细胞色素P450基因对高脂饮食诱导不同周龄小鼠动脉粥样硬化的保护作用

目的研究血管内皮高表达CYP2C8基因能否改善小鼠动脉粥样硬化。方法以20和40周龄APOEKO+/-CYP2C8Tg+/-和CYP2C8Tg+/-基因(血管内皮特异性CYP2C8+/-转基因)的小鼠(n=10/组)为研究对象,相同基因背景和周龄的同窝APOEKO+/-和C57BL/6小鼠设为对照。采用PCR技术鉴定小鼠CYP2C8+/-基因;油红O染色检测APOEKO+/-CYP2C8Tg+/-、CYP2C8Tg+/-、APOEKO+/-和C57BL/6小鼠主动脉斑块形成面积;酶比色检测APOEKO+/-CYP2C8Tg+/-、CYP2C8Tg+/-、APOEKO+/-和C57BL/6小鼠血清TG、TCH、HDL。结果 20和40周龄APOEKO+/-CYP2C8Tg+/-和CYP2C8Tg+/-小鼠主动脉斑块形成面积与同周龄野生型小鼠相比明显减少,并且明显改善了血脂代谢状态。结论高表达CYP2C8基因能够改善西方饮食诱导的不同周龄小鼠的动脉粥样硬化。     

细胞色素P450基因对高脂饮食诱导不同周龄小鼠动脉粥样硬化的保护作用机制

目的在高脂饮食诱导小鼠动脉粥样硬化中研究CYP2C8基因对动脉粥样硬化的作用及相关机制。方法 :以20和40周龄APOEKO+/-CYP2C8Tg+/-和CYP2C8Tg+/-转基因的小鼠为研究对象,相同基因背景和周龄的同窝APOEKO+/-和C57BL/6小鼠设为对照。在第5,20,40周时测各组动物EET含量,用Real-time PCR法检测各组小鼠的主动脉PPAR-γ和MCP-1基因表达水平,Western blot分析各组小鼠的主动脉(p-)eNOS和NF-κB蛋白的表达与小鼠的肝脏PI3K、(p-)AKT、(p-)ERK和(p-)P38等信号通路蛋白的表达情况。结果 :在高脂饮食中,CYP2C8Tg+/-组和APOEKO+/-CYP2C8Tg+/-组的EET浓度明显增高。Western blot显示:高表达CYP2C8在肝脏中明显上调PI3K、(p-)AKT、(p-)ERK和(p-)P38蛋白;在主动脉明显上调(p-)eNOS蛋白,下调NF-κB蛋白。Real-time PCR分析显示高表达CYP2C8在主动脉中下调MCP-1蛋白。结论 :本研究高表达CYP2C8基因具有显著的抗炎作用,这一作用是...     

氯沙坦对ApoE-/-小鼠动脉粥样斑块稳定性和MMP-1及其抑制物表达的影响

目的:探讨氯沙坦(LST)对载脂蛋白E基因缺陷(ApoE-/-)小鼠主动脉粥样斑块稳定性和基质金属蛋白酶-1(MMP-1)及MMP-1组织抑制物(TIMP-1)蛋白表达影响及可能机制。方法:将27只8周龄雄性ApoE-/-小鼠随机等分3组,即对照组、低剂量LST[5mg/(kg.d)]组及高剂量LST[25mg/(kg.d)]组。给药16周后处死动物,以常规生化法测定血脂的水平。将主动脉根部连续石蜡切片、HE染色后,观察小鼠主动脉粥样斑块的形成。用免疫组化染色法检测观察粥样斑块中MMP-1和TIMP-1蛋白表达的水平。结果:3组血脂的水平差异无统计学意义。LST干预后动脉粥样斑块纤维帽厚,脂质核心小,斑块趋于稳定。LST组主动脉斑块中MMP-1蛋白的表达、TIMP-1的比值均显著低于对照组(P0.01),且高剂量LST较低剂量LST的作用更明显(P0.01)。结论:LST可通过降低斑块中MMP-1的表达,调节MMP-1/TIMP-1之间的平衡,对粥样斑块具有稳定作用,且呈剂量依赖性,独立于其调节血脂代谢。     

