沙利度胺对大鼠颈动脉损伤后新生内膜形成的影响

目的：观察沙利度胺局部给药对大鼠颈动脉损伤后新生内膜形成和血管再狭窄的影响,并探讨其可能机制。方法：48只SD大鼠随机分成假手术组（A组）、单纯手术组（B组）和沙利度胺组（C组）,A组仅分离和结扎右颈外动脉,B组和C组行右颈总动脉血管成形术,C组在损伤血管局部给予沙利度胺。在术后7d和14d分别测定血清中血管内皮生长因子（VEGF）和肿瘤坏死因子（TNF）-α水平、观察血管内膜损伤后形态学变化、用免疫组织化学法观察组织VEGF和巨噬细胞表达水平。结果：在血管损伤后14d,B组VEGF和TNF-α水平明显高于A组和C组（P〈0．01）,B组管腔面积明显缩小（P〈0．01）,而新生内膜面积明显增加（P〈0．01）,同时B组血管内膜VEGF和巨噬细胞的表达亦较A组和B组增加（P〈0．01）。结论：沙利度胺局部给药可抑制血管损伤后新生内膜形成和血管再狭窄的发生。     

沙利度胺对大鼠颈动脉损伤后新生内膜形成的影响

目的：观察沙利度胺局部给药对大鼠颈动脉损伤后新生内膜形成和血管再狭窄的影响,并探讨其可能机制。方法：48只SD大鼠随机分成假手术组（A组）、单纯手术组（B组）和沙利度胺组（C组）,A组仅分离和结扎右颈外动脉,B组和C组行右颈总动脉血管成形术,C组在损伤血管局部给予沙利度胺。在术后7d和14d分别测定血清中血管内皮生长因子（VEGF）和肿瘤坏死因子（TNF）-α水平、观察血管内膜损伤后形态学变化、用免疫组织化学法观察组织VEGF和巨噬细胞表达水平。结果：在血管损伤后14d,B组VEGF和TNF-α水平明显高于A组和C组（P〈0．01）,B组管腔面积明显缩小（P〈0．01）,而新生内膜面积明显增加（P〈0．01）,同时B组血管内膜VEGF和巨噬细胞的表达亦较A组和B组增加（P〈0．01）。结论：沙利度胺局部给药可抑制血管损伤后新生内膜形成和血管再狭窄的发生。     

Effects of probucol on rat carotid artery responses to balloon catheter injury

Balloon catheter injury to the rat common carotid artery has been widely used for testing potential therapies for post-angioplasty restenosis. However, the model has become somewhat discredited because a number of drugs that inhibit intimal thickening, measured 14 days after balloon catheter injury, have been found to be ineffective in clinical trials. Probucol has recently been shown to reduce the incidence of post-angioplasty restenosis in a number of small clinical trials, making it possible to reassess the validity of the rat balloon injury model. The effects of probucol on the underlying causes of intimal thickening in balloon-injured rat carotid arteries were quantified. Probucol inhibited medial smooth muscle cell proliferation by 23% on day 4 after injury (P=0.009), and by 65% on day 10 after injury (P=0.026). Smooth muscle cell migration was reduced by 64% (P=0.008) in probucol-treated animals. In marked contrast, intimal smooth muscle cell proliferation was significantly increased by 41% (P=0.024) by probucol. There was no significant effect on intimal thickening or smooth muscle cell death. These data suggest that drugs that inhibit both medial smooth muscle cell proliferation and migration in the rat balloon injury model may prove useful in the treatment of post-angioplasty restenosis.     

