A combination of CMC and α-MSH inhibited ROS activated NLRP3 inflammasome in hyperosmolarity stressed HCECs and scopolamine-induced dry eye rats

An important mechanism involved in dry eye (DE) is the association between tear hyperosmolarity and inflammation severity. Inflammation in DE might be mediated by the NLRP3 inflammasome, which activated by exposure to reactive oxygen species (ROS). A combination of carboxymethylcellulose (CMC) and α-melanocyte stimulating hormone (α-MSH) may influence DE through this mechanism, thus avoiding defects of signal drug. In this study, we assessed whether treatment comprising CMC combined with α-MSH could ameliorate ocular surface function; we found that it promoted tear secretion, reduced the density of fluorescein sodium staining, enhanced the number of conjunctival goblet cells, and reduced the number of corneal apoptotic cells. Investigation of the underlying mechanism suggested that the synergistic effect of combined treatment alleviated DE inflammation through reduction of ROS level and inhibition of the NLRP3 inflammasome in human corneal epithelial cells. These findings indicate that combined CMC + α-MSH treatment could ameliorate lesions and restore ocular surface function in patients with DE through reduction of ROS level and inhibition of NLRP3 signalling.