羟基红花黄色素A对氧化低密度脂蛋白诱导的血管平滑肌细胞增殖的抑制作用

目的探讨羟基红花黄色素A(HSYA)抑制氧化低密度脂蛋白(ox-LDL)诱导血管平滑肌细胞(VSMC)增殖与细胞外信号调节激酶1/2(ERK1/2)和丝裂原活化蛋白激酶磷酯酶-1(MKP-1)基因转录及蛋白表达之间的关系。方法 HSYA 10μmol.L-1和ox-LDL 35 mg.L-1与VSMC共培育48 h,MTT检测细胞存活率,流式细胞术检测细胞周期,逆转录PCR(RT-PCR)观察ERK1/2和MKP-1基因表达,Western印迹法观察ERK1/2和MKP-1蛋白表达。结果与ox-LDL 35 mg.L-1模型组比较,加入HSYA 10μmol.L-1组细胞存活率明显下降,G0/G1期细胞明显增多,ERK1 mRNA表达下降了42.2%(P<0.01),MKP-1 mRNA显著增加了86.9%(P<0.01),p-ERK1/2蛋白表达降低了39.9%(P<0.01),MKP-1蛋白表达增加了80.6%(P<0.01);加入PD98059 10μmol.L-1组,细胞存活率明显降低了58.3%(P<0.01),G0/G1期细胞明显增多(P<0.01),ERK1 mRNA表达下降了45.9%(P<0.01);p-ERK1/2蛋白表达下降了45.9%(P<0.01);PD98059 10μmol.L-1+HSYA 10μmol.L-1同时加入,细胞生存率下降了61.9%(P<0.01),G0/G1期细胞明显增多(P<0.01),ERK1 mRNA表达进一步减少(P<0.01),MKP-1 mRNA增加了110%(P<0.01),p-ERK1/2蛋白表达下降了51.2%(P<0.01),MKP-1蛋白表达增加了62.4%(P<0.01)。结论 HSYA通过增强MKP-1蛋白表达、降低p-ERK1/2蛋白活性和抑制细胞周期运转的机制抑制VSMC增殖。     

姜黄素烟酸酯对血管平滑肌细胞增殖及ERK1/2信号通路的影响

目的探讨姜黄素烟酸酯(curcumin trinicotinate,Cur Tn)对血管平滑肌细胞(vascular smooth muscle cell,VSMC)增殖的影响及其可能机制。方法体外培养VSMC,体积分数为0.1的FBS刺激VSMC生长。MTT法观察CurT n对VSMC活力的影响;流式细胞术分析细胞周期;Western blot检测PCNA、p-ERK1/2、CyclinD 1蛋白的表达。结果 CurT n抑制VSMC增殖并呈现一定量效、时效关系,并且使G1期的细胞比例增加,S期细胞比例下降,PCNA蛋白表达下调。同时发现CurT n能明显抑制p-ERK1/2、CyclinD 1蛋白表达。结论 CurT n能明显抑制VSMC增殖,其作用机制可能与p-ERK1/2、CyclinD 1蛋白表达下调有关。     

小白菊内酯抑制胎牛血清诱导的大鼠血管平滑肌细胞增殖及信号转导机理

目的　探讨小白菊内酯的抗动脉粥样硬化机理与IκBα ,环氧合酶 2 (COX 2 ) ,p2 1,p2 7蛋白表达的关系。方法　培养大鼠胸主动脉血管平滑肌细胞(VSMC) ,Western印迹杂交法检测IκBα ,COX 2 ,p2 1,p2 7蛋白表达 ,流式细胞仪检测VSMC周期情况 ,[3H ]TdR参入测定VSMC的DNA合成。结果小白菊内酯 (30 μmol·L- 1)以时间依赖关系上调IκBα ,p2 1,p2 7蛋白表达和以时间依赖关系抑制COX 2蛋白表达 ,10～ 30 μmol·L- 1以剂量依赖关系使VSMC周期中的G0 /G1期细胞比例明显增多 ,S期细胞比例显著减少 ,同时抑制VSMC的 [3H]TdR参入。结论　①小白菊内酯可能通过上调IκBα蛋白表达抑制核因子 κB活性 ,从而抑制COX 2蛋白表达 ,通过抑制COX 2蛋白表达来抑制VSMC增殖 ;②小白菊内酯可能通过上调调控G1 S周期转换的p2 1,p2 7蛋白来抑制VSMC增殖。     