重组腺病毒介导的人一氧化氮合酶基因转染对大鼠颈总动脉球囊损伤后新生内膜的影响

目的 :研究重组腺病毒介导的人内皮型一氧化氮合酶基因 (eNOS)表达生成的一氧化氮合酶 (NOS)对球囊损伤后大鼠颈总动脉新生内膜的抑制作用。方法 :在 2 93细胞内扩增、纯化Ad LacZ和Ad eNOS ,鉴定其是否携带有LacZ和eNOS基因。建立大鼠颈总动脉球囊损伤模型后 ,将磷酸缓冲液 (PBS)、Ad LacZ和Ad eNOS在体内分别转染到损伤血管段 ,以X gal染色、苏木精 伊红染色 ,免疫组化及计算机图像分析处理等方法观察转染动脉节段外源性eNOS蛋白表达及其对新生内膜的影响。结果 :重组腺病毒携带有eNOS基因 ,并且在损伤血管段得到有效表达。转染后PBS组、Ad LacZ组和Ad eNOS组的新生内膜面积分别为 (0 .187± 0 .0 18)、(0 .134± 0 .0 6 1)和 (0 .0 6 3± 0 .0 2 6 )mm 2 ,新生内膜与中膜面积比值 (I/M)分别为 1.5 76± 0 .2 73、1.342± 0 .35 7和 0 .5 6 0± 0 .16 1。与PBS组、Ad LacZ组相比Ad eNOS组无论新内膜面积 ,还是管腔狭窄程度都明显减小。结论 :腺病毒介导的eNOS基因转染能有效抑制球囊损伤后血管内膜的增生 ,可防治血管成形术后再狭窄     

瑞舒伐他汀对大鼠颈总动脉球囊损伤后内膜增生和PTEN表达的影响

目的 观察瑞舒伐他汀对大鼠颈总动脉损伤后内膜增生及总PTEN、P-PTEN蛋白表达的影响。方法 将48只雄性SD大鼠随机分为组A和组B,每组24只。两组分别建立大鼠左颈总动脉球囊损伤模型。其中组A和组B均取左颈总动脉（行球囊损伤侧）分别作为损伤组和治疗组,另取组A的右颈总动脉（未行球囊损伤侧）作为正常对照组。组B于损伤前3 d始连续每天给予瑞舒伐他汀5 mg/(kg·d)灌胃,组A予9 g/L氯化钠溶液灌胃。组A和组B大鼠分别于建模后7 d或14 d,取颈总动脉制做病理切片观察动脉内膜增生。用Western blot检测总PTEN和P-PTEN蛋白的表达。结果 共40只大鼠完成本实验。①与正常对照组比较,血管损伤后7 d,新生内膜形成,损伤14 d内膜面积、内膜/中膜面积的比值增大,管腔面积明显减少（与正常对照组比较,P<0.05）。损伤后14 d,治疗组的管腔面积较损伤组增加26％（P<0.05）。②损伤组总PTEN和P-PTEN的表达均较正常对照组增高,P-PTEN/总PTEN的比值增大（P<0.05）。治疗组P-PTEN/总PTEN的比值较损伤组明显降低（P<0.05）。结论 ①瑞舒伐他汀可抑制大鼠颈动脉球囊损伤后内膜增生。②瑞舒伐他汀可降低P-PTEN/总PTEN的比值。③此二项作用可能具有相关性。     

Alpha-lipoic acid inhibits fractalkine expression and prevents neointimal hyperplasia after balloon injury in rat carotid artery

Vascular inflammation induced by the proinflammatory cytokine/NF-kappaB pathway is one of the key mechanisms in the development of neointimal hyperplasia. Accumulating evidence suggests that a recently identified chemokine, fractalkine, is involved in arterial inflammation and atherogenesis. However, no study has examined the expression of neointimal fractalkine and the effects of pharmacological agents on this process. The purposes of this study were to measure neointimal fractalkine expression in the rat carotid artery following balloon injury and to determine if alpha-lipoic acid (ALA) inhibits fractalkine expression and neointimal hyperplasia. Balloon injury of the rat carotid artery induced fractalkine expression in the medial as well as neointimal regions. ALA inhibited this expression and consequently prevented neoinitmal hyperplasia in a balloon-injured rat carotid artery. Additionally, ALA inhibited TNF-alpha-stimulated fractalkine expression in cultured vascular smooth muscle cells (VSMCs), a process which is mediated through the NF-kappaB pathway. In addition to fractalkine, ALA successfully inhibited TNF-alpha-stimulated expression of vascular cell adhesion molecule-1 and monocyte chemotactic protein-1 in cultured VSMCs. These data suggest that the cytokine-fractalkine system is involved in the pathogenesis of restenosis. The present study supports the possibility that ALA, which inhibits the NF-kappaB/fractalkine pathway, may be used to prevent neointimal hyperplasia after angioplasty or stenting.     

