Orientador: Laurecir Gomes / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T02:08:34Z (GMT). No. of bitstreams: 1 Oliveira_SilviaBorgesPimentelde_D.pdf: 1168180 bytes, checksum: da1367852d18352f97fbfe0c374bf4c0 (MD5) Previous issue date: 2007 / Resumo: Interações entre o epitélio e o mesênquima/estroma são importantes em diversos estágios da morfogênese, na diferenciação celular e na função geral de diversas glândulas. Na próstata, a função secretora do epitélio nos animais adultos é regulada por andrógenos que tem participação direta na manutenção do estado ativo da glândula. Sabe-se que o endotélio é um dos primeiros elementos prostáticos a responder à eliminação do estímulo androgênico e a responder à sua reposição. Entretanto, a célula endotelial não apresenta receptor para andrógenos, o que leva a crer que a modulação do seu comportamento ocorra indiretamente pela ação de fatores locais produzidos por diferentes tipos celulares. Este trabalho teve como objetivo isolar, caracterizar e cultivar células endoteliais prostáticas, assim como avaliar a possível regulação do seu comportamento por células musculares lisas que correspondem ao principal tipo celular do estroma prostático. Culturas primárias de células endoteliais da próstata de ratos foram obtidas e caracterizadas a partir de sua morfologia e expressão do fator von Willebrand e dos receptores Flk-1 (VEGFR-1) e Flt-1 (VEGFR-2) marcadores específicos de células endoteliais, e de sua habilidade em formar estruturas parecidas com capilares quando cultivadas sobre Matrigel. Não foi observado efeito sobre a proliferação celular quando estas células foram cultivadas na presença de meio condicionado por células musculares lisas, sobre diferentes substratos (plástico, colágeno, matrigel). Entretanto, o meio condicionado pelas células musculares lisas reforçou o efeito de indução da diferenciação em estruturas similares a capilares. Foi também detectado que o meio condicionado inibe a secreção de angiopoietina-1 pelas células endoteliais quando cultivadas sobre colágeno e estimula a secreção de angiopoietina-2 quando as células foram cultivadas sobre Matrigel. Os dados obtidos demonstram que o protocolo utilizado resultou em uma população homogênea de células endoteliais prostáticas e que, as células musculares lisas, produzem fatores solúveis capazes de regular diferencialmente o comportamento das células endoteliais, de acordo com o substrato / Abstract: Interactions between the epithelium and mesenchyme/stroma are important in different stages of morphogenesis, differentiation and function of most glands. In the prostate, the secretory function of the epithelium in adult animals is regulated by androgens, which have direct roles in maintaining prostate activity. It is well known that the endothelium is the first prostatic compartment to respond to androgen deprivation and to its reposition after castration. However, the endothelial cell does not express the androgen receptor and this led us to believe that the altered behavior in response to androgen is modulated by soluble factors produced by other cell types that can sense androgen levels. The objective of this work was to isolated, characterize and culture prostatic endothelial cells, as well as to evaluate its possible regulation by smooth muscle cells, which are the predominant cell type in the prostate stroma. Primary cultures of rat ventral prostate endothelial cells were isolated, maintained in culture and characterized by their morphology, expression of von Willebrand factor, Flk-1 (VEGFR-1) and Flt-1 (VEGFR-2) receptors, and ability to form capillary-like structures on Matrigel. When these cells were cultured in the presence of smooth muscle cell conditioned medium, on different substrata (plastic, collagen, matrigel) there was no variation in cell proliferation. However, the smooth muscle cell conditioned medium reinforced the formation of capillary-like structures in Matrigel. It was also observed that the smooth muscle cell conditioned medium inhibited the secretion of angiopoietin-1 when the cells were cultured on collagen and stimulated the secretion of angiopoietin-2 when the cultured on Matrigel. Altogether, our data indicate that the protocol employed here resulted in a highly homogenous population of prostate-derived endothelial cells and that smooth muscle cells produce soluble factors capable of differentially regulating the behaviour of endothelial cell, as a function of the substratum / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural

