Increased corticosterone levels in plasma and hippocampus and their relationship with hippocampal ATP depletion in senescence accelerated mice

早衰小鼠ＳＡＭＰ８９００时和１６００时，血浆皮质酮水平均明显高于正常对照小鼠ＳＡＭＲ１；大脑皮层和海马区皮质酮水平在１６００时亦显著高于ＳＡＭＲ１，而下丘脑皮质酮含量与ＳＡＭＲ１相比无差别．同时，ＳＡＭＰ８大脑海马ＡＴＰ，ＡＤＰ和ＡＭＰ水平均低下，而皮层ＡＴＰ，ＡＤＰ和ＡＭＰ水平无改变．切除ＳＡＭＰ８小鼠肾上腺６０ｈ后，海马区低水平的ＡＴＰ，ＡＤＰ和ＡＭＰ被逆转，而皮层未受影响．给切除肾上腺的ＳＡＭＰ８补充皮质酮（１０ｍｇ·ｋｇ－１，ｉｐ，１２ｈ一次，共５次）后，海马区ＡＴＰ，ＡＤＰ和ＡＭＰ水平再次被显著降低，皮层仍未受影响．上述结果说明，ＳＡＭＰ８小鼠大脑海马ＡＴＰ水平低下是肾上腺依赖的，ＳＡＭＰ８血浆和海马区皮质酮水平升高可能与海马ＡＴＰ和ＡＤＰ水平降低有关．     

快速老化小鼠脑内能量代谢及学习记忆能力的研究

目的观察快速老化小鼠(SAM)这一较理想的阿尔茨海默病模型,其脑内能量代谢及学习记忆能力随增龄的动态变化情况,研究脑内能量代谢与学习记忆能力的关系。方法选择2,6和12月龄雄性快速老化小鼠(SAMP8)为研究对象,同月龄的抗快速老化小鼠(SAMR1)作为对照。应用新物体识别、Morris水迷宫、穿梭箱等实验研究快速老化小鼠学习记忆能力的变化;应用小动物氟脱氧葡萄糖正电子断层扫描(FDG-PET)技术检测小鼠脑内葡萄糖摄取水平;应用高效液相色谱法检测小鼠海马内ATP,ADP和AMP等能量物质的增龄性变化;应用Western蛋白印迹法检测糖酵解及三羧酸循环葡萄糖代谢关键酶己糖激酶(HK)和丙酮酸脱氢酶(PDH)及葡萄糖转运蛋白的表达情况;应用分光光度法检测HK和PDH的活性。结果在新物体识别实验中,2,6和12月龄SAMP8的1和24 h优先指数显著低于同月龄SAMR1(P<0.05)。在Morris水迷宫实验中,学习期6月龄和12月龄SAMP8的逃避潜伏期显著高于同月龄SAMR1(P<0.05);测试期6月龄和12月龄SAMP8穿环次数显著少于同月龄SAMR1(P<0.05)。在穿梭箱实验中,6月龄和12月龄SAMP8的学习期成功回避次数显著低于同月龄SAMR1(P<0.05),SAMP8的测试期成功回避次数显著低于同月龄SAMR1(P<0.05),表明SAMP8的物体识别记忆能力、空间学习记忆能力及主动回避反应能力呈增龄性衰退。FDG-PET结果显示,2,6和12月龄SAMP8全脑、海马、皮层葡萄糖摄取低于同月龄SAMR1,且SAMP8葡萄糖摄取随着增龄而减少。与同月龄SAMR1比较,6月龄和12月龄SAMP8海马的ATP,ADP和AMP含量均显著降低(P<0.05)。2,6和12月龄SAMP8小鼠海马中HK和PDH的蛋白表达和活性均随着增龄而逐渐降低,其中12月龄SAMP8海马的HK和PDH活性显著低于同月龄SAMR1(P<0.01)。结论 SAMP8学习记忆能力随增龄进行性衰退,SAMP8脑内能量代谢随增龄逐渐降低,其学习记忆能力的衰退可能与其脑内能量代谢的异常相关。     

