Preservation and Vascularization of Cardiac Extracellular Matrix after Myocardial Infarction

心肌梗死后心脏细胞外基质的保存和血管化

• 批准号: 10335142
• 负责人: Jianjun Guan
• 金额: $ 45.65万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10335142
• 关键词: 3-Dimensional; Affect; Antibodies; Area; Attenuated; Blood Vessels; Blood capillaries; Cardiac; Cicatrix; Clinical Trials; Collagen; Deposition; Dose-Limiting; Drug Delivery Systems; Endothelial Cells; Extracellular Matrix; Extracellular Matrix Degradation; FGF2 gene; Fibroblasts; Gelatinase A; Gelatinase B; Goals; Growth Factor; Heart; Hydrogels; Inflammation; Injections; Matrix Metalloproteinase Inhibitor; Matrix Metalloproteinases; Mediating; Modeling; Monitor; Morphogenesis; Myocardial Infarction; Myofibroblast; Outcome; Pathway interactions; Peptides; Pharmaceutical Preparations; Principal Investigator; Rattus; Research; Role; Signal Pathway; Structure; System; Testing; Therapeutic; Thick; Time; Tissues; Toxic effect; Transforming Growth Factor beta; Vascularization; Work; angiogenesis; base; cell motility; coronary fibrosis; density; heart function; heart preservation; implantation; improved; in vitro Model; in vivo; inhibitor; innovation; novel therapeutics; preservation; prevent; programs; protein expression; side effect; spatiotemporal

Following myocardial infarction (MI), the degradation of cardiac extracellular matrix (ECM) mainly by upregulated matrix metalloproteinase-2/9 (MMP-2/9), and the progression of cardiac fibrosis after myofibroblast formation, progressively deteriorate cardiac function. As such, impeding MMP-2/9 bioactivity, and inhibiting myofibroblast formation will improve cardiac function. However, the ideal therapeutic strategies to simultaneously achieve both goals remain to be established. Currently, systemic delivery of broad spectrum MMP inhibitors did not show consistent outcomes in clinical trials. MMP-2/9 expression is spatiotemporal in infarcted hearts over the course of post-MI. Yet current systemic delivery approach cannot spatiotemporally deliver MMP inhibitors to the infarcted area. To attenuate cardiac fibrosis, systemic delivery of TGFβ inhibitors or anti-TGFβ antibodies represents a major approach. However, it only decreases the content of active TGFβ. It cannot inhibit TGFβ signaling pathway to prevent myofibroblast formation. Furthermore, the small organic MMP and TGFβ inhibitors have toxicity concerns. The objective of this project is to create drug delivery systems that can be specifically delivered into infarcted hearts to concurrently preserve cardiac ECM, and prevent cardiac fibrosis. Localized delivery will eliminate dose-limiting side effects. The systems will spatiotemporally release MMP-2/9 specific and non-toxic inhibitor, peptide CTTHWGFTLC (CTT), to specifically modulate local MMP-2/9 bioactivity. The systems will also gradually release a multifunctional growth factor bFGF that have anti-fibrotic and proangiogenesis functions. The preserved ECM will thus be vascularized. Vascularization is critical for cardiac ECM as otherwise its structure and composition change over time. In our preliminary work, we have created a fast gelation and degradable hydrogel-based release system capable of efficiently retaining drugs in beating hearts. The system can release CTT for 4 weeks. After being injected into infarcted hearts, the released CTT preserved collagen, increased tissue thickness, and improved cardiac function. Better than many other small organic MMP inhibitors, CTT did not induce cardiac fibrosis. Besides, CTT promoted endothelial cell migration in the presence of TGFβ that is upregulated after MI. These results demonstrate that CTT is potentially a better MMP inhibitor for cardiac therapy than those small organic inhibitors. We have further created a release system that continuously releases both CTT and bFGF. bFGF is known for its angiogenic effect. We found that bFGF is capable of inhibiting TGFβ-induced cardiac fibroblast differentiation into myofibroblast through TGFβ/Erk1/2 pathway. After 4 weeks of implantation, the CTT/bFGF release systems not only increased tissue thickness and preserved collagen composition, but also promoted the formation of a high density of capillaries and remarkably reduced cardiac fibrosis, leading to the increase of cardiac function. Based on our preliminary studies, we hypothesize that localized and spatiotemporal delivery of CTT and bFGF into infarcted hearts, will concurrently attenuate cardiac ECM degradation, vascularize the preserved ECM, and prevent cardiac fibrosis, leading to a significant increase in cardiac function. AIM 1 will test the hypothesis that optimal CTT release profiles will efficiently attenuate MMP-2 bioactivity to prevent MMP-2 mediated ECM degradation. AIM 2 will test the hypothesis that optimal bFGF release profiles will simultaneously promote endothelial cell morphogenesis and prevent cardiac fibroblasts from differentiating into myofibroblasts. AIM 3 will test the hypothesis that delivery of CTT and bFGF release systems after MI will concurrently preserve and vascularize cardiac ECM, and prevent cardiac fibrosis. This project is innovative because it creates translational drug delivery systems to establish: 1) role and efficacy of an efficient MMP-2/MMP-9 inhibitor CTT in cardiac therapy; 2) mechanism and efficacy of bFGF in inhibiting cardiac fibrosis while promoting angiogenesis; and 3) how sustained release of CTT and bFGF simultaneously achieves these three goals. The system is relatively simple and multifunctional. Therefore, it is translational.

