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Hurst, Katrina M. « Modulation of Synaptic Plasticity : Endocannabinoids and Novel G-protein Coupled Receptors Expression and Translational Effects in Interneurons ». BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6940.
Texte intégralRésumé :
Learning and memory are important processes that occur in the brain. The brain is comprised of neurons that make connections with each other known as synapses. Synaptic plasticity is widely believed to be the physiologic mechanism by which learning and memory occur. Synapses can either be strengthened through a process known as long-term potentiation (LTP) or weakened through long-term depression (LTD). The area of the brain that is most studied for its role in learning and memory is the hippocampus, which has been shown to be involved in memory consolidation. The detection of endocannabinoids and their receptors has opened a whole new field of study in regards to synaptic plasticity. Cannabinoid receptor 1 (CB1) and transient receptor potential vanilloid 1 (TRPV1) are among the commonly studied endocannabinoid receptors found in the central nervous system. In the brain, these receptors' natural ligands, anandamide and 2-arachidonylglycerol (2-AG), are found in abundance. Yet not all forms of observed plasticity are accounted for by just these two receptors, so studies into other G-protein coupled receptors (GPCRs) continues. One GPCR, GPR55 is found in many regions of the brain, as well as lysophosphatidylinositol (LPI), its specific ligand. Here we have researched the role of GPR55 in modulating synaptic plasticity in the hippocampus. Using quantitative reverse transcription PCR and immunohistochemistry, we have found GPR55 to be expressed in the hippocampus with highest expression in pyramidal cells, the main excitatory neurons in the hippocampus. Using field and whole cell electrophysiology, we have investigated its effects on synaptic plasticity, discovering that activation of GPR55 by LPI significantly enhances LTP. In memory behavioral assays there are no significant differences between GPR55 KO mice and wild type littermates, indicating that it may not be involved in endogenous memory processes. However, our electrophysiology data makes GPR55 a potential target for treating memory disorders such as dementia. We have also investigated GPR18 and GPR119 for their potential roles in synaptic plasticity. First, we confirmed their expression in the hippocampus and then investigated the effects of their agonists on plasticity. Another receptor, TRPV1 has been studied to alter plasticity. However, the study of how protein translation and RNA transcription involvement in TRPV1 plasticity in mammals has not been investigated. While translation and transcription are known to be important in many forms of LTP, it is unknown whether these processes are important for TRPV1-induced LTD. We are investigating their necessity via whole cell patching and using translation and transcription inhibitors Anisomycin and Actinomycin D, both previously used in slice electrophysiology.
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PII, Youry. « Involvement of auxin and LTP proteins in the regulation of root nodule formation in Medicago truncatula - Sinorhizobium meliloti Symbiosis ». Doctoral thesis, Università degli Studi di Verona, 2009. http://hdl.handle.net/11562/337398.
Texte intégralRésumé :
Questo progetto di dottorato ha avuto come obiettivi: i) valutazione del ruolo del’auxina di derivazione batterica nella simbiosi rizobio-leguminosa, che dà origine a noduli di tipo indeterminato, ii) lo studio funzionale di MtN5, una proteina di tipo “Pathogenesis Related”, che viene indotta precocemente durante la nodulazione e che presenta omologie di sequenza con membri della famiglia delle Lipid Transfer Protein vegetali.
L’auxina (acido indol-3-acetico, IAA) è un ormone vegetale implicato in molti aspetti che riguardano la vita e lo sviluppo delle piante; un suo coinvolgimento nello sviluppo del nodulo radicale era stato ipotizzato già all’inizio del secolo scorso. Studi successivi hanno dimostrato un’inibizione del trasporto acropeto di IAA nella radice a seguito dell’infezione con rizobi, con un conseguente accumulo di fitormone a livello del sito di infezione. E’ stato dimostrato che la maggior parte dei batteri della rizosfera che producono effetti di promozione sulla crescita della pianta, rizobi inclusi, possiedono vie biosintetiche per IAA. I rizobi sono in grado di sintetizzare auxina in coltura liquida e, molto probabilmente, mantengono questa capacità anche durante la nodulazione. Ad oggi, però, i dati riguardanti il ruolo dell’auxina batterica nello sviluppo dei noduli sono ancora controversi; sono stati infatti documentati sia effetti stimolatori che inibitori.
Molti degli eventi che stanno alla base dell’associazione simbiotica tra rizobi e leguminose devono ancora essere chiariti. Ad esempio, la natura e la funzione dei segnali ormonali scambiati tra ospite e simbionte non sono ancora stati compresi nel dettaglio, così come le differenze e i parallelismi nella risposta delle leguminose verso il simbionte e verso i patogeni della radice. A tal riguardo, recenti osservazioni hanno dimostrato che la repressione della via di segnalazione intracellulare dell’auxina risulta in una maggiore resistenza innata delle piante verso microrganismi patogeni.
Piante di Medicago truncatula, specie modello per le leguminose che producono noduli di tipo indeterminato, e Medicago sativa (erba medica), specie correlata di interesse agronomico, sono state nodulate sia con rizobi wild-type e che con rizobi in grado di iper-produrre IAA (S. meliloti IAA). I risultati ottenuti hanno dimostrato che piante nodulate con S. meliloti IAA producevano un numero maggiore di noduli (aumento del 50% in M. sativa e
aumento del 100% in M. truncatula) e un apparato radicale più ramificato. Inoltre il contenuto di auxina nei noduli prodotti da rizobi IAA è mediamente 10 volte superiore alla concentrazione dei noduli prodotti da rizobi wild-type. I livelli di espressione dei geni responsabili del trasporto di auxina è stato valutato mediante RT-PCR quantitativa (qRT-PCR) e il carrier di efflusso MtPIN2 è risultato significativamente più espresso (circa 2 volte) nel tessuto radicale di piante nodulate con rizobi IAA rispetto alle radici infettate con il rizobio di controllo. Questi risultati suggeriscono che l’effetto di promozione osservato sulla nodulazione e sull’accrescimento della radice laterale siano dovuti alla produzione di IAA nel nodulo e ad una sua redistribuzione all’interno dell’apparato radicale.
E’ stato ampiamente dimostrato che l’ossido nitrico (NO) agisce come secondo messaggero nell’induzione di radici laterali e avventizie stimolata da auxina. Considerando la comune organogenesi tra radici laterali e avventizie e noduli indeterminati, in questo lavoro abbiamo dimostrato che esiste un collegamento tra auxina e NO nella via di segnalazione che porta all’induzione del nodulo.
Per mezzo di uno screening preliminare, condotto mediante qRT-PCR e volto ad individuare geni differenzialmente espressi in piante nodulate con rizobi IAA e piante nodulate con rizobi wild-type, fu osservato che il gene MtN5 era più espresso negli apparati radicali di piante infettate con rizobi iperproduttori di auxina. Il prodotto genico di MtN5 è stato annotato come una Lipid Transfer Protein (LTP) putativa. Le LTP vegetali sono caratterizzate dalla capacità sia di legare lipidi in vitro che di inibire la crescita di microrganismi. In questo progetto di tesi è stato dimostrato che MtN5 possiede la capacità di legare lisolipidi e che, come molti altri membri di questa famiglia di proteine, possiede attività antimicrobica in vitro, in particolare contro Fusarium semitectum, Xanthomonas campestris e S. meliloti.
Lo studio del profilo di espressione conferma che MtN5 viene precocemente indotta durante la nodulazione e che è specificamente localizzata all’interno del nodulo radicale. Inoltre, l’infezione di piante con F. semitectum provoca l’accumulo di MtN5 nel tessuto radicale.
La funzione di MtN5 nella nodulazione è stata studiata mediante la generazione di radici avventizie transgeniche, sia overesprimenti che silenziante per il gene di interesse. Le radici
silenziate per MtN5 sviluppano circa la metà dei noduli rispetto a radici di controllo, mentre in radici transgeniche over-esprimenti MtN5 il numero di noduli è risultato incrrementato del 300% rispetto al controllo. I risultati ottenuti dimostrano che MtN5 facilita l’interazione simbiotica tra M. truncatula e S. meliloti, agendo probabilmente negli stadi precoci dell’infezione, e suggeriscono che MtN5 potrebbe avere un ruolo nella protezione dei noduli verso patogeni della radice. Ulteriori studi sono comunque necessari per ottenere una immagine più chiara del ruolo di MtN5 sia nella simbiosi che nella risposta verso i patogeni.The present thesis has had two main focuses: i) the evaluation of the role of bacteria-derived auxin in the symbiosis between rhizobia and legumes that bear indeterminate nodules, ii) the functional study of MtN5, a pathogenesis related protein which presents sequence homology with the members of the plant Lipid Transfer Proteins (LTP) family and is precociously induced during nodulation. Auxin (indol-3-acetic acid, IAA) is a phytohormone involved in many aspects of plants growth and development; The role of auxin in the development of the rhizobia-legumes symbiosis was first hypothesised at the beginning of the twentieth century. More recent studies have demonstrated that auxin is accumulated at the site of infection as a consequence of the inhibition of the acropetal auxin transport in roots upon rhizobia inoculation. The production of IAA has also been documented in plant-associated rhizobacteria, including rhizobia, that have promoting effects on plants growth. When grown in liquid media, rhizobia can synthesize auxin and most likely they retain the same capability also during the nodule development. However, up to date, the data concerning the role of bacteria-derived auxin in the establishment of the symbiotic association are still contradictory, since both stimulatory and inhibitory effects have been documented. Thus, there are still open questions in the understanding of the events that result in the establishment of the symbiosis. First of all the nature and the function of the hormonal signal(s) exchanged between the host and the symbiont are not thoroughly unfolded, as well as the parallelisms and the differences in the responses of legumes against root pathogens and root symbiont. In these regards, recent findings have pointed out that plants innate immunity results, at least in part, from the down-regulation of the auxin signalling pathway. Medicago truncatula and Medicago sativa plants were nodulated with both wild-type and auxin hyper-synthesising rhizobia (Sinorhizobium meliloti IAA). The results obtained showed that plants nodulated with S. meliloti IAA produced a higher number of root nodules (50% more nodules in M. sativa and 100% more nodules in M. truncatula) and a more branched root apparatus. The root nodules elicited by S. meliloti IAA had a higher IAA content (at least 10-fold) when compared to control nodules. The expression levels of the auxin carriers were evaluated and the efflux facilitator MtPIN2 resulted more abundant (about 2-fold) in the root tissue of IAA plants when compared to wild-type plants These data suggested that such promoting effects on nodulation and lateral root growth might be due to the increased auxin content detected in IAA nodule produced by auxin hyper-synthesising rhizobia, as well as to a redistribution of the phytohormone in the root tissue. It has been largely demonstrated that nitric oxide (NO) acts as second messenger in the auxin-induced pathway that leads to formation of lateral and adventitious roots. Since root nodules have the same organogenetic origin of lateral and adventitious roots, the possible connection between NO and root nodule induction was investigated and we demonstrated that NO participate in the signalling pathway for root nodule induction. During a preliminary screening carried out by means of qRT-PCR, it has been found that N5 gene of M. truncatula was more abundantly expressed in roots nodulated with S. meliloti IAA with respect to roots infected by wild-type rhizobia. The gene product of MtN5 was annotated as putative Lipid Transfer Protein (LTP). LTPs are characterized by their ability to bind lipids in vitro and the majority of them exhibits antimicrobial activity. In this thesis, it has been demonstrated that the recombinant MtN5 protein is able to bind lysolipids and possesses inhibitory activity against Fusarium semitectum, Xanthomonas campestris and S. meliloti. The studies of the expression pattern of both MtN5 transcript and MtN5 protein confirmed that it is precociously induced during nodulation and revealed that it is specifically localized in the root nodule. In addition, when M. truncatula plants are infected with the root pathogenic fungus F. semitectum, MtN5 protein is accumulated in the root apparatus. The function of MtN5 in nodulation has been studied through the generation of transgenic adventitious roots, both over-expressed and silenced for the gene of interest. MtN5-silenced roots developed approximately 50% fewer nodules as compared to control roots, whereas in hairy roots over-expressing MtN5 the nodule number was increased by about 300% with respect to control roots. Collectively the data indicate that MtN5 facilitates the symbiotic interaction between M. truncatula and S. meliloti, probably acting in the early stages of rhizobia infection, and suggest that it might have a role in the protection of nodules against root pathogen. However, further studies are needed to have a clear picture of the role played by MtN5 in both symbiosis and defence response against pathogens.
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Andrews, Shantaya. « Localization of SIP470, a Plant Lipid Transfer Protein in Nicotiana tabacum ». Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3520.
