颅脑损伤促进的坐骨神经再生

BACKGROUND:Studies have shown that craniocerebral injury can promote the repair of sciatic nerve injury in rats, but its precise mechanism remains unclear. OBJECTIVE:To further explore the action mechanism of craniocerebral injury on the repair of sciatic nerve injury using morphology and histology. METHODS:Sixty specific-pathogen-free healthy male Sprague-Dawley rats were randomly divided into two groups. Rats with craniocerebral injury and sciatic nerve injury were considered as the experimental group. Rats with simple sciatic nerve injury were considered as the control group. Classical Feeney method was used in models of craniocerebral injury and SunderlandV sciatic nerve injury. At 8 and 12 weeks after modeling, sciatic nerve index was detected. Masson staining and NF200 immunofluorescence staining were used to observe the nerve regeneration at the anstomotic site. Transmission electron microscope was used to observe the number of regenerative axons. RESULTS AND CONCLUSION:At 8 and 12 weeks after modeling, compared with the control group, gait and sciatic nerve index recovered better in the experimental group. In the experimental group, Masson staining showed fewer nerve membrane collagen fibers, and the axon arranged neatly. NF200 immunohistochemistry showed that in the experimental group, the density of regenerated nerves was high, and nerves were regularly distributed. Transmission electron microscopy showed that in the experimental group, regenerative axons were regularly arranged, collagen scar was less, and myelin layer arranged regularly. Results suggested that the craniocerebral injury in rats may promote the repair of peripheral nerve injury by reducing scar collagen in nerve endings.     

Ginsenoside Rg1 promotes peripheral nerve regeneration in rat model of nerve crush injury

Searching for effective drugs which are capable of promoting nerve regeneration after nerve injuries has gained extensive attention. Ginsenoside Rg1 (GRg1) is one of the bioactive compounds extracted from ginseng. GRg1 has been shown to be neuroprotective in many in vitro studies, which raises the possibility of using GRg1 as a neuroprotective agent after nerve injuries. However, such a possibility has never been tested in in vivo studies. The present study was designed to investigate the efficacy of GRg1 in promoting nerve regeneration after nerve crush injury in rats. All rats were randomly divided into four groups (n = 8 in each group) after crush injury and were intraperitoneally administrated daily for 4 weeks with 1 mg/kg, or 5 mg/kg GRg1 (low or high dose GRg1 groups), or 100 μg/kg mecobalamin or normal saline, respectively. The axonal regeneration was investigated by retrograde labeling and morphometric analysis. The motor functional recovery was evaluated by electrophysiological studies, behavioral tests and histological appearance of the target muscles. Our data showed that high dose GRg1 achieved better axonal regeneration and functional recovery than those achieved by low dose GRg1 and mecobalamin. The final outcome of low dose GRg1 and mecobalamin was similar in both morphological and functional items, which was significantly better than that in saline group. These findings show that GRg1 is capable of promoting nerve regeneration after nerve injuries, suggesting the possibility of developing GRg1 a neuroprotective drug for peripheral nerve repair applications.     

辣椒素受体干预大鼠周围神经压榨性损伤后再生

目的:于大鼠坐骨神经压榨性损伤模型基础上观察辣椒素受体拮抗剂AMG517对神经损伤后再生过程的影响。方法:采用2.5%戊二醛固定标本、1%四氧化锇后固定、分别制备半薄切片(1μm)和超薄切片(60nm)、并进行甲苯胺蓝及醋酸铀-枸橼酸铅染色,对一侧坐骨神经损伤的损伤近端、损伤中心及损伤远端之有髓及无髓神经的数量及其结构特点进行观察和计数。结果:坐骨神经压榨性损伤后,损伤远端发生Wallerian变性,尔后,由损伤近端逐渐开始出现神经突起及雪旺细胞的再生。如果损伤前30 min于同侧足底皮下注射辣椒素受体拮抗剂ANG517(300μg/kg BW)后,损伤近端(距损伤中心0.2 cm)、损伤中心及损伤远端(距损伤中心0.2 cm)部位有髓和无髓神经簇再生的数量明显多于未用药组,尤以损伤后2周时表现更为明显。结论:辣椒素受体作为位于周围神经末梢的伤害性感受器,其功能状态的变化可以影响神经再生过程;抑制辣椒素受体可以加快或促进周围神经损伤后再生。     

