G蛋白在快速老化痴呆小鼠SAMP8脑组织中的异常表达

摘要 目的：探索在不同月龄小鼠SAMP8皮层和海马中G蛋白的异常表达情况。方法：以正常老化小鼠SAMR1为对照,利用Western-blot方法检测Gαq/11、Gαi和GαS蛋白在8月龄和18月龄小鼠SAMP8的异常表达。结果：与同月龄SAMR1相比,GαS、Gαi和Gαq蛋白在8月龄小鼠SAMP8皮层和海马组织中的表达无明显异常（p﹥0.05）,而到18月龄时,SAMP8皮层部位Gαq表达量明显低于SAMR1（p﹤0.05）,海马部位Gαq和 Gαi的表达量也明显低于SAMR1（p﹤0.05）。结论：18月龄SAMP8脑组织中Gαq和 Gαi的异常表达参与了阿尔海默病（Alzheimer’s, AD）的病理进展,并有望作为AD治疗的一个靶点。     

快速老化小鼠SAMP8研究进展

快速老化小鼠SAMP8(senescence-accelerated mouseprone/8)是一个从普通的遗传群AKR/J系小鼠中通过表型选择培育出的快速老化小鼠,表现为早期增龄性学习记忆缺陷,同时伴有Aβ淀粉样蛋白沉积,是目前公认的有效的研究阿尔采末病(Alzheimer’s disease,AD)动物模型。同属SAMR1表现为抗快速老化,具有正常的老化特性,常用作正常对照。目前SAMP8已被广泛应用于研究快速学习记忆缺陷的发病机制,以及评价抗衰老及改善学习记忆功能的药物等。     

淫羊藿苷对快速老化小鼠SAMP8脑线粒体的保护作用

目的：探讨淫羊藿苷（ICA）对快速老化小鼠SAMP8脑线粒体功能的影响。方法：将8月龄快速老化小鼠SAMP8随机分为模型组、盐酸多奈哌齐1mg/kg组、吡啦西坦200mg/kg组、ICA75mg/kg组和150mg/kg组,每组6只;8只同月龄抗快速老化小鼠SAMR1作为正常对照组。给药30d后,提取小鼠脑线粒体,测定线粒体呼吸功能、肿胀度、膜电位、活性氧（ROS）和ATP含量。结果：与SAMR1正常对照组相比,SAMP8小鼠脑线粒体呼吸功能显著降低,表现为线粒体Ⅲ态呼吸明显降低,Ⅳ态呼吸改变不明显,呼吸控制指数和磷氧比值降低（P〈0.05）;线粒体膜肿胀度增高,膜电位降低,线粒体内ROS含量增高,而ATP含量明显降低（P〈0.05）。与SAMP8模型组相比,ICA75mg/kg和150mg/kg均可明显改善SAMP8小鼠脑线粒体结构和呼吸功能（P〈0.05,P〈0.01）。结论：ICA可明显改善SAMP8小鼠脑线粒体结构和功能。     

H102对APP转基因小鼠突触相关蛋白表达的影响

目的:观察H102对APP转基因小鼠脑内超微结构-突触后致密区(PSD-95)和突触素表达的影响.方法:将16只APP转基因小鼠随机分为模型组和给药组,每组8只.并设同月龄同背景C57BL/6J小鼠为正常组.给药组侧脑室注射H102生理盐水溶液,正常组和模型组侧脑室注射等体积生理盐水,3 μL/d,注射30 d后行行为学检测即水迷宫测试,然后取出并固定脑组织,利用免疫组化及Western blot方法测定小鼠脑组织突触素、PSD-95及shank1的表达.结果:定位航行实验给药组APP转基因小鼠逃避潜伏期从第2天较模型组差异有统计学意义(P<0.05),较正常组从第3天差异无统计学意义(P>0.05);空间探索实验第三象限停留时间和跨越平台次数较模型组差异有统计学意义(P<0.05),较正常组差异无统计学意义(P>0.05).模型组皮质和海马出现突触紊、PSD-95及shank1表达减少;注射H102后突触素、PSD-95及shank1表达较正常对照组差异无统计学意义(P>0.05).结论:H102对阿尔茨海默病(AD)治疗有一定的应用价值.     

