正常人成纤维细胞老化过程中活性氧水平的变化

目的 研究正常人成纤维细胞在老化过程中细胞活性氧水平的变化。方法 取常规体外培养的原代人成纤维细胞,按不同传代数（PD22－24和PD50－52）分为两组,代表老化过程中两个阶段（早期和中－晚期）,用流式细胞仪检测罗丹明123显示细胞活性氧水平,同时用β-半乳糖苷酶组化染色,形态观察衰老细胞,用群体倍增时间和流式细胞周期分析显示细胞增殖情况。结果 中－晚期细胞中衰老细胞增多,活性氧水平增高,未出现增殖阻滞。结论 正常人成纤维细胞在老化过程中细胞活性氧水平呈升高趋势。     

地黄寡糖抗糖尿病药理作用及机制研究回顾

现代医学对糖代谢的过程及其调节机制已较明确，并正在走向深入。糖代谢是机体自稳机能(homoostasis)的一个重要方面，Besedovsky等(1977)以神经内分泌系统与免疫系统之间的相互作用及其物质基础为依据，提出了“神经内分泌免疫调节”(neuroenctocrine-immuno-modulation，NIM)网络学说，这个学说的实质是机体神经系统、内分泌系统与免疫系统之间具有共     

枝管藻多糖对实验性高脂血大鼠血脂和过氧化水平的影响

目的:观察枝管藻多糖对实验性高脂血大鼠血脂和过氧化水平的影响。方法:以Wistar大鼠为研究对象,用高脂饲料建立高脂血症大鼠模型,分别ig枝管藻多糖和烟酸肌醇酯(枝管藻多糖的剂量为150mg·kg~(-1)·d~(-1),300mg·kg~(-1)·d~(-1),烟酸肌醇酯的剂量为 100mg·kg~(-1)·d~(-1)),连续40d。于实验的第 30天和第40天,各采血一次,分别测定血清 TC,TG,LDL-C,HDL-C,MDA,ROS含量和 SOD活性。结果:枝管藻多糖能显著抑制们喂高脂饲料大鼠的 TG(P<0.05)水平的升高,显著降低高脂血症大鼠的血清 TC(P<0.05)和TG(P<0.05)含量,但对血清LDL-C和HDL-C含量的变化几乎无影响;明显降低高脂血大鼠血清ROS,MDA含量,提高血清 SOD活性(P<0.01或 P<0.05)。结论:枝管藻多糖能够显著改善高脂血大鼠体内过氧化状态,但其抗高脂血效果低于烟酸肌醇酯。     

A commercial mixture of the brominated flame retardant pentabrominated diphenyl ether (DE-71) induces respiratory burst in human neutrophil granulocytes in vitro.

Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants (BFRs), which have become ubiquitous in the environment. This study investigates the effects of the pentabrominated diphenyl ether mixture, DE-71, on human neutrophil granulocytes in vitro. DE-71 enhanced production of reactive oxygen species (ROS) in a concentration-dependent manner measured as lucigenin-amplified chemiluminescence. Octabrominated diphenyl ether (OBDE), decabrominated diphenyl ether (DBDE), and the non-brominated diphenyl ether did not induce ROS formation at the concentrations tested. DPI (4 microM), an inhibitor of the NADPH oxidase completely inhibited DE-71 induced ROS formation, highlighting a role for NADPH oxidase activation. The protein kinase C inhibitor BIM (0.25 microM) and the selective chelator of intracellular calcium, BAPTA-AM (5 microM), also inhibited NADPH oxidase activation, indicating a calcium-dependent activation of PKC. ROS formation was also inhibited by the tyrosine kinase inhibitor tyrphostin (1 microM), the phospholipase C inhibitor ET-18-OCH3 (5 microM), and the phosphatidylinositol-3 kinase inhibitor LY294002 (25 microM). Alterations in intracellular calcium were measured using fura-2/AM, and a significant increase was measured after exposure to DE-71 both with and without extracellular calcium. The tetra brominated compound BDE-47 also enhanced ROS formation in a concentration dependent manner. The combination of DE-71 with the bacteria-derived N-formyl peptide fMLP and PCB153 induced an additive effect in the lucigenin assay. We suggest that tyrosine kinase mediated activation of PI3K could result in enhanced activation of calcium-dependent PKC by enhanced PLC activity, followed by intracellular calcium release leading to ROS formation in neutrophil granulocytes.     

