The response patterns of stress-stricken cells
Toxins, an undersupply of nutrients, an infection with viruses, heat, physical or mental overload - this and more puts the body in a state of stress. Although the word stress is used frequently, very few people know exactly what happens in the body when it is exposed to stressful situations. In such situations, the body starts an anti-stress program in the affected areas with which it tries to protect itself from damage caused by stress. German researchers recently took a closer look at this process.
When cells in the body come under stress, they start certain processes and reaction patterns. Scientists from the Julius Maximilians University in Würzburg (JMU) Biozentrum were able to identify new details of these stress reactions. With the new findings, neurodegenerative and stress-related diseases could be better understood and more effective therapies developed, the researchers hope. The study results were recently published in the journal "Molecular Cell".
What do cells do when they get stressed?
The cells often react to stress by reducing the formation of new proteins. This saves them important resources that they can then use to more effectively repair cell damage. They can also survive better and longer under stress with the additional resources. Such a process can be observed under the microscope. So-called stress granules become visible when stressed. These are the smallest parts of proteins and messenger RNAs that arise when the cells stop their protein production.
After the stress, the big cleanup begins
When the stressful situation has been resolved, the cells return to their normal state and resume their usual work. The numerous stress granules are reduced again and everything goes as usual. If these clean-up processes cannot be properly completed, this can have fatal health consequences.
Too much stress makes you sick
The Würzburg researchers refer to recent studies that suggest that the stress granules are involved in at least two incurable neurodegenerative diseases. These are the incurable nerve disease amyotrophic lateral sclerosis (ALS), which leads to muscle wasting first and later to fatal paralysis, and frontotemporal dementia (FTD), the second most common dementia disease among people under 65 years of age. The team of researchers is building on this knowledge with its current study and making unexpected discoveries.
What happens if stress granules cannot be resolved?
The so-called protein ZFAND1 is necessary for the normal dissolution of the stress granules. "If ZFAND1 is missing, some granules can no longer be broken down and change their structure instead," says study leader Professor Alexander Buchberger in a press release on the study results. These abnormal stress granules then have to be disposed of by cellular garbage disposal (autophagy). According to Buchberger, this process is much more complex.
Even if some laypeople may not be able to do much with the information for the time being, the scientists emphasize the great importance for medical research. "The accumulation of abnormal stress granules is seen as a possible cause of neurodegenerative diseases," explains Buchberger. The elucidation of the mechanisms of action in the formation and dissolution of stress granules is important in order to better understand the pathogenic effects of stress and to find possible points of attack for therapies for stress-related diseases.
Study discovers new player in stress
The researchers demonstrated that the ZFAND1 protein does not directly affect the breakdown process. Instead, it uses a special enzyme complex that is used to break down defective proteins. This enzyme complex is called a proteasome. ZFAND1 brings the proteasome into contact with the stress granules. As a result, these are broken down. This finding is completely new. So far, science has assumed that defective proteins from the stress granules are disposed of as part of autophagy.
New study is about to start
In further studies, Buchberger and his team want to focus more closely on the composition of stress granules and deal with the defective proteins that have to be removed by the proteasome. The goal of the researchers is to elucidate the regulatory processes surrounding the formation and dissolution of stress granules in more detail and thus also to better understand the phenomenon of stress.
Fight stress actively
The Würzburg study provides further proof of the illness-causing effects of stress. It is all the more important to give the cells enough time to clean up. Targeted stress relief can support this process. Yoga, autogenic training, progressive muscle relaxation and various natural remedies are just a few ways to actively combat the increasing stress. (vb)