许旺细胞的体外培养提纯

许旺细胞是组织工程修复神经损伤的种子细胞，能否获得大量且高纯度的许旺细胞对于组织工程学至关重要。许旺细胞的培养纯化技术日趋完善，其经典的培养方法有植块法和酶消化法，在此基础上改进的去除成纤维细胞的方法有差速贴壁法、免疫选择法、阿糖胞苷补充法、刺激因子增殖法等。最近比较新的提纯方法有磁性活细胞分离法、层粘连蛋白纯化法、三维支架联合培养法。另外还有一些因子，如胎牛血清浓度等影响许旺细胞的扩增。这些技术的主要目的就是在体外获得大量的高纯度许旺细胞，以满足组织工程修复神经的需要。许旺细胞的体外培养和提纯方法众多，且已取得初步进展，但在此技术完全成熟之前尚还有许多问题有待解决，如周期长、细胞活性低、在传代培养中细胞生物学特性不稳定等。     

Altered gene expression in Schwann cells of connexin32 knockout animals

The discovery that the dominant X-linked form of Charcot-Marie-Tooth disease (CMTX), a genetic disease of the peripheral nervous system (PNS), is associated with mutations in connexin32 (Cx32) has brought attention to the importance of connexins in glial cell biology. To gain further insight into the consequences of Cx32 deficiency, we have undertaken a detailed characterization of the gene expression profile of Schwann cells isolated from the sciatic nerve of wild-type and Cx32-null mice. Schwann cells exhibit two distinct phenotypes, myelinating and nonmyelinating, which are defined by their different morphology with respect to axons and by their unique profile of gene expression. Our findings show that, regardless of the mouse genotype, cultured Schwann cells express similar levels of messages for a number of connexins and for genes characteristic of both the myelinating and the nonmyelinating phenotypes. Furthermore, we have identified Cx36, a member of the gamma subclass of connexins, which are preferentially expressed in neuronal cells of mouse brain and retina, as an additional connexin present in Schwann cells. Mice lacking Cx32, however, exhibited a marked up-regulation of glial fibrillary acidic protein (GFAP), a cytoskeletal protein usually synthesized only by nonmyelinating Schwann cells. This observation was extended to the PNS in vivo and did not reflect a general perturbation of the expression of other nonmyelinating Schwann cell genes. These findings demonstrate that the absence of Cx32 results in a distinct pattern of gene dysregulation in Schwann cells and that Schwann cell homeostasis is critically dependent on the correct expression of Cx32 and not just any connexin. Identifying the relationship between increased GFAP expression and the absence of Cx32 could lead to the definition of specific roles for Cx32 in the control of myelin homeostasis and in the development of CMTX.     

雪旺细胞和神经干细胞共移植治疗大鼠帕金森病的实验研究

目的 研究雪旺细胞（SCs）和神经干细胞（NSCs）共移植治疗大鼠帕金森病（PD）的疗效。方法 18只PD模型的SD大鼠随机平均分成3组：对照组、NSCs组及共移植组。PBS、NSCs及SCs加NSCs分别植入PD大鼠右侧纹状体内。NSCs来源于孕14～16d胎鼠中脑腹侧的脑组织．SCs来源于1～3dSD新生鼠的坐骨神经。结果 移植10周后NSCs组及共移植组中纹状体区都出现TH染色阳性的神经元，与NSCs组相比，共移植组中的神经元体积及细胞核均较大。细胞数量多（P〈0．05）。与对照组相比，NSCs组及共移植组中大鼠的行为学均有明显的好转（P〈0．01），但NSCs组和共移植组相比，行为学的改变无明显差异（P〉0．05）。结论 SCs和NSCs共移植能有效治疗PD模型大鼠。     

