BGU researchers: Stress can raise health risks

BGU researchers discover how prolonged stress can raise risk of autoimmune diseases.

By JUDY SIEGEL-ITZKOVICH
PROF. ALON MONSONEGO 370 (photo credit: Dani Machlis/BGU)
PROF. ALON MONSONEGO 370
(photo credit: Dani Machlis/BGU)
Calm down and take it easy. Exposure to chronic stress can – at least in mice – make one more likely to develop autoimmune disease, in which the immune system malfunctions and attacks tissues in the body itself.
The mechanisms that bring this about were characterized for the first time recently by researchers at Beersheba’s Ben-Gurion University of the Negev and published in the European Journal of Immunology.
Dr. Idan Harpaz and Prof. Alon Monsonego of BGU’s Faculty of Health Sciences, in conjunction with Prof. Hagit Cohen, showed that ongoing stress increases the susceptibility to an autoimmune disease similar to multiple sclerosis.
The family of autoimmune diseases is very large and ranges from alopecia areata (a kind of baldness), amyotrophic lateral sclerosis (Lou Gehrig’s disease) and celiac disease to type 1 diabetes, Grave’s disease (of the thyroid), lupus erythematosus, multiple sclerosis, psoriasis and rheumatoid arthritis.
The research showed that the phenomenon is caused, among other things, by damage to the release of adequate levels of glucocorticoids (steroid hormones termed cortisol in humans and corticosterone in rodents) in response to stimulus – most likely due to a lack of sensitivity to glucocorticosteroids in specific cells of the immune system. These cause pathogenic inflammation, and the glucocorticoids cannot effectively inhibit the cells that encourage inflammation, which is what generally happens.
The researchers also found that exposure to high levels of glucocorticoids in those suffering from chronic stress reduced the number of immune cells. This increased the number of cells that encouraged pathogenic inflammation compared to those that inhibit it. These mechanisms were found to appear more significantly in females than in males and may explain, in part, the higher rates of autoimmune disease in women than in men.
Exposure to stress is one of the most common sources of damage to the body, both physically and emotionally. The reaction to stress is characterized by the release of important hormones such as glucocorticoids, which enable the organism to handle stressful situations (fight or flight). The glucocorticosteroids are released following brain signaling to the adrenal cortex, called the hypothalamic-pituitary-adrenal (HPA) axis.
At the same time, high levels of glucocorticoids in those suffering from chronic stress harm the body’s immune system and its ability to adequately cope with immune challenges essential to gain homeostasis.
Altogether, the results of the current study suggest that while a high level of glucocorticoids generally protects against the worsening of autoimmune diseases in those exposed to chronic stress, steroids could lead to a worsening of their symptoms.
Therefore, even though steroids is one of the treatments for chronic inflammation, use of such a treatment – particularly in patients suffering from chronic stress – should be carefully weighed and considered.
The Beersheba researchers believe that testing the function of the HPA axis can be an important diagnostic tool for determining how well the immune system is functioning.
The researchers are also investigating the effects of glucocorticoids in aging and agerelated neurodegenerative diseases, such as Alzheimer’s, and report that there is apparently a connection between the effects of glucocorticoids on the immune system and aging.