mesenchymal stem cell

Mesenchymal stem cells, or MSCs, are a kind of adult stem cell found in the body's connective and supporting tissues, most famously in bone marrow and in fat. They are multipotent, with a classic talent for becoming the cells of the skeleton's structural tissues: bone, cartilage, and fat. Picture them as a maintenance crew for the body's framework, the cells that help lay down and renew the hard and cushioning materials that hold everything together.

Beyond turning into those few tissue types, MSCs are valued for the chemical signals they release. Rather than rebuilding tissue mainly by becoming it, they appear to work largely by secreting molecules that calm inflammation and nudge nearby cells to repair themselves. They are also relatively easy to collect and grow compared with many other stem cells, which is a large part of why they have been so widely tested. Because many researchers argue they are more supportive stroma than true stem cell, the more careful name mesenchymal stromal cell is often preferred.

This combination of accessibility and broad biological activity has made MSCs the subject of an enormous number of clinical trials. It has also, unfortunately, made them a favorite of unregulated clinics that market unproven MSC injections for almost any ailment. The honest picture is mixed: MSCs are genuinely interesting and useful in research, a few specific uses are supported by evidence, but the sweeping cure-all claims sold to patients run far ahead of what has actually been demonstrated.