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1.
采用石英晶体微天平(QCM)非侵入式实时监测乳鼠原代心肌细胞于金晶体电极上的动态黏附响应与不同浓度肌力药物下的粘弹性响应。在乳鼠原代心肌细胞黏附铺展于金晶体电极表面后,加入不同浓度的正性肌力药物异丙肾上腺素与负性肌力药物维拉帕米,监测QCM频率(F)以及动态电阻(R)的实时变化,采用粘弹性指数CVI(CVI=ΔR/ΔF)表征细胞的粘弹性变化,并通过光学显微镜观察药物作用下细胞的形态变化。结果表明:随着异丙肾上腺素浓度的增加,药物引起的QCM频率下降、电阻增加与CVI增大的幅度均增大;光学显微镜下观测到细胞收缩,符合CVI变大、细胞变硬的响应;随着维拉帕米浓度的增加,药物引起的QCM频率升高、电阻下降与CVI减小的幅度均增大;光学显微镜下观测到细胞舒张,符合CVI变小、细胞变软的响应。说明QCM与原代心肌细胞结合作为心血管药物筛选细胞模型与工具有很大的应用前景。  相似文献   

2.
用石英晶体微天平(quartz crystal microbalance,QCM)和活细胞成像技术实时监测人脐静脉内皮细胞(HUVEC)在ITO石英晶体电极上的动态粘附响应过程。在ITO晶体电极上加入不同浓度的HUVEC,测定细胞在QCM上谐振频率以及耗散的实时变化。通过ITO电极与光学显微镜的联用,监测了HUVEC在药物处理前后的动态变化过程。用细胞粘弹性指数(QCM的动态电阻变化与频移变化之比,CVI=ΔR/Δf)表征细胞的粘弹性变化,同时通过活细胞成像技术的联用,实时监测细胞的形态变化。结果表明:细胞浓度为10万个/m L时,细胞在ITO电极上铺展完全且粘弹性最大。抑制剂y-27632和激动剂凝血酶thrombin药物处理细胞前后,在显微镜的实时监测下细胞形态变化不明显,但CVI粘弹性指数变化较大,说明QCM信号比光学信号更为敏感,且在药物筛选方面有有很大的应用前景。  相似文献   

3.
摘要 目的:探讨丹参多酚酸盐(Sal B)对大鼠损伤后心肌修复的机制。方法:构建新生大鼠心肌细胞H9c2体外缺氧/复氧(H/R)模型,并分组为空白对照组、缺氧/复氧组(模型组)、缺氧/复氧+TNF-α表达质粒组(TNF-α组)和缺氧/复氧+Sal B处理组(Sal B组)。为检测细胞迁移实验,分组为对照组、模型组、H/R+DMSO+Vector组、H/R+Sal B+Vector组、H/R+DMSO+TNF-α组和H/R+Sal B+TNF-α组。通过MTT实验检测各组H9c2细胞活力;免疫荧光检测H9c2心肌细胞中TNF-α细胞表面受体TNFR-1和TNFR-2的表达水平;Western-blot和RT-qPCR检测TNF-α的mRNA和蛋白表达水平以及血管生成蛋白表达水平的影响;Transwell实验检测Sal B对缺氧/复氧处理的H9c2细胞迁移的影响。结果:与对照组相比,模型组H9c2心肌细胞的活力显著下降(P<0.05);与模型组相比,Sal B组中H9c2心肌细胞的活力显著升高(P<0.05)。免疫荧光检测结果显示,H9c2心肌细胞质膜上TNFR-1和TNFR2均有表达。Western-blot和RT-qPCR结果显示,与模型组相比,Sal B组中H9c2心肌细胞的TNF-α的mRNA和蛋白表达水平均显著升高(P<0.01),TNF-α组H9c2心肌细胞的TNF-α、Ang-2和VEGF-1蛋白的表达水平均显著升高(P<0.01),Ang-1蛋白表达水平显著降低(P<0.01)。细胞迁移结果显示,与对照组相比,模型组和H/R+DMSO+Vector组H9c2细胞迁移能力显著下降(P<0.01);与H/R组和H/R+DMSO+Vector组相比,H/R+Sal B+Vector组、H/R+DMSO+TNF-α组和H/R+Sal B+TNF-α组H9c2细胞迁移能力显著升高(P<0.05)。结论:Sal B能够通过上调TNF-α调控血管生成蛋白表达和促进H/R H9c2心肌细胞迁移,从而促进血管生成。  相似文献   

