稳定表达GFP-Parkin融合蛋白的SH-SY5Y细胞系的建立和功能初探

目的:建立稳定表达GFP-Parkin的SH-SY5Y细胞系,并检测Parkin对MPP~+引起的SH-SY5Y细胞损伤的保护作用。方法:将Parkin编码序列克隆到载体pEGFP-C1中,构建重组质粒pEGFP-Parkin,转染SH-SY5Y细胞,通过G418筛选,建立稳定表达GFP-Parkin的SH-SY5Y细胞系;荧光显微镜和Western印迹鉴定Parkin表达,MTT法检测Parkin对MPP~+致细胞损伤的保护作用。结果:酶切鉴定及测序结果表明重组质粒pEGFP-Parkin构建正确;荧光显微镜下可见细胞内有GFP-Parkin的融合表达,Western印迹检测发现相对分子质量79×103的蛋白条带;MTT结果显示Parkin能够减弱MPP~+对SH-SY5Y细胞的损伤,与对照组相比,存活率高约15%,差异显著(P0.05)。结论:构建了稳定表达GFP-Parkin的SH-SY5Y细胞系,为进一步研究Parkin的细胞保护作用和其他功能机制奠定了基础。     

前列腺细胞REGⅣ基因功能的初步研究

目的:探讨人再生基因Ⅳ(REGIV)在前列腺细胞中的表达及意义.方法:构建REGIV基因的全序列过表达质粒.将全序列过表达质粒采用脂质体转染的方式转入前列腺细胞系PC-3中.应用Real-time-PCR方法检测REGIV基因mRNA表达,Westembloting检测REGIV基因蛋白质表达,MTT法分析细胞增殖活性.结果:通过荧光显微镜观察计数,细胞转染成功.REGIV基因的全序列过表达使REGIV基因mRNA的表达,蛋白表达提高,细胞增殖能力增强.结论:应用全序列过表达技术可以使前列腺癌REGIV表达水平特异性增高.前列腺癌增值能力的增强说明REGW可能与肿瘤快速增长有关.     

小鼠DLL1真核表达载体的构建及其在肿瘤细胞中的表达

目的:构建带绿色荧光蛋白的小鼠DLL1全长基因真核表达载体,并在肿瘤细胞中表达。方法:利用PCR特异性引物扩增出DLL1基因全长,将克隆的基因片段插入带绿色荧光蛋白的真核表达载体pIRES2-EGFP质粒中。然后利用脂质体将重组质粒pIRES2-EGFP-DLL1转染进小鼠B16黑色素瘤细胞中,并通过G418筛选后选取生长良好、荧光强度高的三株单克隆进行mRNA水平DLL1表达的鉴定。结果:成功扩增小鼠DLL1的全长基因。克隆入质粒载体后,通过DNA序列测定证实其序列正确。将构建的pIRES2-EGFP-DLL1质粒转染小鼠B16黑色素瘤细胞,经过G418筛选和荧光显微镜观察后,挑选得到GFP阳性率90%以上的稳定转染细胞株。RT-PCR检测稳定转染细胞的mDLL1的表达显著增加,进一步证实了pIRES2-EGFP-DLL1的表达效能。结论:成功构建了小鼠DLL1基因的真核表达质粒,证实其在真核细胞B16中可以表达。     

Mpl与绿色荧光蛋白融合基因的真核载体构建及表达

目的:探索Mpl与绿色荧光蛋白GFP基因共同转粢哺乳动物细胞NIH3T3的方法.方法:采用PCR方法将GFP基因与Mpl基因构建融合荧光蛋白的真核表达载体,用脂质体介导转染NIH3T3细胞和筛选稳定细胞系,使用荧光显微镜方法和Westernblotting检测转染效果.结果:利用PCR方法有效扩增了Mpl基因,构建了融合荧光蛋白的真核表达载体,序列分析表明所构建的含Mpl基因的质粒与设计相同,使用荧光显微镜方法和Western blotting检测Mpl融合绿色荧光蛋白表达载体成功转染NIH3T3细胞.结论:成功构建了Mpl荧光表达载体,融合基因可以在NIH3T3细胞中稳定表达,为进一步研究Mpl的生物学活性及其与hNUDC蛋白相互作用提供了重要的理论依据.     

