Made available in DSpace on 2015-04-20T12:31:32Z (GMT). No. of bitstreams: 1 thais tibery.pdf: 4504254 bytes, checksum: a80d65e77dee7ec1a7763c37d5698623 (MD5) Previous issue date: 2013-08-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The installation process of leishmaniasis in the host is determined by a complex association between factors related to virulence of the parasite and the host immune response. Factors such as parasite species, its virulence and tropism, besides the genetic condition and host immune trigger different clinical forms in American cutaneous leishmaniasis (ACL). As a result, it is of paramount importance to understand the mechanisms of the immune response against the parasite, cell types, cytokines and response profile involved in this process, since these factors may confer some resistance to the parasite and/or prevent the development reinfection. 33 patients with ACL caused by Leishmania (Viannia) guyanensis, L. (V.) naiffi and L. (Leishmania) amazonensis. The predominant species found was L. (V.) guyanensis representing 73% of cases. The comparative analysis of the cellular and cytokine profile evaluated by the techniques of flow cytometry and ELISA in infected patients was significantly higher than in individuals without infection (control). Apparently, the infection caused by L. (V.) guyanensis induces a higher concentration of pro-inflammatory cytokines (IL-2 and INF-γ) than infection caused by L. (L.) amazonensis, what was not observed in infection by L. (V.) naiffi. There was variation in the concentration of cytokines and cell percentage in samples from infected patients before initiating treatment with pentavalent antimony compared to the control group and after treatment. The percentage of CD4+ T cells prior to treatment was greater than CD8+ T cells. Lower percentage of regulatory T cells was observed before treatment. These results indicate that there is influence of immune response modulation on Leishmania infection and infections caused by L. (V.) guyanensis have exacerbated the response to infection caused by the other species studied here. / O processo de instalação da leishmaniose no hospedeiro é determinado por uma complexa associação entre fatores relacionados à virulência do parasito e a resposta imune do hospedeiro. Fatores como a espécie parasitária, sua virulência e tropismo, além da condição genética e imunológica do hospedeiro desencadeiam diferentes formas clínicas na Leishmaniose tegumentar Americana (LTA). Em decorrência disso, é de suma importância compreender os mecanismos da resposta imune contra o protozoário, os tipos celulares, as citocinas e o perfil da resposta envolvida nesse processo, uma vez que, esses fatores podem conferir certa resistência ao parasito e/ou impedir o desenvolvimento de nova infecção. Foram avaliados 33 pacientes com LTA, causada por Leishmania (Viannia) guyanensis, L. (V.) naiffi e L. (Leishmania) amazonensis. A espécie predominante encontrada foi L. (V.) guyanensis representando 73% dos casos. A análise comparativa do perfil celular e das citocinas avaliadas pelas técnicas da Citometria de fluxo e ELISA nos pacientes infectados foi significativamente maior do que nos indivíduos sem infecção (controle). Aparentemente, a infecção causada por L. (V.) guyanensis, induz maior concentração de citocinas pró-inflamatórias (IL-2 e INF-γ) do que infecção causada por L. (L.) amazonensis, o mesmo não foi observado na infecção por L. (V.) naiffi. Verificou-se variação na concentração das citocinas e no percentual celular nas amostras dos pacientes infectados antes do início do tratamento com antimonial pentavalente quando comparado ao grupo controle e ao término do tratamento. O percentual de linfócitos T CD4+ antes do tratamento foi maior do que linfócitos T CD8+. Menor porcentagem de células T regulatórias foi observada antes do tratamento. Esses resultados indicam que existe influência da resposte imune na modulação da infecção por Leishmania e que infecções causadas por L. (V.) guyanensis apresentam resposta mais exacerbada do que a infecção causada pelas outras espécies aqui estudadas.

