DGIST published on July 2 that Professor Seong-Woon Yu’s team in the Department of Brain and Cognitive Sciences found that chronic stress causes the autophagic death of adult hippocampal neural stem cells (NSCs). These findings are expected to open up new strategies for combatting stress-associated neural diseases.
Chronic stress is notorious for its affiliation with varied mental diseases comparable to despair and schizophrenia that have become very severe social issues. Stress may even raise the risk of neurodegenerative ailments, such as Alzheimer’s disease. Nevertheless, the specific mechanisms underlying injury of brain functions haven’t been well known yet.
Professor Yu’s team found for the first time that chronic stress causes autophagic death of adult hippocampal NSCs. Autophagy is a cellular process to guard cells against unfavorable conditions by digestion and recycling of interior cell supplies, whereby cells can take away toxic or old intracellular components and get nutrients and metabolites for survival. However, autophagy can turn into a self-destruction course of under favorable conditions, resulting in autophagic cell death. Autophagic cell death is a type of cell demise distinguished from apoptosis by the causative role of autophagy for cell demise. Using NSCs derived from rodents and genetically-modified mice, the research team found that the death of hippocampal NSCs is prevented and regular brain features are maintained without stress signs when Atg7, one of many dominant autophagic genes, is deleted.
The research staff also further investigated the mechanism controlling the autophagy induction of NSCs in more depth, proving that SGK3 (serum/glucocorticoid regulated kinase) gene is the trigger for autophagy initiation. Therefore, when SGK3 gene is removed, hippocampal NSCs do not undergo cell death and are spared from stress.