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1.
J Nutr Health Aging ; 27(10): 885-893, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37960912

RESUMO

OBJECTIVES: To provide a comprehensive CERT (Consensus on Exercise Reporting Template)-based description of the resistance exercise program implemented in the AGUEDA (Active Gains in brain Using Exercise During Aging) study, a randomized controlled trial investigating the effects of a 24-week supervised resistance exercise program on executive function and related brain structure and function in cognitively normal older adults. DESIGN AND PARTICIPANTS: 90 cognitively normal older adults aged 65 to 80 were randomized (1:1) to a: 1) resistance exercise group; or a 2) wait-list control group. Participants in the exercise group (n = 46) performed 180 min/week of resistance exercise (3 supervised sessions per week, 60 min/session) for 24 weeks. INTERVENTION: The exercise program consisted of a combination of upper and lower limb exercises using elastic bands and the participant's own body weight as the main resistance. The load and intensity were based on the resistance of the elastic bands (7 resistances), number of repetitions (individualized), motor complexity of exercises (3 levels), sets and rest (3 sets/60 sec rest), execution time (40-60 sec) and velocity (as fast as possible). SETTINGS: The maximum prescribed-target intensity was 70-80% of the participants' maximum rate of perceived exertion (7-8 RPE). Heart rate, sleep quality and feeling scale were recorded during all exercise sessions. Those in the wait-list control group (n = 44) were asked to maintain their usual lifestyle. The feasibility of AGUEDA project was evaluated by retention, adherence, adverse events and cost estimation on the exercise program. RESULTS AND CONCLUSIONS: This study details the exercise program of the AGUEDA trial, including well-described multi-language manuals and videos, which can be used by public health professionals, or general public who wish to implement a feasible and low-cost resistance exercise program. The AGUEDA exercise program seems to be feasible by the high retention (95.6%) and attendance rate (85.7%), very low serious adverse event (1%) and low economic cost (144.23 € /participant/24 weeks). We predict that a 24-week resistance exercise program will have positive effects on brain health in cognitively normal older adults.


Assuntos
Treinamento Resistido , Humanos , Idoso , Treinamento Resistido/métodos , Exercício Físico/fisiologia , Terapia por Exercício/métodos , Envelhecimento , Peso Corporal , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Mater Sci Eng C Mater Biol Appl ; 109: 110522, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32228976

RESUMO

Electrochemically reduced graphene oxide (ErGO) films on a biomedical grade CoCr alloy have been generated and characterized in order to study their possible application for use on joint prostheses. The electrodeposition process was performed by cyclic voltammetry. The characterization of the ErGO films on CoCr alloys by XPS revealed sp2 bonding and the presence of CO and CO residual groups in the graphene network. Biocompatibility studies were performed with mouse macrophages J774A.1 cell cultures measured by the ratio between lactate dehydrogenase and mitochondrial activities. An enhancement in the biocompatibility of the CoCr with the ErGO films was obtained, a result that became more evident as exposure time increased. Macrophages on the CoCr with the ErGO were well-distributed and conserved the characteristic cell shape. In addition, vimentin expression was unaltered in comparison with the control, results that indicated an improvement in the CoCr biocompatibility with the ErGO on the material surface. The in vivo response of graphene and graphene oxide was assessed by intraperitoneal injection in wistar rats. Red blood cells are one of the primary interaction sites so hemocompatibility tests were carried out. Rats inoculated with graphene and graphene oxide showed red blood cells of smaller size with a high content in hemoglobin.