Texte intégralRésumé :
SABP2-interacting protein 470 (SIP470), a non-specific lipid transfer protein (nsLTP), was discovered in a yeast two-hybrid screening using SABP2 as bait and tobacco leaf proteins as prey. SABP2 is an important enzyme in systemic acquired resistance that converts salicylic acid to methyl salicylate. Localization studies are an important aspect to understanding the biological function of proteins. nsLTPs are generally considered apoplastic proteins and has been localized intracellularly and extracellularly. Transient expression shows highest expression of SIP470-eGFP at 2 days post infiltration into Nicotiana benthamiana. Confocal microscopy showed localization near the periphery of the cell. Subcellular localization using differential centrifugation showed that SIP470 is localized in the mitochondria. Mitochondria membranes are rich in lipids and have shown lipid exchange with the endoplasmic reticulum in mammalian systems. Co-localization of SIP470-eGFP+mCherry did not express complete co-localization in the targeted organelles. Co-localization pattern suggests possible localization in the endoplasmic reticulum.
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Silva, Renan Gonçalves da. « Análise in silico do gene lipid transfer protein (LTP) de cana-de-açúcar e funcional em transformantes de (Nicotiana tabacum) / ». Jaboticabal, 2017. http://hdl.handle.net/11449/151990.
Texte intégralRésumé :
Orientador: Sonia Marli ZingarettiBanca: janete Apparecida Desiderio
Banca: Juliana da Silva Coppede
Resumo: A grande expansão da cultura de cana-de-açúcar pelo território brasileiro leva à necessidade do desenvolvimento de cultivares melhoradas e adaptadas às diferentes condições de clima a que são submetidas. Os estresses bióticos e abióticos são fatores que afetam a produtividade de uma cultura e entre esses, o estresse hídrico assume grande importância em função do regime de chuvas e do aumento de temperatura iminente nos próximos anos. Analisar a expressão de genes em plantas submetidas a estresses pode contribuir de forma expressiva para elucidar as rotas de defesa das plantas, contribuindo sobremaneira para o melhoramento da cultura e o desenvolvimento de novas variedades. O projeto teve como objetivo obter transformantes de Nicotiana tabacum in vitro com o gene LTP (Lipid Transfer Protein) e avaliar sua funcionalidade em relação ao estresse por deficiência hídrica, em casa de vegetação por hidroponia. Feita a seleção da EST com base em resultados anteriores obtidos pelo grupo de pesquisa, posterior análise em bancos de dados, realizou-se a aquisição do clone no Centro de Estocagem de Genes (BCCCenter) e o re-sequenciamento para comprovar sua identidade. Estudos in silico foram realizados através da utilização de softwares de bioinformática e a análise da função do gene foi realizada a partir da transformação genética de Nicotiana tabacum via Agrobacterium tumefaciens. Seis transformantes de N. tabacum com o inserto de interesse LTP foram obtidos e testados quanto à tolerânci... (Resumo completo, clicar acesso eletrônico abaixo)
The great expansion of sugarcane cultivation across Brazilian territory leads to the need to develop better cultivars and adapted to the different climatic conditions that are submitted. The biotic and abiotic stresses are factors that affect the productivity of a crop and among them, the water stress will assume great importance due to the rainfall regime and the increase of the imminent temperature in the next years. Analyzing the expression of genes in stress - stressed plants can contribute in an expressive way to elucidate as plant defense routes, contribute to the improvement of the culture and the development of new varieties. The objective of this project was to obtain transformers of Nicotiana tabacum in vitro with the LTP (Lipid Transfer Protein) gene and to evaluate its functionality in relation to stress due to water deficiency in a greenhouse by hydroponics. We made EST selection based on previous results obtained by a research group, later analysis in databases, performing a clone acquisition in the Gene Storage Center (BCCCenter) and resequencing to prove its identity. Silicon studies were carried out through the application of bioinformatics software and an analysis of the genetic function was performed from the genetic transformation of Nicotiana tabacum via Agrobacterium tumefaciens. Six N. tabacum transformants with the LTP insert of interest were obtained and tested for tolerance to water deficit by induction of different concentrations of mannitol. Transformer tobacco plants showed better phenotypic performance compared to untransformed plant and good readaptation after stress. The T1 generation these plants will be used in studies for the biological and functional verification of the action of the inserted gene, through the Real-Time qPCR technique.
Mestre
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Mohammad, Sameh. « Long-term depression in the rat hippocampus as a memory model : Interrogating the role of protein synthesis in NMDA- and mGluR-dependent synaptic plasticity ». Thesis, Högskolan i Skövde, Institutionen för vård och natur, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-4715.
Texte intégralRésumé :
Long-term potentiation (LTP) and depression (LTD) are important forms of activity-dependent synaptic plasticity believed to play a role in memory at the cellular level. It has previously been described that synthesis of new proteins is needed to maintain LTP longer than a few hours. Other reports argue that sufficient proteins for stable LTP are already available. The present study aims to examine the role of protein synthesis in LTD, the presumed mirror mechanism of LTP. Experiments were carried out in hippocampal slices from young (12-45 days) and old (12-18 weeks) Sprague-Dawley rats. Extracellular techniques were used to study synaptic responses in the Schaffer-collateral-commissural pathway. Plasticity was induced electrically by low frequency stimulation (2-3 trains at 1 Hz for 15 min) or chemically by brief exposure to certain glutamate receptor agonists (NMDA at 20 µM for 3 min or DHPG at 100 µM for 10 min). Whole slice protein synthesis was quantified by assessing 3H-leucine incorporation. Stable LTD (> 8 h) was be obtained by either electrical or chemical activation. Protein synthesis inhibitors anisomycin (40 uM) and cycloheximide (100 uM) both failed to influence the magnitude of LTD. Moreover, no age difference was found, in terms of stable LTD in both young and old rats under inhibition of protein synthesis. The potency of the inhibitors was found to be high, depressing synthesis down to a few percent. It is concluded that sufficient proteins for generating stable LTD are normally present in the brain, implying a large safety-margin for cellular memory.
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Pascal, i. Capdevila Mariona. « Allergenic protein and epitope recognition in food allergy : a new perspective for the molecular and clinical characterization of shellfish and lipid transfer protein allergy / Reconeixement de proteïnes i epítops al•lergènics en al•lèrgia alimentaria : una nova perspectiva per a la caracterització clínica i molecular de l’al•lèrgia al marisc i a les proteïnes de transferència de lípids ». Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/84070.
Texte intégralRésumé :
Currently food allergy diagnostic tests are not able to predict clinical reactivity in sensitized patients (those with specific IgE against a particular allergen). Traditionally, allergy diagnostic tests used complete extracts of allergenic sources containing multiple molecules, some allergic and others not. This greatly limits the accuracy in the diagnosis and identification of possible allergic reactions to different foods by the existence of cross reactivity. Through the last decades, thanks to advances in the characterization of allergens at molecular level, the concept of Component-Based Diagnosis has been developed. This is based on the reasoning that the presence of specific IgE for the protein actually responsible for the allergic response should be detected and not the one against a mixture of molecules. Furthermore, the study of IgE and IgG4 recognition at epitope level using microarrays of synthetic peptides has been described as a useful tool for diagnosis, prognosis and development of a therapy for food allergy.
The hypothesis of this thesis is that these new methodologies can improve the diagnosis of shellfish and lipid transfer protein (LTP) allergy. The aim of this thesis is to characterize clinically and at a molecular level these two types of food allergies, using these new methodologies.
Regarding shellfish allergy, we found that tropomyosin, sarcoplasmic protein binding of calcium and myosin light chain are the allergens associated with clinical reactivity, i.e, are more common in shrimp allergic patients than in tolerant individuals sensitized shrimp. On the other hand, arginine kinase and hemocyanin allergens would be more involved in the phenomena of cross-reactivity with other arthropods (mites and/or cockroach). Additionally the synthetic peptide microarray has identified differential recognition of IgE and IgG4 epitopes among allergic and tolerant individuals. Regarding allergy to LTP, allergenic proteins ubiquitously distributed in the plant kingdom, we observed that patients suffer from reactions with a wide range of plant foods to which are sensitized, being peach the most common one. Furthermore, these patients have a variety of clinical symptoms from very mild to very severe and life-threatening as in the case of anaphylaxis, which can be attributed to allergens from different families. The component-based diagnosis in a microarray format that includes a diverse panel of allergenic proteins from different families is useful for diagnosing these patients, since the only proteins identified as responsible for the clinical symptoms are the LTPs, although the symptoms are diverse and sometimes more closely resemble to those caused by other allergens such as profilins or homologues of Bet v 1. Moreover, it offers an overview of positive and negative sensitivities in these patients in a single trial, with its multiplex properties. Cases of anaphylaxis with a cofactor involvement, such as NSAIDs, were frequently observed in these patients. The simultaneous presence of these drugs with the food allergen triggers allergic reactions in the individual that would not occur without the presence of the drug or would have been of less severity. We have developed a preliminary in vitro model based on the basophil activation test that allowed us to observe the in vitro effect observed in vivo. We observed an increase of degranulation/activation of basophils when stimulation is done with food in the presence the drug, compared to when stimulated only with food.
In this thesis we can conclude that both the component-based diagnosis and epitope mapping are useful tools for the characterization of food allergy to shellfish proteins and LTP, and that they should be considered to improve the efficiency of diagnosis of these two types of food allergies.Actualment els mètodes diagnòstics de l'al•lèrgia alimentària no són capaços de predir la reactivitat clínica dels pacients sensibilitzats (els que tenen IgE específica davant un determinat al•lergen). Tradicionalment les proves diagnòstiques de l'al•lèrgia han utilitzat extractes complets de fonts al•lergèniques que contenen múltiples molècules, algunes al•lergèniques i altres no. Això limita enormement la precisió en el diagnòstic i la possibilitat d'identificar reaccions al•lèrgiques a diferents aliments per l'existència de reactivitats creuades. Gràcies a la caracterització dels al•lèrgens a nivell molecular, s'ha desenvolupat el concepte del Diagnòstic Basat en Components que es basa en el raonament de detectar la presència d'IgE específica per a la proteïna realment responsable de la resposta al•lèrgica i no per una mescla de molècules. Addicionalment, l'estudi del reconeixement IgE i IgG4 a nivell d'epítops amb microarrays de pèptids sintètics pot ser una eina útil per al diagnòstic, pronòstic i desenvolupament d'una teràpia per l'al•lèrgia alimentària. La hipòtesi d'aquesta tesi és que aquestes noves metodologies poden millorar el diagnòstic de l'al•lèrgia al marisc i a les proteïnes de transferència de lípids (LTP), presents en múltiples aliments vegetals. L'objectiu és doncs caracteritzar clínicament i a nivell molecular aquests dos tipus d'al lèrgies alimentàries, utilitzant aquestes noves metodologies. Respecte a l'al•lèrgia al marisc, els al lèrgens tropomiosina, proteïna sarcoplàsmica d'unió de calci i la cadena lleugera de miosina s'associen amb la reactivitat clínica a la gamba. D'altra banda, els al•lèrgens arginina quinasa i hemocianina estarien més implicats en fenòmens de reactivitat creuada amb altres artròpodes. Addicionalment, amb el microarray de pèptids sintètics s'ha pogut identificar un reconeixement diferencial d'epítops IgE i IgG4 entre pacients al•lèrgics i tolerants. Respecte a l'al•lèrgia a les LTP, els pacients pateixen reaccions amb un ampli ventall d'aliments vegetals, sent el préssec el més freqüent, amb una gran diversitat de símptomes clínics, que poden atribuir-se a al•lèrgens de diferents famílies. El diagnòstic basat en components en el format d'un microarray que inclou proteïnes al•lergèniques de diferents famílies és útil per al diagnòstic d'aquests pacients, ja que permet identificar que les úniques proteïnes responsables els símptomes clínics són les LTP, encara que els símptomes siguin molt variats i en algunes ocasions s'assemblin més als provocats per altres al•lèrgens com les profilines o els homòlegs de Bet v 1. En aquests pacients són freqüents els casos d'anafilàxia en què està involucrat un cofactor, com els antiinflamatoris no esteroïdals. La presència del fàrmac amb l'al•lergen alimentari desencadena reaccions al•lèrgiques que sense el fàrmac no es donarien o serien de menor severitat. Hem desenvolupat un model preliminar in vitro basat en el test d'activació de basòfils que ens ha permès observar in vitro l'efecte observat in vivo. En conclusió, el diagnòstic basat en components i el mapatge d'epítops són eines útils per a la caracterització de l'al•lèrgia alimentària al marisc i a les proteïnes LTP, i s'han de considerar per millorar l'eficiència del diagnòstic d'aquests dos tipus d'al•lèrgies alimentàries.
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Audam, Timothy Ndagi. « Characterization of SIP470, a Family 1 Lipid Transfer Protein and its Role in Plant Stress Signaling ». Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etd/3103.
