bowel MRI and ultrasonography at baseline (T0). At week 52 (T52), patients underwent colonoscopy for assessment of mucosal healing and MRI or ultrasonography for assessment of transmural healing. CDAI was used for the assessment of clinical response and clinical remission. SES-CD was used to assess endoscopic response and remission. Incidence of treatment-related adverse events (TRAEs) was recorded during the study period. Clinical response at week 52 was achieved in 38 (50.5%) patients and clinical remission in 29 (39%). Twenty-six (34%) patients showed mucosal healing, 34 (45%) showed partial endoscopic response. We observed a reduction in SES-CD of at least 50% in 34 (45%) patients as well as an SES-CD ≤ 2 in 26 (35%) patients. All patients with mucosal healing also showed transmural healing. No major TRAEs were observed during treatment. In this multicenter, real life study, we show that UST was well tolerated and effective in inducing clinical response and clinical remission in patients with moderate to severe CD who had previously failed to respond to conventional or biologic therapy. UST showed limited efficacy in inducing deep remission (i.e. mucosal+transmural healing).
Assuntos
Doença de Crohn , Ustekinumab , Terapia Biológica , Doença de Crohn/tratamento farmacológico , Humanos , Estudos Prospectivos , Indução de Remissão , Resultado do Tratamento , Ustekinumab/uso terapêuticoRESUMO
Geena 2 is a tool for filtering, averaging, and aligning MALDI/TOF mass spectra, designed to assist scientists in the analysis of high volumes of data and support them for comparative studies. Three web interfaces are available with different levels of complexity. In this manuscript, we explain how to use Geena 2 with these three interfaces to perform analyses of one's own data. Two support protocols showing how to check the example input file and how to create an input file with own data are also presented. © 2018 by John Wiley & Sons, Inc.
Assuntos
Software , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Guias como Assunto , Interface Usuário-ComputadorRESUMO
The structure and stability of the fluorescent protein monomeric Kusabira Orange (mKO), a GFP-like protein, was studied under different pressure levels and in different chemical environments. At different pH values (between pH 7.4 and pH 4.0) and under a pressure up to 600 MPa (at 25 °C), mKO did not show significant fluorescence spectral changes, indicating a structural stability of the protein. In more extreme chemical conditions (at pH 4.0 in the presence of 0.8 M guanidine hydrochloride), a marked reduction of mKO fluorescence intensity emission was observed at pressures above 300 MPa. This fluorescence emission quenching may be due to the loss of the intermolecular bonds and, consequently, to the destructuration of the mKO chromophore structure. Since the electrostatic and hydrophobic interactions as well as the salt bridges present in proteins are usually perturbed under high pressure, the reduction of mKO fluorescence intensity emission is associated to the perturbation of the protein salt bridges network.
RESUMO
BACKGROUND: Pyoderma gangrenosum (PG) is a rare, neutrophilic, ulcerative skin disease that is difficult to treat, especially when unresponsive to steroids. OBJECTIVES: To determine whether canakinumab is an effective and safe treatment in PG. METHODS: Five adult patients with clinically and histologically confirmed steroid-refractory PG were enrolled in this prospective open-label study. They received canakinumab 150 mg subcutaneously at week 0 with an optional 150 mg at week 2 in case of an inadequate response [Physician's Global Assessment (PGA) ≥ 2], and an optional 150-300 mg at week 8 depending on PGA. The primary clinical end point was clinical improvement (PGA at least -1 from baseline) and/or complete remission (PGA 0 or 1) at week 16. Real-time quantitative polymerase chain reaction was performed on skin samples to quantify cytokine mRNA levels. RESULTS: Interleukin (IL)-1ß and its known target genes IL6, CXCL8 and IL36A were significantly increased in lesional skin of PG. Under canakinumab therapy, four of five patients showed a decrease in target-lesion size, PGA and Dermatology Life Quality Index (DLQI), and three of five achieved complete remission. The mean diameter of target lesions decreased from 4·32 ± 2·6 cm at visit 1 to 0·78 ± 1·3 cm at visit 7 (P = 0·03). Mean DLQI decreased from 15 ± 5 at visit 1 to 8 ± 4 by visit 7 (P = 0·01). Adverse effects were reported in two patients: fatigue in one and worsening of disease at a nontarget lesion in the other. CONCLUSIONS: Our data indicate that IL-1ß plays a key pathogenic role in PG and canakinumab may represent a therapeutic option for steroid-refractory PG.