O carcinoma espinocelular é uma neoplasia maligna que representa aproximadamente 94% de todas as ocorrências presentes em boca e uma das suas principais características celulares é a migração de suas células para formar metástases. A adesão celular é considerada um dos eventos determinantes da migração celular. Para as células formarem uma estrutura tecidual tridimensional as adesões entre células e entre células e matriz extracelular são de grande importância. As junções de adesão celulares surgem, caracteristicamente, pela interação entre receptores adesivos, vias de sinalização e elementos do citoesqueleto. A proteína E-caderina está presente em adesões entre células no tecido epitelial. A proteína FAK está envolvida na maioria dos eventos relacionados à adesão celular estimulada por integrinas. A Vinculina é uma proteína de adesão que se liga ao citoesqueleto de actinomiosina como uma proteína de adesão focal através das integrinas. Estudos recentes sugerem que há alteração na expressão e atividade de proteínas de adesão em tumores malignos. O objetivo deste trabalho foi descrever o padrão de expressão e de regulação da atividade de proteínas de adesão em amostras de tumores de carcinoma espinocelular. Foram realizadas reações de imunoistoquímica para verificar o padrão de distribuição das proteínas E-caderina, Vimentina e FAK-y397 em amostras de tumores de carcinoma espinocelular oral. Verificou-se a diminuição da expressão de E-caderina e de Vinculina em regiões de adesão célula-célula e em contrapartida constatou-se aumento na marcação citoplasmática de Vinculina bem como na marcação de FAK-y397 em todas as amostras de tumores. Apesar dos avanços, ainda são necessários mais estudos observacionais que averiguem não apenas o grau de expressão dessas proteínas de adesão, mas também o seu nível de regulação. A partir dos resultados deste estudo, pode-se sugerir que o controle do nível de expressão e de atividade da adesão celular podem ser considerados como potenciais alvos para a aplicação de terapias coadjuvantes que visam a diminuir ou impedir a progressão tumoral, bem como o desenvolvimento de metástases. / Squamous cell carcinoma is a malignant neoplasm that accounts for approximately 94% of all occurrences present in mouth and one of its main characteristics is the cellular migration of its cells to form metastases. Cell adhesion is considered one of the defining events of cell migration. For a three-dimensional tissue structure, adhesions between cells and between cells and the extracellular matrix is of great importance. Cell adhesion junctions arise characteristically by interaction between adhesive receptors, signaling pathways and cytoskeletal elements. The protein E-cadherin is present in cells in the adhesion between epithelial tissue. The Focal Adhesion Kinase (FAK) protein is involved in most events related to cell adhesion stimulated by integrins. The vinculin is an adhesion protein that binds cytoskeletal protein through integrins activaion. Recent studies suggest that there are alterations in the expression and activity of adhesion proteins in malignant tumors. The aim of this study was to describe the pattern of expression and regulation of the activity of adhesion proteins in tumor samples of squamous cell carcinoma. Immunohistochemical reactions were performed to check the distribution pattern of the protein E-cadherin, vimentin and FAK-y397 in tumor samples of oral squamous cell carcinoma. There was a decrease in the expression of E-cadherin and vinculin in regions of cell-cell adhesion but, on the other hand, it was found to increase in cytoplasmic as well as unscheduled vinculin FAK-y397 in all tumor samples. Despite progress, it is necessary more observational studies that examine not only the degree of expression of these adhesion proteins, but also its level of regulation. From the results of this study it is suggested that the control of the expression level and activity of cell adhesion may be considered as potential targets for application adjuvant therapies that aim to reduce or prevent tumor progression and the development metastases.

