FOXC1 is required for cell viability and resistance to oxidative stress in the eye through the transcriptional regulation of FOXO1A. Hum Mol Genet 2008 Feb 15;17(4):490-505
Date
11/13/2007Pubmed ID
17993506DOI
10.1093/hmg/ddm326Scopus ID
2-s2.0-38849094466 68 CitationsAbstract
Mutations in the human FOXC1 transcription factor gene underlie Axenfeld-Rieger (AR) syndrome, a disorder characterized by anterior segment malformations in the eye and glaucoma. Through the use of an inducible FOXC1 protein, along with an intermediate protein synthesis blocker, we have determined direct targets of FOXC1 transcriptional regulation. FOXC1 regulates the expression of FOXO1A and binds to a conserved element in the FOXO1A promoter in vivo. The zebrafish foxO1a orthologs exhibit a robust expression pattern in the periocular mesenchyme. Furthermore, FOXO1A expression is reduced in cultured human trabecular meshwork (TM) cells and in the zebrafish developing eye when FOXC1 expression is knocked down by siRNAs and morpholino antisense oliognucleotides, respectively. We also demonstrate that reduced FOXC1 expression increases cell death in cultured TM cells in response to oxidative stress, and increases cell death in the developing zebrafish eye. These studies have uncovered a novel role for FOXC1 as an essential mediator of cellular homeostasis in the eye and indicate that a decreased resistance to oxidative stress may underlie AR-glaucoma pathogenesis. Given that FOXO1A influences cellular homeostasis when positively or negatively regulated; the dysregulation of FOXO1A activities in the eye through FOXC1 loss of function mutations and FOXC1 gene duplications provides an explanation into how seemingly similar human disorders can arise from both increases and decreases in FOXC1 gene dose.
Author List
Berry FB, Skarie JM, Mirzayans F, Fortin Y, Hudson TJ, Raymond V, Link BA, Walter MAAuthor
Brian A. Link PhD Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsAnterior Chamber
Binding Sites
Cell Survival
Cells, Cultured
Eye
Forkhead Box Protein O1
Forkhead Transcription Factors
Gene Dosage
Glaucoma
HeLa Cells
Humans
Mutation
Oxidative Stress
Promoter Regions, Genetic
RNA, Messenger
RNA, Small Interfering
Trabecular Meshwork
Transcription, Genetic
Zebrafish
Zebrafish Proteins
