Le développement embryonnaire est un processus complexe finement régulé spatio-temporellement par de nombreux acteurs, qu’ils soient ADN, ARN ou protéines. De récents résultats suggèrent un rôle clef dans le développement et les maladies pour une sous-catégorie des ARNs impliqués dans ces mécanismes, les longs ARNs non-codants (lncRNAs). Caractérisés par leur incapacité à produire des protéines, ils sont difficiles à étudier par leur manque de conservation en séquence et leur expression tissu-spécifique. Ici, nous étudions un lncRNA conservé, Tuna (Tcl1 Upstream Neuron-Associated lncRNA), nécessaire au maintien de l’état pluripotent des cellules souches et essentiel à leur différenciation en neurones. Toutefois, les mécanismes dans lesquels cet ARN est impliqué restent inconnus. Pour y répondre, nous avons analysé des données de séquençage d’ARN de différenciation neuronale d’ESCs murines. Nous avons identifié deux nouvelles isoformes spécifiquement exprimées dans les ESCs, sht.Tuna et alt.Tuna. Cette dernière est le résultat de l’épissage alternatif de l’exon 1 de Tuna. Cet épissage alternatif est également observé chez l’humain, démontrant une conservation du traitement de l’ARN entre la souris et l’Homme. Ces deux isoformes sont plus courtes d’environ 1,5kb à l’extrémité 3’ que le transcrit prédit de Tuna (full.Tuna). En effet, l’isoforme full. Tuna n’a pas pu être détectée dans les ESCs, et la surexpression de sht.Tuna a permis d’améliorer la reprogrammation vers l’état pluripotent. Ceci suggère que le rôle de Tuna est mécanistiquement différent dans les ESCs et les neurones. D’autre part, Tuna présente une région hautement conservée (~200bp) contenant un potentiel cadre de lecture pour un peptide de 48 acides aminés, détectable par surexpression de constructions tagguées FLAG. La mutation du codon AUG de cette séquence codante a abrogé l’effet de l’ARN sur la reprogrammation. Ceci implique un rôle du peptide dans l’acquisition de la pluripotence. Par ailleurs, Tuna a été détecté dans les fractions poly-ribosomales et cytoplasmiques d’ARN, supportant son éventuel potentiel codant. Ensemble, ces résultats démontrent que l’épissage alternatif et le potentiel codant d’un locus propre à un lncRNA est complexe et que cet ARN pourrait avoir de multiples fonctions dépendantes de l’état cellulaire / Embryonic development is a complex process finely regulated in time and place by numerous actors such as DNA, RNA, and proteins. Emerging evidence suggests a key role in development and disease for a subcategory of RNAs implicated in those mechanisms, the long non-coding RNAs (lncRNAs). Characterized by their incapacity to produce proteins, they have proven to be challenging to study due to the lack of sequence conservation and their tissue-specific expression. Here, we focus on a conserved lncRNA, Tuna (Tcl1 Upstream Neuron-Associated lncRNA), that is required for maintaining embryonic stem cells (ESCs) in an undifferentiated state but is also essential for their differentiation towards a neuronal cell fate. However, the mechanism behind this dual role remains largely unknown. To address this, we analyzed available RNA-seq data on mouse ESC differentiation towards neurons. We identified two novel isoforms specifically expressed in ESCs, sht.Tuna and alt.Tuna. The latter isoform was the result of alternative splicing of the exon 1 of Tuna. This alternative splicing was also observed in human ESCs demonstrating a conserved processing of the RNA between mouse and human cells. Both new isoforms were ~1.5kb shorter at the 3'-end than the predicted full transcript of Tuna (full.Tuna). In fact, we failed to detect the full.Tuna isoform in ESCs, and overexpression of sht.Tuna isoform enhanced reprogramming to a pluripotent stem cell state. This suggests that the role of Tuna is mechanistically different in ESCs than in neurons. Besides, Tuna also contains a highly conserved region (~200bp) harboring a predicted 48-amino-acids coding sequence that is detectable upon overexpression if FLAG-tagged. Mutating the start codon of this peptide's coding sequence abrogated the enhanced reprogramming effect. This infers a role for the peptide in the acquisition of a pluripotent state. Moreover, Tuna was detected in poly-ribosomal and cytoplasmic RNA fractions further supporting a peptide coding potential. Taken together, our results demonstrate that alternative splicing and coding potential of a particular lncRNA locus is complex and that a lncRNA may have multiple functionality depending on cell state.

