Brain-derived neurotrophic factor selectively rescues mesencephalic dopaminergic neurons from 2,4,5-trihydroxyphenylalanine-induced injury

Brain-derived neurotrophic factor (BDNF) supports the survival of sensory neurons as well as retinal ganglion cells, basal forebrain cholinergic neurons, and mesencephalic dopaminergic neurons in vitro. Here we examined the ability of BDNF to confer protection on cultured dopaminergic neurons against the neurotoxic effects of 6-hydroxyDOPA (TOPA or 2,3,5,-trihydroxyphenylalanine), a metabolite of the dopamine pathway suggested to participate in the pathology of Parkinson's disease. Cells prepared from embryonic day 14–15 rat mesencephalon were maintained with 10–50 ng/ml BDNF for 7 days prior to addition of TOPA (10–30 μM) for 24 hr. In BDNF-treated cultures, the extensive loss ( >90%) of tyrosine hydroxylase immunopositive cells was virtually (<10%) eliminated, while the equally drastic loss (>90%) of the overall cell population was limited to only a 25–30% recovery. Furthermore, the monosialoganglioside GM1 (1–10 μM), although inactive alone, acted synergistically with subthreshold amounts of BDNF to rescue tyrosine hydroxylase-positive cells against TOPA neurotoxicity. These results add impetus to exploring the therapeutic potential of gangliosides and BDNF in Parkinson's disease. © 1993 Wiley-Liss, Inc.     

Brain-derived neurotrophic factor and substantia nigra dopaminergic neurons in Parkinson''s disease

BACKGROUND:Parkinson's disease (PD) is a chronic, progressive neurodegenerative central nervous system disease which occurs in the substantia nigra-corpus striatum system. The main pathological feature of PD is selective dopaminergic neuronal loss with distinctive Lewy bodies in populations of surviving dopaminergic neurons. In the clinical and neuropathological diagnosis of PD, brain-derived neurotrophic factor mRNA expression in the substantia nigra pars compacta is reduced by 70%, and surviving dopaminergic neurons in the PD substantia nigra pars compacta express less brain-derived neurotrophic factor (BDNF) mRNA (20%) than their normal counterparts. In recent years, knowledge surrounding the relationship between neurotrophic factors and PD has increased, and detailed pathogenesis of the role of neurotrophic factors in PD becomes more important.     

Brain-derived neurotrophic factor in Huntington disease

Trophic factors, administered systemically or delivered via genetically-modified cells grafted into target regions, have been proposed as putative therapeutic agents in human neurodegenerative disorders. In parallel to the study of the beneficial effects in experimental models of particular diseases, a crucial aspect of the study of trophic factors is the gathering of information about the actual trophic factor expression in human diseased states. Brain-derived neurotrophic factor (BDNF) promotes survival and growth of various nerve cell populations during normal development and following various insults in the developing and adult brain. In particular, BDNF prevents cell death of certain striatal populations in excitotoxic models of Huntington disease (HD) following intrastriatal injection of quinolinic acid to the adult rodent brain. The present study examines BDNF expression, by gel electrophoresis and Western blotting, and immunohistochemistry, in the brains of patients who had suffered from HD. Reduced BDNF expression, ranging from 53 to 82%, has been found in the caudate and putamen in HD when compared with age-matched controls. No modifications in BDNF expression levels have been seen in the parietal cortex, temporal cortex and hippocampus. Furthermore, immunohistochemistry has shown reduced BDNF immunoreactivity in caudate neurons, but not in cortical neurons in HD when compared with controls. These data demonstrate selective BDNF decay in regions that are vulnerable to HD, and suggest, in combination with results in experimental models, that a BDNF surplus may have beneficial effects in the treatment of HD.     

脑源性神经营养因子对海马神经元NMDA受体功能下调的逆转作用

应用全细胞膜片钳技术研究BDNF对培养养海马神经元NMDA受体的调控作用。结果发现,培养18d的海马神经元NMDA诱发电流小,BDNF可快速、可逆地增加NMDA诱发电流,而培养10,14d的海马神经元NMDA诱发电流大,BDNF增强NMDA诱发电流不明显。本文结果提示BDNF对功能低下的海马神经元NMDA受体具有上调作用。     