在心肌梗塞（MI）之后，主要是通过上调的基质金属蛋白酶-2/9（MMP-2/9）（MMP-2/9）的心脏外基质（ECM）降解，以及肌纤维细胞形成后心脏纤维化的进展，逐渐减少心脏功能。因此，阻碍MMP-2/9生物活性和抑制肌纤维细胞形成将改善心脏功能。但是，同时实现这两个目标的理想治疗策略仍有待确定。目前，在临床试验中，全身传递广谱MMP抑制剂并未表现出一致的结果。 MMP-2/9表达在MI后的梗塞心脏中是时空的。然而，当前的全身输送方法不能在空间上将MMP抑制剂传递到梗塞区域。为了减弱心脏纤维化，TGFβ抑制剂或抗TGFβ抗体的全身递送代表了一种主要方法。但是，它仅降低活性TGFβ的含量。它不能抑制TGFβ信号传导途径以防止肌纤维细胞形成。此外，小的有机MMP和TGFβ抑制剂具有毒性问题。该项目的目的是创建可以专门输送到感染心脏的药物输送系统，以同时保留心脏ECM并防止心脏纤维化。局部递送将消除限制剂量的副作用。该系统将在空间上释放MMP-2/9的特异性和无毒抑制剂Pepperery Ctthwgftlc（CTT），以特别调节局部MMP-2/9生物活性。该系统还将逐渐释放具有抗纤维化和促血管生成功能的多功能生长因子BFGF。因此，保存的ECM将被血管化。血管化对心脏ECM至关重要，否则其结构和组成随着时间而变化。在我们的初步工作中，我们创建了一个快速的凝胶和可降解的基于水凝胶的释放系统，能够有效地保留在跳动心脏中的药物。该系统可以释放CTT 4周。注入感染的心脏后，释放的CTT保留了胶原蛋白，组织厚度增加并改善了心脏功能。比许多其他小有机MMP抑制剂更好，CTT不会诱导心脏纤维化。此外，CTT在MI后更新的TGFβ存在下促进了内皮细胞迁移。这些结果表明，与那些小的有机抑制剂相比，CTT可能是心脏治疗的MMP抑制剂更好。我们进一步创建了一个发行系统，该系统继续释放CTT和BFGF。 BFGF以其血管生成作用而闻名。我们发现BFGF能够通过TGFβ/ERK1/2途径抑制TGFβ诱导的心脏成纤维细胞分化为肌纤维细胞。植入4周后，CTT/BFGF释放系统不仅增加了组织厚度和保留的胶原蛋白组成，而且还促进了高密度毛细血管的形成和心脏纤维化的大幅降低，从而导致心脏功能的增加。基于我们的初步研究，我们假设将CTT和BFGF局部和空间临时递送到感染心脏中，将同时减轻心脏ECM降解，血管降解，使保留的ECM降解并预防心脏纤维化，导致心脏功能的显着增加。 AIM 1将检验以下假设：最佳CTT释放曲线将有效地衰减MMP-2生物活性，以防止MMP-2介导的ECM降解。 AIM 2将检验以下假设：最佳BFGF释放曲线将简单地促进内皮细胞的形态发生，并防止心脏成纤维细胞分化为肌纤维细胞。 AIM 3将检验以下假设：MI之后的CTT和BFGF释放系统的递送将同时保存和血管性心脏ECM，并防止心脏纤维化。该项目具有创新性，因为它创建了转化药物输送系统以建立：1）有效的MMP-2/MMP-9抑制剂CTT在心脏疗法中的作用和有效性； 2）BFGF在促进血管生成的同时抑制心脏纤维化的机制和有效性； 3）CTT和BFGF的持续释放如何实现这三个目标。该系统相对简单且多功能。因此，它是翻译的。