Visual system homeobox 1 (Vsx1) is a paired-like:CVC homeodomain transcription factor that is expressed in a subset of retinal bipolar cells. Vsx1-null mice have previously been shown to have defects in bipolar cell terminal differentiation characterized by the reduced expression of four OFF bipolar cell-specific markers and electrophysiological defects in the OFF visual signaling pathway. The availability of recently identified bipolar cell markers enables a further characterization of the Vsx1-null mutant. I determined that Vsx1 is expressed in Type 7 ON bipolar cells and observed the upregulation of three cell markers: Cabp5, Chx10, and alpha-gustducin:GFP in this cell type in Vsx1-null mice. These data reveal a trend in which Vsx1 functions as a transcriptional repressor in Type 7 ON bipolar cells and as an activator in Type 2 OFF bipolar cells. Lastly, my data indicate that Vsx1 is required for the expression of two Type 3a bipolar cell markers, however, the mechanism by which it does so appears to be complex, as I was unable to detect Vsx1 protein or reporter gene expression in this cell type. / Graduate

No description available.

A domesticação dos cães produziu-se simultaneamente em várias partes do globo o que ocasionou, o aparecimento por seleção de várias raças. Desde então o cão passou a ser utilizado para várias e diferentes tarefas, dentre elas acompanhar o homem, que usufruiu da sua conveniência, descobrindo que muitas vezes ambos podem sofrer dos mesmos males. Cães da raça Golden Retriever apresentam uma doença geneticamente degenerativa, homóloga a distrofia muscular de Duchenne (DMD) no homem; ambas doenças afetam o gene que produz a distrofina; uma proteína citoesquelética múscular. Uma possível forma de fornecer uma cópia normal do gene para os grupos musculares afetados de um indivíduo consiste no transplante de células tronco os quais podem ser obtidas de células embrionárias, células germinativas, células do sangue de cordão umbilical, células de medula óssea e células de sangue periférico. Estudos com modelos animais tem mostrado que transplante de células tronco fetais ou células tronco pluripotentes podem ter sucesso no tratamento de muitas doenças crônicas, sendo assim, objetivamos delinear uma linha de tratamento para distrofia muscular em cães da raça Golden Retriever, mediante caracterização e uso das células germinativas embrionárias para terapia celular. Foram utilizados 16 fêmeas sem raça definida (SRD), e as cadelas foram selecionadas a partir do exame citológico; as fêmeas foram inseminadas artificialmente, e após 30 dias de gestação os animais foram castrados pela técnica de ovário-salpingohisterectomia. Os embriões coletados possibilitaram a obtenção e estabelecimento de células tronco germinativas embrionárias, de fibroblastos fetais, de células musculares, os quais analisamos através de citometria de fluxo, interação no co-cultivo de células musculares caninas e células germinativas embrionárias e a imunopositividade das células na detecção de Oct-4. Os resultados nos possibilitam afirmar que em embriões com 22 dias de idade gestacional a região paramesonéfrica apresenta-se indiferenciada, diferentemente do que encontramos com 24 dias de idade, no qual o rim primitivo apresenta-se visível diferenciado. As células tronco germinativas embrionárias apresentaram colônias compactas e com alta proliferação de células mononucleares indiferenciadas e que as células tronco germinativas embrionárias apresentaram como principal problema a manutenção das culturas por períodos significativos. / The canine domesticity generated simultaneously in different parts of the World, that created, the begin of selection of many breeds. Since that time, dogs become to be used for different works, since follow men, that usufructed their convinience discovering most of the time that both are soffering the same ill. Dogs from the Golden Retriever breed presented a degenerative and genetically disease, homologous to Duchenne Muscular Dystrophy (DMD) in human, the dystrophin gene affection; a muscle citosckeletical protein. A possibility way to supply a correct gene shape for the affected muscle could be from the stem cell therapy from embrionic stem cell, germ cells, umbilical cord blood cells, bone marrow and perific blood. Researches with animal models are showing sucess on the treatment with fetal stem cells or pluripotents ones in different types of cronic illness, then, we aimed a treatment of the Golden Retriever Muscular Dystrophy using embrionic germ cells meantime characterization and their use on cell therapy. Were uses 16 females crossbreed (SRD), bitches were selected by the vaginal cytology exams; females were artificially inseminated and after 30 days of pregancy, the animals were histectomized. Embryos were collected to stabilish embrionic germ cells, canine fibroblasts, muscle cells, which were analysed by flow cytometre, co culture and OCT-4 detection. The results showed the paramesonephic region of embryos with 22 days of pregnancy presents undifferentiate cells(germ cells), what differs from embryos with 24 days, which primitive kidneys presented differentianted types of cells. Under culture conditions, these cells formed compact colonies with high proliferative potential, but without capacity of maintenance after 30 days.

