earticle

영어

To alleviate ER stress and ER stress-induced apoptosis in recombinant Chinese hamster ovary (rCHO) cells, silencing of growth arrest and DNA damage 153 gene (GADD153), the main pro-apoptotic factor of unfolded protein response, was attempted. The functioning of the stably GADD153-silenced clones under four ER stress inducing conditions were investigated. Under thapsigargin and brefeldin A treatment, the GADD153-silenced clones showed lesser incidence of apoptosis (about 38%) and lesser non-viable cells (about 58%) than the control cells. However, under nutrient deprivation, the beneficial effect of GADD153 silencing was not pronounced because nutrient deprivation led to a cascade of various events including GADD153 induced cell death. GADD153-overexpressing pool cells also substantiated the findings of GADD153 downregulation. Investigation of the mechanism revealed that elevated GADD153 expression results in the exaggerated production of reactive oxygen species (ROS) and that GADD153 silencing promotes translational attenuation facilitating cell recovery from stress. Taken together, the data presented here suggest that GADD153 sensitizes cells to ER stress through mechanisms that involve enhanced oxidant injury and by manipulating the ER client protein load in rCHO cells.