Expression and Role of the BDNF Receptor-TrkB in Rat Adrenal Gland under Acute Immobilization Stress

We reported that plasma brain-derived neurotrophic factor (BDNF) was maximally elevated following a 60-min period of acute immobilization stress and that salivary glands were the main source of plasma BDNF under this stress condition. However, the expression pattern of the BDNF receptor, Tyrosine receptor kinase B (TrkB), under this condition has yet to be determined. We therefore investigated the effect of this stress on the expression level of TrkB in various rat organs using real-time PCR. No significant differences were found between controls and 60 min-stressed rats with respect to TrkB level in various organs. Only adrenal glands showed significantly increased TrkB mRNA levels after 60 min of stress. TrkB mRNA and protein were observed to localize in chromaffin cells. In addition, we investigated whether BDNF-TrkB interaction influences the release of stress hormones from PC12 cells, derived from chromaffin cells. Truncated receptor, TrkB-T1, was identified in PC12 cells using RT-PCR. Exposure of PC12 cells to BDNF induced the release of catecholamine. This BDNF-evoked release was totally blocked by administration of the K252a in which an inhibitor of Trk receptors. Thus, BDNF-TrkB interactions may modulate catecholamine release from adrenal chromaffin cells under acute stress conditions.     

酒精处理影响青春期大鼠海马CA1区BDNF和TrkB的表达

为探讨青春期饮酒致学习记忆力下降的可能机制,本研究观察了青春期大鼠酒精处理后海马CA1区脑源性神经营养因子(BDNF)和酪氨酸激酶受体B(TrkB)的表达变化。实验选用30d龄SD雄性大鼠,以25%的酒精按8g/kg/d灌胃,连续灌7d,动物分别在停酒后0d,3d,7d和14d处死;对照组以等量生理盐水代替酒精按同样方法处理。用免疫组织化学方法(ABC法)检测海马CA1区BDNF和TrkB的表达,Motic3.2图像分析系统测定免疫阳性产物的平均灰度值。结果显示,BDNF的表达在停酒后0d和14d,实验组与相应对照组相比差异无显著性(P>0.05);3d显著升高(P<0.05);7d明显下降(P<0.05)。TrkB的表达在停酒后0d,3d,7d,实验组与相应对照组相比差异无显著性(P>0.05);14d显著下降(P<0.05)。以上结果提示,BDNF表达的相对不足可能是青春期饮酒致学习记忆力持续性下降的原因之一。     

Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence

Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory), at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG), and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4). Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions.     

三种中药复方对慢性束缚应激大鼠皮层和海马BDNF、TrkB的影响

目的： 研究慢性束缚应激时大鼠皮层和海马BDNF、TrkB的变化以及逍遥散、四君子汤、金匮肾气丸3种中药复方对其影响。方法： 用特制束缚架连续束缚7 d与21 d，每天3 h的方法制作大鼠束缚应激模型，用免疫组织化学方法结合图像分析检测大鼠皮层和海马CA1区BDNF、TrkB的变化。结果： 连续束缚7 d、21 d后大鼠大脑额叶皮层与海马CA1区的BDNF均显著低于正常对照组（P<0.05, P<0.01）,尤以21 d模型组明显。连续束缚7 d、21 d后大鼠大脑额叶皮层与海马CA1区的TrkB分别显著高于正常对照组（P<0.05，P<0.01）。3个中药复方均能升高皮层BDNF的积分吸光度和海马中BDNF的阳性细胞数；逍遥散能降低海马和皮层中的TrkB阳性细胞数和海马TrkB的积分吸光度；四君子汤和金匮肾气丸能降低皮层TrkB的积分吸光度；金匮肾气丸能降低皮层TrkB的阳性细胞数；逍遥散升高皮层和海马中BDNF的作用比四君子汤和金匮肾气丸明显。结论： 皮层和海马CA1区BDNF下降参与慢性应激的变化，疏肝、健脾、补肾的中药复方均有一定程度的逆转作用，但以逍遥散的作用较强，优于四君子汤和金匮肾气丸。     

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。     

ERK与TrkB在大鼠星形胶质细胞的表达(英文)

本文探讨了ERK(extracellular signal-regulated kinase)和TrkB(tyrosine kinase receptor B)在星形胶质细胞的表达。生后2~3d的SD大鼠在无菌条件下取脑,以胰蛋白酶消化制备细胞悬液。用GFAP免疫细胞化学方法鉴定星形细胞,通过免疫细胞化学与蛋白印迹方法检测TrkB,ERK1和ERK2在星形胶质细胞的表达。结果显示,星形胶质细胞的纯度达95%以上,在星形胶质细胞的细胞质观察到ERK1免疫阳性染色;TrkB免疫阳性染色位于细胞膜、细胞质和细胞核。化学发光法检测后ERK1和ERK2两条蛋白条带清晰可见。以上结果提示大鼠大脑皮质星形胶质细胞表达TrkB,ERK1和ERK2,TrKB/ERK通路可能与星形胶质细胞增殖有关。     

