| Objective: Myocardial infarction due to coronary artery interrupt, causing thefeeding areas continuous ischemia resulting from a larger range of myocardial necrosis,chronic myocardial infarction visible myocardial necrosis gradually replaced by scartissue ventricular remodeling, and ultimately leading to heart failure. Clinical treatmentmedication, surgical intervention and coronary artery bypass surgery.however, all ofthem are limiting. Those methods can not instead of necrotic myocardium. Cell-basedtherapy is the promising regeneration treatment for cardiac diseases. But the repair ofmyocardial regeneration by cell transplantation is restricted by the source of cells,immune rejection, ethics and imprecise efficacy. Looking for a new kind of seed cellshas become a trend in the field of myocardial regeneration. Recent studies show thatcardiac stem cell (CSC) exist in adult heart and the source of myocardial renewal. Andin vitro studies have shown that CSC can differentiate like cardiac stem cells and canexpress a-actin, connexin43. CSC is a kind of undifferentiated cell. Those surfacemarkers of stem cell are expressed in CSC’s cytomembrane, such as c-kit，Sca-1and soon. By now, c-kit-positive CSC and Sca-1positive CSC have more proliferation anddifferentiation capacity. CSC have the proficiency of differentiate into myocardial cells.But neither of those cells in the human body have similar biological characteristics isunclear. This study is aimed at detecting c-kit，Sca-1，a-actin and Cx43’s expression andcorrelation in human cardiac tissues by immunohistochemical S-P method and clearingadded value and distribution of stem cells after myocardial infarction. And whethercardiac stem cell can differentiate into myocardial cell in human by the expression ofmyocardial cell’s specific proteins. This can provide ideas for the future of CSCresearch and clinical applications.Methods: A total of75cases, autopsy archived paraffin blocks were taken fromthe Department of Pathology and Forensic medicine, Dalian Medical University.25 cases were selected for normal myocardium group,50cases were myocardial infarctiongroup and all the cases were confirmed by histological examination. The death time waswithin one week after myocardial infarction, and all the cases were autopsied within48hours after death. For each specimen, pieces of tissue had been taken from the leftventricular anterior wall, lateral wall, and posterior wall, interventricular septal andapical, paraffin-embedded serial sections, using the immunohistochemical S-P methodfor the detection of the expression of c-kit, Sca-1, a-actin and cx43in normalmyocardium, myocardium infarction area and the area surrounding the infarction.Inorder to know whether CSC can differentiate in to cardiac cells.Results:1.Sca-1was weakly expressed in normal myocardium, stronglypositive expression in myocardial infarction and the infarction surrounding area,mainly expressed in the cytoplasm or membrane of cells. Positive rates were12%，94%，82%. c-kit expressed in the cytoplasm or membrane of cells.It was weakly expressed innormal myocardium, strong positive expression in myocardial infarction. The positiveexpression in infracted myocardium (72%,58%) wassignificantly higher than that of normal myocardium. The differences of theirexpression in normal myocardium, myocardialinfarction, and infarction surrounding areas were statisticallysignificant (P <0.05).2. Sca-1and c-kit expression roughly the same position, mainlylocated in the infracted area and infarct surrounding area. But the expression of c-kitwas significantly lower than Sca-1.3. Spearman rank correlation test showedthat expression of Sca-1and c-kit in the myocardial infarction group has a significantcorrelation.4.Part Sca-1positive cells can be seen a-actin antibody expression of brownand tan, but negative expression of Cx43. c-kit positive cells can be seen Cx43antibodyexpression of brown and tan, but negative expression of a-actin.Conclusion:1. The expression of Sca-1and c-kit in the infracted areas and infarctsurrounding areas are significantly higher than the normal myocardial tissue. And，Sca-1positive cells number is far greater than c-kit positive cells. Tip Sca-1positivecells are the main cell populations in CSC.2. Sca-1positive cells in myocardial infarction heart visible positive expression ofa-actin, c-kit positive cells in myocardial infarction heart visible positive expression ofCx43, suggesting they differentiate into myocardial cells. |
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