抗血小板药物与阻断CD40信号对动脉粥样硬化的影响

目的探讨抗血小板药物、抗CD40L(CD40配体)抗体及合用对动脉粥样硬化的影响.方法雄性载脂蛋白E基因敲除小鼠随机分为模型对照组(n=10)、抗血小板药物组(n=10,阿司匹林 氯吡格雷)、抗CD40L抗体组(n=8,抗CD40L抗体)、合用组(n=9,阿司匹林 氯吡格雷 抗CD40L抗体).并取与载脂蛋白E基因敲除小鼠有相同遗传背景的健康雄性近交系C57BL/6小鼠6只作为正常对照组.测血脂、可溶性血管细胞黏附分子-1(sVCAM-1)和可溶性细胞间黏附分子-1(sICAM-1)浓度.观察主动脉组织病理形态学改变,免疫组织化学法测定斑块部位巨噬细胞、平滑肌细胞百分率.Western杂交分析测定基质金属蛋白酶-9的蛋白表达.结果抗血小板药物及抗CD40L抗体治疗可明显降低sVCAM-1和sICAM-1浓度(P＜0.01),减轻动脉粥样硬化病变,减少斑块部位巨噬细胞,增加平滑肌细胞数量(P＜0.01),对血脂无影响(P＞0.05),合用则作用增强(P＜0.05).抗CD40L抗体可降低基质金属蛋白酶-9的表达(P＜0.01),抗血小板治疗无此作用.结论抗血小板治疗及阻断CD40信号可抑制炎症反应,减轻动脉粥样硬化病变,稳定斑块,对血脂无影响,联合治疗有协同作用.     

抗血小板药物抑制动脉粥样硬化进展及机制研究

目的:观察阿司匹林和氯吡格雷对动脉粥样硬化病变进展的影响,并探讨抗血小板治疗抑制CD40CD40配体(CD40L)系统的作用。方法:8周龄雄性载脂蛋白E基因敲除小鼠随机分为模型组(n=10)、阿司匹林组(n=10)、氯吡格雷组(n=10)、抗血小板药物合用组(n=10)和抗CD40L抗体组(n=8)。另取与载脂蛋白E基因敲除小鼠有相同遗传背景的健康雄性近交系C57BL/6小鼠6只作为正常对照组。检测炎性指标及血小板表达CD40L的水平,观察主动脉组织病理形态学改变,免疫组织化学法测定斑块部位巨噬细胞、平滑肌细胞、CD4+T细胞与CD40L表达的百分率。结果:阿司匹林和氯吡格雷可抑制血小板表达CD40L,降低可溶性CD40L、可溶性血管细胞黏附分子1和可溶性细胞间粘附分子1浓度,减轻动脉粥样硬化病变,减少斑块部位巨噬细胞、CD4+T细胞和CD40L的表达,增加平滑肌细胞数量(P<0.05);对可溶性CD40L和血小板CD40L表达的抑制作用,氯吡格雷强于阿司匹林(P<0.05),其他方面两药无显著差异(P>0.05)。联合用药,作用叠加(P<0.01～0.05),对斑块的影响相当于抗CD40L抗体的疗效(P>0.05)。结论:阿司匹林和氯吡格雷可通过抑制CD40CD40L系统,抑制炎症反应,减轻动脉粥样硬化病变,稳定斑块,两药联用,作用更强。     

