凝血酶对大鼠血管平滑肌细胞血小板源性生长因子基因表达的影响

为了研究凝血酶对血管平滑肌细胞血小板源性生长因子基因表达的影响 ,探讨凝血酶刺激血管平滑肌细胞增殖的机制 ,通过培养SD大鼠胸主动脉血管平滑肌细胞 ,以3 H -TdR掺入率作为评价凝血酶促血管平滑肌细胞增殖的指标 ;用反转录聚合酶链反应检测凝血酶对血管平滑肌细胞血小板源性生长因子A链mRNA表达的影响 ;用Dotblot检测凝血酶对血管平滑肌细胞血小板源性生长因子B链mRNA表达的影响。结果表明 ,凝血酶促血管平滑肌细胞增殖呈浓度依赖性和时间依赖性 ,血管平滑肌细胞在基础状态下可检测到血小板源性生长因子A和B链mRNA表达 ,凝血酶刺激血管平滑肌细胞后 2h血小板源性生长因子A链mRNA表达开始增加 ,4～ 6h达高峰 ,持续 12h ,2 4～ 48h恢复正常。提示凝血酶对血管平滑肌细胞具有较强的促增殖作用 ,凝血酶促血管平滑肌细胞的增殖作用部分可能是通过诱导血管平滑肌细胞血小板源性生长因子A链mRNA的表达来实现的。     

葛根素对血管平滑肌细胞增殖及Bcl-2蛋白和凝血酶受体mRNA表达的影响

目的观察葛根素对凝血酶诱导的血管平滑肌细胞增殖及Bcl-2蛋白和凝血酶受体mRNA表达的影响,旨在认识葛根素作用的分子机制。方法以细胞计数法和流式细胞仪DNA含量测定,细胞周期分析法观察凝血酶及葛根素对血管平滑肌细胞增殖和DNA合成的影响。凝血酶及葛根素等各处理因素作用24 h后,用免疫印迹法检测Bcl-2蛋白表达,以半定量逆转录聚合酶链反应检测凝血酶受体mRNA的表达。结果凝血酶对血管平滑肌细胞有明显促增殖作用,促增殖效应在24 h末达峰值,且凝血酶浓度在0.1~1.0 u/L之间有剂量依赖关系;葛根素呈剂量依赖性地抑制凝血酶诱导的细胞增殖、DNA合成及血管平滑肌细胞Bcl-2蛋白的表达;高浓度(1.5×10-3mol/L)葛根素可显著抑制凝血酶诱导的凝血酶受体mRNA上调。结论葛根素能抑制凝血酶诱导的血管平滑肌细胞增殖,这可能与其抑制Bcl-2蛋白有关,并部分与其抑制凝血酶受体mRNA表达有关。     

凝血酶对大鼠血管平滑肌细胞血小板源生长因子受体基因表达的影响

为了研究凝血酶对血管平滑肌细胞血小板源生长因子受体基因表达的影响 ,探讨凝血酶刺激血管平滑肌细胞增殖的机制 ,通过培养SD大鼠胸主动脉血管平滑肌细胞 ,用斑点杂交检测凝血酶对血管平滑肌细胞血小板源生长因子受体mRNA的表达。结果发现培养的血管平滑肌细胞在基础状态下可表达血小板源生长因子α受体和 β受体mRNA ,凝血酶在作用于血管平滑肌细胞 2～ 12h抑制了血管平滑肌细胞血小板源生长因子α受体 β受体mRNA的表达 ,2 4～ 48h后血管平滑肌细胞血小板源生长因子α受体 β受体mRNA的表达恢复到基础状态。提示凝血酶对血管平滑肌细胞具有较强的促增殖作用 ;凝血酶显著降低了血管平滑肌细胞血小板源生长因子α受体 β受体mRNA的表达     

表皮生长因子受体在血管紧张素Ⅱ促血管平滑肌细胞增殖中的作用

目的探讨表皮生长因子受体在血管紧张素Ⅱ促大鼠血管平滑肌细胞增殖效应中的作用。方法用反义表皮生长因子受体寡核苷酸脂质体复合物转染SD大鼠血管平滑肌细胞,用逆转录聚合酶链反应、Western-Blot-ing分别检测转染后表皮生长因子受体mRNA及蛋白的表达情况,用氚标胸腺嘧啶脱氧核苷掺入实验检测血管平滑肌细胞的增殖情况。结果反义组大鼠血管平滑肌细胞表皮生长因子受体mRNA表达(0.18±0.03)较正义组(0.61±0.11)及对照组(0.66±0.09)明显减少(P<0.05),反义组大鼠血管平滑肌细胞表皮生长因子受体蛋白的表达(43.1±8.4)较正义组(92.6±10.5)及对照组(100.7±11.3)明显减少(P<0.05);反义组细胞的氚标胸腺嘧啶脱氧核苷掺入率(1055.1±95.7)较正义组(1882.4±129.7)及对照组(2013.3±121.3)明显降低(P<0.05)。结论表皮生长因子受体在血管紧张素Ⅱ促血管平滑肌细胞增殖中起重要作用。     