Assuntos
Ligas de Cromo , Materiais Revestidos Biocompatíveis , Técnicas Eletroquímicas , Grafite , Macrófagos/metabolismo , Teste de Materiais , Animais , Ligas de Cromo/química , Ligas de Cromo/farmacologia , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Grafite/química , Grafite/farmacologia , Masculino , Camundongos , Oxirredução , Ratos , Ratos Wistar
3.
Biomacromolecules ; 11(7): 1763-72, 2010 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-20527810

RESUMO

New therapeutic strategies for the treatment of neoplastic pathologies and, in particular, metastasis processes are based on the inhibitory effect of angiogenic processes. The present article deals with the design, preparation, and application of new "polymer drugs" with a clear inhibitory effect of the activation of fibroblast growth factors, which plays an important role in the proliferation of vascular cells and, consequently, in tumor angiogenesis. Two different copolymer systems based on 5-methacrylamide-2-naphthalenesulfonic acid (MANSA) and butylacrylate (BA) or vinylpyrrolidone (VP) were prepared by free radical copolymerization and exhaustively characterized. The molecular weight of the copolymers was moderate but both families presented very homogeneous macromolecular populations with a polydispersity index very close to unity, which indicates that MANSA presents a noticeable effect on the polymerization processes. The system poly(BA-co-MANSA) provides amphiphilic copolymers that give rise to the formation of oriented micelles with a core of the hydrophobic BA segments and a shell of MANSA components. The average size of these self-assembling nanoparticles is between 20 and 100 nm, depending on the composition of the copolymer system. However, poly(VP-co-MANSA) systems are more hydrophilic and give more homogeneous and water-soluble macromolecules. The bioactivity of both systems was studied by the analysis of proliferation of Balb/c 3T3 fibroblasts in the presence of acidic fibroblast growth factor (aFGF) as a function of the concentration of poly(BA-co-MANSA) or poly(VP-co-MANSA), and the results obtained demonstrated that the MANSA-containing polymers were not toxic for cells, but induced a clear inhibition of cell proliferation in the presence of aFGF. The effect was polymer-concentration dependent, but the activity was noticeably higher for poly(BA-co-MANSA) copolymers, owing to the self-assembled micellar morphology of the nanoparticles, which placed the sulfonic groups in the more adequate position to interact with the growth factor. These systems offer a good alternative for low toxicity treatments of angiogenic, processed based on inhibition of the activity of growth factors.


Assuntos
Portadores de Fármacos/química , Polímeros/química , Polímeros/uso terapêutico , Células 3T3 , Acrilamidas , Animais , Materiais Biocompatíveis , Proliferação de Células/efeitos dos fármacos , Fator 1 de Crescimento de Fibroblastos/antagonistas & inibidores , Camundongos , Micelas , Nanopartículas , Naftalenossulfonatos , Neovascularização Patológica/tratamento farmacológico
4.
Neurol Res ; 28(2): 127-30, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16551428

RESUMO

OBJECTIVES: Because fibroblast growth factor (FGF) causes the intracellular accumulation of activated signal transducer and activator of transcription 3 (STAT3), we assessed whether dobesilate, a synthetic FGF inhibitor that has been reported to show antiproliferative and proapoptotic activities in glioma cell cultures, down-regulates the STAT3 signaling pathway in growing cultures of those cells. Because STAT3 signaling pathway plays pleiotropic roles in tumor proliferation, maintenance of STAT3 in its inactive state may prevent glioma growth and spreading. METHODS: Rat glioma C6 cells were treated with dobesilate and cultures were evaluated immunocytochemically for STAT3 activation and enhancement of the expression rate of cyclin D1 and bcl-XL. RESULTS: Dobesilate abrogates the accumulation of activated STAT3 in glioma cells. The decrease in the intracellular levels of activated STAT3 by the dobesilate treatment runs parallel with a significant attenuation of cyclin D1 and bcl-XL expression. CONCLUSION: Treatment with inhibitors of FGF down-regulates the STAT3 signaling pathway. These alterations could be correlated to the already observed inhibition of cell proliferation and promotion of apoptosis in glioma cell cultures by dobesilate. The reported results may open new avenues for developing new treatments against these tumors.


