地西他滨联合三氧化二砷抑制急性髓系白血病细胞系增殖和促进凋亡

目的 探讨地西他滨(DAC)联合三氧化二砷(ATO)对急性髓系白血病(AML)细胞增殖、凋亡的影响及潜在分子机制。方法 DAC和ATO单药或联合处理AML细胞系，CCK8法检测细胞活力；Compusyn软件分析两药联合的协同效应；流式细胞术分析细胞凋亡率及细胞周期分布；Western blot检测凋亡相关蛋白多聚ADP核糖聚合酶(PARP)和磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(Akt)蛋白表达。结果 DAC及ATO单药以浓度依赖的方式抑制AML细胞增殖，两药联合可协同抑制AML细胞增殖、诱导细胞凋亡和周期阻滞(P<0.05)。两药联合显著降低AML细胞PI3K及Akt的磷酸化水平(P<0.05)。结论 DAC联合ATO可能通过抑制PI3K/Akt通路发挥抗AML效应，为两药联合临床治疗AML提供一定理论依据。     

坎地沙坦抑制血管紧张素Ⅱ诱导的大鼠胸主动脉平滑肌A7r5细胞增殖和迁移及机制

目的探讨坎地沙坦对血管紧张素Ⅱ(AngⅡ)诱导的血管平滑肌细胞增殖和迁移及对连接子蛋白43(Cx43)的影响和机制。方法体外培养A7r5大鼠胸主动脉平滑肌细胞,随机分为对照组、 AngⅡ组及AngⅡ联合坎地沙坦组。CCK-8法检测A7r5细胞的增殖, Transwell~(TM)小室实验和划痕实验检测A7r5细胞的迁移能力;免疫荧光细胞化学技术检测A7r5细胞Cx43的表达和分布, Western blot法检测A7r5细胞Cx43、骨桥蛋白(OPN)、增殖细胞核抗原(PCNA)、磷酸化的丝裂原激活胞外调节激酶1/2(p-MEK1/2)及磷酸化的胞外信号调节激酶1/2(p-ERK1/2)的蛋白水平。结果与对照组相比, AngⅡ组细胞增殖和迁移能力增强;与单用AngⅡ组相比, AngⅡ组联合坎地沙坦组的细胞增殖和迁移能力随坎地沙坦浓度增加而降低; Cx43表达在A7r5细胞膜和核膜,与对照组相比, AngⅡ组Cx43表达增强, Cx43、 OPN、 PCNA、 p-MEK1/2及p-ERK1/2蛋白水平均较AngⅡ组明显增加, AngⅡ联合坎地沙坦组Cx43表达及各蛋白水平均明显降低。结论坎地沙坦可降低AngⅡ诱导平滑肌细胞的增殖和迁移,可能与抑制Cx43及MEK/ERK表达有关。     

Nephrin稳定血管紧张素Ⅱ诱导的足细胞细胞骨架改变的机制研究

 目的：研究足细胞裂孔膜分子nephrin调节血管紧张素Ⅱ（AngⅡ）诱导的足细胞骨架分布改变的分子机制。方法：用AngⅡ及AngⅡ受体拮抗剂氯沙坦或Akt抑制剂LY294002刺激足细胞,FITC-phalloidin染色标记F-actin,分析足细胞骨架运动。Real-time RT-PCR、RT-PCR和Western blotting检测nephrin mRNA和蛋白表达。转染nephrin全长表达质粒（pcDNA3.1-mNPHS1）,建立稳定转染足细胞系,Western blotting检测转染细胞的Akt磷酸化水平,FITC-phalloidin染色分析高表达nephrin对F-actin分布影响。结果：AngⅡ和LY294002刺激后,足细胞的F-actin重组,应力纤维减少,形成F-actin外周环。氯沙坦显著抑制F-actin重排。AngⅡ刺激后nephrin mRNA和蛋白表达显著降低,Akt磷酸化水平降低。pcDNA3.1-mNPHS1转染显著上调足细胞Akt磷酸化水平,促进足细胞短线状足突形成,部分抑制AngⅡ诱导的骨架重排。结论：PI3K/Akt是nephrin和AngⅡ的共同下游通路。Nephrin能通过PI3K/Akt途径部分稳定AngⅡ诱导的足细胞细胞骨架改变。     