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。     

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。     

快速老化痴呆模型小鼠海马细胞凋亡检测及金属硫蛋白3对其的影响

目的：研究快速老化痴呆模型小鼠（SAMP8）海马CA1区神经元细胞凋亡的变化及不同浓度的金属硫蛋白3（MT3）对其的影响．并且与金属硫蛋白1（MT1）作用相比较。方法：给予7月龄SAMP8小鼠腹腔注射age浓度的MT3及MT1,28d后灌注取脑。进行海马CA1区Tunel试剂盒染色。结果：8月龄的SAMP8小鼠海马区神经元细胞凋亡指数明显高于对照组SAMR1小鼠。高浓度MT3组凋亡指数最低,差异有统计学意义。相同浓度MT3组和MT1对照组间差异无统计学意义。结论：SAMP8小鼠海马结构存在大量的神经元细胞凋亡;MT3有抑制细胞凋亡的作用,并有浓度依赖关系;MT3和MT1对细胞凋亡的影响无差异。     

通络醒脑泡腾片对SAMP8小鼠海马的NeuN蛋白及其超微结构的影响

目的 观察通络醒脑泡腾片对快速老化小鼠亚系8(SAMP8)海马的NeuN蛋白及其超微结构的影响.方法 将SAMP8小鼠随机分为SAMP8组、安理申组、通络醒脑泡腾片组(高、中、低剂量),另取抗快速老化小鼠亚系1(SAMR1)作为对照组,分组后连续给药60d,采用Morris水迷宫和避暗法评价其学习记忆的改变;采用免疫组化法考察海马Aβ和NeuN蛋白的表达;采用电镜法考察海马的超微结构.结果 通络醒脑泡腾片能够缩短SAMP8模型小鼠的潜伏期、明显地增加平台所在象限的时间百分比和进入目标象限的次数,可显著地减少(避暗)错误次数和延长逃避潜伏期;能够下调海马Aβ的表达并上调NeuN蛋白的表达,可显著地减少核糖体的丢失,降低线粒体的肿胀度,改善海马的超微结构.结论 通络醒脑泡腾片可通过抑制Aβ沉积,提高NeuN的表达来修复神经元,保护线粒体,从而提高SAMP8小鼠的学习记忆能力.     

G蛋白在快速老化痴呆小鼠SAMP8脑组织中的表达

目的:观察在不同月龄小鼠SAMP8皮质和海马中G蛋白的表达情况.方法:利用Western-blot方法检测Gαq/11、Gαi和GαS蛋白在8月龄和18月龄快速老化痴呆小鼠SAMP8的表达,并以正常老化小鼠SAMR1作为对照研究.结果:与同月龄SAMR1相比,Gαq/11、Gαi和Gαs蛋白在8月龄小鼠SAMP8皮质和海马组织中的表达无明显异常(P＞0.05),而到18月龄时,SAMP8皮质部位Gαq/11表达量低于SAMR1(P＜0.05),海马部位Gαq/11和Gαi的表达量低于SAMR1(P＜0.05).结论:18月龄SAMP8脑组织中Gαq/11和Gαi的异常表达参与了阿尔茨海默病(AD)的病理进展,并有望作为AD治疗的一个靶点.     

