Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-10T13:08:46Z No. of bitstreams: 1 Robespierre Augusto Joaquim Araujo Silva.pdf: 876319 bytes, checksum: 0f2c3e9ca22ca2262229c589230deed3 (MD5) / Made available in DSpace on 2017-02-10T13:08:46Z (GMT). No. of bitstreams: 1 Robespierre Augusto Joaquim Araujo Silva.pdf: 876319 bytes, checksum: 0f2c3e9ca22ca2262229c589230deed3 (MD5) Previous issue date: 2015-03-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The objective of this study was to evaluate the influence of different extenders [Tris buffer (Tris), Tris-egg yolk (EY) and Tris-soybean lecithin 1% (SL1) and 2% (SL2)] and the removal of seminal plasma process in goat sperm stored at 5 ºC for 48 hours. Semen was collected four goats (two Toggenburg and two American Alpine), using an artificial vagina twice a week for four weeks. Ejaculates with greater than 60% motility were pooled and each pool seminal (n = 8) was used in a repeat. The pool was divided equally, half diluted without removal of seminal plasma (non washed semen – NW), and packaged in straws of 0.25 mL (200x106 sperm/mL). The second half of the pool was subjected to removal of the seminal plasma (washed semen - W) by double centrifugation (2200 g/10 min) then diluted and packaged as mentioned above. Then, the samples were chilled to 5 °C (90 min) and kept under refrigeration for 48 hours. Computer analysis of sperm kinetics (CASA) and the evaluation of the plasma membrane (PMi) and acrosomal (ACi) integrity and mitochondrial membrane potential (MMP) were determined within five minutes after reaching 5 °C (T0), and after 24 (T24) and 48 (T48) hours of storage. No influence extender (p>0.05) was observed for sperm kinetic variables of NW semen, however, independent extender, progressive motility (PM), linearity (LIN), straightness (STR), straightline velocity (VSL) and average path velocity (VAP) were lower (p<0.05) in T48 compared to T0, a fact confirmed for total motility (TM) of SL2 group. In washed semen, TM and MP of EY group was higher (p <0.05) than the other groups throughout chilling period. After removal of the seminal plasma did not influence the cooling time (p>0.05) in any of the kinetic variables SL2 group. However, LIN, STR, VSL values for Tris-EY and SL1 groups, and PM and VAP values for Tris-EY group, were lower in T48 compared to T0. It was observed also that in the T48 TM, PM, VSL and VAP variables of LS2 group, and PM variable of Tris-EY group were higher in semen washed when compared to semen non whased. The PMi was not influenced by the type of extender, but in NW semen PMi of Tris-EY and SL2 groups was lower (p <0.05) in T48 compared to T0. Greater (p <0.05) PMi was observed for the washed compared to non washed semen. The ACi and kinetics (curvilinear velocity – VCL) were not affected (p>0.05) by extender, or by storage time or the removal of seminal plasma. Thus, it is concluded that the soybean lecithin can be used as a substitute for egg yolk for cooling of goat semen and which removal of the seminal plasma enhances the preservation of the caprine semen. / O objetivo deste estudo foi avaliar a influência de diferentes diluidores [Tris tampão (Tris), Tris-Gema (TG) e Tris-lecitina de soja 1% (LS1) e 2% (LS2)] e do processo de remoção do plasma seminal no sêmen caprino armazenado a 5 ºC por 48 horas. O sêmen foi colhido de quatro caprinos (dois Toggenburg e dois Alpino Americano), com vagina artificial, duas vezes por semana, durante quatro semanas. Ejaculados com motilidade superior a 60% foram agrupados e cada pool seminal (n=8) foi utilizado em uma repetição. O pool foi igualmente dividido, sendo metade diluído, sem remoção do plasma seminal (sêmen não lavado – NL), e envasado em palhetas de 0,25 mL (200x106 espermatozoides/mL). A segunda metade do pool foi submetida a remoção do plasma seminal (sêmen