Cellular senescence determines endothelial cell damage induced by uremia

Renal dysfunction is closely associated with endothelial damage leading to cardiovascular disease. However, the extent to which endothelial damage induced by uremia is modulated by aging is poorly known. Aging can render endothelial cells more susceptible to apoptosis through an oxidative stress-dependent pathway. We examined whether senescence-associated to oxidative stress determines the injury induced by the uremia in endothelial cells.     

中药独活及其单体蛇床子素体外抗血管生成的实验研究

目的：探讨独活醇提物及其单体蛇床子素对体外血管生成的抑制作用及其可能的机制.方法：采用MTT法观察中药独活醇提物及蛇床子素对人脐静脉血管内皮细胞（human umbilical vein endothelial cell.HUVEC）和人肠癌LoVo细胞增殖的影响,Transwell小室趋化实验、体外小管形成实验以及流式细胞术,观察并比较独活醇提物及蛇床子素对HUVEC迁移、小管形成、凋亡及周期的影响.结果：3.75-30μg/ml的独活醇提物及蛇床子素作用48h时对HUVEC的细胞增殖抑制率分别在5.16％-10.15％和22.64％-65.56％之间,对LoVo细胞增殖抑制率分别在2.86％-7.29％和5.15％-24.39％之间.体外小管及小管迁移实验显示,3.75-30μg/ml的蛇床子素作用24h时HUVEC小管形成数目减少,且管腔不完整.3.75-30μg/ml的独活醇提物和蛇床子素处理12h对HUVEC迁移抑制率分别在-2.16％至8.00％和13.70％至63.04％之间.3.75-30μg/ml的独活醇提物和蛇床子素诱导HUVEC细胞凋亡率分别在6.1％-14.4％和18.8％-89.5％之间.独活醇提物和蛇床子素作用HUVEC 24h后,使内皮细胞周期主要阻滞在G0-G1期,蛇床子素对细胞周期影响强于独活醇提物.结论：蛇床子素在体外抑制血管生成作用强于独活醇提物,说明蛇床子素可能是独活醇提物中发挥抗血管生成作用的主要成分,其作用机制可能与抑制HUVEC增殖、迁移和小管形成,诱导HUVEC凋亡,阻滞HUVEC细胞周期有关.     

萝卜硫素通过Src/PI3K/Akt通路调控人脐静脉内皮细胞NO的生成机制

目的:研究萝卜硫素(SFN)促进人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)生成一氧化氮(NO),参与内皮细胞修复的作用机制.方法:采用MTT法检测SFN对HUVEC细胞存活率的影响;检测SFN对HUVEC NO释放量的影响;采用Western blot法...     

腺病毒介导的小鼠内皮抑素治疗胃癌的研究

目的:探讨人血管生成素-1(angiopoietin-1,Ang-1)对人脐静脉内皮细胞(human umbilican vein endothelia cell,HUVEC)增殖和凋亡的影响,以进一步研究其生物学作用及其在肿瘤发生中的作用机制.方法:构建pcDNA3.1-V5-HisC-Ang-1真核表达载体,并瞬时转染293细胞;取新生儿脐带经胶原酶消化等方法分离培养HUVEC;分别通过MTT比色和细胞计数法,分析Ang-1瞬时转染上清对HUVEC增殖的影响;通过流式细胞仪分析在血浆饥饿实验条件下,Ang-1对HUVEC凋亡的影响.结果:成功克隆了Ang-1基因,构建了其正义真核表达载体,并在293细胞中瞬时表达;成功进行了HUVEC的原代分离及传代培养;MTT法检测HUVEC增殖结果:只加培养液组、加空载体转染上清组、加Ang-1转染上清组HUVEC OD490值分别为0.36±0.11,0.40±0.03,0.68±0.10(P＜0.05);细胞计数法检测结果依次为:(10.13±2.06)×104,(8.7±1.73)×104,(15.03±1.98)×104(P＜0.05).流式细胞仪检测HUVEC凋亡率依次为:21%,19%和6%.结论:Ang-1能显著促进血管内皮细胞体外增殖,抑制血浆饥饿时HUVEC的凋亡.     