Assuntos
Neoplasias Encefálicas/metabolismo , Dobesilato de Cálcio/farmacologia , Ciclina D1/metabolismo , Glioma/metabolismo , Fator de Transcrição STAT3/metabolismo , Proteína bcl-X/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Ciclina D1/efeitos dos fármacos , Ciclina D1/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Fatores de Crescimento de Fibroblastos/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Glioma/tratamento farmacológico , Glioma/genética , Inibidores do Crescimento/farmacologia , Hemostáticos/farmacologia , Ratos , Fator de Transcrição STAT3/efeitos dos fármacos , Fator de Transcrição STAT3/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética , Proteína bcl-X/efeitos dos fármacos , Proteína bcl-X/genética
5.
Eur J Med Res ; 10(9): 369-72, 2005 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-16183547

RESUMO

Aberrant angiogenesis is essential for the progression of solid tumors and hematological malignancies. Antiangiogenic therapy is one of the most promising approaches to treat such diseases. Dobesilate is an oral agent for treatment of vascular complications of diabetic retinopathy. We have examined the possibility that this compound could interfere with the process of angiogenesis in a mouse gelatine sponge assay using acidic fibroblast growth factor (aFGF) as an inducer of neovascularization. According to the results reported here, dobesilate remarkably reduced vessel ingrowth in aFGF-containing subcutaneous sponges in mice. These findings suggest that dobesilate could be an effective agent in the treatment of angiogenesis-dependent diseases involving FGFs.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Dobesilato de Cálcio/uso terapêutico , Neovascularização Patológica/prevenção & controle , Animais , Fator 1 de Crescimento de Fibroblastos/farmacologia , Esponja de Gelatina Absorvível , Camundongos , Camundongos Endogâmicos C57BL
6.
Neurosci Lett ; 308(3): 185-8, 2001 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-11479019

RESUMO

Suramins and suradistas, an important group of potential anti-cancer agents, inhibit fibroblast growth factor (FGF) mitogenic activity. It has been shown that naphthalenesulfonates, with a common chemical function to the family of suramins and suradistas, mimic their inhibitory activity, abolishing FGF-induced angiogenesis in vivo, and inducing apoptosis of C6 glioma cells in culture. In the present report, we show that intratumoral administration of 1-naphthalenemonosulfonate induces a considerable regression of gliomas in rats, significantly enhances apoptosis, and attenuates tumor angiogenesis. These findings may lead to new approaches for the treatment of glioblastoma, a most common primary malignant brain tumor of very poor prognosis, as well as of other angiogenesis-dependent malignancies.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Naftalenossulfonatos/farmacologia , Neovascularização Patológica/tratamento farmacológico , Inibidores da Angiogênese/farmacologia , Animais , Apoptose/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/fisiologia , Marcação In Situ das Extremidades Cortadas , Transplante de Neoplasias , Neovascularização Patológica/fisiopatologia , Ratos , Ratos Sprague-Dawley , Células Tumorais Cultivadas/transplante
7.
J Biol Chem ; 276(38): 35723-34, 2001 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-11423536

RESUMO

Platelet factor-4 is a protein belonging to the family of ELR-negative CXC chemokines which binds to fibroblast growth factor and inhibits its mitogenic activity. Platelet factor-4 also inhibits tumor growth by mechanisms involving antiangiogenesis. Antiangiogenic activity in vitro has also been shown for the 24-residue C-terminal fragment of the protein, which decreases the affinity between basic fibroblast growth factor and its cell-surface receptor. In this study, the preferential conformation of this fragment in solution has been determined and has been found to be composed of two helical subdomains. In addition, we show that the fragment forms a specific 1:1 complex with acidic and basic fibroblast growth factors and that both subdomains are probably required for inhibition of fibroblast growth factor-driven mitogenesis. Finally, we show that the binding of the fragment alters the structure of the fibroblast growth factors, although some of such alterations do not seem related with the inhibition of mitogenic activity. Since this fragment has recently been shown to inhibit fibroblast growth factor-induced angiogenesis in vivo when injected intraperitoneally, these results are relevant for developing new antiangiogenic treatments.