Lysophosphatidic acid activates satellite glia cells and Schwann cells

Pruritus is a common and disabling symptom in patients with hepatobiliary disorders, particularly in those with cholestatic features. Serum levels of lysophosphatidic acid (LPA) and its forming enzyme autotaxin were increased in patients suffering from hepatic pruritus, correlated with itch severity and response to treatment. Here we show that in a culture of dorsal root ganglia LPA 18:1 surprisingly activated a large fraction of satellite glia cells, and responses to LPA 18:1 correlated inversely with responses to neuronal expressed transient receptor potential channels. LPA 18:1 caused only a marginal activation of heterologously expressed TRPV1, and responses in dorsal root ganglion cultures from TRPV1-deficient mice were similar to controls. LPA 18:1 desensitized subsequent responsiveness to chloroquine and TGR5 agonist INT-777. The LPA 18:1-induced increase in cytoplasmatic calcium stems from the endoplasmatic reticulum. LPA receptor expression in dorsal root ganglia and Schwann cells, LPAR1 immunohistochemistry, and pharmacological results indicate a signaling pathway through LPA receptor 1. Peripheral rat Schwann cells, which are of glial lineage as the satellite glia cells, were also responsive to LPA 18:1. Summarizing, LPA 18:1 primarily activates rather glial cells than neurons, which may subsequently modulate neuronal responsiveness and sensory sensations such as itch and pain.     

体外诱导人脐带间充质干细胞分化为许旺细胞

背景：人脐带Wharton’s Jelly源间充质干细胞避免了伦理的限制,来源丰富,可以作为种子细胞进行组织修复。 目的：观察体外诱导脐带Wharton’s Jelly中间充质干细胞向许旺细胞分化的可行性。 方法：分离、培养脐带Wharton’s Jelly中间充质干细胞,流式细胞术鉴定细胞表面标志。利用神经细胞培养基、碱性成纤维生长因子、表皮生长因子、维甲酸、血小板源性生长因子等采用两步法将脐带间充质干细胞诱导分化为许旺细胞,倒置显微镜下观察细胞形态变化。利用免疫细胞化学染色法检测巢蛋白、S-100、纤维酸性蛋白的表达,反转录-聚合酶链反应、免疫印记技术检测许旺细胞特异性蛋白产物表达。 结果与结论：脐带细胞培养第7天形态发生变化,部分细胞变成梭形。原代细胞培养10 d左右可达80%~90%融合,细胞呈梭形。分离培养的细胞表达具有间充质干细胞表面特有标志：CD44(91.4%),CD29(91.3%),CD105(99.2%),不表达CD34(0.2%),CD45(0.9%),CD14(0.6%)。脐带Wharton’s Jelly中间充质干细胞经第一阶段诱导后,细胞由短梭形变成长梭形或纺锤形,并出现聚集现象,由形状规则、表面圆滑的球形细胞团形成。第二阶段诱导后,有长梭形细胞从球形细胞团爬出,96 h后细胞形态多为长梭形,伴有多极现象。免疫细胞化学染色结果示：长梭形多极细胞具有许旺细胞特异的纤维酸性蛋白、S100蛋白染色。结果表明脐带Wharton’s Jelly中间充质干细胞可在体外诱导分化为许旺细胞。     

Ultrastructural and cytochemical characteristics of cultured rat Schwann cells

Summary Schwann cell cultures were established from sciatic nerve of 3 day-old rats. Described are the ultrastructural, histochemical and ultracytochemical properties of amyelic cultured rat Schwann cells. Ultrastructural characteristics of the cultured Schwann cells are compared to the Schwann cells of 3 day-old and adult rat sciatic nerve. These findings serve as a basis for comparison when studying experimentally induced alterations in the cultured Schwann cells as well as changes due to myelination in vitro.     