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Fármacos Dermatológicos/administração & dosagem , Pioderma Gangrenoso/tratamento farmacológico , Administração Cutânea , Adulto , Idoso , Anticorpos Monoclonais Humanizados , Citocinas/metabolismo , Esquema de Medicação , Resistência a Medicamentos , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Pioderma Gangrenoso/metabolismo , Esteroides/uso terapêutico , Resultado do Tratamento , Adulto JovemRESUMO
Classical galactosemia is an autosomal recessive inborn error of metabolism due to mutations of the GALT gene leading to toxic accumulation of galactose and derived metabolites. With the benefit of early diagnosis by neonatal screening and early therapy, the acute presentation of classical galactosemia can be prevented. However, despite early diagnosis and treatment, the long term outcome for these patients is still unpredictable because they may go on to develop cognitive disability, speech problems, neurological and/or movement disorders and, in females, ovarian dysfunction. The objectives of the current study were to report our experience with a group of galactosemic patients identified through the neonatal screening programs in northeastern Italy during the last 30years. No neonatal deaths due to galactosemia complications occurred after the introduction of the neonatal screening program. However, despite the early diagnosis and dietary treatment, the patients with classical galactosemia showed one or more long-term complications. A total of 18 different variations in the GALT gene were found in the patient cohort: 12 missense, 2 frameshift, 1 nonsense, 1 deletion, 1 silent variation, and 1 intronic. Six (p.R33P, p.G83V, p.P244S, p.L267R, p.L267V, p.E271D) were new variations. The most common variation was p.Q188R (12 alleles, 31.5%), followed by p.K285N (6 alleles, 15.7%) and p.N314D (6 alleles, 15.7%). The other variations comprised 1 or 2 alleles. In the patients carrying a new mutation, the biochemical analysis of GALT activity in erythrocytes showed an activity of <1%. In silico analysis (SIFT, PolyPhen-2 and the computational analysis on the static protein structure) showed potentially damaging effects of the six new variations on the GALT protein, thus expanding the genetic spectrum of GALT variations in Italy. The study emphasizes the difficulty in establishing a genotype-phenotype correlation in classical galactosemia and underlines the importance of molecular diagnostic testing prior to making any treatment.
Assuntos
Galactosemias/genética , UDPglucose-Hexose-1-Fosfato Uridiltransferase/genética , Adolescente , Adulto , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Galactosemias/diagnóstico , Estudos de Associação Genética , Humanos , Lactente , Recém-Nascido , Itália , Masculino , Mutação de Sentido Incorreto , Triagem Neonatal , Adulto JovemRESUMO
The TP53 tumor-suppressor gene is frequently mutated in human cancer. Missense mutations can add novel functions (gain-of-function, GOF) that promote tumor malignancy. Here we report that mutant (mut) p53 promotes tumor malignancy by suppressing the expression of a natural occurring anti-inflammatory cytokine, the secreted interleukin-1 receptor antagonist (sIL-1Ra, IL1RN). We show that mutp53 but not wild-type (wt) p53 suppresses the sIL-1Ra production in conditioned media of cancer cells. Moreover, mutp53, but not wtp53, binds physically the sIL-1Ra promoter and the protein-protein interaction with the transcriptional co-repressor MAFF (v-MAF musculoaponeurotic fibrosarcoma oncogene family, protein F) is required for mutp53-induced sIL-1Ra suppression. Remarkably, when exposed to IL-1 beta (IL-1ß) inflammatory stimuli, mutp53 sustains a ready-to-be-activated in vitro and in vivo cancer cells' response through the sIL-1Ra repression. Taken together, these results identify sIL-1Ra as a novel mutp53 target gene, whose suppression might be required to generate a chronic pro-inflammatory tumor microenvironment through which mutp53 promotes tumor malignancy.