O estabelecimento de cultivo de células-tronco embrionárias (ESC) ainda não foi realizado com sucesso. Verificação de marcadores de pluripotência e diferenciação nos três folhetos germinativos são necessárias para validação de uma linhagem celular pluripotente. O objetivo deste estudo foi estabelecer e caracterizar o cultivo de ESC suínas usando Matrigel e comparar a expressão dos marcadores de pluripotência Oct-4, CD9 e α6-integrina em embriões. Blastocistos in vitro ou in vivo foram submetidos à imunocirurgia para cultura da massa celular interna, fixados para imunocitoquímica ou extração de RNA total para RT-PCR. Nenhuma colônia de ESC foi obtida usando co-cultivo em fibroblastos embrionários murinos (MEF) ou em Matrigel. Expressão de Oct-4, CD9 e α6-integrina foi detectada por PCR. Os produtos de PCR de CD9 e α6-integrina tiveram suas sequências nucleotídicas determinadas e comparadas com bases de dados públicas. O produto de CD9 foi idêntico à seqüência do CD9 suíno e o produto de α66integrina foi similar à humana e eqüina. Reação de Imunocitoquímica revelou a presença de Oct-4 no citoplasma de células da massa celular interna e do trofoblasto. CD9 e α6-integrina foram observados preferencialmente em células do trofoblasto. Não foi possível comparar a expressão dos marcadores de pluripotência entre ESC e embriões em suínos. Porém, este estudo descreve pela primeira vez a expressão de CD9 e α6-integrina em blastocistos suínos, os quais podem não estar relacionados com células pluripotentes embrionárias suínas. / Establishment of embryonic stem cell (ESC) culture in pigs has not been achieved. Verification of pluripotency markers and differentiation in the three embryonic layers are necessary for validation of a pluripotent cell line. The objective of this study was to establish and characterize porcine ESC culture using Matrigel and compare the expression of pluripotency markers Oct-4, CD9 and α6-integrin with embryos. In vitro or in vivo porcine blastocysts were submitted to immunosurgery for culture of inner cell mass, fixation for immunocytochemistry or total RNA extraction for RT-PCR. No ESC colonies were obtained using co-culture on mouse embryonic fibroblasts (MEF) or on Matrigel. Expression of Oct-4, CD9 and α6-integrin was detected by PCR. CD9 and α6-integrin PCR products had their nucleotide sequence assessed and compared with public nucleotide database. CD9 product was identical to CD9 porcine sequences and α6-integrin product was similar to human and equine α6-integrin. Immunocytochemistry revealed Oct-4 expression in cytoplasm of the inner cell mass and trophoblast cells. CD9 and α6-integrin were observed preferentially on trophoblast cells. It was not possible to compare expression of pluripotency markers between porcine ESC and embryos. However, this study describes for the first time expression of CD9 and α6-integrin in porcine blastocysts, which may not be related to pluripotent porcine embryonic cells.

O estabelecimento de cultivo de células-tronco embrionárias (ESC) ainda não foi realizado com sucesso. Verificação de marcadores de pluripotência e diferenciação nos três folhetos germinativos são necessárias para validação de uma linhagem celular pluripotente. O objetivo deste estudo foi estabelecer e caracterizar o cultivo de ESC suínas usando Matrigel e comparar a expressão dos marcadores de pluripotência Oct-4, CD9 e α6-integrina em embriões. Blastocistos in vitro ou in vivo foram submetidos à imunocirurgia para cultura da massa celular interna, fixados para imunocitoquímica ou extração de RNA total para RT-PCR. Nenhuma colônia de ESC foi obtida usando co-cultivo em fibroblastos embrionários murinos (MEF) ou em Matrigel. Expressão de Oct-4, CD9 e α6-integrina foi detectada por PCR. Os produtos de PCR de CD9 e α6-integrina tiveram suas sequências nucleotídicas determinadas e comparadas com bases de dados públicas. O produto de CD9 foi idêntico à seqüência do CD9 suíno e o produto de α66integrina foi similar à humana e eqüina. Reação de Imunocitoquímica revelou a presença de Oct-4 no citoplasma de células da massa celular interna e do trofoblasto. CD9 e α6-integrina foram observados preferencialmente em células do trofoblasto. Não foi possível comparar a expressão dos marcadores de pluripotência entre ESC e embriões em suínos. Porém, este estudo descreve pela primeira vez a expressão de CD9 e α6-integrina em blastocistos suínos, os quais podem não estar relacionados com células pluripotentes embrionárias suínas. / Establishment of embryonic stem cell (ESC) culture in pigs has not been achieved. Verification of pluripotency markers and differentiation in the three embryonic layers are necessary for validation of a pluripotent cell line. The objective of this study was to establish and characterize porcine ESC culture using Matrigel and compare the expression of pluripotency markers Oct-4, CD9 and α6-integrin with embryos. In vitro or in vivo porcine blastocysts were submitted to immunosurgery for culture of inner cell mass, fixation for immunocytochemistry or total RNA extraction for RT-PCR. No ESC colonies were obtained using co-culture on mouse embryonic fibroblasts (MEF) or on Matrigel. Expression of Oct-4, CD9 and α6-integrin was detected by PCR. CD9 and α6-integrin PCR products had their nucleotide sequence assessed and compared with public nucleotide database. CD9 product was identical to CD9 porcine sequences and α6-integrin product was similar to human and equine α6-integrin. Immunocytochemistry revealed Oct-4 expression in cytoplasm of the inner cell mass and trophoblast cells. CD9 and α6-integrin were observed preferentially on trophoblast cells. It was not possible to compare expression of pluripotency markers between porcine ESC and embryos. However, this study describes for the first time expression of CD9 and α6-integrin in porcine blastocysts, which may not be related to pluripotent porcine embryonic cells.

