Digenic inheritance of STUB1 variants and TBP polyglutamine expansions explains the incomplete penetrance of SCA17 and SCA48

PurposeThis study aimed to unravel the genetic factors underlying missing heritability in spinocerebellar ataxia type 17 (SCA17) caused by polyglutamine-encoding CAG/CAA repeat expansions in the TBP gene. Alleles with >49 CAG/CAA repeats are fully penetrant. Most patients, however, carry intermediate TBP_41-49 alleles that show incomplete penetrance.MethodsUsing next-generation sequencing approaches, we investigated 40 SCA17/TBP_41-54 index patients, their affected (n = 55) and unaffected (n = 51) relatives, and a cohort of patients with ataxia (n = 292).ResultsAll except 1 (30/31) of the index cases with TBP_41-46 alleles carried a heterozygous pathogenic variant in the STUB1 gene associated with spinocerebellar ataxias SCAR16 (autosomal recessive) and SCA48 (autosomal dominant). No STUB1 variant was found in patients carrying TBP_47-54 alleles. TBP_41-46 expansions and STUB1 variants cosegregate in all affected family members, whereas the presence of either TBP_41-46 expansions or STUB1 variants individually was never associated with the disease.ConclusionOur data reveal an unexpected genetic interaction between STUB1 and TBP in the pathogenesis of SCA17 and raise questions on the existence of SCA48 as a monogenic disease with crucial implications for diagnosis and counseling. They provide a convincing explanation for the incomplete penetrance of intermediate TBP alleles and demonstrate a dual inheritance pattern for SCA17, which is a monogenic dominant disorder for TBP_≥47 alleles and a digenic TBP/STUB1 disease (SCA17-DI) for intermediate expansions.     

Intracellular delivery of Neuroglobin using HIV-1 TAT protein transduction domain fails to protect against oxygen and glucose deprivation

Neuroglobin (Ngb) is a heme protein that is primarily localised in the retina and the brain. Its physiological role is largely unknown. It has been reported that its overexpression protects neurons from hypoxia in vitro and in vivo, suggesting that the rapid modulation of the Ngb level in the nerve cells may be a promising stroke treatment strategy.     

β淀粉样蛋白及代谢酶类在阿尔茨海默病和糖尿病模型小鼠脑内的表达

目的观察阿尔茨海默病(AD)和糖尿病模型小鼠脑内β淀粉样蛋白(Aβ)及代谢相关酶类的表达情况,以便从分子水平找到糖尿病并发AD的实验室依据。方法 5月龄双转基因痴呆症模型小鼠(APP/PS1双转基因小鼠)、ob/ob T2DM肥胖模型小鼠和野生型C57BL/6J小鼠为对照,分别用免疫组化染色、ELISA和Western blot检测脑内老年斑(SP)、Aβ含量及Aβ代谢酶类的表达情况。结果 APP/PS1小鼠大脑皮质及海马均可见一定数量的SP;ob/ob小鼠大脑皮质内偶可见SP,而对照组未见SP。与对照小鼠相比,APP/PS1与ob/ob小鼠脑内Aβ40、Aβ42的含量明显升高(P0.05);但APP/PS1小鼠脑内Aβ水平显著高于ob/ob小鼠(P0.05)。APP在APP/PS1小鼠脑内的表达显著高于其他两组小鼠;在ob/ob小鼠脑内的表达要强于对照小鼠(P0.05)。Aβ生成的关键酶BACE1在APP/PS1与ob/ob小鼠脑内的表达显著高于对照小鼠(P0.05),但其在APP/PS1小鼠脑内的表达要强于ob/ob小鼠(P0.05)。Aβ降解的关键酶IDE在APP/PS1与ob/ob小鼠脑内的表达显著低于对照小鼠(P0.05),且在ob/ob小鼠脑内表达最低。结论 Aβ生成与降解的异常以及其异常聚集沉积不仅发生在早期AD脑内,同时也发生在T2DM脑内,提示Aβ过表达可能是促进2型糖尿病并发AD的重要原因之一。     

