普拉克索和罗匹尼罗对体外培养的多巴胺神经元的神经营养作用

目的 :探讨新型选择性多巴胺D3受体激动剂普拉克索和罗匹尼罗对多巴胺神经元的神经营养作用及其机制。方法 :在大鼠的腹侧中脑细胞和不同部位星形胶质细胞培养基中加入普拉克索和罗匹尼罗刺激 ,观察药物对多巴胺神经元存活的影响。结果 :药物直接作用或从黑质区星形胶质细胞培养基中提取的条件培养液均可使酪氨酸羟化酶 (TH )阳性神经元数量增加 ,同时培养液中脑源性神经营养因子 (BDNF)和胶质细胞源性神经营养因子(GDNF)含量增加。而其他脑区的星形胶质细胞不能产生类似作用。结论 :普拉克索和罗匹尼罗对多巴胺神经元具有神经营养作用 ,这可能是由于其使特定区域星形胶质细胞产生并分泌了神经营养因子。     

Decreased expression of glial cell line-derived neurotrophic factor signaling in rat models of neuropathic pain

1. In an attempt to clarify whether glial cell line-derived neurotrophic factor (GDNF), a survival factor for subpopulations of primary afferent neurons, is involved in the states of neuropathic pain, we observed changes in the expressions of GDNF and its signal-transducing receptor Ret after nerve injury in two rat models of neuropathic pain. 2. In the rats treated with sciatic nerve ligation (chronic constrictive injury (CCI) model) or spinal nerve ligation at L5 (SNL model), the thresholds of paw withdrawal in response to mechanical or heat stimuli began to decrease on the injured side within the first week after the operation and the decreases in the thresholds persisted for more than 2 weeks. 3. In CCI-treated rats, the GDNF contents in L4 and L5 dorsal root ganglia (DRGs) on the injured side were markedly decreased at day 7 after the operation and stayed at low levels at day 14. In SNL-treated rats, comparable reductions of GDNF levels in L4 and L5 DRGs on the injured side were observed at 14 postoperative days. 4. Significant decreases of the percentages of DRG neurons expressing Ret were also observed at L4 DRGs in CCI-treated rats at 7 and 14 postoperative days and in SNL-treated rats at 14 days. 5. In CCI- or SNL-treated rats, continuous intrathecal administration of GDNF (12 microg day-1) using an osmotic pump suppressed the increased sensitivities to nociceptive stimuli to control levels. 6. The present results suggested that the dysfunction of GDNF signaling in the nociceptive afferent system may contribute to the development and/or maintenance of neuropathic pain states.     

Lithium treatment alters brain concentrations of nerve growth factor,brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in a rat model of depression

Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) are proteins involved in neuronal survival and plasticity of dopaminergic, cholinergic and serotonergic neurons in the central nervous system. Since decreased size and impaired function of some neuronal populations may be relevant in depression it has been hypothesized that these molecules may have a functional role in the pathophysiology as well as treatment of depression. Using an animal model of depression, the Flinders Sensitive Line (FSL) rats and their controls, the Flinders Resistant Line (FRL), we investigated the effects of chronic lithium treatment on brain NGF, BDNF and GDNF. Lithium was administered as food supplementation during 6 wk. NGF, BDNF and GDNF measurements were performed by enzyme-linked immunosorbent assay (ELISA). Lithium altered the brain concentrations of neurotrophic factors in the hippocampus, frontal cortex, occipital cortex and striatum. Moreover, the changes were different in the two rat strains. Our data support the notion that neurotrophic factors play a role in depression and in the mechanism of the action of lithium.     

Glial cell line-derived neurotrophic factor receptor alpha 2 (GFRA2) gene is associated with tardive dyskinesia

Introduction  

Tardive dyskinesia (TD) has a pharmacogenetic component in which the interaction of antipsychotic exposure with individual genetic variation mediates risk. The glial cell line-derived neurotrophic factor (GDNF) signalling pathway has been associated with neuroprotective effects in central dopaminergic neurons and spinal motor neurons. Clinical trials have also investigated whether GDNF may ameliorate Parkinson’s disease symptoms.     