<p>The tolerance towards the semi-allogenic foetus is obtained through both systemic and local changes in the maternal immune response. Locally, in the decidua, the cell composition differs from that found in the blood; natural killer (NK) cells and macrophages being the major cell types. Decidual macrophages (dMØ), which are alternatively activated, and trophoblasts, placental cells of foetal origin, are believed to participate in the foetal tolerance at the foetal-maternal interface. To test the recruitment ability of macrophages and trophoblasts, and to test if these cells are responsible for the special cell composition in the decidua, a migration assay was established. In this migration assay peripheral blood mononuclear cells (PBMC) were allowed to migrate through Matrigel-coated transwell inserts into lower wells containing a recruiting stimulus. After testing several conditions, a protocol was established for further use. The results showed that <em>in vitro</em> alternatively activated macrophages, which display many of the surface markers as dMØ, hold a recruiting ability and recruit monocytes. Further there was an indication that trophoblasts also hold a recruiting ability. Neither cell types were shown to recruit NK cells. In conclusion, this study presents a suitable protocol for assessing chemotactic factors and different cell type’s ability to recruit cells from blood. Although the experiments need to be repeated and extended and the recruitment ability of dMØ needs to be evaluated in detail before a final conclusion can be drawn, the preliminary data indicated that macrophages and trophoblasts can recruit monocytes.</p>

The skeletal muscle is a dynamic tissue that has the ability to change and modify itself to fit the level of required activity; a phenomenon called muscle plasticity. Most studies of muscle plasticity are carried out in situ, a condition for which it is difficult to study and discern between the intrinsic properties of skeletal muscle, the myokines released by muscle fibers and the neurotrophic factors released by neurons innervating skeletal muscles that play various roles in the mechanisms of muscle plasticity. Another approach is to study the morphological and contractile properties of single adult muscle fibers under culture conditions for which one can fully control the level of activity and exogenous factors affecting muscle plasticity. However, the survival of single muscle fiber in culture is very low as most fibers degenerated or supercontracted within 5-7 days. The first objective of this study was to optimize fiber survival in culture. The application of chronic stimulation and beta-adrenergic agonists are two major factors that prevent muscle atrophy and loss of force in denervated muscles in situ. So, objective two was to determine if chronically stimulated single fibers in culture also improve fiber survival and contractile characteristic under culture conditions. The third objective was the same for salbutamol, a beta 2-adrenergic agonist. In regard to the optimization of fiber survival, the Minimum Essential Medium (MEM) was a better medium than Dulbecco’s Modified Eagle Medium (DMEM), changing 50% of the culture medium every two days also improved fiber survival compared to changing the medium every day. Interestingly, inhibiting the proliferation of satellite cells with AraC largely improved fiber survival when fibers were kept under resting conditions, but not when they were chronically stimulated. Finally, under conditions in which proliferation of satellite cells was inhibited, the use of a collagen/laminin mixture as adhering substrate to improve fiber adhesion to glass coverslip gave rise to a better fiber survival than Matrigel that contains not only collagen and laminin but several growth factors. The results suggest i) that when satellite cells (or fibroblasts) are allowed to proliferate they appear to contribute to the degeneration of fibers under resting conditions and ii) that the release of myokines by skeletal muscle fibers (or cytokines by other cells) likely play a role in fiber survival. Contrary to the situation in situ, neither the chronic stimulation nor salbutamol improved fiber survival and contractile characteristics of muscle fibers in culture suggesting that some important factors in culture are missing to allow chronic stimulation and salbutamol to reduce muscle atrophy and loss of force.