Colorectal cancer (CRC) is the fourth most common cause of cancer related deaths in the UK with the prognosis dependent on the degree of tumour invasion and presence of metastasis at diagnosis. An important step in the invasion and metastasis of solid tumours is the loss of cell-cell junctions and the acquirement of a more motile mesenchymal phenotype which is facilitated by the epithelial-mesenchymal transition (EMT). The presence of EMT is linked with a more aggressive, invasive tumour and subsequent poor prognosis. In addition to roles in motility and invasion, EMT can induce a cancer stem cell phenotype in a subset of tumour cells. Cancer stem cells (CSCs) are a subpopulation of cells capable of self-renewal and maintaining a cellular population whilst displaying increased therapeutic resistance. Induction of EMT and CSCs can be regulated by common signalling pathways with expression of EMT transcription factors inducing CSCs expression. Understanding the signalling pathways regulating EMT and CSC formation in cancer is important for preventing of metastasis and combating therapeutic resistance. Aspirin’s role in cancer prevention has been established for a number of years with aspirin treatment reducing the incidence of CRC. Recently, evidence has emerged suggesting aspirin treatment may have post-diagnosis benefits and increase survival rates of CRC patients. A potential mechanism for the post-diagnosis benefit of aspirin is the inhibition of EMT and CSC formation which both facilitate tumour progression and metastasis. Aspirin has been demonstrated to suppress the migratory and invasive capacity of lung cancer cell lines by inhibiting EMT. Whilst aspirin has been shown to inhibit platelet-induced EMT in CRC, the direct effects of aspirin on EMT in CRC cell lines has not been established. I hypothesis that aspirin inhibits cell migration, invasion and EMT in CRC which results in a reduction in the CSC population and contributes to the clinical benefit of post-diagnosis aspirin. Using CRC cell lines, I have demonstrated that aspirin treatment inhibits cell migration, invasion, motility and promotes an epithelial phenotype. These results have been confirmed in human organoids and mouse intestinal adenoma in vivo models. Aspirin also promotes a budding phenotype in Apc deficient organoids and reduces expression of stem cell markers in both mouse and human tissue. Aspirin inhibits the mTOR and Wnt signalling pathways in vivo which have the ability to regulate EMT and CSCs although signalling dependency has not been determined. Regardless, aspirin is decreasing the cancer stem cell population and promoting a non-invasive epithelial phenotype which may explain some of the previously described post-diagnosis benefits.

Although wild birds are natural hosts of avian influenza viruses (AIVs), these viruses can be highly contagious to poultry and a zoonotic threat to humans. The propensity of AIV for genetic variation through genetic shift and drift allows virus to evade vaccine mediated humoral immunity. An alternative approach to current vaccine development is induction of CD8+ T cells which responds to more conserved epitopes than humoral immunity and targets a broader spectrum of viruses. Since the memory CD8+ T lymphocyte responses in chickens to individual AIV proteins have not been defined, the modulation of responses of the memory CD8+ T lymphocytes to H5N9 AIV hemagglutinin (HA) and nucleocapsid (NP) proteins over a time course were evaluated. CD8+ T lymphocyte responses induced by intramuscular inoculation of chickens with AIV HA and NP expressing cDNA plasmids or a non-replicating human adenovirus vector were identified through ex vivo stimulation with virus infected, major histocompatibility complex (MHC) matched antigen presenting cells (APCs). The IFN? production by activated lymphocytes was evaluated by macrophage production of nitric oxide and ELISA. MHC-I restricted memory T lymphocyte responses were determined at 10 days and 3, 5, 7 and 9 weeks post-inoculation (p.i). The use of non-professional APCs and APC driven proliferation of cells with CD8+ phenotype correlated with the activation of CD8+ T lymphocytes. The responses specific to nucleocapsid protein (NP) were consistently greater than those to the hemagglutinin (HA) at 5 weeks when the CD8+ T cell responses were maximum. By 8 to 9 weeks p.i., responses to either protein were undetectable. The T lymphocytes also responded to stimulation with a heterologous H7N2 AIV infected APCs. Administration of booster dose induced secondary effector cell mediated immune responses which had greater magnitudes than primary effector responses at 10 days p.i. Flow cytometric analysis (FACS) of the T lymphocytes demonstrated that memory CD8+ T lymphocytes of chickens can be distinguished from naive lymphocytes by their higher expression of CD44 and CD45 surface antigens. CD45 expression of memory lymphocytes further increases upon ex vivo stimulation with APCs expressing AIV. This is the first characterization of avian memory responses following both primary and secondary expression of any individual viral protein.

