骨髓间质干细胞联合脑源性神经营养因子用于大鼠脑出血的实验研究

目的观察骨髓间质干细胞(MSCs)联合脑源性神经营养因子(BDNF)治疗大鼠脑出血(ICH)的疗效。方法建立大鼠ICH模型,体外培养标记纯化的MSCs,经侧脑室植入脑部,同时局部注入BDNF。记录对照组、BDNF组、MSCs组和MSCs+BDNF组7d、14d、21d大鼠神经功能改善程度;免疫组化法检测MSCs脑内迁移及分化;电子显微镜观察神经凋亡细胞。结果 MSCs组大鼠运动功能有明显改善,MSCs+BDNF组对ICH损伤的修复作用最明显。MSCs+BDNF组各时间点MSCs阳性细胞数及NEUN、GFAP、CNP免疫阳性细胞数均高于MSCs组(P<0.01),且MSCs+BDNF组神经细胞凋亡程度最轻。结论 MSCs脑部移植可促进大鼠ICH损伤部位结构和功能修复,BDNF对其修复具有协同作用。     

大鼠脑出血模型应用骨髓间质干细胞治疗的实验研究

目的 :研究骨髓间质干细胞 (MSCs)移植对脑出血大鼠的治疗效果及机制。方法 :分离MSCs后进行培养、扩增 ,并用流式细胞仪进行荧光三标检测鉴定 ,将标记后的MSCs通过颈动脉、颈静脉、侧脑室 3种途径移植入脑出血大鼠体内 ,用爬行计分法观察大鼠神经功能的改善程度 ,免疫组化法观察在脑内的迁移及分化。结果 :MSCs增殖明显 ,经流式细胞仪检测显示CD90、CD10 6阳性、CD45阴性 ,通过侧脑室、颈动脉移植后大鼠神经功能改善明显 ,移植的MSCs主要迁移到海马区、出血灶等处 ,且分化为神经细胞。结论 :MSCs移植治疗脑出血具有较好的疗效 ,可能分化为神经细胞是其主要机制之一。     

星形胶质细胞诱导成年骨髓基质细胞分化成神经元样细胞的实验研究

目的探讨星形胶质细胞能否在体外诱导成年大鼠骨髓基质细胞向神经元方向分化。方法采用新生鼠海马组织来源的星形胶质细胞与转染有绿色荧光蛋白基因的骨髓基质细胞(MSCs)进行共培养,并分成三组:共培养组、共培养 脑源性神经营养因子(BDNF)组、单纯碱性成纤维生长因子(bFGF) BDNF诱导分化组,在相差显微镜下每日观察、记录MSCs的诱导分化状况,并应用免疫荧光染色技术对分化后的MSCs进行鉴定,同时应用流式细胞术测定MSCs分化前后及星形胶质细胞的DNA含量。结果共培养第4天,部分MSCs已初步具备神经元形态:折光性强的锥形或圆形胞体及长的多极突起,免疫荧光染色呈微管相关蛋白(MAP-2ab)、神经元特异性烯醇化酶(NSE)阳性;DNA的含量测定结果显示诱导分化后第7天未发现有四倍体、六倍体细胞。结论(1)星形胶质细胞可以在体外诱导成年大鼠MSCs向神经元方向分化,这种分化并不是由细胞融合引起的。(2)星形胶质细胞具有调控神经元的分化、促进神经元成熟的功能。     

Intravenous transplantation of bone marrow mesenchymal stem cells promotes neural regeneration after traumatic brain injury

To investigate the supplement of lost nerve cells in rats with traumatic brain injury by intravenous administration of allogenic bone marrow mesenchymal stem cells, this study established a Wistar rat model of traumatic brain injury by weight drop impact acceleration method and administered 3 × 106 rat bone marrow mesenchymal stem cells via the lateral tail vein. At 14 days after cell transplantation, bone marrow mesenchymal stem cells differentiated into neurons and astrocytes in injured rat cerebral cortex and rat neurological function was improved significantly. These findings suggest that intravenously administered bone marrow mesenchymal stem cells can promote nerve cell regeneration in injured cerebral cortex, which supplement the lost nerve cells.     

