吡咯喹啉醌对D-半乳糖致衰老大鼠海马神经元的影响

目的观察吡咯喹啉醌(PQQ)对D-半乳糖(D-gal)致大鼠海马神经细胞衰老的影响。方法用大剂量D-gal致大鼠脑老化模型,侧脑室注射PQQ,50 d后行脑组织切片H-E染色和尼氏染色,观察海马神经元的形态学变化,流式细胞仪检测细胞的凋亡率;用TBA法和Fenton反应测海马组织自由基含量;W estern b lot观察C-FOS蛋白的表达。结果D-gal处理组鼠海马神经元胞体变小,尼氏小体的吸光度值(A)降低,细胞凋亡率和自由基含量增加,C-FOS蛋白的表达降低;而同时PQQ处理后,与对照组相比海马神经元的胞体变大,尼氏小体的A值增加,自由基含量和神经元的凋亡率无明显增加,PQQ剌激了C-FOS蛋白的表达。结论PQQ能延缓D-gal引起的大鼠海马神经细胞衰老。     

耐辐射奇球菌抗辐射小分子化合物研究进展

耐辐射奇球菌作为世界上“抗性最强”的细菌,能够在强辐射、严寒、干旱和酸性环境中继续生存.耐辐射奇球菌之所以对射线及干旱等恶劣环境有较强的抗性,与其自身的生物学结构及功能有关,相关研究报道了其超强的DNA损失修复机制以及蛋白质损伤修复及清除能力.早期研究发现类胡萝卜素是其抗辐射、抗紫外线作用的一种小分子,近期发现锰离子络合物在其抗辐射作用中发挥了重要作用.该文将对耐辐射奇球菌中与抗辐射有关的小分子物质进行综述,以期为开发抗辐射、抗氧化先导化合物提供思路.     

Antioxidant and pro-oxidant properties of pyrroloquinoline quinone (PQQ): implications for its function in biological systems

Pyrroloquinoline quinone (PQQ) is a novel redox cofactor recently found in human milk. It has been reported to function as an essential nutrient, antioxidant and redox modulator in cell culture experiments and in animal models of human diseases. As mitochondria are particularly susceptible to oxidative damage we studied the antioxidant properties of PQQ in isolated rat liver mitochondria. PQQ was an effective antioxidant protecting mitochondria against oxidative stress-induced lipid peroxidation, protein carbonyl formation and inactivation of the mitochondrial respiratory chain. In contrast, PQQ caused extensive cell death to cells in culture. This surprising effect was inhibited by catalase, and was shown to be due to the generation of hydrogen peroxide during the autoxidation of PQQ in culture medium. We conclude that the reactivities of PQQ are dependent on its environment and that it can act as an antioxidant or a pro-oxidant in different biological systems.     

吡咯喹啉醌对NMDA诱发大鼠海马神经元损伤的影响

目的探讨吡咯喹啉醌（PQQ）对N-甲基-D-天冬氨酸（NMDA）诱发海马神经元损伤的影响。方法体外原代培养新生大鼠海马神经元，毒性剂量的NMDA诱致海马神经元损伤，预加PQQ，镜下观察神经元的形态变化，琼脂糖凝胶电泳观察细胞的死亡情况，激光共聚焦显微镜观察细胞内Ca^2＋浓度的变化。结果体外培养8d的海马神经用0．1mmol／LNMDA处理后，细胞内Ca^2＋快速增加，细胞以坏死和凋亡两种形式死亡，细胞的存活率降低；预先给予PQQ可明显减少细胞内Ca^2＋的增加，减少细胞死亡。结论PQQ对NMDA诱发的海马神经元损伤具有保护作用。     

PQQ‐Dependent Alcohol Dehydrogenase (QEDH) of Pseudomonas aeruginosa is involved in catabolism of acyclic terpenes

Growth of Pseudomonas aeruginosa on acyclic terpene alcohols such as geraniol depends on the presence of the atuRABCDEFGH gene cluster and a functional acyclic terpene utilisation (Atu) pathway. The proteins encoded by the atu gene cluster are necessary but not sufficient for growth on acyclic terpenes. Comparative 2‐dimensional polyacrylamide gel electrophoresis of soluble P. aeruginosa proteins revealed the presence of an additional spot (besides Atu proteins) that is specifically expressed in geraniol cells but is absent in isovalerate‐grown cells. The spot was identified as PA1982 gene product a pyrroloquinoline quinone (PQQ) dependent ethanol oxidoreductase (QEDH). Inactivation of PA1982 by insertion mutagenesis resulted in inability of the mutant to utilise ethanol and in reduced growth on geraniol. Growth on ethanol was restored by transferring an intact copy of the PA1982 gene into the mutant. The PA1982 gene product was purified from recombinant Escherichia coli and revealed PQQ‐dependent oxidoreductase activity with a variety of substrates including acyclic terpene derivates at comparable V_max‐values. Our results show that QEDH participates in oxidation of acyclic terpene derivates in addition to the well‐known function in ethanol metabolism. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

