This subproject is one of many research subprojects utilizing theresources provided by a Center grant funded by NIH/NCRR. The subproject andinvestigator (PI) may have received primary funding from another NIH source,and thus could be represented in other CRISP entries. The institution listed isfor the Center, which is not necessarily the institution for the investigator.This progress report has been prepared on the basis of the work that has been done during the current budget period (March 2007- January 2008).
The specific aim for the second year was to characterize the effect of secreted factors from human retinal progenitor cells (HRPC), maintained under normoxia or hypoxia, on neovascularization. In most in-vitro models of neovascularization, the formation of new blood vessel-like structures is slow and is very difficult to examine during the early stages. Hypoxia can affect both HRPC and HUVEC gene expression independently, and the factors released in this setting can modulate HRPC-EC interactions, which may result in several neovascularization disorders, e.g., retinopathy and age related macular degeneration.The rationale for our approach is that several different cell types, including retinal, retinal pigmented epithelial cells (RPE), endothelial (EC) cells and pericytes, participate in the development of retinopathies, and associated neovascularization. However, most in vitro models have looked at the impact of only one cell type at a time, or their secreted factors, on neovascularization. To our knowledge, however, there are no clear-cut reports on retinal neovascularization, which describe the factors contributed by specific cell types that could induce these ocular disorders. Communication between cells is an essential process in embryological development and is important for the maintenance of normal tissue physiology. The present experiment was designed to investigate the hypothesis that EC will alter retinal cell, and vise-versa, by altering the expression of genes that regulate neovascularization. In order to examine gene expression by either cell type in a co-culture system, we developed a co-culture system for EC and retinal cells using Transwell system. Transwell with 0.3 membranes allows process contact and medium diffusion between cells, but prohibits cell migration through the membrane. In our present research, we establish contacting and non-contacting co-culture models of HRPC/HUVEC.
Showing the most recent 10 out of 291 publications
