Effects of OX40–OX40 ligand interaction on the levels of ROS and Cyclophilin A in C57BL/6J mice atherogenesis

Background

An increasing amount of evidence shows that the OX40–OX40L interaction serves an important function in atherosclerosis. However, the mechanism of the OX40 signaling pathway remains unclear. This study investigates the effect of OX40–OX40L interaction on the levels of intracellular reactive oxygen species (ROS) and the secretion of Cyclophilin A (CyPA) in C57BL/6J mice atherogenesis.

Methods

The atherosclerotic plaque model was established by placing a rapid perivascular carotid collar on C57BL/6J mice fed with a western-type diet. In vivo, the expressions of CyPA in mouse plaque and lymphocytes were detected by immunohistochemical and Western blot analyses, respectively. In vitro, the expression of CyPA protein in cultured lymphocytes of C57BL/6J mice was assessed by using Western blot analysis. The level of ROS was detected through flow cytometry.

Results

CyPA expression was significantly increased in the atherosclerotic lesions and lymphocytes from C57BL/6J mice. The ROS levels in OX40⁺-lymphocytes were increased in vitro and in vivo. After stimulating the OX40–OX40L interaction, the ROS and CyPA levels in lymphocytes were obviously increased in vitro, whereas anti-OX40L mAb significantly down-regulated the anti-OX40 mAb-induced ROS generation and inhibited CyPA secretion in lymphocytes.

Conclusion

The OX40–OX40L interaction up-regulates intracellular levels of ROS in C57BL/6J mice and increases CyPA secretion in lymphocytes. Increased CyPA secretion may serve an important function in atherosclerotic plaque formation.     

A low glycaemic diet improves oral glucose tolerance but has no effect on β-cell function in C57BL/6J mice

Aim: Clinical studies have suggested a role for dietary glycaemic index (GI) in body weight regulation and diabetes risk. Here, we investigated the long‐term metabolic effects of low and high glycaemic diets using the C57BL/6J mouse model. Methods: Female C57BL/6J mice were fed low or high glycaemic starch in either low‐fat or medium‐fat diets for 22 weeks. Oral and intravenous glucose tolerance tests were performed to investigate the effect of the experimental diets on glucose tolerance and insulin resistance. Results: In this study, a high glycaemic diet resulted in impaired oral glucose tolerance compared to a low glycaemic diet. This effect was more pronounced in the group fed a medium‐fat diet, suggesting that a lower dietary fat content ameliorates the negative effect of a high glycaemic diet. No effect on body weight or body fat content was observed in either a low‐fat diet or a medium‐fat diet. Static incubation of isolated islets did not show any differences in basal (3.3 mM glucose) or glucose‐stimulated (8.6 and 16.7 mM glucose) insulin secretion between mice fed a low or high glycaemic diet. Conclusion: Together, our data suggest that the impaired glucose tolerance seen after a high glycaemic diet is not explained by altered β‐cell function.     

消斑肽对C57BL/6J小鼠动脉粥样硬化斑块的影响

恨现从中华眼镜蛇毒素中提取一种多肽能抑制血管平滑肌细胞地殖,并在一定范围内杀伤快速增殖的平滑肌细胞。为验证消斑肽是否具有消除动脉粥样硬化斑块和预防再狭窄的药物效应,选用动脉粥样硬化敏感株近交系Ｃ５７ＢＬ／６Ｊ小鼠,经致动脉粥样硬化饮食饲喂１７周。使用消斑肽腹腔注射３．２μｇ／ｇ治疗４周,在主动脉窦部连续切片,油经Ｏ染色并在显微镜下观察,使用Ｒｏｂｅｒｔｓ ＆ Ｔｈｏｍｐｓｏｎ评分判定斑块消退情况。     

