Chronic obstructive pulmonary disease (COPD) is a progressive lung disease that makes it difficult to breathe. According to the American Lung Association, approximately 11 million people in the United States have been diagnosed with COPD. However, it’s estimated that 24 million people may have the disease and not know it. The two main types of COPD are chronic bronchitis and emphysema. Many people with COPD have a combination of both.COPD causes one or more the following changes in the lungs and airways:
- The air sacs and airways lose their ability to stretch.
- The walls of the air sacs are destroyed.
- The walls of the airways become thickened and inflamed.
- The airways become clogged with mucus.
These changes reduce the amount of air flowing into and out of the lungs, depriving the body of much-needed oxygen and making it increasingly harder to breathe.
There’s currently no cure for COPD. There are only treatments to improve quality of life and to slow the progression of the disease. However, there’s promising research that suggests stem cells may help treat people with this type of lung disease.
Stem Cells 101
Stem cells are essential to every organism and share three main characteristics:
- They can renew themselves through cell division.
- Although they’re initially indistinguishable, they can differentiate themselves and take on the properties of several different structures and tissues, as the need arises.
- They can be transplanted into another organism, where they will continue to divide and replicate.
Stem cells may be obtained from four- to five-day-old human embryos called blastocysts. These embryos are usually available from an in vitro fertilization. Some stem cells also exist in various structures of the adult body, including the brain, blood, and skin. They’re dormant in the adult body and don’t divide unless activated by an event, such as an illness or injury. However, they are able to create tissue for other organs and body structures, so they may be used to heal or even regenerate, or regrow, damaged tissue. The stem cells can be extracted from the body and separated from other cells. They’re then returned to the body, where they can begin to promote healing in the affected area.
Stem Cells in the Lung
Until recently, it was believed that adult lungs didn’t contain any stem cells. Researchers at Brigham and Women’s Hospital in Massachusetts turned conventional wisdom on its head when they discovered the presence of stem cells in the lungs. In the 2011 study, they cited evidence of stem cells in 12 adult donor lungs and nine lungs from fetuses that had died of natural causes.
These undifferentiated cells were capable of forming different parts of the lungs, including the air sacs and the small airways. When injected into mice with surgically damaged lungs, the stem cells divided to form new lung structures. The structures that the stem cells created were able to combine with and support the mice’s own lung tissues. This discovery opened the door to the possibility of finding new and improved treatments for COPD.
COPD and Stem Cell Treatments
Since the presence of stem cells in the adult lung was confirmed only very recently, there are no stem cell treatments currently available to people with COPD. However, researchers see stem cell therapy as a promising new direction for COPD treatment research. They believe stem cells may benefit people with the disease by:
- reducing inflammation in the airways, which may help prevent further damage
- building new, healthy lung tissue, which can replace any damaged tissue in the lungs
- stimulating the formation of new capillaries, which are small blood vessels, in the lungs, which may lead to improved lung function
Researchers envision that stem cells can one day be used to generate new, healthy lungs in people with chronic lung disease. It will probably take several years of research before stem cell treatment can be attempted in people with COPD. However, if this treatment comes to fruition, people with COPD may no longer have to go through painful and risky lung transplant surgeries. It may even pave the way for finding a cure for COPD.
Written by Debra Stang
Medically Reviewed by George Krucik, MD MBA on 04 March 2016