PPARγ基因真核表达载体的构建及其在乳腺癌MDA-MB-231细胞中的表达

目的:构建以绿色荧光蛋白(GFP)为报告基因的重组表达质粒pEGFP-C1-PPARγ,观察小鼠PPARγ基因在MDA-MB-231细胞中的表达及定位.方法:采用克隆和亚克隆技术构建小鼠PPARγ基因真核表达栽体,脂质体Lip2000介导转染MDA-MB-231细胞,real-time PCR和western-blot验证其mRNA和蛋白的表达,荧光显微镜观察该基因亚细胞定位.结果:酶切和测序结果证实重组质粒含有PPARγ编码区序列且插入方向正确,转染后观察该基因亚细胞定位于胞核,胞质有弥散分布.结论:成功构建了小鼠PPARγ基因真核表达载体,该基因在MDA-MB-231细胞中成功表达,PPARγ基因主要集中表达于胞核.     

小鼠DLL1真核表达载体的构建及其在肿瘤细胞中的表达

目的：构建带绿色荧光蛋白的小鼠DLL1全长基因真核表达载体,并在肿瘤细胞中表达。方法：利用PCR特异性引物扩增出DLL1基因全长,将克隆的基因片段插入带绿色荧光蛋白的真核表达载体pIRES2-EGFP质粒中。然后利用脂质体将重组质粒pIRES2-EGFP-DLL1转染进小鼠B16黑色素瘤细胞中,并通过G418筛选后选取生长良好、荧光强度高的三株单克隆进行mRNA水平DLL1表达的鉴定。结果：成功扩增小鼠DLL1的全长基因。克隆入质粒载体后,通过DNA序列测定证实其序列正确。将构建的pIRES2-EGFP-DLL1质粒转染小鼠B16黑色素瘤细胞,经过G418筛选和荧光显微镜观察后,挑选得到GFP阳性率90%以上的稳定转染细胞株。RT-PCR检测稳定转染细胞的mDLL1的表达显著增加,进一步证实了pIRES2-EGFP-DLL1的表达效能。结论：成功构建了小鼠DLL1基因的真核表达质粒,证实其在真核细胞B16中可以表达。     

GDF5基因真核表达载体的构建及其在恒河猴骨髓间充质干细胞中的表达

目的克隆人软骨组织生长分化因子5（GDF5）基因及构建GDF5基因真核表达载体,观察其在恒河猴骨髓间充质干细胞（MSCs）中的表达情况。方法采用反转录聚合酶链式反应（RT-PCR）从人胎儿软骨组织克隆hGDF5基因全长cDNA,插入pEGFP-C2载体,构建重组真核表达质粒pEGFP-C2-GDF5。重组质粒脂质体介导法转染MSCs细胞,荧光显微镜观察报告基因的表达,RT-PCR法检测目的基因表达。结果成功克隆人软骨组织GDF5基因和构建GDF5真核表达质粒pEGFP-C2-GDF5,克隆在载体上的基因长度为1505bp,包含全部cDNA编码序列1505bp,测序显示与Genbank上的序列一致。重组质粒转染恒河猴MSCs细胞得到表达,绿色荧光蛋白在转染24h后开始表达,72h达高峰,然后表达逐渐减弱。转染后72h可检测到GDF5mRNA表达。结论人GDF5基因在恒河猴MSCs细胞的成功表达为应用恒河猴模型开展基于细胞的基因疗法修复骨和软骨损伤研究奠定了必要基础。     

Beclin-1 shRNA对低氧诱导的SH-SY5Y细胞自噬的影响

目的：构建Beclin-1基因短发夹干扰RNA（shRNA）慢病毒载体,感染人SH-SY5Y细胞,观察沉默Beclin-1基因后低氧对SH-SY5Y细胞自噬的影响。方法：构建特异性靶向Beclin-1基因的shRNA慢病毒表达载体和阴性对照序列慢病毒载体;再将载体转染入SH-SY5Y细胞;RT-PCR检测Beclin-1的mRNA表达;Western blot检测Beclin-1蛋白表达;CCK-8法测定Beclin-1 shRNA对SH-SY5Y细胞活力的影响。再将空白对照、阴性对照、转染型三种细胞分别以21%常氧及5%低氧培养,Western blot检测各组细胞LC3蛋白表达;电镜观察自噬小体。结果：Beclin-1 shRNA能明显抑制SH-SY5Y细胞Beclin-1的mRNA及蛋白的表达;沉默Beclin-1基因后,Beclin-1 shRNA组细胞存活率与阴性对照组相比无差异;成功建立了稳定表达Beclin-1 shRNA的SH-SY5Y细胞。5%低氧处理后,与阴性对照组相比较,Beclin-1 shRNA组细胞中LC3Ⅱ/LC3Ⅰ比值下调,细胞内自噬小体数量减少。结论：慢病毒介导的Beclin-1shRNA对SH-SY5Y细胞的活力无影响,但可以抑制低氧诱导的自噬。     

