Long-term nerve regeneration in diabetic keratopathy mediated by a novel NGF delivery system
Abstract
Diabetic keratopathy (DK) is a common chronic metabolic disorder that causes ocular surface complications. Among various therapeutic approaches, local delivery of nerve growth factor (NGF) remains the most effective treatment for DK. However, achieving a sustained therapeutic effect with NGF and the frequent drug delivery burden remain challenging during clinical practice. Here, we developed a novel adeno-associated virus (AAV)-based NGF delivery system that achieved one-year-long-lasting effects by a single injection. We refined the corneal stromal injection technique, resulting in reduced corneal edema and improved AAV distribution homogeneity. AAV serotype AAV.rh10 exhibited high tropism and specificity to corneal nerves. A dose of 2×109 vector genomes (vg) was determined to achieve efficient Ngf gene expression without inducing corneal immune responses. Moreover, NGF protein was highly expressed in trigeminal ganglion (TG) through a retrograde transport mechanism, indicating the capacity for repairing corneal nerve damage both at the root and corneal nerve endings. In a mouse DK model, a single injection of AAV-Ngf into the corneal stroma led to marked corneal nerve regeneration for over 5 months. Together, we provide a novel therapeutic paradigm for long-term effective treatment of DK and this therapeutic approach is superior to current DK therapies.
· We developed a novel and minimally invasive intrastromal injection technique and identified AAV.rh10 as the optimal serotype for efficient corneal nerve transduction.
· AAV.rh10 can transfect both the corneal subepithelial nerve endings and retrograde transport to the ophthalmic branch of the trigeminal ganglion.
· AAV.rh10-Ngf outperforms the commercial rhNGF eye drop in terms of the extended duration of the protective effects on corneal nerve regeneration.
· A single injection of AAV.rh10-Ngf maintained effectiveness throughout the 5-month observation period in a diabetic keratopathy mouse model.
