睫状神经营养因子的基因结构及受体

睫状神经营养因子最初由于能促进鸡胚胎睫状神经节副交感神经元存活而被发现,现已知道它对神经系统的细胞具有更广泛的作用。最近研究表明睫状神经营养因子与成血细胞因子的一个亚家族成员在结构上相似并共用受体成分。     

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。     

睫状神经营养因子受体研究进展

本文综述了睫状神经营养因子(CNTF)受体各个亚基的分子和基因结构,对CNTF受体信号转导机理进行概括,并探讨了CNTF与造血生长因子在信号转导上的相似性,以阐明CNTF对于造血系统的可能作用。     

睫状神经营养因子对大鼠去神经骨骼肌的营养作用

目的：通过测定SD大鼠坐骨神经离断后比目鱼肌（SOL）和趾长伸肌（EDL）肌纤维横截面积,观察持续给睫状神经营养因子（CNTF）对神经骨骼肌萎缩的影响。结果：SD大鼠坐骨神经离断后,持续给0．2mg/kg.d的CNTF20天后,损伤侧SOL和EDL肌纤维横截面积分别比实验对照组高27％（P＜0．01）和14％,SOL肌纤维横截面积比EDL增加的幅度大,而给予0．05mg/kg.d的CNTF20天后,动物肌纤维横截面积与实验对照组无明显差异。结论：CNTF可显著改善坐骨神经离断后SD大鼠骨骼肌的萎缩,并且CNTF效应的强弱与用药剂量和肌肉类型有关,0．2mg/kg.dCNTF作用明显强于0．05mg/kg.dCNTF,慢肌（SOL）比快肌（EDL）对CNTF更敏感。     

睫状神经营养在子研究进展

睫状神经营养因子（ＣＮＴＦ）分布于神经系统的非神经细胞，具有广泛的生物学活性，可以提高体内外各种类型外周神经元的存活。ＣＮＴＦ受体在神经系统和骨骼肌中广泛存在，在运动神经系统及与运动系统有关的部位大量表达。其对运动神经元的生理效应为临床应用于肌萎缩性脊髓侧索硬化及帕金森氏症开辟了前景。ＣＮＴＦ与造血生长因子在结构与功能上具有一定的相关性。     

睫状神经营养因子研究进展

睫状神经营养因子（ＣＮＴＦ）分布于神经系统的非神经细胞，具有广泛的生物学活性，可以提高体内外各种类型外周神经元的存活。ＣＮＴＦ受体在神经系统和骨骼肌中广泛存在，在运动神经系统及与运动系统有关的部位大量表达。其对运动神经元的生理效应为临床应用于肌萎缩性脊髓侧索硬化及帕金森氏症开辟了前景。ＣＮＴＦ与造血生长因子在结构与功能上具有一定的相关性。     

睫状神经节神经营养因子在大鼠坐骨神经生后发育中的表达—免疫组…

用免疫组织化学ＡＢＣ技术和计算机图像处理系统研究了１ｄ龄，１月龄、２月龄和３月龄大鼠坐骨神经中睫状神经节神经营养因子样免疫反应的分布及其强度的变化。结果表明，在４个年龄组中均存在阳性免疫的。阳性免疫反应见于雪旺细胞胞浆，轴突和髓鞘呈阴性。睫状神经节神经营养因子免疫反应以１月龄鼠最高，２月龄次之，３月龄最低。本文的结果提示，睫状神经节神经营养因子在出后即存在于雪旺细胞中，其含量随周围神经的发育而有所     

运动训练对大鼠肾上腺睫状神经营养因子表达的影响

目的研究大鼠游泳运动训练对大鼠肾上腺睫状神经营养因子(CNTF)表达的影响。方法成年SD大鼠分四组,除正常组外,三个负重组分别给予占体重1%、3%、5%负重,进行6周游泳训练,每天1h,取各组大鼠肾上腺,用RT-PCR研究CNTF mRNA水平变化。结果肾上腺能检测到CNTF mRNA表达,与正常组比较,轻度和中度负重组肾上腺CNTF mRNA表达明显增加(P<0.05)。结论轻、中度负重游泳训练明显增加肾上腺CNTF基因水平,提示CNTF可能与游泳负重导致机体的神经内分泌调节有关。     

