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Nanoparticle-mediated expression of an angiogenic inhibitor ameliorates ischemia-induced retinal neovascularization and diabetes-induced retinal vascular leakage.

Park K, Chen Y, Hu Y, Mayo AS, Kompella UB, Longeras R, Ma JX - Diabetes (2009)

Bottom Line: Injection of K5-NP significantly reduced retinal vascular leakage and attenuated retinal neovascularization, when compared with the contralateral eyes injected with Control-NP in oxygen-induced retinopathy rats.No toxicities of K5-NP were detected to retinal structure and function.K5-NP mediates efficient and sustained K5 expression in the retina and has therapeutic potential for diabetic retinopathy.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.

ABSTRACT

Objective: The aim of the study is to evaluate the effect of nanoparticle-mediated gene delivery of angiogenic inhibitors on retinal inflammation, vascular leakage, and neovascularization in diabetic retinopathy.

Research design and methods: An expression plasmid of plasminogen kringle 5 (K5), a natural angiogenic inhibitor, was encapsulated with poly(lactide-coglycolide) to form K5 nanoparticles (K5-NP). Expression of K5 was determined by Western blot analysis and immunohistochemistry, and retinal vascular leakage was measured by permeability assay. Retinal neovascularization was evaluated using fluorescein-angiography and counting preretinal vascular cells in rats with oxygen-induced retinopathy. Effects of K5-NP on retinal inflammation were evaluated in streptozotocin-induced diabetic rats by leukostasis assay and Western blot analysis of intracellular adhesion molecule and vascular endothelial growth factor. Possible toxicities of K5-NP were evaluated using histology examination, retinal thickness measurement, and electroretinogram recording.

Results: K5-NP mediated efficient expression of K5 and specifically inhibited growth of endothelial cells. An intravitreal injection of K5-NP resulted in high-level expression of K5 in the inner retina of rats during the 4 weeks they were analyzed. Injection of K5-NP significantly reduced retinal vascular leakage and attenuated retinal neovascularization, when compared with the contralateral eyes injected with Control-NP in oxygen-induced retinopathy rats. K5-NP attenuated vascular endothelial growth factor and intracellular adhesion molecule-1 overexpression and reduced leukostasis and vascular leakage for at least 4 weeks after a single injection in the retina of streptozotocin-induced diabetic rats. No toxicities of K5-NP were detected to retinal structure and function.

Conclusions: K5-NP mediates efficient and sustained K5 expression in the retina and has therapeutic potential for diabetic retinopathy.

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Histology and ERG response in the eyes injected with K5-NP. Adult rats received an intravitreal injection of K5-NP or control-NP. The animals were killed, and the eye sections were stained with hematoxylin and eosin (three rats per time point). A–F: Representative images of the eyes at 1 (A, D), 2 (B, E), and 4 (C, F) weeks after the injection. Scale bar: 20 μm. G and H: ERG was recorded from six rats at 4 weeks after the injection of K5-NP and Control-NP to nondiabetic and diabetic rats and age-matched untreated nondiabetic and diabetic rats. Amplitudes of A- and B-waves from scotopic and photopic ERG were averaged and compared (mean ± SD, n = 6). □, Normal; , normal + control-NP; , normal + K5-NP; ■, STZ; ▧, STZ + control-NP; ▩, STZ + K5-NP. GCL, ganglion cell layer; INL, inner nuclear layer; ONL, outer nuclear layer; RPE, retinal pigment epithelium. (A high-quality digital representation of this figure is available in the online issue.)
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Figure 8: Histology and ERG response in the eyes injected with K5-NP. Adult rats received an intravitreal injection of K5-NP or control-NP. The animals were killed, and the eye sections were stained with hematoxylin and eosin (three rats per time point). A–F: Representative images of the eyes at 1 (A, D), 2 (B, E), and 4 (C, F) weeks after the injection. Scale bar: 20 μm. G and H: ERG was recorded from six rats at 4 weeks after the injection of K5-NP and Control-NP to nondiabetic and diabetic rats and age-matched untreated nondiabetic and diabetic rats. Amplitudes of A- and B-waves from scotopic and photopic ERG were averaged and compared (mean ± SD, n = 6). □, Normal; , normal + control-NP; , normal + K5-NP; ■, STZ; ▧, STZ + control-NP; ▩, STZ + K5-NP. GCL, ganglion cell layer; INL, inner nuclear layer; ONL, outer nuclear layer; RPE, retinal pigment epithelium. (A high-quality digital representation of this figure is available in the online issue.)

Mentions: Possible toxicities of K5-NP were evaluated structurally by histological analysis. The eyes from rats with K5-NP injection and those with Control-NP injection were sectioned, stained, and examined under light microscope at 1, 2, and 4 weeks after the injection. No difference was observed in number of retinal nuclear layers or thickness of the retina among the rats injected with K5-NP and the control (Fig. 8A–F). We also measured the retinal thickness at the same six retinal locations in each eye as described in supplementary methods. There is no significant difference in retinal thickness in the rats treated with K5-NP and controls (supplementary Fig. 2, available in the online appendix). Similarly, K5-NP did not increase apoptotic cells in the retina (supplementary Fig. 3, available in the online appendix).