Assuntos
Inibidores da Angiogênese/metabolismo , Fator 1 de Crescimento de Fibroblastos/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Fator Plaquetário 4/metabolismo , Sequência de Aminoácidos , Inibidores da Angiogênese/química , Inibidores da Angiogênese/farmacologia , Fluorescência , Humanos , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Fator Plaquetário 4/química , Fator Plaquetário 4/farmacologia , Estrutura Secundária de Proteína , Soluções
8.
FASEB J ; 15(3): 550-2, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11259363

RESUMO

Platelet factor 4 (PF-4) is a CXC-chemokine with strong anti-angiogenic properties. We have shown previously that PF-4 inhibits angiogenesis by associating directly with fibroblast growth factor 2 (FGF-2), inhibiting its dimerization, and blocking FGF-2 binding to endothelial cells. We now have characterized a small peptide domain (PF-447-70) derived from the C-terminus of PF-4, which conserves anti-angiogenic effects of the parent protein. PF-447-70 inhibited internalization of 125I-FGF-2 by endothelial cells in a time-dependent manner. The peptide reduced FGF-2-stimulated cell migration to control levels in wounded monolayers of bovine capillary endothelial cells. PF-447-70 also reduced FGF-2 induced phosphorylation of MAP kinases ERK-1 and ERK-2, which are essential for migration and survival of endothelial cells. In a serum-free ex vivo angiogenesis assay, the peptide blocked microvessel outgrowth by 89%. A single amino acid substitution within PF-447-70 abolished all inhibitory activities. To simulate a real anti-angiogenic treatment situation, we administered PF-447-70 systemically to mice implanted subcutaneously with FGF-2 containing gelatin sponges with the result of sparse, scattered, and immature vessel growth. The small peptide fragment derived from the angio-inhibitory CXC-chemokine PF-4 might be used as a starting point to develop anti-angiogenic designer drugs for angiogenesis-dependent pathologies such as cancer, diabetic retinopathy, and rheumatoid arthritis.


Assuntos
Endotélio Vascular/citologia , Fator 2 de Crescimento de Fibroblastos/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Fator Plaquetário 4/química , Fator Plaquetário 4/farmacologia , Sequência de Aminoácidos , Animais , Aorta , Divisão Celular , Movimento Celular , Células Cultivadas , Meios de Cultura Livres de Soro , Técnicas de Cultura , Endotélio Vascular/efeitos dos fármacos , Ativação Enzimática , Humanos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Modelos Biológicos , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Fator Plaquetário 4/genética , Estrutura Terciária de Proteína , Ratos , Receptores Proteína Tirosina Quinases/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo
9.
Chembiochem ; 2(9): 673-85, 2001 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-11828504

RESUMO

An effective strategy has been designed for the synthesis of oligosaccharides of different sizes structurally related to the regular region of heparin; this is illustrated by the preparation of hexasaccharide 1 and octasaccharide 2. This synthetic strategy provides the oligosaccharide sequence containing a D-glucosamine unit at the nonreducing end that is not available either by enzymatic or chemical degradation of heparin. It may permit, after slight modifications, the preparation of oligosaccharide fragments with different charge distribution as well. NMR spectroscopy and molecular dynamics simulations have shown that the overall structure of 1 in solution is a stable right-hand helix with four residues per turn. Hexasaccharide 1 and, most likely, octasaccharide 2 are, therefore, chemically well-defined structural models of naturally occurring heparin-like oligosaccharides for use in binding and biological activity studies. Both compounds 1 and 2 induce the mitogenic activity of acid fibroblast growth factor (FGF1), with the half-maximum activating concentration of 2 being equivalent to that of heparin. Sedimentation equilibrium analysis with compound 2 suggests that heparin-induced FGF1 dimerization is not an absolute requirement for biological activity.


Assuntos
Anticoagulantes/farmacologia , Fatores de Crescimento de Fibroblastos/metabolismo , Heparina/farmacologia , Oligossacarídeos/farmacologia , Anticoagulantes/síntese química , Anticoagulantes/química , Biotransformação/efeitos dos fármacos , Sequência de Carboidratos , Heparina/química , Ácido Idurônico/química , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Mitógenos/farmacologia , Modelos Moleculares , Oligossacarídeos/síntese química , Oligossacarídeos/química , Espectrofotometria Ultravioleta
10.
Biochemistry ; 39(17): 4982-93, 2000 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-10819962

