Inherited and acquired eye diseases that target photoreceptors and/or retinal pigment epithelium (RPE) are a significant cause of visual morbidity in humans. The existence of regionally specific stem cell populations in human tissue, including brain, has raised interest in the therapeutic applications of stem cell biology. Innovative methods of propagating precursor cells from ocular tissue may produce populations of transplantable cells capable of preventing or repairing photoreceptor or RPE degeneration. This proposal outlines a five-year plan to 1) use a novel tissue culture technique to isolate and expand precursor cells obtained from retina and/or pigmented epithelial regions of fetal and adult human eyes, 2) characterize their growth and differentiation potential in response to different culture treatments and 3) examine their capacity to repopulate or rescue photoreceptors in animal models of retinal degeneration. Using a culture method developed in the host laboratory, we demonstrate that free-floating spheres of pigmented and nonpigmented cells can be successfully propagated from the posterior segment of human fetal eyes. Cells prompted to migrate from these spheres undergo differentiation and adopt distinct morphologies and patterns of pigmentation and cell marker expression. In particular, non-pigmented spheres from retina and pigmented spheres from the ciliary body produced neurons, while pigmented spheres from RPE produced regularly arranged sheets of pigmented epithelium. Building on these preliminary experiments, we will focus immediate efforts on dissecting additional specimens from both fetal and postnatal enucleated human eyes and monitoring their growth and differentiation potential over time. These studies will be carried over to the second and third years of the grant period, when we will also begin to examine the effects of specific growth factors and conditioned media on sphere behavior. During the final years of the project, strategies are proposed to examine the therapeutic potential of the different sphere populations in two distinct rat models of retinal degeneration. Together, these experiments are designed to build on recent advances in the burgeoning field of stem cell biology and apply them to the basic and clinical science of ophthalmology.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Clinical Investigator Award (CIA) (K08)
Project #
1K08EY015138-01
Application #
6705142
Study Section
Special Emphasis Panel (ZEY1-VSN (05))
Program Officer
Dudley, Peter A
Project Start
2004-02-01
Project End
2009-01-31
Budget Start
2004-02-01
Budget End
2005-01-31
Support Year
1
Fiscal Year
2004
Total Cost
$164,731
Indirect Cost
Name
University of Wisconsin Madison
Department
Pediatrics
Type
Other Domestic Higher Education
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
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Meyer, Jason S; Shearer, Rebecca L; Capowski, Elizabeth E et al. (2009) Modeling early retinal development with human embryonic and induced pluripotent stem cells. Proc Natl Acad Sci U S A 106:16698-703
Gamm, David M; Wright, Lynda S; Capowski, Elizabeth E et al. (2008) Regulation of prenatal human retinal neurosphere growth and cell fate potential by retinal pigment epithelium and Mash1. Stem Cells 26:3182-93
Gamm, David M; Melvan, J Nicholas; Shearer, Rebecca L et al. (2008) A novel serum-free method for culturing human prenatal retinal pigment epithelial cells. Invest Ophthalmol Vis Sci 49:788-99
Gamm, David M; Wang, Shaomei; Lu, Bin et al. (2007) Protection of visual functions by human neural progenitors in a rat model of retinal disease. PLoS One 2:e338
Gamm, David M; Nelson, Aaron D; Svendsen, Clive N (2005) Human retinal progenitor cells grown as neurospheres demonstrate time-dependent changes in neuronal and glial cell fate potential. Ann N Y Acad Sci 1049:107-17