GDNF的研究进展

<正> 1993年Lin等从大鼠B49胶质细胞系中分离、纯化并成功克隆了一种新的神经营养因子即胶质细胞源性神经营养因子(glial cell line-derived neurotrophic factor,GDNF)。最初,因其对多巴胺能神经元具有特异性营养活性而被广泛重视。后来的研究发现,GDNF对胆碱能运动神经元也有强的活性[1]。此外,其对感觉神经元、交感神经元也有一定的作     

GDNF在成年猴脊髓表达的免疫组织化学研究

目的探讨多肽生长因子GDNF在成年猴脊髓的表达分布情况。方法取云南成年健康雄性猕猴T8脊髓节段制作20μm厚的连续冰冻切片,间隔取片后以抗GDNF抗体行免疫组化ABC染色。光学显微镜下观察GDNF样免疫阳性反应物在脊髓的分布。结果阳性反应物GDNF-IR在成年猴脊髓腹角神经元、背角神经元、Clarke核神经元、背角Lissauer束、背角Ⅰ、Ⅱ板层和中央管(Ⅹ板层)均有分布。结论成年猴脊髓存在多肽生长因子GDNF的表达,提示其在成年猴脊髓的生理过程中发挥作用,而且这种作用具有复杂性和多面性。     

GDNF基因逆转录病毒表达载体的构建与鉴定

应用基因重组技术将大鼠 GDNF c DNA克隆到逆转录病毒载体 p L XSN中 ,用限制性内切酶酶切分析重组质粒p L XSN-GDNF中 GDNF基因的插入方向 ,用 PCR、斑点杂交和 Southern杂交对重组质粒作进一步鉴定。结果表明 :GDNF c D-NA已正确地克隆到逆转录病毒载体 p L XSN中而构建成重组逆转录病毒载体 ,成功构建的真核细胞表达载体可作为基因治疗的高效基因转移载体。本研究为进一步开展 GDNF基因治疗 Parkinson' s disease和 Alzheimer' s disease等中枢神经系统疾病提供了资料。     

慢性脑缺血大鼠大脑皮质中的神经生长因子表达

目的：研究慢性脑缺血时大鼠大脑皮质中神经生长因子（NGF）的表达变化,探讨缺血性脑损伤及修复机制。方法：永久性结扎Wistar大鼠双侧颈总动脉,取慢性脑缺血30、120d组。行为学测试,免疫组化ABC法染色,计数大鼠大脑皮质中的NGF阳性神经元数及测量平均灰度值。结果：大鼠慢性脑缺血时,大脑皮质中NGF的表达,第120d比第30d及对照组显著增强,而30d与对照组无显著性差异,同时伴有学习和记忆力下降。结论：慢性脑缺血时,NGF在大脑皮质中的表达将随时间逐渐增强,对坏死神经元起保护作用。     

GDNF在脑疾病中研究进展

胶质细胞源性神经营养因子是近年来发现的一种蛋白质，特异性保护多巴胺能神经元，增加乙酰胆碱转移酶的活性，促进损伤后感觉及运动神经元的再生，对抗谷氨酸所致的神经元变性。在脑缺血性疾病中治疗效果持不同见解。近年研究显示外源性GDNF对多种神经疾病有神经保护作用，现就这一方面的研究做一综述。     

脑缺血再灌注损伤后神经元损伤机制及治疗研究进展

近年来 ,对脑缺血再灌注损伤的研究越来越深入 ,大量的实验研究表明 ,脑缺血再灌注损伤对脑损害的机制是非常复杂的 ,本文就脑缺血再灌注损伤的相关病理生理机制及治疗方面的进展进行综述。1脑缺血再灌注损伤的病因机制1.1兴奋性氨基酸 (EAA)与缺血再灌注损伤EAA是一种神经递质 ,神经系统内EAA主要是谷氨酸(Glutamate) ,EAA受体有三种亚型 :N -甲基 -D -天门冬氨酸受体 (NMDA)、α -氨基羟甲基恶唑丙酸受体 (AMPA)、亲代谢受体。其中NMDA受体是受配基调节的离子通道 ,对Ca2 + 具有通透性 ,可被Mg2 + 电压依赖性阻断。EAA造成的…     

