Smoking causes lungs to lose their ability to heal

London March 3 (IANS) Are you a chain smoker? Beware. Cigarette smoke has the potential to block self-healing processes in the lungs by eroding molecules responsible for the renewal of lung cells and certain proteins essential for breathing consequently leading to chronic obstructive pulmonary disease (COPD) claimed a study.

In patients with COPD -- manifested mainly through cough bronchitis and breathing difficulties -- the lung s natural self-healing no longer takes place.

In healthy patients the so-called WNT/beta-catenin signalling pathway is responsible for the lung s homeostasis. Until now it was not clear why it was silenced in patients with COPD said Melanie Konigshoff from Helmholtz Zentrum Munchen -- German Research Centre for Environmental Health.

The new study revealed that one of the Frizzled molecules -- Frizzled 4 when exposed to smoke -- plays an important role in halting lung s natural self-healing process.

In the lung tissue of COPD patients and especially that of smokers there were significantly fewer Frizzled 4 receptors than in non-smokers the researchers said.

Frizzled 4 is a receptor molecule that sits on the surface of lung cells where it regulates their self-renewal via WNT/beta-catenin explained Wioletta Skronska-Wasek doctoral student at Helmholtz Zentrum Munchen.

However if the cells are exposed to cigarette smoke Frizzled 4 disappears from the surface and cell growth comes to a halt Skronska-Wasek added in the paper reported in the American Journal of Respiratory and Critical Care Medicine.

Inhibition of Frizzled 4 signalling on the cells led to decreased WNT/beta-catenin activity and consequently to reduced wound healing and repair capacity the researchers noted.

On the other hand the activation of the Frizzled 4 receptor can restore the WNT/beta-catenin signalling pathway and consequently lead to repair in the lung Konigshoff said.

--IANS
rt/vgu/vm