Effect of umbilical cord blood mesenchymal stem cell transplantation on remaining myocardial tissues of dogs with acute myocardial infarction

Nan MA; Hong ZHONG; Dehai CHEN; Yu JIN; Genfa SHAN

ABSTRACT

BACKGROUND:

Cell apoptosis and ventricle reconstitution following myocardial infarction are of mutual cause-effect, and they cause vicious cycle. How to reduce the apoptosis events following myocardial infarction is one of keys to saving heart function.

OBJECTIVE:

To observe the effect of umbilical cord blood mesenchymal stem cell (UCBSMC) transplantation on remaining myocardial tissue of dogs with acute myocardial infarction.

DESIGN:

A randomized controlled observation.

SETTING:

Department of Cardiothoracic Surgery, Xinhua Hospital.MATERIALS This study was carried out in the Central Laboratory of Xinhua Hospital from October 2005 to May 2007.Thirty-six adult hybrid dogs, male and female in half, were provided by the Animal Experimental Center of Xinhua Hospital.

METHODS:

Thirty-six dogs were divided into cell transplantation group and control group, with 18 dogs in each according to table of random digit. Mesenchymal stem cells were isolated from the umbilical cord blood of full-term pregnant hybrid dogs, cultured and amplified. Then, they were labeled with Laz gene, in vitro induced with 5-azacytidine, and transplanted into the dogs with acute myocardial infarction in the cell transplantation group. Rats in the control group were injected with the same amount of normal saline. Each dog was euthanized by anesthesia for harvesting myocardial specimen 1,4 and 8 weeks after transplantation.MAIN OUTCOME

MEASURES:

① Remaining and apoptosis index detected by TUNEL method. ② Myocardial cell volume and histomorphology detected by confocal microscopy. ③ Histological change of myocardial collagen network detected by haematoxylin-basic fuchsin-picric acid staining.

RESULTS:

Thirty-six involved experimental dogs all entered the stage of final analysis. ①The apoptosis index in the cell transplantation group was significantly lower than that in the control group 1, 4 and 8 weeks after cell transplantation (P ＜0.05). ② Myocardial cell volume in the cell transplantation group 1, 4 and 8 weeks after cell transplantation was significantly larger than that in the control group (P ＜ 0.05). ③ Collagen fiber in the myocardial tissue of dogs in the cell transplantation group was arranged in order and regularly, and in contrast that in the control group was not, and fibers in the control group fused partially.

CONCLUSION:

UCBSMC transplantation reduces the apoptosis of myocardial cells, promotes the hypertrophy of remaining myocardial cells, regulates myocardial collagen network and improves heart function.