人直肠癌组织中脑特异性新生血管抑制因子1表达及该因子抗肿瘤血管生成作用的观察

 目的 探讨直肠癌组织中脑特异性血管生长抑制因子1（BAI1）基因的表达情况及BAI1对肿瘤血管生成和肿瘤生长的作用。 方法 提取20例直肠癌患者（II期6例，III期14例）手术切除的直肠癌、无转移淋巴结、有转移淋巴结组织和直肠腺癌细胞株CC95总RNA，应用逆转录聚合酶链反应方法检测BAI1的表达。将背部皮下接种CC95细胞（1×105个）的BALB/C裸鼠随机分成3组，每组10只，分别在接种后第1、3、5、7、9天于荷瘤部位注射RPMI1640、腺病毒载体（Ad-LacZ）或基因重组BAI1表达腺病毒载体（Ad-hBAI1），每次0.2 ml，载体含量2 μg。每组中5只裸鼠于接种后第15天断颈处死，取肿瘤组织行抗Ⅷ因子抗体染色,观察微血管密度（MVD）；另5只接种后每天观察肿瘤体积的变化，共观察21 d。 结果 20例患者中，7例（临床II期6例、III期1例）肿瘤组织BAI1表达呈阳性，13例无表达；无转移淋巴结均呈阳性表达，有转移淋巴结均无表达。CC95细胞均无BAI1表达。在BALB/C裸鼠肿瘤移植实验中，Ad-hBAI1组肿瘤组织内血管增生受到明显抑制，MVD（6.2±2.3）明显低于RPMI1640组（16.7±1.9）和Ad-LacZ组（13.4±4.3）（均为P＜0.05）；肿瘤生长速度明显低于RPMI1640组和Ad-LacZ组（均为P＜0.01）。 结论 BAI1在人直肠癌及转移的淋巴结组织中表达降低；局部注射Ad-hBAI1表达载体可抑制肿瘤血管生成并抑制肿瘤的生长。     

HBV基因组转染对小鼠NIH3T3细胞内基质金属蛋白酶组织抑制因子的转录调控作用

ObjectiveTo understand the mechanism of liver cirrhosis after the infection of hepatitis B virus.MethodsMouse fibroblast NIH3T3 cells were transfected with 3.2 kb HBV DND by exposure of the cells to calcium phosphate.The change of the levels of mRNA for tissue inhibitor of metalloproteinase 1and 2(TIMP1,2) was detected in mouse fibroblast NIH3T3 cells and the cells of transfection with HBV Genome by in situ hybridization.ResultsThe levels of mRNA for TIMP1 and TIMP2 were increased significantly.ConclusionHBV infection can induce the expression of the mRNA for TIMP1 and TIMP2.     

BDNF在Parkinson病小鼠的表达及丙戊酸盐对其影响的研究

为观察Parkinson病(PD)小鼠脑源性神经营养因子(BDNF)含量的变化及丙戊酸盐(valproate,VPA)对BDNF表达的影响,探讨VPA对PD病神经元的保护作用,本研究采用C57BL/6小鼠1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methy1-4-phenyl-1,2,3,6-tetrahydropyridine,MPTP)法建立PD模型。小鼠随机分为4组:盐水对照组(NS+NS)、模型组(NS+MPTP)、模型给药组(VPA+MPTP)和单独给药组(VPA+NS)。MPTP造模方法为每日颈部皮下注射MPTP(20 mg/kg),连续8 d。VPA在MPTP造模前1 d开始给药(400 mg/kg,i.p.),共14 d。单独给药组给予VPA,同时用等量的生理盐水代替MPTP。盐水对照组仅给予等量的生理盐水。采用原位分子杂交方法观察BDNF的表达,并对检测部位恒定视野内BDNF的阳性细胞进行灰度扫描和统计学分析。结果显示:与盐水对照组相比,模型组、模型给药组和单独给药组小鼠纹状体、海马、皮质内BDNF的表达均增强。该结果提示,PD小鼠神经元内BDNF增多,可能有利于受损神经元的修复;丙戊酸盐可能通过促进BDNF的表达而保护神经元。     