反义p38 MAPK寡核苷酸对AT1R介导的血管收缩的影响及其机制

目的研究反义p38 MAPK寡核苷酸在血管紧张素Ⅱ1型受体（AT1R）介导的血管平滑肌收缩反应中的作用及其机制。方法采用反义寡核苷酸（ASODN）基因封闭技术来特异性调控p38 MAPK的表达,观察p38 MAPK在AT1R介导的大鼠主动脉血管平滑肌收缩中的作用及其与血管平滑肌肌球蛋白轻链激酶（MLCK）的关系。结果 AngⅡ诱导大鼠主动脉产生浓度依赖性的收缩,AT1R拮抗剂losartan和p38 MAPK-ASODN处理均可拮抗AngⅡ诱导的血管收缩反应。同时,AngⅡ处理可明显升高血管MLCK的活性,AT1R拮抗剂和p38 MAPK-ASODN也明显抑制了AngⅡ的这一作用。结论 p38 MAPK参与了AT1R介导的血管收缩反应的调节,其机制与MLCK调节途径有关。     

PI3K / Akt / mTOR 信号通路介导的N822K 突变对c-KIT 抑制剂诱导的AML 细胞凋亡的影响

目的:研究c-KIT N822K 突变对c-KIT 抑制剂诱导AML 细胞凋亡的影响,并初步探讨相关的分子机制。方法:以c-KIT N822K 突变的Kasumi-1 细胞为实验组,以HL-60、NB4 细胞为非c-KIT N822K 突变的对照组,分别用0、0.04、0.16、0.64 μmol/ L 的c-KIT 抑制剂舒尼替尼处理这三株AML 细胞24 h 后收集细胞,采用Western blot 检测凋亡相关蛋白和PI3K/ Akt/ mTOR 通路蛋白水平,比较各组细胞相关信号通路蛋白的变化。结果:随着舒尼替尼浓度的增加,HL-60 及NB4 细胞中Bax 及CytoC、Caspase-9、Actived-Caspase-3、PARP 蛋白剪切体等促凋亡相关蛋白表达均上调(P<0.05),抗凋亡蛋白Bcl-2表达均下调(P<0.01),在具有N822K 突变的Kasumi-1 细胞中这一变化趋势则明显减弱;Kasumi-1 细胞中c-myc 蛋白及PI3K、Akt、4EBP1、mTOR 等PI3K/ Akt/ mTOR 通路蛋白的磷酸化水平均出现剂量依赖性下调(P<0.05),而HL-60 细胞和NB4 细胞则无此变化。结论:N822K 突变引起的c-KIT 结构性激活可影响c-KIT 抑制剂舒尼替尼对Kasumi-1 细胞的凋亡诱导作用,其机制可能与PI3K/ Akt/ mTOR 通路抑制有关。     

丹参酮Ⅱa对急性髓系白血病NB4细胞增殖和凋亡的影响及其机制

目的观察丹参酮Ⅱa对急性髓系白血病细胞增殖和凋亡的影响,并初步分析其作用机制.方法人急性髓系白血病细胞NB4分别用不同浓度的丹参酮Ⅱa处理,11.2μmol/L柔红霉素作为阳性对照,未给予药物作为阴性对照.观察NB4细胞增殖、细胞周期、凋亡及相关通路蛋白的变化.结果丹参酮Ⅱa可明显抑制NB4细胞增殖,诱导细胞周期发生G1期阻滞,促进其凋亡,具有浓度依赖性(P<0.05).丹参酮Ⅱa可剂量性下调p-PI3K/PI3K、p-AKT/AKT及m-TOR的表达(P<0.05).结论丹参酮Ⅱa可抑制NB4细胞增殖,诱导细胞周期发生G1期阻滞,促进其凋亡,可能与抑制PI3K/AKT/m-TOR信号通路有关.     

