Endothelial progenitor cells,potential biomarkers for diagnosis and prognosis of ischemic stroke: protocol for an observational case-control study

Ischemic stroke is a devastating,life altering event which can severely reduce patient quality of life.Despite years of research there have been minimal therapeutic advances.Endothelial progenitor cells(EPCs),stem cells involved in both vasculogenesis and angiogenesis,may be a potential therapeutic target.After a stroke,EPCs migrate to the site of ischemic injury to repair cerebrovascular damage,and their numbers and functional capacity may determine patients'outcome.This study aims to determine whether the number of circulating EPCs and their functional aspects may be used as biomarkers to identify the type(cortical or lacunar)and/or severity of ischemic stroke.The study will also investigate if there are any differences in these characteristics between healthy volunteers over and under 65 years of age.100 stroke patients(50 lacunar and 50 cortical strokes)will be recruited in this prospective,observational case-controlled study.Blood samples will be taken from stroke patients at baseline(within 48 hours of stroke)and days 7,30 and90.EPCs will be counted with flow cytometry.The plasma levels of pro-and anti-angiogenic factors and inflammatory cytokines will also be determined.Outgrowth endothelial cells will be cultured to be used in tube formation,migration and proliferation functional assays.Primary outcome is disability or dependence on day 90 after stroke,assessed by the modified Rankin Scale.Secondary outcomes are changes in circulating EPC numbers and/or functional capacity between patient and healthy volunteers,between patient subgroups and between elderly and young healthy volunteers.Recruitment started in February 2017,167 participants have been recruited.Recruitment will end in November 2019.West Midlands-Coventry&Warwickshire Research Ethics Committee approved this study(REC number:16/WM/0304)on September8,2016.Protocol version:2.0.The Bayraktutan Dunhill Medical Trust EPC Study was registered in ClinicalTrials.gov(NCT02980354)on November 15,2016.This study will determine whether the number of EPCs can be used as a prognostic or diagnostic marker for ischemic strokes and is a step towards discovering if transplantation of EPCs may aid patient recovery.     

他汀类药物对急性缺血性脑卒中患者外周血内皮祖细胞的影响

目的：观察他汀类药物对急性缺血性脑卒中（AIS）患者外周血内皮祖细胞（EPC）数量及迁移能力的影响。方法：15例发病1周内的AIS患者,给予阿托伐他汀20mg·d^-1,治疗4周,用药前及用药后每周分别检测外周血EPC数量及迁移能力;9名健康对照者于入组前及第2、4周随访。结果：阿托伐他汀治疗第2周开始EPC数量逐渐增多,且第3和第4周增多较为显著（P〈0．05）;EPC的迁移能力在治疗第2和第3周显著提高（P〈0．05）,而第4周则有下降的趋势。EPC数量及迁移能力的变化与低密度脂蛋白的下降无显著相关性。结论：他汀类药物可能提高AIS患者外周血EPC的数量及迁移能力。     

Growth factor- and cytokine-stimulated endothelial progenitor cells in post-ischemic cerebral neovascularization

Endothelial progenitor cells are resident in the bone marrow blood sinusoids and circulate in the peripheral circulation. They mobilize from the bone marrow after vascular injury and home to the site of injury where they differentiate into endothelial cells. Activation and mobilization of endothelial progenitor cells from the bone marrow is induced via the production and release of endothelial progenitor cell-activating factors and includes specific growth factors and cytokines in response to peripheral tissue hypoxia such as after acute ischemic stroke or trauma. Endotheli- al progenitor cells migrate and home to specific sites following ischemic stroke via growth factor/ cytokine gradients. Some growth factors are less stable under acidic conditions of tissue isch- emia, and synthetic analogues that are stable at low pH may provide a more effective therapeutic approach for inducing endothelial progenitor cell mobilization and promoting cerebral neovascularization following ischemic stroke.     