胶质细胞源性神经营养因子与神经病理性疼痛

胶质细胞源性神经营养因子(glial cell line-derived neurotrophic factor,GDNF)是神经营养因子家族成员之一,GD-NF对中枢和周围神经系统多种神经元的生长、发育、分化、维持和损伤修复起重要作用。另外,GDNF还参与中枢和外周水平神经病理性疼痛的形成和发展。该文主要就GDNF和神经病理性疼痛的研究作一简要综述。     

Glial cell line-derived neurotrophic factormediated enhancement of noradrenergic descending inhibition in the locus coeruleus exerts prolonged analgesia in neuropathic pain

Background and Purpose

The locus coeruleus (LC) is the principal nucleus containing the noradrenergic neurons and is a major endogenous source of pain modulation in the brain. Glial cell line-derived neurotrophic factor (GDNF), a well-established neurotrophic factor for noradrenergic neurons, is a major pain modulator in the spinal cord and primary sensory neurons. However, it is unknown whether GDNF is involved in pain modulation in the LC.

Experimental Approach

Rats with chronic constriction injury (CCI) of the left sciatic nerve were used as a model of neuropathic pain. GDNF was injected into the left LC of rats with CCI for 3 consecutive days and changes in mechanical allodynia and thermal hyperalgesia were assessed. The α₂-adrenoceptor antagonist yohimbine was injected intrathecally to assess the involvement of descending inhibition in GDNF-mediated analgesia. The MEK inhibitor U0126 was used to investigate whether the ERK signalling pathway plays a role in the analgesic effects of GDNF.

Key Results

Both mechanical allodynia and thermal hyperalgesia were attenuated 24 h after the first GDNF injection. GDNF increased the noradrenaline content in the dorsal spinal cord. The analgesic effects continued for at least 3 days after the last injection. Yohimbine abolished these effects of GDNF. The analgesic effects of GDNF were partly, but significantly, inhibited by prior injection of U0126 into the LC.

Conclusions and Implications

GDNF injection into the LC exerts prolonged analgesic effects on neuropathic pain in rats by enhancing descending noradrenergic inhibition.     

Glial-cell-line-derived neurotrophic factor: gene promoter and receptors

These patents claim the structure of the glial-cell-line-derived neurotrophic factor (GDNF) gene promoter and of novel GDNF receptors. Since GDNF is a potent survival and growth factor for various neuronal (and non-neuronal) cell populations, knowledge of these molecules may have significant diagnostic and therapeutic applications.     

The mechanism of heme oxygenase-1 action involved in the enhancement of neurotrophic factor expression

Heme oxygenase-1 (HO-1) is up-regulated in response to oxidative stress and catalyzes the degradation of pro-oxidant heme to carbon monoxide (CO), iron and bilirubin. Bilirubin is a potent antioxidant and neuroprotectant. Neurotrophic factors of BDNF and GDNF also play important roles in survival and morphological differentiation of dopaminergic neurons. We have previously found that HO-1 induction by adenovirus containing human HO-1 gene (Ad-HO-1) in substantia nigra of rat increases BDNF and GDNF expression. We here further examined the possible mechanism of HO-1 action involved in the enhancement of neurotrophic factor expression. Treatment of anti-BDNF/GDNF antibody significantly enhanced dopaminergic neuronal death, whereas Ad-HO-1 co-treatment was able to antagonize the apoptosis-inducing effect of these antibodies. The confocal imaging shows that HO-1 induction appeared in dopaminergic neuron, astrocyte and microglia at 24 h after injecting Ad-HO-1. HO-1 induced-BDNF/GDNF mRNA expression in substantia nigra was 26/21 folds of that of the contralateral Ad-injected side. The downstream product bilirubin increased GDNF expression through ERK and PI3K-Akt pathways, and also enhanced NFκB (p65 and p50) nuclear translocation in glia-enriched cultures. In addition, bilirubin also enhanced BDNF expression through similar pathway in cortical neuron-enriched cultures. We also examined the effect of another HO-1 product, CO, by using CO donor. [Ru(CO)₃Cl₂]₂ increased neurotrophic factor expression via sGC-PKG pathway in both neuron and glia. These results indicate that the downstream products of HO-1, i.e. bilirubin and CO, modulate BDNF and GDNF expression in neuron and astrocyte.     

Glial cell line-derived neurotrophic factor concentration dependently improves disability and motor activity in MPTP-treated common marmosets

Glial cell line-derived neurotrophic factor (GDNF) has previously reduced motor deficits and preserved nigral dopamine neurones in rhesus monkeys with a unilateral MPTP-induced lesion of substantia nigra. We now report on the ability of GDNF to reverse motor deficits induced by parenteral administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to common marmosets resulting in bilateral degeneration of the nigrostriatal pathway. Prior to GDNF administration, all MPTP-treated animals showed akinesia or bradykinesia, rigidity, postural instability and tremor. Intraventricular injection of GDNF (10, 100 or 500 microg) at 9 and 13 weeks post MPTP treatment resulted in a concentration dependent improvement in locomotor activity and motor disability which became significant after administration of 100 and 500 microg of GDNF. The most prominent improvements were in alertness, checking movements, and posture. It is concluded that intraventricular GDNF administration improves bilateral Parkinsonian motor disability following MPTP treatment and this may reflect an action of GDNF on remaining nigral dopaminergic neurones.     