Le cancer du rein compte parmi les 10 types de cancers les plus fréquents chez l’Homme. Il n’existe aujourd’hui aucun marqueur biomoléculaire dans ce type de cancer, et dans le cas d’un cancer métastatique, l’arsenal thérapeutique aujourd’hui disponible manque d’efficacité. Les différents processus mis en jeu lors de la progression tumorale sont encore mal connus. La connaissance de ces processus pourrait permettre de mettre en évidence de nouvelles cibles thérapeutiques, ainsi que des marqueurs biomoléculaires pronostiques ou diagnostiques de la maladie. Dans un premier projet, et afin de mieux comprendre les mécanismes de la progression tumorale et d’identifier de nouvelles cibles thérapeutiques potentielles et de nouveaux marqueurs biomoléculaires dans le cancer du rein, un nouveau modèle innovant a été généré à partir d’une lignée tumorale de RCC murine. Ce modèle de réimplantations successives de cellules tumorales issues de tumeur primaire ou de métastases a permis de générer différentes lignées cellulaires montrant une agressivité accrue au cours des passages. En utilisant une stratégie de biologie des systèmes, ce modèle pourra permettre de mettre en évidence des cibles d’études prometteuses qui pourraient être de nouvelles cibles thérapeutiques ou de nouveaux marqueurs biomoléculaires dans le RCC. L’interleukine-34 est l’exemple d’une cible d’étude d’ores et déjà été sélectionnée, mettant en évidence la puissance du modèle généré. Dans un second projet, les rôles de certains membres de la matrice extracellulaire tumorale ont été évalués en utilisant cette même lignée de RCC murine (collagène de type I, fibronectine, matrigel). Cette étude a permis de mettre en évidence le potentiel pro-invasif et pro-métastatique du dépôt de collagène de type I dans les tumeurs. Des récepteurs activés par le collagène sont proposés comme potentiellement impliqués dans les effets induits par le collagène de type I dans le modèle. Ces deux projets permettent et permettront de mieux comprendre certains mécanismes de la progression tumorale, ainsi que de mettre en évidence des marqueurs biomoléculaires et de nouvelles cibles thérapeutiques. / Kidney cancer is one of the 10 commonest human cancers. To date, no biomolecular markers are available in this type of cancer, and in the case of metastatic cancer, the therapeutic arsenal is still inefficient. The different processes involved in cancer progression are still poorly understood. Understanding those processes could highlight new therapeutic targets, and new prognostic or diagnostic biomolecular markers of this disease. For a first project, a new innovative model has been generated from a murine RCC cell line as a tool to understand cancer progression mechanisms and to identify new therapeutic target and new biomolecular markers in kidney cancer. This model of sequential reimplantation of cancer cells isolated from primary tumours or metastases allowed us to generate different cell lines showing increased aggressiveness after passages. Using a systems biology strategy, this model will allow us to identify new potential therapeutic targets and new biomolecular markers in RCC. Interleukin-34 is an example of an already selected target, showing the power of the model generated. For a second project, the role of some members of extracellular matrix (collagen type I, fibronectin, matrigel).was studied using this same murine RCC cell line. This study demonstrated the potential pro-invasive and pro-metastatic roles of collagen type I deposition in tumors. Collagen-activated receptors are proposed as mediators of the effect induced by collagen type I in this model. Those two projects have and will continue to contribute to a better understanding of cancer progression mechanisms, and will bring out new biomolecular markers and new therapeutic targets.

