UNASSIGNED: Mitochondria play a key role in maintaining cellular homeostasis during stress responses, and @entity2383 contributes to @entity105 , aging, and @entity16 . We here investigated ionizing radiation (IR)-induced @entity2383 in @entity1 neural progenitor stem cells (NSCs), their differentiated counterparts and @entity1 normal fibroblasts. Long-term fractionated radiation (FR) with low doses of X- @entity16039 for 31  days enhanced mitochondrial activity as evident by elevated mitochondrial membrane potential (    m) and mitochondrial complex IV (cytochrome c oxidase) activity to fill the energy demands for the chronic DNA damage response in differentiated cells. Subsequent reduction of the antioxidant @entity2041 via continuous activation of mitochondrial oxidative phosphorylation caused oxidative stress and genomic instability in differentiated cells exposed to long-term FR. In contrast, long-term FR had no effect on the mitochondrial activity in NSCs. This cell type showed efficient DNA repair, no @entity2383 , and resistance to long-term FR. After high doses of acute single radiation (SR) (>5  Gy), cell cycle arrest at the G2 phase was observed in NSCs and @entity1 fibroblasts. Under this condition, increase in mitochondria mass, mitochondrial DNA, and intracellular reactive @entity26 species (ROS) levels were observed in the absence of enhanced mitochondrial activity. Consequently, cellular senescence was induced by high doses of SR in differentiated cells. In conclusion, we demonstrated that mitochondrial radiation responses differ according to the extent of DNA damage, duration of radiation exposure, and cell differentiation.

A comparison of radiation-induced XXXX between neural progenitor stem cells and differentiated cells.

@entity1 :: ('9606', 'Species') :: ['human'] @entity16039 :: ('255564', 'Species') :: ['rays'] @entity16 :: ('MESH:D009422', 'Disease') :: ['neurological disease'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity2041 :: ('MESH:D005978', 'Chemical') :: ['glutathione'] @entity105 :: ('MESH:D063646', 'Disease') :: ['carcinogenesis'] @entity2383 :: ('MESH:D028361', 'Disease') :: ['mitochondrial dysfunction', 'mitochondrial damage']
@entity2383 :: (MESH:D028361,Disease) :: ['mitochondrial damage']
