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Intravitreal plasmin injection activates endogenous matrix metalloproteinase-2 in rabbit and human vitreous
Akiomi Takano1, Akira Hirata, Yasuya Inomata
1Department of Ophthalmology and Visual Science, Kumamoto University Graduate School of Medical Sciences, Honjo, Kumamoto, Japan.
Purpose:
To investigate the effect of exogenous plasmin administration on the activity of endogenous matrix metalloproteinase-2 (MMP-2) in rabbit and human vitreous.
Design:
Experimental animal study and interventional case series.
Methods:
Human plasmin was injected into rabbit eyes. The active/pro-MMP-2 ratio in vitreous samples was calculated using the gelatin zymography. Scanning electron microscopy (SEM) was performed to observe the retinal surface. To evaluate the time course of MMP-2 activity, vitreous samples were collected after the injection of 0.5 IU of plasmin, and the active/pro-MMP-2 ratio was calculated in the same manner. Immunohistochemical analysis was performed to confirm the presence of MT1-MMP in the rabbit eye. Human vitreous samples obtained from vitreous surgeries were also used for similar studies.
Results:
The active/pro-MMP-2 ratios in the vitreous after the injection of 0.25 IU or 0.5 IU of plasmin were significantly higher than that of the control (P < .05). SEM demonstrated that plasmin-treated eyes showed a smooth retinal surface that was dose-dependent. Time course evaluation of the active/pro-MMP-2 ratio in the vitreous after the administration of 0.5 IU of plasmin found a significant difference between the 5 and 15 minutes data points compared with that seen for the control. Immunohistochemical study revealed the presence of MT1-MMP in the inner retina. In human samples, the active/pro-MMP-2 ratio after the plasmin injection was significantly higher than the ratio observed before injection.
Conclusions:
Our results suggested that activation of endogenous MMP-2 by exogenous plasmin is associated with the induction of posterior vitreous detachment.
Insights
Exogenous plasmin administration activates endogenous matrix metalloproteinase-2 (MMP-2) in the vitreous, potentially inducing posterior vitreous detachment. This study investigated plasmin
Area of Science:
- Ophthalmology
- Biochemistry
- Cell Biology
Background:
- Matrix metalloproteinase-2 (MMP-2) plays a role in vitreous structure.
- Understanding MMP-2 activation is crucial for vitreoretinal diseases.
Purpose of the Study:
- To investigate the effect of exogenous plasmin on endogenous matrix metalloproteinase-2 (MMP-2) activity in rabbit and human vitreous.
- To explore the association between plasmin-induced MMP-2 activation and posterior vitreous detachment.
Main Methods:
- Experimental animal study (rabbits) and interventional case series (humans).
- Exogenous plasmin administration into rabbit eyes.
- Vitreous sample analysis using gelatin zymography to determine active/pro-MMP-2 ratios.
- Scanning electron microscopy (SEM) for retinal surface observation.
- Immunohistochemical analysis for MT1-MMP presence.
Main Results:
- Plasmin injection significantly increased the active/pro-MMP-2 ratio in rabbit and human vitreous.
- A dose-dependent smoothing of the retinal surface was observed via SEM in plasmin-treated rabbit eyes.
- MT1-MMP was detected in the inner retina of rabbits.
- Elevated MMP-2 activity correlated with time post-plasmin administration.
Conclusions:
- Exogenous plasmin activates endogenous MMP-2 in the vitreous.
- Plasmin-induced MMP-2 activation is linked to the induction of posterior vitreous detachment.