肺炎衣原体感染对C57BL/6J小鼠动脉粥样硬化形成的影响

目的:研究肺炎衣原体(CP)感染对C57BL/6J小鼠动脉粥样硬化(AS)形成的影响。方法:48只8周龄雄性C57BL/6J小鼠分为感染-高脂组、高脂组和感染组和对照组,喂养40周,取主动脉根部标本分析AS斑块面积,采用直接免疫荧光法检查血管壁CP抗原,微量免疫荧光法(Micro-IFA)检测CP特异性抗体IgG。结果:感染-高脂组小鼠平均AS斑块面积较高脂组增大[(135249±43748)μm2∶(96378±30945)μm2,P<0·05],感染组和对照组小鼠无AS样斑块形成。结论:CP感染可加速高脂饮食C57BL/6J小鼠的主动脉AS发展。     

慢性复合式应激对C57BL/6J小鼠凝血功能的影响

目的探讨慢性应激对C57BL/6J小鼠凝血功能的影响。方法将20～25g雄性C57BL/6J小鼠分成应激组及相应的对照组。应激组小鼠独笼饲养,将6个日相和6个夜相刺激及一个全天刺激随机安排到1w内,每w刺激顺序随机重新组合,连续8w。对照组动物则每5～6只小鼠合笼饲养,自由给水,整个实验过程中不接受任何刺激。两组动物均于刺激后的1、2、4、8w经内眦取血,用于空腹血糖含量,3、5、8w取血用于纤维蛋白原及凝血因子的检测。结果①与对照组相比较,应急组小鼠各时间点血糖含量均明显高于对照组(P0.01)。②纤维蛋白原含量检测显示,刺激后的3、5、8w应激组小鼠均低于对照组(P0.01);而出、凝血时间检测结果显示,刺激后各时间点应激组小鼠与对照组无显著差异。结论复合式慢性应激刺激可成功引起C57BL/6J小鼠处于应激状态,对C57BL/6J小鼠凝血功能造成一定的影响。     

C57BL/6J小鼠慢性应激形成过程中血细胞变化特点

目的 观察C57BL/6J小鼠慢性应激形成过程中血细胞的变化特点.方法 将20～25 g雄性C57BL/6J小鼠分成应激组及对照组.应激组小鼠独笼饲养,将6个日相和6个夜相刺激及一个全天刺激随机安排到1 w内,每周刺激顺序随机重新组合,连续8 w.对照组动物每5～6只小鼠合笼饲养,自由给水,整个实验过程中不接受任何刺激.两组动物均于刺激后的1、2、4、8 w经内眦取血,用于空腹皮质醇含量、血细胞计数及白细胞分类的检测.结果 与对照组相比较,应激组小鼠各时间点血浆皮质醇含量均明显高于对照组(P<0.01).刺激后的2、4、8 w应激组小鼠红细胞及血红蛋白含量均低于对照组(P<0.05或P<0.01),刺激后4和8 w应激组小鼠白细胞均低于对照组(P<0.01);而血小板计数和白细胞分类刺激后各时间点应激组与对照组无显著差异.结论 复合式慢性应激刺激可成功引起C57BL/6J小鼠处于应激状态,对C57BL/6J小鼠血细胞生成造成一定的影响.     

肺炎衣原体感染增强C57BL/6J小鼠氧化应激加速动脉粥样硬化发展

目的研究肺炎衣原体感染对C57BL/6J小鼠氧化应激及动脉粥样硬化形成的影响。方法48只C57BL/6J小鼠分为感染高脂组、高脂组、感染组和对照组,每组12只,喂养40周,作血清抗CP抗体和血脂水平检测,取主动脉根部标本分析动脉粥样硬化斑块面积,主动脉弓部标本检测超氧阴离子的产生。结果所有接种CP的小鼠,抗CP抗体IgG滴度均大于1∶128,未接种CP者抗CP抗体阴性,感染高脂组和高脂组小鼠血清总胆固醇、低密度脂蛋白水平明显高于对照组,感染高脂组、高脂组和感染组超氧阴离子的产生明显高于对照组[(1974.25±650.49)、(701.00±105.16)、(455.62±77.54)counts·mg-1·min-1比(142.25±31.82)counts·mg-1·min-1,P<0.001],氧化荧光染料定位分析发现感染高脂组、高脂组和感染组小鼠主动脉超氧阴离子产生明显增多,且感染高脂组小鼠平均粥样硬化斑块面积大于高脂组[(135249±43748)μm2比(96378±30945)μm2,P<0.05]。结论肺炎衣原体感染可加速高脂饮食C57BL/6J小鼠的主动脉粥样硬化发展,并引起C57BL/6J小鼠主动脉超氧阴离子产生增多,提示活性氧产生增多、氧化应激增强可能是肺炎衣原体感染加速动脉粥样硬化发展的机制之一。     