Assuntos
Proteínas de Ligação a DNA/genética , Inflamação/genética , Proteína Antagonista do Receptor de Interleucina 1/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Linhagem Celular Tumoral , Células HT29 , Células Hep G2 , Humanos , Inflamação/imunologia , Proteína Antagonista do Receptor de Interleucina 1/biossíntese , Proteína Antagonista do Receptor de Interleucina 1/genética , Interleucina-1beta/farmacologia , Células MCF-7 , Fator de Transcrição MafF/metabolismo , Mutação , Neoplasias/genética , Neoplasias/mortalidade , Proteínas Nucleares/metabolismo , Prognóstico , Regiões Promotoras Genéticas/genética , Ligação Proteica , Interferência de RNA , RNA Interferente Pequeno , Microambiente Tumoral/imunologiaRESUMO
OBJECTIVES: Breast cancer is the most common form of cancer affecting women, and the strongest risk factor remains family history. Although screening in asymptomatic women seems able to reduce breast-cancer related mortality, it is of limited usefulness in young women and patients with familial breast cancer syndrome. New diagnostic tools useful for breast cancer management are urgently needed. The aim of the present paper is to look for new candidate tumor markers useful for diagnosis in these patients. DESIGN AND METHODS: In this prospective study 292 serum samples (100 from healthy people, 100 from sporadic breast cancer patients and 92 from familial breast cancer patients) were analyzed by SELDI-TOF-MS. All samples both from cancer patients and healthy subjects were run in duplicate and randomly spotted on CM10 and IMAC30 protein chip array. Data were analyzed using the expression differential mapping (EDM) tool, decisional tree and multivariate analysis. A further in silico investigation was performed in order to hypothesize the identity of evidenced peptides. RESULTS: EDM highlighted thirteen and sixteen significant differentially expressed peaks by CM10 and IMAC30 protein chip respectively. Subsequent analysis showed that two peaks at m/z 11730 and 5066 were differentially expressed in sporadic and familial breast cancer patients respectively, while a peak at m/z 8127 was overexpressed only in familial breast cancer patients. The diagnostic power of protein peaks was tested by decisional tree; sensitivity and specificity ranged from 17% to 91.67%. CONCLUSIONS: We show that the serum profile of familial breast cancer patients was different when compared with that of sporadic breast cancer patients. We hypothesized the identity of the most significant peaks, and further studies are now planned in order to definitively establish the identity.
Assuntos
Biomarcadores Tumorais/sangue , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Predisposição Genética para Doença , Proteômica/métodos , Proteínas Sanguíneas/análise , Neoplasias da Mama/sangue , Estudos de Casos e Controles , Detecção Precoce de Câncer , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Estudos Prospectivos , Análise Serial de Proteínas , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Estatísticas não ParamétricasRESUMO
Sézary syndrome (SS) is an incurable leukemic variant of cutaneous T-cell lymphoma and its pathogenesis is still unknown. Diagnosis/prognosis may strongly ameliorate the management of SS individuals. Here, we profiled the expression of 470 microRNAs (miRNAs) in a cohort of 22 SS patients, and we identified 45 miRNAs differentially expressed between SS and controls. Using predictive analysis, a list of 19 miRNAs, including miR-21, miR-214, miR-486, miR-18a, miR-342, miR-31 and let-7 members were also found. Moreover, we defined a signature of 14 miRNAs including again miR-21, potentially able to discriminate patients with unfavorable and favorable outcome. We validated our data for miR-21, miR-214 and miR-486 by qRT-PCR, including an additional set of array-independent SS cases. In addition, we also provide an in vitro evidence for a contribution of miR-214, miR-486 and miR-21 to apoptotic resistance of CTCL cell line.
Assuntos
Biomarcadores Tumorais/genética , Sobrevivência Celular/genética , Perfilação da Expressão Gênica , MicroRNAs/genética , Síndrome de Sézary/genética , Neoplasias Cutâneas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose/genética , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Nucleossomos/metabolismo , Síndrome de Sézary/metabolismo , Síndrome de Sézary/mortalidade , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/mortalidade , Linfócitos T/metabolismo , Regulação para CimaRESUMO
We describe the prediction of the structural and functional effects of mutations on the enzyme galactose-1-phosphate uridyltransferase related to the genetic disease galactosemia, using a fully computational approach. One hundred and seven single-point mutants were simulated starting from the structural model of the enzyme obtained by homology modeling methods. Several bioinformatics programs were then applied to each resulting mutant protein to analyze the effect of the mutations. The mutations have a direct effect on the active site, or on the dimer assembly and stability, or on the monomer stability. We describe how mutations may exert their effect at a molecular level by altering H-bonds, salt bridges, secondary structure or surface features. The alteration of protein stability, at level of monomer and/or dimer, is the main effect observed. We found an agreement between our results and the functional experimental data available in literature for some mutants. The data and analyses for all the mutants are fully available in the web-accessible database hosted at http://bioinformatica.isa.cnr.it/GALT.
