Induction of interleukin-8 production by angiotensin Ⅱ in rat vascular smooth muscle cells

Objective:Interleukin-8(IL-8) represents the prototypical chemokine that is made by a wide variety of cell types.Previously studies have suggested that angiotensin Ⅱ(Ang Ⅱ) is involved in atherogenesis through induction ofproinflammatory cytokines such as interleukin-6 or monocyte chemoattractant protein-1 (MCP-1) in vascular smooth muscle cells(VSMCs),while the role orang Ⅱ on IL-8 expression in VSMCs is poorly studied.Methods:In this study,VSMCs were isolated from the thoracic aorta of Sprague-Dawley rats.The expression of smooth muscle α-actin was confirmed by an immunohistochemical method.Semi-quantitative RT-PCR and enzyme-linked immunosorbent assay (ELISA) analyses were conducted to detect IL-8 expression.Results:In the present study we found that Ang Ⅱ significantly increased the expression of IL-8 both at the mRNA and protein levels in rat VSMCs in a dose- and time-dependent manner.Conclusion:These findings suggested that Ang Ⅱ may participate in atherosclerosis through induction of inflammatory mediator in VSMCs.     

Effect of angiotensin Ⅱ and angiotensin Ⅱ type 1 receptor antagonist on the proliferation,contraction and collagen synthesis in rat hepatic stellate cells

Background Angiotensin Ⅱ （Ang Ⅱ） is a very important vasoactive peptide that acts upon hepatic stellate cells （HSCs）, which are major effector cells in hepatic cirrhosis and portal hypertension. The present study was aimed to investigate the effects of Ang Ⅱ and angiotensin Ⅱ type 1 receptor antagonist （AT1RA） on the proliferation, contraction and collagen synthesis in HSCs.
Methods HSC-T6 rat hepatic stellate cell line was studied. The proliferation of the HSC cells was evaluated by MTT colorimetric assay while HSC DNA synthesis was measured by ^3H-thymidine incorporation. The effects of angiotensin Ⅱ and AT1RA on HSCs contraction were studied by analysis of the contraction of the collagen lattice. Cell culture media were analyzed by RT-PCR to detect secretion of collagen Ⅰ （Col Ⅰ）, collagen Ⅲ （Col Ⅲ） and transforming growth factor β1 （TGF-β1） by enzyme linked immunosorbent assay. HSC was harvested to measure collagen Ⅰ, collagen Ⅲ and tissue inhibitor of metalloproteinase-1 （TIMP-1） mRNA expression.
Results Ang Ⅱ （（1×10^-10-1×10^-4）mol/L）stimulated DNA synthesis and proliferation in HSCs compared with untreated control cells. AT1RA inhibited angiotensin Ⅱ induced proliferation of HSCs. A linear increase in the contractive area of collagen lattice correlated with the concentration of angiotensin Ⅱ （1×10^-9-1×10^-5 mol/L） and with time over 48 hours. AT1RA blocks angiotensin Ⅱ induced contraction of collagen lattice. Col Ⅰ, Col Ⅲ and TGF-β1 levels of the Ang Ⅱ group were higher than those of control group and this increase was downregulated by AT1RA. The mRNA expressions of Col Ⅰ, Col Ⅲ and TIMP-1 were higher in HSCs from the Ang Ⅱ group than the control group and downregulated by AT1RA.
Conclusions Angiotensin Ⅱ increased DNA synthesis and proliferation of HSCs in a dose-dependent manner, stimulated the contraction of HSCs dose- and time-dependently. Angiotensin also promoted excretion of Col I, Col Ⅲ and TGF-β1 lev     

INHIBITORY EFFECT OF ANGIOTENSIN Ⅱ TYPE 1 RECEPTOR-ASSOCIATED PROTEIN ON VASCULAR SMOOTH MUSCLE CELL GROWTH AND NEOINTIMAL FORMATION

Objective To investigate the mechanism of a novel angiotensin n type 1 receptor-associated protein (ATRAP) interfering with angiotensin Ⅱ type 1 (AT1) receptor-mediated vascular smooth muscle cell (VSMC) growth and neointimal formation. Methods VSMCs isolated from thoracic aorta of adult Sprague-Dawley ( SD) rats were used in this study. ATRAP Cdna was subcloned into pcDNA3 vector and then transfected into VSMCs. DNA synthesis and extracellular signal-regulated kinase (ERK) and phospho-ERK expressions in VSMCs were assayed by measurement of 3H thymidine incorporation and Western blotting, respectively. Morphological changes were observed in the balloon injured artery with or without transfection of ATRAP Cdna using 12-week-old male SD rats. Results ATRAP overexpression in VSMCs inhibited angiotensin Ⅱ (Ang Ⅱ) -induced 3H thymidine incorporation 48 hours after Ang Ⅱ stimulation (P ＜ 0.05). In VSMC, Ang Ⅱ stimulation increased the phosphorylation of ERK, which reached the peak around 60 minutes. The activation of phospho-ERK was significantly decreased by ATRAP (P ＜ 0.05). Neointimal formation was markedly inhibited by ATRAP overexpression in injuried arteries. Conclusions The AT1 receptor-derived activation of ERK plays an essential role in Ang Ⅱ-induced VSMC growth. The growth inhibitory effects of ATRAP might be due to interfering with AT1 receptor-mediated activation of ERK in VSMC growth and neointimal formation.     

