Treating amyotrophic lateral sclerosis with allogeneic Schwann cell-derived exosomal vesicles: a case report

Schwann cells are essential for the maintenance and function of motor neurons,axonal networks,and the neuromuscular junction.In amyotrophic lateral sclerosis,where motor neuron function is progressively lost,Schwann cell function may also be impaired.Recently,important signaling and potential trophic activities of Schwann cell-derived exosomal vesicles have been reported.This case report describes the treatment of a patient with advanced amyotrophic lateral sclerosis using serial intravenous infusions of allogeneic Schwann cell-derived exosomal vesicles,marking,to our knowledge,the first instance of such treatment.An 81-year-old male patient presented with a 1.5-year history of rapidly progressive amyotrophic lateral sclerosis.After initial diagnosis,the patient underwent a combination of generic riluzole,sodium phenylbutyrate for the treatment of amyotrophic lateral sclerosis,and taurursodiol.The patient volunteered to participate in an FDA-approved single-patient expanded access treatment and received weekly intravenous infusions of allogeneic Schwann cell-derived exosomal vesicles to potentially restore impaired Schwann cell and motor neuron function.We confirmed that cultured Schwann cells obtained from the amyotrophic lateral sclerosis patient via sural nerve biopsy appeared impaired(senescent)and that exposure of the patient’s Schwann cells to allogeneic Schwann cell-derived exosomal vesicles,cultured expanded from a cadaver donor improved their growth capacity in vitro.After a period of observation lasting 10 weeks,during which amyotrophic lateral sclerosis Functional Rating Scale-Revised and pulmonary function were regularly monitored,the patient received weekly consecutive infusions of 1.54×1012(×2),and then consecutive infusions of 7.5×1012(×6)allogeneic Schwann cell-derived exosomal vesicles diluted in 40 mL of Dulbecco’s phosphate-buffered saline.None of the infusions were associated with adverse events such as infusion reactions(allergic or otherwise)or changes in vital signs.Clinical lab serum neurofilament and cytokine levels measured prior to each infusion varied somewhat without a clear trend.A more sensitive in-house assay suggested possible inflammasome activation during the disease course.A trend for clinical stabilization was observed during the infusion period.Our study provides a novel approach to address impaired Schwann cells and possibly motor neuron function in patients with amyotrophic lateral sclerosis using allogeneic Schwann cell-derived exosomal vesicles.Initial findings suggest that this approach is safe.

Chondroitinase ABC combined with Schwann cell transplantation enhances restoration of neural connection and functional recovery following acute and chronic spinal cord injury

Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal cord.Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury.We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal directions.Such Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder functions.Importantly,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord injury.These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.

RNA sequencing of exosomes secreted by fibroblast and Schwann cells elucidates mechanisms underlying peripheral nerve regeneration

Exosomes exhibit complex biological functions and mediate a variety of biological processes,such as promoting axonal regeneration and functional recove ry after injury.Long non-coding RNAs(IncRNAs)have been reported to play a crucial role in axonal regeneration.Howeve r,the role of the IncRNA-microRNAmessenger RNA(mRNA)-competitive endogenous RNA(ceRNA)network in exosome-mediated axonal regeneration remains unclear.In this study,we performed RNA transcriptome sequencing analysis to assess mRNA expression patterns in exosomes produced by cultured fibroblasts(FC-EXOs)and Schwann cells(SCEXOs).Diffe rential gene expression analysis,Gene Ontology analysis,Kyoto Encyclopedia of Genes and Genomes analysis,and protein-protein intera ction network analysis were used to explo re the functions and related pathways of RNAs isolated from FC-EXOs and SC-EXOs.We found that the ribosome-related central gene Rps5 was enriched in FC-EXOs and SC-EXOs,which suggests that it may promote axonal regeneration.In addition,using the miRWalk and Starbase prediction databases,we constructed a regulatory network of ceRNAs targeting Rps5,including 27 microRNAs and five IncRNAs.The ceRNA regulatory network,which included Ftx and Miat,revealed that exsosome-derived Rps5 inhibits scar formation and promotes axonal regeneration and functional recovery after nerve injury.Our findings suggest that exosomes derived from fibro blast and Schwann cells could be used to treat injuries of peripheral nervous system.

