Stem cells used to induce hearts to repair themselves

Washington: A team of researchers has used stem cell exosomes to induce damaged mouse hearts to self-repair.

Temple University School of Medicine (TUSM) researchers are harnessing the communications vesicles excreted by stem cells and using them to induce the damaged heart to repair itself.

Researcher Raj Kishore said that if a person's goal is to protect the heart, this is a pretty important finding as one can robustly increase the heart's ability to repair itself without using the stem cells themselves.

Kishore added that their work shows a unique way to regenerate the heart using secreted vesicles from embryonic stem cells. The group is also beginning to determine which members of the "work crew" within the vesicles may be responsible for the damage repair.

In the current study, Kishore's team used a mouse model of myocardial infarction, heart attack. After infarct, mice received exosomes from either embryonic stem cells or exosomes from another type of cell called a fibroblast; mice receiving the fibroblast exosome served as the control group.

The results were unmistakable. Mice that received exosomes from embryonic stem cells showed improved heart function after a heart attack compared to the control group. More heart muscle cells survived after infarct, and the heart exhibited less scar tissue.

Fewer heart cells committed suicide, a process known as programmed cell death, or apoptosis. There was greater capillary development around the area of injury in the stem cell exosome group, which improved circulation and oxygen supply to the heart muscle. Further, there was a marked increase in cardiac progenitor cells, that is, the heart's own stem cells, and these survived and created new heart cells. The heartbeat was more powerful in the experimental group compared to the control group, and the kind of unhealthy enlargement that compensates for tissue damage was minimized.

The research appears in journal Circulation Research.