Human umbilical cord blood-derived mesenchymal stem cells promote regeneration of crush-injured rat sciatic nerves

Several studies have demonstrated that human umbilical cord blood-derived mesenchymal stem cells can promote neural regeneration following brain injury. However, the therapeutic effects of human umbilical cord blood-derived mesenchymal stem cells in guiding peripheral nerve regeneration remain poorly understood. This study was designed to investigate the effects of human umbilical cord blood-derived mesenchymal stem cells on neural regeneration using a rat sciatic nerve crush injury model. Human umbilical cord blood-derived mesenchymal stem cells (1 × 10 6 ) or a PBS control were injected into the crush-injured segment of the sciatic nerve. Four weeks after cell injection, brain-derived neurotrophic factor and tyrosine kinase receptor B mRNA expression at the lesion site was increased in comparison to control. Furthermore, sciatic function index, Fluoro Gold-labeled neuron counts and axon density were also significantly increased when compared with control. Our results indicate that human umbilical cord blood-derived mesenchymal stem cells promote the functional recovery of crush-injured sciatic nerves.     

Transplantation of mesenchymal stem cells from human umbilical cord versus human umbilical cord blood for peripheral nerve regeneration

BACKGROUND: Mesenchymal stem cells (MSCs) appear to be a good alternative to Schwann cells in the treatment of peripheral nerve injury. Fetal stem cells, like umbilical cord blood (UCB) and umbilical cord (UC) stem cells, have several advantages over adult stem cells.OBJECTIVE: To assess the effects of UC-derived MSCs (UCMSCs) and UCB-derived MSCs (UCBMSCs) in repair of sciatic nerve defects. DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the laboratory of Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, from July to December 2009. MATERIALS: UCMSCs were provided by the Research Institute of Biotechnology, Dongguk University. UCBMSCs were provided by the Laboratory of Stem Cells and Tumor Biology, College of Veterinary Medicine, Seoul National University. Dulbecco's modified Eagle's medium (DMEM) was purchased from Gibco-BRL, USA. METHODS: Seven-week-old Sprague-Dawley rats were randomly and evenly divided into three groups: DMEM, UCBMSCs, and UCMSCs. A 10-mm defect in the left sciatic nerve was constructed in all rats. DMEM (15 μL) containing 1 × 106 UCBMSCs or UCMSCs was injected into the gap between nerve stumps, with the surrounding epineurium as a natural conduit. For the DMEM group, simple DMEM was injected. MAIN OUTCOME MEASURES: At 7 weeks after sciatic nerve dissection, dorsal root ganglia neurons were labeled by fluorogold retrograde labeling. At 8 weeks, electrophysiology and histomorphometry were performed. At 2, 4, 6, and 8 weeks after surgery, sciatic nerve function was evaluated using gait analysis.RESULTS: The UCBMSCs group and the UCMSCs group exhibited similar sciatic nerve function and electrophysiological indices, which were better than the DMEM group, as measured by gait analysis (P < 0.05). Fluorogold retrograde labeling of sciatic nerve revealed that the UCBMSCs group demonstrated a higher number of labeled neurons; however, the differences were not significant. Histomorphometric indices were similar in the UCBMSCs and UCMSCs groups, and total axon counts, particularly axon density (P < 0.05), were significantly greater in the UCBMSCs and UCMSCs groups than in the DMEM group. CONCLUSION: Transplanting either UCBMSCs or UCMSCs into axotomized sciatic nerves could accelerate and promote sciatic nerve regeneration over 8 weeks. Both treatments had similar effects on nerve regeneration.     

