Effect of eyelid UVB irradiation on gene expression of rat meibomian gland

We have developed a rat model of UVB-induced ocular surface and eyelid damages mimicking ocular rosacea, a common chronic inflammatory and neurovascular ocular surface disease associated with meibomian gland dysfunction. Rat eyelids were exposed to UVB for 5 minutes daily (300mJ/cm2) for 5 days. UVB-exposed rats displayed altered meibocyte activity and lipid production, ductal epithelial hyper-keratinization, apoptosis, mitochondrial dysfunction and oxidative stress. Corneal epithelial defects, barrier disruption and abnormal innervation occurred 2 weeks after UVB exposure, subsequent to meibomian gland dysfunction. The aim of this study was to investigate the transcriptomic signature associated with meibomian gland dysfunction induced by UVB in rats. We revealed pathways related to keratinization, cell cycle and proliferation, DNA damage and repair, inflammation, immune responses, oxidative responses, and fatty acid metabolism. These regulations supported the observed functional changes of meibomian gland and were consistent with the transcriptomic signature of human meibomian gland dysfunction. Overall design: We compared gene expression profile in meibomian gland between UVB-irradiated and non-irradiated rats.