Texte intégralRésumé :
SIP470, a putative tobacco lipid transfer protein, was identified in a yeast two-hybrid screen to interact with SABP2. SABP2 is a critical role in SA-mediated signaling in tobacco and other plants. In vitro studies using purified recombinant SIP470 confirmed that it is a lipid binding protein. In an attempt to determine its role in mediating stress responses, Arabidopsis T-DNA insertion knockout lines lacking SIP470 homolog were used for the analysis. These mutant plants were defective in basal resistance against microbial pathogens. Expression of defense gene PR-1 was also delayed in these mutant plants. Interestingly, these mutant plants were not defective in inducing systemic acquired resistance. Besides biotic stress, these mutant plants also showed increased susceptibility to abiotic stresses. To directly study the role of SIP470 in tobacco plants, transgenic tobacco lines, with reduced levels of SIP470 expression, were generated using RNAi and transgenic lines overexpressing SIP470 were also generated.
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CENTINI, BARBARA. « Correlazione tra deterioramento cognitivo, plasticità sinaptica corticale e livelli liquorali di amiloide-β1-42 nella Sclerosi multipla ». Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/208702.
Texte intégralRésumé :
La presenza di disturbi cognitivi nei pazienti con Sclerosi Multipla (MS) era già stata descritta nel 1877 da Charcot; comunque solo negli ultimi 30 anni si è assistito ad una attenzione degli studiosi in merito alla comprensione delle compromissioni cognitive quantitative e qualitative presenti in questi pazienti. Circa il 45-65% dei pazienti con MS mostra disfunzioni cognitive di una certa entità, tali disturbi vanno da disturbi selettivi di specifiche funzioni a una compromissione grave e diffusa. Le disfunzioni cognitive frequentemente osservate nei pazienti con MS, sono associate con alterazioni della materia grigia, atrofia cerebrale e alterazioni della connettività e plasticità sinaptica. Recenti studi mostrano come anchvi e l'infiammazione acuta può esacerbare i deficit cognitivi indipendentemente dal sistema funzionale primariamente coinvolto.In questo studio noi misuriamo i livelli di amiloide beta 1-42 e proteina tau in pazienti con MS e CIS (Clinical Isolated Syndrome) , da sempre le due proteine sono state associate con il deterioramento cognitivo presente nei pazienti con malattia di Alzheimer (AD). Nella AD, l'amiloide beta 1-42 si accumula nel tessuto nervoso in placche extracellulari insolubili; questo fenomeno rende possibile la spiegazione del fatto che la forma solubile della beta 1-42 amiloide sia ridotta nel liquido cefalo rachidiano di questi pazienti. Nel nostro campione di pazienti affetti da MS, i livelli di amiloide beta 1-42 erano significativamente più bassi in pazienti con deficit cognitivi e erano inversamente correlati con il numero di lesioni GD+ alle immagini della risonanza magnetica (MRI). Sono state inoltre evidenziate correlazioni positive tra i livelli di amiloide beta 1-42 e i deficit di attenzione e concentrazione. Inoltre, l'anormale neuroplasticità della corteccia cerebrale è stata esplorata con TBS (theta brust magnetic stimulation). Da questa analisi è emerso che in pazienti con deficit cognitivi c'è una correlazione positiva tra i livelli di amiloide beta 1-42 presenti nel CSF e l'ampiezza dei long-term-potentiation (LPT) indotti dalla TBS. Nessuna correlazione è stata invece individuata tra la concentrazione della proteina tau, MRI, parametri cognitivi e gli effetti della TBS in questi pazienti. Insieme questi risultati indicano che nella MS l'infiammazione del SNC è capace di alterare il metabolismo della beta amiloide, riducendo la sua concentrazione nel liquido cerebro spinale e portando ad un danneggiamento della plasticità sinaptica e delle funzioni cognitive.Cognitive dysfunction is of frequent observation in Multiple Sclerosis (MS). It is associated with grey matter pathology, brain atrophy and altered connectivity, and recent evidence showed that acute inflammation can exacerbate mental deficits independently of the primary functional system involved. In the present study, we measured cerebrospinal fluid (CSF) levels of amyloid-1-42 and tau protein in MS and in Clinical Isolated Syndrome (CIS) patients, since both proteins have been associated with cognitive decline in Alzheimer's disease (AD). In AD, amyloid-1-42 accumulates in the brain as insoluble extracellular plaques, possible explaining why soluble amyloid-ß1–42 is reduced in the CSF of these patients. In our sample of MS patients, amyloid-1-42 levels were significantly lower in patients cognitively impaired and were inversely correlated with the number of Gadolinium-enhancing (Gd+) lesions at the magnetic resonance imaging (MRI). Positive correlations between amyloid-1-42 levels and measures of attention and concentration were also found. Furthermore, abnormal neuroplasticity of the cerebral cortex, explored with theta burst magnetic stimulation (TBS), was observed in cognitively impaired patients, and a positive correlation was found between amyloid-1-42 CSF contents and the magnitude of long-term potentiation (LTP)-like effects induced by TBS. No correlation was conversely found between tau protein concentrations and MRI findings, cognitive parameters, and TBS effects in these patients. Together, our results indicate that in MS central inflammation is able to alter amyloid- metabolism, by reducing its concentration in the CSF, and leading to impairment of synaptic plasticity and cognitive function.
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Graupner, Michael. « Induction and Maintenance of Synaptic Plasticity ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1221145787153-31869.
Texte intégralRésumé :
Synaptic long-term modifications following neuronal activation are believed to be at the origin of learning and long-term memory. Recent experiments suggest that these long-term synaptic changes are all-or-none switch-like events between discrete states of a single synapse. The biochemical network involving calcium/calmodulin-dependent protein kinase II (CaMKII) and its regulating protein signaling cascade has been hypothesized to durably maintain the synaptic state in form of a bistable switch. Furthermore, it has been shown experimentally that CaMKII and associated proteins such as protein kinase A and calcineurin are necessary for the induction of long-lasting increases (long-term potentiation, LTP) and/or long-lasting decreases (long-term depression, LTD) of synaptic efficacy. However, the biochemical mechanisms by which experimental LTP/LTD protocols lead to corresponding transitions between the two states in realistic models of such networks are still unknown. We present a detailed biochemical model of the calcium/calmodulin-dependent autophosphorylation of CaMKII and the protein signaling cascade governing the dephosphorylation of CaMKII. As previously shown, two stable states of the CaMKII phosphorylation level exist at resting intracellular calcium concentrations. Repetitive high calcium levels switch the system from a weakly- to a highly phosphorylated state (LTP). We show that the reverse transition (LTD) can be mediated by elevated phosphatase activity at intermediate calcium levels. It is shown that the CaMKII kinase-phosphatase system can qualitatively reproduce plasticity results in response to spike-timing dependent plasticity (STDP) and presynaptic stimulation protocols. A reduced model based on the CaMKII system is used to elucidate which parameters control the synaptic plasticity outcomes in response to STDP protocols, and in particular how the plasticity results depend on the differential activation of phosphatase and kinase pathways and the level of noise in the calcium transients. Our results show that the protein network including CaMKII can account for (i) induction - through LTP/LTD-like transitions - and (ii) storage - due to its bistability - of synaptic changes. The model allows to link biochemical properties of the synapse with phenomenological 'learning rules' used by theoreticians in neural network studies.
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Graupner, Michael. « Induction and Maintenance of Synaptic Plasticity ». Doctoral thesis, Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A23857.
Texte intégralRésumé :
Synaptic long-term modifications following neuronal activation are believed to be at the origin of learning and long-term memory. Recent experiments suggest that these long-term synaptic changes are all-or-none switch-like events between discrete states of a single synapse. The biochemical network involving calcium/calmodulin-dependent protein kinase II (CaMKII) and its regulating protein signaling cascade has been hypothesized to durably maintain the synaptic state in form of a bistable switch. Furthermore, it has been shown experimentally that CaMKII and associated proteins such as protein kinase A and calcineurin are necessary for the induction of long-lasting increases (long-term potentiation, LTP) and/or long-lasting decreases (long-term depression, LTD) of synaptic efficacy. However, the biochemical mechanisms by which experimental LTP/LTD protocols lead to corresponding transitions between the two states in realistic models of such networks are still unknown. We present a detailed biochemical model of the calcium/calmodulin-dependent autophosphorylation of CaMKII and the protein signaling cascade governing the dephosphorylation of CaMKII. As previously shown, two stable states of the CaMKII phosphorylation level exist at resting intracellular calcium concentrations. Repetitive high calcium levels switch the system from a weakly- to a highly phosphorylated state (LTP). We show that the reverse transition (LTD) can be mediated by elevated phosphatase activity at intermediate calcium levels. It is shown that the CaMKII kinase-phosphatase system can qualitatively reproduce plasticity results in response to spike-timing dependent plasticity (STDP) and presynaptic stimulation protocols. A reduced model based on the CaMKII system is used to elucidate which parameters control the synaptic plasticity outcomes in response to STDP protocols, and in particular how the plasticity results depend on the differential activation of phosphatase and kinase pathways and the level of noise in the calcium transients. Our results show that the protein network including CaMKII can account for (i) induction - through LTP/LTD-like transitions - and (ii) storage - due to its bistability - of synaptic changes. The model allows to link biochemical properties of the synapse with phenomenological 'learning rules' used by theoreticians in neural network studies.
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Steer, Ruth. « Investigations of the extracellular deposition of latent TGF-beta binding protein-1 (LTBP-1) ». Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/investigations-of-the-extracellular-deposition-of-latent-tgfbeta-binding-protein1-ltbp1(41e0ee4f-5030-4333-8a52-e0d21d1fc649).html.
Texte intégralRésumé :
LTBP-1 is a large extracellular glycoprotein that is a component of the large latent TGF-β complex. The extracellular sequestration of latent TGF-β in the extracellular matrix (ECM) is fundamental to the regulation of TGF-β bioavailability and activity. LTBP-1 is described to contribute to the regulation of TGF-β bioavailability through mediating the extracellular sequestration of newly secreted latent TGF-β with fibrillin microfibrils in the ECM. However it is not well understood how LTBP-1, and thus latent TGF-β, becomes deposited into the ECM. Previous work by our group suggested that LTBP-1 interactions with the glycosaminoglycan heparan sulphate (HS) at the cell-matrix interface might facilitate the association of LTBP-1 with fibrillin microfibrils. Using recombinant LTBP-1 fragments and mutants, LTBP-1 interaction with HS have been fine-mapped. Deposition of a LTBP-1 HS-binding mutant, and of LTBP-1 when HS was depleted, was studied in cell cultures; findings presented here demonstrate that HS may not be critical for the deposition of LTBP-1 into the ECM. Contributions of fibrillin and fibronectin to LTBP-1 deposition were investigated, and data presented here support published findings that fibrillin is not always required for LTBP-1 deposition. In addition, the dependency of LTBP-1 deposition upon fibronectin was suggested to differ between different cell types (epithelial and mesenchymal). How LTBP-1 may be stabilised within the ECM through crosslinking by tissue transglutaminase was investigated using recombinant fragments and cell culture studies. Tissue transglutaminase was found to promote the extracellular incorporation of LTBP-1, and novel cross-links within LTBP-1, and between LTBP-1 and fibrillin-1, but not LTBP-1 and fibronectin, were identified. Additionally, results indicated that LTBP-1 was present in extremely high molecular weight assemblies in the ECM of cultured fibroblasts. Collectively, these results have contributed to current knowledge of how LTBP-1 becomes deposited into the ECM. They indicate that the deposition of LTBP-1 is not underpinned by HS, may be cell type-specific, and that LTBP-1 may potentially self-assemble extracellularly into homotypic structures that may associate with fibrillin microfibrils.
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Eckert, Jana Kristin. « Funktionelle Analyse von Mutanten des LPS-bindenden Proteins (LBP) ». Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2009. http://dx.doi.org/10.18452/15955.
