人酪氨酸羟化酶RNA探针制备的研究

目的 制备地高辛标记的人酪氨酸羟化酶（ｈＴＨ２）ｃＲＮＡ探针。方法 用分子克隆技术重组质粒ｐＧＥＭＴＨ２。用体外转录法制备地高辛标记ｈＴＨ２ｃＲＮＡ探地，经限制性内切酶分析，显示重组质粒含有酪氨酸羟化，酶基因片段，且插入位点正确。使用斑点杂交证实我们制备的探针是敏感可靠的。结果 杂交阳性部位呈紫蓝色，深浅与稀释度成正比。     

大鼠代谢型谷氨酸受体第5亚型基因片段的克隆

从大鼠的尾壳核组织中提取总 RNA,以 RT-PCR方法扩增出大鼠 m Glu R5 长度约 43 5 bp的 c DNA片段。将这一片段克隆到 PGEM-T载体中进行序列分析 ,结果证实所克隆的 c DNA是编码正确的大鼠 m Glu R5 的一段基因序列。克隆的这段大鼠m Glu R5 特异性基因片段可用于制作探针 ,利用原位杂交技术检测其 m RNA在正常或异常状况下的表达 ;也可制作反意 c DNA或反意 m RNA以研究 m Glu R5 在生理或病理状态下的作用 ;还可进行反意 c DNA或反意 m RNA基因治疗。总而言之 ,克隆的这段基因 ,对研究 m Glu R5 在生理及病理条件下的功能变化 ,以及对与其有关疾病的基础研究和临床应用具有重要意义     

老年小鼠大脑mGluR5表达变化的~(18)F-FPEB micro-PET显像研究

目的:联合利用18F-FPEB micro-PET显像和Western Blot的方法,观察老年小鼠大脑代谢型谷氨酸受体第5亚型(metabotropic glutamate receptor 5,m Glu R5)的变化规律。方法:分别选取2月龄(青年组)和16月龄(老年组)的雄性C57BL/6小鼠,每组6只。将两组小鼠分别行18F-FPEB micro-PET显像,对比分析两组全脑各脑区的标准摄取值(standard uptake value,SUV)。应用Western Blot的方法检测前额叶皮层和海马内m Glu R5的表达情况。应用旷场实验检测小鼠焦虑水平的变化。结果:Micro-PET结果显示:与青年鼠相比,m Glu R5在全脑多个脑区(纹状体、海马、皮层、丘脑、下丘脑、杏仁核)18F-FPEB摄取显著降低。Western Blot结果显示,老年小鼠前额叶皮层和海马内m Glu R5的表达量减少,与青年组相比有统计学差异(P0.05)。行为学检测提示,与青年组相比,老年鼠具有焦虑样的行为。结论:老年小鼠具有焦虑样的症状,可能与全脑多脑区m Glu R5的表达降低有关。     

地高辛标记的大鼠p75 RNA探针的制备和应用

目的制备用地高辛标记的神经生长因子低亲和力受体(p75)的RNA探针.研究p75在海马组织中的表达.方法设计p75引物,构建p75/pGEM-T重组质粒,分别用ApaⅠ和Sac Ⅰ进行酶切得到线性化DNA片段,以Sp6和T7聚合酶转录合成酶合成地高辛标记的(dig-)正反义RNA探针.运用点膜杂交的方法检验探针的敏感度,运用该探针,通过原位杂交分析p75在海马中的表达.结果构建了p75/pGEM-T质粒,获得高效价的正、反义dig-p75 RNA探针,应用该探针发现p75 mRNA在海马中的表达.结论成功制备了地高辛标记的p75RNA探针,为进一步研究p75在海马中发育和损伤过程中的表达打下基础.     