RESUMO

A shortened genetically engineered form of acidic fibroblast growth factor (aFGF), that includes amino acids 28-154 of the full-length sequence (154 residues) plus Met in substitution of Leu27, does not induce cell division even though it is recognized by the cell membrane receptor, triggers the early mitogenic events, and retains the neuromodulatory, vasoactive, and cardio- and neuroprotective properties of the native full-length molecule. Taken together, these properties make this truncated aFGF a promising compound in the treatment of a wide assortment of neurological and cardiovascular pathologies where aFGF mitogenic activity is dispensable. Differences in biological activities between the shortened aFGF and the wild-type form have been attributed to lack of stability, and to the specific amino acid sequence missing at the N-terminus. Here we show that this shortened aFGF form has a three-dimensional structure even more stable than the wild-type protein at the mitogenic assay conditions; that this structure is similar to that of the wild type except at site 1 of interaction with the cell membrane receptor; that its lack of mitogenic activity cannot be attributed to the specific missing sequence; and that the vasodilatory activity of aFGF seems impaired by alterations of the three-dimensional structure of site 2 of interaction with the cell membrane receptor.


Assuntos
Fator 1 de Crescimento de Fibroblastos/química , Conformação Proteica , Sequência de Aminoácidos , Animais , Fator 1 de Crescimento de Fibroblastos/farmacologia , Isquemia/prevenção & controle , Espectroscopia de Ressonância Magnética , Mitógenos/química , Mitógenos/farmacologia , Dados de Sequência Molecular , Neurotransmissores/química , Neurotransmissores/farmacologia , Relação Estrutura-Atividade , Vasodilatadores/química , Vasodilatadores/farmacologia
11.
Neurosci Lett ; 275(2): 149-51, 1999 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-10568521

RESUMO

Fibroblast growth factors (FGFs) are powerful angiogenic polypeptides that are involved in the autocrine growth stimulation of gliomas. We report here that addition to glioma cell cultures of 1,3,6-naphthalenetrisulfonate (NTS), an inhibitor of the mitogenic activity of FGFs, significantly enhanced apoptosis, as assessed by terminal deoxynucleotidyl transferase (TdT) assay. The pro-apoptotic effect of NTS was time-dependent. These findings suggest that FGF may play a pivotal role in the survival of glioma cells, and support a clinical interest of NTS as a leading compound for the development of new antitumorals.


Assuntos
Apoptose/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Glioma/tratamento farmacológico , Naftalenossulfonatos/farmacologia , Animais , Glioma/patologia , Marcação In Situ das Extremidades Cortadas , Ratos , Células Tumorais Cultivadas
12.
Neurol Res ; 21(5): 481-7, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10439429

RESUMO

1,3,6-naphthalenetrisulfonate (NTS) can inhibit the proliferation in vitro of cells of various origin including glioma. We have studied the effects of NTS on intra-tumoral angiogenesis and tumor growth in the rabbit cornea after implantation of C6 rat glioma cells. It was found that neovascularization and glioma growth were abolished by topical administration of NTS. This effect could be mediated by both induction of programmed cell death and inhibition of growth, in endothelium and in tumor cells, most likely as a consequence of the disruption of the autocrine and paracrine effects of FGF released from endothelial and tumor cells. The results suggest that NTS is a promising candidate to lead the development of new angiogenesis inhibitors for the treatment of cancer and other diseases whose progression is dependent upon the development of new blood vessels.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/irrigação sanguínea , Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Naftalenossulfonatos/uso terapêutico , Proteínas de Neoplasias/antagonistas & inibidores , Neovascularização Patológica/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Astrocitoma/patologia , Córnea , Feminino , Naftalenossulfonatos/farmacologia , Transplante de Neoplasias , Coelhos , Ratos , Células Tumorais Cultivadas/transplante
13.
Neurol Res ; 21(2): 191-4, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10100207

RESUMO

Growth factor-induced angiogenesis was studied using subcutaneously implanted gelatin sponges loaded with 10 mg ml-1 of acidic fibroblast growth factor (aFGF) in 20 micrograms ml-1 PBS heparin. The administration of 1,3,6-naphthalenetrisulfonate (NTS) directly into the sponge (20 mg ml-1) or intraperitoneally (200 mg kg-1) blocks invasion of the sponge by vasculature. Since angiogenesis is essential for tumor progression, the findings of the present study that NTS is an efficient inhibitor of neovascularization warrant further investigation of the potential clinical utility of this angiostatic agent for treating tumor growth and metastasis.