La maladie de Steinert est la plus fréquente des dystrophies musculaires de l’adulte. Les mécanismes moléculaires responsables de cette maladie sont en grande partie inconnus. Afin de faire progresser les recherches sur cette maladie, il est essentiel de pouvoir disposer de modèles cellulaires in vitro possédant une grande capacité proliférative. Il est également important de pouvoir disposer de modèles cellulaires non seulement du muscle squelettique, mais aussi du cerveau et du cœur, deux organes touchés par la maladie. La reprogrammation de cellules somatiques humaines en cellules souches induites à la pluripotence (iPS) est une nouvelle technique apparue en 2007 (Yamanaka et al, 2007). Mon projet de recherche a porté sur la reprogrammation de fibroblastes humains DM1 en iPS DM1. Nous avons été en mesure de dériver plusieurs lignées d’iPS à partir de fibroblastes de patients atteints de la DM1. Nous avons été en mesure de réaliser une caractérisation préliminaire d’une des lignées attestant le caractère pluripotent des cellules souches obtenues. Nous avons également été capables de générer des précurseurs de neurones, à partir de ces iPS, exprimant les marqueurs MAP2 et TAU. Les résultats obtenus nous permettent de penser que l’objectif initial de reprogrammer des fibroblastes de patients en iPS a été atteint. / Steinert disease is the most common adult muscular dystrophy. Unfortunately, the molecular mechanisms of that disease still misunderstood. To increase the knowledge’s, it is essential to have some cellular models available with a good proliferation capacity. It is also important to be able to establish in vitro models of heart and brain, which are also affected by the disease. Since 2007, it is possible to turn somatic cells into pluripotent stem cells. My project was to differentiate human fibroblasts of patients into induced pluripotent stem cells. We were able to reach that goal. A preliminary characterization was done to show the pluripotency of those cells. We were also able to differentiate those cells into neurons precursors expressing MAP2 and TAU proteins. Those results allow us to think that the original goal of establish induced pluripotent stem cells from Steinert patients is reach.

Les cellules souches humaines induites à la pluripotence (hiPSCs) ont été conçues pour la première fois en 2007 par l’équipe du Docteur Yamanaka, au Japon. Ce sont des cellules somatiques reprogrammées par un virus permettant, par exemple, la différenciation neuronale à des fins d'étude de maladies neuro-développementales telle que la Schizophrénie. Le prélèvement des cellules somatiques se fait aujourd'hui majoritairement par des méthodes assez invasives, notamment les biopsies de peau ou prélèvements sanguins. Ceci peut représenter un frein à leur utilisation notamment chez les enfants et surtout les enfants malades. La différenciation neuronale privilégiée est la voie dopaminergique (DA) car c'est ce type cellulaire qui est principalement atteint chez les schizophrènes. C'est pourquoi on priorise pour ce projet l'utilisation de cellules contenues dans l'urine, qui seront reprogrammées via un virus non-intégratif, le virus de Sendaï (SeV). La différenciation neuronale nous permettra d'obtenir des neurones DA fonctionnels, caractérisés par électrophysiologie. Les expériences ont montré une très grande efficacité de reprogrammation cellulaire au niveau des cellules d'urine, ainsi qu'un grand potentiel de différenciation neuronale, malgré quelques différences observées entre les lignées saines et schizophréniques. Grâce à ce projet, la réalisation d'un modèle cellulaire pour la Schizophrénie a pu être établie. Les différences notées entre les lignées pendant la différenciation ouvrent une nouvelle voie pour approfondir l'étude de la maladie au niveau cellulaire et moléculaire. / Human Induced Pluripotent Stem Cells (hiPSCs) were conceived for the first time in 2007 in Japan, by Doctor Yamanaka’s team. These are somatic cells reprogrammed thanks to a retrovirus allowing, for example, neuronal differentiation for the purpose of neurodevelopmental disorders studies such as Schizophrenia. Today, the removal of somatic cells is mainly made by enough invasive methods, including skin and blood biopsies. This can represent a brake in their use predominantly children, mainly sick children. The preferred neuronal differentiation is the dopaminergic (DA) way because it's the mostly cell type affected in schizophrenics. That's why we prioritize the use of urine cells for this project, reprogrammed via a non integrative virus, the Sendai virus (SeV). The neuronal differentiation enables us to get functional DA neurons characterized by electrophysiology. Experimentations show a huge efficiency of urine cells reprogramming as well as a great potential of neuronal differentiation despite some distinctions between the two lines. Thanks to this project, the achievement of a cellular model for Schizophrenia could be established. The differences noticed between the two lines during the differentiation open up a new way to make cellular and molecular studies of this disease deeper.

