丁苯酞对缺氧缺糖条件下血管内皮细胞VEGF和HIF-1α表达的影响

目的: 探讨丁苯酞(NBP)保护缺氧缺糖(OGD)细胞损伤的机制。方法: 对人脐静脉内皮细胞(HUVECs)予以OGD损伤,MTT法检测细胞活性;Hoechst 33342染色检测细胞核形态;免疫荧光法观察血管内皮生长因子(VEGF)和缺氧诱导因子-1α(HIF-1α)表达,IPP软件分析荧光强度,进行定量分析;Western blotting检测加以验证。结果: NBP在0.01- 10 μmol/L浓度之间剂量依赖性减少了OGD导致的细胞活性下降和细胞核形态改变。NBP促进了OGD后HUVECs内VEGF和HIF-1α的表达,均高于OGD组,荧光定量分析差异显著。两者表达的高峰分别为OGD后6 h和8 h。结论: NBP可以促进内皮细胞在缺氧缺糖条件下HIF-1α的表达,从而引起下游VEGF的表达增多,最终保护内皮细胞免受缺氧缺糖损伤。     

消肿止痛合剂通过VEGF-Dll4/Notch信号通路减轻大鼠血管内皮细胞缺氧损伤

目的:研究消肿止痛合剂对大鼠皮瓣血管内皮细胞功能及VEGF-Dll4/Notch信号通路中相关蛋白表达的影响。方法:体外分离并培养大鼠皮瓣血管内皮细胞,将细胞分为对照组、缺氧组、缺氧+消肿止痛剂组(缺氧+消肿组)、缺氧+消肿止痛剂+axitinib(VEGF受体抑制剂)组及缺氧+消肿止痛剂+MK-0752(Notch通路阻断剂)组。采用ELISA法测定血清中VEGF含量,采用细胞calcein-AM和PI双染色法判断缺氧后1 d、2 d和3 d死活细胞数量,Western blot检测了24 h和48 h细胞内VEGF-A、Notch和Dll4蛋白的表达量。结果:与对照组相比,缺氧24 h和48 h后VEGF含量显著增加,细胞死亡率显著增加,且VEGF-A、Notch和Dll4的蛋白表达量显著增加(P0.05);与缺氧组细胞相比,消肿止痛合剂干预后,VEGF的含量显著增加,细胞死亡率显著降低,且VEGF-A、Notch和Dll4的蛋白表达量显著升高(P0.05)。与消肿止痛合剂组相比,VEGF受体抑制剂干预细胞后,消肿止痛合剂对缺氧损伤的血管内皮细胞的保护作用减弱,细胞死亡率明显增加,VEGF的含量降低,且VEGF-A、Notch和Dll4的蛋白表达量降低(P0.05)。Notch通路阻断剂干预细胞后,细胞存活率不变,VEGF-A的蛋白表达水平增加,Notch和Dll4蛋白表达增加的趋势被有效抑制(P0.01)。结论:消肿止痛合剂可改善大鼠皮瓣血管内皮细胞的功能,其机制与影响VEGF-Dll4/Notch信号转导通路有关。     

Dll4-Notch信号传递途径在血管发生中的作用

血管发生(angiogenesis)依赖多种促进血管发生因子和抑制血管发生因子之综合的交互作用所调控。血管内皮生长因子(VEGF)和Notch信号传递途径(Notch signaling pathway)参与此过程。之前研究已证明Notch信号传递途径在胚胎发育和肿瘤血管发生(tumour angiogenesis)中扮演重要的角色,而最近研究则发现在血管发育过程中Dll4-Notch信号传递途径扮演着前所未知的新角色,并阐明因Notch信号传递减少而引起血管缺陷之机制,从而揭示破坏肿瘤血管发生的新药物靶点。本文着重于介绍Notch信号传递途径的组成;Dll4-Notch在血管发生中的作用;以及Dll4-Notch对肿瘤治疗的意义。     