阻断CD40-CD40配体系统对动脉粥样硬化的影响

目的探讨阻断CD40-CD40配体系统对动脉粥样硬化的影响。方法18只载脂蛋白E基因敲除小鼠随机分为阳性对照组(n=10)和抗CD40配体抗体组(n=8),并以近交系C57BL/6小鼠作为正常对照。测定血脂、可溶性血管细胞粘附分子1和可溶性细胞间粘附分子1浓度。观察主动脉组织病理形态学改变,免疫组织化学法测定斑块部位巨噬细胞、平滑肌细胞和CD4 T细胞百分率。Western杂交分析测定基质金属蛋白酶9的蛋白表达。结果抗CD40配体抗体治疗可明显降低可溶性血管细胞粘附分子1和可溶性细胞间粘附分子1浓度(P<0.01),对血脂无明显影响(P>0.05);可减轻动脉粥样硬化病变,减少斑块部位巨噬细胞和CD4 T细胞,增加平滑肌细胞数量(P<0.05),降低基质金属蛋白酶9的表达(P<0.01)。结论阻断CD40-CD40配体系统可使血清可溶性粘附分子浓度下降,抑制炎症反应,从而减轻动脉粥样硬化病变,对血脂无影响。     

氯吡格雷对实验性动脉粥样硬化形成的影响

目的:观察抗血小板药物氯吡格雷对实验性动脉粥样硬化形成的影响.方法:29只雄性日本大耳白兔分为正常组(n=9)、模型组(n=10)和氯吡格雷组[4 mg/(kg·d),n=10].后两组建立高胆固醇饲料并免疫损伤诱发的主动脉粥样硬化模型.测血脂和血清C-反应蛋白(CRP)浓度.观察主动脉组织病理形态学改变并定量分析病变程度,免疫组化法测定斑块部位的巨噬细胞和平滑肌细胞阳性细胞百分数.结果:与模型组相比,氯吡格雷组的主动脉斑块面积/内膜面积减少27.52%,内膜厚度和内膜厚度/中膜厚度分别减少54.52%和50.98%,斑块中巨噬细胞百分数从(57.50±8.40)%减至(40.93±7.08)%,平滑肌细胞百分数从(37.28±3.35)%增至(53.16±6.96)%,血清CRP浓度从(267.86±49.89)ng/ml降至(189.82±77.02)ng/ml,均有显著性差异(P＜0.05～0.01).结论:氯吡格雷能够减轻动脉炎症反应,抑制动脉粥样硬化的形成.     

普萘洛尔对大鼠动脉粥样硬化斑块内基质金属蛋白酶-9(MMP-9)及金属蛋白酶组织抑制剂-1(TIMP-1)表达的影响

目的 研究普萘洛尔对大鼠动脉粥样硬化斑块内基质金属蛋白酶-9(MMP-9)及金属蛋白酶组织抑制剂-1(TIMP-1)表达的影响,探讨β-受体阻滞剂稳定动脉粥样硬化斑块的机制.方法 30只Wistar大鼠经高脂、高维生素D、免疫损伤处理17 w造成动脉粥样硬化模型后,随机分为对照组和普萘洛尔组,每组15只.所有大鼠在继续高脂喂养基础上,普萘洛组予普萘洛尔5 mg·kg-1·d-1灌胃;对照组予生理盐水1 ml/d灌胃.分组处理1 w后处死全部大鼠,取主动脉粥样斑块用免疫组织化学方法检测动脉粥样硬化斑块内CD68巨噬细胞浸润、MMP-9及TIMP-1表达.结果 普萘洛尔组巨噬细胞浸润数目及MMP-9的表达较对照组明显减少(P<0.01),TIMP1表达明显增高(P<0.05).结论 普萘洛尔可减少大鼠动脉粥样硬化斑块处巨噬细胞浸润及MMP-9的表达,增高斑块处TIMP-1表达,具有稳定动脉粥样硬化斑块的作用.     