4.
应用牵张刺激培养细胞的模型 ,观察胶原、纤维连接蛋白、层粘连素对牵张刺激心肌细胞肥大的影响 ,探讨细胞外间质 -整合素受体在超负荷心肌肥大的跨膜信号传导机制中的作用。结果发现 ,胶原、纤维连接蛋白、层粘连素明显有助于培养心肌细胞的贴壁、伸展。牵张刺激后 ,胶原、纤维连接蛋白基质组心肌细胞的 3H -亮氨酸掺入率和心肌细胞表面积均显著大于对照组 ,而层粘连素组无显著变化 ;可溶性纤维连接蛋白、RGD肽均可显著抑制牵张刺激诱导的培养心肌细胞 (胶原为粘附基质 )的3H -亮氨酸掺入率升高和心肌细胞表面积增大 ,而层粘连素无明显作用。结果表明 ,特异的细胞外间质 -整合素在超负荷心肌肥大机制中发挥了跨膜信号传导作用。  相似文献   

5.
探讨藏药镰形棘豆(OFB)提取物对缺氧/复氧(H/R)H_9C_2心肌细胞损伤的保护作用。方法:采用三气培养箱培养法建立H_9C_2心肌细胞缺氧/复氧损伤模型。实验分为3组:正常细胞对照组;缺氧/复氧损伤组(H/R);7个药物加缺氧/复氧损伤组(H/R+OFB);于缺氧/复氧开始时分别加入终浓度为0.1 mg/L、1 mg/L、10 mg/L、100 mg/L、300 mg/L、600 mg/L、1 000 mg/L的镰形棘豆提取物,以细胞活力为指标,利用MTS法测定药物对细胞活力的影响。检测镰形棘豆乙酸乙酯水甲醇压柱组分与氯仿萃取组分不同给药剂量对H_9C_2心肌细胞缺氧/复氧损伤的影响。结果:与模型组相比药物处理组显著升高缺氧/复氧H_9C_2心肌细胞活力(p0.05)。结论:藏药镰形棘豆对H_9C_2心肌细胞的缺氧/复氧损伤有保护作用。  相似文献   

6.
目的:观察促凋亡蛋白p53上调凋亡调控因子(PUMA)在高糖所致H9C2心肌细胞凋亡中的作用及机制。方法:H9C2心肌细胞随机分为对照组(使用5.5mmol/L葡萄糖作用于细胞)和高糖组(使用35 mmol/L葡萄糖作用于细胞,HG组)分别刺激6 h, 12 h, 24 h和48 h,每组设复孔5个,TUNEL染色检测细胞凋亡率;RT-PCR及Western blot法分别测定PUMA mRNA及蛋白表达情况;JC-1法检测线粒体膜电位;Western blot测定caspase-3表达和细胞色素c(Cyt C)释放。H9C2细胞随机分为四组,对照组、高糖(35 mmol/L)、HG+si-scramble组(使用si-scramble转染心肌细胞24 h,使用35mmol/L葡萄糖作用于细胞)和Si-PUMA组(使用si-PUMA转染心肌细胞24 h,使用35mmol/L葡萄糖作用于细胞),观察抑制PUMA表达对高糖诱导细胞凋亡率、线粒体膜电位、Cyt C的影响。结果:与对照组相比,高糖刺激心肌细胞组TUNEL染色阳性率、活化caspase-3和PUMA表达明显升高(P<0.0...  相似文献   