Regulatory expression of Neurensin-1 in the spinal motor neurons after mouse sciatic nerve injury

Axonal regeneration after crush injury of the sciatic nerve has been intensely studied for the elucidation of molecular and cellular mechanisms. Neurite extension factor1 (Nrsn1) is a unique membranous protein that has a microtubule-binding domain and is specifically expressed in neurons. Our studies have shown that Nrsn1 is localized particularly in actively extending neurites, thus playing a role in membrane transport to the growing distal ends of extending neurites. To elucidate the possible role of Nrsn1 during peripheral axonal regeneration, we examined the expression of Nrsn1 mRNA by in situ hybridization and Nrsn1 localization by immunocytochemistry, using a mouse model. The results revealed that during the early phase of axonal regeneration of motor nerves, Nrsn1 mRNA is upregulated in the injured motor neuron. Nrsn1 is localized in the cell bodies of motor neurons and at the growing distal ends of regenerating axons. These results indicate that Nrsn1 plays an active role in axonal regeneration as well as in embryonic development.     

A synthetic oxygen carrier in fibrin matrices promotes sciatic nerve regeneration in rats

Tissue-engineering nerve conduits have been studied for a long time in bridging large nerve defects. However, the low oxygen availability within the nerve conduits, which results in death of migratory Schwann cells (SC) or loss of the newly formed tissue’s function, is still an obstacle for axonal regeneration. Thus, it was hypothesized that an oxygen-enriched conduit would enhance axonal regeneration and functional recovery in vivo. To address this issue, perfluorotributylamine (PFTBA) enriched fibrin hydrogel was prepared and injected into collagen–chitosan conduits. The conduit containing PFTBA-enriched fibrin hydrogel was then used to bridge a 12-mm sciatic nerve defect in rats. The control rats were bridged with collagen–chitosan conduits filled with fibrin matrices without PFTBA. It was found that axonal regeneration and functional recovery in the combined PFTBA group were significantly higher than those in the control group without PFTBA. Further investigations showed that the mRNA and protein levels of S-100, brain-derived neurotrophic factor and nerve growth factor were enhanced by PFTBA at 1 and 3 weeks after surgery. However, the mRNA and protein levels of vascular endothelial growth factor were in a similar range between the combined PFTBA group and the control group without PFTBA. In addition, immunohistochemical results showed that the morphological appearances of regenerated nerve and survival of SC were enhanced by PFTBA at 4 and 12 weeks after surgery. In conclusion, PFTBA-enriched nerve conduit is capable of enhancing axonal regeneration, which provides a new avenue for achieving better functional recovery in the treatment of nerve defect.     

神经节苷脂M_1对兔子运动神经再生影响的实验研究

目的研究局部应用神经节苷脂M1(GM1)对兔子运动神经-面神经损伤的修复作用,为临床早期应用神经节甘脂M1,促进面神经损伤再生提供理论和实验依据。方法将18只健康成年新西兰大白兔按随机原则分为实验组(神经节苷脂M1组)和空白对照组。建立兔面神经损伤后再生的实验模型,实验组于面神经吻合处滴注2.0μL(10μg)GM1溶液,空白对照组于面神经吻合后未作任何处理,分别在术后2周、4周、8周观察面神经的传导速度及组织学变化。结果术后2周、4周神经传导速度,实验组分别为(5.35±0.74)m/s,(14.25±1.3)m/s,空白对照组分别为(3.32±0.30)m/s,(8.10±0.92)m/s,实验组与空白对照组比较,差异有统计学意义(P0.05),术后8周神经传导速度,实验组与空白对照组比较差异无统计学意义(P0.05),光学显微镜观察术后2周、4周实验组神经再生状况优于空白对照组,光学显微镜观察术后8周实验组与空白对照组神经再生状况差别不大。结论兔面神经横断伤后立即应用神经节苷脂M1对面神经损伤后早期(2周,4周)再生恢复有明显的促进作用。     

