脑源性神经营养因子Val66Met功能基因多态性与抗抑郁剂疗效

目的：探讨脑源性神经营养因子（BDNF）Val66Met功能基因多态性与抗抑郁剂临床疗效的相关性。方法：302例抑郁症患者给予抗抑郁剂治疗8周。于治疗前和治疗2、4、6、8周后采用汉密尔顿抑郁量表（HAMD）评定抑郁严重程度和疗效。以治疗后HAMD总分≤7分为临床痊愈,将302例患者分为痊愈组160例和未痊愈组142例,抽取患者静脉血,采用Illumina GoldenGate定制芯片分析BDNFVal66Met基因多态性并进行基因分型。结果：痊愈组基因型分布A/A31例（19.4%）、A/G92例（57.5%）和G/G37例（23.1%）,未痊愈组分别为28例（19.7%）、78例（54.9%）和36例（25.4%）（χ2=0.054,P=0.817）;痊愈组等位基因频率分布A154例（48.1%）和G166例（51.9%）,未痊愈组分别为134例（47.2%）和150例（52.8%）（χ2=0.247,P=0.884）。3种BDNFVal66Met基因型患者间在性别、年龄、受教育年限、病程、发病次数、有无精神疾病家族史、HAMD基线及减分率上差异均无统计学意义（P均〉0.05）。结论：BDNFVal66Met基因多态性不是影响抗抑郁剂治疗近期疗效的主要因素。     

Prefrontal cognition in schizophrenia and bipolar illness in relation to Val66Met polymorphism of the brain-derived neurotrophic factor gene

The measures of prefrontal cognition have been used as endophenotype in molecular-genetic studies. Brain-derived neurotrophic factor (BDNF) has been implicated in cognitive functions and in the pathogenesis of major psychoses. This study investigates the relationship between Val66Met polymorphisms of the BDNF gene and prefrontal cognitive function in 129 patients with schizophrenia and 111 patients with bipolar mood disorder. Cognitive tests included the Wisconsin Card Sorting Test (WCST), with such domains as number of perseverative errors, non-perseverative errors, completed corrected categories, conceptual level responses, and set to the first category, and the N-back test, where mean reaction time and percent of correct reactions were measured. Genotyping for Val66Met BDNF polymorphism was done by polymerase chain reaction method. In schizophrenia, no relationship between Val66Met polymorphism of the BDNF gene and the results of the WCST was observed. Patients with Val/Val genotype had a higher percentage of correct reactions in the N-back test than those with the remaining genotypes. Bipolar patients with Val/Val genotype obtained significantly better results on three of five domains of the WCST. No relationship between BDNF polymorphism and the results of the N-back test was found in this group. A limitation to the results could be variable psychopathological state and medication during cognitive testing and lack of Hardy-Weinberg equilibrium in schizophrenia group. Val66Met polymorphism of the BDNF gene may be associated with cognitive performance on the WCST in bipolar mood disorder but not in schizophrenia. An association of this polymorphism with performance on the N-back test in schizophrenia and not in bipolar illness may suggest that in schizophrenia, the BDNF system may be connected with early phases of information processing.     

No association between the Val66Met polymorphism of the brain-derived neurotrophic factor gene and bipolar disorder in a Japanese population: a multicenter study.

BACKGROUND: Two previous studies reported a significant association between a missense polymorphism (Val66Met) in the brain-derived neurotrophic factor (BDNF) gene and bipolar disorder; however, contradictory negative results have also been reported, necessitating further investigation. METHODS: We organized a multicenter study of a relatively large sample of 519 patients with bipolar disorder (according to DSM-IV criteria) and 588 control subjects matched for gender, age, and ethnicity (Japanese). Genotyping was done by polymerase chain reaction-based restriction fragment length polymorphism or direct sequencing. RESULTS: The genotype distributions and allele frequencies were similar among the patients and control subjects. Even if the possible relationships of the polymorphism with several clinical variables (i.e., bipolar I or II, presence of psychotic features, family history, and age of onset) were examined, no variable was related to the polymorphism. CONCLUSIONS: The Val66Met polymorphism of the BDNF gene is unrelated to the development or clinical features of bipolar disorder, at least in a Japanese population.     