Nanoparticle-mediated expression of an angiogenic inhibitor ameliorates ischemia-induced retinal neovascularization and diabetes-induced retinal vascular leakage.

Park K, Chen Y, Hu Y, Mayo AS, Kompella UB, Longeras R, Ma JX - Diabetes (2009)

Histology and ERG response in the eyes injected with K5-NP. Adult rats received an intravitreal injection of K5-NP or control-NP. The animals were killed, and the eye sections were stained with hematoxylin and eosin (three rats per time point). A–F: Representative images of the eyes at 1 (A, D), 2 (B, E), and 4 (C, F) weeks after the injection. Scale bar: 20 μm. G and H: ERG was recorded from six rats at 4 weeks after the injection of K5-NP and Control-NP to nondiabetic and diabetic rats and age-matched untreated nondiabetic and diabetic rats. Amplitudes of A- and B-waves from scotopic and photopic ERG were averaged and compared (mean ± SD, n = 6). □, Normal; , normal + control-NP; , normal + K5-NP; ■, STZ; ▧, STZ + control-NP; ▩, STZ + K5-NP. GCL, ganglion cell layer; INL, inner nuclear layer; ONL, outer nuclear layer; RPE, retinal pigment epithelium. (A high-quality digital representation of this figure is available in the online issue.)
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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Figure 8: Histology and ERG response in the eyes injected with K5-NP. Adult rats received an intravitreal injection of K5-NP or control-NP. The animals were killed, and the eye sections were stained with hematoxylin and eosin (three rats per time point). A–F: Representative images of the eyes at 1 (A, D), 2 (B, E), and 4 (C, F) weeks after the injection. Scale bar: 20 μm. G and H: ERG was recorded from six rats at 4 weeks after the injection of K5-NP and Control-NP to nondiabetic and diabetic rats and age-matched untreated nondiabetic and diabetic rats. Amplitudes of A- and B-waves from scotopic and photopic ERG were averaged and compared (mean ± SD, n = 6). □, Normal; , normal + control-NP; , normal + K5-NP; ■, STZ; ▧, STZ + control-NP; ▩, STZ + K5-NP. GCL, ganglion cell layer; INL, inner nuclear layer; ONL, outer nuclear layer; RPE, retinal pigment epithelium. (A high-quality digital representation of this figure is available in the online issue.)
Mentions: Possible toxicities of K5-NP were evaluated structurally by histological analysis. The eyes from rats with K5-NP injection and those with Control-NP injection were sectioned, stained, and examined under light microscope at 1, 2, and 4 weeks after the injection. No difference was observed in number of retinal nuclear layers or thickness of the retina among the rats injected with K5-NP and the control (Fig. 8A–F). We also measured the retinal thickness at the same six retinal locations in each eye as described in supplementary methods. There is no significant difference in retinal thickness in the rats treated with K5-NP and controls (supplementary Fig. 2, available in the online appendix). Similarly, K5-NP did not increase apoptotic cells in the retina (supplementary Fig. 3, available in the online appendix).

Bottom Line: Injection of K5-NP significantly reduced retinal vascular leakage and attenuated retinal neovascularization, when compared with the contralateral eyes injected with Control-NP in oxygen-induced retinopathy rats.No toxicities of K5-NP were detected to retinal structure and function.K5-NP mediates efficient and sustained K5 expression in the retina and has therapeutic potential for diabetic retinopathy.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.

ABSTRACT

Objective: The aim of the study is to evaluate the effect of nanoparticle-mediated gene delivery of angiogenic inhibitors on retinal inflammation, vascular leakage, and neovascularization in diabetic retinopathy.

Research design and methods: An expression plasmid of plasminogen kringle 5 (K5), a natural angiogenic inhibitor, was encapsulated with poly(lactide-coglycolide) to form K5 nanoparticles (K5-NP). Expression of K5 was determined by Western blot analysis and immunohistochemistry, and retinal vascular leakage was measured by permeability assay. Retinal neovascularization was evaluated using fluorescein-angiography and counting preretinal vascular cells in rats with oxygen-induced retinopathy. Effects of K5-NP on retinal inflammation were evaluated in streptozotocin-induced diabetic rats by leukostasis assay and Western blot analysis of intracellular adhesion molecule and vascular endothelial growth factor. Possible toxicities of K5-NP were evaluated using histology examination, retinal thickness measurement, and electroretinogram recording.

Results: K5-NP mediated efficient expression of K5 and specifically inhibited growth of endothelial cells. An intravitreal injection of K5-NP resulted in high-level expression of K5 in the inner retina of rats during the 4 weeks they were analyzed. Injection of K5-NP significantly reduced retinal vascular leakage and attenuated retinal neovascularization, when compared with the contralateral eyes injected with Control-NP in oxygen-induced retinopathy rats. K5-NP attenuated vascular endothelial growth factor and intracellular adhesion molecule-1 overexpression and reduced leukostasis and vascular leakage for at least 4 weeks after a single injection in the retina of streptozotocin-induced diabetic rats. No toxicities of K5-NP were detected to retinal structure and function.

Conclusions: K5-NP mediates efficient and sustained K5 expression in the retina and has therapeutic potential for diabetic retinopathy.

Show MeSH
Related in: MedlinePlus