同型半胱氨酸对球囊损伤大鼠颈动脉原癌基因表达及新生内膜增生的影响

目的观察高蛋氨酸饮食诱导的高同型半胱氨酸(Hcy)血症对大鼠颈动脉球囊损伤后血管组织原癌基因c-fos及c-jun mRNA表达及新生内膜增生的影响,探讨Hcy在血管球囊损伤后新生内膜过度增生中的作用及可能机制.方法采用RT-PCR方法检测血管组织c-fos及c-jun mRNA表达情况,并做半定量分析.采用光镜和计算机图像分析定量方法观察高Hcy血症对大鼠颈动脉内皮损伤后新生内膜增生的影响.结果低蛋氨酸组和高蛋氨酸组c-fos及c-jun mRNA的表达[分别为(1.40±0.21)、(1.43±0.25)及(1.68±0.27)、(1.71±0.30)]均高于对照组[分别为(1.10±0.15)、(1.00±0.13),P<0.05和0.01)],高蛋氨酸组也明显高于低蛋氨酸组(P<0.05).与对照组比较,低蛋氨酸组、高蛋氨酸组的新生内膜增生明显,计算机图像定量分析表明血管损伤后14 d,低和高蛋氨酸组新生内膜增生面积和内∕中膜面积比率比对照组分别增加87%、98%和97%、109%(均为P<0.01), 管腔面积在低、高蛋氨酸组比对照组分别减少45%、55%(P<0.05).结论 (1)高Hcy血症能使球囊损伤后颈动脉新生内膜增生恶化,预示高Hcy血症可能是血管内皮球囊损伤后再狭窄的一个独立危险因素;(2)Hcy能上调血管内皮损伤后动脉组织原癌基因c-fos及c-jun mRNA的表达,且呈浓度依赖性,这可能是其促使血管内皮损伤后新生内膜过度增生的机制之一.     

慢病毒载体在大鼠颈动脉球囊损伤模型中的应用及观察

目的:研究携带绿色荧光蛋白(Green fluorescent protein,GFP)的慢病毒转染球囊损伤大鼠颈动脉的效率和可行性,为利用慢病毒载体介导的基因治疗预防血管再狭窄奠定基础。方法:将携带GFP的慢病毒载体(pGC-LV-GFP载体)和慢病毒包装质粒供转染293T细胞,完成慢病毒颗粒包装及滴度测定。包装产生的慢病毒Lenti-GFP转染至球囊损伤的大鼠颈动脉。术后28d,损伤及病毒转染血管段标本分别行荧光显微镜、光镜检查,评估慢病毒的转染效率及内膜增生情况,并与假手术组(Sham组)、PBS对照组进行比较。结果:经包装产生的Lenti-GFP滴度为2×109TU/mL;术后28d,Sham组与PBS组血管中膜弹力层仅见微弱的自发性绿色荧光,而Lenti-GFP组动脉壁全层可见较强的绿色荧光分布;PBS组与Lenti-GFP转染组大鼠损伤的颈动脉均可见明显内膜增生,内膜和中膜面积之比差异无统计学意义。结论:Lenti-GFP成功转染至球囊损伤的大鼠颈动脉,并能维持目的基因稳定长期的表达,是血管再狭窄基因治疗的理想载体。     

TNFalpha increases the inflammatory response to vascular balloon injury without accelerating neointimal formation

