高氧环境下ROS对肠上皮细胞表达TNF-α和HIF-1-α的影响

目的探讨长时间高氧治疗对机体造成严重不良反应的原因。方法用不同浓度的H_2O_2(100、200、400μM)和85%的高氧对肠上皮细胞干预24 h后,采用免疫组织化学方法检测高氧对TNF-α和HIF-1-α的影响。结果与对照组相比,高氧组和各H_2O_2组TNF-α和HIF-1-α表达水平显著增加(P<0.05),并且高氧组明显高于H_2O_2组。结论高氧环境中肠上皮细胞的损伤伴随着ROS的增加,因此认为在高氧环境中ROS对肠道损伤发挥着重要作用。     

Hypoxia and succinate antagonize 2-deoxyglucose effects on glioblastoma

Glioblastoma multiforme (GBM) are highly proliferative brain tumors characterized by a hypoxic microenvironment which controls GBM stem cell maintenance. Tumor hypoxia promotes also elevated glycolytic rate; thus, limiting glucose metabolism is a potential approach to inhibit tumor growth. Here we investigate the effects mediated by 2-deoxyglucose (2-DG), a glucose analogue, on primary GBM-derived cells maintained under hypoxia. Our results indicate that hypoxia protects GBM cells from the apoptotic effect elicited by 2-DG, which raises succinate dehydrogenase activity thus promoting succinate level decrease. As a consequence hypoxia inducible factor-1α (HIF-1α) degradation occurs and this induces GBM cells to acquire a neuronal committed phenotype. By adding succinate these effects are reverted, as succinate stabilizes HIF-1α and increases GBM stem cell fraction particularly under hypoxia, thus preserving the tumor stem cell niche.2-DG inhibits anaerobic glycolysis altering GBM cell phenotype by forcing tumor cells into mitochondrial metabolism and by inducing differentiation.     

Hypoxia-induced iNOS expression in microglia is regulated by the PI3-kinase/Akt/mTOR signaling pathway and activation of hypoxia inducible factor-1alpha

Exposure to hypoxia induced microglia activation and animal studies have shown that neuronal cell death is correlated with microglial activation following cerebral ischemia. Thus, it is likely that toxic inflammatory mediators produced by activated microglia under hypoxic conditions may exacerbate neuronal injury following cerebral ischemia. The hypoxia-inducible factor-1 (HIF-1) is primarily involved in the sensing and adapting of cells to changes in the O(2) level, which is regulated by many physiological functions. However, the role of HIF-1 in microglia activation under hypoxia has not yet been defined. In the current work, we investigate the signaling pathways of HIF-1alpha involved in the regulation of hypoxia-induced overexpression of inducible NO synthase (iNOS) in microglia. Exposure of primary rat microglial cultures as well as established microglial cell line BV-2 to hypoxia induced the expression of iNOS, indicating that hypoxia could lead to the inflammatory activation of microglia. iNOS induction was accompanied with NO production. Moreover, the molecular analysis of these events indicated that iNOS expression was regulated by the phosphatidylinositol 3-kinase (PI3-kinase)/AKT/ mammalian target of rapamycin (mTOR) signaling pathway and activation of hypoxia inducible factor-1alpha (HIF-1alpha). Thus, during cerebral ischemia, hypoxia may not only directly damage neurons, but also promote neuronal injury indirectly via microglia activation. In this study, we demonstrated that hypoxia induced iNOS expression by regulation of HIF-1alpha in microglia.     

乳腺癌组织中ING4、HIF-1α和HIF-2α表达及与肿瘤微血管新生的关系

目的 探讨乳腺癌组织中生长抑制因子4(ING4)、缺氧诱导因子-1α(HIF-1α)和缺氧诱导因子-2α(HIF-2α)表达及与肿瘤微血管新生的关系.方法 选取择期行手术治疗的乳腺癌病人107例,利用实时荧光定量PCR技术检测乳腺癌和癌旁组织中HIF-1α、HIF-2α、ING4和血管内皮生长因子(VEGF)基因表达,免疫组化染色检测乳腺癌和癌旁组织中微血管密度(MVD).结果 乳腺癌组织中HIF-1α mRNA、HIF-2α mRNA相对表达量均高于癌旁组织,而ING4 mRNA 相对表达量低于癌旁组织,差异有统计学意义(P<0.05);HIF-1α mRNA相对表达量与淋巴结转移有关(P<0.05),HIF-2α mRNA相对表达量与肿瘤大小、淋巴结转移有关(P<0.05),ING4 mRNA相对表达量与临床分期、淋巴结转移有关(P<0.05);乳腺癌组织中VEGF mRNA相对表达量和MVD计数均高于癌旁组织,均差异有统计学意义(P<0.05);Pearson相关分析显示,乳腺癌组织中HIF-1α mRNA、HIF-2α mRNA相对表达量均与VEGF mRNA相对表达量和MVD计数呈正相关(r=0.382、0.417和0.408、0.491,P<0.05),ING4 mRNA相对表达量均与VEGF mRNA相对表达量和MVD计数呈负相关(r=-0.395、-0.502,P<0.05).结论 乳腺癌组织中HIF-1α、HIF-2α基因表达升高,而ING4基因则被抑制,可能共同参与了乳腺癌组织中血管新生.     

