Abstract
Purpose:
Human pluripotent stem cells (hPSCs) possess the unique ability to readily differentiate into any cell type of the body. As such, they can serve as comprehensive and novel tools for drug screening, disease modeling, and cell replacement therapies. Although previous studies have demonstrated the ability to differentiate hPSCs to a retinal lineage, the ability to derive retinal ganglion cells (RGCs) from hPSCs has been largely overlooked to date. Establishing a method to acquire RGCs from hPSCs would serve as a novel system to study human retinogenesis as well as establishing a foundation for the development of patient specific therapies for diseases of retinal ganglion cells, such as glaucoma.
Methods:
Following previously established protocols, hPSCs were induced to differentiate towards a retinal fate and RGCs were subsequently characterized by the RGC-associated transcription factors BRN3 and Islet-1. The developmental process underlying this RGC differentiation was further analyzed by immunocytochemistry and RT-PCR analysis for the expression of expected RGC associated characteristics.
Results:
Within the first 40 days of differentiation, RGCs were readily identifiable within differentiating cultures of hiPSCs based on their progression through a CHX10-positive retinal progenitor intermediary as well as their later adoption of the RGC-specific transcription factor BRN3. Analysis of these differentiating cultures at various timepoints by immunocytochemistry and RT-PCR analysis revealed that these cells expressed numerous characteristics of RGCs, including the expression of MATH5 and PAX6, as well as morphological characteristics associated with RGCs. In addition, treatment with intrinsic and/or extrinsic factors were tested for their ability to modulate RGC specification.
Conclusions:
The data presented within this study demonstrates the ability of hiPSCs to serve as a reliable source of patient-derived RGCs, as seen by their ability to proceed through predicted developmental stages that yield a mature RGC population possessing many RGC-associated characteristics. This protocol will be advantageous for future studies into the normal and abnormal development of RGCs and as such, will be instrumental as a tool to study optic neuropathies that affect this cell population.
Keywords: 721 stem cells •
698 retinal development •
531 ganglion cells