Matrix metalloproteinase-9 expression in retinal ganglion cell layer and effect of topically applied brimonidine tartrate 0.2% therapy on this expression in an endothelin-1-induced optic nerve ischemia model


AKTAŞ Z., GÜRELİK İ. G. , UYAR GÖÇÜN F. P. , AKYÜREK N., önol m., HASANREİSOĞLU B.

International Ophthalmology, vol.30, no.3, pp.253-259, 2010 (Scopus) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 3
  • Publication Date: 2010
  • Doi Number: 10.1007/s10792-009-9316-9
  • Journal Name: International Ophthalmology
  • Journal Indexes: Scopus
  • Page Numbers: pp.253-259
  • Keywords: Brimonidine, Endothelin-1, Matrix metalloproteinase-9, Retinal ganglion cell layer
  • Gazi University Affiliated: Yes

Abstract

The purpose of this research is to investigate the expression of matrix metalloproteinase-9 (MMP-9) in retinal ganglion cells (RGC) and the impact of topically applied brimonidine tartrate 0.2% (BMD) on this expression in an endothelin-1 (ET-1)- induced chronic optic nerve (ON) ischemia model of rabbit. Osmotically driven minipumps were implanted in one eye of 16 New Zealand albino rabbits to deliver ET-1 at the constant rate of 0.5 ll/h for 2 weeks. ET-1 was given with (group 3) and withouttopical BMD therapy (group 1). Groups 2 and 4 were taken as controls. MMP-9 expression by immunohistochemically and proportion of cells undergoing apoptosis in RGC layer were investigated. The correlation between the MMP-9 immunopositivity and the proportion of cells undergoing apoptosis in the RGC layer was evaluated. MMP-9immunopositivity was found to be significantly higher in both groups 1 and 3 compared to that of the controls. There was no difference between groups 1 and 3 regarding MMP-9 expression (p = 0.495). A positive correlation was found between the proportion of cells undergoing apoptosis and MMP-9 expressions in the RGC layer in group 1 (p = 0.031, r = 0.754). MMP-9 expression in the RGC layer seems to significantly increase in the ET-1-induced chronic ON ischemia model. Topical BMD therapy does not seem to affect this MMP-9 expression. © Springer Science+Business Media B.V. 2009.