人GDNF在原代培养的大鼠成纤维细胞中的表达

目的：研究人脑胶质细胞源性神经营养因子（GDNF）在治疗神经系统疾病中的作用,克隆其前体蛋白cDNA序列,并用于真核细胞表达,方法：提取我国自建的脑胶质瘤BT325细胞总RNA,用逆转录PCR法扩增GDNF全长cDNA并构建其真核表达载体pCI-neo-GDNF,然后转染原代培养的成纤维细胞,免疫组织化学及原位杂交检测GDNF在细胞中的表达。结果：从国人脑胶质瘤细胞中扩增到558bp的GDNF全长cDNA,并在GDNF转基因原代成纤维细胞中检测到重组GDNF的转录和表达。结论：克隆到的GDNF全长cDNA片段,可用于真核细胞表达,其转基因细胞脑内移植后应能治疗包括帕金森病的内的神经系统变性疾病。     

环磷酰胺下调大鼠睾丸OCT-4和GDNF表达

目的探讨抗肿瘤药物环磷酰胺对大鼠睾丸和精原干细胞相关因子OCT-4和GDNF表达的影响。方法 12只8周龄大鼠随机分为对照组和实验组,每组6只;实验组每天腹腔注射环磷酰胺50 mg/kg,连续3 d,用药4周后PAS染色法观察大鼠睾丸组织学变化,精原细胞,生精小管直径和附睾尾部精子数量。免疫组织化学法检测精原干细胞相关分子OCT-4和GDNF表达水平。结果与对照组比较,实验组大鼠体重、睾丸和附睾重量均显著减轻,睾丸组织学无明显改变,附睾精子活动度降低,附睾精子和精原细胞数量减少。实验组GDNF表达明显减少,而OCT-4表达水平无明显变化。结论环磷酰胺短期用药可造成精子发生的损害,其中精原细胞的减少可能与损害后GDNF表达下调有关。     

重组腺病毒介导GDNF基因在多种细胞的高效转移和表达

用作者等所构建的重组腺病毒AdCMVgdnf直接感染多种细胞系和大鼠中脑原代神经元细胞，多重感染复数为20PFU／ml。采用免疫组织化学染色方法检测GDNF表达，观察所构建的GDNF重组腺病毒在各种细胞中介导GDNF基因转移和基因表达的能力。结果表明在一系列神经细胞或非神经细胞中，GDNF重组腺病毒均可介导GDNF基因的高效转移和表达。提示GDNF重组腺病毒可作为帕金森氏病基因治疗的高效基因转移载体。     

稳定表达的人GDNF基因对PC12细胞的分化作用研究

目的　利用自行构建的 BHK- h GDNF基因工程细胞 ,研究 GDNF是否具有促进大鼠嗜铬细胞瘤细胞系 PC12细胞分化的作用。　方法　从人胎儿脑组织中提取总 RNA,用 RT- PCR的方法克隆人 GDNF基因 ;利用L ipofecam ine将构建的真核表达载体 p TARGET/ h GDNF(± )转染 BHK- 2 1细胞 ,在含有 G418的选择培养基中筛选出稳定表达人 GDNF的 BHK- h GDNF基因工程细胞。用免疫组织化学的方法检测 BHK- h GDNF基因工程细胞中人 GDNF的表达。并且用 BHK- h GDNF基因工程细胞培养的上清液培养 PC12细胞 ,观察 GDNF是否具有促进大鼠嗜铬细胞瘤细胞系 PC12细胞分化作用。　结果　构建的正向和反向真核表达载体 p TARGET/ h GDNF(± )的酶解消化和测序结果正确 ;用正向真核表达载体 p TARGET/ h GDNF( )转染 BHK- 2 1细胞后免疫组织化学的结果证明 BHK- h GDNF细胞能够表达人 GDNF;BHK- h GDNF基因工程细胞培养上清液可以促进 PC12细胞分化。　结论　构建的 BHK- h GDNF基因工程细胞中表达的人 GDNF可以促进 PC12细胞分化     

Depletion of glial cell line-derived neurotrophic factor in substantia nigra neurons of Parkinson's disease brain