Human bone marrow stem cells exhibit neural phenotypes and ameliorate neurological deficits after grafting into the ischemic brain of rats

There is now evidence to suggest that bone marrow mesenchymal stem cells (MSCs) not only differentiate into mesodermal cells, but can also adopt the fate of endodermal and ectodermal cell types. In this study, we addressed the hypotheses that human MSCs can differentiate into neural cells when implanted in the brain and restore sensorimotor function after experimental stroke. Purified human MSCs were grafted into the cortex surrounding the area of infarction 1 week after cortical brain ischemia in rats. Two and 6 weeks after transplantation animals were assessed for sensorimotor function and then sacrificed for histological examination. Ischemic rats that received human MSCs exhibited significantly improved functional performance in limb placement test. Histological analyses revealed that transplanted human MSCs expressed markers for astrocytes (GFAP(+)), oligodendroglia (GalC(+)), and neurons (beta III(+), NF160(+), NF200(+), hNSE(+), and hNF70(+)). The morphological features of the grafted cells, however, were spherical in nature with few processes. Therefore, it is unlikely that the functional recovery observed by the ischemic rats with human MSC grafts was mediated by the integration of new "neuronal" cells into the circuitry of the host brain. The observed functional improvement might have been mediated by proteins secreted by transplanted hMSCs, which could have upregulated host brain plasticity in response to experimental stroke.     

大鼠胚胎神经干细胞移植治疗脑出血的实验研究

目的 研究大鼠胚胎神经干细胞移植治疗脑出血的可行性。方法 从孕龄16天的大鼠胚胎脑组织中分离、培养神经干细胞并诱导其分化，通过免疫组化学技术研究其特性。制作大鼠脑出血模型，3天后将未分化的神经干细胞注入血肿同侧或对侧的尾状核内，记录损伤和移植后的大鼠运动功能。不同时间杀死大鼠，研究移植后的干细胞在体内分化和迁徙的情况。结果 实验中分离、培养的神经干细胞体外能够被诱导分化成神经元、光突胶质细胞和星形胶质细胞，血肿同侧移植干细胞的大鼠运动功能的改善显著好于血肿对侧移植干细胞组及未移植干细胞的对照组。免疫组化方法证实移植后的干细胞在体内可分化成神经元和胶质细胞，并向损伤区域迁徙。结论 大鼠胚胎神经干细胞体内、体外均具有多向分化潜能，其分化成各种类型神经细胞的比例与所处的外界环境有关，在脑内靠近损伤部位移植胚胎神经干细胞后能够有效改善脑出血动物的运动功能。     

Intraventricular transplantation of embryonic stem cell-derived neural stem cells in intracerebral hemorrhage rats

In the present study, we attempted to explore cell transplantation therapy for intracerebral hemorrhage (ICH) using embryonic stem (ES) cells. Collagenase-induced ICH rats were used as model animals. Mouse ES cells were differentiated into nestin-positive neural stem cells in vitro by alltrans retinoic acid (ATRA). ATRA-treated ES cells (10(5)) were transplanted into the lateral ventricle in the hemisphere contralateral to the hemorrhage 7 days after collagenase infusion. Twenty-eight days after transplantation, ES-derived neurons and astrocytes were observed around the hematoma cavities of the brain in all of the ten rats receiving grafts. Graft-derived neurons were found in the subependymal area of the lateral ventricle as cellular nodules. Although one of the ten rats receiving grafts showed uncontrolled growth of astroglia derived from the ES cells, intraventricular transplantation of ATRA-treated ES cells is an effective delivery system of neuronal lineage-committed progenitor cells toward the site of ICH.     

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.     

