Novel organotypic culture model of adult mammalian neurosensory retina in co-culture with retinal pigment epithelium

Purpose: The purpose of this study was to assess survival of adult mammalian neurosensory retina cultured in contact with the layer of a choroid-retinal pigment epithelium (RPE) explant. Methods: The entire adult porcine neurosensory retina and RPE-choroid layer were placed in tissue culture by juxtaposing both tissues in their original orientation. Culture of the neurosensory retina alone and freshly prepared retina were used as control. After 3 days in culture retinal explants were fixed and processed for immunohistochemistry and TUNEL technique. Results: We observed limited nuclei loss and significant reduction in apoptotic cells in nuclear cell layers (GCL, INL, and ONL) and decreased Muller cell hypertrophy in retina-RPE cultures compared to retinal cultures alone. In addition, cultures were characterized by reduced upregulation of GFAP, vimentin as well as SIN and increased glutamine synthetase expression. Conclusions: As any tissue culture model, retinal tissue culture is a short-term system and since degenerative processes begin quite early it may be a good model to investigate degenerative process m in the retina. However, our model of culture of retina adjacent to the RPE-choroid layer improves the maintenance of neural retina as evidenced by reduced apoptosis in nuclear cell layers (GCL, INL, and ONL) and reduced gliosis as indicated by the diminished expression of glial-specific proteins and increased glutamine synthetase compared to cultures of retina alone. Thus the retina-RPE-choroid culture system can enable the evaluation of interactions between RPE and neural retina, the role of signaling molecules a well the effect of pharmaceuticals on retinal biology. (C) 2008 Elsevier B.V. All rights reserved.