La neurogenèse adulte permet la formation de nouveaux neurones dans les bulbes olfactifs de la souris. Les propriétés des cellules souches neurales situées dans la zone sous-ventriculaire (ZSV) et des précurseurs sont régulées par la niche contenant des cellules de support et une matrice extracellulaire (MEC). Des facteurs contenus dans le liquide cérébrospinal (LCS), produits par les plexus choroïdes (PC), contrôlent aussi la niche. L'homéoprotéine Otx2 est secrétée dans le LCS par les PC, et internalisée spécifiquement par certaines cellules du parenchyme cérébral. Otx2 est impliquée dans différentes étapes du développement du cerveau, dont celui des PC, et peut agir de manière non-cellulaire-autonome. Ma thèse vise à comprendre comment Otx2 régule les fonctions des PC et participe à la neurogenèse adulte. Grâce à des études génomiques d'un modèle murin knockdown (KD) d'Otx2 dans les PC adultes, nous avons montré que (i) les PC de différents ventricules présentent des profils d'expression différents (ii) le KD d'Otx2 modifie l'expression de gènes impliqués dans des fonctions importantes des PC (iii) la dérégulation de certains gènes après KD est spécifique d'un type de PC. Une étude protéomique suggère (iv) qu'Otx2 pourrait être impliquée à d'autres niveaux que la régulation transcriptionnelle. L'étude de la neurogenèse adulte dans des modèles murins KD d'Otx2 nous a permis de montrer que (i) l'expression d'Otx2 dans les PC régule la neurogenèse adulte (ii) Otx2 transfère dans les astrocytes de la ZSV (iii) le transfert d'Otx2 est suffisant pour réguler la neurogenèse (iv) le KD d'Otx2 dans les PC modifie l'expression de protéines de la MEC secrétées par les astrocytes. / Adult neurogenesis in mice involves neural stem cells in the subventricular zone (SVZ) whose progenitors integrate into the olfactory bulbs. The neurogenic niche, which contains supporting cells and extracellular matrix (ECM), regulates the properties (proliferation, migration and differentiation) of progenitor cells. This niche is influenced by factors from cerebrospinal fluid (CSF), which is produced by the choroid plexus (CP) in the brain ventricles. The Otx2 homeoprotein transcription factor is secreted into CSF by CP, and taken up by a specific subset of cells within the brain parenchyma. Otx2 is involved in various stages of brain development, including CP development, and has non-cell autonomous functions. The aim of my thesis is to understand how Otx2 regulates adult CP function and participates in adult SVZ neurogenesis. Through genomic studies, we investigated the consequence of Otx2 knockdown (KD) in adult CP and found: (i) adult CP from different ventricles exhibit different expression profiles; (ii) Otx2 KD alters the expression of genes with important CP functions; and (iii) deregulation of certain genes after Otx2 KD can be CP specific. Through proteomics studies, we found that (iv) adult Otx2 could be involved in functions beyond transcriptional regulation, such as RNA processing.To evaluate the role of Otx2 in SVZ neurogenesis, we also used Otx2 KD mouse models. We found that: (i) the expression of Otx2 in CP regulates adult neurogenesis; (ii) Otx2 transfers to astrocytes of the SVZ; (iii) Otx2 transfer is sufficient to regulate adult neurogenesis; and (iv) Otx2 KD in CP alters the expression of ECM proteins secreted by astrocytes in the neurogenic niche.