六味地黄汤对快速老化小鼠海马差异表达基因的影响

目的研究六味地黄汤(LW)对快速老化小鼠(senescenceacceleratedmouse,SAM)海马差异表达基因的影响,揭示LW增强认知功能的分子作用机制。方法应用快速老化小鼠亚系SAMP8和SAMR1海马差异表达cDNA芯片,比较SAMP8和SAMR1、SAMP8阴性对照和SAMR1阳性对照、石衫碱甲处理的SAMP8和SAMP8阴性对照以及LW处理的SAMP8和SAMP8阴性对照8个基因表达谱,并对LW的药物效应基因进行比较。结果给予SAMP8LW后,基因DUSP12、NSF、STUB1、CAMKⅡα、AMFR、UQCRFS1和11个新基因的表达出现显著差异,这些基因涉及蛋白酪氨酸磷酸酶家族、苏氨酸/丝氨酸蛋白激酶家族、泛素连接酶和线粒体功能等,LW对SAMP8海马的基因表达具有明显的调控作用。结论提示LW作用于认知功能也许是通过维持正常的细胞增殖和分化、保护正常的突触传递、调节Ca2+信号转导、改善线粒体的功能等途径实现的,基因DUSP12、NSF、STUB1、CAMKⅡα、AMFR、UQCRFS1和11个新基因可能是LW改善学习记忆功能的潜在作用靶标。     

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。     

运动对快速老化小鼠海马突触素表达的影响

目的研究运动对快速老化小鼠（SAMP8）海马突触素表达的影响,探讨运动改善阿尔茨海默病（AD）学习记忆功能的机制。方法 3月龄SAMP8小鼠40只随机分为运动组（采用跑笼运动训练）和对照组,2个月后HE染色观察2组海马神经元形态改变;免疫组化技术检测2组海马突触素表达。结果 5月龄SAMP8小鼠对照组海马部分神经元细胞变性、死亡,核浓缩,空泡变性;运动组偶有神经元细胞变性、死亡,大部分细胞形态正常。海马突触素表达运动组较对照组显著增高（P〈0.05）。结论运动可以延缓SAMP8小鼠海马神经元变性,提高海马突触素表达,这可能是运动改善AD学习记忆功能的重要机制之一。     

Depressive behavior and alterations in receptors for dopamine and 5-hydroxytryptamine in the brain of the senescence accelerated mouse (SAM)-P10

The senescence accelerated mouse (SAM) is known as a murine model of aging. SAM consists of senescence accelerated-prone mouse (SAMP) and senescence accelerated-resistant mouse (SAMR). Previous studies reported that SAMP10 exhibits age-related learning impairments and behavioral depression in a tail suspension test after 7 months. We investigated the changes in emotional behavior in a forced swimming test and in receptors for dopamine and 5-hydroxytryptamine (5-HT) in SAMP10. SAMP10 at 8 months showed an increase of immobility in the test compared with SAMR1. Treatment with desipramine (25 mg/kg, i.p., 3 days) in SAMP10 caused a decrease in immobility. In the cortex from SAMP10, [3H]quinpirole binding to D2/D3 dopamine receptors increased significantly compared with control SAMR1. In the hippocampus from SAMP10, [3H]8-hydroxy DPAT binding to 5-HT1A receptor increased. In midbrains from SAMP10, bindings of [3H]quinpirole and [3H]8-hydroxy DPAT increased. [3H]SCH23390 binding to D1/D5 receptors and [3H]ketanserin binding to 5-HT2 receptor in brain regions examined in SAMP10 were similar to those in SAMR1. The present findings represent the first neurochemical evidence of an increase of D2/D3 and 5-HT1A receptors in SAMP10. SAMP10 may be a useful model of aging associated depressive behavior.     

The age-related degeneration of oligodendrocytes in the hippocampus of the senescence-accelerated mouse (SAM) P8: a quantitative immunohistochemical study

The senescence-accelerated mouse (SAM) is known as a murine model for accelerated aging. The SAMP8 shows age-related deficits of learning and memory at an earlier age than control mice (SAMR1). We investigated the changes in oligodendrocytes in the brain of SAMP8, using immunohistochemistry for myelin basic protein (MBP) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) as an oligodendrocyte marker. SAMP8 at 10 months old showed a decrease in MBP-immunoreactivity (IR) and CNP-IR in the hippocampal CA1 subfield, compared with SAMR1. There were no significant differences in MBP and CNP old in the cerebral cortex and the optic tract between SAMR1 and SAMP8 at 10 months. Furthermore, we measured the area of MBP-IR in the CA1 subfield of both strains and found that the area of MBP-IR in SAMP8 had decreased progressively with age, compared with SAMR1. These results suggest that age-related degeneration of oligodendrocytes had occurred in the hippocampus of SAMP8.     