Post-traumatic stress disorder risk and brain-derived neurotrophic factor Val66Met

Brain-derived neurotrophic factor (BDNF), which regulates neuronal survival, growth differentiation, and synapse formation, is known to be associated with depression and post-traumatic stress disorder (PTSD). However, the molecular mechanism for those mental disorders remains unknown. Studies have shown that BDNF is associated with PTSD risk and exaggerated startle reaction (a major arousal manifestation of PTSD) in United States military service members who were deployed during the wars in Iraq and Afghanistan. The frequency of the Met/Met in BDNF gene was greater among those with PTSD than those without PTSD. Among individuals who experienced fewer lifetime stressful events, the Met carriers have significantly higher total and startle scores on the PTSD Checklist than the Val/Val carriers. In addition, subjects with PTSD showed higher levels of BDNF in their peripheral blood plasma than the non-probable-PTSD controls. Increased BDNF levels and startle response were observed in both blood plasma and brain hippocampus by inescapable tail shock in rats. In this paper, we reviewed these data to discuss BDNF as a potential biomarker for PTSD risk and its possible roles in the onset of PTSD.     

No association between the brain-derived neurotrophic factor gene Val66Met polymorphism and tardive dyskinesia in schizophrenic patients

OBJECTIVE: This study investigated whether the brain-derived neurotrophic factor (BDNF) gene Val66Met single-nucleotide polymorphism (SNP) is associated with antipsychotic-induced tardive dyskinesia (TD) in schizophrenia. METHODS: Genotyping was performed for the BDNF gene Val66Met SNP in Korean schizophrenic patients with (n=83) and without TD (n=126) who were matched for antipsychotic drug exposure and other relevant variables. RESULTS: The frequencies of genotypes (chi2=2.37, p=0.306) and alleles (chi2=0.03, p=0.867) did not differ significantly between these two groups. CONCLUSION: These findings suggest that the BDNF polymorphism does not play a major role in the susceptibility to TD in schizophrenic patients.     

Interaction between catechol-O-methyltransferase (COMT) Val108/158Met and brain-derived neurotrophic factor (BDNF) Val66Met polymorphisms in age at onset and clinical symptoms in schizophrenia

Summary. Catechol-O-methyltransferase (COMT) gene is one of the candidate genes for schizophrenia because it codes an enzyme that participates in the metabolic inactivation of dopamine and noradrenaline and a limiting factor of dopamine metabolism in the prefrontal cortex. COMT gene lies on chromosome 22q11.2, which has been associated with schizophrenia susceptibility. A single-nucleotide polymorphism of COMT gene at position 108/158 results in an amino acid substitution from valine (val) to methionine (met), which modifies its enzymatic activity and may change the brain morphology and expressional behaviors. On the other hand, brain-derived neurotrophic factor (BDNF) plays a critical role in the development of mesolimbic dopaminergic- related systems. BDNF also contains a functional single-nucleotide polymorphism at codon 66 (Val66Met) of its prodomain and this polymorphism is responsible for schizophrenia susceptibility. In this study, we first investigated the relationship between COMT Val108/158Met polymorphism and age at onset as well as levels of clinical symptoms in 158 of chronic schizophrenia inpatients and then we investigated the gene-by-gene interaction between COMT Val108/158Met polymorphism and BDNF Val66Met polymorphism with age- and sex-matched control subjects (n = 318). We concluded that the COMT Val108/158Met polymorphism was not related to either the onset at age or the levels of clinical symptoms after long-term antipsychotic treatment in schizophrenia.     

Association of the paternally transmitted copy of common Valine allele of the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene with susceptibility to ADHD

Attention deficit hyperactivity disorder (ADHD) is a common, highly heritable, neurodevelopmental disorder with onset in early childhood. Genes involved in neuronal development and growth are, thus, important etiological candidates and brain-derived neurotrophic factor (BDNF), has been hypothesized to play a role in the pathogenesis of ADHD. BDNF is a member of the neurotrophin family and is involved in the survival and differentiation of dopaminergic neurons in the developing brain (of relevance because drugs that block the dopamine transporter can be effective therapeutically). The common Val66Met functional polymorphism in the human BDNF gene (rs 6265) was genotyped in a collaborative family-based sample of 341 white UK or Irish ADHD probands and their parents. We found evidence for preferential transmission of the valine (G) allele of BDNF (odds ratio, OR=1.6, P=0.02) with a strong paternal effect (paternal transmissions: OR=3.2, P=0.0005; maternal transmissions: OR=1.00; P=1.00). Our findings support the hypothesis that BDNF is involved in the pathogenesis of ADHD. The transmission difference between parents raises the possibility that an epigenetic process may be involved.     

