AUTHOR=Li Jinyan , Chen Yijia , Ouyang Shuai , Ma Jingyu , Sun Hui , Luo Lixia , Chen Shuyi , Liu Yizhi 

TITLE=Generation and Staging of Human Retinal Organoids Based on Self-Formed Ectodermal Autonomous Multi-Zone System

JOURNAL=Frontiers in Cell and Developmental Biology

VOLUME=Volume 9 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2021.732382

DOI=10.3389/fcell.2021.732382

ISSN=2296-634X

ABSTRACT=Methods for stem cell-derived, three-dimensional retinal organoids induction have been established and shown great potential for retinal development modeling and retinal replacement therapy. Herein, we reported a simple and robust method to generate retinal organoids based on “self-formed ectodermal autonomous multi-zone” (SEAM) system, a two-dimensional induction scheme that can synchronously generate multiple ocular cell lineages. Characterized by distinct morphological changes, the differentiation of the obtained retinal organoids could be staged into the early and late differentiation phases. During the early differentiation stage, retinal ganglion cells, cone photoreceptor cells (PRs), amacrine cells, and horizontal cells developed; whereas rod PRs, bipolar cells, and Müller glial cells were generated in the late differentiation phase, resembling early-phase and late-phase retinogenesis in vivo. Additionally, we modified the maintenance strategy for the retinal organoids and successfully promoted their long-term survival. Using 3D immunofluorescence image reconstruction, the substantial mature cone and rod PRs were demonstrated. Besides, the retinal pigment epithelium (RPE) with distinct boundary was generated and the ciliary margin was observed by co-suspending retina organoids with the zone containing RPE. The obtained RPE could be expanded and displayed similar features and marker expression to mature RPE. Thus, this research described a robust system which enabled to generate retina organoids with substantial mature PRs, RPE and the ciliary margin without the need of exogenous factors, providing a new platform for research of retinogenesis and the NR-RPE interaction.