大鼠三叉神经脊束核尾侧亚核内代谢型谷氨酸受体的分布及谷氨酸样阳性终末的来源

本文用抗磷酸激活的谷氨酰胺酶的单克隆抗体和抗代谢型谷氨酸受体五种亚型（1，1α，2／3，5）的4种抗体，研究了三叉神经脊束核尾侧亚核和三叉神经半月节内磷酸激活的谷氨酰胺酶样免疫反应阳性神经元和终末以及五种代谢型谷氨酸受体的分布，同时结合HRP逆标技术对三叉神经脊束核尾侧亚核内磷酸激活的谷氨酰胺酶样阳性终末的来源进行了观察．发现磷酸激活的谷氨酰胺酶样阳性胞体和终末主要集中在三叉尾侧亚核的Ⅰ、Ⅱ层；半月节内仅有它的阳性胞体。半月节内HRP逆标神经元中呈磷酸激活的谷氨酰胺酶样阳性者占71．4％，这些双重反应阳性神经元占半月节内磷酸激活的谷氨酰胺酶样阳性神经元的33．2％．五种代谢型谷氨酸受体亚型中，只有5型密集地分布于三叉尾侧亚核的Ⅰ、Ⅱ层。以上结果说明：（1）三叉尾侧亚核内的磷酸激活的谷氨酰胺酶样阳性终末主要位于其浅层，它们主要来源于三叉神经的初级传入；（2）三叉尾侧亚核的代谢型谷氨酸受体五种亚型中，只有5型可能参与西口部伤害性刺激信息的传递；（3）三叉尾侧亚核内磷酸激活的谷氨酰胺酶样阳性终末的分布与代谢型谷氨酸受体5型的分布互相匹配。     

代谢型谷氨酸受体在基底神经节功能中的作用

代谢型谷氨酸受体 (m etabotropic glutamate receptors,m Glu Rs)是与 G蛋白耦联的受体 ,目前已克隆出 8种不同编码的基因 [1 - 5 ] 。根据它们氨基酸序列的同源性、信号转导的机制以及对激动剂的选择性 ,可将其分为 G- 、 G- 和 G- 三组。 G - 组包括 m Glu R1 和 m Glu R5 ;G - 组包括m Glu R2 和 m Glu R3;G- 组包括 m Glu R4、m Glu R6 、m Glu R7和 m Glu R8。目前研究表明 ,代谢型谷氨酸受体与神经突触传递的调控、突触发育的可塑性、长时程增强效应 (L TP)、长时程抑制效应 (L TD)、学习记忆、神经元退化和保护等…     

地高辛标记大鼠下丘脑生长激素释放因子cRNA探针的制备及应用

制备地高辛标记大鼠下丘脑释放因子ｃＲＮＡ探针；方法；大鼠下丘脑生长激素释放因子的重组质粒ｃＤＮＡ＝ＰＧＥＭ４经转化扩增后，用碱性裂妥法获取质粒ｃＤＮＲ并纯化。用限制性内切酶ＥＣＯＲＩ酶切，以线性ｃＤＮＡ为模板，在Ｔ７和Ｓｐ６ＲＮＡ聚合酶作用下，采用体外转录法分别合成地高辛素标记的大鼠下丘脑生激素释放因子ｃＲＮＡ和ＲＮＡ探针。     

CD147 shRNA质粒表达载体的构建及鉴定

目的构建表达细胞外基质金属蛋白酶诱导因子(CD147,EMMPRIN)基因序列特异性的短发夹样RNA(short hairpin RNA,shRNA)载体。方法根据CD147基因序列及shRNA设计原则,化学合成两段编码短发夹RNA寡核苷酸序列,将其定向克隆到pGenesil-1.1质粒表达载体中,重组构建RNAi质粒,并对重组质粒进行酶切分析。结果限制性内切酶Eco31I和SacI酶切显示设计合成的shRNA编码序列被成功插入pGenesil-1.1质粒载体中,酶切结果证实插入片段与设计序列完全一致,成功构建针对基因CD147的shRNA质粒表达载体。结论成功构建人CD147基因重组载体,为研究CD147蛋白的生物学效应和骨肉瘤的治疗提供实验依据。     