Gαq蛋白和T淋巴细胞稳态增殖在自身免疫中的作用研究

异源三聚体G蛋白在跨膜信号转导中扮演重要角色,介导信号从细胞表面传递到细胞内部。哺乳动物细胞中1 000多种G蛋白偶联受体（GPCR）的信号传导并将其转化为细胞应答都是G蛋白共同功能。根据α亚基单位的不同,G蛋白可分为4个亚家族：Gs、Gi/o、Gq/11和G12/13。大多数的α亚基高表达于免疫细胞表面。     

成年小鼠脑创伤后海马组织中Hes1的表达

目的:观察和分析创伤性脑损伤后成年小鼠海马组织中Hes1的表达情况.方法:雄性C57BL/6小鼠66只,随机分为假手术(NC)组33只和创伤性脑创伤(TBI)组33只,通过单侧液压性损伤(FPI)的方法建立小鼠创伤性脑创伤模型.分别在成模后6 h、1 d、3 d和7 d通过颈椎脱臼处死小鼠,2组每个时间点各选取小鼠6只,采用实时荧光定量PCR检测海马中Hes1 mRNA的表达;创伤后3 d,每组分别选取小鼠6只和3只分别用Western blot法和荧光免疫组织化学染色方法检测Hes1蛋白的表达情况.实时荧光定量PCR和Western blot均以GAPDH作为内参照.结果:TBI组所有标本中均检测到Hes1的表达.TBI组与相应的NC组海马组织中Hes1 mRNA的表达情况各时点比较差异均有统计学意义(P＜0.05);TBI组创伤后3 d海马的蛋白表达量与NC组比较差异均有统计学意义(P＜0.05).Hes1蛋白在NC组小鼠伤侧海马组织的细胞中广泛表达,而TBI组创伤后3 d Hes1蛋白的表达量明显降低.结论:Hes1可能参与了神经发生过程,并在随后的损伤修复中起重要的作用.     

Rac1 和 WAVE2 蛋白在高脂饮食 C57BL/6J 幼鼠肾小球中的表达及意义

目的 探讨 Rac1 和 WAVE2 蛋白在高脂饮食诱导的 C57BL/6J 幼鼠肾小球中的表达及意义。 方法 32 只 3 周龄雄性 C57BL/6J 幼鼠随机分为正常饮食组和高脂饮食组, 每组 16 只。 分别给予标准饲料（脂肪含量 10%）与高脂饲料（脂肪含量 60%）喂养 4 周。 HE 染色和 PAS 染色观察小鼠肾脏的病理形态学改变;应用免疫组织化学技术及蛋白免疫印迹技术检测 Rac1 和 WAVE2 蛋白的表达。 结果 与正常饮食组相比, 高脂饮食喂养的 C57BL/6J 幼鼠出现了肾小球系膜基质轻度增生以及渗出等病理改变。 同时高脂饮食组小鼠肾小球 Rac1 和 WAVE2 蛋白的表达明显增强。 结论 Rac1 和 WAVE2 蛋白可能共同参与了高脂饮食诱导的 C57BL/6J 幼鼠肾小球的损伤。     

G蛋白抑制肽GCIP-27对大鼠慢性心力衰竭的影响

目的探讨G蛋白抑制肽GCIP-27对多柔比星(Dox)诱导的大鼠慢性心力衰竭的作用。方法 48只SD大鼠随机分为对照组、模型组、氯沙坦组、GCIP-27组,分别给予生理盐水、Dox、Dox+氯沙坦、Dox+GCIP-27(10、30、90μg·kg~(-1),ip,bid)。给予Dox复制模型后,再继续喂养大鼠,于d71,经胸高频彩超诊断仪测定大鼠心功能;称量大鼠体重、心脏质量、左心室质量,计算心脏质量指数和左心室质量指数;HE染色后观察大鼠心肌组织病理形态学改变。结果 Dox可明显诱导大鼠发生慢性心力衰竭;氯沙坦6mg·kg~(-1)、GCIP-27(30、90μg·kg~(-1),bid)能明显抑制大鼠左心室重构,提高心脏的射血分数和短轴缩短率,降低心脏质量指数和左心室质量指数,减少心肌组织的损伤。结论 GCIP-27能抑制慢性心力衰竭大鼠的左心室重构,改善心脏功能。     