脑卒中后抑郁大鼠额前皮质小胶质细胞表达BDNF及其受体TrkB

目的:探讨脑卒中后抑郁(post-stroke depression,PSD)大鼠额前皮质小胶质细胞表达脑源性神经营养因子(BDNF)及其高亲和力受体酪氨酸激酶受体B(TrkB)的情况,了解小胶质细胞在PSD发病机制中的作用。方法:将健康成年SD大鼠随机分为正常组、抑郁组、脑卒中组和PSD组,每组10只。卒中组采用线栓法建立局灶性脑缺血模型;抑郁组采用慢性不可预见的中等应激刺激(CUMS)结合孤养法建立大鼠慢性应激抑郁模型;PSD组采用线栓法建立局灶性脑缺血模型后,再加以CUMS及孤养法建立PSD大鼠模型。于造模后第29 d(4周后)及第57 d(8周后)应用免疫荧光双标染色法检测各组大鼠额前皮质小胶质细胞表达BDNF及其高亲和力受体TrkB的情况。结果:造模后第29 d PSD组额前皮质OX42(小胶质细胞标记物)与BDNF免疫荧光双标阳性细胞及与TrkB免疫荧光双标阳性细胞平均光密度值均最小,正常对照组均最大。单因素方差分析结果显示:PSD组与各对照组(抑郁组、脑卒中组、正常组)相比,差异均有统计学意义(P0.05);抑郁组及脑卒中组均较正常对照组小(P0.05)。造模后第57 d PSD组额前皮质OX42与BDNF免疫荧光双标阳性细胞及OX42与TrkB免疫荧光双标阳性细胞平均光密度值均为最小,正常对照组均最大。PSD组与各对照组(抑郁组、脑卒中组、正常组)相比,差异均有统计学意义(P0.05);抑郁组也较正常对照组小(P0.05);脑卒中组也较正常对照组小(P0.05);抑郁组与脑卒中组相比,差异无统计学意义(P0.05)。结论:PSD大鼠额前皮质小胶质细胞表达BDNF及TrkB,其平均光密度值在PSD急性期及慢性期均明显减少,可能与PSD发病机制相关。小胶质细胞可能通过减少BDNF及其高亲和力受体TrkB的表达在PSD发病过程中发挥了重要的作用。     

急、慢性应激对大鼠海马BDNF表达的时序性影响

 摘要：目的 观察急性应激和重复低强度强迫游泳应激后大鼠海马BDNF及BNDF mRNA在不同时间点的动态表达;观察慢性应激条件下动物行为改变。方法 采用反转录－聚合酶链反应（RT-PCR）方法,观察急性和慢性应激对大鼠海马BDNF mRNA的动态表达的影响;采用Western bloting方法检测海马BDNF 蛋白表达量的变化。结果 急性应激导致动物海马BDNF mRNA及其产物表达增加,3小时后表达逐渐降低,与对照组比较差异具有显著性;慢性应激后BDNF蛋白表达呈降低趋势,并在多时点显著低于急性应激组 (p<0.05)。结论 急性应激显著增强大鼠海马BDNF表达;慢性应激组大鼠BNDF mRNA表达存在一定适应现象,且多时点表达量显著低于急性应激组。     

右美托咪定对抑郁症大鼠行为及海马BDNF和mTOR蛋白表达的影响

目的:观察右美托咪定(DEX)对抑郁症大鼠行为及海马脑源性神经营养因子(BDNF)和哺乳动物雷帕霉素靶蛋白(mTOR)表达的影响并探讨其机制。方法:实验设5组,即假手术(sham)组、抑郁症模型(model)组及DEX(2.5、5和10μg/kg)组,每组12只大鼠。抑郁症动物模型采用卵巢摘除加慢性不可预知性温和应激法制备。DEX各剂量组大鼠连续腹腔注射给药21 d。强迫游泳及旷场实验观察大鼠行为变化。Morris水迷宫实验评价大鼠空间学习和记忆能力。海马神经元病理变化采用尼氏染色法检测。大鼠海马白细胞介素1β(IL-1β)、IL-6和肿瘤坏死因子α(TNF-α)mRNA的表达水平采用RT-qPCR法检测。Western blot检测海马IL-1β、IL-6、TNF-α和BDNF蛋白表达水平及蛋白激酶A(PKA)、cAMP反应元件结合蛋白(CREB)、原肌球蛋白相关激酶B(TrkB)、磷脂酰肌醇3-激酶(PI3K)、蛋白激酶B(Akt)和mTOR蛋白的磷酸化水平。结果:与model组相比,DEX各剂量组大鼠强迫游泳不动时间明显降低,自发活动明显增加,逃避潜伏期明显降低,穿越平台次数明显...     

