白肉灵芝水提物对脑缺血大鼠海马神经元的保护作用

试验旨在探讨白肉灵芝水提物（Ganoderma leucocontextum aqueous extracts,GLAE）对脑缺血后海马神经元的保护作用及机制。将50只健康大鼠分为对照组、模型组、GLAE低（0.05 mg/（g·BW））、中（0.1 mg/（g·BW））、高（0.2 mg/（g·BW））剂量组。利用双侧颈总动脉夹闭法建立大鼠脑缺血模型,GLAE组灌胃不同剂量的GLAE干预,对照组和模型组灌胃同体积的生理盐水,连续2周。用跳台试验方法检测记忆获得、记忆巩固和记忆再现障碍大鼠的学习记忆能力,HE染色观察大鼠海马组织的病理形态的变化,比色法检测海马组织一氧化氮合酶（nitric oxide synthase,NOS）活性和一氧化氮（nitric oxide,NO）含量,Western blotting和实时荧光定量PCR法分别检测海马组织生长相关蛋白-43（growth associated protein-43,GAP-43）和脑源性神经生长因子（brain derived neurotrophic factor,BDNF）的水平。结果显示,与对照组相比,模型组大鼠跳台试验的逃避潜伏期显著缩短、电击次数显著增加（P<0.05）;海马神经元细胞出现明显核固缩、排列松散紊乱等退行性改变,细胞数量显著减少（P<0.05）;海马组织NOS活性和NO含量均显著降低（P<0.05）;大鼠海马组织GAP-43蛋白表达量显著升高（P<0.05）;海马组织BDNF mRNA表达量显著下调（P<0.05）。与模型组相比,GLAE干预后,大鼠逃避潜伏期均显著延长、电击次数均显著减少（P<0.05）;GLAE高剂量组大鼠CA1区和齿状回锥体神经元细胞形态明显改善,神经元数量显著增加（P<0.05）;GLAE低剂量组对NOS活性影响不明显（P>0.05）,显著增加NO含量（P<0.05）,GLAE中、高剂量组NOS活性和NO含量均显著升高（P<0.05）;GLAE低、中、高剂量组海马组织GAP-43蛋白表达量均显著增加（P<0.05）;GLAE低、中、高剂量组海马组织BDNF mRNA表达量均显著增加（P<0.05）。以上结果表明,GLAE可通过提高NOS活性和NO水平、促进海马神经发生和功能恢复对脑缺血后海马神经元损伤有一定的保护作用,从而改善大鼠认知功能,0.2 mg/g GLAE效果最好。     

大鼠BDNF基因真核表达载体的构建

从23日龄大鼠脑组织中抽提总RNA,应用RT-PCR技术扩增脑源性神经营养因子(BDNF)基因片段,将此片段克隆入T载体,酶切反应鉴定。然后双酶切BDNF-T载体和空质粒pEGFP(N1),将所获目的片段和线性空载体用T4 DNA连接酶连接,构建真核表达载体pEGFP(N1)-BDNF,并进行酶切反应鉴定及DNA测序。序列测定的结果与GenBank比较,所克隆的BDNF基因从起始密码子ATG到终止密码子TAG全长共750 bp序列完全相同。结果表明成功构建真核表达载体pEGFP(N1)-BDNF,为进一步研究BDNF基因表达,神经系统疾病治疗和生物制药奠定基础。     

Hyperbaric oxygen therapy activates CREB/BDNF signaling pathway to reduce synaptic damage in hippocampal neurons of Alzheimer disease mice