脂筏蛋白质组学分析揭示快速老化因素对SAMP8 小鼠海马组织的关键影响

摘要：目的 探讨快速老化小鼠SAMP8老年性痴呆的关键细胞学机制。方法 以2月龄和8月龄SAMP8小鼠 各40只为痴呆相关快速老化动物模型,以同月龄各40只正常老化小鼠SAMR1为对照,从小鼠海马组织提取脂筏蛋 白,采用高效液相色谱-串联质谱法分析。脂筏蛋白质组学检测数据导入DAVID生物信息学分析工具,进行Gene Ontology（GO）生物信息学分析和Kyoto Encyclopedia of Genes and Genomes（KEGG）代谢网络分析,并用线粒体膜电位 和Morris水迷宫方法验证生物信息学分析结果。结果 与SAMR1小鼠比较,快速老化的SAMP8小鼠出现明显的认 知障碍。GO 分析显示,老年期 SAMP8 小鼠脂筏蛋白组中线粒体相关蛋白大幅度减少。KEGG 分析显示,老年期 SAMP8小鼠海马组织线粒体的氧化磷酸化功能大幅度衰退。线粒体膜电位分析显示,老年期SAMP8小鼠海马组织 线粒体膜电位大幅度降低。结论 在老化过程中,SAMP8小鼠海马组织最关键的细胞变化是线粒体氧化磷酸化功 能的过度衰退,这可能是其痴呆发生的重要细胞学机制。     

淫羊藿苷对快速老化小鼠SAMP8学习记忆功能影响的研究

目的:研究淫羊藿苷(Icaritin,ICA)对快速老化小鼠SAMP8学习记忆功能的影响。方法:按体重随机挑选10只8月龄抗快速老化小鼠SAMR1和50只同月龄快速老化小鼠SAMP8,并将SAMP8随机分为5组(模型组、多奈哌齐组和ICA50mg/kg、100mg/kg、200mg/kg组),灌胃给药1个月,在给药前后分别用Morris水迷宫、SMG-2迷宫和跳台方法检测SAMR1和SAMP8的学习记忆功能能力。结果:与给药前相比,给药后的快速老化小鼠SAMP8定位航行和空间搜索能力以及被动反应能力得到提高。结论:ICA可以改善SAMP8的学习记忆能力。     

Intranasal Tat Alters Gene Expression in the Mouse Brain

Intranasal (IN) delivery of HIV-1 Tat in aging mice was investigated as a possible model for HIV-1 infection in the brain. After IN administration, the distribution of [¹²⁵I]-labeled Tat in the brains of Swiss Webster mice was evaluated by autoradiography and gamma counting. [¹²⁵I]-labeled Tat was detected at the highest concentrations in the olfactory bulb, cervical nodes, and trigeminal nerve tract. In another experiment, APPSw transgenic mice were used to model chronic Tat exposure. The mice were treated intranasally with 6 μg Tat (n = 4) or vehicle (n = 4) three times per week for 4 weeks. Total RNA was isolated from the frontal cortex, and differential gene expression analysis was performed using gene microarrays. Gene ontology profiles indicated innate immunity, inflammatory and apoptotic responses. Five genes of interest in the Tat-treated mice that were significantly elevated in the microarrays were validated by RT-PCR. One gene, the Toll-like receptor 9 (Tlr9), has previously been shown to activate signaling cascades leading to innate immunity and enhanced HIV-1 gene expression. A second gene, Fas, plays a key role in neuroinflammation. Two cysteine-rich cytokines associated with chemotaxis were elevated: MCP-1 (Ccl2), which is chemotactic for monocytes, and Ccl17 (TARC), which is chemotactic for lymphocytes. Finally, the gene sestrin was significantly elevated and has been associated with oxidative stress, in particular amyloid beta-induced oxidative stress. This IN Tat model of neuroinflammation may be useful to study HIV-1-induced neurodegeneration. This paper was presented at an NIMH workshop “HIV Preclinical–Clinical Therapeutics Research Meeting”, May 5–16, 2006.     

