COPD大鼠模型气道MMP-9和TIMP-1表达的研究

目的:探讨基质金属蛋白酶-9(MMP-9)及组织金属蛋白酶抑制因子-1(TIMP-1)在慢性阻塞性肺疾病(COPD)大鼠模型气道的表达.方法:Wistar大鼠25只随机分为COPD模型组和正常对照组,采用单纯被动吸烟法建立COPD大鼠模型,以酶联免疫吸附法(ELISA)测定两组大鼠血清及支气管肺泡灌洗液(BALF)中MMP-9和TIMP-1的表达水平.结果:COPD组血清及BALF中MMP-9和TIMP-1的表达明显高于正常组(P＜0.05和P＜0.01);COPD组血清及BALF的MMP-9/TIMP-1低于正常组血清及BALF的MMP-9/TIMP-1,差异有统计学意义(P＜0.05);COPD组和正常组BALF中MMP-9和TIMP-1水平高于血清中MMP-9和TIMP-1水平,但差异无统计学意叉(P＞0.05).结论:MMP-9和TIMP-1平衡失调参与了COPD的发病,调节MMP-9和TIMP-1的平衡可能是治疗COPD的新方法.     

肺结核并发纤维化患者BALF和血清MMP及TIMP-1检测的临床意义

目的:探讨肺结核并发纤维化患者支气管肺泡灌洗液(BALF)及血清中基质金属蛋白9(MMP-9)及基质金属蛋白酶组织抑制剂l(TIMP-1)含量与肺纤维化及肺功能的关系.方法:酶联免疫(ELISA)法检测我院2009年3月至2009年9月68例肺结核并发纤维化患者(纤维化组)及30例无肺部疾病患者(对照组)的支气管肺泡灌洗液及血清中MMP-9及TIMP-1的含量,同时进行肺功能检查.结果:纤维化组患者的BALF及血清MMP-9的含量与对照组怠者相比无统计学意义,但纤维化组患者的BALF及血清TIMP-1的含量显著高于对照组(P＜0.05),且纤雏化组患者的BALF及血清MMP-9/TIMP-1比值低于对照组(P＜0.05).患者的动脉血氧分压、肺活量等肺功能指标与TIMP-1呈正相关,而与MMP-9/TIMP-1比值呈负相关(P＜0.05).结论:肺结核患者肺纤维化的发生可能与TIMP-1水平升高及MMP-9/TIMP-1比值降低相关,降低TIMP-9的水平可能是防止肺结核惠者并发肺纤维化的一种新途径.     

组织蛋白酶S与ApoE-/-小鼠动脉粥样硬化的实验研究

目的:观察组织蛋白酶S(Cathepsin S)在不同周龄我脂蛋白E基因缺陷(ApoE-/-)小鼠主动脉的表达,初步探讨Cathepsin S对ApoE-/-小鼠动脉粥样硬化(As)病变的影响.方法:将16只8周龄ApoE-/-小鼠随机分为两组:16周龄组(n=8),24周龄组(n=8),均饲以高脂饮食,分别在16周龄和24周龄处死动物.采用普通光镜、病理图象分析法测定主动脉As斑块面积及管腔面积;免疫组织化学染色方法观察组织蛋白酶S(Cathepsin S)在不同周龄ApoE-/-小鼠主动脉的表达.结果:16周龄组ApoE-/-小鼠主动脉根部出现As病变;与16周龄组ApoE-/-小鼠相比,24周龄组ApoE-/-小鼠主动脉根部As病变显著增强(P＜0.01),免疫组化显示Cathepsin S表达明显增加(P＜0.01).结论:Cathepsin S在ApoE-/-小鼠主动脉的表达随As病变程度增强而显著增加.     