Le système nerveux central est un site particulier vis-à-vis du système immunitaire, en raison de la présence de la barrière hémato-encéphalique et de la barrière sang-liquide céphalorachidien. Les plexus choroïdes ont été considérés comme une voie d’entrée de certains lymphocytes dans le système nerveux central. Et le liquide céphalo-rachidien a été considéré comme une voie préférentielle de circulation des cellules immune au cours de la surveillance neuro-immunitaire de l’ensemble des compartiments cérébraux, puisque le LCR circule des ventricules, aux espaces sous-arachnoïdiens ainsi qu’aux velum et citernes internes. L’implication du système plexus choroïdes-liquide céphalorachidien dans l’infiltration cellulaire et la distribution des différents effecteurs immuns a été évaluée. Premièrement, nous avons analysé la relation entre le LCR et la répartition des différentes cellules immune au sein du système nerveux central, dans deux modèles d’encéphalite autoimmune expérimentale, utilisé comme modèle de la sclérose en plaque. Deuxièmement, nous avons recherché les partenaires moléculaires pouvant être impliqués dans la mise en place d’une inflammation, tels que les molécules d’adhésion exprimés par l’épithélium choroïdien, et les chimiokines pouvant être sécrétées dans le liquide céphalorachidien. Nos résultats identifient les plexus choroïdes comme une source de chimiokines sécrétées dans le liquide céphalorachidien, ce dernier orchestrant la distribution des différents effecteurs immunitaire au cours de l’inflammation / The central nervous system is an immunologically specialized site, because of the blood-brain barrier and the blood-cerebrospinal fluid barrier. The choroid plexuses had been considered as a preferential site for the entry of lymphocytes into the CNS. And the cerebrospinal fluid has been considered as a preferential pathway of circulation for immune cells during physiological neuroimmune surveillance, in all cerebral compartments, as the cerebrospinal fluid circulates from the ventricles to the subarachnoid spaces as well as the velum and internal cisterns. We evaluate the involvement of the choroid plexus-cerebrospinal fluid system in the cerebral infiltration and distribution of immune cells in CNS inflammation. First we realized a time course analysis of the different type of immune cell association with the CSF-containing compartments in two experimental autoimmune encephalomyelitis, models of multiple sclerosis. Secondly, we analyzed the molecular partners that could be involved in CNS inflammation development, such as adhesion molecules expressed on the choroid plexus, and chemokines secreted into the cerebrospinal fluid. Results identified the choroid plexuses as a source of chemokines, released into the cerebrospinal fluid that orchestrates the immune cell invasion during CNS inflammation

Plus de 50 % des handicaps neurodéveloppementaux sont dus à une exposition périnatale à des stress toxiques ou oxydants. Comprendre comment le cerveau est protégé au cours du développement périnatal et pourquoi ses mécanismes de défense sont dépassés lorsque l’enfant est soumis à un stress important est donc crucial. La barrière sang – liquide céphalorachidien (LCR), localisée au niveau des plexus choroïdes, présente une capacité de détoxification élevée et pourrait donc avoir un rôle prépondérant dans la protection du cerveau au stade périnatal. Nous avons étudié la capacité de plusieurs enzymes choroïdiennes à protéger l'environnement liquidien cérébral pendant la période postnatale chez le rat, et évalué si leurs activités pouvaient être induites par la voie du nuclear factor erythroid-2-related factor 2 (Nrf2). Le facteur Nrf2 peut en effet moduler l’expression de différents gènes codant pour des enzymes de détoxification. Nous avons montré que les glutathion transférases (Gst) et les glutathion peroxydases (Gpx), intervenant respectivement dans l’inactivation des molécules toxiques et dans la régulation du stress oxydant, présentaient des activités choroïdiennes élevées pendant la période postnatale, et avons caractérisé fonctionnellement leur capacités de neuroprotection. Le traitement des ratons avec du diméthylfumarate (DMF), inducteur de la voie Nrf2, induit la migration nucléaire de Nrf2, augmente l’activité choroïdienne Gst, et réduit de 40 % le passage cérébral de toxiques substrats des Gst. Ces données montrent la capacité neuroprotectrice précoce des plexus choroïdes, et indique qu’elle peut être induite pharmacologiquement / More than 50 % of intellectual or sensory-motor deficits in children are due to perinatal exposure to oxidative stress or toxicants. Understanding brain protection mechanisms during development is crucial to design therapeutic strategies to address these disabilitating disorders. The choroid plexuses, forming an interface between the blood and the cerebrospinal fluid (CSF), have a high detoxifying capacity, suggesting their involvement in neuroprotection. The nuclear factor erythroid-2-related factor 2 (Nrf2) pathway can modulate the expression of several genes encoding for antioxidant proteins and detoxifying enzymes. We studied the ability of several choroidal enzyme families to protect the brain fluid environment during the postnatal period in rat and explored whether this protection can be enhanced by Nrf2 pathway. We focused on glutathione transferases (Gsts), which conjugate toxic compounds to glutathione, and glutathione peroxidases (Gpxs), which detoxify reactive oxygen species. Gst and Gpx specific activities were high during the postnatal period in choroid plexuses compared to the cerebral cortex, and their neuroprotective functions were efficient. The Nrf2 factor is expressed in choroid plexuses during the perinatal period. Treatment of rat pups with Nrf2 activator dimethylfumarate induced Nrf2 nuclear translocation and increased Gst activities in choroid plexus tissues. The dimethylfumarate treatment resulted in a large decrease of the blood-to-CSF permeability of a prototypical Gst substrate. These data substantiate the early neuroprotective functions of choroid plexuses, which can be enhanced upon treatment with clinically used pharmacological compounds

No description available.

