In vitro Study of Adult Bone Marrow Mesenchymal Stem Cells Derived from Albino Rats and their Cardiomyogenic Differentiation

Mesenchymal stem cells (MSCs) are pluripotent adult stem cells residing within the bone marrow (BM) capable of self renewal, production of large number of differentiated progeny and regeneration of tissues. This study aimed at isolating the adult rats BM-MSCs and stimulating their in vitro differentiation into cardiomocytes. The BM, isolated from young male white rats (Rattus norvegicus albinos) and maintained in culture at 37C° and 5%CO2. The culture system which permits to direct differentiation of the MSCs into cardiomyocyte-like characteristics was treated with rat embryonic heart muscle extract (HME), and differentiated cells were detected with immunocytochemistry examination using anti - myosin and anti - cardiotin antibodies as markers. The MSCs had fibroblast like morphology before HME treatment, but their morphology began to change after treatment. Treated MSCs increased in size and had formed a ball and a stick like morphology and were connecting with adjoining cells after one week and began to form myotube like structures at the end of second week. After three weeks of treatment, the differentiated cells could be distinguished by the presence of a number of branches and began to interface with each other to form cardiac like cells. The differentiated cells were positive for myosin and cardiotin. The morphological changes were not seen in control cells. We can conclude that HME may contain certain growth factors that stimulate the differentiation of BM-MSCs to the muscular pathway