Induction of tyrosine kinase receptor b by retinoic acid allows brain-derived neurotrophic factor-induced amyloid precursor protein gene expression in human SH-SY5Y neuroblastoma cells

Retinoic acid (RA) is a potent regulator of morphogenesis, growth and cell differentiation. Incubation with RA causes arrest of proliferation and neurite extension in SH-SY5Y cells, a neuroblastoma cell line of human origin. In these cells, RA regulates the expression of the β-amyloid precursor protein. The retinoid increases the levels of intracellular and secreted forms of APP (amyloid precursor protein), APP–mRNA levels and the activity of the APP promoter in transient transfection studies. These responses require long periods of exposition to the ligand, thus suggesting a nondirect effect of the RA receptors on the APP gene. Also in these cells, RA induces the expression of TrkB, the tyrosine kinase receptor for brain-derived neurotrophic factor (BDNF), and 4 days of pretreatment with retinoic acid confers BDNF responsiveness to the APP promoter.     

基于BDNF/TrkB/p-CREB信号通路探讨血府逐瘀胶囊促进神经再生防治卒中后抑郁的作用及机制

目的 探讨血府逐瘀胶囊对卒中后抑郁（post-stroke depression,PSD）大鼠抑郁症状的改善作用,并基于神经再生关键通路脑源性神经营养因子（brain derived neurotrophic factor,BDNF）/酪氨酸激酶受体B(tyrosine kinase receptor,TrkB)/磷酸化环腺苷酸应答元件结合蛋白（phosphorylated cAMP response element-binding protein,p-CREB）探讨其机制。方法 采用短暂大脑中动脉梗塞（transient middle cerebral artery occlusion,tMCAO）复合慢性不可预知应激（chronic unpredictable mild stimulation,CUMS）方法复制PSD大鼠模型。大鼠随机分为假手术组、模型组及血府逐瘀低、高剂量（0.43、0.86 g/kg）组和氟西汀（1.8 mg/kg）组,每组18只。连续给予药物干预28 d,利用神经功能评分、糖水偏好实验、旷场实验、强迫游泳实验考察血府逐瘀胶囊对PSD大鼠神经功能损伤以及抑郁症...     

Effect of high-BDNF microenvironment stem cells therapy on neurogenic bladder model in rats

BackgroundThe purpose of this study is to explore the effects of high-BDNF microenvironment produced by engineered immortalized mesenchymal stem cells (imMSCs) on the neurogenic bladder (NB) and investigate underlying mechanism.MethodsMale Sprague-Dawley rat (12-week-old, weighing about 370–400 g) were purchased from a Korean company (Orient Bio Co. Seongnam, Korea) and divided into the following groups (n=32): sham control group (n=8), NB group (n=8), NB + ImMSCs group (n=8), NB + ImMSCs (BDNF) group (n=8). The major pelvic ganglion (MPG) was observed under anesthesia. Three NB groups of rats were then subjected to bilateral MPG injury. The sham control group of rats was treated with sham surgery. Cystometry were performed before the rats were sacrificed, and then MPG and bladder were collected for histochemical and Western blot analysis.ResultsMSCs treatment improves lower urinary tract function, and the NB + ImMSCs (BDNF) group is better than the NB + ImMSCs group (P<0.01). MSCs treatment accelerates recovery of injured nerve tissue, and the NB + ImMSCs (BDNF) group is better than the NB + ImMSCs group (P<0.01). In high BDNF environment, apoptosis was reduced more significantly and muscle tissue recovered more rapidly (P<0.01). High-BDNF microenvironment activates more BDNF/TrkB/CREB signaling pathways (P<0.01).ConclusionsIn a rat NB model caused by nerve injury, imMSCs have certain effects on nerve tissue repair. At the same time, it was proved that increasing the expression of BDNF which had specific effect on nerve injury repair could more effectively repair injured MPG in local microenvironment. The mechanism may be related to the activation of the BDNF/TrkB/CREB signaling pathway and the reduction of apoptosis by highly expressed BDNF.     

