Sirtuin 2 inhibitors rescue alpha-synuclein-mediated toxicity in models of Parkinson's disease

The sirtuins are members of the histone deacetylase family of proteins that participate in a variety of cellular functions and play a role in aging. We identified a potent inhibitor of sirtuin 2 (SIRT2) and found that inhibition of SIRT2 rescued alpha-synuclein toxicity and modified inclusion morphology in a cellular model of Parkinson's disease. Genetic inhibition of SIRT2 via small interfering RNA similarly rescued alpha-synuclein toxicity. Furthermore, the inhibitors protected against dopaminergic cell death both in vitro and in a Drosophila model of Parkinson's disease. The results suggest a link between neurodegeneration and aging.     

慢病毒载体介导的APP695过表达SH-SY5Y细胞系的构建和鉴定

目的通过构建pLVX-APP695-PGK-Puro慢病毒载体,用以建立可以稳定过表达APP695蛋白的SH-SY5YAPP695细胞株。方法利用PCR方法扩增目的基因片段APP695,并构建pLVX-APP695-PGK-Puro慢病毒载体,鉴定后将构建好的载体与慢病毒包装系统共转染293T细胞,并以最适感染复数感染神经母细胞瘤SH-SY5Y细胞,筛选稳转SH-SY5Y-APP695细胞株并用PCR和Western blot鉴定稳转株细胞APP695表达。结果对pLVX-APP695-PGK-Puro载体进行酶切鉴定及DNA测序证明构建过表达APP695的重组慢病毒载体成功,PCR和Western blot显示构建的SH-SY5Y细胞稳转株成功。结论成功构建APP695基因的慢病毒载体并成功构建了SH-SY5Y-APP695细胞株,该载体可在SH-SY5Y细胞株中高水平表达APP695。     

人B7-H4慢病毒表达载体的构建

目的构建人B7-H4慢病毒表达载体。方法将RT-PCR扩增的B7-H4基因全长编码序列克隆到慢病毒转移载体,通过脂质体转染293细胞,包装成人B7-H4慢病毒颗粒。RT-PCR、流式细胞术和Western blot鉴定B7-H4在重组慢病毒感染293细胞中表达,50%组织培养感染剂量法（TCID50法）检测重组慢病毒滴度。结果成功构建了pMD18-T-hB7-H4质粒和pEZ-Lv105-hB7-H4质粒。基因测序分析证实人B7-H4编码序列成功整合到质粒载体。TCID50法测定Lenti-hB7-9H4慢病毒滴度为1.7×10^9 copies/mL。RT-PCR、流式细胞术和Western blot证实Lenti-hB7-H4慢病毒转染细胞后可有效表达人B7-H4 mRNA和蛋白质。结论成功构建了表达人B7-H4的慢病毒颗粒。     

Hereditary early-onset Parkinson's disease caused by mutations in PINK1

Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the substantia nigra. We previously mapped a locus for a rare familial form of PD to chromosome 1p36 (PARK6). Here we show that mutations in PINK1 (PTEN-induced kinase 1) are associated with PARK6. We have identified two homozygous mutations affecting the PINK1 kinase domain in three consanguineous PARK6 families: a truncating nonsense mutation and a missense mutation at a highly conserved amino acid. Cell culture studies suggest that PINK1 is mitochondrially located and may exert a protective effect on the cell that is abrogated by the mutations, resulting in increased susceptibility to cellular stress. These data provide a direct molecular link between mitochondria and the pathogenesis of PD.     

Molecular pathways of neurodegeneration in Parkinson's disease

Parkinson's disease (PD) is a complex disorder with many different causes, yet they may intersect in common pathways, raising the possibility that neuroprotective agents may have broad applicability in the treatment of PD. Current evidence suggests that mitochondrial complex I inhibition may be the central cause of sporadic PD and that derangements in complex I cause alpha-synuclein aggregation, which contributes to the demise of dopamine neurons. Accumulation and aggregation of alpha-synuclein may further contribute to the death of dopamine neurons through impairments in protein handling and detoxification. Dysfunction of parkin (a ubiquitin E3 ligase) and DJ-1 could contribute to these deficits. Strategies aimed at restoring complex I activity, reducing oxidative stress and alpha-synuclein aggregation, and enhancing protein degradation may hold particular promise as powerful neuroprotective agents in the treatment of PD.     