7.
目的: 探讨地佐辛通过调控微小RNA-7a-5p(miR-7a-5p)/泛素E3连接酶10(TRIM10)表达影响缺氧复氧(H/R)诱导的大鼠心肌细胞H9C2氧化应激和凋亡的作用机制。方法: 将H9C2细胞分为对照组(细胞正常培养)、H/R组(缺氧处理3 h,复氧培养4 h)、不同剂量地佐辛干预组(分别采用10-7、10-6、10-5 mmol/L的地佐辛预处理H9C2细胞24 h,再进行H/R处理)、H/R+miR-7a-5p组(转染miR-7a-5p mimics至H9C2细胞,然后进行H/R处理)、H/R+miR-NC组(转染miR-NC至H9C2细胞,然后进行H/R处理)、H/R+地佐辛+anti-miR-7a-5p组(10-5 mmol/L的地佐辛预处理转染anti-miR-7a-5p的H9C2细胞24 h,再进行H/R处理)、H/R+地佐辛+anti-miR-NC组(10-5 mmol/L的地佐辛预处理转染anti-miR-NC的H9C2细胞24 h,再进行H/R处理),每组细胞设置3个复孔,实验重复3次。酶联免疫吸附法检测细胞中氧化应激指标丙二醛(MDA)含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力,流式细胞术检测细胞凋亡,蛋白印迹(Western blot)法检测B淋巴细胞瘤-2(Bcl-2)、B淋巴细胞瘤-2相关蛋白(Bax)和泛素E3连接酶10(TRIM10)蛋白表达,实时荧光定量PCR(RT-qPCR)检测miR-7a-5p和TRIM10 mRNA表达。双荧光素酶报告基因实验验证miR-7a-5p与TRIM10调控关系。结果: 与对照组比较,H/R组MDA含量、细胞凋亡率、Bax蛋白表达及TRIM10的mRNA和蛋白表达均升高(P<0.05),而SOD和GSH-Px活力、Bcl-2蛋白表达和miR-7a-5p表达均降低(P<0.05)。与H/R组比较,不同剂量地佐辛干预组MDA含量、细胞凋亡率、Bax蛋白表达及TRIM10的mRNA和蛋白表达均降低(P<0.05),而SOD和GSH-Px活力、Bcl-2蛋白表达和miR-7a-5p表达均升高(P<0.05),且不同剂量地佐辛干预组间各指标两两比较差异均显著(P<0.05)。与H/R+miR-NC组比较,H/R+miR-7a-5p组MDA含量、细胞凋亡率、Bax蛋白表达及TRIM10蛋白表达均降低(P<0.05),而SOD和GSH-Px活力、Bcl-2蛋白表达均升高(P<0.05)。miR-7a-5p靶向负调控TRIM10表达。与H/R+地佐辛+anti-miR-NC组比较,H/R+地佐辛+anti-miR-7a-5p组MDA含量、细胞凋亡率、Bax蛋白表达及TRIM10蛋白表达均升高(P<0.05),而SOD和GSH-Px活力、Bcl-2蛋白表达均降低(P<0.05)。结论: 地佐辛可降低H/R诱导的大鼠心肌细胞H9C2氧化应激和凋亡,其可能通过调控miR-7a-5p/TRIM10轴发挥作用。  相似文献   

8.
9.
目的:观察乙醛脱氢酶2(ALDH2)对高糖诱导的H9C2心肌细胞存活及凋亡的影响,并探讨腺苷酸活化蛋白激酶(AMPK)/FOXO3a信号通路在高糖导致的心肌细胞凋亡中的调控作用。方法:以30 mmol/L葡萄糖诱导培养H9C2心肌细胞48 h,经ALDH2激动剂Alda-1及AMPK抑制剂Compound C干预后,用MTT法检测细胞的存活情况,TUNEL试剂盒检测细胞凋亡情况,Western blot检测ALDH2、磷酸化AMPK和FOXO3a蛋白的表达水平。结果:与对照组相比,高浓度葡萄糖培养H9C2心肌细胞后,细胞的存活率显著降低、凋亡指数明显升高,磷酸化AMPK的表达水平明显上调,ALDH2和磷酸化FOXO3a的蛋白表达显著降低(P0.05)。ALDH2的激动剂Alda-1处理可显著提高高糖诱导的H9C2心肌细胞的存活率、降低其凋亡率,减少磷酸化AMPK的蛋白表达,增加ALDH2的表达和FOXO3a蛋白的磷酸化;而进一步采用AMPK的抑制剂Compound C处理,可显著抑制Alda-1对高糖诱导的H9C2心肌细胞的这些影响。结论:ALDH2的激动剂Alda-1对高糖诱导的心肌细胞凋亡具有保护作用,可能与其激活AMPK,进而抑制心肌细胞FOXO3a的活性有关。  相似文献   