Q39, a novel synthetic Quinoxaline 1,4-Di-N-oxide compound with anti-cancer activity in hypoxia

Hypoxia is one of the inevitable circumstances in various tumors and results in tumor resistance to radiotherapy and chemotherapy. The present data showed that 3-(4-bromophenyl)-2-(ethylsulfonyl)-6-methylquinoxaline 1,4-dioxide (Q39), derived from Quinoxaline 1,4-Di-N-oxide, possessed high anti-cancer activity in hypoxia. Cytotoxicity assay demonstrated that Q39 is a potential and high efficient anti-cancer compound in all tested cell lines with IC50 values of 0.18+/-0.03-8.88+/-1.12 microM in hypoxia and 0.33+/-0.04-8.74+/-1.28 microM in normoxia . In the following work concerning the mechanism of Q39 in hypoxia, we confirmed that Q39 could cause the apoptosis of K562 cells in a time-dependent manner. By fluorescence stain assay, Q39-induced mitochondria membrane potential (Delta Psi m) loss was observed in K562 cells in hypoxia. Based on the western blotting, Q39 decreased the protein expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) in hypoxia. The compound caused the activation of caspase-3 and subsequent cleavage of its substrate poly (ADP-ribose) polymerase (PARP) in hypoxia. Meanwhile, we found the upregulation of Bax by Q39 in K562 cells as well as the downregulation of Bcl-2. Q39 also influenced the expression of Mitogen-Activated Protein Kinase (MAPKs) and other proteins relative to mitochondria induced apoptosis. In addition, Q39-mediated apoptosis was not reversed after treatment with the JNK-specific inhibitor. In summary, the present study demonstrated Q39 was a novel compound against cancer cells in hypoxia. The mitochondrial pathway mediated by Bcl-2 protein family and MAPKs and the HIF-1 pathway might be involved in signaling Q39-induced apoptosis.     

五味子乙素对HK-2细胞缺氧损伤的保护作用

卢爱龙 1, 谭小月 2, 张勉之 3△, 吴银娜摘要： 目的 探讨五味子乙素 （Sch B） 对氯化钴 （CoCl2） 诱导的人类近端肾小管上皮 （HK-2） 细胞缺氧损伤的保护作用及其可能机制。方法 取离体培养 HK-2 细胞, 随机分为 4 组。对照 （C） 组： 细胞未经任何处理。CoCl2组 （化学乏氧组）： 加入 600 μmol/L 的 CoCl2 处理 24 h。Sch B 预保护（CoCl2+ Sch B）组： 分别加入终浓度为 1 μmol/L 和 10 μmol/L Sch B 预处理 2 h 后, 其余操作同 CoCl2 组。Sch B 组： 分别加入终浓度 1 μmol/L 和 10 μmol/L Sch B 处理 2 h。CCK-8 试剂盒检测各组细胞活性; AnnexinV-FITC/PI 双标记流式细胞仪检测各组细胞凋亡率; Western Blot 检测各组缺氧诱导因子-1α（HIF-1α）蛋白表达; RT-PCR 检测各组 HIF-1α和诱导型一氧化氮合酶（iNOS） mRNA 表达。结果 与对照组相比, CoCl2组细胞活性明显降低, 细胞凋亡率、 HIF-1α蛋白表达量和 iNOS mRNA 表达量显著增加, HIF-1α mRNA 表达量差异无统计学意义; Sch B 预保护组较 CoCl2组细胞活性显著增加, 细胞凋亡率、 HIF-1α蛋白表达量、 HIF-1α及 iNOS mRNA 表达量均显著减少; Sch B 组与对照组细胞活性、 细胞凋亡率差异无统计学意义, Sch B 组几乎不表达 HIF-1α蛋白。结论 Sch B 可能通过抑制 HIF-1α蛋白和 iNOS mRNA 的表达减少 HK-2 细胞的凋亡, 从而对 HK-2 细胞缺氧损伤起保护作用。     

缺氧诱导因子-1/2在肝细胞癌中的研究进展

肝细胞癌(hepatocellular carcinoma,HCC)是全球范围内高发性恶性肿瘤之一,目前对于肝癌的临床治疗非常的有限.仅有的一线治疗药物索拉菲尼(Sorafenib)和乐伐替尼(Lenvatinib)也未能显著的延长患者生存期.因此,寻找新的治疗靶点尤为迫切.大量数据表明,缺氧是实体瘤的一个重要特征,在...     