缺氧对C57BL/6J小鼠瘦素及其受体基因表达的影响

目的　研究缺氧对小鼠瘦素及其受体 (包括转运性受体Ra、Rc和功能性受体Rb)mRNA表达变化的影响,以进一步明确瘦素和呼吸功能的关系。方法　利用医学自动测控缺氧仓(XQ Ⅰ型)复制机体常压缺氧状态,将小鼠分为正常对照组、缺氧 24h组、缺氧 48h组,然后利用逆转录 聚合酶链反应(RT-PCR)分别定量检测瘦素及其受体mRNA表达水平。根据cDNA条带的灰度值计算其相对含量,各种产物与磷酸甘油醛脱氢酶 (GADPH)的比值表示其相对表达水平。结果(1)缺氧 24h组和缺氧 48h组瘦素mRNA表达水平分别为 0.903±0.190、0.856±0.336,显著高于正常对照组(0.508±0.207,P均<0.05); (2)缺氧 24h组和缺氧 48h组RamRNA表达水平分别为0 724、0.700,分别为正常对照组 (0 630)的 115%、111%; (3)缺氧 24h组和缺氧 48h组RbmRNA表达水平分别为 0.381±0.038、0.345±0.042,与正常对照组(0.258±0.049)比较差异均有统计学意义(P均<0.05); (4)缺氧 24h组和缺氧 48h组RcmRNA表达水平分别为 0.299、0.292,分别为正常对照组(0.133)表达水平的 224%、219%。结论　缺氧作为一种独立因素可在一定范围内刺激机体瘦素、瘦素受体Ra、Rb、Rc基因表达增加,从而在正向调节机体呼吸功能中发挥重要作用。     

MSCs对辐射诱导C57BL/6J鼠胸腺瘤的抑制作用

目的 观察MSCs对辐射诱导C57BL/6J鼠胸腺瘤模型的抑制作用.方法 无菌分离C57BL/6J鼠股骨,全骨髓贴壁法培养MSCs.将实验分为三组:正常组对照组、辐射组及MSCs治疗组.应用深部X线放射治疗机对C57BL/6J鼠进行全身照射,1次/w,共4次.末次照射结束后第二日,治疗组小鼠经尾静脉回输MSCs,1次/w,共2次.6个月后无菌取出各组的C57BL/6J鼠胸腺,研磨制成单细胞悬液,流式细胞仪检测CD45表达.提取组织RNA,利用RT-PCR检测caspase-3表达.结果 MSCs对辐射诱导C57 BL/6J鼠胸腺瘤模型CD45+的表达,治疗组CD45阳性百分率高于模型组(P＜0.01),模型组CD45阳性百分率低于正常对照组(P＞0.05).MSCs对辐射诱导C57BL/6J鼠胸腺瘤模型胸腺caspase-3的表达,治疗组Caspase-3 mRNA表达高于模型组(P＜0.05),高于正常对照组(P＜0.05),模型组Caspase-3mRNA表达接近于正常对照组(P＞0.05).结论 MSCs对辐射诱导C57BL/6J鼠胸腺瘤模型有抑制作用.     

Oral infection of C57BL/6 mice with Toxoplasma gondii: a new model of inflammatory bowel disease?