No description available.

Skeletal muscle satellite cells located between the plasma membrane and the basal lamina of muscle fibres, could for many years, only be studied in situ by electron microscopy. The introduction of immunohistochemistry and the discovery of molecular markers of satellite cells then made them accessible for light microscopic studies and a wealth of information is today available. Satellite cells are myogenic stem cells that can be activated from a quiescent state to proliferate for self-renewal or differentiate into myogenic cells. The satellite cells are involved in muscle growth during fetal and postnatal development and play a key role in repair and regeneration of damaged muscle fibres. The satellite cells are also essential for muscle fibre hypertrophy and maintenance of muscle mass in the adult. When the present thesis was initiated, studies on satellite cells in human skeletal muscle relied on the neuronal cell adhesion molecule (NCAM) as a marker for satellite cell identification. The results from different studies varied markedly. Therefore the aims of the present thesis were i) to develop a highly reliable method using light microscopy for satellite cell identification and quantification in biopsies of human skeletal muscle in normal and pathological conditions. A molecular marker for the myofibre basal lamina or plasma membrane to enhance the reliability of myonuclei and satellite cell identification were to be included. Furthermore unbiased morphometric methods should be used in the quantification process. ii) to evaluate which molecular markers which had been described for satellite cell and stem cell identification in different cell states (quiescence, activated or differentiated) are the most useful for studies on human skeletal muscle. iii) to further explore the function and heterogeneity of satellite cells with respect to different markers in human skeletal muscle by studying the effects of strength-training, intake of anabolic substances and pathological conditions. A new immunofluorescence method was developed where in the same tissue section, two satellite cell markers, the basal lamina and nuclei were monitored. From the evaluation of different markers it was found that both NCAM and Pax7 identified the majority of satellite cells but that both markers were needed for reliable identification. The members of the myogenic regulatory family were evaluated and by using the new method MyoD and myogenin were found to be useful markers to identify activated and differentiated satellite cells. Upon re-examination of biopsies from power-lifters, power-lifters using anabolic substances and untrained subjects it was observed that the new results on satellite cell frequency were significantly different from those obtained when using staining for NCAM and nuclei alone. In addition three subtypes of satellite cells (94.4% NCAM+/Pax7+, 4.2% NCAM+/Pax7– and 1.4% NCAM–/Pax7+) were observed. Thus the multiple marker method gave more information about satellite cells heterogeneity in human muscle and we propose that this is more reliable than previous methods. Low numbers of MyoD or myogenin stained satellite cells were observed in both untrained and strength trained subjects. Other markers such as DLK1/FA1, a member of the EGF-like family and c-Met, the receptor for hepatocyte growth factor showed that satellite cell heterogeneity in human muscle is far greater than previously shown. Furthermore, new evidence is presented for so called fibre splitting observed in hypertrophic muscle fibres to be due to defect regeneration of partially damaged fibres.

Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2017-06-01T14:19:33Z No. of bitstreams: 1 arquivototal.pdf: 3473301 bytes, checksum: 4d22636d8d38c872a66d2aa8bf1d2e3f (MD5) / Made available in DSpace on 2017-06-01T14:19:33Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3473301 bytes, checksum: 4d22636d8d38c872a66d2aa8bf1d2e3f (MD5) Previous issue date: 2016-12-15 / Monocytes and macrophages represent keys components of the immune response. Based on the expression of LPS co-receptor CD14 and CD16 expression, FCγ III receptor, monocytes are classified into 3 subtypes: classical monocytes, which are CD14hiCD16-; intermediate monocytes, which are CD14hiD16+; and non-classical monocytes, CD14lowCD16+. AD is a chronic