抑郁症大鼠模型海马区及前额叶组织BDNF因子、Trkb蛋白表达的实验研究

目的:观察抑郁症大鼠模型脑组织不同部位神经营养因子水平的变化及抗抑郁药物使用后改变。方法:将成年SD大鼠30只分为正常对照组、模型对照组、药物干预组,每组10只,雌雄对半;正常组正常养殖,模型组采用慢性不可预知应激结合孤养方式制备抑郁模型大鼠4周。药物干预组采用模型组造模过程4周后给予药物(氟西汀)给入,自实验开始之后每周观察大鼠体重、糖水消耗、旷场实验指标的变化,最后采用荧光定量PCR法观察大鼠脑部BDNF因子及Trkb的表达。结果:与正常对照组大鼠相比,模型组大鼠体重增加缓慢、糖水消耗减少、旷场试验各项指标较正常组间差异具有统计学意义;荧光定量PCR结果显示:模型组较对照组各脑区BDNF及Trkb受体表达减少,药物干预组脑区BDNF及Trkb受体表达显著高于模型对照组。结论:脑部BDNF因子及Trkb的表达在抑郁症发生与治疗中有所改变。     

Non-viral transfer of BDNF and uPA stimulates peripheral nerve regeneration

Peripheral nerves connect brain and spinal cord with the extremities and inner organs, and nerves injury can lead the disability and social exclusion. Growth factors and other natural stimulators of regeneration processes look very promising as future medicines. In our study, we tested the influence of genetic constructions that contain genes of brain-derived neurotrophic factor and urokinase plasminogen activator on nerve's structure and function after traumatic and ischemic injuries. Injection of pVax1-hBDNF and pVax1-muPA after traumatic injury led to better restoration of nerve's structure and function compared to similar parameters of control group mice. In ischemic injury model pVax1-hBDNF and pVax1-muPA slowed and reduced the damage progression and stimulated nerve regeneration as well. However, the treatment with pVax1-muPA was less effective after the traumatic injury. As we chose a non-viral method of gene delivery during our study the optimal conditions of plasmid intramuscular delivery were also determined.     

逍遥丸对皮质酮诱导小鼠抑郁样行为的干预机制※

目的:观察逍遥丸对皮质酮诱导小鼠抑郁样行为的干预作用,并探讨其分子机制。方法:将50只ICR雄性小鼠,随机分为5组:正常组、皮质酮模型组、阳性对照氟西汀组(20 mg/kg)、低剂量逍遥丸(200 mg/kg)组、高剂量逍遥丸组(600 mg/kg),通过皮下注射皮质酮诱导小鼠抑郁模型。持续35天后,采用糖水偏好实验和强迫游泳实验评价动物抑郁样行为;采用ELISA方法测小鼠血清中皮质酮含量及小鼠海马组织中脑源性神经营养因子(BDNF)的含量。结果:皮质酮可以降低糖水偏好值、增加小鼠强迫游泳的不动时间,而逍遥丸可以显著提高糖水偏好值、减少小鼠不动时间;长期注射皮质酮可增加血清皮质酮水平,降低海马组织中BDNF含量,而逍遥丸可以降低小鼠血清中皮质酮的含量并且能够提高海马组织中BDNF含量。结论:逍遥丸可以有效降低小鼠血清中皮质酮的含量并增加小鼠海马中BDNF含量,改善神经营养系统,产生抗抑郁样作用。     

The role of BDNF methylation and Val66Met in amygdala reactivity during emotion processing

