Medical College of Wisconsin
CTSICores SearchResearch InformaticsREDCap

PITX2 is involved in stress response in cultured human trabecular meshwork cells through regulation of SLC13A3. Invest Ophthalmol Vis Sci 2011 Sep 29;52(10):7625-33

Date

08/30/2011

Pubmed ID

21873665

Pubmed Central ID

PMC3183983

DOI

10.1167/iovs.10-6967

Scopus ID

2-s2.0-84863833810 (requires institutional sign-in at Scopus site)   25 Citations

Abstract

PURPOSE: Mutations of the PITX2 gene cause Axenfeld-Rieger syndrome (ARS) and glaucoma. In this study, the authors investigated genes directly regulated by the PITX2 transcription factor to gain insight into the mechanisms underlying these disorders.

METHODS: RNA from nonpigmented ciliary epithelium cells transfected with hormone-inducible PITX2 and activated by mifepristone was subjected to microarray analyses. Data were analyzed using dCHIP algorithms to detect significant differences in expression. Genes with significantly altered expression in multiple microarray experiments in the presence of activated PITX2 were subjected to in silico and biochemical analyses to validate them as direct regulatory targets. One target gene was further characterized by studying the effect of its knockdown in a cell model of oxidative stress, and its expression in zebrafish embryos was analyzed by in situ hybridization.

RESULTS: Solute carrier family 13 sodium-dependent dicarboxylate transporter member 3 (SLC13A3) was identified as 1 of 47 potential PITX2 target genes in ocular cells. PITX2 directly regulates SLC13A3 expression, as demonstrated by luciferase reporter and chromatin immunoprecipitation assays. Reduction of PITX2 or SLC13A3 levels by small interfering RNA (siRNA)-mediated knockdown augmented the death of transformed human trabecular meshwork cells exposed to hydrogen peroxide. Zebrafish slc13a3 is expressed in anterior ocular regions in a pattern similar to that of pitx2.

CONCLUSIONS: The results indicate that SLC13A3 is a direct downstream target of PITX2 transcriptional regulation and that levels of PITX2 and SLC13A3 modulate responses to oxidative stress in ocular cells.

Author List

Strungaru MH, Footz T, Liu Y, Berry FB, Belleau P, Semina EV, Raymond V, Walter MA

Author

Elena V. Semina PhD Chief, Professor in the Ophthalmology and Visual Sciences department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Cell Survival
Cells, Cultured
Gene Expression Regulation
Homeodomain Proteins
Humans
Hydrogen Peroxide
In Situ Hybridization
Oligonucleotide Array Sequence Analysis
Organic Anion Transporters, Sodium-Dependent
Oxidative Stress
Plasmids
RNA, Small Interfering
Reverse Transcriptase Polymerase Chain Reaction
Symporters
Trabecular Meshwork
Transcription Factors
Transcriptional Activation
Transfection
Zebrafish