胰岛素对SHR大鼠血管平滑肌细胞体外增殖相关基因表达的影响

目的　探讨胰岛素对体外培养的血管平滑肌细胞 (vascularsmoothmusclecell,VSMC)增殖相关基因表达的影响。方法　用贴块法分离培养VSMC ,应用含 4 4 8个与细胞增殖相关基因靶基因芯片分析大鼠血管平滑肌细胞在胰岛素干预后基因表达的差异 ,RT PCR检测胰岛素作用后VSMC中bFGF、TGFβ、PDGF、MatrixGla和OPN各目的基因mRNA相对表达水平 ,采用免疫组织化学检测胰岛素作用后VSMC肌动蛋白 (α SMactin)。结果　胰岛素组VSMC的3 H TdR掺入值 (cpm)比对照组高 5 4 .6 % (P <0 0 1) ;基因芯片分析发现与细胞增殖相关等 36个基因的mRNA胰岛素干预前后培养的细胞表达差异 (8 0 4 % ) ;RT PCR检测MatrixGla和OPN在培养的VSMC中mRNA的表达量 ,胰岛素组明显高于对照组 (P <0 0 5 ) ,同时bFGF、TGFβ、PDGF的表达也是胰岛素组明显高于对照组 (P <0 0 5 ) ;α SMactin免疫组化结果显示对照组的α SMactin比胰岛素组染色深。结论　提示胰岛素介导大鼠血管平滑肌细胞增殖是多基因效应 ,胰岛素促进了VSMC的增殖与VSMC表型转换有关。     

中药调控高血压血管平滑肌细胞增殖的研究进展

血管平滑肌细胞作为血管中膜的主要成分,其异常增殖是高血压血管重构以及血管增殖性疾病的主要病理基础。中药治疗高血压的临床效果肯定,目前对中药治疗高血压的机制等相关研究越来越深入。本文就近年来中药调控高血压血管平滑肌细胞增殖的研究进展做一综述。     

瘦素对自发性高血压大鼠血管平滑肌细胞增殖的影响

目的 探讨leptin对自发性高血压大鼠血管平滑肌细胞的增殖影响，并研究leptin b型受体在VSMC中的表达。方法 本文主要采用培养的自发性高血压大鼠（SHR）血管平滑肌细胞（VSMC），研究Leptin受体b(OB-Rb)的mRNA的表达，以及对平滑肌细胞增殖的影响。结果 OB－Rb的mRNA仅在SHR大鼠的平滑肌细胞表达，而没有在正常对照大鼠（WKY）的平滑肌细胞中表达。Leptin仅仅可以刺激SHR大鼠VSMC的DNA合成率的增加而对WKY大鼠的VSMC则无作用。同样，Leptin对VSMC细胞增殖的作用，也仅仅在SHR大鼠可以发现，而WKY大鼠则没有。结论 上述研究的结果显示；高血压时，Leptin是一种对血管平滑肌细胞的增殖因子，也许在高血压的发生，发展过程中起重要的作用。     

血管紧张素Ⅱ对血管平滑肌细胞增殖的调节作用

肾素－血管紧张素系统在调节血压、维持水电解质平衡等方面起重要作用，近来研究表明血管紧张素Ⅱ（ＡｎｇⅡ）对心肌细胞、成纤维细胞及血管平滑肌细胞（ＶＳＭＣ）具有生长激素样作用，可能参与了阻塞性血管疾病如冠心病、血管成形术后再狭窄的发生。随着ＡｎｇⅡ受体分...     

瘦素对自发性高血压大鼠血管平滑肌细胞增殖的影响

目的探讨leptin对自发性高血压大鼠血管平滑肌细胞的增殖影响,并研究leptin b型受体在VSMC中的表达.方法本文主要采用培养的自发性高血压大鼠(SHR)血管平滑肌细胞(VSMC),研究Leptin受体b(OB-Rb)的mRNA的表达,以及对平滑肌细胞增殖的影响.结果 OB-Rb的mRNA仅在SHR大鼠的平滑肌细胞表达,而没有在正常对照大鼠(WKY)的平滑肌细胞中表达.Leptin仅仅可以刺激SHR大鼠VSMC的DNA合成率的增加,而对WKY大鼠的VSMC则无作用.同样,Leptin对VSMC细胞增殖的作用,也仅仅在SHR大鼠可以发现,而WKY大鼠则没有.结论上述研究的结果显示;高血压时,Leptin是一种对血管平滑肌细胞的增殖因子,也许在高血压的发生、发展过程中起重要的作用.     