The distribution of nerve growth factor (NGF), ciliary neurotrophic factor (CNTF), glial cell line-derived neurotrophic factor (GDNF), brain derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) in substantia nigra pars compacta (SNc) of Parkinson's disease (PD) brains was investigated by immunofluorescence. Cases studied included four 69–77 year old neurologically normal male controls and four 72–79 year old male PD patients. Integrated optical densities (IODs) of immunofluorescence over individual neuromelanin-containing neurons and in areas of neuropil and the number of neurons on H & E stained adjacent sections were quantitated with the use of the BioQuant Image Analyzer. Data were statistically analyzed by ANOVA, including the unpaired two-tailed Student t-test and the Mann–Whitney test. The results showed 55.8% (P<0.0001) dropout of SNc neurons in PD brains compared to age-matched controls. Despite considerable neuronal dropout, immunofluorescent NTFs in the PD brains showed differential reductions that were consistent within the group as compared to age-matched controls: reductions were GDNF, 19.4%/neuron (P<0.0001), 20.2%/neuropil (P<0.0001); CNTF, 11.1%/neuron (P<0.0001), 9.4%/neuropil (P<0.0001); BDNF, 8.6%/neuron (P<0.0001), 2.5%/neuropil. NGF, NT-3 and NT-4 showed no significant differences within surviving neurons or neuropil. Since the depletion of GDNF both within surviving neurons and neuropil was twice as great as that of CNTF and BDNF and since the other NTFs showed no changes, GDNF, of the tested NTFs, is probably the most susceptible and the earliest to decrease in the surviving neurons of SNc. These observations suggest a role for decreased availability of GDNF in the process of SNc neurodegeneration in PD.     

Chromaffin cell mitogenesis by neurturin and glial cell line-derived neurotrophic factor.

Neurturin and glial cell line-derived neurotrophic factor are novel mitogens for normal adult rat chromaffin cells in vitro. These neurotrophic factors differ from the previously described adult chromaffin cell mitogens, nerve growth factor and basic fibroblast growth factor, in that their effects are potentiated by depolarization and activation of protein kinase C. Neurturin and glial cell line-derived neurotrophic factor signal via the receptor tyrosine kinase, ret, but may also act independently of ret. Both depolarization and phorbol esters act synergistically with neurturin to up-regulate ret protein expression in chromaffin cell cultures, suggesting a mechanism for potentiation of mitogenesis. However, a direct role for ret in mitogenesis has not been established. Stimulation by neurturin causes increased phosphorylation of extracellular signal-regulated kinases 1 and 2 in cultured chromaffin cells, and mitogenesis is prevented by inhibitors of their phosphorylation. Inhibitors of phosphatidylinositol 3-kinase also prevent mitogenesis.The present findings suggest the hypothesis that neurotrophic factors and neurally derived signals might cooperatively regulate chromaffin cell proliferation in vivo in the rat. In addition, trans-synaptic stimulation might provide a route by which epigenetic factors could influence the development of adrenal medullary hyperplasia in humans with hereditary multiple endocrine neoplasia syndromes 2A and 2B by affecting expression and/or activation of ret.     

Alterations in expression of the neurotrophic factors glial cell line-derived neurotrophic factor, ciliary neurotrophic factor and brain-derived neurotrophic factor, in the target-deprived olfactory neuroepithelium

Neuronal growth factors play an important role in the development and maintenance of the nervous system. In the olfactory system, neurogenesis and synapse formation occur not only during development but throughout life and it would be expected that growth factors play a significant role in these ongoing processes. We have examined the expression of three neurotrophic factors, glial cell line-derived neurotrophic factor, ciliary neurotrophic factor and brain-derived neurotrophic factor in the normal rat olfactory system and following synaptic target ablation (olfactory bulbectomy). We found that brain-derived neurotrophic factor immunoreactivity was confined to the horizontal basal cells of the olfactory neuroepithelium and was unaltered by bulbectomy. Glial cell line-derived neurotrophic factor immunoreactivity was present in the mature olfactory neurons and also their synaptic target cells in the olfactory bulb. Following bulbectomy, glial cell line-derived neurotrophic factor immunoreactivity was abolished from the neuroepithelium. Ciliary neurotrophic factor was present throughout the olfactory neuronal lineage with strongest immunoreactivity in the horizontal basal cells and mature olfactory neurons as well as several cell types in the olfactory bulb. Postbulbectomy, there was loss of strong ciliary neurotrophic factor immunoreactivity in olfactory neurons, however, low levels persisted in the remaining neuronal population. Horizontal basal cell immunoreactivity persisted over three months. Our results would be consistent with glial cell line-derived neurotrophic factor expression in mature olfactory neurons being dependent upon functional synaptic contact with the olfactory bulb. Alternatively, this factor may be acting as target-derived growth factor for olfactory neurons, a role in keeping with its function in spinal motoneurons and in the nigrostriatal system. Brain-derived neurotrophic factor is implicated in the trophic support of immature neurons. Ciliary neurotrophic factor is clearly important in this unique neuronal system but elucidation of its role awaits further investigation.     

