Loxosceles laeta, conocida como “araña del rincón” o “araña casera”, es el principal artrópodo de importancia clínica en nuestro país debido a las graves alteraciones fisiológicas, con secuelas irreversibles que produce su mordedura en humanos pudiendo llevar a la muerte. El objetivo de este trabajo fue explorar y caracterizar parcialmente las enzimas proteolíticas presentes en este veneno; las enzimas evaluadas fueron proteolíticas sobre caseína y dimetilcaseína (DMC), así como la acción pro-coagulante sobre plasma humano citratado. El veneno fue fraccionado usando una columna cromatográfica de filtración molecular sobre Sephadex G-100, equilibrado con buffer acetato de amonio 0,05M pH 5,0. Mediante PAGE-SDS se determinó que la proteasa que hidroliza DMC es de naturaleza monomérica, con un peso aproximado de 35 kDa. En los ensayos de inhibición, con el agente quelante EDTA y el inhibidor de serinoproteasas (PMSF), se obtiene una inhibición de 60,4% de la actividad proteolítica usando 5 mM de EDTA y empleando 5 mM de PMSF la actividad pro-coagulante se redujo al 6,7%. Las pruebas de inmunodifusión doble, usando el antiveneno loxoscélico comercial (INS-Perú) mostraron la antigenicidad de las proteasas en estudio, así como del antiveneno total. Se concluye que el veneno de la araña L. laeta contiene por lo menos 2 tipos de proteasas, una del tipo metaloproteasa y la otra serinoproteasa, siendo ambas enzimas reconocidas por el antiveneno loxoscélico comercial.

Background: Caveolin-1 (Cav-1), the major component of caveolae, is a multifunctional scaffolding protein that serves as a platform for the cell’s signal-transduction and plays a role in inflammation. However, its role in inflammatory bowel disease (IBD), a chronic inflammatory condition in the gastrointestinal tract, is not clear. A recent study shows that Cav-1 mediates angiogenesis in dextran sodium sulphate (DSS)-induced colitis. These results contradict our data, in which Cav-1 levels decreased significantly in 2,4,6-trinitrobenzene sulphonic acid (TNBS)–induced colitis. Methods: To test whether Cav-1 is involved in IBD pathogenesis, various models representing different dominant Th subtype responses and mimicking the immune pathologic mechanisms of different clinical IBD setting were employed: acute colitis was induced by intra-rectal administration of a single dose of TNBS in BALB/c and C57BL/6J mice, or by drinking 3% DSS water for 6 days in C57BL/6J mice. Chronic colitis was induced by administration of TNBS once a week for 7 weeks in BALB/c mice. To assess the effects of complete loss of Cav-1, Cav-1 knock-out (Cav-1-/-) and control wild-type C57BL/6J mice received a single TNBS administration. To further test the possible role of Cav-1, one of two peptides (that either mimicked (Caveolin scaffolding domain; CSD) or antagonized (Caveolin-1 binding domain; CBD1) Cav-1)) was administered intraperitoneally to mice receiving TNBS. Body weight and clinical scores were monitored. Colon Cav-1 and pro-inflammatory cytokine levels were quantified by ELISA. Inflammation was evaluated through histological analysis. Results: Cav-1 levels in mouse colon tissue were significantly decreased in TNBS-induced colitis mice when compared to normal mice and also inversely correlated with colon inflammation and cytokine levels. Furthermore, a loss of Cav-1 (Cav-1-/-) showed increased clinical and inflammatory scores and increased body weight loss. Mice receiving peptides to alter Cav-1 levels, showed surprising effects. The mimicking peptide (CSD) showed decreased Cav-1 levels, while the antagonizing peptide (CBD1) showed increased Cav-l levels. These changes in levels were associated with clinical and inflammatory scores and body weight loss that supported the TNBS-induced data. DSS-induced colitis mice showed increased disease activity index, however no significant difference in Cav-1 levels was found between colitis and normal mice. Conclusions: Cav-1 plays an important role in the protection of TNBS-induced colitis, but not in DSS-induced colitis, an entirely different result from a previous report, suggesting that enhancement of Cav-1 expression and functions may be beneficial to IBD treatment in some specific clinical settings. Further studies are warranted.