梅花鹿Col X基因的RNAi重组慢病毒载体的构建及鉴定

研究十型胶原蛋白(Collagen type X,Col X),在软骨内成骨过程中所起的作用.本研究针对梅花鹿ColX基因设计筛选2条高分RNAi靶序列,在T4 DNA连接酶的作用下分别与慢病毒载体质粒plvthm连接,形成重组质粒S2-plvthm/S3-plvthm;PCR筛选阳性克隆并测序鉴定.用Lipofectamine 2000介导S2-plvthm/S3-plvthm,pCMVdr8.91,pMD2G三质粒共转染293T细胞.结果显示:转染24 h后,观察到表达荧光蛋白的293T细胞.收集培养液后进行1 000 g离心5 min,所得上清液含有重组慢病毒的组分.S2-plvthm/S3-plvthm上清液中病毒滴度分别达到9.96×107TU/L和7.18×107TU/L.以此病毒感染梅花鹿角柄骨膜细胞,并进行微粒体培养,72 h后出现肉眼可见的白色微团,该细胞团有荧光表达.本试验成功地构建了针对梅花鹿Col X基因的慢病毒裁体,为了研究Col X蛋白在鹿茸角骨化中的作用奠定了基础.     

靶基因Bi-1RNAi重组慢病毒载体的构建与鉴定

目的构建靶向人Bax Inhibitor-1（Bi-1）基因的shRNA慢病毒重组载体。方法借助siRNA设计工具,并结合文献资料选取Bi-1基因编码序列中有效的干扰靶点,根据连接载体中的酶切位点自行设计并人工合成干扰靶点的一对反义脱氧寡核苷酸链,先定向克隆到pU6载体（pU6-Bi-1-shRNA）,再经双酶切后克隆到慢病毒包装质粒LunIG,得到靶向Bi-1基因沉默的慢病毒包装重组质粒LunIG-Bi-1。重组质粒经PCR法进行初筛后,再通过双酶切电泳和目的基因沉默效果的检测保证插入序列的正确性。结果靶向沉默Bi-1基因的shRNA序列成功插入到慢病毒包装质粒LunIG中。结论靶向Bi-1基因沉默的慢病毒shRNA包装重组质粒构建成功。     

绵羊IGF1基因慢病毒表达载体的构建及其促肌细胞生长作用研究

【目的】克隆绵羊IGF-1基因CDS区,构建绵羊IGF-1基因慢病毒表达载体,分析IGF-1基因在绵羊成肌细胞增殖过程中的作用。【方法】提取绵羊肝组织总RNA,通过RT-PCR方法获得IGF-1全长CDS序列,经测序鉴定后与慢病毒载体pLEX-mcs连接,构建pLEX-IGF-1慢病毒重组表达质粒,并在293T细胞中进行病毒包装和生产。分离培养绵羊原代成肌细胞,并用重组慢病毒使其感染,建立稳定转染pLEX-IGF-1的绵羊成肌细胞系。通过绘制细胞生长曲线,分析过表达IGF-1对绵羊成肌细胞生长的影响;采用流式细胞仪检测细胞周期变化。【结果】克隆获得长518bp的IGF-1CDS区序列。成功构建了pLEX-IGF-1载体,其可在绵羊细胞系中进行稳定表达。通过Western blotting检测显示,IGF-1在293T细胞以及绵羊原代成肌细胞中获得表达,细胞生长曲线显示,稳定表达IGF-1的成肌细胞比对照细胞生长速度显著加快(第1天差异显著(P0.05),第2~6天差异极显著(P0.01));细胞周期测定结果显示,稳定表达IGF-1的成肌细胞比对照细胞较早进入S期,且在S期的细胞数目比对照细胞多29.35%。【结论】绵羊IGF-1能够有效促进绵羊成肌细胞的生长。     

