Stem cell oxygenation and ischemic tissue regeneration

干细胞氧合和缺血组织再生

• 批准号: 9768533
• 负责人: Jianjun Guan
• 金额: $ 38.55万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-22 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9768533
• 关键词: Affect; Anatomy; Bone Marrow; Cell Survival; Cells; Data; Differentiation and Growth; Endothelial Cells; Endothelium; Engraftment; Goals; Growth Factor; Hindlimb; Hydrogels; Implant; In Vitro; Inferior; Insulin-Like Growth Factor I; Ischemia; Limb structure; Mesenchymal Stem Cells; Modeling; Monitor; Muscle; Muscle Fibers; Natural regeneration; Oxygen; Peripheral arterial disease; Platelet-Derived Growth Factor; Principal Investigator; Reactive Oxygen Species; Research; Role; Signal Pathway; Skeletal Muscle; Stem cells; System; Testing; Tissues; Treatment Efficacy; Vascularization; angiogenesis; base; blood perfusion; cell type; density; efficacy testing; experience; improved; in vivo; innovation; limb regeneration; mortality; mouse model; muscle regeneration; novel; paracrine; programs; repaired; stem cell therapy; tissue regeneration

Program Director/Principal Investigator (Last, First, Middle): GUAN, JIANJUN Project Summary Critical limb ischemia (CLI) is a severe peripheral artery disease with high rates of limb loss and mortality. It is featured by low blood perfusion, extensive tissue ischemia, and degenerated skeletal muscle. Quick vascularization to restore blood perfusion, and fast muscle regeneration to restore normal function, represent the optimal goals for CLI treatment. Currently there is no efficient treatment available, although stem cell therapy is one of the most promising strategies. Most of stem cell types promote vascularization and muscle regeneration mainly by paracrine effects while some may also differentiate into endothelial and skeletal muscle cells. However, current stem cell therapy experiences low efficacy largely due to inferior cell survival and paracrine effects under the extremely low oxygen condition (<1%) of ischemic limbs. In this project, we propose a new cell delivery system that continuously releases appropriate concentration of O2 to simultaneously improve stem cell survival and paracrine effects, resulting in quick vascularization and muscle regeneration. Paracrine effects concurrently provide multiple growth factors critical for vascularization and muscle regeneration, which cannot be readily achieved by growth factor therapy. In our preliminary studies, we have created a hydrogel-based cell delivery system that releases O2. When tested using bone marrow-derived mesenchymal stem cells (MSCs), the released O2 increased cell survival under ischemic conditions in vitro without increasing reactive oxygen species (ROS) content. It also upregulated MSC paracrine effects especially in terms of secreting proangiogenic/promyogenic growth factors like PDGF and IGF-1. After implanting into ischemic limbs, the O2 releasing cell delivery system not only augmented MSC survival, but also fully restored blood perfusion and muscle contractility in 4 weeks. The contribution of MSCs to vascularization is mainly from paracrine effects as only a low percentage of cells were differentiated into endothelial cells. Meanwhile, both MSC paracrine effects and myogenic differentiation contributed to muscle regeneration. These preliminary data suggest that increasing both MSC survival and paracrine effects can significantly enhance vascularization and muscle regeneration in ischemic limbs. Yet, cell survival and paracrine effects do not always increase concurrently. Based on our preliminary studies and above discussion, we hypothesize that stem cell delivery systems with optimal O2 release profiles that simultaneously increase MSC survival and paracrine effects, will significantly accelerate vascularization and muscle regeneration in ischemic limbs. Aim #1 will test the hypothesis that optimal O2 release profiles will promote MSC survival and paracrine effects under ischemic conditions. Aim #2 will test efficacy of the created cell delivery systems using a model of hindlimb ischemia. This project is innovative because it develops a safe and long-term O2 release system to establish the role, mechanism, and efficacy of controlled O2 release in augmenting both stem cell survival and paracrine effects in ischemic tissues for accelerated regeneration. The proposed stem cell delivery system is also translational. OMB No. 0925-0001/0002 (Rev. 03/16 Approved Through 10/31/2018) Page Continuation Format Page

项目总监/首席研究员（最后，第一，中间）：江恩 项目摘要 关键的肢体缺血（CLI）是一种严重的外周动脉疾病，肢体损失和死亡率高。这是 低血液灌注，广泛的组织缺血和退化的骨骼肌。快速血管化 恢复血液灌注和快速肌肉再生以恢复正常功能，代表 CLI治疗。目前尚无有效的治疗，尽管干细胞疗法是最多的治疗方法之一 有希望的策略。大多数干细胞类型主要促进血管形成和肌肉再生 效果虽然有些也可能分化为内皮和骨骼肌细胞。但是，当前的干细胞 治疗的疗效很低，主要是由于细胞下的生存和旁分泌作用极为低。 缺血性四肢的氧气状况（<1％）。在这个项目中，我们提出了一个不断的新细胞输送系统 释放适当的O2浓度以同时改善干细胞存活和旁分泌作用， 导致快速的血管形成和肌肉再生。旁分泌效应同时提供多重增长 对于血管形成和肌肉再生至关重要的因素，生长因子无法轻易实现 治疗。 在我们的初步研究中，我们创建了一个基于水凝胶的细胞输送系统，该系统释放了O2。测试时 使用骨髓来源的间充质干细胞（MSC），释放的O2在 体外缺血状况，而无需增加活性氧（ROS）含量。它也上调了MSC 旁分泌作用尤其是在分泌促血管生成/临时生长因子（如PDGF和IGF-1）方面。 植入缺血性四肢后，O2释放细胞输送系统不仅增加了MSC的生存，而且还会增加 还可以在4周内完全恢复血液灌注和肌肉收缩力。 MSC对血管形成的贡献 主要来自旁分泌作用，因为只有低比例的细胞分化为内皮细胞。 同时，MSC旁分泌效应和肌原性分化都导致肌肉再生。这些 初步数据表明，增加MSC生存和旁分泌效应都可以显着增强 缺血性四肢的血管形成和肌肉再生。但是，细胞存活和旁分泌作用并不总是 同时增加。 基于我们的初步研究及以上讨论，我们假设使用 最佳的O2释放曲线，同时增加MSC存活和旁分泌效应，将显着 在缺血性肢体中加速血管生成和肌肉再生。 AIM＃1将检验以下假设：最佳O2释放曲线将促进MSC生存和旁分泌效应 在缺血状态下。 AIM＃2将使用后肢缺血模型测试创建的细胞输送系统的功效。 该项目具有创新性，因为它开发了一个安全且长期的O2释放系统，以确立该角色， 机理以及受控O2释放在增强干细胞存活和旁分泌作用方面的功效 缺血组织加速再生。提出的干细胞输送系统也是转化的。 OMB编号0925-0001/0002（Rev. 03/16批准通过10/31/2018）页面延续格式页面