Comparative proteomic analysis of human embryonic stem cell-derived and primary human retinal pigment epithelium

Abstract

Human embryonic stem cell-derived retinal pigment epithelial cells (hESC-RPE) provide an unlimited cell source for retinal cell replacement therapies. Clinical trials using hESC-RPE to treat diseases such as age-related macular degeneration (AMD) are currently underway. Human ESC-RPE cells have been thoroughly characterized at the gene level but their protein expression profile has not been studied at larger scale. In this study, proteomic analysis was used to compare hESC-RPE cells differentiated from two independent hESC lines, to primary human RPE (hRPE) using Isobaric tags for relative quantitation (iTRAQ). 1041 common proteins were present in both hESC-RPE cells and native hRPE with majority of the proteins similarly regulated. The hESC-RPE proteome reflected that of normal hRPE with a large number of metabolic, mitochondrial, cytoskeletal, and transport proteins expressed. No signs of increased stress, apoptosis, immune response, proliferation, or retinal degeneration related changes were noted in hESC-RPE, while important RPE specific proteins involved in key RPE functions such as visual cycle and phagocytosis, could be detected in the hESC-RPE. Overall, the results indicated that the proteome of the hESC-RPE cells closely resembled that of their native counterparts.

RETRACTED: Drug Flux across RPE Cell Models: The Hunt for an Appropriate Outer Blood–Retinal Barrier Model for Use in Early Drug Discovery

“…In addition to clinical cell replacement therapy applications [19], the RPE cells differentiated from human embryonic (hESC) or human-induced pluripotent stem cells (hiPSC) are valuable in retinal research as they display a mature RPE phenotype after differentiation [20][21][22][23][24]. However, there is rather limited knowledge regarding the compound permeation of small molecular-weight compounds across hESC-RPE cells [25,26], and therefore, the applicability of hESC-RPE in early drug development is still unclear.…”

Functional Voltage-Gated Calcium Channels Are Present in Human Embryonic Stem Cell-Derived Retinal Pigment Epithelium

“…Stem cell‐derived RPE provides great potential for novel cell transplantation therapies and research has already proceeded to clinical trials . Essential for the success of these therapies, stem cell‐derived RPE has been shown to perform several key RPE functions . However, the functionality of the ion channels and specifically the voltage‐gated Ca 2+ channels in these cells remain poorly known, even though many of the critical RPE functions are related to Ca 2+ activity.…”

“…Regardless of the close resemblance between stem cell‐derived and native RPE demonstrated for their proteome , capability of phagocytosis , VEGF secretion , and visual cycle , many important differences have also been reported. These include a lower efficiency in the phagocytosis of POSs as well as differences in growth factor secretion and expression of adhesion junction and membrane transport genes .…”

“…Remarkably, such therapies are already being subjected to clinical trials for AMD and Stargardt's macular dystrophy as well as to several preclinical trials . Stem cell‐derived RPE has been demonstrated to resemble native tissue in many respects: it has been shown to have a proteome closely similar to the native counterpart , phagocytose photoreceptor outer segment (POS) fragments , secrete vascular endothelial growth factor (VEGF) , and participate in the functional visual cycle . However, much is still not understood about the genetic characteristics of stem cell‐derived RPE or its behavior after transplantation .…”

Proteomic and phosphoproteomic analysis identifies novel liver-related signaling in retinal pigment epithelial cells during epithelial-mesenchymal transition

“…A variety of studies have examined RPE protein expression using a variety of methods and cell systems, including immortalized cell lines such as ARPE-19 line (39,40), human donor eyes (41), and more recently RPE derived from human stem cells (42,43). We here add to this prior work by providing extensive proteomic and phosphoproteomic analysis of human stem cell derived RPE, identifying over 8000 total proteins and over 8000 phosphosites quantified across five experimental conditions.…”