abstract: Specific dendritic morphologies are a hallmark of neuronal identity, circuit assembly, and behaviorally relevant function. Despite the importance of dendrites in brain health and disease, the functional consequences of dendritic shape remain largely unknown. This dissertation addresses two fundamental and interrelated aspects of dendrite neurobiology. First, by utilizing the genetic power of Drosophila melanogaster, these studies assess the developmental mechanisms underlying single neuron morphology, and subsequently investigate the functional and behavioral consequences resulting from developmental irregularity. Significant insights into the molecular mechanisms that contribute to dendrite development come from studies of Down syndrome cell adhesion molecule (Dscam). While these findings have been garnered primarily from sensory neurons whose arbors innervate a two-dimensional plane, it is likely that the principles apply in three-dimensional central neurons that provide the structural substrate for synaptic input and neural circuit formation. As such, this dissertation supports the hypothesis that neuron type impacts the realization of Dscam function. In fact, in Drosophila motoneurons, Dscam serves a previously unknown cell-autonomous function in dendrite growth. Dscam manipulations produced a range of dendritic phenotypes with alteration in branch number and length. Subsequent experiments exploited the dendritic alterations produced by Dscam manipulations in order to correlate dendritic structure with the suggested function of these neurons. These data indicate that basic motoneuron function and behavior are maintained even in the absence of all adult dendrites within the same neuron. By contrast, dendrites are required for adjusting motoneuron responses to specific challenging behavioral requirements. Here, I establish a direct link between dendritic structure and neuronal function at the level of the single cell, thus defining the structural substrates necessary for conferring various aspects of functional motor output. Taken together, information gathered from these studies can inform the quest in deciphering how complex cell morphologies and networks form and are precisely linked to their function. / Dissertation/Thesis / Ph.D. Neuroscience 2013

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A presenÃa de metÃstase permanece como a principal causa de morte pelo cÃncer. Diante da ausÃncia de terapia farmacolÃgica para o tratamento de tumores secundÃrios, a pesquisa de novas drogas com potencial antimetastÃtico à de suma importÃncia para o desenvolvimento de novos fÃrmacos anticÃncer. Neste quadro, decidimos avaliar o potencial antimetastÃtico da biflorina, uma o-naftoquinona isolada das raÃzes da Capraria biflora. Em ensaio de proliferaÃÃo celular por Alamar blue, observamos que esta quinona possui atividade citotÃxica contra melanoma humano (MDAMB-435) a partir da concentraÃÃo 5 ÂM em 24h de exposiÃÃo. PorÃm, nessa mesma dose, nÃo houve efeito citotÃxico em 12h de exposiÃÃo. Ensaios de azul de tripan e cristal violeta mostraram que nas concentraÃÃes de 1,0; 2,5 e 5,0 ÂM durante 12h de exposiÃÃo a biflorina nÃo possui efeito citotÃxico. Utilizando as concentraÃÃes de 1,0; 2,5 e 5,0 ÂM (12h exposiÃÃo) foram realizados ensaio de migraÃÃo e invasÃo celular. Nestes ensaios observamos que a biflorina diminui a motilidade e a invasividade da cÃlula MDAMB-435. Em anÃlise morfolÃgica das cÃlulas, utilizando coloraÃÃo de May-Grunwald-Giemsa e coloraÃÃo de actina por faloidina, observamos que a biflorina altera a organizaÃÃo do citoesqueleto de actina, com a presenÃa de cÃlulas menores, retraÃdas e cÃlulas maiores com expansÃes filamentosas semelhantes à filopÃdios. Em ensaio de Western blot observou-se a diminuiÃÃo na expressÃo da molÃcula de adesÃo N-caderina e inibiÃÃo da via de sinalizaÃÃo PI3K/Akt. Estes resultados conferem à biflorina um potencial antimetastÃtico bastante promissor. / Metastasis remains the leading cause of death from cancer. Due to the absence of pharmacological therapy for the treatment of secondary tumors, the search for new drugs with antimetastatic potential is important to the development of new anticancer drugs. In this context we decided to evaluate the antimetastatic potential of biflorin, an o-naphthoquinone isolated from roots of Capraria biflora. In cell proliferation assay using Alamar blue, we found that this quinone has cytotoxic activity against human melanoma cells line (MDAMB-435) at 5 ÂM concentration during 24 hours of exposure. However, with this same dose, there was no cytotoxic effect within 12 hours of exposure. Trypan blue and crystal violet assay showed that biflorina has no cytotoxic effect at 1.0, 2.5 and 5.0 ÂM during 12 hours of exposure. Migration assay and cell invasion assay were performed using concentrations of 1.0, 2.5 and 5.0 ÂM (12h exposure). In these trials we found that biflorin decreases cell motility and invasiveness. In morphological analysis of cells stained using May-Grunwald-Giemsa and actin stain by phalloidin, we observed that biflorin alters the organization of the actin cytoskeleton, with the presence of smaller, retracted and larger cells. In Western blot assay we observed a decrease in the expression of the adhesion molecule N-cadherin and inhibition of PI3K/AKT signaling pathway. These results give biflorin as an agent with promising antimetastatic potential.

