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Homing of Stem Cells in Stroke Therapeutics

中风治疗中干细胞的归巢

基本信息

批准号：
7869384
负责人：
SOPHIA K KHALDOYANIDI
金额：
$ 25.51万
依托单位：
SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-06-15 至 2012-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7869384
关键词：
2&apos ,3&apos -Cyclic-Nucleotide Phosphodiesterases Accident and Emergency department Acute Adhesions Adhesiveness Adhesives Adult Animal Model Animals Antibodies Apical Area Arteries Astrocytes Behavior Behavioral Binding Biology Bioluminescence Blood Cells Bone Marrow Brain Brain Injuries Brain Neoplasms CD34 gene Cell Adhesion Cell Count Cell Therapy Cell membrane Cells Cerebrum Cicatrix Clinical Clinical Trials Commissure Contralateral Corpus Callosum Craniocerebral Trauma Cutaneous Data Dendrites Development Disease Dose E-Selectin Electrons Endothelial Cells Exhibits Fiber Figs - dietary Financial compensation Fluorescein-5-isothiocyanate Fluorescence Fucosyltransferase Glial Fibrillary Acidic Protein Glutamates Glycoproteins Gold Harvest Head Health care facility Histology Home environment Homing Hour Housing Human Hypoxia Image Immune Immunofluorescence Immunologic Immunohistochemistry Implant In Vitro Infarction Inflammation Injection of therapeutic agent Injury Institutes Intermediate Filaments Intervention Ischemic Brain Injury Label LacZ Genes Left Ligands Lymphocyte antigen Magnetic Resonance Imaging Measures Mediating Microcirculation Middle Cerebral Artery Occlusion Modeling Molecular Chaperones Mus Neuroectoderm Neurologic Neurons Neurotransmitters Nuclear Nuclear Envelope Oligodendroglia Oranges Outcome Measure Outcome Study P-Selectin P-selectin ligand protein Parkinson Disease Pathology Patients Peripheral Pharmaceutical Preparations Physiological Play Polysaccharides Process Rattus Reaction Recovery of Function Resources Role Route Safety Sagittaria Selectins Series Side Site Source Spectrum Analysis Spinal Injuries Stem cells Stress Stroke Structure Synapses Texas red Therapeutic Therapeutic Effect Time Tissues Translating Translations Transplantation Umbilical Cord Blood Umbilical cord structure Undifferentiated Vascular Endothelial Cell Vascular Endothelium Work acute stroke base brain repair cell type cholinergic comparative efficacy hippocampal pyramidal neuron human stem cells implantation in vivo injured insight migration minimally invasive neovascularization nerve stem cell nestin protein neurofilament neurogenetics neuroprotection new technology novel novel strategies post stroke pre-clinical preclinical study public health relevance receptor reconstitution regenerative relating to nervous system research study response shear stress stem cell population success sugar

