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， 导致腿部供血动脉逐渐变窄和闭塞。PAD通常表现为 跛行（腿部疼痛和严重的行走限制），但有些患者进展为肢体威胁性缺血 和截肢跛行的标准疗法有局限性，因此仍需要开发 改善肢体功能的治疗，同时减少对昂贵的护理和程序的需求。 前期工作我们已经开发并验证了猪后肢缺血模型（髂股动脉 动脉切除），其概括了人类PAD/跛行的病理生理学的关键方面，并使用 它测试脂肪来源的间充质干细胞（ADMSC）的功效。我们的初步工作表明， 将ADMSC注射到结扎/切除的髂动脉的床中产生（i）增加的动脉生成，（ii） 增强的肌肉灌注，和（iii）与对照组相比，ADMSC治疗组猪的跑步机行走能力增加。 未经处理的猪 假设，具体目标。我们的中心假设是动脉外输送自体ADMSC 或衍生的外泌体将改善缺血后肢的血流动力学、组织学和功能终点 与PAD猪模型中的相关动脉生成有关。我们将使用猪来探索我们的假设。 在高胆固醇血症和高血压背景下的后肢缺血模型（用高浓度的 脂肪/高果糖/高盐饮食），其模拟PAD。中心假设将探讨与三个 具体目标： 目标1.为了确定ADMSC或ADMSC衍生的外泌体的动脉外施用是否会 刺激动脉生成，改善血流动力学/灌注终点，并调节局部炎症 环境中的PAD的猪模型。 目的2：确定动脉外注射ADMSC或外泌体是否会改善缺血性脑损伤。 在PAD猪模型中的肌病和跑步机性能。 目的3：确定ADMSCs和单核细胞联合应用是否会诱导动脉生成 在灌注的猪动脉系统中。 创新我们将使用临床相关的PAD大动物模型和新技术， 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ADMSC的衍生物（即，外泌体），如果有效，其提供了许多优点， 传统的细胞疗法此外，我们将描述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.