Background: Caveolin-1 (Cav-1), the major component of caveolae, is a multifunctional scaffolding protein that serves as a platform for the cell’s signal-transduction and plays a role in inflammation. However, its role in inflammatory bowel disease (IBD), a chronic inflammatory condition in the gastrointestinal tract, is not clear. A recent study shows that Cav-1 mediates angiogenesis in dextran sodium sulphate (DSS)-induced colitis. These results contradict our data, in which Cav-1 levels decreased significantly in 2,4,6-trinitrobenzene sulphonic acid (TNBS)–induced colitis. Methods: To test whether Cav-1 is involved in IBD pathogenesis, various models representing different dominant Th subtype responses and mimicking the immune pathologic mechanisms of different clinical IBD setting were employed: acute colitis was induced by intra-rectal administration of a single dose of TNBS in BALB/c and C57BL/6J mice, or by drinking 3% DSS water for 6 days in C57BL/6J mice. Chronic colitis was induced by administration of TNBS once a week for 7 weeks in BALB/c mice. To assess the effects of complete loss of Cav-1, Cav-1 knock-out (Cav-1-/-) and control wild-type C57BL/6J mice received a single TNBS administration. To further test the possible role of Cav-1, one of two peptides (that either mimicked (Caveolin scaffolding domain; CSD) or antagonized (Caveolin-1 binding domain; CBD1) Cav-1)) was administered intraperitoneally to mice receiving TNBS. Body weight and clinical scores were monitored. Colon Cav-1 and pro-inflammatory cytokine levels were quantified by ELISA. Inflammation was evaluated through histological analysis. Results: Cav-1 levels in mouse colon tissue were significantly decreased in TNBS-induced colitis mice when compared to normal mice and also inversely correlated with colon inflammation and cytokine levels. Furthermore, a loss of Cav-1 (Cav-1-/-) showed increased clinical and inflammatory scores and increased body weight loss. Mice receiving peptides to alter Cav-1 levels, showed surprising effects. The mimicking peptide (CSD) showed decreased Cav-1 levels, while the antagonizing peptide (CBD1) showed increased Cav-l levels. These changes in levels were associated with clinical and inflammatory scores and body weight loss that supported the TNBS-induced data. DSS-induced colitis mice showed increased disease activity index, however no significant difference in Cav-1 levels was found between colitis and normal mice. Conclusions: Cav-1 plays an important role in the protection of TNBS-induced colitis, but not in DSS-induced colitis, an entirely different result from a previous report, suggesting that enhancement of Cav-1 expression and functions may be beneficial to IBD treatment in some specific clinical settings. Further studies are warranted.