lavado – L) por dupla centrifugação (2200 g/10min) e depois diluída e envasada como citado anteriormente. Em seguida, as amostras foram refrigeradas até 5 ºC (90 min) e mantidas sob refrigeração por 48 horas. Análise computadorizada da cinética espermática (CASA) e a avaliação da integridade de membrana plasmática (iMP) e acrossomal (iAC) e do potencial de membrana mitocondrial (PMM) foram determinadas cinco minutos após atingir 5 ºC (T0), após 24 (T24) e 48 (T48) horas de armazenamento. Nenhuma influência do diluidor (p>0,05) foi observada para as variáveis de cinética espermática do sêmen NL, porém, independente do diluidor, motilidade progressiva (MP), linearidade (LIN), retilinearidade (STR), velocidade em linha reta (VSL) e velocidade média do percurso (VAP) foram menores (p<0,05) no T48 em relação ao T0, fato também observado para motilidade total (MT) do grupo LS2. No sêmen lavado, MT e MP do grupo Gema foi superior (p<0,05) aos demais grupos durante todo período de refrigeração. Após a remoção do plasma seminal não houve influência do tempo de refrigeração (p>0,05) sobre quaisquer das variáveis cinéticas do grupo LS2. Entretanto, os valores de LIN, STR, VSL para os grupos Tris-Gema e LS1, e MP e VAP para o grupo Tris-Gema, foram inferiores no T48 em relação ao T0. Observou-se, ainda, que no T48 as variáveis de MT, MP, VSL e VAP do grupo LS2, e MP do grupo Tris-Gema foram superior no sêmen lavado quando comparado ao sêmen não lavado. A iMP não foi influenciada pelo tipo de diluidor, porém no sêmen NL a iMP dos grupos Tris-Gema e LS2 foi inferior (p<0,05) no T48 em relação ao T0. Maior (p<0,05) iMP foi observada para o sêmen lavado em relação ao não lavado. A iAC e a cinética (velocidade curvilinear-VCL), não foram influenciadas (p>0,05) pelo diluidor, nem pelo tempo de armazenamento ou pela remoção do plasma seminal. Assim, conclui-se que a lecitina de soja pode ser utilizada como substituto à gema de ovo para refrigeração do sêmen caprino e que a remoção do plasma seminal melhora a conservação do sêmen dessa espécie.

Made available in DSpace on 2016-04-28T20:17:26Z (GMT). No. of bitstreams: 1 2006-Juan Rojas Pereira.pdf: 760746 bytes, checksum: 1798bbe7196bc85bf9d9b42cb797bfc4 (MD5) Previous issue date: 2006-03-17 / The aim of this work was to verify the isolation of Cryptococcus neoformans from bird droppings at some petshops trading in Rio de Janeiro borough-RJ, as well as to perform biochemical serogruping and to evaluate the virulence in vitro . 1268 samples from several birds at 25 commercial establishments distributed on 16 neighbourhoods in Rio de Janeiro Borough-RJ were collected.The biochemical serogrouping was carried out in CGB culture medium plates while protease and phospholipase production indicating virulence factors through specific media containing bovine soralbumin and yolk were performed in vitro respectively. Both virulence and serogrouping assays for 64 strains were carried out. From the total of samples, 85 (6,7%) were considered positive. Positivity feature was verified for birds, as well as Melopsittacus undulatus birds droppings, Serinus canaria and other sort of birds showed a greater member of seedlings. According to serogrouping, from the total of 56 samples, 54 were classified as serogrouping AD (Cryptococcus neoformans var. neoformans) and just two of them to serogrouping BC (Cryptococcus neoformans var gattii) possibly.All the strains showed to be protease and phospholipase producers and most as hard ones. Of the isolated 56 all were fit in the biotypes "Killer" I and II (var neoformans). Talking into account the possibility of high level infection for human and animal helth, the presence of this ethiological agent on such kind of establishments, it might be a great concern to sanitary surveillance policy for controllling the infection, furthermore. / O