Effects of Serum Containing Xinlikang (心力康) on Angiotensin Ⅱ Induced Hypertrophy in Cultured Neonatal Rat Cardiomyocytes

Objective: To evaluate the effects of Xinlikang (心力康,XLK) on angiotensinⅡ(AngⅡ) induced hypertrophic cultured neonatal rat's cardiomyocyte (CMC). Methods: Primary cultured neonatal rat's CMCs with the purity certified by immunohistochemical technique, were divided into three groups. Rats in the normal control group were untreated; those in the model group were established into hypertrophic models but underwent no treatment; and those in the XLK group were established to hypertrophic models and treated with XLK containing serum obtained from rats with aorta coarctation after 8 days of feeding with XLK. MTT and phase-contrast microscope were used to evaluate the effect of XLK on cell activity, pulsating rhythm and surface area; Atrial natriuretic peptide (ANP) expression was determined by radioimmunoassay; Protein content was determined by Bradford method; and DNA synthesis was detected by flow cytometric assay. Results: Immunohistochemistry results showed that more than 90% of the cells wereα-sarcometin actin stained positive cells. No significant effect of XLK on normal CMC was found. AngⅡcould significantly induce hypertrophy in CMCs, and XLK could significantly decrease the increased surface area and the accelerated pulsating rate in them. ANP expression was 780±38 Mg/L in the model group, and 430±23μg/L in the control group, and the elevated expression of ANP in model rats was significantly decreased in the XLK group;The DNA content in the G0/G1 and G2/M phases was significantly enhanced and at the same time it was accompanied with increase of total protein content in the model rats after being stimulated by AngⅡfor 24 h, showing that serum-containing XLK could also significantly suppress total protein synthesis (P<0. 05). Conclusion: XLK could improve AngⅡmediated pathological growth of CMCs without influencing the growth of normal CMCs, suggesting that XLK is probably an effective drug for treatment of myocardial hypertrophy and heart failure.     

氯沙坦对糖尿病大鼠肾组织血管紧张素Ⅱ及其1型受体mRNA表达的影响

目的研究氯沙坦对实验性糖尿病大鼠肾组织血管紧张素Ⅱ(AngⅡ)1型受体mRNA表达的影响。方法纯种雄性Wistar大鼠分为3组,A组(n=11)为正常对照组,B组(n=11)为糖尿病为干预组,C组(n=9)为糖尿病大鼠氯沙坦干预组。以链脲佐菌素制备糖尿病大鼠模型。饲养18周后取出肾脏检测AngⅡ水平、AngⅡ1型受体mRNA表达,收集24h尿测定尿白蛋白排泄及肌酐并心脏内取血检测血AngⅡ及肌酐。AngⅡ1型受体mRNA表达采用RT-PCR,以-actin作为内对照。尿白蛋白排泄采用大鼠白蛋白特异的酶免疫分析试剂盒。结果血、肾组织AngⅡ在A、B、C三组间无显著性差异。肾组织AngⅡ1型受体mRNA表达在B组大鼠(0.62±0.17)显著低于A组(1.13±0.82,P<0.01)及C组(1.13±0.62,P<0.01)。尿白蛋白排泄在B组大鼠(2.18±1.98mg/d)显著高于A组(0.41±0.47mg/d,P<0.01)及C组(0.65±0.89mg/d,P<0.01)。结论氯沙坦处理能升高糖尿病大鼠肾组织的AngⅡ1型受体mRNA表达,但不改变血液及肾组织AngⅡ水平。     

INHIBITORY EFFECT OF ANGIOTENSIN Ⅱ TYPE 1 RECEPTOR-ASSOCIATED PROTEIN ON VASCULAR SMOOTH MUSCLE CELL GROWTH AND NEOINTIMAL FORMATION