蛇菰多糖降低实验性肝损伤大鼠肝脏BDNF和TrkB的表达

目的蛇菰多糖(BPS)对D-半乳糖(D-gal)所致实验性肝损伤大鼠的肝功能及肝组织内BDNF、TrkB蛋白和凋亡相关蛋白表达的影响。方法将大鼠随机分为对照组(control),D-gal组(皮下注射D-半乳糖200 mg/kg),BPS低(D-gal+BPS-L)、中(D-gal+BPS-M)、高(D-gal+BPS-H)剂量组,分别每天灌胃50、100和200 mg/kg BPS,共6周。心脏取血检测血清谷丙转氨酶(ALT)和谷草转氨酶(AST)水平;HE染色法观察肝组织形态;免疫组织化学染色检测BDNF和TrkB的定位;Western blot检测BDNF、TrkB、Bcl-2、caspase-3和Bax蛋白表达;ELISA测定肝组织内丙醛(MDA)含量和超氧化物歧化酶(SOD)活性。结果与对照组相比,D-gal组肝细胞水肿、点状坏死;血清ALT和AST水平升高(P<0.05),SOD活性降低、MDA含量升高(P<0.05);Bax、caspase-3、BDNF、TrkB表达增加(P<0.05),Bcl-2表达降低(P<0.05);与D-gal组相比,BP...     

Association between BDNF Polymorphism and Depressive Symptoms in Patients Newly Diagnosed with Type 2 Diabetes Mellitus

PurposeLittle is known about the relationship between brain-derived neurotrophic factor (BDNF) gene polymorphisms and psychiatric symptoms in diabetes patients. We investigated the effects of BDNF Val/66/Met polymorphism, glucose status, psychological susceptibility, and resilience on anxiety and depression symptoms in patients newly diagnosed with type 2 diabetes mellitus (T2DM).Materials and MethodsWe examined biochemical factors and BDNF polymorphism in 89 patients who were newly diagnosed with T2DM. Psychiatric symptoms were investigated with the Hospital Anxiety and Depression Scale (HADS), and the Connor-Davidson Resilience Scale (CD-RISC) and Impact of Event Scale (IES) were used to assess psychological resilience and susceptibility to psychological distress, respectively. Logistic regression analyses were conducted to investigate factors associated with psychiatric symptoms.ResultsWe determined that 62 patients (70%) were Met-carriers. No significant differences were found between the Val/Val homozygous and Met-carrier groups regarding age, sex, body mass index, and clinical factors related to glycemic control and lipid profiles. HADS-anxiety and HADS-depression scores and IES factor scores were higher in the Met-carrier than the Val/Val homozygous group. Hemoglobin A1c (HbA1c) level was significantly inversely correlated with the severity of depressive symptoms. Resilience factors showed significant inverse correlations, and IES factors showed positive correlations with depressive symptom severity. In the logistic regression analysis model, depressive symptoms were significantly associated with HbA1c and BDNF polymorphism, whereas only the hyperarousal factor of the IES scale was associated with anxiety.ConclusionDepressive symptoms are associated with the presence of the Met-carriers and lower HbA1c in patients newly diagnosed with T2DM.     

The brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is not significantly correlated to Transient Global Amnesia: Preliminary results of an on-going study in Brescia Province,Italy

