retinal pigment epithelium is responsible for maintaining the structural integrity of the retina by an efficient defense against free radicals, photo-oxidative exposure and light energy. for this purpose the main rpe line of defense is melanosomes. melanin content of retinal pigment epithelium cells in adults and neonates reveals remarkable variations. in the current study we compared melanogen...

Objective(s): It is known that extremely low frequency-pulsed electromagnetic fields (ELF-PEMF) influence multiple cellular and molecular processes. Retinal pigment epithelial (RPE) cells have a significant part in the emergence and pathophysiology of several ocular disorders, such as neovascularization. This study assessed the impact of ELF-PEMF on the proangiogenic features of RPE cells. Mate...

Retinitis pigmentosa (RP) is an incurable retinal degenerative disease with unknown mechanism of progression. Mer tyrosine kinase (MERTK), which encodes a receptor the Tyro3/Axl/Mer family kinases, one causal genes RP. MERTK reportedly expressed in pigment epithelium (RPE) and essential for phagocytosis photoreceptor outer segment. Here, we established induced pluripotent stem cells (iPSC) from...

Asymmetrical secretion of vascular endothelial growth factor (VEGF) by retinal pigment epithelial (RPE) cells in situ is critical for maintaining the homeostasis of the retina and choroid. VEGF is also involved in the development and progression of age-related macular degeneration (AMD). We studied the effect of tumor necrosis factor-α (TNF-α) on the secretion of VEGF in polarized and non-polar...

PURPOSE To describe, illustrate, and account for two cell types plausibly derived from RPE in geographic atrophy (GA) and choroidal neovascularization (CNV) of AMD, using melanosomes, lipofuscin, and basal laminar deposit (BLamD) as anatomical markers. METHODS Human donor eyes with GA (n = 13) or CNV (n = 39) were histologically processed, photodocumented, and analyzed for frequencies of occu...

Retinal pigment epithelium (RPE) transplantation is a particularly promising treatment of retinal degenerative diseases affecting RPE-photoreceptor complex. Embryonic stem cells (ESCs) provide an abundant donor source for RPE transplantation. Herein, we studied the time-course characteristics of RPE cells derived from three-dimensional human ESCs cultures (3D-RPE). We showed that 3D-RPE cells p...

PURPOSE To determine the effect of age on the proportion of apoptotic cells in the RPE and cellular density in human eyes in situ. METHODS RPE flatmounts prepared from 22 adult human cadaver eyes (11 pairs; ages 19-87) were stained for apoptotic cells by a TUNEL technique. The density of RPE cells was also measured. The flatmount was divided into four concentric regions centered on the fovea ...

PURPOSE To investigate conditions promoting the differentiation of cultured human retinal pigment epithelial (RPE) cells and assess the differentiation potential of telomerase-immortalized RPE cells. METHODS Serially passaged RPE 340 (parental) cells have limited replicative ability and senesce after 50 to 60 population doublings (PD)s. RPE 340 cells transfected with the catalytic component o...

Age-related macular degeneration (AMD) is characterized by the loss or dysfunction of retinal pigment epithelium (RPE) and is the most common cause of vision loss among the elderly. Stem-cell-based strategies, using human embryonic stem cells (hESCs) or human-induced pluripotent stem cells (hiPSCs), may provide an abundant donor source for generating RPE cells in cell replacement therapies. Des...