Orai1在载脂蛋白E基因敲除小鼠动脉粥样硬化斑块形成中的表达

目的探讨Orai1在载脂蛋白E基因敲除(Apo E-/-)小鼠动脉粥样硬化斑块形成过程中的表达。方法选取7~8周龄雄性Apo E-/-小鼠及野生型C57BL/6J小鼠,高脂饲喂20、27和33周后,在各个时点处死动物。取主动脉制备连续切片,HE、Masson染色计算机图像分析仪测定斑块面积占管腔面积百分比,及胶原成分占斑块面积百分比;油红O染色分析斑块中脂质含量;免疫组织化学染色测定平滑肌细胞阳性表达Orai1的百分比;Western Blot定量分析Orai1在易损斑块形成过程中的动态表达。结果与同周龄C57BL/6J小鼠相比,Apo E-/-小鼠主动脉Orai1表达增高,且随着其周龄增加,Orai1在Apo E-/-小鼠主动脉的表达动态升高(P0.05)。结论 Orai1参与动脉粥样硬化斑块形成的病理过程,在其形成过程中其表达上调。     

异位胰蛋白酶在动脉粥样斑块中的表达分布及其与斑块稳定性关系的探索

目的:探讨动脉粥样斑块组织中异位胰蛋白酶的表达分布及其对斑块稳定性的潜在影响。方法:20只8周龄雄性新西兰白兔随机分入对照组和动脉粥样硬化实验组(实验组),每组10只。对照组予普通饲料,实验组予高胆固醇高脂饲料,持续喂养17周后处死,切取主动脉和冠状动脉组织,分别进行病理和生化检查。结果:实验组的主动脉及冠状动脉组织中异位胰蛋白酶、基质金属蛋白酶-9(MMP-9)及促炎细胞因子白细胞介素(IL)-6、IL-β及肿瘤坏死因子α(TNF-α)表达较对照组显著上调(均P0.01);激活型MMP-9(actMMP-9)与前体型MMP-9(proMMP-9)的比值显著增高(P0.05);粥样斑块组织内可见异位胰蛋白酶大量表达,上调的异位胰蛋白酶与MMP-9分布一致,均主要分布在粥样斑块中。结论:作为proMMP-9的有效激动剂,动脉粥样斑块组织中大量表达的异位胰蛋白酶可能是引发粥样斑块炎症反应及破裂的一个重要因素。     

南蛇藤素对载脂蛋白E基因敲除小鼠主动脉壁C反应蛋白及组织因子表达的影响

目的探讨南蛇藤素对高脂饲养载脂蛋白E基因敲除小鼠在动脉粥样硬化病变形成的早期动脉壁内C反应蛋白和组织因子表达的影响。方法8周龄雄性载脂蛋白E基因敲除小鼠12只,随机分为南蛇藤素干预组或二甲基亚砜溶剂对照组,每组各6只。均给予高脂饲养8周,在高脂饲养的后4周,分别给予南蛇藤素2mg/(kg·d)或相当剂量的二甲基亚砜腹腔注射。麻醉处死小鼠后,取小鼠主动脉,以石蜡包埋,行主动脉根部连续切片;以HE染色观察形态学变化,免疫组织化学法检测主动脉壁内C反应蛋白和组织因子的表达水平,以Image Pro Plus6.0软件进行图像分析。结果南蛇藤素干预组主动脉粥样硬化斑块面积明显小于对照组,分别为4947±1277μm2和8403±2535μm2(P<0.05);南蛇藤素组主动脉粥样斑块面积/血管壁面积比值明显小于对照组(P<0.05);南蛇藤素组动脉壁C反应蛋白表达水平较对照组明显减少,平均光密度值分别为0.0152±0.0052与0.0256±0.0026(P<0.05);动脉粥样硬化斑块内组织因子表达水平较对照组明显减少,平均光密度值分别为0.0326±0.0132与0.0763±0.0347(P<0.05)。结论南蛇藤素可能通过抑制载脂蛋白E基因敲除小鼠炎症反应和动脉壁中C反应蛋白的表达而发挥抗动脉粥样的作用;还可能通过减少粥样斑块中组织因子的产生,而进一步起到稳定动脉粥样硬化斑块的作用。     

