一氧化氮抑制内皮素促血管平滑肌细胞增殖作用的信号转导途径

培养的家兔胸主动脉血管平滑肌细胞（ＶＳＭＣ）分别以内皮素（ＥＴ－１）、一氧化氮（ＮＯ）前体Ｌ－Ａｒｇ和ＮＯ供体ＳＩＮ－１刺激,或用ＥＴ－１＋Ｌ－Ａｒｇ、ＥＴ－１＋ＳＩＮ－１联合刺激,测ＶＳＭＣ＾３Ｈ－ＴｄＲ掺入、丝裂素活化蛋白激酶（ＭＡＰＫ）活性及蛋白激酶Ｃ（ＰＫＣ）活性的改变,以研究ＮＯ抑制ＥＴ－１促ＶＳＭＣ增殖作用的信号转导途径。结果表明：（１）ＥＴ－１ １０＾－８ｍｏｌ／Ｌ单独刺激,＾３Ｈ－     

γ—干扰素对内皮素促平滑肌细胞增殖效应的影响

血管内皮细胞分泌的内皮素(ET)不仅是强烈的血管收缩剂,而且具有强烈的促血管平滑肌细胞(VSMC)增殖的效应。近年来发现许多细胞因子除参与免疫调节外,还参与心血管功能的调节。γ-干扰素(IFN-γ)具有抑制VSMC增殖,调节细胞分化、增生的作用。本工作在培养的自发性高血庄大鼠(SHR)和对照WKY大鼠的VSMC上,观察了IFN-γ和ET对VSMC增殖和钙含量的影响,以探讨IFN-γ和ET对VSMC增殖的相互调控关系。     

内皮素对离体大鼠主动脉及主动脉平滑肌细胞作用的研究

本研究着重探讨内皮素对大鼠主动脉的收缩作用及对主动脉平滑肌细胞细胞周期及能量代谢的影响。浓度为1.0～18.0nmol/L的内皮素可引起大鼠主动脉产生浓度依赖性收缩,其EC_(50)为3.75±0.75nmol/L。正常对照组中平滑肌细胞S G_2M期细胞的比例基本稳定在26.3％～29.6％的范围内;浓度为10.0和1000.0pmol/L的内皮素可使S G_2M期细胞比例明显增高,上述变化呈良好的浓度依赖性(P<0.01);内皮素作用3～24h,随作用时间延长,S G_2M期细胞比例逐步增多,呈明显的时间依赖性(P<0.01)。10.0pmol/L的内皮素作用10min后ATP含量增至对照组的139.05±1.11％(P<0.01);20min后ATP含量为对照组的65.25±5.09％(P<0.01),低于对照组水平。结果表明,内皮素具有缩血管作用及促平滑肌细胞增殖作用,上述作用可能在高血压的发病机制中有一定的意义。     

内皮素—1对血管平滑肌细胞增殖作用的研究进展（综述）

内皮素（ＥＴ）是迄今所发现的最强的内源性血管收缩肽,它有三种异构体,其中ＥＴ－１不仅缩血管活性最强,而且对血管平滑肌细胞（ＶＳＭＣ）具有丝裂原作用。本文从ＥＴ－１的合成和分泌,对ＶＳＭＣ的增殖作用以及丝裂原信息传递途径三方面,综述了目前ＥＴ－１对ＶＳＭＣ增殖作用的研究进展。     

内皮素－1对血管平滑肌细胞增殖作用的研究进展（综述）

内皮素（ＥＴ）是迄今所发现的最强的内源性血管收缩肽,它有三种异构体,其中ＥＴ－１不仅缩血管活性最强,而且对血管平滑肌细胞（ＶＳＭＣ）具有丝裂原作用。本文从ＥＴ－１的合成和分泌,对ＶＳＭＣ的增殖作用以及丝裂原信息传递途径三方面,综述了目前ＥＴ－１对ＶＳＭＣ增殖作用的研究进展。     

17β—雌二醇抑制内皮素诱导的血管平滑肌细胞增殖作用

目的和方法：利用组织块贴壁法进行大鼠VSMC培养,胰蛋白酶分散细胞法传代。实验采用第4-6代细胞。采用氚-胸腺嘧啶核苷（[^3H]-TdR)掺入和细胞计数来作为VSMC增殖的指标,以RT-PCR的方法检测ETAR的表达,观察17β-雌二醇（E2）对内皮素-I（endothelin-l,ET-1)介导的血管平滑肌细胞（VSMC）增殖反应以及对内皮素A型受体（ETAR）表达的影响。结果：ETAR特异性拮抗剂BQ123能完全阻断ET-1介导的VSMC增殖反应;E2可明显抑制ET-1促进VSMC增殖的作用,RT-PCR结果显示E2能抑制ETAR的表达,12h时抑制作用最为明显;E2受体阻断剂Tamoxifen亦能部分抑制ET-1对VSMC的增殖及ETAR的mRNA的表达。结论：ET-1促进VSMC增殖作用主要通过ETAR介导的,雌激素可通过抑制ETARmRNA表达来发挥对ET-1促进VSMC增殖的抑制作用。     