ERK1/2及JNK参与DL0805抑制血管紧张素Ⅱ引起的大鼠离体胸主动脉环收缩

目的研究Rho激酶抑制剂DL0805对血管紧张素Ⅱ(AngⅡ)引起的大鼠离体胸主动脉环收缩反应的影响及其可能的机制。方法测定离体血管张力观察大鼠胸主动脉环收缩反应,Western blot检测大鼠离体胸主动脉环ERK1/2和JNK蛋白磷酸化,和AngⅡ1型受体(AT1R)蛋白表达水平。结果 DL0805(10、25和50μmol/L)浓度依赖性地抑制AngⅡ(100 nmol/L)引起的内皮完整或去内皮的大鼠离体胸主动脉环收缩(P<0.01,P<0.001),DL0805(25和50μmol/L)抑制AngⅡ(100 nmol/L)诱导的ERK1/2和JNK的活化(P<0.05,P<0.01和P<0.001),但DL0805(5、25和50μmol/L)对AngⅡ刺激的血管环AT1R蛋白表达水平无显著影响。结论 DL0805抑制AngⅡ引起的大鼠离体胸主动脉环收缩,其机制可能与其抑制AngⅡ诱导的ERK1/2和JNK活化有关。     

阿糖胞苷通过调控miR-126表达抑制急性髓系白血病细胞增殖及诱导细胞凋亡的分子机制研究北大核心CSCD

目的:探讨阿糖胞苷是否可通过调控微小RNA-126(miR-126)表达抑制急性髓系白血病细胞增殖及诱导细胞凋亡。方法:体外培养急性髓系白血病细胞HL-60,分别加入不同浓度的阿糖胞苷处理;采用甲基噻唑基四唑(MTT)检测细胞增殖;流式细胞术检测细胞凋亡;实时荧光定量聚合酶链反应(qRT-PCR)检测miR-126的表达量;分别将miR-126 mimics、antimiR-126转染至HL-60细胞,采用上述方法检测细胞增殖及凋亡;Western blot检测增殖标记蛋白细胞增殖核抗原67(Ki67)、活化的含半胱氨酸的天冬氨酸蛋白水解酶3(Cleaved-caspase-3)与磷脂酰肌醇-3-激酶(PI3K)/蛋白激酶B(AKT)信号通路相关蛋白磷酸化磷脂酰肌醇-3-激酶(p-PI3K)、磷酸化蛋白激酶B(p-AKT)的表达量。结果:阿糖胞苷可显著降低细胞增殖率(P<0.05),增高细胞凋亡率(P<0.05),抑制Ki67、p-PI3K、p-AKT表达(P<0.05),促进miR-126、Cleaved-caspase-3表达(P<0.05);转染miR-126 mimics后,细胞增殖率显著降低(P<0.05),细胞凋亡率显著升高(P<0.05),Ki67蛋白水平显著降低(P<0.05),Cleavedcaspase-3蛋白水平显著升高(P<0.05),而转染anti-miR-126的作用与之相反;转染anti-miR-126可降低阿糖胞苷对HL-60细胞增殖及凋亡的作用,并可促进p-PI3K、p-AKT的表达(P<0.05)。结论:阿糖胞苷可能通过上调miR-126表达及抑制PI3K/AKT信号通路的活化从而抑制急性髓系白血病细胞增殖及诱导细胞凋亡。     