Assuntos
Biologia Computacional/métodos , Galactosemias/enzimologia , Galactosemias/genética , Mutação Puntual , UTP-Hexose-1-Fosfato Uridililtransferase/química , UTP-Hexose-1-Fosfato Uridililtransferase/genética , Domínio Catalítico , Humanos , Modelos Moleculares , Conformação Proteica , Multimerização Proteica , Estabilidade Proteica , UTP-Hexose-1-Fosfato Uridililtransferase/metabolismoRESUMO
The content of 27 cytokines was measured in blood plasma from 19 children with severe uncomplicated burns (group 1) and complicated burns (septic toxemia, toxemia, and pneumonia; group 2). Before surgical treatment (day 4 (+/-2) after burn), significant differences were found in the concentrations of interleukin-1 receptor antagonist, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor-alpha, interferon-gamma, MCP-1, and granulocyte colony-stimulating factor. Cytokine concentration in group 2 patients was much higher than in group 1 patients and healthy children. The concentrations of interleukin-6, interleukin-8, and MCP-1 in group 1 patients significantly surpassed the normal level. Cytokine concentration in the plasma and wound exudates and myeloperoxidase activity in wound exudates from 4 patients of group 2 were measured over 18 days after burn. The inflammatory response was characterized by an increase in the content of interleukin-1beta, interleukin-8, MCP-1, tumor necrosis factor-alpha, MIP-1alpha, and granulocyte-macrophage colony-stimulating factor in the wound (as compared to that in the plasma). Activity of myeloperoxidase in all patients was shown to correlate with the amount of MIP-1alpha (r=0.47), tumor necrosis factor-alpha (r=0.47), and granulocyte-macrophage colony-stimulating factor (r=0.55, p<0.05). Interleukin-8 concentration was beyond the limits of calibration. No correlation was found between the concentration of any of 27 cytokines in blood plasma and exudate. Our results indicate that during active surgical treatment, the wound serves as the source of inflammatory cytokines. Cytokines play a role in the systemic response and increase the degree of local inflammation, which modulates the number and activity of wound neutrophils.
Assuntos
Queimaduras/sangue , Queimaduras/imunologia , Citocinas/sangue , Exsudatos e Transudatos/imunologia , Inflamação , Infecções Bacterianas/sangue , Infecções Bacterianas/imunologia , Queimaduras/complicações , Queimaduras/patologia , Criança , Pré-Escolar , Citocinas/imunologia , Humanos , Inflamação/sangue , Inflamação/etiologia , Inflamação/imunologia , CicatrizaçãoRESUMO
In order to simulate the conformational changes occurring when a protein interacts with its receptor, we firstly evaluated the structural differences between the experimental unbound and bound conformations for selected proteins and created theoretical complexes by replacing, in each experimental complex, the protein-bound with the protein-unbound chain. The theoretical models were then subjected to additional modeling refinements to improve the side chain geometry. Comparing the theoretical and experimental complexes in term of structural and energetic factors is resulted that the refined theoretical complexes became more similar to the experimental ones. We applied the same procedure within an homology modeling experiment, using as templates the experimental structures of human interleukin-1beta (IL-1beta) unbound and bound with its receptor, to build models of the homologous proteins from mouse and trout in unbound and bound conformations and to simulate the interaction with the related receptors. Our results suggest that homology modeling techniques are sensitive to differences between bound and unbound conformations, and that modeling with accuracy the side chains in the complex improves the interaction and molecular recognition. Moreover, our refinement procedure could be used in protein-protein interaction studies and, also, applied in conjunction with rigid-body docking when is not available the protein-bound conformation.
Assuntos
Simulação por Computador , Citocinas/química , Modelos Moleculares , Receptores de Citocinas/química , Sequência de Aminoácidos , Animais , Citocinas/metabolismo , Bases de Dados de Proteínas , Humanos , Ligação de Hidrogênio , Interleucina-1beta/química , Interleucina-1beta/metabolismo , Camundongos , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica , Estrutura Secundária de Proteína , Receptores de Citocinas/metabolismo , Receptores de Interleucina-1/química , Receptores de Interleucina-1/metabolismo , Homologia Estrutural de Proteína , Termodinâmica , TrutaRESUMO
In this study the anti-angiogenic action of a novel non-peptide RGDS-analog named RAM was tested in vitro and in vivo. RAM inhibited FGF-2-induced chemotaxis by 80% in an adhesion-independent way. Further, it induced HUVEC-apoptosis in collagen-seeded HUVEC, indicating that such pro-apoptotic effect was adhesion-independent. In vivo studies revealed that RAM inhibited FGF-2 induced angiogenesis by 60% in the mouse Matrigel-assay and in the chicken-egg chorion-allantoic membrane assay. Finally, RAM was markedly more stable in serum as compared to the template RGDS and after 24 h incubation in 100% serum was significantly more active than RGDS. Taken together these results show that RAM exerts anti-chemotactic and pro-apoptotic effects, by an unexpected adhesion-independent mechanism, as we have recently shown for the template RGDS molecule [Blood 103 (2004) 4180], and has in vivo relevant anti-angiogenic properties, with marked stability in serum; therefore, RAM represents a novel promising anti-angiogenic molecule.