Opioids are powerful analgesics. Despite their high efficacy for the management of moderate to severe pain, their clinical utility is limited due to the occurrence of adverse effects. The main problem associated with opioid use is the differential rate of tolerance development to the various pharmacological effects of opioids, with tolerance to respiratory depression occurring at a slower rate than analgesic and euphoric effects. The development of analgesic tolerance, where the efficacy of the drug progressively diminishes with repeated administration, requires higher doses of the drug to achieve a maximum effect. Reports have implicated inflammation as a major driver of analgesic tolerance development. With surmounting evidence that the prototypical opioid, morphine induces pro-inflammatory cytokine release in the brain, spinal cord, and gastrointestinal tract, a question arises of whether pro-inflammatory cytokine release in the gut as a result of chronic morphine treatment is paralleled with the development of morphine antinociceptive tolerance. This dissertation investigated the rate at which antinociceptive tolerance to various doses of morphine developed to a different degree in the presence of colonic inflammation. Using a mouse model, colonic inflammation was induced with 2,4,6-Trinitrobenzenesulfonic acid (TNBS) and then the mice were pelleted with 25 mg, 50 mg (2x25), or 75 mg morphine pellet. Antinociceptive tolerance to morphine was determined in a warm-water tail-immersion assay upon an administration of a morphine challenge dose (10 mg/kg). Inflammatory cytokine expressions and protein levels were measured from whole colon using qPCR and ELISA, respectively. Morphine antinociceptive tolerance was significantly enhanced in the presence of colonic inflammation in a dose and time dependent manner. With a daily injection of 0.5 mg/kg peripheral opioid receptor antagonist 6β-N-heterocyclic substituted naltrexamine derivative (NAP), mice pelleted with 25 mg, 50 mg (2x25), or 75 mg morphine pellets were tested on day 5, 4, or 3, respectively. Tolerance to morphine as well as the enhanced tolerance observed in the presence of colonic inflammation was prevented with daily NAP treatment. However, NAP did not block morphine-induced or TNBS-induced inflammation. Collectively, our findings indicate that inflammation is a major modulator of morphine antinociceptive tolerance and peripheral opioid receptors may be responsible for mediating antinociceptive tolerance.

Inflammatory bowel disease causes structural and functional alterations in the enteric nervous system (ENS). Since the onset of intestinal inflammation involves the activation of resident immune cells as well as rapid influx of infiltrating cells, we proposed that changes in the ENS are a result of the release of toxic inflammatory factors. We hypothesized that early damage to the ENS in inflammation is caused by harmful levels of nitric oxide (NO) generated by the enzyme inducible nitric oxide synthase (iNOS) found in immune cells. This was assessed in the 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-model of colitis in rats. Large increases in infiltrating granulocytes, particularly neutrophils and blood-derived monocytes were found in the muscularis layers adjacent to the ENS. A rapid increase in iNOS immunoreactivity in the muscularis regions during early stages of inflammation (6 – 24 hr) was observed. Whether high NO levels generated by chemical donors could be toxic to neurons was tested in a co-culture model of myenteric neurons, smooth muscle and glia enzymatically isolated from neonatal rats. Exposure of co-cultures to NO for 48 hr resulted in significant, concentration dependent decrease in neuron survival. We then developed a model that permitted the direct study of immune cell interactions with myenteric neurons. Myenteric neurons were co-cultured with activated peritoneal immune cells that expressed iNOS and generated high NO levels (49 + 6.2µM) for 48 hr. This caused significant neuronal death, reducing neuron number by 19 + 5%, and disruption of axons. Pre-treatment of immune cells with a selective iNOS-inhibitor, L-NIL resulted in neuron numbers that were not significantly different from control (96 + 2%) suggesting that NO played a central role in mediating the damaging effects of immune cells. Lastly, when direct contact between immune cells and neurons was prevented in the previous experiment through use of trans-wells, unanticipated neurotrophic effects were observed. Increased axon outgrowth (282 + 57%) was detected in addition to loss of the neurotoxic effects in spite of similar experimental conditions. We concluded that proximity and contact plays an important role in determining the nature of immune cell mediated alterations in enteric neurons. / Thesis (Master, Physiology) -- Queen's University, 2009-11-30 10:09:38.384