Células multipotentes mesenquimais estromais (CTM) são células adultas multipotentes que podem ser isoladas a partir de diferentes tecidos e são capazes de atingir sítios danificados, exercer papéis na regeneração tecidual e modular a resposta imune. Estas células demonstraram resultados discrepantes em estudos in vivo dependentes de sua fonte de obtenção. Há na literatura hipóteses de que o mecanismo predominante pelo qual as CTMs atuam no reparo tecidual estaria relacionado à sua atividade parácrina, criando um microambiente com sinais tróficos. Nesse sentido, a avaliação do conteúdo do secretoma destas células é de grande interesse. Portanto, este projeto teve como objetivo analisar o meio condicionado de CTMs obtidas de diferentes fontes (tecido adiposo, músculo esquelético e tubas uterinas) de mesmos indivíduos. A abordagem experimental consistiu em proteômica shotgun (nanocromatografia líquida acoplada a espectrometria de massas em tandem) com o intuito de identificar alvos diferentemente expressos entre as culturas que possam sugerir funções específicas de cada linhagem celular. Os dados espectrais foram obtidos pelo modo de aquisição dependente de dados (Top15). Os dados adquiridos foram processados pelas plataformas MaxQuant e TPP (Trans-Proteomic Pipeline). Foi realizada análise qualitativa de vias enriquecidas por meio do programa Ingenuity utilizando as proteínas em comum nos secretoma de todas as CTMs analisadas. Essa análise permitiu observar vias enriquecidas de proliferação celular, migração celular e desenvolvimento do sistema cardiovascular, demonstrando que as proteínas secretadas por quaisquer das CTMs analisadas podem ser relacionadas a resultados encontrados na literatura utilizando estas células para terapias para patologias. As análises estatísticas para determinar se haveria dependência da composição do secretoma em função do indivíduo doador ou tecido fonte das CTMs revelaram proteínas diferencialmente expressas entre todos os grupos. Estas proteínas diferencialmente expressas são relacionadas à proliferação, sinalização e interação celular, além de modulação do sistema imune e da angiogênese. Neste contexto, podemos concluir que o secretoma das CTMs é muito semelhante, que as CTMs isoladas de quaisquer tecidos ou indivíduos são capazes de secretar moléculas que possivelmente exercem benefícios em determinado tratamento. Entretanto, estes benefícios podem ser exacerbados ou suprimidos pelas moléculas diferencialmente expressas, as quais são dependentes tanto dos tecidos quanto dos indivíduos dos quais as CTMs foram obtidas / Multipotent Mesenchymal Stromal Cells (MSCs) are multipotent adult cells that can be isolated from different tissues and are able to reach damaged sites, play a role in tissue regeneration and modulate immune response. These cells showed conflicting results in studies in vivo depending on their tissue origin. It is hypothesised that the predominant mechanism by which MSCs function could be related to its paracrine activity, creating a microenvironment with trophic signals. Accordingly, the evaluation of the content of the secretome of these cells is of great interest. Towards this end, this project analyzed the proteins of conditioned medium of MSCs obtained from different sources from the same donors (adipose tissue, uterine tubes and skeletal muscle). The MSCs were characterized by flow cytometry for the presence of membrane markers and by differentiation in vitro into adipocytes, chondrocytes, and osteoblasts. The conditioned media were obtained and the protein profile was analysed by liquid nanochromatography coupled to tandem mass spectrometry. Spectral data were obtained by full-acquisition mode MS / dd-MS2 (Top15). The acquired data were processed by MaxQuant software and TPP (Trans-Proteomic Pipeline). Qualitative analysis of enriched pathways through the Ingenuity program using the shared proteins between the cell lineages was performed.It showed enriched pathways related to cell proliferation, cell migration and development of the cardiovascular system. This allows considering that the secreted proteins from the analyzed MSCs might be related to findings in the literature using these cells for therapies. After this, the proteins were analyzed for differential expression by comparing the MSCs into groups of different sources or different donors. In which were observed differentially expressed proteins related to proliferation, cell signaling and interaction, modulation of the immune system and angiogenesis. In this context, we can conclude that MSC\'s secretome is very similar in the analyzed lineages, and that any MSCs are able to secrete molecules which potentially exert for certain treatment benefits. However, these benefits can be exacerbated or annulled by differentially expressed molecules, which are dependent both as the individual and tissues from which MSCs were obtained