Orientador: Nicola Amanda Conran Zorzetto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T11:46:04Z (GMT). No. of bitstreams: 1 DiasJunior_PedroPaulo_M.pdf: 932681 bytes, checksum: a8ceae0940e26759a4abe344de43b8f4 (MD5) Previous issue date: 2012 / Resumo: A resposta vascular inflamatória envolve a interação complexa entre células. A adesão dos neutrófilos aos sítios inflamatórios é constituído de várias etapas que envolvem a interação das moléculas de adesão com os neutrófilos, intermediado pela L-selectina (CD62L) e pelas integrinas ?2, LFA-1 e Mac-1 (CD11a/CD18 e CD11b/CD18) com ligantes sobre o endotélio. Os eritrócitos podem aderir ao endotélio vascular usando as moléculas de adesão CD 36 e integrina VLA-4 entre outras moléculas de adesão. O mecanismo de adesão das plaquetas envolve o sequestro celular no local da lesão tecidual através da interação de quatro receptores sinérgicos: a glicoproteína GPIb/IX (CD42b/CD42a), a integrina ?2?1 (GPIa/IIa; CD49b/CD41a), a integrina ?IIb?3 (GPIIb/IIIa; CD41a/CD61), e a integrina ?5?1 (GPIc/IIIa; CD51/CD61). Em doenças associadas com a inflamação vascular, tais como a doença falciforme e aterosclerose, alterações na adesão de leucócitos à parede vascular desempenham um papel central na fisiopatologia da doença. O CD40L e o LIGHT são proteínas citocinas pertencente ao fator de necrose tumoral (TNF), tendo como receptores o CD40L, LTBR e o HVEM, respectivamente. Diante disso, este estudo objetivou avaliar os efeitos das proteínas inflamatórias CD40L e LIGHT nas propriedades adesivas dos neutrófilos, hemácias e plaquetas. Os neutrófilos, hemácias e plaquetas foram separados do sangue periférico e foram realizados ensaios de adesão estática e citometria de fluxo após estimulo destas células com as proteínas recombinantes, CD40L e LIGHT. Após incubação com CD40L ou LIGHT, os neutrófilos e hemácias da circulação periférica apresentaram alterações quanto às propriedades adesivas em relação aos neutrófilos e hemácias não estimulados. As plaquetas estimuladas com as citocinas não demonstraram alteração nas propriedades adesivas. Neutrófilos incubados com anticorpos bloqueadores das integrinas Mac-1 e LFA-1 apresentaram uma reversão no aumento das propriedades adesivas após estimulo com CD40L ou LIGHT. Os neutrófilos estimulados com as citocinas apresentaram uma diminuição na expressão proteíca de CD62L, característica de ativação celular. Nao foi observado nenhuma diferença quanto a expressão das integrinas Mac-1 e LFA-1 nos neutrófilos após estímulo com as citocinas. Esses resultados sugerem que essas proteínas inflamatórias podem aumentar as propriedades adesivas de neutrofilos (intermediado por um aumento na afinidade das integrinas) e hemácias. A presença de altas concentrações destas citocinas na circulação, como encontrados em algumas patologias caracterizadas por inflamação vascular, pode resultar em conseqüências importantes, como a indução da adesão dos leucócitos e hemácias à parede vascular / Abstract: The vascular inflammatory response involves a complex interaction between cells. The adhesion of neutrophils to inflammatory sites is composed of several stages involving the interaction of adhesion molecules on neutrophils and on the endothelium. These interactions are mediated by Lselectin (CD62L) and the ?2 integrins, LFA-1 and Mac-1 (CD11a/CD18 and CD11b / CD18, respectively) with ligands on the endothelium. The red cells may adhere to vascular endothelial adhesion molecules using CD 36 and the VLA-4 integrin and other adhesion molecules. The mechanism of adhesion of platelets involves the adhesion of these cells at the site of tissue injury through the interaction of four synergistic receptors: glycoprotein GPIb/IX (CD42b/CD42a), integrin ?2?1 (GPIa/IIa; CD49b/CD41a), integrin ?IIb?3 (GPIIb / IIIa, CD41a/CD61), and integrin ?5?1 (GPIC/ IIIa; CD51/CD61). In diseases associated with vascular inflammation, such as sickle cell disease and atherosclerosis, changes in leukocyte adhesion to the vascular wall plays a central role in the pathophysiology of the disease. The CD40L and LIGHT cytokines are proteins belonging to the tumor necrosis factor (TNF) family, and interact with the receptors, CD40L, LTBR and HVEM, respectively. Thus, this study aimed to evaluate the effects of the inflammatory proteins, CD40L and LIGHT, on the adhesive properties of neutrophils, erythrocytes and platelets. Neutrophils, erythrocytes and platelets were separated from peripheral blood and static adhesion assays and flow cytometry were performed after stimulation of these cells with the recombinant proteins, CD40L and LIGHT. After incubation with CD40L or