Bone marrow–derived stem cells active in pulmonary fibrosis

Adult stem cells have long been thought to be restricted in their potential to differentiate and regenerate tissues in which they reside. A study by Sem Phan and colleagues from the University of Michigan, in the January 15 issue of the Journal of Clinical Investigation, suggests that the collagen overproduction and deposition in the lung causing idiopathic pulmonary fibrosis may develop from cells derived from bone marrow stems cells, rather than parenchymal lung fibroblasts.

The authors induced pulmonary fibrosis in mice that had been altered with bone marrow labeled with a fluorescent green marker protein. In these mice, cells derived from bone marrow–derived stem cells fluoresce green, while those cells that reside in the lung do not. Most of the collagen-producing fibroblasts observed in the lungs of these mice fluoresced green, indicating that they were of bone marrow origin.

In an accompanying commentary Sarah Dunsmore and Steven Shapiro from Harvard Medical School discuss this new concept in pulmonary fibrosis. They state “understanding the mechanisms of engraftment will be important as clinical applications of bone marrow stem cell therapy are explored. The clinical implications of these findings are significant; for example, we might now consider bone marrow stem cell therapy to correct structural alterations in the lung.” They conclude “translation of our understanding of disease pathogenesis into clinical practice will bring us closer to our real goal – improving the lives of our patients and ultimately curing disease.

TITLE: Bone marrow–derived progenitor cells in pulmonary fibrosis

AUTHOR CONTACT:
Sem H. Phan
University of Michigan Medical School, Ann Arbor, Michigan, USA.
Phone: (734) 763-6454
Fax: (734) 936-1938
E-mail: shphan@umich.edu