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P. chrysosporium est un champignon saprophyte capable de dégrader de nombreux xénobiotiques, ce qui le rend particulièrement intéressant pour des applications en bioremédiation. Plusieurs publications mettent en avant l'importance de la maîtrise de l'homéostasie métallique dans la production de certaines enzymes lignolytiques. La présence de manganèse est en effet nécessaire à la production des manganèses peroxydases, alors qu'à l'inverse une carence permettra la production de lignines peroxydases. Cependant, la caractérisation de transporteurs impliqués dans le contrôle de l'homéostasie métallique n'a fait l'objet de recherches poussées que chez le champignon modèle S. cerevisiae. L'analyse des transporteurs putatifs de manganèse de 26 espèces fongiques représentant 20 ordres fongiques a permis de constituer un répertoire de 281 transporteurs de manganèse. L'analyse phylogénétique a permis de mettre en évidence que des processus de duplication, mais également de délétion, avaient eu lieu en particulier chez S. cerevisiae. Cependant ce dernier ne possède pas de transporteurs de manganèse appartenant à la famille des Cation Diffusion Facilitator. Dans le génome de P. chrysosporium, onze transporteurs de manganèse appartenant à différentes familles de gènes ont été identifiés. Le niveau d'expression de ces différents gènes a été étudié notamment en condition lignolytique. Ces transporteurs ont également été clonés afin de vérifier leurs fonctions par complémentation en système hétérologue. Cette étude a permis de mettre en évidence les transporteurs de manganèse putatifs de nombreux organismes fongiques, ainsi que l'absence d'une famille de transporteurs impliquée dans les mouvements de manganèse chez S. cerevisiae / P. chrysosporium is a saprophytic fungus able to degrade many xenobiotics which makes it particularly attractive for applications in bioremediation. Several publications highlight the importance of metal homeostasis in the production of lignolytics enzymes. Indeed the presence of manganese is required for the production of manganese peroxidase. Conversely, deficiency allows the production of lignins peroxidases. Characterization of transporters involved in the control of manganese homeostasis has been only researched in the model S. cerevisiae. Analysis of putative manganese transporters of 26 fungal species representing 20 orders of fungus was used to form a repertory of 281 transporters of manganese. Phylogenetic analysis allowed to highlight that duplication process, but also deletion, had occurred particularly in S. cerevisiae. However this one is devoid of transporters belonging to the manganese Cation Diffusion Facilitator. Eleven transporters belonging to gene families in which manganese transporters have been found were identified in the P. chrysosporium?s genome. Expression level of these genes was examined particularly in ligninolytic condition. Transporters have also been cloned in order to verify their functions by complementation in heterologous system. This study allowed to identify putative manganese transporters of numerous fungal organisms and the lack of a transporters family involved in the manganese transport in S. cerevisiae

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and toxikology Student: Zuzana Matiašková Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Role of selected ABC and SLC transporters in transmembrane permeability of maraviroc: effect on transport in placenta Antiretroviral drug maraviroc is an inhibitor of CCR5-trophic HIV virus and belongs to the group of entry inhibitors. Nowadays, maraviroc is administered as part of combination antiretroviral therapy (cART) primarily in adults, children over the age of two and pregnant women to reduce the risk of transmission of HIV to the fetus. The knowledge of interactions of maraviroc with drug transporters in placenta is crucial for optimizing the therapy during pregnancy, both in terms of efficacy and potential adverse effects. Maraviroc is known substrate of ABCB1 transporter, which plays a protective role to the fetus by its efflux activity in the apical membrane of trophoblast. However, the results of recent study employing dually perfused human placenta suggest involvement of other transport mechanisms in the maraviroc transplacental pharmaocokinetics, especially those operating in the opposite direction to ABCB1. The aim of this study was to evaluate in vitro studies whether, besides ABCB1,...