10.
目的:探讨外源性硫化氢(H2S)恢复缺氧后适应对衰老H9C2细胞的保护作用及相关机制。方法:H9C2细胞(心肌细胞系)用30 μmol/L过氧化氢(H2O2)处理2 h后再培养3 d,诱导生成衰老细胞。衰老H9C2细胞被随机分5组(n=8):正常组(Control)、缺氧/复氧组(H/R)、H/R+NaHS组、缺氧后适应(PC)组、PC+NaHS组。缺氧/复氧(H/R)模型:衰老H9C2细胞用缺氧液(无血清、无糖培养基,pH=6.8)培养3 h,然后正常培养6 h;缺氧后适应(PC)模型:方法同H/R模型,缺氧结束复氧前连续进行3次5 min间隔的复氧/再缺氧处理,随后复氧6 h。ELISA试剂盒分别检测大鼠晚期糖基化终末产物(AGEs)含量和caspase-3活性;CCK-8试剂盒检测细胞活力;DCFH-DA染色检测活性氧(ROS)水平;Hoechst 33342染色检测细胞凋亡率;Real-time PCR检测相关基因mRNA水平。结果:30 μmol/L H2O2可诱导H9C2细胞衰老但不会导致其凋亡;与Control组比较,H/R和PC均降低细胞活力,增加细胞凋亡率、ROS水平及caspase-3、caspase-9和Bcl-2 mRNA水平(P<0.01);且PC组与H/R组比较,上述指标变化无明显差异;在H/R和PC组加入NaHS,可显著提高细胞活力,降低细胞凋亡率和氧化应激;PC+NaHS对上述指标的作用明显强于H/R+NaHS。结论:外源性H2S能够恢复PC对衰老H9C2细胞的保护作用,其机制与抑制氧化应激和细胞凋亡有关。  相似文献   

11.
We estimated the grazing impact of the heterotrophic flagellate Collodictyon triciliatum on the harmful, bloom-forming cyanobacterium Microcystis aeruginosa in an experimental pond during a Microcystis bloom from summer to winter in 2010. For these experiments, we calculated the grazing rates from the digestion rate of C. triciliatum and its food vacuole contents. During the study period, M. aeruginosa exhibited one bloom event with a maximum density of 1.1 × 105 cells ml?1. The cell density of C. triciliatum fluctuated from below the detection limit to 291 cells ml?1. The number of M. aeruginosa cells ingested by C. triciliatum food vacuoles ranged between 0.4 and 10.8 cells flagellate?1, and the digestion rate of C. triciliatum at 25 °C was 0.73 % cell contents min?1. The grazing rate of C. triciliatum on the M. aeruginosa prey was 0.2–6.9 cells flagellate?1 h?1, and its grazing impact was 0.0–25.3 % standing stock day?1. The functional response of C. triciliatum to the M. aeruginosa prey followed the Michaelis–Menten model of significance (r 2 = 0.873, p < 0.001) in our experimental systems, in which the prey concentration varied from 1.0 × 104 to 2.1 × 106 cells ml?1. The maximum grazing rate was 6.2 prey cells grazer?1 h?1, and the half-saturation constant was 1.2 × 105 cells ml?1. We present evidence that C. triciliatum grazing explained the remarkable decrease in M. aeruginosa cell density in the pond. The present study is the first demonstration of the high potential of protistan grazing on M. aeruginosa to reduce cyanobacterial blooms.  相似文献   

