Stem Cells and Dynamic Materials Improve Cardiac Function Post-mycardial Infarcti

干细胞和动态材料改善心肌梗塞后的心脏功能

• 批准号: 8191706
• 负责人: Adam J Engler
• 金额: $ 23.18万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8191706
• 关键词: A Mouse; Address; Age; Animal Model; Antibodies; Atomic Force Microscopy; B-Lymphocytes; Benchmarking; Biological Assay; Cardiac; Cardiac Myocytes; Cardiac Output; Cardiomyoplasty; Cause of Death; Cell Aging; Cell Culture Techniques; Cell Differentiation process; Cell Line; Cells; Cicatrix; Collagen; Competitive Binding; Congestive Heart Failure; Control Animal; Coronary artery; Cues; Detergents; Differentiation Antigens; EFRAC; Engineering; Engraftment; Ensure; Environment; Ethylmaleimide; Extracellular Matrix; Failure; Fertilization; Foreign-Body Reaction; Gel; Genes; Growth Factor; Heart; Histology; Hour; Hyaluronic Acid; Hyaluronidase; Hydrogels; Immunofluorescence Immunologic; In Vitro; Infarction; Injectable; Injection of therapeutic agent; Injury; Label; Left; Measurement; Measures; Mesenchymal Stem Cells; Metabolic; Methods; Modeling; Monitor; Muscle; Myocardial; Myocardial Infarction; Myocardium; Natural regeneration; Necrosis; Osteoblasts; Outcome; Physiologic intraventricular pressure; Polymerase Chain Reaction; Property; Rattus; Relative (related person); Sarcomeres; Shapes; Site; Sprague-Dawley Rats; Stem cells; Structure; Sulfhydryl Compounds; Supplementation; Surface; Techniques; Testing; Therapeutic; Time; Tissue Engineering; Tissues; United States; adult stem cell; angiogenesis; base; biomaterial compatibility; bone; cell age; cell behavior; cell type; crosslink; cytotoxicity; design; embryonic stem cell; functional restoration; heart function; improved; in vivo; novel; novel strategies; polyacrylamide gels; prevent; progenitor; regenerative therapy; response; scaffold; subcutaneous

DESCRIPTION (provided by applicant): The fibrotic scar that results after a myocardial infarction (MI) is stiff extracellular matrix (ECM), owing to the enhanced secretion of collagen as the tissue thins and undergoes necrosis. Pervious methods to improve myocardial function post-MI, e.g. cardiac patches and cell injections, do not sufficiently mimic the intrinsic properties of the matrix, such as stiffness (denoted E). Moreover, they often employ adult stem cells which have not been shown to have significant remodeling capacity and instead are more responsive to aberrant matrix conditions; thus cells have been observed to improperly differentiate into osteoblast-like cells or to fail to differentiate altogether in infarcted myocardium that is 3-fold too stiff, i.e. EInfarct >> ECARDIO. We have recently developed a dynamic, thiol-modified hyaluronic acid (HA-S)-based hydrogel that displays developmentally appropriate stiffness over time via time-dependent crosslinking. We have also shown that this can improve cardiac progenitor differentiation in mature cardiomyocytes by nearly an order of magnitude over soft matrix that does not remodel. In this proposal, we will first extend our findings to embryonic stem cells (ESCs), which should be even more effective at matrix remodeling than previous stem cell types. Expression of cardiac-specific genes in 2D and 3D HA-S hydrogels will first be monitored in ESCs to determine if HA-S can induce cardiomyogenesis relative to cardiac progenitor cells and age-matched control animals, and if not, at least ensure that it enhances differentiation over HA-S hydrogels that have had their time-dependent crosslinking removed by treatment with iodacetamide. Matrix secretion, assembly, and remodeling (via degradation by hyaluronidase) will also be measured and compared to cardiac progenitor cells to ensure that ESCs can indeed remodel matrix effectively and that cells can migrate sufficiently in the material. Cells and HA-S hydrogels will subsequently be used in a subcutaneous rat model to ensure biocompatibility and monitor hydrogel properties in vivo, e.g. time-dependent stiffening. Finally in a rat model of MI, ESCs and/or cardiac progenitor will be used in conjunction with the HA-S to determine to what degree our HA-S hydrogel can improve myocardial function post-MI versus convention treatments, e.g. cell injection. PUBLIC HEALTH RELEVANCE: As a leading cause of death in the United States, congestive heart failure (CHF) post-myocardial infarction (MI) has incited the need to develop novel techniques that prevents the formation of a stiff, scarred muscle wall which impairs heart function. Over the past two decades, novel strategies using stem cell patches or injections have not been able to sufficiently remodel the tissue and restore its function, which may be in part due to their inability to address specific design criteria of the diseased niche, e.g. stiffness (denoted E); often the addition of adult stem cells into this niche results in stem cells responding to the environment rather than remodeling it, and as such, aberrant stem cell behavior occurs given that the niche is 3- to 4-fold too stiff, EInfarct, relative to healthy muscle, ECARDIO. Materials have also been proposed in conjunction with cells to treat MI, but they often do not adequately mimic native myocardial design requirements or use cells with sufficient capacity to remodel the niche. In response, we have engineering a hyaluronic acid (HA)-based material that has time-dependent crosslinking to specifically mimic how the myocardium stiffens from soft embryonic stem cells (ESCs), EESC, to the stiffer heart wall, ECARDIO; time-dependent stiffening induces cardiac progenitors to express 3-fold more mature cardiac markers versus static cultures. It also causes 85% of progenitors to form mature, contractile sarcomeres versus only 15% for static cultures. When combined with ESCs that are uniquely tuned to remodel and shape their niche as they develop, this HA- and ESC-based approach may be able to sufficiently protect ESCs as they develop, migrate into the scarred host myocardium, and subsequently remodel it to attempt to restore some level of contractile function. In this proposal, we will first study to what extent the engineered HA material enhances cardiac differentiation and matrix secretion, assembly, and remodeling in ESCs. After understanding this interaction and better, the combination will be introduced subcutaneously in a rat model to determine biocompatibility and then in used in a rat infarct model to assess its ability to improve cardiac outcome.