胶质细胞源性神经营养因子对比目鱼肌切除后相关运动神经元群降钙素基因相关肽表达的影响

目的：探讨鞘内注射胶质细胞源性神经营养因子(GDNF)对比目鱼肌(SOL)切除后相关运动神经元Mn群降钙素基因相关肽(CGRP)表达的影响。方法：应用霍乱毒素B亚单位结合胶体金(CB-Au)逆行标认神经元复合免疫细胞化学反应的非荧光双标法,显示标记SOL-Mn群CGRP样免疫反应(CGRP-LI)。结果：(1)与对照组相比,SOL切除后SOL-Mn群CGRP-LI强阳性Mn比率由正常的23．48%分别上升到68．8%(3d)、65．32% (10d);此后逐步降低到11．3%(30d)。(2)SOL切除后,鞘内注射GDNF强阳性Mn比率可达70．91%(30d)。结论：鞘内注射GDNF可以显著提高靶肌肉切除后相关Mn群CGRP的表达,提示GDNF对运动神经元的部分神经营养作用可能是通过上调CGRP实现的。     

Stroke induces widespread changes of gene expression for glial cell line-derived neurotrophic factor family receptors in the adult rat brain

Gene expression for glial cell line-derived neurotrophic factor (GDNF) family ligands and receptors was analyzed with in situ hybridization after two focal ischemic insults of different severities. Focal ischemia was induced in rats by either 30 min or 2 h of middle cerebral artery occlusion (MCAO), causing damage to the striatum only, or involving also the parietal cortex, respectively. We found modest, transient elevation of GDNF mRNA in the dentate granule cell layer. In addition, the number of GDNF mRNA-expressing cells increased in the cortex and striatum after 2 h or 30 min of MCAO, respectively. No changes of neurturin or persephin mRNA expression were detected. Both c-Ret and GFRalpha1 mRNA levels were markedly increased in the ipsilateral cortex outside the ischemic lesion at 6-24 h after the 2-h insult, whereas GFRalpha2 expression was decreased in cortical areas both within and outside the lesion. Similar increases of c-Ret and GFRalpha1 mRNA levels were detected in the striatum, and to a lesser extent, in the cortex following 30 min of MCAO. The 2-h insult also gave rise to transient increases of c-Ret and GFRalpha1 mRNA in hippocampal subregions. Thirty minutes and 2 h of MCAO lead to elevated c-Ret, and GFRalpha1 or GFRalpha2 mRNA expression, respectively, in the ipsilateral ventroposterolateral thalamic nucleus. Both insults induced increased levels of GFRalpha1 mRNA in the subventricular zone of the lateral ventricle.Our data indicate major changes of GDNF family signaling in the forebrain, regulated mainly through altered receptor levels, in the post-ischemic phase. These changes could enhance neuroprotective and neuroregenerative responses both to endogenous and exogenous GDNF ligands.     

Adenosine induces expression of glial cell line-derived neurotrophic factor (GDNF) in primary rat astrocytes

Adenosine, which accumulates rapidly during ischemia due to the breakdown of ATP, has beneficial effects in many tissues. We examined whether adenosine induces the production of glial cell line-derived neurotrophic factor (GDNF) in cultured astrocytes. We evaluated GDNF mRNA expression and GDNF production in astrocytes cultured with adenosine and the adenosine selective receptor agonists 5-(N-ethylcarboxamido) adenosine (NECA), N(6)-cyclopentyladenosine (CPA) and 2-p-(2-carboxyethyl) phenethylamino-5'-N-ethylcarboxamindo-adenosine hydrochloride (CGS 21680). Moreover, we examined the possibility that the expression of GDNF is regulated differently in cultured astrocytes from the stroke-prone spontaneously hypertensive rat (SHRSP) than in those from Wistar Kyoto rats (WKY). In this study, we confirmed that adenosine and the selective A(2B) adenosine receptor agonist NECA induced the expression of GDNF in cultured astrocytes. The A(2B) receptor antagonist alloxazine was able to inhibit the increase in extracellular GDNF produced by adenosine. Furthermore, the amounts of GDNF produced were significantly reduced in astrocytes of the adenosine-treated SHRSP compared with those of WKY. These results indicate that adenosine induces the expression of GDNF, and adenosine A(2B) receptors participate in the regulation of GDNF levels in astrocytes. This expression was attenuated in astrocytes of SHRSP compared with those of WKY.     

