WEST HAVEN, Conn. — Reporting in the April 5 issue of Science, U.S. Department of Veterans Affairs (VA) researchers have found that a common molecule plays a key role in reducing inflammation of injured tissue. The findings could lead to new treatments for asthma or other types of lung inflammation.
The CD44 receptor molecule -- a docking port where cells bind with sugars that direct their response to injury -- represents a vital link within the healing process. Researchers found that lung injuries among mice lacking CD44 receptors developed inflammation that persisted until the receptors were restored.
Senior author Dr. Paul Noble, of the VA Connecticut Health Care System, said these findings will help researchers better understand why persistent inflammation occurs and develop a better understanding of the body’s healing process.
"This is helping us understand some of the basic healing mechanisms and what circumstances promote inflammation where more common causes like infection just aren’t present," said Noble.
The healing process involves four basic steps:
Injury -- In the case of the lungs, injury can be caused by inhaling dust, smoke or other airborne pollutants. Inflammation -- When inflamed, lung tissue signals CD44 receptors that repair is needed. The cells then focus their attention on the injury.
Cleaning -- Without CD44 conveying the need to clean up the cellular waste that occurs in injury and healing, irritation may intensify rather than subside.
Scar Tissue -- Once inflammation subsides, the injury knits scar tissue and healing is complete.
Investigators theorize that future application of their findings might link cases of persistent inflammation and slow healing to faulty CD44 receptors, although further research will be needed to pursue these ideas.
"If we can understand these mechanisms then we can potentially interrupt them at various stages," said Noble.
The project was funded by the VA and the National Heart Lung and Blood Institute. Dr. Noble and co-authors Priit Teder, M.D., Ph.D.; Dianhua Jiang, Ph.D.; Jiurong Liang, Ph.D.; Lauren Cohn, M.D., are affiliated with the VA Connecticut Healthcare System in West Haven and Yale University. Also co-authoring the study were R. William Vandivier, M.D., and Peter M. Henson, Ph.D. of the National Jewish Medical and Research Center in Denver, Colorado, and Ellen Pure, Ph.D. of the Wistar Institute in Philadelphia, Pennsylvania.
Research is an intrinsic part of the VA mission that benefits veterans and non-veterans.
Journal
Science