基于钙激活氯离子通道检测胞质内第二信使Ca2+

目的 建立一种基于钙激活氯离子通道(CaCC)可敏感检测胞质内第二信使Ca2+的细胞模型.方法 构建氯离子通道蛋白1(ANO1)和YFP-H148Q/I152 L真核表达载体,应用脂质体转染法构建共表达ANO1和YFP-H148Q/I152 L的FRT细胞,倒置荧光显微镜观察其表达情况,流式细胞仪检测细胞纯度;应用膜片...     

基于CaCC的P2ry2调节剂细胞筛选模型的建立及应用

目的:构建基于钙激活氯离子通道(CaCC)的高通量P2Y₂嘌呤受体(P2ry2)调节剂细胞筛选模型。方法:采用RT-PCR方法验证Fischer大鼠甲状腺滤泡上皮细胞(FRT细胞)中P2ry2的mRNA表达水平,切胶回收PCR扩增产物并进行序列测序和比对,进一步应用Western blot检测FRT细胞的P2ry2蛋白表达水平。构建钙激活氯离子通道ANO1和对卤族元素敏感的黄色荧光蛋白双突变体YFP-H148Q/I152L真核表达载体,应用脂质体转染、抗生素筛选和有限稀释,获取共表达ANO1和YFP-H148Q/I152L的FRT细胞。采用倒置荧光显微镜观察共表达ANO1和YFP-H148Q/I152L细胞的情况,并应用荧光淬灭动力学实验验证模型的有效性;荧光淬灭动力学实验验证细胞模型是否可筛选P2ry2调节剂,并应用Fura-2/AM荧光探针法检测细胞内游离钙的变化,探究胞内Ca²⁺浓度与P2ry2调节剂的剂量依赖关系;用Z′因子评价本模型的稳定性和可重复性。结果:FRT细胞内源性表达P2ry2;倒置荧光显微镜中观察到ANO1在细胞膜上表达...     

Ano2是钙激活氯离子通道的分子基础

目的 探讨Ano2是否为钙激活氯离子通道的分子基础.方法 用RT-PCR技术扩增Ano2编码基因,将Ano2连接到真核表达载体pEGFP-N3;通过脂质体介导将Ano2转染至FRT细胞,抗生素筛选获得稳定表达Ano2的细胞系;倒置荧光显微镜下观察Ano2在FRT细胞中的表达和分布,Western blot检测Ano2的表达;全细胞膜片钳技术研究Ano2的电生理学特性.结果 成功构建pEGFP-Ano2真核表达载体;Ano2表达在FRT细胞膜上;Ano2电流呈Ca2+、时间和电压依赖性,电流和电压关系呈外向整流.结论 Ano2是钙激活氯离子通道的分子基础.     

稳定表达UT-A2的FRT细胞系的建立与鉴定

目的：建立稳定表达尿素通道蛋白A2（UT—A2）的FRT细胞系，为寻找UT—A2抑制剂提供细胞模型。方法：通过真核表达质粒-脂质体介导的方法，将UT—A2 cDNA与真核表达载体pUB6／V5连接后的重组质粒转染入FRT细胞，经稳定筛选建立稳定表达UT—A2的FRT细胞系。功能检测实验将细胞分为对照组和稳定转染组，用2mol／L尿素负荷试验检测稳定表达UT—A2的FRT细胞膜的尿素通透性。结果：经BSD筛选21d后得到稳定表达UT—A2的细胞株；Western blotting证实UT—A2蛋白稳定表达；免疫荧光分析结果提示UT—A2的质膜定位。2mol／L尿素试验证实了该细胞系具有明显尿素通透性。结论：在非肾脏上皮细胞获得了稳定质膜定位表达UT—A2的FRT细胞株，该细胞株可用于UT—A2抑制剂的筛选。     

