Building Vascularized Skeletal Muscle for Tissue Engineering/Regeneration

描述(申请人提供)：我们的目标是开发一种用于创建血管组织和器官的平台技术。这一提议的一个关键概念框架是，血管不仅将输送氧气和营养物质，还将向祖细胞提供诱导信号，从而刺激生物工程组织的适当发展。这种对血管的诱导作用已经在包括胰腺和肝脏在内的各种生物环境中显示出来。在这项提案中，我们将重点构建血管化的骨骼肌组织作为原型。我们将使用三种细胞构建块：内皮细胞集落形成细胞(ECFCs)、间充质祖细胞(MPC)和肌肉卫星细胞(SCs)。比肖夫博士的实验室已经证明了人类内皮祖细胞和基质干细胞在体内自组装成灌流血管网络的强大能力--即生物工程血管。Arany博士在干细胞和骨骼肌分化方面拥有专业知识，并在骨骼肌中发现了一种由转录辅助激活因子PGC-1介导的新的、强大的血管生成途径。干细胞是形成多核肌管的前体细胞，在细胞培养中开始表达骨骼肌特异性基因；然而，在这些条件下，成人肌肉的完全分化和组织无法实现。我们的假设得到了初步数据的支持，即由人内皮祖细胞和间充质干细胞构建的新生血管网络与共同植入的干细胞之间的相互作用将导致骨骼肌在细胞和分子水平上快速和更完整的分化。如果正确，这将为构建血管化骨骼肌植入物修复受损或丢失的肌肉提供一种手段。我们将通过组织成三个具体目标的实验来探索这一假设，这些实验将在两年内联合进行。这些目标的成功将为评估这些结构被整合到功能性肌肉组织中的能力提供一个起点。此外，该结果还将为组织工程和组织再生中血管驱动的实质细胞分化提供一个新颖的创新平台。

DESCRIPTION (provided by applicant): Our goal is to develop a platform technology for creating vascularized tissues and organs. A key conceptual framework of this proposal is that blood vessels will not only deliver oxygen and nutrients, but will also provide inductive signals t progenitor cells and thereby stimulate appropriate development of bio-engineered tissues. Such an inductive role for blood vessels has been shown in various biological contexts including pancreas and liver. In this proposal we will focus on building vascularized skeletal muscle tissue as a prototype. We will use three cellular building blocks: endothelial colony forming cells (ECFCs), mesenchymal progenitor cells (MPCs), and muscle satellite cells (SCs). Dr. Bischoff's laboratory has demonstrated the robust capacity of human EPCs and MPCs to self-assemble into perfused vascular networks in vivo - i.e. bio-engineered vessels. Dr. Arany has expertise with SCs and skeletal muscle differentiation, and has identified a novel and powerful angiogenic pathway in skeletal muscle mediated by the transcriptional coactivator PGC-1. SCs are progenitor cells that form multinucleated myotubes and begin to express skeletal muscle-specific genes in cell culture; however, full adult muscle differentiation and organization is not achieved in these conditions. Our hypothesis, supported by preliminary data, is that the interplay between the nascent vascular network built from human endothelial and mesenchymal progenitor cells and the co- implanted SCs cells will result in rapid and more complete skeletal muscle differentiation at the cellular and molecular level. If correct, this would provide a means to construct vascularized skeletal muscle implants for repair of damaged or lost muscle. We will pursue this hypothesis through experiments organized into three specific aims to be conducted over two years, jointly between the two laboratories. Success in these aims will provide a launch point for assessing the ability of these constructs to be incorporated into functional muscle tissue. In addition, the results will provide a novel and innovative platform for vascular-driven parenchymal cell differentiation in tissue engineering and tissue regeneration.