Adult Stem Cells Migrate to Lung, Contribute to Pulmonary Fibrosis

Findings: UCLA researchers for the first time identified and then stopped a type of adult stem cell from migrating to the lung and contributing to pulmonary fibrosis in an animal model. Pulmonary fibrosis (i.e, idiopathic pulmonary fibrosis) in humans is a devastating terminal disorder that causes an overabundance of scar tissue to form in the lung.

Impact: The new study may offer novel therapies to treat idiopathic pulmonary fibrosis– currently there are no effective treatments and the mortality rate is approximately 70 percent within five years of diagnosis. Over 80,000 individuals in the United States suffer from the disease.

Authors: Dr. Robert M. Strieter, study senior author and Chief of the Division of Pulmonary and Critical Care Medicine, and Vice Chair of the Department of Medicine at the David Geffen School of Medicine at UCLA, is available for interviews.

Journal: The research appears in the August 2 edition of the peer-reviewed Journal of Clinical Investigation. A PDF of the full study is available.

Background: Previously it was thought that idiopathic pulmonary fibrosis was due to resident fibroblasts/myofibroblasts located in the lung, according to Strieter. “We now have evidence that a specific adult stem cell travels to the lung through the bloodstream where it then can produce collagen that leads to the scar tissue formation.” Using an animal model, researchers also showed that the mechanism causing the adult stem cell to travel to the lung could be blocked, thus reducing the amount of collagen build-up in the lung and reducing pulmonary fibrosis. Researchers will next further study the regulation of the expression of the receptor that is involved in the recruitment process of these cells.

Strieter notes that the new study may also provide insight into new treatments for other disorders, such as connective-tissue diseases (i.e., rheumatoid arthritis) and liver cirrhosis, which, like idiopathic pulmonary fibrosis, all are associated with an overabundance of scar tissue formation. The study is funded by the National Institutes of Health.