抗病毒基因MxA真核表达载体的构建及在鸡细胞中的表达

将人抗病毒蛋白基因MxA与携带增强型绿色荧光蛋白(EGFP)基因的真核表达质粒重组后构建MxA基因真核表达载体pEGFP-C1-MxA.经PCR和酶切方法鉴定后,重组质粒在脂质体介导下转染鸡成纤维细胞和睾丸组织原代细胞,通过荧光观察,RT-PCR及细胞免疫组化检测目的基因的表达.结果表明,MxA基因片段已经被克隆到pEGFP-C1表达载体,成功构建了MxA基因真核表达载体pEGFP-C1-MxA.经该重组质粒转染后的鸡细胞的胞质中呈现颗粒状分布的绿色荧光,RT-PCR扩增出EGFP和MxA基因的特异性片断,免疫组化结果显示EGFP报告基因在细胞内的阳性表达,并表现出MxA的表达特征,间接证明了MxA可在鸡细胞中表达.MxA基因真核表达载体的成功构建以及在鸡细胞中的表达为进一步研究MxA基因在抗禽病毒性疾病中的应用打下了基础.     

PPARγ基因真核表达载体的构建及其在乳腺癌MDA—MB-231细胞中的表达

目的：构建以绿色荧光蛋白（GFP）为报告基因的重组表达质粒pEGFP—C1—PPARγ,观察小鼠PPARγ基因在MDA-MB-231细胞中的表达及定位。方法：采用克隆和亚克隆技术构建小鼠PPARγ基因真核表达载体,脂质体Lip2000介导转染MDA—MB-231细胞,real—time PCR和western—blot验证其mRNA和蛋白的表达,荧光显微镜观察该基因亚细胞定位。结果：酶切和测序结果证实重组质粒含有PPAIh编码区序列且插入方向正确,转染后观察该基因亚细胞定位于胞核,胞质有弥散分布。结论：成功构建了小鼠PPARγ基因真核表达载体,该基因在MDA—MB-231细胞中成功表达,PPARγ基因主要集中表达于胞核。     

TET2在帕金森病细胞模型中的表达及机制研究

目的:迄今为止,帕金森病(PD)发生的分子机制尚未完全阐明,本研究旨在体外细胞模型中寻找PD新型表观遗传标志物,探索其发病机制。方法:本次研究使用的细胞为神经母细胞瘤细胞系SH-SY5Y。首先,我们用CCK-8检测细胞活力,选取合适浓度的MPP+构建PD细胞损伤模型。再用PBS和MPP+分别处理SH-SY5Y细胞,用RT-qPCR检测了几个甲基化酶与去甲基化酶DNMT1,DNMT3A,DNMT3B及TET1, TET2, TET3的mRNA的表达水平,并用蛋白印迹检测TET2蛋白水平,免疫荧光检测了TET2蛋白定位。进一步用慢病毒转染SH-SY5Y细胞敲低TET2后,检测细胞增殖。结果:本研究发现,MPP+对SH-SY5Y细胞增殖的抑制具有时间与浓度依赖性,我们最终选择2.5 mM MPP+作为后续的细胞处理浓度。与对照组相比,MPP+处理细胞TET2的mRNA及蛋白水平表达均增加,且蛋白进入细胞核增加;同时发现,敲低TET2表达可以延缓MPP+对SH-SY5Y细胞增殖的抑制作用。结论:在当前的研究中,我们报道了TET2蛋白可能是PD新型的表观遗传学标志物,提示我们将来也许可以使用TET2抑制剂来治疗PD,因此本研究有可能为PD提供新的治疗方向和靶点。     