脉心康对载脂蛋白E基因敲除小鼠主动脉核因子κB和基质金属蛋白酶9表达的调控

目的观察脉心康对载脂蛋白E基因敲除小鼠主动脉核因子κB、基质金属蛋白酶9mRNA表达水平的调控作用。方法6周龄载脂蛋白E基因敲除小鼠,随机分为高脂血症组(模型组)、洛伐他汀组及脉心康组,相同遗传背景的同龄正常C57BL6J小鼠为正常对照组。原位杂交观察各组主动脉核因子κB和基质金属蛋白酶9mRNA表达的强度。结果各给药组与模型组比较,核因子κBmRNA、基质金属蛋白酶9mRNA阳性细胞表达率均明显降低(P<0.01)。光镜下发现正常对照组主动脉壁内皮细胞、平滑肌细胞胞质内核因子κBmRNA、基质金属蛋白酶9mRNA阳性表达细胞极少见;模型组主动脉壁内皮细胞、平滑肌细胞胞质内阳性表达的棕褐色颗粒较多见,且棕褐色颗粒染色均较深;脉心康组主动脉壁可见内皮细胞、平滑肌细胞胞质内阳性表达的棕褐色颗粒,但远较模型组少,棕褐色颗粒染色深浅较均匀。结论脉心康可降低载脂蛋白E基因敲除小鼠主动脉核因子κB、基质金属蛋白酶9mRNA表达,发挥抗动脉粥样硬化、稳定斑块的作用。     

血管紧张素Ⅱ对载脂蛋白E敲除小鼠主动脉粥样硬化斑块细胞外基质金属蛋白酶诱导因子表达影响

目的探讨血管紧张素Ⅱ对载脂蛋白E敲除小鼠主动脉粥样硬化斑块细胞外基质金属蛋白酶诱导因子表达的影响。方法载脂蛋白E基因敲除小鼠经高脂饮食饲养建立动脉粥样硬化模型,用血管紧张素Ⅱ干预。用免疫组织化学法观察粥样硬化斑块内细胞外基质金属蛋白酶诱导因子表达,用RT-PCR及Western blotting检测主动脉内细胞外基质金属蛋白酶诱导因子表达。结果血管紧张素Ⅱ干预组细胞外基质金属蛋白酶诱导因子在动脉粥样硬化斑块内阳性表达较对照组明显增加;血管紧张素Ⅱ干预组主动脉内细胞外基质金属蛋白酶诱导因子mRNA及蛋白表达较对照组明显增加。结论血管紧张素Ⅱ能诱导主动脉粥样硬化斑块内细胞外基质金属蛋白酶诱导因子的表达。     

南蛇藤素对载脂蛋白E基因敲除小鼠斑块内胶原、巨噬细胞移动抑制因子和基质金属蛋白酶9表达的影响

目的观察南蛇藤素对载脂蛋白E基因敲除小鼠斑块中胶原、巨噬细胞移动抑制因子和基质金属蛋白酶9表达的影响。方法8周龄雄性载脂蛋白基因敲除小鼠12只,随机分为南蛇藤素干预组和动脉粥样硬化模型组,每组各6只,同龄的雄性C57BL/6J小鼠6只作为正常对照,各组均给以高脂饮食饲养8周,在高脂饲养的后4周,分别予以南蛇藤素和相当剂量的溶剂二甲基亚砜腹腔注射,每日1次,连续用药4周;处死后行主动脉连续石蜡切片、HE染色观察组织形态学改变,苦味酸-天狼星红染色检测斑块内胶原含量,免疫组织化学方法观察主动脉斑块内巨噬细胞移动抑制因子和基质金属蛋白酶9蛋白表达的强度。结果模型组形成了早期斑块,南蛇藤素组斑块面积较模型组明显减小,分别为4270.74±1027.64μm2和8971.19±1665.76μm2(P<0.01),南蛇藤素组斑块内胶原含量显著高于模型组(平均光密度分别为0.0275±0.0068和0.0142±0.0054,P<0.01);南蛇藤素组与模型组比较斑块内基质金属蛋白酶9表达明显降低(平均光密度分别为0.0054±0.0020和0.0263±0.0080,P<0.001),巨噬细胞移动抑制因子的表达也明显降低(平均光密度分别为0.0114±0.0016和0.0227±0.0039,P<0.001)。结论南蛇藤素可能通过下调载脂蛋白E基因敲除小鼠斑块内基质金属蛋白酶9和巨噬细胞移动抑制因子表达,抑制胶原的降解进而发挥抗动脉粥样硬化及稳定斑块作用。     