五味子乙素对慢性应激抑郁大鼠海马BDNF/TrkB/CREB通路的影响

目的 研究五味子乙素对慢性应激抑郁大鼠海马脑源性神经营养因子（BDNF）/酪氨酸激酶B（TrkB）/环磷腺苷效应元件结合蛋白（CREB）信号通路的影响。方法 40只SD大鼠随机选择10只作为对照组,其余大鼠采用慢性不可预知温和应激（chronic unpredictable mild stress,CUMS）结合孤养制备抑郁症模型,造模结束后随机分为3组：模型组、盐酸氟西汀（3 mg·kg^-1）组、五味子乙素（5 mg·kg^-1）组,每天ig给药1次,连续8周。分别于造模前、造模后及给药后进行旷场、悬尾、强迫游泳行为学实验;通过苏木素-伊红（HE）染色观察大鼠海马形态学改变;免疫组织化学染色（IHC）法观察大鼠海马BDNF蛋白表达;实时荧光定量PCR（qRT-PCR）法检测大鼠海马BDNF、TrkB、CREB mRNA相对表达量;Westernblotting检测大鼠海马BDNF、TrkB、CREB蛋白相对表达量。结果 与对照组比较,模型组大鼠旷场实验水平、垂直得分显著降低（P＜0.05）,悬尾不动时间和强迫游泳漂浮时间显著增加（P＜0.05）;HE染色结果显示海马神经元结构损伤,IHC结果显示海马BDNF表达明显降低;海马BDNF、TrkB、CREB mRNA及蛋白相对表达显著降低（P＜0.05）。与模型组比较,盐酸氟西汀及五味子乙素组大鼠水平、垂直得分显著增加（P＜0.05）,不动时间和漂浮时间显著减少（P＜0.05）;海马神经元结构明显复原,海马组织中BDNF染色明显增加;BDNF、TrkB、CREB mRNA和蛋白相对表达量显著增加（P＜0.05）。结论 五味子乙素可以改善慢性应激抑郁大鼠抑郁样行为、海马区神经元数量及形态,其机制可能与上调BDNF/TrkB/CREB信号通路有关。     

脑源性神经营养因子及其受体TrkB在大鼠正常面神经核的分布

目的研究脑源性神经营养因子(BDNF)及其受体TrkB在大鼠正常面神经核的分布和细胞定位.方法利用BDNF和TrkB的抗体及地高辛标记的BDNF多相寡核苷酸探针,应用免疫组化和原位杂交方法对正常成年大鼠面神经核BDNF及其受体TrkB的分布进行了研究.结果 BDNF及其mRNA在面神经核各亚核中均有分布,以腹侧核阳性细胞数为多,TrkB受体更广泛分布于面神经核各亚核的神经元胞浆中.胶质细胞中同时有BDNF及其mRNA和TrkB受体的表达.结论 BDNF对正常面神经核功能的维持起重要作用;BDNF除靶源性来源外,可能还有自分泌和旁分泌方式产生;胶质细胞除表达并向神经元提供BDNF外,本身也受BDNF的调节.     

电针联合脂肪源性干细胞移植对脑缺血/再灌注大鼠BDNF及其受体TrkB表达的影响

目的:探讨电针联合脂肪源性干细胞(ADSC)移植对大鼠缺血/再灌注损伤后海马区BDNF及其受体TrkB表达的影响。方法:成年大鼠随机分为模型组、电针组、ADSC移植组、电针+ADSC组。NSS法行神经功能损害评分,采用Western bolt法及实时荧光定量PCR检测海马区BDNF和TrkB表达。结果:电针+ADSC组海马区PKH-26标记的细胞个数高于ADSC组。与模型组比较,各治疗组NSS评分均显著降低,海马区BDNF和TrkB表达上调。其中电针+ADSC组NSS评分低于电针组和ADSC组,而BDNF和TrkB表达显著增加。结论:电针联合脂肪源性干细胞移植促进脑缺血再灌注大鼠神经功能恢复作用优于单独治疗组,其机制可能与电针上调海马区BDNF和TrkB的表达,改善干细胞生存内环境,促进移植的ADSC迁移和存活有关。     