Spinal cord injury (SCI) has presented itself as a multifaceted pathology that is largely inhibitory to regeneration, and therefore to functional recovery, even though spinal cord neurons have been found to be innately regenerative. Thus, having identified the key players in the inhibition of this innate regeneration, SCI researchers have focused on two major types of approaches: (1) blocking inhibitory cues and (2) promoting innate regeneration. Schwann cells (SCs) have long been shown to promote and enhance functional recovery after SCI through providing supplemental myelination and trophic and tropic factors to regenerating axons, though singular approaches rarely address the complex SCI pathology. Guidance channels and scaffolds have been shown to provide physical support and directional cues to regeneration axons. Therefore, a combinatorial approach in which SCs migrate into and throughout a guidance scaffold would be an ideal research focus for treating SCI. However, cell migration into guidance scaffolds has been shown to be problematic. This study attempts to assess and improve two- and three-dimensional SC migration on electrospun scaffolds. Additionally, we evaluate the ability of SCs, seeded on Matrigel-coated electrospun scaffolds, to improve functional recovery in rats with completely transected spinal cords.

Mechanistic insights on molecular and cellular mechanisms whereby KSHV induces Kaposi?s sarcoma (KS) are key for our understanding of KS tumors and for the development of new therapies. We have previously developed an animal model for KSHV induced KS using murine bone marrow cells transfected with a KSHVBac36. We found that although these cells lacked attributes of transformed cells in vitro, they were able to cause KS-like tumors in vivo. In vivo tumorigenesis correlated with upregulation of both KSHV lytic genes and host angiogenesis suggesting that that cues provided from the microenvironment played a major role in regulating viral and host gene expression related with KSHV-induced tumorigenesis. Our goal thus, was to identify these molecular cues regulating pathogenic gene expression in KSHV infected cells in vivo. An important difference between cells kept in vitro versus in vivo is the lack of environmental extracellular matrix (ECM) signals. Therefore the mECK36 cells were cultured in vitro in matrigel, a basement membrane preparation rich in ECM proteins and its individual components, to discern the effect of host signaling by the ECM on KSHV infected cells. Investigation of gene expression through Real Time RT-PCR identified several viral and host genes associated with tumorigenesis such as KSHV vGPCR and angiogenesis associated VEGF and EGF- receptors were upregulated in response to this environment. Further analysis of the molecular activity of the cell indicated the change in transcription was due to the activation of integrin signaling, as assessed by phosphorylation of the Focal Adhesion Kinase (FAK) protein. Our results show that integrin signaling occurring in vivo through interaction with ECM serves to enhance the pathogenic viral and host gene expression of KSHV infected cells and that EGFR upregulation can be correlated with these conditions. These results points to the integrin signaling pathway or the EGF-Receptor as promising targets for therapy and prevention of KS tumors.

