【Animal modeling】-Repair effect of embryonic stem cells on ischemia-damaged myocardium in pregnant mice

  Objective: To discuss whether fetal mouse embryonic stem cells can enter the pregnant mother through the blood circulatory system and stop the repair of the ischemic myocardial tissue of the pregnant mouse.

  Methods: Twenty-four 6-8 week old C57 female mice were randomly divided into sham operation group (n=8), operation+pregnancy group (n=8) and operation group+non-pregnancy group (n=8). The myocardial infarction model was established by the method of the left anterior descending coronary artery, and the mice in the pregnant group after the operation were crossed with e-GFP transgenic male mice. The three groups of mice were detected by electrocardiogram and echocardiography before operation, after operation, and after pregnancy and childbirth to compare the changes in their cardiac function; after immunohistochemical staining, the changes in the myocardial structure of the mice in each group were observed, and the myocardial function of the pregnant mice was detected. Whether to express fluorescent protein or not to determine whether there are embryo-derived Gfp-positive cells. At the same time, the existence of Gfp gene in the blood DNA of pregnant mice was detected by ordinary semi-quantitative PCR amplification technology.

  Results: The postoperative ECG results of the mice in the operation + conception group and the operation + non-pregnancy group showed that the ST segment was significantly elevated, indicating obvious myocardial ischemia. Symptoms lessened than before pregnancy. Ultrasound results also proved that the mice showed obvious myocardial infarction after the operation. Although the postpartum cardiac cavity structure of the mice in the operation + conception group did not change significantly compared with those before pregnancy, the cardiac function indicators were lower than those in the sham operation group, but were different from those in the operation + non-operation group. Compared with the pregnant group, the cardiac function index was significantly increased (P<0.05). In addition, after immunohistochemical staining and PCR detection, it was found that the myocardial infarction area of the surgery + conception group had GFP positive expression, while the other two groups were GFP negative.

  Conclusion: Fetal mouse embryonic stem cells can pass through the placental barrier, migrate into the maternal and pregnant mice along with the blood, and stop repairing the ischemia-damaged myocardium.