The density of Na/K adenosine triphosphatase (ATPase) pumps in retinal pigment epithelial (RPE) cells in different retinal regions was quantified by measuring the binding of 3H-ouabain to RPE in cow and human eyecups. In bovine eyes, pump density was estimated in RPE samples isolated from three retinal regions outlined with a 7-mm trephine: one from the posterior pole in the area centralis and ...

No cure has been discovered for age-related macular degeneration (AMD), the leading cause of vision loss in people over the age of 55. AMD is complex multifactorial disease with an unknown etiology, although it is largely thought to occur due to death or dysfunction of the retinal pigment epithelium (RPE), a monolayer of cells that underlies the retina and provides critical support for photorec...

The retinal pigment epithelium (RPE), a monolayer located between the photoreceptors and the choroid, is constantly damaged by oxidative stress, particularly because of reactive oxygen species (ROS). As the RPE, because of its physiological functions, is essential for the survival of the retina, any sustained damage may consequently lead to loss of vision. Exosomes are small membranous vesicles...

PURPOSE To examine the stability of retinoic acid administered to cultured bovine retinal pigment epithelial (RPE) cells and to determine if RPE cells metabolize retinoic acid by a cytochrome P-450 mechanism. METHODS Retinoic acid metabolism was examined in cultured RPE cells and subcellular fractions quantitatively by a thin-layer chromatography procedure and qualitatively by normal and reve...

The newt is an amazing four-limbed vertebrate that can regenerate various body parts including the retina. In this animal, when the neural retina (NR) is removed from the eye by surgery (retinectomy), both the NR and the retinal pigment epithelium (RPE) eventually regenerate through the process of reprogramming and proliferation of RPE cells. Thus far, we have pursued the onset mechanism of adu...

Abstract Background Human pluripotent stem cells (hPSCs) provide a promising cell source for retinal replacement therapy but often lack standardized production and live-cell shipment logistics as well rigorous analyses of surgical procedures transplantation in the delicate macula area. We have previously established xeno- feeder cell-free system hPSC differentiated pigment epithelial (RPE) cell...

We have investigated the activities of four lysosomal enzymes in RPE cells isolated from three regions of the canine fundus: the tapetal area, the central pigmented area and the peripheral area. The results obtained with freshly isolated cells showed that the activities of acid phosphatase, B-glucuronidase and N-acetyl-B-glucosaminidase were significantly higher in RPE cells derived from the pe...

PURPOSE Nucleotide signaling plays a role in retinal pigment epithelial (RPE) function, and receptors for nucleotides are potential therapeutic targets for various ocular diseases. The purpose of this study was to investigate the expression of P2Y receptor subtypes in native and cultured human RPE cells. METHODS Intracellular Ca(2+) levels were monitored using real-time fluorescence imaging i...

Photoreceptors are the most numerous and metabolically demanding cells in the retina. Their primary nutrient source is the choriocapillaris, and both the choriocapillaris and photoreceptors require trophic and functional support from retinal pigment epithelium (RPE) cells. Defects in RPE, photoreceptors, and the choriocapillaris are characteristic of age-related macular degeneration (AMD), a co...

Human embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells could replace lost tissue in geographic atrophy (GA) but efficacy has yet to be demonstrated in a large-eyed model. Also, production of hESC-RPE has not yet been achieved in a xeno-free and defined manner, which is critical for clinical compliance and reduced immunogenicity. Here we describe an effective differentia...