Assuntos
Antineoplásicos/uso terapêutico , Fator 1 de Crescimento de Fibroblastos/toxicidade , Naftalenossulfonatos/uso terapêutico , Neovascularização Patológica/prevenção & controle , Animais , Depressão Química , Fator 1 de Crescimento de Fibroblastos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Recombinantes/toxicidade
14.
J Allergy Clin Immunol ; 103(4): 690-7, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10200021

RESUMO

BACKGROUND: By resisting digestion in the stomach, the major bovine milk allergen, beta-lactoglobulin, is believed to act as a transporter of vitamin A and retinol to the intestines. beta-Lactoglobulin has 2 intramolecular disulfide bonds that may be responsible for its allergic effects. OBJECTIVE: This study was carried out to assess the importance of disulfide bonds to the allergenicity and digestibility of beta-lactoglobulin. METHODS: beta-Lactoglobulin was subjected to reduction by the ubiquitous protein thioredoxin, which was itself reduced by the reduced form of nicotinamide adenine dinucleotide phosphate by means of nicotinamide adenine dinucleotide phosphate-thioredoxin reductase. Digestibility was measured with a simulated gastric fluid; results were analyzed by SDS-PAGE. Allergenicity was assessed with an inbred colony of high IgE-producing dogs sensitized to milk. RESULTS: As found for other proteins with intramolecular disulfide bonds, beta-lactoglobulin was reduced specifically by the thioredoxin system. After reduction of one or both of its disulfide bonds, beta-lactoglobulin became strikingly sensitive to pepsin and lost allergenicity as determined by skin test responses and gastrointestinal symptoms in the dog model. CONCLUSION: The results provide new evidence that thioredoxin can be applied to enhance digestibility and lower allergenicity of food proteins.


Assuntos
Digestão , Lactoglobulinas/imunologia , Lactoglobulinas/metabolismo , Hipersensibilidade a Leite/prevenção & controle , Leite , Tiorredoxinas/metabolismo , Animais , Bovinos , Sistema Digestório/patologia , Modelos Animais de Doenças , Cães , Humanos , Lactoglobulinas/química , Leite/efeitos adversos , Leite/imunologia , Leite/metabolismo , Modelos Moleculares , Oxirredução , Pepsina A/metabolismo , Testes Cutâneos , Tiorredoxina Dissulfeto Redutase/metabolismo
15.
J Neurophysiol ; 81(4): 1970-3, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10200232

RESUMO

The neural pathways subserving the sensation of temperature are virtually unknown. However, recent findings in the monkey suggest that the sensation of cold may be mediated by an ascending pathway relaying in the posterior part of the thalamic ventromedial nucleus (VMpo). To test this hypothesis we examined the responses of neurons to thermal stimulation of the skin and determined the perceptual effects of microstimulation in the VMpo region in awake patients undergoing functional stereotactic surgery. In 16 patients, microstimulation in the VMpo region evoked cold sensations in a circumscribed body part. Furthermore, at some of these sites thalamic neurons were found that responded to innocuous cooling of the skin area corresponding to the stimulation-evoked cold sensations. These data provide the first direct demonstration of a pathway mediating cold sensation and its location in the human thalamus.