Objective To investigate the mechanism of a novel angiotensin Ⅱ type 1 receptor-associated protein （ATRAP） interfering with angiotensin Ⅱ type 1 （AT1） receptor-mediated vascular smooth muscle cell （VSMC） growth and neointimal formation. Methods VSMCs isolated from thoracic aorta of adult Sprague-Dawley （SD） rats were used in this study. ATRAP cDNA was subcloned into pcDNA3 vector and then transfected into VSMCs. DNA synthesis and extracellular signal-regulated kinase （ERK） and phospho-ERK expressions in VSMCs were assayed by measurement of ^3H thymidine incorporation and Western blotting, respectively. Morphological changes were observed in the balloon injured artery with or without transfection of ATRAP cDNA using 12-week-old male SD rats. Results ATRAP overexpression in VSMCs inhibited angiotensin Ⅱ （Ang Ⅱ）-induced ^3H thymidine incorporation 48 hours after Ang Ⅱ stimulation （ P 〈 0. 05 ）. In VSMC, Ang Ⅱ stimulation increased the phosphorylation of ERK, which reached the peak around 60 minutes. The activation of phospho-ERK was significantly decreased by ATRAP （ P 〈 0. 05 ）. Neointimal formation was markedly inhibited by ATRAP overexpression in injuried arteries. Conclusions The AT1 receptor-derived activation of ERK plays an essential role in Ang Ⅱ-induced VSMC growth. The growth inhibitory effects of ATRAP might be due to interfering with AT1 receptor-mediated activation of ERK in VSMC growth and neointimal formation.     

血管紧张素Ⅱ和血小板源生长因子对血管平滑肌和心肌细胞细胞周 …

目的 观察血管紧张素Ⅱ（ＡｎｇⅡ）和血小板源生长因子ＢＢ（ＰＤＧＦ－ＢＢ）对血管平滑肌细胞和心肌细胞中细胞周期素和Ｐ２７蛋白表达量的不同影响,方法 培养的血管平滑肌细胞或乳鼠心肌细胞,加入ＡｎｇⅡ１０＾－６ｍｏｌ／Ｌ,ＰＤＧＦ－ＢＢ２０ｎｇ／ｍｌ后２４小时收集细胞,用碘化丙啶（ＰＩ）标记细胞ＤＮＡ,以确定细胞所处的周期,用细胞周期素（ＣｙｃｌｉｎＤ,ＣｙｃｌｉｎＥ,ＣｙｃｌｉｎＡ）或Ｐ２７蛋白的单     

钙离子,血管紧张素Ⅱ受体在血管紧张素Ⅱ促心肌细胞蛋白质…

通过＾３Ｈ－Ｌｅｕ掺入量的测定与ＲＮＡ狭线杂交技术，初步探讨血管紧张素Ⅱ受体，Ｃａ＾２＋在血管紧张素Ⅱ刺激乳鼠心肌细胞蛋白质合成中的作用，并观察血管紧张素Ⅱ对原癌基因ｃ－ｆｏｓ表达，结果发现培养液中加入钙通道阻断剂（ｖｅｒａｐａｍｉｌ），细胞外钙螯合剂（ＥＧＴＡ），肌浆网钙释放抑制剂（ｄａｎｔｒｏｌｅｎｅ）和细胞内钙螯合剂（Ｆｕｒａ－２／ＡＭ）可使血管紧张素Ⅱ介导的＾３Ｈ－Ｌｅｕ掺入量较单独加血管     

丹参酮ⅡA对体外兔血管平滑肌细胞增殖和迁移的影响

目的观察丹参酮A对体外兔血管平滑肌细胞(VSMC)增殖和迁移的影响,并初步探讨丹参酮A的作用机制。方法采用兔胸主动脉,用组织贴块法培养,设立空白对照组,加入不同浓度的丹参酮A共同孵育24 h、48 h和72 h,采用MTT法观察该药对细胞增殖的影响;划痕法观测细胞迁移情况;采用流式细胞仪分析细胞周期和DNA含量;TRITC-鬼笔环肽标记F-actin,观察该药物对细胞骨架微丝结构的影响。结果1同一时间点,丹参酮A各浓度组显著抑制体外培养兔VSMC增殖和迁移。细胞的A570值(24 h、48 h、72 h分别为r=-0.762,P=0.000;r=-0.837,P=0.000;r=-0.944,P=0.000)、迁移距离(24 h、48 h、72 h分别为r=-0.966,P=0.000;r=-0.980,P=0.000;r=-0.966,P=0.000)与浓度呈负相关;2作用24 h后,处于G0/G1期的VSMC百分比增加,细胞DNA含量减少,凋亡率增加。兔VSMC在G0/G1期所占比例(r=0.962,P=0.000)、凋亡率(r=0.982,P=0.000)和浓度呈正相关;3药物干预组和对照组相比,兔VSMC的细胞骨架结构有所改变,对照组中细胞骨架呈极性分布,定向伸展,可见伪足;药物干预组细胞骨架呈非极性分布,未见伪足。结论丹参酮A对体外兔VSMC的增殖和迁移有抑制作用,上述作用可能是通过阻滞兔VSMC通过细胞周期的限制点,使其停滞于G0/G1期,诱导细胞凋亡以及影响细胞骨架微丝结构来实现。     