人硫氧还蛋白1在大肠杆菌中的重组表达及其对高糖导致的人脐静脉内皮细胞损伤的保护作用

目的 克隆人硫氧还蛋白1(hTRX1)基因并构建其原核表达载体,获得重组人硫氧还蛋白1(rhTRX1),评价rhTRX1对高糖导致的人脐静脉内皮细胞(HUVEC)损伤的保护作用.方法 采用逆转录PCR方法扩增hTRX1基因片段,插入pET22b(+)质粒并转化大肠杆菌Rosetta-gami(2),获得工程菌Rosetta-gami(2)-pET22ab(+)/hTRX1.用SDS-PAGE电泳和Western blot鉴定重组蛋白的正确性,用镍亲和层析纯化重组蛋白.采用高糖制备HUVEC损伤模型,MTT比色法检测HUVEC的存活率,生化方法测定HUVEC中乳酸脱氢酶(LDH)的外漏率以及细胞上清液中一氧化氮(NO)的水平.结果 构建的工程菌及其产生的重组蛋白rhTRX1正确.与正常对照组比较,高糖损伤组HUVEC的存活率降低、LDH外漏率明显升高,NO的水平明显地降低.不同剂量rhTRX1处理组HUVEC的存活率升高、LDH的外漏率明显降低,NO的水平明显地升高.结论 成功克隆并在大肠杆菌中表达rhTRX1、获得结构正确的rhTRX1,rhTRX1对高糖诱导的HUVEC损伤具有保护作用.     

Nitric oxide acts on the mitochondria and protects human endothelial cells from apoptosis

Proliferation of small blood vessels in synovial tissues is one of the pathologic features of rheumatoid arthritis. In this study we tested the hypothesis that nitric oxide (NO) protects endothelial cells (ECs) against apoptogenic agents in vitro. Human umbilical-vein endothelial cells (HUVECs) were cultured with and without NO donor S -nitro- N -acetylpenicillamine (SNAP) and further incubated in the presence or absence of Z-leucine-leucine-leucine-aldehyde (LLL-CHO), etoposide, or C2-ceramide. After cultivation, apoptosis of HUVECs was quantified on the basis of disruption of mitochondrial transmembrane potential (DeltaPsim), activation of caspases, and the presence of hypodiploid DNA-positive cells. Treatment of HUVECs with LLL-CHO, etoposide, or C2-ceramide induced DeltaPsim, activation of caspase-3, caspase-8, and caspase-9 and the appearance of hypodiploid DNA-positive cells. NO production in HUVECs was clearly increased by SNAP. Apoptotic cell death in HUVECs induced by LLL-CHO, etoposide, and C2-ceramide was significantly suppressed by SNAP treatment. HUVECs in vitro expressed Bcl-2, Bcl-xL, and Bax; however, expression was not changed by SNAP treatment in the presence or absence of LLL-CHO, etoposide, or C2-ceramide. Although the molecule(s) responsible for the protective effects of NO remains to be identified, our data imply that NO protects HUVECs against mitochondrial perturbation caused by apoptogenic agents. These results suggest that NO promotes endothelial-cell proliferation and angiogenesis in the synovial tissues of patients with rheumatoid arthritis and that NO may be a therapeutic target for rheumatoid arthritis.     

Protective Effect of Telmisartan on Endothelial Cells Exposed to High Glucose Levels in vitro

Objectives To investigate the effect of telmisartan on human umbilical vein endothelial cells （HUVEC） exposed to high glucose in vitro and the related mechanism. Methods HUVECs were incubated with telmisartan and glucose （5 mmol/L, 30 mmot/L） at 0 h, 12 h, 24 h, 36 h, 48 h, respectively. The level of malondialdehyde （MDA） and superoxide dismutase （SOD） in the supernatant of cultured endothelial cells was measured by thiobarbituric acid test and xanthine oxidase test. The expression of PPAR-γ was determined at 24 hour with Western blot technique. Results When the endothelial cells were cultured in high glucose environment, the MDA level was significantly increased, but the SOD activity and the protein expression of PPAR-γ were markedly decreased. However, the high glucose-induced effects were inhibited by telmisartan intervention. Conclusion Telmisartan can decrease oxidative stress and increase PPAR-γ expression of endothelial cells in high glucose environment. （S Chin J Cardio12009 ; 10 （4） ： 222 -226）     

Recent developments in the inhibition of angiogenesis: examples from studies on platelet factor-4 and the VEGF/VEGFR system