Assuntos
Temperatura Baixa , Neurônios Aferentes/fisiologia , Percepção/fisiologia , Tálamo/citologia , Tálamo/fisiologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Eur J Biochem ; 260(2): 559-67, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10095795

RESUMO

Kinetoplastid membrane protein-11 (KMP-11) is a major component of the cell surface of kinetoplastids, and acts as a potent B- and T-cell immunogen during Leishmania infection. Here we report that the Leishmania infantum KMP-11 secondary structure adopts mainly an alpha-helical conformation at pH 7.5 and that its urea- and thermally-induced unfolding constitute a fully reversible two-step process. This allows estimation of a half-denaturation temperature of approximately 65 degrees C, a delta GDH2O at 20 degrees C of approximately 14.63 kJ.mol-1, and an increment of the reaction heat of approximately 183.92 kJ.mol-1 and an entropy of approximately 543.4 J.mol-1.deg-1, respectively, for the native-denatured equilibrium of the KMP-11 in solution. We also report that the KPM-11 protein is induced to adopt a molten globule state at a pH range between pH 4 and pH 6. As a whole, the stability and the specific features of the denaturing effect induced by changes in pH are similar in KMP-11 to various other lipoproteins.


Assuntos
Leishmania infantum/química , Glicoproteínas de Membrana/química , Dobramento de Proteína , Proteínas de Protozoários/química , Sequência de Aminoácidos , Animais , Dicroísmo Circular , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Conformação Proteica , Desnaturação Proteica , Estrutura Secundária de Proteína , Termodinâmica , Ureia
17.
Neurosci Lett ; 255(1): 1-4, 1998 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-9839712

RESUMO

The central neuroprotective effects against ischemic injury of fibroblast growth factor (FGF), administered either directly into the central nervous system or systemically, is well documented. Here we show in a rat model of transient retinal ischemia that the neuroprotective effect of systemically administered acidic fibroblast growth factor (aFGF, FGF-1) extends to the retina. Histological findings show a lower decrease of retinal ganglion cells and inner nuclear layer cells (P < 0.0001) in animals receiving FGF-1. These results suggest that FGF may function as a natural protection agent during transient retinal ischemia and further document that an efficient neuroprotection of central nervous tissues can be obtained by systemic administration of this protein. Our data may, thus, contribute to the development of novel and safe therapeutic approach for the treatment of the ischemic injury of the retina.


Assuntos
Fator 1 de Crescimento de Fibroblastos/administração & dosagem , Isquemia/patologia , Fármacos Neuroprotetores/administração & dosagem , Vasos Retinianos/efeitos dos fármacos , Animais , Feminino , Fator 1 de Crescimento de Fibroblastos/farmacologia , Humanos , Injeções Intra-Arteriais , Masculino , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Sprague-Dawley , Vasos Retinianos/patologia
18.
J Mol Biol ; 281(5): 899-915, 1998 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-9719643

RESUMO

Recent data show that anti-angiogenesis may provide a promising route to treat cancer. Fibroblast growth factors (FGFs) are powerful angiogenic polypeptides, whose mitogenic activity requires the presence of heparin-like compounds. It has been shown that angiogenesis promoted by FGFs on inhibition by monoclonal antibodies and antisense targeting can also inhibit tumour growth. Derivatives of suramin, a polysulfonated binaphthyl urea and binaphthylsulfonated derivatives of distamycin, suradistas, constitute an important group of potential anti-cancer agents. These compounds compete with heparin in forming tight complexes with FGFs. This inhibits the recognition of these growth factors by their tyrosine kinase membrane receptors thereby suppressing their angiogenic activity. Here we show that 1,3,6-naphthalenetrisulfonate, a common chemical function of the suramins and suradistas with the highest anti-angiogenic activity inhibits the mitogenic activity of acidic fibroblast growth factor, and that this inhibition is relieved by increasing concentrations of heparin in the assay. We have also solved the three-dimensional structure in solution of the protein complexed to this compound. The structural data provide clues that may help in understanding the inhibitory effect of suramins and suradistas, and could contribute to the development of new anti-tumoral drugs.