Epigenetic alterations of the brain‐derived neurotrophic factor (BDNF) gene have been associated with psychiatric disorders in humans and with differences in amygdala BDNF mRNA levels in rodents. This human study aimed to investigate the relationship between the functional BDNF‐Val⁶⁶Met polymorphism, its surrounding DNA methylation in BDNF exon IX, amygdala reactivity to emotional faces, and personality traits. Healthy controls (HC, n = 189) underwent functional MRI during an emotional face‐matching task. Harm avoidance, novelty seeking and reward dependence were measured using the Tridimensional Personality Questionnaire (TPQ). Individual BDNF methylation profiles were ascertained and associated with several BDNF single nucleotide polymorphisms surrounding the BDNF‐Val⁶⁶Met, amygdala reactivity, novelty seeking and harm avoidance. Higher BDNF methylation was associated with higher amygdala reactivity (x = 34, y = 0, z = ?26, t₍₁₆₆₎ = 3.00, TFCE = 42.39, p_(FWE) = .045), whereby the BDNF‐Val⁶⁶Met genotype per se did not show any significant association with brain function. Furthermore, novelty seeking was negatively associated with BDNF methylation (r = ?.19, p = .015) and amygdala reactivity (r = ?.17, p = .028), while harm avoidance showed a trend for a positive association with BDNF methylation (r = .14, p = .066). The study provides first insights into the relationship among BDNF methylation, BDNF genotype, amygdala reactivity and personality traits in humans, highlighting the multidimensional relations among genetics, epigenetics, and neuronal functions. The present study suggests a possible involvement of epigenetic BDNF modifications in psychiatric disorders and related brain functions, whereby high BDNF methylation might reduce BDNF mRNA expression and upregulate amygdala reactivity.     

神经生长因子和脑源性神经营养因子在脑胶质瘤内的表达

目的研究NGF(NeverGrowth Factor,神经生长因子)、BDNF(BrainDerivedNeurotrophicFactor,脑源性神经营养因子)在脑胶质瘤内的表达,探讨它们与肿瘤病理分级、实体肿瘤部位的关系,以及它们在肿瘤发生过程中的作用。方法通过免疫组织化学SP染色方法检测70例胶质瘤和5例正常脑组织中NGF和BDNF的表达。结果NGF和BDNF阳性细胞表达率明显高于正常脑组织内的表达,有统计学意义(P<0.05);在不同病理级别胶质瘤之间阳性细胞表达率也有差异,分别是:I级16.56%,11.24%;II级32.45%,18.23%;III级40.91%,21.44%;IV级24.71%,15.39%,正常脑组织内的表达率为7.06%,5.98%,且有统计学意义(P<0.05)。NGF和BDNF阳性细胞表达率在不同部位胶质瘤内各不相同,分别为:颞叶42.57%,24.19%;顶叶35.62%,20.09%;小脑28.67%,16.17%;额叶21.45%,12.42%,差异有显著性(P<0.05)。结论NGF和BDNF在脑胶质瘤内高表达;NGF和BDNF阳性细胞表达与胶质瘤的病理级别、肿瘤部位有关;NGF和BDNF可能参与了胶质瘤的发生。     

阴茎勃起神经再生模型和机制的研究

探明神经性勃起功能障碍(NED)的分子生物学机制以期对该类疾病进行神经调控干预,是男科学研究的当务之急。本文回顾了急性神经损伤、前列腺癌、糖尿病和帕金森病所致的NED的研究进展。通过利用大鼠阴茎勃起神经的盆腔大神经节(MPG),在体外构建一个三维培养体系来研究各种生长因子和细胞信号通路对神经再生的影响。体外结果表明脑源性神经生长因子(BDNF)通过JAK/STAT信号通路可显著促进NED的恢复,并在体内证实了该效应。因此,通过调控JAK/STAT信号通路来达到神经调控干预措施预防治疗神经性勃起功能障碍成为可能。     

A neurotrophic model for stress-related mood disorders.

There is a growing body of evidence demonstrating that stress decreases the expression of brain-derived neurotrophic factor (BDNF) in limbic structures that control mood and that antidepressant treatment reverses or blocks the effects of stress. Decreased levels of BDNF, as well as other neurotrophic factors, could contribute to the atrophy of certain limbic structures, including the hippocampus and prefrontal cortex that has been observed in depressed subjects. Conversely, the neurotrophic actions of antidepressants could reverse neuronal atrophy and cell loss and thereby contribute to the therapeutic actions of these treatments. This review provides a critical examination of the neurotrophic hypothesis of depression that has evolved from this work, including analysis of preclinical cellular (adult neurogenesis) and behavioral models of depression and antidepressant actions, as well as clinical neuroimaging and postmortem studies. Although there are some limitations, the results of these studies are consistent with the hypothesis that decreased expression of BDNF and possibly other growth factors contributes to depression and that upregulation of BDNF plays a role in the actions of antidepressant treatment.     