Orientador: Luiz Claudio Di Stasi / Resumo: A Doença Inflamatória Intestinal (DII) é uma doença com etiologia desconhecida e sem terapêutica curativa disponível, englobando, fundamentalmente, duas doenças distintas: a Doença de Crohn (DC) e a Retocolite Ulcerativa (RCU), ambas caracterizadas por uma inflamação crônica do intestino, com períodos de exacerbação seguidos de intervalos prolongados com remissão dos sintomas, cujo tratamento com os fármacos disponíveis apresentam sérios efeitos colaterais. Portanto, o desenvolvimento de novas estratégias de tratamento que combinem eficácia e segurança é uma importante meta na terapia da DII. Produtos de origem natural, especialmente oriundos de fontes vegetais com propriedades de modificar a microbiota intestinal têm sido amplamente estudados como agentes preventivos e/ou curativo destas doenças, visto que a manipulação da microbiota intestinal tem se mostrado como uma estratégia importante na manutenção da homeostase colônica. Neste contexto, muitos frutos de origem tropical, com ampla utilização pela população e ricos em fibras e/ou componentes que ativos como antioxidantes e/ou anti-inflamatórios podem representar uma nova estratégia complementar para a prevenção ou cura da DII. Dentre eles se destacam os frutos das espécies Theobroma grandiflorum (cupuaçu) e Musa spp AAA (banana nanica), ricos em fibras alimentares e compostos fenólicos, os quais são potencialmente benéficos no tratamento e prevenção da DII. O objetivo do presente trabalho foi avaliar os efeitos de uma d... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

<p>Currently, there is no effective cure for Inflammatory Bowel Disease (IBD), medications are aimed solely at alleviating symptoms and not curative. Great scientific efforts have been aimed at elucidating the mechanisms underlying the pathogenesis of IBD. Macrophages—antigen presenting cells—play a chief role in the pathophysiology of IBD. It has been proposed that CD36 receptor present on the surface of macrophages, may play a role in the inflamed intestine. CD36-expressing macrophages have been implicated in a variety of human diseases; however the role of CD36+ macrophages in the intestine has been limited. The aim of this study was to decipher whether or not CD36+ F4/80+ macrophages are inflammatory in the colonic intestine. Our study discovered the proportion of CD36+ F4/80+ macrophages were markedly upregulated in active IBD patients and TNBS-induced colitis mice. CD36+ macrophages isolated from the LPMC of the small and large intestine of Balb/c treatment groups(a) 12TNBS, (b) MHS+12TNBS, and (c) MHS+PA mice confirmed these macrophages expressed some level of proinflammatory cytokine TNF-α. Two macrophage ligands, LCFA: Palmitic Acid and PGN, in conjunction or separately, appeared to be two culprits which induced MHS macrophages to produce TNF-α both in vitro and in vivo. It is possible these two ligands may work in concert, however the mouse model has yet to be examined. The precise role(s) of these CD36+ F4/80+ macrophages requires further scientific inquiry and elucidation in the context of intestinal inflammation. It is quite possible understanding the mechanisms and roles of these macrophages will greatly advance our knowledge in the pathophysiology of IBD and potential therapeutic treatments or targets.</p> / Master of Science (MSc)

Orientador: Luiz Claudio Di Stasi / Resumo: A Doença Inflamatória Intestinal engloba duas principais doenças sendo elas a Doença de Crohn e a Retocolite Ulcerativa onde ambas se caracterizam por uma inflamação crônica do intestino, com períodos de exacerbação seguidos de intervalos prologados com remissão dos sintomas. Sua etiologia é considerada multifatorial e ainda pouco elucidada. Considerando-se que não existe cura, que os fármacos utilizados são de alto custo, além de apresentarem sérios efeitos colaterais e ainda muitos pacientes não responderem a esses tratamentos disponíveis, a busca por estratégias complementares de prevenção e tratamento dessa doença que combinem eficácia e segurança, como o uso de alimentos funcionais, compostos antioxidantes e