Made available in DSpace on 2015-07-22T20:49:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-28 / O objetivo deste trabalho é avaliar as anormalidades da esclera, coroide e retina de coelhos induzidas pela dieta hipercolesterolêmica, além da possibilidade de prevenção dessas anormalidades com administração sistêmica de rosiglitazona. Para isto, 54 coelhos new zealand foram distribuídos em quatro grupos: grupo-controle (GC) recebeu dieta normal; grupo 1 recebeu dieta hipercolesterolêmica; grupo 2 recebeu dieta hipercolesterolêmica associada à administração diária de 3 mg de rosiglitazona a partir do 14º dia do início do experimento; e grupo 3 recebeu dieta hipercolesterolêmica associada à administração diária de 3 mg de rosiglitazona desde o início do experimento. Os coelhos foram pesados e submetidos à dosagem sérica de colesterol total, triglicerídeos, high density lipoprotein (HDL) colesterol e glicemia de jejum no início do experimento, no 14º dia e no momento da eutanásia (42º dia). A esclera e coroide foram submetidas à análise histológica e histomorfométrica. A retina foi submetida à análise imuno-histoquímica com o anticorpo monoclonal anticalretinina (CR) e anticorpo anti-glial fibrillary acidic protein (GFAP). Quando positivo para o marcador anticalretinina, duas análises quantitativas foram realizadas. Na primeira, foram contadas todas as células ganglionares imunorreativas. Na segunda, todas as células e elementos celulares imunorreativos foram avaliados pelo exame de morfometria de cores. Os dados foram analisados pelo teste nãoparamétrico de Kruskal-Wallis e teste de Shapiro-Wilks-Testand. Valores abaixo de 0,05 foram considerados estatisticamente significantes. Os resultados referentes ao peso demonstraram significativo aumento nos grupos 1 e 3 em relação ao GC no 14º dia (p<0,009), enquanto no 42º dia os grupos 1, 2 e 3 apresentaram representativamente mais peso que o GC (p<0,023). Quanto às variáveis laboratoriais, destacaram-se o aumento significativo da glicose e colesterol total de G1 em relação ao controle (p<0,001), assim como o acentuado aumento da HDL no G3 em relação aos demais grupos (p<0,001), no 14º dia. A HDL manteve-se expressivamente elevada no G3 em relação aos demais grupos no momento da eutanásia (p<0,001). À análise histomorfométrica da esclera e coroide obteve-se normalidade do GC. Por outro lado, o G1 mostrou marcante aumento da espessura da esclera e coroide em relação ao GC (p=0,008), enquanto que no G3 houve espessamento de esclera e coroide menor que no G1 (p=0,048). Elevado número de histiócitos foi observado na parede escleral do grupo submetido à dieta hipercolesterolêmica (G1), seguido de forma decrescente por G2, G3 e GC. A análise imuno-histoquímica da retina com o anticorpo monoclonal anticalretinina ressaltou número mais alto de células ganglionares imunorreativas no G1 que no G3 (p=0,002). O exame de morfometria de cores revelou significativa imunorreatividade das células e elementos celulares do G1 em relação aos outros grupos (p<0,001). Nesta análise evidenciou-se também acentuada imunorreatividade das células e elementos celulares de G2 e G3 em relação ao GC (p≤0,002). GFAP foi negativo em todos os grupos. Neste modelo, os achados permitem concluir que a hipercolesterolemia provoca anormalidades precoces histomorfométricas e imuno-histoquímicas do complexo esclerocoriorretiniano; e a ativação dos receptores do PPAR gama-ocular, a partir da dieta oral de rosiglitazona, foi efetiva em atenuar tais anormalidades nessas estruturas. / The purpose of this study is to evaluate scleral, choroid and retinal abnormalities in rabbits induced by a hypercholesterolemic diet and the prevention of these abnormalities after oral administration of rosiglitazone in rabbits. Fifty-four new zealand rabbits were divided into four groups: the control group (CG) was fed a normal diet; group 1 G1), a hypercholesterolemic diet; group 2 (G2) a hypercholesterolemic diet associated with daily administration of 3 mg of rosiglitazone from day 14 after the beginning of the diet; and group 3 G3), a hypercholesterolemic diet associated with daily administration of 3 mg