LIGHT, neutrophils and red blood cells from the peripheral circulation showed alterations in adhesive properties compared to unstimulated neutrophils and erythrocytes. Platelets stimulated with cytokines showed no changes in adhesive properties. Neutrophils incubated with antibodies that block the functions of integrins Mac-1 and LFA-1 reversed the increase in adhesive properties after stimulation with CD40L or LIGHT. Neutrophils stimulated with cytokines showed a decrease in the protein expression of CD62L, a characteristic of cellular activation. No difference was observed in the expression of the integrins Mac-1 and LFA-1 on neutrophils after stimulation with cytokines. These results suggest that these inflammatory proteins can increase the adhesive properties of neutrophils (mediated by an increase in the affinity of the integrin) and erythrocytes. The presence of high concentrations of these cytokines in the circulation, as found in certain vascular diseases characterized by inflammation, can result in important consequences, such as the induction of the adhesion of leukocytes and red blood cells to the vascular wall / Mestrado / Ciencias Biomedicas / Mestre em Ciências Médicas

Orientador: Mônica Barbosa de Melo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T09:58:06Z (GMT). No. of bitstreams: 1 Cruz_PedroRodriguesSousada_M.pdf: 4934964 bytes, checksum: 906273ac9e66e4d8efa634ae942458bf (MD5) Previous issue date: 2012 / Resumo: As doenças falciformes são...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Sickle cell diseases are...Note: The complete abstract is available with the full electronic document / Mestrado / Genetica Animal e Evolução / Mestre em Genética e Biologia Molecular

Abstract Bone resorbing osteoclasts require tight attachment of their plasma membrane to the bone surface in order to retain the specific microenvironment and thus to be able to dissolve the bone matrix underneath. Cadherins are transmembrane glycoproteins usually mediating homophilic calcium-dependent cell-cell adhesion. In the present work we have studied the effects of the cadherin CAR sequence HAV-containing hexapeptide AHAVSE on osteoclasts. The primary attachment of osteoclasts to bone surface is not affected by the peptide, suggesting that it is not mediated by cadherins. Treatment of osteoclast cultures with AHAVSE decreased the number of resorption pits and the total resorbed area. Furthermore, we show rapid inactivation of osteoclasts with AHAVSE, which is seen as a decrease in the percentage of osteoclasts with actin rings. Pan-cadherin antibodies localized cadherin-like molecule in the sealing zone area of osteoclasts. These results suggest that cadherin-like molecules may mediate the tight attachment of osteoclasts in the sealing zone area and that the decrease of resorption in AHAVSE-treated osteoclast cultures is due to prevention of sealing zone formation. We studied the polarity of mesenchymal osteoblasts using osteosarcoma cell line UMR-108 and endosteal osteoblasts in situ in bone tissue cultures. Immunofluorescence confocal microscopy revealed that the vesicular stomatitis virus glycoprotein (VSV G) was targeted to the culture medium-facing surface. In endosteal osteoblasts, VSV G protein was found in the surface facing the bone marrow and circulation. On the contrary, Influenza virus hemagglutinin (HA) was localized to the bone substrate-facing surface of the UMR-108 cells. Electron microscopy showed that VSV particles were budding from the culture medium-facing surface, whereas Influenza viruses budded from the bone substrate-facing plasma membrane. These findings suggest the bone attaching plasma membrane of osteoblasts is apical, and the circulation or bone marrow facing plasma membrane is basolateral in nature. Gap junctions often mediate communication between different cells and cell types. In the present work, we demonstrate that rat osteoclasts show connexin-43 staining localizing in the plasma membrane of the cells in cell-cell contacts and over the basolateral membrane of osteoclasts. The effects of heptanol and Gap 27, known gap- junctional inhibitors, were studied using the well-characterized pit formation assay. The inhibitors decreased the number and activity of osteoclasts, suggesting a defect in the fusion of mononuclear osteoclast precursors to multinucleated mature osteoclasts. Furthermore, the total resorbed area and the number of resorption pits also decreased in the cultures. These results suggest that gap-junctional connexin-43 plays a functional role in osteoclasts, and that the blocking of gap junctions decreases both the number and the activity of osteoclasts.