12.
The inotropic responses to prostaglandins (PG) A1, E1, E2 and F were studied in isolated cat myocardial tissue. PGA1 and F exhibited no significant inotropic effects, whereas, PGE2 and PGE1 produced negative inotropic effects at concentrations of 2.8 × 10−7 and 2.8 × 10−6 M in isolated cat papillary muscles.In isolated perfused cat hearts, PGE1 (2.8 × 10−6M) produced a negative inotropic effect along with a significant increase in coronary flow. As flow declined, the negative inotropic effect became more severe. PGE1 at 2.8 × 10−9 M produced a sustained increase in coronary flow and oxygen consumption with no inotropic effect. PGE2 and F did not exert significant changes in coronary flow or contractile force.Thus prostaglandins do not appear to exert significant positive inotropic effects at physiologic or at generally accepted pharmacologic concentrations in isolated cat heart preparations. At extremely high concentrations, prostaglandins E1 and E2 exert a negative inotropic effect; however, this would not explain the protective effect of these prostaglandins in circulatory shock.  相似文献   

13.
The formation and orientation of the mitotic spindle is a critical feature of mitosis. The morphology of the cell and the spatial distribution and composition of the cells'' adhesive microenvironment all contribute to dictate the position of the spindle. However, the impact of the dimensionality of the cells'' microenvironment has rarely been studied. In this study we present the use of a microwell platform, where the internal surfaces of the individual wells are coated with fibronectin, enabling the three-dimensional presentation of adhesive ligands to single cells cultured within the microwells. This platform was used to assess the effect of dimensionality and cell shape in a controlled microenvironment. Single HeLa cells cultured in circular microwells exhibited greater tilting of the mitotic spindle, in comparison to cells cultured in square microwells. This correlated with an increase in the time required to align the chromosomes at the metaphase plate due to prolonged activation of the spindle checkpoint in an actin dependent process. The comparison to 2D square patterns revealed that the dimensionality of cell adhesions alone affected both mitotic timings and spindle orientation; in particular the role of actin varied according to the dimensionality of the cells'' microenvironment. Together, our data revealed that cell shape and the dimensionality of the cells'' adhesive environment impacted on both the orientation of the mitotic spindle and progression through mitosis.  相似文献   

14.
对镜湖萼花臂尾轮虫(Brachionus calyciflorus)夏季种群内4个生化遗传特征上互不相同的克隆(克隆A、B、C和D)在4个斜生栅藻(Scenedesmus obliquus)密度(1.0×106、2.0×106、4.0×106和8.0×106 cells·L-1)下的生活史特征进行了研究.结果表明:食物密度对各克隆轮虫的存活率和繁殖率均有不同的影响.4克隆中克隆C的世代时间最短,克隆B的世代时间、生命期望和平均寿命最长,克隆A的后代混交雌体百分率最高;净生殖率和个体适合度在4克隆间无显著差异.镜湖萼花臂尾轮虫在2.0×106 cells·L-1的食物密度下净生殖率最低;在1.0×106cells·L-1的食物密度下平均寿命和生命期望最短,而后代混交雌体百分率却最高;在8.0×106cells·L-1的食物密度下种群内禀增长率最高,平均寿命和生命期望最长;在高食物密度(4.0、8.0×106cells·L-1)下个体适合度较大.克隆C的个体适合度在密度为3.9×106cells·L-1时最小,而克隆D的个体适合度在食物密度为6.34×106cells·L-1时最大.食物密度的变化可能是7月份之后镜湖萼花臂尾轮虫从水环境中消失的原因,而4克隆轮虫个体适合度的相似性则可能是镜湖轮虫共存于同一水体的原因之一.  相似文献   

