Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Invest Ophthalmol Vis Sci ; 55(3): 1607-15, 2014 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-24550358

RESUMEN

PURPOSE: The neonatal Fc receptor (FcRn) plays a critical role in the homeostasis and degradation of immunoglobulin G (IgG). It mediates the transport of IgG across epithelial cell barriers and recycles IgG in endothelial cells back into the bloodstream. These functions critically depend on the binding of FcRn to the Fc domain of IgG. The half-life and distribution of intravitreally injected anti-VEGF molecules containing IgG-Fc domains might therefore be affected by FcRn expressed in the eye. In order to establish whether FcRn-Fc(IgG) interactions may occur in the eye, we studied the mRNA and protein distribution of FcRn in postmortem ocular tissue. METHODS: We used qPCR to study mRNA expression of the transmembrane chain of FcRn (FCGRT) in retina, optic nerve, RPE/choroid plexus, ciliary body/iris plexus, lens, cornea, and conjunctiva isolated from mouse, rat, pig, and human postmortem eyes and used immunohistochemistry to determine the pattern of FcRn expression in FCGRT-transgenic mouse and human eyes. RESULTS: In all four tested species, Fcgrt mRNA was expressed in the retina, RPE/choroid, and the ciliary body/iris, while immunohistochemistry documented FcRn protein expression in the ciliary body epithelium, macrophages, and endothelial cells in the retinal and choroidal vasculature. CONCLUSIONS: Our results demonstrate that FcRn has the potential to interact with IgG-Fc domains in the ciliary epithelium and retinal and choroidal vasculature, which might affect the half-life and distribution of intravitreally injected Fc-carrying molecules.


Asunto(s)
Ojo/metabolismo , Regulación del Desarrollo de la Expresión Génica , Antígenos de Histocompatibilidad Clase I/genética , Inmunidad Celular , Macrófagos/inmunología , ARN Mensajero/genética , Receptores Fc/genética , Animales , Animales Recién Nacidos , Ojo/inmunología , Antígenos de Histocompatibilidad Clase I/biosíntesis , Humanos , Inmunohistoquímica , Recién Nacido , Macrófagos/metabolismo , Ratones , Ratas , Receptores Fc/biosíntesis , Porcinos
2.
Nature ; 499(7458): 306-11, 2013 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-23868260

RESUMEN

Aberrant neovascularization contributes to diseases such as cancer, blindness and atherosclerosis, and is the consequence of inappropriate angiogenic signalling. Although many regulators of pathogenic angiogenesis have been identified, our understanding of this process is incomplete. Here we explore the transcriptome of retinal microvessels isolated from mouse models of retinal disease that exhibit vascular pathology, and uncover an upregulated gene, leucine-rich alpha-2-glycoprotein 1 (Lrg1), of previously unknown function. We show that in the presence of transforming growth factor-ß1 (TGF-ß1), LRG1 is mitogenic to endothelial cells and promotes angiogenesis. Mice lacking Lrg1 develop a mild retinal vascular phenotype but exhibit a significant reduction in pathological ocular angiogenesis. LRG1 binds directly to the TGF-ß accessory receptor endoglin, which, in the presence of TGF-ß1, results in promotion of the pro-angiogenic Smad1/5/8 signalling pathway. LRG1 antibody blockade inhibits this switch and attenuates angiogenesis. These studies reveal a new regulator of angiogenesis that mediates its effect by modulating TGF-ß signalling.


Asunto(s)
Endotelio Vascular/metabolismo , Glicoproteínas/fisiología , Neovascularización Retiniana/metabolismo , Transducción de Señal , Factor de Crecimiento Transformador beta1/metabolismo , Animales , Células Cultivadas , Endotelio Vascular/citología , Glicoproteínas/genética , Glicoproteínas/metabolismo , Técnicas In Vitro , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Neovascularización Retiniana/genética , Vasos Retinianos/metabolismo , Factor de Crecimiento Transformador beta1/farmacología
3.
Nat Protoc ; 7(6): 1086-96, 2012 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-22576107

RESUMEN

The mouse retinal vasculature provides a powerful model system for studying development and pathologies of the vasculature. Because it forms as a two-dimensional flat plexus, it is easily imaged in its entirety in whole-mount retinal preparations. In order to study molecular signaling mechanisms, it is useful to visualize the expression of specific genes in the entire vascular plexus and retina. However, in situ hybridization on whole-mount retinal preparations is problematic because isolated retinas have a tendency to curl up during hybridization and are difficult to stain. Here we provide a detailed protocol that overcomes these difficulties and visualizes the mRNA distribution of one or two genes in the context of the counterstained retinal vasculature. The protocol takes 3-4 d for single-probe stains, with an additional 2 d for immunohistochemistry co-labeling. In situ hybridization with two probes adds a further 3 d.