An agonist of toll-like receptor 5 has radioprotective activity in mouse and primate models

The toxicity of ionizing radiation is associated with massive apoptosis in radiosensitive organs. Here, we investigate whether a drug that activates a signaling mechanism used by tumor cells to suppress apoptosis can protect healthy cells from the harmful effects of radiation. We studied CBLB502, a polypeptide drug derived from Salmonella flagellin that binds to Toll-like receptor 5 (TLR5) and activates nuclear factor-kappaB signaling. A single injection of CBLB502 before lethal total-body irradiation protected mice from both gastrointestinal and hematopoietic acute radiation syndromes and resulted in improved survival. CBLB502 injected after irradiation also enhanced survival, but at lower radiation doses. It is noteworthy that the drug did not decrease tumor radiosensitivity in mouse models. CBLB502 also showed radioprotective activity in lethally irradiated rhesus monkeys. Thus, TLR5 agonists could potentially improve the therapeutic index of cancer radiotherapy and serve as biological protectants in radiation emergencies.     

绵羊MSTN基因慢病毒表达载体的构建及其对成肌细胞的分化作用

【目的】构建新疆细毛羊MSTN基因慢病毒表达载体,研究其在细毛羊成肌细胞分化中的作用,并探讨其作用机制。【方法】采用RT-PCR技术,扩增MSTN编码区序列,克隆入plex-mcs慢病毒表达载体,构建plex-MSTN慢病毒表达载体,并进行酶切及测序鉴定。将plex-MSTN包装成plex-MSTN慢病毒。用酶消化法分离培养新疆细毛羊成肌细胞,慢病毒感染制备MSTN过表达成肌细胞系,通过马血清诱导分化,Western blotting检测分化细胞MSTN基因的表达,免疫荧光分析分化肌管的融合率及肌管直径,Realtime RT-PCR检测分化相关基因的表达。【结果】 克隆的新疆细毛羊MSTN基因编码区全长序列（1 128 bp）与NCBI上公布的序列99.9%同源,仅在外显子2上存在单碱基突变;Western blotting检测结果显示,MSTN过表达成肌细胞过表达MSTN蛋白;免疫荧光检测表明,MSTN过表达成肌细胞的肌管融合率与肌管直径分别为5.69%和12.35 μm,显著低于非转化成肌细胞（10.21%和18.5 μm）（P<0.05）;Realtime RT-PCR结果显示,MSTN过表达成肌细胞中的Myogenin、p21、MyoD-基因表达显著下调,Smad3基因表达极显著上调（P<0.01）。【结论】 成功构建了细毛羊MSTN基因慢病毒表达载体,MSTN基因对细毛羊成肌细胞的分化具有显著的抑制作用,确定了MSTN基因与Myogenin、p21、MyoD及Smad3基因在成肌细胞分化过程中的调控关系。     

Regulation of cell fate decision of undifferentiated spermatogonia by GDNF

The molecular control of self-renewal and differentiation of stem cells has remained enigmatic. Transgenic loss-of-function and overexpression models now show that the dosage of glial cell line-derived neurotrophic factor (GDNF), produced by Sertoli cells, regulates cell fate decisions of undifferentiated spermatogonial cells that include the stem cells for spermatogenesis. Gene-targeted mice with one GDNF-null allele show depletion of stem cell reserves, whereas mice overexpressing GDNF show accumulation of undifferentiated spermatogonia. They are unable to respond properly to differentiation signals and undergo apoptosis upon retinoic acid treatment. Nonmetastatic testicular tumors are regularly formed in older GDNF-overexpressing mice. Thus, GDNF contributes to paracrine regulation of spermatogonial self-renewal and differentiation.     