中药乙肝散逆转肝纤维化过程中肝组织TIMP-1及MMP-2表达变化的实验研究

目的探讨中药乙肝散逆转免疫性肝纤维化过程中肝组织TIMP-1(金属蛋白酶组织抑制因子-1) 及MMP-2(间质金属蛋白酶-2)表达的变化.方法雄性Wistar大鼠尾静脉注射白蛋白建立免疫损伤性肝纤维化模型后,分组加用不同浓度的乙肝散颗粒饲料喂养12周,流式细胞仪定量分析大鼠肝组织TIMP-1和MMP-2基因表达量,观察大鼠肝组织病理、苦味酸-天狼红染色、Ⅳ胶原免疫组化、α-SMA(α平滑肌肌动蛋白)免疫组化、肝匀浆Hyp(羟脯氨酸).结果乙肝散应用组肝组织TIMP-1表达量较模型对照组明显降低(P<0.01),MMP-2变化无统计学差异;同时肝组织Ⅰ胶原、Ⅲ胶原、Ⅳ胶原水平和Hyp含量明显降低(P<0.01或P<0.05).结论中药乙肝散在逆转肝纤维化过程中对抑制肝组织TIMP-1基因表达具有一定作用,TIMP-1在肝纤维化的逆转中起重要作用.     

七味育肝颗粒对肝纤维化大鼠的防治作用*

目的: 探讨七味育肝颗粒对肝纤维化大鼠的防治作用及对基质金属蛋白酶-13(MMP-13)/基质金属蛋白酶抑制因子-1(TIMP-1)失衡的影响。方法: 取大鼠随机分为空白对照组、模型对照组、秋水仙碱组(1.0×10^-4 g/kg)、七味育肝颗粒各干预组(3.7、7.4、14.8 g/kg)组(n=8),采用皮下注射四氯化碳、灌胃乙醇6周来复制肝纤维化动物模型,造模的同时给药组每天灌胃给药,观测七味育肝颗粒对大鼠肝功能、肝组织病理学及肝纤维化相关指标的影响,采用免疫组化法测定肝组织MMP-13、TIMP-1的表达水平。结果: 与空白对照组比较,模型对照组大鼠血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)以及肝组织透明质酸(HA)、Ⅲ型前胶原(PCⅢ)、Ⅳ型胶原(C-Ⅳ)、TIMP-1显著升高,而MMP-13显著下降,缓解肝组织纤维化病理变化(P＜0.01);与模型对照组比较,3.7、7.4、14.8 g/kg七味育肝颗粒能明显降低ALT、AST以及HA、PCⅢ、C-Ⅳ,缓解肝组织纤维化病理变化,改善肝功能,提高MMP-13活性而降低TIMP-1活性,缓解MMP-13/TIMP-1的失衡状态(P＜0.05, P＜0.01),其中七味育肝颗粒对TIMP-1及MMP-13/TIMP-1的影响有一定的量效关系趋势(P＜0.01)。结论: 七味育肝颗粒具有防治肝纤维化的作用,而改善MMP-13/TIMP-1平衡状态可能是七味育肝颗粒防治肝纤维化作用的机制之一。     

MMP-3、TIMP-3在人胃癌组织中的表达及意义

目的:探讨MMP-3和TIMP-3在人胃癌组织中的表达及其意义.方法:根据胃癌的病理大体分型将40例胃癌组织分为早期组和晚期组.其中,早期组同时不伴有淋巴结转移,晚期组伴有淋巴结转移.采用光镜、透射电镜和免疫组化方法对这两组胃癌组织的超微结构,MMP-3,TIMP-3表达和MMP-3/TIMP-3的比值进行检测.结果:MMP-3和TIMP-3主要表达于癌细胞胞浆内.早期组MMP-3阳性表达细胞较少,晚期组阳性细胞较多,二者数密度和面密度比较,具有统计学意义(P＜0.01);早期组TIMP-3阳性表达细胞较多,晚期组阳性细胞较少,二者比较,具有统计学意义(P＜0.01)MMP-3/TIMP-3的比值在胃癌晚期较早期增大,具有统计学意义(P＜0.01);电镜观察显示胃癌早期淋巴细胞浸润较多,癌细胞穿基膜不明显,晚期则淋巴细胞浸润较少,癌细胞穿基膜明显.结论:MMP-3,TIMP-3的表达程度和MMP-3/TIMP-3的比值可作为判定胃癌的侵袭和转移的指标,对其预后的判断具有参考价值.     