Infection with Toxoplasma gondii is naturally acquired through the oral route by ingestion of undercooked or raw meat containing cysts of the parasite or through ingestion of contaminated water or food contaminated with cysts or oocysts. Following peroral infection with 100 cysts of the ME49 strain of T. gondii, C57BL/6 mice die within 13 days after infection, whereas BALB/c mice survive. At day 7 of infection, massive necrosis of the villi and mucosal cells in the ilea is observed in C57BL/6 but not BALB/c mice. CD4(+) T cells, interferon-gamma, tumor necrosis factor-alpha, and inducible nitric oxide synthase mediate the development of necrosis. These findings indicate a Th1-type immunopathology, with parasite replication appearing to be involved in the first 3 days of infection. Murine and human studies on the immunopathogenesis of inflammatory bowel disease (e.g., Crohn's disease) also indicate a Th1-type immunopathology. The shared and distinct features of oral infection of mice with T. gondii and murine models of inflammatory bowel disease are discussed herein.     

Interferon-γ is not involved in the intestinal manifestations of the acute murine semiallogenic graft-versus-host disease

BACKGROUND: The acute murine semiallogenic graft-versus-host disease (GvHD) is known to be associated with Th1 cytokines secreting lymphocytes in the spleen and lymph nodes. However, whether this cytokine secretion pattern is also involved in the intestinal manifestations of acute GvHD (crypt hyperplasia and villous atrophy) is not known, so far. METHODS: We first investigated the secretion of interleukin (IL) 4 (indicative of Th2-type differentiation) and interferon (IFN) 7 (Th1-type differentiation) by splenic and by small bowel lamina propria lymphocytes. In addition, animals were treated with neutralizing antibodies to IL-4 or IL-12. The effect of this treatment on the intestinal morphology was examined. Second, we also investigated the effect of donor-derived IFN-gamma by using donor lymphocytes from IFN-gamma knock-out animals. Third, animals were treated with the fusion protein OX40-Ig which interferes with the OX40-OX40L interaction and thereby inhibits the intestinal manifestations of acute GvHD. RESULTS: We found that, whereas splenic lymphocytes secrete an excess of IFN-gamma, lymphocytes of the intestinal lamina propria secrete less IFN-gamma and IL-4 than control animals. When OX40-Ig is administered to animals with acute GvHD, the intestinal histology normalizes as well as the secretion of IFN-y and IL-4, indicating that the intestinal morphology is not affected by the secretion of IFN-gamma by lamina propria lymphocytes. The treatment of animals suffering from acute GvHD with anti-IL-4 and anti-IL-12, which blocks the differentiation of IFN-gamma secreting T-lymphocytes, did not significantly affect the development of crypt hyperplasia or villous atrophy. Furthermore, donor lymphocytes of IFN-gamma knock-out animals also induced the intestinal manifestations of acute GvHD. CONCLUSIONS: These findings indicate that IFN-gamma is not crucial for the development of crypt hyperplasia and villous atrophy in the murine semiallogenic GvHD.     

