The retinal pigment epithelium: An important player of retinal disorders and regeneration

- RPE cells undergo proliferation and transformation after a traumatic retinal injury.
- In humans, this process causes a retinal disorder leading to loss of vision.
- In certain adult amphibians, a similar process leads to retinal regeneration.
- In both systems, RPE cells acquire multipotency while losing their epithelial form.
- Potencies of such RPE-derived cells are obviously different between systems.

The retinal pigment epithelium (RPE) is a partner of the neural retina and is indispensable for vision. In humans, proliferation and transformation (cell-type switching) of RPE cells after a traumatic injury of the neural retina causes a retinal disorder leading to loss of vision. In contrast, in certain adult amphibians such as Xenopus laevis and the newt, a similar process in RPE cells leads to regeneration of the entire retina. In this review, on the basis of accumulating evidence in basic biology and medical sciences, similarities and differences between these RPE-mediated retinal disorders and regeneration in adult vertebrates are highlighted, providing a connection to future research that should be designed to establish clues for the treatment of pathogenesis caused by RPE while promoting RPE-mediated retinal regeneration in a patient's eyes.