compostos bioativos se apresentam como uma perspectiva promissora. Com base nisso, a espécie vegetal Hibiscus esculentus L. conhecida popularmente como quiabo, foi selecionada para o presente estudo com o objetivo de avaliar a atividade anti-inflamatória intestinal das dietas enriquecidas com o fruto no modelo experimental da inflamação intestinal induzida por ácido trinitrobenzenosulfônico em ratos. Para tanto, a farinha dos frutos foi incorporada na dieta de ratos Wistar machos nas concentrações de 5% e de 10% por 28 dias antes e 7 dias após a indução do processo inflamatório intestinal. Os animais foram mortos no 35º dia e seus cólons foram extraídos. Para a caracterização da atividade anti-inflamatória intestinal foram analisados parâmetros macroscópicos (escore,... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Inflammatory Bowel Disease comprises two major diseases, Crohn´s disease and ulcerative colitis where both are characterized by chronic inflammation of the intestine, with periods of exacerbation followed by prolonged intervals with remission of symptoms. This disease is multifactorial with complex and not fully elucidated etiology. Considering that there is no cure and the drugs may cause serious side effects, and many patients do not respond to the available treatments, researches focused on the development of new treatment strategies are important. The pursuit of complementary strategy of prevention and treatment of disease that combine effectiveness and safety, such as the use of functional foods, antioxidant compounds and bioactive compounds if known as a promising perspective. Based on this, a vegetable species Hibiscus esculentus L., populary known as okra, was selected for this study with the objective to evaluate the activity of enriched diet in the experimental model of intestinal inflammation induced by trinitrobenzenesulfonic acid in rats. For this, a fruit flour was incorporated in the diet of male Wistar rats in concentrations of 5% and 10% for 28 days before and 7 days after of induction of intestinal inflammation by TNBS. The animals were killed on the 35th day and their colons were removed. For the characterization of the intestinal antiinflammatory activity, were performed macroscopic studies (score, lesion length, weight ratio length of the colon, occurrenc... (Complete abstract click electronic access below) / Mestre

Neste trabalho foi estudado o potencial imunorregulador da crotoxina (CTX) obtida do veneno de C. d. terrificus, em modelo experimental de colite induzida pelo TNBS em camundongos. A CTX foi capaz de diminuir a perda de peso, o score clínico e histológico, síntese de MPO e citocinas pró-inflamatórias. Menor número de neutrófilos e macrófagos com fenótipos M1 e M2 na lâmina própria foi observado nos grupos TNBS/CTX em relação ao TNBS. A CTX induziu TGF-b e IL-10, PGE2 e LXA4. A neutralização in vivo dessas citocinas ou o bloqueio da síntese desses eicosanoides indica que estas moléculas exercem papel relevante na ação moduladora da CTX no quadro inflamatório. As análises das diferentes populações celulares da lâmina própria, linfonodos e Placas de Peyer mostraram que não houve diferença nos linfócitos CD4+Tbet+ entre os grupos TNBS e TNBS/CTX. No entanto, a CTX promoveu aumento de CD4+FoxP3+ e diminuição de CD4+RORg+. Estes resultados indicam que a CTX é capaz de modular a resposta inflamatória aguda intestinal melhorando o quadro clinico observado nos animais. / In this work it was analyzed the immunomodulatory effect of crotoxin (CTX) isolated from C.d. terrificus snake venom, on the experimental model of colitis induced by TNBS in mice. The CTX was able to inhibit the weight loss, clinical and histological score, MPO synthesis and pro-inflammatory cytokines. Lower number of neutrophils and macrophage (M1 and M2) in lamina propria was observed in TNBS/CTX mice compared with the TNBS group. In contrast, the CTX induced increased TGF-b, IL-10, PGE2 and LXA4. The in vivo neutralization of these cytokines or eicosanoids synthesis indicates that these molecules exert significant role in the modulatory effect of CTX. The analyzes of distinct cell populations from lamina propria, lymph nodes and Peyers pathes showed no difference in CD4+Tbet+ between TNBS or TNBS/CTX mice. However, CTX induced an increase of CD4+FoxP3+ and decreased CD4+RORgt+. Together, these results indicate that CTX is able to modulate intestinal acute inflammatory response induced by TNBS improving the clinical status of the mice.