inflammatory cutaneous disease, with multifactorial etiology. Our group performed comparative analysis of monocytes subtypes through the study of the frequency and medium fluorescence intensity of surface molecules (HLADR, CCR5, CD80, CD86, PD1L) and cytokine (IL-6, TNF, IL10) in adults and children by using flow cytometry. The study was performed in two stages. First we compared the subtypes of monocytes from healthy adults and children, and then between healthy children and children with atopic dermatitis (AD). The role of monocyte activation and modulation of the inflammatory process is the subject of our investigation. The results of this study showed that: (1) the relative frequency of monocytes subtypes was similar in adults, healthy children and children with AD, with a predominance of classical monocytes; (2) Classical, intermediate and nonclassical monocytes of children with AD have higher HLA-DR expression when compared to those of healthy children, and monocytes of healthy children have higher expression than healthy adults; (3) adults, healthy children and DA children have higher frequency and expression of CCR5 in intermediate and nonclassical that in classical monocytes; (4) the frequency and expression of CD80 was higher in intermediate and nonclassical monocytes both in children and healthy adults and CD86 expression was more pronounced in intermediate monocytes, in these two groups, beyond wich the expression of CD80 and CD86 molecules on classical monocytes of children with AD was higher than in healthy children; (5) PD1L frequency in monocytes subtypes was similar in adults and children, however, there is a higher expression of this molecule in children classical monocytes when compared to healthy adults classical monocytes. In addition, atopic children have higher expression of this molecule on classical monocytes than healthy children; (6) intermediate and nonclassical monocytes of healthy adults and children have greater inflammatory activity than classical monocytes when evaluating the frequency and expression of IL-6 and TNF-α, contrary to what is observed in children with AD who have greater frequency and expression of IL-6 and TNF-α in classical monocytes compared to healthy children; (7) intermediate and nonclassical monocytes have increased IL10 production than classical monocytes in healthy adults and children. Thus, our results revealed that the relative monocytes frequency is constant in the three studied population groups, but the frequency and expression of surface molecules and cytokines presented significant peculiarities. Summarizing, healthy children have greater expression of HLA-DR molecule than healthy adults, and atopic children have greater expression than healthy children. Monocytes subtypes more involved inflammatory response in healthy adults and children are intermediate and nonclassical monocytes, while classical monocytes in atopic children are more involved in inflammatory response than the same subtype in healthy children. These findings revealed changes in the innate immunity of children with atopic dermatitis extremely important for understanding the pathophysiology of disease. / Os monócitos e macrófagos representam componentes fundamentais da resposta imune. Com base na expressão do co-receptor de LPS CD14 e na expressão do CD16, receptor FCγIII, os monócitos são classificados em 3 subtipos: monócitos clássicos, que são CD14hiCD16-; monócitos intermediários, que são CD14hiD16+; e monócitos não-clássicos, ou CD14lowCD16+. A DA é uma doença inflamatória cutânea crônica, de etiologia multifatorial. Nosso grupo realizou análise comparativa entre os subtipos monocitários por meio do estudo da frequência e da média de intensidade de fluorescência (MFI) de moléculas de superfície (HLA-DR, CCR5, CD80, CD86, PD1L) e da produção de citocinas (IL6, TNFα, IL10) em adultos e crianças utilizando a citometria de fluxo. A pesquisa foi executada em duas etapas. Primeiro comparamos os subtipos de monócitos entre adultos e crianças saudáveis e em seguida, entre crianças sadias e crianças portadoras de dermatite atópica (DA). O papel dos monócitos na ativação e modulação do processo inflamatório foi objeto da nossa investigação. Os resultados desse estudo mostraram que: (1) a frequência relativa dos subtipos de monócitos foi similar em adultos, crianças saudáveis e crianças