title: Progenitor cells from the porcine neural retina express photoreceptor markers after transplantation to the subretinal space of allorecipients.
abstract: Work in rodents has shown that cultured retinal progenitor cells (RPCs) integrate into the degenerating retina, thus suggesting a potential strategy for treatment of similar degenerative conditions in humans. To demonstrate the relevance of the rodent work to large animals, we derived progenitor cells from the neural retina of the domestic pig and transplanted them to the laser-injured retina of allorecipients. Prior to grafting, immunocytochemical analysis showed that cultured porcine RPCs widely expressed neural cell adhesion molecule, as well as markers consistent with immature neural cells, including nestin, Sox2, and vimentin. Subpopulations expressed the neurodevelopmental markers CD-15, doublecortin, beta-III tubulin, and glial fibrillary acidic protein. Retina-specific markers expressed included the bipolar marker protein kinase Calpha and the photoreceptor-associated markers recoverin and rhodopsin. In addition, reverse transcription-polymerase chain reaction showed expression of the transcription factors Dach1, Hes1, Lhx2, Pax6, Six3, and Six6. Progenitor cells prelabeled with vital dyes survived as allografts in the subretinal space for up to 5 weeks (11 of 12 recipients) without exogenous immune suppression. Grafted cells expressed transducin, recoverin, and rhodopsin in the pig subretinal space, suggestive of differentiation into photoreceptors or, in a few cases, migrated into the neural retina and extended processes, the latter typically showing radial orientation. These results demonstrate that many of the findings seen with rodent RPCs can be duplicated in a large mammal. The pig offers a number of advantages over mice and rats, particularly in terms of functional testing and evaluation of the potential for clinical translation to human subjects. Disclosure of potential conflicts of interest is found at the end of this article.
authors.affiliation: Stem Cell Research, Children's Hospital of Orange County, Orange, California, USA. hklassen@uci.edu
authors.forename: Henry
authors.initials: H
authors.lastname: Klassen
authors.forename: Jens Folke
authors.initials: JF
authors.lastname: Kiilgaard
authors.forename: Tasneem
authors.initials: T
authors.lastname: Zahir
authors.forename: Boback
authors.initials: B
authors.lastname: Ziaeian
authors.forename: Ivan
authors.initials: I
authors.lastname: Kirov
authors.forename: Erik
authors.initials: E
authors.lastname: Scherfig
authors.forename: Karin
authors.initials: K
authors.lastname: Warfvinge
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Young
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D018929:Cell Culture Techniques; D002469:Cell Separation; D000089662:Doublecortin Protein; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D009474:Neurons / Q000166:cytology*; D010786:Photoreceptor Cells / Q000378:metabolism*; D012160:Retina / Q000166:cytology* / Q000637:transplantation*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*; D034421:Sus scrofa; D014184:Transplantation, Homologous
chemical_list: D015415:Biomarkers; C000714848:Dcx protein, rat; D000089662:Doublecortin Protein; D005136:Eye Proteins