Cell transplantation for the treatment of spinal cord injury–bone marrow stromal cells and choroid plexus epithelial cells

Transplantation of bone marrow stromal cells(BMSCs) enhanced the outgrowth of regenerating axons and promoted locomotor improvements of rats with spinal cord injury(SCI).BMSCs did not survive long-term,disappearing from the spinal cord within 2–3 weeks after transplantation.Astrocyte-devoid areas,in which no astrocytes or oligodendrocytes were found,formed at the epicenter of the lesion.It was remarkable that numerous regenerating axons extended through such astrocyte-devoid areas.Regenerating axons were associated with Schwann cells embedded in extracellular matrices.Transplantation of choroid plexus epithelial cells(CPECs) also enhanced axonal regeneration and locomotor improvements in rats with SCI.Although CPECs disappeared from the spinal cord shortly after transplantation,an extensive outgrowth of regenerating axons occurred through astrocyte-devoid areas,as in the case of BMSC transplantation.These findings suggest that BMSCs and CPECs secret neurotrophic factors that promote tissue repair of the spinal cord,including axonal regeneration and reduced cavity formation.This means that transplantation of BMSCs and CPECs promotes "intrinsic" ability of the spinal cord to regenerate.The treatment to stimulate the intrinsic regeneration ability of the spinal cord is the safest method of clinical application for SCI.It should be emphasized that the generally anticipated long-term survival,proliferation and differentiation of transplanted cells are not necessarily desirable from the clinical point of view of safety.     

Neural stem cell transplantation in a double-layer collagen membrane with unequal pore sizes for spinal cord injur y repair

A novel double-layer collagen membrane with unequal pore sizes in each layer was designed and tested in this study.The inner,loose layer has about 100-μm-diameter pores,while the outer,compact layer has about 10-μm-diameter pores.In a rat model of incomplete spinal cord injury,a large number of neural stem cells were seeded into the loose layer,which was then adhered to the injured side,and the compact layer was placed against the lateral side.The results showed that the transplantation of neural stem cells in a double-layer collagen membrane with unequal pore sizes promoted the differentiation of neural stem cells,attenuated the pathological lesion,and significantly improved the motor function of the rats with incomplete spinal cord injuries.These experimental findings suggest that the transplantation of neural stem cells in a double-layer collagen membrane with unequal pore sizes is an effective therapeutic strategy to repair an injured spinal cord.     

Stem cell transplantation for spinal cord injury:a meta-analysis of treatment effectiveness and safety

