Roscovitine对TNF-α诱导的大鼠血管平滑肌细胞增殖及细胞周期的影响

目的观察Roscovitine对TNF-α诱导的大鼠血管平滑肌细胞(VSMC)增殖及细胞周期的影响。方法组织贴块法培养大鼠VSMC细胞,采用TNF-α诱导其增殖,加入不同浓度的Roscovitine预处理15 h,将细胞分为:对照组、TNF-α组、Roscovitine 5、10、15、30μmol·L~(-1)组。MTT比色法检测细胞增殖活性;Western blot检测增殖细胞核抗原(PCNA);流式细胞仪检测细胞周期;荧光定量RT-PCR及Western blot检测细胞周期蛋白(Cyclin A、Cyclin B、Cyclin D、Cyclin E)、细胞周期蛋白依赖激酶(CDK4、CDK5)、细胞周期抑制蛋白(p53、p21、p27)的表达。结果 Roscovitine能抑制VSMC增殖;抑制细胞周期从G_0/G_1期向S期转化。与TNF-α组比较,Roscovitine 5、10、15、30μmol·L~(-1)组能降低细胞周期蛋白Cyclin A、Cyclin B、Cyclin D、Cyclin E蛋白表达,降低细胞周期蛋白依赖激酶CDK4、CDK5蛋白表达,升高细胞周期抑制蛋白p53、p21、p27蛋白表达(P<0.05)。结论 Roscovitine可抑制大鼠VSMC细胞周期进程及增殖活性。     

Apelin-13促血管平滑肌细胞增殖作用研究

目的研究G蛋白偶联受体APJ的内源性配体Ape-lin-13对血管平滑肌细胞(vascular smooth muscle cells,VSMC)生长增殖影响及其与细胞周期蛋白D1(cyclin D1)的关系,发现Apelin-APJ新功能。方法培养大鼠胸主动脉血管平滑肌细胞,噻唑蓝比色法(MTT)观察VSMC增殖;流式细胞仪分析细胞周期;Western blot检测cyclinD1的表达。结果Apelin-13能促进血管平滑肌细胞增殖,降低G0/G1期细胞百分比,升高S+G2+M期细胞百分比,并可剂量依赖性刺激细胞cyclin D1的表达增加。结论Apelin-13能通过推动细胞周期由G0/G1期进入S期而促进血管平滑肌细胞增殖,其作用机制与促进cyclin D1表达增高有关。     

蜂毒素对人胚肺成纤维细胞生长的抑制作用及其机制探讨

目的研究蜂毒素(melittin)对人胚肺成纤维细胞(MRC-5)生长的抑制作用及其机制。方法采用MTT法检测蜂毒素对MRC-5细胞的增殖抑制作用;流式细胞仪检测细胞周期;RT-PCR法检测细胞中Cyclin D1、CDK4及E2F-1mRNA的表达变化;Western blot法检测Cyclin D1、CDK4、p21及E2F-1蛋白表达。结果与对照组比较,蜂毒素处理组细胞增殖明显受到抑制,并呈剂量和时间依赖性(P<0.05);流式细胞仪检测结果发现,随着浓度的增大,G0/G1期细胞百分比逐渐上升,S期细胞百分比逐渐下降;同时Western blot结果提示蜂毒素(1,2,4 mg.L-1)可以明显降低Cyclin D1、CDK4及E2F-1表达,而上调p21表达。结论蜂毒素能抑制MRC-5细胞增殖,其机制可能与干扰该细胞G0/G1期相关基因的转录相关且抑制Cyclin D1/E2F信号转导。     

