The Way Toward Lung Regeneration?
The Way Toward Lung Regeneration?
Petersen TH, Calle EA, Zhao L, et al
Science. 2010 Jun 28. [Epub ahead of print]
Basic scientists at Yale have made important steps toward lung regeneration. In essence, they stripped rat lungs of all cells, leaving just the connective tissue matrix. This acellular "scaffold," with its ghostly outline of airways, parenchyma, and vascular structures, was then "seeded" with cultured epithelial and endothelial cells derived from rodent stem cells. Remarkably, the various cell types "knew" where to home in on, and they began to settle and repopulate the skeletal matrix. The resulting organ had mechanical properties similar to those of native lungs. Moreover, when implanted in rats in vivo, the organs were able to participate in gas exchange for up to 120 minutes.
Chronic lung diseases -- chronic obstructive pulmonary disease (COPD), pulmonary hypertension, fibrosis, and cancer -- constitute one of the greatest challenges in medicine. Approximately 400,000 deaths from these causes occur annually in the United States, and mortality will only increase over the next decades as the population ages. Each of these conditions represents an unmet need for which medical treatment is mostly palliative and for which aggressive remedies such as lung transplants are rarely available, expensive, and associated with complications.
Unlike many human tissues, lung regeneration does not occur in vivo, although attempts are ongoing to promote lung regrowth using a variety of growth factors. The concept of growing replacement tissues and organs in vitro is an ambitious one, but the concept of growing replacement organs from an outline and stem cells has been applied to other organs with some success. Thus this is a logical approach for lung regeneration, albeit an enormously challenging one.
Keeping the reconstructed tissues alive and functioning indefinitely will, of course, be the next hurdle, and it is a huge one. But another significant problem, that of implant rejection, will not be an issue if lung stem cells can be obtained from the intended recipient. The present achievement is obviously a very long way from being applicable to humans, but it shows one way that we may be able to address the unmet needs of chronic lung diseases in the future. It represents a proof-of-concept and demonstrates again the important potential role of stem cells in addressing major diseases and the growing importance and promise of such basic research.
Abstract
Tissue-Engineered Lungs for in Vivo Implantation
Petersen TH, Calle EA, Zhao L, et al
Science. 2010 Jun 28. [Epub ahead of print]
Study Summary
Basic scientists at Yale have made important steps toward lung regeneration. In essence, they stripped rat lungs of all cells, leaving just the connective tissue matrix. This acellular "scaffold," with its ghostly outline of airways, parenchyma, and vascular structures, was then "seeded" with cultured epithelial and endothelial cells derived from rodent stem cells. Remarkably, the various cell types "knew" where to home in on, and they began to settle and repopulate the skeletal matrix. The resulting organ had mechanical properties similar to those of native lungs. Moreover, when implanted in rats in vivo, the organs were able to participate in gas exchange for up to 120 minutes.
Viewpoint
Chronic lung diseases -- chronic obstructive pulmonary disease (COPD), pulmonary hypertension, fibrosis, and cancer -- constitute one of the greatest challenges in medicine. Approximately 400,000 deaths from these causes occur annually in the United States, and mortality will only increase over the next decades as the population ages. Each of these conditions represents an unmet need for which medical treatment is mostly palliative and for which aggressive remedies such as lung transplants are rarely available, expensive, and associated with complications.
Unlike many human tissues, lung regeneration does not occur in vivo, although attempts are ongoing to promote lung regrowth using a variety of growth factors. The concept of growing replacement tissues and organs in vitro is an ambitious one, but the concept of growing replacement organs from an outline and stem cells has been applied to other organs with some success. Thus this is a logical approach for lung regeneration, albeit an enormously challenging one.
Keeping the reconstructed tissues alive and functioning indefinitely will, of course, be the next hurdle, and it is a huge one. But another significant problem, that of implant rejection, will not be an issue if lung stem cells can be obtained from the intended recipient. The present achievement is obviously a very long way from being applicable to humans, but it shows one way that we may be able to address the unmet needs of chronic lung diseases in the future. It represents a proof-of-concept and demonstrates again the important potential role of stem cells in addressing major diseases and the growing importance and promise of such basic research.
Abstract
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