葛根素对大鼠主动脉球囊损伤后血小板活化及凝血酶受体表达的影响

目的研究球囊损伤后血管内膜增生的过程、血小板活化水平、凝血酶受体mRNA的变化及葛根素的影响。方法将72只雄性W istar大鼠随机分为对照组、手术组和葛根素治疗组,分别在术后3、7、14和28 d通过组织学检查、放射免疫法和逆转录聚合酶链反应技术检测内膜增生的情况、血小板表面GMP-140的数目、凝血酶受体mRNA的水平及葛根素〔50 mg/(kg.d)〕腹腔注射对它们的影响。结果①凝血酶受体mRNA在正常血管组织表达极弱,球囊损伤术后3 d已显著增加,术后14 d达峰值,术后28 d开始下降。②GMP-140于术后3 d明显升高,术后7 d开始下降。③术后3 d已有增殖的血管平滑肌细胞移行至内膜层;术后7 d内膜开始增生;术后14 d血管平滑肌细胞的增殖及内膜增生更为明显;术后28 d血管平滑肌细胞的增殖明显减弱,细胞外基质增加,内膜继续增生。④使用葛根素后血小板表面GMP-140的数目减少,血管平滑肌细胞的增殖减弱,但凝血酶受体mRNA表达及内膜增生程度未见明显变化。结论血管内皮损伤后内膜增生的过程中血小板活化、凝血酶受体mRNA表达增加,葛根素抑制血小板的活化及血管平滑肌细胞的增殖,但对凝血酶受体mRNA的表达及内膜增生的程度无明显影响。     

反义EGFR寡核苷酸对AngⅡ促血管平滑肌细胞增殖效应的影响

目的探讨脂质体介导的反义表皮生长因子受体（EGFR）寡核苷酸基因转染对血管紧张素Ⅱ（AngⅡ）促大鼠血管平滑肌细胞（VSMC）增殖的影响。方法用EGFR寡核苷酸脂质体复合物转染Sprague-Dawley大鼠VSMC,通过RT-PCR、Western-Bloting分别检测转染后EGFR mRNA及蛋白的表达情况,用3H-Tdr掺入法检测经EGFR寡核苷酸转染再用AngⅡ刺激VSMC的增殖情况。结果反义EGFR寡核苷酸转染大鼠VSMC后,EGFR mRNA及蛋白的表达较正义组及对照组显著减少（P<0.01）;用AngⅡ刺激后,反义组细胞的3H-Tdr掺入较正义组及对照组显著降低（P<0.01）。结论脂质体介导的反义EGFR寡核苷酸转染可以减弱AngⅡ的促VSMC增殖效应。     

肾上腺髓质素及其受体系统抑制溶血磷脂酸诱导的大鼠主动脉平滑肌细胞增殖

目的观察溶血磷脂酸对肾上腺髓质素及其受体系统生成的影响和肾上腺髓质素在溶血磷脂酸促进血管平滑肌细胞增殖中的作用。方法贴块法培养大鼠胸主动脉血管平滑肌细胞,H3-TdR掺入测定血管平滑肌细胞DNA合成,γ-32P-ATP标记的同位素法测定丝裂原活化蛋白激酶活性,放射免疫法测定血管平滑肌细胞中肾上腺髓质素的含量。结果溶血磷脂酸促进大鼠血管平滑肌细胞肾上腺髓质素生成,上调血管平滑肌细胞肾上腺髓质素及其受体CRLR、RAMP2和RAMP3mRNA表达;肾上腺髓质素可抑制溶血磷脂酸刺激大鼠血管平滑肌细胞3H-TdR掺入,抑制溶血磷脂酸诱导的丝裂原活化蛋白激酶激活。结论溶血磷脂酸上调血管平滑肌细胞肾上腺髓质素及其受体系统,肾上腺髓质素及其受体抑制血管平滑肌细胞增殖的作用与其抑制丝裂原活化蛋白激酶激活有关。     

