Neuroepithelial Interactions in Corneal Disease and Repair.

About This Grant

SUMMARY/ABSTRACT Neuro-epithelial interactions in corneal disease and repair, Elmira Jalilian (PI) Diabetes mellitus (DM) is a critical global health issue currently affecting 415 million adults and projected to exceed 640 million by 2040. Diabetic corneal neuropathy, defined by progressive nerve fiber loss in the cornea, occurs in approximately 50% of patients with DM. If these patients experience corneal damage, the regenerated corneal epithelium fails to recover full functionality, leading to further corneal complications. The reduced nerve density and impaired functionality of the remaining nerve fibers leads to disruption of corneal epithelial homeostasis (CEH) and the hindering of reparative processes essential for preserving corneal integrity. A key mechanism regulating CEH and repair is the interaction between corneal epithelial cells (CECs) and corneal nerves (the V1 ophthalmic branch of trigeminal nerves or TgV1s). Despite the recognized role of TgV1s in regulating ocular surface integrity through neurotrophic factors, these factors have not been able to fully explain the neuronal contribution to CEH and repair. In the field of ocular biology, there is growing interest in extracellular vesicles (EVs) as novel mediators of cell-cell communication. While the majority of EV-related research in corneal biology has centered on the therapeutic potential of mesenchymal stem cell (MSC)-derived EVs, there are few studies probing the role of cell-type-specific (CTS) EVs in regulating corneal health and disease. Our preliminary data demonstrated that healthy TgV1s secrete functional EVs. When these TgV1 EVs were internalized by CECs, the expression of proteins involved in proliferation, migration, and cell-cell adhesion were increased in vitro, and sequencing data from TgV1 EV-treated CECs showed a uniquely modulated transcriptional program compared with either untreated CECs or MSC EV-treated CECs. In vivo, TgV1 EV-treated corneas exhibited enhanced epithelial cell adhesion, barrier integrity, greater epithelial thickness, more uniform morphology, and stronger epithelial–stromal attachment. Therefore, we hypothesize that TgV1 EVs have selectively-enriched molecular cargo, targeted to CECs, that facilitates CEH and repair. We further hypothesize that TgV1 EVs are compromised in DM, and multi-omics analyses will specifically identify functional pathways altered by hyperglycemia-associated DM. In Aim 1 we will characterize TgV1 EVs from both healthy and DM mice and study their functional effect on both CECs (in vitro) and the epithelium (in vivo). Our in vitro studies will assess cellular proliferation, differentiation, adhesion, and barrier function. Our in vivo studies will examine the effect on corneal epithelial wound healing (nonpathologic) and non-wounded corneas (by blocking EV uptake), followed by histological and anatomical assessments. In Aim 2 we will conduct molecular studies (transcriptomic and proteomic) on TgV1 EVs (healthy and DM) and CECs (healthy and hyperglycemic, before and after introduction of TgV1 EVs) to identify regulatory mediators that promote or degrade epithelial homeostasis and repair. This research will advance our understanding of the crucial role of CTS EVs and pave the way for the development of novel therapeutics targeting EV-mediated mechanisms in corneal and other ocular diseases.