移植人脐带间充质干细胞修复大鼠脊髓损伤

背景：已知人脐带间充质干细胞对脊髓损伤存在着潜在的治疗价值,然而,当前对移植人脐带间充质干细胞治疗脊髓损伤及机制方面研究很少。 目的：观察人脐带间充质干细胞对脊髓损伤大鼠的治疗效果。 方法：40只Wistar大鼠建立脊髓损伤模型,38只造模成功后随机摸球法分为3组：空白对照组：只接受单纯损伤,不做任何移植;DMEM移植组：损伤后1周予以5 μL DMEM局部移植;细胞移植组：损伤后1周予以5 μL准备好的人脐带间充质干细胞局部移植(细胞数1×106)。移植后对实验动物通过BBB评分、体感诱发电位与运动诱发电位观察后肢功能恢复情况。分别于损伤后2,4,6,8,10周随机于细胞移植组抽取大鼠2只,免疫组织化学染色观察人脐带间充质干细胞存活、迁移、分化,通过胶质纤维酸性蛋白阳性细胞染色比较各组损伤局部胶质瘢痕形成面积。 结果与结论：BBB评分损伤后4周细胞移植组高于其他两组(P < 0.05),损伤后12周细胞移植组与其他两组相比SEP、MEP潜伏期缩短、波幅值增高(P < 0.05)。免疫组织化学染色示人脐带间充质干细胞可向神经元、星形胶质细胞和少突胶质细胞分化,分化的少突胶质细胞并包绕轴突形成髓鞘。细胞移植组损伤局部胶质瘢痕面积均小于其他两组(P < 0.05),空白对照组、DMEM移植组间差异无显著性(P > 0.05)。提示未经体外诱导的人脐带间充质干细胞可于损伤大鼠脊髓体内向神经元、星形胶质细胞、少突胶质细胞分化,减小胶质瘢痕,并促进脊髓损伤大鼠神经功能的恢复。     

Comparison of the efficacy in promoting peripheral nerve regeneration between the human umbilical cord mesenchymal stem cells and umbilical cord blood mesenchymal stem cells in a perineurial conduit model

BACKGROUND: Mesenchymal stem cells (MSCs) appear to be alternatives for Schwann cell at the repair of peripheral nerve injury using cell therapy strategy. Fetal stem cell-like umbilical cord blood (UCB) and umbilical cord (UC) stem cells have several advantages over adult stem cells.OBJECTIVE: The purpose of this study was to assess nerve regeneration following transplantation of undifferentiated mesenchymal stem cells from umbilical origin, UCB and UC at the sciatic nerve defect DESIGN, TIME and SETTING: The randomized, controlled animal study was performed at the Laboratory of Department of Oral and Maxillofaical Surgery, Seoul National Univiersity Dental Hospital, from July to November 2008MATERIALS: Umiblical cord blood mesenchymal stem cell (obtained from Research Institute of Biotechnology, Dongguk University), umbilical cord blood mesenchymal stem cell (obtained from the lab of stem cell and tumor biology, College of Veterinary Medicine, Seoul National University) and Dulbecco’s modified Eagle’s medium (LG-DMEM; Gibco-BRL, USA) were used in this studyMETHODS: Six-week-old rats were randomly grouped into a DMEM group (n=10), a UCBMSC group (n=10) and a UCMSC group (n=10). At the axotomy defecct (5mm in length), UCBMSC or UCMSC (1 x 1,000,000 cells in 15 μl media) were injected into the gap between the nerve stumps, with the surrounding epineurium as a natural conduit. For a control group, the defect was filled with DMEM. An approval for animal disposal by the ethics committee of Seoul Natonal University was done.MAIN OUTCOME MEASURES: The sciatic function index (at 2, 4, 6 and 8 weeks postoperatively), retrograde labeling (at 7 weeks after axotomy), and electrophysiological and histomorphometric analysis (at 8 weeks postoperatively) was done. RESULTS: The UCBMSC group and the UCMSC group exhibited better nerve recovery than the DMEM group as measured by gait analysis (p<0.05) and electrophysiolocial assessment(p<0.05). However, there were no differences between the UCBMSC and the UCMSC groups. After retrograde labeling, the UCBMSC group demonstrated a higher number of labeled neurons, but the diffefences between the groups were not significant. Histomorphometric analysis revelaed that axon density, total axon count, and myelin thickness of the UCBMSC and UCMSC groups were higher than that of the DMEM group. Furthermore, significant differences in axon density were noted(p<0.05). On the other hand, the mean axon counts, axon densities, myelin thickness, and G-ratios of the UCBMSC and the UCMSC groups were similar. CONCLUSION: Our results revealed that transplanting either UCBMSC or UCMSC into axotomized sciatic nerves accelerated and enhanced regeneration during a period of 8 weeks.     

