The use of stem cells to repair the injured lung

The structure of the lung is complex, it contains at least 40 different cell types. The lung interacts with the outside environment and the circulatory system. These features make the lung particularly susceptible to injury and disease.

Stem cells with reparative properties can be found within the lung. Also, outside sources of stem cells can contribute to the repair of the injured lung. These include multipotent stem cells from the bone marrow and pluripotent stem cells derived from the early embryo or from adult cells, which are made to reverse to a pluripotent state by the addition of viral vectors or non-viral agents. For stem cells of outside sources to have a reparative function, the cells need to reach the injured lung, either by internal mobilization of stem cells from other parts of the body (e.g. bone marrow) or by administration of exogenous cell sources.

Much research is currently undertaken to define the mechanisms by which stem cells repair the injured tissue. These include the possibility of engraftment of exogenous cells or the release of growth factors from the cells to aid repair. There is not as yet a clear consensus as to the mechanisms of repair. CURRENT RESEARCH AND TIMELINES: Interest is now focused on developing appropriate animal models to test the safety and efficacy of stem cell therapies and to understand the mechanisms by which stem cells undertake this task.