portadoras de DA, com predomínio de monócitos clássicos; (2) monócitos clássicos, intermediários e não-clássicos de crianças atópicas apresentaram maior expressão de HLA-DR que os mesmos subtipos em crianças sadias e essas, que adultos sadios; (3) adultos, crianças saudáveis e crianças doentes apresentaram maior frequência e expressão de CCR5 em monócitos intermediários e monócitos não-clássicos; (4) a frequência e expressão do CD80 foi maior em monócitos intermediários e não clássicos tanto em crianças como em adultos saudáveis e a expressão de CD86 foi maior em monócitos intermediários desses dois grupos. Já a expressão das moléculas de CD80 e CD86 em monócitos clássicos de crianças portadoras de DA foi maior que em crianças saudáveis; (5) a frequência de PD1L nos subtipos de monócitos foi semelhante em adultos e crianças, entretanto, houve maior expressão dessa molécula em monócitos clássicos de crianças que em adultos saudáveis e crianças atópicas apresentaram maior expressão desta molécula em monócitos clássicos que crianças saudáveis; (6) monócitos intermediários e não-clássicos de adultos e crianças saudáveis apresentaram maior atividade inflamatória que monócitos clássicos ao se avaliar a frequência e expressão de IL-6 e TNF-α, ao contrário do que se observou em crianças com DA, que apresentaram maior frequência e expressão de IL-6 e TNF-α em monócitos clássicos que as crianças saudáveis; (7) monócitos intermediários e não-clássicos demonstraram maior produção de IL10 que monócitos clássicos em adultos e crianças saudáveis. Nossos resultados mostraram, portanto que a frequência relativa de monócitos é constante nos três grupos populacionais estudados, mas a frequência e expressão de moléculas de superfície e citocinas apresentam particularidades significativas. Em resumo, crianças atópicas apresentam maior expressão de HLA-DR que crianças saudáveis e essas, que adultos saudáveis. Os subtipos de monócitos mais envolvidos na resposta inflamatória em adultos e crianças sadias são monócitos intermediários e não-clássicos, enquanto monócitos clássicos de crianças atópicas são mais inflamatórios quando comparados ao mesmo subtipo em crianças saudáveis. Essas descobertas revelam alterações na imunidade inata de crianças portadoras de dermatite atópica de extrema importância para a compreensão da fisiopatologia da doença.

Perivascular cells of microvascular niches are the prime candidates for being a reservoire of mesenchymal stem cell (MSC)-like cells in many tissues and organs that could serve as a potential source of cells and a target of novel cell-based therapeutic approaches. In the present study, by utilising typical markers of pericytes (neuronal-glial antigen 2, NG2, a chondroitin sulphate proteoglycan) and those of MSCs (CD146 and CD105) and primitive pluripotent cells (sex-determining region Y-box 2, Sox2), the phenotypic traits and the distribution of murine and rat retinal perivascular cells were investigated in situ. Our findings indicate that retinal microvessels of juvenile rodents are highly covered by NG2-positive branching processes of pericytic (perivascular) cells that are less prominent in mature capillary networks of the adult retina. In the adult rodent retinal vascular bed, NG2 labeling is mainly confined to membranes of the cell body resulting in a pearl-chain-like distribution along the vessels. Retinal pericytes, which were identified by their morphology and NG2 expression, simultaneously express CD146. Furthermore, CD146-positive cells located at small arteriole-tocapillary branching points appear more intensely stained than elsewhere. Evidence for a differential expression of the two markers around capillaries that would hint at a clonal heterogeneity among pericytic cells, however, is lacking. In contrast, the expression of CD105 is exclusively restricted to vascular endothelial cells and Sox2 is detected neither in perivascular nor in endothelial cells. In dissociated retinal cultures, however, simultaneous expression of NG2 and CD105 was observed. Collectively, our data indicate that vascular wall resident retinal pericytes share some phenotypic features (i.e. CD146 expression) with archetypal MSCs, which is even more striking in dissociated retinal cultures (i.e. CD105 expression). These findings might have implications for the treatment of retinal pathologies.