不同生长期小鼠胸腺T细胞不同亚群的变化及ROCK抑制剂对衰老小鼠胸腺再生的促进作用

目的研究各发育阶段小鼠胸腺细胞、胸腺上皮细胞(TEC)和脾脏中T细胞的变化,探索Rho相关卷曲蛋白激酶(ROCK)抑制剂对衰老小鼠胸腺再生的作用。方法取幼年、青年、中年及老年期C57BL/6雌鼠的胸腺和脾脏,流式细胞术分析小鼠胸腺细胞、TEC及脾脏中T细胞亚群;ROCK抑制剂体外处理衰老进程中小鼠TEC,荧光酶联斑点分析仪观察细胞增殖情况;ROCK抑制剂处理20月龄衰老小鼠,流式细胞术检测小鼠胸腺细胞、TEC及脾脏中T细胞亚群的变化。结果随月龄增加,胸腺细胞、TEC总数及各细胞亚群数量均显著降低;脾脏中总CD4⁺T细胞及CD8⁺T细胞比例无显著性改变,但CD4+初始T细胞、CD8+初始T细胞和CD4+近期胸腺迁出细胞(RTE)在脾脏中所占比例呈下降趋势;ROCK抑制剂在体外促进衰老进程中小鼠TEC增殖,ROCK抑制剂在体内使衰老小鼠胸腺细胞、TEC以及外周脾脏中T淋巴细胞各亚群数量明显增加。结论随着小鼠月龄增加,胸腺呈进行性退化。ROCK抑制剂可以显著缓解衰老小鼠胸腺的萎缩,促进衰老小鼠胸腺再生。     

小鼠胚胎干细胞诱导的神经前体细胞大脑皮层移植对AD大鼠的治疗作用

目的与方法：将小鼠胚胎干细胞无血清诱导为神经前体细胞后移植到叠氮钠所致的阿尔茨海默氏病（AD）大鼠额叶皮层，采用免疫组化观察移植细胞的存活、分化以及细胞移植对AD大鼠Morris水迷宫记忆功能的作用。结果： 胚胎干细胞形成的胚胎样体经N2选择性培养基选择生长5 d后，85％以上的小鼠胚胎干细胞分化为nestin阳性的神经前体细胞。移植到AD 大鼠额叶皮层后4-6周，神经前体细胞存活良好，大部分移植细胞保持为未分化的nestin阳性的神经前体细胞并呈克隆生长，部分细胞发出类似于神经元的长突起。移植后4周，AD大鼠的空间记忆能力明显提高。结论： 胚胎干细胞来源的神经前体细胞移植到AD大鼠额叶皮层后能存活并分化为神经元，能改善AD大鼠的记忆功能障碍。     