普萘洛尔对大鼠动脉粥样硬化斑块内MMP-9及TIMP-1表达的影响

目的探讨普萘洛尔对大鼠动脉粥样硬化斑块内基质金属蛋白酶-9(MMP-9)及金属蛋白酶组织抑制剂-1(TIMP-1)表达的影响。方法30只Wistar大鼠经高脂、高维生素D、免疫损伤处理17周造成动脉粥样硬化模型,随机分为对照组和普萘洛尔组,每组15只。所有大鼠在继续高脂喂养基础上,普萘洛组予普萘洛尔5mg/(kg.d)灌胃;对照组予生理盐水1ml/d灌胃,一周后处死全部大鼠,取主动脉粥样硬化斑块用免疫组织化学方法检测动脉粥样硬化斑块内巨噬细胞浸润、MMP-9及TIMP-1表达。结果普萘洛尔组巨噬细胞浸润数目及MMP-9的表达较对照组明显减少(P0.01),TIMP-1表达明显增高(P0.05)。结论普萘洛尔减少大鼠动脉粥样硬化斑块处巨噬细胞浸润及MMP-9表达,增加TIMP-1表达,具有稳定动脉粥样硬化斑块作用。     

血栓素受体拮抗剂S18 886对ApoE-/-小鼠动脉粥样硬化的影响

目的了解血栓素受体拮抗剂S18886对ApeE-/-小鼠颈总动脉粥样硬化斑块炎细胞浸润和形态学的影响。方法制作不破坏内弹力板的环包颈总脉模型,分别每天灌喂S188865mg/kg·b.w.、氯吡格雷25mg/kg·b.w.和空白水6周。结果应用S18886药物小鼠的右颈总动脉内膜损伤面积明显被抑制,内膜/中膜比值小于对照组和氯吡格雷组(P<0.05);内膜/总血管壁面积比值也明显低于对照组和氯吡格雷组(P<0.05);S18886组小鼠斑块部位细胞间粘连分子-1(ICAM-1)水平和巨噬细胞的浸润明显降低;对照组动脉斑块内的α-平滑肌肌动蛋白显著减低,S18886和氯吡格雷组斑块内的α-平滑肌肌动蛋白明显减低。结论血栓素受体拮抗剂S18886通过减低ICAM-1,抑制斑块部位的炎细胞浸润,回缩并稳定动脉粥样硬化斑块。     

阿托伐他汀对兔动脉粥样硬化斑块近心端基质金属蛋白酶9表达的影响

目的 研究阿托伐他汀对兔主动脉粥样硬化斑块近心端基质金属蛋白酶9（MMP-9）表达的影响。方法 将30只雄性新西兰大白兔随机分为正常对照组（9只）、高脂饮食组（11只）、阿托伐他汀组（10只）。后两组给予高胆固醇饲料建立主动脉粥样硬化模型，至第9周始，高脂饮食组同时服用1．5mg·kg^-1·d^-1淀粉，阿托伐他汀组服用阿托伐他汀1．5mg·kg^-1·d^-1。处死兔后，对主动脉大体标本进行观察，发现内膜增生合并粥样斑块形成者视为模型建立成功。应用免疫组化法测定斑块近心端的巨噬细胞和平滑肌细胞阳性面积百分率以及MMP-9的表达。结果 ①高脂饮食组和阿托伐他汀组主动脉可见新生内膜形成，内一中膜厚度比值分别为1．41±0．34、0．63±0．12。②斑块中巨噬细胞分布部位正是MMP-9阳性表达区域，均聚集于斑块近心端。高脂饮食组和阿托伐他汀组主动脉斑块近心端巨噬细胞阳性面积百分比分别为（26．5±4．3）％、（12．4±1．5）％，MMP-9吸光度（A值）分别为0．081±0．014、0．022±0．004，两组比较差异均有统计学意义（P〈0．01）。③高脂饮食组与阿托伐他汀组平滑肌细胞阳性面积百分比分别为（47．2±12．3）％、（50．4±10．8）％，差异无统计学意义（P〉0．05）。结论 动脉粥样硬化斑块内巨噬细胞及MMP-9表达主要位于主动脉粥样硬化斑块近心端，阿托伐他汀能显著减少此区域巨噬细胞聚集及MMP-9的表达。     