The leading cause of breast cancer-associated death is metastasis. During metastasis, tumor cells metastasize from primary tumors to distant organs via the circulatory and lymphatic systems. However, in 80% of solid tumors, metastasis via the lymphatic system precedes metastasis via the vascular system. There is a lot of information about metastasis through the circulatory system. However, not much information is available about the tumor cell dissemination through the lymphatic system or the lymphatic microenvironment that aids in this process in breast cancer metastasis. In addition, the molecular properties of tumor cells as they exit the primary tumor into the afferent lymphatics en route to the sentinel lymph nodes (SLNs) are not yet known.<br><div><br></div><div>This project aims to determine why and how tumor cells metastasize to the lymphatic system. The proposal is based on the hypothesis that active migration is needed for tumor cells to spread via the lymphatic vessels. Thus, finding and understanding the molecules that contribute to this can be a breakthrough for breast cancer metastasis therapy.<br></div><div><br></div><div>The goals of this thesis are to 1) Examine the molecular, genetic, and proteomic characteristics of circulatory tumor cells and compare these to the primary tumor and lung metastasis, 2) Examine the role of Toll-like receptors in tumor cell migration to the lymph node, and 3) Identify the difference in protein expression among two different types of breast cancer (Triple-Negative and Luminal A) and understand their aggressive biology.<br></div>

Le système endocannaboïde (eCB) est constitué des ligands, des récepteurs – les plus étudiés étant les récepteurs CB1 et CB2 – et les enzymes de synthèse et de dégradation. Les ligands étant lipophiles, ils ne sont pas encapsulés dans des vésicules, ce qui place les enzymes de synthèse et de dégradation dans une position de régulateurs clés. Plusieurs études démontrent une participation du système eCB à des processus de développement dans le système nerveux central (SNC). La rétine est un modèle important pour l’étude de ces processus car elle contient plusieurs types cellulaires bien connus, dont le patron de développement est clairement établi. Pour l’instant très peu est connu sur l’expression du système eCB durant le développement rétinien. C’est dans ce cadre que les patrons d’expression du récepteur CB1 et de l’enzyme de dégradation FAAH ont été étudiés pendant le développement rétinien postnatal chez le rat. Pour identifier les types cellulaires exprimant ces protéines, des co-marquages ont été accomplis pour le récepteur CB1 ou FAAH et des marqueurs des types cellulaires rétiniens. À P1, les cellules ganglionnaires, amacrines, horizontales et mitotiques expriment le récepteur CB1. Les cellules ganglionnaires et amacrines cholinergiques sont FAAH-positives. Au cours du développement, certains types cellulaires démontrent une expression transitoire de ces deux protéines, suggérant une implication du système eCB dans les processus de développement. Nos données démontrent également une importante expression du système eCB dans la rétine adulte, ce qui soutient l’hypothèse de son implication dans la réponse rétinienne. En bref, des études fonctionnelles in vitro sur des rétines de non-mammifères ont révélées que le récepteur CB1 modulait la réponse des cônes et des cellules bipolaires. Malgré la récente démonstration de sa présence dans la rétine, il n’existe pas de d’étude sur le rôle du récepteur CB2 dans la rétine. Dans cette thèse, les conséquences fonctionnelles de l’élimination des récepteurs CB1 ou CB2 ont été évaluées chez des souris transgéniques. Les réponses rétiniennes ont été enregistrées par électrorétinographie chez des souris cnr1-/- (CB1R-KO) et cnr2-/- (CB2R-KO). Nos données suggèrent une implication différente pour chaque récepteur dans la formation de la réponse rétinienne / The endocannabinoid (eCBs) system is composed of the ligands, the receptors - the most studied are CB1R and CB2R – and the synthesizing and degradative enzymes. The lipophilic ligands are not stored in vesicles, thereby placing the synthesizing and degradative enzymes as key regulators of the receptor function. The eCB system is thought to participate to developmental processes in the central nervous system (CNS). The rodent retina is a valuable model to study CNS development, as it contains well identified cell types with established developmental timelines. Very little is known about the distribution of this neuromodulationsystem in the developing retina. In this thesis, the expression patterns of CB1R and eCB degradative enzyme FAAH were investigated in the rat retina during postnatal development. To identify the cells expressing these proteins, co-stainings were carried out for CB1R or FAAH and retinal cell type markers. At P1, CB1R was expressed in ganglion, amacrine, horizontal and mitotic cells, whereas FAAH was present in ganglion and cholinergic amacrine cells. In the course of development, both CB1R and FAAH were transiently expressed in some cell type, suggesting a role of the eCB system in developmental processes. Furthermore, our data demonstrated an important expression of both proteins in adult animals, supporting the hypothesis that the eCB system is involved in retinal functions. Briefly, functional in vitro studies on non-mammalian retinae have revealed an effect of CB1R on cone photoreceptors and bipolar cells response. Despite the recent demonstration of CB2R mRNA and protein presence in the retina, there are no data on CB2R functional role in retina have been published. In this thesis, the consequences of removing either CB1R or CB2R from the retina of transgenic mice were evaluated. Retinal response was recorded by electroretinogram in cnr1-/- (CB1R-KO) and cnr2-/- (CB2R-KO) mice. This data suggests that both receptors are involved in shaping the retinal response to light and they have different roles in this process.