冠状动脉粥样硬化性心脏病患者凝血酶激活的纤溶抑制物及其编码区基因多态性的研究

目的 探讨凝血酶激活的纤溶抑制物(thrombin aetiralable fibrinolysis inhibitor,TAFI)及其编码基因CPB2单核苷酸多态性与冠状动脉粥样硬化性心脏病(冠心病)之间的联系.方法 应用聚合酶链反应-限制性片段长度多态性分析技术(polymerase chain reaction-restriction fragment length polymorphism,PCR-RFLP)检测210例冠心病患者和190名正常对照者的TAFI基因编码区Thr325Ile、Tnr147Ala多态性分布特点,同时应用发色底物法和ELISA法分别测定TAFI的活性及抗原,并进一步分析基因多态性与TAFI的活性及抗原之间的关系.结果 冠心病组(心肌梗死组及心绞痛组)血浆中TAFI的活性及抗原水平均较对照组显著增高,差异有统计学意义.CPB2基因C1040T(Thr325Ile)及G505A(Thr147Ala)2个位点的3种基因型在冠心病组和对照组的频率分布分别为C1040C(Thr325Thr)67(31.9%)、64(33.6%);C1040T(Thr325Ile)109(51.9%)、92(48.4%);T1040T(Ile325Ile)34(16.2%)、34(17.8%);G505G(Ala147 Ala)75(35.7%)、72(37.8%);G505A(Thr147Ala)112(53.3%)、96(50.5%);A505A(Thr147Thr)23(10.9%)、22(11.7%),经x2检验,基因型分布符合Hardy-Weinberg平衡,并且两组之间各种基因型频率分布差异无统计学意义(P>0.05).在冠心病组和对照组Thr325Ile不同的基因型对TAFI活性没有影响;对TAFI抗原含量的影响则以Thr325Thr纯合基因型者血浆TAFI抗原浓度最高,较其他两型差异有统计学意义(P<0.05),Thr325Ile与TIle325Ile型之间则差异无统计学意义(P>0.05).而Tnr147Ala基因多态性与血浆中TAFI活性及抗原水平之间的差异均无统计学意义(P>0.05).结论 TAFI具有抑制纤溶的作用,可能是冠心病发病的危险因子.TAFI编码区基因Thr325Ile的多态性对血浆中TAFI抗原水平有明显影响,但Thr325Ile、Thr147Ala的多态性与冠心病的发生没有明显的相关性.     

Impaired neurogenesis, neuronal loss, and brain functional deficits in the APPxPS1-Ki mouse model of Alzheimer's disease

Amyloid-β peptide species accumulating in the brain of patients with Alzheimer's disease are assumed to have a neurotoxic action and hence to be key actors in the physiopathology of this neurodegenerative disease. We have studied a new mouse mutant (APPxPS1-Ki) line developing both early-onset brain amyloid-β deposition and, in contrast to most of transgenic models, subsequent neuronal loss. In 6-month-old mice, we observed cell layer atrophies in the hippocampus, together with a dramatic decrease in neurogenesis and a reduced brain blood perfusion as measured in vivo by magnetic resonance imaging. In these mice, neurological impairments and spatial hippocampal dependant memory deficits were also substantiated and worsened with aging. We described here a phenotype of APPxPS1-Ki mice that summarizes several neuroanatomical alterations and functional deficits evocative of the human pathology. Such a transgenic model that displays strong face validity might be highly beneficial to future research on AD physiopathogeny and therapeutics.     

羟丁酸钠对缺氧缺血后新生大鼠海马CA1区Bcl-2、Bax蛋白表达的影响

目的：观察羟丁酸钠(GHB)对新生大鼠缺氧缺血性脑损伤（HIBD）后海马CA1区神经元Bcl-2、Bax蛋白表达的影响。方法：生后 7 d SD大鼠采用Rice等法，制成HIBD动物模型。新生大鼠随机分成假手术（sham）组、缺氧缺血（HI）组、GHB组。其中GHB组包括GHB50（50 mg/kg）、GHB100（100 mg/kg）、GHB200（200 mg/kg）亚组。各组在缺氧完成后 1 h、3 h、24 h、72 h 和 168 h 时点取脑切片作HE染色，用免疫组化染色观察Bcl-2、Bax蛋白的表达。结果：①光镜下HE染色结果：HI组海马CA1区锥体细胞排列紊乱，锥体细胞减少，海马带宽窄不一，可见细胞肿胀和核碎裂。GHB50组和GHB100组可减轻锥体细胞层病理改变。②免疫组化染色结果：HI组缺血缺氧后1h海马CA1区 Bcl-2、Bax表达开始增强，24 h 时达到高峰，其后逐渐减弱。在GHB50组和GHB100组可使Bcl-2表达明显高于HI组（P<0.05，P<0.01），Bax表达明显低于HI组（P<0.05，P<0.05）。结论：GHB可通过对Bcl-2、Bax表达的调控抑制新生大鼠HIBD后海马CA1区神经元损伤。     