米诺环素抗兔动脉粥样硬化作用及机制

目的 观察米诺环素对动脉粥样硬化斑块干预治疗后基质金属蛋白酶的分子病理学改变,评价该药对动脉粥样硬化的治疗效果,并分析其作用机制.方法 40只新西兰兔,随机取5只设为正常对照组.另35只建立动脉粥样硬化斑块兔模型(经腹主动脉使用兔气囊致动脉去上皮化损伤,并连续用高脂饲料喂养3个月)后,除在实验过程死亡或患病5只兔外,其余随机分4组,即动脉粥样硬化模型组(8只,继续高脂喂养1个月)、普食恢复组(7只,改用常规饲料喂养1个月)、氟伐他汀组[7只,给予氟伐他汀1mg/(kg·d)连续干预治疗1个月]和米诺环素组[8只,连续给予米诺环素3mg/(kg·d)治疗1个月].各组动物分别麻醉后处死并切取腹主动脉,按常规石蜡包埋切片,以Masson染色法观察动脉粥样硬化斑块病理形态学变化,免疫组织化学法检测动脉粥样硬化斑块内炎症细胞及基质金属蛋白酶表达水平,原位杂交Tunel染色法检测细胞凋亡.结果 动脉管壁组织经Masson染色观察显示,正常对照组未见异常病理变化,模型组和普食恢复组均呈现典型动脉粥样硬化病变特征,而米诺环素和氟伐他汀两治疗组病变明显减轻,尤以前者改善突出.各组动脉粥样硬化斑块巨噬细胞含量及基质金属蛋白酶3和9的表达水平与病变程度相一致,前三者间在各组动物中的表达水平均呈正相关关系(P<0.001).斑块内巨噬细胞含量、基质金属蛋白酶3和9的水平在米诺环素组均显著低于模型组和普食恢复组(P<0.05),且在米诺环素组可见平滑肌细胞明显增加.结论 米诺环素具有改善动脉粥样硬化病变程度和稳定动脉粥样硬化斑块的作用.     

Aspirin, but not clopidogrel, reduces collateral conductance in a rabbit model of femoral artery occlusion.

OBJECTIVES: The objective of this study was to test the potential of aspirin and clopidogrel to influence collateral artery growth (arteriogenesis). BACKGROUND: Aspirin and clopidogrel are antiplatelet agents commonly used in the treatment of ischemic cardiovascular disease. Both inhibit platelet aggregation; however, they differ mechanistically because aspirin acts via cyclooxygenase (COX) inhibition, while clopidogrel noncompetitively antagonizes the P2Y12 adenosine diphosphate receptor. We hypothesized that aspirin, due to its anti-inflammatory effects through inhibition of COX activity could inhibit arteriogenesis. Given that clopidogrel does not affect COX activity, it would be less likely to interfere with collateral artery growth. METHODS: Fifty-four New Zealand White rabbits received either saline, aspirin (10 mg/kg), or clopidogrel (10 mg/kg) for seven days after femoral artery ligation. Maximal collateral conductance was assessed with fluorescent microspheres under maximal vasodilation; cellular migration and proliferation (Ki-67) was evaluated by quantitative immunohistology. RESULTS: Collateral conductance was significantly reduced by aspirin treatment, whereas clopidogrel had a neutral effect (saline: 0.94 +/- 0.04; clopidogrel: 0.94 +/- 0.05; aspirin: 0.64 +/- 0.03 ml x min(-1) x 100 mm Hg(-1) x g(-1); p < 0.001). Ki-67 proliferation indexes were consistent with these results (saline: 23.1 +/- 2.9%; clopidogrel: 23.5 +/- 1.1%; aspirin: 19.2 +/- 1.1% Ki-67-positive cells). Immunohistochemistry showed COX expression in collateral arteries and a significantly decreased monocyte/macrophage accumulation in the perivascular tissue after aspirin treatment. Cell adhesion molecule expression on monocytes after activation was significantly reduced by aspirin, which might explain the reduced migratory ability. CONCLUSIONS: In summary, clopidogrel had a neutral effect on natural arteriogenesis. Aspirin significantly inhibited collateral artery growth, probably due to its anti-inflammatory effect. Additional studies are needed to substantiate these results before translation into clinical practice.     

