The miR-216a-Dot1l Regulatory Axis Is Necessary and Sufficient for Müller Glia Reprogramming during Retina Regeneration

Unlike the adult mammalian retina, Müller glia (MG) in the adult zebrafish retina are able to dedifferentiate into a “stem cell”-like state and give rise to multipotent progenitor cells upon retinal damage. We show that miR-216a is downregulated in MG after constant intense light lesioning and that miR-216a suppression is necessary and sufficient for MG dedifferentiation and proliferation during retina regeneration. miR-216a targets the H3K79 methyltransferase Dot1l, which is upregulated in proliferating MG after retinal damage. Loss-of-function experiments show that Dot1l is necessary for MG reprogramming and mediates MG proliferation downstream of miR-216a. We further demonstrate that miR-216a and Dot1l regulate MG-mediated retina regeneration through canonical Wnt signaling. This article reports a regulatory mechanism upstream of Wnt signaling during retina regeneration and provides potential targets for enhancing regeneration in the adult mammalian retina. [Display omitted] •miR-216a is suppressed in Müller glia during retina regeneration•miR-216a suppression stimulates Müller glia reprogramming and proliferation•Dot1l is a target of miR-216a and required for Müller glia proliferation•miR-216a and Dot1l regulate Müller glia reprogramming through canonical Wnt signaling Unlike the adult mammalian retina, Müller glia in the adult zebrafish retina are able to reprogram into a stem cell-like state and give rise to multipotent progenitor cells upon retinal damage. Kara et al. show that miR-216a suppression stimulates Müller glia reprogramming through upregulation of the H3K79 methyltransferase Dot1l and activation of Wnt/β-catenin signaling.