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T. Oshitari, P. Polewski, S. Roy; Increased Synthesis of Extracellular Matrix and Vascular Permeability in Early Diabetic Retinopathy . Invest. Ophthalmol. Vis. Sci. 2005;46(13):442.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: To examine the effect of combined antisense oligonucleotides (AS oligos) against overexpression of extracellular matrix components, fibronectin (FN), laminin (LM), and collagen IV (Coll IV) in diabetic rat retinas and its effect on vascular permeability in early diabetic retinopathy. Methods: Specific AS oligos capable of simultaneously reducing FN, Coll IV, and LM overexpression in microvascular endothelial cells in vitro was used in this study to determine their efficacy in retinas of streptozotocin–induced diabetic rats. A cocktail containing 3µM dose for each of the three AS oligos (against FN, Coll IV and LM) was administered monthly by intravitreal injection together with polyoxyethylene–polyspermine, a carrier molecule. As control for specificity of antisense effect, rats were also injected intravitreally with 3 µM random oligonucleotides monthly. Four and 8 weeks post AS oligos treatment, retinal FN, Coll IV, and LM protein levels were determined by Western Blot analysis, and retinal vascular permeability was determined from images of retinal whole mounts and cryosections obtained after FITC–BSA (30 mg/kg) tail vein injection immediately prior to sacrifice. Results: After 4 weeks of diabetes, no significant change either in retinal FN, Coll IV and LM protein levels or in retinal vascular permeability was observed. After 8 weeks of diabetes, retinal FN, Coll IV, and LM protein level was significantly increased (195.0 ± 37.8%, 190.5 ± 48.0%, 183.0 ± 54.2%, respectively) compared to those in control non–diabetic rats. When diabetic rats were treated with combined AS oligos and examined 8 weeks post treatment, the FN, Coll IV and LM protein level was significantly reduced (148.7 ± 29.3% vs 195.0 ± 37.8%, 146.0 ± 28.2% vs 190.5 ± 48.0%, 127.9 ± 47.3% vs 183.0 ± 54.2%, respectively, compared to those of diabetic retinas, P < 0.05). Treatment with random oligonucleotides had no effect after 8 weeks post treatment (201.4 ± 46.1% vs 195.0 ± 37.8%, 183.8 ± 30.9% vs. 183.0 ± 54.2%, 201.7 ± 40.7% vs 190.5 ± 48.0%, respectively). After 8 weeks of diabetes, retinal vascular permeability was also significantly increased (337.2 ± 64.3% of control, P < 0.01). The combined AS oligos treatment resulted in significant reduction in vascular permeability (179.1 ± 23.5% of control, P < 0.05, compared to that of diabetic retinas). Conclusions: The combined AS oligos strategy is effective in simultaneously reducing FN, Coll IV, and LM overexpression and vascular leakage in the retinal capillaries of short–term diabetic rats. Abnormally thickened capillary basement membrane may result in vascular leakage in the diabetic retina.
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