亮氨酸脑啡肽抑制培养大鼠主动脉平滑肌细胞增殖

实验以培养的ＳＤ大鼠胸主动脉平滑肌细胞为模型,用四唑盐比色地及＾３Ｈ－ＴｄＲ掺入技术动态观察发现亮氨酸脑啡肽可显著抑制血管平滑肌细胞的增殖及ＤＮＡ的合成,阿片受体阻断剂纳洛酮对ＶＳＭＣｓ的增殖及ＤＮＡ的合成无影响,但ＮＡＬ可拮抗亮氨酸脑啡肽对ＶＳＭＣｓ增殖的抑制作用。     

白介素-10抑制TNF-α诱导的血管平滑肌细胞增殖

研究观察了重组人白介素 10 (rhIL 10 )对肿瘤坏死因子 (TNF α)刺激的离体大鼠胸主动脉血管平滑肌细胞增殖、细胞周期及对p4 4 /p4 2丝裂素活化蛋白激酶的影响。实验培养大鼠主动脉血管平滑肌细胞 ,采用MTS/PES法确定血管平滑肌细胞 (vascularsmoothmusclecells,VSMCs)的增殖状态 ;应用流式细胞术测定细胞周期 ;利用p4 4 / 4 2磷酸化抗MAPK抗体的蛋白免疫印迹法测定MAPK蛋白表达。结果显示 :( 1)TNF α处理组与对照组相比 ,TNF α对VSMC增殖具有明显的刺激作用 (P <0 0 5 )。rhIL 10单独应用对VSMCs生长没有影响 (P >0 0 5 )。在TNF α刺激下 ,低至 10ng/ml的rhIL 10可抑制VSMCs的生长 (P <0 0 5 )。流式细胞术测定的结果显示 ,rhIL 10分别可使TNF α作用下的VSMC大部分处于G0 /G1期 ,与对照组相比有明显差异 (P <0 0 1)。 ( 2 )TNF α对p4 4 /p4 2MAPK蛋白表达有显著的增强作用 ,此作用可被rhIL 10抑制。结果提示 ,rhIL 10可抑制TNF α诱导的VSMC增殖及p4 4 /p4 2丝裂素活化蛋白激酶的表达     

Minimally modified low density lipoproteins induce aortic smooth muscle cell proliferation via the activation of mitogen activated protein kinase

We have investigated the effects of modifying LDL by Cu++ and various hemoglobin preparations on aortic smooth muscle cell proliferation and on the activation of mitogen activated protein kinase. We found that at very low concentrations (10 g/ml), LDL modified by all of the above agonists markedly stimulated cell proliferation (5–10 fold). This was accompanied by a 2–3 fold stimulation in mitogen activated protein kinase (MAPK) activity. We conclude that modification of LDL under situations that are closer to those found in vivo (i.e. hypoxic conditions), may involve the activation of MAPK as a common biochemical mechanism of action. This in turn, contributes to aortic smooth muscle cell proliferation.     

内源性一氧化碳在大鼠高血压发病中的作用

本实验研究内源性血红素氧化酶／一氧化碳系统在大鼠高血压发病听作用。２,４二甘油次卟啉锌是体内ＨＯ活必抑制剂 。     

pp60c-src在血管平滑肌细胞内丝裂原活化蛋白激酶激活中的作用

观察ｐｐ６０ｃ－ｓｒｃ在血管紧张素Ⅱ（ＡｎｇⅡ）诱导血管平滑肌细胞（ＶＳＭＣｓ）内丝裂原活化蛋白激酶（ＭＡＰＫ）激活中的作用,以了解ＡｎｇⅡ促ＶＳＭＣｓ增殖的信号转导过程。将合成的反义ｃ－ｓｒｃ寡脱氧核苷酸（ｏｌｉｇｏｄｅｏｘｙｎｕｃｌｅ－ｏｔｉｄｅｓ,ＯＤＮｓ）以脂质体包裹转染培养的大鼠ＶＳＭＣｓ,用Ｗｅｓｔｅｒｎ印迹测得细胞裂解液中ｐｐ６０ｃ－ｓｒｃ含量明显下降,免疫沉淀方法测得ｐｐ６０ｃ－ｓ     

内源性一氧化碳参与呼吸节律调节

本文旨在探讨内源性一氧化碳（carbon monoxide,CO）对呼吸节律的调节作用。采用新生Sprague—Dawley大鼠,制备离体延髓脑片标本,分别灌流CO、血红素氧合酶（heme oxygenase,HO）底物高铁血红素（hemin）和HO抑制剂ZnPP-9,观察舌下神经根呼吸样传出放电节律的变化。实验分为5组：单纯人工脑脊液（artificial cerebrospinal fluid,ACSF）对照组、ZnPP-9组、外源性CO组、Hemin组和ZnPP-9＋Hemin组。结果如下：在ZnPP-9组,舌下神经根节律性放电频率（discharge frequency,DF）增快（P〈0．05）;在外源性CO组,舌下神经根节律性DF减慢（P〈0.05）;在Hemin组和ZnPP-9＋Hemin组,舌下神经根节律性DF增快（P〈0．05）。结果表明,内源性CO对呼吸节律可能具有调节作用。     