SOD1真核表达载体的构建及表达

目的:构建人铜锌超氧化物歧化酶(SOD1)基因真核表达载体,并在HeLa细胞中进行表达。方法:应用RT-PCR从人外周血中扩增SOD1基因开放阅读框(ORF),采用TA克隆技术,将目的片段插入到pUCm-T载体中进行鉴定,重组的质粒命名为pUCm-T-SOD1。随后,将SOD1进一步克隆到真核表达载体pTracer-CMV/Bsd中。用脂质体将经过测序、验证的重组pTracer-CMV/Bsd-SOD1质粒转染HeLa细胞,荧光显微镜下观察绿色荧光蛋白的表达,转染HeLa细胞,经杀稻瘟菌素(Blasticidin)筛选4周,用RT-PCR、Western blot检测SOD1的表达。结果:成功构建了pTracer-CMV/Bsd-SOD1真核表达质粒,转染HeLa细胞,发现转染成功的细胞均发绿色荧光;RT-PCR及Western blot检测结果表明,所转染的SOD1在HeLa细胞中成功表达。结论:成功构建了能够同时表达绿色荧光蛋白和SOD1的真核表达质粒pTracer-CMV/Bsd-SOD1,为进一步研究SOD1在基因治疗中的作用奠定了基础。     

真核表达载体pEGFP-claudin-1的构建及其在293T细胞中的表达

目的:构建真核表达载体pEGFP-claudin-1,并在293T细胞中进行表达.方法:用反转录聚合酶链反应(RT-PCR)方法扩增claudin-1开放读码框(ORF)基因,将其插入到pEGFP-C3载体的Xho Ⅰ和BamH Ⅰ酶切位点,构建真核表达载体pEGFP-claudin-1,酶切鉴定并测序.通过脂质体法转染293T细胞,进行荧光检测和Western blot分析.结果:构建了含有claudin-1 ORF的真核表达质粒pEGFP-claudin-1,转染293T细胞后,经荧光可见细胞膜有EGFP-claudin-1 融合蛋白的表达,Western blot检测发现有相对分子质量(Mr)49 000的蛋白条带.结论:成功地构建真核表达载体pEGFP-claudin-1,并在293T细胞中表达,为研究claudin-1的功能奠定了基础.     

小鼠Tim-2基因在L929细胞表达后促进铁蛋白的内吞

目的获取BALB／c小鼠T细胞免疫球蛋白域．黏蛋白域蛋白-2（T cell immunoglobulin and mucin domain containing molecules-2，Tim-2）基因，构建真核表达载体在L929细胞中表达并研究其功能。方法RT-PCR获取BALB／c小鼠Tim-2基因，T-A克隆后经测序鉴定后酶切，插入pEGFP-N1真核表达载体，脂质体转染L929细胞，荧光显微镜观察外源基因的表达，然后加入铁蛋白与转染细胞作用。结果外源基因在L929细胞中得到高效表达，荧光显微镜的结果显示，外源基因定位于细胞膜上，并能促进细胞对铁蛋白的内吞。结论Tim-2基因在真核细胞中表达后定位于细胞膜上，并促进细胞对铁蛋白的内吞。     

真核表达载体pIRES2-EGFP-Axin的构建及其在神经胶质瘤细胞内的表达

目的:构建真核表达载体pIRES2EGFPAxin,并在神经胶质瘤细胞系C6中进行表达。方法:用PCR的方法扩增Axin基因,构建真核表达载体pIRES2EGFPAxin,经NheI及SalI双酶切鉴定并测序。通过脂质体法转染C6细胞,用荧光显微镜检测细胞中增强型绿色荧光蛋白(EGFP)的表达,用免疫组化染色的方法检测细胞中Axin的表达。结果:构建了真核表达载体pIRES2EGFPAxin,用脂质体法转染神经胶质瘤细胞C6后,经荧光显微镜和免疫组化染色法检测,可见细胞内有EGFP及Axin的表达。结论:成功地构建真核表达载体pIRES2EGFPAxin,并在神经胶质瘤细胞C6中表达,为研究Axin对肿瘤的生物学作用以及Axin在肿瘤基因治疗中的应用奠定了基础。     

MAGE-3基因真核表达载体构建及在小鼠黑色素瘤细胞中的表达

目的　扩增人黑色素瘤抗原 3(Melanomaantigen 3,MAGE 3)基因 ,构建真核表达载体 ,并在小鼠黑色素细胞瘤B16中进行表达。方法　采用PCR扩增MAGE 3基因 ,连接到真核表达载体pIRES2 EGFP中 ,构建真核表达载体pIRES2 EGFP MAGE 3,脂质体法转染小鼠黑色素瘤B16细胞。G4 18筛选阳性克隆 ,荧光显微镜和RT PCR分别检测阳性克隆中增强型绿色荧光蛋白 (Enhancedgreenfluorescentprotein ,EGFP)的表达和MAGE 3mRNA的表达。结果　从pUC19 MAGE 3重组质粒中扩增获得一条约 95 0bp的片段 ,成功构建了真核表达载体pIRES2 EGFP MAGE 3,转染B16细胞后筛选得到阳性克隆 ,可见融合蛋白表达产生明亮的绿色荧光 ,RT PCR检测到MAGE 3mRNA的表达。结论　成功构建了真核表达载体pIRES2 EGFP MAGE 3,获得了稳定表达该载体的小鼠黑色素瘤B16细胞系 ,为研究MAGE 3在肿瘤免疫治疗中的应用奠定了基础。     