Assuntos
Fator 1 de Crescimento de Fibroblastos/química , Naftalenos/química , Naftalenossulfonatos/química , Ácidos Sulfônicos/química , Sequência de Aminoácidos , Antineoplásicos/química , Antineoplásicos/farmacologia , Distamicinas/farmacologia , Fator 1 de Crescimento de Fibroblastos/antagonistas & inibidores , Heparina/metabolismo , Inositol/análogos & derivados , Inositol/química , Espectroscopia de Ressonância Magnética , Mitógenos/antagonistas & inibidores , Modelos Moleculares , Dados de Sequência Molecular , Naftalenos/farmacologia , Naftalenossulfonatos/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Ligação Proteica/fisiologia , Estrutura Secundária de Proteína , Ácidos Sulfônicos/farmacologia , Suramina/farmacologia
19.
Eur J Biochem ; 248(1): 30-6, 1997 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-9310356

RESUMO

The triphenylmethane derivative aurintricarboxylic acid has been used to inhibit angiogenesis, vascular smooth muscle cell proliferation and cell transformation, an effect that has been attributed to its relatively nonspecific inhibitory activity of protein-nucleic acid interactions. Here, we show that this compound binds to acidic fibroblast growth factor, a prototypic member of a family of protein mitogens activated by heparin, altering its physicochemical properties and decreasing its mitogenic activity. Counteraction of the effects of aurintricarboxylic acid by heparin shows that the two compounds have opposite and reversible effects on acidic fibroblast growth factor structure and biological activity. The studies reported here may contribute to a deeper understanding of the inhibition of fibroblast-growth-factor-dependent mitogenesis of relevance to future pharmacologic developments.


Assuntos
Ácido Aurintricarboxílico/farmacologia , Fator 1 de Crescimento de Fibroblastos/química , Fator 1 de Crescimento de Fibroblastos/efeitos dos fármacos , Células 3T3 , Animais , Ácido Aurintricarboxílico/química , Dicroísmo Circular , Estabilidade de Medicamentos , Fator 1 de Crescimento de Fibroblastos/farmacologia , Humanos , Substâncias Macromoleculares , Camundongos , Mitógenos/farmacologia , Conformação Proteica/efeitos dos fármacos , Espectrometria de Fluorescência , Ultracentrifugação
20.
Proc Natl Acad Sci U S A ; 94(10): 5372-7, 1997 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-9144244

RESUMO

Thioredoxin, a ubiquitous 12-kDa regulatory disulfide protein, was found to reduce disulfide bonds of allergens (convert S-S to 2 SH) and thereby mitigate the allergenicity of commercial wheat preparations. Allergenic strength was determined by skin tests with a canine model for food allergy. Statistically significant mitigation was observed with 15 of 16 wheat-sensitive animals. The allergenicity of the protein fractions extracted from wheat flour with the indicated solvent was also assessed: the gliadins (ethanol) were the strongest allergens, followed by glutenins (acetic acid), albumins (water), and globulins (salt water). Of the gliadins, the alpha and beta fractions were most potent, followed by the gamma and omega types. Thioredoxin mitigated the allergenicity associated with the major protein fractions-i.e, the gliadins (including the alpha, beta, and gamma types) and the glutenins-but gave less consistent results with the minor fractions, the albumins and globulins. In all cases, mitigation was specific to thioredoxin that had been reduced either enzymically by NADPH and NADP-thioredoxin reductase or chemically by dithiothreitol; reduced glutathione was without significant effect. As in previous studies, thioredoxin was particularly effective in the reduction of intramolecular (intrachain) disulfide bonds. The present results demonstrate that the reduction of these disulfide bonds is accompanied by a statistically significant decrease in allergenicity of the active proteins. This decrease occurs alongside the changes identified previously-i.e., increased susceptibility to proteolysis and heat, and altered biochemical activity. The findings open the door to the testing of the thioredoxin system in the production of hypoallergenic, more-digestible foods.


Assuntos
Hipersensibilidade Alimentar/prevenção & controle , Gliadina/imunologia , Glutens/análogos & derivados , Hipersensibilidade Imediata/prevenção & controle , Proteínas de Plantas/imunologia , Tiorredoxinas/farmacologia , Animais , Animais Recém-Nascidos , Ditiotreitol/farmacologia , Cães , Farinha , Hipersensibilidade Alimentar/imunologia , Glutens/imunologia , Hipersensibilidade Imediata/imunologia , Testes Cutâneos , Tiorredoxina Dissulfeto Redutase/farmacologia , Triticum/imunologia
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