OBJECTIVE: The aim of this study was to evaluate the effectiveness and safety of stem cell transplantation for spinal cord injury(SCI).DATA SOURCES: PubM ed, EMBASE, Cochrane, China National Knowledge Infrastructure, China Science and Technology Journal, Wanfang, and Sino Med databases were systematically searched by computer to select clinical randomized controlled trials using stem cell transplantation to treat SCI, published between each database initiation and July 2016. DATA SELECTION: Randomized controlled trials comparing stem cell transplantation with rehabilitation treatment for patients with SCI. Inclusion criteria:(1) Patients with SCI diagnosed according to the American Spinal Injury Association(ASIA) International standards for neurological classification of SCI;(2) patients with SCI who received only stem cell transplantation therapy or stem cell transplantation combined with rehabilitation therapy;(3) one or more of the following outcomes reported: outcomes concerning neurological function including sensory function and locomotor function, activities of daily living, urination functions, and severity of SCI or adverse effects. Studies comprising patients with complications, without full-text, and preclinical animal models were excluded. Quality of the included studies was evaluated using the Cochrane risk of bias assessment tool and Rev Man V5.3 software, provided by the Cochrane Collaboration, was used to perform statistical analysis. OUTCOME MEASURES: ASIA motor score, ASIA light touch score, ASIA pinprick score, ASIA impairment scale grading improvement rate, activities of daily living score, residual urine volume, and adverse events.RESULTS: Ten studies comprising 377 patients were included in the analysis and the overall risk of bias was relatively low level. Four studies did not detail how random sequences were generated, two studies did not clearly state the blinding outcome assessment, two studies lacked blinding outcome assessment, one study lacked follow-up information, and four studies carried out selective reporting. Compared with rehabilitation therapy, stem cell transplantation significantly increased the lower limb light touch score(odds ratio(OR) = 3.43, 95% confidence interval(CI): 0.01 – 6.86, P = 0.05), lower limb pinprick score(OR = 3.93, 95%CI: 0.74 – 7.12, P = 0.02), ASI grading rate(relative risk(RR) = 2.95, 95%CI: 1.64 – 5.29, P = 0.0003), and notably reduced residual urine volume(OR = –8.10, 95%CI: –15.09 to –1.10, P = 0.02). However, stem cell transplantation did not significantly improve motor score(OR = 1.89, 95%CI: –0.25 to 4.03, P = 0.08) or activities of daily living score(OR = 1.12, 95%CI: –1.17 to 4.04, P = 0.45). Furthermore, stem cell transplantation caused a high rate of mild adverse effects(RR = 14.49, 95%CI: 5.34 – 34.08, P 0.00001); however, these were alleviated in a short time. CONCLUSION: Stem cell transplantation was determined to be an efficient and safe treatment for SCI and simultaneously improved sensory and bladder functions. Although associated minor and temporary adverse effects were observed with transplanted stem cells, spinal cord repair and axon remyelination were apparent. More randomized controlled trials with larger sample sizes and longer follow-up times are needed to further validate the effectiveness of stem cell transplantation in the treatment of SCI.     

Co-transplantation of Schwann cells and bone marrow stromal cells versus single cell transplantation on repairing hemisected spinal cord injury of rats

BACKGROUND: Bone marrow stromal cells (BMSCs) or Schwann cells (SCs) transplantation alone can treat spinal cord injury. However, the transplantation either cell-type alone has disadvantages. The co-transplantation of both cells may benefit structural reconstruction and functional recovery of spinal nerves.OBJECTIVE: To verify spinal cord repair and related mechanisms after co-transplantation of BMSCs and SCs in a rat model of hemisected spinal cord injury.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Department of Histology and Embryology, Mudanjiang Medical College from January 2008 to May 2009.MATERIALS: Rabbit anti-S-100, glial fibrillary acidic protein, neuron specific enolase and neurofilament-200 monoclonal antibodies were purchased from Sigma, USA.METHODS: A total of 100 Wistar rats were used in a model of hemisected spinal cord injury. The rats were randomly assigned to vehicle control, SCs transplantation, BMSCs transplantation, and co-transplantation groups; 25 rats per group. At 1 week after modeling, SCs or BMSCs cultured in vitro were labeled and injected separately into the hemisected spinal segment of SCs and BMSCs transplantation groups through three injection points [5 μL (1 × 107 cells/mL)] cell suspension in each point). In addition, a 15 μL 1 × 107 cells/mL SCs suspension and a 15 μL 1 × 107 cells/mL BMSC suspension were injected into co-transplantation group by the above method.MAIN OUTCOME MEASURES: The Basso-Beattie-Bresnahan (BBB) locomotor rating scale and somatosensory evoked potential (SEP) tests were used to assess the functional recovery of rat hind limbs following operation. Structural repair of injured nerve tissue was observed by light microscopy, electron microscopy, immunohistochemistry, and magnetic resonance imaging (MRI). In vivo differentiation, survival and migration of BMSCs were evaluated by immunofluorescence.RESULTS: BBB scores were significantly greater in all three transplantation groups compared with vehicle control group 8 weeks after transplantation. In particular, the co-transplantation group displayed the highest scores among the groups (P < 0.05). Moreover, recovery of SEP latency and amplitude was observed in all the transplantation groups, particularly after 8 weeks. Again, the co-transplantation group exhibited the greatest improvement (P < 0.05). In the co-transplantation group, imaging showed a smooth surface and intact inner structure at the injury site, with no scar formation, and a large number of orderly cells at the injured site. Axonal regeneration, new myelination, and a large amount of cell division were detected in the co-transplantation group by electron microscopy. Neuron specific enolase (NSE)- and glial fibrillary acidic protein (GFAP)-positive cells were observed in the spinal cord sections 1 week following co-transplantation by immunofluorescence staining.CONCLUSION: Co-transplantation of SCs and BMSCs effectively promoted functional recovery of injured spinal cord in rats compared with SCs or BMSCs transplantation alone. This repair effect is probably achieved because of neuronal-like cells derived from BMSCs to supplement dead neurons in vivo.     