S18886, a selective TP receptor antagonist, inhibits development of atherosclerosis in rabbits

OBJECTIVE: To investigate the effect of S18886, a novel TP (thromboxane A2 and prostaglandin endoperoxide) receptor antagonist, on the development of aortic fatty streaks and advanced lesions in a rabbit model of atherosclerosis and restenosis. METHODS AND RESULTS: The right iliac artery of 96 rabbits (8 groups, n=12/group) was balloon injured, then the animals were fed a cholesterol-enriched diet for 6 weeks. In Groups 1-4, concomitant oral administration of S18886 at 5 mg/kg/day over the 6-week-period reduced the intima to media ratio of lesions in the uninjured aorta and injured iliac artery, the accumulation of macrophages and the expression of ICAM-1 compared with 1 mg/kg/day S18886, 30 mg/kg/day aspirin and placebo, with no effect on body weight or plasma cholesterol levels. In Groups 5-8, 2 weeks of treatment with 5 mg/kg/day S18886 reduced the intima to media ratio of restenosing lesions when pre-formed iliac artery lesions underwent a second balloon injury at week 6. The smaller lesions resulting from S18886 treatment correlated with a significant decrease in the neointimal area occupied by macrophages, as well as in ICAM-1 expression, with no effect on the smooth muscle component. Aspirin treatment had no significant effect on the neointimal smooth muscle component, but partially inhibited macrophage infiltration, without inhibiting ICAM-1 expression. CONCLUSION: Inhibition of the TP receptor using S18886 causes a significant decrease in the recruitment of monocyte/macrophages within fatty streaks in the uninjured aorta and within primary and restenosing atherosclerotic lesions in the iliac artery of rabbits. Since TP receptor agonists, such as thromboxane A2, prostanoid endoperoxides and isoprostanes participate in vessel wall inflammation and are localized and increased in atherosclerotic plaques, treatment with S18886 may enhance atherosclerotic lesion stability by attenuating inflammatory processes that ultimately lead to plaque rupture.     

血管紧张素转化酶2基因转染对实验性动脉硬化兔斑块炎症的影响

目的 探讨血管紧张素转化酶2(ACE2)基因转染是否能通过使血管紧张素(Ans)Ⅱ转化为Ang1-7而抑制动脉硬化斑块的炎症反应.方法 克隆小鼠ACE2基因,并构建复制缺陷重组腺病毒质粒Ad-ACE2;用球囊损伤内皮细胞及高脂饲养建立兔动脉硬化模型,喂养3个月,将38只新西兰大白兔随机分为Ad-ACE2及Ad-EGFP两组,每组19只.Ad-ACE2组注射ACE2的腺病毒(2.5×109pfu/m1)入兔的腹主动脉中,Ad-EGFP组注射Ad-EGFP,注射1个月后处死动物,取腹主动脉,检测巨噬细胞和单核细胞趋化因子(MCP-1)蛋白的表达;同时应用实时定量PCR检测MCP-1基因的表达.结果 Ad-ACE2组的动脉硬化斑块中的巨噬细胞阳性表达率(13.6%±4.2%)明显低于Ad-EGFP组(23.6%±6.9%,P<0.01);而基因转染后MCP-1蛋白的表达(13.2%±0.4%)明显低于Ad-EGFP组(25.0%±7.4%,P<0.01).结论 ACE2基因转染抑制了MCP-1的蛋白表达及巨噬细胞浸润程度,提示ACE2基因具有抑制动脉粥样硬化斑块炎症的作用.     