BDNF在挤压伤脊髓背角表达的时相变化

目的:了解BDNF在挤压伤脊髓背角的表达变化.方法:用本室建立的成年SD大鼠(T13-L1)脊髓挤压伤模型,分别于术后24h,7h,21h处死动物并设正常对照组,取L3节段脊髓制作20μm厚冰冻连续切片,用抗BDNF抗体按ABC法行免疫组织化学染色.观察挤压伤位点尾侧端(L3)背角BDNF免疫反应物的分布,记录其免疫反应强度,计数其免疫阳性神经元和胶质细胞数.结果:BDNF的阳性反应物主要分布于正常脊髓背角的神经元和胶质细胞.术后24h,BDNF的免疫反应强度较正常者明显增强并维持至7h(P<0.05),术后21h又进一步增强并高过术后24h者水平(P<0.01).BDNF的免疫阳性细胞数则从术后24h至21h进行性增加(P<0.01).结论:脊髓挤压伤后早期,BDNF在损伤位点尾侧端背角的表达明显增加,提示BDNF在脊髓挤压伤的早期反应中可能起作用.     

BDNF基因修饰神经干细胞移植后大鼠脊髓损伤移植处的基因表达变化

目的：了解脑源性神经营养因子（Brain-derived neurotrophic factor,BDNF）基因修饰神经干细胞移植到大鼠脊髓损伤处后的基因表达变化，为脊髓损伤修复提供基础研究资料。方法：大鼠随机分为4组：正常对照组，手术对照组，神经干细胞（Neural stem cells,NSCs）移植组，BDNF－NSCs移植组，各组分4个时相点（7d、1个月、2个月、3个月），利用细胞移植、X-gal组化、免疫组化、原位杂交等方法，观察了移植处细胞的标记基因（LacZ）表达和BDNF、胶质纤维酸性蛋白（GFAP）、神经丝－200（NF－200）的表达。结果：大鼠脊髓损伤移植处细胞中，有标记基因阳性细胞，BDNF强烈表达，尤其是BDNF－NSCs移植组的移植后1周和1个月时。各组各时相点均有GFAP和NF－200免疫反应阳性细胞和纤维。结论：BDNF基因修饰神经干细胞能在脊髓损伤移植处存活，强烈表达BDNF，BDNF基因修饰神经干细胞可以作为脊髓损伤修复的移植材料。     

Brain-derived neurotrophic factor Val66Met and psychiatric disorders: meta-analysis of case-control studies confirm association to substance-related disorders, eating disorders, and schizophrenia.

BACKGROUND: There is an increasing recognition that the pathophysiology of mental disorders could be the result of deregulation of synaptic plasticity with alterations of neurotrophins. The valine (Val)66-to-methionine (Met) variant, located in the pro brain-derived neurotrophic factor (BDNF) sequence, has been extensively studied through linkage and association approaches in several psychiatric disorders. METHODS: We performed a meta-analysis restricted to individual case-control studies in different categories of mental disorders and BDNF Val66Met polymorphism. We included data from 39 case-control studies encompassing psychiatric phenotypes: eating disorders, substance-related disorders, mood disorders, and schizophrenia, among others. RESULTS: The association of Val66Met was confined to three diagnoses: substance-related disorders, eating disorders, and schizophrenia. The Val/Met and the Met/Met genotypes increase the risk for eating disorders up to 33%, while these same genotypes confer a 21% protective effect in substance-related disorders. The homozygous carriers Met/Met showed a 19% increased risk of schizophrenia with respect to the heterozygous state. CONCLUSIONS: The study confirms the association of Val66Met to substance-related disorders, eating disorders, and schizophrenia. It remains to be determined if other variants in tight linkage disequilibrium with Val66Met could configure an extended functional haplotype that would explain observed discrepancies in risk estimations across studies.