Runx2 regulates peripheral nerve regeneration to promote Schwann cell migration and re-myelination

Runx2 is a major regulator of osteoblast differentiation and function;however,the role of Runx2 in peripheral nerve repair is unclea r.Here,we analyzed Runx2expression following injury and found that it was specifically up-regulated in Schwann cells.Furthermore,using Schwann cell-specific Runx2 knocko ut mice,we studied peripheral nerve development and regeneration and found that multiple steps in the regeneration process following sciatic nerve injury were Runx2-dependent.Changes observed in Runx2 knoc kout mice include increased prolife ration of Schwann cells,impaired Schwann cell migration and axonal regrowth,reduced re-myelination of axo ns,and a block in macrophage clearance in the late stage of regeneration.Taken together,our findings indicate that Runx2 is a key regulator of Schwann cell plasticity,and therefore peripheral nerve repair.Thus,our study shows that Runx2 plays a major role in Schwann cell migration,re-myelination,and peripheral nerve functional recovery following injury.

Chemokine platelet factor 4 accelerates peripheral nerve regeneration by regulating Schwann cell activation and axon elongation

Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.

Gp78 regulates PMP22 and causes ER stress and autophagy in EV71-VP1-overexpressing mouse Schwann cells

Background:During Enterovirus type 71(EV71)infection,the structural viral protein 1(VP1)activates endoplasmic reticulum(ER)stress associated with peripheral myelin protein 22(PMP22)accumulation and induces autophagy.However,the specific mechanism behind this process remains elusive.Methods:In this research,we used the VP1-overexpressing mouse Schwann cells(SCs)models co-transfected with a PMP22 silencing or Autocrine motility factor receptor(AMFR/gp78)overexpressing vector to explore the regulation of gp78 on PMP22 and its relationship with autophagy and apoptosis.Results:The activity of gp78 could be influenced by EV71-VP1,leading to a decrease in the ubiquitination and degradation of PMP22,resulting in PMP22 accumulation in ER.In VP1-overexpressing mouse SCs,all three ER stress sensors,including pancreatic endoplasmic reticulum kinase(PERK),activating transcription factor 6(ATF6)and inositol-requiring enzyme 1(IRE1)and the related downstream signals(C/EBP-homologous protein(CHOP)and Caspase 12)were activated,as well as the ER-resident chaperone Glucose-regulated protein 78(GRP78).In addition,VP1 upregulated the autophagy marker Microtubule-associated protein 1 light chain 3 beta(LC3B),while PMP22 silencing or gp78 overexpression reversed the phenomenon.Meanwhile,PMP22 silencing or gp78 overexpression increased proliferation of EV71-VP1-transfected mouse SCs.Conclusion:Gp78 could regulate PMP22 accumulation through ubiquitination degradation and cause ER stress and autophagy in EV71-VP1-overexpressing mouse SCs.Therefore,the gp78/PMP22/ER stress axis might emerge as a promising therapeutic target for myelin and neuronal damage induced by EV71 infection.

良性腺性Schwann瘤

目的 :报道罕见的Schwann瘤 1例及复习该瘤的病理特征。方法 :应用组织化学和免疫组织化学染色检测肿瘤组织中梭形细胞成分和腺性结构。结果 :肿瘤由典型Schwann瘤和腺性成分组成。腺性结构表达Leu 7、GFAP、MBP、CEA、AE1 AE3、34 βE12。 结论

补阳还五汤提取液对Schwann细胞氧化损伤的保护作用

本实验建立了Schwann细胞的体外氧化损伤模型,从对Schwann细胞的抗氧化损伤作用探讨补阳还五汤的疗效机制。用原代培养的Schwann细胞建立氧化损伤模型,将培养细胞分为氧化损伤组,补阳还五汤处理组及正常组:(1)应用MTT方法检测细胞的活性;(2)应用生化技术检测细胞内超氧化物歧化酶(SOD)的含量;(3)采用荧光探针Fluo-3-AM标记细胞,用激光共聚焦显微镜观察H_2O_2对Schwann细胞内游离钙([Ca2+])抗氧化损伤的影响。结果显示:与对照组相比,H2O2处理组细胞活性降低(P<0.01),SOD含量明显减少(P<0.01),而补阳还五汤预处理后细胞内[Ca2+]i升高明显被减弱(P<0.01),细胞存活率明显升高(P<0.01)。以上结果表明补阳还五汤能通过抗过氧化损伤保护Schwann细胞。

