title: Subretinal transplantation of putative retinal pigment epithelial cells derived from human embryonic stem cells in rat retinal degeneration model.
abstract: OBJECTIVE
  To differentiate the human embryonic stem cells (hESCs) into the retinal pigment epithelium (RPE) in the defined culture condition and determine its therapeutic potential for the treatment of retinal degenerative diseases.
  
  
  METHODS
  The embryoid bodies were formed from hESCs and attached on the matrigel coated culture dishes. The neural structures consisting neural precursors were selected and expanded to form rosette structures. The mechanically isolated neural rosettes were differentiated into pigmented cells in the media comprised of N2 and B27. Expression profiles of markers related to RPE development were analyzed by reverse transcription-polymerase chain reaction and immunostaining. Dissociated putative RPE cells (10(5) cells/5 µL) were transplanted into the subretinal space of rat retinal degeneration model induced by intravenous sodium iodate injection. Animals were sacrificed at 1, 2, and 4 weeks after transplantation, and immnohistochemistry study was performed to verify the survival of the transplanted cells.
  
  
  RESULTS
  The putative RPE cells derived from hESC showed characteristics of the human RPE cells morphologically and expressed molecular markers and associated with RPE fate. Grafted RPE cells were found to survive in the subretinal space up to 4 weeks after transplantation, and the expression of RPE markers was confirmed with immunohistochemistry.
  
  
  CONCLUSIONS
  Transplanted RPE cells derived from hESC in the defined culture condition successfully survived and migrated within subretinal space of rat retinal degeneration model. These results support the feasibility of the hESC derived RPE cells for cell-based therapies for retinal degenerative disease.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Un Chul
authors.initials: UC
authors.lastname: Park
authors.forename: Myung Soo
authors.initials: MS
authors.lastname: Cho
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Park
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Seung-Yup
authors.initials: SY
authors.lastname: Ku
authors.forename: Young Min
authors.initials: YM
authors.lastname: Choi
authors.forename: Shin Yong
authors.initials: SY
authors.lastname: Moon
authors.forename: Hyeong Gon
authors.initials: HG
authors.lastname: Yu