人羊膜上皮细胞侧脑室移植治疗脑出血大鼠实验研究

目的 探讨人羊膜上皮细胞(hAECs)侧脑室移植对脑出血(ICH)大鼠脑水肿与神经功能恢复的影响.方法 分离培养hAECs,用Hoechst33258和增强绿色荧光蛋白(EGFP)标记hAECs,将其移植入脑出血大鼠侧脑室中,测试大鼠28 d内的运动功能变化与脑水肿的动态变化,并行免疫组织化学观察.结果 移植hAECs沿大鼠侧脑室壁生长,细胞存活4 w以上.巢蛋白(nestin)与波形蛋白(vim)免疫组化检测呈阳性表达,病灶周围小胶质细胞OX-42染色阳性细胞减少.移植组ICH大鼠脑含水量减少,神经功能明显改善.结论 hAECs移植到ICH大鼠侧脑室可存活,表达神经元特异性抗原,并减轻ICH大鼠脑水肿,改善运动功能.     

Neural differentiation of human Wharton's jelly-derived mesenchymal stem cells improves the recovery of neurological function after transplantation in ischemic stroke rats

Human Wharton’s jelly-derived mesenchymal stem cells(h WJ-MSCs)have excellent proliferative ability,differentiation ability,low immunogenicity,and can be easily obtained.However,there are few studies on their application in the treatment of ischemic stroke,therefore their therapeutic effect requires further verification.In this study,h WJ-MSCs were transplanted into an ischemic stroke rat model via the tail vein 48 hours after transient middle cerebral artery occlusion.After 4 weeks,neurological functions of the rats implanted with h WJ-MSCs were significantly recovered.Furthermore,many h WJ-MSCs homed to the ischemic frontal cortex whereby they differentiated into neuron-like cells at this region.These results confirm that h WJ-MSCs transplanted into the ischemic stroke rat can differentiate into neuron-like cells to improve rat neurological function and behavior.     

脑出血大鼠脑内神经干细胞移植的研究

目的分离并克隆新生大鼠神经干细胞,研究其移植入脑出血大鼠脑内的生物学特征,了解神经干细胞移植治疗脑出血的可行性.方法用尾状核注射Ⅶ型胶原酶制作脑出血模型,从Wistar新生大鼠脑室下区分离并克隆神经干细胞,经Brdu(5-溴脱氧尿嘧啶)掺入标记后移植入脑出血同侧的侧脑室或脑出血对侧的尾状核中.经免疫组织化学鉴定了解移植细胞在大鼠脑内的生存、迁移及分化情况.结果将稳定培养的神经干细胞移植入脑出血大鼠脑内,发现移植后4 d移植细胞仍存在.侧脑室移植组中移植细胞多在侧脑室周边区存在,尾状核移植组可见移植细胞开始向对侧迁移.免疫荧光双标证实细胞大多分化成神经元,少部分分化成胶质细胞.结论神经干细胞移植入脑出血大鼠脑内后能够存活,并能有效地穿过室管膜和向脑出血部位迁移.移植细胞在脑内大部分分化成神经元,少部分分化成胶质细胞.     

Neuronal differentiation following transplantation of expanded mouse neurosphere cultures derived from different embryonic forebrain regions

In vitro, expanded neurospheres exhibit multipotent properties and can differentiate into neurons, astrocytes and oligodendrocytes. In vivo, cells from neurospheres derived from mouse fetal forebrain have previously been reported to predominantly differentiate into glial cells, and not into neurons. Here we isolated stem/progenitor cells from E13.5 lateral ganglionic eminence (LGE), medial ganglionic eminence (MGE) and cortical primordium, of a green fluorescent protein (GFP)-actin transgenic mouse. Free-floating neurospheres were expanded in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) and implanted after five to six passages into the striatum, hippocampus and cortex of neonatal rats. Cell suspensions of primary LGE tissue were prepared and grafted in parallel. Grafted cells derived from the primary tissue displayed widespread incorporation into all regions, as visualized with the mouse-specific antibody M2, or mouse satellite DNA in situ hybridization, and differentiated into both neurons, astrocytes and oligodendrocytes. Grafts of neurosphere cells derived from the LGE, MGE and cortical primordium differentiated primarily into astrocytes, but contained low but significant numbers of GFP-immunoreactive neurons. Neurons derived from LGE neurospheres were of three types: cells with the morphology of medium-sized densely spiny projection neurons in the striatum; cells with interneuron-like morphologies in striatum, cortex and hippocampus; and cells integrating into SVZ and migrating along the RMS to the olfactory bulb. MGE- or cortical primordium-derived neurospheres differentiated into interneuron-like cells in both striatum and hippocampus. The results demonstrate the ability of in vitro expanded neural stem/progenitor cells to generate both neurons and glia after transplantation into neonatal recipients, and differentiate in a region-specific manner into mature neurons with morphological features characteristic for each target site.     