细菌脂多糖对小鼠生长发育和骨骼发育的影响

目的:研究细菌脂多糖(LPS)对小鼠宫内胎儿死亡(IUFD)、生长发育迟缓(IUGR)和骨骼发育迟缓的影响。方法:LPS低中高组小鼠于妊娠d15-17分别腹腔注射不同剂量LPS(25μg/kg、50μg/kg、75μg/kg),LPS+2-苯叔丁基硝酮(PBN,活性氧ROS拮抗剂)组在LPS(75μg/kg)处理前30min和后3h经腹腔各给予100mg/kg的PBN,对照组给予等容量生理盐水。孕鼠于妊娠d18处死。另给药1d时取LPS高剂量组LPS+PBN组和对照组于LPS处理后6h处死孕鼠。结果:①小鼠妊娠d15-17给予LPS后,中高剂量组平均每窝死胎数明显高于对照组,活胎体重、身长和尾长下降,并呈明显的剂量-效应关系;LPS高剂量导致IUGR和骨骼发育迟缓;PBN处理明显抑制LPS对胎儿的作用。②LPS使母肝、胎肝和胎盘组织脂质过氧化,GSH含量显著降低。PBN显著抑制LPS的这些作用。结论:母鼠妊娠晚期接触LPS引起IUFD、IUGR和骨骼发育迟缓,ROS至少部分参与了LPS的引起IUFD、IUGR和骨骼发育迟缓。     

ROS指标在保健食品抗氧化功能检测中的应用及灵敏性比较

目的：将ROS指标应用于保健食品抗氧化功能检测中，并进行敏感性比较。方法：SPF级昆明种雄性小鼠，12月龄，按体重随机分为老龄组对照组、大豆异黄酮低、中、高剂量组（分别为0．08g／kgBW、0．17g／kgBW、0．50g／kgBW），每组10只动物。连续灌胃给予受试物42d后，断头处死动物，取肝脏。以胶原酶和胰蛋白酶联合酶解肝组织，制备肝组织单细胞悬液；以流式细胞术测定肝细胞ROS水平；同时制备肝组织匀浆，以分光光度法测定肝细胞MBA含量及SOD、GSH—Px活性。结果：流式仪直方图分析显示，随着受试物给予剂量的增加，各剂量组肝细胞ROS水平均明显降低（P〈0．05）；低、高剂量组肝细胞内MDA含量明显减少（P〈0．05），中、高剂量组GSH—Px活性明显增加（P〈0．05），高剂量组,SOD活性亦明显增加（P〈0．05）；其余剂量组各指标差异无统计学意义（P〉0．05）。结论：大豆异黄酮通过降低肝细胞自由基水平而起到抗氧化作用，以FCM检测肝细胞ROS水平可更好地对保健食品的抗氧化功能进行筛选与评价。     

A comparative study of the antioxidant/prooxidant activities of eugenol and isoeugenol with various concentrations and oxidation conditions

Eugenol (compound 1 in Fig. 1, 4-allyl-2-methyoxyphenol) and isoeugenol (compound 2 in Fig. 1, 4-propenyl-2-methoxyphenol), both used as a flavor agent in cosmetic and food products, have both prooxidant and antioxidant activities. Their adverse effects such as allergic and inflammatory reaction may be due to their prooxidant activity. To clarify the mechanisms of their cytotoxicity and the factors affecting their antioxidant/prooxidant activities, we investigated the cytotoxicity, ROS production, and cellular glutathione (GSH) levels induced by eugenol and isoeugenol in a human submandibular cell line. The cytotoxicity (MTT method) of eugenol was 1 order of magnitude lower than that of isoeugenol (CC₅₀: eugenol, 0.395 mM; isoeugenol, 0.0523 mM); and ROS production (CDF staining) was induced significantly by isoeugenol, but not by eugenol. Under treatment with H₂O₂ (100 μM) plus horseradish peroxidase (1 μg/ml) for 30 min or with visible light irradiation for 5 min, eugenol caused biphasic ROS production characterized by enhanced at lower eugenol concentrations (5–10 μM) and decreased at higher concentrations (500 μM). In contrast, isoeugenol enhanced ROS production over a wide range of concentrations (5–500 μM). Isoeugenol at 1000 μM significantly reduced GSH levels compared with eugenol at the same concentration. The high cytotoxicity of isoeugenol may be attributed to its induction of high ROS production and low GSH levels, possibly as a result of benzyl radical formation. In contrast, the cytotoxicity of eugenol is likely to be mediated by ROS-independent mechanisms, possibly involving phenoxyl radicals and/or eugenol quinone methide.     