重组人内皮抑素通过激活Dll4/Notch通路抑制大鼠动脉粥样硬化斑块内血管新生

目的:观察重组人内皮抑素(rh ES)对大鼠动脉粥样硬化(AS)斑块内新生血管的抑制作用,探讨Dll4/Notch信号通路在其中的调控机制。方法:雄性Wistar大鼠随机分为正常对照组(N组)、AS组和AS+rh ES组,每组10只。N组始终喂基础饲料,其余2组采用高脂喂养、维生素D3负荷及球囊损伤动脉内膜建立大鼠AS模型。AS+rh ES组以10 mg·kg~(-1)·d~(-1)的rh ES腹腔注射4周,另2组注射等量生理盐水。采血检测各组的总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、C反应蛋白(CRP)、白细胞介素-1(IL-1)和肌钙蛋白I(Tn I)等;免疫组化CD31染色观察新生血管密度;Western blot法检测主动脉内Dll4、Notch1蛋白表达。结果:与N组比较,AS组和AS+rh ES组的TC、TG、LDL-C、CRP和L-1水平均显著升高(P0.05),但上述指标在AS组和AS+rh ES组之间差异无统计学显著性。CD31染色结果显示,AS组的新生血管表达最丰富;与AS组比较,AS+rh ES组的新生血管密度显著下降(P0.05)。AS组的Dll4和Notch1蛋白水平显著低于N组(P0.05);相比AS组,AS+rh ES组的Dll4和Notch1蛋白水平显著升高(P0.05)。结论:rh ES能够抑制大鼠AS斑块内血管新生,Dll4/Notch通路的激活可能是rh ES抑制斑块内的血管新生的信号机制。     

丁苯酞减轻H2O2诱导的人脐静脉和脐动脉内皮细胞氧化损伤

目的探讨丁苯酞(NBP)对过氧化氢(H_2O_2)诱导的血管内皮细胞(人脐静脉和脐动脉)氧化损伤的保护作用及发生机制。方法体外培养人脐静脉内皮细胞(HUVECs)和人脐动脉内皮细胞(HUAECs)。用四甲基偶氮唑盐(MTT)法筛选合适的H_2O_2剂量建立两种细胞的氧化应激损伤模型。在加入H_2O_2前2 h,分别用两种剂量的丁苯酞(5和10μmol/L)预孵育细胞,用MTT法检测细胞活力,罗丹明123检测线粒体膜电位,Annexin V/PI双染法检测凋亡细胞,Fura-4/AM检测细胞内游离钙。结果 H_2O_2刺激可导致HUVECs和HUAECs细胞活力下降,线粒体膜电位下降,细胞内游离钙增多,细胞凋亡率上升(P0.05)。丁苯酞可改善H_2O_2诱导的上述变化。结论丁苯酞可通过减轻H_2O_2造成的氧化损伤来保护血管内皮细胞。     

阻断Dll4-Notch信号通路对哮喘小鼠Th17细胞分化的影响

目的:探讨哮喘小鼠体内Delta样配体4(Delta-like ligand 4,Dll4)-Notch信号通路阻断对辅助性T细胞17(Th17细胞)分化的影响。方法:30只雄性BALB/c小鼠随机分为正常对照组、生理盐水对照组、哮喘模型组、Dll4单克隆抗体干预组和Ig G对照组。肺组织切片进行免疫组织化学染色,定性分析Dll4的表达。流式细胞术分析各组小鼠脾脏Th17细胞在CD4~+T淋巴细胞中的比例。采用Western blot法检测小鼠脾脏分离淋巴细胞中维甲酸相关孤儿受体γt(retinoid-related orphan receptorγt,RORγt)的蛋白表达。应用酶联免疫吸附实验(enzymelinked immunosorbent assay,ELISA)检测各组小鼠血清中白细胞介素17(interleukin 17,IL-17)的含量。结果:与哮喘模型组比较,Dll4单克隆抗体干预组Dll4表达存在明显差异。与哮喘模型组比较,Dll4单克隆抗体干预组脾脏分离CD4~+T淋巴细胞中Th17细胞的比例和RORγt表达水平均存在统计学显著性(P0.05)。Dll4单克隆抗体干预组小鼠血清IL-17的表达与哮喘模型组之间的差异也存在统计学显著性(P0.01)。结论:阻断Dll4-Notch信号通路对哮喘小鼠Th17细胞分化起到抑制作用。     