人羊膜间充质干细胞移植对大鼠脊髓损伤神经功能恢复的影响

目的 观察人羊膜间充质干细胞( hAD - MSCs)移植对大鼠脊髓损伤神经功能恢复的影响.方法 建立大鼠脊髓全横断损伤模型,脊髓横断后立即以明胶海绵吸附10μl hAD- MSCs(约2×105个)或等量PBS液植入脊髓两断端之间.术后每周应用BBB评分评价大鼠后肢运动功能;采用免疫荧光染色观察hAD - MSCs在脊髓内的存活、分化情况;免疫组织化学染色观察受损脊髓远端组织NF - 200表达.结果 hAD - MSCs移植组神经功能明显恢复,BBB评分逐周增加,与对照组比较差异有统计学意义(P＜0.05).hAD - MSCs植入后2周在宿主脊髓中存在MAB1281染色阳性细胞,但不表达MAP -2和GFAP.hAD - MSCs移植后大鼠受损脊髓远端神经组织NF - 200表达明显强于对照组.结论 hAD - MSCs移植可促进大鼠脊髓损伤后的神经功能恢复,其机制可能与hAD - MSCs促进受损脊髓远端组织表达NF - 200有关.     

脐带间充质干细胞向成骨细胞分化的潜能

背景：人脐带间充质干细胞含量丰富,较为原始,分化能力强,免疫原性低,是细胞治疗的理想靶细胞。 目的：体外分离培养脐带间充质干细胞并将其定向诱导为成骨细胞。 方法：无菌条件下培养脐带间充质干细胞,分为诱导组和对照组,诱导组用成骨诱导液处理、对照组为干细胞培养液处理。倒置光显微镜观察细胞形态,MTT法测细胞增殖,荧光双染法检测细胞活力,流式细胞仪检测细胞周期与细胞表面标记。诱导后：检测碱性磷酸酶,Von Kossa染色分析钙盐沉积,RT-PCR检测骨桥蛋白基因、碱性磷酸酶、骨唾液蛋白mRNA的表达。 结果与结论：传代细胞形态稳定、活力好,高标达CD44。诱导后von Kossa染色表现为阳性。碱性磷酸酶活性诱导组比对照组高(P < 0.05),不同时间点比较21 d最高(P < 0.05)。RT-PCR显示：诱导组21,28d 碱性磷酸酶mRNA表达均较与对照组增强(P < 0.05)。诱导组有骨唾液蛋白和骨桥蛋白基因mRNA表达。提示,人脐带间充质干细胞能够定向分化为成骨细胞。     

Functional recovery and microenvironmental alterations in a rat model of spinal cord injury following human umbilical cord blood-derived mesenchymal stem cells transplantation

BACKGROUND: Transplantation of human umbilical cord blood-derived mesenchymal stem cells (MSCs) has been shown to benefit spinal cord injury (SCI) repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE: To observe changes in nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and interleukin-8 (IL-8) expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS: Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS: A total of 62 Wister rats were randomly assigned to control (n = 18), model (n = 22, SCI + PBS), and transplantation (n = 22, SCI + MSCs) groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine (BrdU)-labeled MSCs (24 hours before injection) were intravascularly transplanted. MAIN OUTCOME MEASURES: The rats were evaluated using the Basso, Beattie and Bresnahan (BBB) locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation.RESULTS: A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant functional improvement in the transplantation group compared to the model group (P< 0.05), which was maintained for 2-3 weeks. Compared to the model group, NGF and BDNF levels were significantly increased in the injured region following MSCs transplantation at 3 weeks (P < 0.05), but IL-8 levels remained unchanged (P > 0.05).CONCLUSION: MSCs transplantation increased NGF and BDNF expression in injured spinal cord tissue. MSCs could promote neurological function recovery in SCI rats by upregulating NGF expression and improving regional microenvironments.     