Reduced hippocampal volumes in healthy carriers of brain-derived neurotrophic factor Val66Met polymorphism: Meta-analysis

Abstract

Objectives. Converging evidence suggests that the brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism affects brain structure. Yet the majority of studies have shown no effect of this polymorphism on hippocampal volumes, perhaps due to small effect size. Methods. We performed a meta-analysis of studies investigating the association between Val66Met BDNF polymorphism and hippocampal volumes in healthy subjects by combining standardized differences between means (SDM) from individual studies using random effect models. Results. Data from 399 healthy subjects (255 Val-BDNF homozygotes and 144 carriers of at least one Met-BDNF allele) in seven studies were meta-analysed. Both the left and right hippocampi were significantly larger in Val-BDNF homozygotes than in carriers of at least one Met-BDNF allele (SDM = 0.41, 95% Confidence Interval = 0.20; 0.62, z = 3.86, P = 0.0001; SDM = 0.41; 95% Confidence Interval = 0.20; 0.61, z = 3.81, P = 0.0001, respectively), with no evidence of publication bias. Conclusions. Healthy carriers of BDNF gene Val66Met polymorphism show bilateral hippocampal volume reduction. The effect size was small, but the same direction of effect was seen in all meta-analyzed studies. The association with the BDNF gene Val66Met polymorphism makes hippocampal volume a potential candidate for an endophenotype of disorders presenting with reduced hippocampal volumes.     

Association of brain-derived neurotrophic factor (BDNF) Val66Met polymorphism with Parkinson's disease in a Greek population

Brain-derived neurotrophic factor (BDNF) enhances survival of dopaminergic neurons in the substantia nigra, whereas in patients with Parkinson's disease (PD), the expression of BDNF mRNA is decreased, thus making BDNF a candidate gene for PD susceptibility. The association between BDNF Val66Met polymorphism and PD has been evaluated in several studies with controversial results. Thus, we determined the distribution of BDNF Val66Met polymorphism in 184 Greek patients with sporadic PD and 113 control participants using polymerase chain reaction-restriction fragment length polymorphism, and explored the association of the polymorphism with certain clinical parameters of the disease. Our results do not support a major role for the BDNF Val66Met polymorphism in PD in the Greek population.     

The Val66Met coding variant of the brain-derived neurotrophic factor (BDNF) gene does not contribute toward variation in the personality trait neuroticism.

BACKGROUND: The val66met variant located within the brain-derived neurotrophic factor gene (BDNF) has previously been associated with human neuroticism, a dimension of personality strongly predictive of depressive illness. METHODS: Here we report an attempt to replicate this association using three populations of extreme neuroticism scorers derived from two large English cohorts (n = 88,142 and n = 20,921). On the basis of the current literature, which indicates that an effect of BDNF may only become apparent in those individuals exposed to stress, a gene-environment interaction was also sought. RESULTS: No statistically significant effects were identified, although simulations indicated that the samples held sufficient power to detect a main effect accounting for just .75% of variation and an interaction accounting for 4% of variation. CONCLUSIONS: These data do not support the hypothesis that the val66met BDNF polymorphism contributes toward variation in the human personality trait neuroticism, at least as indexed by the Eysenck Personality Questionnaire.     

