Stem Cells Wanted: Alive Not Dead
Stem cell therapies are taking off, in a surprisingly unregulated way. While most humans have to go to places like South Korea to receive them, horses, dogs, cats, pigs and tigers are already being treated in North America. The most overzealous stem cell companies bluster about their currently unlicensed ability to beat down cancer, diabetes, blindness and a whole raft of other diseases, a stretch given the paucity of clinical data available, yet such therapies are nevertheless generating a new buzz in the treatment world.
For all this showboating, stem cell therapies remain incredibly difficult to implement, with lots of practical problems still facing a system usually based on harvesting a patient's stem cells, modifying them, bulking up their numbers in a dish, then reinfusing them to try and repair damage or disease. One of the biggest challenges is keeping stem cells alive and in their natural immature state once they're outside the body, where they inhabit a specially-designed cosy little niche that keeps them well-fed and happy. Re-creating such a niche in a dish is hard.
One of the ways to improve stem cell survival in the lab is to mix them with a supportive layer of nanny cells that nourish, cuddle, calm and generally look after the cells. One team of researcher's in Massachusetts found that adding fat cells in this nannying role kept stem cells alive longer, perhaps due to the unique spectrum of fatty proteins they secreted, such as adiponectin and TNFa. Another team found that adding specialised blood vessel cells, called perivascular cells, as nanny cells drastically improved the survival and usefulness of their stem cells, and did this much better than the standard MSC's currently used by many stem cell research labs. In both cases, the nanny cells had to be in direct contact with the stem cells in order to exert their positive effects.
The sum of this research implies that generating a really good niche in a dish might involve mixing lots of nanny cells of different origin, like fat, bone and blood, in one big culture to capture as many aspects of the biological stem cell home as possible.