(Press-News.org) LOS ANGELES (Jan. 30, 2012) – Injecting specialized cardiac stem cells into a patient's heart rebuilds healthy tissue after a heart attack, but where do the new cells come from and how are they transformed into functional muscle?
Researchers at the Cedars-Sinai Heart Institute, whose clinical trial results in 2012 demonstrated that stem cell therapy reduces scarring and regenerates healthy tissue after a heart attack, now have found that the stem cell technique boosts production of existing adult heart cells (cardiomyocytes) and spurs recruitment of existing stem cells that mature into heart cells. The findings, from a laboratory animal study, are published in EMBO Molecular Medicine online.
"We're finding that the effect of stem cell therapy is indirect. It stimulates proliferation of dormant surviving host heart tissue, and it attracts stem cells already in the heart. The resultant new heart muscle is functional and durable, but the transplanted stem cells themselves do not last long," said Eduardo Marbán, MD, PhD, director of the Heart Institute. Marbán, the article's senior author, invented the experimental stem cell procedures and technology tested in humans.
Consistent with previous studies, the researchers found that the heart's native stem cells are not responsible for the normal replenishment of lost heart cells, but they do contribute to rebuilding heart tissue after heart attack.
This study shows that existing heart cells contribute to formation of new heart cells in the normal heart: Through a gradual cycling process, dying heart cells are replaced by new ones. The researchers found that this cycling process escalates in response to heart attack, enabling existing heart cells to assist in the development of new ones. Further, these effects can be amplified through stem cell therapy.
The investigational therapy turns on genes that bolster cell production from both sources – existing heart cells and existing stem cells – essentially boosting the heart's normal means of cell replacement and its natural responses to injury. The injection of stem cells also improves heart structure and function.
Marbán and his clinical and research teams in 2009 performed the first procedure in which a heart attack patient's own heart tissue was used to grow specialized stem cells that were injected back into the heart. Earlier this year, they reported results of a clinical trial that found significant reduction in the size of heart attack-caused scars in patients who underwent the experimental stem cell procedure, compared to others who did not.
Although the preliminary results are positive, the researchers do not know precisely how the research treatment works.
"Understanding the cellular sources and mechanisms of heart regeneration is the first step toward refining our strategies to more effectively regenerate healthy tissue after heart attacks," said Marbán, the Mark S. Siegel Family Professor.
###The animal study was supported by National Institutes of Health grant R01 HL083109, the California Institute for Regenerative Medicine and the Cedars-Sinai Board of Governors Heart Stem Cell Center.
The process to grow cardiac-derived stem cells involved in the clinical trial was developed earlier by Marbán when he was on the faculty of Johns Hopkins University. The university has filed for a patent on that intellectual property and has licensed it to Capricor Inc., a biotechnology company in which Dr. Marbán is a founder and equity holder. The company provided no funding for this study.
Citation (if research): EMBO Molecular Medicine, "Cardiomyocyte proliferation and progenitor cell recruitment underlie therapeutic regeneration after myocardial infarction in the adult mouse heart," Dec. 19, 2012.
VIDEOLINK ENABLED - Thanks to a new, state-of-the-art in-house studio, Cedars-Sinai Medical Center can now instantly broadcast quality HD video directly to newsrooms around the world.
Cedars-Sinai Heart Institute study: Stem cells boost heart's natural repair mechanisms
2013-01-30
ELSE PRESS RELEASES FROM THIS DATE:
Program to overcome early US math deficiencies could improve workforce
2013-01-30
COLUMBIA, Mo. -- One in five adults in the United States lacks the math competency expected of an eighth grader, according to the United States Center for Educational Statistics. University of Missouri researchers identified how a lack of a specific math skill in first grade correlated to lower scores on a seventh grade math test used to determine employability and wages in adults. Intervention programs designed to overcome this early math deficiency could prepare students for later employment, help them make wiser economic choices and improve the future U.S. workforce.
"Our ...
Vegetarianism can reduce risk of heart disease by up to a third
2013-01-30
The risk of hospitalisation or death from heart disease is 32% lower in vegetarians than people who eat meat and fish, according to a new study from the University of Oxford.
Heart disease is the single largest cause of death in developed countries, and is responsible for 65,000 deaths each year in the UK alone. The new findings, published in the American Journal of Clinical Nutrition, suggest that a vegetarian diet could significantly reduce people's risk of heart disease.
