Alex Fonollosa1, Maria Valcarcel2, Clarisa Salado2, Xandra Pereiro3, Elena Vecino3. 1. Begiker-Ophthalmology Research Group, Department of Ophthalmology, Faculty of Medicine and Nursing, BioCruces Health Research Institute, Cruces Hospital, University of the Basque Country UPV/EHU, Bilbao, Spain; Experimental Ophthalmo-Biology Group, Department Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, Leioa, Spain. Electronic address: afonollosacalduch@gmail.com. 2. Innoprot SL, Parque Científico y Tecnológico de Bizkaia, Derio, Spain. 3. Experimental Ophthalmo-Biology Group, Department Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, Leioa, Spain.
Abstract
PURPOSE: To assess the effect of somatostatin (SST) on the permeability of human retinal pigment epithelial cells. METHODS: We conducted two experiments, exposing cells from human-fetal retinal pigment epithelium (hfRPE) cultures to vascular endothelial growth factor (VEGF), with or without SST pretreatment, in one, and to hypoxic conditions, again with or without SST pretreatment, in the other. The paracellular permeability of hfRPE was assessed by measuring transepithelial electrical resistance (TER) and fluorescein isothiocyanate-sodium (FITC-sodium) flux. Immunochemistry analysis was used to assess the expression of occludin and Zonula occludens-1(ZO-1). RESULTS: Both VEGF and hypoxia increased permeability of the hfRPE, as measured by TER and tracer flux, and decreased occludin and ZO-1staining, as measured by immunochemistry. Pretreatment of cultures with SST partially counteracted these effects. CONCLUSIONS: Somatostatin may play a role in the regulation of permeability across retinal pigment epithelium. It may act as an anti-permeability factor in the retina through the enhancement of tight junction function.
PURPOSE: To assess the effect of somatostatin (SST) on the permeability of human retinal pigment epithelial cells. METHODS: We conducted two experiments, exposing cells from human-fetal retinal pigment epithelium (hfRPE) cultures to vascular endothelial growth factor (VEGF), with or without SST pretreatment, in one, and to hypoxic conditions, again with or without SST pretreatment, in the other. The paracellular permeability of hfRPE was assessed by measuring transepithelial electrical resistance (TER) and fluorescein isothiocyanate-sodium (FITC-sodium) flux. Immunochemistry analysis was used to assess the expression of occludin and Zonula occludens-1(ZO-1). RESULTS: Both VEGF and hypoxia increased permeability of the hfRPE, as measured by TER and tracer flux, and decreased occludin and ZO-1staining, as measured by immunochemistry. Pretreatment of cultures with SST partially counteracted these effects. CONCLUSIONS:Somatostatin may play a role in the regulation of permeability across retinal pigment epithelium. It may act as an anti-permeability factor in the retina through the enhancement of tight junction function.