γ-干扰素对大鼠血管平滑肌细胞增殖及增殖细胞核抗原表达的影响

为观察γ 干扰素对血管平滑肌细胞增殖的影响及探讨其作用机制 ,培养大鼠主动脉血管平滑肌细胞 ,以γ 干扰素 (5 0 0ku L)刺激血管平滑肌细胞 2 4h后 ,通过氚标记胸腺嘧啶脱氧核苷掺入法及Western杂交印迹法观察γ 干扰素作用 2 4h对大鼠血管平滑肌细胞DNA合成及增殖细胞核抗原表达的影响。结果发现γ 干扰素明显抑制 10 %胎牛血清刺激血管平滑肌细胞引起的增殖细胞核抗原表达增多及氚标记胸腺嘧啶脱氧核苷掺入增高 (P <0 .0 1) ,表明γ 干扰素具有较强的抑制大鼠血管平滑肌细胞增殖的作用。     

姜黄素对血管平滑肌细胞增殖及cyclinD1和p21wafl/cipl蛋白表达的影响

目的 观察姜黄素(curcumin)抑制大鼠血管平滑肌细胞(VSMC)增殖和诱导细胞周期停滞的作用,以及对细胞周期蛋白cyclinDl,p21wafl/cipl表达的影响.方法 采用组织贴块法体外培养大鼠VSMC,MTT法测定姜黄素对VSMC增殖的抑制作用,流式细胞仪分析细胞周期分布,Western印迹法检测cyclinDl,p21wafl/cipl蛋白的变化.结果 MTT示不同浓度姜黄素(7.5～120 μmol/L)在24～72 h范围内,浓度和时间依赖性抑制VSMC增殖;30 μmol/L以上浓度姜黄素显著抑制增殖的VSMC细胞周期进程,使S及G2/M期减少(P<0.05),G0/G1期增加(P<0.05);30 μmol/L的姜黄素可抑制cyclinDl表达,促进p21wafl/cipl蛋白表达.结论 姜黄素具有明确的抑制VSMC增殖和细胞周期停滞的作用,其与cyclinDl,p21wafl/cipl蛋白变化有关.     

凝血酶促血管平滑肌细胞增殖的信号转导研究进展

血管平滑肌细胞异常增殖在动脉粥样硬化和血管成形术后狭窄等血管增殖性疾病的发病机制中起着重要作用.近来研究表明,凝血酶具有生长激素样作用,参与了血管增殖性疾病的发展.本文就凝血酶及其受体的特性,促血管平滑肌细胞(VSMC)增殖的信号转导作一综述.     

胆固醇对血管平滑肌细胞增殖及迁移的作用

目的探讨胆固醇对血管平滑肌细胞增殖及迁移的作用。方法体外培养人血管平滑肌细胞株(VSMC),以12.5 mg/L、25.0 mg/L、50.0 mg/L不同浓度胆固醇(CH)分别作用细胞24 h、48 h、72 h后,MTT法检测VSMC的增殖情况;流式细胞术检测细胞进入S期的数量;EDU试剂盒检测CH作用后细胞的DNA合成;划痕实验检测VSMC迁移情况;Real-time PCR检测细胞中miR145的表达水平。结果 12.5 mg/L、25.0 mg/L、50.0 mg/L CH作用VSMC后可增加细胞活力,促进细胞增殖,与对照组比较,进入S期的VSMC细胞数量明显增多,细胞迁移增加(P0.05);与对照组比较,25.0 mg/L、50.0 mg/L CH可诱导VSMC DNA合成增加,并且明显降低miR-145的表达水平(P0.05)。结论 CH可诱导VSMC进入S期细胞增多,促进细胞增殖,并且增加细胞的DNA合成及细胞迁移,其机制可能与抑制miR-145的表达有关。     

