12 hours after cerebral ischemia is the optimal time for bone marrow mesenchymal stem cell transplantation

Cell therapy using stem cell transplantation against cerebral ischemia has been reported. However, it remains controversial regarding the optimal time for cell transplantation and the transplantation route. Rat models of cerebral ischemia were established by occlusion of the middle cerebral artery. At 1, 12 hours, 1, 3, 5 and 7 days after cerebral ischemia, bone marrow mesenchymal stem cells were injected via the tail vein. At 28 days after cerebral ischemia, rat neurological function was evaluated using a 6-point grading scale and the pathological change of ischemic cerebral tissue was observed by hematoxylin-eosin staining. Under the fluorescence microscope, the migration of bone marrow mesenchymal stem cells was examined by PKH labeling. Caspase-3 activity was measured using spectrophotometry. The optimal neurological function recovery, lowest degree of ischemic cerebral damage, greatest number of bone marrow mesenchymal stem cells migrating to peri-ischemic area, and lowest caspase-3 activity in the ischemic cerebral tissue were observed in rats that underwent bone marrow mesenchymal stem cell transplantation at 12 hours after cerebral ischemia. These findings suggest that 12 hours after cerebral ischemia is the optimal time for tail vein injection of bone marrow mesenchymal stem cell transplantation against cerebral ischemia, and the strongest neuroprotective effect of this cell therapy appears at this time.     

Stem cell‐based cell therapy for Huntington disease: A review

Huntington disease (HD) is a devastating neurodegenerative disorder and no proven medical therapy is currently available to mitigate its clinical manifestations. Although fetal neural transplantation has been tried in both preclinical and clinical investigations, the efficacy is not satisfactory. With the recent explosive progress of stem cell biology, application of stem cell‐based therapy in HD is an exciting prospect. Three kinds of stem cells, embryonic stem cells, bone marrow mesenchymal stem cells and neural stem cells, have previously been utilized in cell therapy in animal models of neurological disorders. However, neural stem cells were preferably used by investigators in experimental HD studies, since they have a clear capacity to become neurons or glial cells after intracerebral or intravenous transplantation, and they induce functional recovery. In this review, we summarize the current state of cell therapy utilizing stem cells in experimental HD animal models, and discuss the future considerations for developing new therapeutic strategies using neural stem cells.     

骨髓间充质干细胞治疗脑出血后神经功能障碍的研究进展

本文目的是对骨髓间充质干细胞治疗脑出血后功能障碍的研究进展进行综述，为脑出血的治疗提供参考。脑出血是一种对脑组织损害严重的疾病，在全世界范围内造成了沉重的公共健康负担。该病具有高致残率、高死亡率的特点，且治疗效果欠佳。骨髓间充质干细胞在移植后具有能定向分化为神经元并旁分泌神经营养因子的功能，成为治疗脑出血的新选择。     

Stem cell‐based cell therapy in neurological diseases: A review

Human neurological disorders such as Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis (ALS), Alzheimer's disease, multiple sclerosis (MS), stroke, and spinal cord injury are caused by a loss of neurons and glial cells in the brain or spinal cord. Cell replacement therapy and gene transfer to the diseased or injured brain have provided the basis for the development of potentially powerful new therapeutic strategies for a broad spectrum of human neurological diseases. However, the paucity of suitable cell types for cell replacement therapy in patients suffering from neurological disorders has hampered the development of this promising therapeutic approach. In recent years, neurons and glial cells have successfully been generated from stem cells such as embryonic stem cells, mesenchymal stem cells, and neural stem cells, and extensive efforts by investigators to develop stem cell‐based brain transplantation therapies have been carried out. We review here notable experimental and preclinical studies previously published involving stem cell‐based cell and gene therapies for Parkinson's disease, Huntington's disease, ALS, Alzheimer's disease, MS, stroke, spinal cord injury, brain tumor, and lysosomal storage diseases and discuss the future prospects for stem cell therapy of neurological disorders in the clinical setting. There are still many obstacles to be overcome before clinical application of cell therapy in neurological disease patients is adopted: 1) it is still uncertain what kind of stem cells would be an ideal source for cellular grafts, and 2) the mechanism by which transplantation of stem cells leads to an enhanced functional recovery and structural reorganization must to be better understood. Steady and solid progress in stem cell research in both basic and preclinical settings should support the hope for development of stem cell‐based cell therapies for neurological diseases. © 2009 Wiley‐Liss, Inc.     