生长素对载脂蛋白E基因敲除小鼠动脉粥样硬化斑块与炎症因子的影响

目的观察生长素对载脂蛋白E基因敲除(ApoE~(-/-))小鼠血浆白细胞介素8(IL-8)、单核细胞趋化因子1(MCP-1)、肿瘤坏死因子α(TNF-α)水平和血管壁核转录因子κBp65(NFκBp65)表达及动脉粥样斑块的影响。方法8周龄雄性ApoE~(-/-)小鼠12只饲以西方类型膳食12周建立动脉粥样硬化模型,遗传背景相同的6只8周龄雄性C57BL/6J小鼠饲以同类型膳食作对照。第8周时模型组分为腹腔内注射生长素(100μg/kg)组(n=6)和注射生理盐水(0.1mL)组(n=6),C57BL/6J小鼠亦给予生理盐水(0.1mL)腹腔内注射。第12周时眼眶取血,分离血浆,酶联免疫吸附试验(ELISA)法检测IL-8、MCP-1、TNF-α水平。取小鼠主动脉进行苏丹Ⅳ染色,观察主动脉粥样硬化病变面积占主动脉内膜面积的比例,行主动脉窦HE及油红O染色,观察主动脉窦动脉粥样斑块面积占管腔总面积的比例,行主动脉免疫组化染色,观察NFκBp65的表达。结果与C57BL/6J小鼠比较,ApoE~(-/-)小鼠和ApoE~(-/-)+生长素小鼠总胆固醇和低密度脂蛋白胆固醇高[(6.7±0.5),(7.6±2.0)比(5.5±0.2)mmol/L,(5.6±0.3),(6.0±0.5)比(2.2±0.1)mmol/L,均P0.05],ApoE~(-/-)+生长素小鼠高密度脂蛋白胆固醇比ApoE~(-/-)组高[(0.5±0.1)比(0.3±0.1)mmol/L,P0.05]。与C57BL/6J小鼠比较,ApoE~(-/-)小鼠主动脉粥样硬化病变面积占主动脉内膜面积比例增加[(15.1±1.7)%比0],ApoE~(-/-)+生长素小鼠主动脉粥样病变面积占主动脉内膜面积比例较ApoE~(-/-)小鼠降低[(10.1±0.5)%比(15.1±1.7)%,P0.05];C56BL/6J小鼠主动脉窦无动脉斑块形成(0%),ApoE~(-/-)组和ApoE~(-/-)+生长素组均有动脉斑块形成,但ApoE~(-/-)+生长素组小鼠主动脉窦斑块面积占管腔总面积的比例较ApoE~(-/-)组低[(22.6±2.2)%比(32.4±3.2)%,P0.01]。ApoE~(-/-)小鼠TNF-α、IL-8和MCP-1水平较C57BL/6J小鼠增高[分别为(24.5±1.7)比(10.1±0.5)ng/L,(33.5±16.7)比(16.8±8.8)ng/L,(78.0±5.6)比(13.5±1.8)ng/L;均P0.05],ApoE~(-/-)+生长素组TNF-α、IL-8和MCP-1水平较ApoE~(-/-)组降低[分别为(15.5±1.0)比(24.5±1.7)ng/L,(22.0±1.2)比(33.5±16.7)ng/L,(45.5±4.5)比(78.0±5.6)ng/L;均P0.05]。ApoE~(-/-)小鼠血管壁NF-κBp65表达较C57BL/6J增高,ApoE~(-/-)小鼠+生长素组血管壁NF-κBp65表达较ApoE~(-/-)小鼠组降低(P0.05)。结论生长素通过抑制炎症反应减少ApoE~(-/-)小鼠动脉粥样斑块形成。     