As células mesenquimais estromais multipotentes (CMM) são na atualidade uma fonte atrativa para aplicações na engenharia de tecidos e na terapia celular. Devido à baixa disponibilidade nos tecidos (0,01%-0,0005%) e às elevadas doses necessárias para uma infusão (aproximadamente 106 células/Kg paciente) tornou-se necessário o desenvolvimento de tecnologias de expansão in vitro, eficientes e de custo reduzido, que permitam a obtenção de CMM com manutenção das características funcionais (diferenciação e inibição da proliferação de linfócitos), imunofenotípicas e citogenéticas. As CMM são células aderentes, ou seja, necessitam de um substrato sólido para se aderir e proliferar. O procedimento convencional de expansão em garrafas estáticas, geralmente envolve um processo laborioso em que não há correto controle e monitoramento dos parâmetros de cultivo e possui uma maior susceptibilidade à contaminação devido à excessiva manipulação para atingir o número ideal de células. Além disso, este tipo de cultivo não permite uma produção em larga escala. Em função disso, o presente trabalho foi proposto com o objetivo de desenvolver um bioprocesso escalonável, economicamente viável e eficiente para expansão de CMM derivadas da medula óssea em microcarregadores. Para isso, as células foram cultivadas em microcarregador Cyotdex 3, em frasco spinner com o meio -MEM suplementado com 15% de SFB. Foram avaliadas neste trabalho, a adesão celular aos microcarregadores, crescimento, metabolismo, recuperação celular final e avaliação das propriedades funcionais e imunofenotípicas pré e pós cultivo, comparando ao cultivo já estabelecido em garrafas estáticas. De maneira geral, os resultados obtidos mostraram que foi possível expandir CMM utilizando a tecnologia de microcarregadores. A análise do metabolismo celular mostrou que não houve exaustão de nutrientes importantes como glicose e glutamina durante o cultivo, tampouco formação dos subprodutos lactato e amônia em concentrações inibitórias. As células recuperadas após a expansão mantiveram as características imunofenotípicas e funcionais. A produção média (n=10) foi de aproximadamente 4,9x105 cel/mL. Como o sistema utilizado permite o escalonamento, se utilizássemos um biorreator de 1L, seria possível a produção de aproximadamente 5x108 células que seriam suficientes para tratar mais de 3 pacientes de até 70Kg na dose de 2x106 células/Kg. Para expansão da mesma quantidade de células na forma tradicional seriam necessárias 135 garrafas de 175 cm2 com um custo total de expansão duas vezes superior à estimativa do custo de expansão utilizando microcarregadores. / Multipotent mesenchymal stromal cells are currently an attractive source for applications in tissue engineering and cell therapy. Due to the low availability in tissues (0,01%-0,0005%) and the high doses necessary for an infusion (about 106 cells/Kg patient), it has become necessary the development of effective and low cost technologies for in vitro expansion that enable to obtain MSC with maintenance of functional (differentiation and inhibition of lymphocytes proliferation), immunophenotypic and cytogenetics characteristics. MSC are adherent cells, i.e., they need a solid substrate to adhere and proliferate. The conventional procedure for expansion in static flasks normally involves a laborious process in which there is no suitable control and monitoring of the cultivation parameters besides presenting a higher susceptibility to contamination due to excessive manipulation to reach the ideal amount of cells. Moreover, this kind of cultivation does not allow a large scale production. For this reason, this work was proposed with the objective to develop a low cost, effective and scalable bioprocess for expansion of bone marrow-derived MSC in microcarriers. Cells grew on microcarriers Cyotdex 3, in spinner flasks with the -MEM medium supplemented with 15% FBS. We evaluated the cell adhesion to microcarriers, growth, metabolism, final cell recovery, and the functional and immunophenotypic properties before and after cultivation, comparing them with the cultivation already established in static flasks. In general, the results obtained showed that it was possible to expand MSC using microcarriers technology. The analysis of the cell metabolism showed that there was no depletion of important nutrients such as glucose and glutamine during cultivation, neither formation of lactate and ammonia subproducts in inhibitory concentrations. The cells recovered after the expansion kept the immunophenotypic and functional characteristics. The mean production (n=10) was about 4,9x105 cel/mL. As the system used allows the scale-up, if we had used a bioreactor of 1L it would had been possible to produce approximately 5x108 cells that would be enough to treat more than three patients of up to 70kg with a dose of 2x106 cells/kg. For the expansion of the same amount of cells in the traditional way, it would be necessary 135 T-flasks of 175 cm2 with total cost twice higher than the estimate cost of expansion using microcarriers.

