Stem Cell Mobilization in Diabetes

描述(由申请人提供)：本提案概述了一项转化性研究计划，以调查干细胞/祖细胞(SPC)动员和招募在治疗糖尿病神经性下肢溃疡中的作用。技术将包括血细胞流式细胞术，伤口活检的组织化学，以及一种测量完整血小板内皮型一氧化氮合酶(ENOS)活性的新方法。作为一种加速骨髓SPC动员的工具，我们将使用高压氧(HBO2)，它可以刺激骨髓eNOS的活性。我们假设糖尿病患者的eNOS活性受损，改善血糖管理将改善eNOS活性、骨髓中SPC的动员、SPC向伤口的募集，这些变化将刺激伤口愈合。具体目的1.证明eNOS活性是糖尿病患者SPC动员的一个变量。试验将在糖尿病患者和正常、健康的成年人中进行。主要的焦点是测试血小板eNOS活性是否与循环中SPC的基线数量和HBO2介导的SPC动员相关。第二个目标是检查eNOS活性是否与血糖控制相关。具体目的2.评估伤口变量与糖尿病患者新生血管形成相关的可行性，以及它们是否与糖尿病患者的愈合相关。这项研究将涉及患有不同严重程度的神经性溃疡的糖尿病患者，他们正在根据当前推荐的指南接受临床治疗。在一组难治性伤口的患者中，这包括高压氧。我们将研究临床实践如何影响eNOS活性、循环中的SPC和伤口内的生化特征，包括生长因子、蛋白酶和蛋白酶抑制剂的存在。将比较现有神经性溃疡和急性穿刺性活检伤口之间的SPC募集和生化特征。我们假设，更好的糖尿病治疗将提高eNOS的活性，伤口愈合率取决于伤口内循环中SPC的数量和影响SPC归巢和功能的生化因素。这些研究将由一个多学科小组进行。所获得的信息将为一项多中心临床试验提供基础，以测试糖尿病治疗是否可以调节SPC的动员和在伤口上的招募，eNOS活性是否与这些变化相关，以及糖尿病溃疡愈合是否与这些改善有关。公共卫生相关性：这项建议概述了一项研究计划，以调查干细胞/祖细胞(SPC)动员和招募在治愈糖尿病神经性下肢溃疡中的作用。我们假设内皮型一氧化氮合酶(ENOS)活性因糖尿病和葡萄糖管理而受损。作为一种刺激骨髓中SPC动员的工具，我们将使用高压氧(HBO2)，我们将确定临床管理实践--包括HBO2--如何改变循环SPC以及伤口特征。

DESCRIPTION (provided by applicant): This proposal outlines a translational research plan to investigate the role of stem/progenitor cell (SPCs) mobilization and recruitment for healing diabetic neuropathic lower extremity ulcers. Techniques will involve blood cell flow cytometry, histochemistry on wound biopsies, and a novel method for measuring endothelial nitric oxide synthase (eNOS) activity in intact platelets. As a tool to hasten SPCs mobilization from the bone marrow we will use hyperbaric oxygen (HBO2), which stimulates bone marrow eNOS activity. We hypothesize that eNOS activity is impaired in diabetics and that improved glucose management will improve eNOS activity, SPCs mobilization from the bone marrow, SPCs recruitment to wounds, and these changes will stimulate wound healing. Specific aim 1. To document eNOS activity as a variable for SPCs mobilization in diabetics. Trials will be carried out with diabetics and normal, healthy adults. The primary focus is to test whether platelet eNOS activity correlates with baseline number of circulating SPCs and HBO2-mediated SPCs mobilization. A secondary goal is to examine whether eNOS activity is correlated with glycemic control. Specific aim 2. To assess feasibility of evaluating wound variables associated with neo-vascularization and whether they correlate with healing in diabetic patients. This study will involve populations of diabetics with neuropathic ulcers of varying severity who are undergoing clinical treatments according to current recommended guidelines. In a sub-set of patients with refractory wounds, this includes hyperbaric oxygen. We will examine how clinical practices influence eNOS activity, circulating SPCs, and biochemical characteristics within wounds including the presence of growth factors, proteases and inhibitors of proteases. SPCs recruitment and biochemical characteristics will be compared between the existing neuropathic ulcer and an acute punch biopsy wound. We hypothesize that better management of diabetes will improve eNOS activity, and that wound healing rate depends on the number of circulating SPCs and biochemical factors within the wound that influence SPCs homing and function. These studies will be carried out by a multidisciplinary team. Information obtained will provide a foundation for a multi-centered clinical trial to test whether diabetic management can modulate SPCs mobilization and recruitment to wounds, whether eNOS activity is correlated with these changes, and whether diabetic ulcer healing is related to these improvements. PUBLIC HEALTH RELEVANCE: This proposal outlines a research plan to investigate the role of stem/progenitor cell (SPCs) mobilization and recruitment for healing diabetic neuropathic lower extremity ulcers. We hypothesize that endothelial nitric oxide synthase (eNOS) activity is impaired due to diabetes and glucose management. As a tool to stimulate mobilization of SPCs from the bone marrow we will use hyperbaric oxygen (HBO2), and we will determine how clinical management practices - including HBO2 - modify circulating SPCs as well as wound characteristics.