Nature: new research shows how stress weakens defenses

September 17, 2019 / BIOON / -- the laboratory research of Dr mark Alkema, Professor of neurobiology, reveals how the "escape" response damages the body's long-term health This study was carried out in an online worm Cryptostrongylus elegans is a common research model, and the relevant research results were published in the journal Nature When people perceive danger or stress, the body releases stress hormones such as adrenaline Adrenaline makes the heart beat faster, increases blood flow to the brain and muscles, and stimulates the body to produce sugar as a fuel The surge in adrenaline triggers a "fight or flight" response, enabling people to flee predators or respond to threats Photo source: Dr nature Alkema, in collaboration with Professor Diego Rayes of the National University of South in Argentina, studied the health effects of repeated activation of "fight or flight" responses by nematodes This small worm is a popular biological model, which helps to solve many basic problems in biology, from development to brain function and disease Animals are under different forms of pressure These changes can be sudden, such as the emergence of carnivores, or gradual, such as chronic food shortages, high temperatures, or oxidation "Similar to humans, the reactivation of the escape response of C elegans greatly shortens their life span," said Jeremy Florman, a doctoral student at the Alkema laboratory Escape response is crucial for worms to escape predators But we found that there was a cost; reactivation of the escape response reduced the worm's ability to cope with other challenges in the environment "In this study, the researchers found that the escape response of Caenorhabditis elegans activates a pair of neurons that release tyramine, a substance similar to adrenaline in invertebrates In contrast, exposure to environmental challenges, such as high temperature and oxidative stress, reduces tyramine release Therefore, the stress hormone provides a switch to regulate the animal's response to acute or long-term stressors Alkema and Rayes continue to demonstrate that tyramine stimulates the insulin pathway by activating the intestinal adrenergic receptor The activation of insulin pathway can meet the energy demand of animals for escape response On the other hand, the down regulation of insulin pathway helps to protect cells from environmental pressure and prolong their life span "This shows how the dynamic regulation of stress neurohormones regulates the balance between acute and long-term stress responses," Alkema said Caenorhabditis elegans always amazes me: it constantly reveals the basic molecular and neural mechanisms, and may even be the basis of extremely complex human biology and diseases In view of the amazing conservatism of worms to human stress response mechanism, it will be very interesting to observe whether human fight or escape response and stress neurohormone have negative effects on health and aging through activating insulin pathway "References: Mar í a Jos é De Rosa et al, The flight response impairs cytoprotective mechanisms by activating the insulin pathway, Nature (2019) Doi: 10.1038/s41586-019-1524-5