title: Modeling human retinal development with patient-specific induced pluripotent stem cells reveals multiple roles for visual system homeobox 2.
abstract: Human induced pluripotent stem cells (hiPSCs) have been shown to differentiate along the retinal lineage in a manner that mimics normal mammalian development. Under certain culture conditions, hiPSCs form optic vesicle-like structures (OVs), which contain proliferating progenitors capable of yielding all neural retina (NR) cell types over time. Such observations imply conserved roles for regulators of retinogenesis in hiPSC-derived cultures and the developing embryo. However, whether and to what extent this assumption holds true has remained largely uninvestigated. We examined the role of a key NR transcription factor, visual system homeobox 2 (VSX2), using hiPSCs derived from a patient with microphthalmia caused by an R200Q mutation in the VSX2 homeodomain region. No differences were noted between (R200Q)VSX2 and sibling control hiPSCs prior to OV generation. Thereafter, (R200Q)VSX2 hiPSC-OVs displayed a significant growth deficit compared to control hiPSC-OVs, as well as increased production of retinal pigmented epithelium at the expense of NR cell derivatives. Furthermore, (R200Q)VSX2 hiPSC-OVs failed to produce bipolar cells, a distinctive feature previously observed in Vsx2 mutant mice. (R200Q)VSX2 hiPSC-OVs also demonstrated delayed photoreceptor maturation, which could be overcome via exogenous expression of wild-type VSX2 at early stages of retinal differentiation. Finally, RNAseq analysis on isolated hiPSC-OVs implicated key transcription factors and extracellular signaling pathways as potential downstream effectors of VSX2-mediated gene regulation. Our results establish hiPSC-OVs as versatile model systems to study retinal development at stages not previously accessible in humans and support the bona fide nature of hiPSC-OV-derived retinal progeny.
authors: Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors: M Joseph
authors: MJ
authors: Phillips
authors: Enio T
authors: ET
authors: Perez
authors: Jessica M
authors: JM
authors: Martin
authors: Samantha T
authors: ST
authors: Reshel
authors: Kyle A
authors: KA
authors: Wallace
authors: Elizabeth E
authors: EE
authors: Capowski
authors: Ruchira
authors: R
authors: Singh
authors: Lynda S
authors: LS
authors: Wright
authors: Eric M
authors: EM
authors: Clark
authors: Patrick M
authors: PM
authors: Barney
authors: Ron
authors: R
authors: Stewart
authors: Sarah J
authors: SJ
authors: Dickerson
authors: Michael J
authors: MJ
authors: Miller
authors: E Ferda
authors: EF
authors: Percin
authors: James A
authors: JA
authors: Thomson
authors: David M
authors: DM
authors: Gamm
mesh_terms: D000328:Adult; D019943:Amino Acid Substitution; D000818:Animals; D019521:Body Patterning / Q000235:genetics; D002454:Cell Differentiation; D002460:Cell Line; D019070:Cell Lineage; D057809:HEK293 Cells; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism*; D008297:Male; D051379:Mice; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010786:Photoreceptor Cells / Q000378:metabolism / Q000473:pathology; D012160:Retina / Q000196:embryology* / Q000378:metabolism* / Q000473:pathology; D051245:Retinal Bipolar Cells / Q000378:metabolism / Q000473:pathology; D055213:Retinal Pigment Epithelium / Q000196:embryology / Q000473:pathology; D017423:Sequence Analysis, RNA; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome / Q000235:genetics
chemical_list: D018398:Homeodomain Proteins; D014157:Transcription Factors; C490289:VSX2 protein, human
keywords: Homeobox genes; Neurogenesis; Retina; Transcription factors; VSX2 protein; human induced pluripotent stem cells