Assuntos
Inibidores da Angiogênese/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Oligopeptídeos/farmacologia , Inibidores da Angiogênese/química , Animais , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Embrião de Galinha , Estabilidade de Medicamentos , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oligopeptídeos/químicaRESUMO
High-performance liquid chromatography purification followed by mass spectrometry analyses highlighted that human senile cataractous lens includes a 8182 Da species which is absent in the normal lens, whereas a 8566/8583 Da species is present in both lenses. Western blot analysis identified both species as ubiquitin. The species at lower molecular weight is a shorter form due to the cleavage of the C-terminal residues 73-76. As it is the last amino acid of ubiquitin which is involved in the protein degradation mechanism, we suggest that this structure modification compromises the function of ubiquitin and consequently the physiologically occurring degradation of the lens proteins.
Assuntos
Catarata/etiologia , Cristalino/química , Ubiquitina/química , Ubiquitina/fisiologia , Idoso , Catarata/metabolismo , Cromatografia Líquida de Alta Pressão , Humanos , Modelos Moleculares , Peso Molecular , Mapeamento de Peptídeos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Ubiquitina/isolamento & purificaçãoRESUMO
Computational tools can bridge the gap between sequence and protein 3D structure based on the notion that information is to be retrieved from the databases and that knowledge-based methods can help in approaching a solution of the protein-folding problem. To this aim our group has implemented neural network-based predictors capable of performing with some success in different tasks, including predictions of the secondary structure of globular and membrane proteins, the topology of membrane proteins and porins and stable alpha-helical segments suited for protein design. Moreover we have developed methods for predicting contact maps in proteins and the probability of finding a cysteine in a disulfide bridge, tools which can contribute to the goal of predicting the 3D structure starting from the sequence (the so called ab initio prediction). All our predictors take advantage of evolution information derived from the structural alignments of homologous (evolutionary related) proteins and taken from the sequence and structure databases. When it is necessary to build models for proteins of unknown spatial structure, which have very little homology with other proteins of known structure, non-standard techniques need to be developed and the tools for protein structure predictions may help in protein modeling. The results of a recent simulation performed in our lab highlights the role of high performing computing technology and of tools of computational biology in protein modeling and peptidomimetic design.
Assuntos
Integrina beta3/farmacologia , Modelos Químicos , Conformação Proteica , Bases de Dados Factuais , Previsões , Humanos , Integrina beta3/química , Estrutura Molecular , Redes Neurais de Computação , Peptídeos/farmacologia , Análise de Sequência de Proteína , Relação Estrutura-AtividadeRESUMO
Homology modelling of the human eIF-5A protein has been performed by using a multiple predictions strategy. As the sequence identity between the target and the template proteins is nearly 30%, which is lower than the commonly used threshold to apply with confidence the homology modelling method, we developed a specific predictive scheme by combining different sequence analyses and predictions, as well as model validation by comparison to structural experimental information. The target sequence has been used to find homologues within sequence databases and a multiple alignment has been created. Secondary structure for each single protein has been predicted and compared on the basis of the multiple sequence alignment, in order to evaluate and adjust carefully any gap. Therefore, comparative modelling has been applied to create the model of the protein on the basis of the optimized sequence alignment. The quality of the model has been checked by computational methods and the structural features have been compared to experimental information, giving us a good validation of the reliability of the model and its correspondence to the protein structure in solution. Last, the model was deposited in the Protein Data Bank to be accessible for studies on the structure-function relationships of the human eIF-5A.