血管紧张素Ⅱ激活巨噬细胞株p38MAPK信号通路并诱导其增殖

目的：探讨血管紧张素Ⅱ(AngⅡ)激活巨噬细胞p38MAVK信号通路的模式变化及其对巨噬细胞株增殖的影响。方法：用Western blot测定细胞p38MAPK磷酸化表达；用细胞免疫组化观察细胞p38MAPK激活后核移位；用MTT法观察细胞增殖。结果：AngⅡ(1μmol／L)可诱导RAW264．7细胞p38MAVK磷酸化表达，15～30分钟达到高峰，随时间呈峰形变化。AngⅡ呈剂量依赖性诱导RAW264．7细胞p38MAPK磷酸化。p38MAPK特异性抑制剂SB202190可显著抑制RAW264．7细胞p38MAVK磷酸化，并呈剂量依赖性。AngⅡ可诱导RAW264．7细胞增殖，SB202190可显著抑制AngⅡ诱导的RAW264．7细胞增殖。结论：AngⅡ可激活RAW264．7巨噬细胞株p38MAPK信号通路，并通过p38MAPK信号通路调控RAW264．7细胞增殖。     

血管紧张素Ⅱ2型受体对大鼠血管平滑肌增殖的影响及其机制

目的：观察血管紧张素Ⅱ（AngⅡ）2型受体（AT2R）对培养的大鼠血管平滑肌细胞 （VSMC）增殖的影响。方法： 将AT2R cDNA转染到培养的大鼠VSMC中， 分别观察AngⅡ、AngⅡ＋losartan、AngⅡ+PD123319等不同处理因素处理对VSMC的 细胞数目以及PCNA、 NOS表达的影响。 结果：losartan 处理组细胞数目和PCNA表达量少于AngⅡ处理组，NOS表达量高于AngⅡ处理组， 而PD123319处理组细胞数目和PCNA表达量显著高于AngⅡ处理，NOS表达量较之为少。结论： 激活AT2R能拮抗AngⅡ的由AT1R介导的促细胞增殖作用，这种作用可能与激活AT2R后NOS表达增多使 NO合成增多有关。     

Dual repressive effect of angiotensin II-type 1 receptor blocker telmisartan on angiotensin II-induced and estradiol-induced uterine leiomyoma cell proliferation

BACKGROUND: Although uterine leiomyomas or fibroids are the most common gynecological benign tumor and greatly affect reproductive health and well-being, the pathophysiology and epidemiology of uterine leiomyomas are poorly understood. Elevated blood pressure has an independent, positive association with risk for clinically detected uterine leiomyoma. Angiotensin II (Ang II) is a key biological peptide in the renin-angiotensin system that regulates blood pressure. METHODS: In this study, we investigated the potential role of Ang II (1-1000 nM) in the proliferation of rat ELT-3 leiomyoma cells in vitro. RT-PCR and western blot analysis with cell proliferation and DNA transfection assays were performed to determine the mechanism of action of Ang II. RESULTS: Ang II induced ELT-3 leiomyoma cell proliferation (P < 0.01) and the expression of Ang II type 1 receptor (AT(1)R) and AT(2)R mRNA and protein was confirmed. Regarding the intracellular signaling pathway, the Ang II-induced cell proliferation was AT(1)R-, epidermal growth factor receptor-, extracellular-regulated kinase- and protein kinase C-dependent but was not dependent on the AT(2)R or phosphatidylinositol-3 kinase or JAK kinase. The AT(1)R blocker telmisartan, effectively repressed Ang II-induced and estradiol-induced cell proliferation (P < 0.01). AT(1)R, but not AT(2)R, plays a role in Ang II-induced ELT-3 cell proliferation. CONCLUSIONS: These experimental findings in vitro highlight the potential role of Ang II in the proliferation of leiomyoma cells.     