脑力苏胶囊对血管性痴呆小鼠脑组织NGF表达的影响

目的：研究脑力苏胶囊对血管性痴呆（VD）模型小鼠脑组织神经生长因子（NGF）表达的影响,以探讨脑力苏胶囊治疗VD的部分作用机理。方法：采用结扎双侧颈总动脉方法制备血管性痴呆小鼠动物模型,用酶联免疫吸附法（ELISA法）测定给药后VD小鼠脑组织内神经生长因子（NGF）的含量变化。结果：给药15 d后,VD小鼠脑内神经生长因子（NGF）较模型对照组显著增高。结论：脑力苏胶囊可增加VD大鼠脑内神经生长因子（NGF）的含量,可能与改善VD小鼠的认知功能障碍作用相关。     

High-Throughput Proteomic-Based Identification of Oxidatively Induced Protein Carbonylation in Mouse Brain

PURPOSE: The major initiative of this study was to implement a novel proteomic approach in order to detect protein carbonylation in aged mouse brain. Several lines of evidence indicate that reactive oxygen species (ROS)-induced protein oxidation plays an essential role in the initiation of age-related neuropathologies. Therefore, the identification of free radical or peroxide substrates would provide further insight into key biochemical mechanisms that contribute to the progression of certain neurological disorders. METHODS: Historically, ROS targets have been identified by conventional immunological two-dimensional (2-D) gel electrophoresis and mass spectrometric analyses. However, specific classes of proteins, such as transmembrane-spanning proteins, high-molecular-weight proteins, and very acidic or basic proteins, are frequently excluded or underrepresented by these analyses. In order to fill this technologic gap, we have used a functional proteomics approach using a liquid chromatography tandem mass spectrometric (LC-MS/MS) analysis coupled with a hydrazide biotin-streptavidin methodology in order to identify protein carbonylation in aged mice. RESULTS: Our initial studies suggest an ability to identify at least 100 carbonylated proteins in a single LC-MS/MS experiment. In addition to high-abundance cytosolic proteins that have been previously identified by 2-D gel electrophoresis and mass spectrometric analyses, we are able to identify several low-abundance receptor proteins, mitochondrial proteins involved in glucose and energy metabolism, as well as a series of receptors and tyrosine phosphatases known to be associated with insulin and insulin-like growth factor metabolism and cell-signaling pathways. CONCLUSIONS: Here we describe a rapid and sensitive proteomic analysis for the identification of carbonylated proteins in mouse brain homogenates through the conjunction of liquid chromatography and tandem mass spectrometry methods. We believe the ability to detect these post-translationally modified proteins specifically associated with brain impairments during the course of aging should allow one to more closely and objectively monitor the efficacy of various clinical treatments. In addition, the discovery of these unique brain biomarkers could also provide a conceptual framework for the future design of alternative drugs in the treatment of a variety of age-related neurodegenerative disorders.     

The Effects of Clioquinol on P-glycoprotein Expression and Biometal Distribution in the Mouse Brain Microvasculature