Asunto(s)
Expresión Génica , Hibridación in Situ/métodos , Retina/fisiología , Proteínas Adaptadoras Transductoras de Señales , Animales , Proteínas de Unión al Calcio , Técnicas In Vitro , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas de la Membrana/genética , Ratones , ARN Mensajero/análisis
4.
Am J Pathol ; 180(1): 399-409, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22067912

RESUMEN

Retinal pathologies are frequently accompanied by retinal vascular responses, including the formation of new vessels by angiogenesis (neovascularization). Pathological vascular changes may also include less well characterized traits of vascular remodeling that are non-neovascular, such as vessel pruning and the emergence of dilated and tortuous vessel phenotypes (telangiectasis). The molecular mechanisms underlying neovascular growth versus non-neovascular remodeling are poorly understood. We therefore undertook to identify novel regulators of non-neovascular remodeling in the retina by using the dystrophic Royal College of Surgeons (RCS) rat and the retinal dystrophy 1 (RD1) mouse, both of which display pronounced non-neovascular remodeling. Gene expression profiling of isolated retinal vessels from these mutant rodent models and wild-type controls revealed 60 differentially expressed genes. These included the genes for apelin (Apln) and for its receptor (Aplnr), both of which were strongly up-regulated in the mutants. Crossing RD1 mice into an Apln-null background substantially reduced vascular telangiectasia. In contrast, Apln gene deletion had no effect in two models of neovascular pathology [laser-induced choroidal neovascularization and the very low density lipoprotein receptor (Vldlr)-knockout mouse]. These findings suggest that in these models apelin has minimal effect on sprouting retinal angiogenesis, but contributes significantly to pathogenic non-neovascular remodeling.


Asunto(s)
Péptidos y Proteínas de Señalización Intercelular/fisiología , Degeneración Retiniana/fisiopatología , Vasos Retinianos/metabolismo , Adipoquinas , Animales , Apelina , Neovascularización Coroidal/genética , Neovascularización Coroidal/metabolismo , Neovascularización Coroidal/fisiopatología , Expresión Génica , Silenciador del Gen , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Ratones , Microvasos/metabolismo , Mutación/genética , Ratas , Retina , Degeneración Retiniana/genética , Degeneración Retiniana/metabolismo , Telangiectasia Retiniana/prevención & control , Regulación hacia Arriba
5.
J Cell Physiol ; 213(1): 221-8, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17476691

RESUMEN

Tumor necrosis factor-alpha (TNF-alpha) is known to induce changes in endothelial cell morphology and permeability, but the mechanisms have not been extensively characterized. TNF-alpha rapidly induced RhoA activation and myosin light chain phosphorylation, but caused only small changes to cortical F-actin, without significantly increasing paracellular permeability up to 30 min after stimulation. TNF-alpha subsequently caused a progressive increase in permeability and in stress fiber reorganization, cell elongation, and intercellular gap formation over 8-24 h. Consistent with the increased permeability, Occludin and JAM-A were removed from tight junctions and ZO-1 was partially redistributed. Rho/ROCK but not MLCK inhibition prevented the long-term TNF-alpha-induced changes in F-actin and cell morphology, but ROCK inhibition did not affect permeability. These results suggest that the gradual increase in permeability induced by TNF-alpha does not reflect contractile mechanisms mediated by Rho, ROCK, and MLCK, but involves long-term reorganization of tight junction proteins.


Asunto(s)
Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Proteínas de Unión al GTP rho/metabolismo , Actinas/metabolismo , Permeabilidad de la Membrana Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Células Cultivadas , Células Endoteliales/citología , Humanos , Proteínas de la Membrana/metabolismo , Quinasa de Cadena Ligera de Miosina/metabolismo , Miosinas/metabolismo , Ocludina , Uniones Estrechas/efectos de los fármacos , Quinasas Asociadas a rho
6.
FEBS Lett ; 580(9): 2388-94, 2006 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-16616143

RESUMEN

Occludin is an integral-membrane protein that contributes to tight junction function. We have identified casein kinase I epsilon (CKI epsilon) as a binding partner for the C-terminal cytoplasmic domain of occludin by yeast two-hybrid screening. CKI epsilon phosphorylated occludin and co-localised and co-immunoprecipitated with occludin from human endothelial cells. Amino acids 265-318 of occludin were sufficient for CKI epsilon binding and phosphorylation. Deletion of the C-terminal 48 amino acids of occludin increased CKI epsilon binding and phosphorylation, suggesting that this region inhibits CKI epsilon binding. These data identify CKI epsilon as a novel occludin kinase that may be important for the regulation of occludin.


Asunto(s)
Caseína Cinasa 1 épsilon/metabolismo , Células Endoteliales/enzimología , Proteínas de la Membrana/metabolismo , Procesamiento Proteico-Postraduccional/fisiología , Uniones Estrechas/enzimología , Caseína Cinasa 1 épsilon/genética , Células Cultivadas , Células Endoteliales/citología , Humanos , Proteínas de la Membrana/genética , Ocludina , Fosforilación , Unión Proteica/fisiología , Estructura Terciaria de Proteína/genética , Eliminación de Secuencia , Uniones Estrechas/genética , Técnicas del Sistema de Dos Híbridos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...