Baicalin ameliorates inflammation response in diabetic dry eye models through the inhibition of the PERK/TXNIP/NLRP3 pathway

Diabetes mellitus is an important risk factor for dry eye. Dry eye may cause structural and functional disorders in corneal epithelial cells, seriously affecting the visual quality of diabetic patients. Baicalin (BA), a constituent of Scutellariae baicalensis, has anti-inflammatory and antioxidant properties. However, whether BA exerts a therapeutic effect on patients with diabetic dry eye and the underlying mechanism are unclear. Here, we explored the underlying mechanism of baicalin in diabetic dry eye. In cells, we used high glucose-stimulated human corneal epithelial (HCE-T) cells for modelling. There were differences in the expression of the pathway-related proteins p-PERK, NLRP3, TXNIP, and IL-1β under different glucose concentrations, and the highest expression of relevant proteins was observed with 25 mmol/L glucose. BA protected against high glucose-induced HCE-T-cell injury and Apoptosis. In addition, BA inhibited the PERK/TXNIP/NLRP3 axis and thus attenuated the inflammatory response of HCT-T cells, but the effect that was reversed by the PERK agonist CCT020312. We used C57BL/6 mice injected intraperitoneally with streptozotocin (STZ) to establish the animal model. BA suppressed the PERK/TXNIP/NLRP3 pathway and ameliorated corneal inflammation in diabetic dry eye model mice. Moreover, BA increased tear secretion and decreased corneal fluorescence scores in diabetic dry eye model mice. Thus, our study demonstrates the important value of BA in alleviating diabetic dry eye and provides new insights into the development of diabetic dry eye.

PERK; baicalin; diabetes mellitus; dry eye; inflammation.