Bone marrow mesenchymal stem cells with Nogo-66 receptor gene silencing for repair of spinal cord injur y

We hypothesized that RNA interference to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells before transplantation might further improve neurological function in rats with spinal cord transection injury. After 2 weeks, the number of neurons and BrdU-positive cells in the Nogo-66 receptor gene silencing group was higher than in the bone marrow mesenchymal stem cell group, and significantly greater compared with the model group. After 4 weeks, behavioral performance was signiifcantly enhanced in the model group. Af-ter 8 weeks, the number of horseradish peroxidase-labeled nerve ifbers was higher in the Nogo-66 receptor gene silencing group than in the bone marrow mesenchymal stem cell group, and signiifcantly higher than in the model group. The newly formed nerve ifbers and myelinated ner ve ifbers were detectable in the central transverse plane section in the bone marrow mesenchymal stem cell group and in the Nogo-66 receptor gene silencing group.     

Transplantation of human bone marrow stromal cell‐derived Schwann cells reduces cystic cavity and promotes functional recovery after contusion injury of adult rat spinal cord

The aim of this study was to evaluate whether transplantation of human bone marrow stromal cell‐derived Schwann cells (hBMSC‐SC) promotes functional recovery after contusive spinal cord injury of adult rats. Human bone marrow stromal cells (hBMSC) were cultured from bone marrow of adult human patients and induced into Schwann cells (hBMSC‐SC) in vitro. Schwann cell phenotype was confirmed by immunocytochemistry. Growth factors secreted from hBMSC‐SC were detected using cytokine antibody array. Immunosppressed rats were laminectomized and their spinal cords were contused using NYU impactor (10 g, 25 mm). Nine days after injury, a mixture of Matrigel and hBMSC‐SC (hBMSC‐SC group) was injected into the lesioned site. Five weeks after transplantation, cresyl‐violet staining revealed that the area of cystic cavity was smaller in the hBMSC‐SC group than that in the control group. Immunohistochemstry revealed that the number of anti‐growth‐associated protein‐43‐positive nerve fibers was significantly larger in the hBMSC‐SC group than that in the control group. At the same time, the number of tyrosine hydroxylase‐ or serotonin‐positive fibers was significantly larger at the lesion epicenter and caudal level in the hBMSC‐SC group than that in the control group. In electron microscopy, formation of peripheral‐type myelin was recognized near the lesion epicenter in the hBMSC‐SC group. Hind limb function recovered significantly in the hBMSC‐SC group compared with the control group. In conclusion, the functions of hBMSC‐SC are comparable to original Schwann cells in rat spinal cord injury models, and are thus potentially useful treatments for patients with spinal cord injury.     

