Sep
09
2017

Young Heart Stem Cells Can Cure Old Hearts

Young heart stem cells can cure old hearts in rats. This is what research at the Cedars-Sinai Heart Institute in Los Angeles found. You may not be that impressed, because this talks about rats and not humans. But this is a brand-new concept, so of course research of animal experiments is first.

The heart experiment

Dr. Eduardo Marbán, MD, PhD, is the research director of the Cedars-Sinai Heart Institute. His idea was to take cardiac stem cells (called cardiosphere-derived cells) from hearts of newborn rats. He injected them into 22 months old rats. The human equivalent for 22 months old rats are older people with older hearts. Within one months of the stem cells’ injections the older rats had normal functioning hearts. Their telomeres were also normal. Telomeres are the caps of the chromosomes of the heart cells. The researchers were astonished to find that the previously short telomeres had become longer. This happened within only one month of the stem cell injections. To Marbán’s surprise the older rats also grew hair faster and gained 20% of their previous exercise tolerance limit. In other words, the injection of heart stem cells had rejuvenated the old rats.

Dr. Marbán has previously shown that exosomes play an important role with stem cell regeneration of old heart cells. These particles from the stem cell donor contain RNA and other growth factors.

Overview of how stem cells can reverse heart failure

Cardiovascular disease includes high blood pressure, coronary artery disease, stroke and congestive heart failure. About 2600 Americans die from cardiovascular disease each day in the US. This is roughly one death every 34 seconds. With old age, if a heart attack does not kill you, congestive heart failure will. With heart failure your heart ceases to pump enough blood through your system. Nutrients and oxygen need to reach all of our cells or it means death for the patient. With the knowledge of this serious background, stem cells have come into the focus in an attempt to combat congestive heart failure.

Animal experiments with stem cells in mice, rats and pigs have shown some progress in restoring better heart function. Researchers used different sources of stem cells, like cardiac stem cells that reside in the heart muscle itself. They also used other stem cell sources. Among these were myoblasts (from muscle), mesenchymal stem cells (from fat tissue) and bone marrow stem cells. Several smaller human trials showed that improvement of heart function was possible following a heart attack. In the procedure the surgeon opened coronary arteries and injected stem cells into the affected damaged heart muscle. How can we assess the result of a successful stem cell treatment? By measuring the left ventricular ejection fraction. This means that the heart can deliver a larger volume of blood every minute. The heart pumps more blood from the left ventricle with each heartbeat than before the treatment.

Other experiments that rejuvenate tissues of older animals

Another line of experiments in this paper shows that certain growth factors are necessary to activate stem cells.

  1. One experiment from the 1950’s describes the stitching together of the skin on their flanks joined an old and a young rat. After this procedure the blood vessels grew and joined the two animals circulatory systems. The older animals knee cartilage damage was no longer there, as the cells from the young animals’ blood had healed the damage.
  2. Research had no knowledge of this fact at that time. But another research group in the 2000’s repeated the experiment and could prove that the stem cells of the young animals activated the growth factors in the old animals.
  3. In 2004 Dr. Rando noted that muscle cells of aging mice were aging because of a lack of stimulation of the local skeletal muscle stem cells. These are satellite cells. Experiments similar to the rat experiment showed that there were factors in the blood of young mice that could re-activate stem cells in the muscles of old mice. Agility and movement of the older mice improved. The improvement in the older mice with knee arthritis disappearing and liver cells rejuvenating was astounding.

More evidence that rejuvenation of heart cells is possible

  1. Amy J. Wagers, a former colleague of Dr. Rando carried on experiments with respect to rejuvenation of hearts in mice. She and her colleagues found what stimulated the hearts of old mice. It was a protein called GDF11 (from young mice).  This 2016 publication describes the action of GDF11.
  2. A 2014 paper describes that GDF11 was able to restore aging muscles to a youthful state. But the researchers were also able to rejuvenate stem cell function in general with GDF11.
  3. Another paper describes that blood from young mice stimulates the brain of older animals to achieve rejuvenation. It is the protein of the young stem cells (called GDF11) and possibly other growth factors to bring about this rejuvenation. It works not only on heart cells, but also on hippocampus tissue in dementia models. This may be important in humans for treatment of Alzheimer’s disease.

“We can turn back the clock instead of slowing the clock down.” Dr. Toren Finkel said. He is the director of the Center for Molecular Medicine at the National Heart, Lung and Blood Institute. He went on to say: “That’s a nice thought, if it pans out.” But others who caution that overstimulation of stem cells could cause cancers say: “It is quite possible that it will dramatically increase the incidence of cancer,” Dr. Irina M. Conboy said, a professor of bioengineering at the University of California, Berkeley. “You have to be careful about overselling it.”

Degenerative changes in humans responding to stem cells

Many degenerative changes in humans respond to stem cell treatments. Are there stem cells present in degenerative tissue in humans similar to the animal experiments described above? Are the stem cells merely providing growth factors so the dormant stem cells jump into action and regenerate? Could it be that in future therapists could give a certain growth factor mix  intravenously to a patient, and the same effect as stem cell injections would be posssible? These are all unanswered questions, but research in the next decade should answer at least some of those questions.

Growth hormone improving heart function in heart failure patients

In 2008 a metaanalysis of human studies of congestive heart failure and treatment with human growth hormone (HGH) injections was a research topic. It showed an average increase of the ejection fraction by 4.3%. There were also increased cardiac output, decreased systemic vascular resistance and improved hemodynamic effects. The question is whether the effect is a direct effect on the heart muscle cells by HGH or whether HGH was recruiting dormant heart muscle stem cells. This is not clear at this point.

Young Heart Stem Cells Can Cure Old Hearts

Young Heart Stem Cells Can Cure Old Hearts

Conclusion

We have entered an exciting period of medical research. Although there is only a record of many animal experiments, there is overwhelming evidence that the same principles are true in humans. Many stem cell protocols for humans have already seen use for various applications. But stem cell treatments for heart disease are still in their early stages. As it becomes obvious from my review of this topic, some patients who were part of clinical trials have already experienced positive results. Congestive heart failure or poor pump performance following a heart attack have improved following various stem cell procedures. In the next few years there likely will be a proliferation of treatment options for patients. Although some critics have pointed out a possibility of cancer developing as a side effect of stem cell treatment, no evidence is noticeable at this point.

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About Ray Schilling

Dr. Ray Schilling born in Tübingen, Germany and Graduated from Eberhard-Karls-University Medical School, Tuebingen in 1971. Once Post-doctoral cancer research position holder at the Ontario Cancer Institute in Toronto, is now a member of the American Academy of Anti-Aging Medicine (A4M).