动脉粥样硬化斑块内FIZZ1表达促进平滑肌细胞清道夫受体-A上调

目的探讨ApoE基因敲除鼠动脉粥样硬化斑块内FIZZ1表达情况及其对平滑肌细胞清道夫受体A(SR-A)表达的影响.方法C57BL/6J ApoE基因敲除鼠及C57BL/6J野生型小鼠各9只,分别喂养高脂饲料及普通饲料,24周后处死小鼠,石蜡包埋血管后做连续切片,行HE染色及FIZZ1免疫组化.用氧化型低密度脂蛋白(ox-LDL)以及终浓度分别为3×10-6mmol/L、9×10-6mmol/L、2.7×10-5mmol/L的FIZZ1刺激培养的平滑肌细胞,激光共聚焦显微镜确认SR-A表达后,流式细胞术检测FIZZ1对ox-LDL诱导的平滑肌细胞SR-A表达的影响.结果ApoE基因敲除鼠高脂饲养24周后,主动脉根部明显形成动脉粥样硬化,可见FIZZ1在动脉粥样硬化斑块内明显表达,同龄野生型C57BL/6J鼠正常血管壁内,未见FIZZ1表达,重组FIZZ1能明显促进ox-LDL诱导的平滑肌细胞SR-A表达(与对照组比较,P<0.01).结论C57BL/6J野生型小鼠正常血管不表达FIZZ1,C57BL/6JApoE基因敲除鼠动脉粥样斑块表达FIZZ1,FIZZ1促进ox-LDL诱导的平滑肌细胞SR-A表达,提示FIZZ1可能在ApoE基因敲除鼠动脉粥样硬化进展中起一定的促进作用.     

FIZZ1在ApoE基因敲除鼠动脉粥样斑块中的表达

背景FIZZ1是一种与炎症相关的缺氧诱导的有丝分裂因子,在肺部疾病缺氧状态下具有刺激肺动脉平滑肌细胞增殖等作用。目的探讨FIZZ1在ApoE基因敲除鼠粥样斑块表达情况及其对平滑肌细胞增殖的影响。方法应用C57BL/6J ApoE基因敲除鼠构建动脉血管粥样硬化模型并与普通C57BL/6J野生型小鼠进行对照研究,通过对动脉血管HE染色及FIZZ1免疫检测斑块FIZZ1表达,同时给以不同浓度FIZZ1刺激培养的平滑肌细胞,MTT法测定FIZZ1对平滑肌细胞增殖的影响。结果ApoE基因敲除鼠高脂饲养24周后,主动脉根部明显形成动脉粥样硬化,斑块体积较大,免疫组化可见FIZZ1在粥样硬化斑块内明显表达,同龄野生型C57BL/6J鼠血管壁内,未见FIZZ1表达,重组FIZZ1能促进体外培养的平滑肌细胞增殖(与对照组比较,差别具有统计学意义,P<0.05)。结论C57BL/6J野生型小鼠正常血管不表达FIZZ1,C57BL/6J ApoE基因敲除鼠粥样斑块表达FIZZ1,FIZZ1具有促进平滑肌细胞增殖的作用,提示其可能在动脉粥样硬化进展中起一定的作用。     

FIZZ1在ApoE基因敲除鼠动脉粥样斑块中的表达

背景 FIZZ1是一种与炎症相关的缺氧诱导的有丝分裂因子,在肺部疾病缺氧状态下具有刺激肺动脉平滑肌细胞增殖等作用. 目的 探讨FIZZ1在ApoE基因敲除鼠粥样斑块表达情况及其对平滑肌细胞增殖的影响.方法 应用C57BL/6J ApoE基因敲除鼠构建动脉血管粥样硬化模型并与普通C57BL/6J野生型小鼠进行对照研究,通过对动脉血管HE染色及FIZZ1免疫检测斑块FIZZ1表达,同时给以不同浓度 FIZZ1刺激培养的平滑肌细胞,MTT法测定FIZZ1对平滑肌细胞增殖的影响.结果 ApoE基因敲除鼠高脂饲养24周后,主动脉根部明显形成动脉粥样硬化,斑块体积较大,免疫组化可见FIZZ1在粥样硬化斑块内明显表达,同龄野生型C57BL/6J鼠血管壁内,未见FIZZ1表达,重组FIZZ1能促进体外培养的平滑肌细胞增殖(与对照组比较,差别具有统计学意义,P＜0.05).结论 C57BL/6J野生型小鼠正常血管不表达FIZZ1,C57BL/6J ApoE基因敲除鼠粥样斑块表达FIZZ1,FIZZ1具有促进平滑肌细胞增殖的作用,提示其可能在动脉粥样硬化进展中起一定的作用.     

