Abstract: Objective〖HTSS〗To investigate the expression of thioredoxin-2(Trx-2) in anterior capsule of lens and its relationship with apoptosis and oxidative stress in elderly cataract patients.
〖WTHZ〗Methods〖HTSS〗Forty cases 40 eyes of elderly cataract patients underwent phacoemulsification cataract extraction were chosen as study group, 20 cases 20 eyes elderly patients treated with transparent lens extraction(non-cataract) due to trauma were chosen as control group. The positive expression of Trx-2 in anterior capsule of lens was determined by immunohistochemistry. Protein expression of apoptosis related molecules［P53 gene(P53), B-cell lymphoma-2(Bcl-2), Apoptosis signal-regulating kinase 1(ASK1)］, contents of oxidative stress indexes［superoxide dismutase(SOD), catalase(CAT) activity and glutathione(GSH), malondialdehyde(MDA)］ levels were compared between study group , control group, Trx-2(+) and Trx-2(-) specimens in study group.
〖WTHZ〗Results〖HTSS〗Positive rate of Trx-2 expression in study group was significantly lower than that in control group(P＜0.05). Protein expressions of P53 and ASK1 in anterior capsular membrane of study group were higher than those in control group, while protein expressions of bcl-2 was lower than that in control group. Supernatant levels of SOD, CAT and GSH were lower than those in control group, and level of MDA was higher than that in control group(P＜0.01). In study group, the protein expression levels of P53 and ASK1 in Trx-2(+)specimens were lower than those of Trx-2(-), protein expression level of bcl-2 was higher than that of Trx-2(-). levels of SOD, CAT and GSH in Trx-2(+) were higher than those in Trx-2(-), level of MDA was lower than that in Trx-2(-)(P＜0.05 or P＜0.01).
〖WTHZ〗Conclusion〖HTSS〗Expression of Trx-2 in anterior lens capsule of elderly cataract patients decreases, and its anti-apoptosis、 anti-oxidative stress are weakened, which may be one of the important molecular mechanisms leading to the occurrence and development of the disease.

Key words: cataract, thioredoxin-2, apoptosis , oxidative stress