甘草查尔酮A抑制小鼠黑色素瘤B16F10细胞增殖机制研究

目的研究甘草查尔酮A抑制B16F10细胞增殖机制。方法 SRB法检测甘草查尔酮A对B16F10细胞增殖影响,Giemsa染色法观察细胞形态变化,比色法检测B16F10细胞内、外黑色素含量,Annexin V-FITC/PI双染检测细胞凋亡率,流式细胞术测定细胞周期分布,Q-PCR法检测细胞凋亡相关基因B淋巴细胞-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、细胞周期蛋白(Cyclin E2)和细胞周期蛋白依赖性激酶-2(CDK2)的mRNA表达。结果甘草查尔酮A能有效抑制B16F10细胞增殖,呈现浓度依赖性和时间依赖性;随药物浓度增加,细胞增殖速度降低,细胞形态由树突状变为固缩圆球状,并伴有黑色素颗粒物出现,且细胞内、外黑色素含量呈浓度依赖性增加趋势,甘草查尔酮A能使细胞阻滞在G1期,在低浓度时,诱导细胞分化,高浓度时,诱导细胞凋亡;同时,甘草查尔酮A下调凋亡相关蛋白Bcl-2/Bax比率,抑制周期相关蛋白Cyclin E2、CDK2的mRNA表达。结论甘草查尔酮A抑制B16F10细胞增殖机制可能是通过使B16F10细胞G1期阻滞,进而诱导细胞分化和凋亡。     

橘红素上调Cyclin B1和抑制ERK磷酸化诱导人胃癌AGS细胞周期阻滞

目的探讨橘红素对人胃癌AGS细胞增殖和周期的作用及其机制。方法采用MTT法观察橘红素对人AGS胃癌细胞增殖的作用;流式细胞仪检测橘红素对细胞周期的影响;Western blot检测橘红素对Cyclin B1、Cyclin D1、Cyclin E1和ERK、p-ERK蛋白表达的影响。结果橘红素可明显抑制AGS胃癌细胞的增殖(P<0.01),呈时间和剂量依赖性。橘红素作用于AGS细胞24 h,S期细胞百分比明显增高,与对照组比较差异有统计学意义(P<0.01);作用48和72 h,S期阻滞消失,G2/M期细胞百分比增高(P<0.05,P<0.01)。作用48 h,橘红素可上调Cyclin B1蛋白的表达(P<0.05,P<0.01),对Cyclin D1和Cyclin E1蛋白表达无明显影响;对ERK蛋白表达无影响,可降低p-ERK蛋白的表达(P<0.01),且呈剂量依赖性。结论橘红素可明显抑制人AGS胃癌细胞的增殖,使细胞阻滞于S期和G2/M期,主要机制可能是通过抑制ERK磷酸化和上调CyclinB1蛋白表达。     

中介素对缺氧/复氧大鼠肾小管上皮细胞增殖作用及细胞周期的影响及其机制

目的探讨中介素(intermedin,IMD)对大鼠近端肾小管上皮细胞NRK-52E缺氧/复氧(H/R)后细胞增殖、细胞周期的影响。方法 NRK-52E细胞随机分为对照组,模型组:缺氧/复氧组(H/R)、H/R+空质粒组、H/R+IMD质粒组。MTT法检测细胞增殖,比色法检测培养基上清LDH含量,流式细胞术检测细胞周期,Real time-PCR法和Western blot法检测cyclin D1、CDK、p57 mRNA及蛋白表达,间接免疫荧光染色检测cyclin D1亚细胞定位。结果 1与对照组相比,H/R组培养基中LDH含量升高了106%,同时细胞存活率明显下降,与H/R组比较,H/R+IMD组培养基中LDH含量下降了33.85%(P<0.01),而细胞存活率增高(79.15%±1.42%vs 61.22%±1.63%,P<0.05),2细胞周期结果显示,与对照组相比,H/R组细胞G0/G1期比例增加,S期细胞比例降低(P<0.05);与H/R组比较,H/R+IMD组G0/G1期细胞比例明显降低,而S及G2期细胞比例增加(P<0.05)。3H/R可增加cyclin D1、CDK4及p57的表达也增加(与对照组比较,P<0.05);而IMD可进一步上调cyclin D1、CDK4的表达,同时下调p57的表达,与对照组及H/R组相比差异具有显著性(P<0.05)。4免疫荧光检测结果可见,cyclin D1呈红色荧光,在NRK-52E细胞内主要表达在细胞核中。结论 IMD可以上调cyclin D1、CDK4蛋白表达,下调p57的表达,促进细胞周期进展,从而加速肾组织IRI后细胞增殖和修复。     

