RESUMO
Minor fibrillar collagens are recognized as the organizers and nucleators during collagen fibrillogenesis but likely serve additional functions. The minor fibrillar collagens include collagens type V and XI. Mutations of collagens type V and XI can cause Ehlers-Danlos, Stickler's, and Marshall's syndromes in human. We have characterized the spatiotemporal expression patterns of Col11a1, Col11a2, Col5a1 as well as Col5a3 in zebrafish embryos by in situ hybridization. Col5a1 is expressed in developing somites, neural crest, the head mesenchyme, developing cranial cartilage, pharyngeal arches and vertebrae. Col5a3 is detected in the notochord, mesenchyme cells in the eyes and lens. Both Col11a1 and Col11a2 have similar expression patterns, including notochord, otic vesicle, and developing cranial cartilages. Zebrafish may therefore serve as a valuable vertebrate model system for the study of diseases associated with collagens type V and XI mutations.
Assuntos
Colágenos Fibrilares/genética , Colágenos Fibrilares/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Sequência de Aminoácidos , Animais , Região Branquial/metabolismo , Modelos Animais de Doenças , Embrião não Mamífero/metabolismo , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Olho/embriologia , Olho/metabolismo , Colágenos Fibrilares/química , Hibridização In Situ , Mesoderma/citologia , Crista Neural/metabolismo , Notocorda/metabolismo , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Somitos/metabolismo , Coluna Vertebral/metabolismo , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismoRESUMO
Synucleins are small proteins associated with neurodegenerative diseases and some forms of cancer. Most studies of this group of proteins have been directed to the elucidation of their role in the brain and their connection to the formation of depositions in brain tissues. Here we describe the localization of different types of synucleins in ocular tissues. By Western blot analysis, all members of the synuclein family are found in the retina and optic nerve, where their relative ratio varies. The data on immunohistochemical staining show that different members of the synuclein family have different localizations in ocular tissues. Alpha-synucleins and beta-synucleins are present predominantly in the inner plexiform layer, whereas gamma-synuclein is in the nerve fiber layer. In transgenic mice overexpressing alpha-synuclein, a different pattern of localization depending on the promoter used for the expression was observed. In Alzheimer's disease patients, immunohistochemical staining for gamma-synuclein revealed the loss of immunoreactivity in the nerve fiber layer and the nerve fiber layer and the appearance of immunopositive cells in or near the outer nuclear layer. We conclude that, in mature eyes, synucleins are present predominantly in the retina and optic nerve, and the immunoreactivity of gamma-synuclein changes specifically in the retina of Alzheimer's disease patients. In transgenic mice overexpressing alpha-synuclein, immunopositive deposits in the optic nerve and accumulation of immunoreactivity in specific retinal cells were found.