Polar auxin transport provides essential directional and positional information for many developmental processes in plants. At the cellular level, it is realized by both passive diffusion and the active transport through the membrane proteins - AUX1/LAXes, PINs and ABCBs. The aim of this thesis was to characterize the role of ABCB1, ABCB4 and ABCB19 proteins in polar auxin transport using transformed tobacco BY-2 cell lines. It was shown that the plasma membrane (PM) localization of the ABCB1, 4 and 19 is not polar. The ABCB4 was also more stable on PM after the treatment with auxin influx inhibitors; making use of ABCB4-cell line helped to uncover new characteristics of markers of endocytosis - the FM- dyes. The induction of ABCB19 has led to a decrease in 3 H-NAA accumulation with characteristic auxin starvation phenotype, similar to PIN7 overexpressing cell line, that could be rescued in case of PIN7 cell line by application of the auxin efflux inhibitor NPA; however, the accumulation of auxin in ABCB19-overexpressing cell line was less sensitive to NPA and the rescue of the auxin starvation phenotype was ineffective. Importantly, unique property of the ABCB4 was demonstrated: It displayed dual, auxin-concentration-dependent auxin transport activity in Arabidopsis roots, tobacco BY-2 and yeast cells. The...

O desenvolvimento humano pode ser influenciado pelo ambiente. Estímulos recebidos ao longo da vida determinam seu progresso e sucesso. Estímulos positivos levam ao desenvolvimento de habilidades, melhorando funções cognitivas e da memória, enquanto estímulos negativos podem predispor a patologias como o estresse. Eventos estressantes durante a infância aumentam a predisposição para o desenvolvimento de transtornos psiquiátricos ao longo da vida. A separação materna, modelo animal de estresse pós-natal, promove diversas alterações comportamentais e encefálicas. Animais submetidos à separação materna apresentam comportamentos que mimetizam doenças psiquiátricas humanas. Por outro lado, diversos trabalhos sugerem que o enriquecimento ambiental pode ter efeito benéfico na reversão ou atenuação de modificações comportamentais e encefálicas promovidas por modelos animais de depressão, esquizofrenia, ansiedade e hiperatividade. Esses aspectos motivaram-nos a estudar se as alterações causadas por estresse podem ser revertidas ou atenuadas pelo enriquecimento do ambiente. Há evidências que sugerem um importante envolvimento de células gliais e de transportadores de glutamato presentes nessas células em modelos animais de transtornos psiquiátricos. Sendo assim, investigamos a expressão de mRNA e proteínas de dois transportadores de glutamato gliais e um neuronal, do receptor de glutamato AMPA, de marcadores gliais GFAP, S100?, glutamina sintase (GS) e do marcador de neurônios maduros NeuN na camada molecular e granular do giro denteado do hipocampo de ratos de 60 dias. Observamos que a separação materna diminui a expressão das proteínas GLAST, GLT-1, GS e NeuN, reduz a expressão dos genes Gria1 (AMPA) e S100?, e aumenta a expressão da proteína EAAC1 no giro denteado. Nossos dados sugerem uma reversão das alterações causadas pela separação materna em relação ao gene Gria1/AMPA e às proteínas GLAST, GLT-1 e EAAC1 após o enriquecimento ambiental. Portanto, o enriquecimento ambiental pode reverter as modificações causadas pela separação materna nas vias glutamatérgicas. Esses efeitos benéficos podem ser investigados para auxiliar no tratamento de transtornos psiquiátricos relacionados à separação materna. / Human development can be influenced by the environment. Stimuli received throughout life determine its progress and success. Positive stimuli lead to development of skills, improving cognitive and memory functions, while negative stimuli may predispose to pathologies such as stress. Stressful events during childhood increase the predisposition to psychiatric disorders throughout life. Maternal separation, an animal model of postnatal stress, promotes several behavioral and encephalic changes. Animals submitted to maternal separation stage behaviors associated with psychiatric diseases in humans. On the other hand, some researches have suggested that environmental enrichment may have some beneficial effects on the reversal or attenuation of behavioral and encephalic modifications promoted by animal models of depression, schizophrenia, anxiety and hyperactivity, which motivates us to study if these changes, stirred by this kind of stress, can be reversed or mitigated by environmental enrichment. There are evidences suggesting the involvement of glial cells and glutamate transporters existent in these cells in psychiatric disorders and animal models of these disorders. Therefore, we investigated mRNA and protein expression of two glial and one neuronal glutamate transporters, AMPA glutamate receptor, glial markers GFAP, S100?, glutamine synthase (GS), and the NeuN neuronal marker in the molecular and granular layer of the hippocampal gyrus in sixty-days-old rats. We observed that maternal separation decreases expression of GLAST, GLT-1, GS and NeuN proteins, reduces Gria1 (AMPA) and S100? gene expression, and increases EAAC1 protein expression in the dentate gyrus. After environmental enrichment, our data suggests a reversal of the maternal separation changes in the Gria1/AMPA gene and the GLAST, GLT-1 and EAAC1 proteins. Therefore, environmental enrichment may reverse the maternal separation changes in the glutamatergic pathways. These beneficial effects may be investigated to aid in the treatment of psychiatric disorders related to maternal separation.