Effect of brain-derived neurotrophic factor Val66Met polymorphism and serum levels on the progression of mild cognitive impairment

Abstract

Objectives. Abnormalities in neurotrophic systems have been reported in Alzheimer's disease (AD), as shown by decreased serum brain-derived neurotrophic factor (BDNF) levels and association with BDNF genetic polymorphisms. In this study, we investigate whether these findings can be detected in patients with mild cognitive impairment (MCI), which is recognized as a high risk condition for AD. We also address the impact of these variables on the progression of cognitive deficits within the MCI-AD continuum. Methods. One hundred and sixty older adults with varying degrees of cognitive impairment (30 patients with AD, 71 with MCI, and 59 healthy controls) were longitudinally assessed for up to 60 months. Baseline serum BDNF levels were determined by sandwich ELISA, and the presence of polymorphisms of BDNF and apolipoprotein E (Val66Met and APOE*E4, respectively) was determined by allelic discrimination analysis on real time PCR. Modifications of cognitive state were ascertained for non-demented subjects. Results. Mean serum BDNF levels were reduced in patients with MCI and AD, as compared to controls (509.2±210.5; 581.9±379.4; and 777.5±467.8 pg/l respectively; P<0.001). Baseline serum BDNF levels were not associated with the progression of cognitive impairment upon follow-up in patients with MCI (progressive MCI, 750.8±463.0; stable MCI, 724.0±343.4; P=0.8), nor with the conversion to AD. Although Val66Met polymorphisms were not associated with the cross-sectional diagnoses of MCI or AD, the presence of Met-BDNF allele was associated with a higher risk of disease-progression in patients with MCI (OR=3.0 CI_95% [1.2–7.8], P=0.02). We also found a significant interaction between the APOE*E4 and Met-BDNF allele increasing the risk of progression of cognitive impairment in MCI patients (OR=4.4 CI_95% [1.6–12.1], P=0.004). Conclusion. Decreased neurotrophic support, as indicated by a reduced systemic availability of BDNF, may play role in the neurodegenerative processes that underlie the continuum from MCI to AD. The presence of Met-BDNF allele, particularly in association with APOE*E4, may predict a worse cognitive outcome in patients with MCI.     

BDNF Val66Met基因多态性的研究进展

1982年德国生物学家Barde和同事从猪脑中分离出脑源性神经营养因子(Brain-derived Neuro-trophic Factor,BDNF),发现其在促进神经细胞的增殖、再生、突触重塑及调节神经递质的释放等方面发挥着重要的作用.人类的BDNF编码基因位于11号染色体短臂11p13.该编码基因由11个外显子组成,可编码一个前体肽.成熟的BDNF蛋白即由该肽经过蛋白酶水解形成[1].人类BDNF的氨基酸编码序列与神经生长因子(Nerve Growth Factor,NGF)序列具有惊人的相似性,因此BDNF被归属为神经生长因子家族(Nerve Growth Factor Family,NGFf)成员[2].     

Brain-derived neurotrophic factor Val66Met polymorphism and dexamethasone/CRH test results in depressed patients

Data suggest that both neurotrophic and hypothalamic-pituitary-adrenocortical (HPA) systems are involved in the pathophysiology of depression. The aim of the present study was to investigate whether the non-conservative brain-derived neurotrophic factor (BDNF) Val66Met polymorphism has an impact on HPA axis activity in depressed patients. At admission, the dexamethasone/CRH (DEX/CRH) test was performed in 187 drug-free in-patients suffering from major depression or depressed state of bipolar disorder (DSM-IV criteria). Moreover, genotyping of BDNF Val66Met polymorphism was carried out using the fluorescence resonance energy transfer method (FRET). Homozygous carriers of the Met/Met genotype showed a significantly higher HPA axis activity during the DEX/CRH test than patients carrying the Val/Val or Val/Met genotype (ACTH, cortisol). Our results further contribute to the hypothesized association between HPA axis dysregulation and reduced neuroplasticity in depression and are consistent with the assumption that BDNF is a stress-responsive intercellular messenger modifying HPA axis activity.     

共患学习障碍的注意缺陷多动障碍儿童脑源性神经营养因子与5-羟色胺的关联性研究

目的 探讨脑源性神经营养因子(BDNF)与血清5-羟色胺(5-HT)在伴学习障碍(LD)的注意缺陷多动障碍(ADHD)患儿中的作用及关系. 方法 选择河南省精神卫生中心门诊及病房自2011年1月至2011年10月收治的ADHD患儿40例,其中伴LD患儿15例,不伴LD患儿25例,选择同期健康体检儿童25例作为正常对照组,比较3组受试者血清BDNF、5-HT的水平并分析ADHD伴LD组患儿血清BDNF及5-HT水平的相关性. 结果 ADHD伴LD组、ADHD不伴LD组及正常对照组BDNF水平依次降低,差异有统计学意义(P＜0.05);与ADHD伴LD组比较,ADHD不伴LD组及正常对照组5-HT水平升高,差异有统计学意义(P＜0.05);ADHD伴LD组患儿血清BDNF、5-HT水平呈负相关关系(r=-0.084,P=0.004). 结论 伴LD的ADHD患儿中存在BDNF及5-HT异常,二者可能相互作用共同参与ADHD的病理过程.     