of rosiglitazone since the beginning of the experiment. The rabbits were weighed and underwent the following examinations: seric dosages of total cholesterol, triglycerides, cholesterol HDL, and fasting glycemia at the beginning of the experiment, on the 14th day and on the 42nd, the euthanasia day. The sclera and choroid underwent histologic and histomorphometric analyses and the retina underwent immunohistochemical analysis with anti-calretinin (CR) and anti-glial fibrillary acidic protein (GFAP) antibody. When positive for the anti-calretinin marker, two quantitative analyses were performed. In the first analysis, all immunoreactive ganglion cells were counted. In the second analysis, all immunoreactive cells and cell elements were studied with the color morphometry method. The data were evaluated using the nonparametric Kruskal-Wallis and the Shapiro – Wilk tests. Values of p<0.05 were considered statistically significant. The results obtained showed a significant weight increase in Groups 1 and 3 in relation to CG on Day 14 (p<0.009). Additionally, a significant weight increase was observed in G1, G2 and G3 in relation to CG on Day 42 (p<0.023). The lab results showed a significant increase in glucose and total cholesterol in G1 in relation to CG (p<0.001) on Day 14, as well as a significant HDL increase in G3, when compared with the other groups (p<0.001) on Day 14. HDL in G3 was significantly high when compared to the other groups, on the euthanasia day (p<0.001). The results obtained regarding weight showed a significant increase in Groups 1, 2 and 3 in relation to CG on Day 14 (p<0.01) and Day 42 (p<0.02). The lab results showed a significant increase in glucose and total cholesterol in Groups 1, 2 and 3 in relation to CG (p<0.01) on Day 14, as well as a significant increase in HDL in G3 when compared with the other groups, on euthanasia day (p<0.01). The histomorphometric analysis of CG sclera and choroid presented normal results. Conversely, G1 showed a significant increase in sclera and choroid thickness in relation to CG (p= 0,008), whereas G3 showed thickness lower than in G1 (p=0,048). A larger number of histiocytes were observed on the scleral wall of the group that was fed the hypercholesterolemic diet (G1), followed, in a descending order, by groups 2 and 3, and the control group. The immunohistochemical analysis of the retina with the anti-calretinin monoclonal antibody showed that G1 presented a larger number of immunoreactive ganglion cells than G3 (p = 0.002). The color morphometry showed significant immunoreactivity of G1 cells and cell elements when compared with the other groups (p<0.001). A significant immunoreactivity of G2 and G3 cells and cell elements in relation to CG was also observed (p<0.002). GFAP results were negative in all groups. The findings of this proposed study model suggest that hypercholesterolemia induces early histomorphometric and immunohistochemical abnormalities in the sclerochorioretinal complex and that the activation of PPAR gamma in ocular cells attenuated these abnormalities with the administration of the oral rosiglitazone diet. / TEDE / BV UNIFESP: Teses e dissertações

Orientador: José Andrés Yunes / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T16:36:11Z (GMT). No. of bitstreams: 1 Conte_AnaLuizaOngaroSeidinger_D.pdf: 7461860 bytes, checksum: a44751dc1556a30853dcde70f024aed9 (MD5) Previous issue date: 2012 / Resumo: O gene supressor de tumor TP53 é um dos mais bem caracterizados genes cujo papel na etiologia é conhecido tanto em tumores hereditários como esporádicos. Mutações germinativas neste gene normalmente estão associadas à Síndrome de Li-Fraumeni, uma síndrome de predisposição ao câncer cujos portadores apresentam alto risco de desenvolvimento de uma variedade de tumores ao longo da vida. Uma mutação específica deste gene é altamente prevalente na população brasileira, chegando a estar presente em 0.3% da população saudável. Esta mutação, a R337H, não foi descrita como uma mutação associada a um amplo espectro tumoral e, sim, como uma mutação tecido-específica associada somente ao desenvolvimento do tumor do córtex da adrenal (TCA). Entretanto, algumas evidências indicavam que ela poderia contribuir para a etiologia de outros tumores, além do TCA. A R337H foi encontrada em 06 famílias com Síndrome de Li- Fraumeni like e em 2.4% de pacientes diagnosticadas com câncer de mama. Com o objetivo de obter maiores evidências sobre a contribuição da R337H na etiologia de outros tumores além do TCA, investigamos a prevalência desta mutação em 493 pacientes diagnosticados com diferentes tumores pediátricos. Além disto, buscamos investigar alterações cromossômicas que poderiam estar associadas ao processo de tumorigênese em portadores desta mutação. Os resultados mostraram que além do TCA e câncer de mama, a R337H está fortemente associada ao carcinoma de plexo coroide (69%) e ao osteossarcoma (7%) na faixa etária pediátrica. Em nossa instituição, foi observado um aumento da incidência relativa do carcinoma de plexo coroide em relação ao papiloma de plexo coroide. Uma deleção do gene TP53 em células do sangue periférico sob a forma de um mosaico foi identificada nos pacientes portadores da R337H que desenvolveram o TCA. Os dados mostraram que se trata de uma deleção intersticial do cromossomo 17, a qual especula-se ter ocorrido durante o período embrionário. Os resultados sobre a prevalência desta mutação em diferentes tumores pediátricos poderão contribuir para um adequado aconselhamento genético das famílias em que a R337H está presente. Adicionalmente, o mosaicismo encontrado nos portadores da R337H que desenvolveram o TCA nos permitiu formular uma hipótese sobre a tumorigênese adrenocortical associada à R337H e talvez possa também contribuir para a futura compreensão do comportamento oncogênico desta mutação / Abstract: The tumor suppressor gene TP53 is a well characterized gene whose role in the etiology of hereditary and sporadic cancer is well established. Germline mutations in this gene are usually associated with the Li-Fraumeni Syndrome (LFS), a cancer predisposition syndrome in which individuals are at a high risk to develop a wide spectrum of tumors during their lives. A specific mutation of TP53 gene is highly prevalent among the Brazilian population, reaching 0.3% of healthy individuals. This mutation, R337H, was not described as a mutation associated to a wide spectrum of tumors but as a tissue-specific mutation, predisposing individuals only to adrenocortical tumors (ACT). However, some evidences have indicated that it could contribute to the etiology of other tumors besides ACT. The R337H was found in six families diagnosed with LFS-like and also in 2.4% of patients diagnosed with breast cancer. In order to obtain more evidence regarding the role of R337H in the etiology of tumors besides ACT, we have investigated the prevalence of this mutation among 493 pediatric patients diagnosed with cancer. Moreover, we have looked for chromosomal changes potentially involved in tumorigenic process among R337H carriers. Our results demonstrated that, besides ACT and breast cancer, the R337H mutation is strongly associated to choroid plexus carcinoma (69%) and osteosarcoma (7%) in the pediatric age. At our institution it was observed a raise in the relative incidence of choroid plexus carcinoma to choroid plexus papilloma. It was identified a mosaic of cells presenting TP53 deletion in peripheral blood of R337H carriers who developed ACT. Our data showed that is an interstitial deletion affecting the short arm of chromosome 17 that may have occurred during the embryonic life. The results regarding the R337H prevalence among different pediatric tumors may potentially contribute to a more accurate genetic counseling of families bearing this mutation. Additionally, the TP53 deletion found in R337H carriers who developed ACT prompted us to formulate a hypothesis on the adrenocortical tumorigenesis associated to this mutation. Finally, our findings may be useful to better understand the oncogenic behavior of this mutation / Doutorado / Genetica Animal e Evolução / Doutor em Genetica e Biologia Molecular

