The retinal pigment epithelial cells of the adult newt and rat under conditions of in vitro organotypic culture

Cellular and Molecular Preconditions for Retinal Pigment Epithelium (RPE) Natural Reprogramming during Retinal Regeneration in Urodela

“…After the retina was removed or the optic nerve and blood vessels were cut, RPE cells acquired the ability to function as “cleaners” both within and outside the epithelial layer. The same has been repeatedly observed in subsequent experiments, particularly in 3D RPE tissue cultures [59]. Comparing this ability in the RPE of adult newts and albino rats cultured in vitro under similar conditions, we found that cells of the rat RPE also could detach from the layer and convert into melanophages, but the number of such cells was far smaller than in newts [8,59].…”

“…It should be noted that persistent, low-level proliferative activity is not unique to the adult newt RPE but has also been observed in the marginal zone of RPE in freshly hatched chicks [ 57 ] and adult rodents [ 58 ]. Rare BrdU-labeled cells at the periphery of the RPE were also revealed in our experiments with in vitro cultures of the posterior eye segments from adult albino rat [ 59 ].…”

Shared Triggering Mechanisms of Retinal Regeneration in Lower Vertebrates and Retinal Rescue in Higher Ones

“…Recently we showed that in the rat NR isolated from RPE and cultivated "whole amount" in 3D conditions in vitro the intensive incorporation of DNA synthesis precursor (BrdU) is localized in photoreceptor inner segments -cell compartments extremely rich with mitochondria (Novikova et al, 2010b). We believe that increased synthetic activity of mitochondrial DNA in photoreceptors is an attempt of photoreceptor cells to rescue and avoid apoptosis.…”

“…Nowadays using organotypic 3D culturing of the posterior sector (RPE+choroids+sclera) of the rat eye we found that RPE also gave rise to macrophages: double nuclei cells, morphologically different from typical monocytes, and expressing macrophage-specific antigenes Novikova et al, 2010b). Alternatively or additionally, the RPE of mammals can proliferate and then participate in the formation of multilaminar layer of cells with characteristics of mesenchimal ones in connective tissue.…”

“…FGF-FGFR-MEK cascade and Pax6 up-regulation depended on changes of the cell-ECM and/or cell-cell interaction are supposed important for realization of the first steps of NR regeneration (Avdonin, 2010;Susaki & Chiba, 2007). In the in vitro -in vivo like systems it was shown that cells of isolated RPE could be induced to faster dedifferentiation by additing of FGF2 to culture medium (Ikegami et al, 2001;Novikova et al 2010b). …”