MMP-3、TIMP-3在人胃癌组织中的表达及意义

目的:探讨MMP-3和TIMP-3在人胃癌组织中的表达及其意义.方法:根据胃癌的病理大体分型将40例胃癌组织分为早期组和晚期组.其中,早期组同时不伴有淋巴结转移,晚期组伴有淋巴结转移.采用光镜、透射电镜和免疫组化方法对这两组胃癌组织的超微结构,MMP-3,TIMP-3表达和MMP-3/TIMP-3的比值进行检测.结果:MMP-3和TIMP-3主要表达于癌细胞胞浆内.早期组MMP-3阳性表达细胞较少,晚期组阳性细胞较多,二者数密度和面密度比较,具有统计学意义(P＜0.01);早期组TIMP-3阳性表达细胞较多,晚期组阳性细胞较少,二者比较,具有统计学意义(P＜0.01)MM-3/TIMP-3的比值在胃癌晚期较早期增大,具有统计学意义(P＜0.01);电镜观察显示胃癌早期淋巴细胞浸润较多,癌细胞穿基膜不明显,晚期则淋巴细胞浸润较少,癌细胞穿基膜明显.结论:MMP-3,TIMP-3的表达程度和MMP-3/TIMP-3的比值可作为判定胃癌的侵袭和转移的指标,对其预后的判断具有参考价值.     

外源性雌、孕激素对裸鼠人子宫内膜异位症病灶中MMP-2、TIMP-2及VEGF蛋白表达的影响

目的:探讨雌、孕激素对异位内膜及MMP-2、TIMP-2、VEGF蛋白表达的影响.方法:将育龄妇女正常分泌晚期子宫内膜注入裸鼠盆腹腔,建立EMs裸鼠模型,随机分为四组,分别予雌激素(E)、孕激素(P)、雌激素+孕激素(E+P)及对照(C)组生理盐水肌肉注射.术后18天处死裸鼠,取异位组织,采用免疫组化方法(PV6001/6002法)检测各组异位内膜MMP-2、TIMP-2、VEGF蛋白表达水平,与种植前子宫内膜比较.结果:异位内膜较正常内膜MMP-2、VEGF蛋白表达增强,TIMP-2蛋白表达减弱(P均<0.01);E组、P组、E+P组MMP-2/TIMP-2比值及VEGF蛋白表达均高于C组(P均<0.01).E+P组同E组相比MMP-2/TIMP-2比值及VEGF蛋白表达无差别(P均>0.05).结论:异位内膜的侵袭性和血管新生能力增强,且对激素的反应不同于正常内膜.     

CXCL8对小鼠动脉粥样硬化发生发展的影响及其分子机制研究

目的:探讨趋化因子8(CXCL8)对小鼠动脉粥样硬化(AS)发生发展的影响及其可能机制。方法:40只雄性Apo E-/-小鼠随机分为AS组和CXCL8抑制剂(G31P)组,每组各20只,另选取20只雄性C57BL/6J小鼠作为对照组。AS组小鼠予高脂饲料喂养12周,G31P组小鼠予高脂饲料喂养12周的同时皮下注射G31P(注射剂量为500μg/kg),对照组的小鼠予普通饲料喂养12周。ELISA法检测小鼠血清中的甘油三脂(TG)、低密度脂蛋胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、总胆固醇(TC)水平,实时聚合酶链反应(RT-PCR)法检测小鼠主动脉组织中CXCL8及基质金属蛋白酶9(MMP9)mRNA的表达量,Western-blot法检测主动脉CXCL8及MMP9蛋白表达量。结果:高脂饮食喂养12周后,AS组小鼠血清中的TG、LDL-C、TC水平均高于G31P组,而HDL-C水平明显低于G31P组(P0.05);G31P组小鼠血清中的TG、LDL-C、TC水平均高于对照组,HDL-C水平低于对照组(P0.05)。AS组小鼠主动脉组织中的CXCL8、MMP9的m RNA表达量及蛋白表达量高于G31P组(P0.05),G31P组小鼠主动脉组织中的的CXCL8、MMP9的m RNA表达量及蛋白表达量高于对照组(P0.05)。结论:CXCL8在AS小鼠主动脉组织中呈高表达,CXCL8可能通过影响MMP9的表达在一定程度上参与了AS的发生发展,抑制CXCL8的表达或可延缓AS的发生发展。     