Ang II attenuates IGF-1-stimulated Na+, K(+)-ATPase activity via PI3K/Akt pathway in vascular smooth muscle cells

We have investigated the role of phosphatidylinositol 3-kinase (PI3K) and serine/threonine protein kinase B (Akt) in mediating vascular smooth muscle cells (VSMC) sodium pump (Na+, K(+)-ATPase) regulatory interactions between insulin-like growth factor-1 (IGF-1) and angiotensin II (Ang II). Treatment with IGF-1 (100 nM) for 30 min or Ang II (100 nM) for 10 min increased sodium pump activity. Pretreatment with Ang II for 10 min, abolished IGF-1 increased sodium pump activity. Given separately for 6 h, Ang II and IGF-1 stimulated alpha1 mRNA accumulation. Phosphorylation on Ser473 of Akt was increased after treatment with both IGF-1 and Ang II. Pretreatment with 100 nM of PI3K inhibitor Wortmannin (WT) for 30 min decreased: IGF-1 and Ang II-stimulated pump activity, phosphorylation of Akt and PI3K protein expression. Pretreatment with Ang II attenuated IGF-1-stimulated sodium pump activity, phosphorylation of Akt and PI3K protein expression. IGF-1 increased the association between IRS-1 and p85, and Ang II as well as PI3K inhibition decreased this IGF-1 effect. These results suggest that Ang II, which increases pump activity alone, reduces the IGF-1 stimulation of sodium pump activity by attenuating PI3K/Akt signaling. These results implicate PI3K/Akt pathways in Ang II/IGF-1 regulation of the sodium pump in VSMC.     

IL-38 通过调控PI3K/ Akt/ GSK3β/ NFATc1 信号通路抑制骨质疏松的机制研究

目的:探讨IL-38 抑制骨质疏松的作用并研究其分子机制。方法:共纳入2014 年6 月~2016 年12 月我院收治的138 例骨质疏松患者作为研究对象。另选取120 例同期在我院骨科进行骨折手术的无骨质疏松患者作为对照。采用ELISA 法检测实验对象血清IL-38 水平。构建IL-38-C57BL/6J 转基因小鼠,建立骨质疏松小鼠模型,将野生型、IL-38 转基因小鼠分别设置为假手术组(Sham 组)与卵巢切除组(Ovariectomy,OVX 组)。术后8 周取小鼠血清,检测碱性磷酸酶(ALP)、血钙及血磷水平。另取小鼠的脊柱与双侧股骨,通过病理切片分析股骨组织形态结构,用骨密度仪检测脊柱骨密度变化。将各组小鼠的骨髓基质细胞(BMSCs)进行分离并检测其体外增殖能力,Western blot 检测各组BMSCs 的PI3K、Akt、GSK3β与NFATc1 的磷酸化水平。小鼠成骨细胞MC3T3-E1 转染IL-38 后,Western blot 检测PI3K、Akt、GSK3β与NFATc1 磷酸化水平的变化,流式细胞术检测IL-38 对细胞凋亡的影响。结果:骨质疏松组患者的血清IL-38 水平显著低于对照组(P<0.05)。野生型与IL-38 转基因OVX 小鼠的血钙、血磷水平均显著高于Sham 组(P<0.05),而ALP 水平显著低于Sham 组(P<0.05)。另外,IL-38 转基因OVX 小鼠的血钙和血磷水平均显著低于野生型OVX 小鼠(P<0.05)。股骨病理切片及脊柱骨密度分析显示,野生型与IL-38 转基因OVX 小鼠均出现骨组织形态结构破坏和骨密度下降,并且IL-38 转基因OVX 小鼠的骨组织形态结构破坏和骨密度下降情况均较野生型OVX 小鼠显著减轻(P<0.05)。IL-38 转基因OVX 小鼠BMSCs 的体外增殖能力显著高于野生型OVX 组(P<0.05)。IL-38 转基因OVX 小鼠BMSCs 的PI3K、Akt 与NFATc1 磷酸化水平均显著低于野生型OVX 组(P<0.05),GSK3β磷酸化水平显著高于野生型OVX 组(P<0.05)。MC3T3-E1 细胞转染IL-38 后PI3K、Akt 与NFATc1 的磷酸化水平均显著降低(P<0.05),GSK3β的磷酸化水平显著升高(P<0.05)。流式细胞检测显示转染IL-38 后MC3T3-E1 细胞的凋亡显著减少(P<0.05)。结论:骨质疏松患者的血清IL-38 水平显著降低,IL-38 可能通过调控PI3K/ Akt/ GSK3β/ NFATc1 信号通路促进BMSCs 增殖、抑制成骨细胞凋亡,从而抑制骨质疏松的进展。     