多步法分离和纯化雪旺细胞的实验研究

目的 改进雪旺细胞（SCs)的体外培养条件，以获得足够数量较纯净的雪旺细胞应用于周围神经修复。方法 5-7d的SD仔鼠坐骨神经，采用混合酶长时间多次消化法分离雪旺细胞，阿糖胞苷（cytosine arabinoside,Ara-C),G-418(geneticin)抑制成纤维细胞生长，氟丝扣林促进雪旺细胞分裂增殖，低浓度胰酶快速消化传代进一步纯雪旺细胞。结果 使用上述方法可以获得大量的高分裂增殖，低浓度胰酶快速消化传代进一步纯雪旺细胞。结果 使用上述方法可以获得大量的高分裂增殖，低浓度胰酶快速消化传代进一步纯化雪旺细胞。结果 使用上述方法可以获得大量的高纯度雪旺细胞，经抗S-100蛋白单抗通过SABX法染色鉴定，雪旺细胞纯度可达到97%以上。结论 本文所使用的方法是培养和纯化雪旺细胞较为理想的方法，可以满足目前组织工程神经修复的需要。     

GABA uptake by purified rat Schwann cells in culture

Purified rat Schwann cells maintained in culture for up to 6 months retained their ability to take up the neurotransmitter γ-aminobutyric acid (GABA) by a high-affinity mechanism. Although cultured fibroblasts also accumulated GABA, they did so by a low affinity mechanism. These results indicate that Schwann cells continue to express a high affinity GABA transport system in the absence of signals from neurons.     

大鼠雪旺氏细胞支持人胚胎神经干细胞的生长并诱导其分化

目的 探讨大鼠雪旺氏细胞对人胚胎神经干细胞生长和分化的作用。方法 实验分为三组：组一：干细胞生长于培养雪旺氏细胞1天后的培养液中；组二：干细胞与雪旺氏细胞共培养；组三：干细胞生长于DMEM／F12培养液中，观察干细胞的形态学变化和免疫荧光的.组一的神经球分化生长，绝大多数细胞tubulin-β阳性，少数为GalC或GFAP阳性；组二中，在雪旺氏细胞生长密集和稀少的地方，干细胞分别表明为不分化和明显分化两种状态；组三的神经干细胞无法正常生长。结论 大鼠雪旺氏细胞分泌物支持人胚胎神经干细胞的生长并诱导其分化。     

Human fetal Schwann cells in culture: phenotypic expressions and proliferative capability

In this report we examined the phenotypic expressions and the proliferative capability of cultured human fetal Schwann cells. Antigens that were expressed included laminin, nerve growth factor receptor, neural cell adhesion molecule, S-100 protein, and that recognized by the monoclonal antibody HNK-1. In addition, HLA-A,B,C and HLA-DR, respectively, class I and class II antigens of the major histocompatibility complex, were demonstrated on Schwann cells. Mitotic capability was high, with an average of 34% of Schwann cells undergoing proliferation over a 2-day period.     

Schwann cells and peripheral nervous system myelin in the rat retina

Summary Within the retinal nerve fiber layer of a 6-week-old Sprague-Dawley rat, scattered aggregates of PNS myelinated axons have been found and described. We believe this is likely to represent a normal but rare phenomenon in the rat.     

Improvement of Parkinsonian behavior with co-grafts of Schwann cells and neural stem cells in the rat