Les interfaces sang-cerveau comme la barrière hémato-encéphalique (BHE), les plexus choroïdes (PC) ou les organes circumventriculaires (OCV), constituent des barrières physiologiques nécessaires au fonctionnement du système nerveux central. Ces barrières sont à la fois « physiques », constituées de jonctions serrées, et « enzymatiques ». Longtemps considérées comme immatures chez le fœtus, ces barrières sont en réalité présentes précocement au cours du développement. Leurs caractéristiques et leurs propriétés restent peu connues chez l'homme. Nos travaux montrent que les PC expriment, précocement au cours du développement, des protéines de jonction serrée, les claudines (CLDN) 1, 2 et 3 chez le rat et chez l'homme. Cette expression est dynamique au cours du développement avec une apparition progressive de la CLDN2 pouvant avoir un lien avec la sécrétion du liquide céphalo-rachidien. Les CLDN 1 et 3 sont identifiées chez le fœtus humain au niveau de l'organe sous-commissural (OSC), un des OCV. La CLDN5 est exprimée précocement au niveau de la BHE chez le rat et chez l'homme et son expression est altérée dans un modèle d'excitotoxicité néonatale. Nos travaux montrent également que l'analyse du profil des CLDN est utile en pathologie tumorale notamment dans la compréhension et le diagnostic de tumeurs développées à partir des PC ou de l'OSC. Enfin, diverses enzymes antioxydantes et de détoxification dont l'époxyde hydrolase microsomale sont exprimées à 22 semaines d'aménorrhée principalement au niveau des PC du fœtus humain. Ces données suggèrent des capacités de détoxification des PC, d'installation précoce au cours du développement chez l'homme / Blood-brain interfaces including blood-brain barrier (BBB), choroid plexuses (CP) or circumventricular organs (CVO) are physiological barriers required for brain homeostasis. These barriers are “physical”, with tight junctions, and “enzymatic”. Though long considered immature in fetuses, these barriers are present from an early stage of development. Their characteristics and their properties are largely unknown in humans. Our work demonstrates that CP express tight junction-associated proteins claudins (CLDN) 1, 2, and 3 at early stages of development in rat and human. This expression is dynamic during development as shown by the progressive increase of CLDN2 immunopositivity that may follow increase in cerebrospinal fluid secretion. CLDN 1 and 3 are identified in human fetal subcommissural organ (SCO), one of the CVO. CLDN5 is early expressed in rat and human BBB and its expression is disrupted by excitotoxic injury. Our work also shows that CLDN immunohistochemical profile is useful in tumoral pathology, notably to better understand and diagnose tumors arising from CP or the SCO. Finally, various antioxidant and detoxifying enzymes such as the microsomal epoxide hydrolase are expressed at 22 weeks of gestation in the human fetus, mainly in CP. These results suggest a high detoxifying capacity for the CP during development in humans

Abstract Collagen XVIII is a multidomain basement membrane proteoglycan with three tissue-specific isoforms. Endostatin, the C-terminal part of collagen XVIII, has antiangiogenic properties, while the frizzled-like domain of the longest isoform is suggested to be capable of inhibiting the Wnt/β-catenin signaling network. This study utilized several genetically modified mouse lines and electron microscopy to achieve new information on the biological role of collagen XVIII, its different isoforms, and the frizzled domain. Lack of collagen XVIII was found to affect the integrity of basement membranes of various tissues, leading to an abnormally loosened network structure. In the choroid plexus, the change in the basement membrane ultrastructure caused alterations in the production of the cerebrospinal fluid and predisposed to the development of hydrocephalus. In the kidney, broadening of the proximal tubular basement membrane was shown to be due specifically to the lack of the short isoform, while the lack of the two longer isoforms led to podocyte foot process effacement. Moreover, lack of collagen XVIII was found to cause softening of the kidney glomeruli and the levels of serum creatinine were elevated in the mutant animals, indicating altered