海藻纤维膜片促进大鼠损伤坐骨神经的再生

背景：课题组和青岛大学高分子材料研究所合作研制的海藻纤维生物膜,具有优良的生物相容性,常被用作制备各种复合材料。 目的：观察海藻纤维膜片包绕覆盖神经断端吻合口对大鼠坐骨神经损伤后再生的影响。 方法：切断36只雄性Wistar大鼠右侧坐骨神经,随机分组：对照组行神经外膜端端吻合;实验组行神经外膜端端缝合,将海藻纤维膜片包绕并覆盖神经吻合口远近端各约0.5 cm,形成封闭再生室。术后观察海藻纤维膜片降解吸收规律及缝合处粘连情况,组织学切片行苏木精-伊红染色、锇酸染色、白细胞介素2及白细胞介素4免疫组织化学染色。 结果与结论：术后4-6周,实验组海藻纤维膜片逐渐被降解吸收,与周围组织粘连较少,炎性细胞浸润程度较轻,纤维组织增生较少。两组术后1,7,14 d的白细胞介素2及白细胞介素4含量比较差异无显著性意义。实验组术后6周再生神经纤维分布规则且大小较为均一,其神经纤维数量、轴突大小及髓鞘厚度等指标均显著优于对照组(P < 0.05)。表明海藻纤维膜片具有良好的生物降解性和组织相容性,其包绕覆盖坐骨神经形成的神经再生密闭室可促进大鼠损伤坐骨神经再生。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

吡非尼酮对大鼠坐骨神经损伤后瘢痕形成及功能恢复的实验研究

目的探讨大鼠坐骨神经损伤后细胞因子抑制剂吡非尼酮对神经吻合口处瘢痕形成及神经功能恢复的影响。方法选用健康雄性SD大鼠60只,制作右侧坐骨神经损伤模型,术后随机分为3组,分别为对照组、低剂量组和高剂量组,每组20只,分别给予0 mg/kg、25 mg/kg、100 mg/kg吡非尼酮混悬液灌胃。术后于第4、12周分别行坐骨神经功能指数、神经电生理测定,然后取材进行Ⅰ型胶原蛋白免疫组织化学染色,最终对实验结果进行图像分析和统计学处理。结果坐骨神经功能指数:术后第4周,三组之间两两比较,差异无统计学意义(P0.05);术后第12周,低剂量组优于对照组(P0.01),高剂量组优于低剂量组(P0.01);神经电生理:术后第4周,三组之间神经传导速度、潜伏期、波幅两两比较,差异无统计学意义(P0.05);术后第12周,与对照组相比,低剂量组和高剂量组神经传导速度显著增快(P0.05),潜伏期缩短(P0.05),波幅升高(P0.05),且高剂量组优于低剂量组(P0.05);Ⅰ型胶原蛋白沉积量:术后第4周,与对照组相比,低剂量组和高剂量组神经吻合口处Ⅰ型胶原蛋白沉积量明显减少(P0.01),低剂量组与高剂量组相比,差异无统计学意义(P0.05);术后第12周,与对照组相比,低剂量组和高剂量组神经吻合口处Ⅰ型胶原蛋白沉积量明显减少(P0.01),且高剂量组比低剂量组减少更明显(P0.05)。结论吡非尼酮能明显减少神经吻合口处Ⅰ型胶原蛋白沉积,有效抑制瘢痕形成,促进神经功能恢复。     

重组人睫状神经营养因子对大鼠坐骨神经再生长的影响

目的: 观察重组人睫状神经营养因子(CNTF)对大鼠坐骨神经再生长的影响,并与神经生长因子(NGF)的作用进行比较。方法: 随机将动物分成正常对照组、模型组、CNTF给药小剂量组(48 μg/kg)、中剂量组(216 μg/kg)、大剂量组(1 080 μg/kg)、NGF 给药组(20 μg/kg),每组各10只。模型组采用大鼠坐骨神经切断再缝合法造成坐骨神经损伤模型,给药组采用不同药物剂量对神经损伤部位肌肉注射给药45 d后,测定神经动作电位潜伏期和传导速度。结果: 与模型组相比较,CNTF各给药组神经动作电位潜伏期显著缩短(P<0.01),传导速度显著增快(P<0.01);同时,216 μg/kg、1 080 μg/kg CNTF组和NGF组对神经动作电位潜伏期的影响无显著差别(P>0.05),但是216 μg/kg、1 080 μg/kg CNTF组的神经动作电位传导速度比NGF组显著增快(P<0.01)。结论: CNTF对大鼠坐骨神经再生具有一定的促进作用,而且其作用可能优于NGF。     