高血压病患者动脉血管平滑肌细胞NO含量及作用

目的：探讨在基础状态下高血压病患者（ＥＨ）动脉血管平滑肌细胞（ＶＳＭＣ）的一氧化氮合酶（ＮＯＳ）和一氧化氮（ＮＯ）的变化特点及其ＶＳＭＣ增殖的影响。方法：采用血压正常者（ＮＴ）及ＥＨ患者的肠纱膜动脉进行分离培养,对比观察ＮＴ和ＥＨ组的动脉ＶＳＭＣ的ＮＯＳ活性、ＮＯ含量、细胞计数和细胞周期的变化,研究ＥＨ患者动脉ＶＳＭＣ的ＮＯＳ－ＮＯ系统的变化与细胞增殖的关系。结果：（１）在基础状态下,Ｅ组动脉ＶＳ     

氟伐他汀对高血压血管平滑肌细胞增殖的影响

目的:探讨氟伐他汀对自发性高血压大鼠血管平滑肌细胞增殖的抑制作用.方法:培养自发性高血压大鼠主动脉血管平滑肌细胞,不同浓度的氟伐他汀和甲羟戊酸干预后,进行细胞计数和3H-TdR掺入率的测定.结果:(1)氟伐他汀呈浓度依赖性(10-5～10-7mol)抑制血管平滑肌细胞数目的增加和3H-TdR的掺入率;(2)10-3mol的甲羟戊酸几乎完全逆转了氟伐他汀对血管平滑肌细胞增殖的抑制作用.结论:氟伐他汀抑制了高血压大鼠血管平滑肌细胞的增殖;甲羟戊酸代谢途径可能参与了血管平滑肌细胞的增殖过程.     

Increased expression of osteoprotegerin in vascular smooth muscle cells from spontaneously hypertensive rats

Osteoprotegerin (OPG) is a secreted protein of the tumor necrosis factor receptor family,whichregulates bone mass by inhibiting osteoclast differentiation and activation.Although OPG is expressed ubiquitouslyand abundantly in many tissues and cell types including vascular cells,the role of OPG in other tissues is unknown.Our previous studies demonstrated that OPG was highly expressed in vascular smooth muscle cells (VSMC) andupregulated during vascular lesion formation.Methods and Results We documented,by Northern blot analysis,that the expression of OPG was more prevalent in the aorta and cultured VSMC from spontaneously hypertensive rats(SHR) compared to Wistar-Kyoto rats (WKY).In addition,we found that the expression of Angiotensin Ⅱ (Ang Ⅱ)type Ⅰ receptor (AT1R) in SHR VSMC was at significantly increased levels than in WKY VSMC.Furthermore,AngⅡ potently induced the expression of OPG in VSMC in a time- and dose-dependent manner through the AT1Rsignaling pathway.Conclusions OPG expression was substantially greater in SHR VSMC,suggesting that OPGmay be an important determinant of vascular remodeling in SHR.(J Ceriatr Cardiol 2004;1:49-54.)     

氟伐他汀对高血压血管平滑肌细胞增殖的影响

目的：探讨氟伐他汀对自发性高血压大鼠血管平滑肌细胞增殖的抑制作用。方法：培养自发性高血压大鼠主动脉血管平滑肌细胞,不同浓度的氟伐他汀和甲羟戊干预后,进行细胞计数和＾３Ｈ－ＴｄＲ掺入率的测定。结果：（１）氟伐他汀呈浓度依赖性（１０＾－５￣１０＾－７ｍｏｌ）抑制血管平滑肌细胞数目的增加和＾３Ｈ－ＴｄＲ的掺入率;（２）１０＾－３ｍｏｌ的甲羟戊酸几科完全逆转了氟伐他汀对血管平滑肌细胞增殖的抑制作用。结论：     

Coculture of vascular endothelial cells and smooth muscle cells from spontaneously hypertensive rats

