Heart regenerates after infarction
High blood pressure can be a trial of patience for doctors and for sufferers, whose blood pressure often has to be monitored over a long time until it can be regulated. This will now be made easier by a pressure sensor that is inserted in the femoral artery. If a person’s blood flows through their
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Up until today scientists assumed that the adult heart is unable to regenerate. Now, researchers and cardiologists from the Max Delbr?nter for Molecular Medicine (MDC) Berlin-Buch and the Charité - Universit?medizin Berlin (Germany) have been able to show that this dogma no longer holds true.
Dr. Laura Zelarayán and Assistant Professor Dr. Martin W. Bergmann were able to show that the body`s own heart muscle stem cells do generate new tissue and improve the pumping function of the heart considerably in an adult organism, when they suppress the activity of a gene regulator known as beta-catenin in the nucleus of the heart cells. ( PNAS , online December 10, 2008, doi: 10.1073/pnas.0808393105).
The gene regulator beta-catenin plays an important role in the development of the heart in embyros. Dr. Zelarayán and Dr. Bergmann could now show that beta-catenin is also important for the regeneration of the adult heart. They suppressed this factor in the nucleus of the heart cells in mice.
This way they activated heart precursor cells (stem cells) to turn on the regeneration of heart in adult mice. Four weeks after blocking beta-catenin, the pumping function of the heart of the animals had improved and the mice survived an infarction much better than those animals with a functioning beta-catenin gene. An important contribution to this project has been a transgenic mouse line generated by Professor Walter Birchmeier`s (MDC) laboratory.
Markers identified for Heart Muscle Stem Cells
In addition, the researchers have proven that heart muscle stem cells exist. So far, these cells had not been characterized clearly. They could demonstrate that two markers for heart cells - the structural protein alpha myosin heavy chain and the transcriptionfactor Tbx5 - are also expressed on heart precursor cells. “The evidence of cells with these markers in the adult heart demonstrates that stem cells dating back from heart development survive in niches in the adult heart”, Dr. Bergmann explains.
The researchers in Germany collaborated with scientists in the Netherlands and Belgium. For this research, Dr. Bergmann was awarded the Wilhelm P. Wintersteinpreis this summer. The research group of Dr. Bergmann, a guest researcher at the MDC who recently became Deputy of the Department of Cardiology at the Asklepios Clinic St. Georg in Hamburg, belongs to the research group of Professor Rainer Dietz (MDC and Charité).
The first demonstration that a single adult stem cell can self-renew in a mammal was reported at the American Society for Cell Biology (ASCB) 48th Annual Meeting, Dec. 13-17, 2008 in San Francisco. The transplanted adult stem cell and its differentiated descendants restored lost function to mice with hind limb muscle tissue damage. The adult
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Researchers at the University of Pennsylvania School of Medicine have discovered stem cells in the esophagus of mice that were able to grow into tissue-like structures and when placed into immune-deficient mice were able to form parts of an esophagus lining. The investigators report their findings online this month in the Journal of Clinical Investigation.
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Researchers at Children’s Hospital of Pittsburgh of UPMC have been able to effectively repair damaged heart muscle in an animal model using a novel population of stem cells they discovered that is derived from human skeletal muscle tissue. The research team - led by Johnny Huard, PhD - transplanted stem cells purified from human muscle-derived
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A protein that was first identified for playing a key role in regulating normal heart rhythms also appears to be significant in helping muscle cells survive the forces of muscle contraction. The clue was a laboratory mouse that seemed to have a form of muscular dystrophy. A group of proteins called ankyrins, or anchor proteins,
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Natural changes in voltage that occur across the membrane of adult human stem cells are a powerful controlling factor in the process by which these stem cells differentiate, according to research published by Tufts University scientists. Tufts doctoral student Sarah Sundelacruz, Professor of Biology Michael Levin, and Chair of Biomedical Engineering David L. Kaplan (corresponding
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