Altered expression of nectin-like adhesion molecules in the peripheral nerve after sciatic nerve transection

Following axotomy several processes involving cell-cell interaction occur, such as loss of synapses, axon guidance, and remyelination. Two recently discovered families of cell-cell adhesion molecules, nectins and nectin-like molecules (necls) are involved in such processes in vitro and during development, but their roles in nerve injury have been largely unknown until recently. We have previously shown that axotomized motoneurons increase their expression of nectin-1 and nectin-3 and maintain a high expression of necl-1. We here investigate the expression of potential binding partners for motoneuron nectins and necls in the injured peripheral nerve. In situ hybridization (ISH) revealed a decreased signal for necl-1 mRNA in the injured nerve, whereas no signal for necl-2 was detected before or after injury. The signals for necl-4 and necl-5 mRNA both increased in the injured nerve and necl immunoreactivity displayed a close relation to axon and Schwann cell markers. Finally, signal for mRNA encoding necl-5 increased in axotomized spinal motoneurons. We conclude that peripheral axotomy results in altered expression of several necls in motoneurons and Schwann cells, suggesting involvement of the molecules in regeneration.     

晶状体损伤促进视神经再生的作用及机制

目的：研究晶状体损伤对视神经再生的促进作用,并探讨巨噬细胞所起的作用。方法：成年 SD 大鼠钳夹造成视神经损伤模型(NC),戳伤晶状体(LP),玻璃体内注射酵母多糖(ZI)或注射体外活化的单核/巨噬细胞 (MI),动物以此分组。用 Nissl 染色法显示存活的视网膜节细胞(RGCs),用抗 GAP-43抗体标记轴突再生 RGCs,用抗 ED-1抗体标记活化的单核/巨噬细胞。结果：NC LP 组存活的 RGCs 比 NC 组明显增加,再生的 RGCs 及活化的单核/巨噬细胞都有明显增多的结果。NC ZI 组与 NC MI 组也有类似结果。结论：晶状体损伤具有显著促进视神经再生的作用,其机制可能与趋化并激活巨噬细胞有关。     

神经电生理对臀部肌注致坐骨神经损伤的诊断价值

目的：探讨神经电生理检测对臀部肌注致坐骨神经损伤的诊断意义。方法：对34例患者进行腓总神经、胫神经的神经传导速度（NCV）检测，并对胫骨前肌、腓肠肌、股二头肌长短头、椎旁肌L4-S1进行针极肌电图检测。结果：34例病例中，腓总神经传导速度NCV异常29例（85．3％），胫神经13例（38．2％），腓总神经、胫神经同时异常8例（23．5％）。经统计学处理，与正常对照组比较差异有显著意义（P〈0．01）。肌电图示，有失神经电位改变者：胫前肌为29例（85．3％），股二头肌短头为29例（85．3％），腓肠肌为13例（38．2％），股二头肌长头为13例（38．2％）。结论：神经电生理检测对臀部肌注致坐骨神经损伤的诊断可提供客观依据。     

