Regulation of UV-B-Induced Inflammatory Mediators by Activity-Dependent Neuroprotective Protein (ADNP)-Derived Peptide (NAP) in Corneal Epithelium

Abstract

The corneal epithelium, representing the outermost layer of the cornea, acts as a barrier to protect the eye against external insults such as ultraviolet B (UV-B) radiations. The inflammatory response induced by these adverse events can alter the corneal structure, leading to visual impairment. In a previous study, we demonstrated the positive effects of NAP, the active fragment of activity-dependent protein (ADNP), against oxidative stress induced by UV-B radiations. Here, we investigated its role to counteract the inflammatory event triggered by this insult contributing to the disruption of the corneal epithelial barrier. The results indicated that NAP treatment prevents UV-B-induced inflammatory processes by affecting IL-1β cytokine expression and NF-κB activation, as well as maintaining corneal epithelial barrier integrity. These findings may be useful for the future development of an NAP-based therapy for corneal disease.

Involvement of Vasoactive Intestinal Peptide Family Members in Diabetic Keratopathy

“…Therefore, NAP's ability to counteract the generation of ROS sets the stage for investigating its effect against hyperglycemia-induced ROS. Furthermore, NAP mitigated the UV-B-induced inflammatory event and the subsequent epithelial corneal barrier damage by reducing the expression of IL-1β in corneal epithelial cells, which affects NF-κB activation and protects the integrity of the corneal epithelial barrier [182]. It is important to underline that, in addition to epithelial cells, keratocytes, and endothelial cells being present in the cornea, so, too, are antigen-presenting cells (APCs) comprising dendritic cells and macrophages [183].…”