肝素十二糖对血管平滑肌细胞增殖作用的研究

目的:研究肝素十二糖(dp12)对血管平滑肌细胞(vascular smooth muscle cells,VSMCs)增殖作用的影响,并分析其分子水平的作用机制。方法:通过以10%新生牛血清诱导牛胸主动脉血管平滑肌细胞增殖建立模型,然后考察实验室精制的不同浓度的肝素寡糖对血管平滑肌细胞增殖作用的影响;四甲基偶氮唑盐法(MTT)检测dp12对VSMCs增殖的影响;流式细胞仪检测细胞周期分布;RT-PCR法检测ERK1/2转录变化情况;Western Blotting法检测ERK1/2和p-ERK1/2的表达。结果:MTT结果显示不同浓度的dp12可以明显抑制由10%新生牛血清诱导的血管平滑肌细胞的增殖;细胞周期实验揭示dp12抑制血清诱导的VSMCs从G1期进入S期,影响细胞周期;dp12通过下调ERK基因的转录进而下调ERK1/2的表达,此外dp12抑制ERK1/2的磷酸化进而影响细胞增殖。结论:dp12使VSMCs在G1期/S期阻滞,通过抑制ERK基因的转录和ERK蛋白的磷酸化抑制VSMCs增殖,可能是dp12抗VSMCs增殖的机制之一。     

Endothelin—1 promoted proliferation of vascular smooth muscle cell through pathway of extracellular signal—regulated kinase and cyclin D1

目的:探讨内皮素-1是否通过细胞周期蛋白质D1与细胞外调节蛋白激酶通路促进人脐动脉平滑肌细胞增殖。方法:采用MTT法观察ET-1和PD98059对人脐动脉平滑肌细胞生长的作用;[~3H]TdR法观察对细胞DNA合成的作用;流式细胞仪法观察对细胞增殖周期的影响;蛋白质印迹法观察对细胞外调节蛋白激酶和细胞周期蛋白质D1表达的影响。结果:首先,同没有ET-1组和PD98059组比较,ET-1促进平滑肌细胞增殖(P<0.05)。PD98059抑制ET-1诱导的血管平滑肌细胞增殖。第二,与没有ET-1组比较,ET-1促进平滑肌细胞DNA合成(P<0.05)。第三,ET-1促进平滑肌细胞增殖周期从G_0/G_1期向S期的转变,与没有ET-1组比较,G_0/G_1期细胞百分比明显减少,S期细胞百分比明显增加(P<0.05)。第四,ET-1增加细胞外信号调节性激酶的磷酸化水平和细胞周期蛋白质D1的蛋白表达,ERK的抑制剂可以抑制细胞外信号调节性激酶的磷酸化水平和细胞周期蛋白质D1的蛋白表达,与没有ET-1组比较,磷酸化-ERK和细胞周期蛋白质D1表达明显增强,对非磷酸化ERK表达没有影响。结论:内皮素-1可以通过细胞周期调节素D1与细胞外信号调节性激酶通路促进平滑肌细胞增殖。     

紫杉醇对U373细胞周期阻滞及增殖抑制的机制研究

目的研究紫杉醇(PTX)诱发神经胶质瘤U373细胞的周期阻滞和增殖抑制的相关机制。方法 MTT检测细胞增殖抑制率,流式细胞术检测细胞周期分布,免疫细胞荧光化学观察细胞形态学变化,RT-PCR和Western blot检测细胞周期相关CyclinB1、CyclinD1、CDK1、CDK2和p53的表达变化。结果 PTX可以明显抑制U373细胞的增殖活性,抑制作用呈时间浓度依赖性;细胞周期分析显示,实验组细胞G2/M期比例增高;细胞免疫荧光检测实验组细胞阻滞于有丝分裂期;RT-PCR和Western blot显示,PTX可以增加CDK1和CyclinB1表达,降低CyclinD1表达(P<0.05),而对CDK2无明显影响。结论 PTX能够抑制神经胶质瘤U373细胞增殖,引起有丝分裂期阻滞,诱导细胞凋亡,与其细胞周期相关蛋白表达水平密切相关。     

