» Articles » PMID: 21229256

Similarities and Differences Between Primary and Secondary Degeneration of the Optic Nerve and the Effect of Minocycline

Overview
Specialty Ophthalmology
Date 2011 Jan 14
PMID 21229256
Citations 16
Authors
Affiliations
Soon will be listed here.
Abstract

Purpose: To investigate the mechanism of secondary degeneration of the optic nerve, and to evaluate the neuroprotective effect of minocycline in this process.

Methods: A partial transection model that morphologically separates primary and secondary degeneration was applied unilaterally in 152 Wistar rat eyes. The involvement of pro-apoptotic, pro-survival and inflammatory pathways was analyzed by quantitative real-time PCR and immunohistochemistry at multiple time points. The neuroprotective effect of daily intraperitoneal injections of minocycline 22 mg/kg/day was evaluated at 7, 11 and 21 days post-injury. Retrograde labeling of retinal ganglion cells (RGCs) with fluorogold was via the superior colliculus, and surviving RGCs were counted using retinal whole mounts.

Results: Both primary and secondary degeneration led to a significant up-regulation of the pro-apoptotic genes, GADD45α, ei24 and CDK2, and the pro-survival gene, IAP-1. These processes differed, however, in their reaction to minocycline. Minocycline protected RGC death from secondary degeneration at 11 days (6 ± 8% loss compared to 37 ± 7% in the saline-treated group, n = 15, P = 0.012), and at 21 days (42 ± 7% versus 64 ± 7% respectively, n = 15, P = 0.06) after partial transection. In contrast, its effect on primary degeneration was not significant.

Conclusions: While the genetic profile supported similarities between primary and secondary degeneration of the optic nerve, the specific effect of minocycline on secondary degeneration revealed a potential difference between the two. The mechanism underlying secondary degeneration, and its role in optic neuropathies such as glaucoma, awaits further studies.

Citing Articles

Secondary Degeneration Impairs Myelin Ultrastructural Development in Adulthood following Adolescent Neurotrauma in the Rat Optic Nerve.

Lins B, Anyaegbu C, McGonigle T, Hellewell S, Patel P, Reagan H Int J Mol Sci. 2023; 24(4).

PMID: 36834755 PMC: 9966883. DOI: 10.3390/ijms24043343.


Gadd45 in Neuronal Development, Function, and Injury.

Sultan F, Sawaya B Adv Exp Med Biol. 2022; 1360:117-148.

PMID: 35505167 DOI: 10.1007/978-3-030-94804-7_9.


Insulin Signaling as a Therapeutic Target in Glaucomatous Neurodegeneration.

Al Awamlh S, Wareham L, Risner M, Calkins D Int J Mol Sci. 2021; 22(9).

PMID: 33925119 PMC: 8124776. DOI: 10.3390/ijms22094672.


Dimethyl Fumarate Promotes the Survival of Retinal Ganglion Cells after Optic Nerve Injury, Possibly through the Nrf2/HO-1 Pathway.

Mori S, Kurimoto T, Maeda H, Nakamura M Int J Mol Sci. 2021; 22(1).

PMID: 33396673 PMC: 7795407. DOI: 10.3390/ijms22010297.


Quantitative profiling of regional protein expression in rat retina after partial optic nerve transection using fluorescence difference two‑dimensional gel electrophoresis.

Lam C, Li K, Do C, Chan H, To C, Kwong J Mol Med Rep. 2019; 20(3):2734-2742.

PMID: 31524249 PMC: 6691257. DOI: 10.3892/mmr.2019.10525.


References
1.
Levkovitch-Verbin H, Kalev-Landoy M, Habot-Wilner Z, Melamed S . Minocycline delays death of retinal ganglion cells in experimental glaucoma and after optic nerve transection. Arch Ophthalmol. 2006; 124(4):520-6. DOI: 10.1001/archopht.124.4.520. View

2.
Zhang Y, Metz L, Yong V, Bell R, Yeung M, Patry D . Pilot study of minocycline in relapsing-remitting multiple sclerosis. Can J Neurol Sci. 2008; 35(2):185-91. DOI: 10.1017/s0317167100008611. View

3.
Libby R, Li Y, Savinova O, Barter J, Smith R, Nickells R . Susceptibility to neurodegeneration in a glaucoma is modified by Bax gene dosage. PLoS Genet. 2005; 1(1):17-26. PMC: 1183523. DOI: 10.1371/journal.pgen.0010004. View

4.
Chen M, Ona V, Li M, Ferrante R, Fink K, Zhu S . Minocycline inhibits caspase-1 and caspase-3 expression and delays mortality in a transgenic mouse model of Huntington disease. Nat Med. 2000; 6(7):797-801. DOI: 10.1038/77528. View

5.
Yuan L, Neufeld A . Activated microglia in the human glaucomatous optic nerve head. J Neurosci Res. 2001; 64(5):523-32. DOI: 10.1002/jnr.1104. View