球囊损伤大鼠主动脉内皮后血小板活化及凝血酶受体表达的变化

目的 探讨经皮冠状动脉腔内成形术后再狭窄的发生机制。方法建立大鼠主动脉内皮球囊损伤模型，分别于术后3天、7天、14天和28天，通过组织学检查、放射免疫法和逆转录一聚合酶链反应技术检测主动脉球囊损伤后内膜增生的情况、血小板表面GMP-140数目和凝血酶受体mRNA表达的变化。结果凝血酶受体mRNA在正常血管组织的表达较弱，球囊损伤术后第3天已显著增加，术后第14天达峰值，术后第28天开始下降。GMP-140于术后第3天明显升高，术后第7天开始下降。内皮损伤术后第3天已有增殖的血管平滑肌细胞移行至内膜层；术后第7天内膜开始增生；术后第14天血管平滑肌细胞的增殖及内膜增生更为明显；术后第28天血管平滑肌细胞的增殖明显减弱，细胞外基质增加，内膜继续增生。结论血管内皮损伤内膜增生的过程中血小板活化．凝血酶受体mRNA表达增加。     

多沙唑嗪抑制大鼠血管平滑肌细胞增殖的实验研究

为探讨多沙唑嗪对大鼠血管平滑肌细胞增殖的抑制作用。将不同浓度的多沙唑嗪作用于体外培养的血管平滑肌细胞，采用氚-胸腺嘧啶核苷（^3H-TdR)掺入的方法检测平滑肌细胞的增殖。结果发现，多沙唑嗪能够抑制血管平滑肌细胞和不表达α1受体的成纤维细胞的增殖，用不可逆的α1受体阻滞剂酚苄明处理平滑肌细胞，多沙唑嗪仍表现为抑制增殖的作用。以上提示，多沙唑嗪对大鼠平滑肌细胞增殖的抑制作用与其对α1受体的阻滞作用无关。     

Rho and Rho kinase mediate thrombin-stimulated vascular smooth muscle cell DNA synthesis and migration.

Aberrant regulation of smooth muscle cell proliferation and migration is associated with the pathophysiology of vascular disorders such as hypertension, atherosclerosis, restenosis, and graft rejection. To elucidate molecular mechanisms that regulate proliferation and migration of vascular smooth muscle cells, we determined whether signaling through the small G protein Rho is involved in thrombin- and phenylephrine-stimulated proliferation and migration of rat aortic smooth muscle cells (RASMCs). Thrombin and the thrombin peptide SFLLRNP stimulated DNA synthesis of RASMCs as measured by [3H]thymidine incorporation. Both ligands also increased cell migration as measured by the Boyden chamber method. L-Phenylephrine failed to induce either of these responses but increased inositol phosphate accumulation and mitogen-activated protein kinase activation in these cells, which indicated that the cells were responsive to alpha1-adrenergic stimulation. The C3 exoenzyme, which ADP-ribosylates and inactivates Rho, fully inhibited both thrombin-stimulated proliferation and migration but had no effect on inositol phosphate accumulation. In addition, Y-27632, an inhibitor of the Rho effector p160ROCK/Rho kinase, decreased thrombin-stimulated DNA synthesis and migration. To directly examine Rho activation, Rho-[35S]GTPgammaS binding was measured. The addition of the thrombin peptide SFLLRNP, but not phenylephrine, to RASMC lysates resulted in a significant increase in Rho-[35S]GTPgammaS binding. Thrombin and SFLLRNP, but not phenylephrine, also increased membrane-associated Rho in intact RASMCs, consistent with selective activation of Rho by thrombin. These results indicate that thrombin activates Rho in RASMCs and establish Rho as a critical mediator of thrombin receptor effects on DNA synthesis and cell migration in these cells.     

凝血酶诱导CBP高表达刺激大鼠血管平滑肌细胞增殖的研究

目的:探讨凝血酶诱导大鼠CBP高表达影响大鼠血管平滑肌细胞(VSMCs)增殖的作用机制.方法:采用10-3、10-2、0.1、1、10 U/ml的凝血酶干预体外培养的VSMCs 30min.RT-PCR法、蛋白印记法分别检测rCBPmRNA和蛋白质的表达变化.流式细胞技术检测细胞周期,评价细胞增殖能力.结果:凝血酶可在...     

凝血酶通过内皮素介导刺激肾小球系膜细胞增生

研究内皮素－１在凝血酶刺激有肾小球系膜细胞增生中的作用。方法在培养肾小球系膜细胞中进行试验。（１）ＨＭＣ在凝血酶刺激下增生,呈剂量依赖并与刺激时间有关,当凝血酶１６Ｕ／ｍｌ刺激１６小时时ＨＭＣ增生达高峰;     

川芎嗪对血管平滑肌细胞增殖及表达c-myc基因的影响

为观察川芎嗪对血管平滑肌细胞增殖的影响,在建立凝血酶诱导的体外培养的兔主动脉血管平滑肌细胞增殖模型后,应用免疫细胞化学方法观察川芎嗪对血管平滑肌细胞表达ｃ－ｍｙｃ基因蛋白的影响;并用流式细胞术观察了血管平滑肌细胞增殖周期的变化。结果发现,川芎嗪能够显著抑制凝血酶诱导的血管平滑肌细胞ｃ－ｍｙｃ基因蛋白表达增加,使血管平滑肌处于ＧＩ期的细胞数显著增多,Ｓ期和Ｇ２＋Ｍ期的细胞数显著减少。结果提示,川芎嗪对凝血酶诱导的血管平滑肌细胞增殖有显著抑制作用,其机制与抑制ｃ－ｍｙｃ基因表达有关。     

Phenotype-related alteration in expression of natriuretic peptide receptors in aortic smooth muscle cells.

