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31.
《Biomedical and environmental sciences : BES》2015,(11):799-807
ObjectiveThe roles of cerebrovascular oxidative stress in vascular functional remodeling have been described in hindlimb-unweighting (HU) rats. However, the underlying mechanism remains to be established.
MethodsWe investigated the generation of vascular reactive oxygen species (ROS),Nox2/Nox4 protein and mRNA levels, NADPH oxidase activity, and manganese superoxide dismutase (MnSOD) and glutathione peroxidase-1 (GPx-1) mRNA levels in cerebral and mesenteric smooth muscle cells (VSMCs) of HU rats.
ResultsROS production increased in cerebral but not in mesenteric VSMCs of HU rats compared with those in control rats.Nox2 and Nox4 protein and mRNA levels were increased significantly but MnSOD/GPx-1 mRNA levels decreased in HU rat cerebral arteries but not in mesenteric arteries. NADPH oxidases were activated significantly more in cerebral but not in mesenteric arteries of HU rats. NADPH oxidase inhibition with apocynin attenuated cerebrovascular ROS production and partially restored Nox2/Nox4 protein and mRNA levels, NADPH oxidase activity, and MnSOD/GPx-1 mRNA levels in cerebral VSMCs of HU rats.
ConclusionThese results suggest that vascular NADPH oxidases regulate cerebrovascular redox status and participate in vascular oxidative stress injury during simulated microgravity. 相似文献
MethodsWe investigated the generation of vascular reactive oxygen species (ROS),Nox2/Nox4 protein and mRNA levels, NADPH oxidase activity, and manganese superoxide dismutase (MnSOD) and glutathione peroxidase-1 (GPx-1) mRNA levels in cerebral and mesenteric smooth muscle cells (VSMCs) of HU rats.
ResultsROS production increased in cerebral but not in mesenteric VSMCs of HU rats compared with those in control rats.Nox2 and Nox4 protein and mRNA levels were increased significantly but MnSOD/GPx-1 mRNA levels decreased in HU rat cerebral arteries but not in mesenteric arteries. NADPH oxidases were activated significantly more in cerebral but not in mesenteric arteries of HU rats. NADPH oxidase inhibition with apocynin attenuated cerebrovascular ROS production and partially restored Nox2/Nox4 protein and mRNA levels, NADPH oxidase activity, and MnSOD/GPx-1 mRNA levels in cerebral VSMCs of HU rats.
ConclusionThese results suggest that vascular NADPH oxidases regulate cerebrovascular redox status and participate in vascular oxidative stress injury during simulated microgravity. 相似文献
32.
研究关附甲素(Guanfu base A,GFA)的抗房颤和抗氧化作用。大鼠尾静脉注射乙酰胆碱-氯化钙混合液(Ca Cl210 mg/m L,Ach 66μg/m L),连续7 d建立房颤模型。SD大鼠分为正常组、模型组、GFA治疗组(6 mg/kg,12 mg/kg)、胺碘酮(Amiodarone,Ami)治疗组(50 mg/kg)以及洛伐他汀(Lovastatin,Lov)治疗组(10 mg/kg)。测定大鼠房颤持续时间和有效不应期(AERP),用实时荧光定量PCR方法和Western blot方法测定氧化应激相关基因表达,试剂盒测定抗氧化酶的活性。结果显示:与模型组相比,GFA(6 mg/kg,12 mg/kg,po)治疗4 d后能缩短房颤持续时间,延长AERP,超氧化物歧化酶的活力提高,丙二醛含量明显下降。心房肌p22phox、p47phox、p67phox、gp91phox表达下调,膜Rac-1与胞浆Rac-1比值显著下降,缝隙连接蛋白(connexin40)表达升高。提示GFA(6 mg/kg,12 mg/kg)能有效抑制房颤引起的大鼠心房氧化应激损害,抑制房颤发生。 相似文献
33.