Texte intégralRésumé :
LBP vermittelt im Wirtsorganismus die direkte Immunantwort auf bakterielle Liganden wie das Lipopolysaccharid (LPS) von Gram-negativen oder Lipopeptide von Gram-positiven Bakterien. In dieser Arbeit wurde die Funktionsweise von LBP weiter aufgeklärt. Im ersten Teil der Arbeit wurde eine natürlich vorkommende Mutation des LBP (c998t), die an Position 333 zu einem Austausch der Aminosäure Prolin zu Leucin führt, hinsichtlich ihrer Auswirkungen auf Struktur und Funktionalität des Proteins untersucht. Westernblot-Analysen des rekombinant hergestellten Proteins und humaner Seren von Mutationsträgern weisen auf einen Zerfall des mutierten Proteins hin. Es kommt zu einer Beeinträchtigung der Bindung bakterieller Liganden und einer deutlichen Reduktion der LBP-vermittelten Zytokinausschüttung von Immunzellen. Der hier untersuchte Polymorphismus hat eine Allelfrequenz von 0,072 in einer gesunden europäischen Population. Genotypanalysen von Patientengruppen zeigten, dass es durch die Mutation zu einer deutlich erhöhten Mortalität bei Patienten mit septischen Komplikationen und einer durch Gram-negative Erreger verursachten Pneumonie kommt. Unsere Ergebnisse zur eingeschränkten Funktion des LBP-c998t bieten eine erste Erklärung dafür, wie diese Mutation vermutlich die Fähigkeit, Krankheiten zu bewältigen, beeinträchtigt. Innerhalb dieser Arbeit ging es um die Analyse der Bindung von bakteriellen Liganden an LBP. Dabei wurde eine potentiell gemeinsame Bindungsstelle für Liganden untersucht, die von Gram-positiven und Gram-negativen Bakterien stammen und später von den Toll-like Rezeptoren (TLRs) 2 und -4 erkannt werden. Dazu wurden Bindungsversuche zwischen Lipopeptiden und LPS mit einer zweiten LBP-Variante (LBP-E94/95) durchgeführt. Beim LPS führt dies zu einem Bindungsverlust. Auch für die Lipopeptide war durch die Mutationen die Interaktion mit LBP beeinträchtigt, was die These einer gemeinsamen Bindungsstelle von TLR2- und TLR4-Liganden an das Protein weiter unterstützt.LBP enhances the innate immune reaction against bacterial ligands like LPS from gram negative or lipopeptides from gram positive bacteria in the host. Here we investigated the function of LBP using two recombinant mutants of the protein. The first part of this work examines a natural occurring mutation of LBP (c998t) leading to an amino acid exchange of proline to leucine at position 333 with regard to the impact on structure and function of the protein. Western blot analyses of the recombinant protein and sera obtained from individuals differing in the LBP genotype indicate the disaggregation of the mutated protein. Thereby binding of bacterial ligands to LBP is diminished and the LBP mediated cytokine secretion of immune cells is reduced. The gene polymorphism leading to the occurrence of the mutation is present with an allelic frequence of 0.072. A recent study has shown that this LBP-SNP led to a higher mortality in patients with septic complications and gram negative pneumonia. The results presented here, showing the negative impact on the function of LBP due to the mutation, may therefore be a first explanation on how this mutation affects the ability of people to deal with disease. Within this work binding of ligands to LBP was also explored. It was investigated whether ligands which are later recognized by Toll-like receptors (TLRs) 2 and – 4 share a common binding site on LBP. Assays with immobilized lipopeptides and LPS were performed with a second mutated LBP (LBP-E94/95). LPS binding to LBP is diminished completely. Here we showed that binding of lipopeptide to LBP is affected likewise, furthermore supporting the hypothesis of a common binding site for TLR2- and TLR4- ligands.
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Corlu, Anne. « Communications cellulaires et differenciation tissulaire. Role de la liver regulating protein (lrp) ». Rennes 1, 1992. http://www.theses.fr/1992REN10132.
Texte intégralRésumé :
Le controle de l'expression des genes specifiques des cellules differenciees est regule en partie par les facteurs circulants, matriciels et les interactions cellulaires. Au niveau du foie adulte, les contacts intercellulaires entre les hepatocytes et les autres types cellulaires du lobule, sont essentiels. In vitro, la coculture avec des cellules epitheliales non-parenchymateuses (rlecs) permet aux hepatocytes de stabiliser leur activite fonctionnelle pendant plusieurs semaines. Le but de notre travail a ete de: 1) rechercher la ou les molecule(s) impliquee(s) dans les interactions entre les hepatocytes et les rlecs et de preciser leur role au niveau du foie de rats adultes; 2) etudier la distribution et le role de cette ou ces molecule(s) dans les tissus non hepatiques de ces animaux. Nous avons mis en evidence par une approche immunologique, l'existence d'une proteine membranaire impliquee dans les interactions entre les hepatocytes et les rlecs mediant le maintien du phenotype differencie de l'hepatocyte in vitro. Une methode de purification a ete mise en place afin de sequencer des fragments de cette proteine. Actuellement, aucune homologie precise avec une proteine connue n'a ete retrouvee. Cette nouvelle proteine a ete nommee liver regulating protein. Au plan structural, elle est exprimee par toutes les cellules du sinusoide hepatique et par les cellules de trois groupes de tissus: le pancreas exocrine, les tissus hematopoietiques et les gonades. Les molecules exprimees dans ces differents tissus, possedent des caracteres communs avec la lrp mais presentent aussi des differences notamment au niveau des poids moleculaires. Au plan biologique, nous avons observe que l'etablissement de contacts entre les cellules hematopoietiques de moelle osseuse et des rlecs permet la survie et la proliferation a long terme des monocytes-macrophages, tout comme dans les cocultures de cellules stromales de moelle osseuse-cellules hematopoietiques. De meme, l'etablissement de contacts entre les cellules de sertoli et les rlecs ou les spermatocytes pachytene stimule la secretion de transferrine par les cellules de sertoli. Ces effets sont inhibes en presence d'anticorps anti-lrp. L'ensemble de nos observations demontre que les molecules lrp sont impliquees dans les communications cellulaires mediant le controle de l'activite fonctionnelle hepatique, sertolienne et la differenciation de cellules hematopoietiques. Le fait que ces tissus presentent des similitudes par leurs caracteres phenotypiques et/ou leur formation au cours du developpement, permet d'envisager la possibilite d'un processus commun de segregation cellulaire a un stade precoce de l'organogenese, ou la lrp pourrait intervenir comme signal de reconnaissance
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Ražanskas, Raimundas. « Interaction of Hepatitis B virus core protein and its mutant forms with human liver proteins ». Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101116_164120-74438.
Texte intégralRésumé :
Hepatitis B virus (HBV) is a major human pathogen, but up to now little is known about its core protein (HBc) interactions with host proteins. The role of mutated HBc proteins in enhanced pathogenicity of mutant viruses is also unclear. In this work, the yeast two-hybrid system was employed to find human proteins interacting with HBV core mutants HBc1 and HBc2, as well as with the wild-type core protein. All HBc variants strongly and specifically interacted with human proteins GIPC1 and GIPC2. Common protein interaction domain PDZ in both GIPC1 and GIPC2 was identified as the region interacting with the C-end of HBc. A putative PDZ-interacting motif was identified at the C-end of the HBc protein, and variation of this sequence influenced determined interactions. Human proteins FLJ20850 and IKKγ (NEMO) strongly and specifically interacted with mutants HBc1 and HBc2 only. Gene structure and expression FLJ20850 protein, which was never before described in scientific literature, were analyzed bioinformatically. Detailed analysis of interacting protein pairs revealed regions, responsible for discovered interactions. IKKγ is known as an important regulator of transcription factor NF-kB, therefore HBc1 influence on NF-kB activity in human cells was evaluated experimentally. Determined protein interactions potentially add to understanding of HBV replication and pathogenicity and could serve as targets for developing of new antivirals.Hepatito B virusas (HBV) yra plačiai paplitęs žmogaus patogenas, bet iki šiol mažai ištirta jo šerdies baltymo (HBc), o ypač natūraliai aptinkamų mutantinių formų įtaka viruso dauginimuisi ir patogeniškumui. Šiame darbe mielių dviejų hibridų metodu atrinkti žmogaus kepenų baltymai, sąveikaujantys su laukinio tipo baltymu bei mutantais HBc1 ir HBc2. Su visomis tirtomis HBc atmainomis stipriausiai ir specifiškiausiai sąveikavo žmogaus baltymai GIPC1 ir GIPC2. Detaliau tiriant šias sąveikas nustatyta, kad HBc baltymo C-galas sąveikauja su GIPC1 ir GIPC2 baltymų PDZ domenais. HBc baltymo C-gale aptiktas PDZ domenų atpažįstamos sekos motyvas ir parodyta, kad šios sekos pokyčiai įtakoja HBc sąveiką su GIPC1 ir GIPC2. Vien su mutantais HBc1 ir HBc2 stipriausiai ir specifiškiausiai sąveikavo žmogaus baltymai FLJ20850 ir IKK (NEMO). Anksčiau netyrinėto nežinomos funkcijos žmogaus baltymo FLJ20850 raiška ir geno struktūra apibūdinta naudojantis bioinformatinėmis duomenų bazėmis. Detaliau tiriant mutantų sąveikas su FLJ20850 ir IKK buvo nustatytos baltymų sritys, apsprendžiančios tarpusavio sąveiką. IKK baltymas reguliuoja transkripcijos veiksnio NF-κB aktyvumą, todėl buvo tiriama ir mutanto HBc1 įtaka NF-κB aktyvumui žmogaus ląstelėse. Aptiktos baltymų sąveikos gali padėti geriau suprasti HBV dauginimosi ciklą bei patogeniškumą ir tapti naujų antivirusinių vaistų taikiniais.
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SECCI, PIETRO PAOLO. « La separazione dalla prole reverte le modificazioni nell'espressione di BDNF, proteina Arc, spine dendritiche, LTP e neurogenesi osservate durante la gravidanza e dopo il parto ». Doctoral thesis, Università degli Studi di Cagliari, 2011. http://hdl.handle.net/11584/266279.
Texte intégralRésumé :
La gravidanza, il parto e il periodo post partum costituiscono particolari condizioni fisiologiche durante le quali il cervello femminile è sottoposto a modificazioni funzionali e morfologiche necessarie per l’insorgenza e il mantenimento del comportamento materno.
Il BDNF (Brain Derived Neurotrofic Factor), così come la proteina Arc (Activity-Regulated Cytoskeletal), costituisce un mediatore chiave della plasticità neuronale e la sua azione a lungo termine ha un ruolo importante nell’apprendimento, memoria, comportamento affettivo ed emozionale (1); entrambi inoltre sono in grado di regolare l’architettura neuronale (2).
Nel mio studio ho misurato le quantità di BDNF, di proteina Arc, la densità delle spine dendritiche (DSD), il potenziamento sinaptico a lungo termine (LTP) e la neurogenesi nell’ippocampo di femmine di ratto durante la gravidanza e dopo il parto. Inoltre ho valutato gli stessi parametri nelle madri private della prole una settimana dopo il parto.
Nel giro dentato i livelli di BDNF, Arc e DSD risultano essere aumentati al termine della gravidanza e durante l’allattamento, un effetto associato a un’incremento della LTP in confronto agli animali di controllo. La sottrazione della prole ha indotto una drastica riduzione dei livelli di BDNF, Arc e DSD, i cui valori sono scesi al di sotto dei livelli di controllo. Infine è stato osservato un incremento della neurogenesi al termine della gravidanza e in seguito alla sottrazione dei cuccioli e una riduzione durante l’allattamento.
La variazione dei livelli di espressione di BDNF e Arc, della DSD, i cambiamenti dell’LTP e della neurogenesi indotti dalla maternità e dalla separazione dei cuccioli possono avere un ruolo cruciale nella regolazione del comportamento materno.
------------------------------------------------------------------------------------------------------------------------Pregnancy, delivery and post partum period are among the most important physiological condition in which the brain of female undergo to the functional and morphological modification needed to adapt the behavior to the onset of motherhood.
Brain Derived Neurotrofic Factor (BDNF) is a key mediator of neuronal plasticity. Long term action of BDNF plays a key role in learning and memory, emotional and affective behaviour (1). Activity-regulated cytoskeleton-associated protein (Arc) also plays a relevant role in synaptic plasticity. A role for BDNF-Arc signalling in the regulation of neuronal architecture has been clearly demonstrated (2).
In my study the amount of BDNF, Arc protein, dendritic spines density (DSD), long term potentiation (LTP) and neurogenesis were measured in hippocampus of female rats during pregnancy and after delivery. The same parameters were also evaluated after delivery in the mothers deprived of their pups one week after birth.
In the dentate gyrus BDNF, Arc protein and DSD started to be markedly increased in the late pregnancy and during lactation, an effect associated to a significant increase of LTP and to a dramatic reduction of neurosteroid content compared to control rats. Separation of pups from their dams induced a marked reduction of DSD, BDNF and Arc protein, the amount of which felt at values markedly lower than control. Finally, we observed an increase of neurogenesis in the late pregnancy and after the separation of pups from their dams and a reduction during lactation.
The motherhood-induced change in the amount of DSD, BDNF, Arc, LTP and neurogenesis as well as the reversal by pups separation suggest a crucial role of neuronal plasticity in the regulation of maternal care. ---------------------------------------------------------------------------------------
1) Lu B. 2003, BDNF and activity-dependent synaptic modulation, Learn Mem.; 10(2):86-98.
2) Scharfman HE, Mercurio TC, Goodman JH, Wilson MA, MacLusky NJ 2003 Hippocampal excitability increases during the estrous cycle in the rat: a potential role for brain-derived neurotrophic factor, J Neurosci.;23(37):11641-52.
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Noret, Lamy Isabelle. « Differenciation des progeniteurs hepatocytaires et hematopoietiques : etude de la liver regulating protein (lrp) ». Rennes 1, 1996. http://www.theses.fr/1996REN1B041.
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Croy, Johnny Eugene. « Characterization of ligand binding to the low density lipoprotein receptor-related protein (LRP) / ». Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2003. http://wwwlib.umi.com/cr/ucsd/fullcit?p3112870.