objetivo do presente trabalho foi verificar o isolamento de Cryptococcus neoformans em excretas de aves comercializadas em pet-shops localizados no Munic?pio do Rio de Janeiro RJ, realizar a sorogrupagem bioqu?mica e avaliar a virul?ncia in vitro . Foram colhidas 1268 amostras de diversas aves em 25 estabelecimentos distribu?dos em 16 bairros do referido munic?pio. A sorogrupagem bioqu?mica foi realizada em meio CGB, enquanto a determina??o da produ??o de protease e de fosfolipase como fatores de virul?ncia, foi realizada in vitro pelo emprego de meios espec?ficos contendo respectivamente soroalbumina bovina e gema de ovo. Do total de amostras avi?rias coletadas, 85 (6,70%) mostraram-se positivas. A positividade foi verificada isoladamente para as aves, sendo que as excretas de Melopsittacus undulatus, Serinus canaria e outras aves de maior procura destacaram-se pelo maior n?mero de isolados. A sorogrupagem realizada para 56 cepas revelou que 54 amostras pertencem ao sorogrupo AD (Cryptococcus neoformans variedade neoformans) e duas, possivelmente ao sorogrupo BC (C. neoformans var gattii). Todas as cepas mostraram-se produtoras de protease e de fosfolipase e a maioria revelou-se forte produtora destas enzimas. Dos 56 isolados todos se encaixaram nos bi?tipos Killer I e II (var neoformans). A presen?a deste agente em tais estabelecimentos comerciais deve ser motivo de preocupa??o para as autoridades sanit?rias, considerando-se a possibilidade de infec??o para o homem e para outros animais ali comercializados.

Os conhecimentos sobre os mecanismos regulatórios responsáveis pelo crescimento dos fungos filamentosos apresentam lacunas e sua compreensão é necessária para o desenvolvimento de uma terapêutica antifúngica mais adequada, assim como para incrementar a síntese de produtos de interesse comercial. Assim sendo, estudar o envolvimento do Ca2+ na resposta de um fungo modelo como A. nidulans sob fontes de carbono diferentes constitui um meio de gerar conhecimentos sobre as características de crescimento dos fungos filamentosos, de sua resposta a adaptação ambiental e dos mecanismos que controlam essa resposta. Analisou-se na linhagem A26 e na AP27, esta última com ruptura do gene da plcA, o gradiente de Ca2+ citosólico, a morfologia das hifas, a germinação e o ciclo de divisão nuclear quando as linhagens tinham calcineurina ou calmodulina inibidas e quando os canais de Ca2+ estavam bloqueados ou abertos. Os níveis de Ca2+ citosólico na linhagem A26, crescendo em presença de glicose, foram maiores que os detectados em meio suplementado com pectina. O ciclo de germinação e divisão celular no AP27, independentemente da fonte de carbono, mostrou-se mais lento se comparado com a linhagem A26, provavelmente devido ao fato de seus estoques intracelulares de Ca2+, tanto em nível vesicular quanto citosólico, serem menores. A linhagem AP27 apresentou ramificações dicotômicas nas pontas das hifas e nas hifas laterais em ambas as fontes de carbono nas quais foi cultivada, o que não se observou na linhagem A26. Quando calcineurina foi inibida por ciclosporina A, as hifas das duas linhagens, em ambas condições de cultivo, alongaram-se menos e apresentaram-se mais ramificadas, no entanto este efeito foi mais pronunciado em presença de glicose, e entre as duas linhagens pode-se dizer que foi mais intenso na linhagem AP27, demonstrando a importância dos níveis de cálcio na atividade desta enzima e conseqüentemente no desenvolvimento normal das hifas. A abertura dos canais de Ca2+, por ionóforo, produziu hiperramificação em ambas as linhagens, mas principalmente quando cresciam em pectina e ao contrário do efeito observado em presença de verapamil, que bloqueia os canais de Ca2+, não promoveram hifas laterais e nem pontas dicotômicas. No entanto o outro bloqueador dos canais de Ca2+ testado, ácido caurenóico, apresentou