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...     

Antidepressant-like effects of paeoniflorin on post-stroke depression in a rat model

ABSTRACT

Background: Post-stroke depression (PSD) is one of the most prevalent emotional disorders after stroke and often results in poor outcomes. However, the underlying physiopathologic mechanism and effective treatment of PSD remain poorly elucidated.

Objective: To investigate whether paeoniflorin has antidepressant-like activity in a rat model of PSD.

Methods: Rats were randomly divided into four groups: sham-operated control (Sham), PSD, paeoniflorin (with PSD) and fluoxetine group(with PSD). PSD was developed by the right middle cerebral artery occlusion followed 21 days chronic unpredictable mild stress combined (CUMS) with raised alone. Tests of sucrose preference and open field were used to assess the depression-like behavior. Neurological function was evaluated by neurological deficit score and beam balance test. Expression of phosphorylated CREB (p-CREB) and brain-derived neurotrophic factor (BDNF) in the CA1 region of the hippocampal complex was evaluated by western blot and immunofluorescence.

Results: Te depressive-like behaviors markedly improved after paeoniflorin and fluoxetine treatment. Furthermore, paeoniflorin treatment significantly increased BDNF and p-CREB expression in the CA1 region.

Conclusions: Observed results suggested that paeoniflorin could ameliorate the symptoms and improve the functional capability of PSD rats, similar to the effect of fluoxetine.

Abbreviations: PSD: post-stroke depression; CUMS: chronic unpredictable mild stress stimulation; MCAO: middle cerebral artery occlusion; OFT: open field test; SPT: sucrose preference test, NDS: neurological deficit score, BBT: beam balance test; BDNF: brain-derived neurotrophic factor protein; p-CREB: phosphorylated Cyclic-AMP responsive element binding protein     

盐酸戊乙奎醚对吗啡依赖大鼠相关脑区p-CREB及M5受体的影响

目的 观察盐酸戊乙奎醚(PHC)对吗啡依赖大鼠相关脑区p-CREB及M5受体的影响.方法 将雄性SD大鼠30只随机分为对照组(NS组)、吗啡依赖组(MOR组)和PHC治疗组(PHC组),每组10只.连续7d交替皮下注射吗啡(10 mg/kg,每天1次)或生理盐水,诱导大鼠的吗啡依赖位置偏爱效应.实验第8天停用吗啡,NS组与MOR组腹腔注射等体积的生理盐水;PHC治疗组则腹腔注射PHC 1.5 mg/kg.30 min后各组大鼠行CPP测试.Western blot法检测大鼠中脑腹侧被盖区、伏隔核、前额叶皮层p-CREB的蛋白表达;实时定量聚合酶链反应(PCR)检测大鼠中脑腹侧被盖区、伏隔核、前额叶皮层M5受体的mRNA水平.结果 (1)PHC治疗组的灰区停留时间与MOR组比较显著缩短[(422±103)s 比(622 ±97)s,P＜0.01].(2)MOR组中脑腹侧被盖区、伏隔核、前额叶皮层组织中p-CREB水平显著高于NS组[(0.93±0.06)、(0.67±0.10)、(0.89±0.14)比(0.31±0.02)、(0.20±0.01)、(0.40±0.07),P＜0.01];与MOR组比较,PHC组中脑腹侧被盖区、伏隔核、前额叶皮层组织中p-CREB水平显著降低[(0.65±0.05)、(0.58±0.04)、(0.67±0.09),P＜0.05或P＜0.01].(3)MOR组中脑腹侧被盖区、伏隔核、前额叶皮层组织中M5受体的mRNA含量较NS组显著增高(1.80、0.22、0.50比1.00、0.13、0.32,P＜0.01);与MOR组比较,PHC 组能明显降低中脑腹侧被盖区、伏隔核、前额叶皮层组织中M5的mRNA含量(0.65、0.09、0.07,P＜0.01).结论 PHC能抑制吗啡依赖大鼠条件性位置偏爱的表达,该效应可能与PHC下调中脑腹侧被盖区、伏隔核、前额叶皮层组织中M5受体,抑制p-CREB表达有关.     