BACKGROUND: Due to the lack of autograft transplant rejection, Schwann cells (SCs) can promote the proliferation of embryonic stem cells and the induction of dopaminergic neurons. Mesencephalic stem cells can be induced to produce dopaminergic neurons. The therapeutic effects of co-grafts of SCs and neural stem cells (NSCs) deserves further study and verification in Parkinsonian animal models.OBJECTIVE: To investigate the effects of Schwann cells and mesencephalic NSC co-grafts in Parkinsonian animal models on animal behavior and histology.DESIGN: Randomized controlled experiment.SETTING: Fudan University; Institute of Neuroscience, Chinese Academy of Sciences.MATERIALS: The following animals were obtained from the Experimental Animal Center, Shanghai Institute for Biological Science, Chinese Academy of Sciences: 5 Sprague-Dawley rats, embryonic day (E) 13–16; 16 neonatal Sprague-Dawley rats, postnatal day 1–3; and 18 adult SD rats of both genders. Animal experimentation met animal ethical approval.METHODS: The experiment was performed at the Department of Anatomy, Histology and Embryology, Shanghai Medical Center, Fudan University from September 2005 to January 2007. The mesencephalic NSCs were obtained from the brains of SD rats at E 13–16, and SCs were harvested from the sciatic nerves of neonatal rats at day 1–3. Hemiparkinsonian rats (n =18) were selected for transplantation after estimating rotational behavior in response to apomorphine and were randomly assigned to three groups: control group, NSC group, and co-graft group. There were 6 rats in each group. Either phosphate buffered saline (PBS), NSCs, or SCs plus NSCs were transplanted into the right neostriatum of Parkinsonian rats, respectively.MAIN OUTCOME MEASURES: ① Rotational behavior was induced by apomorphine (0.05 mg/kg, I.p.) 2, 4, 6, 8, and 10 weeks after transplantation, and the number of rotations were counted. ② Differentiation and survival of dopaminergic neurons in the right neostriatum were quantified by tyrosine hydroxylase immunohistochemistry 10 weeks after grafting.RESULTS: All 18 Parkinsonian rats were included in the final analysis,without any loss. ①Rotation behavior and turning: Compared with the control group, the percent of apomorphine-induced rotations were significantly decreased (P < 0.01) in both the NSC group and co-graft group. ②Differentiation and survival of dopaminergic neurons in each group: TH-immunoreactive neurons were detected in the striatum of both the NSC group and co-graft group 10 weeks after transplantation. The neuronal volume, size of the nucleus, and neuronal numbers were larger in the co-graft group compared to the NSC group (P < 0.05).CONCLUSION: SC and NSC co-grafts not only improve Parkinsonian behavior in rats, but also improve the survival of NSCs.     

Olfactory ensheathing cells promote migration of Schwann cells by secreted nerve growth factor

Transplantation of Schwann cells (SCs) and olfactory ensheathing cells (OECs) have emerged as very promising therapies for spinal cord repair. The important features of interaction between SCs and OECs are beginning to be appreciated, although the underlying mechanism remains unclear. In the present study, we tested the effects of OECs on SCs migration using a range of in vitro migration assays. We found that SCs migrated abundantly upon OECs monolayer, and the migration-promoting effects were identified to be due to the secreted diffusible factors in OEC-derived conditioned medium (OEC-CM). Furthermore, neutralizing nerve growth factor (NGF) in OEC-CM with NGF antibody could block this effect. Moreover, we found that NGF promotes SCs migration even on astrocyte monolayer. Taken together, these findings provide the first evidence that OECs can promote SCs migration in astrocytic environment by secreted NGF.     

人NT-3基因转染对雪旺细胞生物学行为的影响

目的观察神经营养素-3(NT-3)基因转染对雪旺细胞生物学行为的影响.方法采用逆转录聚合酶链反应(RT-PCR)方法,从人肝脏组织总RNA中克隆NT-3 cDNA,构建重组真核表达载体pIRES2-EGFP-NT-3;应用混合酶消化法分离、纯化雪旺细胞;采用阳性脂质体介导法将重组质粒pIRES2-EGFP-NT-3转染雪旺细胞,观察外源性NT-3对雪旺细胞生物学行为的影响.结果成功地从人肝脏组织中克隆了NT-3 cDNA,构建了重组真核表达载体pIRES2-EGFP-NT-3;分离、纯化得到了高纯度的雪旺细胞;将重组质粒转染雪旺细胞,与对照组相比,转染NT-3基因的雪旺细胞形态正常;经NT-3抗体免疫组化染色见NT-3转染组雪旺细胞胞浆呈深棕色着色,轴突着色清晰可见,与对照组相比,明显变长;空载体转染组及空白对照组胞浆及轴突着色均较淡;对各组细胞胞浆着色进行半定量分析,结果表明NT-3基因转染组灰度值显著高于对照组(P<0.01).结论 NT-3基因转染后雪旺细胞NT-3含量明显增加,轴突变长,本实验结果有望为面神经损伤后的修复提供新的途径.     