Abstract Type XIII collagen is a transmembrane protein consisting of a short intracellular portion, a transmembrane anchor, and a long extracellular domain with a mainly collagenous sequence. Histochemical and cell biological studies have revealed that type XIII collagen has a wide distribution in various tissues and that it is mostly localized to cell-cell and cell-matrix contacts. In order to study type XIII collagen at the molecular level, the protein was expressed in insect cells as a homotrimer. The recombinant protein was found to reside in the plasma membrane of insect cells with its N-terminus intracellular and C-terminal part extracellular, i. e. in a type II orientation. The trimerization of type XIII collagen chains was initiated by 21 amino acid residues adjacent to the transmembrane domain on the extracellular side, and this sequence was found to be conserved in several other collagenous transmembrane proteins. In addition to the transmembrane form, the ectodomain of type XIII collagen was secreted into the cell culture medium, a result of proteolytic cleavage by furin-like proteases at the non-collagenous NC1 domain. The ectodomain was purified from the insect cell culture medium with a typical collagenous composition and conformation, and it showed as a 150 nm-long rod in rotary shadowing electron microscopy. Furthermore, the recombinant ectodomain showed high affinity binding to several extracellular matrix proteins, e. g. fibronectin, nidogen-2, and perlecan, as well as to heparin. The type XIII collagen ectodomain also showed selective recognition to collagen receptor integrins. Integrin α1 and α11 I domains bind to type XIII collagen with a high affinity, and both integrins α1β1 and α11β1 mediate cell attachment to type XIII collagen. The present results suggest that type XIII collagen shares common aspects with other collagenous transmembrane proteins in terms of chain association and ectodomain shedding. However, it is notably distinct in its structure and binding specificity compared to other types of collagen and cell-surface proteins. The data imply that type XIII collagen might participate in multiple cell-cell and cell-matrix interactions.

Cell adhesion to the extracellular matrix is mediated by the integrin family of adhesion receptors. Integrin receptor engagement initiates the formation of multimolecular protein complexes, termed integrin adhesion complexes (IACs), at the cell membrane. IACs are complex signalling hubs that are enriched in tyrosine-based phosphorylation events and form a mechanochemical connection between integrin receptors and the actin cytoskeleton. Dysregulation of individual IAC components has been reported to influence a wide range of biological processes that contribute to disease. Literature-curated and proteomic analyses of IACs have revealed an unanticipated molecular complexity of IACs in a variety of experimental contexts; however, a global consensus view of the composition of IACs, and a description of how the complex network of interactions in IACs influences global cell function, is currently lacking. Here, multiple existing and new proteomic datasets detailing the protein composition of IACs were analysed to identify a systems-level description of IACs and to enable interrogation of IAC structure, topology and dynamics. Quantitative IAC proteomes derived from multiple cell types were integrated to generate a 2,412-protein ‘meta-adhesome’ database of proteins enriched to fibronectin-induced IACs. To investigate the putative functional adhesion landscape in an objective manner, the meta-adhesome was analysed using a combination of hierarchical clustering, gene ontology and interaction network analyses. An emergent property of the meta-adhesome was the definition of a consensus adhesome: 60 proteins commonly identified from IAC datasets that likely represent an IAC protein core composition. The consensus adhesome highlights how integrins connect to actin via multiple pathways and consists of both canonical and underappreciated IAC components. To investigate the robustness of the IAC network, the effects of pharmacological perturbation of the key IAC kinases FAK and Src on IACs were examined. FAK activity was inhibited with the small molecule inhibitor AZ13256675, and mass spectrometry-based protein quantification revealed that IAC protein composition was unaffected upon FAK inhibition. Moreover, IAC composition was also insensitive to Src inhibition using AZD0530 and to simultaneous FAK and Src inhibition. In contrast, phosphorylation of IAC components, cell migration and cell proliferation were reduced upon FAK and/or Src inhibition. These data suggest that IAC protein composition is robust to perturbation of key kinases, while flux of signals propagated through IACs via phosphorylation is kinase dependent. To examine IAC dynamics, the composition of IACs during IAC assembly and IAC disassembly were examined in the context of the meta-adhesome and consensus adhesome using IAC proteomic datasets. These analyses revealed the temporal dynamics of specific functional protein modules at IACs and detailed the compositional dynamics of the core cell adhesion machinery. In summary, these studies describe both a systems-level and a reductionist view of the IAC proteome, investigate the effects of kinase inhibition on IAC composition and chart IAC dynamics during their assembly and disassembly. These data demonstrate the usefulness of the meta-adhesome and consensus adhesome for future analyses of IAC proteomes.