Regulation of neural development by glial cell line-derived neurotrophic factor family ligands

Glial cell line-derived neurotrophic factor (GDNF) and its three relatives constitute a novel family of neurotrophic factors, the GDNF family ligands. These factors signal through a multicomponent receptor complex comprising a glycosylphosphatidylinositol-anchored cell surface molecule (GDNF family receptor (GFR) alpha) and RET tyrosine kinase, triggering the activation of multiple signaling pathways in responsive cells. Recent gene-targeting studies have demonstrated that GDNF family ligands are essential for the development of a diverse set of neuronal populations and we have now started to understand how these ligands uniquely regulate the formation and sculpting of the nervous system. Recent studies have also revealed interactions by multiple extracellular signals during neural development. The deciphering of GDNF family ligand signaling in neural cells promises to provide vital new insights into the development and pathology of the nervous system.     

Cellular and developmental patterns of expression of Ret and glial cell line-derived neurotrophic factor receptor alpha mRNAs

 Glial cell line-derived neurotrophic factor (GDNF) has recently been shown to signal by binding to GDNF receptor-alpha (GDNFR-α), after which the GDNF-GDNFR-α associates with and activates the tyrosine kinase receptor Ret. We have localized Ret messenger RNA (mRNA) in the developing and adult rodent and compared with to the expression of GDNF and GDNFR-α mRNA. Ret mRNA is strongly expressed in dopamine neurons and α-motorneurons as well as in thalamus, ruber and occlumotor nuclei, the habenular complex, septum, cerebellum, and brain stem nuclei. Ret mRNA was also found in several sensory systems, in ganglia, and in nonneuronal tissues such as teeth and vibrissae. Very strong Ret mRNA signals are present in kidney and the gastrointestinal tract, where Ret and GDNF mRNA expression patterns are precisely complementary. The presence of Ret protein was confirmed in adult dopamine neurons using immunohistochemistry. GDNFR-α mRNA was strongly expressed in the developing and adult dopamine neurons. It was also found in neurons in deep layers of cortex cerebri, in hippocampus, septum, the dentate gyrus, tectum, and the developing spinal cord. In the kidney and the gastrointestinal tract, GDNFR-α mRNA and Ret mRNA distribution overlapped. Dorsal root ganglia, cranial ganglia, and developing peripheral nerves were also positive. GDNFR-α was additionally found in sensory areas and in developing teeth. Sensory areas included inner ear, eye, olfactory epithelium, and the vomeronasal organ, as well as developing tongue papillae. The temporospatial pattern of expression of GDNFR-α mRNA did not always match that of Ret mRNA. For instance, GDNFR-α mRNA was also found in the developing ventral striatum, including the olfactory tubercle, and in hippocampus. These areas seemed devoid of Ret mRNA, suggesting that GDNFR-α might also have functions unrelated to Ret. Received: 2 January 1997 / Accepted: 26 February 1997     

转染胶质细胞源性神经营养因子诱导神经干细胞分化

背景：神经干细胞为神经系统功能重建和神经再生提供了一条新的途径,解决其定向诱导分化问题仍是目前的研究热点。 目的：探讨转染胶质细胞源性神经营养因子基因诱导大鼠胚胎神经干细胞向神经元和多巴胺能神经元分化的作用。 方法：构建PcDNA3-GDNF-GFP表达质粒,用脂质体介导该质粒转染大鼠胚胎神经干细胞并进行诱导分化,荧光显微镜观察转染情况,免疫荧光染色检测β微管蛋白Ⅲ和酪氨酸羟化酶表达。 结果与结论：胶质细胞源性神经营养因子基因转染后3 d,可观察到细胞呈绿色荧光细胞球状。诱导分化7 d,神经干细胞分化为神经元以及多巴胺神经元的比例明显增高。结果表明胶质细胞源性神经营养因子基因可以促进神经干细胞向神经元以及多巴胺能神经元分化。 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