Brain-derived neurotrophic factor and post-stroke depression

Brain-derived neurotrophic factor (BDNF) is well known to play a critical role in cognition. Its role in mood disorders, including post stroke depression (PSD), is also recognized with more evidence surfacing. In patients with PSD, their serum BNDF level is lower than in those without depression. Furthermore, antidepressants could enhance BDNF expression in the brain, resulting in an alleviation of depression symptoms. Such therapeutic effect can be abolished in animals with the BDNF gene deleted. In PSD patients, the presence of stroke may contribute to the development of depression, including affecting the expression of BDNF. However, the mechanisms of BDNF in the development of PSD remain largely unknown. Lower BDNF levels may have existed in some patients before stroke onset, making them vulnerable to develop depressive symptoms. Meanwhile, the hypoxic environment induced by stroke could possibly downregulate BDNF expression in the brain. Current antidepressant treatments are not specific for PSD and there is a lack of treatments to address the linkage between stroke and PSD. This review summarizes the current knowledge of BDNF in PSD. By regulating BDNF expression, a synergistic effect may be achieved when such treatments are applied together with existing antidepressants.     

Brain-derived neurotrophic factor

Zusammenfassung Der brain-derived neurotrophic factor (BDNF) gehört zur Familie der Neurotrophine und spielt eine wichtige Rolle beim axonalen und dendritischen Wachstum von Neuronen und der Gehirnplastizität. Die Proform von BDNF (pro-BDNF) wird in den synaptischen Spalt ausgeschüttet und dort durch die Protease Plasmin zum maturen BDNF abgebaut. BDNF fördert die synaptische Plastizität und eine Langzeitpotenzierung. Neuere Untersuchungsergebnisse deuten auf eine Beteiligung von BDNF und dessen genetischer funktioneller Polymorphismen bei der Pathogenese verschiedener psychischer Erkrankungen wie z. B. Depression, Manie, Schizophrenie, Essstörungen, Demenz und Huntington-Erkrankung hin. Die BDNF-Konzentration im Gehirn, aber auch im Serum wird durch verschiedene Faktoren beeinflusst. Sie ist z. B. durch Stress vermindert und wird durch Lernprozesse, verschiedene antidepressive Therapiemodalitäten, körperliche Aktivität und Diät erhöht. Die Bestimmung der BDNF-Serumspiegel könnte diagnostische Bedeutung erlangen. Daneben könnte die gezielte Beeinflussung der BDNF-Verfügbarkeit durch verschiedene Maßnahmen eine Relevanz zur Therapie und möglicherweise auch zur Prävention oben genannter psychischer Krankheitsbilder gewinnen.     

Brain-derived neurotrophic factor and substantia nigra dopaminergic neurons in Parkinson’s disease☆

Parkinson＇s disease （PD） is a chronic, progressive neurodegenerative central nervous system disease which occurs in the substantia nigra-corpus striatum system. The main pathological feature of PD is selective dopaminergic neuronal loss with distinctive Lewy bodies in populations of surviving dopaminergic neurons. In the clinical and neuropathological diagnosis of PD, brain-derived neurotrophic factor mRNA expression in the substantia nigra pars compacta is reduced by 70%, and surviving dopaminergic neurons in the PD substantia nigra pars compacta express less brain-derived neurotrophic factor （BDNF） mRNA （20%） than their normal counterparts. In recent years, knowledge surrounding the relationship between neurotrophic factors and PD has increased, and detailed pathogenesis of the role of neurotrophic factors in PD becomes more important.     

Brain-derived neurotrophic factor levels in first episode of psychosis: A systematic review

AIM: To systematically review studies measuring peripheric brain-derived neurotrophic factor (BDNF) levels on first-episode psychosis patients and variables related to them. METHODS: A systematic search was made of articles published in the Medline database from 2002 up to June 2014. Included are original studies that report enzyme-linked immunosorbent assay measurement of BDNF levels in serum or plasma in patients with a diagnosis of first episode psychosis (FEP) and age- and gender- matched healthy controls. RESULTS: Of the initially identified 147 articles, only 18 satisfied the inclusion criteria. Of this, 15 found a significant reduction in patients with FEP compared with age- and gender - matched controls. CONCLUSION: Peripheral BDNF levels are generally reduced in FEP patients. There are some factors that may influence BDNF levels that need to be further studied. Furthermore, a future meta-analysis in this topic is needed.     