Transient Global Amnesia (TGA) is a well defined pure amnesic clinical syndrome characterized by acute loss of memory in middle aged people. The aetiology of TGA is still unknown but clinical and neuroimaging studies support a hippocampi involvement, and some reports suggested a possible common genetic background in cases of familial TGA. A single nucleotide polymorphism (SNP) in the Brain-derived neurotrophic factor (BDNF) gene that causes a valine to methionine substitution at codon 66 (Val66Met) has been demonstrated to affect human memory and hippocampal function in the development and maintenance of adult neurons. Aim of this study was to evaluate the role of BDNF Val66Met polymorphism on TGA risk and all TGA clinical features. Ninety-eight TGA patients and 93 age-matched controls were enrolled in the study. Each patient underwent clinical and neurological examination, routine blood examination, EEG, Jugular vein valve (JVI) competence assessment, and neuroimaging study. TGA characteristics were carefully recorded. The distribution of BDNF genotype did not differ in TGA patients compared to controls (BDNF GG: 58.2% vs 55.9%, GA: 33.7% vs 36.6%, AA: 8.1% vs 7.5%, P = .91) as well as allele frequency (BDNF G, TGA vs CON: 75.0% vs 74.2, P = .47). No significant differences in age at onset, disease duration and recurrence or the presence of predisposing factors between TGA patients carrying BDNF AA, BDNF GA and BDNF GG genotype were found. This study, that firstly looked at genetic background in TGA, did not show a significant correlation between the BDNF Val66Met polymorphism and age of onset, risk factors, duration or recurrence of TGA.     

脑源性神经营养因子预处理后急性高眼压下大鼠视网膜TrkB的表达变化

目的：检测脑源性神经营养因子(BDNF)干预后大鼠视网膜TrkB的表达变化。为受损后视网膜节细胞的保护及外源性BDNF的应用提供一定的理论基础。方法：大鼠左眼分为急性眼高压及BDNF预处理组。使左眼眼压升高至闪光视网膜电图b波消失的临界眼压并维持60 min,分别存活1～14 d后处死,冰冻切片行尼氏染色及TrkB的免疫组织化学。结果：急性高眼压组各时间点节细胞层细胞数目均显著少于BDNF预处理组;1、3 d时TrkB的表达明显增加,7、14 d时则明显减少;BDNF预处理组在存活1、3 d时TrkB的表达明显增加,7 d时则下降至正常对照组水平,14 d时再次明显增加。结论：急性高眼压后大鼠视网膜内TrkB的表达存在时空变化,TrkB表达的上调提示视网膜对BDNF的需求增加。     

哮喘小鼠C_7～T_5节段脊髓后角BDNF及其受体TrkB的表达研究

目的探讨在哮喘发病中,脑源性神经营养因子(BDNF)及其高亲和力受体酪氨酸激酶B(TrkB)在哮喘小鼠C7～T5节段脊髓后角内的表达变化。方法BALB/c小鼠20只,按随机数字表法均分为正常对照组和哮喘组,利用AniRes2005肺功能仪测小鼠气道阻力、免疫荧光方法和Western blot方法检测各组小鼠C7～T5节段脊髓后角内BDNF及其高亲和力受体TrkB的表达变化。结果哮喘组小鼠吸气阻力和呼气阻力明显高于正常组(P<0.01),哮喘模型建立成功。免疫荧光结果显示哮喘组C7～T5节段脊髓后角内BDNF及TrkB阳性产物的平均光密度值(MOD)显著高于正常对照组(P<0.01),Western blot方法检测也得到了相同的结果。结论哮喘小鼠C7～T5节段脊髓后角内BDNF及TrkB的表达升高。     

脑室注射BDNF对抑郁症大鼠海马神经元前体细胞微管相关蛋白Doublecortin表达的影响

目的 探讨脑源性神经营养因子(brain-drived neurotrophic factor,BDNF)对抑郁症大鼠海马神经元前体细胞微管相关蛋白Doublecortin(DCX)表达的影响,为BDNF如何影响神经元前体细胞的增殖、迁移提供实验依据.方法 成功建立抑郁症大鼠模型后,向脑室注射0.5 μg BDNF,取脑组织行冰冻切片.采用免疫组织化学和免疫荧光技术观察DCX阳性细胞表达情况及表达部位.结果 相对于未注射BDNF的抑郁症大鼠,注射组大鼠海马区域DCX阳性细胞数明显增多,且与未注射组存在明显差异(P＜0.05).结论 BDNF可能通过调控抑郁症大鼠海马神经元前体细胞微管相关蛋白DCX的表达,从而影响抑郁症时神经元前体细胞的分化和迁移.     