Association analysis of brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism in schizophrenia and bipolar affective disorder.

Brain-derived neurotrophic factor (BDNF) has been implicated in the pathogenesis of schizophrenia and bipolar disorder. A functional polymorphism Val66Met of BDNF gene was studied in patients with schizophrenia (n=336), bipolar affective disorder (n=352) and healthy controls (n=375). Consensus diagnosis by at least two psychiatrists, according to DSM-IV and ICD-10 criteria, was made for each patient using a structured clinical interview for DSM-IV Axis I disorders (SCID). No association was found between the studied polymorphism and schizophrenia or bipolar affective disorder either for genotype or allele distribution (for genotype: p=0.210 in schizophrenia, p=0.400 in bipolar disorder; for alleles: p=0.260 in schizophrenia, p=0.406 in bipolar disorder). Results were also not significant when analysed by gender. For males genotype distribution and allele frequency were (respectively): p=0.480 and p=0.312 in schizophrenia, p=0.819 and p=0.673 in bipolar affective disorder. Genotype distribution and allele frequency observed in the female group were: p=0.258 for genotypes, p=0.482 for alleles in schizophrenia; p=0.432 for genotypes, p=0.464 for alleles in bipolar affective disorder. A subgroup of schizophrenic (n=62) and bipolar affective patients (n=28) with early age at onset (18 years or younger) was analysed (p=0.328 for genotypes, p=0.253 for alleles in schizophrenia; p=0.032 for genotypes, p=0.858 for alleles in bipolar affective disorder).     

Brain-Derived Neurotrophic Factor Gene Val66Met Polymorphism Is a Risk Factor for Attention-Deficit Hyperactivity Disorder in a Turkish Sample

ObjectiveAttention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that negatively affects different areas of life. We aimed to evaluate the associations between the Val66Met polymorphism of brain-derived neurotrophic factor (BDNF) and ADHD and to assess the effect of the BDNF polymorphism on the neurocognitive profile and clinical symptomatology in ADHD.MethodsTwo hundred one ADHD cases and 99 typically developing subjects (TD) between the ages of 8 and 15 years were involved in the study. All subjects were evaluated using a complete neuropsychological battery, Child Behavior Checklist, the Teacher''s Report Form (TRF) and the DSM-IV Disruptive Behavior Disorders Rating Scale-teacher and parent forms.ResultsThe GG genotype was significantly more frequent in the patients with ADHD than in the TD controls, and the GG genotype was also significantly more frequent in the ADHD-combined (ADHD-C) subtype patients than in the TDs. However, there were no significant associations of the BDNF polymorphism with the ADHD subtypes or neurocognitive profiles of the patients. The teacher-assessed hyperactivity and inattention symptom count and the total score were higher, and the appropriately behaving subtest score of the TRF was lower in the GG genotypes than in the GA and AA (i.e., the A-containing) genotypes.ConclusionWe found a positive association between the BDNF gene Val66Met polymorphism and ADHD, and this association was observed specifically in the ADHD-C subtype and not the ADHD-predominantly inattentive subtype. Our findings support that the Val66Met polymorphism of BDNF gene might be involved in the pathogenesis of ADHD. Furthermore Val66Met polymorphism of BDNF gene may be more closely associated with hyperactivity rather than inattention.     

脑源性神经营养因子基因多态性与精神分裂症的关联研究

目的:探讨脑源性神经营养因子(BDNF)基因多态性与精神分裂症的关联性.方法:以111例精神分裂症发作期患者与362例正常对照为研究对象,通过TagMan探针单核苷酸多态性(SNP)基因分型技术对BDNF基因及基因上游10 kb区域的标签SNPs rs6265和rs11030101进行基因分型,比较各组间基因型、等位基...