RESUMEN
Understanding the conditions leading to harmful algal blooms, especially those produced by toxic dinoflagellate species, is important for environmental and health safety. In addition to investigations into the environmental conditions necessary for the formation of toxic blooms, we postulate that investigating gene expression in proliferating cells is essential for understanding bloom dynamics. Expressed sequence tags were produced from cultured cells of the toxic dinoflagellate Alexandrium catenella sampled during the initiation phase of growth using Sanger's method and by 454 pyrosequencing. A significant proportion of identified genes (ca. 25%) represented enzymes and proteins that participate in a variety of cellular regulatory mechanisms that may characterize proliferating cells, e.g., control of the cell cycle and division, regulation of transcription, translation and posttranslational protein modifications, signaling, intracellular trafficking, and transport. All of the several genes selected for gene expression assays due to their involvement in metabolism and the cell cycle were overexpressed during exponential growth. These data will be useful for investigating the mechanisms underlying growth and toxin production in toxic Alexandrium species and for studying and monitoring the development of toxic blooms.
Asunto(s)
Dinoflagelados/crecimiento & desarrollo , Regulación de la Expresión Génica , Genes Protozoarios , Proteínas Protozoarias/metabolismo , Proliferación Celular , Biología Computacional , Dinoflagelados/genética , Dinoflagelados/metabolismo , Biblioteca de Genes , Genes Protozoarios/genética , Fotosíntesis , Proteínas Protozoarias/genética , ARN Protozoario/genética , ARN Protozoario/aislamiento & purificación , Análisis de Secuencia de ADNAsunto(s)
Quemaduras Químicas/cirugía , Enfermedades de la Córnea/cirugía , Células Epiteliales/trasplante , Quemaduras Oculares/inducido químicamente , Metaloproteinasa 9 de la Matriz/metabolismo , Mucosa Bucal/citología , Implantación de Prótesis , Animales , Quemaduras Químicas/enzimología , Trasplante de Células , Células Cultivadas , Terapia Combinada , Enfermedades de la Córnea/enzimología , Modelos Animales de Enfermedad , Células Epiteliales/metabolismo , Técnica del Anticuerpo Fluorescente Indirecta , Queratina-4/metabolismo , Masculino , Prótesis e Implantes , Conejos , Hidróxido de Sodio , Trasplante AutólogoRESUMEN
The SLC45A2 gene encodes a Membrane-Associated Transporter Protein (MATP). Mutations of this gene cause oculocutaneous albinism type 4 (OCA4). However, the molecular mechanism of its action in melanogenesis has not been elucidated. Here, we discuss the role of MATP in melanin production. The SLC45A2 gene is highly enriched in human melanocytes and melanoma cell lines, and its protein, MATP, is located in melanosomes. The knockdown of MATP using siRNAs reduced melanin content and tyrosinase activity without any morphological change in melanosomes or the expression of melanogenesis-related proteins. Interestingly, the knockdown of MATP significantly lowered the melanosomal pH, as verified through DAMP analysis, suggesting that MATP regulates melanosomal pH and therefore affects tyrosinase activity. Finally, we found that the reduction of tyrosinase activity associated with the knockdown of MATP was readily recovered by copper treatment in the in vitro L-DOPA oxidase activity assay of tyrosinase. Considering that copper is an important element for tyrosinase activity and that its binding to tyrosinase depends on melanosomal pH, MATP may play an important role in regulating tyrosinase activity via controlling melanosomal pH.
Asunto(s)
Antígenos de Neoplasias/metabolismo , Melanosomas/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Monofenol Monooxigenasa/metabolismo , Línea Celular Tumoral , Humanos , Concentración de Iones de Hidrógeno , Indoles/metabolismo , Melaninas/metabolismo , Melanocitos/metabolismo , Melanoma/metabolismo , Proteínas de la Membrana/metabolismo , Mutación/genética , Oxidación-ReducciónRESUMEN
PURPOSE: To investigate the efficacy of an endoscopic vitrectomy in Seoul-type keratoprosthesis (S-Kpro) exchange procedures. METHODS: Nine S-Kpro-implanted rabbit eyes were enrolled in the S-Kpro exchange. Six eyes underwent an antecedent vitrectomy by an endoscopic system and then the S-Kpro exchange (endoscopy group). In the other three eyes, previously placed S-Kpros were removed, and a conventional vitrectomy was performed using the Eckardt keratoprosthesis, followed by an implantation of new S-Kpros (Eckardt group). All eyes were evaluated with slit lamp biomicroscopy and ultrasonography weekly to evaluate the time up to the development of the total retinal detachment (RD). RESULTS: Vitreous traction membranes were found around the prolene haptics of the fixation sites in all the S-Kpro implanted rabbits; they were excised precisely through an endoscopic view in the endoscopy group. The mean survival time up to the RD development was 9.75 +/- 4.70 weeks in the endoscopy group. In contrast, total retinal detachment or dialysis over 180 degrees developed during surgery in all three eyes in the Eckardt group. CONCLUSIONS: Antecedent endoscopic vitrectomy was safe and effective for the S-Kpro exchange in a rabbit model by removing the vitreous traction near the haptics before the exchange procedures.