Mesp1 Gene Triggers Stem Cells To Become Heart, Blood Or Muscle
May 3, 2013

Mesp1 Gene Links Heart, Blood And Skeletal Muscle

Brett Smith for — Your Universe Online

When geneticists at the University of Minnesota began work on what they thought was a regulatory gene, they probably had no idea their work would redefine the tiny snippet of genetic material as a key player in stem cell differentiation.

According to the team´s report in the journal Cell Stem Cell, the gene Mesp1 is responsible for differentiation of heart, blood and muscle cells from stem cells.

“Previous research indicated that this gene was the ℠master regulator´ for development of the heart, and that its activity prevented the differentiation of other cell types,” said co-author Michael Kyba, an associate professor in the University of Minnesota Medical School´s Department of Pediatrics.

“Our work reveals that this gene acts differently, and that it plays a role in the development of blood and skeletal muscle as well,” Kyba said. “The outcome depends on the chemical signals that cells expressing this factor sense in their environment.”

The researchers chose Mesp1 because it was thought to be an important regulator of cardiac differentiation by blocking the delineation of stem cells into other types.

In the study, the researchers examined the activity of Mesp1 to see what it does at different points in the course of a stem cells development and found the gene can affect much more than previously believed.

Using “pulse inductions of gene expression” after stem cell differentiation, the team found that instead of promoting cardiac cells, the gene causes the development of precursors of different cell types. The effects of the gene could also be seen by fine-tuning the cells´ culture environment.

“This is totally out of the blue, but our discovery brings some conflicting findings about Mesp1 together,” said co-author Sunny Chan, a postdoctoral researcher at the University. “Some previous studies reported Mesp1 could not make heart cells in certain contexts. We now know why.”

The researchers also found Mesp1 is active in cells that eventually become adult stem cells in the bone marrow where they form new blood cells, and stem cells in the skeletal muscles.

“We are amazed at what a single gene can do,” Chan said. “By understanding what Mesp1 does, we are more likely to make different cell types from stem cells more efficiently.  We are one step closer to using stem cell technology for regenerative medicine.”

Advances in stem cell research could easily translate into new therapies for sufferers of heart disease. Doctors at the Scripps Clinic in San Diego have just announced the treatment of a heart failure patient with stem cells derived from the patient´s own body fat.

In the treatment process, about half a cup of fat is taken from the patient via liposuction. The fat then is processed so the scientists can retrieve what are called adipose-derived stem and regenerative cells. The recovered cells are then injected into the patient's heart using a special syringe. The entire process is said to take about two days.

Researchers at the Scripps Clinic said it would be too early to tell what kind of impact the cells are having on the health of their patient.