Age-related alterations in the expression of glial cell line-derived neurotrophic factor in the senescence-accelerated mouse brain

Senescence-accelerated mouse prone 8 (SAMP8) and prone 10 (SAMP10) are useful murine model of accelerated aging. SAMP8 shows marked impairment of learning and memory, whereas SAMP10 shows brain atrophy and aging-associated depressive behavior. This study examined the expression of glial cell line-derived neurotrophic factor (GDNF) in SAMP8 and SAMP10 brains, relative to that in SAM resistant 1 (SAMR1) controls, which age normally. Hippocampal GDNF mRNA expression decreased in an age-dependent manner (10- vs 2-month-old animals) in the SAMR1, but not in the SAMP8 or SAMP10 strains. Furthermore, GDNF mRNA expression in 2-month-old SAMP8 and SAMP10 strains was less than in SAMR1 specimens of the same age. The number of surviving neurons in the CA1 region decreased with age in SAMP8 and SAMP10, and also decreased relative to the number of neurons in 10-month-old SAMR1 controls. Immunohistochemistry revealed that cells that were positive for GDNF-like activity in 10-month-old SAMP8 and SAMP10 were diffusely distributed, in part, around the pyramidal cell layer in the hippocampus. These findings suggest that low GDNF expression in young SAMP8 and SAMP10 may be involved in hippocampal dysfunctions, such as age-related learning impairment and neuronal death.     

淫羊藿苷对快速老化小鼠SAMP10脑组织单胺类及氨基酸类神经递质的影响

目的:探讨淫羊藿苷(ICA)对快速老化小鼠SAMP10脑组织单胺类及氨基酸类神经递质的影响。方法:本实验采取8月龄快速老化小鼠SAMP10为实验对象,随机分为模型SAMP10组、阳性药多奈哌齐组(1mg/kg)、ICA 3个剂量(50、100、200mg/kg)组,每组12只,以12只同月龄抗快速老化小鼠SAMR1为正常对照。灌胃给药30d,一天一次,高效液相-电化学法检测快速老化小鼠SAMP10大脑皮层的去甲肾上腺素(NE)、5-羟色胺(5-HT)、多巴胺(DA)及其代谢产物3,4-二羟苯乙酸(DOPAC)和高香草酸(HVA)的含量来探讨ICA对SAMP10脑组织单胺类神经递质的影响,通过检测谷氨酸(Glu)、谷氨酰胺(Gln)、天冬氨酸(Asp)、γ-氨基丁酸(GA-BA)、牛磺酸(Tau)、甘氨酸(Gly)的含量来探讨ICA对SAMP10脑组织氨基酸类神经递质的影响。结果:ICA可显著降低SAMP10大脑皮层内Glu、Gln、GABA含量(P<0.01),升高NE、DA、DOPAC、5-HT、HVA、Asp以及Tau的含量(P<0.01或P<0.05),但对SAMP10大脑皮层内Gly的含量并没有显著影响(P>0.05)。结论:ICA可能通过升高脑内单胺类神经递质的含量、调节兴奋性氨基酸类递质的代谢平衡以及调节抑制性氨基酸的代谢平衡达到改善SAMP10的学习记忆的作用。     

Effects of Liuwei Dihuang decoction and its compatible prescriptions on the function of hypothalamus-pituitary-adrenal axis in senescence-accelerated mouse