Streptococcus sanguis 12 adhesins mediating attachment to saliva-coated hydroxyapatite beads (S-HA) were isolated and characterized. Cell surface fibrils were released from this organism by a method of freeze-thawing followed by brief homogenization. Fibrils in the homogenate were precipitated by ultracentrifugation or ammonium sulphate precipitation. This precipitate was shown to contain fibrils by electron microscopy. Sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis (PAGE) analysis of fibrils showed a single band which stained with Coomassie blue and periodate-Schiff. The molecule had a Mr in excess of 300,000. This protein has been given the name long-fibril protein (LFP). Antibody raised against the LFP reacted with long fibrils of S. sanguis 12. LFP was degraded by subtilisin, pronase, papain, and trypsin, but not by chymotrypsin and muramidases. Fibrils were hydrolyzed by subtilisin into discrete lower Mr protein bands which reacted with both anti-fibril and anti-LFP serum. F(ab')₂ prepared from anti-fibril IgG inhibited adhesion of S. sanguis 12 to pH modified S-HA, indicating that fibrils were acting as an adhesin mediating attachment via the neuraminidase-sensitive receptor on S-HA. Five recombinant clones expressing surface antigens of S. sanguis 12 were isolated by ligating a partial digest of S. sanguis 12 chromosomal DNA with the plasmid vector pUC 18, and transforming into Escherichia coli JM83. Recombinant clones were screened by a colony immunoassay with antisera raised against either S. sanguis 12 whole cells or with anti-fibril serum. Positive clones were then analyzed by SDS-PAGE, Western blotting and restriction endonuclease digestion of recombinant plasmids. One recombinant plasmid, pSA2 expressed two proteins of Mrs of 20,000 and 36,000. The 36,000-Mr protein has been designated as SsaB (S. sanguis adhesin B). Both proteins were purified to homogeneity by gel filtration and ion exchange chromatography. Anti-SsaB serum was used in an immunogold bead labelling experiment to demonstrate that this protein was present on the surfaces of S. sanguis 12 and in the non-saliva-aggregating variant 12na, but not on the non-adhering non-aggregating hydrophilic variant 12L. Western blot analysis with anti-SsaB and anti-20 kd sera showed that both SsaB and the 20 kd proteins were present in cell extracts of S. sanguis 12 and its variants. SsaB inhibited adhesion of S. sanguis 12na to S-HA, indicating that it was the adhesin which mediates the binding to the pH-sensitive receptor. SsaB was found to be present on all S. sanguis strains tested, but not on other oral streptococci. Chemical cross-linking studies of SsaB on S. sanguis 12 cell surface suggested that this protein may be present in a higher Mr complex. This study provides direct evidence that binding of S. sanguis 12 to S-HA involves at least two adhesin-receptor interactions. The adhesin mediating binding to the neuraminidase-sensitive receptor on S-HA involves the long fibrils and the adhesin binding to the acid labile receptor is a 36,000 Mr protein. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

Angiogenesis is a physiological process by which new blood vessels develop from preexisting vasculature. The process of converting endothelial cells into fully developed blood vessels involves multiple coordinated cellular events that occur through the collaboration that exists between a variety of growth factors, receptors and adhesion molecules. The immunoglobulin-containing and proline rich receptor-1 (IGPR-1) is an IgSF containing adhesion molecule that has been recently identified as a novel regulator of angiogenesis in vitro. In this study, we provide evidence that IGPR-1 promotes cell survival in porcine aortic endothelial cells (PAE) and plays a role in the inhibition of p38 MAPK in vitro. Deletion of the extracellular domain of IGPR-1 abolished IGPR-1’s ability to inhibit phosphorylation of p38 MAPK and promote the survival of endothelial cells. Likewise, mutation of serines 186 (A186-IGPR-1) and 220 (A220-IGPR-1) on the cytoplasmic domain of IGPR-1 was also found to reduce both the promotion of cell survival and inhibition of p38 MAPK. These findings suggest that both domains of IGPR-1 are important for endothelial cell survival and the activation p38 MAPK.