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Laepple, Christiane Hildegard [Verfasser]. « Modifikation der Expression des Lipopolysaccharid Bindenden Protein (LBP) durch Methylxanthine / Christiane Hildegard Laepple ». Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2009. http://d-nb.info/1023664895/34.
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Lam, Ching-po. « Analysis of LMP-1 variants in EBV related Hodgkin's disease ». Click to view the E-thesis via HKUTO, 2003. http://sunzi.lib.hku.hk/hkuto/record/B3197109X.
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Werth, Nadine. « Untersuchungen zur Bedeutung des Lipopolysaccharid-bindenden Proteins (LBP) für Mikroorganismen des Magen-Darm-Traktes von BALB/c-LBP+/+ - und BALB/c-LBP-/- (Knock-out)-Mäusen ». Doctoral thesis, Universitätsbibliothek Leipzig, 2006. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-34148.
Texte intégralRésumé :
Durch Forschungsarbeiten der neueren Zeit ist die Bedeutung der Akut-Phase-Proteine als wichtiger Bestandteil der unspezifischen Abwehr im Organismus sichtbar geworden. Die möglichen Wechselwirkungen zwischen der physiologischen Magen-Darm-Flora und diesen Proteinen sind jedoch weitesgehend unbekannt. In dieser Arbeit wurde die Magen-Darm-Flora von einem LBP-/--Knock-out-Maus-Stamm und dem Wildstamm (jeweils 20 Tiere) untersucht. Dabei wurde die aerobe Gesamtkeimzahl, die aerobe und anaerobe Gram-negative Gesamtkeimzahl und die Gesamtkeimzahl der auf MRS-Agar gewachsenen Keime in Darminhaltsproben der Darmabschnitte Jejunum, Zäkum und Kolon von oben genannten Mäusen erfasst. Zusätzlich wurden sieben serologische Untersuchungen bei 40 Tieren durchgeführt, um mögliche parallele immunologische Reaktionen des Körpers auf Bestandteile der physiologischen Magen-Darm-Flora zu erfassen und vergleichend zu betrachten. Bei den Untersuchungen konnten hochsignifikante Unterschiede bezüglich der Höhe und Zusammensetzung der aeroben Gesamtkeimzahl, der aeroben Gram-negativen Gesamtkeimzahl, der anaeroben Gram-negativen Gesamtkeimzahl und der Laktobazillen-Gesamtkeimzahl festgestellt werden. Dabei waren bei der LBP-/--Gruppe, den gendeletierten Mäusen, die aerobe Gesamtkeimzahl signifikant erhöht, die anderen Keimzahlen, insbesondere die Keimzahlen der aeroben und anaeroben Gram-negativen Bakterien und der Laktobazillen signifikant erniedrigt. Zusätzlich konnten Abweichungen verschiedener Koloniemerkmale wie Hämolyseverhalten, Koloniemorphologie und Genausprägung zwischen der LBP-/-- und der LBP+/+-Gruppe festgestellt werden. Bei den serologischen Untersuchungen konnten die Ergebnisse der mikrobiologischen Untersuchungen bestätigt werden. Es wurden signifikante Erhöhungen der relativen Antikörperspiegel gegenüber ausgewählten bakteriellen Strukturen, von Mikroorganismen, welche auch signifikant häufiger von den jeweiligen Gruppen isoliert werden konnten, festgestellt. Diese Ergebnisse lassen auf einen möglichen Zusammenhang zwischen der Gendeletion, also der Nichtexpression von LBP, und der Zusammensetzung der Magen-Darm-Flora schließen. Inwiefern dies auf direkten oder indirekten Einfluss des LBP auf die Magen-Darm-Flora zurückzuführen ist, müssen weitere Untersuchungen zeigen. Dabei sollten noch andere Einflussfaktoren, wie z. B. die Varianz des LBP in seiner genotypischen Ausprägung, berücksichtigt werden.
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Knierim, Jan Holger. « Charakterisierung LPS-inhibierender Effekte von Lipoproteinen und Lipopolysaccharid Bindendem Protein (LBP) in murinem Serum ». Doctoral thesis, [S.l.] : [s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=963608681.
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Guttman, Miklos. « Intracellular and extracellular interactions of the low density lipoprotein receptor related protein (LRP-1) ». Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3387199.
Texte intégralRésumé :
Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed February 12, 2010). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Vassiliou, Gerard. « Binding of [alpha]2-macroglobulin ([alpha]2M) and RAP to the low-density lipoprotein receptor related protein (LRP/[alpha]2MR) ». Thesis, The University of Sydney, 1994. https://hdl.handle.net/2123/26713.
Texte intégralRésumé :
The low density lipoprotein receptor-related protein/az-macroglobulin receptor (LRP/oczMR) is a multifunctional receptor of 600 kDa which bindsto a number of diverse ligands including apolipoprotein E- containing triacylglycerol-rich lipoproteins; (Jug-macroglobulin (azM) which has been complexed with proteases or reacted with methylamine; plasminogen activator-inhibitor complexes; lipoprotein lipase; Pseudomonas exotoxin A; and a 39 kDa protein, termed receptor associated protein (RAP) which co-purified with the LRP/azMR It is presumed that this receptor is able to bind to these ligand because it contains four clusters of cysteine-rich, class A motifs. These motifs contain a high content of negatively charged, acidic amino acids which are thought to bind by ion-pairing to the positively charged, basic amino acids of the ligands.
a2M purified from plasma was used to investigate the nature binding of this ligand to the LRP/ aZMR 1251-a2M" bound to primary skin fibroblasts with a dissociation constant of about 0.3 nM and a mean binding capacity of 37 fmol/ mg cell protein. The binding of 1251-a2M" is not altered if this ligand is derivatized by acetylation or reductive methylation, treatments which modify the lysine groups of the protein. Furthermore, 1251-0L2M" binding is resistant to polyanionic substances such as heparin and dextran sulfate. In contrast, the binding of low density lipoprotein (LDL) to its receptor, which is by ion pairing, is inhibited by acetylation or reductive methylation of the ligand and is also inhibited by heparin and dextran sulfate. I conclude that 1251-a2M" does not bind to its receptor by ion pairing.
Suramin, a polyanionic drug currently undergoing trials as an anti-Cancer agent, effectively inhibits the cell surface binding of 125I-a2M‘ at pharmacological concentrations. Binding of 1251-a2M‘ to the LRP/azMR purified from rat liver was also inhibited by suramin showing that Suramin directly inhibited the receptor interaction of this ligand.
I have also investigated the proposal that RAP binds to heparan sulfate proteoglycans (HSP). 125I RAP binds to two sites on the surface of fibroblasts: a high-affinity site binds RAP with a dissociation constant (Kd) of 1.4 nM which is similar to the Kd previously reported for the interaction of RAP with the LRP/azMR. RAP also binds to a low-affinity site (Kd = 188 nM) with a capacity of more than lOOO—fold the maximum amount of LRP/azMR on the cell surface. 125I-RAP binding to the low-affinity site was abolished by heparin or Suramin. However, maximal digestion of the glycosaminoglycan chains of HSP with heparinase or culturing the cells in chlorate, an inhibitor of proteoglycan sulfation, did not affect the binding of 1251-RAP or of 1251-a2M". Comparison of 1251-RAP degradation at two different concentrations suggests that the low-affinity high-capacity site on the surface of human fibroblasts participates in the endocytosis of 1251-RAP. The nature of the low-affinity site remains to be elucidated but I can exclude the glycosaminoglycan chains of HSP.
24
Farmer, Paul Kenneth. « Characterization of a calcium-dependent protein kinase (CDPK) and a CDPK-related protein kinase (CRK) including N-myristoylation, subcellular distribution, substrate specificity, and activation by lip ». Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/25438.
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Baron, Olga. « Functional analysis of lipopolysaccharide binding proteins/Bactericidal permeability increasing proteins in immune responses of the freshwater snail, Biomphalaria glabrata ». Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAJ016.
Texte intégralRésumé :
Les LBP/BPIs sont des protéines importantes de la réponse antimicrobienne des mammifères, encore mal caractérisées chez les invertébrés. L'objectif de ce projet était d'élucider le rôle des LBP/BPIs dans la réponse immunitaire du gastéropode B. glabrata. Nous avons montré que l'une des LBP/BPI (BgLBP/BPI1) était une protéine majeure de la glande albumène et des masses d'oeufs et possédait les activités attendues des BPIs telle que la capacité de perméabilisation des bactéries.De plus, nous avons découvert une nouvelle activité biocide (anti-oomycète) inconnue jusqu'alors chez les LBP/BPI, et démontré que BgLBP/BPI1 influence à la fois la production d'oeufs et leur protection contre les infections à oomycètes. Nous avons ensuite examiné la diversité et l'évolution des BgLBP/BPIs et montré qu'au moins 5 LBP/BPIs, regroupées en 3 clades phylogénétiques, étaient exprimées chez B. glabrata. Une étude de l'expression de représentants de ces 3 clades a montré qu'ils étaient exprimés dans différents tissus, appuyant l'hypothèse de l'acquisition de spécificités fonctionnelles par les membres de cette famille multigéniqueLBP/BPIs are important immune factors of the mammalian antimicrobial response,poorly characterized in invertebrates. The aim of this work was to elucidate the role of LBP/BPIs in the immune response of the fresh-water snail B. glabrata. Firstly, we showed that one member, BgLBP/BPI1, was highly abundant in the albumen gland and the egg masses. Importantly, in addition to the expected activities of BPIs, such as the induction of bacterial permeability, we discovered a novel biocidal (antioomycete) activity that was unsuspected so far. We demonstrated that BgLBP/BPI1 is a major fitness-related protein, acting on both egg production and offspring protection against oomycete infections. Then, we investigated the sequence diversity and evolution of this LBP/BPI protein family and showed that at least 5 LBP/BPIs were expressed in B. glabrata, belonging to three distinct phylogenetic clades. Expression studies of representatives of the three clades showed that they are expressed in different tissues, differently regulated, and therefore supported the hypothesis of the acquisition of functional specificities by the members of this multigenic family
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Moindrot, Séverine. « Etudes structurales par rmn et modelisation moleculaire d'une proteine antimicrobienne d'origine vegetale et d'un complexe entre une proteine vegetale de transfert de lipides (ltp) et la prostaglandine b 2 ». Orléans, 2000. http://www.theses.fr/2000ORLE2017.
Texte intégralRésumé :
Les ns-ltps (non-specific lipid transfert proteins) vegetales constituent une famille de proteines homologues qui ont la propriete de transferer de facon non specifique les lipides entre deux membranes. La fonction biologique de ces proteines n'est pas encore entierement determinee. Elles pourraient intervenir dans les mecanismes de defense des plantes contre des agents pathogenes, en particulier elles joueraient un role dans la formation de la cuticule, couche protectrice des plantes. Ces proteines possedent une structure helicoidale et une cavite hydrophobe pouvant accueillir une ou deux chaines lipidiques. L'objectif de cette these est d'elargir la base structurale existante afin preciser les relations structure-fonction et d'etudier la capacite des ns-ltps de complexer des substrats hydrophobes. Nous avons etudie un complexe entre la ns-ltp de ble et la prostaglandine b 2 par rmn et modelisation moleculaire. Cette etude a permis de montrer que la ns-ltp de ble peut inserer dans sa cavite un ligand possedant plusieurs liaisons vinyliques et des groupements hydroxyles. Ceci relance l'interet de l'utilisation des ns-ltps pour la solubilisation de molecules hydrophobes ayant des proprietes pharmaceutiques interessantes. Nous avons ensuite determine la structure en solution de la proteine ace-amp 1 issue des graines d'oignon qui presente des homologies de sequence avec les ns-ltps. Cette proteine possede une puissante activite antimicrobienne mais pas d'activite de transfert contrairement aux ns-ltps. L'etude de cette proteine a permis de mettre en evidence l'absence de cavite hydrophobe a l'interieur de la proteine et donc d'expliquer sur le plan structural la non-activite de transfert de ace-amp 1. A l'aide des techniques de fluorescence et d'absorbance, nous avons etudie les effets de pression et de temperature sur la ns-ltp de ble. Cette etude a permis de montrer que les modifications entrainees par l'augmentation de la pression ou de la temperature ne sont pas tres importantes et qu'elles correspondent a des changements conformationnels locaux. Nous avons etudie la cavite de la ns-ltp de ble par rmn 1 2 9xe ou le xenon est utilise comme sonde specifique des cavites. Les premieres experiences rmn 1 2 9xe nous ont permis de montrer des interactions specifiques entre le xenon et les protons bordant la cavite.
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PEREZ, FERNANDA dos S. A. « Influência da temperatura de cultivo na expressão de proteínas recombinantes de interesse terapêutico no espaço periplásmico bacteriano, utilizando o promotor lambda PL ». reponame:Repositório Institucional do IPEN, 2015. http://repositorio.ipen.br:8080/xmlui/handle/123456789/25195.
