NOV 07, 2018 08:47 AM PST

Zebrafish Bacterial Gut Protein Delays Death by Septic Shock

WRITTEN BY: Nouran Amin

At the University of Oregon, researchers identified a novel anti-inflammatory protein that is secreted by the common gut bacterium in zebrafish.

The protein, Aeromonas immune modulator (AimA), was found to reduce inflammation in the gut and delay death by septic shock. AimA is a mutual beneficial protein for both the bacterium and their host, the zebrafish.

Image Credit: yourgenome.org

"We used zebrafish as a model host because we could perform many tests and search in an unbiased way for new anti-inflammatory factors,” explains study co-author and professor of biology Karen Guillemin.

Results of the study were published in the journal eLife which sheds light on the role of resident microbes and the levels of an inflammatory response.

"One of the major questions about how we coexist with our microbial inhabitants is why we don't have a massive inflammatory response to the trillions of the bacteria inhabiting our guts," says Guillemin. "We set out to test whether gut bacteria actively secrete factors that prevent an excessive inflammatory response, which would be detrimental not only to the host but also to the bacterial residents.”

Using protein crystallography, researchers were able to identify the structural similarity of AimA to a class of proteins called lipocalins, which include other proteins that modulate inflammation in humans.

"That structural similarity suggested to us that the bacterial protein may function like the human protein" Guillemin said. "In particular, rather than doing something specific to counteract inflammation caused by one kind of bacteria, maybe it was doing something more generally to temper the host's immune response."

Researchers discovered that the AimA protein reduced inflammation but also induced a lethal inflammatory response, known as septic shock. However, what they also found was AimA could counteract the sepsis extending the lifespan of the zebrafish.

"The bacteria were experiencing this inflammation, which is detrimental to them," says Guillemin. "Inflammation involves the production of antimicrobial compounds like reactive oxygen species that are designed for clearing bacteria, so, now, a beneficial bacterium is going to be at a disadvantage if it's experiencing too much of this inflammatory response."

Watch this short video below to learn more about inflammation:

"Most studies of beneficial microbes have focused exclusively on the benefits to the host and have tended to find very generic microbial molecules, such as metabolic byproducts, as the mediators," she said. "The discovery of AimA is exciting because it is a very specific specialized product that a mutualist is making for maintaining that mutualism. I suspect there are many more of these mutualism factors to be found."

 

Findings of the research study are pertinent to drug discovery with applications of treating human diseases associated with excessive inflammation such as intestinal inflammation, including inflammatory bowel diseases, or used in the prevention of chronic inflammation associated with metabolic syndrome and sepsis.

Source: ScienceDaily, eLife

 

About the Author
  • Nouran enjoys writing on various topics including science & medicine, global health, and conservation biology. She hopes through her writing she can make science more engaging and communicable to the general public.
You May Also Like
SEP 21, 2019
Drug Discovery & Development
SEP 21, 2019
HIV Therapeutics Places Risk of Neural Tube Defects
In a study published in the New England Journal of Medicine, women taking an HIV therapeutic drug containing dolutegravir have a higher risk of giving birt...
SEP 21, 2019
Drug Discovery & Development
SEP 21, 2019
Chemotherapeutics react differently to radiation
Patients with various types of cancer are almost always treated with a combination of chemotherapy and radiotherapy. In chemotherapy, therapeutics consist ...
SEP 21, 2019
Drug Discovery & Development
SEP 21, 2019
Gel Reduces Surgical Scarring
Scientists have found that spraying a gel on the internal tissues of animal post-surgery has significantly reduced scarring—which can often lead to d...
SEP 21, 2019
Chemistry & Physics
SEP 21, 2019
Chemists Synthesized Effective Antidote For Uranium Poisoning
Uranium poisoning is unusual to the general population but does happen to miners, mineral mill and fabrication workers. Through inhaling and ingestion, ura...
SEP 21, 2019
Drug Discovery & Development
SEP 21, 2019
Can FDA Approved Ketamine Drug Spravato Really Treat Depression?
President Trump is allegedly in support of a new drug to combat depression. He even urged the Department of Veterans Affairs to purchase it and “get ...
SEP 21, 2019
Drug Discovery & Development
SEP 21, 2019
Transplanted Brain Stem Cells Survive Without Anti-Rejection Drugs
Researchers at Johns Hopkins Medicine have successfully transplanted brain cells without the need of immune-suppressing drugs. Findings of the study were p...
Loading Comments...