Abstract
Purpose :
Investigation of neurokinin receptor-1 (NKR-1) expression in ocular tissues following unilateral UVR-B irradiation in vivo in a mouse model.
Methods :
Six-week-old C57Bl/6 mice were unilaterally exposed to a 3.2-fold and 5-fold cataract threshold dose (0.94 J/cm2; 1.45 J/cm2) of UVR-B. UVR-B irradiation in the 300-nm wavelength region (UVR-B peak at 312 nm) was performed in mydriasis using a Bio-Spectra system. After latency periods of 3 and 7 days post exposure, eyes were fixed in 4% paraformaldehyde, embedded in paraffin, sectioned and stained with fluorescence coupled antibody for substance P receptor (NKR-1) and DAPI for cell nuclei staining. The same was performed in animals receiving only anaesthesia but no UVR-B exposure. The concentration of NKR-1 in ocular tissue lysates of exposed and contralateral eyes was quantified by enzyme-linked immunosorbent assay (ELISA). All animal experiments were conducted according to the regulations of the German Tierschutzgesetz and the ARVO declaration of the use of animals in eye and vision research.
Results :
UVR-B exposure induced NKR-1 upregulation after 7 days in the exposed and contralateral eyes in the epithelium and endothelium of the cornea, in the endothelial cells of the iris vessels, in the anterior lens epithelium, in the nuclear bow epithelium of the lens, pronounced in the inner plexiform layer of the retina. Furthermore, NKR-1 upregulation of exposed and unexposed eyes were detected after 3 days in the iris and anterior lens epithelium.
Conclusions :
Neurokinin-1 receptor is present ubiquitously in ocular tissues and UVR-B exposure triggers NKR-1 upregulation in the exposed and unexposed eye. The involvement of inflammation in ultraviolet radiation induced cataract and the role of neuroinflammatory peptides such as substance P and its receptor, NKR-1, needs further investigation.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.