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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-11-12T10:39:15Z
No. of bitstreams: 0Made available in DSpace on 2015-11-12T10:39:15Z (GMT). No. of bitstreams: 0
Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Harding, Clare R. « Legionella pneumophila pathogenesis : establishment of a new insect infection model and characterisation of the effector protein LtpD ». Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/12779.
Texte intégralRésumé :
Legionella pneumophila is the causative agent of Legionnaires’ disease, severe pneumonia acquired from inhalation of contaminated water droplets. In the lung, L. pneumophila infects alveolar macrophages and creates a compartment named the Legionella containing vacuole (LCV), which avoids degradation and recruits components of the secretory pathway. LCV creation depends on the action of the Dot/Icm system that translocates over 275 effectors into the host cell. To study the function of these effectors, models that approximate human disease are required. Here, I characterise the larvae of Galleria mellonella as an infection model for L. pneumophila. Infection resulted in larval mortality and bacterial replication in a strain- and Dot/Icm-dependent manner. Flagella expression was dispensable for bacterial virulence, however secreted phospholipases and the Dot/Icm effector SdhA were shown to be important in virulence. Deletion of SdhA resulted in disruption of the LCV membrane and destruction of haemocytes. The importance of SdhA expression was confirmed in a mammalian model, validating the utility of G. mellonella. In the second part of this study, the novel protein LtpD was characterised. LtpD was translocated via the Dot/Icm secretion system and localised to the LCV. A series of truncation mutants defined a C-terminal 153 amino acid domain as required for LCV localisation. This region was shown to bind directly to the lipid phosphoinositide 3-phosphate. Further analysis revealed that LtpD also interacted with the enzyme inositol monophosphatase 1, however did not change the enzyme’s activity in vitro. Deletion of LtpD resulted in a subtle growth defect in mammalian macrophages at late time points during infection. This growth defect was also seen the G. mellonella and mouse lungs, confirming that LtpD is a virulence factor of L. pneumophila. In summary, here I present an infection model to investigate L. pneumophila virulence and further characterisation of the Dot/Icm effector LtpD.
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林正甫 et Ching-po Lam. « Analysis of LMP-1 variants in EBV related Hodgkin's disease ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B3197109X.
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Ražanskas, Raimundas. « Hepatito B viruso šerdies baltymo ir jo mutantinių formų sąveika su žmogaus kepenų baltymais ». Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101116_164107-53995.
Texte intégralRésumé :
Hepatito B virusas (HBV) yra plačiai paplitęs žmogaus patogenas, bet iki šiol mažai ištirta jo šerdies baltymo (HBc), o ypač natūraliai aptinkamų mutantinių formų įtaka viruso dauginimuisi ir patogeniškumui. Šiame darbe mielių dviejų hibridų metodu atrinkti žmogaus kepenų baltymai, sąveikaujantys su laukinio tipo baltymu bei mutantais HBc1 ir HBc2. Su visomis tirtomis HBc atmainomis stipriausiai ir specifiškiausiai sąveikavo žmogaus baltymai GIPC1 ir GIPC2. Detaliau tiriant šias sąveikas nustatyta, kad HBc baltymo C-galas sąveikauja su GIPC1 ir GIPC2 baltymų PDZ domenais. HBc baltymo C-gale aptiktas PDZ domenų atpažįstamos sekos motyvas ir parodyta, kad šios sekos pokyčiai įtakoja HBc sąveiką su GIPC1 ir GIPC2. Vien su mutantais HBc1 ir HBc2 stipriausiai ir specifiškiausiai sąveikavo žmogaus baltymai FLJ20850 ir IKK (NEMO). Anksčiau netyrinėto nežinomos funkcijos žmogaus baltymo FLJ20850 raiška ir geno struktūra apibūdinta naudojantis bioinformatinėmis duomenų bazėmis. Detaliau tiriant mutantų sąveikas su FLJ20850 ir IKK buvo nustatytos baltymų sritys, apsprendžiančios tarpusavio sąveiką. IKK baltymas reguliuoja transkripcijos veiksnio NF-κB aktyvumą, todėl buvo tiriama ir mutanto HBc1 įtaka NF-κB aktyvumui žmogaus ląstelėse. Aptiktos baltymų sąveikos gali padėti geriau suprasti HBV dauginimosi ciklą bei patogeniškumą ir tapti naujų antivirusinių vaistų taikiniais.Hepatitis B virus (HBV) is a major human pathogen, but up to now little is known about its core protein (HBc) interactions with host proteins. The role of mutated HBc proteins in enhanced pathogenicity of mutant viruses is also unclear. In this work, the yeast two-hybrid system was employed to find human proteins interacting with HBV core mutants HBc1 and HBc2, as well as with the wild-type core protein. All HBc variants strongly and specifically interacted with human proteins GIPC1 and GIPC2. Common protein interaction domain PDZ in both GIPC1 and GIPC2 was identified as the region interacting with the C-end of HBc. A putative PDZ-interacting motif was identified at the C-end of the HBc protein, and variation of this sequence influenced determined interactions. Human proteins FLJ20850 and IKKγ (NEMO) strongly and specifically interacted with mutants HBc1 and HBc2 only. Gene structure and expression FLJ20850 protein, which was never before described in scientific literature, were analyzed bioinformatically. Detailed analysis of interacting protein pairs revealed regions, responsible for discovered interactions. IKKγ is known as an important regulator of transcription factor NF-kB, therefore HBc1 influence on NF-kB activity in human cells was evaluated experimentally. Determined protein interactions potentially add to understanding of HBV replication and pathogenicity and could serve as targets for developing of new antivirals.
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Nieuwoudt, Melanie. « LTP1 and LOX-1 in barley malt and their role in beer production and quality ». Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86558.
Texte intégralRésumé :
Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Selection of raw materials for a consistent and high quality end product has been a challenge for brewers globally. Various different factors may influence quality and although a great number of methods for malt analysis exist today for the prediction of end product quality, some still do not accurately represent malt performance in beer. This research focussed on determining parameters in malts to predict two of the major beer quality determining factors namely, foam- and flavour stability. Specific biochemical markers in barley malt such as lipid transfer protein 1 (LTP1) lipoxygenase-1 (LOX-1), anti-radical/oxidant potential (AROP), free amino nitrogen and intact protein were determined and used in beer quality prediction from malt character. These biochemical quality predictions were then correlated with the end product beer quality as assessed in sensory analysis trials on micro-brewed beers. Being such a multi-faceted factor in beer, LTP1 have already become an attractive field of study. LTP1 is primarily associated with stable beer foam, as a foam protein in its own right, and acting as a lipid scavenger. This protein is also theorised to play a role in the stability of beer flavour by possibly acting as anti-oxidant. Lastly LTP1 is known to have anti-yeast activity, which could negatively impact fermentation. In this study LTP1 and its lipid bound isoform LTP1b were successfully purified in an economical and easy five step protocol. Both isoforms showed temperature stability at temperatures >90°C and prefer more neutral and basic pH environments. Although the reported antioxidant activity was not observed, both purified LTP1 and LTP1b inhibited lipoxygenase-1 (LOX-1) activity, which is responsible for the enzymatic breakdown of linoleic acid to form 2(E)-nonenal. This is a novel finding that links LTP1 also to flavour stability. LTP1 exhibited anti-yeast activity whereas LTP1b lost most if not all the activity. However, since most of the LTP1 is converted to LTP1b and glycosylated isoforms during the brewing process fermentation will not be greatly influenced, while foam and flavour stability could still be promoted by the presence of LTP1b. Flavour deterioration of the final packaged product is partially due to the enzymatic production of 2(E)-nonenal by LOX-1 and the presence of free oxygen radical species, limited anti-radical/oxidant potential (AROP) and LTP1. The development of two 96-well micro-assays based on the ferrous oxidation-xylenol orange (FOX) assay for the determination of LOX-1 and AROP was successfully accomplished and compared well with established assays. The LOXFOX and AROP-FOX assays were specifically developed for the on-site, high throughput comparative determination of LOX-1 and AROP in malt and other brewery samples. The AROP-FOX and LOX-FOX micro-assays and a number of established assays were used to categorise malts in different predicted quality groups, various biochemical markers were measured which included LOX activity, LTP1 content, FAN values, intact protein concentration and AROP. An excellent trend (R2=0.93) was found between FAN/LOX and LTP1/LOX which also correlated with the novel observation that LOX-1 activity is inhibited by LTP1 at various concentrations. These trends could assist brewers in optimal blending for not only high quality end products but also fermentation predictions. To determine whether these biochemical markers selected for screening in barley malt are predictive of shelf life potential of the end product, sensory trials were performed. Three barley malt cultivars were selected for LOX, AROP, LTP1, protein and FAN content and used in micro-brewery trials at 0 and 3 months and evaluated using sensory analysis. Good correlation was found between the biochemical predictors and sensory trial for the best quality malt and beer. These parameters were therefore highly relevant for predicting shelf life potential, although additional research is required to elucidate the effect of LTP1 and LOX-1 on each other during the brewing process, since it seems that high LOX-1 concentrations could be leading to LTP1 decreases. With this study it is proposed that if more detailed protein or FAN characterisation is used together with the screening of LOX-1, LTP1 and AROP, an more accurate shelf life prediction, based on malt analysis, is possible and with the help of these parameters brewers can simply blend malts accordingly.
AFRIKAANSE OPSOMMING: Die keuse van roumateriaal om 'n konstante eindproduk van goeie kwaliteit te lewer, was nog altyd 'n uitdaging vir brouers wêreldwyd aangesien verskeie faktore 'n invloed het op die kwaliteit van die produk. Alhoewel daar tans verskeie metodes vir moutanalise bestaan wat die eindproduk–kwaliteit voorspel, is daar min wat werklik die eindproduk kwaliteit soos voorspel deur moutanalise verteenwoordig. Hierdie navorsing fokus op die bepaling van mout-eienskappe om twee van die belangrikste bierkwaliteitvereistes, naamlik skuim- en geurstabiliteit te voorspel. Spesifieke biochemiese eienskappe in garsmout soos lipiedtransportproteien-1 (LTP1), lipoksigenase-1 (LOX-1), antioksidant-antiradikaal potensiaal (AROP), vry aminostikstof (FAN) is geïdentifiseer en gebruik in voorspelling van bierkwaliteit vanaf moutkarakter. Hierdie biochemiese kwaliteit voorspellings is dan gekorreleer met die eindproduk soos ge-evalueer d.m.v sensoriese analise op mikro-gebroude bier. Omdat LTP1 soveel fasette in bier beïnvloed, het dit reeds 'n aanloklike studiefokus geword. LTP1 word hoofsaaklik geassosieer met stabiele skuimkwaliteit in bier en tree op as 'n lipiedmop (“lipid scavenger”). Die proteien speel teoreties ook 'n rol in die stabiliteit van bier geur deur moontlik as 'n anti-oksidant op te tree. Laastens is LTP1 bekend vir sy antigis aktiwiteit wat moontlik 'n negatiewe uitwerking op fermentasies het. Gedurende hierdie navorsing is LTP1 en sy lipiedbinding isoform LTP1b suksesvol gesuiwer met 'n ekonomies en eenvoudige 5-stap protokol. Beide isoforme het stabiliteit by temperature >90°C en meer neutrale en basiese pH omgewings getoon. Alhoewel die voorheen gerapporteerde anti-oksidant aktiwiteit vir LTP1 nie bevestig kon word nie, is daar wel gevind dat beide LTP1 en LTP1b, LOX-1, wat verantwoordelik is vir die ensimatiese afbraak van linoleensuur na 2(E)-nonenal, se aktiwiteit inhibeer. Dit is 'n unieke bevinding wat LTP1 ook koppel aan geurstabiliteit. LTP1 het antigis aktiwiteit getoon, maar LTP1b het die meeste, indien nie alle antigis-aktiwiteit verloor. Omdat die meeste van die LTP1's omgeskakel word na LTP1b's en geglikosileerde isoforme tydens die brouproses, sal fermentasie nie beduidend beinvloed word nie, maar die skuim- en geurstabiliteit sal steeds bevorder word deur die blote teenwoordigheid van die LTP1b. Geurverval van die finale verpakte produk is gedeeltelik a.g.v die ensimatiese produksie van 2(E)-nonenal deur LOX-1 en die teenwoordigheid van vry suurstofradikaal spesies, beperkte AROP en LTP1. Die ontwikkeling van twee 96-putjie mikroessaïs, gebasseer op die yster oksidasie-xilenol oranje (FOX) essai vir die bepaling van LOX-1 en AROP, was suksesvol en het goed vergelyk met reeds gevestigde essaïs. Die LOX-FOX en AROP-FOX mikroessaïs is spesifiek ontwikkel vir die residente, hoë deurvloei vergelykende bepaling van LOX-1 en AROP in mout en ander brouery-monsters. Die AROP-FOX en LOX-FOX mikroessaïs en 'n paar gevestigde essaïs is gebruik om moute te kategoriseer in die verskillende voorspelde kwaliteitsgroepe. Die biochemiese merkers wat gemeet is het die volgende ingesluit: LOX aktiwiteit, LTP1 inhoud, FAN waardes, proteïen konsentrasie en AROP. 'n Merkwaardige korrelasie (R2=0.93) is gevind tussen FAN/LOX en LTP1/LOX wat ook ooreenstem met die waarneming dat LOX-1 aktiwiteit onderdruk word deur LTP1 by verskeie konsentrasies. Hierdie korrelasies kan brouers help met optimale versnitting van moute vir, nie net die hoogste kwaliteit eindproduk nie, maar ook vir fermentasie voorspellings. Om te bepaal of hierdie geselekteerde biochemiese merkers in mout die potensieële raklewe van die eindproduk verteenwoordig, is sensoriese evaluerings uitgevoer. Drie gars-mout kultivars is geselekteer o.g.v LOX-, AROP-, LTP1-, proteïen- en FAN-inhoud en gebruik in mikro-brouery proewe en op 0 en 3 maande en is ge-evalueer deur sensoriese analise. Goeie korrelasie is gevind tussen die biochemiese voorspellers en sensoriese evaluering vir die beste kwaliteit mout en bier. Hierdie maatstawwe is daarom uiters relevant vir voorspelling van die potensiele rakleeftyd, alhoewel addisionele navorsing nodig is om die effek van LTP1 en LOX-1 op mekaar gedurende die brouproses te bepaal. Dit blyk dat 'n hoë LOX-1 konsentrasies kan lei tot 'n afname in LTP1. Met hierdie studie word dit voorstel dat, as meer gedetaileerde proteien of FAN karakterisering saam met LOX-1, LTP1, en AROP analise uitgevoer word, 'n meer akkurate raklewe voorspelling moontlik is en met behulp van hierdie parameters kan brouers moute dienooreenkomstig versnit.