miR-195通过下调IGF-1R的表达抑制胶质母细胞瘤的增殖和迁移

目的:探讨miR-195对胶质母细胞瘤(Glioblastoma,GBM)增殖和迁移的影响,并阐明其分子调控机制。方法:采用qRT-PCR检测不同级别胶质瘤中miR-195的表达。将miR-195转染至胶质瘤U251细胞后,应用qRT-PCR验证转染效率,MTT及划痕实验检测U251细胞的增殖及迁移能力的改变,qRT-PCR及Western blot检测胰岛素样生长因子1受体(Insulin-like growth factor 1receptor, IGF-1R)的mRNA和蛋白表达;利用质粒转染过表达miR-195后,同时过表达IGF-1R,再应用MTT及划痕实验检测U251细胞的增殖及迁移能力的变化。结果:随着胶质瘤级别的增加,miR-195的表达逐渐降低,各级别胶质瘤中miR-195的表达差异有统计学意义(P0.05)。体外转染miR-195至U251细胞24、48、72 h后,转染组细胞活力和迁移能力均较对照组显著降低(P0.05),细胞中IGF-1R的mRNA和蛋白的表达也明显减少(P0.05);通过转染IGF-1R过表达质粒可显著逆转miR-195过表达对U251细胞增殖及迁移的抑制作用。结论:miR-195可能通过下调IGF-1R的表达,进而抑制胶质母细胞瘤的增殖和迁移。     

SH-SY5Y细胞α-突触核蛋白的过表达可部分抵抗鱼藤酮诱导的氧化应激

帕金森病（Parkinson’s disease,PD）的发病机制涉及到遗传和环境因素。环境因素通过线粒休导致氧化应激和α-突触核蛋白（α—synuclein）聚集,但其确切的作用机制尚不明确。本文利用过表达α-突触核蛋白-增强型绿色荧光蛋白（enhanced green fluorescent protein．EGFP）的人多巴胺能神经母细胞瘤细胞株SH—SY5Y为模型,研究α-突触核蛋白对鱼藤酮诱导氧化应激的影响,从而进一步了解α-突触核蛋白和细胞存活之间的关系。（1）用荧光显微镜观察融合绿色荧光蛋白的α-突触核蛋白的表达情况;（2）用实时定量PCR检测α-突触核蛋白基因的表达;（3）用免疫细胞化学测定α-突触核蛋白的分布;（4）用不同浓度的鱼藤酮作用细胞后,以MTT法测细胞的活力、DCF法检测细胞的氧化应激状态、黄嘌呤氧化酶法检测超氧化物歧化酶的活力,并用流式细胞仪分析细胞的凋亡。实时定量PCR结果显示,α-突触核蛋白基因表达量在α-突触核蛋白过表达的细胞要高于SH—SY5Y细胞,在荧光显微镜下可见绿色荧光蛋白和α-突触核蛋白的表达。鱼藤酮可使细胞活力下降、线粒体complex Ⅰ的活性降低,诱导细胞内氧化应激,而过表达α-突触核蛋白的细胞可以部分抵抗鱼藤酮的毒性作用,表现为细胞抗氧化能力迅速增高（P〈0．05）和鱼藤酮诱导的细胞凋亡数目明显降低。本研究证明α-突触核蛋白对鱼藤酮产生的氧化应激有部分抵抗作用,而使过表达α-突触核蛋白的SH—SY5Y细胞对鱼藤酮的毒性作用表现出一定的耐受性。这种耐受性也可能是细胞对外界损害的一种代偿反应,从而促进细胞的存活。     

人冠状病毒OC43感染性克隆的构建

摘要 目的：构建携带绿色荧光报告基因的人冠状病毒OC43感染性克隆。方法：设计带有绿色荧光蛋白的人冠状病毒OC43感染性克隆基因组序列,分段合成后利用融合聚合酶链式反应等方法得到8个亚基因组片段,通过酵母转化关联重组技术获得重组质粒,转染HEK-293T细胞进行病毒拯救,收获转染细胞培养上清感染靶细胞分析病毒拯救情况。结果：获得人冠状病毒OC43感染性克隆重组质粒,将该质粒转染细胞后成功获得携带绿色荧光蛋白报告基因的人冠状病毒OC43重组病毒。结论：成功构建了人冠状病毒OC43感染性克隆并获得重组病毒,为针对冠状病毒的基础和应用研究提供了有效工具。     