OBJECTIVE To investigate age-related functional change of hypothalamus-pituitary-adrenal(HPA)axis in senescence accelerated mouse(SAM)and the effects of Liuwei Dihuang decoction(LW)and its San-bu(three tonics)and San-xie(three eliminators)components on the function of HPA axis.METHODS Male SAM-resistance/1(SAMR1)and SAM-prone/8(SAMP8)at the ages of 6and 12 months old were used.SAMP8 were orally administered with LW,three tonics and three eliminators at the doses of 10,6.4and 3.6g·kg-1·d-1,respectively,for consecutive 60 d.Serum level of CORT was assayed with ELISA method.The levels of hypothalamic CRH and pituitary ACTH was determined with radioimmunoassay.RESULTS The levels of hypothalamic CRH,pituitary ACTH and serous CORT were much higher in 6 and 12 months old SAMP8 than those in age-matched SAMR1,which suggested the abnormal function of HPA axis in SAMP8.Oral administration of LW and three tonics significantly decreased the level of hypothalamic CRH of 6 and 12 months old SAMP8,and reduced the levels of pituitary ACTH and serous CORT of 6 month old SAMP8.Three eliminators significantly decreased the level of hypothalamic CRH of 6 months old SAMP8.The results indicated that oral administration of LW,three tonics and three eliminators improved the function of HPA axis of SAMP8.CONCLUSION The results showed the hyperactivity of HPA axis of SAMP8,and LW improved the hyperactivity of 6 month old SAMP8.Three tonics and three eliminators had similar effects as LW,which had better effect after compatibility.     

快速老化小鼠——研究衰老及衰老相关疾病的动物模型

快速老化小鼠 (Senescenceacceleratedmouse,SAM)分为快速老化亚系 (Senescenceacceleratedmouse/ prone,SAMP)及抗快速老化亚系 (Senescenceacceleratedmouse/re sistance ,SAMR)。由日本京都大学首次培育成功 ,目前共有12个亚系 ,不同亚系具有不同的病理表现型 ,其中许多具有与人类衰老相似的病理学特征。人类许多老年性疾病如肺泡扩张、骨质疏松、骨关节疾病、学习记忆功能障碍、情感紊乱 (抑郁 )、白内障、听觉障碍、脑萎缩、免疫缺陷等在SAMP不同亚系上均有不同程度的体现 ,而SAMR亚系的各项生理指标及生存期限与正常动物相似。因此 ,SAM (SAMP、SAMR)为探讨衰老及衰老相关疾病的发生机制 ,评价药效及其作用机制提供了良好的动物模型。     

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。     

Sertraline and clomipramine inhibit nucleotide catabolism in rat brain synaptosomes.

The effects of sertraline, a selective serotonin reuptake inhibitor, and clomipramine, a tricyclic antidepressant, were tested on ecto-nucleotidases from synaptosomes of cerebral cortex and hippocampus of rats. Sertraline and clomipramine (100-500 microM) inhibited NTPDase, but not ecto-5'-nucleotidase activity in both cerebral cortex and hippocampus. In cortical synaptosomes, sertraline inhibited both ATP and ADP hydrolysis in the concentrations tested. The inhibitory effect varied from 21% to 83% for ATP hydrolysis and 48% to 75% for ADP hydrolysis. The inhibition promoted by sertraline in hippocampal synaptosomes varied from 38% to 89% for ATP hydrolysis and 45% to 77% for ADP hydrolysis. A significant inhibition of cortical NTPDase activity by clomipramine was observed in the all concentrations tested (35-72% and 36-87% for ATP and ADP hydrolysis, respectively). Similar effects were observed in hippocampus (29-91% and 48-83% for ATP and ADP hydrolysis, respectively). There was no inhibitory effect of sertraline and clomipramine on AMP hydrolysis in cerebral cortex and hippocampus. Our results have shown that classical antidepressants inhibit the extracellular catabolism of ATP. Therefore, it is possible to suggest that changes induced by antidepressants on bilayer membrane could affect NTPDase activities and consequently, modulating ATP and adenosine levels in the synaptic cleft.