LIPOSUCTION has long epitomised unbridled vanity. Now those who undergo the procedure can claim to be serving the public good. According to a paper published in the Public Library of Science by Gregorio Chazenbalk, of the University of California, Los Angeles, and his colleagues, fatty tissue extracted during liposuction may prove instrumental in a sort of stem-cell therapy.
Until now the most exciting advances in regenerative medicine have centred on two types of stem cell. James Thomson became the first scientist to isolate stem cells from human embryoes 15 years ago. Embryonic stem cells promise to repair tissue damaged by disease or injury because they are able to become any sort of cell in the body, or pluripotent in the argot. But because extracting them involves destroying the embryoes, their use has been controversial. Then, in 2007, Dr Thomson and Shinya Yamanaka, in separate projects, showed how to use genes to reprogram adult human cells back to a pluripotent state. (Dr Yamanaka won the Nobel prize for his work last year.) Although iPS cells avoid the ethical quicksand of embryonic stem cells, they can sometimes cause cancer.
Most adult stem cells have the ability to renew themselves, but cannot become any cell type. They are also prone to dying after transplantation. One variety, however, called multilineage differentiating stress enduring cells, or muse cells for short, seems to avoid these problems. Muse cells were discovered in 2010 by Mari Dezawa at Tohoku University in Japan. Isolated from bone marrow and skin tissue, they were able to self-renew and differentiate into all manner of cells and helped to repair damaged tissue in animal tests. Promisingly, they did not form tumours.
The rub is that muse cells have hitherto proved tricky to obtain and use. Until, that is, Dr Chazenbalk realised that fat (or "adipose") tissue extracted during abdominal liposuction is a plentiful source of them. Using relatively simple steps, such as exposing the cells to low temperature and depriving them of oxygen and nutrients, Dr Chazenbalk was able to kill off unneeded adipose cells and release only muse adipose-tissue (AT) cells.
Instead of killing muse AT cells, such inhospitable conditions appear to awaken them from their dormant state. The cells displayed several markers of pluripotency, including OCT3/4, one of the genes that Dr Yamanaka used in his 2007 experiment. Dr Chazenbalk prompted them to differentiate into muscle, bone, fat, heart, brain and liver cells. Encouragingly, they also showed patterns of gene expression suggesting they were unlikely to form tumours. Dr Chazenbalk has yet to transplant these cells into animals, though the cells’ ability to thrive under stress makes them a good candidate.