Iron chelator Deferoxamine protects human neuroblastoma cell line SH-SY5Y from 6-Hydroxydopamine-induced apoptosis and autophagy dysfunction

BackgroundIntracellular iron involves in Fenton’s reaction-mediated Hydroxyl radical (OH·) generation by reacting with the neurotoxic agent 6-Hydroxydopamine (6-OHDA) autoxidation derivative Hydrogen Peroxide (H₂O₂). Several studies have been conducted so far on the neuroprotective activities of the iron chelator Deferoxamine (DFO) but little or no clear evidence about the underlying cellular mechanism is available.MethodsThe present study was conducted on Human neuroblastoma cell line SH-SY5Y in the absence or presence of 6-OHDA or H₂O₂ and / or DFO. Following incubation, cell viability assay, intracellular reactive oxygen species (ROS) determination, flow cytometric quantification of apoptotic cells followed by nuclear staining, intracellular tracking of transfected fusion construct of microtubule-associated protein 1B-light chain with Green fluorescent protein - Red fluorescent protein (LC3B-GFP-RFP reporters) and immunocytochemistry of intracellular Cathepsin protein by confocal microscopy, were conducted. In addition, western blotting was carried out to detect expressions of apoptotic and autophagy related proteins.ResultsThis study confirmed the neuroprotective potential of DFO by inhibiting 6-OHDA-mediated cell death and ROS generation. Reduced percentage of apoptotic cells and appearance of altered nuclei architecture followed by a reduced expression of cleaved PARP (Poly-ADP-ribose Polymerase) and cleaved Caspase-3 were observed upon DFO treatment against 6-OHDA, and as well as against H₂O₂ in SH-SY5Y cell lines. Besides, DFO induced the intracellular autophagolysosome formation (red puncta) rather than autophagosome (yellow puncta) only. Thereafter it was observed that DFO restored the expression of intracellular lysosomal protease Cathepsin and reduced the expression of the LC3-II.ConclusionTaken together, this study clearly demonstrated that the anti-Fenton activity of DFO inhibited apoptosis and caused blockade in ALP or autophagy dysfunction in SH-SY5Y cell lines. These outcomes further suggest that DFO provides neuroprotection by inhibiting apoptosis and inducing the progression of Autophagy- lysosomal pathway (ALP).     

Intron 2 of human beta-globin in 3′-untranslated region enhances expression of chimeric genes

The possibility of enhancing heterologous gene expression in mammalian cells by the introduction of an intron in 3′ untranslated region (UTR) was investigated. To this end, a fragment of human betaglobin gene with intron 2 and flanked exon regions was introduced into the vector-encoding green fluorescent protein TagGFP2 after the TagGFP2 stop-codon (Int⁺). The distance between the stop-codon and the exon junction was 35 nucleotides. It ensured that Int+ mRNA was resistant to degradation by nonsense mediated decay (NMD) machinery. A control vector Intcontained corresponding intronless sequence of the beta-globin mRNA. On the same plasmid, the second gene encoded far-red fluorescent protein Katushka was used to normalize fluorescence for transfection efficiency and expression level in individual cells. Transiently transfected HEK293T cells were analysed by flow cytometry. It was shown that cells transfected with plasmid carrying the Int+ gene possess 1.8 ± 0.2 fold higher green fluorescence compared to Intcells. The observed effect was used to enhance expression of destabilized variants of yellow fluorescent protein TurboYFP-dest with high degradation rate in mammalian cells. We believe that introduction of beta-globin intron in the 3′-UTR of the chimeric gene can be used to enhance its expression and may be advantageous in some cases when usage of 5′ UTR intron is inappropriate.     