己酮可可碱对肺纤维化大鼠MMP-2和TIMP-1表达的影响

目的观察己酮可可碱(pentoxifylline, PTX)对博来霉素致肺纤维化大鼠肺组织基质金属蛋白酶2(matrix metalloproteinase-2)和基质金属蛋白酶组织抑制剂1(tissue inhibitor of matrix metalloproteinase-1)表达的影响,初步探讨其抗肺纤维化的作用机制.方法 SD大鼠36只,随机分为模型组、治疗组和对照组.模型组和治疗组气管内注射博来霉素诱导肺纤维化,对照组在相同条件下给予生理盐水.第二天起治疗组大鼠腹腔给予己酮可可碱6mg/kg.d,其余两组相同条件下给予生理盐水.治疗的第7d和28d,处死动物取出肺组织,用RT-PCR和免疫组化ABC法观察各组鼠肺组织MMP-2和TIMP-1表达的变化. 结果与模型组比较,治疗组经PTX作用的第7d和28d肺组织中MMP-2和TIMP-1 mRNA的基因转录均有减少,MMP-2 mRNA表达分别降低33.4%和35.5%(P＜0.001),TIMP-1 mRNA表达分别降低25.3%和33.0%(P＜0.05).免疫组化结果则显示,PTX作用的第7d和28dMMP-2分别较模型组降低30.7%和41.7%(P＜0.05),TIMP-1分别降低13.1%和19.8%(P＜0.05).结论 PTX对肺纤维化不同时期肺组织中MMP-2和TIMP-1的表达均有一定程度的降低作用,其可能通过调整MMP-2和TIMP-1比值使其趋于平衡,从而延缓甚至抑制纤维化的进程.     

Aliskiren单用及联用氟伐他汀对动脉粥样硬化斑块稳定性的影响

目的:观察和比较肾素抑制剂aliskiren单用或与氟伐他汀(fluvastatin)联用对动脉粥样硬化斑块稳定性的影响。方法:选择4周龄雄性ApoE-/-小鼠通过喂以高脂饮食8周建立动脉粥样硬化模型,将其随机分为5组:模型对照组、aliskiren组、肼屈嗪组、氟伐他汀组、aliskiren与氟伐他汀联合用药组,所有组别均治疗12周。取主动脉根部组织评估斑块面积(HE染色)、斑块内新生血管数量(CD31染色)及斑块稳定性指标(胶原蛋白染色、弹力纤维染色、Mac-3染色、MCP-1染色)。结果:与模型对照组比较,aliskiren单用显著降低动脉粥样硬化斑块面积,减少斑块内新生血管数量以及巨噬细胞浸润、炎症因子表达,增加斑块内弹力纤维及胶原蛋白含量(P0.05或P0.01)。与aliskiren单用组比较,aliskiren与氟伐他汀联用进一步降低斑块面积,改善斑块的稳定性(P0.05或P0.01)。与aliskiren组比较,肼屈嗪组降压幅度相似(P0.05)。与模型对照组比较,肼屈嗪没有明显抑制斑块进展以及改善斑块的稳定性(P0.05)。结论:Aliskiren能够抑制动脉粥样硬化斑块的进展,减少斑块内新生血管形成,改善斑块的稳定性,而其与氟伐他汀联用的治疗效果更佳。     

The Complementary Effects of Atorvastatin and Exercise Treatment on the Composition and Stability of the Atherosclerotic Plaques in ApoE Knockout Mice

Aim

This study aimed to investigate the effects of combined atorvastatin and exercise treatment on the composition and stability of the atherosclerotic plaques in apolipoproteinE (apoE) knockout mice.

Methods

Forty male, apoE^−/− mice were fed a high-fat diet for 16 weeks. Thereafter, while maintained on high-fat diet, they were randomized into four (n = 10) groups for 8 additional weeks: Group CO: Control. Group AT: Atorvastatin treatment (10 mg/Kg/day). Group EX: Exercise-training on treadmill. Group AT+EX: Atorvastatin and simultaneous exercise training. At the study’s end, plasma cholesterol levels, lipids and triglycerides were measured, along with the circulating concentrations of matrix-metalloproteinases (MMP-2,3,8,9) and their inhibitors (TIMP-1,2,3). Plaque area and the relative concentrations of collagen, elastin, macrophages, smooth muscle cells, MMP-2,3,8,9 and TIMP-1,2,3 within plaques were determined. Lastly, MMP activity was assessed in the aortic arch.