Generation of neural stem cell-like cells from bone marrow-derived human mesenchymal stem cells

Under appropriate culture conditions, bone marrow (BM)-derived mesenchymal stem cells are capable of differentiating into diverse cell types unrelated to their phenotypical embryonic origin, including neural cells. Here, we report the successful generation of neural stem cell (NSC)-like cells from BM-derived human mesenchymal stem cells (hMSCs). Initially, hMSCs were cultivated in a conditioned medium of human neural stem cells. In this culture system, hMSCs were induced to become NSC-like cells, which proliferate in neurosphere-like structures and express early NSC markers. Like central nervous system-derived NSCs, these BM-derived NSC-like cells were able to differentiate into cells expressing neural markers for neurons, astrocytes, and oligodendrocytes. Whole-cell patch clamp recording revealed that neuron-like cells, differentiated from NSC-like cells, exhibited electrophysiological properties of neurons, including action potentials. Transplantation of NSC-like cells into mouse brain confirmed that these NSC-like cells retained their capability to differentiate into neuronal and glial cells in vivo. Our data show that multipotent NSC-like cells can be efficiently produced from BM-derived hMSCs in culture and that these cells may serve as a useful alternative to human neural stem cells for potential clinical applications such as autologous neuroreplacement therapies.     

Pluripotent stem cells engrafted into the normal or lesioned adult rat spinal cord are restricted to a glial lineage

Proliferating populations of undifferentiated neural stem cells were isolated from the embryonic day 14 rat cerebral cortex or the adult rat subventricular zone. These cells were pluripotent through multiple passages, retaining the ability to differentiate in vitro into neurons, astrocytes, and oligodendrocytes. Two weeks to 2 months after engraftment of undifferentiated, BrdU-labeled stem cells into the normal adult spinal cord, large numbers of surviving cells were seen. The majority of the cells differentiated with astrocytic phenotype, although some oligodendrocytes and undifferentiated, nestin-positive cells were detected; NeuN-positive neurons were not seen. Labeled cells were also engrafted into the contused adult rat spinal cord (moderate NYU Impactor injury), either into the lesion cavity or into the white or gray matter both rostral and caudal to the injury epicenter. Up to 2 months postgrafting, the majority of cells either differentiated into GFAP-positive astrocytes or remained nestin positive. No BrdU-positive neurons or oligodendrocytes were observed. These results show robust survival of engrafted stem cells, but a differentiated phenotype restricted to glial lineages. We suggest that in vitro induction prior to transplantation will be necessary for these cells to differentiate into neurons or large numbers of oligodendrocytes.     