Th22型免疫反应在动脉粥样硬化疾病中的动态变化

目的:探讨Th22型免疫反应与动脉粥样硬化(AS)之间的关系,为治疗AS提供新的理论依据。方法:8周龄C57BL/6J背景的载脂蛋白E缺陷型(Apo E~(-/-))小鼠为实验组(n=24),同龄C57BL/6J小鼠为对照组(n=24),两组小鼠均给予高脂饮食,分别于0周、4周、8周、12周处死,并采用油红O染色检测不同时间点主动脉根部斑块的进展,流式细胞术检测Th22细胞在两组小鼠脾脏中比例变化,实时荧光定量反转录聚合酶链式反应(RT-PCR)检测主动脉中白细胞介素-22(IL-22)、白细胞介素-22受体1(IL-22R1)及其转录因子芳香烃受体(Ah R)、T盒21转录因子(T-bet)的信使核糖核酸(mRNA)表达量变化,酶联免疫吸附测定法(ELISA)检测血清中的IL-22含量变化。结果:实验组小鼠主动脉根部粥样斑块面积[主动脉根部斑块面积/主动脉管腔面积(%)]、Th22细胞[CD4+IL-22+/CD4~+(%)]数量、IL-22、IL-22R1、AhR、T-bet的mRNA在主动脉中的表达量以及IL-22在血清中的含量均高于同时间点对照组小鼠,且各时间点(0周除外)差异有统计学意义(P0.05)。实验组组内前后两时间点对比,主动脉粥样斑块面积及AhR、T-bet的mRNA表达量:4周与0周、8周与4周、12周与8周比较差异均有统计学意义;Th22细胞数量:4周与0周、8周与4周比较差异均有统计学意义,12周与8周比较差异无统计学意义;IL-22、IL-22R1的mRNA表达量及血清中IL-22含量:4周与0周比较差异有统计学意义,8周与4周、12周与8周比较差异无统计学意义。结论:亢进的Th22型免疫反应具有促进AS进程的作用,其机制有待进一步探讨。     

RELMɑ/FIZZ1信号通路对载脂蛋白E基因敲除小鼠动脉粥样硬化斑块内血管新生的影响

目的 探讨类抵抗素分子ɑ或炎症区域分子1（RELMɑ/FIZZ1）对载脂蛋白E（ApoE）基因敲除小鼠动脉粥样硬化斑块稳定性及血管新生的影响及其信号通路。方法 8周龄C57BL/6J ApoE基因敲除鼠20只,喂食高脂饲料12周后随机分为模型组及RELMɑ/FIZZ1组,另选10只C57BL/6J野生型小鼠作为对照组;RELMɑ/FIZZ1组于尾部血管注射重组RELMɑ/FIZZ1干预2周后结束实验。取小鼠主动脉制备石蜡包埋切片,进行HE染色,利用图像软件定量测量斑块面积、血管横截面积及校正斑块面积,采用免疫组织化学染色测定主动脉血管壁RELMɑ/FIZZ1及CD34阳性反应强度。提取主动脉RNA,采用全基因表达谱筛选出显著表达差异的基因和发生变化的细胞通路。结果 与对照组相比,模型组动脉粥样硬化明显,斑块面积增加,粥样硬化斑块内RELMɑ/FIZZ1表达明显。RELMɑ/FIZZ1刺激后RELMɑ/FIZZ1及CD34阳性反应强度增强,校正斑块面积比模型组显著性增加（31.58%±6.65%比24.16%±3.59%,P<0.01）,明显刺激血管新生（P<0.05）。相对于对照组,RELMɑ/FIZZ1组有显著性上调基因391个,下调基因465个;活性显著性上调信号通路12条,活性显著性下调信号通路10条,共计22条。结论 RELMɑ/FIZZ1刺激血管新生,造成粥样斑块不稳定,其机制与Atg9a、Gng8等基因显著性表达及细胞肌动蛋白骨架调节通路、缝隙连接信号通路的激活密切相关。     