A high-throughput drug screen targeted to the 5'untranslated region of Alzheimer amyloid precursor protein mRNA

The authors employed a novel approach to identify therapeutics effective in Alzheimer disease (AD). The 5'untranslated region (5'UTR) of the mRNA of AD amyloid precursor protein (APP) is a significant regulator of the levels of the APP holoprotein and amyloid beta (Abeta) peptide in the central nervous system. The authors generated stable neuroblastoma SH-SY5Y transfectants that express luciferase under the translational control of the 146-nucleotide APP mRNA 5'UTR and green fluorescent protein (GFP) driven by a viral internal ribosomal entry site. Using a high-throughput screen (HTS), they screened for the effect of 110,000 compounds obtained from the library of the Laboratory for Drug Discovery on Neurodegeneration (LDDN) on the APP mRNA 5'UTR-controlled translation of the luciferase reporter. This screening yielded several nontoxic specific inhibitors of APP mRNA 5'UTR-driven luciferase that had no effect on the GFP expression in the stable SH-SY5Y transfectants. Moreover, these compounds either did not inhibit or inhibited to a much lower extent the expression of the luciferase reporter regulated by a prion protein (PrP) mRNA 5'UTR, used as an alternative mRNA structure to counterscreen APP mRNA 5'UTR in stably transfected SH-SY5Y cell lines. The hits obtained from this robust, specific, and highly quantitative HTS will be characterized to identify agents that may be developed into useful future therapeutic agents to limit APP translation and Abeta production for AD.     

UBE2T基因对结直肠细胞增殖和凋亡的影响

目的:探讨人类泛素结合酶E2T(Ubiquitin-conjugating enzyme E2T,UBE2T)基因对结肠细胞增殖和凋亡的影响。方法:体外培养人正常结直肠粘膜细胞FHC,采用将UBE2T基因慢病毒质粒转染至FHC细胞48 h后,通过MTT法检测细胞增殖情况,western blotting检测细胞中增殖相关蛋白UBE2T蛋白、Ki67、促凋亡蛋白Bax和抗凋亡蛋白Bcl-2的表达,流式细胞术检测细胞凋亡率。结果:与转染空质粒的FHC细胞相比,UBE2T基因慢病毒质粒转染FHC细胞48 h后,细胞增殖能力显著上调(P0.05),UBE2T蛋白明显增加,Ki67的表达明显增加(P0.05),细胞凋亡率显著降低(P0.05),且Bax的表达明显下调而Bcl-2的表达上调(P0.05)。结论:UBE2T基因能够促进正常结肠粘膜细胞的增殖,并抑制其凋亡。     

Effects of Amyloid Precursor Protein Overexpression on NF-κB,Rho-GTPase and Pro-Apoptosis Bcl-2 Pathways in Neuronal Cells

Background:Alzheimer’s disease (AD) is a neurodegenerative disorder that causes cognitive dysfunction. Previous studies have suggested that amyloid plaques, mainly comprising of amyloid-beta peptides, play a pivotal role in AD pathophysiology. This study focuses on the evaluation of the effects of amyloid precursor protein (APP) overexpression on NF-κB, Rho-GTPase and Bcl-2 mediated pro-apoptotic pathways in neuronal cells. Methods:A lentiviral transduction system was used to generate SH-SY5Y cells overexpressing APP. Immunoblotting was conducted to determine expression levels of NF-κB, Rho-GTPase, and Bcl-2 family proteins in the APP overexpressed cells.Results:In the NF-κB signaling pathway, APP-overexpressing SH-SY5Y cells showed that there was a reduction of p-NF-κB (p< 0.05) and IKKα. Subsequently, there was upregulation of protein expression of NF-Κb, IKKβ and IκBα. On the other hand, protein expression of RhoC (p< 0.05) and Rac1/2/3 was upregulated as compared to the control group. Meanwhile, a decrease in RhoA, Cdc42 (p< 0.05) and p-Rac1/cdc42 protein levels was observed in the APP-overexpressed group. Lastly, in the pro-apoptotic pathway, the expression of Bcl-2, Bid, Bok and Puma (p< 0.05) was up regulated in the APP-overexpressed group. Downregulation of Bad and Bim expression was observed in the APP-overexpressed as compared to the control group, and Bax expression remained unchanged in the APP-overexpressed group.Conclusion:APP overexpression regulated signaling in the NF-κB, Rho-GTPase and Bcl-2 family pathways in neuronal cells, suggesting that these are involved in promoting neuronal survival and modulating synaptic plasticity in AD. However, further studies are essential to elucidate the APP-mediated mechanism of action.Key Words: Alzheimer’s disease, Amyloid precursor protein, Bcl-2 family proteins, NF-κB, Rho-GTPase