New approach to protect the hearts of patients with muscular dystrophyMay 13, 2008A team of researchers has recently shown that the administration of sildenafil protects the heart in mice with Duchenne muscular dystrophy. This study was led by Dr. Christine Des Rosiers from the Université de Montréal and the Montreal Heart Institute, in collaboration with Dr. Basil Petrof of the Research Institute of the McGill University Health Centre (MUHC) and Dr. Christian Deschepper of the Institut de recherches cliniques de Montréal. The study findings are published today in the online edition of the Proceedings of the National Academy of Sciences. "This achievement was a true team initiative and is the culmination of sustained efforts on the part of Dr. Maya Khairallah, who was a doctoral student at the time, and all of the researchers from participating centres," says Dr. Des Rosiers. "I'm pleased that my work has sparked interest in an eventual application for humans," says Dr. Khairallah. The study received financial support from the Canadian Institutes of Health Research, the Fonds de la recherche en santé du Québec, the Heart and Stroke Foundation of Canada, the Muscular Dystrophy Association and the National Heart, Lung and Blood Institute in the U.S. Improved cardiac function and reduced cell death The researchers explain that the choice of sildenafil was based on their previous studies indicating that the hearts of dystrophic mice do not function as effectively and are more susceptible to stress-induced cell death. These studies suggested that this may be due to a decrease in the formation of a molecule named cGMP (cyclic guanosine monophosphate). In the present study, researchers used two different approaches to increase cGMP production in the heart, with the result that the hearts were able to function more effectively and were less susceptible to cell death. "One of these approaches involved the use of sildenafil, which increased cGMP concentration by preventing its degradation by the phosphodiesterase 5 enzyme," explains Dr. Petrof, who works at the MUHC's Meakins-Christie Laboratories. "Our work had shown for many years the benefits of cGMP on the heart and the present study confirms the therapeutic potential of this molecule", adds Dr. Deschepper. About muscular dystrophy Muscular dystrophy is characterized by weakness and progressive degeneration of the muscles, including the heart muscle. It is caused by a genetic mutation of dystrophin, a protein that acts as the "backbone" of muscular cells. This disease, whose most common forms are those of Duchenne and Becker, has an incidence of one in 6,000 births and a prevalence of roughly one in 3,600 boys. The first signs of muscular weakness appear at roughly age 5, leading to a progressive loss in the ability to walk by the age of 13. Cardiac problems can occur at the age of 10 and progress very quickly, affecting the majority of patients by the age of 20. They are also an important cause of death among patients with muscular dystrophy. "Research on this disease used to focus on the degeneration of skeletal muscles," says Dr. Des Rosiers, "but it is important to take into account all muscular problems, including cardiac problems, when treating these patients so that we can improve their quality of life." The researchers point to another study showing the beneficial effects of a medication similar to sildenafil on the other muscles of dystrophic mice. Thus, the benefits of this approach may not be limited to the heart. Sildenafil is already prescribed for erectile dysfunction and pulmonary hypertension. However, Dr. Petrof mentions that "further clinical studies will be required before Viagra is prescribed to dystrophic young children." "These experimental results give us hope that one day it will be possible to treat with this approach cardiac problems in patients with muscular dystrophy, and perhaps even treat other heart diseases," Dr. Jean-Claude Tardif, director of the Montreal Heart Institute Research Centre and professor of medicine at the Université de Montréal. "It also demonstrates our researchers' commitment to conducting basic research that has the potential to transform the practice of medicine." University of Montreal |
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| Related Muscular Dystrophy Current Events and Muscular Dystrophy News Articles Study opens new avenue for developing treatments for genetic muscle-wasting disease Scientists from the Ottawa Hospital Research Institute (OHRI) and the University of Ottawa have identified a promising new approach for developing drugs to treat Spinal muscular atrophy (SMA), the leading inherited cause of death in infants and toddlers. Researchers discover chemical that may protect hearts of muscular dystrophy patients Researchers at the University of Minnesota Medical School have discovered a chemical that may, over the long term, protect the hearts of Duchenne muscular dystrophy patients - a fatal and most common form of muscular dystrophy in children. New clues about the basis of muscle wasting disease New findings that shed light on how genetic damage to muscle cell proteins can lead to the development of the rare muscle-wasting disease, nemaline myopathy, are reported today (15 March) in the Biochemical Journal. Using own skin cells to repair hearts on horizon A heart patient's own skin cells soon could be used to repair damaged cardiac tissue thanks to pioneering stem cell research of the University of Houston's newest biomedical scientist, Robert Schwartz. Fetal surgery continues to advance Repairing birth defects in the womb. Inserting a tiny laser into the mother's uterus to seal off an abnormal blood flow and save fetal twins. Advancing the science that may allow doctors to deliver cells or DNA to treat sickle cell anemia and other genetic diseases before birth. Research at UCSB points to potential treatment for kidney disease Research performed at UC Santa Barbara points to the drug rapamycin as a potential treatment for kidney disease. Researchers trace effects of genetic defect in myotonic muscular dystrophy Research on the genetic defect that causes myotonic muscular dystrophy has revealed that the mutation disrupts an array of metabolic pathways in muscle cells through its effects on two key proteins. Identification of the gene responsible for a new form of adult muscular dystrophy A study published in today's online edition the American Journal of Human Genetics, allowed the first identification of a new form of adult onset muscular dystrophy. 'Jekyll and Hyde' cell may hold key to muscular dystrophy, fibrosis treatment: UBC research A team of University of British Columbia researchers has identified fat-producing cells that possess "dual-personalities" and may further the development of treatments for muscle diseases such as muscular dystrophy and fibrosis. Investigators identify gene mutations in patients with Becker muscular dystrophy Investigators in The Research Institute at Nationwide Children's Hospital have identified a link between specific modifications of the dystrophin gene and the age of cardiac disease onset in patients with Becker muscular dystrophy (BMD). More Muscular Dystrophy Current Events and Muscular Dystrophy News Articles |
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