大鼠体神经-内脏神经吻合后脑源性神经营养因子及其受体的表达变化

为了研究大鼠体神经-内脏神经吻合后脑源性神经营养因子(BDNF)及其受体酪氨酸激酶B(TrkB)在脊髓前角神经元中的表达变化,以正常大鼠为对照,运用RT-PCR技术检测大鼠体神经-内脏神经吻合术后不同时间脊髓腰4(L4)前角神经元中BDNF及TrkB mRNA的表达变化。结果显示,在正常大鼠L4前角神经元中,BDNF及TrkB的mRNA均存在一定水平的表达;体神经-内脏神经吻合术后7d、14d、1m和2m,BDNF和TrkBm RNA的表达均升高,术后7d达到高峰,14d开始下降;2m时BD-NF mRNA的表达量仍显著高于正常组(P<0.01),而TrkB mRNA的表达量到2m时虽仍高,但与正常组相比,其差异已无统计学意义(P>0.05)。上述结果表明,大鼠体神经-内脏神经反射弧建立后,脊髓L4前角神经元的内源性BDNF及其受体TrkB的表达均增高,它们可能作为保护性因子有利于受损神经元的存活和再生。     

抑郁模型大鼠海马区脑酪氨酸激酶受体B活性的变化

目的:从基因水平探讨抑郁症模型大鼠海马区脑酪氨酸激酶受体B活性(TrkB)的变化。方法:SD♂大鼠,分为正常对照组,7,14,21 d不同时程慢性应激刺激组,运用敞箱实验(Open-Field-test) 与糖水消耗量指标评定大鼠行为学改变,釆用免疫组织化学法检测TrkB蛋白表达,实时定量聚合酶链反应对TrkB进行定量分析。结果:实验前各组大鼠水平运动得分与垂直运动评分无差异,与正常对照组相比,7,14,21 d应激组水平﹑垂直运动得分均明显降低(P<0.05),各组间相比无明显差异(P>0.05)。 14,21 d应激组其糖水偏爱度持续减少(P<0.05),免疫组织化学检测结果显示,7,21 d应激组海马区TrkB表达与正常对照组明显降低(P<0.05), 7,21 d 应激组TrkB的mRNA含量亦明显低于正常组。结论:提示不同时程慢性应激刺激海马的神经再生变化与TrkB的中介机制相关联。     

白松片对抑郁模型大鼠海马脑源性神经营养因子和酪氨酸激酶B表达的影响

目的采用慢性应激复制抑郁大鼠模型,观测白松片对抑郁模型大鼠海马BDNF、TrkB表达的影响,探讨白松片的抗抑郁作用机制。方法将大鼠随机分为正常组、模型组、白松片组、氟西汀组,采用连续21d慢性轻度不可预见性应激配合孤养复制抑郁模型。运用免疫组化方法研究白松片对抑郁模型大鼠海马CA1、CA3区锥体细胞和齿状回颗粒细胞BDNF、TrkB蛋白表达的影响。结果与正常组相比,模型组大鼠海马CA1、CA3区和齿状回BDNF、TrkB免疫反应阳性神经元平均灰度值上升,分别为107. 73±3. 43、119. 40±6. 36、109. 20±4. 65;与模型组相比,白松片组大鼠海马CA1、CA3区和齿状回BDNF、TrkB免疫反应阳性神经元平均灰度值下降,分别为105. 80±3. 32、109. 87±4. 82、105. 00±2. 56。结论白松片增加抑郁模型大鼠海马BDNF、TrkB的表达,可能是其抗抑郁作用的分子机制之一。     

匹罗卡品癫痫大鼠海马TrkB受体表达与苔藓纤维突触重建的关系

目的 探讨匹罗卡品诱导慢性癫痫大鼠海马齿状颗粒细胞苔藓纤维突触重建与神经营养素受体TrkB表达的关系。方法 取匹罗卡品诱导大鼠急性癫痫持续状态及慢性自发性颞叶癫痫发作期大鼠脑片，用免疫组织化学方法检测TrkB及突触体素(P38，一种突触形成标志物)在大鼠海马的表达。结果 急性癫痫持续状态诱导颗粒细胞表达TrkB一过性增高，第2次表达高峰呈现在7～30d；P38免疫反应性在齿状回内分子层则呈进行性增加，与neo-Timm显示的异常苔藓纤维出芽相一致。结论 TrkB受体激活有助于海马齿状回苔藓纤维轴突生长及突触形成从而有利于颞叶癫痫的发生。