筋脉通含药血清对高糖培养的Schwann细胞诱导型一氧化氮合酶和NADPH氧化酶p22-phox亚基表达的影响

目的:探讨筋脉通含药血清对高糖培养的Schwann细胞诱导型一氧化氮合酶(inducible nitric oxide synthase,i NOS)蛋白表达及烟酰胺腺嘌呤二核苷酸磷酸(nicotinamide adenine dinucleotidephosphate,NADPH)氧化酶p22-phox亚基mRNA表达的影响。方法:雄性Wistar大鼠随机分为3组,分别灌胃筋脉通、维生素C或蒸馏水制备含药血清和对照血清。取新出生大鼠的双侧坐骨神经用于制备Schwann细胞。将体外培养的Schwann细胞分为高糖组、筋脉通组(加入筋脉通含药血清)、维生素C组(加入维生素C含药血清)及正常对照组。培养48h后,采用免疫荧光法检测Schwann细胞内i NOS蛋白的表达,实时荧光定量聚合酶链式反应法检测NADPH氧化酶p22-phox亚基mRNA的表达。结果:高糖培养的Schwann细胞内i NOS蛋白表达及NADPH氧化酶p22-phox亚基mRNA表达均较正常对照组明显升高(P<0.01);与高糖组比较,筋脉通组i NOS蛋白表达及NADPH氧化酶p22-phox亚基mRNA表达明显降低(P<0.01),且明显优于维生素C组(P<0.01)。结论:筋脉通含药血清可以下调高糖培养的Schwann细胞i NOS蛋白及NADPH氧化酶p22-phox亚基mRNA的表达。

电刺激对背根节神经元/Schwann细胞联合培养体系髓鞘蛋白P0表达的影响

目的:建立体外背根节神经元与Schwann细胞联合培养模型,观察短时低频电刺激对Schwann细胞髓鞘蛋白表达的影响。方法:培养和纯化背根节神经元与Schwann细胞,制成背根节神经元/Schwann细胞联合培养体系。于L-ascorbic acid诱导的同时,施予低频电刺激(20Hz,100μs,3V),持续作用1h,分别于L-ascorbicacid诱导后第0,2,4,8和10d取各组培养基上清以ELISA测定其中脑衍生物神经生长因子(BDNF)的水平。另外,于诱导后第7d和14d检测培养体系中髓鞘蛋白P0的表达。结果:电刺激组各时间点BDNF的浓度较对照组显著升高(P<0.01)。经电刺激作用后,联合培养体系中P0表达上调(P<0.05)。然而,电刺激结束后在培养液中加入TrkB-Fc,P0的表达水平则显著降低(P<0.05)。结论:在神经元存在的条件下,短时低频电刺激可促进离体Schwann细胞合成P0,初步认为该作用通过刺激神经元分泌BDNF增多所致。

Schwann细胞表达β1,4半乳糖基转移酶-Ⅰ对神经元轴突生长的影响

为了探讨周围神经Schwann细胞中不同β1,4半乳糖基转移酶-1(β-1,4-GalT-I)表达水平对神经元轴突生长的影响,本实验首先构建了正、反义β-1,4-GalT-I表达质粒,然后将构建的不同浓度的正、反义表达质粒超表达于分离、纯化的大鼠Schwann细胞,最后将转染的Schwann细胞与分离的大鼠背根神经节共培养;根据共培养神经元轴突延伸的数目和面积,分析Schwann细胞中不同β-1,4-GalT-I表达水平对神经元轴突生长的影响。结果发现:转染正义β-1,4-GalT-I的Schwann细胞能促进共培养神经节神经元轴突的长出和延伸。在一定的转染浓度内,这种促神经生长作用随转染浓度增大而增强,而转染反义β-1,4-GalT-I却有相反的作用。提示周围神经Schwann细胞中表达β-1,4-GalT-I可能在维持正常神经的功能和促进损伤神经的修复发挥重要作用。