miR-210对血管内皮细胞VEGF-Notch信号通路的调控

目的: 观察过表达miR-210对血管内皮细胞中血管内皮生长因子(VEGF)-Notch信号通路相关分子表达的影响,探讨miR-210调控血管新生的分子机制。方法: 采用常规方法培养人脐静脉内皮细胞(HUVE-12)。通过转染LV- miR-210-GFP重组慢病毒载体上调内皮细胞miR-210表达,实验分为miR-210过表达组(LV- miR-210-GFP)和对照组(LV-GFP)。采用real-time PCR检测miR-210的表达变化,流式细胞术检测ephrin-A3的表达,采用real-time PCR、Western blotting、免疫荧光细胞化学染色法分别检测VEGF-Notch信号通路相关分子VEGF、VEGF 2(VEGFR 2)、Notch1的mRNA和蛋白表达水平。结果: Real-time PCR结果显示,与对照组相比,miR-210过表达组miR-210表达水平上调了(32.10±1.26)倍;流式细胞术结果显示,miR-210过表达组阳性细胞率 较对照组 明显增加(P<0.05)。Real-time PCR结果显示,miR-210过表达组 VEGF、VEGFR2、Notch1 mRNA分别较对照组上调了(7.40±0.67)、(2.50±0.10)、(9.70±0.72)倍,P<0.05;免疫荧光结果显示,miR-210过表达组VEGF和VEGFR2红色荧光信号均显著强于对照组(P<0.05)。Western blotting 结果显示,miR-210过表达组血管内皮细胞中Notch1的蛋白表达量(4.22±0.60)较对照组明显升高(P<0.05)。结论: miR-210过表达可显著上调VEGF-Notch信号通路分子的表达水平。     

HIF-1α在结外鼻型NK/T细胞淋巴瘤血管生成中的作用及意义

目的: 研究缺氧诱导因子-1α(HIF-1α)在结外鼻型NK/T细胞淋巴瘤血管生成中的作用及意义。方法: 采用免疫组化法检测50例人结外鼻型NK/T细胞淋巴瘤中HIF-1α、血管内皮生长因子(VEGF)和血管内皮生长因子受体2(VEGFR2)的表达情况,用CD34单克隆抗体标记血管内皮细胞,并计算肿瘤微血管密度(MVD),用SPSS 13.0软件分析HIF-1α与VEGF、VEGFR2及肿瘤MVD的相关性。结果: (1)50例中有39例(78%)肿瘤细胞HIF-1α阳性,27例(54%)VEGFR2阳性,与淋巴结反应性增生组织中淋巴细胞的表达情况比较均有显著差异(P<0.05);(2)HIF-1α蛋白阳性表达组VEGF和VEGFR2的阳性表达率分别为72%和64%,明显高于HIF-1α蛋白阴性表达组(P<0.05);(3)HIF-1α、VEGFR和VEGFR2蛋白表达与肿瘤MVD相关(P<0.01);(4)15例伴有血管中心性浸润的结外鼻型NK/T细胞淋巴瘤病例均表达HIF-1α。结论: HIF-1α可促进结外鼻型NK/T细胞淋巴瘤肿瘤血管生成,其作用机制可能与VEGF/VEGFR2通路有关。     

乳腺癌细胞源Exosomes在促肿瘤血管生成中的作用及机制

目的观察乳腺癌细胞源Exosomes对脐静脉内皮细胞(HUVECs)的生物学效应,初步探讨肿瘤细胞源Exosomes在恶性肿瘤血管病理新生中的作用。方法收集乳腺癌MDA-MB-231细胞培养上清液,以超速及密度梯度离心提取Exosomes;MTT法检测细胞增殖;用流式细胞仪测定细胞周期;Transwell小室法检测迁移能力;基质胶成管实验观察成管结构的形成;PCR检测EGFR及VEGF mRNA表达;用ELISA及Western blot检测细胞EGFR及其下游ERK、Akt及VEGF/VEGFR2表达。结果乳腺癌MDA-MB-231细胞源Exosomes以时间-剂量依赖性促进HUVECs细胞增殖(P0.05)。并且,在作用24 h后,S期细胞比例增加,G1/S期细胞比例下降(P0.05);同时,HUVEC迁移及体外管腔形成能力显著提高(P0.05)。并且MDA-MB-231源Exosomes促进了HUVECs细胞EGFR蛋白的表达,使得磷酸化ERK与Akt蛋白的表达增加,同时促进了VEGF蛋白的分泌,并促进了VEGF/VEGFR2蛋白表达(P0.05)。结论乳腺癌细胞源Exosomes促进HUVECs的增殖、迁移及体外成管能力,其机制可能与EGFR蛋白与其下游MAPK/ERK和PI3K/Akt信号通路的持续活化,以及VEGF/VEGFR2蛋白的表达有关。     

miR-29c促进前列腺癌PC3细胞凋亡

目的研究miR-29c对前列腺癌PC3细胞凋亡的影响及其机制。方法以人正常前列腺上皮细胞系(RWPE-1)为对照,检测前列腺癌PC3细胞系中miR-29c、血管内皮生长因子(VEGF)及血管内皮生长因子受体2(VEGFR2)的表达;免疫荧光(IF)检测p-VEGFR2在细胞中的定位;miR-29c过表达腺病毒感染PC3,real-time PCR检测miR-29c及VEGF的表达;Western blot检测VEGF、t-VEGFR2、p-VEGFR2、BAX和Bcl-2的表达;hoechst 33258染色法检测PC3细胞凋亡;流式细胞计量术(FCM)检测PC3细胞早期凋亡率。结果与RWPE-1相比,PC3细胞miR-29c表达降低,VEGF及VEGFR2表达升高(P0.001);与对照组相比,miR-29c过表达组VEGF、p-VEGFR2及Bcl-2的表达显著降低(P0.001),BAX的表达显著升高(P0.001),细胞凋亡与早期凋亡率显著增加(P0.001)。结论重新表达miR-29c可以显著抑制VEGF/VEGFR2信号通路并促进PC3细胞凋亡。     

