|Human mesenchymal stem cells being grown on a scaffold as a way of repairing bone. University of Cambridge on Flickr|
Muscle stem cells don't respond as well to the cries of injured muscle tissue, and blood-forming stem cells in the bone marrow become prone to forming the wrong assortment of cells, not to mention accumulating mutations that lead to forms of leukemia.
Now, a group at Tulane University has shown that another group of stem cells lose their potential over time--the so-called mesenchymal stem cells. They published their work in STEM CELLS Translational Medicine.
Mesenchymal stem cells (or MSCs) live in the bone marrow and fat and can mature into bone, cartilage and fat tissue. They also migrate to areas of the body where they seem to tame immune reactions. They are being studied by scientists working to develop therapies for bone or muscle disease in addition to autoimmune diseases like rheumatoid arthritis and multiple sclerosis. The idea is that the cells will be able to calm the immune reaction that leads to those diseases.
The team of researchers from Tulane were specifically trying to use MSCs to treat people with multiple sclerosis, and wanted to investigate the performance of cells from older versus younger people. They took MSCs from people older than 60 and from people younger than 35 and tested them in mice with an induced autoimmune disorder that mimics MS.
Lo and behold, the mice that received the stem cells taken from older people developed significantly advanced disease compared with those receiving the younger cells.
The team isn't saying that older people are just out of luck when it comes to possible MSC therapies that may be developed. But they do think they and other scientists have some work to do understanding how those cells age and finding ways of making the cells from older people more effective. A press release from the journal quotes Bruce Bunnel, who led the work:
"The most interesting question to me that came out of this is what is aging doing that is changing these cells? What is going on in the biological environment in the human body that is changing these cells? If you can figure that out, you may be able to improve the quality of these cells."Amy Adams