AIM To investigate the effect of hyperbaric oxygen (HBO) on synaptic damage of hippocampal neurons in APP/PS1 transgenic (TG) mice and its possible mechanism. METHODS The 6-month-old male APP/PS1 TG mice were randomly divided into TG group, HBO group and cAMP response element binding protein (CREB) inhibitor H89 group, with 10 mice in each group. Ten male wild-type (WT) C57BL/6 mice of the same age were used as negative control group (WT group). The mice in HBO and H89 groups were treated with HBO for 6 cycles, while the mice in WT group and TG group were not treated. The learning and memory abilities were observed by Morris water maze. The nesting ability of the mice was detected by nesting test. The Nissl bodies in hippocampal neurons were observed by Nissl staining. The mRNA expression of CREB and brain-derived neurotrophic factor (BDNF) in hippocampus was detected by real-time PCR. The protein levels of synapsin (SYN), postsynaptic density protein 95 (PSD95), growth-associated protein 43 (GAP43), CREB, phosphorylated CREB (p-CREB) and BDNF in the hippocampus were determined by Western blot. RESULTS Compared with WT group, the learning and memory abilities of the mice in TG group were signilficantly reduced (P<0.05). In addition, the nesting score, the number of Nissl bodies in the hippocampal neurons, the mRNA expression of CREB and BDNF, and the protein levels of SYN, PSD95, GAP43, p-CREB and BDNF were also decreased significantly (P<0.05). Compared with TG group, the learning and memory abilities of the mice in HBO group were improved (P<0.05). Meanwhile, the nesting scores of the mice were significantly increased (P<0.05), the neurons in the hippocampus were arranged neatly, and the number of Nissl bodies, the relative mRNA expression of CREB and BDNF,and the protein levels of SYN, PSD95, GAP43, p-CREB and BDNF were also increased significantly (P<0.05). Compared with HBO group, the mice in H89 group had poor learning and memory abilities, lowered nesting scores and decreased number of Nissl bodies. Futhermore, the relative mRNA expression of CREB and BDNF, and the protein levels of SYN, PSD95, GAP43, p-CREB and BDNF were also decreased significantly (P<0.05). CONCLUSION HBO improves the learning and memory abilities of APP/PS1 TG mice, and its mechanism may be related to activating the CREB/BDNF signaling pathway to reduce synaptic damage of hippocampal neurons in mice.     

橄榄苦苷对小鼠脑缺血再灌注损伤的保护作用

本研究为探讨橄榄苦苷联合依达拉奉对小鼠脑缺血再灌注损伤的影响及其保护作用机制,将50只健康小鼠分成假手术组、模型组、橄榄苦苷组、依达拉奉组、橄榄苦苷＋依达拉奉组。利用双侧颈总动脉结扎方法制备慢性脑缺血再灌注小鼠模型,造模后药物处理21 d,用放射免疫法检测脑组织肿瘤坏死因子α（TNF-α）、白细胞介素1（IL-1β）、白细胞介素10（IL-10）含量,用比色法检测脑组织ATP酶、髓过氧化物酶（MPO）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性及丙二醛（MDA）含量,用免疫组织化学法及Western blotting法检测大脑皮层脑源性神经营养因子（BDNF）的表达。结果显示,与假手术组相比,模型组脑组织TNF-α、IL-1β、MDA的含量及MPO活性极显著升高（P<0.01）,IL-10、ATP酶、SOD、CAT水平均极显著降低（P<0.01）,大脑皮层BDNF表达水平极显著降低（P<0.01）。与模型组比较,橄榄苦苷或依达拉奉治疗后,脑组织TNF-α、IL-1β、MDA的含量及MPO活性极显著降低（P<0.01）,IL-10、ATP酶、SOD、CAT水平均极显著升高（P<0.01）,大脑皮层BDNF表达水平极显著升高（P<0.01）。橄榄苦苷和依达拉奉联合治疗后脑缺血再灌注损伤的恢复更加显著。综上所述,橄榄苦苷和依达拉奉对小鼠脑缺血再灌注损伤具有明显的保护作用,其机制可能与改善神经功能、减少自由基损伤和抑制炎症因子水平有关,橄榄苦苷和依达拉奉联合治疗可以发挥更好的作用。     

Curcumin attenuates the effects of transport stress on serum cortisol concentration, hippocampal NO production, and BDNF expression in the pig

Curcumin, the active component of curcuma longa, has been reported to be effective in alleviating chronic stress-induced disorders in rodents by modulating neuroprotection and neuroendocrine functions of the central nervous system, especially hippocampus. However, it is unclear whether curcumin can attenuate the subacute stress response induced by 2 h of road transport in the pig. Therefore, the present study was designed to identify the changes of serum cortisol concentration, hippocampal nitric oxide (NO) production, and related gene expression in response to 2 h of transport and to explore whether curcumin treatment (8 mg/kg, p.o.) for 21 d before transport may alleviate the stress-induced responses in the hippocampus of pigs. We found that 2 h of transport elevated serum cortisol concentration (P < 0.01), increased hippocampal NO content, and reduced brain-derived neurotrophic factor (BDNF) mRNA expression in pigs not treated with curcumin, whereas these stress responses were all reversed or attenuated in curcumin-treated pigs. In addition, the stress-induced increase in the expression of constitutive nitric oxide synthase (cNOS) and enzyme activities of total NOS, cNOS, and inducible NOS (iNOS) was also reversed or attenuated in curcumin-treated pigs. However, neither transport nor curcumin caused significant alterations in hippocampal expression of 11β-hydroxysteroid dehydrogenase type 1 and type 2 (11β-HSD1 and 2), glucocorticoid and mineralocorticoid receptors (GR and MR), or pro-/anti-apoptotic molecules (Bax-α and Bcl-xL). These results suggest that curcumin can alleviate subacute stress response in pigs through its neuroprotective effects on modulating hippocampal NO production and BDNF expression.     

