Electroacupuncture promotes peripheral nerve regeneration after facial nerve crush injury and upregulates the expression of glial cell-derived neurotrophic factor

The efficacy of electroacupuncture in the treatment of peripheral facial paralysis is known, but the specific mechanism has not been clarified. Glial cell-derived neurotrophic factor(GDNF) has been shown to protect neurons by binding to N-cadherin. Our previous results have shown that electroacupuncture could increase the expression of N-cadherin mRNA in facial neurons and promote facial nerve regeneration. In this study, the potential mechanisms by which electroacupuncture promotes nerve regeneration were elucidated through assessing the effects of electroacupuncture on GDNF and N-cadherin expression in facial motoneurons of rabbits with peripheral facial nerve crush injury. New Zealand rabbits were randomly divided into a normal group(normal control, n = 21), injury group(n = 45) and electroacupuncture group(n = 45). Model rabbits underwent facial nerve crush injury only. Rabbits in the electroacupuncture group received facial nerve injury, and then underwent electroacupuncture at Yifeng(TE17), Jiache(ST6), Sibai(ST2), Dicang(ST4), Yangbai(GB14), Quanliao(SI18), and Hegu(LI4; only acupuncture, no electrical stimulation). The results showed that in behavioral assessments, the total scores of blink reflex, vibrissae movement, and position of apex nasi, were markedly lower in the EA group than those in the injury group. Hematoxylin-eosin staining of the right buccinator muscle of each group showed that the cross-sectional area of buccinator was larger in the electroacupuncture group than in the injury group on days 1, 14 and 21 post-surgery. Toluidine blue staining of the right facial nerve tissue of each group revealed that on day 14 post-surgery, there was less axonal demyelination and fewer inflammatory cells in the electroacupuncture group compared with the injury group. Quantitative real time-polymerase chain reaction showed that compared with the injury group, N-cadherin mRNA levels on days 4, 7, 14 and 21 and GDNF mRNA levels on days 4, 7 and 14 were significantly higher in the electroacupuncture group. Western blot assay displayed that compared with the injury group, the expression of GDNF protein levels on days 7, 14 and 21 were significantly upregulated in the electroacupuncture group. The histology with hematoxylin-eosin staining and Nissl staining of brainstem tissues containing facial neurons in the middle and lower part of the pons exhibited that on day 7 post-surgery, there were significantly fewer apoptotic neurons in the electroacupuncture group than in the injury group. By day 21, there was no significantly difference in the number of neurons between the electroacupuncture and normal groups. Taken together, these results have confirmed that electroacupuncture promotes regeneration of peripheral facial nerve injury in rabbits, inhibits neuronal apoptosis, and reduces peripheral inflammatory response, resulting in the recovery of facial muscle function. This is achieved by up-regulating the expression of GDNF and N-cadherin in central facial neurons.

Laminin-coated multifilament entubulation, combined with Schwann cells and glial cell line-derived neurotrophic factor, promotes unidirectional axonal regeneration in a rat model of thoracic spinal cord hemisection

Biomaterial bridging provides physical substrates to guide axonal growth across the lesion.To achieve efficient directional guidance,combinatory strategies using permissive matrix,cells and trophic factors are necessary.In the present study,we evaluated permissive effect of poly(acrylonitrile-co-vinyl chloride)guidance channels filled by different densities of laminin-precoated unidirectional polypropylene filaments combined with Schwann cells,and glial cell line-derived neurotrophic factor for axonal regeneration through a T10 hemisected spinal cord gap in adult rats.We found that channels with filaments significantly reduced the lesion cavity,astrocytic gliosis,and inflammatory responses at the graft-host boundaries.The laminin coated low density filament provided the most favorable directional guidance for axonal regeneration which was enhanced by co-grafting of Schwann cells and glial cell line-derived neurotrophic factor.These results demonstrate that the combinatorial strategy of filament-filled guiding scaffold,adhesive molecular laminin,Schwann cells,and glial cell line-derived neurotrophic factor,provides optimal topographical cues in stimulating directional axonal regeneration following spinal cord injury.This study was approved by Indiana University Institutional Animal Care and Use Committees(IACUC#:11011)on October 29,2015.

Glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor regulate the interaction between astrocytes and Schwann cells at the trigeminal root entry zone

The trigeminal root entry zone is the zone at which the myelination switches from peripheral Schwann cells to central oligodendrocytes.Its special anatomical and physiological structure renders it susceptible to nerve injury.The etiology of most primary trigeminal neuralgia is closely related to microvascular compression of the trigeminal root entry zone.This study aimed to develop an efficient in vitro model mimicking the glial environment of trigeminal root entry zone as a tool to investigate the effects of glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor on the structural and functional integrity of trigeminal root entry zone and modulation of cellular interactions.Primary astrocytes and Schwann cells isolated from trigeminal root entry zone of postnatal rats were inoculated into a two-well silicon culture insert to mimic the trigeminal root entry zone microenvironment and treated with glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor.In monoculture,glial cell line-derived neurotrophic factor promoted the migration of Schwann cells,but it did not have effects on the migration of astrocytes.In the co-culture system,glial cell line-derived neurotrophic factor promoted the bidirectional migration of astrocytes and Schwann cells.Brain-derived neurotrophic factor markedly promoted the activation and migration of astrocytes.However,in the co-culture system,brain-derived neurotrophic factor inhibited the migration of astrocytes and Schwann cells to a certain degree.These findings suggest that glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor are involved in the regulation of the astrocyte-Schwann cell interaction in the co-culture system derived from the trigeminal root entry zone.This system can be used as a cell model to study the mechanism of glial dysregulation associated with trigeminal nerve injury and possible therapeutic interventions.

Neurotrophic factor-based pharmacological approaches in neurological disorders

Aging is a physiological event dependent on multiple pathways that are linked to lifespan and processes leading to cognitive decline.This process represents the major risk factor for aging-related diseases such as Alzheimer’s disease,Parkinson’s disease,and ischemic stroke.The incidence of all these pathologies increases exponentially with age.Research on aging biology has currently focused on elucidating molecular mechanisms leading to the development of those pathologies.Cognitive deficit and neurodegeneration,common features of aging-related pathologies,are related to the alteration of the activity and levels of neurotrophic factors,such as brain-derived neurotrophic factor,nerve growth factor,and glial cell-derived neurotrophic factor.For this reason,treatments that modulate neurotrophin levels have acquired a great deal of interest in preventing neurodegeneration and promoting neural regeneration in several neurological diseases.Those treatments include both the direct administration of neurotrophic factors and the induced expression with viral vectors,neurotrophins’binding with biomaterials or other molecules to increase their bioavailability but also cell-based therapies.Considering neurotrophins’crucial role in aging pathologies,here we discuss the involvement of several neurotrophic factors in the most common brain aging-related diseases and the most recent therapeutic approaches that provide direct and sustained neurotrophic support.

Secretion of nerve growth factor,brain-derived neurotrophic factor,and glial cell-line derived neurotrophic factor in co-culture of four cell types in cerebrospinal fluid-containing medium

The present study co-cultured human embryonic olfactory ensheathJng cells, human Schwann cells, human amniotic epithelial cells and human vascular endothelial cells in complete culture medium- containing cerebrospinal fluid. Enzyme linked immunosorbent assay was used to detect nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor secretion in the supernatant of co-cultured cells. Results showed that the number of all cell types reached a peak at 7-10 days, and the expression of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor peaked at 9 days. Levels of secreted nerve growth factor were four-fold higher than brain-derived neurotrophic factor, which was three-fold higher than glial cell line-derived neurotrophic factor. Increasing concentrations of cerebrospinal fluid （10%, 20% and 30%） in the growth medium caused a decrease of neurotrophic factor secretion Results indicated co-culture of human embryonic olfactory ensheathing cells, human Schwann cells human amniotic epithelial cells and human vascular endothelial cells improved the expression of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor. The reduction of cerebrospinal fluid extravasation at the transplant site after spinal cord injury is beneficial for the survival and secretion of neurotrophic factors from transplanted cells.