Combined use of Y-tube conduits with human umbilical cord stem cells for repairing nerve bifurcation defects

Given the anatomic complexity at the bifurcation point of a nerve trunk, enforced suturing between stumps can lead to misdirection of nerve axons, thereby resulting in adverse consequences. We assumed that Y-tube conduits injected with human umbilical cord stem cells could be an effective method to solve such problems, but studies focused on the best type of Y-tube conduit remain controversial. There-fore, the present study evaluated the applicability and efifcacy of various types of Y-tube conduits containing human umbilical cord stem cells for treating rat femoral nerve defects on their bifurcation points. At 12 weeks after the bridging surgery that included treatment with different types of Y-tube conduits, there were no differences in quadriceps femoris muscle weight or femoral nerve ultrastructure. However, the Y-tube conduit group with longer branches and a short trunk resulted in a better outcome according to retrograde labeling and electro-physiological analysis. It can be concluded from the study that repairing a mixed nerve defect at its bifurcation point with Y-tube conduits, in particular those with long branches and a short trunk, is effective and results in good outcomes.     

Human umbilical cord mesenchymal stem cell-loaded amniotic membrane for the repair of radial nerve injury

In this study, we loaded human umbilical cord mesenchymal stem cells onto human amniotic membrane with epithelial cells to prepare nerve conduits, i.e., a relatively closed nerve regeneration chamber. After neurolysis, the injured radial nerve was enwrapped with the prepared nerve conduit, which was fixed to the epineurium by sutures, with the cell on the inner surface of the conduit. Simultaneously, a 1.0 mL aliquot of human umbilical cord mesenchymal stem cell suspension was injected into the distal and proximal ends of the injured radial nerve with 1.0 cm intervals. A total of 1.75 x 107 cells were seeded on the amniotic membrane. In the control group, patients received only neurolysis. At 12 weeks after cell transplantation, more than 80% of patients exhibited obvious improvements in muscular strength, and touch and pain sensations. In contrast, these improvements were observed only in 55-65% of control patients. At 8 and 12 weeks, muscular electrophysiological function in the region dominated by the injured radial nerve was significantly better in the transplantation group than the control group. After cell transplantation, no immunological rejections were observed. These findings suggest that human umbilical cord mesenchymal stem cell-loaded amniotic membrane can be used for the repair of radial nerve injury.     

大鼠肌肉注射移植人脐带间充质干细胞的安全性

背景：目前国内关于间充质干细胞肌肉注射安全性方面的研究报道较少。 目的：观察人脐带间充质干细胞肌肉注射后,移植大鼠各项生理指标及注射局部肌肉组织的病理学变化。 方法：SPF级雄性Wistar大鼠51只,取3只作为空白对照,剩余48只随机均分为4组：低、中、高浓度细胞移植组分别于大鼠左下肢腓肠肌外侧肌肉注射2.5×109 L-1,5×109 L-1,1.5×1010 L-1人脐带间充质干细胞悬液,共注射2个位点,每个位点注射0.1 mL,2个位点间隔约0.5 cm;溶媒对照组同法注射50 g/L葡萄糖溶液。分别于注射后1 d及1,2,4周进行大鼠尿常规、血液学、血液生化学和病理组织学检查。 结果与结论：人脐带间充质干细胞肌肉注射后对大鼠尿常规及肝脏、肾脏均无明显影响;仅引起总胆红素一过性升高,以及血小板、乳酸脱氢酶和肌酸激酶同工酶轻度炎症反应性升高;高浓度细胞移植可引起肌肉注射局部明显炎症反应。提示人脐带间充质干细胞免疫原性极低,在掌握了细胞移植的适宜浓度及剂量的前提下,以肌肉注射的方式进行异种移植不会引起受者严重的免疫排斥反应。     