十全大补汤对阿尔茨海默病小鼠骨髓源性细胞向脑内迁移及分化的影响

目的探讨十全大补汤对阿尔茨海默病(AD)小鼠骨髓源性细胞(BMDC)向脑内迁移及分化的影响。方法将增强型绿色荧光蛋白(GFP)转基因小鼠的骨髓细胞通过股静脉移植入实验小鼠制作成嵌合鼠模型,并通过海马内注射纤维化Aβ1-42(fAβ42)建立AD模型,分为实验组(口服十全大补汤组)和对照组(给水组)。利用流式细胞术检测鼠血中GFP及CD11b阳性细胞比例,利用免疫荧光染色法检测鼠脑海马fAβ42注射病灶及病灶周围GFP阳性细胞的分布,利用免疫组化染色法检测鼠脑非病灶临近部位GFP阳性细胞的分布,利用免疫荧光染色法确定鼠脑GFP细胞的表型。结果骨髓移植成功,嵌合鼠79%以上血白细胞由移植来源的骨髓细胞产生,十全大补汤能够促进血中CD11b阳性的单核巨噬细胞系统的增殖。注射fAβ42能够引起BMDC向病灶处的迁移和聚集,实验组和对照组间无明显差异;但十全大补汤可以明显增加距离病灶区相对远的脑区的BMDC数量。脑内GFP细胞呈现小胶质细胞(MG)表型。结论十全大补汤能促进AD小鼠血单核巨噬细胞增殖,引起BMDC归巢,进而分化为MG,加强了对fAβ42的吞噬,同时在非病变脑区起免疫监督作用。在应用BMDC治疗AD等神经系统疾病中,同时应用十全大补汤,提供了一种新的治疗契机。     

丁苯酞预处理对脑缺血再灌注损伤大鼠基质金属蛋白酶-9、基质金属蛋白酶组织抑制因子-1和血脑屏障的影响

目的:探讨丁苯酞预处理对脑缺血再灌注损伤大鼠基质金属蛋白酶-9(MMP-9)、基质金属蛋白酶组织抑制因子-1(TIMP-1)和血脑屏障的影响.方法:90只雄性SD大鼠随机分为假手术组,模型组,NBP预处理低剂量组、中剂量组、高剂量组.采用线栓法制作大脑中动脉栓塞(MCAO)模型,缺血2h再灌注24 h后以干湿重法测定脑组织含水量,伊文思蓝(EB)评估血脑屏障的破坏程度,实时PCR检测MMP-9及TIMP-1 mRNA的表达水平.结果:脑缺血再灌注后,脑组织含水量及EB含量明显增加,MMP-9和TIMP-1表达均增强,与假手术组比较差异有统计学意义.丁苯酞预处理各组脑组织含水量及EB含量较模型组明显下降,MMP-9表达显著减少,TIMP-1表达明显增加,丁苯酞预处理中、高剂量组差异无统计学意义.结论:丁苯酞预处理对脑缺血再灌注损伤大鼠可通过调节MMP-9/TIMP-1的表达,降低血脑屏障通透性,减轻脑水肿,发挥预防性保护作用.     

The effect of peripheral nerve injury on disease progression in the SOD1(G93A) mouse model of amyotrophic lateral sclerosis

Around 20% of familial cases of amyotrophic lateral sclerosis have been shown to carry mutations in Cu/Zn superoxide dismutase 1 (Cu/Zn SOD1). Transgenic mice over-expressing human mutant SOD1 genes have been developed and in this study we examined the effect of nerve injury on disease progression in these mice. Firstly, disease progression in uninjured mice was characterised using physiological methods. Muscle force, contractile characteristics and motor unit survival was established at 90 days, an early symptomatic stage and also at the end-stage of the disease, at 130 days. In addition, muscle histochemistry was examined and the extent of motoneuron survival established morphologically. By 90 days of age, there is a significant reduction in muscle force, and nearly 40% of motoneurons within the sciatic motor pool have already died. By 130 days, the muscles are significantly weaker, and there is a dramatic change in the phenotype of extensor digitorum longus (EDL), which changes from a fast fatigable muscle, to a fatigue resistant muscle with a high oxidative capacity. By this stage of the disease, only 40% of motor units in EDL survive, with only 29% of motoneurons surviving within the sciatic motor pool. Following injury to the sciatic nerve in SOD1^(G93A) mice, there is an acceleration in disease progression so that 90 day old mice show deficits that are only seen at the end stage in uninjured SOD1^(G93A) mice. It is therefore possible that mutant SOD1 toxicity increases the vulnerability of motoneurons and muscles to stressful stimuli such as nerve injury.     