The effect of endothelium-released vasoactive factors on vascular smooth muscle cell (VSMC) proliferation was studied in a coculture system. Isolated aortic endothelial cells and smooth muscle cells from 4-week-old spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto (WKY) rats were cocultured. After coculture, the VSMC proliferation rate was examined by 3H-thymidine incorporation assay and the levels of the vasoactive factors in medium were determined by enzyme immunoassay (EIA). The results indicate that the proliferation rate of VSMCs in SHR was significantly higher than in WKY rats when VSMCs were cultured alone. When SHR vascular endothelial cells (VECs) were cocultured with VSMCs, the proliferation rate of SHR VSMCs was enhanced; however, there was no growth promoting effect in WKY VSMCs. When WKY VECs were cocultured with VSMCs, no VSMC proliferation effect was observed. When VSMCs were cultured alone, the endothelin-1 (ET-1) secretion in SHR was significantly higher than in WKY rats. When VECs and VSMCs were cocultured, the ET-1 concentration increased in both SHR VEC and WKY VEC coculture groups in a similar manner; but the SHR VECs tended to release more thromboxaneA2 (TXA2) and less PGI2 than WKY VECs. These results suggest that some kind of interaction between SHR VSMCs and SHR VECs is responsible for the high proliferation of SHR VSMCs but not the effects of SHR VECs per se.     

Differential effects of antihypertensive agents on proliferation of vascular smooth muscle cells from spontaneously hypertensive rats.

We have previously shown that Ca-antagonists and alpha-blockers substantially inhibit the cellular proliferation of cultured rat vascular smooth muscle cells (VSMC). This study explored whether these inhibitory effects on cellular proliferation differ between cultured VSMC from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). SHR VSMC proliferated much faster than WKY VSMC in 10% FCS. Cellular proliferation, determined by both cell number count and 3H-thymidine incorporation, was significantly blunted in the presence of either nifedipine (Nif) or bunazosin (Bun). The magnitude of these inhibitory effects was more pronounced for SHR cells than WKY cells (% reduction of 3H-thymidine uptake with Nif: 62.1 +/- 7.8% for SHR vs 75.3 +/- 10.2% for WKY, n = 6, p less than 0.05, and with Bun: 70.2 +/- 7.8% for SHR vs 82.1 +/- 9.9% for WKY, n = 6, p less than 0.05). In contrast, the intracellular water volume was unaffected by these antihypertensive agents based on equilibrium distribution of 3-O-methyl-D-glucose14C. It is concluded that SHR VSMC grow much faster than WKY VSMC and that this abnormality is innate to the SHR cells. It is also concluded that both Ca-antagonists and alpha-blockers exerted a substantial inhibitory effect on cellular proliferation of the cultured VSMC of either SHR or WKY. Furthermore, the greater inhibition of proliferation in the SHR VSMC suggests that Ca mediated- and/or alpha-receptor mediated processes of cellular proliferation of SHR could differ from that of WKY and that these abnormalities may contribute to the hyperproliferative changes of VSMC in this model.     

Autocrine effects of endothelin on in vitro proliferation of vascular smooth muscle cells from spontaneously hypertensive and normotensive rats

According to previous studies, endothelin-1 (ET-1) is the most potent growth factor in the regulation of vascular smooth muscle cell (VSMC) proliferation in spontaneously hypertensive rats (SHR). To evaluate if the dominant effect of ET-1-induced VSMC proliferation is achieved by autocrine regulation, aortic smooth muscle cells from four-week-old SHR and WKY (Wistar-Kyoto) rats were cultured in 24-well dishes, and the effects of ET-1 on VSMC proliferation were determined by (a) 3H-thymidine incorporation assays with different ET-1 blocking treatments, including a specific anti-ET-1 antibody; BQ-123, an ETA receptor blocker; and BQ-788, an ETB receptor blocker; and (b) examining the ET-1 blockade on the effects of treatment with other growth factors, including thrombin and angiotension II (AT-II). These results demonstrated that the anti-ET-1 antibody, BQ-123, BQ-788, and BQ-123 plus BQ-788 all caused dose-dependent inhibition of proliferation. A 90% inhibitory effect was observed at the maximum doses used except for BQ-123. The ET-1 receptor blockers inhibited thrombin-induced VSMC growth; however, they did not efficiently inhibit AT-II-induced VSMC growth. These results indicate that the autocrine effects of ET-1 play a predominant role in the proliferation of VSMCs from SHR and WKY rats. They also suggest that thrombin-induced VSMC growth is mediated by the autocrine effects of ET-1, and angiotensin II-induced VSMC growth is mediated by other signal pathways.     