马齿苋总黄酮对血小板源性生长因子致家兔血管平滑肌细胞增殖的抑制作用

目的：研究马齿苋总黄酮（Portulaca totalflavone,PTF）对血小板源性生长因子-BB型（PDGF-BB）致血管平滑肌细胞（Vascularsmoothmuscle cell,VSMC）增殖的影响并探讨其机制。方法：采用组织贴壁法培养家兔胸主动脉血管平滑肌细胞,细胞计数法观察PTF（8、24、72mg/L）对PDGF-BB所致的VSMC增殖作用的影响;氚-胸腺嘧啶核苷（3H-TdR）掺入方法测定VSMC DNA的合成;流式细胞仪分析增殖细胞周期,荧光分光光度计测定VSMC内[Ca2＋]i。结果：PTF以浓度依赖方式抑制PDGF-BB诱导的VSMC增殖、DNA合成,血管平滑肌细胞处于G1/G0期的细胞数增多,而G2/S期的细胞数显著减少（P〈0.01）;能抑制高K＋诱导的VSMC内[Ca2＋]i升高（P〈0.01）。结论：PTF可明显抑制PDGF-BB诱导的VSMC增殖,其作用机制可能与其降低VSMC内高钙浓度[Ca2＋]i有关。     

重组人内抑素对佐剂性关节炎大鼠成纤维样滑膜细胞周期和PCNA表达的影响

目的观察重组人内抑素(rhEndostatin)对佐剂性关节炎(AA)大鼠成纤维样滑膜细胞(FLS)细胞周期及增殖细胞核抗原(PCNA)表达的影响,探讨rhEndostatin抑制AAFLS增殖的分子机制。方法制备AA大鼠模型,应用流式细胞仪分析rhEndostatin对AA FLS细胞周期的影响;分别采用实时荧光定量PCR和Western blot方法,定量分析rhEn-dostatin对AA大鼠滑膜组织PCNA mRNA及蛋白表达的影响。结果与正常组相比,AA FLS G1期细胞减少(P<0.01),S期和G2/M期细胞增加(P<0.01);AA大鼠滑膜组织PCNA mRNA和蛋白表达增加(P<0.05,P<0.01)。与AA模型组相比,rhEndostatin治疗组细胞G1期比例增加(P<0.01),S期和G2/M期细胞比例减少(P<0.01);滑膜组织PCNA mRNA和蛋白表达减少(P<0.01)。结论rhEn-dostatin可引起AA FLS细胞周期G1期阻滞,该作用可能与其抑制AA FLS PCNA表达有关。     

戊地昔布联合阿霉素对人乳腺癌细胞增殖的抑制作用及其机制研究

目的:研究戊地昔布联合阿霉素对人乳腺癌细胞(MCF-7)增殖的抑制作用及其机制。方法:将人MCF-7细胞随机分为空白对照组、溶剂对照组、阿霉素(0.25mg·L-1)组、戊地昔布(25、50、100μmol·L-1)组及联用组(阿霉素0.25mg·L-1+戊地昔布25、50、100μmol·L-1),加入相应药物继续培养,检测培养24、48、72h(n=6)后各组人MCF-7细胞的增殖抑制率;检测戊地昔布25μmol·L-1时培养48h后各组细胞周期和增殖细胞核抗原(PCNA)蛋白、细胞周期蛋白(CyclinD1)及环氧酶2(COX-2)蛋白表达。结果:与溶剂对照组比较,除戊地昔布25μmol·L-1培养24h外,阿霉素组、戊地昔布组及联用组增殖抑制率均明显增加(P均<0.01),且呈浓度、时间依赖性;与阿霉素组和戊地昔布组比较,联用组增殖抑制率均明显增加(P均<0.01)。戊地昔布组细胞阻滞于G0/G1期,S期细胞比例明显减少(P<0.05);联用组细胞阻滞于G0/G1期和G2/M期。与溶剂对照组比较,戊地昔布组、阿霉素组及联用组PCNA、CyclinD1蛋白表达均明显降低(P<0.05或P<0.01),仅戊地昔布组和联用组COX-2蛋白表达明显降低(P<0.05或P<0.01)。结论:戊地昔布与阿霉素联用具有协同抑制人MCF-7细胞增殖的作用,可能与抑制CyclinD1和PCNA蛋白表达从而阻滞细胞周期有关。     

