L’ostéoarthrose (OA) est une maladie articulaire dont l’incidence augmente avec le vieillissement de la population. Elle se caractérise par une détérioration progressive du cartilage articulaire accompagnée du remodelage de l’os sous-chondral et du changement des tissus mous de l’articulation. La douleur et le dysfonctionnement de l’articulation affectée sont généralement attribués à l’inflammation et l’épanchement de la synovie. Plusieurs évidences indiquent que l’inflammation de la membrane synoviale contribue grandement à la pathogenèse de l’OA. En effet, la synthèse et l’expression des enzymes protéolytiques qui dégradent la matrice cartilagineuse sont régulées par de nombreuses cytokines retrouvées au sein de ce foyer inflammatoire. Deux d’entre elles, l’interleukine-1 beta (IL-1β) et le «tumor necrosis factor » alpha (TNF-α), jouent un rôle majeur dans le déclenchement de l’inflammation associée à l’OA. Ces cytokines pro-inflammatoires agissent notamment sur les synoviocytes et les chondrocytes en activant NF-κB qui, à son tour, active les gènes de cytokines. Cette boucle de régulation positive amplifie et perpétue la réponse inflammatoire. Récemment, il a été rapporté que l’activation de NF-κB par TNF-α peut être potentialisée par EXTL3, un récepteur transmembranaire ; mais le mécanisme sous-jacent de cet effet demeure inconnu. Toutefois, les niveaux important d’EXTL3 et de son ligand Reg1B chez les patients arthrosiques, laissent croire que ces protéines jouent un rôle dans le développement de l’OA. Notre objectif était d’étudier le mécanisme par lequel EXTL3 amplifie l’activation de NF-κB par TNF-α et d’examiner si ce phénomène se produit aussi avec l’IL-1β. Nous avons utilisé les cellules C28/I2, une lignée cellulaire de chondrocytes, comme modèle d’étude. Les transfections transitoires avec un vecteur d’expression, les techniques d’immunofluorescence (IF), d’immunoprécipitation (IP) et d’immunobuvardage de type Western (IB); ont été utilisées dans le cadre de diverses approches expérimentales. Les résultats obtenus par transfection ont révélé que la protéine EXTL3 potentialisait l’activation de NF-κB aussi bien par IL-1β que par TNF-α. Ce résultat signifie que la potentialisation de l’activité NF-κB par EXTL3 n’est pas spécifique à TNF-α. D’autre part, l’IP avec TNFRI et TRAF2 a révélé la présence d’EXTL3 dans le complexe TNF-α/TNFRI/TRAF2 qui se forme au niveau de la membrane plasmique. De plus, ceci a été confirmé in vivo par microscopie confocale montrant la co-localisation de TNFRI-TRAF2-EXTL3 dans la membrane nucléaire, suggérant ainsi la formation d’un complexe identique au niveau des membranes plasmique et nucléaires. Toutefois, la présence du ligand Reg1B et/ou de la glucosamine inhibait la formation de ce complexe au niveau de la membrane plasmique, tout comme ils abolissaient la potentialisation de l’activité NF-κB par EXTL3. Ces résultats suggèrent non seulement que le recrutement d’EXTL3 libre dans le complexe TNF-α/TNFR1 est requis pour amplifier l’activation de NF-κB par TNF-α, mais aussi la capacité du ligand Reg1B et de la glucosamine à moduler cette activation à travers la baisse ou l’inhibition de l’interaction EXTL3-TNFR1. Les données de cette étude constituent une avancée majeure dans la compréhension des événements moléculaires qui contrôlent l’activation de NF-κB par les cytokines pro-inflammatoires. Ces résultats pourraient conduire au développement de nouvelles approches thérapeutiques pour le traitement de l’inflammation associée à l’OA et impliquant une activation incessante de NF-κB. / Osteoarthritis (OA) is an articular disease with a particularly high incidence in the elderly. This disease is characterized by the progressive degeneration of the cartilage followed by subchondral bone remodelling and a change in the soft tissues of the joint. Local chronic pain and joint malfunction are generally attributed to the inflammation of the synovial membrane, which in itself has been shown to significantly contribute to the pathogenesis of OA. In fact, the synthesis and expression of many proteolytic enzymes which degrade cartilage matrix are regulated by numerous cytokines originating from these inflammation sites. Two pro-inflammatory cytokines, the tumor necrosis factor alpha (TNF-α) and the interleukine-1β (Il-1β), play a major role in triggering inflammation associated with OA. These cytokines act on synoviocytes and chondrocytes by activating the transcription factor NF-κB, which in turn activates the cytokines’ genes. This positive regulating loop amplifies and maintains inflammatory responses. Recently, studies have shown that the over-expression of the REG receptor/EXTL3, a transmembranous