Which metabolic pathways do bacteria use to regulate inflammatory processes?
In various examinations, doctors have already found that omega-3 fatty acids prove to be health-promoting for the cardiovascular system. In addition, these fatty acids also play an important role in human immune defense. Researchers are now investigating the metabolic pathways through which pathogenic bacteria influence inflammatory processes.
In their current study, scientists from Friedrich Schiller University in Jena and the internationally recognized Harvard Medical School in Boston explained how omega-3 fatty acids keep the immune system fit. The experts published the results of their study in the English-language journal "Nature".
What do omega-3 fatty acids do for the body?
Omega-3 fatty acids are an important part of a healthy diet. Omega-3 fatty acids are found in vegetable oil and fish, for example, and are considered essential food components. The fatty acids promote the health of the cardiovascular system. They also play a major role in immune defense and provide the important building blocks for so-called inflammation-dissolving substances, which are also called resolvins. These resolvins, for example, promote the resolution of inflammatory reactions due to a microbial infection. The current study explains the underlying cellular mechanisms of the dissolution phase of inflammatory reactions.
Macrophages control the inflammatory process
The research showed that certain disease-causing bacteria have a targeted influence on the function of special immune cells. These immune cells called macrophages control the entire inflammation process using different fatty acids.
What exactly is inflammation?
"Inflammation is a defense reaction of the body to a harmful stimulus, such as invading pathogens or tissue injury," explains Prof. Dr. Oliver Werz from the University of Jena in a press release from the university. The goal of inflammation is to eliminate the harmful stimuli. In addition, destroyed and damaged tissue is to be regenerated. "To do this, however, it is necessary that the triggering of the inflammatory process and its decay are precisely regulated by the immune system," adds the expert.
How do chronic inflammations develop?
If these processes are not in balance, there is a risk of chronic inflammation. Examples include arteriosclerosis or autoimmune diseases. In the study, the doctors were able to observe that so-called pathogenic pathogens such as Staphylococcus aureus and Escherichia coli trigger opposite effects in different populations of macrophages. M1 macrophages are mainly active in the inflammatory phase. The M1 macrophages stimulate the production of inflammatory signaling substances (prostaglandins and leukotrienes).
M2 macrophages form inflammation-dissolving substances
There are also M2 macrophages that are in the foreground during the inflammation's decay process, the authors say. The bacteria cause these M2 macrophages to increasingly form inflammation-dissolving substances such as resolvins, lipoxins, maresines and protectins from the omega-3 fatty acids. The researchers have long known that M1 macrophages interact with pathogenic germs. A completely new finding, however, is that bacteria stimulate M2 macrophages to release inflammation-resolving substances from omega-3 fatty acids. "Activating both phases of the inflammation makes perfect sense, because in this way the immune system ensures that after a successfully warded off infection, the harmless bacteria are removed from the tissue and the inflammatory reactions are stopped," explains Prof. Oliver Werz.
More research is needed
The question remains whether the results of the study can be used in the future for the treatment of inflammatory diseases. The new findings will therefore be used in further studies as part of a funding program from the Carl Zeiss Foundation. In addition, the experts from the Collaborative Research Center ChemBioSys also worked with the data from the current study to carry out a sub-project on the modulation of macrophages by natural products. (as)