title: Generation of retinal ganglion-like cells from reprogrammed mouse fibroblasts.
abstract: OBJECTIVE
  Somatic cells can be reprogrammed into an embryonic stem cell-like pluripotent state by Oct-3/4, Sox2, c-Myc, and Klf4. Sox2 as an essential reprogramming factor also contributes to the development of the eye and the retina. This study was conducted to determine whether induced pluripotent stem (iPS) cells express retinal progenitor cell (RPC)-related genes and whether iPS cells can directly differentiate into retinal ganglion cells (RGCs).
  
  
  METHODS
  Mouse iPS cells were induced by the ectopically expressed four factors in tail-tip fibroblasts (TTFs). The expression of RPC-related genes in iPS cells was analyzed by RT-PCR and immunofluorescence. iPS cells were induced to differentiate into RGCs by the addition of Dkk1 + Noggin (DN) + DAPT and overexpression of Math5. iPS-derived retinal ganglion (RG)-like cells were injected into the retina, and the eyes were analyzed by immunohistochemistry.
  
  
  RESULTS
  iPS cells inherently express RPC-related genes such as Pax6, Rx, Otx2, Lhx2, and Nestin. Overexpression of Math5 and addition of DN can directly differentiate iPS into retinal ganglion-like cells. These iPS-derived RG-like cells display long synapses and gene expression patterns, including Math5, Brn3b, Islet-1, and Thy1.2. Furthermore, inhibiting Hes1 by DAPT increases the expression of RGC marker genes. In addition, iPS-derived RG-like cells were able to survive but were unable to be integrated into the normal retina after transplantation.
  
  
  CONCLUSIONS
  The four factor iPS cell inherently expressed RPC-related genes, and the iPS cell could be further turned into RG-like cells by the regulation of transcription factor expression. These findings demonstrate that iPS cells are valuable for regeneration research into retinal degeneration diseases.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Mengfei
authors.initials: M
authors.lastname: Chen
authors.forename: Qin
authors.initials: Q
authors.lastname: Chen
authors.forename: Xuerong
authors.initials: X
authors.lastname: Sun
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Shen
authors.forename: Bingqian
authors.initials: B
authors.lastname: Liu
authors.forename: Xiufeng
authors.initials: X
authors.lastname: Zhong
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Leng
authors.forename: Chunmei
authors.initials: C
authors.lastname: Li
authors.forename: Weizhong
authors.initials: W
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Chai
authors.forename: Bing
authors.initials: B
authors.lastname: Huang
authors.forename: Qianying
authors.initials: Q
authors.lastname: Gao
authors.forename: Andy Peng
authors.initials: AP
authors.lastname: Xiang
authors.forename: Yehong
authors.initials: Y
authors.lastname: Zhuo
authors.forename: Jian
authors.initials: J
authors.lastname: Ge
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D017690:Cell Transplantation; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D000090062:Kruppel-Like Factor 4; D051379:Mice; D008807:Mice, Inbred BALB C; D012165:Retinal Ganglion Cells / Q000166:cytology* / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics; D014162:Transfection
chemical_list: D015415:Biomarkers; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D014157:Transcription Factors