In a new study by scientists at the Cedars-Sinai Heart Institute, stem cells taken from younger hearts have been demonstrated to reverse the aging process.
“It’s extremely exciting,” said Dr. Eduardo Marbán, primary investigator on the research and director of the Cedars-Sinai Heart Institute. Witnessing “the systemic rejuvenating effects,” he said, “It’s kind of like an unexpected fountain of youth.”
The investigation appearing in the European Heart Journal, details how the researchers set out to observe the effects of cardiac stem cells on various aspects of the heart, including its function and structure. Prior applications of Cardiosphere-derived cells (CDC) resulted in positive effects, but this was the first time its effects in the aging process were tested.
Cedars-Sinai researchers instead took CDC cells from newborn mice and injected it into the hearts of older mice, while another group of older mice were injected with saline.
Blood, echocardiographic, haemodynamic and treadmill stress tests were performed on all mice after injections, with the older groups tested 1 month later. The mice given the Cardiosphere-derived cells saw a number of benefits compared to their saline counterparts. They had improved heart functionality, were able to exercise 20 percent longer, regrew hair at a faster
rate, and had longer heart cell telomeres. This is important because telomeres are compounds found at the ends of chromosomes whose shortening is directly correlated to the aging process.“The way the cells work to reverse aging is fascinating. They secrete tiny vesicles that are chock-full of signaling molecules such as RNA and proteins. The vesicles from young cells appear to contain all the needed instructions to turn back the clock.” said Marbán.
The CDC injections also led to a range of non-cardiac-specific effects, such as speeding hair growth, reducing systemic levels of inflammatory biomarkers, improving renal function, and helping to prevent weight loss secondary to cachexia or sarcopenia. Notably, stem cell therapy was associated with lengthening in heart cell telomeres, resulting from activation of the enzyme telomerase. Promisingly, rejuvenating effects were also seen when human heart cells from older donors were co-cultured with young CDCs.
Genetic analysis identified treatment-related changes in the expression of 37% of the 168 genes implicated in tissue aging and cellular senescence pathways, primarily those involved in cell cycle control and immune response. “Most of the CDC-related changes (85.5%) directionally recapitulated the gene expression patterns of young animals,” the authors write in their published paper.
The working hypothesis is that the cells secrete exosomes, tiny vesicles that “contain a lot of nucleic acids, things like RNA, that can change patterns of the way the tissue responds to injury and the way genes are expressed in the tissue,” Marbán said.
It is the exosomes that act on the heart and make it better as well as mediating long-distance effects on exercise capacity and hair regrowth, he explained.
With respect to future prospects, Marbán said he’s begun to explore delivering the cardiac stem cells intravenously in a simple infusion — instead of injecting them directly into the heart, which would be a complex procedure for a human patient — and seeing whether the same beneficial effects occur.
Although the tests on rats have shown that CDCs have shown cardiac and systemic rejuvenation on the aging process, there is much work to do before the anti-aging treatment is tested on people, let alone over the table.
Reaffirming this, Lilian Grigorian-Shamagian, co-primary investigator and the first author of the study, explained, “We have much to study, including whether the extracellular vesicles are able to reproduce all the rejuvenating effects we detect with CDCs.”