描述（由申请人提供）：心肌梗塞（MI）后产生的纤维化疤痕是僵硬的细胞外基质（ECM），这是由于组织变薄和坏死时胶原蛋白分泌增加所致。改善 MI 后心肌功能的现有方法，例如心脏贴片和细胞注射不能充分模拟基质的固有特性，例如硬度（表示为 E）。此外，他们经常使用尚未被证明具有显着重塑能力的成体干细胞，而是对异常基质条件更敏感；因此，在僵硬3倍的梗塞心肌中，即EInfarct >> ECARDIO，观察到细胞无法正确分化为成骨细胞样细胞或无法完全分化。我们最近开发了一种基于动态硫醇改性透明质酸 (HA-S) 的水凝胶，它通过时间依赖性交联随着时间的推移显示出适合发育的刚度。我们还表明，与不重塑的软基质相比，这可以将成熟心肌细胞中的心脏祖细胞分化提高近一个数量级。 在这项提案中，我们将首先将我们的发现扩展到胚胎干细胞（ESC），它在基质重塑方面应该比以前的干细胞类型更有效。首先在 ESC 中监测 2D 和 3D HA-S 水凝胶中心脏特异性基因的表达，以确定 HA-S 是否可以诱导相对于心脏祖细胞和年龄匹配的对照动物的心肌生成，如果不能，至少确保它相对于通过碘乙酰胺处理消除了时间依赖性交联的 HA-S 水凝胶增强分化。还将测量基质分泌、组装和重塑（通过透明质酸酶降解）并与心脏祖细胞进行比较，以确保 ESC 确实可以有效地重塑基质，并且细胞可以在材料中充分迁移。细胞和 HA-S 水凝胶随后将用于皮下大鼠模型，以确保生物相容性并监测体内水凝胶特性，例如随时间变化的硬化。最后，在 MI 大鼠模型中，ESC 和/或心脏祖细胞将与 HA-S 结合使用，以确定与常规治疗相比，我们的 HA-S 水凝胶可以在多大程度上改善 MI 后的心肌功能。细胞注射。 公众健康相关性：充血性心力衰竭 (CHF) 后心肌梗死 (MI) 是美国的一个主要原因，因此需要开发新的技术来防止形成僵硬、伤痕累累的肌壁，从而损害心脏功能。在过去的二十年中，使用干细胞贴片或注射的新策略未能充分重塑组织并恢复其功能，部分原因可能是它们无法满足患病生态位的特定设计标准，例如，刚度（表示为 E）；通常，将成体干细胞添加到该生态位中会导致干细胞对环境做出反应，而不是对其进行重塑，因此，由于该生态位相对于健康肌肉 ECARDIO 过于僵硬 3 至 4 倍，因此会发生异常干细胞行为，即 EInfarct。还提出了与细胞结合的材料来治疗心肌梗死，但它们通常不能充分模仿天然心肌设计要求或使用具有足够能力重塑生态位的细胞。为此，我们设计了一种基于透明质酸 (HA) 的材料，该材料具有时间依赖性交联，专门模拟心肌从软胚胎干细胞 (ESC) EESC 到较硬心壁 ECARDIO 的硬化过程；时间依赖性硬化诱导心脏祖细胞表达比静态培养物高 3 倍的成熟心脏标志物。它还导致 85% 的祖细胞形成成熟的、可收缩的肌节，而静态培养中只有 15% 的祖细胞形成。当与在发育时经过独特调整以重塑和塑造其生态位的ESC相结合时，这种基于HA和ESC的方法可能能够在ESC发育时充分保护它们，迁移到伤痕累累的宿主心肌中，并随后对其进行重塑以尝试恢复某种程度的收缩功能。在本提案中，我们将首先研究工程化 HA 材料在多大程度上增强 ESC 中的心脏分化和基质分泌、组装和重塑。在更好地了解这种相互作用后，该组合将被皮下引入大鼠模型以确定生物相容性，然后用于大鼠梗塞模型以评估其改善心脏结果的能力。