Enhanced electrical responsiveness in the cerebral cortex with oral melatonin administration after a small hemorrhage near the internal capsule in rats

Intracerebral hemorrhage (ICH) can cause direct brain injury at the insult site and indirect damage in remote brain areas. Although a protective effect of melatonin (ML) has been reported for ICH, its detailed mechanisms and effects on remote brain injury remain unclear. To clarify the mechanism of indirect neuroprotection after ICH, we first investigated whether ML improved motor function after ICH and then examined the underlying mechanisms. The ICH model rat was made by collagenase injection into the left globus pallidus, adjacent to the internal capsule. ML oral administration (15 mg/kg) for 7 days after ICH resulted in significant recovery of motor function. Retrograde labeling of the corticospinal tract by Fluoro‐Gold revealed a significant increase in numbers of positive neurons in the cerebral cortex. Immunohistological analysis showed that ML treatment induced no difference in OX41‐positive activated microglia/macrophage at day 1 (D1) but a significant reduction in 8‐hydroxydeoxyguanosin‐positive cells at D7. Neutral red assay revealed that ML significantly prevented H₂O₂‐induced cell death in cultured oligodendrocytes and astrocytes but not in neurons. Electrophysiological response in the cerebral cortex area where the number of Fluoro‐Gold‐positive cells was increased was significantly improved in ML‐treated rats. These data suggest that ML improves motor abilities after ICH by protecting oligodendrocytes and astrocytes in the vicinity of the lesion in the corticospinal tract from oxidative stress and causes enhanced electrical responsiveness in the cerebral cortex remote to the ICH pathology. © 2014 Wiley Periodicals, Inc.     

Gliosis and brain remodeling after treatment of stroke in rats with marrow stromal cells

The long-term (4-month) responses to treatment of stroke in the older adult rat, using rat bone marrow stromal cells (MSCs), have not been investigated. Retired breeder rats were subjected to middle cerebral artery occlusion (MCAo) alone, or injected intravenously with 3 x 10(6) MSCs, at 7 days after MCAo. Functional recovery was measured using an adhesive-removal patch test and a modified neurological severity score. Bromodeoxyuridine, a cell proliferation marker, was injected daily for 14 before sacrifice. Animals were sacrificed 4 months after stroke. Double immunostaining was used to identify cell proliferation and cell types for axons, astrocytes, microglia, and oligodendrocytes. MSC treatment induced significant improvement in neurological outcome after MCAo compared with control rats. MSC treatment reduced the thickness of the scar wall (P < 0.05) and reduced the numbers of microglia/macrophages within the scar wall (P < 0.01). Double staining showed increased expression of an axonal marker (GAP-43), among reactive astrocytes in the scar boundary zone and in the subventricular zone in the treated rats. Bromodeoxyuridine in cells preferentially colocalized with markers of astrocytes (GFAP) and oligodendrocytes (RIP) in the ipsilateral hemisphere, and gliogenesis was enhanced in the subventricular zone of the rats treated with MSCs. This is the first report to show that MSCs injected at 7 days after stroke improve long-term neurological outcome in older animals. Brain tissue repair is an ongoing process with reactive gliosis, which persists for at least 4 months after stroke. Reactive astrocytes responding to MSC treatment of ischemia may also promote axonal regeneration during long-term recovery.     

Topically applied adipose-derived mesenchymal stem cell treatment in experimental focal cerebral ischemia

In this study, the neuro-modulation effect of topical mesenchymal stem cells (MSCs) was tested in a rodent middle carotid artery occlusion (MCAO) model. Twenty-four hours after MCAO, craniotomy was made and 0.8 × 10⁶ GFP-MSCs were topically applied to the exposed parietal cortex. The MSCs were fixed in position by a thin layer of fibrin glue (N = 30). In the control group, saline were topically applied to the ipsilateral parietal cortex (N = 30). Three days after topical application, few GFP-positive cells were found in the ischemic penumbra. They expressed GFAP and NeuN. Topical MSCs triggered microglial activation, astrocytosis and cellular proliferation at day 3. The recovery of neurological functions were significantly enhanced as determined in Rotarod test and Morris Water Maze test with smaller infarct volume. PCR array showed that expressions of ten genes of neurogenesis were altered in the penumbra region (fold change > 1.25, p < 0.05) in MSCs group: Apoe, Ascl1, Efnb1, Mef2c, Nog, A100a6 and B2m were up-regulated; Pax2, Pax3 and Th were down-regulated. In conclusion, topical application provided a direct and effective transplant method for the delivery of MSCs to the surface of ipsilateral cerebral cortex and the topical MSCs could improve the neurological function from cerebral ischemia resulting from a major cerebral artery occlusion in a rodent experimental model.     