体外诱导人脐带间充质干细胞向肝样细胞的分化

背景：多项研究表明间充质干细胞具有向肝细胞分化的潜能,这将为肝细胞移植、生物人工肝、肝组织工程提供大量种子细胞,也有望在急性肝衰竭、终末期肝病和遗传代谢性肝脏疾病治疗方面带来较大突破。 目的：拟在体外诱导人脐带间充质干细胞向肝样细胞分化,观察其形态及功能变化。 方法：取体外培养第3代处于对数生长期的人脐带间充质干细胞,以1×109 L-1的细胞浓度种植在培养瓶中,加入含体积分数为10%胎牛血清的DMEM/F12培养基,设立3组：实验1组加入20 μg/L肝细胞生长因子+10 μg/L碱性成纤维细胞生长因子,实验2组在其基础上另加入20 μg/L制瘤素,空白对照组不加入任何生长因子。根据细胞生长情况,每周换液两三次。分别于培养7,14,18 d在倒置显微镜下观察细胞形态,采用免疫细胞化学检测甲胎蛋白、白蛋白及细胞角蛋白18的表达,运用PAS法检测糖原的表达。 结果与结论：人脐带间充质干细胞可在含20 μg/L肝细胞生长因子、10 μg/L碱性成纤维细胞生长因子、20 μg/L制瘤素、体积分数为10%胎牛血清的DMEM/F12培养体系中诱导分化为具有肝细胞表型和功能的细胞,且肝细胞生长因子、碱性成纤维细胞生长因子、制瘤素联合应用的诱导效果优于单纯应用前两者。     

Stem cell transplantation for treatment of cerebral ischemia in rats Effects of human umbilical cord blood stem cells and human neural stem cells

BACKGROUND:Exogenous neural stem cell transplantation promotes neural regeneration. However, various types of stem cells transplantation outcomes remain controversial. OBJECTIVE:To explore distribution, proliferation and differentiation of human neural stem cells (hNSCs) and human umbilical cord blood stem cells (hUCBSCs) following transplantation in ischemic brain tissue of rats, and to compare therapeutic outcomes between hNSCs and hUCBSCs. DESIGN, TIME AND SETTING:Randomized controlled animal studies were performed at the Experimental Animal Center of Nanjing Medical University and Central Laboratory of Second Affiliated Hospital of Nanjing Medical University of China from September 2008 to April 2009. MATERIALS:hNSCs were harvested from brain tissue of 10-13 week old fetuses following spontaneous abortion, and hUCBSCs were collected from umbilical cord blood of full-term newborns at the Second Affiliated Hospital of Nanjing Medical University of China. hNSCs and hUCBSCs were labeled by 5-bromodeoxyuridine (BrdU) prior to transplantation. METHODS:Rat models of cerebral ischemia were established by the suture method. A total of 60 healthy male Sprague Dawley rats aged 7-9 weeks were randomly assigned to hNSC transplantation, hUCBSC transplantation and control groups. The rat models in the hNSC transplantation, hUCBSC transplantation and control groups were infused with hNSC suspension, hUCBSC suspension and saline via the caudal vein, respectively. MAIN OUTCOME MEASURES:The distribution, proliferation and differentiation of hNSCs and hUCBSCs in ischemic brain tissue were observed using immunohistochemical methods. Neurological function in rats was assessed using the neurological severity score. RESULTS:The number of BrdU-positive cells was significantly greater in the hNSC transplantation group compared with hUCBSC transplantation group at 14 days following transplantation (P < 0.05). The number of BrdU-positive cells reached a peak at 28 days following transplantation. Nestin-positive, glial fibrillary acidic protein-positive, cyclic nucleotide 3' phosphohydrolase-positive and neuron specific enolase-positive cells were visible following transplantation. No significant difference was determined in the constituent ratio of various cells between hNSC and hUCBSC transplantation groups (P > 0.05). The neurological severity score was significantly decreased in rats at 21 days following transplantation (P < 0.05). No significant difference was detected in neurological severity score between hNSC and hUCBSC transplantation groups at various time points (P > 0.05). CONCLUSION:The transplanted hNSCs and hUCBSCs can migrate into ischemic brain tissue, proliferate and differentiate into neuron-like, astrocyte-like and oligodendrocyte-like cells, and improve neurological function in rats with cerebral ischemia.     

