Mesenchymal Stem Cell Transplantation Improves Heart Remodeling After a Heart Attack


Stem cell scientists from the University of Maryland, Baltimore have used bone marrow mesenchymal stem cells (MSCs) to treat sheep that had suffered a heart attack. They found that the injected stem cells prevented the heart from deteriorating.

This work was a collaboration between the laboratories of Mark Pittenger, ZhonGjun Wu and Bartley Griffith from the Department of Surgery and the Artificial Organ Laboratory.

After a heart attack, the region of the heart that was deprived of oxygen undergoes cell death and is replaced by a heart scar. However, the region next to the dead cells also undergo problematic changes. The cells in these regions adjacent to dead region must contract more forcibly in order to compensate for the noncontracting dead region. These cells enlarge, but some undergo cell death due to inadequate blood supply. There are other changes that can occur, such as abnormalities in Calcium ion handling and poor contractability.

Thus, the problems that result from a heart attack can spread throughout the heart and cause heart failure. In this experiment, the U of Maryland scientists injected MSCs into the sheep hearts four hours after a heart attack to determine if the stem cells could prevent the region adjacent to the dead heart cells from deteriorating.

In this experiment, bone marrow MSCs were isolated from sheep bone marrow and put through a battery of tests to ensure that they could differentiate into bone, cartilage, and fat. Once the researchers were satisfied that the MSCs were proper MSCs, they induced heart attacks in the sheep, and then injected ~200 million MSCs into the area right next to the region of the heart that died.

After 12 weeks, tissue biopsies from these sheep hearts were taken and examined. Also, the sheep hearts were measured for their heart function and structure.

The sheep that did not receive any MSC injections continued to deteriorate and showed signs of stress. The cells adjacent to the dead region expressed a cadre of genes associated with increased cell stress. Furthermore, there was increased cell death and evidence of scarring in the region adjacent to the death region. There was also evidence of Calcium ion-handling problems in the adjacent tissue and increased cell death.

On the other hand, the hearts of the sheep that had received injections of MSCs into the area adjacent to the dead region showed a reduced expression of those genes associated with increased cell stress. Also, these hearts contracted better than those that had not received stem cell injections. There was also less cell death, less scarring, and no evidence of Calcium ion-handling problems.

Changes that occur in the heart after a heart attack are collectively referred to as “remodeling.” Remodeling begins regionally, in those areas near the dead heart cells, but these deleterious changes spread to the rest of the heart, resulting in heart failure. The injections of MSCs into the area next to the dead region clearly prevented remodeling from occurring.

This pre-clinical study is a remarkable study for another reason: the MSCs used in this study were allogeneic. Allogeneic is a fancy way of saying that they did not come from the same animal that suffered the heart attack, but from some other healthy animal. Therefore, the delivery of a donor’s MSCs into the heart of a heart attack patient could potentially prevent heart remodeling.

The main problem with this experiment is that the MSCs were injected directly into the heart muscle. In humans, such a procedure requires special equipment and carries potential risks that include perforation of the heart wall, rupture of the heart wall, or further damaging the heart muscle. Therefore, if such a technology could be adapted to a more practical delivery system in humans, then certainly human clinical trials should be forthcoming.

See Yunshan Zhao, et al., “Mesenchymal stem cell transplantation improves regional cardiac remodeling following ovine infarction.” Stem Cells Translational Medicine 2012;1:685-95.

Merry Christmas to All My Readers!!


Luke 2:1-20:

In those days Caesar Augustus issued a decree that a census should be taken of the entire Roman world. (This was the first census that took place while[a] Quirinius was governor of Syria.) And everyone went to their own town to register.

So Joseph also went up from the town of Nazareth in Galilee to Judea, to Bethlehem the town of David, because he belonged to the house and line of David. He went there to register with Mary, who was pledged to be married to him and was expecting a child. While they were there, the time came for the baby to be born, and she gave birth to her firstborn, a son. She wrapped him in cloths and placed him in a manger, because there was no guest room available for them.

And there were shepherds living out in the fields nearby, keeping watch over their flocks at night. An angel of the Lord appeared to them, and the glory of the Lord shone around them, and they were terrified. But the angel said to them, “Do not be afraid. I bring you good news that will cause great joy for all the people. Today in the town of David a Savior has been born to you; he is the Messiah, the Lord. This will be a sign to you: You will find a baby wrapped in cloths and lying in a manger.”

Suddenly a great company of the heavenly host appeared with the angel, praising God and saying,

“Glory to God in the highest heaven,
and on earth peace to those on whom his favor rests.”
When the angels had left them and gone into heaven, the shepherds said to one another, “Let’s go to Bethlehem and see this thing that has happened, which the Lord has told us about.”

So they hurried off and found Mary and Joseph, and the baby, who was lying in the manger. When they had seen him, they spread the word concerning what had been told them about this child, and all who heard it were amazed at what the shepherds said to them. But Mary treasured up all these things and pondered them in her heart. The shepherds returned, glorifying and praising God for all the things they had heard and seen, which were just as they had been told

A very Merry Christmas to all.  God Bless You – All of You!!!