Dendritic cells (DC) constitute a heterogeneous leukocyte population having in common a unique capacity to induce primary T cell responses and are therefore most attractive candidates for immunomodulatory strategies. Two populations of blood DC (CD11c+ CD123dim and CD11c– CD123high) have been defined so far. However, their direct isolation for experimental purposes is hampered by their low frequency and by the lack of selective markers allowing large scale purification from blood. Here we describe the monoclonal antibody (mAb) M-DC8, which was generated by immunizing mice with highly enriched blood DC. This mAb specifically reacts with 0.2–1% of blood leukocytes and enables their direct isolation by a one-step immunomagnetic procedure from fresh mononuclear cells. These cells can be differentiated from T cells, B cells, NK cells and monocytes using lineage-specific antibodies. M-DC8+ cells express HLA class II molecules, CD33 and low levels of the costimulatory molecules CD86 and CD40. Upon in vitro culture M-DC8+ cells spontaneously mature into cells with the phenotype of highly stimulatory cells as documented by the upregulation of HLA-DR, CD86 and CD40; in parallel CD80 expression is induced. M-DC8+ cells display an outstanding capacity to present antigen. In particular, they proved to be excellent stimulators of autologous mixed leukocyte reaction and to activate T cells against primary antigens such as keyhole limpet hemocyanin. Furthermore, they induce differentiation of purified allogeneic cytotoxic T cells into alloantigen-specific cytotoxic effector cells. While the phenotypical analysis reveals similarities with the two known blood DC populations, the characteristic expression of Fc=γRIII (CD16) and the M-DC8 antigen clearly defines them as a novel population of blood DC. The mAb M-DC8 might thus be a valuable tool to determine circulating DC for diagnostic purposes and to isolate these cells for studies of antigen-specific T cell priming. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

A domesticação dos cães produziu-se simultaneamente em várias partes do globo o que ocasionou, o aparecimento por seleção de várias raças. Desde então o cão passou a ser utilizado para várias e diferentes tarefas, dentre elas acompanhar o homem, que usufruiu da sua conveniência, descobrindo que muitas vezes ambos podem sofrer dos mesmos males. Cães da raça Golden Retriever apresentam uma doença geneticamente degenerativa, homóloga a distrofia muscular de Duchenne (DMD) no homem; ambas doenças afetam o gene que produz a distrofina; uma proteína citoesquelética múscular. Uma possível forma de fornecer uma cópia normal do gene para os grupos musculares afetados de um indivíduo consiste no transplante de células tronco os quais podem ser obtidas de células embrionárias, células germinativas, células do sangue de cordão umbilical, células de medula óssea e células de sangue periférico. Estudos com modelos animais tem mostrado que transplante de células tronco fetais ou células tronco pluripotentes podem ter sucesso no tratamento de muitas doenças crônicas, sendo assim, objetivamos delinear uma linha de tratamento para distrofia muscular em cães da raça Golden Retriever, mediante caracterização e uso das células germinativas embrionárias para terapia celular. Foram utilizados 16 fêmeas sem raça definida (SRD), e as cadelas foram selecionadas a partir do exame citológico; as fêmeas foram inseminadas artificialmente, e após 30 dias de gestação os animais foram castrados pela técnica de ovário-salpingohisterectomia. Os embriões coletados possibilitaram a obtenção e estabelecimento de células tronco germinativas embrionárias, de fibroblastos fetais, de células musculares, os quais analisamos através de citometria de fluxo, interação no co-cultivo de células musculares caninas e células germinativas embrionárias e a imunopositividade das células na detecção de Oct-4. Os resultados nos possibilitam afirmar que em embriões com 22 dias de idade gestacional a região paramesonéfrica apresenta-se indiferenciada, diferentemente do que encontramos com 24 dias de idade, no qual o rim primitivo apresenta-se visível diferenciado. As células tronco germinativas