Protective effects of human umbilical cord mesenchymal stem cell vein transplantation against spinal cord ischemia/reperfusion injury in rats

BACKGROUND: The majority of studies addressing spinal cord ischemia/reperfusion injury (SCIRI) have focused on drugs, proteins, cytokines, and various surgical techniques. A recent study reports that human umbilical cord mesenchymal stem cell (hUCMSC) transplantation achieves good therapeutic effects, but the mechanisms underlying nerve protection remain poorly understood.OBJECTIVE: To observe survival of transplanted hUCMSCs in SCIRI rat models and the influence on motor function in the hind limbs, to determine interleukin-8 expression and cellular apoptosis in spinal cord tissues, and to verify the hypothesis that hUCMSC transplantation exhibits protective effects on SCIRI.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Laboratory of the Department of Orthopedics in the First Affiliated Hospital of Soochow University,China between January 2007 and December 2008.MATERIALS: hUCMSCs were harvested from umbilical cord blood of healthy pregnant women after parturition in the Obstetrical Department of the First Affiliated Hospital of Soochow University, China. Rabbit anti-human BrdU monoclonal antibody was provided by DAKO, USA. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) Kit and enzyme-linked immunosorbent assay (ELISA) Kit were purchased by Wuhan Boster, China. METHODS: A total of 72 healthy, Wistar, adult rats were randomly assigned to three groups: sham-surgery, model, and transplantation, with 24 rats in each group. SCIRI was induced in the model and transplantation groups via the abdominal aorta block method. The inf rarenal abdominal aorta was not blocked in the sham-surgery group. Prior to abdominal aorta occlusion, 0.2-0.3 mL bromodeoxyuridine (BrdU)-labeled hUCMSCs suspension (cell concentration 5 × 10~3/μL) was injected through the great saphenous vein of the hind limb, and an equal volume of physiological saline was administered to the model and sham-surgery groups.MAIN OUTCOME MEASURES: Pathological observation of rat spinal cord tissues was performed by hematoxylin-eosin staining at 6, 24, and 48 hours post-surgery. Immunohistochemistry was applied to determine hUCMSCs survival in the spinal cord. The amount of cellular apoptosis and interleukin-8 expression in spinal cord tissues was assayed utilizing the TUNEL and ELISA methods, respectively. Motor function in the hind limbs was evaluated according to Jacob's score. RESULTS: Numerous BrdU-positive cells were observed in spinal cord tissues from the transplantation group. The number of apoptotic cells and interleukin-8 levels significantly decreased in the transplantation group (P < 0.05), pathological injury was significantly ameliorated, and motor function scores significantly increased (P < 0.05) compared with the model group. CONCLUSION: Via vein transplantation, hUCMSCs were shown to reach and survive in the injury area. Results suggested that the transplanted hUCMSCs contributed to significantly improved pathological changes in the injured spinal cord, as well as motor function, following SCIRI. The protective mechanism correlated with inhibition of cellular apoptosis and reduced production of inflammatory mediators.     

CM-Dil体外标记人脐带间充质干细胞传代示踪的可行性

背景：掌握人脐带间充质干细胞的移植示踪方法是研究其生物学特性的关键。 目的：观察用CM-Dil标记人脐带间充质干细胞及在体外传代示踪的可行性。 方法：采用酶消化法体外分离培养人脐带间充质干细胞,通过流式细胞仪检测细胞免疫表型和细胞周期、体外成脂成骨诱导鉴定该细胞。将第5代细胞用CM-Dil标记,并将细胞传代,荧光显微镜观察体外标记情况。 结果与结论：第3代人脐带间充质干细胞强表达CD44,CD29,低表达CD106,不表达CD34、CD40;有80%以上的细胞处在G0/G1期,成脂成骨诱导后,油红O染色和碱性磷酸酶染色分别阳性。CM-Dil标记人脐带间充质干细胞细胞标记率达90%以上,体外传代后荧光强度逐渐减退,传8代后,荧光基本消失。说明人脐带间充质干细胞增殖、分化能力强,CM-Dil标记细胞示踪方法简单易行。     

Neural cell injury microenvironment induces neural differentiation of human umbilical cord mesenchymal stem cells