To elucidate the physiological and pathophysiological roles of the natriuretic peptide family in vascular smooth muscle cells, in which the natriuretic peptide family is implicated in growth inhibition as well as vasorelaxation, we have examined the phenotype-related expression of three kinds of natriuretic peptide receptors in rat aortic smooth muscle cells. The expression of natriuretic peptide receptors at the mRNA level was studied by Northern blot hybridization, and the expression at the protein level was determined by the cGMP production method and receptor binding assay. In intact aortic media, atrial natriuretic peptide (ANP)-A receptor mRNA and ANP-B receptor mRNA were detected, and the potency of cGMP production by ANP was at least two orders of magnitude stronger than that by C-type natriuretic peptide. Clearance receptor mRNA was undetectable, and only a small amount of the clearance receptor was detected by the binding assay in intact aortic media. By contrast, in cultured aortic smooth muscle cells at the first, fifth, and 17th passages, the ANP-B receptor mRNA level markedly increased; meanwhile, the expression of the ANP-A receptor mRNA became undetectable. C-type natriuretic peptide was one order of magnitude more potent than ANP in cGMP production in cultured aortic smooth muscle cells. The clearance receptor density and its mRNA level increased tremendously in these cultured cells. These results demonstrate that the marked phenotype-related alteration occurs in the expression of natriuretic peptide receptors in rat aortic smooth muscle cells.     

Ultrasonic tissue characterization of collagen in lipid-rich plaques in apoE-deficient mice

The current model of the arterial response to injury suggests that proliferation of vascular smooth muscle cells is a central event. Mitogen activated protein kinases are part of the final common pathway of intracellular signalling involved in cell division and thus constitute an attractive target in attempting to inhibit this proliferation. We hypothesised that antisense oligonucleotides to mitogen activated protein kinase would inhibit serum induced smooth muscle cell proliferation by downregulating the protein. Porcine vascular smooth muscle cells were cultured and an antisense oligonucleotide sequence against the ERK family of mitogen activated protein kinases (AMK1) was introduced by liposomal transfection. Sense oligonucleotides and a random sequence were used as controls. Proliferation was inhibited by AMK1 versus the sense controls, as assessed by tritiated thymidine incorporation (P<0.01). Immunoblots revealed downregulation of the target protein by AMK1 by 63% versus the sense control (P<0.05). In conclusion, antisense oligonucleotides specifically inhibited proliferation and downregulated the target protein. This is consistent with a central role for mitogen activated protein kinases in vascular smooth muscle cell proliferation in the porcine model. In addition, the data suggest a possible role for antisense oligonucleotides in the modulation of the arterial injury response.     

Insulin stimulates endogenous angiotensin II production via a mitogen-activated protein kinase pathway in vascular smooth muscle cells

OBJECTIVE: The present study was designed to determine the effects of insulin on cytosolic angiotensin II production and proliferation in cultured rat vascular smooth muscle cells. DESIGN AND METHODS: Vascular smooth muscle cells were incubated with insulin for 48 h. Cytosolic angiotensin I and II were determined by radioimmunoassays of purified cell homogenates. Angiotensin II was also detected by immunohistochemistry of intact cells. Cell proliferation was determined by pulse labeling with radiolabeled thymidine. Angiotensinogen mRNA expression was determined by slot-blot analysis. RESULTS: Insulin significantly increased cytosolic angiotensin II concentration in vascular smooth muscle cells. Lisinopril, omapatrilat and irbesartan inhibited this increase of angiotensin II, but had no effect on angiotensin I levels. Immunohistochemical staining confirmed the presence of angiotensin II in control and insulin-treated vascular smooth muscle cells. Insulin increased cell proliferation, and addition of lisinopril, omapatrilat or irbesartan inhibited this effect. Insulin also increased expression of angiotensinogen mRNA in cultured vascular smooth muscle cells, but PD98059, a mitogen-activated protein kinase inhibitor, prevented the rise in angiotensinogen expression. CONCLUSION: These results support the concept that insulin stimulates angiotensin II production in cultured vascular smooth muscle cells through a mitogen-activated, protein kinase-dependent pathway that might be a factor in the progression of atherosclerosis. Agents that block the renin-angiotensin system have direct protective effects, reducing vascular angiotensin II and growth of vascular smooth muscle cells and are thus of cardiovascular benefit.