The October 28, 2011 issue of the journal Cell reports that researchers at Weill Cornell Medical College have uncovered the biochemical signals in mice that trigger generation of new lung alveoli, the countless tiny champagne grape-like sacs within the lung where oxygen exchange takes place. The team claim that they have taken an important step forward in their quest to “turn on” lung regeneration. This research may effectively treat millions suffering from respiratory disorders.
It’s common knowledge in the biomedical industry that mice have the ability to regenerate and even expand the capacity of one lung if the other is missing–this study identifies the specific molecular triggers behind this adaptive process. The researchers believe these findings are quite relevant to human beings.
Dr. Shahin Rafii, the Arthur B. Belfer Professor of Genetic Medicine and co-director of the Ansari Stem Cell Institute at Weill Cornell Medical College and this study’s lead investigator said “Several adult human organs have the potential upon injury to regenerate to a degree, and while we can readily monitor the pathways involved in the regeneration of liver and bone marrow, it is much more cumbersome to study the regeneration of other adult organs, such as the lung and heart.”
“It is speculated, but not proven, that humans have the potential to regenerate their lung aveoli until they can’t anymore, due to smoking, cancer, or other extensive chronic damage,” says Dr. Rafii, who is also an investigator at the Howard Hughes Medical Institute. “Our hope is to take these findings into the clinic and see if we can induce lung regeneration in patients who need it, such as those with chronic obstructive pulmonary disease (COPD).”
Dr. Rafii and his colleagues previously uncovered growth factors that control regeneration in the liver and bone marrow. In both cases, they found that endothelial cells produce the key inductive growth factors, described as “angiocrine factors”. The current lung study revealed the same phenomenon: Blood vessel cells in the lungs jump-start alveoli regeneration. “Blood vessels are not just the inert plumbing that carries blood. They actively instruct organ regeneration,” says Dr. Rafii. “This is a critical finding. Each organ uses different growth factors within its local vascular system to promote regeneration.”
In the study, the left lungs of mice were removed for Dr. Bi-Sen Ding to examine the biochemical process of the remaining lung’s regeneration. According to a prior investigation by Dr. Crystal, once the left lungs were removed, the right lungs regenerated by 80%. It replaced the majority of the lost alveoli. They discovered that when the left lung is removed, receptors on endothelial cells in the lung that respond to basic fibroblast growth factor and vascular endothelial growth factor is triggered.
Research lead Dr. Shafin Rafii explained: “Several adult human organs have the potential upon injury to regenerate to a degree, and while we can readily monitor the pathways involved in the regeneration of liver and bone marrow, it is much more cumbersome to study the regeneration of other adult organs, such as the lung and heart [...]”
Co-author Dr. Ronald G. Crystal said “There is no effective therapy for patients diagnosed with COPD. Based on this study, I envision a day when patients with COPDD and other chronic lung diseases may benefit from treatment with factors derived from lung blood vessels that induce lung regeneration.”
Reference:
Rattue, Grace. “Lung Regeneration May Be A Reality Soon.” Medical News Today. Medical News Today, 1 Nov. 2011. Web. 2 Nov. 2011. http://www.medicalnewstoday.com/articles/236928.php.