Le système endocannaboïde (eCB) est constitué des ligands, des récepteurs – les plus étudiés étant les récepteurs CB1 et CB2 – et les enzymes de synthèse et de dégradation. Les ligands étant lipophiles, ils ne sont pas encapsulés dans des vésicules, ce qui place les enzymes de synthèse et de dégradation dans une position de régulateurs clés. Plusieurs études démontrent une participation du système eCB à des processus de développement dans le système nerveux central (SNC). La rétine est un modèle important pour l’étude de ces processus car elle contient plusieurs types cellulaires bien connus, dont le patron de développement est clairement établi. Pour l’instant très peu est connu sur l’expression du système eCB durant le développement rétinien. C’est dans ce cadre que les patrons d’expression du récepteur CB1 et de l’enzyme de dégradation FAAH ont été étudiés pendant le développement rétinien postnatal chez le rat. Pour identifier les types cellulaires exprimant ces protéines, des co-marquages ont été accomplis pour le récepteur CB1 ou FAAH et des marqueurs des types cellulaires rétiniens. À P1, les cellules ganglionnaires, amacrines, horizontales et mitotiques expriment le récepteur CB1. Les cellules ganglionnaires et amacrines cholinergiques sont FAAH-positives. Au cours du développement, certains types cellulaires démontrent une expression transitoire de ces deux protéines, suggérant une implication du système eCB dans les processus de développement. Nos données démontrent également une importante expression du système eCB dans la rétine adulte, ce qui soutient l’hypothèse de son implication dans la réponse rétinienne. En bref, des études fonctionnelles in vitro sur des rétines de non-mammifères ont révélées que le récepteur CB1 modulait la réponse des cônes et des cellules bipolaires. Malgré la récente démonstration de sa présence dans la rétine, il n’existe pas de d’étude sur le rôle du récepteur CB2 dans la rétine. Dans cette thèse, les conséquences fonctionnelles de l’élimination des récepteurs CB1 ou CB2 ont été évaluées chez des souris transgéniques. Les réponses rétiniennes ont été enregistrées par électrorétinographie chez des souris cnr1-/- (CB1R-KO) et cnr2-/- (CB2R-KO). Nos données suggèrent une implication différente pour chaque récepteur dans la formation de la réponse rétinienne / The endocannabinoid (eCBs) system is composed of the ligands, the receptors - the most studied are CB1R and CB2R – and the synthesizing and degradative enzymes. The lipophilic ligands are not stored in vesicles, thereby placing the synthesizing and degradative enzymes as key regulators of the receptor function. The eCB system is thought to participate to developmental processes in the central nervous system (CNS). The rodent retina is a valuable model to study CNS development, as it contains well identified cell types with established developmental timelines. Very little is known about the distribution of this neuromodulationsystem in the developing retina. In this thesis, the expression patterns of CB1R and eCB degradative enzyme FAAH were investigated in the rat retina during postnatal development. To identify the cells expressing these proteins, co-stainings were carried out for CB1R or FAAH and retinal cell type markers. At P1, CB1R was expressed in ganglion, amacrine, horizontal and mitotic cells, whereas FAAH was present in ganglion and cholinergic amacrine cells. In the course of development, both CB1R and FAAH were transiently expressed in some cell type, suggesting a role of the eCB system in developmental processes. Furthermore, our data demonstrated an important expression of both proteins in adult animals, supporting the hypothesis that the eCB system is involved in retinal functions. Briefly, functional in vitro studies on non-mammalian retinae have revealed an effect of CB1R on cone photoreceptors and bipolar cells response. Despite the recent demonstration of CB2R mRNA and protein presence in the retina, there are no data on CB2R functional role in retina have been published. In this thesis, the consequences of removing either CB1R or CB2R from the retina of transgenic mice were evaluated. Retinal response was recorded by electroretinogram in cnr1-/- (CB1R-KO) and cnr2-/- (CB2R-KO) mice. This data suggests that both receptors are involved in shaping the retinal response to light and they have different roles in this process.