Aspirin inhibits ox-LDL-mediated LOX-1 expression and metalloproteinase-1 in human coronary endothelial cells

BACKGROUND: Aspirin is thought to exert salutary effects in vascular disease states by inhibiting platelet aggregation. Endothelial activation, accumulation of oxidized low-density lipoprotein (ox-LDL) and intense inflammation also characterize atherosclerotic plaque in acute myocardial ischemia. Ox-LDL induces expression of lectin-like receptors (LOX-1) on endothelial cells and leads to the expression of matrix metalloproteinases (MMPs), which destabilize the atherosclerotic plaque. We hypothesized that aspirin may interfere with LOX-1 expression and subsequent MMP activation. METHODS AND RESULTS: Cultured human coronary artery endothelial cells (HCAECs) were incubated with aspirin (1-5 mM), sodium salicylate (5 mM) or the cyclo-oxygenase inhibitor indomethacin (0.25 mM) before treatment with ox-LDL. Aspirin, in a dose- and time-dependent fashion, reduced ox-LDL-mediated LOX-1 expression (P<0.01). Ox-LDL also increased MMP-1 expression and activity, and treatment of HCAECs with aspirin decreased this effect (P<0.01). Ox-LDL also enhanced the activity of p38MAPK in HCAECs, and aspirin blocked this effect of ox-LDL (P<0.01). Treatment of HCAECs with salicylate, but not indomethacin, resulted in a suppression of LOX-1 expression, an effect similar to that of aspirin. Importantly, both aspirin and salicylate, but not indomethacin, decreased superoxide anion generation in ox-LDL-treated HCAECs (P<0.05). CONCLUSION: These observations suggest that aspirin inhibits ox-LDL-mediated LOX-1 expression and interferes with the effects of ox-LDL in intracellular signaling (p38MAPK activation) and subsequent MMP-1 activity. These novel effects of aspirin may complement its platelet inhibitory effect in acute myocardial ischemia.     

氟伐他汀对家兔颈动脉粥样斑块巨噬细胞和基质金属蛋白酶的影响

目的观察高胆固醇血症家兔颈动脉粥样斑块内炎性巨噬细胞与MMP-2、MMP-9的表达情况，并研究氟伐他汀干预对巨噬细胞聚集和基质金属蛋白酶（MMPs）表达的影响，探索他汀类药物在稳定颈动脉斑块中的作用及机制。方法24只家兔随机分为对照组、高脂组和治疗组，每组8只，分别给予普通饲料、高脂饲料和高脂饲料加氟伐他汀喂养，测定不同时间点血清总胆固醇（TC）、三酰甘油（TG）、低密度脂蛋白胆固醇（LDL-C）和高密度脂蛋白胆固醇（HDL-C）水平。喂养第12月时处死动物，取颈动脉进行石蜡切片，测量并计算颈动脉I／M比值，SP法进行CD68、MMP-2和MMP-9免疫组织化学染色。结果治疗组血清TC、LDL-C浓度明显低于高脂组（P〈0．01）。治疗组I／M比值明显低于高脂组（P〈0．01）。高脂组颈动脉斑块中见大量CD68阳性细胞，而治疗组CD68阳性细胞数显著少于高脂组（P〈0．01）。颈动脉斑块中MMP-2、MMP-9阳性细胞和染色强度明显增加，治疗组MMP-2和MMP-9的表达较高脂组显著减少（P=0．002和P=0．016）。结论氟伐他汀治疗可以抑制高胆固醇血症家兔颈动脉粥样斑块的形成．减轻斑块内巨噬细胞的浸润并抑制MMP-2和MMP-9的产生，从而起到稳定斑块的作用。     