Spirulina Microalgae and Brain Health: A Scoping Review of Experimental and Clinical Evidence

Spirulina microalgae contain a plethora of nutrient and non-nutrient molecules providing brain health benefits. Numerous in vivo evidence has provided support for the brain health potential of spirulina, highlighting antioxidant, anti-inflammatory, and neuroprotective mechanisms. Preliminary clinical studies have also suggested that spirulina can help to reduce mental fatigue, protect the vascular wall of brain vessels from endothelial damage and regulate internal pressure, thus contributing to the prevention and/or mitigating of cerebrovascular conditions. Furthermore, the use of spirulina in malnourished children appears to ameliorate motor, language, and cognitive skills, suggesting a reinforcing role in developmental mechanisms. Evidence of the central effect of spirulina on appetite regulation has also been shown. This review aims to understand the applicative potential of spirulina microalgae in the prevention and mitigation of brain disorders, highlighting the nutritional value of this “superfood”, and providing the current knowledge on relevant molecular mechanisms in the brain associated with its dietary introduction.     

水牛脑源性神经营养因子基因克隆、序列分析及其在不同组织中的表达研究

本研究克隆了水牛脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)基因序列,并运用生物信息学方法对序列的同源性、生物进化树、蛋白的理化性质及二、三级结构等进行了分析预测,同时利用QRT-PCR方法研究了BDNF mRNA在胎儿水牛及成年水牛不同组织中的表达情况。结果表明,应用RT-PCR技术克隆获得了长800bp水牛BDNF基因序列,其中编码区全长753bp,编码250个氨基酸。多重序列比对分析显示,水牛BDNF核苷酸序列与黄牛、野猪、犬、人、马、小鼠同源性分别为99%、94%、93%、90%、90%和89%;生物进化树分析显示,BDNF基因在不同物种进化过程中具有较高的保守性;BDNF蛋白理论分子质量28 173.36u,等电点9.12;蛋白二级结构由多个α-螺旋、β-折叠、T-转角及无规则卷曲组成,三级结构由多个α-螺旋、3对反向平行的β-折叠结构等构成活性中心(即NGF功能结构域)。QRT-PCR结果显示,BDNF mRNA在胎儿水牛及成年水牛的心脏、肺脏、肾脏、大脑、肌肉、卵巢、睾丸组织中都有表达,且成年水牛的表达量高于胎儿水牛。     

Protective Effects of Oleuropein on Cerebral Ischemia-reperfusion Injury in Mice

To explore the protection role and mechanism of oleuropein and edaravone on cerebral ischemia-reperfusion injury in mice.Fifty mice were divided into five groups:Sham operation group,model group,oleuropein group,edaravone group,oleuropein+edaravone group.The model was established by ligating common carotid artery.After modeling,the mice were administrated with oleuropein,edaravone and oleuropein+edaravone for 21 d,respectively.The contents of TNF-α,IL-1β and IL-10 were detected by radioimmunoassay.The activities of ATPase,MPO,SOD and CAT and MDA content were measured by spectrophotometry.The changes of BDNF expression in cerebral cortex were analyzed by immunohistochemistry and Western blotting.The results showed that compared to sham operation group,the contents of TNF-α,IL-1β,MDA and MPO activity in model group were extremely significantly increased (P<0.01),and the levels of IL-10,ATPase,SOD and CAT in model group were extremely significantly reduced (P<0.01),the BDNF expression in model group was extremely significantly decreased (P<0.01).Compared to model group,the contents of TNF-α,IL-1β,MDA and MPO activity in oleuropein,edaravone,and oleuropein+edaravone groups were extremely significantly decreased (P<0.01),the levels of IL-10,ATPase,SOD and CAT were extremely significantly increased (P<0.01),the BDNF expression was extremely significantly up-regulated in cerebral cortex of treatment group (P<0.01).Furthermore,the oleuropein+edaravone combined administration showed a better effect.The treatments of oleuropein and edaravone had a protective effect on cerebral ischemia reperfusion injury,the mechanisms of which might depend on improving neurological function,reducing free radical lesion and inhibiting inflammatory response.Moreover,the oleuropein+edaravone combination therapy might have an additive effect.