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


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.
Park
Kyoungmin
K
Department of Medicine, Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
Chen
Ying
Y
Hu
Yang
Y
Mayo
Aaron S
AS
Kompella
Uday B
UB
Longeras
Richard
R
Ma
Jian-xing
JX
D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000818:Animals; D002460:Cell Line; D017931:DNA Primers; D005784:Gene Amplification; D006801:Humans; D019344:Lactic Acid / Q000627:therapeutic use; D053758:Nanoparticles / Q000627:therapeutic use; D010446:Peptide Fragments / Q000235:genetics / Q000627:therapeutic use; D010958:Plasminogen / Q000235:genetics / Q000627:therapeutic use; D011100:Polyglycolic Acid / Q000627:therapeutic use; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D051381:Rats; D015861:Retinal Neovascularization / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
D020533:Angiogenesis Inhibitors; D017931:DNA Primers; D010446:Peptide Fragments; D012337:RNA, Ribosomal, 18S; D042461:Vascular Endothelial Growth Factor A; C491499:plasminogen kringle 5; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D010958:Plasminogen