桑黄多糖P1对肝癌HepG2细胞周期和钙调蛋白信号通路的影响

目的探讨桑黄多糖P1抑制人源性肝癌Hep G2细胞增殖的作用机制。方法桑黄多糖P16.25~200 mg·L-1与Hep G2细胞作用48 h,MTT法检测细胞存活率。桑黄多糖P1 100和200 mg·L-1与Hep G2细胞作用48 h,流式细胞术检测细胞周期和凋亡;荧光分光光度法测定细胞内Ca2+浓度;实时荧光定量PCR检测细胞内钙调蛋白(Ca M)、钙调蛋白依赖性蛋白激酶Ⅱ(Ca MKⅡ)、表皮生长因子(EGF)及其受体(EGFR)、K-ras和c-fos基因表达;Western蛋白质印迹法检测细胞内Ca MKⅡ和Kras蛋白表达。结果桑黄多糖P1对Hep G2细胞存活的抑制率随药物浓度的增大而显著提高,100和200 mg·L-1时抑制率高达44.0%和61.3%。桑黄多糖P1 200 mg·L-1处理48 h S期细胞百分含量明显升高,由对照组的(23.3±3.4)%升高至(37.8±2.2)%(P<0.01),而G2/M期细胞百分含量明显降低,由对照组的(15.3±1.2)%降至(3.4±1.9)%(P<0.01);细胞凋亡率无明显变化。与对照组相比,桑黄多糖P1 100和200 mg·L-1处理48 h后Ca M,Ca MKⅡ,EGF,EGFR,K-ras和c-fos mRNA水平显著下降(P<0.01);Western蛋白质印迹检测结果显示,桑黄多糖P1作用48 h后Hep G2细胞内Ca MKⅡ和K-ras蛋白水平与对照组相比显著下降(P<0.01)。桑黄多糖P1 200 mg·L-1处理细胞后,细胞内Ca2+荧光强度显著升高,0~20 min内分别由951增至1430(P<0.01),而对照组一直维持在1150左右。结论桑黄多糖P1可能通过提高细胞内Ca2+浓度以及下调Ca M,Ca MKⅡ,EGF,EGFR,K-ras和c-fos基因的表达,诱导Hep G2细胞S期阻滞,从而抑制Hep G2细胞增殖。     

土槿乙酸抑制人卵巢癌SKOV_3细胞增殖并诱导G_2/M期阻滞

目的探讨土槿乙酸(pseudolaric acid B,PLAB)对人卵巢癌SKOV3细胞增殖和细胞周期的影响。方法 MTT法检测PLAB对细胞生长抑制作用;Hoechst 33342荧光染色分析细胞死亡特征;流式细胞术检测细胞周期;Real time-PCR和Western blot检测周期相关基因Cyclin B1、CDK1和CyclinD1的表达变化。结果 PLAB明显抑制SKOV3细胞生长,且抑制作用呈浓度-作用时间依赖性(P<0.05),其24、48和72 h的IC50值分别为2.44、1.60、2.94μmol.L-1。5μmol.L-1PLAB处理细胞24 h,细胞出现核染色质凝集、凋亡小体等典型凋亡特征,随着PLAB浓度升高,G2/M期细胞比例明显增大并表现出时间依赖性(P<0.05),同时伴有Cyclin B1和CDK1呈高表达状态(P<0.05),Cyclin D1呈低表达状态(P<0.05)。结论 PLAB可抑制SKOV3细胞生长,引起细胞G2/M期阻滞,伴随Cyclin B1和CDK1呈高表达状态,可能与其调控周期相关蛋白降解有关。     