efeito morfológico diferente, pois as hifas tornaram-se curvas o que indica perda de polaridade. O inibidor da calmodulina (TFP) retardou a germinação, principalmente no mutante AP27, quando crescendo em presença de glicose. Lembrando que o complexo Ca2+/CaM ativa a calcineurina e que o mutante apresenta menores níveis de cálcio, esse resultado é justificável. A ruptura do gene plcA não impediu o crescimento e desenvolvimento do mutante, provavelmente porque a função desta enzima poder ser provida por outras partes do genoma, mas comprometeu os níveis intracelulares de cálcio e conseqüentemente a sua morfologia. Este estudo mostra a importância da fosfolipase C, para manutenção dos níveis intracelulares de Ca2+, no desenvolvimento normal das hifas de A. nidulans e, pela primeira vez, demonstra que esses níveis são diferentes quando o fungo cresce em presença de uma fonte de carbono, prontamente metabolizável ou não. Esses resultados conferem ao cálcio um papel modulador nessas condições de cultivo. / The knowledge about regulatory mechanisms responsible for filamentous fungi growth presents lacks and its understanding is important to develop adequate antifungal therapy either to contribute the synthesis of interestingly commercial products. By this way, study Ca2+ relationship to a fungal model as A. nidulans about different carbon sources, constitute knowledge about the filamentous fungi growing characteristics, environment adaptation and its control mechanisms. The strains A26 and AP27 was analyzed, this last one with disruption plcA gene, cytosolic Ca2+ gradient hyphal morfology, germination and nuclear division cycle when these strains had calcineurin or calmodulin inhibition and Ca2+ channel were blocked or opened. Cytosolic Ca2+ levels in A26 strain, growing in the presence of glucose was higher than supplemented media with pectin. AP27 strain, independently of carbon source, demonstrated lower germination and cell division than A26 strains, probably due to the fact that intracellular Ca2+ stocks either vesicular as cytosolic levels were lower. AP27 strain presented dichotomous branching at tip-high and lateral hyphae, at both carbon source that was grown, didnt observed at A26 linkage. When calcineurin was inhibited by cyclosporin A, hyphae from both strains, in both growth conditions, had less elongated and showed more branching, however this effect was more pronounced in presence of glucose, and between both strains was more intense at AP27 strain, indicating the importance of Ca2+ levels at this enzymatic activity and therefore the normal development of hyphae. The opening of Ca2+ channel by ionophore, produced hyperbranching in both strains, even when growth in pectin and in contrast of effect observed in the presence of verapamil, that blocks Ca2+ channels, didnt promote lateral or tip high dichotomous branching. However kaurenoic acid, an another Ca2+ channel blocker tested, presented different morphological effect, because hyphae became curved, indicating loss of polarity. Calmodulin inhibitor (TFP) delayed germination mainly at mutant AP27, when growing in the presence of glucose. Remembering that Ca2+/CaM complex activate calcineurin and the mutant exhibit lower Ca2+ levels, justifying this results. The rupture of plcA gene didnt affected growth and development of mutant, probably because the function of this enzyme can be provided by another parts of genoma, damaged the Ca2+ intracellular levels and consequently its morphology. This study shows the importance of fosfolipase C to maintaining the intracellular Ca2+ levels, at the normal hyphae development of A. nidulans and for the first time, demonstrating that this levels are different when fungi are grown in the presence of carbon source, promptly metabolizable or not. This results gives to Ca2+ as modulator at growth conditions.

