Effects of electroacupuncture on conjunctival cell apoptosis and the expressions of apoptosis-related proteins Caspase-3, Fas and Bcl-2 in rabbits with dry eye syndrome

Objective By observing the effects of electroacupuncture (EA) on the apoptosis of conjunctival cells of rabbits with dry eye syndrome (DES) and the expressions of apoptosis-related proteins Caspase-3, Fas and Bcl-2, to discuss the mechanism of EA in the treatment of DES from the perspective of cell apoptosis. Methods Male New Zealand rabbits were randomly divided into a normal group (NG), a model group (MG), an EA group (EAG) and a sham EA group (SEAG). DES rabbit model was developed by eye drop of 0.1% benzalkonium chloride. The rabbit tear secretion and tear film break-up time (BUT) were measured; terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was used to detect the apoptosis of conjunctival cells; the expressions of Caspase-3, Fas and Bcl-2 proteins in conjunctival cells were detected by immunohistochemistry. Results Compared with the NG, the rabbit tear secretion decreased and the BUT was shortened in the MG (both P <0.01); compared with the MG and the SEAG, the rabbit tear secretion increased and the BUT was prolonged in the EAG (all P <0.05). Compared with the NG, the apoptosis of rabbit conjunctival cells increased ( P <0.01), the expressions of Caspase-3 and Fas proteins increased (both P <0.05), and the expression of Bcl-2 protein decreased ( P <0.01) in the MG; compared with the MG and the SEAG, the apoptosis of rabbit conjunctival cells decreased (both P <0.01), the expressions of Caspase-3 and Fas proteins decreased (all P <0.05), and the expression of Bcl-2 protein increased (both P <0.01) in the EAG. Conclusion EA can inhibit the apoptosis of rabbit conjunctival cells, down-regulate the expressions of apoptosis-related proteins Caspase-3 and Fas, and up-regulate the expression of Bcl-2 protein, which may be one of the mechanisms of EA in treatment of DES.