Submitted by LUCIANA DINIZ ROLA Rola (lanakauz@gmail.com) on 2017-02-20T21:28:43Z No. of bitstreams: 1 Tese_Rola, L.D..pdf: 3390186 bytes, checksum: 5d304c7641470e86a2977f340d4e7767 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-02-23T14:55:14Z (GMT) No. of bitstreams: 1 rola_ld_dr_jabo.pdf: 3390186 bytes, checksum: 5d304c7641470e86a2977f340d4e7767 (MD5) / Made available in DSpace on 2017-02-23T14:55:14Z (GMT). No. of bitstreams: 1 rola_ld_dr_jabo.pdf: 3390186 bytes, checksum: 5d304c7641470e86a2977f340d4e7767 (MD5) Previous issue date: 2017-02-03 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Os cervídeos têm sofrido com a diminuição do seu habitat natural, segregação entre populações e diminuição da diversidade genética. Embora a criopreservação e estocagem de gametas e embriões seja usada como estratégia de preservação de populações selvagens, poucos estudos tem obtido sucesso devido a dificuldades na sua obtenção. Recentes estudos com células tronco de pluripotência induzida (“induced pluripotent stem cells” - iPSC) derivadas de células somáticas humanas e de camundongos conseguiram diferenciação em células germinativas, espermatozoides e oócitos. Deste modo, tem-se o objetivo a longo prazo de produzir gametas viáveis de cervídeos, a partir de células somáticas. Porém, como até a presente data células iPSC ainda não foram derivadas em cervídeos, o enfoque principal neste projeto foi estabelecer protocolos que propiciem a obtenção de linhagens iPSC estáveis. O processo de reprogramação de células somáticas em células iPSC é facilitado pelo uso de células-tronco adultas que possuam capacidade multipotente. Como pouco se conhece a respeito de células-tronco multipotentes em cervídeos, a primeira meta deste trabalho teve como objetivo obter biopsias de diversos tecidos com capacidade multipotente. Entre elas encontram-se as células-tronco do tecido adiposo, chifre e pele. Uma vez estabelecidas, as linhagens de cada tecido foram avaliadas quanto ao seu tempo de duplicação da população celular e foram induzidas à diferenciação em outros tipos de células (adipócitos, condrócitos e osteócitos) para avaliar sua plasticidade in vitro. Ainda, foi caracterizada a expressão de marcadores moleculares por meio da imunocitoquímica (OCT4, SOX2, Nanog, REX1) e RT-qPCR (OCT4, SOX2, Nanog, LIN28, REX1). A segunda meta teve como enfoque a derivação de células iPSC a partir das linhagens tronco multipotentes obtidas anteriormente. A derivação das linhagens iPSC foi testada pelo uso de integração gênica que exprimem quatro fatores de transcrição (c-Myc, Klf4, Oct4 e Sox2) pelos métodos de nucleofecção, lipofecção ou lentiviral. As colônias do tipo iPSC foram obtidas somente pelo método de nucleofecção e foram repicadas isoladamente. Porém, falharam em estabelecer linhagens clonais para posterior caracterização. A terceira meta deste trabalho visou estabelecer linhagens de células semelhantes as germinativas primordiais (“Primordial germ cell-like” PGCLs). Devido a falha em reprogramar as células-tronco adultas em iPSC, foram estabelecidas as linhagens de PGCLs por diferenciação de células de chifre, gordura e pele, passando pela fase de células semelhantes as epiblásticas (“epiblast-like cells” EpiLCs) e posteriormente sendo diferenciadas nas PGCLs. Após diferenciação, as PGCLs foram submetidas a testes de imunocitoquímica (DDX4 e DAZL) e RT-qPCR (DDX4, Stra8, Stella, Fragilis, OCT4). Ainda, foi testada a influência do ácido retinoico e do BMP4, bem como os sistemas de cultivo em adesão e em suspensão para a diferenciação das células multipotentes em PGCLs. / FAPESP: 13/13972-0

As células mesenquimais estromais multipotentes (CMM) são na atualidade uma fonte atrativa para aplicações na engenharia de tecidos e na terapia celular. Devido à baixa disponibilidade nos tecidos (0,01%-0,0005%) e às elevadas doses necessárias para uma infusão (aproximadamente 106 células/Kg paciente) tornou-se necessário o desenvolvimento de tecnologias de expansão in vitro, eficientes e de custo reduzido, que permitam a obtenção de CMM com manutenção das características funcionais (diferenciação e inibição da proliferação de linfócitos), imunofenotípicas e citogenéticas. As CMM são células aderentes, ou seja, necessitam de um substrato sólido para se aderir e proliferar. O procedimento convencional de expansão