32
Chen, Eunice Chungyu. « The mechanism of the low-density lipoprotein receptor-related protein (LRP) in the production of amyloid-[Beta] peptide ». Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p1455306.
Texte intégralRésumé :
Thesis (M.S.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed July 30, 2008). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 42-46).
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Hallberg, Anna. « Amyloid beta inducerad klyvning av NG2 medierad via LRP-1 receptorn ». Thesis, Malmö högskola, Fakulteten för hälsa och samhälle (HS), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-26512.
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Bakgrund: Deposition av fibrillär amyloid beta 1-42 (Aβ) i hjärnan är ett välkänt kännetecken för den neurodegenerativa sjukdomen Alzheimer’s (AD). Dessa ansamlingar påverkar pericyter, en celltyp involverad i blodkärlsfunktion och upprätthållande av blodhjärnbarriären (BBB). Pericyter uttrycker både receptorn low density lipoprotein receptor related protein 1 (LRP-1) till vilken Aβ1-42 binder, och proteoglykanet NG2. NG2 har stor betydelse för pericyters samspel med endotelceller och i sin lösliga form (sNG2) främjar den angiogenes. Tidigare studier har visat att mängden NG2 som klyvs från pericyter förändras när de stimuleras med Aβ1-42. Syfte: Att undersöka om Aβ1-42 påverkar NG2 klyvning via LRP-1 Metod: Human brain vascular pericytes (HBVP) stimulerades med monomera, oligomera och fibrillära Aβ1-42 preparationer. Uttrycket av LRP-1 tystades med small interfering (si) LRP-1 och knockdown efficiency analyserades med Western Blot (WB). Även Aβ1-42 preparationer undersöktes med WB. Cellviabilitet mättes med laktatdehydrogenas (LDH) test och proteininnehåll med Bradford analys. Slutligen mättes mängden sNG2 i pericytmedium med hjälp av enzyme-linked immunosorbant assay (ELISA) baserad på electrochemiluminescence (Mesoscale). Resultat: Preparationerna med monomer och oligomer Aβ1-42 ökade NG2 klyvning. Denna Aβ1-42 inducerade ökning försvann när cellernas LRP-1 tystats. Aβ1-42 fibrillpreparationerna inhiberade däremot NG2 klyvningen oavsett närvaro av LRP-1. Aβ1-42 monomerpreparationer inducerade celldöd hos HBVP med LRP-1 men inte hos de HBVP där LRP-1 tystats, och cellviabiliteten hos HBVP ökade hos celler som stimulerats med Aβ1-42 fibrillpreparation och där LRP-1 tystats. Konklusion: Resultaten visar att Aβ1-42 monomer och oligomer påverkar NG2 klyvning via LRP-1. Däremot verkar Aβ1-42 fibrill istället påverka NG2 klyvning via en annan signalväg. Studien belyser hur Aβ1-42 kan påverka pericyter, vilket kan föreligga vaskulära förändringar kopplade till AD patologi.Background: The deposition of fibrillar amyloid beta 1-42 (Aβ) in the brain is a well-known characteristic for the neurodegenerative Alzheimer’s disease (AD). These accumulations affect pericytes, a cell type implicated in vessel function and maintenance of the blood-brain barrier (BBB). Pericytes express both the receptor low-density lipoprotein receptor related protein 1 (LRP-1), to which Aβ1-42 binds, and the proteoglycan NG2. NG2 is important for the interaction between pericytes and endothelial cells and in its soluble form (sNG2) it promotes angiogenesis. Earlier studies have shown that the amount of NG2 shed from pericytes is altered when stimulated with Aβ1-42. Purpose: To investigate whether the Aβ1-42 influence on NG2 shedding is mediated via LRP-1. Method: Human brain vascular pericytes (HBVP) were stimulated with monomeric, oligomeric and fibrillar preparations of Aβ1-42. Expression of LRP-1 was knocked down by small interfering (si) LRP-1 silencing and knockdown efficiency was analysed with Western blot (WB). Aβ1-42 preparations were also analysed with WB. Cell viability was measured with lactate dehydrogenase (LDH) test and protein concentrations were determined with Bradford assay. Finally the amount of sNG2 in pericytemedium was measured with enzyme-linked immunosorbant assay (ELISA) baserad på electrochemiluminescence (Mesoscale) Results: Monomer and oligomer Aβ1-42 increased NG2 shedding, this Aβ1-42 induced increase was not found in HBVP with a silenced LRP-1. In contrast, fibrillar Aβ1-42 inhibited NG2 shedding regardless of LRP-1 presence. Monomer Aβ1-42 preparations induced cell death of HBVP with LRP-1 but not of HBVP without LRP-1, and cell viability of HBVP lacking LRP-1 was increased after fibrillar Aβ1-42 exposure. Conclusion: The results indicate a monomeric and oligomeric Aβ1-42 induced impact on NG2 shedding via LRP-1. However it appears as if fibrillar Aβ1-42 doesn’t affect NG2 shedding via LRP-1 but rather inhibits the process via another unknown receptor. The study highlights how Aβ1-42 can affect pericytes, which may underlie the vascular changes linked to AD pathology.
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Aya, Rino. « Regeneration of elastic fibers by three-dimensional culture on a collagen scaffold and the addition of latent TGF-β binding protein 4 to improve elastic matrix deposition ». Kyoto University, 2016. http://hdl.handle.net/2433/215396.
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Van, Uden Emily. « The role of the LDL receptor-related protein (LRP) in neurodegeneration : towards a unified theory of alzheimer's disease pathogenesis / ». Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9963654.
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Ahlsén, Hanna. « The Effects of Abiotic Stress on Alternative Splicing in Non-specific Lipid Transfer Proteins in Marchantia polymorpha ». Thesis, Linköpings universitet, Biologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-148937.
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Due to global warming, our planet will experience more extreme weather conditions. Plants can protect themselves against these abiotic stress conditions with their stress response, which includes alternative splicing of certain genes. Alternative splicing is a post-transcriptional process where a single gene gives rise to different mRNAs, which in turn produces different proteins. In plants, this is usually done by intron retention. One type of protein that may be involved in this stress response are the non-specific lipid transfer proteins (LTPs). Indeed, evidence of intron retention has been found in the LTP genes in the liverwort Marchantia polymorpha, called MpLTPd. To investigate whether this alternative splicing is caused by abiotic stress or not, I subjected the moss to two different types of stress trials, drought and cold, and compared the general expression of the intron in MpLTPd2 and MpLTPd3 from the stressed samples to samples from a moss grown under normal conditions. I found that the expression of the intron did change in the stressed moss, but none of the differences were significant. This suggests that alterative splicing in MpLTPd2 and MpLTPd3 is not caused by cold and drought and that the intron-containing protein plays no role in the protection of M. polymorpha against abiotic stress.
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DIAS, LIGIA E. M. F. « Producao de prolactina humana autentica por tecnicas de DNA recombinante ». reponame:Repositório Institucional do IPEN, 1993. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10351.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Bengtsson, Luiza. « Novel integral membrane proteins of the inner nuclear membrane characterization of LUMA native LAP 2b [twobeta] complexes / ». [S.l.] : [s.n.], 2002. http://www.diss.fu-berlin.de/2002/100/index.html.
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Laurent, Matha Valérie. « L'endocytose et le transport aux lysosomes de la procathepsine-D dans les cellules cancéreuses ». Montpellier 1, 2000. http://www.theses.fr/2000MON1T016.
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Pocathikorn, Anothai. « Low density lipoprotein receptor-related protein (LRP) and its mRNA : influence of genetic polymorphisms, a fat load and statin therapy ». University of Western Australia. School of Surgery and Pathology, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0117.
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[Truncated abstract] The low density lipoprotein receptor-related protein (LRP), a member of the low-density lipoprotein (LDL) receptor gene family is involved in numerous biological processes including lipoprotein metabolism. This thesis concerns investigations into some aspects of LRP metabolism/regulation and possible roles in coronary artery disease (CAD). Specific aims were: to investigate the association between polymorphisms in the LRP gene and in its associated protein, the lipoprotein receptor-associated protein (RAP), with the risk of CAD; to extensively examine the influence of the LRP exon 22 C200T polymorphism on lipid metabolism; to develop and characterise assays for the mRNA expression of LRP and 2 other genes relevant to lipid metabolism, the LDL receptor (LDLR), and HMG CoA reductase (HMGCR); and finally, to apply the latter techniques to studies on the influence of genetic variation in LRP, and dietary and drug interventions, on LRP, LDLR and HMGCR mRNA expression in nucleated blood cells from healthy human subjects. Six hundred CAD subjects and 700 similarly aged controls were genotyped for 8 LRP gene polymorphisms as well as for the RAP V311M polymorphism. ... In the final phase of my studies, I examined the influence of 4 weeks therapy with a cholesterol lowering drug, an HMGCR inhibitor, atorvastatin (20mg daily), on the mRNA expression of LDLR, LRP and HMGCR in human nucleated blood cells. Twelve normal Caucasian male subjects aged 49 ? 5 (SD) years were studied. Plasma total cholesterol and LDL-C decreased by averages of 29 % and 41 % after the 4 week period. This was accompanied by an elevation in LDLR mRNA expression by approximately 30 35 %. In contrast, there was no significant effect on LRP and HMGCR mRNA expression. In conclusion, the original findings in this thesis included: demonstration of a strong influence of the LRP exon 22 C200T polymorphism on coronary artery disease and LDLR expression, but without a clear effect on fasting or postprandial lipid levels; data on the biological variation in LDLR and LRP gene expression in nucleated blood cells from normal subjects; the influence of an oral fat load on the expression viii of these genes, finding that LDLR was significantly depressed; and finally, the observation that statin therapy upregulated LDLR in nucleated blood cells.
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Pocathikorn, Anothai. « Low density lipoprotein receptor-related protein (LRP) and its mRNA : influence of genetic polymorphisms, a fat load and statin therapy / ». Connect to this title, 2005. http://theses.library.uwa.edu.au/adt-WU2006.0117.
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Bengtsson, Luiza. « Novel integral membrane proteins of the inner nuclear membrane characterization of LUMA native LAP 2[beta] [2beta] complexes / ». [S.l. : s.n.], 2002. http://www.diss.fu-berlin.de/2002/100/index.html.
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Kesner, Philip. « Acute Cannabinoid Treatment 'in vivo' Causes an Astroglial CB1R-Dependent LTD At Excitatory CA3-CA1 Synapses Involving NMDARs and Protein Synthesis ». Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23518.
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Cannabinoids have been shown to alter synaptic plasticity but the mechanism by which
this occurs at hippocampal CA3-CA1 synapses in vivo is not yet known. Utilizing in vivo
electrophysiological recordings of field excitatory postsynaptic potentials (fEPSP) on
anesthetized rats and mice as well as three lines of conditional knockout mouse models,
the objective was to show a two-part mechanistic breakdown of cannabinoid-evoked
CA3-CA1 long-term depression (LTD) in its induction as well as early and later-phase
expression stages. It was determined that this cannabinoid-induced in vivo LTD requires
cannabinoid type-1 receptors (CB1Rs) on astrocytes, but not CB1Rs on glutamatergic or
GABAergic neuronal axons/terminals. Pharmacological testing determined that
cannabinoid-induced in vivo LTD also requires activation of NMDA receptors (NMDAR)
and subsequent postsynaptic endocytosis of AMPA receptors (AMPAR). There exists a
clear role for NR2B-containing NMDARs in a persistent, transitory form, potentially
related to prolonged or delayed glutamate release (possibly as a result of the astrocytic
network). A key determination of the expression phase is the involvement of new protein synthesis (using translation and transcription inhibitors) – further evidence of the long-term action of the synaptic plasticity from a single cannabinoid dose.