embrionárias apresentaram colônias compactas e com alta proliferação de células mononucleares indiferenciadas e que as células tronco germinativas embrionárias apresentaram como principal problema a manutenção das culturas por períodos significativos. / The canine domesticity generated simultaneously in different parts of the World, that created, the begin of selection of many breeds. Since that time, dogs become to be used for different works, since follow men, that usufructed their convinience discovering most of the time that both are soffering the same ill. Dogs from the Golden Retriever breed presented a degenerative and genetically disease, homologous to Duchenne Muscular Dystrophy (DMD) in human, the dystrophin gene affection; a muscle citosckeletical protein. A possibility way to supply a correct gene shape for the affected muscle could be from the stem cell therapy from embrionic stem cell, germ cells, umbilical cord blood cells, bone marrow and perific blood. Researches with animal models are showing sucess on the treatment with fetal stem cells or pluripotents ones in different types of cronic illness, then, we aimed a treatment of the Golden Retriever Muscular Dystrophy using embrionic germ cells meantime characterization and their use on cell therapy. Were uses 16 females crossbreed (SRD), bitches were selected by the vaginal cytology exams; females were artificially inseminated and after 30 days of pregancy, the animals were histectomized. Embryos were collected to stabilish embrionic germ cells, canine fibroblasts, muscle cells, which were analysed by flow cytometre, co culture and OCT-4 detection. The results showed the paramesonephic region of embryos with 22 days of pregnancy presents undifferentiate cells(germ cells), what differs from embryos with 24 days, which primitive kidneys presented differentianted types of cells. Under culture conditions, these cells formed compact colonies with high proliferative potential, but without capacity of maintenance after 30 days.

Articular cartilage is an avascular and flexible connective tissue found in joints. It produces a cushioning effect at the joints and provides low friction to protect the ends of the bones from wear and tear/damage. It has poor repair capacity and any injury can result pain and loss of mobility. One of the common forms of articular cartilage disease which has a huge impact on patient's life is arthritis. Research on cartilage cell/tissue engineering will help patients to improve their physical activity by replacing or treating the diseased/damaged cartilage tissue. Cartilage cell, called chondrocyte is embedded in the matrix (Lacunae) and has round shape in vivo. The in vitro monolayer culture of primary chondrocyte causes morphological change characterized as dedifferentiation. Transforming growth factor-beta (TGF-β), a cytokine superfamily, regulates cell function, including differentiation and proliferation. The effect of TGF-β1, 2, 3, and their manipulated forms in biological regulation of primary chondrocyte was investigated in this work. A novel method was developed to isolate and purify the primary chondrocytes from knee joint of neonate Sprague-Dawley rat, and the effect of some supplementations such as hyaluronic acid and antibiotics were also investigated to provide the most appropriate condition for in vitro culture of chondrocyte cells. Addition of 0.1mg/ml hyaluronic acid in chondrocyte culture media resulted an increase in primary chondrocyte proliferation and helped the cells to maintain chondrocytic morphology. TGF-β1, 2 and 3 caused chondrocytes to obtain fibroblastic phenotype, alongside an increase in apoptosis. The healing process of the wound closure assay of chondrocyte monolayers were slowed down by all three isoforms of TGF-β. All three types of TGF-β negatively affected the strength of chondrocyte adhesion. TGF-β1, 2 and 3 up regulated the expression of collagen type-II, but decreased synthesis of collagen type-I, Chondroitin sulfate glycoprotein, and laminin. They did not show any significant change in production of S-100 protein and fibronectin. TGF-β2, and 3 did not change expression of integrin-β1 (CD29), but TGF-β1 decreased the secretion