Study on the repair function of radiation-induced salivary gland injury using human amniotic mesenchymal stem cells pre treated with hypoxia.

Objective: To investigate the reparative effect of hypoxia pretreated hAMSCs on radiation-induced damage to salivary gland function in mice.

Methods: hAMSCs were separated from human amniotic tissues by mechanical and enzymatic digestion methods and a 15 Gy electron beam was used to locally irradiate the neck of mouse to create a salivary gland injury model. The mouse models were randomly divided into four groups: control group, IR+PBS group, IR+Nor group and IR+HP group.

Result: Two months after hAMSCs injection, the saliva flow of mice in the IR+PBS group was significantly lower than that of the control group (P<0.05). The saliva flow of mice in the IR+Nor group and IR+HP group were significantly increased compared to the IR+PBS group (P<0.05). The cell apoptosis rate of the IR+PBS group was sensibly higher than that of the blank control group (P<0.05). The cell apoptosis rates of the IR+Nor group and the IR+HP group were lower than that of the IR+PBS group. In addition, the apoptosis rate of the IR+HP group was lower than that of the IR+Nor group (P<0.05). The changes of IOD of α-Amy in each group showed that the expression of α - Amy in the IR+PBS group was significantly lower than that in the blank control group (P<0.05). Compared with the IR+PBS group, the IR+Nor group and the IR+HP group showed an obvious increase in the expression of α-Amy (P<0.05).

Conclusion: Low oxygen pretreatment of hAMSCs could more effectively repair the function of radiation-induced salivary gland compared to normoxic cultivation.