Abstract
Purpose :
The establishment of retinal differentiation platform with induced pluripotent stem cell (iPSC), holds great promise to study and treat retinal degenerations. However, the capacity of targeted differentiation of iPSCs may vary among iPSC lines from different somatic cell sources, which impact the further application. The current study is to assess the ability and efficiency of retinal differentiation among hiPSC lines.
Methods :
hiPSCs derived from both blood cells (B-iPSCs) and urine cells (U-iPSCs) were cultured with mTeSR1. Retinal differentiation procedure was based on a published protocol with slight modification (Zhong X, Nature Communications 2014). Morphological changes were observed and imaged under inverted microscope. Immunofluorescence was done with markers specific for the early and late stages of retinal development. Efficiency of retinal differentiation at early stage was also assessed.
Results :
In initial phase, both B-hiPSCs and U-hiPSCs could form cell aggregates under suspension culture conditions. Both B-hiPSCs and U-hiPSCs had the capacity to form neural retinal (NR) domain and retinal pigment epithelium (RPE) domain. But B-hiPSCs took less time to generate these structures than U-hiPSCs. Subsequently, the collected NR domains self-formed 3D retina cups under suspension condition. These cups consisted of thick transparent continuous NR, expressing retinal stem cell markers, such as PAX6, VSX2, LHX2 ank Ki67. The NR could be further laminated and differentiated into the all major retinal cells including RGC, PRC, amacrine cells. However, B-hiPSCs generated more retinal cups than U-hiPSCs in parallel experiments.
Conclusions :
Human induced pluripotent stem cells reprogrammed from both blood and urine cells have the capacity to generate 3D retinal cups in vitro. However, B-hiPSCs take less time to generate retinal cups and had higher efficiency of retinal differentiation than U-hiPSCs. Work is currently underway to explore the underlying mechanisms.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.