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Lintner, Robert E. « Comparative Functional Analysis and Identification of Regulatory Control in Gene Networks Using the Leucine-Responsive Regulatory protein and its Regulon as a Model System ». University of Toledo Health Science Campus / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=mco1178738358.
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Lefrançois, Louise. « Etude des adhésines HBHA et LBP impliquées dans l'interaction de Mycobacterium avium ssp. paratuberculosis avec les cellules épithéliales intestinales, cibles privilégiées de la bactérie in vivo ». Thesis, Tours, 2012. http://www.theses.fr/2012TOUR4020/document.
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Mycobacterium avium ssp. paratuberculosis (Map), agent étiologique de la paratuberculose, a évolué en deuxtypes dénommés, S pour« Sheep » et C pour « Cattle ». L’intestin grêle est le site primaire de l’infection à Map mais les mécanismes moléculaires impliqués dans l’implantation du bacille restent largement méconnus. L’objectif de mon projet de thèse visait à identifier et caractériser les adhésines exprimées par Map par des approches génétiques et biochimiques. J’ai ainsi purifié la HBHA et la LBP par chromatographie d’affinité puis les ai identifiés en spectrométrie de masse. L’originalité de ce travail repose sur le polymorphisme de ces adhésines observé entre les souches de type C et S. Cette variabilité a été mise en évidence sur le domaine d’interaction avec les sucres sulfatés de la cellule hôte influençant l’affinité des adhésines pour l’héparine. Ce travail de thèse a permis de caractériser pour la première fois ces deux adhésines produites par Map. Le polymorphisme de la HBHA et de la LBP, discriminant les types C et S, ouvre de nombreuses perspectives sur l’évolution de l’espèce M. avium et le rôle de ces adhésines sur le tropisme intestinal, la préférence d’hôte de Map ou encore leur potentiel diagnosticMycobacterium avium subsp. paratuberculosis (Map), the etiological agent of paratuberculosis, has evolved into two types called, S for "Sheep" and C for "Cattle." The small intestine is the primary site of Map infection but the molecular mechanisms involved in the establishment of bacilli are still unknown. The aim of my thesis was to identify and characterize the adhesins expressed by Map by genetic and biochemical approaches. I purified HBHA and LBP by affinity chromatography then identified them by mass spectrometry. The originality of this work is based on the polymorphism of these adhesins observed between strains of type C and S. This variability has been demonstrated in the binding domain involved in interaction with sulfated sugars of host cell influences adhesins affinity for heparin. This thesis has characterized for the first time these two adhesins produced by Map. Specific polymorphism highlighted related to the evolution of the species avium, opens large number questions on their role on the pathogenesis of Map including the cellular tropism, host preference or interest of these antigens to improve diagnostic
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Nahar, Taslima [Verfasser], et Markus [Akademischer Betreuer] Hecker. « Role of the lim-domain proteins LPP and ZYXIN in hypertension-induced cardiovascular remodeling / Taslima Nahar ; Betreuer : Markus Hecker ». Heidelberg : Universitätsbibliothek Heidelberg, 2017. http://d-nb.info/1178010651/34.
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Bouhamyia, Lamiaâ. « Etude de l'expression de LRP (Lung Resistance-related protein) et des anomalies chromosomiques dans les cellules bronchiques normales et carcinomateuses pulmonaires humaines ». Paris 6, 2007. http://www.theses.fr/2007PA066185.
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Les carcinomes bronchiques non à petites cellules (CBNPC) sont caractérisés par une chimiorésistance intrinsèque. Actuellement, il n'existe pas de marqueur biologique prédictif de la réponse à la chimiothérapie. Les protéines principalement impliquées dans cette chimiorésistance sont MRP1, et LRP. Le but de ce travail de thèse a été d’étudier, si LRP codée par le gène LRP situé près de MRP1, est hyperexprimée dans les CBNPC comme MRP1. Nos résultats montrent : une absence de modification aussi bien dans la distribution intracytoplasmique que dans l'expression de LRP au cours de la carcinogenèse en comparant cellules bronchiques normales et CBNPC, indépendamment de l’ADN ploïdie. Une augmentation de l’expression de LRP accompagnée d’une modification de sa localisation dans les CBNPC traités par chimiothérapie néo-adjuvante par rapport aux CBNPC non traités. En conclusion, dans le poumon normal ou tumoral, LRP pourrait avoir un rôle dans la détoxification, sans modification lors de la carcinogenèse. L’augmentation de l’expression de LRP est liée à la chimiothérapie, et non à l’ADN ploïdie ou au gain de chromosomes 16.
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Serackis, Artūras. « Image reconstruction technologies for protein spot parametrisation ». Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20090122_094213-80420.
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The problems of protein parametrisation in two-dimensional electrophoresis (2DE) gel image is analysed in this work. Analysis of the proteins gives possibility to observe the health state of living organisms. In proteomics two-dimensional electrophoresis is used for protein separation in the gel according to their isoelectric point and molecular mass. The resulting gel is scanned and analysed by automatic gel image analysis systems. Those systems are not able to deal with specific protein spot distortions found in the gel image. The over-saturated protein spots prevent proper segmentation of the 2DE gel images. The aim of the work is to investigate the possibility of image reconstruction applications for object parametrisation by creating new methods for protein spot parametrisation in 2DE gel images.
Three main tasks are resolved in this work: new mathematical models for parametrisation of saturated protein spots in 2DE gel images are proposed; new method for over-saturated protein spot search and reconstruction in 2DE gel images is proposed; new method for parametrisation of overlapped protein spots in 2DE gel images is proposed.
The thesis is divided into introduction, four chapters and generalisation. The review of image reconstruction techniques and current 2DE gel image analysis problems are presented in first chapter. In the second chapter – the new mathematical models for parametrisation of saturates protein spots are proposed and experimental investigation results... [to full text]Disertacijoje nagrinėjamos baltymų pėdsakų parametrizavimo dvimatės elektroforezės (2ME) gelių vaizduose problemos. Proteomikoje, analizuojant baltymus, tiriami gyvame organizme vykstantys pokyčiai. 2ME metu baltymai išskiriami pagal jų molekulines savybes. Deja 2ME gelių vaizdų automatinei analizei skirtose programose pritaikytos technologijos netinka iškraipytiems baltymų pėdsakams (dėl baltymų įsisotinimo, persisotinimo ar susiliejimo) aptikti ir parametrizuoti. Pagrindinis disertacijos tikslas – ištirti galimybę taikyti vaizdo rekonstravimo technologijas trimačiams objektams parametrizuoti, sukuriant ir ištiriant baltymų pėdsakų 2ME gelių vaizduose parametrizavimo metodus. Disertacijoje sprendžiami trys pagrindiniai uždaviniai: naujų baltymų pėdsakų matematinių modelių, tinkamų įsisotinusiems baltymų pėdsakams parametrizuoti, kūrimas; baltymų persisotinimų paieškos ir rekonstravimo metodo kūrimas ir susiliejusių baltymų pėdsakų parametrizavimo metodo kūrimas. Disertaciją sudaro įvadas, keturi skyriai ir rezultatų apibendrinimas. Įvadiniame skyriuje nagrinėjamas problemos aktualumas, iškeliamos hipotezės, formuluojamas darbo tikslas bei uždaviniai, mokslinis darbo naujumas, darbo praktinė reikšmė ir disertacijos struktūra. Pirmajame skyriuje apžvelgtos parametrizavimui taikomos vaizdo rekonstravimo technologijos. Skyriuje apžvelgtos vaizdo rekonstravimo technologijos, taikomos objektui parametrizuoti, kai naudojami keli, skirtingu kampu, gauti objekto vaizdai, taikomos... [toliau žr. visą tekstą]
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Alves, José Vitor Ferreira. « Avaliação da antigenicidade de proteínas recombinantes de L. (V.) braziliensis ». Universidade Federal de Goiás, 2014. http://repositorio.bc.ufg.br/tede/handle/tede/4201.
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Leishmaniasis is a group of diseases with distinct clinical, histopathological and immunological characteristics, caused by parasites belonging to the Leishmania genus. The serological tests used until the moment have several limitations. There are a great interest to identify immunogenic proteins of Leishmania to be tested as potential antigens for the development of techniques for the diagnosis of American cutaneous leishmaniasis (ACL). The aim of this study was to produce and purify the recombinant proteins "Leishmania activated C kinase" (rLACK); "Thiol Specific Antioxidant" (TSA), "Leishmania elongation initiation factor" (LeIF) and "Leishmania braziliensis stress inducible protein 1" (LbSTI) to evaluate the antigenicity. The recombinant proteins were produced by recombinant DNA techniques as described by Salay et al. (2007). To perform the ELISA, L.(V.) braziliensis (MHOM/BR/1975/M2903) and L.(L.) amazonensis (IFLA/BR/67/PH8) species were cultivated and the antigenic extracts and recombinant proteins were used as antigens. Sixty serum samples from patients with ATL assisted at Anuar Auad hospital, Goiânia, Goiás, were assayed, and from them, 45 were from patients with localized cutaneous leishmaniasis (LCL) and 15 were from mucosal leishmaniasis (ML). To analyze the specificity of the response of total extract and the recombinant proteins, sera from patients with other pathologies were tested. The total extract of L. (L.) amazonensis, rLACK, rTSA, rLbSTI and rLeIF showed a sensitivity of 85%, 75%, 70%, 76.7% and 56.1% respectively. The specificity of total extract of L. (L.) amazonensis, rLACK, rTSA, rLbSTI, rLeIF were 72.5%, 80%, 60%, 30% and 62.5% respectively. Thus, these results showed that recombinants proteins and total extract of L. (L.) amazonensis were antigenic and the total extract of L. (L.) amazonensis and rLACK were the antigen that had the best sensibility and specificity.
As leishmanioses compreendem um grupo de doenças que apresentam características clínicas, histopatológicas e imunológicas distintas, é causada por parasitos intracelulares que pertencem ao gênero Leishmania. Os testes sorológicos utilizados até o presente, para o diagnóstico, apresentam várias limitações e por isto é de grande importância identificar proteínas imunogênicas da Leishmania, para que sejam testadas como potenciais antígenos para o desenvolvimento de técnicas para o diagnóstico da leishmaniose tegumentar americana (LTA). O objetivo deste estudo foi produzir e purificar as proteínas recombinantes “Leishmania activated C kinase” (rLACK); “Thiol Specific Antioxidant” (TSA), “Leishmania elongation initiation factor” (LeIF) e “Leishmania braziliensis stress inducible protein 1” (LbSTI) e avaliar a sua antigenicidade. As proteínas recombinantes foram produzidas pela técnica de DNA recombinante segundo descrito por Salay et al. (2007). Para a realização do ELISA foram cultivadas as espécies L. (V.) braziliensis (MHOM/BR/1975/M2903) e L. (L.) amazonensis (IFLA/BR/67/PH8) e seus extratos antigênicos e as proteínas recombinantes produzidas foram utilizados como antígenos. Foram utilizadas 60 amostras de pacientes com LTA, atendidos no hospital Anuar Auad, Goiânia, Goiás, sendo que destas, 45 eram de pacientes com leishmaniose cutânea localizada (LCL) e 15 eram de leishmaniose mucosa (LM). Para a análise da especificidade foram utilizados o soro de pacientes com outras patologias. O extrato total de L. (L.) amazonensis, rLACK, rTSA, rLbSTI, rLeIF apresentarem sensibilidade de 85%, 75%, 70%, 76,7%, e 56,1% respectivamente. O extrato total de L. (L.) amazonensis, rLACK, rTSA, rLbSTI, rLeIF obtiveram especificidade de 72,5%, 80%, 60%, 30% e 62,5%, respectivamente. Os resultados do presente trabalho demonstraram que as proteínas recombinantes e o extrato total de L. (L.) amazonensis foram antigênicas e o extrato total de L. (L.) amazonensis e a rLACK foram os antígenos que tiveram as melhores sensibilidades e especificidades.
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Kang, David E. « Genetic and functional characterization of the low density lipoprotein receptor-related protein (LRP) in clearance of soluble amyloid [beta] protein in late-onset Alzheimer's disease : and functional characterization of presenilin 1 in modulation of [beta]-catenin signaling pathway and downstream effects on amyloid [beta] protein / ». Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1999. http://wwwlib.umi.com/cr/ucsd/fullcit?p9943953.
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