G1254023X对白细胞介素6受体、趋化因子CX3CL1的抑制作用及其对冠心病的影响

目的 通过检测G1254023X干预的冠心病(CHD)小鼠主动脉血管直径及白细胞介素6受体(IL-6R)、趋化因子Chemokine(C-X3-C motif) ligand 1(CX3CL1)的表达,初步探究去整合素和金属蛋白酶10(ADAM10)影响CHD的机制.方法 用高脂高糖饲料饲养ApoE基因敲除小鼠制备CHD小鼠模型;采用B超法测量G1254023X组、模型组及空白对照组小鼠的主动脉血管直径;采用酶联免疫吸附实验(ELISA)分别检测三组小鼠外周血IL-6R、CX3CL1的浓度;采用苏木素-伊红染色法(HE)检测小鼠主动脉组织的病理变化;分别用蛋白免疫印记法(WB),免疫组织化学法(IHC)检测三组小鼠主动脉组织中IL-6R、CX3CL1的表达差异.测量G1254023X组、模型组及空白对照组小鼠的主动脉血管直径.结果 模型组小鼠主动脉血管直径显著大于G1254023X组;模型组小鼠主动脉组织病理学变化大于G1254023X组;外周血样本和主动脉组织中IL-6R、CX3CL1浓度G1254023X组显著低于模型组;各项指标G1254023X组与空白对照组无显著差异.结论 特异性ADAM10抑制剂G1254023X可以有效缓解CHD小鼠主动脉血管直径狭窄,抑制IL-6R、CX3CL1的表达,延缓冠心病发展.     

分泌型重组多肽sPD-1-CellⅠ(P/C-1)调节免疫细胞功能活性及抗肿瘤效应的研究

目的构建双结构域重组多肽sPD-1-Cell Ⅰ（P/C-1）分泌型真核表达载体，并研究体内外表达重组多肽在调节免疫细胞功能活性及抗肿瘤方面的作用和机制。方法用PCR方法分别扩增出编码PD-1胞外结构域的cDNA与编码CH50 CellⅠ结构域的cDNA，3片段连接法插入分泌型真核表达载体pSecTagA中，获得真核表达载体pP／C-1；脂质体介导体外转染BHK细胞，G418筛选出阳性克隆，RT-PCR及免疫印迹检测重组多肽P／C-1的表达，MTT法检测表达产物对脾淋巴细胞和腹腔巨噬细胞杀伤活性的影响，建立小鼠H22肝细胞癌移植瘤模型，裸DNA肌肉注射法分别于体内转染sPD-1、CH50和P／C-1基因，观察并比较各处理因素对小鼠的肿瘤生长的抑制作用。结果酶切及测序鉴定结果表明重组多肽P／C-1真核表达载体构建成功，在BHK细胞培养上清中检测到重组多肽P/C-1的表达，后者能显著增强脾淋巴细胞和腹腔巨噬细胞对H22细胞的杀伤作用，体内实验表明，P/C-1转染对肿瘤生长的抑制作用强烈而持久，显著优于sPD-1和CH50治疗组。结论重组多肽P／C-1真核表达载体构建成功，表达产物P／C-1兼有sPD-1和CH50的生物学功能，能够激活巨噬细胞和脾淋巴细胞，发挥二者协同抗肿瘤作用，从而将非特异性和特异性抗肿瘤免疫有机地结合起来，为肿瘤基因治疗提供新的思路。     

Inhibitory effect of ketamine on phosphorylation of the extracellular signal-regulated kinase1/2 following brain ischemia and reperfusion in rats with hyperglycemia

