Suppression of ROS-induced programmed cell death by using antioxidants in transgenic rice cell cultures

초록

Transgenic plant cell cultures are an attractive expression system for the production of industrial and pharmaceutical proteins because of their advantages in safety and low production cost. Human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) was produced and secreted when sugar was depleted in culture medium by transgenic plant cell lines (Oryza sativa L.) using RAmy3D promoter. Formation of reactive oxygen species (ROS) is an inevitable consequence of the aerobic organisms such as animal and plant cells. ROS generated by biotic and abiotic stresses. Therefore, ROS levels need to be controlled and the addition of antioxidants can reduce apoptosis caused by ROS which is generated during cell culture period. Many researchers reported the effects of antioxidants, such as glutathione, ascorbic acid (vitamin C), and vitamin E on plant cells. In this study, the generation of ROS was observed using H2DCFDA staining when transgenic rice cells cultured under direct aeration by sparger. In addition, expression of the two vacuolar processing enzyme gene (OsVPE2 and OsVPE3) by ROS under hyperoxia condition was confirmed by RT-PCR. The effects of N-acetylcystein (NAC), ascorbic acid and reduced glutathione on cell growth and protein production in transgenic rice cell cultures under oxidative stress was investigated. In conclusion, long-term survival of transgenic rice cells and enhanced hCTLA4Ig production were possible by reducing the level of ROS with the addition of various antioxidants in transgenic rice cell cultures.