共表达MAGE-1与EGFP基因的小鼠黑色素瘤细胞系的建立

目的 :构建黑色素瘤抗原 1(MAGE 1)基因的真核表达载体 ,并在小鼠黑色素瘤B16细胞中进行表达。方法 :采用分子生物学的手段 ,构建了MAGE 1与增强型绿色荧光蛋白 (EGFP)基因共表达的质粒pIRES2 EGFP MAGE 1,通过脂质体以共表达质粒转染B16细胞 ,用荧光显微镜检测细胞中EGFP的表达 ,用免疫组化染色法检测细胞中MAGE 1的表达。结果 :成功地构建了真核表达载体pIRES2 EGFP MAGE 1。以其转染B16细胞后 ,经荧光显微镜及免疫组化染色法检测 ,可见细胞内有EGFP及MAGE 1的表达。结论 :成功地建立了可共表达MAGE 1与EGFP基因的B16细胞 ,为MAGE 1在肿瘤免疫治疗中的应用奠定了研究基础。     

共刺激分子配体B7-DC基因真核表达载体和转基因细胞的构建

目的：克隆小鼠B7-DC基因，并构建含该基因的真核表达载体pEF6／-B7-DC-V5His，证明该基因在CHO细胞中的表达方式，为建立B7-DC的转基因小鼠打下基础。方法：从小鼠胸腺中抽提总RNA为模板，通过RT—PCR技术，扩增出B7-DC编码区片段。按常规方法克隆进pEF6V5His载体中，重组质粒经鉴定后采用脂质体法转染CHO细胞，48小时后进行间接免疫荧光实验，72小时后用blasticidin进行筛选，挑选出能稳定表达B7-DC的细胞株。结果：已成功克隆小鼠B7-DC基因并构建了用于表达B7-DC基因的真核表达载体，经间接免疫荧光实验（IFA）证明，该基因在CHO细胞中得到表达。经Western blot检测表明筛选出的转基因细胞稳定表达了B7-DC基因。结论：构建了用于表达B7-DC基因的真核表达载体pEF6／-B7-DC-VSHis，并能在CHO细胞中稳定表达目的基因，为该基因功能的后续研究奠定了基础。     

TMEM16A-Mediated Mucin Secretion in IL-13-Induced Nasal Epithelial Cells From Chronic Rhinosinusitis Patients

Purpose

Chronic rhinosinusitis with nasal polyps (CRSwNP), a mainly Th2 cytokine-mediated disease, often involves mucus secretion. Recent evidence suggests that transmembrane protein 16A (TMEM16A), a calcium-activated Cl^- channel (CaCC), can regulate mucus secretion from airway epithelium by transepithelial electrolyte transport and hydration. However, the role of TMEM16A in mucin production/secretion in the airway epithelium is not clear. This study was conducted to determine the role of TMEM16A in mediating mucin secretion in human nasal polyp epithelial cells (HNPECs) induced by IL-13.

Methods

Human sinonasal mucosa tissue and dissociated sinonasal epithelium from control subjects and patients with CRSwNP were assessed for the expression of TMEM16A and the secretion of human mucin 5AC (MUC5AC) by immunohistochemistry, Western blot analysis, and enzyme-linked immuno-sorbent assay (ELISA). A model of the Th2 inflammatory environment was created by exposure of primary air-liquid interface (ALI)-cultured HNPECs to interleukin-13 (IL-13) for 14 days, with subsequent assessment of TMEM16A expression in cell lysates by Western blotting and MUC5AC secretion in apical washings of cells by ELISA.

Results

The expressions of TMEM16A and MUC5AC were increased in human nasal polyp tissue and dissociated nasal polyp epithelium. TMEM16A was detected in IL-13-treated HNPECs, specifically in MUC5AC-positive cells but not in ciliated cells. IL-13 treatment increased percentages of TMEM16A-positive cells, MUC5AC-positive cells, and cells coexpressing TMEM16A/MUC5AC, the expression of TMEM16A protein, and the secretion of MUC5AC. T16Ainh-A01, a TMEM16A inhibitor, attenuated these IL-13-induced effects.