Cryptococcus gattii é um dos principais agentes de infecção oportunista em todo o mundo. Esse fungo está presente no meio ambiente e, por isso, pode infectar diversos hospedeiros, inclusive seres humanos, nematóides e células ameboides. Acanthamoeba spp. são protozoários de vida livre que fagocitam diversos organismos, especialmente bactérias e fungos. Apesar de macrófagos e amebas serem evolutivamente distantes, eles compartilham diversas etapas comuns no processo de fagocitose e eliminação do patógeno. Além disso, existem teorias de que amebas e macrófagos possuem um ancestral comum. Para averiguar se essas duas células fagocíticas apresentam estratégias antifúngicas similares, nós analisamos o mecanismo de imunidade nutricional. Essa estratégia imunológica reduz a disponibilidade de nutrientes essenciais para o patógeno, inclusive metais de transição como o zinco. Neste trabalho, nós analisamos se há modulação da homeostase de zinco em Acanthamoeba castellanii durante sua interação com C. gattii. Testes de fagocitose e taxa de replicação intracelular (IPR) realizados através da interação de amebas com a linhagem selvagem (WT) e mutante do gene ZIP1 de C. gattii. O mutante utilizado (zip1Δ) é caracterizado pela sua incapacidade de crescer sem a presença de zinco. Nós observamos que a linhagem mutante foi mais fagocitada por células de A. castellanii comparado com WT. Também, o teste de IPR mostrou que a atividade antifúngica das células hospedeiras apresentou-se mais efetiva contra as células mutantes. Entretanto, a sobrevivência de zip1Δ foi maior quando zinco extracelular (10 M) foi adicionado ao meio de interação. Esses resultados sugerem que as células criptocócicas internalizadas podem estar sofrendo uma privação da disponibilidade de zinco no interior do fagossomo. Para analisar alterações nos transportadores de zinco das células hospedeiras durante sua interação com C. gattii, análises de PCR quantitativo em tempo real (RT-qPCR) foram realizadas para os transportadores de zinco das famílias ZIP e ZnT. Uma intensa modulação de alguns genes foi observado após 3 e 24 horas pós-infecção. Além disso, análises de citometria de fluxo mostraram que os níveis de zinco livre das amebas estavam reduzidos devido a presença do fungo. Esses resultados sugerem que amebas podem modular a disponibilidade de zinco, afim de prejudicar o patógeno. / Cryptococcus gattii is one of the most important agents of opportunistic infections worldwide. They are found in the environment, where it can interact with different host types, including humans, nematodes and amoebic cells. Acanthamoeba spp. are free-living protozoa that basically feed on bacteria and yeast through phagocytosis. Macrophages and amoebae, although evolutionarily distant, share conserved mechanisms related to steps of phagocytosis and microbial killing. In addition, it has been hypothesized that amoeba and macrophage have a common ancestor. To investigate if there are similar antifungal strategies between both cellular types, we analyzed the nutritional immunity mechanism. It is a process defined as a reduction of essential nutrients availability to the pathogen, such as zinc. In this context, we investigate if amoeba cells are able to modulate zinc homeostasis during the interaction with C. gattii. Phagocytosis and intracellular replications (IPR) analysis performed through the interaction between amoebae and wild-type (WT) and mutant for the ZIP1 gene (zip1Δ) strains of C. gattii. The mutant is unable to grow in absence of zinc. We found that zip1Δ strain is more readily engulfed by A. castellanii cells compared to WT. In addition, IPR analysis showed that the antifungal activity of such host cells was more effective against the mutant cells. However, the mutant strain survival was increased when additional extracellular zinc (10 M) was added to the interaction medium. This data suggests that engulfed cryptococcal cells might have been experiencing a deprivation of zinc inside the phagosome. To further evaluate alterations of zinc transporters in host cells due to cryptococcal infection, RT-qPCR analysis was performed for the ZIP and ZnT zinc transporter families. An intense modulation of some genes was found after 3 and 24 hours’ post-infection. Furthermore, flow cytometry analysis showed that free zinc levels from amoebae are reduced by the cryptococcal presence. These results indicate that amoebae are able to modulate zinc availability to harm the pathogen.

