Zeb1 RepressesMitfand Regulates Pigment Synthesis, Cell Proliferation, and Epithelial Morphology
- 1 November 2009
- journal article
- research article
- Published by Association for Research in Vision and Ophthalmology (ARVO) in Investigative Ophthalmology & Visual Science
- Vol. 50 (11), 5080-5088
- https://doi.org/10.1167/iovs.08-2911
Abstract
Purpose.: Epithelial-mesenchymal transition (EMT) is important in fibrotic responses, formation of cancer stem cells, and acquisition of a metastatic phenotype. Zeb1 represses epithelial specification genes to enforce epithelial-mesenchymal phenotypic boundaries during development, and it is one of several E-box-binding repressors whose overexpression triggers EMT. The purpose of this study was to investigate the potential role for Zeb1 in EMT leading to the dedifferentiation of retinal pigment epithelial (RPE) cells. Methods.: Real-time PCR was used to examine mRNA expression during RPE dedifferentiation in primary cultures of RPE cells from Zeb1(±) mice and after knockdown of Zeb1 by lentivirus shRNA. Chromatin immunoprecipitation was used to detect Zeb1 at gene promoters in vivo. Results.: Zeb1 is overexpressed during RPE dedifferentiation. Heterozygous mutation or shRNA knockdown to prevent this overexpression eliminates the onset of proliferation, loss of epithelial morphology, and pigment, which characterizes RPE dedifferentiation. Zeb1 binds to the Mitf A promoter in vivo, and Zeb1 mutation or shRNA knockdown derepresses the gene. The authors link Zeb1 expression to cell-cell contact and demonstrate that forcing dedifferentiated RPE cells to adopt cell-cell only contacts via sphere formation reverses the overexpression of Zeb1 and reprograms RPE cells back to a pigmented phenotype. Conclusions.: Overexpression of the EMT transcription factor Zeb1 has an important role in RPE dedifferentiation via its regulation of Mitf. Expression of Zeb1 and, in turn, RPE dedifferentiation, is linked to cell-cell contact, and these contacts can be used to diminish Zeb1 expression and reprogram dedifferentiated RPE cells.This publication has 46 references indexed in Scilit:
- The Epithelial-Mesenchymal Transition Generates Cells with Properties of Stem CellsCell, 2008
- Zeb1 Mutant Mice as a Model of Posterior Corneal DystrophyInvestigative Ophthalmology & Visual Science, 2008
- Zeb1 links epithelial-mesenchymal transition and cellular senescenceDevelopment, 2008
- The zinc finger transcription factor ZFHX1A is linked to cell proliferation by Rb–E2F1Biochemical Journal, 2007
- Microphthalmia Transcription Factor Isoforms in Mast Cells and the HeartMolecular and Cellular Biology, 2007
- Novel mutations in theZEB1 gene identified in Czech and British patients with posterior polymorphous corneal dystrophyHuman Mutation, 2007
- A High-Throughput Study in Melanoma Identifies Epithelial-Mesenchymal Transition as a Major Determinant of MetastasisCancer Research, 2007
- Confluent Monolayers of Cultured Human Fetal Retinal Pigment Epithelium Exhibit Morphology and Physiology of Native TissueInvestigative Ophthalmology & Visual Science, 2006
- The other pigment cell: specification and development of the pigmented epithelium of the vertebrate eyePigment Cell Research, 2006
- Anoikis mechanismsCurrent Opinion in Cell Biology, 2001