氨氯地平对人乳腺癌细胞MCF-7细胞的抑制作用及机制研究

目的观察氨氯地平对人乳腺癌细胞MCF-7周期、周期蛋白相关基因及产物表达的影响,探讨氨氯地平对人乳腺癌MCF-7细胞周期的影响及其机制。方法MTT检测细胞增殖;流式细胞仪分析细胞周期;RT-PCR技术检测细胞周期相关基因cyclinD1、p21mRNA的表达;Western blot检测细胞周期蛋白cyclinD1、p21的蛋白表达。结果氨氯地平剂量和时间依赖性的抑制人乳腺癌MCF-7细胞增殖,IC50为14.439μmol.L-1。经7.22μmol.L-1(1/2IC50)、14.439μmol.L-1(IC50)、28.88μmol.L-1(2IC50)的氨氯地平作用人乳腺癌MCF-7细胞48h,G0/G1期细胞较对照组明显增高(P<0.05);并使人乳腺癌MCF-7细胞中cyclinD1mRNA及蛋白表达降低;p21mRNA及蛋白表达升高。结论氨氯地平对人乳腺癌MCF-7细胞具有抗增殖作用,并使细胞阻滞于G1期。其G1阻滞机制可能与调控细胞周期相关基因cyclinD1、p21mRNA及蛋白的表达相关。     

酪氨酸激酶抑制剂A77-1726阻断IL-13介导STAT6磷酸化和c-fos表达

目的研究酪氨酸激酶抑制剂A77-1726对IL-13介导Dami细胞STAT6磷酸化和c-fos表达的影响,为A77-1726的临床应用和IL-13的信号通路研究提供新的实验依据。方法提取Dami细胞总RNA,RT-PCR检测c-fos mRNA表达。提取Dami细胞总蛋白,Western blot检测磷酸化STAT6和c-fos蛋白表达。凝胶定量软件Quantity One检测电泳条带光密度,统计学分析。结果100μg·L-1IL-13作用Dami细胞,可见STAT6磷酸化,50μmol·L-1A77-1726可阻断IL-13诱导的Dami细胞STAT6磷酸化。IL-13作用Dami细胞,c-fos mRNA表达增高(P<0.05),50μmol·L-1A77-1726阻断了IL-13诱导的Dami细胞c-fos mRNA的表达(P<0.05)。IL-13促进Dami细胞c-fos蛋白表达(P<0.05),50μmol·L-1A77-1726作用Dami细胞,阻断了IL-13诱导的c-fos蛋白表达(P<0.05)。结论酪氨酸激酶抑制剂A77-1726阻断了IL-13介导的白血病Dami细胞STAT6磷酸化和c-fos表达,JAK/STAT6通路是IL-13信号通路之一,IL-13诱导的c-fos表达与STAT6通路相关。     

Luteolin prevents PDGF-BB-induced proliferation of vascular smooth muscle cells by inhibition of PDGF beta-receptor phosphorylation

Luteolin occurs as glycosylated forms in celery, green pepper, perilla leaf and camomile tea, and has been shown to possess antimutagenic, antitumorigenic, antioxidant and antiinflammatory properties. In this study, we have investigated the antiproliferable effect and its mechanism of luteolin on platelet-derived growth factor (PDGF)-BB-induced proliferation of rat aortic vascular smooth muscle cells (VSMCs). Luteolin significantly inhibited PDGF-BB-induced proliferation and DNA synthesis of rat aortic VSMCs in a concentration-dependent manner. In addition, flow cytometry analysis of DNA content revealed blocking of the PDGF-BB-inducible cell cycle progression by luteolin. Pre-incubation of rat aortic VSMCs with luteolin significantly inhibited the PDGF-BB-induced extracellular signal-regulated kinase 1/2 (ERK1/2), Akt and phospholipase C (PLC)-gamma1 activation as well as c-fos gene expression. Consisted with these findings, luteolin inhibited PDGF-Rbeta phosphorylation induced by PDGF-BB in a concentration-dependent manner. These results suggest that the inhibitory effect of luteolin on the PDGF-BB-induced proliferation of rat aortic VSMCs may be mediated by blocking phosphorylation of PDGF-Rbeta.     