自体骨髓间充质源神经干细胞移植应用于中枢神经系统疾病7例

背景：前期应用骨髓间充质源神经干细胞移植治疗模拟神经系统疾病动物实验模型取得较好效果。 目的：观察应用自体骨髓间充质源神经干细胞移植治疗中枢神经系统疾病的临床疗效。 方法：2008-10/2009-04应用自体骨髓间充质源神经干细胞移植治疗中枢神经系统疾病患者7例。骨髓穿刺术抽取自体骨髓血50~60 mL,在体外经过分离培养后,制成骨髓间充质干细胞悬液,由患者自体脑脊液诱导定向分化为神经干细胞,通过腰椎穿刺术经蛛网膜下腔鞘内注射输注方式移植。观察患者移植前后神经功能缺损症状及移植后不良反应。 结果与结论：经移植治疗后3例患者均未见不良反应。出院后随访6个月,7例患者神经功能缺损症状较移植前均有一定程度的改善。提示自体骨髓间充质源神经干细胞移植治疗中枢神经系统疾病所致的神经功能缺损疾病是一种安全、方便、有效的方法。     

Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment

Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors,the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located.Accordingly,the optimal microenvironment for inducing stem cell differentiation is a hot topic.EGb761 is extracted from the leaves of the Ginkgo biloba tree.It is used worldwide and is becoming one of the focuses of stem cell research.Studies have shown that EGb761 can antagonize oxygen free radicals,stabilize cell membranes,promote neurogenesis and synaptogenesis,increase the level of brain-derived neurotrophic factors,and replicate the environment required during the differentiation of stem cells into nerve cells.This offers the possibility of using EGb761 to induce the differentiation of stem cells,facilitating stem cell transplantation.To provide a comprehensive reference for the future application of EGb761 in stem cell therapy,we reviewed studies investigating the influence of EGb761 on stem cells.These started with the composition and neuropharmacology of EGb761,and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation.     

Potential effects of mesenchymal stem cell derived extracellular vesicles and exosomal miRNAs in neurological disorders

Mesenchymal stem cells are multipotent cells that possess anti-inflammatory, antiapoptotic and immunomodulatory properties. The effects of existing drugs for neurodegenerative disorders such as Alzheimer's disease are limited, thus mesenchymal stem cell therapy has been anticipated as a means of ameliorating neuronal dysfunction. Since mesenchymal stem cells are known to scarcely differentiate into neuronal cells in damaged brain after transplantation, paracrine factors secreted from mesenchymal stem cells have been suggested to exert therapeutic effects. Extracellular vesicles and exosomes are small vesicles released from mesenchymal stem cells that contain various molecules, including proteins, mRNAs and microRNAs. In recent years, administration of exosomes/extracellular vesicles in models of neurological disorders has been shown to improve neuronal dysfunctions, via exosomal transfer into damaged cells. In addition, various microRNAs derived from mesenchymal stem cells that regulate various genes and reduce neuropathological changes in various neurological disorders have been identified. This review summarizes the effects of exosomes/extracellular vesicles and exosomal microRNAs derived from mesenchymal stem cells on models of stroke, subarachnoid and intracerebral hemorrhage, traumatic brain injury, and cognitive impairments, including Alzheimer's disease.     