炎症对C57BL/6J小鼠肝脏胆固醇积聚及纤维化的影响

目的 观察炎症对小鼠肝脏内胆固醇蓄积、内质网应激及纤维化的影响.方法 将8周龄雄性C57BL/6J小鼠随机分为对照组(n=6)和炎症组(n=6),均以高脂饮食,炎症组小鼠隔天皮下注射0.5ml 10％酪蛋白以建立慢性炎症模型,对照组注射等量等渗盐水,14周处死.收集血清和肝组织样本,测定血清及肝组织中炎症因子及脂质水平;油红O、天狼猩红和Masson三色染色观察肝脂质沉积、形态改变以及纤维化程度;荧光实时定量PCR检测肝组织单核细胞趋化蛋白1、肿瘤坏死因子(TNF)α 、胆固醇调节元件结合蛋白(SREBP)2、低密度脂蛋白受体、3-羟-3-甲基戊二酰辅酶A还原酶、活化转录因子6、葡萄糖调节蛋白(GRP)78、骨形成蛋白(BMP)7、转化生长因子(TGF)β、层黏连蛋白、Ⅰ/Ⅳ型胶原的mRNA水平.对数据进行两样本均数t检验或近似t检验.结果 血清中,炎症组白细胞介素(IL)6的水平[(32.41±7.42)pg/ml]高于对照组[(12.55±4.75)pg/ml],t=5.522,P＜ 0.01;总胆固醇水平为(10.62±0.48)mmol/L,低于对照组的(14.82±1.56)mmol/L,t=6.303,P＜0.01.肝组织中,炎症组TNFα的mRNA相对表达水平为2.12±0.72,高于对照组的1.05±0.35,t=3.132,P＜0.01;总胆固醇水平为(23.21±8.75)μg/mg,高于对照组的(12.10±2.57)μg/mg,t=2.984,P＜0.05.油红O染色表明,炎症组肝脏脂滴沉积异常增多;天狼猩红和masson三色染色可见炎症组有更为明显的肝纤维化改变.荧光定量PCR检测表明炎症组SREBP-2、GRP78的mRNA相对表达水平分别为2.63±0.13、2.21±0.99,高于对照组的1.01±0.19、1.07±0.47,t值分别为15.641和2.031,P值均＜0.05.TGF β、Ⅰ型胶原的mRNA相对表达水平分别为1.38±0.28、1.71±0.51,高于对照组的1.01±0.14、1.02±0.27,t值分别为3.032和3.152,P值均＜0.05.BMP-7的mRNA相对表达水平为0.55±0.25,低于对照组的1.01±0.15,t=3.765,P＜0.01.结论 慢性炎症可以明显促进小鼠肝脏胆固醇沉积而加重肝细胞损害,刺激内质网应激,从而增加促纤维化因子表达、抑制抗纤维化因子表达,促进肝纤维化发生.     

C57BL/6J小鼠感染多房棘球绦虫未增加一氧化氮的产生

曾报道未感染小鼠的巨噬细胞经体外激活时具有显著的杀虫活性,且认为这种活性与小鼠细胞内亚硝酸产物相关。本研究通过测定感染小鼠尿液中硝酸盐排泄物,以评价一氧化氮(NO)在细胞介导抗多房棘球绦虫感染中的作用。 取6周龄的雌性C57BL/6J小鼠20只,分四组,每组5只,感染组有2组,均肝内注     

Antisense reduction of 11β-hydroxysteroid dehydrogenase type 1 enhances energy expenditure and insulin sensitivity independent of food intake in C57BL/6J mice on a Western-type diet

We recently reported that inhibition of 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) by antisense oligonucleotide (ASO) improved hepatic lipid metabolism independent of food intake. In that study, 11β-HSD1 ASO-treated mice lost weight compared with food-matched control ASO-treated mice, suggesting treatment-mediated increased energy expenditure. We have now examined the effects of 11β-HSD1 ASO treatment on adipose tissue metabolism, insulin sensitivity, and whole-body energy expenditure. We used an ASO to knock down 11β-HSD1 in C57BL/6J mice consuming a Western-type diet (WTD). The 11β-HSD1 ASO-treated mice consumed less food, so food-matched control ASO-treated mice were also evaluated. We characterized body composition, gene expression of individual adipose depots, and measures of energy metabolism. We also investigated glucose/insulin tolerance as well as acute insulin signaling in several tissues. Knockdown of 11β-HSD1 protected against WTD-induced obesity by reducing epididymal, mesenteric, and subcutaneous white adipose tissue while activating thermogenesis in brown adipose tissue. The latter was confirmed by demonstrating increased energy expenditure in 11β-HSD1 ASO-treated mice. The 11β-HSD1 ASO treatment also protected against WTD-induced glucose intolerance and insulin resistance; this protection was associated with smaller cells and fewer macrophages in epididymal white adipose tissue as well as enhanced in vivo insulin signaling. Our results indicate that ASO-mediated inhibition of 11β-HSD1 can protect against several WTD-induced metabolic abnormalities. These effects are, at least in part, mediated by increases in the oxidative capacity of brown adipose tissue.     

