Electrophysiology and Cell Biology of Cardiac Stem Cells

最近发现心脏是干细胞的来源，开辟了新的前景 自体细胞性心肌成形术。这样的心脏干细胞(CSCs)已经从啮齿动物的心脏中分离出来 从人类手术标本中提取。我们在隔离和扩大这些病毒方面取得了实质性进展 取自经皮心内膜心肌活检的细胞。当在悬浮培养中生长时，CSCs形成 自组织球状簇，显示出分化心肌细胞的几个特征。我们现在 建议继续在体外和体内对CSCs和心球进行功能鉴定。 了解CSCs和心球的电生理学可能有助于深入了解心脏事件 发展和修复，对评估细胞移植的安全性和有效性至关重要。这 应用旨在阐明不同阶段的分子和电生理表型。 差异化。之前使用间充质干细胞和骨髓细胞的研究表明 在不显著植入或分化注射细胞的情况下改善心功能 功能心肌细胞。自体心脏干细胞具有最高的植入潜力和 分化为功能性肌细胞。我们建议比较注射后的植入和分化。 心肌梗死动物模型中CSCs或心球的变化。心圈可能会凭借它们的 三维架构，改善细胞植入、增殖、存活和分化。临床试验 在成肌细胞中，(一种目前正在临床试验的自体细胞类型)报告了高发病率的脑室 心律失常可能继发于成肌细胞缺乏电整合。我们的初步数据显示 心肌干细胞表达Cx43，并能与心肌细胞电偶联。 文化。在此，我们计划在体外和体外评估细胞的电耦合和致心律失常的潜能。 活体，使用光学标测、微电极记录和双光子显微镜。另一个重要特征 干细胞的特点是它们能够分泌对心脏功能有有益影响的因子。身份识别 干细胞分泌的因子可能允许在损伤后立即直接输送生长因子，从而避免 细胞扩增的需要。我们将使用蛋白质组学技术来鉴定分泌因子。 在临床翻译方面，这项工作为心力衰竭的治疗带来了革命性的可能性。

Recent discoveries identifying the heart as a source of stem cells have opened up new prospects for autologous cellular cardiomyoplasty. Such cardiac stem cells (CSCs) have been isolated from rodent hearts and from human surgical specimens. We have made substantial progress in isolating and expanding these cells from percutaneously obtained endomyocardial biopsies. When grown in suspension culture, CSCs form self-organizing spherical clusters that display several features of differentiating cardiomyocytes. We now propose to continue functional characterization of CSCs and cardiospheres in vitro and in vivo. Understanding the electrophysiology of CSCs and cardiospheres may provide insights into events in cardiac development and repair and is vital to assessing the safety and efficacy of cell transplantation. This application seeks to elucidate the molecular and electrophysiologic phenotype at different stages of differentiation. Previous work using mesenchymal stem cells and bone marrow cells has demonstrated improvement of cardiac function without significant engraftment or differentiation of the injected cells into functional cardiac myocytes. Autologous cardiac stem cells have the highest potential for engraftment and differentiation into functional myoctes. We propose to compare engraftment and differentiation after injection of CSCs or cardiospheres in an animal model of myocardial infarction. Cardiospheres may, by virtue of their 3-dimensional architecture, improve cell engraftment, multiplication, survival and differentiation. Clinical trials of myoblasts, (an autologous cell type currently in clinical trials) have reported a high incidence of ventricular arrhythmias probably secondary to lack of electrical integration of myoblasts. Our preliminary data reveals that cardiac stem cells express Cx43 and are capable of electrical coupling with ventricular myocytes in co- culture. Here, we plan to evaluate electrical coupling and arrhythmogenic potential of cells in vitro and in vivo, using optical mapping, microelectrode recordings and 2-photon microscopy. Another important feature of stem cells is their ability to secrete factors that have a beneficial effect on cardiac function. Identification of secreted factors by stem cells may permit direct delivery of growth factors immediately after injury obviating the need for cell expansion. We will use proteomic techniques to identify secreted factors.Given the potential of clinical translation, this work opens up the possibility of revolutionizing the treatment of heart failure.