临床孤立综合征患者血清和脑脊液中脑源性与胶质细胞源性神经营养因子水平及其神经保护作用研究

目的 探讨多发性硬化（MS）的早期表现--临床孤立综合征（CIS）患者血清及脑脊液中脑源性神经营养因子（BDNF）、胶质细胞源性神经营养因子（GDNF）水平及其神经保护作用.方法 对27例CIS患者及21例对照者进行研究,CIS患者发作期进行扩展残疾状态量表（EDSS）评分、寡克隆带测定及MRI检查,液相芯片分析技术检测血清及脑脊液BDNF、GDNF浓度.结果 CIS患者发作期血清及脑脊液BDNF[分别为（5.981±0.995）和（0.178±0.008）μg/L]、GDNF浓度[分别为（0.039±0.007）和（0.082±0.011）μg/L]与对照组[血清：（4.374±0.501）、（0.042±0.007）μg/L;脑脊液：（0.152±0.011）、（0.065±0.013）μg/L]比较差异均无统计学意义（均P＞0.05）;脑脊液BDNF与GDNF浓度呈正相关（r=0.777,P=0.000）,血清BDNF与GDNF浓度无相关性（r=-0.375,P=0.126）.血清及脑脊液BDNF、GDNF浓度与EDSS评分、血脑屏障指数、Delpech指数、Tourtellotte合成率及脑萎缩无明显相关性（P＞0.05）.结论 CIS患者体内BDNF与GDNF水平相关,二者可能具有协同的神经保护作用.BDNF及GDNF与CIS患者血脑屏障破坏及中枢神经系统内IgG合成无关,与神经功能残疾及脑萎缩的关系仍需研究.     

Role of PI3-K/Akt pathway and its effect on glial cell line-derived neurotrophic factor in midbrain dopamine cells

AIM: To explore the intracellular mechanisms underlying the survival/differentiation effect of the glial cell line-derived neurotrophic factor (GDNF) on dopamine (DA) cells. METHODS: Midbrain slice culture and primary cell culture were established, and the cultures were divided into 3 groups: control group, GDNF group, and the phosphatidylinositol 3-kinase/Akt (PI3-K/Akt) pathway-inhibited group. Then the expression of tyrosine hydroxylase (TH) was detected by immunostaining as well as Western blotting. RESULTS: GDNF treatment induced an increase in the number of TH-immunoreactive (ir) cells and the neurite number of TH-ir cells, as well as in the level of TH expression in cultures (Number of TH-ir cells in the slice culture: control group, 8.76+/-0.75; GDNF group, 18.63+/-0.95. Number of TH-ir cells and neurite number of TH-ir cells in cell culture: control group, 3.65+/-0.88 and 2.49+/-0.42; GDNF group, 6.01+/-0.43 and 4.89+/-0.46). Meanwhile, the stimulation of cultured cells with GDNF increased the phosphorylation of Akt, which is a downstream effector of PI3-K/Akt. The effects of GDNF were specifically blocked by the inhibitor of the PI3-K/Akt pathway, wortmannin (Number of TH-ir cells in slice culture: PI3-K/Akt pathway-inhibited group, 6.98+/-0.58. Number of TH-ir cells and neurite number of TH-ir cells in cell culture: PI3-K/Akt pathway-inhibited group, 3.79+/-0.62 and 2.50+/-0.25, respectively). CONCLUSION: The PI3-K/Akt pathway mediates the survival/differentiation effect of GDNF on DA cells.     

Sominone enhances neurite outgrowth and spatial memory mediated by the neurotrophic factor receptor,RET

Background and purpose:

Orally administered withanoside IV (a compound isolated from the roots of Withania somnifera) improved memory deficits in mice with a model of Alzheimer''s disease induced by the amyloid peptide Aβ(25-35). Sominone, an aglycone of withanoside IV, was identified as an active metabolite after oral administration of withanoside IV. We aimed to identify receptors or associated molecules of sominone, and to investigate the effects of sominone on memory in normal mice.