Folic acid contributes to peripheral nerve injury repair by promoting Schwann cell proliferation, migration, and secretion of nerve growth factor

After peripheral nerve injury, intraperitoneal injection of folic acid improves axon quantity, increases axon density and improves electromyography results. However, the mechanisms for this remain unclear. This study explored whether folic acid promotes peripheral nerve injury repair by affecting Schwann cell function. Primary Schwann cells were obtained from rats by in vitro separation and culture. Cell proliferation, assayed using the Cell Counting Kit-8 assay, was higher in cells cultured for 72 hours with 100 mg/L folic acid compared with the control group. Cell proliferation was also higher in the 50, 100, 150, and 200 mg/L folic acid groups compared with the control group after culture for 96 hours. Proliferation was markedly higher in the 100 mg/L folic acid group compared with the 50 mg/L folic acid group and the 40 ng/L nerve growth factor group. In Transwell assays, the number of migrated Schwann cells dramatically increased after culture with 100 and 150 mg/L folic acid compared with the control group. In nerve growth factor enzyme-linked immunosorbent assays, treatment of Schwa nn cell cultures with 50, 100, and 150 mg/L folic acid increased levels of nerve growth factor in the culture medium compared with the control group at 3 days. The nerve growth factor concentration of Schwann cell cultures treated with 100 mg/L folic acid group was remarkably higher than that in the 50 and 150 mg/L folic acid groups at 3 days. Nerve growth factor concentration in the 10, 50, and 100 mg/L folic acid groups was higher than that in the control group at 7 days. The nerve growth factor concentration in the 50 mg/L folic acid group was remarkably higher than that in the 10 and 100 mg/L folic acid groups at 7 days. In vivo, 80 μg/kg folic acid was intraperitoneally administrated for 7 consecutive days after sciatic nerve injury. Immunohistochemical staining showed that the number of Schwann cells in the folic acid group was greater than that in the control group. We suggest that folic acid may play a role in improving the repair of peripheral nerve injury by promoting the proliferation and migration of Schwann cells and the secretion of nerve growth factors.

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。

Functional recovery after peripheral nerve injury via sustained growth factor delivery from mineral-coated microparticles

The gold standard for treating peripheral nerve injuries that have large nerve gaps where the nerves cannot be directly sutured back together because it creates tension on the nerve,is to incorporate an autologous nerve graft.However,even with the incorporation of a nerve graft,generally patients only regain a small portion of function in limbs affected by the injury.Although,there has been some promising results using growth factors to induce more axon growth through the nerve graft,many of these previous therapies are limited in their ability to release growth factors in a sustained manner and tailor them to a desired time frame.The ideal drug delivery platform would deliver growth factors at therapeutic levels for enough time to grow axons the entire length of the nerve graft.We hypothesized that mineral coated microparticles(MCMs)would bind,stabilize and release biologically active glial cell-derived neurotrophic factor(GDNF)and nerve growth factor(NGF)in a sustained manner.Therefore,the objective of this study was to test the ability of MCMs releasing growth factors at the distal end of a 10 mm sciatic nerve graft,to induce axon growth through the nerve graft and restore hind limb function.After sciatic nerve grafting in Lewis rats,the hind limb function was tested weekly by measuring the angle of the ankle at toe lift-off while walking down a track.Twelve weeks after grafting,the grafts were harvested and myelinated axons were analyzed proximal to the graft,in the center of the graft,and distal to the graft.Under physiological conditions in vitro,the MCMs delivered a burst release of NGF and GDNF for 3 days followed by a sustained release for at least 22 days.In vivo,MCMs releasing NGF and GDNF at the distal end of sciatic nerve grafts resulted in significantly more myelinated axons extending distal to the graft when compared to rats that received nerve grafts without growth factor treatment.The rats with nerve grafts incorporated with MCMs releasing NGF and GDNF also showed significant improvement in hind limb function starting at 7 weeks postoperatively and continuing through 12 weeks postoperatively when compared to rats that received nerve grafts without growth factor treatment.In conclusion,MCMs released biologically active NGF and GDNF in a sustained manner,which significantly enhanced axon growth resulting in a significant improvement of hind limb function in rats.The animal experiments were approved by University of Wisconsin-Madison Animal Care and Use Committee(ACUC,protocol#M5958)on January 3,2018.