成纤维细胞生长因子21对缺氧复氧心肌细胞的保护作用及机制研究

【摘要】 目的 探讨成纤维细胞生长因子21（FGF21）对缺氧复氧（H/R）心肌细胞的保护作用及对PI3K/AKT通路的影响。方法 重组腺病毒载体Ad FGF21诱导原代心肌细胞过表达FGF21。腺病毒转染心肌细胞后构建H/R损伤模型（3h缺氧联合3h复氧）。实验分为对照组（Con组）、H/R组、H/R+Ad GFP组、H/R+Ad FGF21组4组。心肌细胞存活率评估细胞损伤程度;SOD/MDA检测联合DHE荧光染色评估氧化应激反应（ROS）;流式细胞术评估细胞凋亡;Western blot检测相关蛋白水平。在机制探讨实验中给予PI3K/AKT抑制剂（LY294002）进行干预。结果 与Con组相比,H/R损伤后FGF21蛋白表达显著下调,并伴随心肌细胞活性降低、ROS与凋亡反应激活。腺病毒介导的心肌细胞过表达FGF21能够明显抑制H/R损伤,表现为细胞活力、ROS与凋亡反应均有不同程度改善。FGF21心肌细胞过表达能够增加PI3K/AKT磷酸化水平,而抑制PI3K/AKT通路后FGF21过表达介导的细胞保护功能被逆转。结论 FGF21主要通过PI3K/AKT依赖性途径改善心肌细胞H/R损伤。     

Role of SCOX in determination of Drosophila melanogaster lifespan

In man, COX (cytochrome c oxidase) deficiency is reported to be related to mutation of the SCO2 (synthesis of cytochrome c oxidase 2) gene, which encodes one of the copper-donor chaperones involved in the assembly of mitochondrial cytochrome c oxidase. Such COX deficiency due to the genetic condition leads to heart disease and the Leigh syndrome and is frequently fatal in childhood. Synthesis of cytochrome c oxidase X (SCOX) is a Drosophila orthologue of human SCO2. Here, we generated SCOX-knockdown flies and the full length SCOX transgenic flies to investigate the in vivo roles of SCOX. Our results demonstrated knockdown of SCOX gene in all cells and tissues to be associated with lethality at larval or pupal stages and this correlated with a decrease in ATP level. In contrast, the full length SCOX transgenic flies showed a longer lifespan than wild type flies and control flies carrying Act5C-GAL4 alone and this correlated with an increase in ATP level. Finally, when cultured on paraquat-added medium, full length SCOX transgenic flies also exhibited an elongated lifespan. Therefore, we hypothesized that SCOX plays an important role in ATP production and consumption, which helps to prevent production of mitochondrial reactive oxygen species and/or impairment of mitochondrial activity under oxidative stress.     

Down-regulation of ARNT promotes cancer metastasis by activating the fibronectin/integrin β1/FAK axis

The aryl hydrocarbon receptor nuclear translocator (ARNT) is broadly involved in regulating tumorigenesis by inducing genes that are involved in tumor growth and angiogenesis. Tumorigenesis usually involves normoxic conditions. However, the role of ARNT in tumor metastasis during normoxia remains unclear. Here, we demonstrate that ARNT protein levels were decreased in late-stage human colorectal cancer using immunohistochemical analysis. Down-regulation of ARNT protein promoted cancer cell migration and invasion, which was mediated by activation of the fibronectin/integrin β1/FAK signaling axis. In addition, the enhancement of migration and invasion in ANRT knockdown cells was blocked when ARNT was restored in the cells. In xenografts in severe combined immunodeficiency mice, tumor growth was significantly inhibited in the ARNT-knockdown condition. However, the tail-vein injection animal model revealed that the depletion of ARNT-induced metastatic lung colonies was further enhanced when ARNT expression was recovered post-injection. Interestingly, chemotherapeutic drugs inhibited ARNT expression and promoted the invasion of residual tumor cells. These results suggest that ARNT may play a positive role during tumor growth (either in early-stage tumor growth or in organ metastases), but plays a negative role in tumor migration and invasion. Therefore, the efficiency of ARNT-targeted therapy during different cancer stages should be carefully evaluated.