氯化两面针碱通过Rb/E2F途径抑制肝癌细胞SMMC-7721增殖作用机制研究

氯化两面针碱(Nitidine chloride,NC)是从芸香科植物两面针根部提取的一种天然生物碱,具有很好的抗肿瘤活性,在体外能抑制鼻咽癌,肺癌等细胞的增殖。研究表明NC可导致细胞周期G2/M期阻滞,并诱导细胞凋亡。E2F/RB在细胞周期调控中起重要作用,它们与CyclinD1、CDK4、CyclinE、CDK2构成复杂的反馈调控网路,调节细胞从G1期到S期的过渡,推动了细胞周期的转变。另外,研究表明E2F是重要的转录因子,参与了基因的转录调控。研究肝癌细胞SMMC-7721经两面针碱处理后RB/E2F通路的相关分子水平变化,以及氯化两面针碱在RB/E2F途径抑制肝癌细胞增殖,参与细胞凋亡作用的机制。应用CCK8方法测定NC对SMMC-7721细胞存活率的影响;Annexin-V和碘化丙碇(propidium i-odide,PI)双染法检测细胞凋亡和坏死情况;RT-PCR检测不同剂量NC对E2F、RB mRNA表达影响;WB检测E2F蛋白含量的变化。结果显示NC可抑制肝癌细胞增殖,降低细胞存活率,促进细胞凋亡,明显降低细胞中E2F、RB mRNA和E2F蛋白的表达,并呈浓度依赖性。NC通过作用于E2F/RB调控通路,抑制了E2F/RB的表达,参与了细胞的增殖抑制和诱导了细胞凋亡。     

2,3,4',5-Tetrahydroxystilbene-2-O-β-d-glucoside inhibits platelet-derived growth factor-induced proliferation of vascular smooth muscle cells by regulating the cell cycle

1. 2,3,4',5-Tetrahydroxystilbene-2-O-β-d-glucoside (TSG) has been shown to have an anti-atherosclerotic effect. Vascular smooth muscle cell (VSMC) proliferation contributes to the pathobiology of atherosclerosis. The aim of the present study was to investigate the effects of TSG on platelet-derived growth factor (PDGF)-BB-induced VSMC proliferation and to explore the molecular mechanisms underlying the effects. 2. Cultured rat VSMC were pretreated with TSG (l-50 μmol/L) for 1 h, followed by exposure to PDGF-BB (10 ng/mL) for 24 h, after which cell proliferation and cell cycle stages were examined. The expression of protein cell cycle regulators, including retinoblastoma (Rb), cyclin D1/E, cyclin-dependent kinase (CDK) 2/4, CDK inhibitors p21 and p27 and proliferative cell nuclear antigen (PCNA), was examined. Activation of extracellular signal-regulated kinase (ERK) 1/2 was evaluated to elucidate the possible upstream mechanism by which TSG affects cell cycle regulators. 3. The results showed that TSG dose-dependently inhibited PDGF-BB-induced VSMC proliferation, possibly by blocking the progression of the cell cycle from the G(1) to S phase. In addition, TSG significantly inhibited PDGF-BB-induced phosphorylation of Rb and the expression of cyclin D1, CDK4, cyclin E, CDK2 and PCNA. In addition, TSG suppressed PDGF-BB-induced downregulation of p27 and upregulation of p21, as well as PDGF-BB-induced activation of ERK1/2. 4. Together, the findings of the present study provide the first evidence that TSG can inhibit PDGF-BB-stimulated VSMC proliferation via cell cycle arrest in association with modulation of the expression of cell cycle regulators, which may be mediated, at least in part, by suppression of ERK1/2 activation.     