Hyperbaric oxygen improves functional recovery of rats after spinal cord injury via activating stromal cell-derived factor-1/CXC chemokine receptor 4 axis and promoting brain-derived neurothrophic factor expression

Background: Spinal cord injury (SCI) is a worldwide medical concern. This study aimed to elucidate the mechanism underlying protective effect of hyperbaric oxygen (HBO) against SCI-induced neurologic defects in rats via exploring the stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) axis and expression of brain-derived neurotrophic factor (BDNF). Methods: An acute SCI rat model was established in Sprague-Dawley rats using the Allen method. Sixty rats were divided into four groups (w = 15 in each group): sham-operated, SCI, SCI treated with HBO (SCI + HBO), and SCI treated with both HBO and AMD3100 (an antagonist of CXCR4;SCI + HBO + AMD) groups. The rats were treated with HBO twice a day for 3 days and thereafter once a day after the surgery for up to 28 days. Following the surgery, neurologic assessments were performed with the Basso-Bettie-Bresnahan (BBB) scoring system on postoperative day (POD) 7, 14, 21, and 28. Spinal cord tissues were harvested to assess the expression of SDF-1, CXCR4, and BDNF at mRNA and protein levels, using quantitative real-time polymerase chain reaction, Western blot analysis, and histopathologic analysis. Results: HBO treatment recovered SCI-induced descent of BBB scores on POD 14,(1.25±0.75 vs. 1.03 ±0.66, P< 0.05), 21 (5.27± 0.89 vs. 2.56± 1.24, P< 0.05), and 28 (11.35±0.56 vs. 4.23± 1.20, P<0.05) compared with the SCI group. Significant differences were found in the mRNA levels of SDF-1 (mRNA: day 21, SCI + HBO vs. SCI + HBO + AMD, 2.89± 1.60 vs. 1.56±0.98, P<0.05), CXCR4 (mRNA: day 7, SCI + HBO vs. SCI, 2.99± 1.60 vs. 1.31 ±0.98, P<0.05;day 14, SCI + HBO vs. SCI + HBO + AMD, 4.18± 1.60 vs. 0.80±0.34, P<0.05;day 21, SCI + HBO vs. SCI, 2.10±1.01 vs.1.15±0.03, P<0.05), and BDNF (mRNA: day 7, SCI + HBO vs. SCI, 3.04±0.41 vs. 2.75±0.31, P<0.05;day 14, SCI + HBO vs. SCI, 3.88± 1.59 vs. 1.11 ±0.40, P<0.05), indicating the involvement of SDF-1/CXCR4 axis in the protective effect of HBO. Conclusions: HBO might promote the recovery of neurologic function after SCI in rats via activating the SDF-1/CXCR4 axis and promoting BDNF expression.

