Iris-derived cells from adult rodents and primates adopt photoreceptor-specific phenotypes.
OBJECTIVE
The purpose of this study was to investigate the effects of various genes related to photoreceptor development on rodent and primate iris cells and the potential of iris cells as donor cells for retinal transplantation.


METHODS
Adult rat and monkey iris tissue were cultured in serum-free medium containing basic fibroblast growth factor. Gene deliveries of Crx, Nrl, NeuroD and some combinations (Crx-Nrl, Crx-NeuroD) were performed with recombinant retrovirus. Immunocytochemistry, Western blot analysis, RT-PCR, and intracellular recording were used to examine the expression of photoreceptor-specific phenotypes in the iris-derived cells after gene transfer, . Coculture of the iris-derived cells with embryonic retinal explant was conducted, to investigate the potential integration of these cells in coculture conditions.


RESULTS
Misexpression of Crx induced adult rat iris cells to express several photoreceptor-specific antigens and transcripts, such as rhodopsin, recoverin, cGMP-gated channel, arrestin, interphotoreceptor retinal-binding protein, rhodopsin kinase, and NeuroD. In primates, a combination of Crx and NeuroD was needed to induce monkey iris-derived cells to adopt photoreceptor-specific phenotypes. Furthermore, the photoreceptor-like cells derived from both rat- and primate-iris tissues showed rod photoreceptor-specific electrophysiological response to light stimuli after Crx and Crx-NeuroD gene transfer, respectively. The results further showed that iris-derived cells integrated in the developing host retina in coculture conditions.


CONCLUSIONS
Adult iris-derived cultured cells of both rodents and primates expressed photoreceptor-specific phenotypes by inductions of transcription factors. These iris-derived photoreceptor-like cells have electrophysiological characteristics of rod photoreceptors. Furthermore, they can integrate in the developing retina under coculture conditions.
Akagi
Tadamichi
T
Department of Ophthalmology and Visual Sciences, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
Akita
Joe
J
Haruta
Masatoshi
M
Suzuki
Takuya
T
Honda
Yoshihito
Y
Inoue
Tomoyuki
T
Yoshiura
Shigeki
S
Kageyama
Ryoichiro
R
Yatsu
Takaaki
T
Yamada
Masahiro
M
Takahashi
Masayo
M
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D015153:Blotting, Western; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology*; D018920:Coculture Techniques; D016895:Culture Media, Serum-Free; D004594:Electrophysiology; D005136:Eye Proteins / Q000378:metabolism; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D015870:Gene Expression; D018014:Gene Transfer Techniques; D018398:Homeodomain Proteins / Q000235:genetics; D007150:Immunohistochemistry; D007498:Iris / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D000071068:Lipocalin-2; D054834:Lipocalins; D008252:Macaca fascicularis; D009363:Neoplasm Proteins / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D020419:Photoreceptor Cells, Vertebrate / Q000166:cytology* / Q000502:physiology; D011247:Pregnancy; D051381:Rats; D011916:Rats, Inbred F344; D012160:Retina / Q000196:embryology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics
D051792:Basic Helix-Loop-Helix Proteins; D016895:Culture Media, Serum-Free; D005136:Eye Proteins; D016222:Fibroblast Growth Factor 2; D018398:Homeodomain Proteins; D000071068:Lipocalin-2; D054834:Lipocalins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D015534:Trans-Activators; C097278:Lcn2 protein, rat; C109288:cone rod homeobox protein; C093564:Neurogenic differentiation factor 1