人睫状神经营养因子基因在大肠杆菌中的表达

目的克隆人睫状神经营养因子（ｈＣＮＴＦ）基因，并在大肠杆菌宿主系统中高效表达出具有生物活性的ｈＣＮＴＦ蛋白。方法从人外周神经组织总ＲＮＡ经逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）扩增得到编码人ＣＮＴＦ的全长ｃＤＮＡ片段，此片段经回收和纯化后克隆进ＰＧＥＭ－５Ｚｆ（＋）质粒载体，并进行了ＤＮＡ序列分析，然后进一步亚克隆进Ｔ７启动子表达载体，用ＩＰＴＧ在大肠杆菌宿主中诱导ｈＣＮＴＦ蛋白表达，并以体外培养的鸡胚背根神经节（ＤＲＧ）神经元测定了重组ｈＣＮＴＦ蛋白的神经营养活性。结果成功克隆了人ＣＮＴＦ基因，含重组ＣＮＴＦ质粒的大肠杆菌经０．４ｍｍｏｌ／ＬＩＰＴＧ诱导３小时后，靶蛋白占细菌总蛋白的２５％以上。结论ｈＣＮＴＦ基因的克隆和高效表达为进一步研究其结构功能关系和临床应用打下了基础     

重组睫状神经营养因子对胶质瘤细胞形态和基因表达的影响

重组睫状神经营养因子对胶质瘤细胞形态和基因表达的影响张树辉詹洲陶霞田野苹何成作者单位：２２１００４解放军第九七医院病理科［张树辉（现在４０００３８第三军医大学病理学教研室）、陶霞］；第二军医大学病理学教研室（詹洲、田野苹、何成）研究表明，睫状神经...     

Regulation of ciliary neurotrophic factor receptor alpha in sciatic motor neurons following axotomy.

Spinal motor neurons are one of the few classes of neurons capable of regenerating axons following axotomy. Injury-induced expression of neurotrophic factors and corresponding receptors may play an important role in this rare ability. A wide variety of indirect data suggests that ciliary neurotrophic factor receptor alpha may critically contribute to the regeneration of injured spinal motor neurons. We used immunohistochemistry, in situ hybridization and retrograde tracing techniques to study the regulation of ciliary neurotrophic factor receptor alpha in axotomized sciatic motor neurons. Ciliary neurotrophic factor receptor alpha immunoreactivity, detected with two independent antisera, is increased in a subpopulation of caudal sciatic motor neuron soma one, two and six weeks after sciatic nerve transection and reattachment, while no changes are detected at one day and 15 weeks post-lesion. Ciliary neurotrophic factor receptor alpha messenger RNA levels are augmented in the same classes of neurons following an identical lesion, suggesting that increased synthesis contributes, at least in part, to the additional ciliary neurotrophic factor receptor alpha protein. Separating the proximal and distal nerve stumps with a plastic barrier does not noticeably affect the injury-induced change in ciliary neurotrophic factor receptor alpha regulation, thereby indicating that this injury response is not dependent on signals distal to the lesion traveling retrogradely through the nerve or signals generated by axonal growth through the distal nerve. The prolonged increases in ciliary neurotrophic factor receptor alpha protein and messenger RNA found in regenerating sciatic motor neurons contrast with the responses of non-regenerating central neurons, which are reported to display, at most, a short-lived increase in ciliary neurotrophic factor receptor alpha messenger RNA expression following injury. The present data are the first to demonstrate, in vivo, neuronal regulation of ciliary neurotrophic factor receptor alpha protein in response to injury. Moreover, they suggest that the ability of a subpopulation of spinal motor neurons to regulate ciliary neurotrophic factor receptor alpha levels in response to injury may play a role in their survival and axonal regeneration. Consistent with such a role, we also find relatively high, and probably elevated, levels of ciliary neurotrophic factor receptor alpha immunoreactivity in regenerating axons.     

In vivo localization and characterization of functional ciliary neurotrophic factor receptors which utilize JAK-STAT signaling