神经病理性疼痛大鼠脊髓磷酸化CREB表达的研究

目的研究坐骨神经慢性挤压伤(chronicconstrictioninjury,CCI)后不同时点大鼠脊髓磷酸化cAMP反应成分结合蛋白(p-CREB)含量的变化。方法32只160~180g雄性SD大鼠中,8只为正常对照,其余24只做成CCI模型。用VonFrey细丝测定大鼠后爪触诱发痛的变化,并于术后7、14和30d处死(n=8),取L4~L6脊髓用以免疫印迹(Westernblot)方法测定p-CREB的表达量。结果CCI大鼠结扎侧在术后7、14d出现明显的机械感觉异常(P<0·01),30d后基本消失。与正常大鼠相比,CCI大鼠p-CREB含量在术后7、14d均出现明显升高(P<0·01),术后30d恢复到正常水平。结论CCI大鼠疼痛模型中脊髓p-CREB含量明显增高,并且随疼痛症状消失恢复到正常水平。提示脊髓p-CREB在慢性神经性疼痛中发病机制中有一定的作用。     

吗啡对原代培养大鼠皮质神经元神经甾体水平的影响

目的探讨吗啡慢性处理对大鼠大脑皮质神经元合成释放神经甾体水平的影响及其机制。方法建立原代培养大鼠大脑皮质神经元吗啡依赖样模型,固相萃取结合高效液相色谱-质谱联用法测定细胞培养液中神经甾体水平;免疫印迹法检测神经元中p-CREB水平。结果与盐水对照组相比,吗啡(1μmol.L-1)处理使PREG和DS的水平降低(P<0.01);μ-受体激动剂DAMGO使PREG、DS和PS水平下降,AP水平增高;与吗啡单独处理组相比,μ-阿片受体拮抗剂CTAP与吗啡联合处理使PREG增加(P<0.01)。与盐水对照组相比,吗啡或DAMGO慢性处理均可增加神经元内p-CREB的水平(P<0.01);与吗啡处理组相比,CTAP抑制吗啡诱导的p-CREB的增加。结论μ-阿片受体参与了介导吗啡慢性处理对皮质神经元神经甾体合成释放的影响;神经元内p-CREB水平的变化反映了吗啡引起的神经元适应性改变,提示神经甾体水平的变化可能与吗啡依赖有关。     

链脲佐菌素对大鼠海马p-CREB表达的影响及APP5肽类似物165的治疗作用

目的探讨链脲佐菌素(streptozotocin,STZ)对大鼠海马磷酸化环磷腺苷反应成分结合蛋白(phosphatedcylinc AMP response element binding protein,p-CREB)表达的影响以及APP5肽类似物165的治疗作用。方法将42只Wistar大鼠随机分为对照组、模型组和APP5肽类似物165治疗组。将STZ溶解于人工脑脊液,新鲜配制成浓度为25mg/mL,分别于第1、3天按体重3mg/kg行双侧脑室注射。APP5肽治疗组于3周后开始行APP5肽类似物165灌胃,连续4周。对照组和模型组则以等量生理盐水灌胃。4周后取脑组织海马行免疫组织化学染色和Western-blotting检测p-CREB。结果模型组p-CREB阳性神经细胞数(137.44±22.62)较对照组(27.33±9.91)明显增多(P<0.05),胞质淡染;APP5肽治疗组p-CREB阳性神经元数目(29.78±10.72)与对照组比较差异无统计学意义(P>0.05)。模型组海马p-CREB表达多于对照组和APP5肽治疗组,APP5肽治疗组与对照组接近。结论脑室注射小剂量STZ可使海马p-CREB阳性神经元表达增多,而APP5肽类似物165可使p-CREB阳性神经元表达恢复至正常水平。     

Pharmacological evidence of cholinergic involvement in adult hippocampal neurogenesis in rats

In adult hippocampus, neural progenitor cells give rise to neurons throughout life, and the neurogenesis is modulated by various intrinsic and extrinsic factors. Recent reports showed that lesion of septal cholinergic nuclei projecting to hippocampus suppressed the survival of newborn cells in the dentate gyrus (DG) of hippocampus. Here, we studied whether pharmacological treatment to activate or inhibit the cholinergic system could modulate adult hippocampal neurogenesis. 5'-Bromo-2'-deoxyuridine (BrdU) was injected to label dividing cells before the drug treatment. Immunohistochemical analysis was performed in normal rats chronically treated with an acetylcholinesterase inhibitor donepezil or a muscarinic acetylcholine receptor blocker scopolamine for four weeks. Donepezil increased, but scopolamine decreased, the number of BrdU-positive cells in the DG as compared with the control. Neither drug altered the percentage of BrdU-positive cells that were also positive for a neuronal marker neuronal nuclei, nor net population of proliferative cells labeled with proliferating cell nuclear antigen. We also found that donepezil enhanced, and scopolamine suppressed, the expression level of phosphorylated cAMP response element binding protein (CREB), which is related to cell survival, in the DG. These results indicate that donepezil enhances and scopolamine suppresses the survival of newborn cells in the DG via CREB signaling without affecting neural progenitor cell proliferation and the neuronal differentiation. This is the first evidence that pharmacological manipulation of the cholinergic system can modulate adult hippocampal neurogenesis.     