This study aimed to investigate the neural differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs) under the induction of injured neural cells. After in vitro isolation and culture, passage 5 hUCMSCs were used for experimentation. hUCMSCs were co-cultured with normal or Aβ_1-40-injured PC12 cells, PC12 cell supernatant or PC12 cell lysate in a Transwell co-culture system. Western blot analysis and flow cytometry results showed that choline acetyltransferase and microtubule-associated protein 2, a specific marker for neural cells, were expressed in hUCMSCs under various culture conditions, and highest expression was observed in the hUCMSCs co-cultured with injured PC12 cells. Choline acetyltransferase and microtubule-associated protein 2 were not expressed in hUCMSCs cultured alone (no treatment). Cell Counting Kit-8 assay results showed that hUCMSCs under co-culture conditions promoted the proliferation of injured PC12 cells. These findings suggest that the microenvironment during neural tissue injury can effectively induce neural cell differentiation of hUCMSCs. These differentiated hUCMSCs likely accelerate the repair of injured neural cells.     

脐带源与骨髓源干细胞移植治疗大鼠脊髓损伤的疗效比较

目的 观察人脐带间充质干细胞(HUCMSCs)与大鼠骨髓间充质干细胞(BMSCs)移植治疗大鼠脊髓损伤后的功能恢复和急慢性排斥反应.方法 选取SD大鼠40只按随机数字表随机分成3组:脐带间充质干细胞移植组16只、骨髓间充质干细胞移植组16只和PBS组8只.采用脊髓半切手术制作大鼠脊髓损伤模型,损伤后对脐带间充质干细胞移植组进行HUCMSCs移植,对骨髓间充质干细胞移植组行大鼠BMSCs移植,对PBS组移植同等剂量的PBS.通过BBB评分对各组动物的术后恢复进行评估比较.用ELISA法测定移植后3组动物不同时间点(移植后1周、1个月、2个月及3个月)血中IL-2及IL-10的水平,并通过免疫组化的方法检测移植局部病理切片CD3+细胞浸润的情况.结果 在移植后1周、1个月、2个月及3个月时,检测到干细胞移植组各个时间点大鼠静脉血中IL-2水平较PBS组明显升高,而IL-10水平较PBS组明显下降,差异均有统计学意义(P＜0.05).大鼠骨髓间充质干细胞移植组在移植后1周、1个月、2个月及3个月时大鼠静脉血中IL-2水平较脐带间充质干细胞移植组明显升高,IL-10水平较对照组明显下降,差异均有统计学意义(P＜0.05).三组在急性期(细胞移植后l周)移植局部均有大量CD3+细胞浸润.而移植的慢性期(细胞移植后3个月)大鼠骨髓间充质干细胞移植组仍存在大量CD3+细胞浸润,与其他两组相比差异均有统计学意义(P＜0.05).结论 异体干细胞细胞移植后可发生急、慢性免疫排斥反应.HUCMSCs较大鼠BMSCs有更低的免疫源性,更利于脊髓损伤的功能恢复.     

Migration capacity of human umbilical cord mesenchymal stem cells towards glioma in vivo*

High-grade glioma is the most common malignant primary brain tumor in adults.The poor prognosis of glioma,combined with a resistance to currently available treatments,necessitates the development of more effective tumor-selective therapies.Stem cell-based therapies are emerging as novel cell-based delivery vehicle for therapeutic agents.In the present study,we successfully isolated human umbilical cord mesenchymal stem cells by explant culture.The human umbilical cord mesenchymal stem cells were adherent to plastic surfaces,expressed specific surface phenotypes of mesenchymal stem cells as demonstrated by flow cytometry,and possessed multi-differentiation potentials in permissive induction media in vitro.Furthermore,human umbilical cord mesenchymal stem cells demonstrated excellent glioma-specific targeting capacity in established rat glioma models after intratumoral injection or contralateral ventricular administration in vivo.The excellent glioma-specific targeting ability and extensive intratumoral distribution of human umbilical cord mesenchymal stem cells indicate that they may serve as a novel cellular vehicle for delivering therapeutic molecules in glioma therapy.     

