JUL 13, 2016 08:33 AM PDT

Itaconate Metabolite Hijacks Macrophage Activation

WRITTEN BY: Kara Marker
Macrophages of the immune system are vital for mounting a quick and directed attack on invading pathogens especially along the inflammatory pathway, but often overzealous macrophages can go a bit too far and cause damage with excessive inflammation. Numerous immune suppression therapies exist on the market, but often they can render a person vulnerable to infection while trying to relieve an inflammatory disorder. A new option has surfaced in a new study: a natural metabolite that controls macrophage activity.
 Draw-bridge depicts Itaconate disrupting the TCA cycle flow - Credit: Aleksandra Ziminova
A collaboration of scientists from Washington University, ITMO University, McGill University, and the Max Planck Institute of Immunobiology and Epigenetics is behind the potential new option for suppressing inflammation: itaconate. Their findings were recently published in the journal Cell Metabolism.
 
Macrophages transition between three distinct stages during their lifetime: neutral (M0), pro-inflammatory (M1), and anti-inflammatory (M2). As expected, M1 macrophages are the type that arrives first at the scene of the crime, promoting inflammation to begin the immune attack on whatever pathogen has invaded the body. When a M1 macrophage becomes “overly diligent” though, numerous pathologies can result: cardiac ischemia, metabolic disorders, and even autoimmune diseases.
 
Too much inflammation is dangerous and leads to these diseases because of the absorption of energy resources required to keep the inflammatory pathway up and running. The new study looked at the transition process of macrophages between states, especially between their inactive and pro-inflammatory state. This is where itaconate comes into the picture, a natural metabolite released by macrophages whose role scientists have never quite understood – until now.
 
The researchers found that there seems to be a defined limit of the amount of itaconate that can be produced during the M0 – M1 transition, and as itaconate levels grow closer to the limit, macrophage activation to its pro-inflammatory state is designed to fail. “Itaconate sets the bar controlling M1 macrophage formation, said Alexey Sergushichev, one of the study’s authors.
 
Itaconate’s role within macrophage activation was finally realized when the researchers connected the metabolite to the bodily processes for producing energy from glucose oxidation: cellular respiration and the tricarboxylic acid cycle. An enzyme called succinate dehydrogenase (SDH) provides a component called fumarate to the tricarboxylic acid cycle. This is where the researchers saw itaconate interfering with energy production: itaconate blocks the enzyme entirely.
 
With the tricarboxylic acid cycle and cellular respiration halted without a necessary enzyme, macrophage activation to a pro-inflammatory state fails. In this way, itaconate acts as an anti-inflammatory agent, while it also acts as an antioxidant by blocking glucose oxidation.
 
The successful breakdown of itaconate and its role in macrophage activation is important for understanding how inflammatory diseases develop, as well as for how to treat them. Sergushichev believes that this new insight will lead to the ability of scientists to “artificially manipulate the transition of macrophages from M0 to M1, meaning the possibility of restraining inflammations.”
 


Sources: ITMO University, Current Opinion in Plant Biology
 
About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
JUN 18, 2018
Immunology
JUN 18, 2018
Detecting and Diagnosing Rheumatoid Arthritis Before it Begins
Unique gene signatures and tiny changes in the immune system that occur in the earliest stages of rheumatoid arthritis, an autoimmune disease, could soon b...
JUL 06, 2018
Cell & Molecular Biology
JUL 06, 2018
Small Molecules Found to Dial Down Autoimmunity
Scientists have now identified two combinations of small molecules that tamp down a protein called STING....
JUL 17, 2018
Videos
JUL 17, 2018
Encouraging Progress on HIV Vaccine
In the quest to find a vaccine against HIV which causes AIDS, most attempts have failed. The HIV epidemic began about 35 years ago and in that time only fi...
JUL 31, 2018
Immunology
JUL 31, 2018
The Immune Systems Molecular Alphabet
Lab-designed nucleic acid nanoparticles elicit varied and specific immune response from immune cells based on shape, size, and formulation of each particle....
AUG 15, 2018
Immunology
AUG 15, 2018
Therapeutic Macrophages Improve Rare Lung Disorder
The use of therapeutic macrophage transplantation in mice showed great improvement in rare lung disorder caused by deficient macrophages....
SEP 11, 2018
Cannabis Sciences
SEP 11, 2018
The Potential Anti-cancer Effects of Cannabinoids
They're known for helping to reduce the impact of cancer drug side effects, but it's possible that cannabinoids themselves are cancer fighters....
Loading Comments...