CLONING AND EXPRESSION OF cDNA FOR HUMAN LYMPHO-TOXIN

人淋巴毒素（ｈＬＴ）系由淋巴细胞经抗原或有丝分裂原活化后产生的一类细胞因子，它具有抗瘤、抗病毒活性和许多重要的免疫调节作用，是一种非常有前途的生物制剂。近年来发现的膜相关型淋巴毒素更提示ｈＬＴ可能具有尚未被揭示的免疫调节活性。因此，克隆人ＬＴｃＤＮＡ并在大肠杆菌表达重组ｈＬＴ，对于ｈＬＴ的开发利用和研究其功能都具有重要意义。本实验按照公布的ｈＬＴｃＤＮＡ序列，经计算机分析并结合实验要求设计并合成一对ＰＣＲ引物，采用ＲＴ－ＰＣＲ技术从ＰＨＡ／ＰＭＡ活化２４ｈ的人Ｔ细胞系Ｊｕｒｋａｔ细胞总ＲＮＡ扩增出一５４１ｂｐＤＮＡ片段；经α－互补筛选，质粒小量快速抽提，限制性内切酶酶切鉴定，将该片段定向克隆于ｐＵＣ１８、ｐＵＣ１９质粒载体。限制性内切酶图谱分析和Ｓａｎｇｅｒ双脱氧链终止法序列测定表明：该ＤＮＡ片段与公布的人淋巴毒素ｃＤＮＡ序列完全一致。它包括编码人淋巴毒素成熟肽的全部ｃＤＮＡ序列。再进一步将该ｃＤＮＡ片段克隆于原核表达载体ｐＢＶ２２０，经地高辛标记探针菌落原位杂交筛选，限制性内切酶酶切鉴定方向，筛选出一阳性重组子ｐＢＶ－ｈＬＴ。ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｒｎｂｌｏｔｉｎｇ分析表明：经温控诱导，该重组菌成功     

大鼠IL-10基因真核表达质粒的构建及其在BRL细胞中的表达

目的:构建大鼠IL-10基因的真核表达载体,观察其在大鼠肝细胞系BRL中的表达,比较有无受体介导的脂质体的转染效率.方法:抽提外周血单个核细胞的总RNA,通过RT-巢式PCR方法获得大鼠IL-10的全长编码序列,定向克隆到真核表达载体pcDNA3.0,并进行限制性内切酶酶切及测序鉴定.将重组质粒分别通过脂质体TransfastTM与去唾液酸糖蛋白受体介导的脂质体PEIjet-gal转入大鼠肝细胞系BRL,通过RT-PCR方法检测IL-10 mRNA的表达,比较二者的转染效率,用ELISA法检测后者分泌型IL-10的表达.结果:经酶切及测序鉴定证实,重组质粒插入片段与大鼠IL-10的全长编码序列完全相符.发现受体介导的脂质体PEIjet-gal转染效率明显高于非受体介导的脂质体TransfastTM .通过受体介导的脂质体转染,BRL细胞获得高水平的IL-10表达.结论:成功地构建pcDNA3.0-IL-10重组质粒.受体介导的脂质体对肝细胞有较高的转染活性,可能成为IL-10基因治疗肝纤维化的有效转染载体.     

Depolarization-induced slow current in cerebellar Purkinje cells does not require metabotropic glutamate receptor 1

Activation of cerebellar Purkinje cells by either brief depolarizing steps or bursts of climbing fiber synaptic activation evokes a slow inward current, which we have previously called depolarization-induced slow current or DISC. DISC is triggered by Ca influx via voltage-sensitive Ca channels and is attenuated by inhibitors of vacuolar ATPase or vesicle fusion. This led us to suggest that DISC required vesicular release of glutamate from the somatodendritic region of Purkinje cells. Furthermore, we found that DISC was attenuated by the mGluR1 antagonist 7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester (CPCCOEt), indicating that DISC required autocrine activation of metabotropic glutamate receptor 1 (mGluR1). Here, we have revisited the role of mGluR1 and found that it is, in fact, not required for DISC. CPCCOEt, but not three other specific mGluR1 antagonists (JNJ16259685, α-amino-5-carboxy-3-methyl-2-thiopheneacetic acid (3-MATIDA), Bay 36-7620), attenuated DISC, even though all four of these drugs produced near-complete blockade of current evoked by puffs of the exogenous mGluR1/5 agonist DHPG. Cerebellar slices derived from mGluR1 null mice showed substantial DISC that was still attenuated by CPCCOEt. mGluR5 is functionally similar to mGluR1, but is not expressed at high levels in cerebellar Purkinje cells. 2-Methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP), an mGluR5 antagonist, did not attenuate DISC, and DISC was still present in Purkinje cells derived from mGluR1/mGluR5 double null mice. Thus, neither mGluR1 nor mGluR5 is required for DISC in cerebellar Purkinje cells.     

