Scientists have found a new source of potentially useful stem cells – in liposuctioned fat tissue.
The stem cells discovered in adipose, or fat tissue, are considered "pluripotent," meaning they can be differentiated into essentially any type of body cell, making them potentially useful for a variety of medical uses. Researchers believe that pluripotent stem cells will be used to treat neurological disorders such as Parkinson's and Alzheimer's Diseases.
Until the most recent discovery, made by University of California—Los Angeles researcher Gregorio Chazenbalk and described in the journal PLOS ONE, the two main types of pluripotent stem cells were embryonic and induced pluripotent cells, which are made by re-engineering skin cells. Several years ago, scientists discovered stem cells in fat tissue that could not be differentiated into other types of cells. According to Chazenbalk, the newly-discovered pluripotent stem cells that exist in fat tissue are known as Muse-AT cells and are particularly stress-resistant, meaning they would be useful for treating traumatic injuries.
"This population of cells lies dormant in the fat tissue until it is subjected to very harsh conditions. These cells can survive in conditions in which usually only cancer cells can live," he says. "When you have an injury, it's a harsh environment for cells – there is inflammation and apoptosis (mass cellular death). Anything you put there has a low chance of survival. But these cells are already adapted to the stress, and when you put them in damaged tissue, they can survive at high rates."
That means stem cells from fat tissue could be harvested and frozen and used at a later date, such as when a person suffers an injury. Ideally, researchers would use a person's own stem cells for any sort of therapy, but Chazenbalk says the cells can potentially be reprogrammed, so cells donated from another person would not be rejected by a patient's immune system.
Chazenbalk says his colleagues at Tokohu University in Japan have begun preliminary trials to treat heart attacks in mice with tissue grown using Muse-AT cells.
"When someone has a heart attack, these could be implanted to help regenerate tissue. It could also have use for regrowing skin cells when there is severe burning," he says.
Unlike embryonic and induced pluripotent stem cells, Muse-AT cells show no evidence of developing teratoma, a cancer-like situation where stem cells rapidly divide until a tumor develops. The development of teratoma has made the clinical application of embryonic stem cell therapies slower than many scientists would like.
"This is a huge advantage because you don't have to re-engineer them to not produce teratomas," he says. "These cells are likely to play a critical role for tissue regeneration in the event of acute injury."