em garrafas estáticas, geralmente envolve um processo laborioso em que não há correto controle e monitoramento dos parâmetros de cultivo e possui uma maior susceptibilidade à contaminação devido à excessiva manipulação para atingir o número ideal de células. Além disso, este tipo de cultivo não permite uma produção em larga escala. Em função disso, o presente trabalho foi proposto com o objetivo de desenvolver um bioprocesso escalonável, economicamente viável e eficiente para expansão de CMM derivadas da medula óssea em microcarregadores. Para isso, as células foram cultivadas em microcarregador Cyotdex 3, em frasco spinner com o meio -MEM suplementado com 15% de SFB. Foram avaliadas neste trabalho, a adesão celular aos microcarregadores, crescimento, metabolismo, recuperação celular final e avaliação das propriedades funcionais e imunofenotípicas pré e pós cultivo, comparando ao cultivo já estabelecido em garrafas estáticas. De maneira geral, os resultados obtidos mostraram que foi possível expandir CMM utilizando a tecnologia de microcarregadores. A análise do metabolismo celular mostrou que não houve exaustão de nutrientes importantes como glicose e glutamina durante o cultivo, tampouco formação dos subprodutos lactato e amônia em concentrações inibitórias. As células recuperadas após a expansão mantiveram as características imunofenotípicas e funcionais. A produção média (n=10) foi de aproximadamente 4,9x105 cel/mL. Como o sistema utilizado permite o escalonamento, se utilizássemos um biorreator de 1L, seria possível a produção de aproximadamente 5x108 células que seriam suficientes para tratar mais de 3 pacientes de até 70Kg na dose de 2x106 células/Kg. Para expansão da mesma quantidade de células na forma tradicional seriam necessárias 135 garrafas de 175 cm2 com um custo total de expansão duas vezes superior à estimativa do custo de expansão utilizando microcarregadores. / Multipotent mesenchymal stromal cells are currently an attractive source for applications in tissue engineering and cell therapy. Due to the low availability in tissues (0,01%-0,0005%) and the high doses necessary for an infusion (about 106 cells/Kg patient), it has become necessary the development of effective and low cost technologies for in vitro expansion that enable to obtain MSC with maintenance of functional (differentiation and inhibition of lymphocytes proliferation), immunophenotypic and cytogenetics characteristics. MSC are adherent cells, i.e., they need a solid substrate to adhere and proliferate. The conventional procedure for expansion in static flasks normally involves a laborious process in which there is no suitable control and monitoring of the cultivation parameters besides presenting a higher susceptibility to contamination due to excessive manipulation to reach the ideal amount of cells. Moreover, this kind of cultivation does not allow a large scale production. For this reason, this work was proposed with the objective to develop a low cost, effective and scalable bioprocess for expansion of bone marrow-derived MSC in microcarriers. Cells grew on microcarriers Cyotdex 3, in spinner flasks with the -MEM medium supplemented with 15% FBS. We evaluated the cell adhesion to microcarriers, growth, metabolism, final cell recovery, and the functional and immunophenotypic properties before and after cultivation, comparing them with the cultivation already established in static flasks. In general, the results obtained showed that it was possible to expand MSC using microcarriers technology. The analysis of the cell metabolism showed that there was no depletion of important nutrients such as glucose and glutamine during cultivation, neither formation of lactate and ammonia subproducts in inhibitory concentrations. The cells recovered after the expansion kept the immunophenotypic and functional characteristics. The mean production (n=10) was about 4,9x105 cel/mL. As the system used allows the scale-up, if we had used a bioreactor of 1L it would had been possible to produce approximately 5x108 cells that would be enough to treat more than three patients of up to 70kg with a dose of 2x106 cells/kg. For the expansion of the same amount of cells in the traditional way, it would be necessary 135 T-flasks of 175 cm2 with total cost twice higher than the estimate cost of expansion using microcarriers.