kidney function. The hair follicle cycle was used as a model to study the possible role of the frizzled domain of collagen XVIII in the Wnt/β-catenin signaling cascade. The longer collagen XVIII isoforms were shown to be expressed in the basement membrane facing the dermal papilla and in the hair follicle bulge, containing the follicular stem cells. Lack of the long isoforms led to abnormalities in the progression of the first hair cycle, and the phenotype could be rescued via transgenic delivery of the frizzled domain of the longest isoform, suggesting its involvement in the regulation of the Wnt/β-catening signaling network during the cyclic growth of the hair. / Tiivistelmä Kollageeni XVIII on useista toiminnallisista osista koostuva tyvikalvojen proteoglykaani, jolla on kolme eri kudoksissa esiintyvää isomuotoa. Sen C-terminaalisella endostatiini-osalla on verisuonten kasvua estäviä vaikutuksia, kun taas pisimmän isomuodon frizzled-osan uskotaan estävän Wnt/β-kateniini signalointireitin toimintaa. Tässä tutkimuksessa saatiin uutta tietoa kollageeni XVIII:n, sen eri isomuotojen sekä frizzled-osan biologisesta merkityksestä useiden geenimuunneltujen hiirimallien sekä elektronimikroskopian avulla. Kollageeni XVIII:n puutoksen todettiin vaikuttavan tyvikalvojen rakenteen eheyteen useissa eri kudoksisssa, johtaen epänormaalisti löyhtyvään verkkorakenteeseen. Suonipunoksessa tämä tyvikalvon hienorakenteen muutos vaikutti aivo-selkäydinnesteen tuottumiseen ja altisti vesipään kehittymiselle. Munuaisessa proksimaalisen munuaistiehyen tyvikalvon levenemisen osoitettiin johtuvan lyhyen isomuodon puutoksesta, kun taas kahden pidemmän isomuodon puuttuminen aiheutti podosyyttien jalkalisäkkeiden leviämistä. Lisäksi kollageeni XVIII:n puuttumisen osoitettiin johtavan hiirimallien munuaiskerästen pehmenemiseen sekä veren kreatiniinitason kohoamiseen, viitaten munuaistoiminnan häiriöihin. Karvatuppien syklistä kasvua käytettiin mallina tutkittaessa kollageeni XVIII:n frizzled-osan mahdollisia vaikutuksia Wnt/β-kateniini signalointireittiin. Pidempien kollageeni XVIII isomuotojen osoitettiin tuottuvan karvanystyn tyvikalvossa sekä karvatupin kantasolut sisältävällä pullistuma-alueella. Pitkien isomuotojen puuttuminen johti karvojen ensimmäisen kasvukierron epänormaaliin etenemiseen. Tämä voitiin estää siirtogeenisen frizzled-osan avulla, mikä viittasi sen osallisuuteen Wnt/β-kateniini signalointireitin säätelyyn karvan syklisen kasvun aikana.

No description available.

Streptococcus suis (S. suis) is an important opportunistic pathogen, which can cause septicemia and meningitis in pigs and humans. Previous in vivo observations in S. suisinfected pigs revealed lesions at the choroid plexus (CP). In vitro experiments with primary porcine CP epithelial cells (PCPEC) and human CP epithelial papilloma (HIBCPP) cells demonstrated that S. suis can invade and traverse the CP epithelium, and that the CP contributes to the inflammatory response via cytokine expression. Here, next generation sequencing (RNA-seq) was used to compare global transcriptome profiles of PCPEC and HIBCPP cells challenged with S. suis serotype (ST) 2 infected in vitro, and of pigs infected in vivo. Identified differentially expressed genes (DEGs) were, amongst others, involved in inflammatory responses and hypoxia. The RNA-seq data were validated via quantitative PCR of selected DEGs. Employing Gene Set Enrichment Analysis (GSEA), 18, 28, and 21 enriched hallmark gene sets (GSs) were identified for infected HIBCPP cells, PCPEC, and in the CP of pigs suffering from S. suis ST2 meningitis, respectively, of which eight GSs overlapped between the three different sample sets. The majority of these GSs are involved in cellular signaling and pathways, immune response, and development, including inflammatory response and hypoxia. In contrast, suppressed GSs observed during in vitro and in vivo S. suis ST2 infections included those, which were involved in cellular proliferation and metabolic processes. This study suggests that similar cellular processes occur in infected human and porcine CP epithelial cells, especially in terms of inflammatory response.