Conclusions

The expression of TMEM16A and MUC5AC are increased in CRSwNP, which might be a direct effect of Th2 cytokines present in the sinonasal mucosa in CRSwNP. Down-regulation of TMEM16A expression and MUC5AC secretion in HNPECs by T16Ainh-A01 indicates that TMEM16A might play an important role in mucin secretion in upper airway inflammatory diseases.     

真核表达质粒pcDNA3.1-tau的构建及在HEK293细胞中的稳定表达

背景：阿尔茨海默病患者的痴呆症状严重程度与脑组织中的神经原纤维缠结数量呈正相关,神经原纤维缠结的主要蛋白成分为过度磷酸化的蛋白tau,tau蛋白的病理改变出现在痴呆症状之前并独立于?-淀粉样多肽的异常。  目的：构建tau基因的真核表达质粒,建立稳定表达tau的稳转细胞株。 方法：采用反转录-聚合酶链反应方法,从反转录反应合成的人成神经瘤细胞(SH-SY5Y)的总cDNA中,扩增出约1.0 kb的tau cDNA片段,用BamHⅠ和XhoⅠ双酶切后定向克隆到真核细胞表达载体pcDNA3.1中,用限制性内切酶酶切分析和DNA序列分析鉴定重组质粒;用脂质体介导法将质粒转染入培养的人胚肾细胞,并利用G418进行稳定表达tau的稳转细胞株的筛选,免疫印迹和免疫荧光细胞化学方法检测tau基因的表达。 结果与结论：人tau cDNA已克隆到真核细胞表达载体pcDNA3.1中;免疫印迹和免疫荧光细胞化学结果显示人tau基因在人胚肾细胞中获得表达,tau蛋白表达的阳性信号主要位于细胞胞质,说明成功构建了pcDNA3.1-tau的真核表达质粒,建立了稳定表达tau的稳转细胞株。     

Generation of high-level stable transgene expressing human embryonic stem cell lines using Chinese hamster elongation factor-1 alpha promoter system

The utilization of human embryonic stem cells (hESC) in regenerative medicine largely depends on the development of technologies that will allow efficient genetic manipulation of the cells in vitro. Although a few studies have described the transfection of hESC for generation of reporter lines stably expressing specific transgenes driven by different promoters, the optimal choice of promoter system for driving transgene in hESC has yet to be elucidated. We show for the first time that Chinese hamster elongation factor-1 alpha (CHEF1) promoter robustly drove reporter gene expression higher than the human elongation factor 1 alpha (hEF1 alpha), other constitutive Chinese hamster promoters, human cytomegalovirus (CMV) immediate early enhancer/promoter and SV40 promoters in hESC by quantitative analysis. We also successfully generated stably transfected hESC lines using this CHEF1 promoter system and demonstrated that they continued to express enhanced green fluorescent protein (EGFP) during prolonged undifferentiated proliferation, in differentiated embryoid bodies (EBs), and in teratomas without transgene silencing. By immunofluorescence staining and D ow cytometry analysis, the pluripotent markers, OCT-4, SSEA-4, and TRA-1-60, continued to be expressed in undifferentiated CHEF1-EGFP expressing hESC lines. When the stably transfected hESC were directed to differentiate into neural precursors in vitro, high-level EGFP expression was maintained and co-expression of neural markers, Nestin, and beta-tubulin III was observed. The morphology, karyotype, and telomerase activity of CHEF1-EGFP expressing hESC were normal after >50 continuous passages, and the cells retained the ability to differentiate into derivatives of the three germ layers in vitro as confirmed by RT-PCR analysis and immunocytochemical staining and in vivo teratoma formation. Therefore, stable CHEF1-EGFP hESC lines retained the capability for self-renewal and pluripotency. The novel CHEF1 promoter system described here enables high-level transgene expression in the stably transfected hESC. It may have signi, cant implication for uses in bioprocess development and future development of gene-modified hESC in tissue regeneration and transplantation applications.     

