Stress and Inflammation: A Detrimental Combination in the Development of Neurodegenerative Disease.

Abstract

Chronic stress accelerates the appearance of some neurodegenerative disorders, such as Alzheimer's disease and Parkinson´s disease. On this review we firstly, describe some human epidemiological studies that highlight the possibility that chronic stress could increase the incidence or the rate of incidence of Alzheimer's disease and Parkinson´s disease. Secondly, we discuss the important role of inflammation in the progression and development of these neurodegenerative diseases. Finally, we try to justify the relationship between stress and inflammation with some experimental data. This work strongly suggests that chronic stress could be considered a key factor for the development of neurodegenerative diseases through microglial activation. Keywords: stress; inflammation; neurodegenerative diseasesTo cite this article: Rocío M. de Pablos, et al. Stress and inflammation: a detrimental combination in the development of neurodegenerative disease. Inflamm Cell Signal 2014; 1: e182. doi: 10.14800/ics.182.Copyright: © 2014 The Authors. Licensed under a Creative Commons Attribution 4.0 International License which allows users including authors of articles to copy and redistribute the material in any medium or format, in addition to remix, transform, and build upon the material for any purpose, even commercially, as long as the author and original source are properly cited or credited. IntroductionStress could be simply defined as any disruption of homeostasis, whereas 'stressor' would be any of the myriads of internal or external challenges that cause this disruption [1][2][3][4] . Disturbed homeostasis initiates a series of events called the stress response or cascade; this wellchoreographed response will involve the hypothalamic pituitary adrenal (HPA) axis that is in charge to restore homeostasis. Stress is a condition of human experience and an important factor in the onset of various diseases [5] . In general, it is considered that stress is not reduced only to the dramatic stressful events in our lives but rather to all those little daily problems that are capable of raising the activity of physiological systems sufficiently to cause a wear.Exposure to stressful situations triggers the activation of two systems: the sympatho-adreno-medullary system and the HPA system [6] . The first leads to raise the levels of circulating adrenaline whereas the second run the release of corticosteroid hormones from the adrenal cortex. Corticosteroid hormones have the ability to cross the blood brain barrier owing to their lipophilic properties and 2014; 1: e182. doi: 10.14800/ics.182; © 2014 by Rocío M. de Pablos, et al. http://www.smartscitech.com/index.php/ics Page 2 of 8 interact with to two classes of receptors: mineralocorticoid receptors (MR) and glucocorticoid receptors (GR) [7] . MR and GR have different affinity for corticosterone, whilst MR have great affinity GR show less attraction with the endogenous hormone. They also differ in their distribution; MR are located mainly within limbic regions (eg. amygdala and h...