冠心舒通胶囊对ApoE－/－小鼠动脉粥样硬化斑块内MMP-9和TIMP-1表达的影响

目的 观察中成药冠心舒通胶囊对高脂饮食喂养ApoE^－/－小鼠主动脉粥样硬化斑块病理变化、人组织型基质金属蛋白酶抑制剂1（TIMP-1）、基质金属蛋白酶9（MMP-9）表达的影响,探讨冠心舒通胶囊对粥样斑块稳定性的影响以及对相关机制进行初步研究。方法 将8周龄雄性ApoE^－/－小鼠30只给予高脂喂养,12周时随机分为：模型组、冠心舒通胶囊高剂量［1.8 g/（kg·天）］组和冠心舒通胶囊低剂量［0.6 g/（kg·天）］组,喂养12周后处死,取主动脉中段,大体标本油红O染色观察斑块面积,冰冻切片后HE染色观察斑块厚度,冰冻切片免疫荧光法检测斑块内TIMP-1、MMP-9表达情况。结果 与模型组相比,冠心舒通胶囊组平均斑块浸润面积减小（P<0.05）,弥漫程度减轻,斑块厚度降低,MMP-9表达减少,而且冠心舒通胶囊高剂量组与低剂量组相比,各项统计指标亦有统计学意义（P<0.05） ,TIMP-1表达未见明显变化。结论 冠心舒通胶囊可以对抗ApoE^－/－小鼠动脉粥样硬化斑块的形成和进展,以及通过降低斑块内MMP-9表达,从而抑制胶原纤维分解,稳定易损粥样斑块。     

Increased atherosclerosis and vascular smooth muscle cell activation in AIF-1 transgenic mice fed a high-fat diet

Allograft inflammatory factor-1 (AIF-1) is a cytoplasmic, scaffold signal transduction protein constitutively expressed in inflammatory cells, but inducible in vascular smooth muscle cells (VSMCs) in response to injury or inflammatory stimuli. Although several basic science and population studies have reported increased AIF-1 expression in human and experimental atherosclerosis, a direct causal effect of AIF-1 expression on development of atherosclerosis has not been reported. The purpose of this study is to establish a direct relationship between AIF-1 expression and development of atherosclerosis. AIF-1 expression is detected VSMC in atherosclerotic lesions from ApoE(-/-) mice, but not normal arteries from wild-type mice. AIF-1 expression can be induced in cultured VSMC by stimulation with oxidized LDL (ox-LDL). Transgenic mice in which AIF-1 expression is driven by the G/C modified SM22 alpha promoter to restrict AIF-1 expression to VSMC develop significantly increased atherosclerosis compared with wild-type control mice when fed a high-fat diet (P=0.022). Cultured VSMC isolated from Tg mice demonstrated significantly increased migration in response to ox-LDL compared with matched controls (P<0.001). VSMC isolated from Tg mice and cultured human VSMC which over express AIF-1 demonstrated increased expression of MMP-2 and MMP-9 mRNA and protein and increased NF-κB activation in response to ox-LDL as compared with wild-type control mice. VSMC which over express AIF-1 have significantly increased uptake of ox-LDL, and increased CD36 expression. Together, these data suggest a strong association between AIF-1 expression, NF-κB activation, and development of experimental atherosclerosis.     

Effect of macrophage-derived apolipoprotein E on established atherosclerosis in apolipoprotein E-deficient mice

Apolipoprotein E-deficient (apoE(-/-)) mice have hyperlipidemia and develop spontaneous atherosclerosis in a time-dependent manner. Although macrophage-derived apoE has been shown to prevent the development of atherosclerosis in apoE(-/-) mice, whether it would induce regression of established atherosclerosis is unknown. To determine this, 8-week-old apoE(-/-) mice were transplanted with apoE(+/+) bone marrow. Four weeks after transplantation, when plasma cholesterol levels had reached normal levels, a group of mice (n=12) were killed and their aortic lesions were measured and used as a baseline to judge regression. Twelve and 20 weeks after transplantation, aortic lesion areas of the mice were 9340+/-2184 micrometer(2) (mean+/-SEM, n=8) and 12 211+/-1433 micrometer(2) (n=9), respectively, values not significantly different from the lesion areas of the baseline mice (12 347+/-2487 micrometer(2); n=12, P>0.05). In contrast, apoE(-/-) mice reconstituted with apoE(-/-) bone marrow developed severe atherosclerotic lesions (453 036+/-29 767 micrometer(2), n=7) 20 weeks after transplantation. These data suggest that macrophage-derived apoE was insufficient to induce significant regression of established atherosclerotic lesions in apoE(-/-) mice, although it was sufficient to eliminate hypercholesterolemia and prevent progression of aortic lesions.     