Molecular manipulation targeting regulation of dopaminergic differentiation and proliferation of neural stem cells or pluripotent stem cells

Parkinson's disease (PD) is a severe deliberating neurological disease caused by progressive degenerative death of dopaminergic neurons in the substantia nigra of midbrain. While cell replacement strategy by transplantation of neural stem cells and inducement of dopaminergic neurons is recommended for the treatment of PD, understanding the differentiation mechanism and controlled proliferation of grafted stem cells remain major concerns in their clinical application. Here we review recent studies on molecular signaling pathways in regulation of dopaminergic differentiation and proliferation of stem cells, particularly Wnt/beta-catenin signaling in stimulating formation of the dopaminergic phenotype, Notch signaling in inhibiting stem cell differentiation, and Sonic hedgehog functioning in neural stem cell proliferation and neuronal cell production. Activation of oncogenes involved in uncontrolled proliferation or tumorigenicity of stem cells is also discussed. It is proposed that a selective molecular manipulation targeting strategy will greatly benefit cell replacement therapy for PD by effectively promoting dopaminergic neuronal cell generation and reducing risk of tumorigenicity of in vivo stem cell applications.     

Mesenchymal Stem Cell-Derived Factors Restore Function to Human Frataxin-Deficient Cells

Friedreich’s ataxia is an inherited neurological disorder characterised by mitochondrial dysfunction and increased susceptibility to oxidative stress. At present, no therapy has been shown to reduce disease progression. Strategies being trialled to treat Friedreich’s ataxia include drugs that improve mitochondrial function and reduce oxidative injury. In addition, stem cells have been investigated as a potential therapeutic approach. We have used siRNA-induced knockdown of frataxin in SH-SY5Y cells as an in vitro cellular model for Friedreich’s ataxia. Knockdown of frataxin protein expression to levels detected in patients with the disorder was achieved, leading to decreased cellular viability, increased susceptibility to hydrogen peroxide-induced oxidative stress, dysregulation of key anti-oxidant molecules and deficiencies in both cell proliferation and differentiation. Bone marrow stem cells are being investigated extensively as potential treatments for a wide range of neurological disorders, including Friedreich’s ataxia. The potential neuroprotective effects of bone marrow-derived mesenchymal stem cells were therefore studied using our frataxin-deficient cell model. Soluble factors secreted by mesenchymal stem cells protected against cellular changes induced by frataxin deficiency, leading to restoration in frataxin levels and anti-oxidant defences, improved survival against oxidative stress and stimulated both cell proliferation and differentiation down the Schwann cell lineage. The demonstration that mesenchymal stem cell-derived factors can restore cellular homeostasis and function to frataxin-deficient cells further suggests that they may have potential therapeutic benefits for patients with Friedreich’s ataxia.     

Human neural stem cells genetically modified for brain repair in neurological disorders

Existence of multipotent neural stem cells (NSC) has been known in developing or adult mammalian CNS, including humans. NSC have the capacity to grow indefinitely and have multipotent potential to differentiate into three major cell types of CNS, neurons, astrocytes and oligodendrocytes. Stable clonal lines of human NSC have recently been generated from the human fetal telencephalon using a retroviral vector encoding v‐myc. One of the NSC lines, HB1.F3, carries normal human karyotype of 46XX and has the ability to self‐renew, differentiate into cells of neuronal and glial lineages, and integrate into the damaged CNS loci upon transplantation into the brain of animal models of Parkinson disease, HD, stroke and mucopolysaccharidosis. F3 human NSC were genetically engineered to produce L‐dihydroxyphenylalanine (L‐DOPA) by double transfection with cDNA for tyrosine hydroxylase and guanosine triphosphate cylohydrolase‐1, and transplantation of these cells in the brain of Parkinson disease model rats led to L‐DOPA production and functional recovery. Proactively transplanted F3 human NSC in rat striatum, supported the survival of host striatal neurons against neuronal injury caused by 3‐nitropro‐pionic acid in rat model of HD. Intravenously introduced through the tail vein, F3 human NSC were found to migrate into ischemic lesion sites, differentiate into neurons and glial cells, and improve functional deficits in rat stroke models. These results indicate that human NSC should be an ideal vehicle for cell replacement and gene transfer therapy for patients with neurological diseases. In addition to immortalized human NSC, immortalized human bone marrow mesenchymal stem cell lines have been generated from human embryonic bone marrow tissues with retroviral vectors encording v‐myc or teromerase gene. These immortalized cell lines of human bone marrow mesenchymal stem cells differentiated into neurons/glial cells, bone, cartilage and adipose tissue when they were grown in selective inducing media. There is further need for investigation into the neurogenic potential of the human bone marrow stem cell lines and their utility in animal models of neurological diseases.     