'Most of the difference in risk is probably caused by effects on cholesterol and blood pressure, ...
Erectile dysfunction drug also helps men ejaculate and orgasm
2013-01-30
NEW YORK (January 30, 2013) -- New data suggests the erectile dysfunction (ED) drug Cialis may also be beneficial in helping men who have problems with ejaculation and orgasm, report researchers from NewYork-Presbyterian Hospital/Weill Cornell Medical Center in the February issue of the British Journal of Urology International. Cialis is currently approved for the treatment of ED, benign prostate hypertrophy (BPH) and for treatment of men with both conditions.
Their study, a meta-analysis of 17 double-blind, placebo-controlled clinical trials of men with ED, is the first ...
Pathway for membrane building blocks
2013-01-30
The lipid molecules of membranes, also known as phospholipids, are composed of two elements: A hydrophilic head and two long-chain fatty acids. The molecules form a bilayer in the membrane, with all of the heads pointing outwards and the fatty acid chains hanging in a zip-like interlay position.
Biomembranes are constantly reorganized or renewed, for example whenever cells divide. The cell is constantly creating new phospholipids that have to align themselves – which they do in both layers of the biomembrane. However, cells only produce phospholipids on one side of the ...
How to be a social climber
2013-01-30
The researchers have carried out a social network simulation: each individual is represented by a node, while links, connecting the nodes, represent social interactions. Each individual has the tendency to enhance their social importance, and to do so they necessarily have to connect with the "most central nodes", that is, to the people who count. However, to advance socially an individual has to break with the past: technically speaking, abandon old nodes and connect with the most central ones. But how many have an inclination to break up with old connections to aim high? ...
Understanding the historical probability of drought
2013-01-30
Droughts can severely limit crop growth, causing yearly losses of around $8 billion in the United States. But it may be possible to minimize those losses if farmers can synchronize the growth of crops with periods of time when drought is less likely to occur. Researchers from Oklahoma State University are working to create a reliable "calendar" of seasonal drought patterns that could help farmers optimize crop production by avoiding days prone to drought.
Historical probabilities of drought, which can point to days on which crop water stress is likely, are often calculated ...
Broker fees from mutual funds affect advice; predict worse performance, new study says
2013-01-30
Toronto – Brokers are supposed to recommend investments that are in the best interests of their clients.
But a study published in the February 2013 issue of the Journal of Finance has found that mutual funds offering higher broker fees attract the most investments, especially when the broker is not affiliated with the mutual fund company. Every additional dollar paid to a broker corresponds with another six dollars invested into the fund, and another fourteen dollars if the broker is an unaffiliated third party whose compensation depends exclusively on sales commissions. ...
New target to stop cancer's spread discovered by Georgia State scientists
2013-01-30
Disrupting a key interaction between two types of proteins in cells inhibits the spread of cancerous cells, providing researchers with a new pathway toward developing cancer-fighting drugs, according to new findings by Georgia State University scientists.
Cell migration is essential for the spread of cancerous cells, also known as metastasis, as well as for other diseases. The research team in the labs of Zhi-Ren Liu, professor of biology, and Jenny Yang, professor of biochemistry, studied the interaction of two molecules, p68 RNA helicase and calcium-calmodulin.
Interrupting ...
NTU research embraces laser and sparks cool affair
2013-01-30
Bulky and noisy air-conditioning compressors and refrigerators may soon be a thing of the past.
With the latest discovery by scientists from Nanyang Technological University (NTU), current cooling systems which uses refrigerant harmful to the ozone layer could be replaced by a revolutionary cooling system using lasers.
This discovery, published and featured on the cover of the 24 January 2013 issue of Nature, the world's top scientific journal, could also potentially lead to a host of other innovations. This includes making huge Magnetic Resonance Imaging (MRI) machines, ...
Study finds little progress in participation of early-career RNs in hospital QI
2013-01-30
Nurses are the largest group of health care providers in the U.S., and health care leaders and experts agree that engaging registered nurses (RNs) in quality improvement (QI) efforts is essential to improving our health care system, patient care and our nation's health. Unfortunately, despite studies demonstrating the value of nurse-led quality improvement efforts, far too few nurses are involved in these efforts, and the number is not growing, according to a study published in the Journal of Nursing Care Quality.
The study—part of the RN Work Project funded by the Robert ...