Examining firm adhesion and transmigration of surface engineered MSCs

干细胞疗法为解决世界范围内一些最悲惨的疾病和组织缺陷提供了巨大的希望。间充质干细胞（MSC），也称为结缔组织祖细胞，由于其方便的分离、缺乏显著的免疫原性、易于转染以进行离体修饰、缺乏伦理争议以及其分化成心肌细胞的潜力，其对于治疗包括心脏病在内的许多疾病具有直接的临床效用。然而，有效实施细胞疗法的一个重要障碍是无法将这些细胞高效靶向目标组织。本研究将建立在PI和Co-PI（在过去2年中一直合作）产生的已发表和未发表结果的基础上。本文详述的具体目的旨在解决经工程化以滚动并牢固粘附于血管内皮的间充质干细胞将经历迁移的假设。该项目将包括三个具体目标。我们将评估用滚动配体工程化的MSC牢固粘附到用细胞粘附分子包被的2D表面的能力，并且我们将评估细胞表面修饰对相关归巢受体表达的影响（Aim 1）。我们还将检查修饰的MSC牢固粘附并穿过活化的内皮细胞单层（AIM 2）的能力。除了在静态条件下检查牢固粘附和迁移，以及更好地模拟体内环境外，我们还将分析修饰的MSC在剪切应力条件下牢固粘附和迁移的能力（目的3）。在体内测试化学工程MSC的运输潜力之前，在体外验证我们的假设是很重要的，我们希望在未来的RO 1提案中探索。这一体外工作也将有助于我们进一步建立一个合适的体外模型，用于询问细胞运输行为。 公共卫生相关性：在本项目中，我们将在培养扩增的间充质干细胞表面加入促进细胞滚动的粘附配体，以增强内皮单层上的牢固粘附和跨内皮迁移。 我们还将开发一种体外模型，以检查与在剪切应力条件下预处理的内皮细胞单层的相互作用。

DESCRIPTION (provided by applicant): Stem cell therapies offer enormous hope for solving some of the most tragic illnesses, diseases, and tissue defects world-wide. Mesenchymal stem cells (MSCs), also referred to as connective tissue progenitor cells have immediate clinical utility for treatment of numerous ailments including heart disease due to their convenient isolation, lack of significant immunogenicity, ease of transfection for ex-vivo modification, lack of ethical controversy, and their potential to differentiate into cardiac myocytes. However, a significant barrier to the effective implementation of cell therapies is the inability to target these cells with high efficiency to tissues of interest. This research will build on published and unpublished results generated by the PI and Co-PI (who have been working together during the past 2 years). The specific aims detailed herein are designed to address the hypothesis that mesenchymal stem cells that are engineered to roll and firmly adhere to vascular endothelim will undergo transmigration. The project will consist of three specific aims. We will assess the ability of MSCs engineered with rolling ligands to firmly adhere to 2D surfaces coated with cell adhesion molecules and we will assess the impact of the cell surface modification on the expression of relevant homing receptors (Aim 1). We will also examine the ability of the modified MSCs to firmly adhere and transmigrate through monolayers of activated endothelial cells (AIM 2). In addition to examining firm adhesion and transmigration under static conditions, and to better mimic the in vivo environment, we will analyze the ability of modified MSCs to firmly adhere and transmigrate under shear stress conditions (Aim 3). It is important to validate our hypothesis in vitro prior to testing the trafficking potential of chemically engineered MSCs in vivo which we hope to explore in a future RO1 proposal. This in vitro work would also help us further establish a suitable in vitro model for interrogating cell trafficking behavior. PUBLIC HEALTH RELEVANCE: In this project we will incorporate adhesion ligands that promote cell rolling, onto the surface of culture expanded mesenchymal stem cells to enhance firm adhesion and transendothelial migration on endothelial monolayers. We will also develop an in vitro model to examine interactions with endothelial cell monolayers that are pre-conditioned under shear stress conditions.