RESUMO
Cell-cell interactions of the mucosal epithelia are important for the maintenance and establishment of epithelial barrier function. During events of inflammation, such cell-cell interactions are often disrupted, resulting in a leaky epithelial barrier, which in turn can lead to various inflammatory and infective dysfunctions. Human junctional adhesion molecule (huJAM), found on the mucosal epithelia and vascular endothelia of many major organ systems, is a membrane glycoprotein which resolves to a doublet band of approximately 40 and approximately 37 kDa under SDS-PAGE analysis, representing differentially glycosylated forms of the same protein. huJAM was localized to the lateral membrane of Caco-2 cells (a human colonic epithelial cell line) monolayers, in an area basolateral of the epithelial tight junctions (TJ). Through functional and biochemical assays, we show huJAM to be able to homotypically associate and to participate in TJ restitution after trypsin-EDTA disruption. Furthermore, we also observed a migration of huJAM expression toward areas of cell-cell contacts during events of cell adhesion and monolayer formation. These qualities makes huJAM a likely player in the regulation of cell-cell contacts and the subsequent formation of TJs.
Assuntos
Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Células Epiteliais/metabolismo , Junções Íntimas/metabolismo , Animais , Células CHO , Células CACO-2 , Adesão Celular/fisiologia , Moléculas de Adesão Celular/análise , Permeabilidade da Membrana Celular/fisiologia , Cricetinae , Células Epiteliais/química , Células Epiteliais/citologia , Feminino , Imunofluorescência , Expressão Gênica/fisiologia , Humanos , Hibridização In Situ , Moléculas de Adesão Juncional , Camundongos , Camundongos Endogâmicos BALB C , Testes de Precipitina , RNA Mensageiro/análise , Junções Íntimas/químicaRESUMO
In the developing mammalian retina, spontaneous waves of action potentials are present in the ganglion cell layer weeks before vision. These waves are known to be generated by a synaptically connected network of amacrine cells and retinal ganglion cells, and exhibit complex spatiotemporal patterns, characterized by shifting domains of coactivation. Here, we present a novel dynamical model consisting of two coupled populations of cells that quantitatively reproduces the experimentally observed domain sizes, interwave intervals, and wavefront velocity profiles. Model and experiment together show that the highly correlated activity generated by retinal waves can be explained by a combination of random spontaneous activation of cells and the past history of local retinal activity.
