Phospholipids for enhancing cell-based neovascularization

描述（由申请人提供）：由于晚期血管疾病而发生的氧气减少造成严重的临床问题，包括大量细胞死亡和由此产生的组织损失。与治疗性血管生成的药理学方法相比，基于细胞的策略代表了产生毛细血管网络的直接方法。内皮集落形成细胞（ECFC）是内皮祖细胞的亚群，其在缺氧条件下表现出强大的血管生成潜力，并且可以在体内形成功能性血管网络。脂肪源性干细胞（adipose-derivedstemcells，ASCs）是一种具有促进血管生成和潜在稳定新血管作用的细胞群体.然而，基于细胞的疗法的成功受到在将细胞植入缺血组织环境中时由于细胞凋亡导致的快速细胞死亡的限制，从而显著减少了可用于参与血管发生的细胞的数量。此外，最近的数据表明，来自老年供体的细胞比来自年轻供体的细胞更容易发生凋亡，这可能会影响基于自体细胞的方法在不断增长的老龄化人群中进行组织修复的有效性。 溶血磷脂酸（LPA）是一种血小板衍生的脂质生长因子，存在于血清中，是体内血管生成所必需的。此外，LPA促进祖细胞在体外促凋亡微环境中的存活和活力。我们的中心假设是，局部和持续的介绍LPA将是一个有效的代理，以抑制植入细胞的凋亡，从而使营养因子从细胞的分泌延长，并支持血管形成细胞的生存。该项目的基本原理是，它将为氧微环境的作用以及祖细胞如何参与组织修复提供新的见解，并产生新的方法来增强老年供体细胞的组织修复功效。目标1。确定LPA持续释放对纤维蛋白凝胶内人ECFC和ASC的共培养物的抗凋亡和促血管生成作用。将评估局部LPA释放在缺氧和血清减少条件下抑制细胞凋亡的能力，并定量对这些刺激的血管生成反应。目标2.确定当与LPA洗脱材料共同植入小鼠缺血性后肢模型时，来自老年供体的ASC和ECFC抵抗细胞凋亡和增强血管形成的能力。拟议的研究是创新的，因为它研究了一种新的方法，用于解决植入用于新血管形成的细胞的损失，同时研究多种刺激对血管形成的作用，这对这些方法的临床转化和实现至关重要。我们将阐明LPA递送对延长来自老年供体的ASCs在植入晚期血管疾病的缺血组织部位特征时的活力的贡献。总的来说，这项研究将提供一种新的方法，用于增强植入细胞的功效，用于组织修复，伤口愈合以及组织工程和再生医学中的新兴应用。 公共卫生相关性：开发新的方法来增强植入后的细胞活力和功能，将大大改善患有晚期血管疾病或非愈合组织缺损的人的生活质量。我们试图确定磷脂的局部呈递是否可以抑制植入的血管形成细胞的凋亡，从而导致延长的存活和增强的新血管形成。

DESCRIPTION (provided by applicant): The reduction of oxygen occurring as a result of advanced vascular diseases poses severe clinical problems including massive cell death and resultant tissue loss. Compared to pharmacological methods of therapeutic angiogenesis, cell-based strategies represent a direct approach to generate a capillary network. Endothelial colony forming cells (ECFCs) are a subpopulation of endothelial progenitor cells that exhibit robust angiogenic potential under hypoxic conditions and can form functional vascular networks in vivo. Adipose- derived stem cells (ASCs) are a promising cell population for promoting angiogenesis and potentially stabilizing new vessels. However, the success of cell-based therapies is limited by rapid cell death due to apoptosis upon implanting cells into ischemic tissue environments, dramatically reducing the number of cells available to participate in vasculogenesis. Additionally, recent data suggest that cells derived from older donors are more vulnerable to apoptosis than those from younger donors, potentially compromising the effectiveness of autologous cell-based approaches for tissue repair in the ever-growing aging population. Lysophosphatidic acid (LPA) is a platelet-derived lipid growth factor present within the serum and is required for angiogenesis in vivo. Additionally, LPA promotes the survival and viability of progenitor cells within pro-apoptotic microenvironments in vitro. Our central hypothesis is that localized and sustained presentation of LPA will be an effective agent to inhibit apoptosis in implanted cells, thus enabling prolonged secretion of trophic factors from cells and supporting the survival of vessel-forming cells. The rationale for this project is that it will provide new insights into the role of the oxygen microenvironment and how progenitor cells participate in tissue repair, and yield new approaches for enhancing the efficacy of tissue repair with cells from aged donors. Aim 1. Determine the anti-apoptotic and proangiogenic effect of sustained LPA release on co-cultures of human ECFCs and ASCs within fibrin gels. The ability of localized LPA release to inhibit apoptosis in hypoxic and serum-reduced conditions will be assessed, and the resulting vasculogenic response to these stimuli will be quantified. Aim 2. Determine the capacity of ASCs derived from aged donors and ECFCs to resist apoptosis and enhance vascularization when co-implanted on LPA-eluting materials into a murine ischemic hind limb model. The proposed research is innovative because it examines a novel approach for addressing the loss of cells implanted for neovascularization while investigating the role of multiple stimuli on vessel formation critical for the clinical translation and realization of these approaches. We will elucidate the contributions of LPA delivery on extending the viability of ASCs from older donors when implanted into an ischemic tissue site characteristic of advanced vascular disease. Collectively, this research will provide a novel approach for enhancing the efficacy of implanted cells for cell-based therapies for tissue repair, wound healing, and emerging applications in tissue engineering and regenerative medicine. PUBLIC HEALTH RELEVANCE: The development of new approaches to enhance cell viability and function upon implantation will greatly improve the quality of life for those who suffer from advanced vascular disease or non-healing tissue defects. We seek to determine if the localized presentation of a phospholipid can inhibit apoptosis in implanted vessel- forming cells, thereby resulting in prolonged survival and enhanced neovascularization.