There is now clear evidence for a contributory role of inflammatory processes to restenosis following vascular balloon injury and stent implantation. The aim of the present study was to study the effects of TNFalpha, administered locally in vivo immediately following balloon angioplasty, on the leukocyte adhesive response and extent of neointimal formation in a rabbit model of subclavian artery injury. Initial in vitro studies were performed with normal isolated artery rings to assess the vascular adhesive response to TNFalpha or IL-1beta. Pre-incubation with either cytokine prior to addition of (51)Cr-labelled leukocytes enhanced the adhesion of leukocytes to the artery in both a time- and concentration-dependent manner. Although both cytokines induced an increase in the expression of the adhesion molecules ICAM-1 and VCAM-1, only antibodies to ICAM-1 blocked the enhanced adhesion induced by the cytokines. In artery segments retrieved from rabbits that had previously undergone subclavian artery angioplasty either 24 h or 8 days previously, there was an injury-induced increase in adhesion of leukocytes assessed ex vivo. In segments obtained from rabbits that received a 15 min local infusion of TNFalpha (2 ng/min) to the injured artery immediately after the angioplasty procedure, leukocyte adhesion assessed ex vivo was further significantly enhanced. The pro-adhesive effect of TNFalpha was associated with an increased expression of both ICAM-1 and VCAM-1. However, TNFalpha administration did not alter the extent of neointimal formation observed 8 days after injury. These findings suggest that while TNFalpha may play a role following vascular injury, it does not act alone to induce neointimal formation. Thus anti-inflammatory strategies targeted at multiple cytokines may be more appropriate than targeting a single cytokine to reduce the response to vascular injury.     

依维莫司对大鼠颈总动脉球囊损伤后内膜增生的影响

目的:探讨依维莫司对大鼠颈总动脉球囊损伤模型增生内膜的影响及其可能作用机制.方法:健康雄性SD大鼠36只,随机分为假损伤组(对照组)、颈总动脉球囊损伤组(损伤组)和颈总动脉球囊损伤+口服依维莫司组(依维莫司组),每组12只.依维莫司组于颈总动脉球囊损伤前1天,用依维莫司负荷剂量1.5 mg/kg灌胃,随后给予其剂量0.75 mg·kg-1·d-1灌胃直至第28天,对照组与损伤组给予等量0.9%氯化钠溶液灌胃.各组均于术后第28天取颈总动脉损伤段,观测颈动脉形态学变化,以免疫组化法测定损伤血管内膜真核翻译起始因子4E(eIF-4E)及增殖细胞核抗原(PCNA)的表达情况.结果:对照组血管内膜无增生,eIF-4E、PCNA表达极少;与对照组比较,损伤组新生内膜形成并增生明显,eIF-4E、PCNA表达显著增强;依维莫司组较损伤组新生内膜增生减轻,eIF-4E及PCNA表达明显降低,差异有统计学意义(P＜0.05).结论:依维莫司可抑制大鼠颈总动脉球囊损伤模型新生内膜增殖.其作用机制可能与抑制eIF-4E及PCNA表达有关.     

卡维地洛对大鼠颈动脉球囊损伤后血管内膜增生的影响

目的探讨卡维地洛(CAR)对大鼠颈动脉球囊损伤后内膜增生的影响。方法雄性Wistar大鼠36只,随机分为假手术组、损伤组和CAR组,每组12只,后2组建立大鼠颈动脉球囊损伤模型。3组均于术后7、14天分别处死6只大鼠。观察颈动脉形态学变化,计算新生内膜面积,免疫组织化学检测增殖细胞核抗原(PCNA)阳性细胞的表达。结果假手术组无新生内膜发生。与假手术组比较,损伤组大鼠术后7天,新生内膜形成并增厚,14天内膜增厚更明显(P0.01)。与损伤组比较,CAR组术后14天,新生内膜面积减少44%(P0.01),管腔面积增加82%(P0.01),内膜PCNA表达显著降低(P0.01)。结论 CAR可有效抑制颈动脉球囊损伤后内膜增生。     