To determine if the inhibitory effects of ketamine on the extracellular signal-regulated kinase (ERK) 1/2 are involved in reduction of the hyperglycemia-exaggerated cerebral ischemic lesion, rats with normoglycemia, hyperglycemia, or hyperglycemia supplemented with ketamine were subjected to 15 min of forebrain ischemia, and then, reperfusion for 0.5, 1, and 3h. Phosphorylation of ERK1/2 in the brain tissues was assessed by immunohistochemistry and Western blot analysis. In rats with normoglycemia, we demonstrated a moderate increase of the ERK1/2 phosphorylation in the cingulum cortex and hippocampus CA3 following an ischemic intervention. It quickly dropped to control levels after reperfusion for 0.5h. In rats with hyperglycemia, however, the increase of the ERK1/2 phosphorylation in these areas was significantly higher in all animals reperfused. The neuronal death, detected by the TdT-mediated-dUTP nick end labeling assays, was found in the cingulum cortex (5.23+/-2.34, per high power feild) and hippocampus CA3 areas (6.29+/-3.68, per 1mm(2)) in hyperglycemic group after reperfusion for 3h. With ketamine treatment, the ERK1/2 phosphorylation in cingulum cortex and hippocampus CA1 and CA3 areas was found to be the same as that in normoglycemia rats. Our results suggest that hyperglycemia may increase the ischemic insult through modulation of the signal transduction pathways involving ERK1/2. The inhibitory effects of ketamine on the hyperglycemia-activated ERK1/2 phosphorylation are probably through inhibition of the N-methyl d-aspartate-mediated calcium influx, which subsequently reduce the hyperglycemia-exaggerated cerebral damage.     

Neuropep-1 ameliorates learning and memory deficits in an Alzheimer's disease mouse model,increases brain-derived neurotrophic factor expression in the brain,and causes reduction of amyloid beta plaques

Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloid beta (Aβ) deposits, hyperphosphorylated tau deposition, and cognitive dysfunction. Abnormalities in the expression of brain-derived neurotrophic factor (BDNF), which plays an important role in learning and memory formation, have been reported in the brains of AD patients. A BDNF modulating peptide (Neuropep-1) was previously identified by positional-scanning synthetic peptide combinatorial library. Here we examine the neuroprotective effects of Neuropep-1 on several in vitro neurotoxic insults, and triple-transgenic AD mouse model (3xTg-AD). Neuropep-1 protects cultured neurons against oligomeric Aβ_1–42, 1-methyl-4-phenylpyridinium, and glutamate-induced neuronal cell death. Neuropep-1 injection also significantly rescues the spatial learning and memory deficits of 3xTg-AD mice compared with vehicle-treated control group. Neuropep-1 treatment markedly increases hippocampal and cortical BDNF levels. Furthermore, we found that Neuropep-1-injected 3xTg-AD mice exhibit dramatically reduced Aβ plaque deposition and Aβ levels without affecting tau pathology. Neuropep-1 treatment does not alter the expression or activity of full-length amyloid precursor protein, α-, β-, or γ-secretase, but levels of insulin degrading enzyme, an Aβ degrading enzyme, were increased. These findings suggest Neuropep-1 may be a therapeutic candidate for the treatment of AD.     

Display of the VP1 epitope of foot-and-mouth disease virus on bacteriophage T7 and its application in diagnosis

Foot-and-mouth disease (FMD) is a highly contagious epidemic disease threatening the cattle industry since the sixteenth century. In recent years, the development of diagnostic assays for FMD has benefited considerably from the advances of recombinant DNA technology. In this study, the immunodominant region of the capsid protein VP1 of the foot-and-mouth disease virus (FMDV) was fused to the T7 bacteriophage and expressed on the surface of the bacteriophage capsid protein. The recombinant protein of about 42 kDa was detected by the anti-T7 tag monoclonal antibody in Western blot analysis. Phage ELISA showed that both the vaccinated and positive infected bovine sera reacted significantly with the recombinant T7 particle. This study demonstrated the potential of the T7 phage displaying the VP1 epitope as a diagnostic reagent.