补阳还五汤的抗氧化作用

目的:探讨复方中药制剂补阳还五汤的抗氧化机制。方法:用水煎醇沉法制备补阳还五汤提取液,从新生鼠坐骨神经分离纯化雪旺细胞,建立过氧化氢(H2O2)损伤模型。将培养细胞分为补阳还五汤处理组、氧化损伤组及正常组和空白对照组,培养12 h时,检测丙二醛(MDA)的含量,用免疫组化方法检测Caspase-3的表达,用RT-PCR技术检测胶质细胞源性神经营养因子(GDNF)的表达。结果:与氧化损伤组相比,补阳还五汤处理组的MDA含量明显减弱,Caspase-3呈弱阳性表达,GDNF mRNA的表达量减少不明显。结论:补阳还五汤具有良好的抗过氧化损伤效果,对H2O2引起雪旺细胞的损伤具有保护作用。

人参环氧炔醇对体外培养施万细胞表达神经营养因子的影响及可能机制的研究

目的研究人参环氧炔醇（PND）对体外培养施万细胞（SCs）神经营养因子（NTFs）表达的影响;并探讨其机制。方法用含有不同浓度的PND培养液分别处理SCs,以免疫组织化学法检测PND对SCs NTFs表达的影响;放射免疫方法测定SCs内环磷酸腺苷（cAMP）水平的变化,并进行图像处理及统计学分析。结果PND分别在2.5-20.0μmol/L及5.0--20.0μmol/L剂量范围内可分别促进体外培养SCs NGF及大脑衍生神经营养因子（BDNF）的表达（P〈0.05）,在10μmol/L剂量对两者促进作用均最明显（P〈0.01）;在2.5--20.0μmol/L剂量范围内PND可提高体外培养SCs胞内cAMP含量（P〈0.05）,而在10μmol/L剂量作用最显著（P〈0.01）。结论PND能明显促进体外培养SCs NGF、BDNF的表达和分泌;PND可提高SCs的胞内cAMP水平,并与PND促进体外培养SCs NGF、BDNF表达之间存在相关性,提示其可能是PND提高体外培养SCs NGF、BDNF表达的调控机制及信号传导通路。

雪旺氏细胞分泌的神经营养活性物质的提取及体外生物活性研究

雪旺氏细胞（ＳＣ）分泌多种神经营养因子促进周围神经再生，但ＳＣ分泌的各种蛋白质对周围神经再生的影响尚未完全阐明。为此，从成年大鼠瓦勒氏变性坐骨神经中分离出ＳＣ，经培养获得ＳＣ无血清条件培养液（ＳＣ－ＳＦＣＭ）。通过ＰＭ１０超滤浓缩、Ｄｉｓｃ－ＰＡＧＥ和Ｂｉｏｔｒａｐ电洗脱，从ＳＣ－ＳＦＣＭ中分离出Ｄ蛋白带，分子量在４３～６７Ｋｄ之间。经ＭＴＴ检测，Ｄ带蛋白在２５～５０ｎｇ／ｍｌ浓度时对脊髓前角神经元表现出明显的体外成活作用。Ｄ蛋白带可能是一种有别于已知的ＳＣ源神经营养物质，其活性浓度达到了神经营养因子分子检测水平。

重组睫状神经营养因子对周围神经再生中多种细胞的作用

为了解重组睫状神经营养因子 ( CNTF)对周围神经再生中多种细胞的作用 ,用硅管套接切断的成年大鼠坐骨神经 ,在受损神经局部一次性给予重组睫状神经营养因子 :用免疫组织化学 ABC法结合计算机图像分析观测再生神经中 GAP-4 3、S10 0、CD68、MHC- 免疫反应阳性物质的变化。与生理盐水对照组相比 ,证明 CNTF组再生神经中上述四种物质显著增多。结果提示重组睫状神经营养因子能促进轴突的再生、Schwann细胞的迁入。

