Current State of Stem Cell Therapy for Heart Diseases

Abstract

Heart disease is very common among older adults and is one of the main causes of death worldwide. With age, the functionality of the heart will decrease following the changes in the cardiomyocytes and cardiac tissue. Generally, the number of cardiomyocytes will decrease, the number of senescent cells will increase, the cardiac tissue will become thicker, and the contractility will diminish. Besides, heart diseases such as myocardial infarction and heart failure also will reduce the functionality of the heart. Currently, heart disease is normally treated with medication and surgery. In severe conditions, the patient will be recommended to opt for a heart transplant. However, medication and surgery cannot reverse the pathological changes in the heart, and it is very difficult to find a suitable heart for transplantation. Stem cell therapy offers a glimpse of hope to these patients as the cells can stimulate the proliferation of cardiac progenitor cells and cardiomyocytes as well as secrete the paracrine factors which modulate the tissue environment to promote regeneration. Even though stem cells, e.g., mesenchymal stem cells (MSCs) and embryonic stem cells (ESCs), have been shown to differentiate into cardiomyocytes in vitro, however, there is a lack of evidence to prove that the transplanted cells can reconstitute the myocardium in vivo. The number of clinical trials using stem cells to treat heart disease is still very limited. Results from these trials suggested that stem cell therapy is safe and provides certain benefits to the patients. Nonetheless, there is still a long way to go for the researchers to identify the ideal cell source and therapy protocol to achieve a greater therapeutic effect.KeywordsCardiomyocyteHeart diseasesHeart failureInfarctionMyocardialStem cellTherapy