大蒜素对人喉癌Hep-2细胞增殖、凋亡的影响

目的 研究大蒜素(Allitridi)对人喉癌Hep-2细胞增殖、凋亡的影响,并探讨其作用机制.方法 分别以不同浓度大蒜素(25、50、100 mg·L-1)和顺铂(1.8 mg·L-1)干预对数生长期人喉癌Hep-2细胞,药物干预24 h后经Hoechst染色后利用倒置显微镜观察细胞的形态,采用MTT比色法测定大蒜素对Hep-2细胞的增殖抑制作用,采用FCM测定细胞周期分布、检测细胞凋亡率;采用RT-PCR检测Bax、Bcl-2 mRNA表达水平,Western-blot检测caspase-3蛋白表达.结果 大蒜素各组和顺铂1.8 mg·L-1组人喉癌Hep-2细胞较空白对照组出现不同程度损伤,以大蒜素100 mg·L-1组损伤最为严重;大蒜素(50、100 mg·L-1)组和顺铂1.8 mg·L-1组人喉癌Hep-2细胞增殖抑制率显著升高,细胞周期G0/G1期显著增长、G2/M期显著缩短,细胞凋亡数量明显增多、凋亡率显著升高,凋亡相关基因bcl-2 mRNA表达显著下调而Bax mRNA显著上调、Bax/bcl-2表达比值显著升高,促凋亡蛋白caspase-3表达显著上调,上述均差异有统计学意义(P<0.05,P<0.01).结论 大蒜素对人喉癌Hep-2细胞生长具有抑制作用,其机制可能与大蒜素能够阻滞人喉癌Hep-2细胞周期进程、抑制细胞增殖并促进其凋亡有关.     

Effects of apigenin on the serum- and platelet derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells

The inhibitory effects of apigenin on the growth factor-induced proliferative responses, and expression of mitogen-activated protein (MAP) kinase and its downstream c-fos in rat aortic vascular smooth muscle cells (VSMCs) were investigated. Apigenin significantly inhibited both 5 % fetal bovine serum (FBS)- and 50 ng/mL platelet derived growth factor-BB (PDGF-BB)-induced proliferation on primary cultured rat VSMCs in a concentration-dependent manner. In addition, apigenin resulted in a significant inhibition of the FBS-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK 1/2) and expression of c-fos mRNA. These results suggest that apigenin inhibits FBS- and PDGF-BB-induced VSMC proliferation, and its activity may be mediated, at least in part, by down regulation of ERK 1/2 and its downstream c-fos mRNA.     

Antiproliferative activity of NQ304, a synthetic 1,4-naphthoquinone, is mediated via the suppressions of the PI3K/Akt and ERK1/2 signaling pathways in PDGF-BB-stimulated vascular smooth muscle cells