La zéaralénone (ZEN) est une mycotoxine produite par des Fusarium qui contaminent les cultures céréalières. Oestrogéno-mimétique et perturbateur endocrinien, ses effets toxiques concernent l'appareil reproducteur. En amont de l'évaluation du risque lié à une exposition à de faibles doses de ZEN, nous nous sommes intéressés à l'effet de la ZEN sur le niveau d'expression de transporteurs ABC majeurs. Ces pompes d'efflux sont présentes dans les barrières de l'organisme (notamment les barrières testiculaires et placentaires) où elles jouent un rôle dans la protection des tissus contre la toxicité de leurs substrats xénobiotiques. Dans ce travail nous avons d'abord caractérisé le métabolisme et la distribution tissulaire de la ZEN chez le rat, puis avons évalué son effet respectivement à court et long terme sur l'expression des transporteurs ABC après une exposition gestationnelle et néonatale. Nos résultats mettent en évidence des différences de comportement toxicocinétique de la ZEN en fonction du genre et du statut hormonal, et une réelle exposition fœtale et néonatale via la mère. La ZEN module l'expression des transporteurs ABC majeurs in vivo (dans les organes maternels, le foie foetal, le testicule du jeune adulte exposé J1-J5). Les résultats obtenus sur modèles in vitro (lignées sertolienne et placentaire) suggèrent que ces modulations sont liées en partie à l'interaction de la ZEN avec les récepteurs aux oestrogènes. Les conséquences d'une modulation de l'expression des transporteurs ABC induite par la ZEN pourraient être dramatiques pour le développement et la santé des individus à l'âge adulte et doivent être évaluées / Zearalenone (ZEN) is a mycotoxin produced by Fusarium that infect cereal crops. This Estrogenmimetic and endocrine disruptor affects the reproductive system. Upstream of the risk assessment of exposure to low doses of ZEN, we are interested in the effect of ZEN on the expression level of major ABC transporters. These efflux pumps are present in the barriers of organism (including testicular and placental barriers), where they protect tissues against the toxicity of their xenobiotic substrates. In this work, we first characterized the metabolism and tissue distribution of ZEN in rat and then evaluated respectively its short and long-term effect on ABC transporters expression after gestational and neonatal exposure. Our results highlight differences in the toxicokinetic behavior of ZEN by gender and hormonal status, and fetal and neonatal real exposure via the mother. ZEN modulates the expression of major ABC transporters in vivo (in the maternal organs, fetal liver, testis of young adult exposed J1-J5). The results of in vitro models (sertoli and placental cell lines) suggest that these variations are partly due to the interaction of ZEN with the estrogen receptors. The consequences of expression modulations of ABC transporters induced by ZEN could be dramatic for the development and health of individuals in adulthood and should be evaluated

Linfomas pertencem a um grupo de neoplasias em que há proliferação monoclonal de linfócitos malignos, sendo uma das neoplasias mais frequentemente diagnosticadas em cães. Podem ser classificados quanto à forma anatômica em multicêntrico, mediastinal, digestório e extranodal. Dentre os extranodais, os linfomas cutâneos são classificados histologicamente como epiteliotrópicos e não epiteliotrópicos e são predominantemente de imunfenótipo T, com raros casos do tipo B. A principal característica histopatológica do linfoma epiteliotrópico em cães é o tropismo das células neoplásicas pela epiderme, mucosa ou estruturas anexas, enquanto o linfoma não epiteliotrópico é caracterizado pela infiltração dérmica e subcutânea sem invasão das estruturas anexas. Os linfomas cutâneos caninos têm progressão rápida, são considerados bastante agressivos e com mau prognóstico, com baixa taxa de resposta à quimioterapia. Um dos fatores que podem contribuir para isso é a resistência das células a múltiplas drogas e entre esses mecanismos de resistência estão o efluxo de drogas do meio intracelular para