Results

All intervention groups showed a lower degree of lumen stenosis, with atheromatous plaques containing more collagen and elastin. AT+EX group had less stenosis and more elastin compared to single intervention groups. MMP-3,-8 -9 and macrophage intra-plaque levels were reduced in all intervention groups. EX group had increased TIMP-1 levels within the lesions, while TIMP-2 was decreased in all intervention groups. The blood levels of the above molecules increased during atherosclerosis development, but they did not change after the therapeutic interventions in accordance to their intra-plaque levels.

Conclusion

The two therapeutic strategies act with synergy regarding the extent of the lesions and lumen stenosis. They stabilize the plaque, increasing its content in elastin and collagen, by influencing the MMP/TIMP equilibrium, which is mainly associated with the macrophage amount. While the increased MMP-2,-3,-8 -9, as well as TIMP-1 and TIMP-2 circulating levels are markers of atherosclerosis, they are not correlated with their corresponding concentrations within the lesions after the therapeutic interventions, and cannot serve as markers for the disease development/amelioration.     

Identification of biomarker panels as predictors of severity in coronary artery disease

Matrix metalloproteinases (MMPs) are implicated in atherosclerotic plaque rupture and recondition. Specific tissue inhibitors (TIMPs) control MMP functions. Both MMPs and TIMPs are potential biomarkers of plaque instability. Elevated Apo-CII and CIII and Apo-E levels are recognized as cardiovascular disease risk factors. We aimed to establish the best blood biomarker panel to evaluate the coronary artery disease (CAD) severity. Plasma levels of MMP-3 and MMP-9, TIMP-1 and TIMP-2, Apo-CII, Apo-CIII and Apo-E were measured in 472 patients with CAD evaluated by coronary angiography and electrocardiography, and in 285 healthy controls. MMP-3 and MMP-9 plasma levels in CAD patients were significantly increased (P < 0.001) compared to controls (3.54- and 3.81-fold, respectively). Furthermore, these increments are modulated by CAD severity as well as for Apo-CII and Apo-CIII levels (P < 0.001). TIMPs levels were decreased in CAD versus controls (P < 0.001) and in inverse correlation to MMPs. Standard ROC curve approach showed the importance of panels of biomarkers, including MMP-3, MMP-9, TIMP-1, TIMP-2, Apo-CII and Apo-CIII, for disease aggravation diagnosis. A high area under curve (AUC) value (0.995) was reached for the association of MMP-9, TIMP-2 and Apo-CIII. The unbalance between MMPs and TIMPs in vascular wall and dyslipidaemia creates favourable conditions for plaque disruption. Our study suggests that the combination of MMP-9, TIMP-2 and Apo-CIII values (‘CAD aggravation panel’) characterizes the severity of CAD, that is electrophysiological state, number of involved vessels, stent disposal and type of stent.     

Tanshinone II-A attenuates and stabilizes atherosclerotic plaques in apolipoprotein-E knockout mice fed a high cholesterol diet

Tanshinone II-A (Tan), a bioactive diterpene isolated from Salvia miltiorrhiza Bunge (Danshen), possesses anti-oxidant and anti-inflammatory activities. The present study investigated whether Tan can decrease and stabilize atherosclerotic plaques in Apolipoprotein-E knockout (ApoE(-/-)) mice maintained on a high cholesterol diet (HCD). Six week-old mice challenged with a HCD were randomly assigned to 4 groups: (a) C57BL/6J; (b) ApoE(-/-); (c) ApoE(-/-)+Tan-30 (30 mg/kg/d); (d) ApoE(-/-)+Tan-10 (10mg/kg/d). After 16 weeks of intervention, Tan treated mice showed decreased atherosclerotic lesion size in the aortic sinus and en face aorta. Furthermore, immunohistochemical analysis revealed that Tan rendered the lesion composition a more stable phenotype as evidenced by reduced necrotic cores, decreased macrophage infiltration, and increased smooth muscle cell and collagen contents. Tan also significantly reduced in situ superoxide anion production, aortic expression of NF-κB and matrix metalloproteinase-9 (MMP-9). In vitro treatment of RAW264.7 macrophages with Tan significantly suppressed oxidized LDL-induced reactive oxygen species production, pro-inflammatory cytokine (IL-6, TNF-α, MCP-1) expression, and MMP-9 activity. Tan attenuates the development of atherosclerotic lesions and promotes plaque stability in ApoE(-/-) mice by reducing vascular oxidative stress and inflammatory response. Our findings highlight Tan as a potential therapeutic agent to prevent atherosclerotic cardiovascular diseases.     