丁苯酞对急性缺血性卒中患者外周血内皮祖细胞的影响

目的 观察丁苯酞(NBP)治疗对急性缺血性卒中患者外周血内皮祖细胞(EPCs)水平及美国国立卫生研究院卒中量表(NIHSS)评分的影响;探讨其疗效及潜在机制.方法 筛选首次发病48 h内入院的急性缺血性卒中患者96例,按随机数字表分为NBP治疗组(NBP组)及安慰剂组.NBP治疗30 d为1个疗程.流式细胞仪检测CD34 +/CD133 +/KDR+标记细胞作为EPCs标志.分别检测入院当天(基线期)、治疗第7天、第14天和第30天外周血EPCs水平;并分别于上述时间点及病程90 d时进行NIHSS评分.结果 NBP组第7天、第14天、第30天时EPCs数量较基线期显著增加(均为P＜0.05);且明显高于同期安慰剂组(分别为P＜0.05、P＜0.001、P＜0.001).NBP组第7天NIHSS评分较基线期无明显改善(P ＞0.05);NBP组第14天、第30天NIHSS评分均明显低于基线期(均为P＜0.05)及同期安慰剂组(P ＜0.05、P＜0.001).NBP组第90天NIHSS评分较第30天有进一步降低(P＜0.05).发病后3个月内NBP组缺血事件稍低于安慰剂组(P＞0.05).两组随访期内均无严重不良事件发生.结论 NBP治疗可显著改善急性缺血性卒中神经功能评分,可能通过提高外周血EPCs水平,改善预后,且安全性良好.     

Evidence for high translational potential of mesenchymal stromal cell therapy to improve recovery from ischemic stroke

Although ischemic stroke is a major cause of morbidity and mortality, current therapies benefit only a small proportion of patients. Transplantation of mesenchymal stromal cells (MSC, also known as mesenchymal stem cells or multipotent stromal cells) has attracted attention as a regenerative therapy for numerous diseases, including stroke. Mesenchymal stromal cells may aid in reducing the long-term impact of stroke via multiple mechanisms that include induction of angiogenesis, promotion of neurogenesis, prevention of apoptosis, and immunomodulation. In this review, we discuss the clinical rationale of MSC for stroke therapy in the context of their emerging utility in other diseases, and their recent clinical approval for treatment of graft-versus-host disease. An analysis of preclinical studies examining the effects of MSC therapy after ischemic stroke indicates near-universal agreement that MSC have significant favorable effect on stroke recovery, across a range of doses and treatment time windows. These results are interpreted in the context of completed and ongoing human clinical trials, which provide support for MSC as a safe and potentially efficacious therapy for stroke recovery in humans. Finally, we consider principles of brain repair and manufacturing considerations that will be useful for effective translation of MSC from the bench to the bedside for stroke recovery.     

1000/内皮祖细胞与缺血性脑卒中

背景：内皮祖细胞不仅能够早期预测血管损伤的程度,而且具有修复损伤的内皮细胞、促进新生血管形成管腔结构、参与神经再生的功能。内皮细胞移植已逐渐应用于血管相关性疾病的治疗。目的：文章综述了内皮祖细胞的生物学特性及在缺血性脑卒中领域的最新研究进展,为其临床应用提供理论支持。方法：以“endothelial progenitor cells; ischemic infarction;”为检索词检索Medline、HighWire Press数据库(2000-01/2009-12)。纳入与血管新生、内皮和神经再生密切相关的研究,排除内容陈旧、重复性及缺乏可信度文章。 结果与结论：计算机初检得到126篇文献,根据纳入排除标准,对其中28篇文献进行分析。内皮祖细胞具有修复损伤的内皮细胞、延缓动脉粥样硬化进展、促进缺血组织新生血管形成等功能,它参与缺血性脑卒中后血管新生,防治支架术后血栓形成及再狭窄,预测脑缺血的发生及预后,在防治缺血性脑卒中方面具有广泛的应用前景。关键词：内皮祖细胞;缺血性脑卒中;血管新生;内皮再生;神经再生;综述文献     

对比研究经颈动脉和立体定位注射骨髓间充质干细胞治疗缺血性脑卒中

目的探讨安全高效移植骨髓间充质干细胞(mensenchymal stem cells,MSCs)治疗脑缺血的方法.方法采用连续传代培养的方法纯化MSCs,Brdu标记后分别经颈动脉(1×104/μl,200 μl)和立体定位(1×105/μl,10 μl)注射至大鼠脑缺血2 h再灌注1 d模型,各自设立对照组,观察术后神经功能评分以及脑部Brdu阳性细胞的分布.结果经颈动脉注射组较立体定位注射组爬杆实验评分低(P＜0.05),Brdu阳性细胞存活多,迁移范围更广.结论 MSCs具有卒中后脑保护作用,而经颈动脉的给药方式优于立体定位注射.     

Adult stem cell therapies for neurological disorders: Benefits beyond neuronal replacement?