Brain-derived neurotrophic factor-mediated effects on mitochondrial respiratory coupling and neuroprotection share the same molecular signalling pathways

Intracerebral injection of ibotenate into mouse pups induced grey matter lesions and white matter cysts; co-administration of brain-derived neurotrophic factor (BDNF) produced a dose-dependent reduction in these lesions. In contrast, glial cell line-derived neurotrophic factor (GDNF) had no significant effect, whereas nerve growth factor (NGF) or interleukin-1β (IL-1β) resulted in dose-dependent exacerbation. The neuroprotective effects of BDNF were abolished by co-administration of anti-BDNF antibody or MEK inhibitors, or ABT-737, a BH3 mimetic and Bcl-2 antagonist. The actions of BDNF, GDNF and NGF were measured in a parallel in vitro study on the oxidative metabolism of mouse brain mitochondria. BDNF produced a concentration-dependent increase in the respiratory control index (RCI, a measure of respiratory coupling efficiency, ATP synthesis, and organelle integrity) when co-incubated with synaptosomes containing signal transduction pathways; but GDNF failed to modify RCI, and NGF had only weak effects. BDNF had no effect on pure mitochondria, and enhanced oxidation only when complex I substrates were used. The effect of BDNF was inhibited by anti-BDNF antibody, MEK inhibitors or ABT-737, and also by IL-1β, indicating that the mitochondrial effects are mediated via the same MEK-Bcl-2 pathway as the neuroprotection. The complex I inhibitor rotenone, a compound implicated in the aetiology of Parkinson's disease, inhibited both the in vitro mitochondrial and in vivo neuroprotective effects of BDNF. The ability of BDNF to modify brain metabolism and the efficiency of oxygen utilization via a MEK-Bcl-2 pathway may be an important component of the neuroprotective action observed with this neurotrophin.     

Brain-derived neurotrophic factor mediates macrophage migration inhibitory factor to protect neurons against oxygen-glucose deprivation

Macrophage migration inhibitory factor(MIF)is a chemokine that plays an essential role in immune system function.Previous studies suggested that MIF protects neurons in ischemic conditions.However,few studies are reported on the role of MIF in neurological recovery after ischemic stroke.The purpose of this study is to identify the molecular mechanism of neuroprotection mediated by MIF.Human neuroblastoma cells were incubated in Dulbecco’s modified Eagle’s medium under oxygen-glucose deprivation(OGD)for 4 hours and then returned to normal aerobic environment for reperfusion(OGD/R).30 ng/mL MIF recombinant(30 ng/mL)or ISO-1(MIF antagonist;50μM)was administered to human neuroblastoma cells.Then cell cultures were assigned to one of four groups:control,OGD/R,OGD/R with MIF,OGD/R with ISO-1.Cell viability was analyzed using WST-1 assay.Expression levels of brain-derived neurotrophic factor(BDNF),microtubule-associated protein 2(MAP2),Caspase-3,Bcl2,and Bax were detected by western blot assay and immunocytochemistry in each group to measure apoptotic activity.WST-1 assay results revealed that compared to the OGD/R group,cell survival rate was significantly higher in the OGD/R with MIF group and lower in the OGD/R with ISO-1 group.Western blot assay and immunocytochemistry results revealed that expression levels of BDNF,Bcl2,and MAP2 were significantly higher,and expression levels of Caspase-3 and Bax were significantly lower in the MIF group than in the OGD/R group.Expression levels of BDNF,Bcl2,and MAP2 were significantly lower,and expression levels of Caspase-3 and Bax were significantly higher in the ISO-1 group than in the OGD/R group.MIF administration promoted neuronal cell survival and induced high expression levels of BDNF,MAP2,and Bcl2(anti-apoptosis)and low expression levels of Caspase-3 and Bax(pro-apoptosis)in an OGD/R model.These results suggest that MIF administration is effective for inducing expression of BDNF and leads to neuroprotection of neuronal cells against hypoxic injury.     