Dietary iron restriction increases plaque stability in apolipoprotein-E-deficient mice

Accumulative evidence has supported the role of iron in the development of atherosclerosis. To test whether iron-mediated oxidative stress influences plaque stability, apoliporotein-E (ApoE)-deficient mice (3 months old) were placed on a chow diet or a low-iron diet for 3 months, and the abundance of interstitial collagen and the expression of the matrix degradation-associated enzyme, matrix metalloproteinase-9 (MMP-9), in vascular lesions were assessed. A low-iron diet appeared to reduce iron deposition while substantially increasing collagen content of lesions in mice. Immunostaining demonstrated lower expression of MMP-9 in lesions of iron-restricted animals. Likewise, SDS-PAGE zymography revealed lower gelatinolytic activities in aortic tissues and sera of the same group of animals. When older ApoE-deficient mice (5 months old) received a low-iron diet for 2 months, development of the lesion area was not significantly affected. However, the lesional collagen content was much higher in the iron-restricted group of animals, and MMP-9 expression in aortic tissues from the same group of mice was significantly lower. Treatment of murine J774 macrophages with increasing concentrations of ferric ammonium citrate significantly enhanced the amount of MMP-9 secreted. Together, these data indicate that decreased vascular iron content following dietary iron restriction in ApoE-deficient mice leads to lower matrix degradation capacity and increased plaque stability.     

The anti-inflammatory effects of exercise training promote atherosclerotic plaque stabilization in apolipoprotein E knockout mice with diabetic atherosclerosis

Physical exercise is the cornerstone of cardiovascular disease treatment. The present study investigated whether exercise training affects atherosclerotic plaque composition through the modification of inflammatoryrelated pathways in apolipoprotein E knockout (apoE^−/−) mice with diabetic atherosclerosis. Forty-five male apoE^−/− mice were randomized into three equivalent (n=15) groups: control (CO), sedentary (SED), and exercise (EX). Diabetes was induced by streptozotocin administration. High-fat diet was administered to all groups for 12 weeks. Afterwards, CO mice were euthanatized, while the sedentary and exercise groups continued high-fat diet for 6 additional weeks. Exercising mice followed an exercise program on motorizedtreadmill (5 times/week, 60 min/session). Then, blood samples and atherosclerotic plaques in the aortic root were examined. A considerable (P<0.001) regression of the atherosclerotic lesions was observed in the exercise group (180.339±75.613×10³µm²) compared to the control (325.485±72.302×10³ µm²) and sedentary (340.188±159.108×10³µm²) groups. We found decreased macrophages, matrix metalloproteinase-2 (MMP-2), MMP-3, MMP-8 and interleukin-6 (IL-6) concentrations (P<0.05) in the atherosclerotic plaques of the exercise group. Compared to both control and sedentary groups, exercise training significantly increased collagen (P<0.05), elastin (P<0.001), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) (P<0.001) content in the atherosclerotic plaques. Those effects paralleled with increased fibrous cap thickness and less internal elastic lamina ruptures after exercise training (P<0.05), while body-weight and lipid parameters did not significantly change. Plasma MMP-2 and MMP-3 concentrations in atherosclerotic tissues followed a similar trend. From our study we can conclude that exercise training reduces and stabilizes atherosclerotic lesions in apoE^−/− mice with diabetic atherosclerosis. A favorable modification of the inflammatory regulators seems to explain those beneficial effects.Key words: diabetes, atherosclerosis, exercise, matrix metalloproteinases, plaque stability.     