项目摘要

DESCRIPTION (provided by applicant): Somatic stem cells appear to have their greatest impact on stroke therapeutics not by literally replacing cells but by protecting host neural cells & circuitry from progressive damage as well as catalyzing endogenous host regenerative responses. When such stem cell-mediated actions have been invoked, behavioral improvements have been seen. Neuroectoderm-derived stem cells ("neural stem cells [NSCs]") have been the "gold-standard" for such therapeutics against which any alternative stem cell type must be compared. However, a number of labs have found efficacy from the intravascular administration of human umbilical cord blood-derived stem cells (hUCSCs). The intravascular administration of stem cells allows one to circumvent more invasive neurosurgical implantation, assuming that the cells can efficiently home to the region of injury. An additional advantage of cell-mediated protective therapies (as opposed to pharmacological-mediated interventions) is that the window of opportunity can be as wide as 24-72 hrs, making them well-suited to the realities of when patients with stroke present to health care facilities. Although UCSCs have been promising, the ability to extend their use to actual patients has practical & immunological limitations. In particular, based on extrapolating from animal studies, adult patients would require combining multiple cord blood units in order to obtain sufficient numbers of stem cells to achieve efficacy. Furthermore, combining units places stress on identifying compatible units with no more than 1-2 HLA mismatches to minimize an immune reaction. Also, efficient delivery of cells to where they are most needed & not to areas where they are not required or could even create problems - i.e., homing - is pivotal to the success of all cell-based therapeutics for any pathological condition. UCSCs must have optimal access to injured host cells & their milieu if efficacy & safety are to be maximized. When considering systemic administration of either UCSCs or NSCs for mediating brain repair following stroke, rolling & adhesion on endothelial cells is the critical 1st step in the homing cascade that is necessary for targeting these cells to the injured brain. Most hUCSCs exhibit deficient rolling & adhesion on endothelial cells, severely limiting their therapeutic potential. NSCs have a similar limitation. Recent studies have shown that this deficit can be corrected by pretreating hUCSCs with fucosyltransferase-VI which fucosylates sLeX & completes the P-selectin glycoprotein ligand (PSGL) on the CD34+ cells. The net effect is to increase recognition of the PSGL for selectins on endothelial cells. It is unknown whether this works, however, for brain vascular endothelium. It is also unknown whether this works for NSCs -- again, the "gold standard" -- although they, too, have an incomplete unfucosylated selectin ligand which compromises their homing. We propose first [Aim 1] to determine in vitro the optimal parameters for fucosylating & thereby enhancing the binding of hUCSCs & human NSCs (hNSCs) to inflamed human brain-derived endothelial cells under physiological shear stress (employing a specialized flow chamber). Subsequently [Aim 2], we will use these conditions to administer fucosylated (vs. control) hUCSCs & hNSCs to a rat model of stroke, comparing the 2 stem cell types (for the 1st time) head-to-head. Rats will be injected iv with the stem cells at 24-72 hrs post-middle cerebral artery occlusion. Outcome measures will include behavior; infarct volume (by MRI); spectroscopy (by MRS); migration (by MRI & bioluminescence imaging); sparing of host neurons & their connections (by immunohistochemistry & tract tracing). These data will be correlated with histology. These studies could help provide a strategy for enhancing the homing of stem cells to the brain in a minimally-invasive manner, using cell numbers & a time frame that is practical for providing clinical benefit in acute/subacute stroke, particularly if the stem cells serve to protect extant neural tissue & connections; diminish inflammation, scarring & secondary injury processes; detoxify the milieu; & promote neovascularization. Such studies could also provide insights that extend to other types of CNS pathology & other types of stem cells. PUBLIC HEALTH RELEVANCE: Peripheral intravascular administration of either human umbilical cord-derived stem cells (hUCSCs) or neural stem cells (hNSCs) for acute stroke therapeutics in adults requires a sufficient number of cells with fully expressed homing mechanisms for optimal targeting to the area of compromise. This proposal will assess a new technology that could expand the use of available supplies of either source of stem cells. The process of placing a sugar group - a fucosyl group - on stem cell membranes through a simple enzymatic pre-treatment process has shown in preclinical studies to increase homing of hUCSCs and likely will extend to hNSCs as well. Aim 1 will identify the optimal conditions for preparing the stem cells while Aim 2 will comparatively assess in a rat stroke model the efficacy of hUCSCs vs. hNSCs following peripheral administration 24 hrs post-stroke, particularly under conditions where their homing has been optimized by fucosylation.

