The mitral valve is located between the left atrium and left ventricle of the heart where it serves an important role in preventing backflow of blood into the left atrium as the ventricle contracts. Mitral valve prolapse, a condition that occurs in humans, is characterized by regurgitation of blood into the left atrium, which receives blood from the lungs. Hence, this condition can lead to congestive heart failure as blood backs up in the lungs.
Scientists at Tufts University, Cummings School of Veterinary Medicine, were studying dogs with myxomatous mitral valve disease (similar to mitral valve prolapse in humans) and congestive heart failure when they discovered the presence of specific biomarkers located in extracellular vesicles (i.e. exosomes) that circulate in the blood. Their results were published in the Journal of Extracellular Vesicles. For dogs, myxomatous mitral valve disease is the most common cause of heart disease and congestive heart failure. The team found that the expression of these biomarkers changed with aging and as the disease progressed.
This discovery may lead to new approaches in monitoring disease progression. First author Vicky Yang, D.V.M, Ph.D. stated “There are currently no medical treatments available to delay the progression of these valvular diseases. While these new molecular signatures in exosomes require further study, the findings could open doors to novel molecular targets to slow or halt the progression of mitral valve disease to heart failure.”
Yang, V., Loughran, K., Meola, D., Juhr, C., Thane, K., Davis A., Hoffman, A. “Circulating exosome microRNA associated with heart failure secondary to myxomatous mitral valve disease in a naturally occurring canine model.” Journal of Extracellular Vesicles. Published online July 12, 2017. DOI 10.1080/20013078.2017.1350088.