Involvement of group I mGluRs in LTP induced by strong high frequency stimulation in the dentate gyrus in vitro

The involvement of group I metabotropic glutamate receptors (mGluRs) and ryanodine receptors was investigated in the induction of LTP induced either by application of one standard high frequency stimulation (HFS) or by strong multiple HFS in the medial perforant path to granule cell synapse of the rat dentate gyrus. Whilst a standard brief HFS induced LTP close to 50%, strong stimulation consisting of multiple HFS induced a much larger LTP. mGluR5 was found to be partially involved in the induction of the enhanced LTP induced by the strong HFS but not in the standard LTP induced by the brief HFS. Thus the mGluR5 antagonists LY341495 and MPEP partially inhibited the induction of LTP induced by strong HFS but did not inhibit LTP induced by a standard HFS. Ryanodine was found to partially inhibit LTP induced by the strong HFS but not to inhibit the standard LTP induced by the brief HFS, demonstrating the involvement of Ca-induced Ca release from ryanodine-sensitive Ca stores in the former. These studies demonstrate that the large amplitude LTP induced by strong stimulation involves additional mechanisms to the LTP induced by brief HFS, in particular involving activation of mGluR5 and RyR-sensitive Ca stores.     

Involvement of mGluR5 in the ethanol-induced neuropathic pain-like state in the rat

Alcohol neuropathy has been thought to involve decreased nerve function following chronic ethanol consumption. However, there is no reliably successful therapy, largely due to a lack of understanding of the central underlying mechanisms. The aim of this study was to investigate the mechanisms that contribute to the neuropathic pain-like state induced by chronic ethanol treatment in rats. Rats were chronically treated with ethanol diet (1.25-5% of ethanol) for over 70 days. Mechanical hyperalgesia was observed during ethanol consumption and even after ethanol withdrawal. Under these conditions, an immunohistochemical study showed an increase in metabotropic glutamate receptor 5 (mGluR5) immunoreactivity in the superficial spinal dorsal horn of chronic ethanol-fed rats. Furthermore, immunoblot analysis revealed that the protein level of mGluR5 was clearly increased following chronic ethanol consumption. These findings support the idea that the increased levels of mGluR5 in the spinal cord may be, at least in part, involved in the induction of ethanol-dependent neuropathic pain-like state.     

Subcellular and subsynaptic localization of group I metabotropic glutamate receptors in the nucleus accumbens of cocaine-treated rats

There is significant pharmacological and behavioral evidence that group I metabotropic glutamate receptors (mGluR1a and mGluR5) in the nucleus accumbens play an important role in the neurochemical and pathophysiological mechanisms that underlie addiction to psychostimulants. To further address this issue, we undertook a detailed ultrastructural analysis to characterize changes in the subcellular and subsynaptic localization of mGluR1a and mGluR5 in the core and shell of nucleus accumbens following acute or chronic cocaine administration in rats. After a single cocaine injection (30 mg/kg) and 45 min withdrawal, there was a significant decrease in the proportion of plasma membrane-bound mGluR1a in accumbens shell dendrites. Similarly, the proportion of plasma membrane-bound mGluR1a was decreased in large dendrites of accumbens core neurons following chronic cocaine exposure (i.e. 1-week treatment followed by 3-week withdrawal). However, neither acute nor chronic cocaine treatments induced significant change in the localization of mGluR5 in accumbens core and shell, which is in contrast with the significant reduction of plasma membrane-bound mGluR1a and mGluR5 induced by local intra-accumbens administration of the group I mGluR agonist, (RS)-3,5-dihydroxyphenylglycine (DHPG). In conclusion, these findings demonstrate that cocaine-induced glutamate imbalance has modest effects on the trafficking of group I mGluRs in the nucleus accumbens. These results provide valuable information on the neuroadaptive mechanisms of accumbens group I mGluRs in response to cocaine administration.     

