Loss of cell-extracellular matrix interaction triggers retinal regeneration accompanied by Rax and Pax6 activation.

Nabeshima A, Nishibayashi C, Ueda Y, Ogino H, Araki M.

Genesis. 2013 Jun;51(6):410-9.

Department of Biological Sciences, Developmental Neurobiology Laboratory, Nara Women’s University, Nara 630-8506.

 

Abstract

The whole retina regenerates from retinal pigmented epithelial (RPE) cells by transdifferentiation in the adult newt and Xenopus laevis when it is surgically removed. We produced a transgenic animal line, in which EGFP expression is under the control of Rax pomotor. Using F1 and F2 generations, we analyzed Rax-EGFP expression during retinal regeneration in a tissue culture model. In the culture, 4 zones were distinguished as RPE cells migrating outwards from the periphery of the explant: the explant zone, epithelial zone, transition zone and differentiation zone. Expression of transcription factors such as Pax6 and Rax-EGFP was observed in different zones. Rax-EGFP expression preceded Pax6 expression, and the expression of both genes occurred in RPE cells that had lost contact with the basement membrane facing the choroid. We have developed a new culture method in which RPE tissues are embedded in Matrigel. This method has many advantages over the previous gel-overlay method to reproduce construction of 3D-retinal structures and clearly showed that RPE cells need to be detached from the choroid before entering the regenerationpathway. The present results indicate that the temporal changes in cell-cell and cell-extracellular matrix interactions regulate transdifferentiation.

Copyright © 2013 Wiley Periodicals, Inc.

 

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Additional Information

1. We described a culture model of retina regeneration, in which the whole regeneration processes are totally manipulated.

2. A 3-D retinal structure can be regenerated in the culture from a one-cell epithelium.

3. A review article in a book “Xenopus Development” will describe the detailed story of the present results. It will appear in the coming April published by Wiley.