February 13, 2018
Replenishing the bloodstream with a naturally-occurring protein could soon offer better prospects for successful stem cell therapies in patients who have recently suffered a heart attack, according to new research out of the Sidney Kimmel Medical College of Thomas Jefferson University.
The study, published in the high impact journal "Circulation," looks at how a cardioprotective protein known as CTRP9 could potentially enhance the healing properties of stem cells in vulnerable heart patients.
“The research could eventually make stem-cell therapy a more viable option for treating long-term damage from heart attack,” says senior author Xin-Liang Ma, professor of emergency medicine.
In the aftermath of a heart attack, the site of the injury is often toxic or inhospitable to injected stem cells.
A previous study led by Ma in 2013 revealed that CTRP9 levels generally become depleted after a heart attack.
“That earlier work made us wonder whether we might be able to improve conditions for stem cells if we replaced CTRP9 to normal physiological levels,” said Ma.
In the current study, researchers tested their hypothesis in animal models of diseased and damaged tissue following a heart attack. In animals that received an infusion of CTRP9, newly introduced stem cells survived longer and covered a larger area of damage, helped facilitate repair and prevented the formation of scar tissue.
“Rather than using heart stem cells or bone-marrow-derived stem cells, we chose a source of stem cells that’s more easily extracted," said Dr. Yajing Wang, a research associate professor who assisted Ma in the study. "Other sources may offer other advantages, but fat tissue offers the least invasive source of stem cells for a patient.”
The study also found that restoring normal levels of CTRP9 had beneficial effects on the behavior and secretory patterns of stem cells.
“We demonstrate that CTRP9 stimulates stem cells to secrete a number of proteins and molecules that not only protect stem cells from toxic cellular death, but also shield the heart from oxidative damage after heart attack,” Ma said.
The results of the study, which was supported by grants from the National Institutes of Health, will be used to explore ways to achieve similar outcomes in human applications.