In addition to contributing genes at fertilization, the sperm cell induces the oocyte to leave its arrested state and resume metabolism in the process of activation. A hallmark of oocyte activation is a release of intracellular calcium (Ca2+i) from the endoplasmic reticulum. The mediators of oocyte activation have been studied in many animal models, while little is known in the bovine model. Both Src Family Kinase (SFK) and Phospholipase C (PLC) enzymes have been reported to be involved in oocyte activation in other animal models. In this dissertation are described experiments that define the role of SFK and PLC enzymes in the pathway leading to Ca2+i and calcium induced calcium release in bovine oocyte activation. Western blotting was used to discover that SFKs Src, Hck, and Lck are present in matured bovine oocytes, and Src, Blk, and Yes are present in acrosome reacted bovine spermatozoa. The PLC δ1 and δ3 are present in both matured bovine oocytes and spermatozoa. PLC δ4, γ2, and η2 are present in matured bovine oocytes. Microinjecting a known general SFK inhibitor, PP2, significantly decreases both Ca2+i and cleavage rates. Microinjecting a 13 amino acid peptide that mimics the phosphorylated carboxyl terminal region of pp60c-src decreases both Ca2+i and cleavage rates. Microinjecting a downstream substrate of pp60c-src sequestered any signal produced by Src and decreased Ca2+i and cleavage rates. Microinjecting primary antibodies raised against PLC isotypes blocked both Ca2+i and cleavage rates, giving insight to the mechanism of calcium induced calcium release in the bovine model. The PLC isotypes δ3, δ4, and γ2 decreased Ca2+i oscillations and cleavage rates, indicating they are involved in both IP3R and RyR activation. PLC δ4 and η2 did not impact Ca2+i but did significantly decrease cleavage rates. The data presented in this dissertation increase the understanding of the pathway leading to bovine oocyte activation and further confirm that the detailed pathway differs among animal models.

Abstract not available

共著者あり。共著者名:Munakata Mitsuru, Sato Atsuko, Amishima Masaru, Homma Yukihiko, Kawakami Yoshikazu. / Hokkaido University (北海道大学) / 博士 / 医学

<p>Prostaglandin (PG) E₂ is an eicosanoid derived from the polyunsaturated twenty carbon fatty acid arachidonic acid (AA). PGE₂ has physiological as well as pathophysiological functions and is known to be a key mediator of inflammatory responses. Formation of PGE₂ is dependent upon the activities of three specific enzymes involved in the AA cascade; phospholipase A₂ (PLA₂), cyclooxygenase (COX) and PGE synthase (PGEs). Although the research within this field has been intense for decades, the regulatory mechanisms concerning the PGE₂ synthesising enzymes are not completely established.</p><p>PGE₂ was investigated in human monocytes with or without lipopolysaccharide (LPS) pre-treatment followed by stimulation with calcium ionophore, opsonised zymosan or phorbol myristate acetate (PMA). Cytosolic PLA₂a (cPLA₂a) was shown to be pivotal for the mobilization of AA and subsequent formation of PGE₂. Although COX-1 was constitutively expressed, monocytes required expression of COX-2 protein in order to convert the mobilized AA into PGH₂. The conversion of PGH₂ to the final product PGE₂ was to a large extent due to the action of microsomal PGEs-1 (mPGEs-1). In addition, experiments with inhibitors of extracellular signal regulated kinase and p38 activation, indicated that phosphorylation of cPLA₂α was markedly advantageous for the formation of PGE₂.</p><p>Ellagic acid, a natural polyphenolic compound found in fruits and nuts, was shown to inhibit stimuli induced release of PGE₂ in human monocytes. The effect of ellagic acid was not due to a direct effect on the activities of the enzymes but rather to inhibition of the LPS-induced protein expression of COX-2, mPGEs-1 and cPLA₂a.</p>

The neuropeptides orexin-A and orexin-B were discovered in 1998 and were first described as regulators of feeding behaviour. Later research has shown that they have an important role in the regulation of sleep. Two G protein-coupled receptors, OX1 and OX2 orexin receptors, mediate the cellular responses to orexins. The overall aim of this thesis was to investigate the OX1 orexin receptors signalling to phospholipases. Previous investigations have determined that orexin receptors induce Ca2+ elevations through both receptor-operated Ca2+ channels (ROCs) and store-operated Ca2+ channels (SOCs). In this thesis we investigated the importance of these influxpathways on orexin-mediated phospholipase (PLC) activation. The results demonstrate that ROC influx is enough to fully support orexin-stimulated PLC activation but that SOC influx has a further amplifying role. We also investigated the metabolites generated after PLC activation, inositolphosphates and diacylglycerol (DAG). The results indicate involvement of two different PLC activities with different substrate specificities one of them leading to DAG production without co-occurring IP3 production at low orexin receptor stimulation. The results also suggest that at even lower orexin receptor stimulation DAG is produced via the activation of phospholipase D. In this thesis we also investigated if the ubiquitous phospholipase A2 (PLA2) signalling system is involved in orexin receptor signalling. The results demonstrate that stimulation of the OX1 orexin receptors leads to arachidonic acid (AA) release. This release is fully dependent on Ca2+ influx, probably through ROC, and at the same time the studies demonstrate that ROC influx is partly dependent on PLA2 activation. At low orexin receptor activation the AA release seemed to in part rely on extracellular signal-regulated kinase. We also devised two methods to aid in these investigations. The first method enabled studies of the receptor-operated Ca2+ influx without interference of the co-occurring store-operated Ca2+ influx. This was done by the expression of IP3-metabolising enzymes IP3-3-kinase-A and IP3-5-phosphatase-I. The second method enables quantification of DAG and IP3 signalling in fixed cells using GFP-fused indicators, leading to a semi-quantitative but easily applicable pharmacological assay.

