Inhibition of Matrix Metalloproteinase 9 Enhances Rod Survival in the S334ter-line3 Retinitis Pigmentosa Model

PLoS One. 2016 Nov 28;11(11):e0167102. doi: 10.1371/journal.pone.0167102. eCollection 2016.

Abstract

Retinitis Pigmentosa (RP) is one of the most common forms of inherited visual loss with the initial degeneration of rod photoreceptors, followed by a progressive cone photoreceptor deterioration. Coinciding with this visual loss, the extracellular matrix (ECM) is reorganized, which alters matrix metalloproteinase (MMP) activity levels. A potential pathological role of MMPs, MMP-9 in particular, involves an excitotoxicity-mediated physiological response. In the current study, we examine the MMP-9 and MMP-2 expression levels in the rhodopsin S334ter-line3 RP rat model and investigate the impact of treatment with SB-3CT, a specific MMP-9 and MMP-2 inhibitor, on rod cell survival was tested. Retinal MMP-9 and MMP-2 expression levels were quantified by immunoblot analysis from S334ter-line3 rats compared to controls. Gelatinolytic activities of MMP-9 and MMP-2 by zymography were examined. The geometry of rod death was further evaluated using Voronoi analysis. Our results revealed that MMP-9 was elevated while MMP-2 was relatively unchanged when S334ter-line 3 retinas were compared to controls. With SB-3CT treatment, we observed gelatinolytic activity of both MMPs was decreased and diminished clustering associated with rod death, in addition to a robust preservation of rod photoreceptors. These results demonstrate that up-regulation of MMP-9 in retinas of S334ter-line3 are associated with rod death. The application of SB-3CT dramatically interferes with mechanisms leading to apoptosis in an MMP-9-dependent manner. Future studies will determine the feasibility of using SB-3CT as a potential therapeutic strategy to slow progression of vision loss in genetic inherited forms of human RP.

MeSH terms

  • Animals
  • Cells, Cultured
  • Disease Models, Animal
  • Female
  • Heterocyclic Compounds, 1-Ring / pharmacology*
  • Matrix Metalloproteinase 2 / chemistry*
  • Matrix Metalloproteinase 9 / chemistry*
  • Protease Inhibitors / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Rats, Transgenic
  • Retinal Degeneration / drug therapy*
  • Retinal Degeneration / enzymology
  • Retinal Rod Photoreceptor Cells / cytology*
  • Retinal Rod Photoreceptor Cells / drug effects
  • Retinal Rod Photoreceptor Cells / enzymology
  • Retinitis Pigmentosa / drug therapy*
  • Retinitis Pigmentosa / enzymology
  • Retinitis Pigmentosa / pathology
  • Sulfones / pharmacology*

Substances

  • Heterocyclic Compounds, 1-Ring
  • Protease Inhibitors
  • SB 3CT compound
  • Sulfones
  • Matrix Metalloproteinase 2
  • Mmp2 protein, rat
  • Matrix Metalloproteinase 9
  • Mmp9 protein, rat