TMEM16A/ANO1 suppression improves response to antibody‐mediated targeted therapy of EGFR and HER2/ERBB2

TMEM16A, a Ca²⁺‐activated Cl^? channel, contributes to tumor growth in breast cancer and head and neck squamous cell carcinoma (HNSCC). Here, we investigated whether TMEM16A influences the response to EGFR/HER family‐targeting biological therapies. Inhibition of TMEM16A Cl^? channel activity in breast cancer cells with HER2 amplification induced a loss of viability. Cells resistant to trastuzumab, a monoclonal antibody targeting HER2, showed an increase in TMEM16A expression and heightened sensitivity to Cl^? channel inhibition. Treatment of HNSCC cells with cetuximab, a monoclonal antibody targeting EGFR, and simultaneous TMEM16A suppression led to a pronounced loss of viability. Biochemical analyses of cells subjected to TMEM16A inhibitors or expressing chloride‐deficient forms of TMEM16A provide further evidence that TMEM16A channel function may play a role in regulating EGFR/HER2 signaling. These data demonstrate that TMEM16A regulates EGFR and HER2 in growth and survival pathways. Furthermore, in the absence of TMEM16A cotargeting, tumor cells may acquire resistance to EGFR/HER inhibitors. Finally, targeting TMEM16A improves response to biological therapies targeting EGFR/HER family members.     

RNA干扰致基因表达沉默细胞模型的建立

目的探讨siRNA和shRNA在基因功能研究中的应用。方法用化学方法合成siRNA,以及用常规的分子克隆方法构建shRNA表达载体。以人类K562细胞为实验对象,采用lipofectamine将MDM2基因的siRNA和shRAN表达载体导入细胞后,用多重RT鄄PCR和Westernblot检测目标基因MDM2的表达水平。结果K562细胞瞬时转染MDM2siRNA48h后,MDM2蛋白质表达下降超过60%;稳定转染shRNA表达载体后,MDM2基因在mRNA和蛋白质表达水平下降超过70%。实验结果表明成功地建立了MDM2表达下调的实验细胞模型。结论siRNA和shRNA都能有效地导致目标基因表达沉默,在基因功能研究中瞬时转染和稳定转染需要配合使用以获得更理想的实验结果。     

HIV-1 Nef基因在THP-1细胞的表达和活性检测

目的将HIV-1 Nef基因转染THP-1细胞,获得稳定表达Nef蛋白的细胞克隆,为研究Nef对巨噬细胞生物学活性的影响奠定实验基础。方法将质粒pcDNA3.1(+)-Nef和pcDNA3.1(+()阴性对照)转染THP-1细胞,通过逆转录-聚合酶链反应(RT-PCR)、Western blot、细胞免疫荧光等方法检测目的蛋白在真核细胞内的表达及定位,采用共转染法将荧光报告基因转染THP-1Nef和THP-13.1细胞,通过测定荧光(RLU)值来评价Nef蛋白的生物学活性。结果转染细胞经G418筛选后获得稳定表达Nef的THP-1细胞株,RT-PCR及Western blot结果表明Nef在真核细胞中成功表达,细胞免疫荧光结果显示,THP-1-Nef细胞表达的Nef蛋白主要定位于细胞质中。荧光酶标仪检测转染了HIV-1LTR-Luc和NFκB-Luc荧光报告基因的THP-1-Nef和THP-1-3.1细胞的RLU值。结论成功建立了THP-1-Nef细胞稳定表达细胞株,检测了其生物学活性,为进一步研究其作用机制实验奠定基础。     

The role of TMEM16A (ANO1) and TMEM16F (ANO6) in cell migration

Members of the TMEM16 family have recently been described as Ca²⁺-activated Cl^? channels. They have been implicated in cancer and appear to be associated with poor patient prognosis. Here, we investigate the role of TMEM16 channels in cell migration, which is largely unknown. We focused on TMEM16A and TMEM16F channels that have the highest expression of TMEM16 channels in Ehrlich Lettre ascites (ELA) cells. Due to the lack of specific pharmacological modulators, we employed a miRNA approach and stably knocked down the expression of TMEM16A and TMEM16F channels, respectively. Migration analysis shows that TMEM16A KD clones are affected in their directional migration, whereas TMEM16F KD clones show a 40 % reduced rate of cell migration. Moreover, TMEM16A KD clones have a smaller projected cell area, and they are rounder than TMEM16F KD clones. The morphological changes are linearly correlated with the directionality of cells. TMEM16A and TMEM16F, thus, have an important function in cell migration—TMEM16A in directional migration, TMEM16F in determination of the speed of migration. We conclude that TMEM16A and TMEM16F channels have a distinct impact on the steering and motor mechanisms of migrating ELA cells.