The goal of the present study is to elucidate the modulatory effect of lipid compositions on phospholipase A2 (PLA2) activity. Sphingomyelin (SM) incorporation inhibited catalytic activity and membrane-damaging activity of native and mutated PLA2 toward egg yolk phosphatidylcholine (EYPC) vesicles. The inhibitory effects were through the reduction of membrane fluidity and modulation of the mode of membrane binding of PLA2 at water/lipid interface. The modulated effect of SM depended on inherent structural elements of PLA2. Moreover, cholesterol (Chol) incorporation into EYPC/egg yolk sphingomyelin (EYSM) vesicles relieved the inhibitory effect of sphingomyelin on PLA2 activity via lipid domain formation by SM and Chol. The effects on the interactive mode of PLA2 with phospholipids induced by the physical state changes of membrane bilayers abolished the inhibition of SM on catalytic activity and membrane-damaging activity of PLA2. Additionally, quercetin incorporation increased PLA2 activity and membrane-damaging activity toward EYPC/SM vesicles via its raft-making effect. Quercetin incorporation reduced PLA2 activity and membrane-damaging activity toward EYPC/SM/Chol vesicles via its raft-breaking effect. Membrane-inserted quercetin affected on membrane structure and membrane-bound mode of PLA2 to modulate PLA2 interfacial activity and membrane-damaging activity. Finally, studies on the effects of phosphatidylserine (PS) content on the sensitivity of lipid vesicles mimicking inner and outer plasma membrane toward PLA2 activity revealed that the membrane-binding mode adopted by PLA2 depended on the lipid composition. The effects of PS content on the extent of lipid domain formation and the conformation of PLA2 adopted at water-lipid interface modulate PLA2 catalytic activity. Collectively, these results indicate that lipid composition modulates PLA2 activity via its effects on membrane structure and membrane-bound mode of PLA2

The C type natriuretic peptide receptor (NPRC) also known as NPR3 is a widely expressed single transmembrane-spanning protein. NPRC functions as a homodimer at the cell surface for the metabolic clearance of a broad range of natriuretic peptides from circulation. The intracellular domain of NPRC is coupled to inhibitory G proteins and is involved in mediating signal transduction. In order to further elucidate the role of NPRC in signal transduction a proteomic approach was taken to identify putative protein binding partners for NPRC in different cell-types. An interrogation of the molecular association between NPRC and its identified protein binding partner(s) was carried out in different cell types to identify the specific interacting domains. The physiological role of the association between NPRC and its protein binding partner(s) were investigated in situ. Furthermore NPRC is subject to post translation modifications including glycosylation and phosphorylation. Although evidence suggests NPRC is phosphory ated on serine residues the specific amino acid residues that are phosphorylated and the kinases responsible for their phosphorylation has yet to be determined. A recombinant GST-NPRC fusion protein polyclonal NPRC antibody kinase prediction algorithm and several phosphospecific and substrate motif antibodies were utilized to characterize the phosphorylation state of NPRC in vitro.