title: Preservation of photoreceptors in dystrophic RCS rats following allo- and xenotransplantation of IPE cells.
abstract: OBJECTIVE
  To examine whether iris pigment epithelial (IPE) cells transplanted into the subretinal space of Royal College of Surgeons (RCS) rats have the ability to rescue photoreceptors.
  
  
  METHODS
  Rat IPE (rIPE) or human IPE (hIPE) cells were transplanted subretinally in 23-day-old RCS rats. Sham injection and transplantation of ARPE-19 cells served as controls. After 12 weeks, eyes were evaluated for photoreceptor survival by morphometric analysis and electron microscopy.
  
  
  RESULTS
  Morphometric analysis showed photoreceptor rescue in all transplanted and sham-injected animals (number of photoreceptors/300 microm retina+/-sd: rIPE 41.67 +/- 28; hIPE 29.50 +/- 16; ARPE-19 36.12 +/- 21; sham 16.56 +/- 6) compared to age-matched, control rats (number of photoreceptors/300 microm retina+/-sd: 9.71 +/- 4). Photoreceptor rescue was prominent in IPE cell-transplanted rats and was significantly greater than sham-injected eyes (p = 0.02 for rIPE and p = 0.04 for hIPE).
  
  
  CONCLUSIONS
  Since IPE cells transplanted into the subretinal space have the ability to rescue photoreceptors from degeneration in the RCS rat without any harmful effects, IPE cells may represent an ideal cell to genetically modify and thus carry essential genetic information for the repair of defects in the subretinal space.
authors.affiliation: IZKF Biomat, RWTH University of Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany. GThumann@ukaachen.de
authors.forename: Gabriele
authors.initials: G
authors.lastname: Thumann
authors.forename: Anna Katharina
authors.initials: AK
authors.lastname: Salz
authors.forename: Peter
authors.initials: P
authors.lastname: Walter
authors.forename: Sandra
authors.initials: S
authors.lastname: Johnen
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000502:physiology; D017690:Cell Transplantation / Q000379:methods*; D002478:Cells, Cultured; D006085:Graft Survival / Q000502:physiology; D006801:Humans; D007498:Iris / Q000166:cytology*; D008854:Microscopy, Electron; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology* / Q000648:ultrastructure; D010857:Pigment Epithelium of Eye / Q000502:physiology / Q000637:transplantation* / Q000648:ultrastructure; D051381:Rats; D020318:Rats, Long-Evans; D011922:Rats, Mutant Strains; D012162:Retinal Degeneration / Q000473:pathology / Q000601:surgery*; D014183:Transplantation, Heterologous; D014184:Transplantation, Homologous