Experimental approach:

Phosphorylation levels of 71 molecules were compared between control and sominone-stimulated cortical cultured cells to search for target molecules of sominone. Object location memory and neurite density in the brain were evaluated in sominone-injected mice.

Key results:

Phosphorylation of RET (a receptor for the glial cell line-derived neurotrophic factor, GDNF) was increased in neurons by sominone, without affecting the synthesis and secretion of GDNF. Knockdown of RET prevented sominone-induced outgrowths of axons and dendrites. After a single i.p. injection of sominone into normal mice, they could better memorize scenery information than control mice. Sixty minutes after sominone injection, RET phosphorylation was increased, particularly in the hippocampus of mice. After the memory tests, the densities of axons and dendrites were increased in the hippocampus by sominone administration.

Conclusions and implications:

Sominone could reinforce the morphological plasticity of neurons by activation of the RET pathway and thus enhance memory. Sominone, a compound with low molecular weight, may be a GDNF-independent stimulator of the RET pathway and/or a novel modulator of RET signalling.     

Rehmannia glutinosa induces glial cell line-derived neurotrophic factor gene expression in astroglial cells via cPKC and ERK1/2 pathways independently.

Among four herbs of traditional Chinese medicines (TCMs) used in the therapy of dementia, Rehmannia glutinosa (RG) was found to induce the gene expression of glial cell line-derived neurotrophic factor (GDNF) in C6 glioblastoma cells and primary cultured astrocytes. The RG-induced GDNF mRNA up-regulation in C6 glioblastoma cells was completely attenuated by the presence of a pan-specific protein kinase C (PKC) inhibitor (Ro-31-8220) and a MAPK/ERK kinase 1 (MEK1) inhibitor (U0126). A conventional PKC inhibitor (G?6976) also significantly decreased GDNF gene induction. On the other hand, RG treatment was found to stimulate phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2), which preceded GDNF mRNA induction in C6 glioblastoma cells. However, none of the PKC inhibitors significantly changed RG-stimulated ERK1/2 phosphorylation. Therefore, RG-stimulated GDNF gene expression could be independently up-regulated through cPKC and ERK 1/2 pathways in C6 glioblastoma cells.     

Age-related alterations in the expression of glial cell line-derived neurotrophic factor in the senescence-accelerated mouse brain

Senescence-accelerated mouse prone 8 (SAMP8) and prone 10 (SAMP10) are useful murine model of accelerated aging. SAMP8 shows marked impairment of learning and memory, whereas SAMP10 shows brain atrophy and aging-associated depressive behavior. This study examined the expression of glial cell line-derived neurotrophic factor (GDNF) in SAMP8 and SAMP10 brains, relative to that in SAM resistant 1 (SAMR1) controls, which age normally. Hippocampal GDNF mRNA expression decreased in an age-dependent manner (10- vs 2-month-old animals) in the SAMR1, but not in the SAMP8 or SAMP10 strains. Furthermore, GDNF mRNA expression in 2-month-old SAMP8 and SAMP10 strains was less than in SAMR1 specimens of the same age. The number of surviving neurons in the CA1 region decreased with age in SAMP8 and SAMP10, and also decreased relative to the number of neurons in 10-month-old SAMR1 controls. Immunohistochemistry revealed that cells that were positive for GDNF-like activity in 10-month-old SAMP8 and SAMP10 were diffusely distributed, in part, around the pyramidal cell layer in the hippocampus. These findings suggest that low GDNF expression in young SAMP8 and SAMP10 may be involved in hippocampal dysfunctions, such as age-related learning impairment and neuronal death.     

脑内胶质细胞源性神经营养因子及其受体复合物研究进展

胶质细胞源性神经营养因子(glial cell line-derived neurotrophic factor,GDNF)在脑内广泛分布,通过其受体复合物介导激活细胞内信号转导通路,发挥维持神经元功能和损伤修复等作用。胶质细胞源性神经营养因子家族受体α(GD-NF family receptorα,GFRα)和RET是其受体复合物的主要成员。GDNF和其受体复合物可能参与多种脑部病变的病理生理过程,是潜在的治疗靶点之一。     

白果内酯刺激大鼠星形胶质细胞GDNF和VEGF表达(英文)

