Bilateral inflammation after unilateral UVR-B irradiation

Abstract

The presented study investigates the influence of exposure of one eye to UVR-B on the unexposed, partner eye in vivo in a mouse model. Furthermore, we try to answer the question whether this sympathizing reaction of the partner eye is transmitted via a neurokinin-dependent signaling pathway of substance P (SP) and its neurokinin-1 receptor (NKR-1). In all experiments mice were unilaterally exposed in vivo to UVR-B. The unexposed eyes were completely shielded during exposure time. NKR-1 protein levels in ocular tissues were quantified by immunohistochemical staining and enzyme-linked immunosorbent assay (ELISA). In a second experiment, NKR-1 was blocked with NKR-1 antagonists. Ocular tissues were extracted for the detection of pro-inflammatory cytokine and chemokine expression by ProcartaPlex^TM Multiplex Immunoassay. The UVR-B radiation induces the expression and upregulates NKR-1 in the exposed and unexposed, partner eye. Pretreatment with Fosaprepitant decreased NKR-1 expression in all exposed ocular tissues as well as in the unexposed lens epithelium. Overall, UVR-B exposure triggers NKR-1 upregulation not only in the exposed but also in the partner eye in various ocular tissues. In addition, the clinical approved NKR-1 antagonist Fosaprepitant effectively reduces NKR-1 expression in both mouse eyes.