Platelet derived growth factor (PDGF)-BB is one of the most potent vascular smooth muscle cell (VSMC) proliferative factors, and abnormal VSMC proliferation by PDGF-BB plays an important role in the development and progression of atherosclerosis. The aim of this study was to assess the effect of NQ304 [2-chloro-3-(4-hexylphenyl)-amino-1,4-naphthoquinone], a newly synthesized 1,4-naphthoquinone derivative, on the proliferation of PDGF-BB-stimulated rat aortic VSMCs. Antiproliferative effects of NQ304 on rat aortic VSMCs were examined by direct cell counting and by using [(3)H] thymidine incorporation assays. It was found that NQ304 potently the growth of VSMCs. Preincubation with NQ304 (1-10 microM) significantly inhibited proliferation and DNA synthesis of 50 ng/ml PDGF-BB-stimulated rat aortic VSMCs in a concentration-dependent manner. In addition, we investigated the mechanism of proliferation suppression by NQ304 in PDGF-BB-stimulated rat aortic VSMCs, and found that PDGF-BB-stimulated immediate-early gene expression (c-fos), activator protein (AP)-1 activation, extracellular signal-regulated kinase 1 and 2 (ERK1/2) phosphorylation, and Akt kinase were significantly inhibited by NQ304. An examination of the suppressive effects of NQ304 on PDGF-BB-stimulated VSMC cycle progression showed that NQ304 (10 microM) induced the G1 phase arrest of PDGF-BB-stimulated cell cycle progression by elevating p21(cip1) mRNA expression. These findings suggest that the inhibitory effects of NQ304 on DNA synthesis, proliferation, and cell cycle progression on PDGF-BB-stimulated VSMCs are mediated via the downregulations of AP-1 activation and c-fos expression achieved in turn via the suppressions of the phosphatidylinositol 3-kinase (PI3K)/Akt and ERK1/2 signaling pathways.     

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.     

Inhibitory effects of docetaxel on platelet-derived growth factor (PDGF)-BB-induced proliferation of vascular smooth muscle cells through blocking PDGF-receptor β phosphorylation

The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is an important pathogenic factor for vascular disorders such as atherosclerosis and restenosis after angioplasty. The present study was designed to investigate the inhibitory effects of docetaxel on VSMC proliferation, as well as the molecular mechanism of this inhibition. Docetaxel at 10, 20 and 40 μM significantly inhibited both the proliferation and the DNA synthesis of fetal bovine serum (FBS)- and platelet-derived growth factor (PDGF)-BB-stimulated VSMCs in a concentration-dependent manner. In accordance with these findings, docetaxel blocked the FBS- and PDGF-BB-induced progression of synchronized cells through the G0/G1 phase of the cell cycle. Docetaxel also decreased the expressions of cell cycle-related proteins, including cyclin-dependent kinase (CDK) 2, cyclin E, CDK4, cyclin D1, retinoblastoma protein, and proliferative cell nuclear antigen in PDGF-BB-stimulated VSMCs. Docetaxel significantly inhibited the phosphorylation of extracellular signal-regulated kinase 1/2, Akt, and phospholipase C-γ1, downstream molecule in the PDGF-BB signaling pathway. Docetaxel suppressed the phosphorylation of PDGF receptor (PDGF-R) β, the upstream molecule in PDGF-BB signaling cascade, suggesting that the inhibitory effect of docetaxel on the proliferation of VSMCs may occur by blocking PDGF-Rβ phosphorylation. Thus, docetaxel may be a potential antiproliferative agent for the treatment of atherosclerosis and angioplasty restenosis.[Supplementary Figures: available only at http://dx.doi.org/10.1254/jphs.10276FP].     

钩藤碱和异钩藤碱抑制血管紧张素Ⅱ诱导血管平滑肌细胞增殖及相关机制

目的探讨钩藤碱和异钩藤碱对血管紧张素Ⅱ诱导的血管平滑肌细胞增殖的抑制效应及相关机制。方法建立血管紧张素Ⅱ诱导血管平滑肌细胞增殖模型,通过四甲基偶氮唑盐比色法、流式细胞术和逆转录聚合酶链反应观察钩藤碱和异钩藤碱对其增殖活性、细胞周期、细胞膜AT1R蛋白表达、信号转导通路NF-κB和Stat3蛋白表达、原癌基因c-Myc和c-Fos蛋白表达与mRNA转录的影响。结果血管紧张素Ⅱ明显刺激血管平滑肌细胞增殖,钩藤碱和异钩藤碱呈剂量依赖性抑制血管紧张素Ⅱ诱导的血管平滑肌细胞增殖;在钩藤碱和异钩藤碱干预下,血管平滑肌细胞处于G0/G1期的细胞数明显增多,S期的细胞数明显减少,c-Myc、c-Fos、AT1R、NF-κB、Stat3的蛋白表达以及c-MycmRNA和c-FosmRNA转录也明显降低。结论钩藤碱和异钩藤碱对血管紧张素Ⅱ诱导血管平滑肌细胞增殖有明显抑制效应,其机制与阻滞血管平滑肌细胞G0/G1期向S期转化以及下调AT1R、NF-κB、Stat3、c-Myc、c-Fos蛋白的表达以及c-MycmR-NA和c-FosmRNA转录有关。     

