Generation of retinal ganglion-like cells from reprogrammed mouse fibroblasts.
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.
Chen
Mengfei
M
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
Chen
Qin
Q
Sun
Xuerong
X
Shen
Wenjuan
W
Liu
Bingqian
B
Zhong
Xiufeng
X
Leng
Yunxia
Y
Li
Chunmei
C
Zhang
Weizhong
W
Chai
Fang
F
Huang
Bing
B
Gao
Qianying
Q
Xiang
Andy Peng
AP
Zhuo
Yehong
Y
Ge
Jian
J
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
D015415:Biomarkers; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D014157:Transcription Factors