电针对海洛因成瘾大鼠学习记忆及海马CREB表达的影响

目的：探讨电针对海洛因成瘾大鼠学习记忆的影响及作用机制。方法130只Wistar大鼠随机分为对照组、海洛因成瘾组（简称成瘾组）和海洛因成瘾后作电针治疗组（简称电针组）。进行跳台实验测试大鼠学习记忆能力,并用免疫组化方法检测鼠脑海马环磷酸腺苷反应元件结合蛋白（CREB）和磷酸化CREP（P—CREB）的表达。结果：成瘾组大鼠学习记忆下降（P％0．01）,电针组大鼠学习记忆有所改善（P〈0．01）;成瘾组大鼠海马CREB、P—CREB表达较对照组增高（P〈0．05）,电针组更高（P〈0．01）。结论：电针治疗可在一定程度上对抗海洛因成瘾大鼠所致的学习记忆下降,其机制可能与海马内CREB、P—CREB表达变化有关;CREB、PCREB参与学习记忆及海洛因成瘾的形成。     

电针对慢性痛大鼠痛感觉和情绪成分相关杏仁核内μ-阿片受体等蛋白表达的影响

目的:观察电针对慢性神经痛负性情绪(NA)大鼠痛感觉和情绪成分相关杏仁核内μ-阿片受体(MOR)等蛋白表达变化的影响,探讨电针镇痛的作用机制。方法:雄性Wistar大鼠随机分为正常组、模型组、电针组、麻醉电针组,每组8只。结扎大鼠左侧坐骨神经结合足底反复电刺激造成慢性神经痛NA模型。电针双侧"足三里"-"阳陵泉",每日1次,共7d。测量大鼠双侧足底热痛阈(缩足反应潜伏期,PWL),计算其差值(PWLD)及在条件控制箱停留时间;采用免疫荧光、免疫印迹技术检测中央杏仁核及右侧杏仁核内MOR、环磷酸腺苷反应元件结合蛋白(p-CREB)、α-氨基羟甲基异噁唑丙酸受体亚单位GluR 1(GluA 1)、磷酸化细胞外信号调节激酶1和2(p-ERK 1/2)的表达。结果:与正常组比较,模型组PWLD显著增加(P0.001),条件箱停留时间显著减少(P0.001);电针7d后,电针组或麻醉电针组PWLD明显降低(P0.05),电针组在条件箱停留时间显著增加(P0.05),而麻醉电针组条件箱停留时间无明显变化(P0.05),说明电针干预提高痛阈、减轻NA,麻醉电针组则抑制了电针改善NA的作用。此外,与正常组比较,模型组杏仁核MOR蛋白表达显著增加(P0.05),GluA 1、p-ERK 2、p-CREB蛋白表达显著降低(均P0.05)。电针7d后,电针组该4个蛋白,麻醉电针组MOR、p-ERK 2及p-CREB蛋白表达均显著上调(P0.001,P0.01,P0.05);与电针组比,麻醉电针组GluA 1表达明显降低(P0.05),而MOR、pERK 2、p-CREB的表达差异无统计学意义(P0.05)。结论:重复电针可明显改善慢性痛大鼠痛感觉成分和情感成分,其改善痛情感成分的效应可能与上调大鼠杏仁核GluA 1蛋白表达相关,而杏仁核内MOR、ERK 2、CREB参与痛的感觉和情感成分的作用有待进一步探讨。     

Calcitonin gene-related peptide enhances CREB phosphorylation and attenuates tau protein phosphorylation in rat brain during focal cerebral ischemia/reperfusion

Calcitonin gene-related peptide (CGRP) is a potent vasodilator and immune cell modulator. Exogenous CGRP could increase the cerebral blood flow significantly and protect the ischemic neurons, but its mechanism is not entirely clear. The effect of CGRP on the expressions of CREB and tau in the ipsilateral parietal cortex were detected in focal cerebral ischemia/reperfusion model. The expression of CREB mRNA decreased in ischemia/reperfusion group (I/R group) compared with that of the sham operation group, and it got highest in CGRP group. CREB expression was lesser in I/R group than sham group, but it became more in CGRP group than I/R group. Phospho-CREB became more in I/R group, and it got most in CGRP group in the cortex. No significant difference was observed on Tau mRNA expression in all the groups. The level of tau hyperphosphorylation at Ser199/202 site and total tau in rat parietal cortex were significantly higher in I/R group than sham group. CGRP significantly inhibited tau hyperphosphorylation and the level of total tau also significantly reduced in CGRP group than that in I/R group. CGRP can upregulate the expression of CREB and phospho-CREB and attenuate the level of tau hyperphosphorylation in the ischemic neurons of the parietal cortex during focal cerebral ischemia/reperfusion. Phosphorylating CREB and inhibiting tau phosphorylation are probably involved in the mechanism of protective effect of CGRP to ischemic neurons.