Abstract:

BACKGROUND： Despite the advanced therapeutic strategies of medical intervention and surgical procedures after myocardial infarction, which may improve coronary blood flow and salvage ischemic myocardium, is still not able to salvage necrosis or non-functional myocardium. Stem cells, as the material foundation of heart structures and function, have been proved to be one of safe and effective therapies for the improvement of cardiac function, although it is still extremely controversial. OBJECTIVE; To summarize the clinical research progress on adult stem cells in treatment of ischemic heart disease, evaluate the safety and efficacy of adult stem cell therapy, speculate the mechanisms of adult stem calls on improving heart function, and introduce the future clinical study of adult stem calls. RETRIEVE STRATEGY： English articles of adult stem cells and ischemic heart disease were searched in Pubmed databases published from 1996 to 2007, with the key words ＂adult stem cells, cardiomyocytes, ischemic heart disease＂. Meanwhile, a computer-based search was conducted in China Journal Full-text Database with the key words of ＂adult stem cell, cardiomyocytes, ischemic heart disease＂ between 1996 and 2007. Total 1 303 articles were selected firstly. Inclusive criteria： ①The literatures were closely related to adult stem cell and ischemic heart disease.②The literatures of the same field were selected by the recent publication or the authority magazine publication. Exclusive criteria： repetitive researches.③Meta analysis. LITERATURE EVALUATION： The selected articles were mainly the reviews of the current status and mechanism of stem cell transplantation for ischemic heart disease. There were 626 out of the selected 1 303 articles referring to the animal experiments and in vivo, in vitro, cytological trials, 345 ones were the reviews, statements and reports, remaining 45 were clinical researches. Finally 46 articles were selected for the references. DATA SYNTHESIS： ①Stem cell defining characteristics is the capacity to differentiate into a spectrum of different cell types and renew themselves, which is divided into embryonic stem cells and adult stem cells. Although embryonic stem cells have been shown to have greater potency for proliferation and differentiation than adult stem cells, their lack of availability and ethical issues hamper clinical applications. ②At present, a number of early clinical studies have been published, despite most of the them are small pilot studies that even lack randomization or control groups, the fact that several cell types （including bone marrow mononuclear cells, endothelial progenitor calls, CD133＋ cells, mesenchymal stem cells, skeletal myoblasts）, have been studied using different delivery methods, the overwhelming message from all of these studies is that cell therapy is safe and feasible for ischemic heart disease. In addition, the results of these studies provide the clinical data for the ongoing studies.③Adult stem cells may improve cardiac function by various potential mechanisms, including direct or indirect effects. Differentiation into cardiomyocytes may contribute to cardiac regeneration. Paracnne factors released by progenitor cells may inhibit cardiac apoptosis, affect remodeling, or enhance neovascualrization. New data show that exogenous stem cells may stimulate proliferation of endogenous cardiac precursors. CONCLUSION： At present, despite the action mechanisms of adult stem cells on the functional improvement of heart after myocardial infarction remain unclear, there is a wealth of early clinical data showing safety, feasibility and early efficacy of adult stem cell therapy for ischemic heart disease. Adult stem cell therapies should proceed into randomized, placebo-controlled and double-blind multicenter clinical trials.[著者文摘]