receptor, enhances the activity of cytokine TNF-α in the activation of NF-κB. Unfortunately the mechanism involved in this process is still unknown. In addition, levels of EXTL3 and its ligand REG1B observed in OA patients suggest their possible involvement in the development of OA. Our goal was to study and elucidated the mechanisms used by EXTL3 to amplify NF-κB activation by TNF-α, as well as to examine whether the same phenomenon is occurring with IL-β. A human chondrocytes cell line called C28/I2 as experimental model. The techniques used for the current study were transfection assays, immunoflorescence (IF), immunoprecipitation (IP), and Western blotting (WB). Our transfection data have shown that EXTL3 was able to enhance NF-κB activity induced by TNF-α as well as by IL-1β. This result suggests that the enhanced NF-κB activity by EXTL3 is not specific to TNF-α. The IP experiments with TNFR1 and TRAF2 revealed the presence of EXTL3 in TNF-α/TNFR1 complex which is formed in the plasma membrane. Also, IF assay in combination with confocal microscopy allowed us to detect TNFR1/TRAF2/EXTL3 co-localisation on the nuclear membrane, suggesting the formation of TNF-α/TNFR1 complex on both the nuclear and plasma membranes. Somehow, REG1B, an EXTL3 ligand, and glucosamine were able to inhibit the formation of this complex at the plasma membrane. They were also able to abolish NF-κB activity enhanced by EXTL3. These results suggest that not only EXTL3 recruitment in the TNF-α/TNFR1 complex is required to amplify NF-κB activation by TNF-α, but also that REG1B ligand and glucosamine have the ability to modulate this activation by reducing or inhibiting EXTL3 and TNFR1 interactions. This study’s data represents a major advance in the understanding of molecular events controlling NF-κB activation by pro-inflammatory cytokines. These results could lead to the development of new therapeutics targets, in the treatment of disorders associated to OA and involving recurrent activation of NF-κB.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed June 5, 2008). Includes bibliographical references.

Made available in DSpace on 2015-03-26T13:46:56Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2724286 bytes, checksum: dfc4a98088cd85fae126679628671081 (MD5) Previous issue date: 2011-02-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim of this research was to evaluate the influence of chondroprotective veterinary supplement (nutraceutic) composed of glucosamine and chondroitin sulfate in the repair of osteochondral defects induced in femoral lateral condyle of dogs, by clinical, radiographic, macroscopic, histologic and morfometric analysis. We also aimed to test the safety of the supplement with tests of blood glucose, blood count, liver and kidney function, activated partial tromboplastine and time prothrombin time. Fortyeigth adult dogs with body weight ranging from 10 kg to 25 kg were used. They were divided into four treatments (I, II, III and IV), according to the postoperative period of evaluation (15, 30, 60 and 90 days) and each containing six animals. Within each treatment, six animals (GI) received the supplement daily, while the other six formed the control group (GII). No significant differences were observed between groups for each treatment. Therefore, the conditions in which this study was conducted, the chondroprotective did not cause adverse effects and the treated group did not differ from the control on the repair process of such defects. / O presente trabalho teve como objetivo avaliar a influência de um suplemento condroprotetor (nutracêutico) veterinário comercial, à base de sulfato de condroitina e glucosamina, na reparação de falhas osteocondrais induzidas no côndilo femoral lateral de cães, por meio de análises clínica, radiográfica, macroscópica, histológica e morfométrica. Objetivou-se ainda testar a segurança do produto, por meio dos exames de glicemia, hemograma, funções hepática e renal, tempo de tromboplastina parcial ativada e tempo de protombina. Foram utilizados 48 cães adultos, entre 10 e 25 kg de peso corporal e sem raça definida, distribuídos aleatoriamente entre quatro tratamentos (I, II, III e IV), de acordo com o período de pós-operatório (15, 30, 60 e 90 dias) e contendo cada um deles 12 animais. Dentro de cada tratamento, seis animais (GI) receberam diariamente o condroprotetor, enquanto os outros seis constituíram o grupo controle (GII). Não houve diferença significativa entre os grupos de cada tratamento e, portanto, nas condições em que o presente estudo foi realizado, o condroprotetor não ocasionou efeitos adversos e o grupo tratado não diferiu do controle quanto ao processo de reparação dos defeitos.