of this adhesion protein. Manipulated TGF-β showed huge impact on formation of fibroblast like morphology of chondrocytes with chondrocytic phenotype. These isoforms also decreased the expression of laminin, chondroitin sulfate glycoprotein, and collagen type-I, but they increased production of collagen type-II and did not induce synthesis of fibronectin and S-100 protein. In addition, the strength of cell adhesion on solid surface was reduced by manipulated TGF-β. Only manipulated form of TGF-β1 and 2 could increase the proliferation rate. Manipulation of TGF-β did not up regulate the expression of integrin-β1 in planar culture system. The implications of this R&D work are that the manipulation of TGF-β by combination of TGF-β1, 2, and 3 can be utilized in production of superficial zone of cartilage and perichondrium. The collagen, fibronectin and hyaluronic acid could be recruited for the fabrication of a biodegradable scaffold that promotes chondrocyte growth for autologous chondrocyte implantation or for formation of cartilage.

Dendritic cells (DC) constitute a heterogeneous leukocyte population having in common a unique capacity to induce primary T cell responses and are therefore most attractive candidates for immunomodulatory strategies. Two populations of blood DC (CD11c+ CD123dim and CD11c– CD123high) have been defined so far. However, their direct isolation for experimental purposes is hampered by their low frequency and by the lack of selective markers allowing large scale purification from blood. Here we describe the monoclonal antibody (mAb) M-DC8, which was generated by immunizing mice with highly enriched blood DC. This mAb specifically reacts with 0.2–1% of blood leukocytes and enables their direct isolation by a one-step immunomagnetic procedure from fresh mononuclear cells. These cells can be differentiated from T cells, B cells, NK cells and monocytes using lineage-specific antibodies. M-DC8+ cells express HLA class II molecules, CD33 and low levels of the costimulatory molecules CD86 and CD40. Upon in vitro culture M-DC8+ cells spontaneously mature into cells with the phenotype of highly stimulatory cells as documented by the upregulation of HLA-DR, CD86 and CD40; in parallel CD80 expression is induced. M-DC8+ cells display an outstanding capacity to present antigen. In particular, they proved to be excellent stimulators of autologous mixed leukocyte reaction and to activate T cells against primary antigens such as keyhole limpet hemocyanin. Furthermore, they induce differentiation of purified allogeneic cytotoxic T cells into alloantigen-specific cytotoxic effector cells. While the phenotypical analysis reveals similarities with the two known blood DC populations, the characteristic expression of Fc=γRIII (CD16) and the M-DC8 antigen clearly defines them as a novel population of blood DC. The mAb M-DC8 might thus be a valuable tool to determine circulating DC for diagnostic purposes and to isolate these cells for studies of antigen-specific T cell priming. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Articular cartilage is an avascular and flexible connective tissue found in joints. It produces a cushioning effect at the joints and provides low friction to protect the ends of the bones from wear and tear/damage. It has poor repair capacity and any injury can result pain and loss of mobility. One of the common forms of articular cartilage disease which has a huge impact on patient¿s life is arthritis. Research on cartilage cell/tissue engineering will help patients to improve their physical activity by replacing or treating the diseased/damaged cartilage tissue. Cartilage cell, called chondrocyte is embedded in the matrix (Lacunae) and has round shape in vivo. The in vitro monolayer culture of primary chondrocyte causes morphological change characterized as dedifferentiation. Transforming growth factor-beta (TGF-¿), a cytokine superfamily, regulates cell function, including differentiation and proliferation. The effect of TGF-¿1, 2, 3, and their manipulated forms in biological regulation of primary chondrocyte was investigated in this work. A novel method was developed to isolate and purify the primary chondrocytes