Electrical stimulation of tissues induces cell alignment, directed migration, extended processes, differentiation, and proliferation, but the mechanisms involved remain largely unknown. To reveal effects of electric fields (EF) through the media on cell behavior, voltage (7.45 – 22 V), current density (36 – 106 mA/cm2), duration (2 – 24 hrs), and alternating currents (AC, 2 – 1000 Hz) were varied independently when exposed to cell cultures. It was determined that current density and duration are the primary attribute Schwann cells respond to when an EF is applied through the media. This implies that the number of charges moving across the cell surface may play a key role in EF-induced changes in cell behavior. Identical conditions were used to stimulate cells grown on the surface of a conductive substrate to examine if a scaffold can provide structural and EF cues. The effects of an EF through the substrate were examined by placing a protein gel on the surface during stimulation and observing the morphology of subsequent cell cultures and the physical topology of the gel. EFs were shown to create Ca2+ redistribution across gels and subtle changes in collagen I fibril banding. Stimulated gels were able to induce perpendicular Schwann cell alignment on newly seeded cultures days after initial EF exposure, and the cell response decreased when seeded at longer times, indicating the effects of EF on the matrix environment has a relaxation time. These findings were then integrated into a biodegradable, electrically conductive polypyrrole-poly-ε-caprolactone polymer developed by collaborators. Dorsal root ganglia placed in matrix gels on top of conducting polymer exhibited significantly longer axons when stimulated with DC and AC signals. The overall results demonstrate that EFs have a significant effect on the extracellular environment. The broad implication of this data grants researchers with the ability to physically and metabolically control cell behavior with EFs, including improved wound healing or reduced cancer metastasis. / text

Στόχος της διπλωματικής εργασίας ήταν η εφαρμογή της Μοριακής Απεικόνισης για την λήψη εικόνων παθολογικής αγγειογένεσης σε πειραματικό μοντέλο λευκού κόνικλου Νέας Ζηλανδίας με καρκίνωμα VX2. Στη πρώτη φάση της διπλωματικής εργασίας προσδιορίσαμε ως κατάλληλο μοριακό στόχο για την απεικόνιση της αγγειογένεσης, την ιντεγκρίνη ανβ3. Η επιλογή του στόχου βασίστηκε στο γεγονός ότι το επίπεδο έκφρασης της ιντεγκρίνης ανβ3 αυξάνεται σημαντικά κατά την αγγειογένεση, η οποία έχει διαπιστωθεί ότι συμμετέχει στην ανάπτυξη ενός όγκου και επάγεται από χημικούς παράγοντες σε καταστάσεις ισχαιμίας, ενώ σχετίζεται και με πολλές άλλες ασθένειες. Στη δεύτερη φάση στόχος μας ήταν να γίνει εμφύτευση καρκινικών κυττάρων της σειράς VX2 σε κόνικλο και η δημιουργία ενός carrier animal με όγκο VX2. Η δημιουργία ενός δότη κυττάρων VX2 χρησιμεύει για την επίτευξη συνεχών μετεμφυτεύσεων του όγκου σε κόνικλους που προορίζονται για απεικόνιση του επιλεγμένου μοριακού στόχου. Για τη μελέτη του επιπέδου έκφρασης της ιντεγκρίνης ανβ3 επιλέχθηκαν ως μόρια προς επισήμανση πεπτίδια τα οποία φέρουν την αλληλουχία RGD (Arginine-Glycine-Aspartic acid) μέσω της οποίας αντιδρούν με το μόριο της ιντεγκρίνης ανβ3 και ως κατάλληλο σύστημα απεικόνισης περιστρεφόμενη γ κάμερα. Τελικός στόχος είναι μέσω του δείκτη ανβ3 να μελετήσουμε πως εξελίσσεται χρονικά και χωρικά σε σχέση με τον όγκο η αγγειογένεση. Μελλοντικές προοπτικές είναι η ακριβής παρακολούθηση σε κλινικό επίπεδο της διαδικασίας της αγγειογένεσης μετά από χορήγηση προ-αγγειογενετικών ή αντι-αγγειογενετικών παραγόντων σε περιπτώσεις ισχαιμίας ή καρκίνου αντίστοιχα. / The aim of the study was the aquisition of images of tumor angiogenesis by implementing Molecular Imaging techniques. The small animal experimental platform that was required for the study was the New Zealand White rabbit with VX2 carcinoma. The molecular target for imaging angiogenesis was integrin ανβ3, which is found to be overexpressed in endothelial cells participating in angiogenesis. Angiogenesis is found to be crucial for the development of solid tumors (excessive angiogenesis) and other pathological conditions (insufficient angiogenesis). Tracers that interact with ανβ3 are RGD (Arginine-Glycine-Aspartic acid residues)peptides labeled with radionuclides and suitable imaging modality is rotating gamma camera. Targeted molecular imaging may visualize the early activation of the angiogenic type of endothelial cells.To that end, we hope to gain further insights into the specific temporal and spatial characteristics of the onset of angiogenesis.