人参皂苷Rb1促进小鼠坐骨神经损伤修复的作用及机制研究

目的 构建小鼠坐骨神经损伤（SNI）模型,探讨人参皂苷Rb1对小鼠坐骨神经损伤修复的促进作用及机制。 方法 选取成年雄性昆明小鼠78只,随机分为假手术组（26只）、模型组（26只）、治疗组（26只）。模型制作采用钳夹损伤法,假手术组仅游离坐骨神经。模型制作后30 min,治疗组腹腔注射10 mg/kg人参皂苷Rb1,模型组与假手术组给予同等体积的生理盐水。采用坐骨神经功能指数（SFI）对小鼠坐骨神经功能进行追踪评价;利用HE染色及生长相关蛋白43(GAP43)免疫荧光染色检测损伤14 d后坐骨神经再生修复情况;利用透射电子显微镜观察损伤节段髓鞘的结构改变。损伤后14 d,检测脑源性神经营养因子(BDNF)、神经生长因子(NGF)mRNA水平的表达变化。模型制作后3 d、7 d,利用Ki67、S100β免疫荧光染色检测施万细胞的增殖、迁移能力;利用Real-time PCR检测炎症相关因子以及施万细胞激活相关转录因子mRNA表达水平;通过Western blotting对Sox10在蛋白水平的变化进行验证。 结果 治疗组SFI评分高于模型组小鼠,神经近端、远端HE染色较均一。透射电子显微镜提示,治疗组髓鞘结构、厚度较模型组明显改善,髓鞘内神经纤维排列较为整齐。免疫荧光染色结果显示,治疗组坐骨神经GAP43+轴突伸长明显优于模型组,BDNF、NGF等营养因子表达升高。进一步检测发现,给予Rb1后损伤节段附近Ki67+细胞增殖、S100β+施万细胞迁移明显增多。Real-time PCR结果显示,治疗组肿瘤坏死因子(TNF)-α、白细胞介素(IL)-1β mRNA表达水平明显下降,施万细胞激活相关转录因子表达水平上升。 结论 10 mg/kg Rb1能降低再生组织环境中炎症因子表达水平,增加BDNF、NGF等营养因子的表达水平,促进施万细胞激活,从而促进小鼠坐骨神经损伤后的神经再生。     

Evaluation of collagen nerve guide in facial nerve regeneration

Facial nerve paralysis due to resection of tumors or as a consequence of trauma is a frequently observed complication. Thus, in the present study, we evaluated a collagen nerve guide in facial nerve regeneration across a 5-mm nerve gap. This biological tube was manufactured from 3% collagen, coated over a Teflon tube used only as a template and submitted to thermal dehydration at 105°C for 24h. The collagen tube was implanted at the dorsal ramous of the facial nerve of five adult cats over a gap of 5mm. The facial nerve of the contralateral side was kept intact and used as control. Electrophysiological study was performed from 3 weeks after surgery, and histological and horseradish peroxidase labeling examination was carried out 8 weeks after implantation. Electrophysiological study confirmed the recovery of electrical activity of the collagenimplanted regenerated nerve. Light-microscopic examination of collagen tube-implanted specimens revealed a well vascularized regenerated nerve, which under an electron microscope showed many myelinated axons surrounded by Schwann cells and unmyelinated axons. Horseradish peroxidase staining demonstrated labeling of facial motoneurons in the brainstem and facial nerve terminals in the neuromuscular junction, also confirming restoration of the whole facial nerve tract from the reinnervated muscles, passing through the regenerated site to the brainstem. The collagen tube was very efficient as a nerve guide over a 5mm facial nerve gap and shows great promise as a nerve conduit.     

Oxidized galectin-1 advances the functional recovery after peripheral nerve injury

Oxidized galectin-1 has been shown to promote axonal regeneration from transected-nerve sites in an in vitro dorsal root ganglion (DRG) explant model as well as in in vivo peripheral nerve axotomy models. The present study provides evidence that oxidized galectin-1 advances the restoration of nerve function after peripheral nerve injury. The sciatic nerve of adult rats was transected and the distal nerve was frozen after being sutured into a proximal site with four epineurial stitches. An osmotic pump delivered oxidized galectin-1 peripherally to the surgical site. Functional recovery was assessed by measurement of the degree of toe spread of the hind paw for 3 months after the sciatic nerve lesion. The recovery curves of toe spread in the test group showed a statistically significant improvement of functional recovery after day 21 by the application of oxidized recombinant human galectin-1 (rhGAL-1/Ox) compared to the control group. This functional recovery was supported by histological analysis performed by light microscopic examination. The regenerating myelinated fibers at the site 21 mm distal to the nerve-transected site were quantitatively examined at 100 days after the operation. The frequency distribution of myelinated fiber diameters showed that exogenous rhGAL-1/Ox increased the number and diameter of regenerating myelinated fibers; the number of medium-sized (6–11 μm in diameter) fibers increased significantly (P < 0.05). These results indicate that oxidized galectin-1 promotes the restoration of nerve function after peripheral nerve injury. Thus, rhGAL-1/Ox may be a factor for functional restoration of injured peripheral nerves.     