电针对新生大鼠缺血缺氧后脑组织ChAT和BDNF表达的影响

目的　探讨电针治疗缺血缺氧性脑病的远期疗效及可能机制。方法　 4 2只出生 7d的Wistar大鼠 ,随机分为 3组 :假手术对照组、缺血缺氧组、缺血缺氧后电针治疗组 ,常规饲养 2 2d后 ,取左侧脑组织切片进行尼氏染色、ChAT和BDNF免疫组织化学染色。结果　电针可明显改善缺血缺氧后脑组织神经元内尼氏体脱失现象 ,增加缺血缺氧脑组织内ChAT和BDNF阳性细胞表达。结论　电针对缺血缺氧后脑组织具神经保护效应 ,其机制可能与BDNF表达增加有关     

Neurotrophin gene expression in rat brain under the action of Semax, an analogue of ACTH 4-10

The heptapeptide Semax, an analogue of the N-terminal adrenocorticotropic hormone fragment (4-10) (ACTH(4-10)), has been shown to exert a number of neuroprotective effects. There are some investigations that connected these effects with the increase of neurotrophin gene expression under the peptide drug application in neuron cell cultures [M.I. Shadrina, O.V. Dolotov, I.A. Grivennikov, P.A. Slominsky, L.A. Andreeva, L.S. Inozemtseva, S.A. Limborska, N.F. Myasoedov, Rapid induction of neurotrophin mRNAs in rat glial cell cultures by Semax, an adrenocorticotropic hormone analogue, Neurosci. Lett. 308 (2001) (2) 115-118]. In this work, we examined the action of Semax on rapid changes of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) gene expression in vivo. Male Wistar rats were treated for 1h with Semax (50 microg/kg, single intranasal application) and neurotrophin gene expression in rat brain was analyzed by real-time polymerase chain reaction (PCR). It was revealed that an intranasal application of Semax increased the expression of both neurotrophin genes in rat hippocampus. Bdnf gene expression also increased in the brainstem and cerebellum. Ngf gene expression decreased in rat frontal cortex. Thus, Semax induces rapid, gene- and region-specific changes in neurotrophin gene expression in normal rat brain.     

The concentrations of serum,plasma and platelet BDNF are all increased by treadmill VO2max performance in healthy college men

The most current human-based studies in which brain-derived neurotrophic factor (BDNF) levels in the peripheral blood system are analyzed use it as an indicator that represents BDNF levels in the CNS. However, whether circulating BDNF (serum and plasma) is positively or inversely associated with cardiorespiratory fitness levels (VO_2max) is still controversial, and no study has done to investigate exercise effects on the concentration of BDNF stored in circulating platelets which, in fact, store a large amount of circulating BDNF. Thus, the purpose of this study was to determine the relation between VO_2max and all circulating BDNF levels (serum, plasma and platelets) in college male students (N = 18; age, 19 ± 1 years; height, 173.22 ± 7.65 cm; weight, 78.25 ± 14.25 kg; body fat percent, 13.82 ± 5.68%). Dual X-ray energy absorptiometry whole body scan was used to measure their body composition. After the overnight fast, all participants were performed VO_2max test, and their blood was collected at rest and immediately after the exercise. Our data resulted in significant increases in platelet counts and serum, plasma and platelet BDNF levels immediately after the exercise (p < 0.01). VO_2max had a significant negative correlation with serum BDNF, plasma BDNF and platelet BDNF at rest (p < 0.05) but a significant positive correlation with serum, plasma BDNF, and platelet BDNF immediately after the exercise (p < 0.01). However, our data show no correlation between VO_2max and platelet count both at rest and immediately after the exercise. In conclusion, this is the first study showing that basal BDNF levels are inversely correlated with cardiorespiratory fitness levels but that the inverse correlations turn into positive correlations with all circulating BDNF levels immediately after the exercise. Moreover, it is the first time to provide evidence that platelet BDNF levels are also positively affected by the exercise. However, future studies will be needed to investigate what tissues provide BDNF into the circulating system and to elucidate the role of circulating BDNF.     

低频电磁场对BDNF基因修饰的BMSCs增殖影响的实验研究

目的　探讨低频电磁场（LFEMF）对脑源性神经营养因子（BDNF）基因修饰的骨髓间充质干细胞（BMSCs）增殖的影响。 方法　通过同源重组的方法,用pAd-easy I腺病毒包装系统在体外构建含BDNF基因的重组腺病毒表达载体(rADBDNF);体外分离纯化SD大鼠来源的BMSCs,rADBDNF感染后,用LFEMF（50 Hz、5 mT）进行干预,连续干预3 d,并设对照组、BDNF基因修饰组、LFEMF组。在倒置相差显微镜下,对经台盼蓝染色的各组细胞进行计数;四甲基偶氮唑蓝（MTT）法对各组细胞的增殖效率进行检测;流式细胞仪分析细胞周期变化。 结果　LFEMF作用于BDNF基因修饰后的BMSCs,细胞增殖速率与对照组、BDNF基因修饰组比较,差异有统计学意义（P<0.05）,与LFEMF组相比,差异无统计学意义（P>0.05）,G2/M期细胞数量明显增多。 结论　LFEMF干预可促进BDNF基因修饰后BMSCs增殖。