Cudraflavanone A, a flavonoid isolated from the root bark of Cudrania tricuspidata, inhibits vascular smooth muscle cell growth via an Akt-dependent pathway

In previous studies of the root bark of Cudrania tricuspidata, various isoprenylated xanthones and flavonoids were isolated, some of which have anticancer, hepatoprotective, and antiperoxidative activities. Cytokines and growth factors are involved in the regulation of vascular smooth muscle cells (VSMCs) in atherosclerotic plaques. To assess whether cudraflavanone A isolated from the root bark of C. tricuspidata may be useful in the prevention of atherosclerosis or restenosis after angioplasty, we investigated the ability of cudraflavanone A to inhibit VSMCs growth under 25 ng/mL platelet-derived growth factor BB (PDGF-BB)-stimulated conditions. Cudraflavanone A (0.1-1 microM) significantly inhibited PDGF-BB-induced cell numbers in a concentration-dependent manner. The antigrowth effects of cudraflavanone A on VSMCs were also examined in [3H]-thymidine incorporation and cell cycle assays. Consistent with the inhibitory effect on cell number, PDGF-BB-stimulated [3H]-thymidine incorporation and cell cycle progression in VSMCs was also concentration-dependently reduced by cudraflavanone A. Furthermore, PDGF-BB markedly activated PDGF-beta receptor (PDGF-Rbeta) tyrosine kinase activity, leading to activation of intracellular signals required for VSMC growth. However, PDGF-BB-induced this kinase activity was not affected by cudraflavanone A. PDGF-BB also increased the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), Akt, and phospholipase C gamma (PLCgamma)1, which are important signaling molecules in cell growth. Cudraflavanone A (0.1-1 microM) suppressed PDGF-BB-stimulated Akt activation, which is involved in cell survival, but had no effect on the activation of ERK1/2 and PLCgamma1. Selective modification of Akt activation by cudraflavanone A in VSMCs may suppress intimal thickening after angioplasty and plaque formation in atherosclerosis. These results suggest that cudraflavanone A from C. tricuspidata inhibits PDGF-BB-induced rat aortic VSMC growth via an Akt-dependent pathway.     

银杏叶提取物对肝星状细胞TGF-β_1,CTGF及细胞外基质表达的影响

目的:研究银杏叶提取物对肝星状细胞增殖及转化生长因子(TCF)-β1、结缔组织生长因子(CTCF) mRNA表达及细胞外基质分泌的影响。方法:用不同浓度(0,1,10,100,500 mg·L-1)的银杏叶提取物处理 HSC-T6 24 h及48 h后,用逆转录聚合酶链反应(RT—PCR)法检测各组细胞及空白对照组中TGF—β1,CTGF mRNA的表达;放射免疫法分析上清液中Ⅲ型前胶原、Ⅳ型胶原、透明质酸和层粘连蛋白的含量;MTT及流式细胞仪检测其对肝星状细胞增殖及细胞周期的影响。结果:银杏叶提取物10,100,500 mg·L-1能明显抑制 TGF-β1和CTGF mRNA的表达,降低上清液中Ⅲ型前胶原、Ⅳ型胶原、透明质酸和层粘连蛋白的含量 (P<0．01或P<0．05),在一定范围内呈随剂量增加及时间的延长,抑制效率增加;并可抑制肝星状细胞的增殖,影响HSC-T6的细胞周期,使细胞周期阻滞于G1期。结论:银杏叶提取物可明显抑制HSC-T6的增殖,降低其细胞因子基因表达及细胞外基质的分泌。