Divergent effects of matrix metalloproteinases 3, 7, 9, and 12 on atherosclerotic plaque stability in mouse brachiocephalic arteries

Matrix metalloproteinases (MMPs) are thought to be involved in the growth, destabilization, and eventual rupture of atherosclerotic lesions. Using the mouse brachiocephalic artery model of plaque instability, we compared apolipoprotein E (apoE)/MMP-3, apoE/MMP-7, apoE/MMP-9, and apoE/MMP-12 double knockouts with their age-, strain-, and sex-matched apoE single knockout controls. Brachiocephalic artery plaques were significantly larger in apoE/MMP-3 and apoE/MMP-9 double knockouts than in controls. The number of buried fibrous layers was also significantly higher in the double knockouts, and both knockouts exhibited cellular compositional changes indicative of an unstable plaque phenotype. Conversely, lesion size and buried fibrous layers were reduced in apoE/MMP-12 double knockouts compared with controls, and double knockouts had increased smooth muscle cell and reduced macrophage content in the plaque, indicative of a stable plaque phenotype. ApoE/MMP-7 double knockout plaques contained significantly more smooth muscle cells than controls, but neither lesion size nor features of stability were altered in these animals. Hence, MMP-3 and MMP-9 appear normally to play protective roles, limiting plaque growth and promoting a stable plaque phenotype. MMP-12 supports lesion expansion and destabilization. MMP-7 has no effect on plaque growth or stability, although it is associated with reduced smooth muscle cell content in plaques. These data demonstrate that MMPs are directly involved in atherosclerotic plaque destabilization and clearly show that members of the MMP family have widely differing effects on atherogenesis.     

An HMG-CoA reductase inhibitor, cerivastatin, suppresses growth of macrophages expressing matrix metalloproteinases and tissue factor in vivo and in vitro

BACKGROUND: Unstable atherosclerotic plaques that cause acute coronary events usually contain abundant macrophages expressing matrix metalloproteinases (MMPs) and tissue factor (TF), molecules that probably contribute to plaque rupture and subsequent thrombus formation. Lipid lowering with HMG-CoA reductase inhibitors reduces acute coronary events. METHODS AND RESULTS: To test whether lipid lowering with an HMG-CoA reductase inhibitor retards macrophage accumulation in rabbit atheroma, we administered cerivastatin to immature Watanabe heritable hyperlipidemic rabbits (cerivastatin group, n=10, cerivastatin 0.6 mg x kg(-1) x d(-1); control group, n=9, saline 0.6 mL x kg(-1) x d(-1)) for 32 weeks and measured macrophage accumulation and expression of MMPs and TF. Serum cholesterol levels after 32 weeks were 809+/-40 mg/dL (control group) and 481+/-24 mg/dL (treated group). Cerivastatin diminished accumulation of macrophages in aortic atheroma. Macrophage expression of MMP-1, MMP-3, MMP-9, and TF also decreased with cerivastatin treatment. Cerivastatin reduced the number of macrophages expressing histone mRNA (a sensitive marker of cell proliferation) detected by in situ hybridization but did not alter macrophages bearing a marker of death (TUNEL staining). Cerivastatin treatment (>or=0.01 micromol/L) also reduced growth, proteolytic activity due to MMP-9, and TF expression in cultured human monocyte/macrophages. CONCLUSIONS: These results suggest that lipid lowering with HMG-CoA reductase inhibitors alters plaque biology by reducing proliferation and activation of macrophages, prominent sources of molecules responsible for plaque instability and thrombogenicity.