Bilateral phasic increases in dorsal root ganglia nerve growth factor synthesis after unilateral sciatic nerve crush

The amount of nerve growth factor (NGF) in the L5, L6, and cervical dorsal root ganglia of rats was examined from 1 to 30 days after a unilateral crush lesion of the sciatic nerve and adjacent branches of the lumbar plexus at the level of the sciatic notch. Unilateral nerve crush produced increases in NGF content of lumbar ganglia at 1, 4, and 7–8 days after injury, with increased NGF mRNA at 4 and 7–8 days. Increases in NGF at 1 and 4 days were most pronounced on the unlesioned side while increases at days 7 and 8 were most pronounced on the lesioned side. NGF content increased in cervical ganglia of nerve-lesioned animals at 3 and 7 days after injury and in lumbar and cervical ganglia of sham-operated animals 3–5 days after surgery, with no comparable changes in NGF mRNA. Elevations of ganglionic NGF coincide temporally with some of the alterations in metabolism and morphology which occur in dorsal root ganglion neurons after sciatic nerve crush. However, the bilateral nature of increases in NGF demonstrates that the factor(s) producing the response is not restricted to ganglia axotomized by the injury. The data suggest that ganglionic NGF may be regulated by systemic factors, produced during stress or trauma, as well as by factors from the denervated target tissue and/or regenerating axons.     

The promotion of peripheral nerve regeneration by chitooligosaccharides in the rat nerve crush injury model

Chitooligosaccharides (COSs), the biodegradation product of chitosan, have shown many biological functions. In this study, we examined the possible benefits of treatment with COSs (M.W. 800) on regeneration of rat crushed sciatic nerves. The rats with sciatic nerve crush injury were administered intraperitoneally daily with 3 or 6 mg/kg body weight of COSs over a 3-week period. During and at the end of COSs treatment, a series of functional and histological examinations, including the measurement of withdrawal reflex latency (WRL) values, walking track analysis, electrophysiological assessments, morphometric analysis of gastrocnemius muscle, as well as immunohistochemistry and electromicroscopy to regenerated sciatic nerves, were performed to evaluate the therapeutic outcomes of COSs. The experimental data demonstrated that COSs promoted peripheral nerve regeneration with the desired functional recovery in the rat sciatic nerve crush injury model. This study raises a possibility of developing COSs as a potential neuroprotective agent for peripheral nerve repair applications.     