The ciliary neurotrophic factor receptor is critically involved in embryonic motor neuron development. Postnatally, it may contribute to neuronal maintenance and regeneration. In addition, pharmacological stimulation of the receptor may slow the progression of several neurodegenerative disorders. The widespread nervous system expression of ciliary neurotrophic factor receptor components and the effects of low ciliary neurotrophic factor concentrations on a wide variety of cells in culture combine to suggest that functional ciliary neurotrophic factor receptors are expressed by many classes of neurons in vivo. However, the in vivo signaling properties and distribution of functional ciliary neurotrophic factor receptors have not been directly determined. We developed a novel in vivo assay of functional ciliary neurotrophic factor receptors which revealed that, in the adult nervous system, cranial and spinal motor neurons are very sensitive to ciliary neurotrophic factor and display a rapid, robust increase in phospho-STAT3 in their dendrites, cell bodies and nuclei, which is specifically blocked by the ciliary neurotrophic factor receptor antagonist, AADH-CNTF. In distinct contrast, several other classes of ciliary neurotrophic factor receptor expressing neurons fail to increase phospho-STAT3 levels following ciliary neurotrophic factor treatment, even when ciliary neurotrophic factor is applied at high concentrations. Leukemia inhibitory factor and epidermal growth factor elicit the same cell-type-dependent pattern of phospho-STAT3 increases. Responsive and non-responsive neurons express comparable levels of STAT3.Therefore, in vivo ciliary neurotrophic factor receptor-initiated STAT3 signal transduction is regulated in a very cell-type-dependent manner. The present data suggest that at least some of this regulation occurs at the STAT3 tyrosine phosphorylation step. These unexpected results also suggest that other forms of receptor-initiated STAT3 signal transduction may be similarly regulated.     

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.     

睫状神经营养因子对大鼠脑缺血后髓鞘再生的影响

目的:研究睫状神经营养因子(CTNF)对脑缺血大鼠胼胝体髓鞘再生的影响。方法:48只雄性SD大鼠随机分为假手术组(Sham)、双侧颈总动脉结扎(2-VO)组和CTNF治疗组(CTNF)。利用2-VO法制备大鼠脑缺血损伤模型,在术后24 h内用0. 4μg/kg的CTNF或生理盐水分别给予CTNF治疗组、2-VO组和Sham组大鼠尾静脉注射。给药7 d后通过神经缺损功能评分(NSS)和转棒实验(Rota-Rod)检测各组大鼠神经功能,电镜观察胼胝体内髓鞘超微结构的变化,通过免疫荧光染色观察少突胶质细胞转录因子2(Olig-2)的表达,Western Blot检测髓磷脂碱性蛋白(MBP)的表达。结果:与Sham组相比,2-VO组大鼠神经功能显著受损(P 0. 05);电镜下可观察到大鼠胼胝体髓鞘变薄、完整性差;胼胝体部位Olig-2表达显著减少; MBP表达显著下降(P 0. 05)。经CTNF治疗后7 d的大鼠出现神经功能明显改善(P 0. 05),胼胝体髓鞘结构明显恢复,Olig-2表达明显增加,MBP表达明显增加(P 0. 05)。结论:CTNF处理能够改善脑缺血大鼠神经功能,促进髓鞘再生。     

睫状神经营养因子对视神经损伤的修复作用

视神经损伤后,视网膜神经节细胞进行性损害,轴突变性坏死,再生困难。睫状神经营养因子是一种非靶源性神经营养因子,在视网膜神经节细胞的生长发育中起重要调控作用,主要表现在对损伤的视网膜神经节细胞有促进存活及轴突再生的作用。     

Influence of endogenous and exogenous sex hormones on plasma brain-derived neurotrophic factor

BACKGROUND: Brain-derived neurotrophic factor (BDNF) is a mediator of neuronal plasticity and influences learning, memory and cognitive behaviour. The aim of this study is to assess plasma BDNF variations according to hormonal status. METHODS: A total of 60 subjects were included: 20 fertile ovulatory women, 15 amenorrhoeic women and 25 postmenopausal women. Blood samples were collected after overnight fasting. For 5 out of the 20 fertile women, samples were collected every 2 days throughout the whole menstrual cycle. Following basal evaluation, 10 out of 25 postmenopausal women were administered a hormone replacement therapy (HRT) and reevaluated after 6 months of treatment. Plasma BDNF concentrations were measured by enzyme-linked immunosorbent assay. In fertile women, estradiol (E(2)), progesterone and gonadotrophins were also assessed. RESULTS: In fertile women, luteal phase levels of plasma BDNF were significantly higher than follicular phase levels (P < 0.001). BDNF increased from early follicular phase up to Day 14 of the cycle, reaching a pre-ovulatory peak, similar to E(2). A second rise took place during mid-luteal phase, with a peak on Day 24. Amenorrhoeic subjects, as well as postmenopausal women, showed significantly lower plasma BDNF levels compared with fertile females (P < 0.001). BDNF was positively correlated with E(2) and progesterone and negatively correlated with menopausal age. HRT restored BDNF levels to those present in fertile women during the follicular phase. CONCLUSIONS: Plasma BDNF levels are influenced by hormonal status. Modifications in BDNF circulating levels during the menstrual cycle suggest a potential role for gonadal sex hormones (E(2) and progesterone) in regulating neurotrophin expression.