M.Tech. (Homoeopathy) / Osteoarthritis (OA) is a chronic and debilitating condition, characterized by irreversible damage to the joint space, most commonly affecting the knees, hips, hands and spine (Colledge et al., 2010). OA is the leading cause of joint pain and disability in middle-aged and elderly persons (Long et al., 2001). The prevalence of OA of the knee in adults living in the United Sates has grown from a reported 21 million in 1990 to a total estimate of 26.9 million in 2005 (CDC, 2011). By the age of 65 years, 80% of the total population has been reported as showing radiographic evidence of OA; while a 20-30% of the total population is symptomatic with radiographic evidence of OA (Doherty et al., 2006). Conventional treatment for OA of the knee is aimed at pain management by use of analgesics and non-steroidal anti-inflammatory drugs (NSAIDs). Some negative effects of these drugs include drug dependency, liver and kidney damage, cardiovascular pathologies, gastric upset and depression. Corticosteroid injections are also used to alleviate chronic inflammation and joint pain, but may lead to further joint destruction (Shamoon and Hochberg, 2000; Mayo Foundation for Medical Education and Research, 2011). OsteoEze Gold™ is a nutraceutical product that contains chondroitin sulphate, glucosamine sulphate, vitamin C and manganese. In combination, the constituents of OsteoEze Gold™ have been shown to be useful in the treatment for OA of the knee (Clegg et al., 2006). In addition, studies have shown that these ingredients prove effective in reducing moderate to severe pain in sufferers of OA of the knee (Vidyasagar et al., 2004). The aim of this study was to determine the effect of OsteoEze Gold™ on the inflammatory marker C-reactive protein (CRP) and quality of life in OA of the knee using blood tests and the Arthritic Impact Measurement Scales (AIMS2SF) respectively. This was a 16-week, double blind, placebo-controlled study using matched pairs according to age, gender and severity of symptoms, and formed part of a group study, with another researcher, who utilized the Intermittent and Constant Osteoarthritis Pain scale (ICOAP) Short Physical Performance Battery (SPPB) and the same sample...

Tryptophan, 5-methyl tryptophan, glucosamine, and galactosamine can be separated from each other and hydrolysis products including lysinoalanine by chromatography on a 6 × 260-mm column of W-3H resin. The column is developed at 70°C for 20 min with pH 3.95 (0.4 m Na+) buffer, followed by pH 6.4 (1 m Na+) buffer for 55 min using a Beckman 119 CL amino acid analyzer. The recovery of the internal standards, 5-methyl tryptophan and galactosamine, can then be used to correct for tryptophan and glucosamine losses, respectively. The procedure uses the column and buffers normally employed for protein hydrolysate analysis and does not require additional resin columns, special buffers, or flow rate changes.

No description available.

Plusieurs ligands dérivés de la D-glucosamine, conçus pour différentes réactions catalytiques,ont été synthétisés. Les ligands pour la catalyse homogène basés sur 1,2-glucodiamine ontété préparés, et utilisés dans des réactions d'alkylation allylique, d'hydrogénation et d'additionde Michael.La D-glucosamine a utilisee pour la preparation de catalysateur type de SPAC (SupportedAqueous Phase Catalyst). Ce catalysateur hétérogène été utilisé avec de très bons résultatsdans les réactions de couplage croisé de Suzuki Miyaura. Le catalyseur a également étérecyclé. Des essais de préparation de ligands greffés sur une matrice de silice de type SBA-15ont été réalisés ainsi que des ligands à base de poly (éthylène) glycol. / Several ligands derived from D-glucosamine, designed for different catalytic reactions havebeen synthesized. The ligands for homogeneous catalysis based on 1,2-glucodiamine wereprepared, and used in reactions of allylic alkylation, hydrogenation and Michael addition.Supported Aqueous Phase Catalyst (SAPC) system was prepared from D-glucosamine anduse with very good results in Suzuki Miyaura cross coupling reactions. Catalyst was alsorecycled. Attempt to prepare ligands grafted on SBA-silica matrix were made as well asligands containing poly(ethylene) glycol moiety.

