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Abstract #27232 Published in IGR 12-4
The Wnt Signaling Pathway Protects Retinal Ganglion Cell 5 (RGC-5) Cells from Elevated Pressure
Fragoso MA; Yi H; Nakamura REI; Hackam ASCellular and molecular neurobiology 2010; 1-11
The Wnt pathway is an essential signaling cascade that regulates survival and differentiation in the retina. We recently demonstrated that retinal ganglion cells (RGCs) have constitutively active Wnt signaling in vivo. However, the role of Wnt in RGC viability or function is unknown. In this study, we investigated whether Wnt protects the retinal ganglion cell line RGC-5 from elevated pressure, oxidative stress, and hypoxia injuries. Expression of RGC marker genes in the RGC-5 cultures was confirmed by immunocytochemistry and PCR. We demonstrated that the Wnt3a ligand significantly reduced pressure-induced caspase activity in RGC-5 cells (n = 5, P = 0.03) and decreased the number of TUNEL-positive cells (n = 5, P = 0.0014). Notably, Wnt3a-dependent protection was reversed by the Wnt signaling inhibitor Dkk1. In contrast, Wnt3a did not protect RGC-5 cells from oxidative stress or hypoxia. Furthermore, Wnt3a significantly increased growth factor expression in the presence of elevated pressure but not in the presence of oxidative stress and hypoxia. These results indicate that Wnt3a induces injury-specific survival pathways in RGC-5 cells, potentially by upregulating neuroprotective growth factors. Therefore, activation of the Wnt pathway by Wnt3a could be investigated further as a tool to develop novel molecular therapeutic strategies for the prevention of RGC death in retinal disease. (copyright) 2010 Springer Science+Business Media, LLC.
A.S. Hackam. Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, McKnight Bldg. Rm. 407, 1638 NW 10th Ave., Miami, 33136, FL, United States. ahackam@med.miami.edu
Classification:
3.6 Cellular biology (Part of: 3 Laboratory methods)
11.8 Neuroprotection (Part of: 11 Medical treatment)
