繁殖・生殖工学

[III-15-09] Effect of EAS on post freezing viability of heat stressed bovine cumulus granulosa cells in relation with redox balance

*Khoi Thieu Ho¹, Kohei Homma², Jun Takanari², Hanako BAI¹, Manabu KAWAHARA¹, Kim Khang Nguyen Thi ³, Masashi TAKAHASHI⁴ (1. Graduate School of Agriculture, Hokkaido University, 2. AMINO UP Co. ltd., 3. College of Agriculture, Can Tho University, Can Tho, Viet Nam, 4. Graduate school of Global Food Resources, Hokkaido University)

[Aim]Pre-freezing cell status is important for the post frozen viability. Heat shock (HS) reduces cell funtions with redox disturbance, and induces HSP70 to rescue cells. We have reported that a standardized extract of Asparagus officinalis stem (EAS) induces HSP70 with keeping redox balance in Bovine cumulus-granulosa (CG) cells. We investigated effect of EAS on post freezing viability of HS-CG cells in relation with redox & HSP70 status.[Methods] CG cells were cultured with 5 mg/ml of EAS for 12h at 38.5°C or 41°C. Before freezing, HSP70, HSF1, NRF2 were measured, then cryopreserved. After thawing, cell viability, ROS, glutathione (GSH) levels were analyzed.[Results] Cell viability wasn't affected by EAS in control cells. In contrast, HS decreased cell viability. EAS pretreatment increased viability of HS cells. HS-induced ROS was decreased by EAS pretreatment & increased GSH in thawed cells. The levels of HSP70, HSF1, NRF2 was same in EAS-treated control & HS-treated cells before freezing, respectively, but, EAS+HS synnergistically increased these genes. These results suggest EAS affects post freezing viability of HS-CG cells by restoring redox status.