厄贝沙坦抑制高胆固醇诱导载脂蛋白E基因敲除小鼠动脉粥样硬化的炎症机制

目的探讨厄贝沙坦对载脂蛋白E基因敲除小鼠动脉粥样硬化斑块的影响及炎症机制。方法载脂蛋白E基因敲除小鼠随机分为普食组、高胆固醇饮食组、高胆固醇饮食 厄贝沙坦组,每组15只,分别予蒸馏水、蒸馏水、厄贝沙坦10 mg/(kg.d)灌胃12周。无创血压系统测小鼠血压;内眦动脉取血检测血清总胆固醇和甘油三酯水平;冰冻切片光镜下定位主动脉根部,油红O染色评估斑块大小;实时定量聚合酶链反应和Western blotting方法检测主动脉肿瘤坏死因子α、白细胞介素6、单核细胞趋化蛋白1和血管细胞粘附分子1的表达。结果高胆固醇饮食组小鼠血脂水平明显升高(P<0.01),且斑块面积明显高于普食组(P<0.01);厄贝沙坦明显减小斑块面积(P<0.01),同时降低肿瘤坏死因子α、白细胞介素6、单核细胞趋化蛋白1和血管细胞粘附分子1的表达(P<0.01)。结论血管紧张素Ⅱ1型受体拮抗剂厄贝沙坦可以通过降低炎症因子的表达,从而达到抑制动脉粥样硬化发生发展的目的。     

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。     

高棕榈酸饮食对ApoE基因敲除小鼠动脉粥样硬化的影响

1目的：观察高棕榈酸饮食对载脂蛋白E（ApoE）基因敲除小鼠的血脂、血浆游离脂肪酸水平、动脉粥样硬化斑块面积、斑块中胶原含量和基质金属蛋白酶2表达的影响。方法：将20只6～8周龄雄性ApoE基因敲除小鼠随机分为对照组和高棕榈酸饮食组,每组10只。分别给予普通小鼠饲料和含5％棕榈酸的饮食,连续喂养12周。用比色法检测血脂和血浆游离脂肪酸水平;主动脉根部连续石蜡切片,Masson染色检测斑块内胶原含量,免疫组化法检测主动脉基质金属蛋白酶2的表达。结果：两组血脂水平无明显差异。与对照组相比,高棕榈酸饮食组血浆游离脂肪酸水平显著升高,主动脉斑块内胶原含量显著降低,主动脉基质金属蛋白酶2表达明显增加（P均〈0．05）。结论：高棕榈酸饮食能够升高血浆游离脂肪酸水平,降低斑块内胶原含量,从而降低动脉粥样硬化斑块稳定性,其机制可能与其上调基质金属蛋白酶2的表达有关。     

载脂蛋白E基因敲除小鼠动脉粥样硬化斑块中血小板因子4和Toll样受体2的表达

目的观察高脂饲养的载脂蛋白E基因敲除小鼠动脉粥样硬化斑块表达Toll样受体2和血小板因子4的情况,探讨血小板因子4对内皮细胞Toll样受体2表达的影响。方法高脂饲料喂养载脂蛋白E基因敲除小鼠12周,建立动脉粥样硬化模型。安乐死处死动物,原位灌流固定,取主动脉于10%中性缓冲福尔马林中固定,石蜡包埋连续切片,HE染色观察动脉粥样硬化斑块形态,免疫组织化学检测斑块中Toll样受体2和血小板因子4的表达。结果载脂蛋白E基因敲除小鼠血脂水平明显增高,主动脉HE染色可见态动脉粥样硬化病变。在载脂蛋白E基因敲除小鼠主动脉富含脂质斑块中Toll样受体2表达上调,其中血管内皮细胞、巨噬细胞表达Toll样受体2明显增多。载脂蛋白E基因敲除小鼠主动脉斑块中也发现有血小板因子4表达,主要在内皮细胞和动脉粥样硬化斑块肩部。结论1.载脂蛋白E基因敲除小鼠粥样斑块中Toll样受体2表达上调,并且Toll样受体2主要表达在粥样斑块的内皮细胞和巨噬细胞上。2.载脂蛋白E基因敲除小鼠动脉粥样硬化斑块中可见血小板因子4表达。     