人胚胎雪旺细胞脊髓内移植治疗晚期脊髓损伤

目的 采用人胚雪旺细胞移植治疗晚期脊髓损伤,并探讨其疗效及安全性。方法 显微镜下切除脊髓损伤节段增厚的瘢痕组织,松解粘连,切开囊腔或空洞。取人胚胎背根神经节,培养成雪旺细胞并贴附于可吸收薇乔3-0紫色线及薇乔网的载体上,然后将其移植到脊髓损伤部位。本组共治疗53例,其中男42例,女11例,年龄2～58岁,伤后时间为4个月～19年。结果 雪旺细胞移植后2～8w时随访,按美国脊髓损伤学会（ASIA）脊髓损伤神经功能分类国际标准评价,53例患者的脊髓功能均有部分恢复,其中运动功能由术前（41.49±15.83）分提高到术后（44.62±15.39）分,轻触觉由（57.89±22.87）分提高到（63.94±23.67）分,针刺觉由（55.96±20.99）分提高到（59.68±20.57）分。患者术后无脊髓感染、功能损伤加重及死亡等并发症。术后复查MRI示脊髓无瘤样增生及空洞扩大。结论 人胚雪旺细胞移植治疗晚期脊髓损伤安全可行,能促进晚期脊髓损伤患者脊髓神经功能的部分恢复。     

Stem cells for the treatment of spinal cord injury

This article reviews stem cell-based strategies for spinal cord injury repair, and practical issues concerning their translation to the clinic. Recent progress in the stem cell field includes clinically compliant culture conditions and directed differentiation of both embryonic stem cells and somatic stem cells. We provide a brief overview of the types of stem cells under evaluation, comparing their advantages and disadvantages for use in human clinical trials. We review the practical considerations and risks that must be addressed before human treatments can begin. With a growing understanding of these practical issues, stem cell biology, and spinal cord injury pathophysiology, stem cell-based therapies are moving closer to clinical application.     

Application of magnetic resonance imaging for monitoring stem cell transplantation for the treatment of cerebral ischemia

OBJECTIVE:To identify global research trends in the application of MRI for monitoring stem cell transplantation using a bibliometric analysis of Web of Science.DATA RETRIEVAL:We performed a bibliometric analysis of studies relating to the application of MRI for detecting stem cell transplantation for the treatment of cerebral ischemia using papers in Web of Science published from 2002 to 2011.SELECTION CRITERIA:The inclusion criteria were:(a) peer-reviewed articles on the application of MRI for detecting transplanted stem cells published and indexed in Web of Science;(b) year of publication between 2002 and 2011.Exclusion criteria were:(a) articles that required manual searching or telephone access;(b) some corrected papers.MAIN OUTCOME MEASURES:(1) Annual publication output;(2) distribution according to journals;(3) distribution according to institution;(4) distribution according to country;(5) top cited authors over the last 10 years.RESULTS:A total of 1 498 studies related to the application of MRI for monitoring stem cell transplantation appeared in Web of Science from 2002 to 2011,almost half of which were derived from American authors and institutes.The number of studies on the application of MRI for detecting stem cell transplantation has gradually increased over the past 10 years.Most papers on this topic appeared in Magnetic Resonance in Medicine.CONCLUSION:This analysis suggests that few experimental studies have been investigated the use of MRI for tracking SPIO-labeled human umbilical cord blood-derived mesenchymal stem cells during the treatment of cerebral ischemia.     

Optimal time for subarachnoid transplantation of neural progenitor cells in the treatment of contusive spinal cord injury

This study aimed to identify the optimal neural progenitor cell transplantation time for spinal cord injury in rats via the subarachnoid space. Cultured neural progenitor cells from 14-day embryonic rats, constitutively expressing enhanced green fluorescence protein, or media alone, were injected into the subarachnoid space of adult rats at 1 hour (acute stage), 7 days (subacute stage) and 28 days (chronic stage) after contusive spinal cord injury. Results showed that grafted neural progenitor cells migrated and aggregated around the blood vessels of the injured region, and infiltrated the spinal cord parenchyma along the tissue spaces in the acute stage transplantation group. However, this was not observed in subacute and chronic stage transplantation groups. O4- and glial fibrillary acidic protein-positive cells, representing oligodendrocytes and astrocytes respectively, were detected in the core of the grafted cluster attached to the cauda equina pia surface in the chronic stage transplantation group 8 weeks after transplantation. Both acute and subacute stage transplantation groups were negative for O4 and glial fibrillary acidic protein cells. Basso, Beattie and Bresnahan scale score comparisons indicated that rat hind limb locomotor activity showed better recovery after acute stage transplantation than after subacute and chronic transplantation. Our experimental findings suggest that the subarachnoid route could be useful for transplantation of neural progenitor cells at the acute stage of spinal cord injury. Although grafted cells survived only for a short time and did not differentiate into astrocytes or neurons, they were able to reach the parenchyma of the injured spinal cord and improve neurological function in rats. Transplantation efficacy was enhanced at the acute stage in comparison with subacute and chronic stages.     