Âncoras de glicosilfosfatidilinositol (GPI) são estruturas essenciais para a ancoragem de glicoconjugados e proteínas na superfície celular de protozoários. Trypanosoma cruzi produz uma gama de estruturas únicas de GPI, as quais ancoram mucinas e trans-sialidases, que participam de processos envolvidos na interação entre parasita e hospedeiro. Afim de estudar a biossíntese de âncora de GPI de T. cruzi e possivelmente utilizá-la como um potencial alvo anti-T.cruzi, este trabalho visa sintetizar análogos de âncoras de GPI e analisar o potencial destas moléculas como substratos da via biossintética de GPIs. Neste contexto, um pseudo-dissacarídeo 31 foi sintetizado através de O-glicosilação entre os doadores derivados de azido-glicopiranosídeo (32 ou 33a-d) e o acceptor de mio-inositol (34), preparados a partir de cloridrato de glucosamina (35) e metil-?-D-glucopiranósido (36), respectivamente, usando proteção/desproteção ortogonais. Cinco diferentes dadores de glicosídicos (32 e 33a-d) foram preparados para investigar a influcia dos seus grupos protetores na estereoselectividade da reações de O-glicosilação na presença de diferentes solventes para estudar o favorecimento da configuração ?, presente em GPIs. Ademais, a síntese do aceptor de mio-inositol 34 foi realizada em 12 etapas pela estratégia do rearranjo Ferrier para formar um derivado de ciclitol, além de diversas proteções/desproteções, funcionalizado que permite a introdução regiosselectiva da unidade de azido glicose (32-33a-d) e uma porção de fosfolípido no seu C-1 e posições C-6, respectivamente. Assim, O-glicosilação entre doador 33c e o acceptor 34, foi realizada utilizando TMSOTf como promotor para originar o composto 31c com boa estereoseletividade para ?, com elevado rendimento (~70%). Após a dealilação de 31c, a porção fosfodiéster contendo uma cadeia C-8 (87), preparada pela abordagem do H-fosfonato, foi anexada ao pseudo-dissacarídeo para gerar, após desprotecção global, o composto alvo 30a. A mesma estratégia sintética foi aplicada ao preparo do composto 91 contendo uma cadeia lateral alquil-naftil (90) que está em últmas etapas de desproteção para gerar o composto final 30c. Atualmente, o composto 30a está sendo testado como substrato da biossíntese de âncoras de GPI em membranas microssomais de Euglena gracilis, uma alga unicelular não patogênica, que pode potencialmente ser utilizada como modelo para parasitas humanos filogeneticamente relacionados. Após a incubação do potencial substrato de GPI 30a com membranas microssomais de E. gracilis para geração de metabólitos, será realizada análise do extrato por LC-MS e, eventualmente, isolamento dos produtos formados para posterior caracterização. Os produtos que apresentarem atividade como substrato ou como inibidores da biossíntese de GPI em E. gracilis serão também ensaiados na membrana microsomal do T. cruzi. / Glycosylphosphatidylinositol (GPI) anchors are essential molecules to attach glycoconjugates and proteins in protozoan\'s cell surface. Trypanosoma cruzi produces a range of unique GPI structures that anchor mucins and trans-sialidases which participate in important processes involved in the interaction between parasite and host. As an effort to study T. cruzi GPI anchor biosynthesis and possibly use it as a potential target for an antichagasic drug, this work aims to synthesize GPI anchor analogs (labelled or not) and analyze the potential of these molecules as substrates in the GPI biosynthetic pathway. In this context, a pseudo-disaccharide 31 was synthesized by O-glycosylation reaction between azide glycosyl donors (32 or 33a-d) and myo-inositol acceptor (34), prepared from glucosamine (35) hydrochloride and methyl ?-D-glucopyranoside (36), respectively, using orthogonal protection/ deprotection. Five different glycosyl donors (32 and 33a-d) were prepared to investigate the influence of their protective groups on the stereoselectivity of the O-glycosylation reaction in the presence of different solvents to afford the required GPI ?-linkage. In addition, the synthesis of the myo-inositol acceptor 34 was achieved using several protection/deprotection steps, besides the Ferrier rearrangement, to form a functionalized cyclitol derivative that enables the regioselective introduction of the azide glycoside unit and phospholipid moiety on its C-1 and C-6 positions, respectively. Then, O-glycosylation of acceptor 34 with donor 33c was accomplished in diethyl ether, using TMSOTf as promoter to give exclusively ?