造血干细胞移植在肝脏疾病治疗中的应用与进展

造血干细胞基本来源于骨髓、脐带血及外周血,而终末期肝脏疾病患者身体状况很差,几乎不能耐受较大的创伤,因此用外周血干细胞移植的方法来获得转分化后的肝细胞,是一种很有发展潜力的方法。外周血干细胞移植时如果要获取足够数量的干细胞,必须对外周血进行动员,目前干细胞动员剂分为3种类型：化疗药物、硫酸葡聚糖等聚阴离子制剂、各种重组的人造血细胞刺激因子。对于有着严重肝脏疾病的患者来说,选用各种重组的人造血细胞刺激因子是相对安全的。在造血干细胞的分离方法中,目前应用最广泛的是密度梯度离心法,它可以获得富含单个核细胞的白细胞层,从而初步富集CD34+细胞。随着针对CD34+不同抗原决定簇的单克隆抗体的不断发现,准确、大量、快速阳性分选CD34+细胞的免疫学技术也在迅速开展,如固相分选技术、流式细胞仪分选等。利用造血干细胞的高度增殖能力及多向分化潜能,对其进行体外扩增和定向诱导分化,从而在短时间内产生大量的早期造血祖细胞,以及定向扩增的多种细胞如肝细胞等而应用于移植,目前应用骨髓造血干细胞转分化为肝细胞己获得成功。为判断在移植器官中真正转分化的细胞是否来源于输注的干细胞,常在移植前对输入细胞进行标记,标记的方法包括荧光标记、特殊染色、基因标记、染色体鉴定等,然后应用免疫学和分子生物学、荧光化学技术加以检测。现阶段应用造血干细胞移植治疗肝脏疾病多为基础实验,临床上尚未得到广泛运用。     

Transplantation of adipose tissue-derived stem cells for treatment of focal cerebral ischemia

The neurological functional disabilities caused by cerebral infarction significantly deteriorate life quality and increase the medical and socio-economic costs. Although some molecular agents show potential in acting against the pathological mechanisms in animal studies, none has been proven effective for cerebral ischemia treatment in human patients. New treatment strategy needs to be developed. Stem cell therapy is promising for neural regeneration and thus become one of the current trends. More evidence has shown stem cells, such as embryonic stem cells (ESCs), skeletal muscle satellite cells and mesenchymal stem cells, to be useful in tissue repair and regeneration. However all these stem cells mentioned above have limitations. Adipose tissue-derived stem cells (ADSCs) are an alternative autologous stem cell source for the characters as abundant, easy to obtain, immunological and ethic problem free. So far, this treatment strategy has been rarely adopted on ischemic brain injury. In this study, we investigated the transplantation effects of rat ADSCs for the treatment of cerebral ischemia in rats. ADSCs were isolated from rat adipose tissue and then induced to initiate neural differentiation. Following neural induction, ADSCs developed neural morphology and displayed molecular expression of Nestin, MAP2 and GFAP. We evaluate the neurobehavioral function, infarct volume and cell properties as apoptosis, survival, migration, proliferation, differentiation and immunogenicity. Treatment with i-ADSCs (induction from ADSCs) results in better functional recovery and more reduction in hemispheric atrophy then without i-ADSCs in other groups. Our study demonstrates that i-ADSCs therapy is promising in stroke treatment and finally leads to an efficacious therapeutic modalities for much better outcome in clinical patients.     