GDNF基因修饰的雪旺细胞对大鼠坐骨神经缺损的修复作用

目的 应用携带胶质细胞源性神经营养因子基因的逆转录病毒载体质粒 (pLXSN GDNF)对体外培养的雪旺细胞进行基因修饰 ,并结合细胞外基质凝胶及生物可降解聚乳酸 聚羟基乙酸共聚物 (PLGA)管构建神经移植复合体 ,用于大鼠坐骨神经缺损的修复 ,同时对其促轴突再生及神经元保护作用予以检测评价。方法 40只成年Wistar大鼠随机分为4组 :A组 (n =10 )细胞外基质凝胶 PLGA管桥接组 ;B组 (n =10 )雪旺细胞 细胞外基质凝胶 PLGA管桥接组 ;C组 (n =10 )GDNF基因修饰的雪旺细胞 细胞外基质凝胶 PLGA管桥接组 ;D组 (n =10 )自体神经桥接组。损伤各组 12周时应用神经电生理及甲苯胺蓝染色和透射电镜观测神经再生情况 ,辣根过氧化物酶神经逆行示踪技术用于脊髓前角运动神经元再生评价。结果 12周时再生神经运动传导速度检测、甲苯胺蓝染色轴突形态计量学分析、透射电镜超微结构观察以及脊髓前角运动神经元再生评价结果提示 :C组优于A、B组 ,而与D组相比无明显差异。结论 雪旺细胞的转基因处理可能弥补单纯细胞移植神经营养因子含量的不足 ,而可能达到与自体神经移植相似的效果。

重组睫状神经营养因子对受损周围神经施万细胞相关基因表达的作用

目的 研究重组睫状神经营养因子 (CNTF)对受损周围神经施万细胞基因表达的作用。 方法 用硅管套接切断的大鼠坐骨神经 ,在受损神经局部给予重组CNTF ,术后用免疫组织化学ABC法结合计算机图像分析观测S10 0蛋白 (S10 0 )、生长相关蛋白 4 3(GAP 4 3)、磷酸化酪氨酸 (PTyr)、信号转导子和转录激活子 (STAT) 3的免疫反应阳性物质在修复侧远段神经的分布和相对含量。 结果 CNTF组修复侧远段神经相应区域S10 0、GAP 4 3、PTyr、STAT3阳性物质的含量显著或非常显著高于生理盐水组。 结论 重组CNTF能上调受损神经施万细胞S10 0、GAP 4 3、PTyr和STAT3的表达 ,提示重组CNTF通过强化受损神经施万细胞JAK STAT途径 ,上调其S10 0和GAP 4 3的基因表达。

雪旺细胞源神经营养因子对脊髓损伤的保护作用

目的：观察雪旺细胞源神经营养因子（Ｓｃ－ＮＴＦｓ）对损伤脊髓组织的作用。方法：以７．５ｇ物体从１０ｃｍ高处落下致伤大鼠Ｔ１０脊髓，伤后５，３０，６０ｍｉｎ在损伤局部分别注入Ｓｃ－ＮＴＦｓ５０μｌ，对照组给予等量生理盐水。２４ｈ后一半动物取伤段脊髓标本测水及离子含量。另一半动物３周后行神经功能检查。结果：脊髓损伤后组织水肿，Ｎａ＋、Ｃａ２＋离子浓度升高，Ｋ＋、Ｍｇ２＋离子浓度降低，Ｓｃ－ＮＴＦｓ可显著改善这些变化。Ｓｃ－ＮＴＦｓ使脊髓损伤后神经功能有显著改善。结论：Ｓｃ－ＮＴＦｓ对脊髓损伤具有保护作用，其机制可能与其减少神经细胞离子失衡、改善细胞内环境有关。

雪旺细胞源神经营养因子对背根节感觉神经元的保护作用

目的:了解雪旺细胞源神经营养因子对周围神经高位损伤所致脊髓背根节感觉神经元死亡的保护作用。方法:选出生3周sD鼠高位切断L4、L5神经根,神经近侧断端应用雪旺细胞源神经营养因子或生理盐水,4周后观察损伤神经根背根节感觉神经元的存活率和形态学变化。结果:术后4周,营养因子组神经元的存活率是91.8％,生理盐水组是58.6％;生理盐水组存活神经元胞体明显萎缩。结论:雪旺细胞源神经营养因子对受损的背根节感觉神经元有明显的神经营养活性。

