Texas research team has published a report on the fusion of adult stem cells to damaged heart cells which enables healing of damage. In this case, the stem cells are from peripheral blood – the blood that circulates every day. Presumably, the origin of these cells is the bone marrow.
The review at Physorg.com. includes a discription of the current knowledge on heart repair and stem cells. Quoted is T.H.Yeh, M.D. one of the team from M. D. Anderson, the Texas Heart Institute at St. Luke’s Episcopal Hospital and The University of Texas Health Science Center at Houston.
Because many of the drugs and therapies used to treat cancer can cause heart damage, M. D. Anderson, a world-renowned cancer therapy and research center, also invests in the study of heart disease.
Cardiac adult stem cells seem to do two different things: they divide to form blood vessels and they fuse to injured heart muscle cells or “cardiomyocytes” to cause the muscle cells to demonstrate “stemness.” The original fused cells are now like very special stem cells that are cardiomyocytes that can divide and multiply for months, in order to repair the damage in the heart. Until recently, we were taught that heart muscle cells did not replicate and replace themselves in adults.
Yeh and his co-workers report on adult heart stem cells, three specific proteins, the mechanisms that stimulate their production, and evidence as to how these proteins and stem cells work after heart muscle damage. Two of the proteins, described as “sticky” similar to the two tapes in Velcro, are newly discovered by the team. Another protein, vascular endothelial growth factor or VEGF, was previously known to aid in the development of new blood vessels. In hearts, VEGF causes some of the stem cells to produce blood vessels rather than fuse to the damaged muscle cells. By a series of experiments using antibodies against the proteins in immune deficient mice with induced heart damage, the team has demonstrated one way the heart repairs itself and that the same adult stem cells can lead to new heart blood vessels and new heart muscle cells. The hope is that this discovery will allow us to increase the amount of repair in heart attack patients.
The last author of the original article is James Willerson, M.D., the President of the University of Texas Health Science Center at Houston, and the man who went off to Brazil in order to do one of the first studies of bone marrow stem cells used to treat heart disease. He’s been mentioned on this blog, here and here.
Unfortunately, Willerson is often quoted advocating the creation of new embryonic stem cell lines, and the destruction of more and more human embryos in order to harvest those lines.