4-氨基-2-三氟甲基苯基维甲酸酯对K562细胞分化和细胞周期的影响

目的本研究探讨新型维甲酸衍生物4-氨基-2-三氟甲基苯基维甲酸酯(4-amino-2-trifluoromethyl-phenyl retinate,ATPR)对K562细胞株的抑制增殖和诱导分化活性并对其机制进行研究。方法ATPR作用于K562细胞3d后,通过MTT法检测细胞的增殖,NBT还原实验法分析细胞的分化指标,瑞氏染色法在油镜下观察加药前后细胞形态学变化,FCM检测分析细胞周期,RT-PCR法检测cyclinE、cyclinD1、CDK2、CDK4、CDK6、p21cip1、p27kip1、p57kip2和PCNA mRNA的变化情况。Western blot法检测cyclin D1和CDK4蛋白表达的改变。结果ATPR呈浓度依赖性抑制K562细胞增殖的作用。ATPR诱导分化活性表现为NBT阳性细胞率增加,油镜下观察K562细胞有分化成熟的改变,G0/G1期细胞表达量增加,S期细胞表达量减少,呈G1期阻滞。RT-PCR检测发现cyclin E、cyclin D1、CDK2、CDK4、CDK6表达减少,PC-NA、P21cip1、P27kip1改变不明显,P57kip2表达增加。Western blot检测cyclin D1和CDK4蛋白表达减少。结论ATPR有较强的抑制K562细胞增殖并诱导其分化的活性,并通过上调P57kip2的表达,抑制Cyclin-CDK激酶复合物,发挥细胞周期阻滞的作用。     

降钙素基因相关肽对糖尿病大鼠血管平滑肌细胞增殖的影响(英文)

目的　研究降钙素基因相关肽 (CGRP)对体外培养的糖尿病大鼠血管平滑肌细胞 (VSMC)增殖的影响。方法　用酶标仪和流式细胞仪检测不同浓度CGRP(1 ,1 0 ,1 0 0nmol·L-1 )对糖尿病大鼠VSMC的增殖的影响。结果　CGRP呈浓度和时间依赖性的抑制糖尿病大鼠VSMC增殖 ,格列本脲 (1 μmol·L-1 )部分阻断CGRP(1 0nmol·L-1 )对培养的糖尿病组VSMC的抗增殖作用 ,使其对VSMC的抑制率由(49 .3± 1 .2 ) %减至 (35 .6± 1 .1 ) % ,吡那地尔 (1μmol·L-1 )可增强其抗增殖作用 ,使其对VSMC的抑制率由 (49.3± 1 .2 ) %增至 (58.3± 3 .9) %。CGRP(1 0nmol·L-1 )可使停留于G0 /G1 细胞增多 ,进入S期和G2 /M期的细胞数目减少 ,吡那地尔 (1 μmol·L-1 )能增强其作用。结论　CGRP对糖尿病大鼠VSMC具有显著的抗增殖作用 ,使处于G0 /G1 期细胞增多 ,S和G2 /M期细胞减少。     

ts-SV40LT抗原转基因干细胞增殖活性的温度调控机制分析

目的:研究温度敏感性猿猴病毒40大T抗原(ts-SV40LT)转基因干细胞增殖活性的温度调控机制。方法:用含ts-SV40LT抗原的表达质粒转染脐带间充质干细胞(UCMSCs),将其分别置于33℃和37℃培养,细胞免疫荧光方法检测增殖细胞核抗原(PCNA)活性,PCR-ELISA端粒酶检测法检测端粒酶活性及细胞周期,WesternBlot法检测周期素(Cyclin)D1、CyclinE、周期素依赖性蛋白激酶(CDK)2、CDK4、CDK6、P16和P21的蛋白表达情况,免疫荧光方法检测巢蛋白(Nestin)、神经元特异性烯醇化酶(NSE)和胶质纤维酸性蛋白(GFAP)的表达。结果:细胞在33℃时培养24、48、72h的PCNA阳性表达百分率均高于37℃时,差异有统计学意义(P<0.01)。转染tsSV40LT抗原基因后,细胞在33℃培养箱时的端粒酶活性和PIx值高于37℃时,差异有统计学意义(P<0.01)。33℃时的CyclinD1、CyclinE、CDK2、CDK4、CDK6及Nestin表达量高于37℃时,P16、P21、NSE和GFAP的表达量低于37℃时,差异均有统计学意义(P<0.05或P<0.01)。结论:通过tsSV40LT抗原基因的有效转染可实现干细胞在不同温度环境下的增殖调控。     