施万样细胞对大鼠脊神经节NGF和BDNF表达的影响

目的观察施万样细胞对坐骨神经损伤(sciatic nerve injury,SNI)大鼠脊神经节NGF和BDNF表达的影响,初步探讨施万样细胞对脊神经节的保护作用。方法先将脂肪源性干细胞(adipose-derived stem cells,ADSCs)诱导分化为施万样细胞并对后者进行鉴定,后将二者分别植入脱细胞神经移植物(ANA)中,构建组织工程神经。大鼠随机分为正常对照组、ADSC组和施万样细胞组。后两组建立SNI模型并用相应的组织工程神经桥接损伤的神经。术后4周采用Western Blot和Real-time PCR检测各组大鼠脊神经节神经生长因子(nerve growth factor,NGF)和脑源性神经营养因子(brainderived neurotrophic factor,BDNF)蛋白和m RNA的表达。结果 ADSCs能够诱导分化为施万样细胞并表达施万细胞标记物S100β和GFAP蛋白。施万样细胞组大鼠脊神经节内NGF和BDNF蛋白及m RNA表达量均高于ADSC组(P<0.05)。结论施万样细胞可上调脊神经节NGF和BDNF的表达,对SNI所致的脊神经节内神经元损伤有保护作用。

神经营养因子-3转染的雪旺细胞抑制肌细胞凋亡的实验研究

目的:观察阳离子脂质体转染的神经营养因子-3(neurotrophic factor-3,NT-3)基因修饰的雪旺细胞(SC)的表达和肌细胞凋亡情况,探讨移植复合体对坐骨神经缺损的作用机制。方法:通过阳离子脂质体将NT-3基因转染入体外培养的SC,检测转入前后SC的含量。Wister成年大鼠80只制成坐骨神经缺损模型,根据断端移植物的不同分为A、B、C、D4组。术后不同时间行肌横截面积光镜观察和肌细胞凋亡率检测。结果:NT-3转染SC前后比较差异有显著性(P<0.05)。术后肌横截面积、肌细胞凋亡D组均优于B、C组,B、C组均优于A组(P<0.01),而B、C组肌横截面积相比差异无显著性(P>0.05);而肌细胞凋亡检测B组多于C组。结论:NT-3基因经阳离子脂质体转染效率高,能促进SC的分泌,修复损伤神经和防止失神经肌萎缩细胞凋亡。

睫状神经营养因子和雪旺细胞神经营养活性物质对大鼠视神经损伤后轴突数的影响

目的 观察睫状神经生长因子 ( ciliary neurotrophicfactor,CNTF)和雪旺细胞神经营养活性物质 ( Schwann cellsneurotrophic agent,SCNA)对视神经损伤后轴突的形态和纤维数目变化的作用 .方法 采用镊夹法制作大鼠视神经损伤模型 ,损伤后立即一次性向玻璃体内注射 CNTF( 5 0 ng)或SCNA ( 10μL ) ,在损伤后 1,2 ,3和 4 wk时观察夹伤视神经的形态 ,及进行图像分析和轴突纤维计数 .结果 损伤后视神经轴突减少 ,间质增多 .CNTF组和 SCNA组的轴突数密度在 1wk时分别为正常值 ( 0 .10 65± 0 .0 0 5 6个·μm- 2 )的0 .5 9和 0 .61,而对照组为 0 .5 5 ,实验组与对照组比较差异显著 ( P<0 .0 5 ) .但在夹伤 2 wk后 3个组间、各时间点间数据差异均不显著 ( P>0 .0 5 ) .结论 CNTF及 SCNA一次玻璃体给药能在 1wk内减缓视神经损伤后轴突数目的减少 .