Silencing of lncRNA HOTAIR Using Eyedrops as a Potential Treatment for Diabetes-Associated Retinal Dysregulation and Dysfunction

Purpose: Diabetic retinopathy (DR), a major cause of blindness in working-age adults, is driven by vascular dysfunction mediated by various angiogenic regulators. Although anti-VEGF therapies reduce vision impairment in some patients, they have limitations that leave room for novel treatments. The long non-coding RNA (lncRNA) HOX transcript antisense intergenic RNA (HOTAIR), which is upregulated in the retina in diabetes and regulates a range of factors including VEGF, contributes to DR pathology. Silencing HOTAIR prevents the dysregulation of VEGF and other factors. We explored targeting HOTAIR using siRNA conjugated to n-acetylgalactosamine (GalNAc) moieties for retinal delivery as a means of preventing diabetes-associated pathology in the retina. Methods: GalNAc-modified siHOTAIR was evaluated in human retinal endothelial cells in vitro and using various models in vivo. The effects of GalNAc-modified siHOTAIR were assessed on the RNA, protein, and functional levels. Results: GalNAc-modified siHOTAIR effectively entered retinal endothelial cells in vitro, and inhibited glucose-induced endothelial dysfunction by blocking multiple factors, including VEGF-A. GalNAc-siRNA localized to the retina in vivo following topical delivery, and prevented diabetes-induced pathological retinal changes with efficacy comparable to intravitreal injection. Conclusions: GalNAc-modified siHOTAIR thus represents a potential therapeutic strategy that not only inhibits VEGF but also targets other pathogenic mediators regulated by HOTAIR, potentially offering broader efficacy than anti-VEGF monotherapy. Furthermore, it achieves this via noninvasive, topical delivery, circumventing the need for intravitreal injections required by current treatments. Thus, with further development, GalNAc-modified siHOTAIR may become an overall better approach to treating DR.