Induced pluripotent stem cell technology for spinal cord injury: a promising alternative therapy

Spinal cord injury has long been a prominent challenge in the trauma repair process. Spinal cord injury is a research hotspot by virtue of its difficulty to treat and its escalating morbidity. Furthermore, spinal cord injury has a long period of disease progression and leads to complications that exert a lot of mental and economic pressure on patients. There are currently a large number of therapeutic strategies for treating spinal cord injury, which range from pharmacological and surgical methods to cell therapy and rehabilitation training. All of these strategies have positive effects in the course of spinal cord injury treatment. This review mainly discusses the problems regarding stem cell therapy for spinal cord injury, including the characteristics and action modes of all relevant cell types. Induced pluripotent stem cells, which represent a special kind of stem cell population, have gained impetus in cell therapy development because of a range of advantages. Induced pluripotent stem cells can be developed into the precursor cells of each neural cell type at the site of spinal cord injury, and have great potential for application in spinal cord injury therapy.     

Stem cell transplantation for treating spinal cord injury A literature comparison between studies of stem cells obtained from various sources

OBJECTIVE:To identify global research trends of stem cell transplantation for treating spinal cord injury using a bibliometric analysis of the Web of Science.DATA RETRIEVAL:We performed a bibliometric analysis of data retrievals for stem cell transplantation for treating spinal cord injury from 2002 to 2011 using the Web of Science.SELECTION CRITERIA:Inclusion criteria:(a) peer-reviewed articles on stem cell transplantation for treating spinal cord injury that were published and indexed in the Web of Science;(b) type of articles:original research articles,reviews,meeting abstracts,proceedings papers,book chapters,editorial material,and news items;and(c) year of publication:2002-2011.Exclusion criteria:(a) articles that required manual searching or telephone access;(b) documents that were not published in the public domain;and(c) a number of corrected papers from the total number of articles.MAIN OUTCOME MEASURES:(1) Annual publication output;(2) distribution according to country;(3) distribution according to institution;(4) distribution according to journals;(5) distribution according to funding agencies;and(6) top cited articles over the last 10 years.RESULTS:Bone marrow mesenchymal stem cells and embryonic stem cells have been widely used for treating spinal cord injury.In total,191 studies of bone marrow mesenchymal stem cell transplantation and 236 studies of embryonic stem cell transplantation for treating spinal cord injury appeared in the Web of Science from 2002 to 2011,and almost half of which were derived from American or Japanese authors and institutes.The number of studies of stem cell transplantation for treating spinal cord injury has gradually increased over the past 10 years.Most papers on stem cell transplantation for treating spinal cord injury appeared in journals with a particular focus on stem cell research,such as Stem Cells and Cell Transplantation.Although umbilical cord blood stem cells and adipose-derived stem cells have been studied for treating spinal cord injury,the number of published papers was much smaller,with only 21 and 17 records,respectively,in the Web of Science.CONCLUSION:Based on our analysis of the literature and research trends,we found that stem cells transplantation obtained from various sources have been studied for treating spinal cord injury;however,it is difficult for researchers to reach a consensus on this theme.     