Schwann细胞在壳聚糖纤维上的立体培养

目的 :探讨壳聚糖纤维与体外培养Schwann细胞的相容性和亲和力。方法 :新生SD鼠的臂丛和坐骨神经组织块种植于壳聚糖纤维支架上培养Schwann细胞。结果 :壳聚糖纤维支架上的Schwann细胞为橄榄形或椭圆形 ,细胞在纤维上分裂、迁移 ,形成链状结构 ,细胞突起的末端呈扁平状膨大 ,伸出爪形伪足贴附于纤维。结论 :壳聚糖纤维不仅与Schwann细胞的相容性良好 。

冷酶消化法在分离和培养新生大鼠Schwann细胞的应用

Schwann细胞(SCs)是公认的周围神经组织工程的种子细胞,在周围神经损伤后的再生中扮演着重要的角色。为了快速分离和培养大量的SCs,本研究采用冷酶消化法对Wister乳鼠坐骨神经的细胞进行分离和培养,结果得到的细胞数量超过106,经S-100蛋白免疫组化染色鉴定,SCs的纯度超多了90%。从培养细胞的形态和生长曲线可见,冷酶消化法是一种简单快捷地分离SCs的方法,使用该法得到的SCs具有良好的生物学特性,并在细胞的分离时间、数量、纯度以及生物活性等方面,均达到了实用要求。

体外培养Schwann细胞缺氧模型的建立

目的:建立体外培养Schwann细胞的缺氧模型。方法:取体外培养Schwann细胞,置于通入体积分数为5%CO2和95%N2的有机玻璃盒中继续缺氧培养10、15和20min,用H-E染色观察细胞形态,MTT比色试验检测细胞的活力。结果:缺氧10min组细胞形态及活力与正常组无明显差异;而缺氧15min组的细胞突起回缩,活力为缺氧前的66·3%;缺氧20min组的细胞多数死亡,活力仅为缺氧前的20·6%。结论:本方法可以成功建立有效、简便、易行的Schwann细胞缺氧模型。

Schwann细胞与硫酸肝素-胶原蛋白支架材料的复合

本研究目的是观测硫酸肝素-胶原蛋白支架材料对Schwann细胞的相容性,采用: (1)冷冻干燥法制备硫酸肝素-胶原蛋白支架材料,培养、纯化并鉴定Schwann细胞后,将Hoechst荧光标记的Schwann细胞复合于硫酸肝素-胶原支架材料中,荧光显微镜、扫描电镜及光镜下观察其在材料内部的空间排列形式; (2)以台盼蓝染色、MTT法检测Schwann细胞与硫酸肝素-胶原蛋白共培养时的生物活性。结果显示:作者制备的支架材料具有纵行的、平行排列的微管结构,Schwann细胞在支架材料微管内成线性平行排列,类似于神经基底膜与Schwann细胞形成的Büngner带;台盼蓝染色Schwann细胞死亡率仅6. 47%,MTT法证明Schwann细胞与硫酸肝素-胶原蛋白材料共培养时保有高度的生物活性。本研究结果表明:以硫酸肝素复合胶原蛋白结合特定条件下冷冻干燥技术可以制备在组分和内部空间结构上高度仿生神经的新型神经组织工程支架材料,与Schwann细胞有良好的细胞相容性。

感觉神经和运动神经Schwann细胞的培养研究

为了建立应用于神经组织工程的感觉神经和运动神经的 Schwann细胞的体外培养方法 ,采用联合酶消化法对 SD乳鼠后根神经和股神经运动支的 Schwann细胞进行了培养 ,并经抗 S10 0荧光染色鉴定和双抗体夹心间接 Elisa法测量两种 Schwann细胞培养基中 NGF的表达。结果表明 ,两种培养细胞经荧光染色证明均为 Schwann细胞 ,细胞纯度均超过 95 % ,光镜观察未见形态学差异 ,但 NGF的表达量和表达模式均有显著性差别 (P<0 .0 5 )。提示 ,本实验方法可以获得高纯度的感觉神经和运动神经的 Schwann细胞 ,两者的生物学功能有一定差异。