CX3CL1/CX3CR1 Axis Contributes to Angiotensin II-Induced Vascular Smooth Muscle Cell Proliferation and Inflammatory Cytokine Production

Angiotensin II (Ang II) dysregulation has been determined in many diseases. The CX3CL1/CX3CR1 axis, which has a key role in cardiovascular diseases, is involved in the proliferation and inflammatory cytokine production of vascular smooth muscle cells (VSMCs). In this study, we aim to explore whether Ang II has a role in the expression of CX3CL1/CX3CR1, thus contributing to the proliferation and pro-inflammatory status of VSMCs. Cultured mouse aortic VSMCs were stimulated with 100 nmol/L of Ang II, and the expression of CX3CR1 was assessed by western blot. The results demonstrated that Ang II significantly up-regulated CX3CR1 expression in VSMCs and induced the production of reactive oxygen species (ROS) and the phosphorylation of p38 MAPK. Inhibitors of NADPH oxidase, ROS, and AT1 receptor significantly reduced Ang II-induced CX3CR1 expression. Targeted disruption of CX3CR1 by transfection with siRNA significantly attenuated Ang II-induced VSMC proliferation as well as down-regulated the expression of proliferating cell nuclear antigen (PCNA). Furthermore, CX3CR1-siRNA suppressed the effect of Ang II on stimulating Akt phosphorylation. Besides, the use of CX3CR1-siRNA decreased inflammatory cytokine production induced by Ang II treatment. Our results indicate that Ang II up-regulates CX3CR1 expression in VSMCs via NADPH oxidase/ROS/p38 MAPK pathway and that CX3CL1/CX3CR1 axis contributes to the proliferative and pro-inflammatory effects of Ang II in VSMCs.     

Mechanisms of angiotensin II signaling on cytoskeleton of podocytes

Podocytes are significant in establishing the glomerular filtration barrier. Sustained rennin–angiotensin system (RAS) activation is crucial in the pathogenesis of podocyte injury and causes proteinuria. This study demonstrates that angiotensin II (Ang II) caused a reactive oxygen species (ROS)-dependent rearrangement of cortical F-actin and a migratory phenotype switch in cultured mouse podocytes with stable Ang II type 1 receptor (AT1R) expression. Activated small GTPase Rac-1 and phosphorylated ezrin/radixin/moesin (ERM) proteins provoked Ang II-induced F-actin cytoskeletal remodeling. This work also shows increased expression of Rac-1 and phosphorylated ERM proteins in cultured podocytes, and in glomeruli of podocyte-specific AT1R transgenic rats (Neph-hAT1 TGRs). The free radical scavenger DMTU eliminated Ang II-induced cell migration, ERM protein phosphorylation and cortical F-actin remodeling, indicating that ROS mediates the influence of Rac-1 on podocyte AT1R signaling. Heparin, a potent G-coupled protein kinase 2 inhibitor, was found to abolish ERM protein phosphorylation and cortical F-actin ring formation in Ang II-treated podocytes, indicating that phosphorylated ERM proteins are the cytoskeletal effector in AT1R signaling. Moreover, Ang II stimulation triggered down-regulation of α actinin-4 and reduced focal adhesion expression in podocytes. Signaling inhibitor assay of Ang II-treated podocytes reveals that Rac-1, RhoA, and F-actin reorganization were involved in expressional regulation of α actinin-4 in AT1R signaling. With persistent RAS activation, the Ang II-induced phenotype shifts from being dynamically stable to adaptively migratory, which may eventually exhaust podocytes with a high actin cytoskeletal turnover, causing podocyte depletion and focal segmental glomerulosclerosis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effect of an angiotensin II type 1 receptor blocker on caveolin-1 expression in prostate cancer cells

