A study of mechanisms of retina regeneration in the embryonic chick by Miami University researchers provides insights into how retinal stem cells can be activated and could lead to possible regenerative therapies to treat vision impairment and blindness.
The study, "BMP signaling mediates stem/progenitor cell-induced retina regeneration," is published in the Dec. 14, 2007, Proceedings of The National Academy of Sciences (PNAS). Authors are Katia Del Rio-Tsonis, associate professor of zoology and co-director of the Center for Visual Sciences at Miami University; Tracy Haynes, a Miami postdoctoral associate (first author); Christian Gutierrez, Miami doctoral student in zoology; Juan-Carlos Aycinena, Miami research associate; and Panagiotis A. Tsonis, professor of molecular biology and director, Center for Tissue Regeneration and Engineering, University of Dayton.
Del Rio-Tsonis and her colleagues have established a retina regeneration model in the embryonic chick in which they can manipulate key molecular pathways that could control retina repair and regeneration. The embryonic chick has been shown to regenerate a complete retina in about seven days if a retinectomy is performed on or around embryonic day four and a source of fibroblast growth factor (FGF) is added, say the study authors.
The study shows that bone morphogenetic protein (BMP) signaling is necessary to induce retina regeneration from retina stem/progenitor cells in the embryonic chick. Molecules from the BMP pathway are expressed in chick eyes at embryonic day four and during retina regeneration. The researchers found that BMP regulates the FGF pathway, and that both BMP and FGF were necessary for retina regeneration.
"These results unravel a mechanism for stem/progenitor cell-mediated retina regeneration, where BMP activation establishes a cross-talk with the FGF pathway," say the authors.
"Retina stem/progenitor cells exist in other species including humans. Thus our findings provide insights on how retinal stem cells can be activated for possible regenerative therapies."
Age-related eye diseases, including macular degeneration, are the leading causes of vision impairment and blindness in the United States, according to the National Eye Institute. No effective treatment has been developed to replace retina cells lost in these diseases. The research by Del Rio-Tsonis, Haynes and Gutierrez - funded by the National Eye Institute, National Institute of Aging and Prevent Blindness America - could lead scientists one step closer to potential treatments of eye blinding diseases.