Inhibition of the cyclin D1/E2F pathway by PCA-4230, a potent repressor of cellular proliferation

1. Tight control of cellular growth is essential to ensure normal tissue patterning and prevent pathological responses. Excessive vascular smooth muscle cell (VSMC) proliferation is associated with the pathophysiology of atherosclerosis and restenosis post-angioplasty. Thus, drug targeting of pathological VSMC growth may be a suitable therapeutic intervention in vascular proliferative diseases. 2. In the present study, we investigated the mechanisms underlying VSMC growth arrest induced by the pharmacological agent PCA-4230. Addition of PCA-4230 to cultured VSMCs blocked the induction of cyclin D1 and cyclin A expression normally seen in serum-restimulated cells. Moreover, PCA-4230 inhibited cyclin-dependent kinase 2 (CDK2) activity and abrogated hyperphosphorylation of the retinoblastoma (Rb) gene product. Similarly, PCA-4230-dependent growth arrest of transformed cell lines correlated with reduced level of cyclin D1 protein and inhibition of CDK2 activity. Consistent with these findings, PCA-4230 repressed serum-inducible cyclin A promoter activity, and overexpression of either cyclin D1 or E2F1 efficiently circumvented this inhibitory effect. Importantly, adenovirus-mediated overexpression of E2F1 restored S-phase entry in PCA-4230-treated VSMCs, demonstrating that PCA-4230 represses cyclin A gene expression and VSMC growth via inhibition of the cyclin D1/E2F pathway. 3. Because of its ability to inhibit the growth of human VSMCs and transformed cell lines, future studies are warranted to assess whether PCA-4230 may be a suitable therapeutic intervention for the treatment of hyperproliferative disorders, including cardiovascular disease and cancer.     

Simvastatin inhibits cell cycle progression in glucose-stimulated proliferation of aortic vascular smooth muscle cells by up-regulating cyclin dependent kinase inhibitors and p53

Simvastatin was reported to attenuate platelet-derived growth factor (PDGF)-induced vascular smooth muscle proliferation by up-regulation of cyclin dependent kinase (CDK) inhibitor p27, but had no effect on p16, p21, p53 expression. We investigate the mechanisms by which simvastatin inhibits vascular smooth muscle cell (VSMC) growth in high glucose conditions to mimic diabetes. Simvastatin was added to A7r5 cells cultured in high glucose (25 mM) medium, mimicking diabetes. We used an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay to evaluate cell viability; flow cytometric analysis for cell counts distribution in the cell cycle; and Western blot, immunoblotting, and immunoprecipitation analyses to evaluate the effects of simvastatin on CDK activity and cell cycle regulatory proteins. Cell counts were significantly increased in G0/G1 phase and significantly decreased in S and G2/M phases. In our study, low dose of simvastatin had no significant inhibitory effect on VSMC growth in normal glucose condition. However, both low and high doses of simvastatin inhibited VSMC growth significantly in a dose-dependent manner in high glucose status. We also found that simvastatin inhibited phosphorylation of Rb, promoted expression of p53, p16, p21, p27 and decreased CDK2/4 activity. In conclusion, simvastatin inhibits VSMC proliferation in high glucose status, mimicking diabetes, inducing a G0/G1 phase cell cycle growth arrest by acting on multiple steps upstream of pRb, including inhibition of CDK2/4 expression and up-regulation of p53, p21, p16, and p27. We propose that statins may be used more extensively in diabetic patients regardless of lipid status for preventing atherosclerosis and restenosis after PCI.     

