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.     

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.     

葛根素对血管性痴呆大鼠海马锥体细胞和BDNF表达的影响

为了观察葛根素对血管性痴呆(VD)模型大鼠海马锥体细胞和BDNF表达的影响及其作用机制,本研究采用双侧颈总动脉缺血再灌注,同时腹腔注射硝普钠建立血管性痴呆大鼠模型,选出造模成功者随机分为模型组及葛根素干预组,各为24只,另以条件匹配的24只大鼠为假手术组。分别在造模术后15d,1、2和4个月等时间点,采用水迷宫检测大鼠学习记忆能力的变化,HE染色和免疫组化染色观察大鼠海马神经元的形态学改变及BDNF表达的变化。结果显示:(1)模型组大鼠的逃逸潜伏期(EL)均明显长于假手术组(P<0.01),葛根素干预组大鼠的EL较模型组明显缩短(P<0.05),但仍长于假手术组(P<0.05);(2)模型组大鼠海马CA1区锥体细胞数比假手术组明显减少(P<0.01),葛根素干预组2个月和4个月时点锥体细胞数较模型组明显增多(P<0.01),但仍少于假手术组(P<0.01);(3)模型组大鼠海马BDNF阳性细胞明显减少(P<0.01),除15d和1个月组DG区外,葛根素干预组大鼠海马BDNF阳性细胞数较模型组明显增多(P<0.05),但仍低于假手术组(P<0.05);(4)模型组大鼠海马BDNF阳性细胞平均吸光度值较假手术组明显降低(P<0.01),而葛根素干预组比模型组和假手术组均明显降低(P<0.05)。本研究结果提示,脑缺血再灌注后,海马BDNF阳性神经元和锥体细胞持续减少,在VD学习记忆障碍的发生和发展过程中起重要作用;葛根素对脑缺血再灌注损伤具有保护作用,其机制可能与葛根素上调BDNF的表达、减少锥体细胞的丢失有关。     

大鼠脊髓全横断后脊髓内BDNF表达的变化

为了探讨大鼠脊髓全横断后不同时相(3、7、14、21d)脊髓内BDNF表达的变化,我们采用免疫组织化学ABC法和阳性神经元计数,来检测脊髓全横断后不同时相BDNF的表达。结果发现:(1)BDNF免疫阳性产物主要位于腹角运动神经元,胞浆着色;(2)脊髓全横断后脊髓腹角BDNF阳性细胞数3d开始增多,7d达高峰(P<0.05),14d恢复正常(P>0.05)。提示BDNF表达的变化可能与脊髓可塑性有关。     

实验性抑郁症大鼠缰核和海马BDNF基因表达

目的：研究抑郁症大鼠缰核和海马BDNF基因的表达情况。方法：采用长期未预知应激刺激致大鼠抑郁症模型，运用open-field和forced swinmming test法观察大鼠行为学变化。运用免疫组化法检测缰核和海马BDNT基因的表达。结果：与正常对照组相比，抑郁症模型组大鼠海马和缰核均表现为BDNF阳性细胞数量明显减少。结论：实验性抑郁症大鼠缰核、海马BDNF基因表达水平降低。     

BDNF对急性高眼压后大鼠视网膜三种钙结合蛋白表达的影响

目的：检测外源性BDNF对急性高眼压后大鼠视网膜Parvalbumin（PV），calbindin D-28k（CB）和calretinin（CR）表达的影响。方法：72只SD大鼠随机分成高眼压组、溶媒预处理高眼压组和BDNF预处理高眼压组，每组动物左眼制作急性高眼压模型，右眼为正常对照，动物分别存活1、3、7或14d。用免疫组化方法检测视网膜PV、CB和CR的表达变化。结果：溶媒预处理高眼压组中PV、CB和CR的表达与高眼压组相似。高眼压组中，随着再灌时间延长，内层视网膜中PV和CB标记的神经元数先下调再逐渐恢复，而CR标记的神经元数逐渐减少；再灌1d时PV和CR具有从内核层到内网层的重新分布。在BDNF预处理高眼压组，PV、CB和CR标记的神经元数在再灌1d、7d和14d时与高眼压组比较无明显差异，但在再灌3d时，明显高于后者（P〈0．05）。结论：BDNF预处理对急性高眼压后视网膜的保护作用可能与其再灌早期上调钙结合蛋白的表达有关。