Mengxin Tian Weiren Liu Lei Jin Xifei Jiang Liuxiao Yang Zhenbin Ding Yinghao Shen Yuanfei Peng Dongmei Gao Lixin Li Jian Zhou Shuangjian Qiu Zhi Dai Jia Fan Yinghong Shi 《International journal of clinical and experimental pathology》2015,8(4):3892-3900
Lysyl oxidase like 4 (LOXL4), a member of the secreted copper-dependent amine oxidases that contribute to the assemble and maintenance of the extracellular matrix (ECM), was found to be up-regulated or down-regulated in different cancer types, suggesting its paradoxical roles in cancer. The specific role of LOXL4 in hepatocellular carcinoma (HCC), however, is still yet to be defined. Twenty-eight pairs of HCC specimens were used for LOXL4 mRNA expression analysis. The mRNA expression in HCC cell lines was examined, and HepG2 was selected for LOXL4 small interfering RNA (siRNA) interference to investigate the biological function of LOXL4, LOXL4 immunohistochemical staining was performed using a tissue microarray containing 298 HCC patients. The prognostic and diagnostic value of LOXL4 was evaluated using Cox regression and Kaplan-Meier analysis. LOXL4 mRNA or protein expression was significantly lower in HCC tissues than peritumoral tissues (LOXL4 mRNA expression, P = 0.018; LOXL4 protein expression, P < 0.001). Low LOXL4 expression was associated with lower overall survival (OS) rates and higher cumulative recurrence rates. Multivariate analysis indicated that LOXL4 was an independent prognostic indicator for OS and time to recurrence (TTR). Our results revealed that LOXL4 was down-regulated in HCC and correlated with aggressive tumors and a worse clinical outcome. LOXL4 may be a potential biomarker to identify the HCC patients with a higher risk of recurrence. 相似文献
34.
目的:探讨NADPH氧化酶(Nox)抑制剂对晚期氧化蛋白产物(AOPP)刺激下血管内皮的保护作用。方法:体外培养人脐静脉内皮细胞进行实验,人血清白蛋白(HSA)作为阴性对照,用不同浓度(50、100和200mg/L)AOPP-HSA共同孵育8 h后,利用5-氯甲基二乙酸荧光素标记人急性单核细胞白血病细胞株THP-1的细胞渗出数量反映内皮细胞的通透性,研究不同浓度AOPP-HSA对单层细胞通透性的影响。此外,另将细胞分为HSA组、AOPP-HSA组和AOPP-HSA+二联苯碘(DPI)组,进而探讨AOPP-HSA对Nox活化水平的影响以及DPI对内皮细胞骨架重构和细胞通透性改变的作用。结果:AOPP-HSA可使血管内皮细胞通透性明显增加(P0.05)。AOPP-HSA可导致Nox磷酸化水平上升,并呈剂量依赖性。Nox抑制剂DPI预处理组可抑制AOPP-HSA刺激下Nox磷酸化水平的上升,从而抑制血管内皮细胞通透性增加及细胞骨架重构。结论:AOPP-HSA可通过激活Nox导致血管内皮细胞通透性受损,Nox抑制剂DPI可以降低其通透性及细胞骨架重构,起到一定的保护作用。 相似文献
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38.
目的:通过体外酶学试验研究Apigenin对黄嘌呤氧化酶活性的影响及抑制机制。方法:运用紫外分光光度计测定尿酸生成导致的吸光度变化值,测定波长为292 nm,以黄嘌呤为底物根据测定结果绘制Lineweaver-Burk和Dixon图。结果:Apigenin对黄嘌呤氧化酶具有较强的抑制作用,其Ki值为0.151 3μg/ml,抑制类型为混合型;而别嘌呤醇作为参照,其Ki值为0.62μg/ml,抑制类型为竞争性抑制。结论:Apigenin可明显抑制黄嘌呤氧化酶活性。 相似文献
39.
Immunology of Helicobacter pylori: insights into the failure of the immune response and perspectives on vaccine studies 总被引:7,自引:0,他引:7
Helicobacter pylori infects the stomach of half of the human population worldwide and causes chronic active gastritis, which can lead to peptic ulcer disease, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. The host immune response to the infection is ineffective, because the bacterium persists and the inflammation continues for decades. Bacterial activation of epithelial cells, dendritic cells, monocytes, macrophages, and neutrophils leads to a T helper cell 1 type of adaptive response, but this remains inadequate. The host inflammatory response has a key functional role in disrupting acid homeostasis, which impacts directly on the colonization patterns of H pylori and thus the extent of gastritis. Many potential mechanisms for the failure of the host response have been postulated, and these include apoptosis of epithelial cells and macrophages, inadequate effector functions of macrophages and dendritic cells, VacA inhibition of T-cell function, and suppressive effects of regulatory T cells. Because of the extent of the disease burden, many strategies for prophylactic or therapeutic vaccines have been investigated. The goal of enhancing the host's ability to generate protective immunity has met with some success in animal models, but the efficacy of potential vaccines in humans remains to be demonstrated. Aspects of H pylori immunopathogenesis are reviewed and perspectives on the failure of the host immune response are discussed. Understanding the mechanisms of immune evasion could lead to new opportunities for enhancing eradication and prevention of infection and associated disease. 相似文献
40.
Suppressive effects of the NADPH oxidase inhibitor apocynin on intestinal tumorigenesis in obese KK‐Ay and Apc mutant Min mice 下载免费PDF全文