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The balance between the adhesion of cancer cells to extracellular matrix and their migratory potential, as well as their proteolytic activity, are important parameters that determine cancer cells invasiveness and metastasis. Since thrombin has been implicated in cancer progression, we studied the role(s) of thrombin-activated receptors in the adhesion process. We stably knocked down proteinase-activated receptors (PARs) -1, or -3 in human pancreatic adenocarcinoma PANC-1 cells. PANC-1 cells exhibit rapid adhesion to cell culture treated plastic and much faster kinetics of adhesion to Matrigel coated surface. Knockdown of PAR-1 had no effect on cells'' adhesiveness, while PAR-3 knockdowns (KDs) exhibited much faster adhesion kinetics. PAR-3 KDs also exhibited slower in vitro wound closure than vector-control and PAR-1 KD cells. To study the molecular mechanism(s) of PAR-3 KD cells'' enhanced rate of adhesion, we assayed the expression of the molecules that mediate cell-surface and cell-cell adhesion. ITGαv, as well as ITGα6 and ITGα10 mRNAs, were greatly enriched (>40-fold) in a rapidly-adhering sub-population of PAR-3 KD cells. The whole population of both PAR-1 and -3 KDs exhibited enhanced expression of a number of integrins (ITGs) mRNAs. However, ITGαv mRNA and protein expression was increased in PAR-3 KD and markedly decreased in PAR-1 KD. PAR-3 KD cells also expressed more E-cadherin mRNA and protein. The enhanced adhesion kinetics of PAR-3 KDs was almost fully inhibited by calcium chelation, or by a HAV-motive decapeptide that affects E-cadherin intermolecular interactions. We propose that the enhanced rate of adhesion of PAR-3 KDs results from enhanced expression of E-cadherin, leading to a greater adhesion of free-floating cells to cells rapidly bound to the surface via their integrins, and particularly ITGαv.  相似文献   

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Development is punctuated by morphogenetic rearrangements of epithelial tissues, including detachment of motile cells during epithelial–mesenchymal transition (EMT). Dramatic actin rearrangements occur as cell–cell junctions are dismantled and cells become independently motile during EMT. Characterizing dynamic actin rearrangements and identifying actin machinery driving these rearrangements is essential for understanding basic mechanisms of cell–cell junction remodeling. Using immunofluorescence and live cell imaging of scattering MDCK cells we examine dynamic actin rearrangement events during EMT and demonstrate that zyxin–VASP complexes mediate linkage of dynamic medial actin networks to adherens junction (AJ) membranes. A functional analysis of zyxin in EMT reveals its role in regulating disruption of actin membrane linkages at cell–cell junctions, altering cells' ability to fully detach and migrate independently during EMT. Expression of a constitutively active zyxin mutant results in persistent actin‐membrane linkages and cell migration without loss of cell–cell adhesion. We propose zyxin functions in morphogenetic rearrangements, maintaining collective migration by transducing individual cells' movements through AJs, thus preventing the dissociation of individual migratory cells. J. Cell. Physiol. 222: 612–624, 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

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目的:外泌体是活细胞分泌的来源于多囊泡体的膜性囊泡,其主要作用包括携带与运输。雪旺细胞是周围神经再生中非常优秀的种子细胞,但其迁移能力较差,影响修复效果。本文旨在探讨外泌体和雪旺细胞共培养是否可以促进雪旺细胞迁移。方法:本实验通过分离纯化人脐带干细胞外泌体和大鼠坐骨神经雪旺细胞并鉴定,随后将其共培养于Transwell小室观察雪旺细胞迁移率。结果:通过人脐带干细胞超高速离心法得到的外泌体高表达干细胞标志物CD44(92.2±3.6%)、CD73(99.1±0.6%),并且低表达单核细胞表面抗原CD14(0.5±0.06%)以及造血干细胞表面抗原CD34(0.4±0.07%),外泌体鉴定高表达CD81和CD9;雪旺细胞培养鉴定纯度达(92.3±2.7)%;均符合实验要求。通过Transwell小室实验发现外泌体可以明显促进雪旺细胞的迁移,并且具有一定剂量关系。结论:外泌体可以提高雪旺细胞的迁移能力,从而使雪旺细胞在组织工程领域中的应用产生巨大突破。  相似文献   

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