腰椎穿刺移植自体骨髓间充质干细胞治疗脑梗死后遗症6例

背景：骨髓间充质干细胞具有多向分化潜能,而且取材方便,扩增迅速,免疫原性低,在移植过程避免了免疫排斥等反应,是治疗脑梗死等神经系统疾病的理想种子细胞。 目的：探讨自体骨髓间充质干细胞培养后经腰穿治疗脑梗死后遗症的安全性、可行性及疗效。 方法：6例脑梗死后遗症患者进行自体骨髓间充质干细胞移植,骨穿采集自体骨髓单个核细胞,体外分离培养骨髓间充质干细胞4 d后经腰椎穿刺移植蛛网膜下腔,移植后观察疗效及并发症。 结果与结论：培养后骨髓间充质干细胞数量明显增多,患者手术前后肌力和NIHSS评分通过统计分析有显著性差异(P < 0.05),总体症状改善较术前有明显改善;移植后无严重不良事件发生。结果提示,自体骨髓间充质干细胞培养后移植治疗可使脑梗死后遗症患者症状明显改善,治疗安全有效且不良反应小。     

骨髓间充质干细胞向神经元样细胞的分化及其在细胞移植中的应用☆

学术背景：骨髓间充质干细胞主要存在于骨髓基质中,具有横向分化潜能,在适当的条件下可以向3个胚层的细胞进行分化。 目的：文章就骨髓间充质干细胞生物学特性、神经元诱导分化及其机制、细胞移植方面的最新进展进行综述。 检索策略：应用计算机检索PubMed1999/2007年相关文章,检索词为“bone marrow mesenchymal stem cells”,并限定文章语言种类为English。同时计算机检索中国期刊全文数据库1999/2007年相关文章,检索词为“骨髓间充质干细胞”,并限定文章语言种类为中文。对资料进行初审,并查看每篇文章后的引文。纳入标准：文章所述内容与骨髓间充质干细胞的发展现状及神经元诱导分化及机制和移植研究相关。排除标准：重复研究或较陈旧的文献。 文献评价：共收集到230篇相关文献,72篇文献符合纳入标准,排除的158篇文献为内容陈旧或重复文献。选取29篇文献进行分析,分别涉及骨髓间充质干细胞的分离培养和鉴定8篇、神经元细胞方向分化及其机制17篇、细胞移植治疗各种神经损伤的实验研究4篇。 资料综合：由于尚未找到骨髓间充质干细胞特异性标记物,其在体内的细胞生物学和分子生物学作用机制仍不清楚,如何限定体内外诱导条件使其向所需细胞或组织定向分化以及移植时机、是否具有致瘤性等问题尚需深入研究。但近来在骨髓间充质干细胞向神经细胞方向分化的诱导方法和机制,以及骨髓间充质干细胞移植治疗神经损伤方面取得很多成果。 结论：骨髓间充质干细胞具有易获得、易培养、低免疫原性等特性,已成为具有细胞治疗和基因治疗临床疾病潜在实用价值的有效载体。     

Neuronal differentiation of adipose-derived stem cells and their transplantation for cerebral ischemia

OBJECTIVE:To review published data on the biological characteristics,differentiation and applications of adipose-derived stem cells in ischemic diseases.DATA RETRIEVAL:A computer-based online search of reports published from January 2005 to June 2012 related to the development of adipose-derived stem cells and their transplantation for treatment of cerebral ischemia was performed in Web of Science using the key words "adipose-derived stem cells","neural-like cells","transplantation","stroke",and "cerebral ischemia".SELECTION CRITERIA:The documents associated with the development of adipose-derived stem cells and their transplantation for treatment of cerebral ischemia were selected,and those published in the last 3-5 years or in authoritative journals were preferred in the same field.Totally 89 articles were obtained in the initial retrieval,of which 53 were chosen based on the inclusion criteria.MAIN OUTCOME MEASURES:Biological characteristics and induced differentiation of adipose-derived stem cells and cell transplantation for disease treatment as well as the underlying mechanism of clinical application.RESULTS:The advantages of adipose-derived stem cells include their ease of procurement,wide availability,rapid expansion,low tumorigenesis,low immunogenicity,and absence of ethical constraints.Preclinical experiments have demonstrated that transplanted adipose-derived stem cells can improve neurological functions,reduce small regions of cerebral infarction,promote angiogenesis,and express neuron-specific markers.The improvement of neurological functions was demonstrated in experiments using different methods and time courses of adipose-derived stem cell transplantation,but the mechanisms remain unclear.CONCLUSION:Further research into the treatment of ischemic disease by adipose-derived stem cell transplantation is needed to determine their mechanism of action.     