P38在LPS诱导大鼠雪旺氏(Schwann)细胞TNF-α表达中的作用

研究P38对脂多糖(LPS)诱导的大鼠雪旺氏细胞(Schwann cell)肿瘤坏死因子-alpha(TNF-α)表达的作用.采用Western印迹检测细胞中P38激酶的活性;用P38的特异性抑制剂(SB202190)预处理细胞后,用ELISA检测细胞中TNF-α水平;RT-PCR检测细胞中TNF-αmRNA的表达;用免疫荧光双标法检测磷酸化P38的表达定位.LPS可显著激活雪旺氏细胞中的P38信号通路,其激活高峰在LPS刺激后15～30min,60min后,P38磷酸化水平开始逐渐下降,120min时又升高;用SB202190预处理细胞后,可显著抑制细胞TNF-αmRNA以及TNF-α的表达;LPS刺激细胞后通过与细胞膜表面Toll-like receptor 4(TLR4)结合后引起P38磷酸化,SB202190可抑制该过程.P38信号通路的激活可能是LPS诱导TNF-α表达的前提.通过阻断细胞内信号转导通路来减少TNF-α及其它细胞因子的产生,为抑制周围神经损伤后的炎症以及免疫反应发生提供了一条新的思路.

大鼠骨髓间质细胞向Schwann-like细胞的诱导分化

目的探索成年大鼠骨髓间质细胞(MSCs)向Schwann-like细胞转化的方法和机理。方法分别用变性神经提取液和含有大鼠白血病抑制因子(rLIF)、上皮生长因子(EGF)、碱性成纤维细胞生长因子(bFGF)等的诱导液诱导成年大鼠骨髓间质细胞,观察诱导过程中细胞形态学变化,利用免疫细胞化学染色鉴定诱导细胞性质;同时培养大鼠Schwann细胞作为对照。结果经变性神经提取液诱导后细胞转化为梭形细胞,并排列成网状;经细胞因子诱导后细胞呈梭形排列,S-100,GFAP染色呈阳性反应。结论变性神经提取液中含有促使骨髓间质细胞向Schwann-like细胞分化的必要成份;LIF可能是这些必要成份的重要组成之一。

Schwann细胞移植在脊髓损伤治疗中的应用进展

Schwann细胞具有很强的神经保护和髓鞘化的能力,是脊髓损伤治疗研究中运用最早和最多的细胞之一。目前Schwann细胞常常作为联合治疗的平台,将各种干预手段整合起来。本文主要讨论Schwann细胞在联合治疗脊髓损伤中所遇到的问题,各种有关Schwann细胞的联合治疗的效果,Schwann细胞共移植对神经干细胞的积极影响,Schwann细胞移植后的存活、迁移情况以及内源性Schwann细胞在脊髓损伤修复中的作用。

周围神经损伤后Schwann细胞与轴突再生关系的超微形态学研究

目的观察大鼠坐骨神经损伤后Schwann细胞和轴突再生关系的超微结构变化。方法切断大鼠双侧坐骨神经,在神经断端间留有3 mm间隙构建神经再生室。分为A组和B组,在A组左侧(A1)神经再生室内注入0.1 ml生理盐水,右侧(A2)注入0.05 ml丝裂霉素(40μg/ml)和0.05 ml层粘连蛋白(10μg/ml);在B组左侧(B1)神经再生室内注入0.1 ml丝裂霉素(40μg/ml),右侧(B2)注入0.1 ml层粘连蛋白(10μg/ml),第3天按上述浓度及剂量依次注入,4周进行超微结构观察。结果A1组、A2组和B2组Schwann细胞和轴突再生的超微结构明显优于B1组。结论周围神经损伤后,Schwann细胞和轴突再生之间的关系密不可分,Schwann细胞的存在与否直接影响到轴突的再生,Schwann细胞为轴突的再生提供必要的支持,且外源性层粘连蛋白能够促进Schwann细胞和轴突的再生。