miR-301a调节小鼠巨噬细胞中炎症因子的表达

目的探讨miR-301a对巨噬细胞炎症因子表达水平的影响,从microRNA角度阐明动脉粥样硬化的发病机制,为动脉粥样硬化的防治提供新的思路。方法高脂喂养Apo E-/-小鼠建立动脉粥样硬化模型,收集小鼠主动脉血管,利用real-time PCR检测组织中miR-301a的表达水平;利用脂质体在RAW264.7细胞中转染miR-301a mimic和miR-301a inhibitor,用real-time PCR检测细胞中miR-301a水平,并检测肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)和单核细胞趋化蛋白1(MCP-1)的表达水平,用Western blot检测NF-κB抑制因子(NKRF)蛋白水平,用免疫荧光染色检测p65细胞定位。结果在高脂喂养的Apo E-/-小鼠主动脉血管壁组织中miR-301a的表达水平升高;在RAW264.7细胞中过表达miR-301a可抑制NKRF蛋白水平,促进p65细胞核定位,升高细胞中TNF-α、IL-6和MCP-1的mRNA表达;在RAW264.7细胞中低表达miR-301a可升高NKRF蛋白水平,促进p65细胞质定位,减少细胞中TNF-α、IL-6和MCP-1的mRNA表达。结论在高脂喂养的Apo E-/-小鼠主动脉血管壁组织中miR-301a表达水平升高;在RAW264.7细胞中miR-301a通过调节NKRF的表达影响p65活性进而调控TNF-α、IL-6和MCP-1的mRNA表达,提示microRNA在动脉粥样硬化发病的炎症机制中具有重要作用。     

姜黄素通过影响巨噬细胞的极性延缓动脉粥样硬化进展

目的研究姜黄素对ApoE基因敲除(ApoE~(-/-))小鼠动脉粥样硬化进展及斑块中巨噬细胞极性的影响。方法用高脂高胆固醇饮食饲养ApoE~(-/-)小鼠建立动脉粥样硬化模型,设立姜黄素治疗组、阿托伐他汀治疗组和高脂组;通过免疫组织化学(HE染色、油红O染色、Masson染色、苏木精染色)及免疫荧光染色检测主动脉斑块形态及不同亚型巨噬细胞的含量。通过实时荧光定量PCR检测主动脉组织中炎症因子的表达。结果姜黄素干预能减轻ApoE~(-/-)小鼠主动脉粥样硬化病变,并降低动脉粥样硬化斑块的易损指数。姜黄素降低动脉粥样硬化斑块内M1/M2巨噬细胞的比值,减少M1型巨噬细胞分泌的促炎因子白细胞介素1β(IL-1β)、诱导型一氧化氮合酶(iNOS)和肿瘤坏死因子α(TNF-α)的表达,促进M2型细胞因子IL-10、Ym1和Fizz1的表达。结论姜黄素可通过影响斑块中巨噬细胞的极性、抑制相关的炎症反应,从而延缓ApoE~(-/-)小鼠动脉粥样硬化的进展。     

老龄ApoE基因敲除小鼠动脉粥样硬化斑块的病理观察

目的：观察西方饮食喂养的老龄（≥48周）ApoE基因敲除小鼠血管动脉粥样硬化斑块的病理组织学状况。方法：选取6周龄雄性纯合子ApoE基因敲除小鼠30只，均予以西方饮食喂养，分别在喂养42周（48周龄）、54周（60周龄）、66周（72周龄）时，随机各取10只，取无名动脉做病理检测。酶法检测血脂情况，冰冻切片光镜下观察无名动脉粥样硬化斑块病理情况，图像分析管腔及斑块面积，免疫组化染色观察斑块中骨桥蛋白、α肌动蛋白的表达。von Kossa染色观察斑块钙化情况。结果：西方饮食喂养48周龄后，ApoE基因敲除小鼠主动脉弓内形成广泛而且典型的动脉粥样硬化成熟斑块，60周龄时，无名动脉内斑块面积、其与血管面积比率和自发破裂率最高，不稳定斑块比例最大（P〈0．05～〈0．01）。结论：长期西方饮食喂养ApoE基因敲除小鼠，是研究动脉粥样硬化成熟斑块很好的动物模型。     

Interleukin-1 plays a major role in vascular inflammation and atherosclerosis in male apolipoprotein E-knockout mice