低氧时一氧化碳对PASMC增殖的影响及机制探讨

目的和方法 :应用MTT比色、原位杂交、免疫细胞化学技术检测内源性或外源性CO对低氧状态下PASMC增殖的作用以及对PDGF B和原癌基因bcl 2、突变型p5 3表达的影响 ,探讨CO抑制低氧状态下PASMC增殖的机制。结果 :各组PASMC中PDGF BmRNA原位杂交和PDGF B蛋白的免疫细胞化学染色均为阴性 ,单纯低氧组较正常对照组Bcl 2和突变型P5 3蛋白表达增强 (P <0 .0 1) ,Hemin和CO干预组Bcl 2和突变型P5 3蛋白表达低于单纯低氧组 ,而Hb干预组则高于单纯低氧组 (P <0 .0 1)。结论 :低氧时CO可能通过抑制Bcl 2和突变型P5 3的表达而抑制PASMC的增殖     

Bradykinin B<Subscript>2</Subscript> receptor-mediated proliferation via activation of the Ras/Raf/MEK/MAPK pathway in rat vascular smooth muscle cells

It has been suggested that bradykinin (BK) plays an important role in regulating neointimal formation after vascular injury. However, implication of BK in the growth of rat vascular smooth muscle cells (VSMCs) is controversial. Therefore, we examined the mitogenic effect of BK on VSMCs associated with activation of mitogen-activated protein kinase (MAPK). Both [(3)H]thymidine incorporation and p42/p44 MAPK phosphorylation were activated by BK in time- and concentration-dependent manners. Pretreatment of these cells with neither pertussis toxin nor cholera toxin attenuated the BK-induced responses. Pretreatment of VSMCs with Hoe 140 (a selective B(2) receptor antagonist), U73122 (an inhibitor of phospholipase C), and BAPTA/AM (an intracellular Ca(2+) chelator) inhibited both [(3)H]thymidine incorporation and p42/p44 MAPK phosphorylation in response to BK. BK-induced [(3)H]thymidine incorporation and p42/p44 MAPK phosphorylation were inhibited by pretreatment of VSMCs with tyrosine kinase inhibitors (genistein and herbimycin A), protein kinase C (PKC) inhibitors (staurosporine, Go-6976, and Ro-318220), an MAPK kinase inhibitor (PD98059), and a p38 MAPK inhibitor (SB203580). Overexpression of the dominant negative mutants, H-Ras-15A and Raf-N4, suppressed p42/p44 MAPK activation induced by BK and PDGF-BB, indicating that Ras and Raf may be required for activation of these kinases. From these results, we concluded that the mitogenic effect of BK is mediated through activation of the Ras/Raf/MEK/MAPK pathway similar to that of PDGF-BB. BK-mediated MAPK activation was modulated by Ca(2+), PKC, and tyrosine kinase all of which are associated with cell proliferation in rat cultured VSMCs.     

Overexpression of the type II transforming growth factor-beta receptor inhibits fibroblasts proliferation and activates extracellular signal regulated kinase and c-Jun N-terminal kinase

Transforming growth factor-beta (TGF-beta) is a bimodal regulator of cellular growth. The cellular effects of TGF-beta depend on the intensity of signals emanating from TGF-beta receptors. Low levels of receptor activity are sufficient to stimulate cell proliferation, while higher degrees of receptor activation are associated with growth inhibition. To study the mechanisms of these effects, a tetracycline-inducible expression system was used to overexpress type II TGF-beta receptors in NIH 3T3 fibroblasts. Overexpressed type II TGF-beta receptors suppressed fibroblast proliferation elicited by TGF-beta1, fibroblast growth factor (FGF) or platelet-derived growth factor (PDGF). Accompanying these anti-proliferative effects, increases in extracellular-signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) activity were detected. Furthermore, PDGF alpha-, but not PDGF beta-receptor protein levels were reduced by type II TGF-beta receptor overexpression. In conclusion, our system is an excellent tool to study the molecular mechanisms of growth inhibition by TGF-beta in fibroblasts. Activation of JNK and ERK, or modulation of PDGF receptor expression may be involved in this process.     

Overexpression of heme oxygenase-1 protects smooth muscle cells against oxidative injury and inhibits cell proliferation

To investigate whether the expression of exogenous heme oxygenase-1 (HO-1) gene within vascular smooth muscle cells (VSMC) could protect the cells from free radical attack and inhibit cell proliferation, we established an in vitro transfection of human HO-1 gene into rat VSMC mediated by a retroviral vector. The results showed that the profound expression of HO-1 protein as well as HO activity was 1.8- and 2.0-fold increased respectively in the transfected cells compared to the non-transfected ones. The treatment of VSMC with different concentrations of H2O2 led to the remarkable cell damage as indicated by survival rate and LDH leakage. However, the resistance of the HO-1 transfected VSMC against H2O2 was significantly raised. This protective effect was dramatically diminished when the transfected VSMC were pretreated with ZnPP-IX, a specific inhibitor of HO, for 24 h. In addition, we found that the growth potential of the transfected cells was significantly inhibited directly by increased activity of H