神经干细胞生存因子在大鼠脊髓损伤前后的表达变化(英文)

目的观察大鼠脊髓损伤后干细胞来源的神经干细胞生存因子(SDNSF) mRNA在大鼠正常和损伤脊髓的表达变化,以及SDNSF的表达与Ⅵ类中间丝蛋白的表达之间的关系。方法按改良的Allen重物打击法制备大鼠脊髓损伤模型,采用RT-PCR、原位杂交方法,观察SDNSF mRNA在大鼠脊髓中的表达位置及在损伤脊髓中的表达变化。应用免疫组化的方法,显示脊髓中nestin 的表达。结果 RT-PCR检测SDNSF mRNA在正常大鼠脊髓中的表达,损伤后4天SDNSF 的mRNA表达上升,损伤8天到达高峰,此后SDNSF 的mRNA表达逐渐减少,到16天恢复到正常水平;脊髓切片原位杂交结果发现SDNSF的 mRNA 阳性细胞主要分布于脊髓灰质细胞中,可能是神经元细胞,结果表明正常脊髓可表达SDNSF;脊髓损伤后8天,原位杂交显示SDNSF阳性细胞明显增多。同时与此切片相邻层面的切片免疫组化证实nestin阳性细胞增殖、变大、向周围发出突起,但这些阳性细胞在分布上与SDNSF无关。结论 (1) SDNSF在脊髓中表达于灰质,脊髓损伤后SDNSF的 mRNA表达随时间发生变化。(2)随着脊髓损伤的修复,nestin 阳性细胞增殖,但是这些细胞并不表达SDNSF。     

神经干细胞生存因子在大鼠脊髓损伤前后的表达变化

目的观察大鼠脊髓损伤后干细胞来源的神经干细胞生存因子（SDNSF）mRNA在大鼠正常和损伤脊髓的农达变化,以及SDNSF的表达与Ⅵ类中间丝蛋白的表达之间的关系。方法按改良的Allen重物打击法制备大鼠脊髓损伤模型,采用RT—PCR、原位杂交方法,观察SDNSF mRNA在大鼠脊髓中的表达位置及在损伤脊髓中的表达变化。应用免疫组化的方法,显示脊髓中nestin的表达。结果RT-PCR检测SDNSF mRNA在正常大鼠脊髓中的表达,损伤后4天SDNSF的mRNA表达上升,损伤8天剑达高峰,此后SDNSF的mRNA表达逐渐减少,到16天恢复到正常水平;脊髓切片原位杂交结果发现SDNSF的mRNA阳性细胞主要分布十脊髓灰质细胞中,可能足神经元细胞,结果表明正常脊髓可表达SDNSF;脊髓损伤后8犬,原位杂交硅示SDNSF阳性细胞明显增多。同时与此切片相邻层面的切片免疫组化证实nestin阳性细胞增殖、变大、向周围发出突起,但这些阳性细胞在分布上与SDNSF无关。结论（1）SDNSF在脊髓中表达于灰质,脊髓损伤后SDNSF的mRNA表达随时间发生变化。（2）随着脊髓损伤的修复,nestin阳性细胞增殖,但是这些细胞并不表达SDNSF。     

Differentiation and tropic/trophic effects of exogenous neural precursors in the adult spinal cord

The fate of exogenous neural stem cells (NSCs) in the environment of the adult nervous system continues to be a matter of debate. In the present study, we report that cells of the murine NSC clone C17.2, when grafted into the lumbar segments of the spinal cord of adult rats, survive and undergo partial differentiation. C17.2 cells migrate avidly toward axonal tracts and nerve roots and differentiate into nonmyelinating ensheathing cells. Notably, C17.2 cells induce the de novo formation of host axon tracts aiming at graft innervation. Differentiation and inductive properties of C17.2 cells are independent of the presence of lesions in the spinal cord. The tropic/trophic interactions of C17.2 NSCs with host axons, the avid C17.2 cell-host axon contacts, and the ensheathing properties of these cells are related to their complex molecular profile, which includes the expression of trophic cytokines and neurotrophins such as glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor, glial growth factor receptors such as ErbB-2; and PASK, the mammalian homologue of the fray gene that is involved in axon ensheathment. These results show that NSCs might not only play a critical supportive role in repairing axonal injury in the adult spinal cord but also can be used as probes for exploring the molecular underpinnings of the regenerative potential of the mature nervous system after injury.     

