Abstract
Purpose: :
Induced Pluripotent Stem (iPS) cells are one of the appropriate candidates for the cell source of retinal pigment epithelial (RPE) transplant. Human pluripotent stem cells, such as embryonic stem (ES) cells and iPS cells, are generally maintained on mouse embryonic fibroblasts (MEF), STO cells, or its derivative SNL cells, all of which are mitotically inactivated by treatment with mitomycin C or irradiation. However, these feeder cells have not been yet proven to be suitable for clinical application in terms of exogenous antigens, unidentified viruses, and zoonotic pathogens. In this study, we evaluated the potential of human autologous fibroblast as well as 3T3-J2 cells that have been used as feeder cells of cultured epidermis, and of which clinical safety has been confirmed in over 20 years whether they can be used as feeder cells for the generation and maintenance of iPS cells capable of differentiating into RPE cells.
Methods: :
To generate iPS cells, human dermal fibroblasts were electroporated with episomal vector encoding reprogramming factors. Resulting ES-like colonies were mechanically dissociated and transferred on to 3T3-J2 feeder, human fibroblast feeder, or STO feeder, respectively and cultured further. To confirm the differentiation ability, we subjected 3 lines of iPS cells from each feeder to in vitro directed differentiation into RPE with the modified SFEB method.
Results: :
We were able to establish iPS cells with 3T3-J2 feeder and human fibroblast feeder, of which morphologies were similar to iPS cells established with STO feeder. We also obtained RPE colonies from J2-iPS cells and human fibroblast feeder-iPS cells with similar efficiency compared to STO- iPS cells.
Conclusions: :
Our results demonstrate that 3T3-J2 cells as well as autologous fibroblasts can be used for feeder cells of iPS cells capable of differentiating into RPE. These findings not only offer new option for the establishment of clinical grade iPS cells but also propose the necessity to evaluate the potential of currently available clinically-proven feeder.
Keywords: retinal pigment epithelium • clinical research methodology