HIF-1α在甲状腺肿瘤中的表达及其临床意义

目的探讨HIF-1α蛋白在甲状腺肿瘤组织中的表达及其临床意义。方法应用免疫组织化学Envision法检测140例甲状腺癌组织、50例甲状腺腺瘤及30例正常甲状腺组织中HIF-1α蛋白的表达,分析HIF-1α蛋白的表达与甲状腺癌临床病理特征之间的关系。结果甲状腺癌中HIF-1α阳性表达明显高于正常甲状腺组织和甲状腺腺瘤,差异有统计学意义(P<0.05)。HIF-1α在140例甲状腺癌组织中的表达与是否有颈部淋巴结转移、浸润深度、分化程度以及AJCC分期密切相关(P<0.01)。结论 HIF-1α参与了甲状腺癌的形成过程,并与甲状腺癌的浸润、转移和预后密切相关,可作为辅助甲状腺癌早期鉴别诊断和预测其生物学行为的参考指标。     

HIF-1α反义寡核苷酸对肝癌细胞增殖凋亡的影响及机制

目的：本研究通过应用 HIF-1α反义寡核苷酸（antisense oligodeoxynucleotide,ASODN）处理 SMMC-7721肝癌细胞,观察其对 SMMC-7721肝癌细胞增殖的作用和对细胞周期及凋亡率的影响及其机制。方法肝癌细胞系SMMC-7721分对照组和试验组。对照组细胞常规培养,试验组细胞施加 HIF-1α的 ASODN 干预,设浓度梯度和时间梯度。检测不同药物浓度、不同时间对 SMMC-7721细胞的增殖的作用及对细胞周期和凋亡率的影响。对 bcl-2、bax、surviving mRNA 表达产物相对定量,并对 SMMC-7721细胞胞浆 bcl-2、bax、survivin 蛋白进行相对定量分析。结果与对照组相比,各处理组 OD 值均有显著下降,细胞数量降低,且各实验组相比呈明显的时间-剂量依赖效应,差异有统计学意义（ P <0.05）。不同浓度 HIF-1α的 ASODN 处理细胞后,均可使各处理组 G0/ G1期细胞增多,S 期细胞减少,且呈时间-剂量依赖效应,差异有统计学意义（ P <0.05）。不同浓度 HIF-1α的 ASODN 处理细胞不同时间后,与对照组相比,各实验组 bcl-2 mRNA 和 survivin mRNA 表达均有显著下降,差异有统计学意义（ P <0.05）。而 bax 的 mRNA无明显变化趋势（ P >0.05）。不同浓度 HIF-1α的 ASODN 处理细胞不同时间后,与对照组相比,各实验组 bcl-2和survivin 的蛋白表达显著下降,bax 的蛋白表达显著增加,差异有统计学意义（ P <0.05）。结论 HIF-1α的 ASODN可以将 SMMC-7721肝癌细胞株阻滞于 G0/ G1期,影响细胞周期进程,抑制细胞增殖,促进细胞凋亡。HIF-1α促进增殖抑制凋亡的可能机制是上调肝癌细胞 Survivin 和 bcl-2的表达,下调 bax 的表达。针对 HIF-1α抑制剂的应用为肝癌的治疗提供了新思路。     

HIF-1α抑制剂在白血病治疗中的研究进展

缺氧诱导因子(Hypoxia-inducible factor,HIF-1)是一种氧平衡转录因子,在人体细胞内广泛分布,能在各种缺血缺氧环境中激活并发挥作用.其主要由HIF-1α和HIF-1β2个亚基组成.HIF-1α是唯一的氧气调节亚单位,其激活可引起细胞增殖、凋亡抑制、代谢转移和癌症进展,因此,该基因的启动常提示肿...     

Nickel-induced 1,4-alpha-glucan branching enzyme 1 up-regulation via the hypoxic signaling pathway

Using the mouse Affymetrix gene chip, we found that 1,4-alpha-glucan branching enzyme 1 (GBE1) was one of the most up-regulated genes following nickel exposure. This result was confirmed by Northern blot in two mouse cell lines, four mouse tissues, and three human cell lines. We further found that this gene was also up-regulated by cobalt, hypoxia, the iron chelator (deferoxamine, or DFO), and the prolyl hydroxylase (PH) inhibitor (dimethyloxalyglycine, DMOG), suggesting that hypoxia inducible factor-1alpha (HIF-1alpha) was involved in the up-regulation of this gene. Experiments using HIF-1alpha +/+ and HIF-1alpha -/- mouse cells demonstrated this gene was up-regulated through a HIF-1alpha-dependent hypoxic signaling pathway. Because the hypoxic signaling pathway is believed to be important in the initiation and progression of carcinogenesis, it is important to study genes regulated by this pathway.