o extracelular por meio dos transportadores da família ABC, como a glicoproteína-P, MRP (multiple resistance protein) e BCRP (breast câncer resistance protein) e da LRP (lung resistance protein), uma proteína vault responsável pelo transporte nucleocitoplasmático. O objetivo deste estudo foi caracterizar imunofenotipicamente os linfomas cutâneos, a proliferação celular por meio do marcador Ki67, a expressão das proteínas de resistência glicoproteína-P, MRP, BCRP e LRP e avaliar a relação dessas proteínas com a sobrevida dos animais. Foi realizado um estudo retrospectivo com 21 casos de cães linfomas cutâneos com diagnóstico histopatológico. A técnica de imunoistoquímica foi utilizada para determinar a imunofenotipagem dos linfomas pelos marcadores CD3 e CD20, a proliferação celular por Ki67 e a expressão de glicoproteína-P, MRP, BCRP e LRP. Dos 21 animais, 38% tiveram diagnóstico histopatológico de linfoma epiteliotrópico, 52% eram linfomas não epiteliotrópicos, 5% dos casos de linfoma não tiveram epiteliotropismo definido e 5% foram classificados como neoplasia de células redondas. O imunofenótipo predominante foi CD3+CD20- (76%), 15% dos casos eram CD3-CD20+ e 9% eram CD3+CD20+. A mediana de células marcadas para Ki67 foi de 31%. Com relação aos marcadores de resistência a múltiplas drogas, a mediana da marcação de glicoproteína-P foi de 40%, a de LRP foi de 65% enquanto para MRP e BCRP, 19% e 23%, respectivamente. Os linfomas cutâneos não epiteliotrópicos foram mais frequentes que os epiteliotrópicos e o imunfenótipo predominante foi o T. A ocorrência de linfócitos CD3-CD20+ e CD3+CD20+ indica a necessidade de mais estudos e um painel mais amplo de anticorpos para subtipagem desses linfomas. A glicoproteína-P teve maior expressão nos linfomas não epiteliotrópicos do que nos epiteliotrópicos e não houve correlação entre as proteínas de resistência e o tempo de sobrevida dos animais, sugerindo que, além da biologia da neoplasia, outros mecanismos de resistência a múltiplas drogas diferente dos estudados possam ter um papel relevante na baixa resposta do linfoma cutâneo à quimioterapia. / Lymphoma is a group of blood cell tumors that develop from monoclonal proliferation of malignant lymphocytes. Lymphoma is the most frequent neoplasia in dogs and can be anatomically classified in multicentric, mediastinal, digestive and extranodal. Cutaneous lymphomas an extranodal type of lymphoma are classified histologically in epitheliotropic and non-epitheliotropic and are predominantly of T-cell immunophenotype, and rare cases of B cell phenotype. The main histopathological characteristic of epitheliotropic lymphoma in dogs is the tropism of neoplastic cells by the epidermis, mucosa or adjacent structures, while non-epitheliotropic lymphoma is characterized by dermal and subcutaneous infiltration without invasion of adjacent structures. Canine cutaneous lymphomas have rapid progression, are considered very aggressive and have poor prognosis. These dogs, usually have a low rate of response to chemotherapy which can be associated to an antineoplastic resistance. Among mechanisms of resistance are efflux of drugs from intracellular to extracellular through ABC family transporters such as P-glycoprotein, MRP (multple resistance protein) and BCRP (breast cancer resistance protein) and LRP (lung resistance protein), a vault protein responsible for nucleocytoplasmic transport. The aim of this study was to characterize immunophenotypically cutaneous lymphomas, measure cell proliferation using the Ki67 marker, the expression of resistance proteins P-glycoprotein, MRP, BCRP and LRP and to evaluate the relationship of these proteins with the survival of the animals. A retrospective study was performed with 21 cases of dogs with cutaneous lymphoma with histopathological diagnosis. Immunohistochemical was used to immunophenotyping of lymphomas by CD3 and CD20 markers, Ki67 cell proliferation, and P-glycoprotein, MRP, BCRP and LRP expression. Of the 21 animals, 38% had histopathological diagnosis of epitheliotropic lymphoma, 52% were non-epitheliotropic