The modest capacity of endogenous repair processes in the central nervous system (CNS) justifies the broad interest in the development of effective stem cell based therapies for neurodegenerative disorders and other acute or chronic lesions. Motivated by the ambitious expectation to achieve functional neuronal replacement, several studies have already evidenced a potential benefit of stem cell grafts in animal models of human disorders. Nevertheless, growing evidence suggests that the effects orchestrated by stem cells, in most experimental cases, are not necessarily associated with the generation of new neurons. This hypothesis correlates with the versatile properties of adult and embryonic stem cells. When introduced into the lesioned CNS, nondifferentiated stem cells can have a positive influence through intrinsic neuroprotective capacities related to the production of neurotrophic factors, stimulation of endogenous neurogenesis, and modulation of neuroinflammation. Stem cells are also endowed with a multipotent differentiation profile, suggesting that a positive outcome could result from the replacement of nonneuronal cell types, in particular astrocytes and oligodendrocytes. Focusing on adult stem cells, this Review aims at summarizing experimental observations supporting the concept that, in cell‐based therapies, stem cells operate not through a unidirectional mechanism (e.g., generating neurons) but rather as cellular mediators of a multitude of biological activities that could provide a favorable outcome for diverse nervous disorders. © 2008 Wiley‐Liss, Inc.     

中医药参与干细胞研究相关文献的分析

背景：干细胞是再生医学研究的热点,在干细胞培养诱导过程中加入中药干预的文献报道越来越多。 目的：通过回顾与总结近年来干细胞研究过程中加入中药干预的若干文献,旨在进一步探索中药与干细胞培养、诱导、生长,分化的相关性。 方法：以“中医药”或“中医” 或“中医学”或“中药”及二次检索词“干细胞”为检索词,检索1991-01/2010-01期间CNKI数据库和《中文科技期刊数据库(全文版)》中收录涉及中药应用于干细胞的细胞学实验或临床研究文献进行检索,提取文献中的中药方剂、干细胞类型、应用意义、作者单位、基金资助等指标,建立数据库,进行频次分析。 结果与结论：检索到167篇文献,符合纳入标准的文献共31篇。在干细胞培养、诱导、分化,生长中应用的中药,治法上以活血化瘀、益气、补肾填精为常见;名方、时方、验方及中药有效组分得到广泛应用,尤以益气活血、活血化瘀、补肾填精中药应用得较为集中;文献结果描述中体现了中药具有促进干细胞动员、增殖、分化等作用,可使损伤的组织器官得以修复;相关研究主要集中于国内较为发达的区域;基金资助逐年增加,以国家自然科学基金重点资助为主。中药在干细胞培养、诱导过程中的应用,使中医临证思维融合再生思想,使调和阴阳的治疗目标延伸向了干细胞治疗与再生医学的时代。     

Circulating Endothelial Progenitor Cells in Cerebrovascular Disease

Stroke is associated with high disability and mortality burdens worldwide, but there are few effective and widely available therapies. There is therefore a need to develop treatments that promote the repair and regeneration of ischemic brain tissue. In this regard, a population of adult stem cells-called endothelial progenitor cells (EPCs)-has been identified in peripheral blood that could provide novel approaches in regenerative medicine for curing patients with acute ischemic stroke. There is accumulating evidence that EPCs can repair damaged endothelia and attenuate the development and progression of atherosclerosis. Also, EPCs can be recruited in response to acute ischemic events and participate in reparative vasculogenesis. Most studies related to EPCs have involved patients with cardiovascular diseases, and there is emerging evidence that EPCs represent a risk marker and a potential therapeutic agent in cerebrovascular disease. Here we review the characteristics and biology of EPCs in cerebrovascular disease and discuss the challenges that must be addressed to clarify the role and therapeutic applicability of EPCs in cerebrovascular disease.     

干细胞在心脏再生医学中的作用及中医药研究策略*☆

背景：中医对心脏再生有其独特认识,但中医药介入干细胞与心脏再生医学还处于初步探索阶段。目的：分析和总结干细胞与心脏再生相关的研究进展,对中医药如何介入心脏再生研究进行初步探讨。方法：以关键词“stem cell”与 “cardiac regenerative medicine”检索PubMed数据库、关键词“干细胞”与“中医”检索CNKI中国期刊全文数据库2000/2010的相关文献,语言种类不限,对符合标准的文献证据进行综合提炼分析。保留其中44篇进行归纳总结。结果与结论：分析表明干细胞应用于心脏再生医学的研究已广泛拓展,包括胚胎干细胞、骨髓干细胞、成体心脏干细胞等均显示了再生心肌的能力及其应用前景。中医对心脏再生的认识蕴含在阴阳观、五行母子规律及精气学说中。中医药要介入心脏再生医学,就需要对中医理论在心脏再生医学中的认识进行系统整理,深入挖掘中医复方,重视中药有效组分靶向干细胞及加强对有效方药作用机制的研究。