Injectable Hydrogels to Deliver Gene Therapy for Myocardial Infarct

项目摘要 基质衍生因子-1α(SDF-1α)在心肌梗死后迅速升高，已有研究表明 增加微血管密度，缩小梗塞面积，抑制交界区扩张，减轻不良反应 重塑以保存缺血的心脏组织。然而，这种内在的上调是暂时的，并且 SDF-1α的保护功能迅速下降，从而降低了组织修复的潜力。要与此作斗争 限制，几个小组已经研究了sdf-1α的外源性传递。研究发现，早期阶段 外源sdf-1α促进内源性修复过程，后期sdf-1α表达增加 被证明能改善心脏功能。这些研究激励了一种治疗方法，以提供持续的 SDF-1α的交付和功能效益，在母项目中进行了调查。 尽管短期外源性sdf-1α传递的结果令人鼓舞，但对其影响知之甚少。 急性心肌梗死后持续的SDF-1α进入心肌的作用。对这些影响的进一步调查是 父项目的重要逻辑扩展和组成部分，因为它可能与 SDF-1α短期治疗的疗效。此外，虽然单次注射sdf-1α基因疗法已经 在临床研究中，这些疗法都是在生理盐水中进行的，并证明了有希望的结果。因此， 反复使用基因疗法是否会进一步改善心脏状况仍是个悬而未决的问题。 功能。为了持续输送sdf-1α进入临床研究，更多的信息是必要的，以更好地 了解其影响、作用机制以及任何可能的不利影响。 为了实现这一目标，我们建议延长母项目的目标3。在那里，我们提议使用 弹性蛋白样蛋白-透明质酸(ELP-HA)水凝胶处方已在体外进行了优化 持续释放sdf-1α微环(MC)基因，在体内进行心功能恢复的临床前评估。 在这个多样性补充项目中，我们将评估MI后在体心脏血管的再生 通过对心脏组织进行免疫组织化学染色。研究任何再生的可能机制(S) 我们看到，我们将进行细胞因子分泌的蛋白质组学分析以及RNA测序(RNAseq)。最后， 由于sdf-1、α及其受体CXCR4已知在干细胞归巢至缺血的过程中发挥重要作用。 ，我们将研究其对内源性内皮祖细胞的趋化作用 (EPC)。我们的研究结果不仅将告诉我们持续释放sdf-1α是否有益于血管 和心肌梗死后的心脏再生，但也是SDF-1α提供其好处的机制。这 多样性补充将推动代表不足的少数族裔受训人员的研究生涯走向 向独立过渡。

Project Summary Stromal derived factor-1α (SDF-1α) rapidly increases following myocardial infarction (MI) and has been shown to increase microvascular density, reduce infarct size, inhibit border zone expansion, and attenuate adverse remodeling to preserve the ischemic cardiac tissue. However, this intrinsic upregulation is transient, and the protective function of SDF-1α quickly declines, thereby reducing the potential for tissue repair. To combat this limitation, several groups have investigated the exogenous delivery of SDF-1α. It was found that early-stage delivery of exogenous SDF-1α augmented the endogenous repair process, while late-stage increase in SDF-1α was shown to improve cardiac function. These studies motivate a therapeutic approach to provide sustained SDF-1α delivery and functional benefit, which is investigated in the parent project. Despite encouraging results from short-term exogenous SDF-1α delivery, little is known about the effects of sustained SDF-1α delivery into the myocardium following acute MI. Further investigation of these effects is an important logical extension and integral component of the parent project, as it may be completely distinct from the effects of short-term treatment with SDF-1α. Further, while single delivery of SDF-1α gene therapy is already in clinical studies and demonstrate promising results, these therapies were delivered in saline. Therefore, lingering questions remain as to whether repeated delivery of the gene therapy would further improve cardiac function. For sustained delivery of SDF-1α to enter clinical studies, additional information is necessary to better understand its effects, mechanism of action, as well as any possible adverse effects. Towards this goal, we propose an extension to Aim 3 of the parent project. There, we proposed to use the elastin-like protein-hyaluronic acid (ELP-HA) hydrogel formulation, which has been optimized in vitro for sustained SDF-1α minicircle (MC) gene release, in an in vivo preclinical assessment of cardiac function recovery. In this Diversity Supplement project, we will evaluate the in vivo vascular regeneration of the heart following MI through immunohistochemistry of cardiac tissue. To investigate possible mechanism(s) of any regeneration that we see, we will perform proteomic profiling of cytokine secretions as well as RNA sequencing (RNASeq). Finally, since SDF-1α and its receptor CXCR4 is known to play an important role in stem cell homing to the ischemic myocardium, we will investigate its chemoattractive potential to draw endogenous endothelial progenitor cells (EPCs). The results of our study will inform us not only if sustained delivery of SDF-1α is beneficial to vascular and cardiac regeneration following MI, but also the mechanism by which SDF-1α delivers its benefits. This Diversity Supplement will advance the research career of an underrepresented minority trainee towards the transition to independence.