-Original-

Variation in the Phenotype of Photosensitive Cells Produced from Human Fibroblast Cell Lines

Toshiyuki Ishii¹, Chengzhu Yin¹, Yuko Seko², Akihiro Umezawa³ and Makoto Kaneda¹

¹Department of Physiology, Nippon Medical School, Tokyo, Japan
²Visual Functions Section, Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Saitama, Japan
³Department of Reproductive Biology, Center for Regenerative Medicine, National Institute for Child Health and Development, Tokyo, Japan

Background: Photoreceptors differentiated from somatic cells are a useful tool for transplantation and drug screening. We previously showed that photosensitive cells are differentiated from human fibroblasts by direct reprogramming. In induced pluripotent stem (iPS) cells or embryonic stem (ES) cells, the properties of differentiated cells differ among the source of cell lines. However, whether or not the properties of the photosensitive cells produced by direct reprogramming are controlled by the origin of the cell line remains unknown.
Methods: We compared the morphological and physiological properties of photosensitive cells induced by two fibroblast cell lines.
Results: The differentiated cells had larger somas and more primary processes than the non-infected cells in both cell lines. The degree of morphological change was statistically different between the two cell lines. In addition, physiological responses to light differed between the two cell lines. An outward current (photoreceptor-like response) was observed in both cell lines, while an inward current (intrinsically photosensitive retinal ganglion cell-like response) was observed only in one cell line under light stimulation.
Conclusions: These results suggest that photosensitive cells produced from different cell lines by direct reprogramming might express different phenotypes.

J Nippon Med Sch 2018; 85: 110-116

Keywords
direct reprogramming, differentiation, human fibroblast, photoreceptors, intrinsically photosensitive retinal ganglion cells

Correspondence to
Makoto Kaneda, Department of Physiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan
mkaneda@nms.ac.jp

Received, November 24, 2017
Accepted, December 25, 2017