Apamin inhibits PDGF-BB-induced vascular smooth muscle cell proliferation and migration through suppressions of activated Akt and Erk signaling pathway

The increased proliferation and migration of vascular smooth muscle cells (VSMC) are key process in the development of atherosclerosis lesions. Platelet-derived growth factor (PDGF) initiates a multitude of biological effects that contribute to VSMC proliferation and migration. Apamin, a component of bee venom, has been known to block the Ca^2 +-activated K⁺ channels. However, the effects of apamin in the regulation PDGF-BB-induced VSMC proliferation and migration has not been identified. In this study, we investigate the inhibitory effect of apamin on PDGF-BB-induced VSMC proliferation and migration. Apamin suppressed the PDGF-BB-induced VSMC proliferation and migration with no apparent cytotoxic effect. In accordance with these findings, apamin induced the arrest of cell cycle progression at G0/G1 phase. Apamin also decreased the expressions of G0/G1 specific regulatory proteins including proliferating cell nuclear antigen (PCNA), cyclin D1, cyclin-dependent kinases (CDK) 4, cyclin E and CDK2, as well as increased the expression of p21^Cip1 in PDGF-BB-induced VSMC. Moreover, apamin inhibited PDGF-BB-induced phosphorylation of Akt and Erk1/2. These results suggest that apamin plays an important role in prevention of vascular proliferation and migration through the G0/G1 cell cycle arrest by PDGF signaling pathway. Thus, apamin may be a promising candidate for the therapy of atherosclerosis.     

Losartan和CGRP对血管紧张素Ⅱ诱导血管平滑肌细胞增殖作用的影响

目的比较非肽类血管紧张素Ⅱ受体Ⅰ型阻断剂氯沙坦(Losartan)和血管活性肽降钙素基因相关肽(CGRP)对血管紧张素Ⅱ诱导的血管平滑肌细胞增殖作用的影响,为探讨此两类物质的降压机制提供实验依据。方法采用MTT,3H-参入法和流式细胞仪分别测定血管紧张素Ⅱ刺激下,Losartan或CGRP干预下血管平滑肌细胞的增殖变化,W est-ern b loting法测定不同状态下血管平滑肌细胞内ERK1/2的活性变化。结果Losartan或CGRP能抑制血管紧张素Ⅱ刺激下血管平滑肌细胞的生存率、DNA合成、细胞周期增殖指数,以及细胞内ERK1/2的活性,并呈剂量依赖性。而且,CGRP抑制作用强于Losartan。结论Losartan或CGRP能抑制血管紧张素Ⅱ刺激下血管平滑肌细胞增殖,其细胞内的信号传导途径与ERK1/2有关。     

微小RNA-K1-5p调控G1/S期相关基因的表达影响内皮细胞周期

目的 探讨卡波西肉瘤（Kaposi′s sarcoma,KS）相关疱疹病毒（KSHV）编码的微小RNAs(miR),如miR-K1-5p,对KS细胞周期的调控作用及其机制。方法 该研究进行于2020年1—12月,人脐静脉内皮细胞购自美国ScienCell。生物信息学软件预测miR-K1-5p的靶基因。双萤光素酶试验验证miR-K1-5p的靶基因[细胞周期素依赖性激酶抑制剂4(CDKN4)]。将miR-K1-5p模拟物转染后,行蛋白质印迹法（Western blotting）和q-PCR检测,分析G1/S期相关基因CDKN4、细胞周期蛋白A/细胞周期素依赖性激酶2(Cyclin A/CDK2)、细胞周期蛋白D2/细胞周期素依赖性激酶4(Cyclin D2/CDK4)的表达。碘化丙啶（PI）染色检测miR-K1-5p对内皮细胞（HUVECs）周期的影响。结果 miR-K1-5p靶向CDKN4(miR-K1-5p mimics+CDKN4-WT组、mimics NC+CDKN4-WT组、miR-K1-5p mimics+CDKN4-MUT组、mimics NC+CDKN4-MUT组萤光素酶活...