Topical application of recombinant calreticulin peptide, vasostatin 48, alleviates laser-induced choroidal neovascularization in rats

[摘要] Purpose: Vasostatin 48 (VS48) is apeptide of 48 amino acids derived from calreticulin. This study aimedto investigate the effects of topical application of VS48 eyedrops onexperimental choroidal neovascularization (CNV). Methods: Recombinant VS48 was expressedand purified as a thioredoxin (TRX)-fused protein, TRX-VS48. Theanti-angiogenic effects of TRX-VS48 were validated by migration andtube formation assays performed on cultured endothelial cells, and byrat aorta ring assays. CNV lesions were created in Brown Norway rats bylaser-induced photocoagulation at day 1. After topical TRX-VS48application for 21 days, the CNV lesions were monitored via eitherchoroidal flat mounts on day 21 or by fluorescent angiography on days21, 28, 35, and 42. CNV lesions were evaluated by histologicalanalysis. The retinal function of animals was examined byelectroretinogram (ERG) to evaluate the safety and therapeutic efficacyof TRX-VS48. Results: Application of TRX-VS48inhibited the migration and tube formation of endothelial cells.TRX-VS48 inhibited the growth of sprouting vessels in aorta rings. ERGanalysis revealed that topical TRX-VS48 application for 21 days had noeffect on rat retinal functions. After CNV induction, topical TRX-VS48application for 21 days significantly reduced the size of CNV, asassayed by flat mounts. Fluorescent angiography revealed that the CNVareas in TRX-VS48-treated eyes were significantly reduced compared withTRX-treated eyes on days 21, 28, 35, and 42. Histological analysis alsorevealed attenuated CNV lesions in TRX-VS48-treated eyes. TopicalTRX-VS48 treatment significantly reversed the CNV-induced alterationsin ERG parameters on day 35. Conclusions: Topical TRX-VS48application suppressed laser-induced CNV in rats, thereby constitutinga possible modality for ocular diseases due to excessive angiogenesis.

[学科分类] 生物化学/生物物理