目的:观察白果内酯对大鼠星形胶质细胞GDNF和VEGF表达的影响。方法:应用半定量PCR了解大鼠星形胶质细胞分别经不同浓度白果内酯(0,5,15,50,100μmol·L~(-1))作用12、24和48h后细胞内GDNF和VEGF mRNA的变化,同时应用免疫组化了解经50μmol·L~(-1)作用24h后细胞内GDNF和VEGF蛋白的变化。结果:大鼠星形胶质细胞经50μmol·L~(-1)白果内酯作用12h后,细胞内GDNF和VEGF mRNA水平开始显著增高,经50μmol·L~(-1)作用24h后细胞胞浆内可见明显的VEGF和GDNF蛋白表达。结论:白果内酯可能通过诱导星形胶质细胞GDNF和VEGF的表达对神经细胞起保护作用。     

Mechanisms of antidepressants and serotonin (5-HT)-induced glial cell line-derived neurotrophic factor (GDNF) releases in rat C6 gliobrastoma cells]

Recent studies show that neuronal and glial plasticity are important for the therapeutic action of antidepressants. Here, we demonstrated that amitriptyline, a tricyclic antidepressant, significantly increased GDNF mRNA and GDNF release in C6 cells. Furthermore, different classes of antidepressants increased GDNF release, but non-antidepressant psychotropic drugs did not. The amitriptyline-induced GDNF release was completely inhibited by U0126, a mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor, but was not inhibited by H-89, a protein kinase A inhibitor or calphostin C, a protein kinase C inhibitor. These results suggest that the amitriptyline-induced GDNF release may be regulated through a MEK/MAPK pathway. Next, we examined the effects of monoamines on GDNF release, because antidepressants are known to increase monoamines. 5-HT increased GDNF mRNA and GDNF release, but noradrenaline and dopamine did not. The 5-HT-induced GDNF release was partially, but significantly, blocked by ketanserin, a 5-HT2A receptor antagonist. The 5-HT-induced GDNF release was completely inhibited by U0126, but was not inhibited by H-89 or calphostin C. These results suggest that the 5-HT-induced GDNF release was mediated through a MEK/MAPK pathway and, at least, 5-HT2A receptors. GDNF, as well as other neurotrophic factors, may contribute to explain the therapeutic action of antidepressants and suggest a novel strategy of pharmacological intervention.     

The roles of glial cell line-derived neurotrophic factor, tumor necrosis factor-alpha, and an inducer of these factors in drug dependence

There are few efficacious medications for drug dependence at present. Recent evidence has suggested that various cytokines are involved in the effects of abused drugs, suggesting that these factors play a role in drug dependence. In this article, the roles of glial cell line-derived neurotrophic factor (GDNF) and tumor necrosis factor-alpha (TNF-alpha) in drug dependence are discussed. GDNF inhibits the cocaine-induced upregulation of tyrosine hydroxylase activity in the ventral tegmental area and blocks behavioral responses to cocaine. TNF-alpha attenuates rewarding effects and locomotor sensitization induced by methamphetamine (METH) and morphine (MOR). Moreover, we mentioned the potential of Leu-Ile, which induces the expression of GDNF and TNF-alpha, as a novel therapeutic agent for drug dependence. Leu-Ile inhibits not only the development but also the maintenance of METH- or MOR-induced place preference and locomotor sensitization in mice. The inhibitory effect of Leu-Ile on METH- or MOR-induced place preference is not observed in GDNF heterozygous and TNF-alpha knockout mice. Leu-Ile inhibits METH- or MOR-induced place preference and sensitization by attenuating the METH- or MOR-induced increase in extracellular dopamine levels in the nucleus accumbens via the induction of GDNF and TNF-alpha expression. These findings suggest that Leu-Ile could be a novel therapeutic agent for drug dependence.     

Purification of bioactive glycosylated recombinant glial cell line-derived neurotrophic factor

Glial cell line-derived neurotrophic factor (GDNF) neuroprotective effect on dopaminergic neurons has been described in vitro and in vivo, turning up as a promising drug for the treatment of Parkinson's disease. Unglycosylated bacteria-obtained GDNF has already been successfully delivered for a long period of time through an infusion pump directly to the putamen of Parkinsonian patients. Nevertheless, improved distribution and safety issues need to be solved and alternative strategies to long-term delivery seem necessary. The use of glycosylated GDNF could eliminate some safety concerns regarding the presence of antibodies against exogenous unglycosylated GDNF used for the treatment. Therefore, we have chosen a mammalian expression system as a source of glycosylated GDNF. In the present work, we describe the purification of recombinant rat GDNF from the culture media of baby hamster kidney (BHK) cells through several purification steps. Highly pure N-glycosylated recombinant GDNF has been obtained similar to the endogenous protein. Furthermore, the purified protein is biologically active when tested its ability to induce PC12 neurite outgrowth.