Epithelial stem cells are responsible for the homeostasis of self-renewing epithelia. Moreover they play a central role in wound repair and are the target cell for tumor initiation. My work during the past decade has contributed to the identification of stem cells within the corneal epithelium. Isolation of limbal epithelial stem cells will greatly facilitate their characterization. Furthermore, isolation of pure populations of limbal stem cells will provide the ultimate starting material for epithelial cells needed for transplantation in corneal reconstruction. The lack of specific markers for epithelial stem cells has become a major impediment in their isolation and subsequent biochemical characterization. The goal of this project is to identify specific markers for limbal epithelial stem cells. Towards this end we will: 1) use single cell technology in combination with molecular biology to obtain mRNA from limbal epithelial stem cells and corneal epithelial transit amplifying (TA) cells; 2) use suppressive subtractive hybridization (SSH) and cDNA microarrays to identify genes that are differentially expressed in limbal epithelial stem cells versus corneal epithelial TA cells; and 3) characterize the limbal epithelial stem cell-specific genes and investigate their potential function(s), focusing on those genes that are associated with the cell surface. Data obtained from these studies should lead to the isolation of pure populations of limbal epithelial stem cells. This will facilitate the biochemical characterization of these cells, and will provide a better understanding of the mechanisms involved in the self-renewal of stem cells, and in the mechanisms of limbal and corneal epithelial growth and differentiation.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Small Research Grants (R03)
Project #
1R03EY013711-01
Application #
6415873
Study Section
Special Emphasis Panel (ZEY1-VSN (04))
Program Officer
Fisher, Richard S
Project Start
2001-08-01
Project End
2002-06-30
Budget Start
2001-08-01
Budget End
2002-06-30
Support Year
1
Fiscal Year
2001
Total Cost
$158,500
Indirect Cost
Name
University of Pennsylvania
Department
Dermatology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Zhou, Mingyuan; Li, Xin-min; Lavker, Robert M (2006) Transcriptional profiling of enriched populations of stem cells versus transient amplifying cells. A comparison of limbal and corneal epithelial basal cells. J Biol Chem 281:19600-9
Budak, Murat T; Alpdogan, Onder S; Zhou, Mingyuan et al. (2005) Ocular surface epithelia contain ABCG2-dependent side population cells exhibiting features associated with stem cells. J Cell Sci 118:1715-24
Miller, Stanley J; Lavker, Robert M; Sun, Tung-Tien (2005) Interpreting epithelial cancer biology in the context of stem cells: tumor properties and therapeutic implications. Biochim Biophys Acta 1756:25-52
Sun, Tung-Tien; Lavker, Robert M (2004) Corneal epithelial stem cells: past, present, and future. J Investig Dermatol Symp Proc 9:202-7
Lavker, Robert M; Tseng, Scheffer C G; Sun, Tung-Tien (2004) Corneal epithelial stem cells at the limbus: looking at some old problems from a new angle. Exp Eye Res 78:433-46
Lavker, R M; Sun, T-T (2003) Epithelial stem cells: the eye provides a vision. Eye (Lond) 17:937-42