Differentiation and transplantation of mouse ESC- and iPSC-derived retina-like sheets in retinal degeneration mouse

Abstract

Purpose: To characterize the three-dimentional differentiation of the mESC- and miPSC-derived retinal cell sheets, and evaluate the viability, maturation and integration of retinal cell sheets after transplanted into the degenerative mouse (rd1) retina.

Methods: Rx-GFP knock-in mESC and Nrl-GFP transgenic miPSC were differentiated in three-dimensional cultures into retinal tissue by a modified method by Eiraku et al (Nature, 2011). To determine the stage of the differentiated cultures, they were immunostained along differentiation comparing with the developing mouse retina. Next, the mESC- or miPSC-derived retinal cell sheets were transplanted into the subretinal space of rd1 retina. Their survival, maturation and integration were immunohistologically evaluated.

Results: The three-dimentional culture of the mESC- and miPSC-derived retinal tissue expressed Recoverin, Crx, Calretinin and Rhodopsin in the similar pattern to those of the developing mouse retina. The differentiation day (DD.) 21 of the mESC- and miPSC-derived retinal tissue was approximately equivalent to P1. Accordingly, the less than DD.20 mESC- and miPSC-derived retinal tissue was considered to be the embryonic retinal tissue. After the transplantation, both mESC and iPSC derived retinal cell sheets survived and matured in the subretinal space consisted of the strongly rhodopsin-positive photoreceptor layer with the inner segment (IS) and outer segment (OS). Some transplanted grafts also integrated to host retina. Immuno-stainings of synaptic markers suggested the synaptic formation between the grafts and host retina.

Conclusions: The three-dimensional retina-like sheets derived from mESC and Nrl-GFP miPSC could serve as grafts in transplantation therapy in retinal degeneration.

Keywords: 741 transplantation • 721 stem cells • 500 differentiation