Molecular mechanisms controlling the proliferation of aortic smooth muscle cells in spontaneously hypertensive rats

In order to define the molecular mechanisms involved in the hypertrophy of the arterial walls observed in essential hypertension, vascular smooth muscle cells were isolated from aortas of spontaneously hypertensive (SHR) and control (WKY) rats, and cultured (until the 4th sub-culture) in the presence of growth factors (foetal calf serum: FCS) and various vasoactive drugs. Growth rate was determined by cell counting and measurement of nuclear thymidine incorporation, and activation of phospholipase C by measurement of the inositol phosphates formed from preincorporated tritiated myo-inositol; the expression of the cellular oncogenes, c-fos and c-myc was visualized by hybridization of Northern blots performed from total RNA. In the presence of low concentrations of FCS (2 p. 100, 5 p. 100) angiotensin II (10(-7)M) and bradykinin (3 X 10(-6)M) increase the growth of both kind of cells. The inositol phosphate formation and the expression of c-fos and c-myc are also dose-dependently stimulated by these vasoactive drugs, and the cultures from SHR are more responsive than those from WKY rats. Phospholipase C hyperreactivity therefore appears to be involved in the increased proliferative ability of vascular smooth muscle cells from SHR. However other molecular processes may be involved, as suggested by the growth inhibition exerted by heparin without any action on PLC activity.     

Isolation and characterization of single vascular smooth muscle cells from spontaneously hypertensive rats

To study the properties of vascular smooth muscle in hypertension without the influence of the nerves and endothelium, a procedure was developed to isolate single smooth muscle cells from tail arteries of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) normotensive control rats. Perfusion of intact arteries with a solution of papain and collagenase produced dense populations of viable cells (more than 10(4) cells/ml) that remained relaxed in the presence of physiological levels of calcium. Contractile responses of smooth muscle cells from the SHR were significantly more sensitive to noradrenaline, potassium depolarization, and the calcium channel agonist Bay K 8644 compared with those from WKY rats. Enhanced sensitivity to calcium in the SHR was also observed on readdition of calcium to cells preincubated in noradrenaline or KCl in a calcium-free medium. These results provide evidence for alterations in the properties of vascular smooth muscle in the SHR at the single cell level.     

RhoA activation in vascular smooth muscle cells from stroke-prone spontaneously hypertensive rats.

RhoA is commonly activated in the aorta in various hypertensive models, indicating that RhoA seems to be a molecular switch in hypertension. The molecular mechanisms for RhoA activation in stroke-prone spontaneously hypertensive rats (SHRSP) were here investigated using cultured aortic smooth muscle cells (VSMC). The level of the active form of RhoA was higher in VSMC from SHRSP than in those from Wistar-Kyoto rats (WKY). The phosphorylation level of myosin phosphatase target subunit 1 (MYPT1) at the inhibitory site was also significantly higher in SHRSP, and the phosphorylation levels in both VSMCs were strongly inhibited to a similar extent by treatment with Y-27632, a Rho-kinase inhibitor. The expression levels of RhoA/Rho-kinase related molecules, namely RhoA, Rho-kinase, MYPT1, CPI-17 (inhibitory phosphoprotein for myosin phosphatase) and myosin light chain kinase, were not different between SHRSP and WKY. Valsartan, an angiotensin II (Ang II)- type 1 receptor antagonist, selectively and significantly reduced the RhoA activation in VSMC from SHRSP. The expression levels of the Rho GDP-dissociation inhibitor (RhoGDI) and leukemia-associated Rho-specific guanine nucleotide exchange factor (RhoGEF) did not differ between SHRSP and WKY. In cyclic nucleotide signaling, cyclic GMP (cGMP)-dependent protein kinase Ialpha (cGKIalpha) was significantly downregulated in SHRSP cells, although there were no changes in the expression levels of guanylate cyclase beta and cyclic AMP (cAMP)-dependent protein kinase or the intracellular contents of cGMP and cAMP between the two rat models. These results suggest that the possible mechanisms underlying RhoA activation in VSMC from SHRSP are autocrine/paracrine regulation by Ang II and/or cGKIalpha downregulation.