Células multipotentes mesenquimais estromais (CTM) são células adultas multipotentes que podem ser isoladas a partir de diferentes tecidos e são capazes de atingir sítios danificados, exercer papéis na regeneração tecidual e modular a resposta imune. Estas células demonstraram resultados discrepantes em estudos in vivo dependentes de sua fonte de obtenção. Há na literatura hipóteses de que o mecanismo predominante pelo qual as CTMs atuam no reparo tecidual estaria relacionado à sua atividade parácrina, criando um microambiente com sinais tróficos. Nesse sentido, a avaliação do conteúdo do secretoma destas células é de grande interesse. Portanto, este projeto teve como objetivo analisar o meio condicionado de CTMs obtidas de diferentes fontes (tecido adiposo, músculo esquelético e tubas uterinas) de mesmos indivíduos. A abordagem experimental consistiu em proteômica shotgun (nanocromatografia líquida acoplada a espectrometria de massas em tandem) com o intuito de identificar alvos diferentemente expressos entre as culturas que possam sugerir funções específicas de cada linhagem celular. Os dados espectrais foram obtidos pelo modo de aquisição dependente de dados (Top15). Os dados adquiridos foram processados pelas plataformas MaxQuant e TPP (Trans-Proteomic Pipeline). Foi realizada análise qualitativa de vias enriquecidas por meio do programa Ingenuity utilizando as proteínas em comum nos secretoma de todas as CTMs analisadas. Essa análise permitiu observar vias enriquecidas de proliferação celular, migração celular e desenvolvimento do sistema cardiovascular, demonstrando que as proteínas secretadas por quaisquer das CTMs analisadas podem ser relacionadas a resultados encontrados na literatura utilizando estas células para terapias para patologias. As análises estatísticas para determinar se haveria dependência da composição do secretoma em função do indivíduo doador ou tecido fonte das CTMs revelaram proteínas diferencialmente expressas entre todos os grupos. Estas proteínas diferencialmente expressas são relacionadas à proliferação, sinalização e interação celular, além de modulação do sistema imune e da angiogênese. Neste contexto, podemos concluir que o secretoma das CTMs é muito semelhante, que as CTMs isoladas de quaisquer tecidos ou indivíduos são capazes de secretar moléculas que possivelmente exercem benefícios em determinado tratamento. Entretanto, estes benefícios podem ser exacerbados ou suprimidos pelas moléculas diferencialmente expressas, as quais são dependentes tanto dos tecidos quanto dos indivíduos dos quais as CTMs foram obtidas / Multipotent Mesenchymal Stromal Cells (MSCs) are multipotent adult cells that can be isolated from different tissues and are able to reach damaged sites, play a role in tissue regeneration and modulate immune response. These cells showed conflicting results in studies in vivo depending on their tissue origin. It is hypothesised that the predominant mechanism by which MSCs function could be related to its paracrine activity, creating a microenvironment with trophic signals. Accordingly, the evaluation of the content of the secretome of these cells is of great interest. Towards this end, this project analyzed the proteins of conditioned medium of MSCs obtained from different sources from the same donors (adipose tissue, uterine tubes and skeletal muscle). The MSCs were characterized by flow cytometry for the presence of membrane markers and by differentiation in vitro into adipocytes, chondrocytes, and osteoblasts. The conditioned media were obtained and the protein profile was analysed by liquid nanochromatography coupled to tandem mass spectrometry. Spectral data were obtained by full-acquisition mode MS / dd-MS2 (Top15). The acquired data were processed by MaxQuant software and TPP (Trans-Proteomic Pipeline). Qualitative analysis of enriched pathways through the Ingenuity program using the shared proteins between the cell lineages was performed.It showed enriched pathways related to cell proliferation, cell migration and development of the cardiovascular system. This allows considering that the secreted proteins from the analyzed MSCs might be related to findings in the literature using these cells for therapies. After this, the proteins were analyzed for differential expression by comparing the MSCs into groups of different sources or different donors. In which were observed differentially expressed proteins related to proliferation, cell signaling and interaction, modulation of the immune system and angiogenesis. In this context, we can conclude that MSC\'s secretome is very similar in the analyzed lineages, and that any MSCs are able to secrete molecules which potentially exert for certain treatment benefits. However, these benefits can be exacerbated or annulled by differentially expressed molecules, which are dependent both as the individual and tissues from which MSCs were obtained

Les cellules souches embryonnaires humaines (hESCs) et les cellules souches pluripotentes induites humaines (hiPSCs) ont démontré leur capacité d'auto-renouvellement et peuvent potentiellement se différencier en tous les types de lignées cellulaires. Elles représentent donc une source illimitée de cellules pour le développement de thérapies curatives pour les maladies dégénératives, telles que la dystrophie musculaire de Duchenne (DMD). Cette maladie héréditaire est le résultat de diverses mutations dans le gène de la dystrophine. Ces mutations engendrent un changement dans le cadre de lecture du gène de la dystrophine, abolissant ainsi son expression. Elle se caractérise cliniquement par une progression rapide de la dégénérescence musculaire qui débute tôt dans la vie. Les hiPSCs dystrophiques ont été corrigées par notre collaborateur, le Dr. Hotta, en insérant une paire