Citation: Kinoshita H, Suzuma K, Kaneko J, Mandai M, Kitaoka T, Takahashi M. Induction of functional 3D ciliary epithelium-like structure from mouse induced pluripotent stem cells. Invest Ophthalmol Vis Sci. 2016;57:153-161. DOI:10.1167/ iovs.15-17610 PURPOSE. To generate ciliary epithelium (CE) from mouse induced pluripotent stem (iPS) cells.METHODS. Recently, a protocol for self-organizing optic cup morphogenesis in threedimensional culture was reported, and it was suggested that ocular tissue derived from neural ectoderm could be differentiated. We demonstrated that a CE-like double-layered structure could be induced in simple culture by using a modified Eiraku differentiation protocol.RESULTS. Differentiation of a CE-like double-layered structure could be promoted by glycogen synthase kinase 3b (GSK-3b) inhibitor. Connexin43 and aquaporin1 were expressed in both thin layers, and induced CE-like cells expressed ciliary marker genes, such as cyclinD2, zic1, tgfb2, aldh1a3, wfdc1, otx1, BMP4, and BMP7. Increases in cytoplasmic and nuclear bcatenin in aggregates of the CE-like double-layered structure were confirmed by Western blot analysis. In addition, tankyrase inhibitor prevented the induction of the CE-like double-layered structure by GSK-3b inhibitor. Dye movement from pigmented cells to nonpigmented cells in the mouse iPS cell-derived CE-like structure was observed in a fluid movement experiment, consistent with the physiological function of CE in vivo.CONCLUSIONS. We could differentiate CE from mouse iPS cells in the present study. In the future, we hope that this CE-like complex will become useful as a graft for transplantation therapy in pathologic ocular hypotension due to CE dysfunction, and as a screening tool for the development of drugs for diseases associated with CE function.Keywords: ciliary epithelium, iPS, GSK-3b, b-catenin T he ciliary body (CB) plays important roles in eye homeostasis. It secretes aqueous humor that maintains IOP, controls the lens shape through the ciliary muscle and ciliary zonules, and synthesizes glycoproteins of the vitreous body. The CB contains a double-layered epithelial structure comprising the inner nonpigmented epithelium (NPE), the outer pigmented epithelium (PE), and the underlying stroma. The NPE is continuous with the neural retina (NR) and the iris pigmented epithelium, while the PE lies between the retinal pigment epithelium (RPE) and the outer iris muscle. 1 The NPE and the PE, as well as the NR and RPE, are derived from neural ectoderm. During eye development, the ciliary epithelium (CE) folds to form the ciliary processes, while neural crest cellderived stroma cells underneath the CE also contribute to CB morphogenesis. 2 The PE rests on the connective tissue stroma, and the NPE is polarized with its basal lamina facing the posterior chamber of the eye. The PE and NPE interact via their apical membranes with gap junctions.Water can pass from PE to NPE via gap junctions following NaCl movement 3,4 and exit the NPE to the posterior chamber by using ba...