Inhibition of angiogenesis is an important strategy to block tumor growth and invasion. We discuss herein results from our ongoing investigations on platelet factor-4 (PF-4) and the VEGF/VEGFR system. Platelet factor-4 (PF-4) is an anti-angiogenic ELR-negative chemokine. PF-4 inhibits endothelial cell proliferation and migration, and angiogenesis in vitro and in vivo. We have studied the structure and anti-angiogenic activities of a C-terminal fragment of PF-4 named PF-4 CTF. This molecule retains anti-angiogenic activity, blocks the interaction of angiogenesis factors with their receptors and may also be improved by mutation or domain-swapping. It seems, therefore, to be a good candidate for further development. Furthermore, we have developed a cyclic vascular endothelial growth inhibitor (Cyclo VEGI) from the structure of VEGF-A. In aqueous solution, cyclo-VEGI adopts an alpha helix conformation. Cyclo-VEGI inhibits binding of iodinated VEGF(165) to endothelial cells and angiogenesis. Furthermore, cyclo-VEGI significantly blocks the growth of established intracranial glioma in nude and syngeneic mice and improves survival.     

朱日很滴丸含药血清对ox-LDL损伤的HUVEC转录因子Nrf2核转位的影响

目的:研究朱日很滴丸含药血清对经ox-LDL损伤的HUVEC的保护作用,探讨其可能的作用机制。方法:将氧化低密度脂蛋白(ox-LDL)与人脐静脉内皮细胞(HUVEC)共孵育,建立内皮细胞损伤模型,加入朱日很滴丸含药血清进行干预。MTS法检测朱日很滴丸含药血清对氧化损伤内皮细胞的活性影响;实时荧光定量PCR法(qPCR)和蛋白免疫印迹法(Westorn blot)检测朱日很滴丸含药血清对内皮细胞氧化损伤模型中Nrf2的mRNA水平和蛋白表达的影响;细胞免疫荧光法检测HUVEC中Nrf2蛋白的核转位情况。结果:与空白对照组比较,模型组、溶媒对照血清组细胞存活率明显降低,Nrf2 mRNA及蛋白表达明显下调,核质比明显降低。与溶媒对照血清组相比,朱日很滴丸各剂量20%含药血清组可提高氧化损伤的内皮细胞的活性,Nrf2的mRNA水平和蛋白表达明显上调,朱日很滴丸0.79 g/kg组20%含药血清,Nrf2蛋白的核、质比明显增加;20%含药血清各剂量组细胞核中Nrf2荧光强度明显增强,且有剂量依赖性。结论:朱日很滴丸可明显降低HUVEC的氧化应激损伤,其作用机制可能与促进转录因子Nrf2核转位有关。     

Differential effects of ABT-510 and a CD36-binding peptide derived from the type 1 repeats of thrombospondin-1 on fatty acid uptake, nitric oxide signaling, and caspase activation in vascular cells

ABT-510 is a potent mimetic of an anti-angiogenic sequence from the second type 1 repeat of thrombospondin-1. ABT-510 and the original d-Ile mimetic from which it was derived, GDGV(dI)TRIR, are similarly active for inhibiting vascular outgrowth in a B16 melanoma explant assay. Because GDGV(dI)TRIR and thrombospondin-1 modulate nitric oxide signaling by inhibiting the fatty translocase activity of CD36, we examined the ability ABT-510 to modulate fatty acid uptake into vascular cells and downstream nitric oxide/cGMP signaling. Remarkably, ABT-510 is less active than GDGV(dI)TRIR for inhibiting myristic acid uptake into both endothelial and vascular smooth muscle cells. Correspondingly, ABT-510 is less potent than GDGV(dI)TRIR for blocking a myristate-stimulated increase in cell adhesion to collagen and nitric oxide-driven accumulation of cGMP. ABT-510 at concentrations sufficient to inhibit CD36 fatty acid translocase activity synergizes with thrombin in aggregating platelets and blunts the activity of NO to delay aggregation, but again less than GDGV(dI)TRIR. In contrast, ABT-510 is more potent than GDGV(dI)TRIR for inducing caspase activation in vascular cells. Thus, we propose that ABT-510 is a drug with at least two mechanisms of action, and its potent anti-tumor activity may be in part independent of CD36 fatty acid translocase inhibition.