lymphomas, 5% of lymphoma cases had no definition and 5% were classified as round cell neoplasia. The predominant immunophenotype was CD3+CD20- (76%), 15% of the cases were CD3-CD20 + and 9% were CD3 + CD20 +. The median of cells labeled for Ki67 was 31%. Regarding the markers of resistance to multiple drugs, the median of the P-glycoprotein label was 40%, which 65% of LRP while for MRP and BCRP, 19% and 23%, respectively. Non-epitheliotropic cutaneous lymphomas were more frequent than epitheliotropic lymphomas and the predominant immunophenotype was T. The occurrence of CD3-CD20+ and CD3+CD20+ lymphocytes indicates the need for further studies and a wider panel of antibodies for subtyping these lymphomas. P-glycoprotein had higher expression in non-epitheliotropic lymphomas than in epitheliotropic lymphomas and there was no correlation between resistance proteins and survival time of the animals, suggesting that in addition to the biology of neoplasia other mechanisms of resistance to multiple drugs different from those studied may play a relevant role in the low response of cutaneous lymphoma to chemotherapy.

Thesis (M.D.) -- University of Texas Southwestern Medical Center at Dallas, 2007. / Vita. Bibliography: pp.28-30

Transporters dynamically expressed at the mammary gland transport critical nutrients into the breast milk of nursing mothers to meet the nutritional demands of the suckling infant. However, xenobiotics may interact with these transporters to potentially alter the nutrient composition of milk and compromise neonatal nutrition. The aim of the present study was to quantitatively evaluate the constitutive expression of various nutrient transporters in whole mammary gland tissue and mammary epithelial organoids (MEO) isolated from female Sprague-Dawley rats at various stages of pregnancy, lactation, and involution. Furthermore, the studys aim was to determine if appropriately cultured mammary epithelial organoids (MEO) maintain in vivo transporter expression to lay down critical groundwork for the development of an in vitro screening tool assessing xenobiotic-nutrient transporter interactions. The following transporters were evaluated using quantitative real-time reverse transcription polymerase chain reaction (QRT-PCR): multidrug resistance protein (Mdr) 1a, 1b; multidrug resistance-like protein (Mrp) 1; organic cation transporter (Oct) 1; organic cation/carnitine transporter (Octn) 1, 2, and 3; concentrative nucleoside transporter (Cnt) 1, 2, and 3; equilibrative nucleoside transporter (Ent) 1, 2, and 3; nucleobase transporter (Ncbt) 1 and 2; oligopeptide transporter (Pept) 1 and 2; methotrexate carrier (Mtx) 1; divalent metal transporter (Dmt) 1; and the milk protein ?-casein. Transporter expression patterns in MEO differed from whole tissue for ?-actin, Mdr1a, Mdr1b, Oct1, Octn3, Ent3, Cnt1, Cnt3, Ncbt1, Pept2, Mtx1, and ?-casein. This brings into question whether whole mammary gland tissue is truly appropriate for an understanding of transporter expression in the mammary epithelium. Nevertheless, four general transporter expression patterns emerged in isolated MEO: decline throughout lactation (Mdr1a, Mdr1b, Mrp1 & Dmt1), increase throughout lactation (Cnt1 & Octn3), increase in early lactation (Oct1, Octn2, Ent1, Cnt2, Cnt3, Pept2 & Mtx1) and constant expression throughout lactation (Octn1, Ent2, Ent3, Ncbt1, Ncbt2 & Pept1). These expression patterns will provide insight into the critical windows of nutrient delivery to the breast milk to provide adequate nutritional stimuli to the suckling infant. Furthermore, MEO cultured in an extracellular matrix-rich environment maintained transporter expression at the mRNA level, which underscores the potential of the primary MEO in vitro model system as a screening tool for xenobiotic-transporter interactions at the mammary gland. Transporter expression patterns in MEO were unique for each transporter evaluated. This information accompanied by an in vitro screening tool may allow for predictions of xenobiotic interference with breast milk composition to help safeguard infant health.