Grafting of choroid plexus ependymal cells promotes the growth of regenerating axons in the dorsal funiculus of rat spinal cord: a preliminary report

Nerve regeneration in the central nervous system has been studied by grafting various tissues and cells. In the present study, we demonstrated that choroid plexus ependymal cells can promote nerve regeneration when grafted into spinal cord lesions. The choroid plexus was excised from the fourth ventricle of adult rats (Wistar), minced into small fragments, and grafted into the dorsal funiculus at the C2 level in adult rat spinal cord from the same strain. Electron microscopy and fluorescence histochemistry showed that ependymal cells of the grafted choroid plexus intimately interacted with growing axons, serving to support the massive growth of regenerating axons. CGRP-positive fibers closely interacted with grafted ependymal cells. HRP injection at the sciatic nerve showed that numerous HRP-labeled regenerating fibers from the fasciculus gracilis extended into the graft 7 days after grafting. This regenerating axons from the fasciculus gracilis was maintained for at least 10 months, with some axons elongating rostrally into the dorsal funiculus. Evoked potentials of long duration were recorded at a level ca. 5 mm rostral to the lesion in the rats 8 to 10 months after grafting. These findings indicate that choroid plexus ependymal cells have the ability to facilitate axonal growth in vivo, suggesting that they may be a promising candidate as graft for the promotion of nerve regeneration in the spinal cord.     

Role of endogenous Schwann cells in tissue repair after spinal cord injury

Schwann cells are glial cells of peripheral nervous system, responsible for axonal myelination and ensheathing, as well as tissue repair following a peripheral nervous system injury. They are one of several cell types that are widely studied and most commonly used for cell transplantation to treat spinal cord injury, due to their intrinsic characteristics including the ability to secrete a variety of neurotrophic factors. This mini review summarizes the recent findings of endogenous Schwann cells after spinal cord injury and discusses their role in tissue repair and axonal regeneration. After spinal cord injury, numerous endogenous Schwann cells migrate into the lesion site from the nerve roots, involving in the construction of newly formed repaired tissue and axonal myelination. These invading Schwann cells also can move a long distance away from the injury site both rostrally and caudally. In addition, Schwann cells can be induced to migrate by minimal insults (such as scar ablation) within the spinal cord and integrate with astrocytes under certain circumstances. More importantly, the host Schwann cells can be induced to migrate into spinal cord by transplantation of different cell types, such as exogenous Schwann cells, olfactory ensheathing cells, and bone marrow-derived stromal stem cells. Migration of endogenous Schwann cells following spinal cord injury is a common natural phenomenon found both in animal and human, and the myelination by Schwann cells has been examined effective in signal conduction electrophysiologically. Therefore, if the inherent properties of endogenous Schwann cells could be developed and utilized, it would offer a new avenue for the restoration of injured spinal cord.     

660 nm red light-enhanced bone marrow mesenchymal stem cell transplantation for hypoxic-ischemic brain damage treatment

