Réponse combat-fuite

La réponse combat-fuite a été décrite pour la première fois en 1929 par le physiologiste américain Walter Bradford Cannon. Sa théorie explique que la réaction animale face aux menaces accompagnée d'une décharge générale du système nerveux orthosympathique, amorce l'animal à un combat ou une fuite. Cette théorie est plus tard reconnue comme étant le premier stade du syndrome général d'adaptation régulant les réponses au stress parmi les vertébrés et autres organismes. Physiologie Les catécholamines facilitent les réactions physiques immédiates associées à une préparation pour une action musculaire violente. Ceux-ci incluent notamment :

accélération du rythme cardiaque et de la respiration ;
pâleur ou rougissement, ou les deux cas alternés ;
inhibition de l'estomac et du petit intestin à un point où la digestion ralentit ou s'arrête ;
effet général sur les sphincters du corps ;
constriction des vaisseaux sanguins dans plusieurs parties du corps ;
libération des

Probing the Global Cellular Responses to Lipotoxicity Caused by Saturated Fatty Acids

Manuele Piccolis

Excessive levels of saturated fatty acids are toxic to cells, although the basis for this lipotoxicity remains incompletely understood. Here, we analyzed the transcriptome, lipidome, and genetic interactions of human leukemia cells exposed to palmitate. Palmitate treatment increased saturated glycerolipids, accompanied by a transcriptional stress response, including upregulation of the endoplasmic reticulum (ER) stress response. A comprehensive genome-wide short hairpin RNA (shRNA) screen identified >350 genes modulating lipotoxicity. Among previously unknown genetic modifiers of lipotoxicity, depletion of RNF213, a putative ubiquitin ligase mutated in Moyamoya vascular disease, protected cells from lipotoxicity. On a broader level, integration of our comprehensive datasets revealed that changes in di-saturated glycerolipids, but not other lipid classes, are central to lipotoxicity in this model. Consistent with this, inhibition of ER-localized glycerol-3-phosphate acyltransferase activity protected from all aspects of lipotoxicity. Identification of genes modulating the response to saturated fatty acids may reveal novel therapeutic strategies for treating metabolic diseases linked to lipotoxicity.

CELL PRESS2019

Personality traits in rats predict vulnerability and resilience to developing stress-induced depression-like behaviors, HPA axis hyper-reactivity and brain changes in pERK1/2 activity

Jorge Eduardo Castro Cifuentes, Maria Isabel Cordero Campana, Shanaz Diessler, Cristina Marquez Vega, Maria del Carmen Sandi Perez

Emerging evidence indicates that certain behavioral traits, such as anxiety, are associated with the development of depression-like behaviors after exposure to chronic stress. However, single traits do not explain the wide variability in vulnerability to stress observed in outbred populations. We hypothesized that a combination of behavioral traits might provide a better characterization of an individual's vulnerability to prolonged stress. Here, we sought to determine whether the characterization of relevant behavioral traits in rats could aid in identifying individuals with different vulnerabilities to developing stress-induced depression-like behavioral alterations. We also investigated whether behavioral traits would be related to the development of alterations in the hypothalamic-pituitary-adrenal axis and in brain activity - as measured through phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) - in response to an acute stressor following either sub-chronic (2 weeks) or chronic (4 weeks) unpredictable stress (CUS). Sprague-Dawley rats were characterized using a battery of behavioral tasks, and three principal traits were identified: anxiety, exploration and activity. When combined, the first two traits were found to explain the variability in the stress responses. Our findings confirm the increased risk of animals with high anxiety developing certain depression-like behaviors (e.g., increased floating time in the forced swim test) when progressively exposed to stress. In contrast, the behavioral profile based on combined low anxiety and low exploration was resistant to alterations related to social behaviors, while the high anxiety and low exploration profile displayed a particularly vulnerable pattern of physiological and neurobiological responses after sub-chronic stress exposure. Our findings indicate important differences in animals' vulnerability and/or resilience to the effects of repeated stress, particularly during initial or intermediate levels of stress exposure, and they highlight that the behavioral inhibition profile of an animal provides a particular susceptibility to responding in a deleterious manner to stress.

Elsevier2012

Personality traits in rats predict vulnerability and resilience to developing stress-induced depression-like behaviors, HPA axis hyper-reactivity and brain changes in pERK1/2 activity

Jorge Eduardo Castro Cifuentes, Maria Isabel Cordero Campana, Shanaz Diessler, Cristina Marquez Vega, Maria del Carmen Sandi Perez

Elsevier2012

Physiological impact and stress response to penicillin acylase overproduction in Escherichia coli

Probing the Global Cellular Responses to Lipotoxicity Caused by Saturated Fatty Acids

Personality traits in rats predict vulnerability and resilience to developing stress-induced depression-like behaviors, HPA axis hyper-reactivity and brain changes in pERK1/2 activity

Probing the Global Cellular Responses to Lipotoxicity Caused by Saturated Fatty Acids

Physiological impact and stress response to penicillin acylase overproduction in Escherichia coli

Personality traits in rats predict vulnerability and resilience to developing stress-induced depression-like behaviors, HPA axis hyper-reactivity and brain changes in pERK1/2 activity