Regulation of WNT Signaling by VSX2 During Optic Vesicle Patterning in Human Induced Pluripotent Stem Cells.
Few gene targets of Visual System Homeobox 2 (VSX2) have been identified despite its broad and critical role in the maintenance of neural retina (NR) fate during early retinogenesis. We performed VSX2 ChIP-seq and ChIP-PCR assays on early stage optic vesicle-like structures (OVs) derived from human iPS cells (hiPSCs), which highlighted WNT pathway genes as direct regulatory targets of VSX2. Examination of early NR patterning in hiPSC-OVs from a patient with a functional null mutation in VSX2 revealed mis-expression and upregulation of WNT pathway components and retinal pigmented epithelium (RPE) markers in comparison to control hiPSC-OVs. Furthermore, pharmacological inhibition of WNT signaling rescued the early mutant phenotype, whereas augmentation of WNT signaling in control hiPSC-OVs phenocopied the mutant. These findings reveal an important role for VSX2 as a regulator of WNT signaling and suggest that VSX2 may act to maintain NR identity at the expense of RPE in part by direct repression of WNT pathway constituents. Stem Cells 2016;34:2625-2634.
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Elizabeth E
EE
Capowski
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.|McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Lynda S
LS
Wright
Statistics and Actuarial Science, University of Waterloo, Waterloo, ON, Canada.
Kun
K
Liang
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.|McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, 53705, USA.
M Joseph
MJ
Phillips
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Kyle
K
Wallace
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Anna
A
Petelinsek
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Anna
A
Hagstrom
Aragon Institute for Health Research (IIS Aragón), Lozano Blesa University Hospital, Zaragoza, 50009, Spain.|Department of Ophthalmology, Lozano Blesa University Hospital, Zaragoza, 50009, Spain.
Isabel
I
Pinilla
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Katarzyna
K
Borys
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Jessica
J
Lien
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Jee Hong
JH
Min
Department of Statistics, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Sunduz
S
Keles
Morgridge Institute for Research, Madison, WI, 53715, USA.
James A
JA
Thomson
Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.|McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, 53705, USA.|Department of Ophthamology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, 53705, USA.
David M
DM
Gamm
D019943:Amino Acid Substitution; D052160:Benzothiazoles / Q000494:pharmacology; D015415:Biomarkers / Q000378:metabolism; D019521:Body Patterning / Q000235:genetics*; D002454:Cell Differentiation; D058732:Embryoid Bodies / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics / Q000378:metabolism; D008850:Microphthalmos / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009154:Mutation; D010641:Phenotype; D061251:Primary Cell Culture; D011725:Pyridines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D055213:Retinal Pigment Epithelium / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D060449:Wnt Signaling Pathway / Q000187:drug effects; D051155:Wnt1 Protein / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism
D052160:Benzothiazoles; D015415:Biomarkers; C473711:Chir 99021; D018398:Homeodomain Proteins; C000611186:IWP-2 compound; C497234:MITF protein, human; D051739:Microphthalmia-Associated Transcription Factor; D011725:Pyridines; D011743:Pyrimidines; D014157:Transcription Factors; C490289:VSX2 protein, human; C495247:WNT1 protein, human; D051155:Wnt1 Protein
Human induced pluripotent stem cells (hiPSCs); VSX2; WNT; optic vesicles