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Matrix metalloproteinases and their inhibitors in human vitreous
M A De La Paz1, Y Itoh, C A Toth
1Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Purpose:
To conduct zymographic analysis to study the matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in vitreous samples of patients undergoing pars plana vitrectomy as part of the treatment of vitreoretinal disease.
Methods:
Forty-two vitreous samples were collected at the time of pars plana vitrectomy. Diagnoses included severe (exudative) age-related macular degeneration (AMD) (12), macular hole (10), presumed ocular histoplasmosis syndrome (6), proliferative diabetic retinopathy (PDR) (5), epiretinal membrane (4), vitreomacular traction syndrome (2), macroaneurysm with subretinal hemorrhage (1), central retinal vein occlusion with vitreous hemorrhage (1), and proliferative vitreoretinopathy (1). Gelatin zymography, reverse gelatin-zymography, carboxymethylated transferrin zymography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were performed on the liquid vitreous samples to assess for MMP and TIMP activity.
Results:
Progelatinase A occurred in all vitrectomy samples. In addition, a band consistent with TIMP-2 occurred in all samples on reverse zymography. An inhibitor of MMP of a lower molecular weight than TIMP-1 was found in all the samples. A serine proteinase with a broad band around 180 kDa was found in 2 of the 11 AMD vitreous samples. A 75-kDa metalloproteinase was found in several AMD samples, but it was much more abundant in the PDR samples.
Conclusions:
Metalloproteinases and their endogenous inhibitors are present in human vitreous and may be involved in the pathogenesis of PDR and other vitreoretinal diseases.
Insights
Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are present in human vitreous. These proteins may play a role in proliferative diabetic retinopathy and other vitreoretinal diseases.
Area of Science:
- Ophthalmology
- Biochemistry
- Molecular Biology
Background:
- Vitreoretinal diseases encompass a range of serious ocular conditions.
- Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are crucial in tissue remodeling and degradation.
Purpose of the Study:
- To investigate the presence and activity of MMPs and TIMPs in human vitreous samples.
- To correlate MMP/TIMP profiles with specific vitreoretinal diseases.
Main Methods:
- Zymographic analysis (gelatin, reverse gelatin, carboxymethylated transferrin) was performed on 42 vitreous samples.
- Samples were obtained during pars plana vitrectomy for various vitreoretinal conditions.
- Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was also utilized.
Main Results:
- Progelatinase A (MMP-2) and TIMP-2 were detected in all vitreous samples.
- A lower molecular weight MMP inhibitor, distinct from TIMP-1, was universally present.
- Specific MMPs (75-kDa) were more abundant in proliferative diabetic retinopathy (PDR) samples compared to age-related macular degeneration (AMD).
Conclusions:
- MMPs and TIMPs are integral components of the human vitreous.
- The presence and activity of these enzymes may contribute to the pathogenesis of PDR and other vitreoretinal diseases.