Introduction

Caveolin-1, the major structural protein of caveolae, interacts directly with the AT1 receptor. The biological functions of caveolin-1 in cancer are compound, multifaceted, and depend on cell type, tumour grade and cancer stage. The AT1-R-caveolin complex in caveolae may coordinate angiotensin II (Ang II) induced signalling. The aim of this study was to determine the effect of the angiotensin II receptor type 1 blocker candesartan on caveolin expression in human metastatic prostate adenocarcinoma cells PC-3.

Material and methods

WST-1 and BrdU assays were used as indicators of cell viability and proliferation after angiotensin II and/or candesartan stimulation. Real-time RT–PCR and western blot were used to study the effect of Ang II and/or candesartan on the expression of Cav-1 and AT1-R in PC-3 cells

Results

We found that the expression of caveolin-1 mRNA in the PC-3 cells treated with CV was significantly decreased in comparison with the control (2.9 ±0.17, 4.7 ±0.6, p < 0.05), whereas a higher caveolin-1 mRNA expression was observed in those after Ang II treatment (6.0 ±0.43, 4.7 ±0.6, p < 0.05). Protein analysis indicate that the expression of caveolin-1 protein in the PC-3 cells treated with candesartan was significantly decreased when compared with the control (0.69 ±0.05, 1.6 ±0.12, p < 0.05), whereas higher caveolin-1 protein expression was observed after Ang II treatment (2.5 ±0.20, 1.6 ±0.12, p < 0.05).

Conclusions

These results provide new information on the action of candesartan and may improve the knowledge about AT1 receptor inhibitors, which can be potentially useful in prostate cancer therapy.     

Angiotensin II angiogenic effect in vivo involves vascular endothelial growth factor- and inflammation-related pathways

Although accumulating lines of evidence indicate the proangiogenic role of angiotensin II (Ang II), little is known about the molecular mechanisms associated with such an effect. This study aimed to identify molecular events involved in Ang II-induced angiogenesis in the Matrigel model in mice. C57Bl/6 female mice received a subcutaneous injection of either Matrigel or Matrigel with Ang II (10(-7) M) alone, with Ang II and an AT1 receptor antagonist (candesartan, 10(-6) M), or with Ang II and AT2 receptor antagonist (PD123319, 10(-6) M). After 14 days, angiogenesis was assessed in the Matrigel-plug by histological evaluation and cellular counting. Ang II increased by 1.9-fold the number of cells within the Matrigel (p < 0.01 versus control). Immunohistological analysis revealed the presence of macrophages, endothelial and smooth muscle cells, and the development of vascular-like structure. Such an angiogenic effect was associated with an increase in vascular endothelial growth factor (VEGF) (1.5-fold, p < 0.01), endothelial nitric oxide (eNOS) (1.7-fold, p < 0.01), and cyclooxygenase-2 (1.4-fold, p < 0.05) protein levels measured by Western blotting. Conversely, Ang II treatment did not affect MMP-9 and MMP-2 activity, assessed by zymography. Blockade of AT1 receptor completely prevented the Ang II-induced angiogenesis and protein regulations, whereas that of AT2 was ineffective. Administration of VEGF neutralizing antibody (2.5 microg ip twice a week) and cyclooxygenase-2 selective inhibitor (nimesulide, 30 mg/L) also hampered Ang II proangiogenic effect. In addition, Ang II-induced cell ingrowth was impaired by treatment with nitric oxide synthase inhibitor (L-NAME, 10 mg/kg/day) and in eNOS-deficient mice. Therefore, in an in vivo model, Ang II induced angiogenesis through AT1 receptor, which involved activation of VEGF/eNOS-related pathway and of the inflammatory process.