角膜感染症の病態と治療の検討

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 佐藤 伸一, 東京大学准教授 蕪城 俊克, 東京大学講師 安藤 瑞生, 東京大学特任准教授 神田 浩子, 東京大学講師 田中 剛University of Tokyo(東京大学

Toxicity Evaluation of Antiglaucoma Drugs Using Stratified Human Cultivated Corneal Epithelial Sheets

PURPOSE. To investigate the toxicity profiles of seven antiglaucoma topical eye drops and benzalkonium chloride (BAC) using stratified cultivated human corneal epithelial cell sheets (HCES) in a serum-free culture system. METHODS. A range of prostaglandin analogies and preservatives, including BAC, sofZia (SZ), sodium benzoate (SB), and polyquaternium-1 (PQ) were tested. The barrier function and cell viability were examined by a carboxyfluorescein permeability assay and WST-1 assay. Histological evaluation of the HCES was also performed after application of each solution. RESULTS. The carboxyfluorescein permeability assay had a higher sensitivity for the detection of toxicity of test solutions than the WST-1 assay or histological examination. Latanoprost BAC, latanoprost/timolol BAC, and 0.02% or higher concentration of BAC were the most toxic, followed by latanoprost SB, latanoprost preservative-free, BAC 0.002%, and travoprost/ latanoprost PQ. Travoprost SZ and tafluprost BAC (preserved with 0.001% BAC) was the least toxic in our experimental conditions. CONCLUSIONS. The carboxyfluorescein permeability assay using HCES in a serum-free system was the most useful for the quantification of toxicity of ophthalmic solutions. Among the regimens examined, a BAC concentration of 0.001% or lower or non-BAC preservative sofZia was suggested to be the least toxic to the ocular surface. (Invest Ophthalmol Vis Sci. 2012; 53:5154-5160

Topical Use of Angiopoietin-like Protein 2 RNAi-loaded Lipid Nanoparticles Suppresses Corneal Neovascularization

Corneal neovascularization (CNV) is a sight-threatening condition that is encountered in various inflammatory settings including chemical injury. We recently confirmed that angiopoietin-like protein 2 (ANGPTL2) is a potent angiogenic and proinflammatory factor in the cornea, and we have produced a single-stranded proline-modified short hairpin anti-ANGPTL2 RNA interference molecule that is carried in a lipid nanoparticle (ANGPTL2 Li-pshRNA) for topical application. In this study, we have further examined the topical delivery and anti-ANGPTL2 activity of this molecule and have found that fluorescence-labeled ANGPTL2 Li-pshRNA eye drops can penetrate all layers of the cornea and that ANGPTL2 mRNA expression was dramatically inhibited in both epithelium and stroma at 12 and 24 hours after administration. We also examined the inhibitory effect of ANGPTL2 Li-pshRNA on CNV in a mouse chemical injury model and found that the area of angiogenesis was significantly decreased in corneas treated with ANGPTL2 Li-pshRNA eye drops compared to controls. Together, these findings indicate that this modified RNA interference agent is clinically viable in a topical formulation for use against CNV