描述（由申请人提供）：成体干细胞对中风治疗的最大影响似乎不是通过真正替代细胞，而是通过保护宿主神经细胞和电路免受渐进性损伤以及催化内源性宿主再生反应。当这种干细胞介导的作用被激活时，行为就会得到改善。神经外胚层衍生的干细胞（“神经干细胞[NSC]”）已成为此类疗法的“黄金标准”，任何替代干细胞类型都必须与之进行比较。然而，许多实验室已经发现血管内注射人脐带血干细胞 (hUCSC) 的功效。干细胞的血管内给药可以避免更具侵入性的神经外科植入，假设细胞可以有效地归巢到损伤区域。细胞介导的保护性疗法（相对于药物介导的干预措施）的另一个优点是，机会窗口可以长达 24-72 小时，这使得它们非常适合中风患者就诊于医疗机构时的现实情况。尽管 UCSC 前景广阔，但将其应用扩展到实际患者的能力存在实际和免疫学方面的局限性。特别是，根据动物研究的推断，成年患者需要结合多个脐带血单位才能获得足够数量的干细胞以实现疗效。此外，组合单位强调识别不超过 1-2 个 HLA 错配的兼容单位，以尽量减少免疫反应。此外，将细胞有效输送到最需要的地方，而不是输送到不需要它们甚至可能产生问题的区域（即归巢），对于任何病理状况的所有基于细胞的疗法的成功至关重要。如果要最大限度地提高功效和安全性，UCSC 必须能够最佳地接触受损的宿主细胞及其环境。当考虑全身施用 UCSC 或 NSC 来介导中风后的大脑修复时，内皮细胞的滚动和粘附是归巢级联中关键的第一步，这是将这些细胞靶向受损大脑所必需的。大多数 hUCSC 在内皮细胞上表现出滚动和粘附不足，严重限制了它们的治疗潜力。 NSC 也有类似的局限性。最近的研究表明，这种缺陷可以通过用岩藻糖基转移酶-VI 预处理 hUCSC 来纠正，岩藻糖基转移酶-VI 岩藻糖基化 sLeX 并完成 CD34+ 细胞上的 P-选择素糖蛋白配体 (PSGL)。最终效果是增加内皮细胞上选择素对 PSGL 的识别。然而，尚不清楚这是否适用于脑血管内皮。目前尚不清楚这是否适用于 NSC（再次强调“黄金标准”），尽管它们也具有不完整的非岩藻糖基化选择素配体，这会损害它们的归巢。我们建议首先[目标 1] 确定体外岩藻糖基化的最佳参数，从而增强 hUCSC 和人 NSC (hNSC) 在生理剪切应力下（使用专门的流动室）与发炎的人脑源性内皮细胞的结合。随后[目标 2]，我们将使用这些条件将岩藻糖基化（与对照）hUCSC 和 hNSC 注入中风大鼠模型中，对两种干细胞类型（第一次）进行头对头比较。在大脑中动脉闭塞后24-72小时，对大鼠静脉内注射干细胞。结果衡量将包括行为；梗塞体积（通过 MRI）；光谱（通过 MRS）；迁移（通过 MRI 和生物发光成像）；保留宿主神经元及其连接（通过免疫组织化学和纤维束追踪）。这些数据将与组织学相关。这些研究可以帮助提供一种策略，以微创方式增强干细胞归巢到大脑，使用细胞数量和时间框架，为急性/亚急性中风提供临床益处，特别是如果干细胞用于保护现有的神经组织和连接；减少炎症、疤痕和继发性损伤过程；为环境排毒；并促进新生血管形成。此类研究还可以提供扩展到其他类型的中枢神经系统病理学和其他类型的干细胞的见解。公共卫生相关性：用于成人急性中风治疗的人脐带源性干细胞 (hUCSC) 或神经干细胞 (hNSC) 的外周血管内给药需要足够数量的具有完全表达的归巢机制的细胞，以最佳地靶向受损区域。该提案将评估一项新技术，该技术可以扩大任一干细胞来源的可用供应的使用。临床前研究表明，通过简单的酶预处理过程将糖基（岩藻糖基）置于干细胞膜上的过程可以增加 hUCSC 的归巢，并且也可能扩展到 hNSC。目标 1 将确定制备干细胞的最佳条件，而目标 2 将在大鼠中风模型中比较评估中风后 24 小时外周给药后 hUCSC 与 hNSC 的功效，特别是在其归巢已通过岩藻糖基化优化的条件下。