JSRV-env慢病毒过表达载体构建及其对NIH3T3细胞增殖的影响

为研究绵羊肺腺瘤病毒(Jaagsiekte sheep retrovirus,JSRV)囊膜蛋白(Envelope,env)对NIH3T3细胞(小鼠胚胎成纤维细胞)增殖的影响,构建pCMV-dR8.91-JSRV-env慢病毒过表达载体并感染NIH3T3细胞。将JSRV-env基因连接红色荧光慢病毒报告载体pCMV-dR8.91,基因测序正确后将载体命名为pCMV-dR8.91-JSRV-env。将pCMV-dR8.91-JSRV-env重组质粒和包装辅助质粒共转染HEK 293T细胞包装产生JSRV-env重组慢病毒。将重组慢病毒悬液利用超速离心沉淀法浓缩,real-time PCR测定病毒滴度。浓缩病毒转导NIH3T3细胞72h后,噻唑蓝(MTT)检测细胞增殖情况。结果显示:env同源重组入pCMV-dR8.91载体,测序结果与预期序列一致;pCMV-dR8.91-JSRV-env与包装辅助质粒共转染HEK 293T细胞72h,real-time PCR验证JSRV-env过表达极显著(P0.01),JSRV-env重组慢病毒平均滴度为2.99×10~8 IU/mL;MTT分析显示10μg JSR-env慢病毒感染NIH3T3细胞72h显著促进NIH3T3细胞增殖(P0.05)。综上,成功构建了JSRV-env慢病毒过表达载体,证实JSRV-env能够促进NIH3T3细胞增殖。     

Lewy bodies of Parkinson's disease contain neurofilament antigens

The Lewy body, a histological hallmark of Parkinson's disease, is a filamentous inclusion residing most prominently in pigmented neurons of the brainstem. Immunocytochemical reactions of Lewy bodies were examined with antisera to several filamentous proteins of the nervous system and positive reactions were found with those against neurofilaments. An abnormal organization of the neuronal cytoskeleton may be a pathological feature of Parkinson's disease.     

绿色荧光蛋白在IGF2b基因慢病毒载体感染鲤受精卵中的标记效果

以水母绿色荧光蛋白基因为模板进行PCR扩增得到目的基因(Green fluorescence protein, GFP),然后加上酶切位点BamHI和NheI,构建pLenti6.3IRESEGFP载体,转染DH5α感受态细胞进行菌落PCR,取阳性进行酶切鉴定,再取呈阳性的质粒进行测序,使用浓度为1 μg/μL的质粒与慢病毒表达载体进行连接,通过荧光显微镜观察到绿色荧光,表明本实验获得的GFP和慢病毒载体整合成功;用此转染293T细胞,通过荧光显微镜同样检测到了绿色荧光。使用建鲤的组织提取RNA,然后按照Fermentas公司的MMLV操作说明书进行反转录,得到IGF2b基因后加酶切位点进行扩增,将IGF2b整合到用GFP作为标记基因的慢病毒载体上,再以此转染建鲤未分裂的受精卵,48 h后通过荧光显微镜也观察到了绿色荧光蛋白的表达。试验表明绿色荧光蛋白在IGF2b基因慢病毒载体感染鲤受精卵中的标记是成功的。这些结果为基于含有GFP慢病毒转基因鱼育种技术的开发奠定了基础。     

Mercurial-induced transformation of myosin prevented by adenosine triphosphate and pyrophosphate

Adenosine triphosphate and pyrophosphate prevent the loss of Ca(//)-activated adenosine triphosphatase activity caused by high concentrations of mercurial sulfhydryl reagent. They concomitantly prevent the transformation of myosin into faster-sedimenting products. This is adduced as support for the hypothesis that the strategic sulfhydryl group is not binding adenosine triphosphate at the active site, but is initiating a conformational change upon its reaction with the mercurial reagent.     

Prolactin localization in the primate pituitary by immunofluorescence

Cells which contain prolactin were clearly distinguished from those which contain growth hormone in adult monkey pituitary glands by means of histologic and fluorescent antibody techniques. The results indicate that in primates, as well as in other mammals, prolactin is immunochemically distinguishable from growth homone.     

Parkinson's disease: activity of L-dopa decarboxylase in discrete brain regions

The activity of L-dopa decarboxylase was greatly reduced in the striatum, less so in the hypothalamus, and unchanged in the cortex of brains of patients with Parkinson's disease. However, it appears that even in the striatum enough activity remained to allow for the formation of dopamine from L-dopa in patients treated with large doses of L-dopa.