| First Author | Zayas-Santiago A | Year | 2017 |
| Journal | Invest Ophthalmol Vis Sci | Volume | 58 |
| Issue | 7 | Pages | 3046-3054 |
| PubMed ID | 28622396 | Mgi Jnum | J:256168 |
| Mgi Id | MGI:6115460 | Doi | 10.1167/iovs.17-21720 |
| Citation | Zayas-Santiago A, et al. (2017) Mutant Fibulin-3 Causes Proteoglycan Accumulation and Impaired Diffusion Across Bruch's Membrane. Invest Ophthalmol Vis Sci 58(7):3046-3054 |
| abstractText | Purpose: The mutation R345W in EFEMP1 (fibulin-3) causes macular degeneration. This study sought to determine whether proteoglycan content and diffusion across Bruch''s membrane are altered in Efemp1ki/ki mice carrying this mutation or in Efemp1-/- mice. Methods: Proteoglycans in mouse Bruch''s membranes were stained with Cupromeronic Blue (CB). Heparan sulfated proteoglycan (HSPG) and chondroitin/dermatan sulfate proteoglycan (C/DSPG) distributions were visualized following treatments with chondroitinase ABC (C-ABC) or nitrous acid. Total sulfated glycosaminoglycans (sGAGs) in Bruch''s membrane/choroid (BrM/Ch) were measured with dimethylmethylene blue (DMMB). Matrix metalloprotease (MMP)-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-3 were examined by immunofluorescence and quantified using Image J. Molecules with different Stokes radius (Rs) were allowed simultaneously to diffuse through mouse BrM/Ch mounted in a modified Ussing chamber. Samples were quantified using gel exclusion chromatography. Results: HSPGs and C/DSPGs were markedly increased in Efemp1ki/ki Bruch''s membrane, and MMP-2 and MMP-9 were decreased, but TIMP-3 was increased. Diffusion across Efemp1ki/ki Bruch''s membrane was impaired. In contrast, the proteoglycan amount in Efemp1-/- Bruch''s membrane was not significantly different, but the size of proteoglycans was much larger. MMP-2, MMP-3, and TIMP-3 levels were similar to that of Efemp1+/+ mice, but they were localized diffusely in retinal pigment epithelium (RPE) cells instead of Bruch''s membrane. Diffusion across Efemp1-/- Bruch''s membrane was enhanced. Conclusions: Mutant fibulin-3 causes proteoglycan accumulation, reduction of MMP-2 and MMP-9, but increase of TIMP-3, and impairs diffusion across Bruch''s membrane. Fibulin-3 ablation results in altered sizes of proteoglycans, altered distributions of MMP-2, MMP-9, and TIMP-3, and enhances diffusion across Bruch''s membrane. |