大鼠脑出血后脑组织转铁蛋白表达的实验研究

目的　探讨大鼠自发性脑出血 (ICH)后不同时间脑组织中转铁蛋白 (Tf)的表达及其规律。方法　采用立体定向技术注入自体不凝血建立实验性大鼠ICH模型 ,在不同时间断头取脑 ,免疫组化染色检测脑组织中Tf阳性细胞的表达并与对照组比较。结果　ICH后 6h血肿周围及同侧大脑皮质Tf阳性细胞的表达增高 ,72h达高峰 ,然后下降 ,但第 7d时仍高于对照组 (P <0 0 5 )。结论　ICH后血肿周围和同侧大脑皮质Tf阳性细胞表达增高 ,推测Tf可能参与了ICH后神经元的保护并减轻迟发性脑水肿     

人胚海马神经干细胞体外培养及分化研究

目的 研究人胚胎海马神经干细胞体外长期培养的条件和其在自主分化条件下的分化能力和分化特点。方法 从人胚胎海马分离神经干细胞。采用无血清培养法，进行体外培养、扩增，形成神经球。使神经球贴壁分化，分化培养基不含有任何细胞有丝分裂促进剂。使用5-溴脱氧尿嘧啶核苷(BrdU)标记分裂增生的细胞，观察细胞的分裂增殖情况。使用免疫细胞化学法鉴定神经干细胞及其在不加诱导剂下的自主分化能力。结果 从人胚胎海马分离的神经干细胞具有增殖能力，细胞倍增时间为3．2d。BrdU检测有正在分裂、增殖的细胞。细胞贴壁分化后可以出现Nestin、GFAP、Tuj-1表达阳性的细胞。神经干细胞共培养6个月，传代14代。结论 分离培养的海马神经干细胞具有自我更新和增殖能力，可以长期培养。在不加任何诱导剂的自主分化条件下可以向神经元、胶质细胞分化。少突胶质细胞的培养需要不同的培养条件。分离培养的干细胞具有神经干细胞的特征。可用于基础和临床的相关研究。     

Magnetic resonance tracking of transplanted bone marrow and embryonic stem cells labeled by iron oxide nanoparticles in rat brain and spinal cord

Nuclear magnetic resonance (MR) imaging provides a noninvasive method for studying the fate of transplanted cells in vivo. We studied, in animals with a cortical photochemical lesion or with a balloon-induced spinal cord compression lesion, the fate of implanted rat bone marrow stromal cells (MSCs) and mouse embryonic stem cells (ESCs) labeled with superparamagnetic iron oxide nanoparticles (Endorem). MSCs were colabeled with bromodeoxyuridine (BrdU), and ESCs were transfected with pEGFP-C1 (eGFP ESCs). Cells were either grafted intracerebrally into the contralateral hemisphere of the adult rat brain or injected intravenously. In vivo MR imaging was used to track their fate; Prussian blue staining and electron microscopy confirmed the presence of iron oxide nanoparticles inside the cells. During the first week postimplantation, grafted cells migrated to the lesion site and populated the border zone of the lesion. Less than 3% of MSCs differentiated into neurons and none into astrocytes; 5% of eGFP ESCs differentiated into neurons, whereas 70% of eGFP ESCs became astrocytes. The implanted cells were visible on MR images as a hypointense area at the injection site, in the corpus callosum and in the lesion. The hypointense signal persisted for more than 50 days. The presence of GFP-positive or BrdU-positive and nanoparticle-labeled cells was confirmed by histological staining. Our study demonstrates that both grafted MSCs and eGFP ESCs labeled with a contrast agent based on iron oxide nanoparticles migrate into the injured CNS. Iron oxide nanoparticles can therefore be used as a marker for the long-term noninvasive MR tracking of implanted stem cells.