Brain-derived neurotrophic factor as a potential biomarker of cognitive recovery in schizophrenia

Brain-derived neurotrophic factor (BDNF) has been proposed as a biomarker of schizophrenia and, more specifically, as a biomarker of cognitive recovery. Evidence collected in this review indicates that BDNF is relevant in the pathophysiology of schizophrenia and could play a role as a marker of clinical response. BDNF has been shown to play a positive role as a marker in antipsychotic treatment, and it has been demonstrated that typical antipsychotics decrease BDNF levels while atypical antipsychotics maintain or increase serum BDNF levels. Furthermore, BDNF levels have been associated with severe cognitive impairments in patients with schizophrenia. Consequently, BDNF has been proposed as a candidate target of strategies to aid the cognitive recovery process. There is some evidence suggesting that BDNF could be mediating neurobiological processes underlying cognitive recovery. Thus, serum BDNF levels seem to be involved in some synaptic plasticity and neurotransmission processes. Additionally, serum BDNF levels significantly increased in schizophrenia subjects after neuroplasticity-based cognitive training. If positive replications of those findings are published in the future then serum BDNF levels could be definitely postulated as a peripheral biomarker for the effects of intensive cognitive training or any sort of cognitive recovery in schizophrenia. All in all, the current consideration of BDNF as a biomarker of cognitive recovery in schizophrenia is promising but still premature.     

双相障碍与脑源性神经营养因子外周血mRNA和蛋白表达相关性的研究

目的 探讨脑源性神经营养因子(BDNF)外周血mRNA表达和血清蛋白水平与双相障碍、双相躁狂和双相抑郁的关系.方法 应用TaqMan探针及荧光实时定量逆转录-聚合酶链反应方法,检测并比较双相障碍组(61例)、双相躁狂组(29例)、双相抑郁组(32例)和对照组(61名)外周血白细胞BDNF基因的mRNA表达水平的差异;采用酶联免疫吸附方法测定血清BDNF浓度;应用17项汉密尔顿抑郁量表(HAMD17)和Young氏躁狂量表(YMRS)评定患者抑郁症状严重程度和躁狂症状的严重程度,采用Pearson相关分析分析BDNF基因mRNA表达水平和血清蛋白浓度与HAMD17和YMRS评分的关系.结果 (1)双相障碍组BDNF基因mRNA相对表达水平(0.0077±0.0019)较对照组(0.0096±0.0028)下降(t=-3.74,P＜0.01);双相躁狂组(0.0081±0.0023)、双相抑郁组(0.0073±0.0024)与对照组3组间BDNF基因mRNA相对表达水平的差异有统计学意义(F=7.55,P＜0.01),且双相躁狂组和双相抑郁组均低于对照组(P＜0.05或P＜0.01).(2)双相障碍组BDNF血清蛋白浓度低于对照组(t=-2.90,P＜0.01);双相躁狂组、双相抑郁组与对照组3组间BDNF血清蛋白浓度的差异有统计学意义(F=4.21,P＜0.05);双相躁狂组和双相抑郁组BDNF血清蛋白浓度均低于对照组(P均＜0.05),但双相躁狂组与双相抑郁组比较差异无统计学意义(P＞0.05).(3)双相躁狂组BDNF基因mRNA表达水平及血清蛋白浓度与YMRS评分未见相关(P＞0.05),双相抑郁组BDNF基因mRNA表达水平及血清蛋白浓度与HAMD17评分未见相关(P＞0.05).结论 双相障碍与BDNF水平下调可能相关,这种下降贯穿于躁狂相和抑郁相,而且BDNF的变化不会因双相障碍患者极性的变化而处于两极状态.     

神经营养因子及其受体的基因突变与疾病

神经营养因子在神经系统发育和生理功能发挥中具有重要作用。神经营养因子及其受体的基因缺失及突变是导致某些人类疾病，如各种先天性发育不全、神经退行性疾病和癌症等的“候选基因”或“修饰基因”，本文综述了神经营养因子及其受体突变与疾病的关系。     

Brain-derived neurotrophic factor enhances function rather than survival of intrastriatal dopamine cell-rich grafts