Dopamine neurons from embryonic stem cells.

Embryonic stem (ES) cells are viewed as a potential cell source for transplantation therapy in Parkinson's disease, with major advantages with respect to fetal cells regarding availability and standardization. Both in terms of proliferation and differentiation potential ES cells appear more promising than adult neural stem cells for replacement therapies. However, other cell-based therapies may take advantage of the special characteristics of neural stem cells. For dopamine neuronal replacement therapy, the first requisite is to generate neurons that have a correct and stable midbrain dopamine phenotype. Inductive protocols that mimick sequential developmental events have been recently developed for human ES cells. Genetic engineering techniques can also be used to induce or enhance phenotypic specification. Finally, nuclear transfer technology could provide insights into disease and individual specific mechanisms, helping to develop and test therapies rather than for direct therapeutic application.

Neurología 2004;19(Supl 2):73-76

     

Neural induction of adult bone marrow and umbilical cord stem cells

Recent reports of neural differentiation of postnatally derived bone marrow and umbilical cord cells have transformed our understanding of the biology of cell lineages, differentiation, and plasticity. While much controversy remains, it is clear that adult tissues, and bone marrow in particular, are composed in part of cells with much more diverse lineage capacity than previously thought. Traditionally, cell-based therapies for the CNS have been derived from fetal or embryonic origin. By harnessing the neural potential of readily-available and accessible adult bone marrow and umbilical cord blood stem cells, substantial ethical and technical dilemmas may be circumvented. This review will focus on the potential of adult bone marrow derived cells and umbilical cord blood stem cells for cell replacement and repair therapies of the central nervous system. The various isolation protocols, phenotypic properties, and methods for in vivo and in vitro neural differentiation of mesenchymal stem cells/marrow stromal cells (MSC), hematopoietic stem cells (HSC), multipotent adult progenitor cells (MAPCs), and umbilical cord blood stem cells (UCBSC) will be discussed. Current progress regarding transplant paradigms in various disease models as well as in our understanding of transdifferentiation mechanisms will be presented.     

Cell therapy for central nervous system disorders: Current obstacles to progress

Cell therapy for disorders of the central nervous system has progressed to a new level of clinical application. Various clinical studies are underway for Parkinson's disease, stroke, traumatic brain injury, and various other neurological diseases. Recent biotechnological developments in cell therapy have taken advantage of the technology of induced pluripotent stem (iPS) cells. The advent of iPS cells has provided a robust stem cell donor source for neurorestoration via transplantation. Additionally, iPS cells have served as a platform for the discovery of therapeutics drugs, allowing breakthroughs in our understanding of the pathology and treatment of neurological diseases. Despite these recent advances in iPS, adult tissue‐derived mesenchymal stem cells remain the widely used donor for cell transplantation. Mesenchymal stem cells are easily isolated and amplified toward the cells' unique trophic factor‐secretion property. In this review article, the milestone achievements of cell therapy for central nervous system disorders, with equal consideration on the present translational obstacles for clinic application, are described.     

血小板裂解液对脐带间充质干细胞增殖与分化的影响

背景：脐带间充质干细胞是近年来干细胞生物学研究中发现的重要细胞之一，在细胞治疗领域有着良好的应用前景。血小板裂解液对于干细胞的增殖及诱导分化都存在不同程度的有利作用，在一定程度上甚至可以代替甚至优于血清在培养基中的作用。 目的：对血小板裂解液结合脐带间充质干细胞的研究作一综述。 方法：于万方等中文数据库和PubMed等英文数据库中，以“脐带，间充质干细胞，血小板裂解液，分化，增殖”为关键词检索文献，总结脐带间充质干细胞及血小板裂解液的生物学特性和相关临床应用，并汇总有关血小板裂解液对脐带间充质干细胞增殖活性和诱导分化能力影响的研究结果。 结果与结论：血小板裂解液对脐带间充质干细胞的增殖活性及诱导分化有正面影响，这使血小板裂解液在干细胞移植治疗中将会起到无可比拟的作用。