الفهرس 
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Abstract
Mesenchymal stem cells (MSCs), known as multipotent mesenchymal stromal cells, are self-renewing cells which can be found in almost all postnatal organs and tissues.
Cardiomyopathies resulted in permanent loss of cardiomyocytes as it had no ability of regeneration. This made MSCs a promising tool for cellular therapy because of their ability of self renewal and multipotency.
MSCs were considered ideal candidate for cellular cardiomyoplasty as they were less committed cells which can undergo full cardiogenic differentiation.
MSCs are the spindle shaped plastic-adherent cells isolated from umbilical cord, bone marrow, and other tissue sources, with multipotent differentiation capacity in vitro. These cells can differentiate into a variety of cell types, Including: osteoblasts (bone cells) , chondrocytes (cartilage cells) , Myocytes (muscle cells) ,And adipocytes (fat cells).
Umbilical cord Mesenchymal stem cells have been proposed as potential sources of stem cells for regeneration of the CVS , With the advantage of autologous transplantation which avoids the immune rejection and ethical concerns, MSCs have great application prospect in personalized treatment of cardiovascular diseases.
MSCs obtained from the Wharton’s Jelly (WJ) of umbilical cords (UC) have gained much attention since they can be easily isolated, without any ethical concerns, from a tissue which is discarded after birth.
This study aimed to investigate the in vitro differentiation of mesenchymal stem cells into cardiomyocytes using 5-Aza as future of cardiovascular diseases therapy.
This study was conducted at Clinical Pathology department in collaboration with Obstetrics & Gynecology Departments at Faculty of Medicine, Menuofia University during the period from October 2015 To April 2017.
Ten umbilical cord samples were used for isolation of MSCs. MSCs were isolated from 100% (10/10) samples.
The Umbilical cords were collected under complete aseptic condition from full-term cesarean section patients.
The umbilical cord blood (UCB) was collected while the placenta was still in utero. The umbilical vein was cleansed with alcohol followed by betadine, using strict aseptic techniques.
Umbilical cord tissue cultured by explant method in which the cord was divided into small segments then opened longitudinally, vessels were dissected and removed then the cord tissues were washed with saline. WJ was cut into small pieces of about 1.5-2.5mm then cultured in plastic tissue culture flask 25cm2, incubated for 7 days in 5 ml of fresh complete nutrient medium. At day 7, the tissue removed by changing the medium. Adherent cells were kept in culture and were fed with fresh complete nutrient medium about 1 week later. These cells were kept until the outgrowth of fibroblast-like cells.
MSCs at the base of the flasks were harvested by trypsinization and identified by morphology and flowcytometric analysis of CD44, CD34.
flowcytometric analysis revealed that the isolated MSCs showed positive expression of CD 44(79.72±5.85) , and negative expression of CD34 (1.08±0.43).
During cells proliferation, MSCs were cultured up to passage 5. The non induced (MSCs) displayed highest cumulative cell population followed by Induced (Cardiomyocytes).
MSCs Cells were treated with 10 μM 5-Azacytidine. Media was changed every 3 days. The cells were allowed to differentiate over a period of 12 days. They were observed every day for any morphological changes by inverted and phase contrast microscope.
Induced MSCs (cardiomyocytes) became thinner and aligned parallel to each other. They showed broadening of cytoplasm and multi nucleation extending their cytoplasmic processes with adjacent. On the 12th day they showed ball stike like morphology cells. They showed high positive expression of troponin with a range of(66.70 – 83.40) and mean ± standard deviation of 74.12 ± 6.20 .