Combination of olfactory ensheathing cells and human umbilical cord mesenchymal stem cell-derived exosomes promotes sciatic nerve regeneration

Olfactory ensheathing cells(OECs)are promising seed cells for nerve regeneration.However,their application is limited by the hypoxic environment usually present at the site of injury.Exosomes derived from human umbilical cord mesenchymal stem cells have the potential to regulate the pathological processes that occur in response to hypoxia.The ability of OECs to migrate is unknown,especially in hypoxic conditions,and the effect of OECs combined with exosomes on peripheral nerve repair is not clear.Better understanding of these issues will enable the potential of OECs for the treatment of nerve injury to be addressed.In this study,OECs were acquired from the olfactory bulb of Sprague Dawley rats.Human umbilical cord mesenchymal stem cell-derived exosomes(0–400μg/mL)were cultured with OECs for 12–48 hours.After culture with 400μg/mL exosomes for 24 hours,the viability and proliferation of OECs were significantly increased.We observed changes to OECs subjected to hypoxia for 24 hours and treatment with exosomes.Exosomes significantly promoted the survival and migration of OECs in hypoxic conditions,and effectively increased brain-derived neurotrophic factor gene expression,protein levels and secretion.Finally,using a 12 mm left sciatic nerve defect rat model,we confirmed that OECs and exosomes can synergistically promote motor and sensory function of the injured sciatic nerve.These findings show that application of OECs and exosomes can promote nerve regeneration and functional recovery.This study was approved by the Institutional Ethical Committee of the Air Force Medical University,China(approval No.IACUC-20181004)on October 7,2018;and collection and use of human umbilical cord specimens was approved by the Ethics Committee of the Linyi People’s Hospital,China(approval No.30054)on May 20,2019.     

人脐带间充质干细胞移植对大鼠脊髓损伤神经功能恢复的评价

目的 观察人脐带间充质干细胞（human umbilical cordmesenchymal stem cell，hUCMSC）移植对大鼠脊髓损伤神经功能恢复的影响。方法 SD大鼠70只，随机分为3组：脊髓半切＋hUCMSC组（n=30）、脊髓半切＋PBS组（n=30）和假手术组（n=10）。脊髓半切＋hUCMSC组和PBS组又分为头侧注射、尾侧注射和头尾两侧注射三个亚组。移植后1、7、14、21、28d观察大鼠神经功能恢复情况，应用免疫组化检测移植到脊髓的hUCMSC胶质纤维酸性蛋白（GFAP）和神经元特异性烯醇化酶（NSE）表达情况。结果 大鼠脊髓半切损害后，hUCMSC组动物较PBS组有明显的神经功能恢复。植入后28d在宿主脊髓中存活的hUCMSC细胞MABl281（mouse antiuman nuclei monoclonal antibody）染色阳性，免疫组化双标染色显示MABl28l阳性细胞亦分别有NSE或GFAP表达并向损伤部位迁移，hUCMSC来源的GFAP阳性细胞可见明显的树突生长。结论 hUCMSC移植到宿主损伤脊髓后可以存活、向损伤部位迁移，并向神经元样和星形胶质细胞分化，且可促进大鼠脊髓损伤后神经功能恢复。hUCMSC作为一种来源广泛的干细胞用于治疗脊髓损伤可能具有重要的价值。     

5-氮杂胞苷诱导人脐带间充质干细胞向心肌样细胞的分化☆

背景：5-氮杂胞苷能诱导人脐带间充质干细胞分化为心肌细胞。 目的：以5-氮杂胞苷诱导人脐带间充质干细胞分化为心肌细胞。 方法：采用贴壁培养法分离、纯化人脐带间充质干细胞,以5-氮杂胞苷诱导第3代人脐带间充质干细胞分化为心肌样细胞。 结果与结论：诱导前人脐带间充质干细胞呈典型的梭形;诱导后一二周细胞体积变大,三四周后相邻细胞间胞膜有接触,逐渐相连呈肌管状,细胞胞质内可见细丝样结构。诱导4周后免疫组织化学鉴定人脐带间充质干细胞cTnI表达阳性,未诱导细胞cTnI表达阴性;诱导组Nkx2.5、GATA 4 mRNA表达水平较未诱导组显著增加(P < 0.05)。提示5-氮杂胞苷可能通过调控GATA4、Nkx2.5基因的表达促进人脐带间充质干细胞分化为心肌样细胞,并促进其成熟。