Nonhematopoietic Stem Cells from Umbilical Cord Blood Improve Heart Function After a Heart Attack

Xin Yu, who has dual appointments at Case Western Reserve University, in Cleveland, Ohio and the University of Minnesota Medical School in Minneapolis, Minnesota, has published a remarkable paper in the journal Cell Transplantation that describes the use of a stem cell population from umbilical cord blood to treat mice that had suffered heart attacks. The non-invasive way in which these cells were administered and the tremendous healing qualities of these cells makes paper unique.

In 2005, Water Low at the University of Minnesota Medical School described the isolation and characterization of a unique stem cell population from umbilical cord blood that he called nonhematopoietic umbilical cord blood stem cells or nh-UCBSCs. These cells were used to treat animals with strokes and they induced the growth of new brain cells in the brains of treated mice (see J Xiao, Z Nan, Y Motooka, and WC Low, Stem Cells Dev. 2005 Dec;14(6):722-33).

Yu used these cells to treat male Lewis rats that had suffered heart attacks. In all cases, the rats were subjected to open-heart surgery and the left anterior descending artery was tied off to induce a heart attack. One group of rats were operated on but no heart attacks were induced. A second group was given heart attacks, and then two days later were given intravenous saline infusions. The third group was given a heart attack and then two days later, were injected with one million nonhematopoietic umbilical cord stem cells into their tail veins.

Ten months after the surgery, the heart structure and function of animals from all three groups was assessed with tensor diffusion magnetic imaging, and a pressure‐volume conductance catheter. The hearts were also extirpated from the animals and structurally assessed by means of staining and 3-D imaging.

The stem cell-treated animals were compared with the sham-operated animals and the saline-treated animals. In almost all categories, the stem cell-treated animals had better function. Also, the overall structure of the heart was preserved and looked more like the normal heart than the saline-treated hearts. For example, in the saline-treated group, the heart wall thickness in the infarct zone was reduced by 50% compared to the control rats, and wall thickness at the border zone was also significantly
decreased. However, there were no statistical difference in wall thickness between the stem cell-treated group and the control group.

Additional finds were that the stem cell-treated group had significantly smaller areas of dead cells, more blood vessels, and better heart muscle fiber structure that contracted better.

These data show that the long-term effects of nh-UCBSC administration was to preserve the structure, and, consequently, the function of the heart after a heart attack.

However, the added bonus to this work is that the animals were injected with these cells into the tail vein. The animals did not have to have their chests cracked, or have over-the-wire stent technology to implant these cells; they merely introduced them intravenously. Apparently, the nh-UCBSCs homed to the damaged heart and mediated its healing. If such healing can be translated to human patients, this could truly be a revolutionary find.