from knee joint of neonate Sprague-Dawley rat, and the effect of some supplementations such as hyaluronic acid and antibiotics were also investigated to provide the most appropriate condition for in vitro culture of chondrocyte cells. Addition of 0.1mg/ml hyaluronic acid in chondrocyte culture media resulted an increase in primary chondrocyte proliferation and helped the cells to maintain chondrocytic morphology. TGF-¿1, 2 and 3 caused chondrocytes to obtain fibroblastic phenotype, alongside an increase in apoptosis. The healing process of the wound closure assay of chondrocyte monolayers were slowed down by all three isoforms of TGF-¿. All three types of TGF-¿ negatively affected the strength of chondrocyte adhesion. TGF-¿1, 2 and 3 up regulated the expression of collagen type-II, but decreased synthesis of collagen type-I, Chondroitin sulfate glycoprotein, and laminin. They did not show any significant change in production of S-100 protein and fibronectin. TGF-¿2, and 3 did not change expression of integrin-¿1 (CD29), but TGF-¿1 decreased the secretion of this adhesion protein. Manipulated TGF-¿ showed huge impact on formation of fibroblast like morphology of chondrocytes with chondrocytic phenotype. These isoforms also decreased the expression of laminin, chondroitin sulfate glycoprotein, and collagen type-I, but they increased production of collagen type-II and did not induce synthesis of fibronectin and S-100 protein. In addition, the strength of cell adhesion on solid surface was reduced by manipulated TGF-¿. Only manipulated form of TGF-¿1 and 2 could increase the proliferation rate. Manipulation of TGF-¿ did not up regulate the expression of integrin-¿1in planar culture system. The implications of this R&D work are that the manipulation of TGF-¿ by combination of TGF-¿1, 2, and 3 can be utilized in production of superficial zone of cartilage and perichondrium. The collagen, fibronectin and hyaluronic acid could be recruited for the fabrication of a biodegradable scaffold that promotes chondrocyte growth for autologous chondrocyte implantation or for formation of cartilage.

Multipotent mesenchymal stem cells (MSCs), found in many adult tissues, may be useful for regenerative medicine applications. Their identification and purification have been difficult due to their low frequency and lack of unambiguous markers. Using a magnetic micro-beads negative selection technique to remove contaminating hematopoietic cells from mouse bone marrow stromal cells (BMSCs), our lab recently isolated a highly purified osteoprogenitor (HipOp) population that was also enriched for other mesenchymal precursors, including MSCs (Itoh and Aubin, 2009). To further enhance enrichment, we positively selected BMSCs and HipOps for CD73, a putative MSC marker, which resulted in no significant additional enrichment for osteoprogenitors when the population was tested in vitro. However, we also found that HipOps were enriched in vascular endothelial cells, and that removing these cells by further negative selection with CD31/PECAM resulted in a CD31(-) HipOp population with higher osteogenic capacity than HipOps in vitro and in vivo.

Multipotent mesenchymal stem cells (MSCs), found in many adult tissues, may be useful for regenerative medicine applications. Their identification and purification have been difficult due to their low frequency and lack of unambiguous markers. Using a magnetic micro-beads negative selection technique to remove contaminating hematopoietic cells from mouse bone marrow stromal cells (BMSCs), our lab recently isolated a highly purified osteoprogenitor (HipOp) population that was also enriched for other mesenchymal precursors, including MSCs (Itoh and Aubin, 2009). To further enhance enrichment, we positively selected BMSCs and HipOps for CD73, a putative MSC marker, which resulted in no significant additional enrichment for osteoprogenitors when the population was tested in vitro. However, we also found that HipOps were enriched in vascular endothelial cells, and that removing these cells by further negative selection with CD31/PECAM resulted in a CD31(-) HipOp population with higher osteogenic capacity than HipOps in vitro and in vivo.