These latest findings may lead to the development of new drugs to tackle overactive inflammation, according to the researchers.
Inflammation is part of the body's natural immune response, but an overactive inflammatory response can cause damage to the body's tissues. Chronic inflammation is when the inflammation is persistent. It occurs in a number of diseases, including arthritis, chronic obstructive pulmonary disease (COPD), ear infections and obesity.
There are a number of treatments for chronic inflammatory diseases, but glucocorticoids are among the most common. However, the study researchers, led by Dr. Jian-Dong Li, director of the Institute for Biomedical Sciences at Georgia State, note that exactly how glucocorticoids work to reduce chronic inflammation was unclear.
Past studies have suggested that glucocorticoids work by binding to glucocorticoid receptors before suppressing proinflammatory regulators - such as nuclear factor-κB (NF-κB) or activator protein 1 (AP-1).
In this study, published in the journal Nature Communications, the team found that glucocorticoids also boost expression of interleukin-1 receptor-associated kinase 3 (IRAK-M), which plays a major role in the regulation of inflammatory pathways.
From experiments in mice with inflammation triggered by Haemophilus influenzae - bacteria known to cause meningitis and septic arthritis - the team found that increasing expression of IRAK-M with glucocorticoids reduced inflammation, while use of glucocorticoids among IRAK-M-deficient mice did not.
They explain that boosting IRAK-M expression blocked the activity of MyD88 and IRAK1/4 - proteins that drive inflammation.
A new class of inflammation-suppressing drugs could be in the cards
Based on these findings, Dr. Li and his team say it is possible that a new class of drugs could be created to tackle bacteria-induced inflammation.
"Our study provides new insights into the previously unidentified role of glucocorticoids in suppressing inflammation by targeting the central bottleneck proteins MyD88 and IRAK1/4. It may also lead to the development of new therapeutic strategies to control overactive inflammation."
What is more, the team believes such a drug has the potential to eliminate severe side effects currently seen with long-term use of glucocorticoids, such as liver damage, fluid retention, high blood pressure, weight gain and increased infection risk.
"Chronic inflammatory diseases last for months and years, so you have to have a medicine that can be used for treating inflammation for the long term without having side effects," notes Dr. Li.
In November 2014, Medical News Today reported on a study by researchers from the University of California-Los Angeles indicating Tai Chi - a Chinese martial art - may be effective for reducing inflammation among breast cancer survivors.