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Updated: Jun 22, 2026
Induction and Analysis of Oxidative Stress in Sleeping Beauty Transposon-Transfected Human Retinal Pigment Epithelial Cells
Published on: December 11, 2020
Oxidative stress-mediated induction of MMP-1 and MMP-3 in human RPE cells
Claudia S Alge-Priglinger1, Thomas Kreutzer, Katja Obholzer
1Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
Purpose:
In early exudative age-related macular degeneration (AMD), segmental thinning of Bruch's membrane is associated with ingrowth of choroidal neovascularization into the subretinal space. To determine whether there is a link between oxidative stress and extracellular matrix (ECM) degradation by the retinal pigment epithelium, the present study focused on the effect of oxidative stress on MMP-1 and MMP-3 expression, two enzymes with substrate specificity for components of Bruch's membrane.
Methods:
Cultured human RPE cells were exposed to oxidative stress. To investigate the role of signal transduction proteins, cells were pretreated with the specific inhibitors SB202190 or PD98059. Secreted MMP-1 and MMP-3 were detected by ELISA, MMP-2, and MMP-9 by zymography. Expression of mRNA was determined by quantitative real-time RT-PCR. ECM degradation by retinal pigment epithelium was assessed by immunofluorescence microscopy.
Results:
Oxidative stress increased MMP-1 and MMP-3 protein release but reduced MMP-2 activity. Real-time RT-PCR disclosed increases of MMP-1 and MMP-3 mRNA after oxidative stress with no modulation of TIMP-1. MMP-2 and MMP-9 mRNA was slightly enhanced. PD98059, an inhibitor of ERK1/2, markedly reduced MMP-1 expression, whereas SB202190, an inhibitor of p38 MAPK, was less effective. MMP-3 expression was attenuated by both inhibitors. Oxidative stress-stimulated type I collagen degradation by RPE cells was reduced by simultaneous treatment with a synthetic MMP-inhibitor or a neutralizing antibody against MMP-1.
Conclusions:
MMP-1 and MMP-3 in the retinal pigment epithelium are inducible by oxidative stress. The directional shift in the MMP-1,-3/TIMP-1 ratio is associated with increased type I collagen degradation. This may be an important mechanism contributing to the pathogenesis of early exudative AMD.
Insights
Oxidative stress increases matrix metalloproteinase-1 (MMP-1) and MMP-3 in retinal pigment epithelium, degrading extracellular matrix. This may drive age-related macular degeneration (AMD) pathogenesis.
Area of Science:
- Ophthalmology
- Cell Biology
- Biochemistry
Background:
- Age-related macular degeneration (AMD) involves Bruch's membrane changes and choroidal neovascularization.
- Extracellular matrix (ECM) degradation by retinal pigment epithelium (RPE) is implicated in AMD pathogenesis.
- The role of oxidative stress in ECM degradation by RPE requires further elucidation.
Purpose of the Study:
- To investigate the effect of oxidative stress on matrix metalloproteinase (MMP) expression in human RPE cells.
- To determine the link between oxidative stress and ECM degradation relevant to AMD.
- To identify specific MMPs involved in oxidative stress-induced ECM remodeling.
Main Methods:
- Human RPE cells were subjected to oxidative stress.
- Inhibitors of signal transduction pathways (p38 MAPK, ERK1/2) were used.
- MMP protein and mRNA levels, enzyme activity, and ECM degradation were quantified.
Main Results:
- Oxidative stress upregulated MMP-1 and MMP-3 protein and mRNA expression in RPE cells.
- MMP-1 expression was primarily mediated by the ERK1/2 pathway, while MMP-3 involved both ERK1/2 and p38 MAPK.
- Oxidative stress increased type I collagen degradation by RPE cells, which was inhibited by targeting MMP-1.
Conclusions:
- Oxidative stress induces MMP-1 and MMP-3 in RPE cells.
- The increased MMP-1 and MMP-3 expression leads to enhanced ECM degradation, particularly type I collagen.
- This mechanism contributes to the pathogenesis of early exudative age-related macular degeneration (AMD).