de bases dans l’exon 45 avec les Transcription Activator-Like Effector Nucleases (TALENs) pour rétablir le cadre de lecture du gène. Notre laboratoire a mis au point une procédure en deux étapes pour différencier des hiPSCs en cellules myogéniques. Nous avons d'abord utilisé un milieu de culture myogénique préparé spécialement dans le laboratoire (appelé MB1) pour promouvoir la différenciation des hiPSCs en cellules de type mésenchymateuses. Nous les avons ensuite transduites avec un lentivirus exprimant MyoD, un facteur de transcription myogénique sous le contrôle du promoteur synthétique CAG, afin d'induire leur différenciation en myoblastes. Ces myoblastes modifiés ont été greffés dans le muscle Tibialis anterior d’une souris Rag/mdx, un animal immunodéficient et dystrophique, et ont par la suite fusionné avec les fibres musculaires existantes. La présence de la protéine dystrophine humaine a été confirmée par immunohistofluorescence dans les muscles greffés avec les cellules corrigées génétiquement ainsi que dans le contrôle positif réalisé avec des myoblastes provenant d'un donneur sain. La thérapie cellulaire homotypique à partir de cellules corrigées génétiquement présente de grands avantages pour les patients souffrant de DMD, car elle permet l’expression d’un gène capable de produire une dystrophine fonctionnelle dans les fibres musculaires, de diminuer les risques de rejet de la greffe et d’accroitre la capacité de régénération du muscle et la force musculaire. / Human embryonic stem cells (hESCs) and human-induced pluripotent stem cells (hiPSCs) have shown self-renewal capacity and can potentially differentiate into all types of cell lineages. They represent an unlimited source of cells for the therapy of degenerative diseases, such as Duchenne Muscular Dystrophy (DMD), a disease characterized by a rapid degeneration of muscles that starts early in life. Dystrophic hiPSCs have been corrected by our collaborator, Dr. Hotta, by inserting of a single base pair in the exon 45 with Transcription Activator-Like Effector Nucleases (TALENs) to restore the reading frame of the gene. Our laboratory has developed a two-step procedure to differentiate hiPSCs into myogenic cells. We first used a myogenic culture medium especially developped in the laboratory (called MB-1) to promote the differentiation of hiPSCs into mesenchymal-like precursor cells. We next transduced them with a lentivirus expressing the myogenic transcription factor MyoD under the control of the composite CAG promoter, in order to induce their differentiation into myoblasts. Transduced cells have been grafted in the Tibialis anterior muscle of Rag/mdx mice where they fused with existing muscle fibers. The presence of the human dystrophin protein has been confirmed by immunohistofluorescence in muscles grafted with the genetically corrected cells and in a control graft with myoblasts of a healthy donor. Cell therapy shows great promises for DMD patients since it allows the expression of a normal gene capable of producing a functional dystrophin in muscle fibers and increase the regenerative capacity of the muscle and the muscle strength.

La dystrophie musculaire de Duchenne (DMD) est une myopathie héréditaire due à l'absence de dystrophine. Parmi les thérapies possibles, la greffe autologue de myoblastes dérivés de cellules souches pluripotentes induites (hiPSCs) provenant du patient dystrophique, préalablement corrigés génétiquement, est envisageable. Lors de la première partie de ma recherche, j'ai transplanté des hiPSCs de patient DMD différenciés en myoblastes chez la souris Rag/mdx. Ces cellules avaient été corrigées génétiquement à l'aide d'un vecteur lentiviral codant pour la micro-dystrophine, une dystrophine tronquée, mais toujours fonctionnelle. Mes résultats ont démontré l'expression de cette micro-dystrophine dans certaines fibres hybrides. Cependant, le protocole de différenciation des hiPSCs en myoblastes doit être amélioré. La deuxième partie de mon projet consistait donc à induire la myogenèse à l’aide de protéines recombinantes. Pour cela, des facteurs de transcription régulateurs de la myogenèse, fusionnés à un peptide de pénétration cellulaire, ont été produits et purifiés d’un système bactérien. Leur pénétration dans des cellules mésenchymateuses a été observée in vitro et leurs effets sur les cellules sont en cours d’étude. Lorsque ces approches thérapeutiques seront mises au point, elles pourraient être appliquées cliniquement pour traiter des patients dystrophiques. / Duchenne muscular dystrophy (DMD) is a hereditary myopathy due to the absence of dystrophin. Among the possible therapies, there is the autologous transplantation of genetically corrected myoblasts derived from human induced pluripotent stem cells (hiPSCs) of a dystrophic patient. In the first part of my research project, I have transplanted myoblasts differentiated from iPSCs of a DMD patient in the Rag/mdx mouse. These cells had been previously genetically corrected with a lentiviral vector coding for micro-dystrophin, a functional truncated version of dystrophin. The results demonstrated the expression of this micro-dystrophin in some of the hybrid fibers. However, in order to increase the graft success, the protocol of differentiation of hiPSCs in myoblasts must be improved. The second part of my project was the induction of myogenesis from hiPSCs using recombinant proteins. To accomplish this, myogenic transcription factors fused with a cell penetrating peptide were produced and purified from the bacterial system. Their capacity to enter into mesenchymal-like cells in vitro was observed and their effects on the cells are currently under study. Once optimized, these therapeutic approaches could be clinically applied to treat dystrophic patients.