消肿止痛合剂对大鼠随意皮瓣血管再生的影响

目的:观察消肿止痛合剂对大鼠随意皮瓣血管再生及血管内皮生长因子(VEGF)-Dll4/Notch信号通路的影响.方法:将240只健康SD大鼠随机分为6组,分别为空白组、假手术组、模型组、消肿止痛合剂组(消肿组)、消肿止痛合剂+Notch阻断剂MK-0752(MK)组(消肿+MK组)和消肿止痛合剂组+VEGF受体抑制剂a...     

Semaphorin 3E-Plexin-D1 signaling regulates VEGF function in developmental angiogenesis via a feedback mechanism

Blood vessel networks are typically formed by angiogenesis, a process in which new vessels form by sprouting of endothelial cells from pre-existing vessels. This process is initiated by vascular endothelial growth factor (VEGF)-mediated tip cell selection and subsequent angiogenic sprouting. Surprisingly, we found that VEGF directly controls the expression of Plexin-D1, the receptor for the traditional repulsive axon guidance cue, semaphorin 3E (Sema3E). Sema3E-Plexin-D1 signaling then negatively regulates the activity of the VEGF-induced Delta-like 4 (Dll4)-Notch signaling pathway, which controls the cell fate decision between tip and stalk cells. Using the mouse retina as a model system, we show that Plexin-D1 is selectively expressed in endothelial cells at the front of actively sprouting blood vessels and its expression is tightly controlled by VEGF secreted by surrounding tissues. Therefore, although the Sema3E secreted by retinal neurons is evenly distributed throughout the retina, Sema3E-Plexin-D1 signaling is spatially controlled by VEGF through its regulation of Plexin-D1. Moreover, we show that gain and loss of function of Sema3E and Plexin-D1 disrupts normal Dll4 expression, Notch activity, and tip/stalk cell distribution in the retinal vasculature. Finally, the retinal vasculature of mice lacking sema3E or plexin-D1 has an uneven growing front, a less-branched vascular network, and abnormal distribution of dll4-positive cells. Lowering Notch activity in the mutant mice can reverse this defect, solidifying the observation that Dll4-Notch signaling is regulated by Sema3E-Plexin-D1 and is required for its function in vivo. Together, these data reveal a novel role of Sema3E-Plexin-D1 function in modulating angiogenesis via a VEGF-induced feedback mechanism.     

Dll3 and Notch1 genetic interactions model axial segmental and craniofacial malformations of human birth defects.

Mutations in the Notch1 receptor and delta-like 3 (Dll3) ligand cause global disruptions in axial segmental patterning. Genetic interactions between members of the notch pathway have previously been shown to cause patterning defects not observed in single gene disruptions. We examined Dll3-Notch1 compound mouse mutants to screen for potential gene interactions. While mice heterozygous at either locus appeared normal, 30% of Dll3-Notch1 double heterozygous animals exhibited localized, segmental anomalies similar to human congenital vertebral defects. Unexpectedly, double heterozygous mice also displayed statistically significant reduction of mandibular height and decreased length of the [corrected] maxillary hard palate. Examination of somite-stage embryos and perinatal anatomy and histology did not reveal any organ defects, so we used microarray-based analysis of Dll3 and Notch1 mutant embryos to identify gene targets that may be involved in notch-regulated segmental or craniofacial development. Thus, Dll3-Notch1 double heterozygous mice model human congenital scoliosis and craniofacial disorders.     