OBJECTIVE: To examine the role of the balance between interleukin (IL)-1 and IL-1 receptor antagonist (IL-1Ra) in atherosclerosis and vascular inflammation. METHODS: Transgenic (Tg) mice overexpressing either secreted IL-1Ra or intracellular IL-1Ra1 as well as IL-1Ra-deficient mice (IL-1Ra -/-) were crossed with apolipoprotein E-deficient mice (ApoE -/-). RESULTS: In males fed a cholesterol-rich diet for 10 weeks, average atherosclerotic lesion area within aortic roots was significantly decreased in ApoE -/- secreted IL-1Ra Tg (-47%) and ApoE -/- intracellular IL-1Ra1 Tg (-40%) mice as compared to ApoE -/- non-Tg controls. The extent of sudanophilic lesions was reduced within the thoraco-abdominal aorta in ApoE -/- secreted IL-1Ra (-53%) and ApoE -/- intracellular IL-1Ra1 (-67%) Tg mice. In parallel experiments, we observed early mortality and illness among double deficient mice, whereas ApoE -/- IL-1Ra +/+ and ApoE +/+ IL-1Ra -/- mice were apparently healthy. After 7 weeks of diet, ApoE -/- IL-1Ra -/- mice exhibited massive aortic inflammation with destruction of the vascular architecture, but no signs of atherosclerosis. ApoE -/- IL-1Ra +/+ had atherosclerosis and a moderate inflammatory reaction, whereas ApoE +/+ IL-1Ra -/- mice were free of vascular lesions. Macrophages were present in large amounts within inflammatory lesions in the adventitia of ApoE -/- IL-1Ra -/- mice. CONCLUSION: Our results demonstrate that the IL-1/IL-1Ra ratio plays a critical role in the pathogenic mechanisms leading to vascular inflammation and atherosclerosis in ApoE -/- mice.     

Aerobic Exercise Prevents Insulin Resistance Through the Regulation of miR-492/Resistin Axis in Aortic Endothelium

Previously, we found that miR-492 delayed the progression of atherosclerosis (AS) by acting as an up-stream regulator of resistin. Therefore, we hypothesized that the anti-atherogenic effects of exercise are related to miR-492-mediated downregulation of resistin and repair of endothelial injury. In this study, we investigated the effects of the miR-492/resistin axis on improving endothelial injury in ApoE?/? mice (ApoE-deficient/knockout in C57BL/6 mice) through swimming exercises. Our results showed that the severity of AS and insulin resistance (IR) in these mice were significantly reduced by swimming exercises. In addition, miR-492 expression in the aortic endothelium of ApoE?/? mice was decreased, in addition to increased levels of resistin. Interestingly, swimming exercises increased miR-492 expression while decreasing that of resistin. Taken together, swimming exercises delayed the progression of AS, possibly by upregulating miR-492 and downregulating resistin in aortic endothelium. Therefore, exercises modulated glucose and lipid metabolism, alleviated endothelial IR, and repaired endothelial injury.     

Fcgamma receptor deficiency confers protection against atherosclerosis in apolipoprotein E knockout mice

IgG Fc receptors (FcgammaRs) play a role in activating the immune system and in maintaining peripheral tolerance, but their role in atherosclerosis is unknown. We generated double-knockout (DKO) mice by crossing apolipoprotein E-deficient mice (apoE(-/-)) with FcgammaR gamma chain-deficient mice (gamma(-/-)). The size of atherosclerotic lesions along the aorta was approximately 50% lower in DKO compared with apoE(-/-) control mice, without differences in serum lipid levels. The macrophage and T-cell content of lesions in the DKO were reduced by 49+/-6% and 56+/-8%, respectively, compared with the content in apoE(-/-) lesions. Furthermore, the expression of monocyte chemoattractant protein-1 (MCP-1), RANTES (Regulated on Activated Normal T-cell Expressed and Secreted), and intercellular adhesion molecule-1 (ICAM-1) and the activation of nuclear factor-kappaB (NF-kappaB) were significantly reduced in aortic lesions from DKO mice. In vitro, vascular smooth muscle cells (VSMCs) from both gamma(-/-) and DKO mice failed to respond to immune complexes, as shown by impaired chemokine expression and NF-kappaB activation. ApoE(-/-) mice have higher levels of activating FcgammaRI and FcgammaRIIIA, and inhibitory FcgammaRIIB, compared with wild-type mice. The DKO mice express only the inhibitory FcgammaRIIB receptor. We conclude that FcgammaR deficiency limits development and progression of atherosclerosis. In addition to leukocytes, FcgammaR activation in VSMCs contributes to the inflammatory process, in part, by regulating chemokine expression and leukocyte invasion of the vessel wall. These results underscore the critical role of FcgammaRs in atherogenesis and support the use of immunotherapy in the treatment of this disease.     

