AMD is the leading cause of vision loss in the USA. This devastating condition begins when abnormal deposits called drusen form under the retinal pigment epithelium (RPE) in the macular region of the retina. Drusen disrupt RPE cells and weaken the overlying retina to cause diminished vision. Stem cell research can benefit AMD patients in two ways. New RPE cells can be made from embryonic stem cells (ESC) and then injected under the retina to replace damaged RPE. This stem cell based replacement therapy restores vision in animal models of AMD. Our work at NSCI aims to determine the optimal type of stem cell for replacement of damaged RPE. We have discovered a unique, human RPE stem cell (RPESC) and are working to ascertain that the RPESC is a safe and effective stem cell for replacement therapy of AMD.
Stem cells are also used for drug discovery. The healthy RPE made for replacement therapy can be stressed to produce abnormal cells that display features of AMD. Recreating key characteristics of AMD in cells in the culture dish greatly accelerates screening for drugs using high throughput stem cell-based AMD models. The RPESC discovered at NSCI is uniquely suitable for creating such AMD models and screening tests to discover new AMD drugs is underway.
Retinal Repair by Stem Cell Transplantation 2006 Jeffrey Stern, Sally Temple and Soma De in Stem Cell Frontiers in Regenerative Medicine and Gene-based Therapy edited by Alexander Battler and Jonathan Leor, Springer-London.