Effect of cell-based therapies on functional, hemodynamic, and histologic outcomes in a porcine model of peripheral arterial disease

背景和意义。外周动脉疾病(PAD)是动脉粥样硬化的一种表现 导致供应腿部的动脉逐渐变窄和闭塞。PAD通常显示为 跛行(腿部疼痛和严重行走受限)，但一些患者进展为肢体缺血 和截肢。跛行的标准疗法有其局限性，因此仍有发展的必要。 改善肢体功能的治疗，同时减少昂贵的护理和程序的需要。 前期工作。我们已经建立并验证了猪后肢缺血模型(髂股 动脉切除)，它概括了人类PAD/跛行的病理生理学的关键方面，并使用 目的是测试脂肪来源的间充质干细胞(ADMSCs)的效果。我们的初步工作表明， 在结扎/切除的髂动脉床内注射ADMSCs可产生(I)增加动脉生成，(Ii) 增强肌肉灌流，以及(Iii)与对照组相比，ADMSC组猪的跑步机步行能力增加 未经处理的猪。 假设，明确的目标。我们的中心假设是动脉外输送自体ADMSCs 或衍生的外切体将改善缺血后肢的血流动力学、组织学和功能终点 在猪PAD模型中伴随动脉生成。我们将用一头猪来验证我们的假设 高胆固醇血症和高血压(高胆固醇诱导)大鼠后肢缺血模型 脂肪/高果糖/高盐饮食)，模仿PAD。核心假说将从三个方面进行探讨 具体目标： 目的1.确定动脉外注射ADMSCs或ADMSC来源的外切体是否会 刺激动脉生成，改善血流动力学/灌注终点，调节局部炎症 在猪PAD模型中的环境。 目的2：确定动脉外注射ADMSCs或Exosome是否能改善缺血 猪PAD模型中的肌病和跑步机表现。 目的3：确定ADMSCs和单核细胞联合应用是否会诱导动脉生成 在灌流的猪动脉系统中。 创新。我们将使用与临床相关的大动物PAD模型和新技术，这些技术 由我们的研究小组开发，用于研究缺血肢体的生理学和组织病理学。我们还将 利用猪ADMSCs的衍生物(即外切体)，如果有效，它将提供许多优于 传统的细胞疗法。此外，我们将表征基于细胞的治疗对局部 缺血肢体的炎症环境。

Background & Significance. Peripheral artery disease (PAD) is a manifestation of atherosclerosis that produces progressive narrowing and occlusion of the arteries supplying the legs. PAD usually presents as claudication (leg pain and severe walking limitation), but some patients progress to limb threatening ischemia and amputation. Standard therapies for claudication have limitations, so there remains a need to develop treatments that improve limb function while decreasing the need for expensive care and procedures. Preliminary Work. We have developed and validated a porcine model of hindlimb ischemia (iliofemoral artery excision) which recapitulates key aspects of the pathophysiology of human PAD/claudication, and used it to test the efficacy of adipose-derived mesenchymal stem cells (ADMSCs). Our preliminary work shows that injection of ADMSCs into the bed of the ligated/excised iliac artery produces (i) increased arteriogenesis, (ii) enhanced muscle perfusion, and (iii) increased treadmill walking capacity in ADMSC-treated pigs compared to untreated pigs. Hypothesis, Specific Aims. Our central hypothesis is that extra-arterial delivery of autologous ADMSCs or derived exosomes will improve hemodynamic, histologic, and functional endpoints of the ischemic hindlimb with associated arteriogenesis in a porcine model of PAD. We will explore our hypothesis using a porcine model of hindlimb ischemia on a background of hypercholesterolemia and hypertension (induced with a high fat/ high fructose/ high salt diet), which mimics PAD. The central hypothesis will be explored with three Specific Aims: Aim 1. To determine whether extra-arterial administration of ADMSCs or ADMSC-derived exosomes will stimulate arteriogenesis, improve hemodynamic/ perfusion endpoints, and modulate the local inflammatory environment in a porcine model of PAD. Aim 2: To determine whether extra-arterial injection of ADMSCs or exosomes will improve ischemic myopathy and treadmill performance in a porcine model of PAD. Aim 3: To determine whether combined application of ADMSCs and monocytes will induce arteriogenesis in a perfused porcine artery system. Innovation. We will use a clinically-relevant large-animal model of PAD and novel techniques that were developed by our research group to study the physiology and histopathology of the ischemic limb. We will also utilize a derivative of porcine ADMSCs (i.e., the exosomes) which, if effective, offer numerous advantages over conventional cellular therapy. In addition, we will characterize the effect of cell-based treatments on the local inflammatory environment of the ischemic limb.