嗅鞘细胞培养上清液促进大鼠周围神经损伤后的修复与再生

文题释义：细胞培养上清：细胞在正常生理过程中会释放一些信息物质,包括可溶性因子、细胞外囊泡、蛋白质、各种RNA等,这些物质能够在细胞间通讯,乃至在多种生理过程中发挥重要作用。在细胞培养过程中,这些物质由细胞分泌至细胞培养液中。这种含有细胞分泌的活性物质并去除了细胞碎片等杂质的培养液,称为细胞培养上清。 神经再生：损伤后的神经再生是一个复杂的生理过程,受多种因素的影响和调节。神经再生过程可归纳为3个方面：受损神经近端轴突的萌芽和伸长,再生轴突的髓鞘化,再生轴突与靶器官之间突触连接的重建。神经再生分为中枢神经再生及周围神经再生。受轴突外部再生微环境的影响,中枢神经再生较外周神经再生更为困难。 背景：既往研究发现嗅鞘细胞培养上清可以促进脊髓损伤后轴突再生及功能恢复,但应用于周围神经损伤治疗方面鲜有报道。 目的：探讨嗅鞘细胞培养上清是否有助于周围神经损伤后的神经修复。 方法：分离纯化嗅鞘细胞并鉴定,制备嗅鞘细胞培养上清。在体外环境将嗅鞘细胞培养上清作用于背根神经节组织块,观察背根神经节轴突生长情况;在体内环境将嗅鞘细胞培养上清应用于大鼠坐骨神经缺损模型,观察坐骨神经轴突再生及髓鞘化情况。 结果与结论：①嗅鞘细胞纯度高达(94.4±3.1)%;②与空白对照组和低剂量嗅鞘细胞上清组对比,高剂量嗅鞘细胞上清组背根神经节组织块的5根最长神经轴突平均长度显著增加(P < 0.05);③免疫荧光显示嗅鞘细胞上清处理组与自体神经移植组类似,再生神经贯通缺损区域,并且再生神经排列有序,神经再生情况显著优于空白对照组;④透射电子显微镜观察显示嗅鞘细胞上清处理组再生神经轴突的数量和髓鞘厚度显著高于空白对照组(P < 0.05);⑤结果表明,嗅鞘细胞培养上清能够促进周围神经损伤后轴突再生及再生轴突的髓鞘化,为周围神经损伤提供了一种新的基于嗅鞘细胞的无细胞疗法。 ORCID: 0000-0002-9558-8585(杨雨洁) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

MicroRNA-21促进大鼠雪旺细胞增殖的实验研究

目的:探讨神经损伤后microRNA-21(miR-21)促进雪旺细胞增殖的分子机制。方法:通过实时荧光定量PCR检测miR-21的表达。通过脂质体介导将人工合成的miR-21模拟物(mimic)及其阴性对照转染大鼠雪旺细胞,CCK-8法检测转染miR-21的雪旺细胞的增殖。流式细胞术分析miR-21对雪旺细胞细胞周期的影响。使用Western blotting实验分析转化生长因子β诱导蛋白(TGFBI)和cyclin D1的表达水平。结果:miR-21在损伤模型组中的表达分别为假手术组和正常神经组织的(7.87±0.75)和(7.75±0.80)倍(P0.01)。miR-21 mimic组miR-21的表达分别为对照组和空白组的(2.21±0.14)和(2.29±0.21)倍(P0.05)。转染48 h后miR-21 mimic组CCK-8实验的A450值较阴性对照组和空白对照组增高(P0.05)。实验组细胞增殖指数高于阴性对照组和空白对照组(P0.01)。同时与对照组相比,转染miR-21后48 h实验组细胞TGFBI明显降低,cyclin D1表达增多(P0.05)。结论:miR-21可促进雪旺细胞增殖,其机制可能与其下调TGFBI的表达有关。     

Functional recoveries of sciatic nerve regeneration by combining chitosan-coated conduit and neurosphere cells induced from adipose-derived stem cells

Suboptimal repair occurs in a peripheral nerve gap, which can be partially restored by bridging the gap with various biosynthetic conduits or cell-based therapy. In this study, we developed a combination of chitosan coating approach to induce neurosphere cells from human adipose-derived stem cells (ASCs) on chitosan-coated plate and then applied these cells to the interior of a chitosan-coated silicone tube to bridge a 10-mm gap in a rat sciatic nerve. Myelin sheath degeneration and glial scar formation were discovered in the nerve bridged by the silicone conduit. By using a single treatment of chitosan-coated conduit or neurosphere cell therapy, the nerve gap was partially recovered after 6 weeks of surgery. Substantial improvements in nerve regeneration were achieved by combining neurosphere cells and chitosan-coated conduit based on the increase of myelinated axons density and myelin thickness, gastrocnemius muscle weight and muscle fiber diameter, and step and stride lengths from gait analysis. High expressions of interleukin-1β and leukotriene B4 receptor 1 in the intra-neural scarring caused by using silicone conduits revealed that the inflammatory mechanism can be inhibited when the conduit is coated with chitosan. This study demonstrated that the chitosan-coated surface performs multiple functions that can be used to induce neurosphere cells from ASCs and to facilitate nerve regeneration in combination with a cells-assisted coated conduit.