Differential expression of MMPs and TIMPs in moderate and severe heart failure in a transgenic model

BackgroundAltered expression of matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) accompanies the development of heart failure (HF). However, changes in MMP and TIMP protein levels or activity during the progression from compensated to decompensated failure remains incompletely examined.Methods and ResultsTransgenic mice (Tg) with cardiac-specific overexpression of tumor necrosis factor-α (TNF1.6) develop a sex-related, progressive cardiac dilation and HF. Echocardiographic measures were used to categorize HF severity in male (M) and female (F) Tg and wild-type (WT) mice between 4 and 50 weeks of age. Cardiac TIMPs-1, TIMPs-2, and MMP-3 (enzyme-linked immunosorbent assay), and potential (APMA-activated) MMP-9 activity were measured at similar ages. In situ zymography assessed tissue gelatinase activity. Systolic function, ventricular dimensions, and presence of pleural effusions identified severe HF in younger M Tg mice (by 18 weeks) and older F Tg (>34 weeks). Regardless of age, sex, or HF severity, Tg mice expressed significantly more TIMP-1 (Tg 119–193 pg/mg vs. WT 13–24 pg/mg, P < .001) and potential MMP-9 activity (Tg 0.41–0.58 ng/mg vs. WT 0.015–0.028 ng/mg, P < .002). M Tg expressed elevated MMP-3 (4 weeks, 0.16 ± 0.1 ng/mg protein vs. WT 0.04 ± 0.01 ng/mg, P < .003), which increased with age and HF severity (18 weeks, 0.51 ± 0.3 ng/mg P < .01). F Tg showed no increase in MMP-3 at 4 weeks but a progressive increase with age and HF severity (18 weeks 0.09 ± 0.04 ng/mg, P < .02 vs. Tg M or WT; 34 weeks 0.13 ± 0.02 ng/mg, P < .001 vs. WT). To test the hypothesis that increased MMP-3 may differentially activate MMP-9 in M Tg, in situ zymography was performed and revealed a significant increase in gelatinase activity in M Tg mice relative to both WT and F Tg.ConclusionMMP-3 may regulate activation of MMP-9/gelatinase, the progression of cardiac remodeling, and development of decompensated heart failure.     

Tobacco smoke-induced left ventricular remodelling is not associated with metalloproteinase-2 or -9 activation

AIM: To investigate the role of MMP-2 and MMP-9 in cardiac remodelling induced by tobacco smoke exposure in rats. METHODS: Rats were allocated into two groups: C (n=9): control animals; ETS (n=9): exposed to tobacco smoke. After 4months, the animals underwent echocardiography, morphometric study and determination of MMP-2 and MMP-9 activity. RESULTS: ETS rats had larger diastolic (C=15.6 +/-1.2 mm/kg, ETS=18.0+/-0.9 mm/kg; p < 0.001) and systolic (C=7.3+/-1.2 mm/kg, ETS=9.2+/-0.9 mm/kg; p=0.001) ventricular diameters adjusted for body weight. Fractional shortening (C=53+/-4.8%, ETS=48+/- 3.3%; p=0.031) and ejection fraction (C=0.89+/-0.03, ETS=0.86+/-0.02; p=0.030) were smaller in the ETS group. Myocyte cross-sectional area (C=245+/-8 microm2, ETS=253+/-8 microm2; p=0.028) was higher in ETS rats. There were no differences in MMP-2 (C=50+/-14%; ETS=43+/-11%, p=0.228) or MMP-9 (C=0.36+/-0.3%; ETS=0.62+/-0.3%, p=0.630) activity between the groups. CONCLUSION: MMP-2 and MMP-9 did not participate in the remodelling process induced by tobacco smoke exposure.     