Extracellular matrix upregulates synthesis of glucosylceramide-based glycosphingolipids in primary Schwann cells

The formation of basement membrane around Schwann cells that are in contact with axons is necessary for Schwann cell differentiation and myelin formation in the peripheral nervous system. However, primary Schwann cells grown on basement membrane in the absence of neuronal influence show increased proliferation rather than differentiation, which implies that the signals generated by Schwann cell-basement membrane interactions are multipotential. We examined the effect of matrigel, an exogenous basement membrane preparation, and other extracellular matrix growth surfaces on primary Schwann cells to determine if the resulting interactions play a role in the control of glycosphingolipid synthesis. Isolated primary Schwann cells grown on a thin layer of matrigel rapidly adhered to the surface and exhibited a greater degree of cell spreading when compared to cells grown on the nonspecific substrate polylysine. Labeling of the cells with [³H]galactose between 24 and 48 hr after plating revealed that the incorporation of [³H]galactose into glucosylceramide-based glycosphingolipids increased from 1.5-3-fold on matrigel in comparison to cells grown on polylysine. The major labeled glycolipids under both conditions were GM3 ganglioside and two neutral glycolipids that comigrated with GbOse₄Cer (GalNAcβ1-3Galα1-4Galβ1-1Cer) and GbOse₅Cer (GalNAcα1-3GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-1Cer) standards. There was little or no increase in the incorporation of [³H]leucine, [³H]galactose, or [³H]glucosamine into proteins or [³H]palmitic acid into phospholipids, free ceramides, or sphingomyelin, suggesting that the matrigel-induced increase in the synthesis of the glycolipids was selective. In the absence of serum, there was little or no difference in the levels of glycolipid labeling between cells grown on the two substrata, demonstrating that serum factors were required for matrigel to have this effect. When cells were grown on surfaces coated with individual extracellular matrix components, those cells grown on laminin and collagen IV showed an increase in glycolipid labeling similar to that produced by matrigel, while labeling increased to a lesser degree for the other components tested. Thus, the signals generated by interactions between Schwann cells and basement membrane, particularly the laminin and collagen IV constituents, contribute to the regulation of glycolipid synthesis which in turn may affect cell morphology and proliferation. © 1996 Wiley-Liss, Inc.     

血清和雪旺氏细胞诱导大鼠胚胎神经干细胞分化的比较

目的 比较血清和雪旺氏细胞诱导大鼠胚胎神经干细胞分化的差异。方法 分别采用血清和与雪旺氏细胞共培养的方法诱导大鼠胚胎神经干细胞分化，应用相差显微镜和免疫荧光染色的方法对其进行观察和比较。结果 两种方法都能够诱导绝大多数神经干细胞分化成神经元，少量分化成星形胶质细胞和少突胶质细胞。虽然后一种方法诱导干细胞分化的进程比前一种方法要慢，但细胞形态学上更接近发育成熟的神经元。结论 雪旺氏细胞的分泌物不仅能够诱导共培养的神经干细胞分化，而且使其分化更加成熟。     

Chick embryonic Schwann cells migrate anodally in small electrical fields

Little is known about the cues that guide migrating neural crest derivatives to their targets. This lack of understanding is especially significant in the case of Schwann cells, which have been transplanted into the central nervous system in an effort to promote axonal myelination after injury or disease. We have investigated the response of Schwann cells, cultured from the peripheral nerves of E7/8 chick embryos, to applied electrical fields. We find that they respond by migrating to the anode, and show a significant anodal bias in directionality at 3mV mm^{− 1}. This is the smallest electrical field that has been shown to affect cellular movement or growth in culture, and the anodal direction is surprising given the known cathodal responses of neural crest cells. The effective fields are considerably smaller than endogenous electrical fields that have been measured in embryonic tissues.