Why You Should Stop Smoking

A new research from the University of Alabama at Birmingham, published online yesterday at Science Express, found out that cigarette smoke shuts off a key enzyme in airways that regulates the body's response to inflammation.

This important enzyme is called Leukotriene A4 Hydrolase (LTA4H), and smoking is causing it to not be able to shut down white blood cells that are released as a successful response of the body to inflammation.

The usual process is simple as in case of an inflammation, white blood cells are recruited by a previously unknown substrate of LTA4H called proline-glycine-proline (PGP) – discovered by this new study – and their mission is to attack the cause of the inflammation.

After the problem is solved, LTA4H steps in to shut off PGP, and so stopping the white cells and the body's defensive process.

However, scientists found that “cigarette smoke inhibited LTA4H, preventing it from shutting down PGP.

J. Edwin Blalock, PhD, senior author and professor in the UAB Division of Pulmonary, Allergy and Critical Care Medicine, explains that “a continued presence of PGP means a continued response of neutrophils, a never-ending cycle that supports chronic inflammation.”

According to Blalock, PGP is a biomarker for many lung diseases that include chronic inflammation, like cystic fibrosis or chronic obstructive pulmonary disease (COPD).

Another discovery of this new research is the dual role played by LTA4H, which suppresses or encourages inflammation.

Researchers explains that when inside a cell, LTA4H has a pro-inflammatory job, and it makes and agent called Leukotriene B4 (LTB4), that, just like PGP, calls in the white cells when necessary.

But if LTA4H is found outside the cells, it takes the role of an anti-inflammatory, and it suppresses PGP, thus ending the body's inflammatory response.

“This dual role was poorly understood until we identified PGP,” added Blalock.

“This could have important ramifications for the design of new anti-inflammatory drugs that target LTA4H.”

Well, here you have it, another reason to stop smoking!