血管紧张素Ⅱ对小鼠主动脉壁结构的影响及其机制探讨

目的观察血管紧张素Ⅱ对小鼠主动脉壁结构的影响,并探讨其机制。方法将8月龄C57BL/6J小鼠40只,随机分为试验组和对照组各20只。试验组予4.5 mg/（kg.d）血管紧张素Ⅱ腹腔注射,对照组予12 mg/（kg.d）去甲肾上腺素腹腔注射,每次注射后30 min用鼠尾测压器测量血压并记录,持续14 d。14 d后处死小鼠,取出主动脉壁行病理检验观察动脉壁结构变化,并用免疫组织化学法检测小鼠主动脉壁组织中的基质金属蛋白酶-9（MMP-9）、基质金属蛋白酶-2（MMP-2）和金属蛋白酶组织抑制因子-2（TIMP-2）。结果实验过程中试验组小鼠血压为（134.5±3.5）mmHg,对照组为（132.9±2.7）mmHg,P〉0.05。试验组12只小鼠主动脉管壁中膜变薄,部分可见断裂,7只形成明显主动脉夹层;对照组小鼠主动脉壁则未见明显变化。试验组小鼠主动脉壁组织中MMP-9、MMP-2、TIMP-2表达量分别为0.451 3±0.022 1、0.508 4±0.013 1、0.623 8±0.014 2,对照组分别为0.285 7±0.011 3、0.381 4±0.020 3、0.354 5±0.021 3,两组相比P均〈0.05。结论血管紧张素Ⅱ可能通过升高主动脉壁组织MMP-9、MMP-2和降低TIMP-2损伤小鼠主动脉壁,甚至引起主动脉夹层。     

Occurrence of matrix metalloproteinases and tissue inhibitors of metalloproteinases in tuberculous pleuritis

OBJECTIVE: Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) have been found in high concentrations in pleural effusions. Because MMP and TIMP may play a part in the causation of the fibrosis seen in tuberculous (TB) pleuritis their occurrence was examined. DESIGN: Pleural effusion fluid and plasma concentrations of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1 and TIMP-2 were determined by ELISA in 21 patients with TB pleuritis. To adjust for the total protein content, respective ratios were calculated. Activities of MMP-2 and MMP-9 were measured by gelatine zymography and the MMP-9/MMP-2 ratios calculated. Pleural effusions and plasma of 15 patients with congestive heat failure (CHF) and plasma of 15 healthy persons (CON) served as controls. RESULTS: Immunoreactive pleural fluid concentrations of MMP-1, MMP-2, MMP-8, and MMP-9 were higher in TB compared to CHF, but plasma concentrations were not different between the groups. TB pleural fluid concentrations of MMP-1, MMP-2, TIMP-1, and TIMP-2 were higher compared to TB plasma. MMP-3 was found in trace amounts only. The MMP-9/total protein ratios in pleural fluid were higher in TB compared to CHF (0.4492+/-0.1633 vs 0.0364+/-0.0145, P<0.005) but the TIMP-1 ratios were lower (139.0+/-28.7 vs 517.8+/-183.7, P<0.0005). In TB pleural fluid vs TB plasma, the respective MMP-1, MMP-2, TIMP-1, and TIMP-2 ratios were increased (0.46+/-0.10 vs 0.17+/-0.02; 25.2+/-2.8 vs 4.2+/-0.9; 139.0+/-28.7 vs 27.8+/-8.2; 0.67+/-0.13 vs 0.18+/-0.04, P<0.0005 each). Gelatine zymography demonstrated MMP-2 and MMP-9 bands of different brightness in TB effusions but in CHF effusions the MMP-9 band was barely visible. The MMP-9/MMP-2 effusion ratios were therefore higher in TB compared to CHF (0.46+/-0.15 vs 0.05+/-0.04, P<0.0005). CONCLUSION: Compartmentalized MMP-1, MMP-2, TIMP-1, and TIMP-2 and, compared to CHF, a surplus of MMP-1, MMP-2, MMP-8, and MMP-9 in the pleural space obviously contribute to the fibrotic reactions in TB pleuritis.     