Hippocampal mGluR5 predicts an occurrence of helplessness behavior after repetitive exposure to uncontrollable stress

An individual's behavior is generally based on genetic blueprint and previous experiences. A coping strategy, affected by personal interpretation of past events, can be determined by behavioral controllability of stress. In this study, we examined the relationship between the hippocampal mGluR5 expression and coping strategies to stress. Rats were exposed to stress via inescapable and unpredictable footshocks on PNDs 14 and 90. Coping strategies to stress were also measured. Hippocampal mGluR5 was found to be linked to the behavioral coping strategy, as it increased in rats that showed helplessness behavior (HL (+) group) and decreased in those that did not (HL (−) group). Also, the HL (+) group showed a lack of adaptation in a novel environment but the HL (−) group did not. The results suggest that mGluR5 has a pivotal role in the controllability-based coping strategy. Hippocampal mGluR5 could be a target molecule in the manipulation of neuropsychiatric conditions for which maladaptation is a part of behavioral consequences.     

谷氨酸钠致痫大鼠海马mGluR_5的表达变化

本研究目的为探讨谷氨酸钠 (Glu Na)诱导大鼠癫痫发作时海马 m Glu R5的表达变化。将动物随机分为正常对照组、Glu-Na致痫组及 D-AP-5 (非竞争性 NMDA受体拮抗剂 ) + Glu Na组。通过免疫组织化学方法观察了多克隆抗体抗 m Glu R5在海马各区及齿状回的免疫反应阳性细胞的变化 ,同时观察并记录各组大鼠的行为变化。结果证明 :Glu Na注射后的大鼠均出现严重的癫痫发作。正常组大鼠海马中有丰富的 m Glu R5表达 ,以齿状回颗粒细胞层和 CA1 锥体细胞层的表达为最高 ,而 Glu Na致痫组海马各区 m Glu R5表达明显下调。D-AP-5 + Glu Na组海马各区 m Glu R5表达较之 Glu Na致痫组又上调。同时观察到三个组的m Glu R5的表达主要集中在细胞膜上。结果提示 m Glu R5在癫痫发作后表达下降可能在癫痫诱导过程中具有重要作用 ,其作用机制可能为 NMDA受体依赖性的     

mGluR5 knockout mice display increased dendritic spine densities

Alterations in dendritic spine densities and morphologies have been correlated with the abnormal functioning of the synapse. Specifically the metabotropic glutamate receptor 5 (mGluR5) has been implicated in dendrogenesis and spineogenesis, since its activation triggers various signaling cascades that have been demonstrated to play roles in synaptic maturation and plasticity. Here we used the Golgi impregnation technique to analyze the dendritic spines of mGluR5(-/-) knockout mice in comparison to their heterozygote mGluR5(+/-) littermates. mGluR5(-/-) mice had elevated spine densities irrespective of spine type or location along their dendritic trees in comparison to mGluR5(+/-) animals. Such anatomical changes may underlie the hyperexcitability observed in mGluR5 total knockout mice.     

Protective effect of metabotropic glutamate mGluR5 receptor elimination in a 6-hydroxydopamine model of Parkinson's disease

Pharmacologic or genetic blockade of metabotropic glutamate mGlu5 receptors (mGluR5) has been shown to attenuate parkinsonian motor deficits and protect nigrostriatal neurons from damage in the acute MPTP model of Parkinson's disease (PD), suggesting that therapeutically targeting the mGluR5 receptor may offer a novel approach to improving motor symptoms and/or slowing neurodegeneration in PD. This study further explored the neuroprotective potential of targeting mGluR5 receptors. We examined the behavioral and neurochemical effects of receptor elimination on toxicity induced by intra-striatal application of 6-hydroxydopamine (6-OHDA), thought to represent a comparatively progressive model of PD. mGluR5 knockout (KO) mice and wild-type (WT) littermates received unilateral 6-OHDA infusions. Reflecting the imbalance expected following unilateral infusion, WT but not KO mice demonstrated predominantly ipsilateral forepaw use and robust ipsilateral amphetamine-induced rotation. Further, performance on the vertical pole descent task was profoundly impaired in WT mice, while KO mice completed the task significantly faster. Consistent with the behavioral observations, neurochemical analyses of striatal dopamine depletion showed significantly diminished severity in KO mice with only 64% of striatal dopamine lost, compared to 92% in WT mice. The absence of brain mGluR5 receptors in living KO mice was verified using positron emission tomography (PET). Our findings substantiate the key role of mGluR5 receptors in animal models of PD, strengthening the rationale for the development of mGluR5 antagonists for their neuroprotective, as well as symptomatic, benefit.