Brain-derived neurotrophic factor (BDNF) has been shown to promote the survival of dopaminergic neurons from the substantia nigra in cell culture. In order to assess whether a similar survival-promoting effect is present also in vivo, we grafted fetal nigral tissue to the dopamine-depleted striatum of 6-hydroxydopamine-lesioned rats receiving two-week intraventricular infusions or daily intrastriatal injections of BDNF, NGF, or vehicle. Wheninfused chronically at a high dose (12 μg/day) into the lateral ventricle, BDNF caused a behavioral syndrome of reduced food and water intake, body weight loss, and locomotor hyperactivity in comparison to NGF- and vehicle-infused graft recipients. NGF-infused graft recipients displayed a transient weight loss during the first week of infusion. At 15 days, amphetamine-induced turning was significantly attenuated to 3% of pregraft values in BDNF-infused recipients, whereas functional graft effects were not present in NGF- or vehicle-infused animals. Survival of tyrosine hydroxylase-immunoreactive graft cells, however, was similar in all treatment groups. Notably, NGF- and BDNF-infusions led to a significant size increase of cholinergic host neurons in the medial septal nucleus and the vertical limb of the diagonal band ipsilateral to the infusion, wheras there was no cholinergic neuron hypertophy in vehicle-infused animals. Daily intrastriatalinjections of BDNF (2 μg) produced no weight loss or locomotor hyperactivity, but also enhanced functional graft effects in BDNF-injected, as compared to vehicle-injected animals. Survival rates of grafted tyrosine hydroxylase-immunoreactive cells were, however, similar in both groups. We conclude that, using the administration methods chosen for this study, BDNF may enhance the functional capacity but not the survival of grafted dopamine neurons.     

Brain-derived neurotrophic factor rescues neuronal death induced by methamphetamine.

BACKGROUND: Methamphetamine (MA) induces degeneration of various regions of the brain, resulting in neuropsychiatric damage. Although the underlying mechanisms of MA-induced neurotoxicity have been studied, there are few reports to date regarding the factor(s) that can effectively prevent MA-induced neurotoxicity. Because brain-derived neurotrophic factor (BDNF) has been known to prevent many kinds of neuronal cell death, we investigated whether BDNF inhibits MA-induced neuronal death. METHODS: Using primary cortical neurons, we examined the effect of BDNF on MA-induced neuronal death. In addition, using pharmacologic and molecular biological tools, we elucidated which pathways are involved in this effect. RESULTS: Brain-derived neurotrophic factor dose-dependently blocked MA-induced neuronal death, and this effect was inhibited by phosphatidylinositol-3-kinase inhibitors. In addition, overexpression of activated Akt protects neurons against MA. Furthermore, expression of kinase-defective Akt blocked the effect of BDNF on MA-induced neuronal death. CONCLUSIONS: Brain-derived neurotrophic factor effectively blocks MA-induced neuronal death, and Akt activation is necessary and sufficient for this effect.     

Brain-derived neurotrophic factor and neurotrophin-3 levels in Alzheimer's disease brains

In the present study, we investigated the levels of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in post-mortem brain tissue of Alzheimer's disease (AD) patients, and we observed a significant increase of BDNF concentration in hippocampus and parietal cortex of AD patients, as well as a negative correlation between NT-3 levels and age in hippocampus and putamen of control subjects, and for BDNF in frontal cortex. A defining feature of AD is the post-mortem identification of neuritic plaques and neurofibrillary tangles in the brain, however, a more significant neuropathological finding is the degeneration of cholinergic neurones of the basal forebrain, critically involved in memory and cognition. Neurotrophic factors are partly responsible for the maintenance of neuronal function and structural integrity in the adult brain. Our results provide, therefore, evidence that, under conditions of progressive neurodegeneration the brain stimulates the over expression of certain neurotrophic factors as a possible mechanisms of compensation, and that during senescence the expression of these molecules is regulated.     

Brain-derived neurotrophic factor and subcallosal deep brain stimulation for refractory depression

Objectives. Subcallosal cingulate (SCC) deep brain stimulation (DBS) is a promising experimental treatment for treatment-resistant depression (TRD). Given the role of brain-derived neurotrophic factor (BDNF) in neuroplasticity and antidepressant efficacy, we examined the effect of SCC-DBS on serum BDNF in TRD. Methods. Four patients with TRD underwent SCC-DBS treatment. Following a double-blind stimulus optimization phase of 3 months, patients received continuous stimulation in an open label fashion for 6 months. Clinical improvement in depressive symptoms was evaluated bi-weekly for 6 months using the Hamilton Depression Rating Scale (HDRS). Mature serum BDNF levels were measured before and 9–12 months after surgery. Results. Three patients responded to SCC-DBS: two showed full clinical response (50% reduction in HDRS scores) and one had partial response (35% reduction in HDRS scores) at the clinical endpoint. Interestingly, all four patients showed reduction in serum BDNF concentration from pre-DBS baseline. Conclusions. SCC-DBS for TRD may be associated with decreased levels of serum BDNF. Longitudinal studies with multiple measurements in a larger sample are required to determine the role of BDNF as a biomarker of SCC-DBS antidepressant efficacy.