Bone marrow mesenchymal stem cell transplantation is an effective treatment for neonatal hypoxic-ischemic brain damage. However, the in vivo transplantation effects are poor and their survival, colonization and differentiation efficiencies are relatively low. Red or near-infrared light from 600–1,000 nm promotes cellular migration and prevents apoptosis. Thus, we hypothesized that the combination of red light with bone marrow mesenchymal stem cell transplantation would be effective for the treatment of hypoxic-ischemic brain damage. In this study, the migration and colonization of cultured bone marrow mesenchymal stem cells on primary neurons after oxygen-glucose deprivation were detected using Transwell assay. The results showed that, after a 40-hour irradiation under red light-emitting diodes at 660 nm and 60 mW/cm2, an increasing number of green fluorescence-labeled bone marrow mesenchymal stem cells migrated towards hypoxic-ischemic damaged primary neurons. Meanwhile, neonatal rats with hypoxic-ischemic brain damage were given an intraperitoneal injection of 1 × 106 bone marrow mesenchymal stem cells, followed by irradiation under red light-emitting diodes at 660 nm and 60 mW/cm2 for 7 successive days. Shuttle box test results showed that, after phototherapy and bone marrow mesenchymal stem cell transplantation, the active avoidance response rate of hypoxic-ischemic brain damage rats was significantly increased, which was higher than that after bone marrow mesenchymal stem cell transplantation alone. Experimental findings indicate that 660 nm red light emitting diode irradiation promotes the migration of bone marrow mesenchymal stem cells, thereby enhancing the contribution of cell transplantation in the treatment of hypoxic-ischemic brain damage.     

Synergistic effects of bone marrow stromal cells and a Rho kinase (ROCK) inhibitor,Fasudil on axon regeneration in rat spinal cord injury

Transplanted bone marrow stromal cells (BMSC) promote functional recovery after spinal cord injury (SCI) through multiple mechanisms. A Rho kinase inhibitor, Fasudil also enhances axonal regeneration. This study was aimed to evaluate whether combination therapy of BMSC transplantation and Fasudil further enhances axonal regeneration and functional recovery in rats subjected to SCI. Fasudil or vehicle was injected for 2 weeks. BMSC or vehicle transplantation into the rostral site of SCI was performed at 7 days after injury. Neurological symptoms were assessed throughout the experiments. Fluoro‐Ruby was injected into the dorsal funiculus of the rostral site of SCI at 63 days after injury. The fate of the transplanted BMSC was examined using immunohistochemistry. BMSC transplantation significantly increased the number of Fluoro‐Ruby ‐labeled fibers of the dorsal corticospinal tracts at the caudal site of SCI, enhancing functional recovery of the hind limbs. Some of the engrafted BMSC were positive for Fluoro‐Ruby, neuronal specific nuclear protein and microtubule‐associated protein‐2, suggesting that they acquired neuronal phenotypes and built synaptic connection with the host's neural circuits. Fasudil treatment also improved axonal continuity, but did not promote functional recovery. Combination therapy dramatically increased the number of Fluoro‐Ruby‐labeled fibers of the dorsal corticospinal tracts at the caudal site of SCI, but did not further boost the therapeutic effects on locomotor function by BMSC transplantation. The findings suggest that BMSC transplantation and Fasudil provide synergistic effects on axon regeneration after SCI, although further studies would be necessary to further enhance functional recovery.     

神经干细胞移植治疗脊髓损伤

目的:探讨神经干细胞移植对脊髓损伤大鼠后肢运动功能修复的影响。方法:SD大鼠36只,制成T10脊髓全横断损伤模型。于造模成功后1周采用局部微量注射法移植。随机分三组：A损伤对照组（n=12）仅打开椎管暴露脊髓;B移植对照组（n=12）：注射10μl DMEM/F12培养液;C细胞移植组（n=12）：移植1.0?06/ml的神经干细胞悬液10μl。移植后通过不同时间点BBB行为评分、病理组织学、免疫荧光技术评价大鼠大鼠脊髓功能修复情况及移植细胞在体内的存活、迁移、分化。 结果:在体外成功建立SD大鼠海马源性神经干细胞培养体系;B、C两组大鼠随着时间延长BBB评分均不同程度提高,从移植后2W起C组大鼠评分明显高于B组,两组比较差异有统计学意义（P<0.05）;神经干细胞移植后能够在体内继续存活、迁移并且分化为NF-200、GFAP表达阳性的神经元及星形胶质细胞。 结论:神经干细胞移植治疗脊髓损伤是一种有效的方法。