链脲菌素剂量对C57BL/6J小鼠糖尿病诱导效应的影响

目的 观察不同剂量链脲菌素(STZ)对C57BL/6J小鼠糖尿病诱导效应的影响,探讨其量效关系及最佳剂量范围.方法 将C57BL/6J小鼠按数字随机法分为9个STZ剂量组(A～I组,STZ分别为30、60、80、100、120、150、180、210、240 ms/kg体重),每组15只,腹腔注射;1个对照组,10只,腹腔注射等体积缓冲液.观察各组血糖、体重、血胰岛素和45 d生存率的变化,分析其与STZ剂量的关系.同时取A、C、G及对照组小鼠胰腺、肾脏组织做病理学检杏,并行免疫组化观察胰腺胰岛素及肾脏CD<,68>的表达.结果 C～G组较对照组血糖增高、体重及血胰岛素含量较对照组下降非常显著(P<0.05),且STZ剂量与血糖呈正相关(r=0.984,P<0.05),与血胰岛素含量呈负相关(r=-0.994,P<0.05).C～G组成模率达86.7%～100%,显著高于A、B组的0和40%(P<0.05);45 d生存率为46.7%～73.3%,显著高于H、I组的13.3%和0(P<0.05).A组胰腺、肾脏组织未见明显破坏;C组及G组出现典型的胰岛萎缩变形,胰岛素分泌颗粒减少,肾小球系膜外基质沉着及球周臣噬细胞浸润.结论 C57BL/6J小鼠腹腔注射STZ以80～180 mg/kg体重的剂量制模率高、生存率高,且靶器官损伤典型;该剂量与血糖呈正相关,与血胰岛素含量呈负相关.     

高脂饮食诱导下C57BL/6J小鼠外周血单核细胞变化的研究

目的动态观察高脂饮食诱导小鼠肥胖发生的过程中外周循环单核细胞的变化特点。方法选取5周龄C57BL/6J小鼠80只,适应性饲养1周后随机分为两组:高脂饮食(HF)组予60%脂肪饲料;正常饮食(Con)组予10%脂肪饲料。于相应时间点采集外周血单核细胞,以荧光抗体APC-CD11b、PE-CD115、Alexa Flour-430-Ly6C标记单核细胞和其亚群后,流式细胞仪检测,同时免疫组织化学检测3d和15周时的内脏脂肪组织巨噬细胞表达情况。结果高脂饮食诱导下,外周循环单核细胞亚群比例发生改变,早期巡逻单核细胞(Ly6C-low)比例增加,炎性单核细胞(Ly6C-hi)单核细胞比例减少,后期相反,15d时单核细胞数目减少最明显。结论高脂饮食过程中,外周循环单核细胞及亚群早期呈减少趋势,可能与组织脂肪细胞浸润有关。     

BALB/c和C57BL/6J小鼠高架十字迷宫焦虑表现行为比较*

目的比较BALB/c和C57BL/6J小鼠在高架十字迷宫的焦虑表现。方法记录BALB/c和C57BL/6J在高架迷宫实验中焦虑行为数据（进入开放臂次数、向下探究次数、封闭臂后腿直立次数和进入开放臂时间等）。结果C57BL/6J与BALB/c小鼠相同性别小鼠及同品系雌雄间的入开臂次数、入开臂次数比例、入开臂时间和入开臂时间比例相比,差异均有统计学意义（P<0.01）。结论 C57BL/6J或BALB/c小鼠的雌性小鼠均比雄性小鼠更不焦虑,此次实验中,C57BL/6J雌性小鼠焦虑行为表现最低。