Assuntos
Fatores de Iniciação de Peptídeos/química , Proteínas de Ligação a RNA , Sequência de Aminoácidos , Dicroísmo Circular , Cisteína/química , Bases de Dados como Assunto , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Software , Relação Estrutura-Atividade , Fatores de Tempo , Fator de Iniciação de Tradução Eucariótico 5ARESUMO
Primary structure analysis of the four river buffalo alpha-globin chains showed that haplotypes A and B differ from each other by a substitution at codon 64 that may encode Ala or Asn. The A haplotype encodes two alpha-globin chains, Ialpha1 and IIalpha3, which differ at positions 129 and 131: Ialpha1 has 64 Ala, 129 Phe, 131 Asn; IIalpha3 has 64 Ala, 129 Leu, 131 Ser. The B haplotype encodes two alpha-globin chains, Ialpha2 and IIalpha4, which differ at positions 10 and 11: Ialpha2 has 10 I1e, 11 Gln, 64 Asn; IIalpha4 has 10 Val, 11 Lys, 64 Asn. Apart from the Ala/Asn polymorphism at position 64, amino acid substitutions in allelic and nonallelic alpha-globin chains seem to have arisen by single point mutations. Detection of electrophoretically silent mutations due to neutral amino acid substitutions and their influence on the isoelectric point are discussed. Furthermore, primary structures of river buffalo alpha-globin chains are compared to other species of the Bovidae family to suggest evolutionary events that have characterized the amino acid substitutions of river buffalo hemoglobin.
Assuntos
Búfalos/sangue , Globinas/química , Globinas/genética , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Animais , Carboxipeptidases/farmacologia , Carboxipeptidases A , Bovinos , Evolução Molecular , Globinas/análise , Haplótipos/genética , Focalização Isoelétrica/métodos , Modelos Moleculares , Dados de Sequência Molecular , Fenótipo , Polimorfismo Genético/efeitos dos fármacosRESUMO
In our laboratory we generated one synthetic cyclic peptide (Pep4) and tested it in human mitogen stimulation assays (MSA) and mixed lymphocytes reactions (MLR) generating dose-response curves showing a dose-dependent inhibition of MSA up to 80% and MLR up to 98%. MSA and MLR were repeated after pre incubation of the Pep4 with each separate responder cell subset and subsequent reconstitution: these experiments showed inhibition only when the peptide was present in culture. Pep4 showed species specificity since it was ineffective in inhibiting rat MLR. Combination effect analysis with Pep4 and cyclosporine showed a combination index > 1. This rationally designed peptide (Pep4) shows powerful inhibition of human T cell activation and, although the exact mechanism is still undefined, it seems to exert its major action on the T cell surface, interfering with co receptor interaction and disrupting the same activation signal pathway inhibited by cyclosporine A.
Assuntos
Antígenos CD4/imunologia , Ativação Linfocitária , Linfócitos T/imunologia , Animais , Antígenos CD4/efeitos dos fármacos , Ciclosporina/farmacologia , Humanos , Ativação Linfocitária/efeitos dos fármacos , Teste de Cultura Mista de Linfócitos , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Peptídeos/síntese química , Peptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Ratos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Linfócitos T/efeitos dos fármacosRESUMO
In response to endovascular injury, platelet-derived growth factor-BB (PDGF-BB) and basic fibroblast growth factor (bFGF) are released locally and modulate vascular smooth muscle cells (SMC) proliferation and migration within the vascular wall. The aim of the present in vitro study was to determine how rat aorta SMC respond to the simultaneous exposure to PDGF-BB and bFGF. In a modified Boyden chamber assay bFGF exhibited a dose-dependent effect to inhibit the chemotactic action of PDGF-BB. A comparable result was observed in proliferation assays. In contrast, MIP-1 beta, epidermal growth factor (EGF), fibronectin and acidic FGF (aFGF) did not inhibit the chemotactic effect of PDGF-BB. Denatured bFGF did not exert an inhibitory effect and neutralizing antibodies either to bFGF or to bFGF-receptor abolished the inhibition observed in the presence of bFGF. The role played by PDGF receptor alpha (PDGF-Ralpha) was investigated in PDGF-Ralpha-dominant negative-transfected SMC, by selectively blocking PDGF-BB-binding to PDGF-Ralpha with neomycin, by neutralizing PDGF-Ralpha with a monoclonal antibody and by selectively stimulating PDGF-Ralpha with PDGF-AA; in all cases the effect of bFGF to inhibit PDGF-BB-directed SMC migration was abolished. These in vitro studies show that bFGF significantly inhibits PDGF-BB-induced SMC migration and proliferation and that this effect is mediated by both PDGF-Ralpha and bFGF receptor.