Another article contributed by Dr. Peimer - Thank you!
Stem Cells in the Lung
By Richard Mollard, Ph.D.
The adult lung is thought to possess several different stem cell populations that reside in different parts of the airways and lung surfaces. Although in some cases the identity of the stem cells remains controversial, stem cell populations have been described in alveoli (the tissue at the end of the airways responsible for gas exchange), in bronchioles (the small airway tubes in the lungs) and in the upper airways. Each stem cell population affects the daily turnover of local cell populations during normal lung function and replaces cells in times of disease or injury.
In times of severe lung injury or disease (e.g. chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis and cystic fibrosis), the body's natural repair mechanisms can not effectively replace the damaged tissue. Furthermore, no pharmaceutical treatment has yet been developed to successfully address the pulmonary deficiencies associated with these afflictions. Currently, the only means of increasing quality of life or longevity when lung function is so severely compromised is by lung transplantation; however, the number of organs available is not sufficient to meet demand. Researchers are therefore aiming to develop novel stem cell-based therapies as a means to offer relief to patients suffering from severe respiratory disease.
One body of work suggests that in times of lung trauma certain bone marrow derived stem cell populations are recruited to the lung and effect repair. As a result, research has been initiated using mouse models to transplant healthy bone marrow derived stem cells into mice with lung disease, to determine the extent of repair to the damaged lung. Bone marrow derived stem cells have been reported to engraft in the lung, display characteristics of certain respiratory cell populations and in some cases reduce or inhibit the development of experimental respiratory fibrosis.
Embryonic stem cells represent an attractive source of cells for therapeutics because it is known they can form functional representatives of every cell type of the respiratory system. However, methods for instructing embryonic stem cells to differentiate into functional respiratory tissue in vitro (in culture) have not yet been described. Several research groups are working to develop such methods and deliver healthy replacement respiratory cells into the diseased and injured lung.
In the future it is hoped that stem cell derivatives may be used in transplant settings to offer relief to patients suffering of respiratory disease. With procedures such as nuclear transfer, custom designed embryonic stem cells could be produced from patients with cystic fibrosis, the genetic mutation repaired, and cells implanted into lungs to replace affected tissue with seemingly minimal chance of immune rejection. Before this time, however, specific cell types required for transplantation in a clinical setting need to be identified. Further, it is critical to develop procedures to overcome potential immune rejection of either donor bone marrow derived stem cells or embryonic stem cells. Research is continuing in both of these domains and if successful will provide valuable supplementation and alternatives to current lung donation programs.
Richard Mollard, Ph.D., is a stem cells specialist at the Monash Institute of Reproduction and Development, Clayton, Australia.
Stem Cells in the Lung
By Richard Mollard, Ph.D.
The adult lung is thought to possess several different stem cell populations that reside in different parts of the airways and lung surfaces. Although in some cases the identity of the stem cells remains controversial, stem cell populations have been described in alveoli (the tissue at the end of the airways responsible for gas exchange), in bronchioles (the small airway tubes in the lungs) and in the upper airways. Each stem cell population affects the daily turnover of local cell populations during normal lung function and replaces cells in times of disease or injury.
In times of severe lung injury or disease (e.g. chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis and cystic fibrosis), the body's natural repair mechanisms can not effectively replace the damaged tissue. Furthermore, no pharmaceutical treatment has yet been developed to successfully address the pulmonary deficiencies associated with these afflictions. Currently, the only means of increasing quality of life or longevity when lung function is so severely compromised is by lung transplantation; however, the number of organs available is not sufficient to meet demand. Researchers are therefore aiming to develop novel stem cell-based therapies as a means to offer relief to patients suffering from severe respiratory disease.
One body of work suggests that in times of lung trauma certain bone marrow derived stem cell populations are recruited to the lung and effect repair. As a result, research has been initiated using mouse models to transplant healthy bone marrow derived stem cells into mice with lung disease, to determine the extent of repair to the damaged lung. Bone marrow derived stem cells have been reported to engraft in the lung, display characteristics of certain respiratory cell populations and in some cases reduce or inhibit the development of experimental respiratory fibrosis.
Embryonic stem cells represent an attractive source of cells for therapeutics because it is known they can form functional representatives of every cell type of the respiratory system. However, methods for instructing embryonic stem cells to differentiate into functional respiratory tissue in vitro (in culture) have not yet been described. Several research groups are working to develop such methods and deliver healthy replacement respiratory cells into the diseased and injured lung.
In the future it is hoped that stem cell derivatives may be used in transplant settings to offer relief to patients suffering of respiratory disease. With procedures such as nuclear transfer, custom designed embryonic stem cells could be produced from patients with cystic fibrosis, the genetic mutation repaired, and cells implanted into lungs to replace affected tissue with seemingly minimal chance of immune rejection. Before this time, however, specific cell types required for transplantation in a clinical setting need to be identified. Further, it is critical to develop procedures to overcome potential immune rejection of either donor bone marrow derived stem cells or embryonic stem cells. Research is continuing in both of these domains and if successful will provide valuable supplementation and alternatives to current lung donation programs.
Richard Mollard, Ph.D., is a stem cells specialist at the Monash Institute of Reproduction and Development, Clayton, Australia.