Previous studies have demonstrated that the ionophore clioquinol (CQ), in conjunction with the biometals copper and zinc, increases the expression of P-glycoprotein (P-gp) in human cerebral microvascular endothelial (hCMEC/D3) cells. As P-gp expression and function at the blood-brain barrier (BBB) is of great interest regarding CNS drug access and endogenous toxin trafficking (e.g., amyloid beta), the present study assessed the in vivo translation of these previous in vitro findings. Swiss outbred mice received an 11-day treatment of CQ (30 mg/kg) by oral gavage, after which brain microvessel-enriched fractions (MEFs) and surrounding interfaces (subcortical brain tissue and plasma) were extracted. P-gp expression was quantified in the MEF, and biometal concentrations in all 3 compartments were assessed via inductively coupled plasma mass spectrometry. CQ treatment did not modify the expression of P-gp, nor copper or zinc concentrations in the brain MEF under this treatment regime. Metallomic analysis revealed, however, that CQ reduced potassium and magnesium levels in the brain MEF and also lowered brain iron levels. This study has shown that under this dosing regimen, CQ does not increase BBB P-gp expression in Swiss outbred mice, but that CQ facilitates redistribution of certain metal ions within the brain MEF, plasma, and brain parenchyma.     

Pattern of CXCR7 Gene Expression in Mouse Brain Under Normal and Inflammatory Conditions

The chemokine stromal cell-derived factor-1 (SDF-1)/CXCL12 acting via its G-protein coupled receptor (GPCR) CXCR4 has been implicated in neurogenesis, neuromodulation, brain inflammation, HIV-1 encephalopathy and tumor growth. CXCR7 was identified as an alternate receptor for SDF-1/CXCL12. Characterization of CXCR7-deficient mice demonstrated a role for CXCR7 in fetal endothelial biology, cardiac development, and B-cell localization. Despite its ligand binding properties, CXCR7 does not seem to signal like a conventional GPCR. It has been suggested that CXCR7 may not function alone but in combination with CXCR4. Here, we investigated the regional localization of CXCR7 receptors in adult mouse brain using CXCR7-EGFP transgenic mice. We found that the receptors were expressed in various brain regions including olfactory bulb, cerebral cortex, hippocampus, subventricular zone (SVZ), hypothalamus and cerebellum. Extensive CXCR7 expression was associated with cerebral blood vessels. Using cell type specific markers, CXCR7 expression was found in neurons, astrocytes and oligodendrocyte progenitors. GAD-expressing neurons exhibited CXCR7 expression in the hippocampus. Expression of CXCR7 in the dentate gyrus included cells that expressed nestin, GFAP and cells that appeared to be immature granule cells. In mice with Experimental Autoimmune Encephalomyelitis (EAE), CXCR7 was expressed by migrating oligodendrocyte progenitors in the SVZ. We then compared the distribution of SDF-1/CXCL12 and CXCR7 using bitransgenic mice expressing both CXCR7-EGFP and SDF-1-mRFP. Enhanced expression of SDF-1/CXCL12 and CXCR7 was observed in the corpus callosum, SVZ and cerebellum. Overall, the expression of CXCR7 in normal and pathological nervous system suggests CXCR4-independent functions of SDF-1/CXCL12 mediated through its interaction with CXCR7.     

Attractin mRNA和Attractin蛋白在小鼠睾丸发育过程中的表达变化

目的:通过定量检测和比较Attractin(Atrn)mRNA和Atrn蛋白在小鼠睾丸发育过程中的动态变化,为进一步研究Atrn在睾丸的生理作用提供实验依据。方法:用相对定量法检测Atrn mRNA在生后1、5、10、15、21、28、35、42、56和120天龄小鼠睾丸发育过程中的表达变化,并用Western blot方法检测各天龄小鼠睾丸Atrn蛋白表达。结果:Atrn mRNA和Atrn蛋白在小鼠睾丸发育过程中的表达变化趋势相似,在生后第1天两者均有表达,但是处于相对较低水平,此后是一个逐渐增高的过程,在28天出现较明显上调。在这之后,两者表达变化出现差异。Atrn mRNA在生后28~35天表达最丰富,随后稳定于这一水平,Atrn蛋白表达则是继续增加直至成年。结论:Atrn参与精子发生的启动、精原干细胞的增殖分化、精母细胞的减数分裂和精子形成等过程,并有助于Leydig细胞进一步成熟。     

Trioxolane-Mediated Delivery of Mefloquine Limits Brain Exposure in a Mouse Model of Malaria

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