Atheroprotection via cannabinoid receptor-2 is mediated by circulating and vascular cells in vivo

Low-dose oral tetrahydrocannabinol (THC) reduces progression of atherosclerosis in mice. THC activates central cannabinoid-1 receptors (CB1) with subsequent psychoactive effects as well as peripheral cannabinoid-2 receptors (CB2). In order to dissect the underlying mechanisms, we performed experiments under selective CB2 stimulation as well as after genetic disruption of the CB2 receptor. Atherosclerosis prone apolipoprotein E-deficient mice were crossed with cannabinoid receptor-2 deficient mice to obtain ApoE −/− CB2 −/− double knockout mice. After 8 weeks of a high-cholesterol diet, immunohistochemical stainings of the aortic root revealed that vascular leukocyte infiltration in atherosclerotic plaques was accelerated in ApoE −/− CB2 −/− mice compared with ApoE −/− mice. This was accompanied by increased release of reactive oxygen species as measured using L012-enhanced chemiluminescence, and by decreased endothelial function as assessed in isolated aortic rings in organ chamber experiments. ApoE −/− mice treated with the selective CB2 agonist JWH 133 during a high-cholesterol diet showed decreased atherosclerotic lesion formation, improved endothelial function and reduced levels of reactive oxygen species. To assess whether CB2 expression in circulating cells influences atherosclerosis, irradiated ApoE −/− mice were repopulated with bone marrow-derived cells from ApoE −/− and ApoE −/− CB2 −/− mice and were fed a high-cholesterol diet for 8 weeks. CB2 deficiency in bone marrow-derived cells increased leukocyte infiltration into the vessel wall, but had no impact on plaque formation. Cell culture experiments revealed that CB2 activation diminishes ROS generation in vascular cells. Selective CB2 receptor stimulation modulates atherogenesis via impact on both circulating proinflammatory and vascular cells.     

通瘀煎对ApoE基因敲除小鼠动脉粥样硬化斑块形成的影响及机制

目的探讨通瘀煎对ApoE基因敲除小鼠动脉粥样硬化斑块形成的影响及其作用机制。方法50只ApoE基因敲除小鼠随机分为模型组、阳性药物组(立普妥组)、通瘀煎低、中、高剂量组各10只,以高脂饲料喂养12 w构建动脉粥样硬化模型。另取10只C57BL/6雄性小鼠为空白组,普通饲料喂养。立普妥组给予立普妥5 mg/(kg·d)灌胃,通瘀煎低、中、高剂量组分别以6.5、13.0、26.0 g/(kg·d)剂量灌胃给药,空白组和模型组以等量生理盐水灌胃。末次给药后,处死取材。苏木素-伊红(HE)染色观察主动脉管腔内粥样斑块;透射电镜摄片观察主动脉管腔内的超微结构变化;酶联免疫吸附试验检测血脂、血液流变学、黏附分子、主动脉组织炎症因子的含量;Western印迹法检测主动脉内细胞内信号传导及转录活化子(STAT)3、磷酸化(p)-STAT3、细胞因子信号转导抑制蛋白(SOCS)1的蛋白表达。结果与空白组相比,模型组主动脉病变相对面积、血脂水平、黏附分子及炎症因子含量显著增加(P<0.01);与模型组相比,立普妥组、通瘀煎低、中、高剂量组主动脉病变相对面积明显降低(P<0.01,P<0.05);通瘀煎高剂量组血脂水平、黏附分子、炎症因子含量、p-STAT3蛋白表达均明显降低,而STAT3、SOCS1的蛋白含量明显升高(均P<0.01)。结论通瘀煎能有效抑制ApoE基因敲除小鼠动脉粥样硬化斑块的形成,其机制可能通过降脂、抑制黏附分子聚集、减少炎症反应,抑制增生信号通路白细胞介素-6/STAT3的激活,有效保护主动脉血管壁,从而发挥抗动脉粥样硬化作用。     

Synergistic effect on the attenuation of collagen induced arthritis in tumor necrosis factor receptor I (TNFRI) and interleukin 6 double knockout mice