Rho激酶信号通路参与ET-1诱导的人气道平滑肌细胞迁移和细胞骨架的变化

目的 研究Rho激酶信号通路在内皮素-1(ET-1)诱导的人气道平滑肌细胞(ASMCs)迁移及细胞骨架变化中的作用.方法 组织块贴壁法培养人ASMCs,改良的Boyden小室检测ASMCs的迁移能力;激光共聚焦扫描显微镜观察细胞骨架的变化;Western blotting检测ET-1刺激不同时间后Rho激酶底物肌球蛋白磷酸酶目标亚单位1(MYPT1)的磷酸化水平.结果 ET-1在0.1、1、10、100 nmol/L浓度具有趋化ASMCs的迁移能力,10 nmol/L的ET-1趋化ASMCs迁移的能力最强(与对照组相比,P<0.01).Rho激酶抑制剂Y-27632可浓度依赖性地抑制ET-1趋化的ASMCs跨膜迁移,与ET-1组相比,10μmol/L的Y-27632显著抑制了ASMCs迁移(P<0.01);ET-1(10 nmol/L)刺激后ASMCs细胞骨架和形态改变,伪足生成,应力纤维形成增多,Y-27632可显著抑制ET-1诱导的上述改变;ET-1刺激15、30min后p-MYPT1表达显著增高(与对照组相比,P<0.01),随着刺激时间的延长,p-MYPT1表达下降(P>05).结论 Rho激酶信号通路在ET-1诱导的ASMCs迁移和细胞骨架变化中发挥重要的作用.     

The mechanism of signal transduction during vascular smooth muscle cell proliferation induced by autoantibodies against angiotensin AT1 receptor from hypertension

Background Autoantibodies against angiotensin AT1 receptor have been discovered in patients with preeclampsia or malignant hypertension. Some studies have demonstrated that the autoantibodies are involved in the immunopathogenesis of hypertension and have an agonist effect similar to angiotensin II. Methods Autoantibodies against AT1 receptor were purified from sera of patients with primary hypertension by affinity chromatography. Proliferation of cultured rat vascular smooth muscle cells was detected by bromodeoxyuridine incorporation and activation of signalling molecules detected by Western blotting and electrophoretic mobility shift assay. Results The AT1-RAb caused a significant proliferation similar to the Ang II during first 24 hours. The levels of nuclear factor-KB （NF-KB）, phosphorylated JAK2., phosphorylated STAT1 （pSTAT1） and phosphorylated STAT3 （pSTAT3） molecules were increased in response to the autoantibodies. In contrast, the activations of NF-KB and JAK-STAT were blocked by Iosartan, pyrrolidinedithiocarbamate （a specific inhibitor of NF-KB） and AG490 （a specific inhibitor of the JAK2. tyrosine kinase）. The expressions of NF-KB, pSTAT1 and pSTAT3 reached peak levels at different times. Moreover, the relative densities of electrophoretic bands showed that activation of pSTAT3 was more significant than STAT1 induced by AT1 -RAb. Conclusions These results suggest that the autoantibodies against AT1 receptor have an agonist effect similar to Ang II in proliferation of VSMCs and the NF-KB and JAK-STAT proteins play essential roles. The effect is different from Angll in that STAT3 is the main downstream activating molecule in JAK-STAT signalling pathway.     

内皮素阻断对糖尿病高血压大鼠肾脏AT1受体表达的影响

目的 观察糖尿病高血压大鼠肾脏AT1受体的改变以及内皮素受体阻断剂波生坦的影响。方法 将自发性高血压大鼠建成链脲佐菌素诱导的糖尿病模型（SHR－DM）,设柳平舒组、波生坦＋氨氯地平（络活喜）组、络活喜组和非治疗组,4 一采用免疫组织化学、Western印迹法及逆转录－聚合酶链式反应（RT－PCR）方法检测肾脏AT1受体基因和蛋白表达。结果 与WKY大鼠对照组相比,SHR－DM大鼠存在明显的蛋白尿和肾功能减退,肾脏AngⅡ水平明显升高,ＡＴ１受体的mRNA和蛋白表达则显著下降。波生坦能使上述异常显著减轻。结论 糖尿病高血压大鼠肾脏ＡＴ１受体表达明显下调;波生坦可减轻ＳＨＲ－ＤＭ大鼠肾脏损害并防止ＡＴ１受体表达下调。