The Embryonic King Is Dead, Long Live the Mesenchymal King
When I first started using mesenchymal stem cells (MSCs) to treat orthopedic problems in 2005, embryonic stem cells (ESCs) were king. However, a funny thing happened in 2010, when the number of research papers published on MSCs equaled the number published on ESCs. Since then, things have gotten much worse for ESC research, and MSC research is now clearly dominating the mesenchymal stem cell vs embryonic stem cell battle.
What Is an Embryonic Stem Cell?
Embryonic stem cells (ESC) are the cells that make a baby. They’re pluripotent, meaning that they have the ability to turn into all three cell types, which are ectoderm, endoderm, and mesoderm. Basically, they are stem cells that can turn into most cells of the human body.
What Is a Mesenchymal Stem Cell?
A mesenchymal stem cell (MSC) is different. It’s a stem cell that’s found in adults (or really any individual past the age of embryo). It’s multipotent and can differentiate into a number of cell types that are of the mesodermal lineage. These include osteoblasts (bone cells), chondrocytes (cartilage cells), myocytes (muscle cells), and adipocytes (fat cells).
Mesenchymal Stem Cell vs Embryonic Stem Cell: Why MSC Research Surpassing ESC Research Is a Big Deal
The public was introduced to the concept of stem cells after the Bush administration ban on ESC research. This forced ESC researchers to take their case to the public. In addition, California Prop 71 was the culmination of that fight that garnered national media attention. Scientists sold the public hard that stem cells were a possible miracle cure for many incurable diseases. However, a funny thing happened. It turns out that ESCs not only have ethical problems, they also have a nasty little issue of causing teratomas (weird tumors). At the same time, many scientists began to recognize that we had stem cells right in our own bodies called MSCs. Hence, the race was on to see which stem cell type would become dominant.
As you can see from my updated graph above, MSC research is now blowing ESC research out of the water. This graph shows the number of research papers published per year for each stem cell type as listed in the US National Library of Medicine. I estimated the total for 2017 based on the volume from the first six months of this year.
Why is this happening? MSCs are just more useful. They can be obtained from the patient without any ethical concerns and generally can do most of what ESCs can accomplish. In fact, the graph above doesn’t include other MSC therapies, like bone marrow concentrate (a same-day bone marrow stem cell procedure) or stromal vascular fraction (a same-day fat stem cell procedure).
The upshot? ESC research is slowly dying off and being replaced by MSC research. While this mesenchymal stem cell vs embryonic stem cell research reversal may have started because of the Bush administration ban, it’s accelerated since then because MSCs are just more practical as a therapy. So the king is dead, long live the king!