Made available in DSpace on 2014-12-17T14:03:37Z (GMT). No. of bitstreams: 1 MariliaSNS_TESE.pdf: 2303324 bytes, checksum: d055f1a32ee94b3ffe5f389dbf9dffe0 (MD5) Previous issue date: 2014-04-08 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Compounds derived from fungi has been the subject of many studies in order to broaden the knowledge of their bioactive potential. Polysaccharides from Caripia montagnei have been described to possess anti-inflammatory and antioxidant properties. In this study, glucans extracted from Caripia montagnei mushroom were chemically characterized and their effects evaluated at different doses and intervals of treatment. It was also described their action on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS), and its action on cells of the human colon carcinoma (HT-29). Compounds extracted of C. montagnei contain high level of carbohydrates (96%), low content of phenolic compounds (1.5%) and low contamination with proteins (2.5%). The (FT-IR) and (NMR) analysis showed that polysaccharides from this species of mushroom are composed of &#945;- and &#946;-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed a reduction of colonic lesions in all groups treated with the glucans of Caripia montagnei (GCM). GCM significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that such glucans acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01), nitric oxide (p < 0.001), and myeloperoxidase (p < 0.001). These results were confirmed microscopically by the reduction of cellular infiltration. The increase of catalase activity suggest a protective effect of GCM on colonic tissue, confirming their anti-inflammatory potential. GCM displayed cytostatic activity against HT-29 cells, causing accumulation of cells in G1 phase, blocking the cycle cell progression. Those glucans also showed ability to modulate the adhesion of HT-29 cells to Matrigel? and reduced the oxidative stress. The antiproliferative activity against HT-29 cells displayed by GCM (p <0.001) can be attributed to its cytostatic activity and induction of apoptosis by GCM / Compostos derivados de fungos tem sido alvo de muitos estudos a fim de desenvolver o conhecimento acerca de seu potencial bioativo. Polissacar?deos de Caripia montagnei j? foram descritos por possu?rem propriedades anti-inflamat?ria e antioxidante. Neste estudo, os polissacar?deos extra?dos do fungo Caripia montagnei foram caracterizados quimicamente e seus efeitos sobre as les?es intestinais foram avaliados em diferentes intervalos de tratamento no modelo de colite induzida por ?cido 2,4,6 - trinitrobenzenossulf?nico (TNBS), verificou-se ainda sua a??o sobre c?lulas do carcinoma de c?lon humano, HT-29. Na an?lise realizada no extrato obtido de C. montagnei foi verificado que este ? formado principalmente, por carboidratos (96%) apresentando um baixo teor de compostos fen?licos (1,5%) e baixa contamina??o prot?ica (2,5%). As an?lises por espectroscopia de infra vermelho (FT-IR) e resson?ncia magn?tica nuclear (RMN) mostraram que os polissacar?deos desta esp?cie de fungo s?o &#945; e &#946; -glucanas. O dano col?nico foi avaliado por an?lises macrosc?picas, histol?gicas, bioqu?micas e imunol?gicas. Os resultados mostraram a redu??o das les?es no c?lon em todos os grupos tratados com as glucanas (GCM). GCM reduziram significativamente os n?veis de IL-6 (50 e 75 mg/Kg, p < 0,05), uma importante citocina inflamat?ria. As an?lises bioqu?micas mostraram que essas glucanas atuaram na redu??o dos n?veis de fosfatase alcalina (75 mg/Kg, p < 0,01), ?xido n?trico (p < 0,001) e mieloperoxidase (p < 0,001). Estes resultados foram confirmados pela redu??o da infiltra??o celular observado microscopicamente. O aumento da atividade da catalase, sugere um efeito protetor de GCM no tecido do c?lon, o que confirma o seu potencial anti-inflamat?rio. GCM mostraram atividade citost?tica sobre as c?lulas HT-29, causando ac?mulo de c?lulas na fase G1 e impedindo, assim, a progress?o do ciclo celular. As glucanas deste estudo tamb?m mostraram habilidade em modular a ades?o de c?lulas HT-29 ao Matrigel? e reduzir o estresse oxidativo nessas c?lulas. A atividade antiproliferativa contra c?lulas HT-29 exibida por GCM pode ser atribu?da ? sua a??o citost?tica ou indu??o da apoptose por essas glucanas