Expression of vascular Notch ligands Delta-like 4 and Jagged-1 in glioblastoma

Jubb A M, Browning L, Campo L, Turley H, Steers G, Thurston G, Harris A L & Ansorge O
(2012) Histopathology  60, 740–747
Expression of vascular Notch ligands Delta‐like 4 and Jagged‐1 in glioblastoma Aims: The coordinated expression of the Notch ligands Delta‐like 4 (Dll4) and Jagged (Jag)1 is believed to define appropriate endothelial sensitivity to vascular endothelial growth factor (VEGF). Preclinical data suggest that Dll4‐Notch signalling may confer resistance to anti‐VEGF therapy with bevacizumab, and Jag1 may antagonize Dll4–Notch. The aims of this study were to characterize the expression of Dll4 and Jag1 in primary glioblastomas. Methods and results: Immunohistochemistry was performed on 40 glioblastomas and normal brain using validated antibodies against Dll4 and Jag1. In‐situ hybridization for Dll4 was performed on serial sections and compared with protein expression. Dll4 expression was localized to the cytoplasm and membrane of endothelial cells in all glioblastomas; it was weak or absent in normal brain. Jag1 expression was observed in the cytoplasm and membrane of glomeruloid and non‐glomeruloid endothelial cells from 76% and 67% of glioblastomas, respectively. However, endothelial Jag1 expression was less intense and less prevalent than Dll4. There was no association between Dll4 and Jag1 expression. Conclusions: In summary, Dll4 and Jag1 are expressed in glioblastoma vasculature. These data may define subsets of glioblastoma that might be sensitive (Dll4⁺/Jag1⁺) or resistant (Dll4⁺/Jag1^–) to bevacizumab. Our data also suggest that anti‐Dll4 therapy should be evaluated experimentally in glioblastoma.     

Notch ligand Delta-like1 enhances degranulation and cytokine production through a novel Notch/Dok-1/MAPKs pathway in vitro

Food allergy includes sensitization phase and effect phase, and effect cells degranulate and secrete cytokines in the effect phase, causing allergic clinical symptoms. We have demonstrated that Notch signaling plays an important role in the sensitization phase, but its role in effect phases still remains unclear. In this study, we investigated the role of Notch signaling in degranulation and cytokine production of the effect phase response. A RBL-2H3 cell model was used and Notch signaling was induced by priming with Notch ligands. Our results showed after priming with Notch ligand, Delta-like1(Dll1)-Fc, β-hexosaminidase release, and cytokines production, including TGF-β, IL-1β, IL-4, IL-6, and IL-13, were increased significantly, and the enhancement was abolished after DAPT treatment, a γ-secretase inhibitor, indicating that Dll1 Notch signaling enhanced RBL-2H3 cell degranulation and cytokine production. Western blot analysis showed that Dll1 Notch signaling augmented high-affinity IgE receptors-mediated phosphorylation of MAPKs through suppressing the expression of downstream tyrosine kinases 1 (Dok-1). Besides, a passive systemic anaphylaxis mouse model was used to confirm the role of Notch signaling. And our data showed that allergic clinical features of mice were alleviated, and the level of degranulation was decreased significantly after inhibiting Notch signaling in vivo. Therefore, we demonstrated Notch ligand Dll1 enhanced RBL-2H3 cell degranulation and cytokine production through a novel Notch/Dok-1/MAPKs pathway, suggesting Notch signaling played a key role in the effect phase of food allergy.     

芥子碱对H_2O_2诱导BMSCs成脂分化的影响

目的:探讨中药有效单体芥子碱对过氧化氢(H_2O_2)诱导骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)成脂分化的影响。方法 :先通过全骨髓培养法和流式细胞术鉴定并筛选未分化的大鼠BMSCs;一方面利用H_2O_2诱导BMSCs成脂分化建立模型,一方面采用CCK-8实验检测芥子碱对BMSCs的毒性作用;模型建立成功与芥子碱药用浓度确定后进行油红O半定量实验检测细胞中脂滴含量,筛选出最佳的药物浓度;随后采用油红O染色拍片直接观察药物干预24 h后对BMSCs成脂分化的影响,并且采用qPCR和Western blot实验检测BMSCs中成脂分化相关蛋白——脂肪细胞蛋白2(aP2)、过氧化物酶体增殖物激活受体γ(PPARγ)和葡萄糖转运蛋白4(Glut4)的变化情况。结果:浓度为200μmol/L的H_2O_2作用1 h可诱导BMSCs成脂分化;CCK-8实验结果显示在芥子碱浓度40μmol/L的条件下对BMSCs的活力没有显著影响,同时结合油红O半定量实验结果筛选出芥子碱抑制其成脂分化的最佳浓度为15μmol/L;油红O染色实验观察到芥子碱组(15μmol/L)组脂滴较模型组数量明显减少,qPCR和Western blot实验结果亦显示正常对照组和芥子碱组aP2、PPARγ和Glut4表达均低于模型组(P0.01)。结论:芥子碱能够抑制H_2O_2诱导BMSCs向脂肪细胞分化,其机制可能与PPARγ/AMPK信号通路有关。