-anomer 31c in high yield. After deallylation of 31c, the phosphodiester moiety bearing an octyl chain (87), prepared by the H-phosphonate approach, was appended to the pseudo-disaccharide to yield, after deprotection, target compounds 30a. The same synthetic strategy was applied to the preparation of 30c, even though in the protective form, compound 91 bearing an alkyl-naphthyl side chain (90). Currently, compound 30a is being tested as substrates of GPI anchor biosynthesis in Euglena gracilis cell membranes, a non-pathogenic unicellular algae, which may potentially be used as a model for phylogenetically related human parasites. After incubation of the potential GPI substrate 30a with E. gracilis microsomal membranes for generation of metabolites, the analysis by LC-MS and, eventually, isolation of the products will be performed for further characterization. Products that show any substrate or inhibitory activities will be also assayed in T. cruzi microsomal membrane.

O objetivo do presente estudo é o de comparar funcionalmente ehistologicamente o efeito terapêutico da glicosamina em relação a diacereína no modelo experimental de artrose em ratos. Trinta ratos Wistar foram submetidos a meniscectomia medial do joelho direito. Dez animais receberam 50mg/kg/dia de diacereína a partir do 3o até o 7o mês de pósoperatório (PO), dez animais receberam 40mg/kg/dia de glicosamina e dez animais não receberam nenhuma medicação. Todos foram sacrificados no 7o mês PO. Foram medidos os ângulos de extensão máxima de cada joelho. A análise histológica com hematoxilina-eosina e alcian blue foi feita de cada um dos côndilos tibiais e femorais. Todos os joelhos operados apresentaram amplitude de extensão do joelho mais limitada que o lado contra-lateral (p=0,001), porém os que receberam diacereína apresentavam menor rigidez (p=0,005). Histologicamente, o modelo experimental levou a uma artrose de leve a moderada estatisticamente diferente do joelho contra-lateral não operado (p=0,001). Já os joelhos dos ratos que fizeram uso das medicações não apresentaram diferenças significativas (p=0,3) entre aqueles que tomaram glicosamina e os que fizeram uso da diacereína. As diferenças entre os joelhos operados medicados e não medicados também não foram estaticamente diferentes. Conclusões: O uso terapêutico da diacereína e glicosamina diminuiu a rigidez articular e retardou a progressão da artrose. A diacereína atuou melhor na mobilidade articular do que a glicosamina, porém não houve diferença estatística entre as duas drogas no controle da degeneração articular / The purpose of this study is to compare, based on a functional and histological analysis, the therapeutic effects of glucosamine as compared to diacerhein in an experimental model of arthritis in rats. Thirty Wistar rats were submitted to a medial meniscectomy of the right knee. Ten animals received 50 mg/kg/day of diacerhein from the third through seventh postoperative (PO) months, ten animals received 40mg/kg/day of glucosamine and ten animals received no medication at all. All of these animals were sacrificed during the seventh PO month. The maximum angle of each knee extension was measured. A histological analysis was carried out by hematoxilin-eosin and alcian blue staining of each of the tibial and femoral condyles. All the operated knees presented a more limited range of extension than the non-operated knees (p=0.001), however, the animals that received diacerhein presented less stiffness (p=0.005). Histologically, the experimental model caused a light to moderate arthritis statistically different from the other non-operated knee (p=0.001). No significant differences (p=0.3) were detected between the knees of the rats medicated with glucosamine and those that received diacerhein. The operated medicated knees and non-operated knees also showed no statistical differences. Conclusion: The therapeutic use of diacerhein and glucosamine decreased joint stiffness and delayed the progression of the arthritis. The diacerhein had a more positive effect on joint mobility than the glucosamine, even though there was no statistical difference between the two drugs in controlling the degeneration of the joint

No description available.