Over-expression of BMP4 inhibits experimental choroidal neovascularization by modulating VEGF and MMP-9

Bone morphorgenetic protein (BMP)-4 has been shown to play a pivotal role in eye development; however, its role in mature retina or ocular angiogenic diseases is unclear. Activating downstream Smad signaling, BMP4 can be either pro-angiogenic or anti-angiogenic, depending on the context of cell types and associated microenvironment. In this study, we generated transgenic mice over-expressing BMP4 in retinal pigment epithelial (RPE) cells (Vmd2-Bmp4 Tg mice), and used the laser-induced choroidal neovascularization (CNV) model to study the angiogenic properties of BMP4 in adult eyes. Vmd2-Bmp4 Tg mice displayed normal retinal histology at 10 weeks of age when compared with age-matched wildtype mice. Over-expression of BMP4 in RPE in the transgenic mice was confirmed by real-time PCR and immunostaining. Elevated levels of Smad1,5 phosphorylation were found in BMP4 transgenic mice compared to wildype mice. Over-expression of BMP4 was associated with less severe CNV as characterized by fluorescein angiography, CNV volume measurement and histology. While control mice showed increased levels of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9 after laser injury, Vmd2-Bmp4 Tg showed no increase in either VEGF or MMP-9. Further, we found that TNF-induced MMP-9 secretion in vitro was reduced by pretreatment of RPE cells with BMP4. The inhibition of MMP-9 was Smad-dependent because BMP4 failed to repress TNF-induced MMP-9 expression when Smad1,5 was silenced by siRNA. In summary, our studies identified an anti-angiogenic role for BMP4 in laser-induced CNV, mediated by direct inhibition of MMP-9 and indirect inhibition of VEGF.     

The cis-9,trans-11 isomer of conjugated linoleic acid (CLA) lowers plasma triglyceride and raises HDL cholesterol concentrations but does not suppress aortic atherosclerosis in diabetic apoE-deficient mice

OBJECTIVE: Reduction in atherosclerosis has been reported in experimental animals fed mixtures of conjugated linoleic acid (CLA). In this study, the major naturally occurring CLA isomer (cis-9,trans-11) was tested in an atherosclerosis-prone mouse model. METHODS: In a model of insulin deficient apoE deficient mice, 16 animals were fed for 20 weeks with supplemental CLA (09.%, w/w) and compared with a similar number of mice of this phenotype. A control comparison was made of metabolic changes in non-diabetic apoE deficient mice that develop little atherosclerosis over 20 weeks. At 20 weeks, plasma lipids were measured and aortic atherosclerosis quantified by Sudan staining in the arch, thoracic and abdominal segments. RESULTS: The diabetic apoE deficient mice developed marked dyslipidemia, primarily as cholesterol-enriched chylomicron and VLDL-sized lipoproteins and atherosclerosis in the aortic arch. However, there were no significant differences between CLA fed and non-CLA fed mice in either phenotype in plasma cholesterol concentration (in diabetic: 29.4+/-7.7 and 29.5+/-5.9 mmol/L, respectively) or in the area of aortic arch atherosclerosis (in diabetic: 24.8+/-10.3 and 27.6+/-7.7%, respectively). However, among diabetic mice the triglyceride concentration in triglyceride-rich lipoproteins was significantly lower in those fed CLA (for plasma 2.2+/-0.8 to 1.1+/-0.3 mmol/L; P<0.001), a significant difference that was seen also in the non-diabetic mice in which HDL cholesterol increased significantly with CLA (0.35+/-0.12-0.56+/-0.15 mmol/L). CONCLUSION: In this atherosclerosis-prone model, the diabetic apoE deficient mouse, supplemental 0.9% CLA (cis-9,trans-11) failed to reduce the severity of aortic atherosclerosis, although plasma triglyceride concentration was substantially lowered and HDL cholesterol raised.