OBJECTIVE: To evaluate any additive effect on attenuation of collagen induced arthritis (CIA) in tumor necrosis factor receptor I (TNFRI) and interleukin 6 (IL-6) double knockout (DKO) mice. METHODS: CIA was induced in wild-type (Wt), TNFRI knockout (TNFRIKO), IL-6 knockout (IL-6KO), and DKO mice. Comparative studies were performed among these different mouse genotypes observing clinical (incidence, arthritis score), histological, radiologic, and immunological aspects. RESULTS: More than 90% of the Wt, TNFRIKO, and IL-6KO mice developed definite CIA, while only 20% of the DKO mice did so. Severity of arthritis, indicated by the arthritis score, was significantly reduced in both the TNFRIKO and IL-6KO mice compared with the Wt mice. Moreover, the severity of arthritis in the DKO mice was significantly reduced compared with each single KO mouse (by arthritis scores; DKO vs TNFRIKO, IL-6KO mice, p < 0.05). In addition, histological and radiologic changes were also significantly reduced in the DKO mice compared with each single KO mouse (by histological and radiologic scores; DKO vs TNFRIKO, IL-6KO mice, p < 0.05 and p < 0.01 respectively). In immunological studies, serum anti-type II collagen (anti-CII) antibody concentrations were significantly decreased in the DKO mice compared with each single KO mouse (DKO vs TNFRIKO, IL-6KO mice, p < 0.01). CONCLUSION: Simultaneous blockade of TNFRI and IL-6 showed synergistic rather than additive effects on the attenuation of CIA. Combinations of anti-TNF-a and anti-IL-6 therapy may provide clinical benefits for treatment of rheumatoid arthritis compared with therapy against each single cytokine.     

Gangliosides play pivotal roles in the regulation of complement systems and in the maintenance of integrity in nerve tissues

Gangliosides are considered to be essential in the maintenance and repair of nervous tissues; however, the mechanisms for neurodegeneration caused by ganglioside defects are unknown. We examined gene expression profiles in double knockout (DKO) mice of GM2/GD2 synthase and GD3 synthase genes and showed that the majority of complement genes and their receptors were up-regulated in cerebellum in DKO mice. Inflammatory reactions were demonstrated in those tissues by measuring up-regulated inflammatory cytokines, indicating the presence of complement activation and inflammation as reported in Alzheimer''s disease. Immunoblotting of fractionated membrane extracts by sucrose density gradient revealed that complement-regulatory molecules such as decay-accelerating factor and CD59 were dispersed from glycolipid-enriched microdomain/rafts in DKO cerebellum. Immunohistostaining of these molecules showed disordered membrane localization. These results suggested that dysfunction of complement-regulatory molecules may be due to abnormal glycolipid-enriched microdomain/rafts that triggered complement activation, subsequent inflammation, and neurodegeneration in DKO mice. Generation of the triple KO mice lacking complement activity in addition to the two glycosyltransferases suggested that complement activation is involved in the inflammatory reactions and neurodegeneration caused by the ganglioside deficiency.     

Age-dependent accumulation of mitochondrial DNA deletions in the aortic root of atherosclerosis-prone apolipoprotein E-knockout mice

PurposeTo investigate whether mitochondrial DNA (mtDNA) damage, specifically deletion, contributes to the development of atherosclerosis or is simply a secondary effect of the primary factors causing atherosclerosis.Materials and methodsmtDNA deletion was detected by PCR in the aortic root of atherosclerosis-prone C57BL/6J apolipoprotein (Apo) E gene deficient (−/−) mice and control C57BL/6J mice at different ages. Atherosclerotic plaques in the Apo E−/− mice were assessed using frozen sections of the aortic root. The protein levels of COX III and 8-oxoguanine glycosylase (OGG1) were determined.Resultswhile mtDNA deletions accumulated significantly in mice as young as 2- month-old, atherosclerotic plaques were not detected until mice were 6 months old or older, suggesting that mtDNA deletion occurs prior to the formation of atherosclerotic plaques in the aortic root of these mice. Moreover, the expression levels of mtDNA-encoded COX III protein in both 2-month-old and 16-month-old C57BL/6J ApoE−/− mice were significantly lower than those in C57BL/6J mice (p < 0.05). Additionally, the protein level of 8-oxoguanine glycosylase (OGG1), a mitochondrial enzyme that functions in DNA excision repair, decreased with age in these mice, indicating that age-related down-regulation of mtDNA excision repair also contributes to atherosclerosis in C57BL/6J ApoE−/− mice.ConclusionThese results reveal that mtDNA deletions occur during the early “initiation” stage of atherosclerosis in C57BL/6J ApoE−/− mice and have the potential to promote atherosclerosis.