Roscovitine抑制大鼠颈总动脉球囊损伤后内膜增生的研究

目的:观察roscovitine对球囊损伤后大鼠颈总动脉血管平滑肌细胞及内膜增生的抑制作用,以期提供新型的支架涂层药物。方法:建立大鼠颈总动脉球囊损伤模型模拟经皮冠状动脉腔内介入术(PCI)术后再狭窄,干预组损伤局部给予roscovitine(200μmol/L)孵育10分钟。14天后取材,免疫荧光染色观察roscovitine对局部血管平滑肌细胞增殖的作用;HE染色观察roscovitine对内膜增生的作用。结果:本研究建立了大鼠颈总动脉球囊损伤模型,球囊损伤后14天,局部血管平滑肌细胞增殖活跃、内膜增生明显。Roscovitine干预后,血管平滑肌细胞增殖率明显降低,内膜增生被显著抑制,管腔狭窄率和内膜中膜面积比值显著降低。结论:Roscovitine显著抑制大鼠颈总动脉球囊损伤后局部血管平滑肌细胞增殖,进而有效抑制内膜增生,降低再狭窄发生率。     

腺病毒介导的人p27kip1基因转染对球囊损伤后兔颈动脉新生内膜增生的抑制作用

目的 研究腺病毒介导的p27kip1基因及其蛋白产物高表达对球囊损伤后兔颈动脉新生内膜增生的抑制作用。方法 建立兔颈动脉球囊损伤模型,将LacZ重组腺病毒（AdLacZ）和人p27kipl重组腺病毒（Adhp27kipl）在体内分别转染损伤动脉节段,以Western　blot、x-gal染色、HE染色、兔疫组化及计算机图像处理方法观察转染动脉节段中外源性p27kipl蛋白表达及其对新生内膜增生的影响。结果 与AdLacZ转染组及未转染组比较,Adhp27kip1转染的动脉节段内p27kip1蛋白呈高表达,表达高峰在7～14 d,持续4周以上;转染4周后未转染组、AdLacZ转染组及Adhp27kip1转染组的新生内膜面积分别为1.106mm2、0.988mm2及0.278mm2;管腔狭窄率分别为87.07％、65.40％及32.14％。结论 外源性p27kip1基因及其蛋白产物在损伤动脉节段内高表达可显著抑制新生内膜增生及管腔狭窄。     

Local delivery of green tea catechins inhibits neointimal formation in the rat carotid artery injury model

It has been shown that green tea catechins (GTC) suppress proliferation of vascular smooth muscle cells (VSMCs) and that epigallocatechin-3-gallate (EGCG), which is a major constituent of GTC, selectively inhibits the platelet-derived growth factor-BB (PDGF-BB)-induced intracellular signaling transduction pathway. Vascular smooth muscle cell proliferation is one of major mechanisms of restenosis following percutaneous coronary intervention. This study tested whether GTC can inhibit VSMC proliferation and prevent neointimal formation in a rat carotid artery injury model. Vascular smooth muscle cell proliferation inhibition was analyzed with [³H]thymidine incorporation. Green tea catechins were applied to the endothelium-denuded carotid arteries of rats for 20min. Angiography and morphometric analysis was performed after 2 weeks. Green tea catechins decreased [³H]thymidine incorporation stimulated with PDGF-BB dose dependently. In the absence of PDGF-BB, the decrement of [³H]thymidine incorporation was evident above a concentration of 10µg/ml of GTC. Carotid arteriographic evaluation showed that the minimum luminal diameter in the GTC-treated group (n = 12) was 5.9 ± 1.6 arbitrary units (a.u.) and was significantly larger than in the control group (4.3 ± 1.4 a.u., n = 10) (P < 0.05). The GTC-treated group also showed a significant reduction in neointimal formation compared with the control group (0.29 ± 0.11 vs 0.42 ± 0.10mm², P < 0.05). To identify the active ingredients, we performed a similar experiment using EGCG. The effects of EGCG were similar to those of GTC. Green tea catechins effectively inhibited VSMC proliferation. Neointimal formation was prevented in the rat carotid artery injury model by local delivery of GTC. As EGCG showed similar effects, it may be one of the major constituents of GTC having these effects.