Perforin and Granzyme B Have Separate and Distinct Roles during Atherosclerotic Plaque Development in Apolipoprotein E Knockout Mice

The granzyme B/perforincytotoxic pathway is a well established mechanism of initiating target cell apoptosis. Previous studies have suggested a role for the granzyme B/perforin cytotoxic pathway in vulnerable atherosclerotic plaque formation. In the present study, granzyme B deficiency resulted in reduced atherosclerotic plaque development in the descending aortas of apolipoprotein E knockout mice fed a high fat diet for 30 weeks while perforindeficiency resulted in greater reduction in plaque development with significantly less plaque area than granzyme Bdeficient mice. In contrast to the descending aorta, no significant change in plaque size was observed in aortic roots from either granzyme Bdeficient or perforindeficient apolipoprotein E knockout mice. However, atherosclerotic plaques in the aortic roots did exhibit significantly more collagen in granzyme B, but not perforin deficient mice. Together these results suggest significant, yet separate roles for granzyme B and perforin in the pathogenesis of atherosclerosis that go beyond the traditional apoptotic pathway with additional implications in plaque development, stability and remodelling of extracellular matrix.     

血清MMP-8、IL-6表达与缺血性脑血管病患者颈动脉粥样硬化斑块的关系研究

目的：研究血清基质金属蛋白酶-8(MMP-8)、白细胞介素-6(IL-6)表达与缺血性脑血管病患者颈动脉粥样硬化斑块的关系。 方法：选取2012 年9 月至2013 年11 月就诊60 例缺血性脑血管病患者为研究组和健康体检者60 例为对照组。按照超声影像学 资料并参考患者颈动脉斑块类型把研究组分为不稳定斑块类型(18 例),稳定斑块类型(22 例)以及斑块性质介于两组之间为中间 类型(20 例)。采用双抗体夹心酶联免疫吸附试验(ELISA)对血清MMP-8、IL-6 水平进行测定,探讨血清MMP-8、IL-6 表达与不同 程度缺血性脑血管病患者颈动脉粥样硬化斑块的关系。结果：研究组血清MMP-8、IL-6 水平显著高于对照组,差异均有统计学意 义(P<0.01);三种不同类型斑块血清中MMP-8、IL-6 水平差异均有统计学意义(P<0.01);Spearman 等级相关性分析发现,研究组患 者颈动脉斑块稳定程度与血清MMP-8、IL-6 浓度水平存在显著正相关关系(P<0.01);线性相关分析发现,研究组血清MMP-8 水 平与IL-6 水平呈正相关关系(P<0.01)。结论：缺血性脑血管病患者血清MMP-8、IL-6 水平明显升高,其与颈动脉斑块不稳定程度 相关,同样与缺血性脑血管病发病机制方面存在相关协同作用。     

Plaque oxysterols induce unbalanced up-regulation of matrix metalloproteinase-9 in macrophagic cells through redox-sensitive signaling pathways: Implications regarding the vulnerability of atherosclerotic lesions

An imbalance in the matrix metalloproteinases/tissue inhibitors of metalloproteinases (MMPs/TIMPs) contributes to atherosclerotic plaque destabilization and rupture. Here we determined whether oxysterols accumulating in advanced atherosclerotic lesions play a role in plaque destabilization. In human promonocytic U937 cells, we investigated the effects of an oxysterol mixture of composition similar to that in advanced human carotid plaques on the expression and synthesis of MMP-9 and its endogenous inhibitors TIMP-1 and TIMP-2. A marked increment of MMP-9 gene expression, but not of its inhibitors, was observed by real-time RT-PCR; MMP-9 gelatinolytic activity was also found increased by gel zymography. Consistently, a net increment of MMP-9 protein level was also observed by immunoblotting. Using antioxidants or specific inhibitors or siRNAs, we demonstrated that the oxysterol mixture induces MMP-9 expression through: (i) overproduction of reactive oxygen species, probably by NADPH-oxidase and mitochondria; (ii) up-regulation of mitogen-activated protein kinase signaling pathways via protein kinase C; and (iii) up-regulation of activator protein-1- and nuclear factor-κB-DNA binding. These results suggest, for the first time, that oxysterols accumulating in advanced atherosclerotic lesions significantly contribute to plaque vulnerability by promoting MMP-9/TIMP-1/2 imbalance in phagocytic cells.