advertisement
Abstract #26445 Published in IGR 12-3
Mechanism of retinal ganglion cells death in secondary degeneration of the optic nerve
Levkovitch-Verbin H; Dardik R; Vander S; Melamed SExperimental Eye Research 2010; 91: 127-134
In central nervous system injury, the secondary degeneration process is known to play a major role in determining the final extent of impairment. Here, we investigated the mechanism of retinal ganglion cell (RGC) death in secondary degeneration of the optic nerve using a unique model that allows morphological separation between primary and secondary degeneration. A partial transection model was applied unilaterally in 110 Wistar rat eyes. The rate of apoptosis was evaluated in primary and secondary degeneration over a period of 6 months using the Hoechst staining technique. The involvement of caspase 3 and members of the Bcl-2 family (Bax, Bad, Bcl-2 and Bcl-xl) was evaluated at multiple time points for 6 months after the injury by immunohistochemistry and RT-PCR. We found that in secondary degeneration of the optic nerve, RGCs died by apoptosis from day 3-6 months following the injury, peaking at 3 months (16.3% (plus or minus) 2.5% apoptotic cells, p < 0.01). Both primary and secondary degeneration of the optic nerve resulted in caspase 3 activation, which was longer and more intense in the former. Similarly, both primary and secondary degeneration led to significant (p < 0.05) downregulation of the pro-survival genes Bcl-2 and Bcl-x-L and up-regulation of the pro-apoptotic genes Bax and Bad (p < 0.05), with a suggested delay in secondary degeneration. Thus, secondary degeneration of the optic nerve leads to RGC apoptosis over long periods in a similar mechanism as in primary degeneration.
H. Levkovitch-Verbin. Sam Rothberg Ophthalmic Molecular Biology Laboratory, Goldschleger Eye Institute, Sheba Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, 52621 Tel-Hashomer, Israel. Hani.Verbin@Sheba.health.gov.il
Classification:
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)
11.8 Neuroprotection (Part of: 11 Medical treatment)
3.5 Molecular biology incl. SiRNA (Part of: 3 Laboratory methods)
3.6 Cellular biology (Part of: 3 Laboratory methods)