吡咯喹啉醌对D-半乳糖致大鼠皮层衰老的影响

目的观察吡咯喹啉醌(PQQ)对D-半乳糖致大鼠皮层神经细胞衰老的影响。方法用D-半乳糖致大鼠脑老化模型,侧脑室注射PQQ,50d后组织切片行H-E和尼氏染色观察皮层神经细胞的形态学变化,测皮层细胞的凋亡率和自由基,免疫组化法和SDS-PAGE检测Bcl-2/Bax和c-fos基因的表达。结果D-半乳糖处理组皮层神经细胞胞体变小,尼氏小体的光密度值降低,细胞的凋亡率和自由基的含量增加,Bcl-2/Bax和c-fos蛋白的表达降低;而PQQ处理组神经细胞胞体的直径和尼氏小体的含量高于对照组,PQQ降低了由D-半乳糖引起皮层组织自由基和细胞凋亡率的增加,Bcl-2/Bax和c-fos表达增加。结论PQQ能延缓由D-半乳糖引起的大鼠皮层神经细胞的衰老。     

Acute and subchronic toxicity studies of pyrroloquinoline quinone (PQQ) disodium salt (BioPQQ™) in rats

The potential use of pyrroloquinoline quinone disodium salt (BioPQQ™), as a supplemental food ingredient, was evaluated in a range of oral toxicity studies in rats including an acute study, a 14-day preliminary and a 28-day repeated-dose study, and a 13-week subchronic study. The median lethal dose of BioPQQ™ was shown to be 1000–2000 mg/kg body weight (bw) in male and 500–1000 mg/kg bw in female rats. In the 14-day study, high doses of BioPQQ™ resulted in increases in relative kidney weights with associated histopathology in female rats only, while a follow-up 28-day study in female animals resulted in increases in urinary protein and crystals. These findings were reversible, and resolved during the recovery period. In the 13-week study, a number of clinical chemistry findings and histopathological changes were noted, which were deemed to be of no toxicological significance, as the levels were within the historical control range, were not dose-dependent, occurred at a similar frequency in control groups, or only occurred in the control group. Based on these findings, a no-observed-adverse-effect level of 100 mg/kg bw/day was determined for BioPQQ™ in rats, the highest dose tested in the 13-week study.     

侧脑室注射吡咯喹啉醌对大鼠学习记忆的影响

目的 观察吡咯喹啉醌(PQQ)对大鼠学习记忆能力的影响.方法 侧脑室注射PQQ,60 d后用水迷宫仪进行定位航行和空间探索实验,行脑组织切片,用免疫组化法和Western印迹观察海马组织巢蛋白、神经生长因子及其受体的表达.结果 与对照组相比,PQQ处理后,大鼠学习找平台所需的次数减少和找到平台所需的时间显著缩短,在第一象限和中环停留的时间显著延长,此变化呈剂量依赖性;海马组织巢蛋白阳性神经元数目增加了,神经生长因子的表达高于对照组.结论 PQQ能促进鼠海马神经细胞的生长发育和学习记忆能力.     

吡咯喹啉醌对γ辐射小鼠防护作用的初步研究

目的 研究吡咯喹啉醌(PQQ)对γ辐射小鼠的防护作用。方法 将40只昆明小鼠随机分四组,即未照射组、单纯照射组、照射前给药组、照射后给药组。给药组小鼠口服PQQ剂量按体重计每天2mg/kg,连续给药7天。采用⁶⁰Coγ射线单次全身照射,剂量5Gy。于照射后第8天,颈椎脱臼处死小鼠,收集血清、制备肝匀浆,进行各项生化指标测定。制作肝HE染色切片。结果 照射后小鼠血清及肝脏中SOD、T-AOC显著下降(P<0.05),MDA显著升高(P<0.05)。照射给药组小鼠血清SOD、T-AOC含量显著升高(P<0.05),MDA含量显著减低(P<0.05);肝脏中SOD含量显著升高(P<0.05)。所有照射组小鼠肝组织都有肝板排列紊乱,出现肝细胞水肿,变性、坏死现象。结论 γ辐射引发小鼠全身性的氧化应激,肝脏是重要的辐射敏感器官。PQQ对γ辐射小鼠的防护作用机制是:PQQ能直接清除自由基,同时能调动照射小鼠的全身自由基清除系统,尤其是SOD的活性,降低自由基含量。     

吡咯喹啉醌对UVA诱导人皮肤成纤维细胞衰老的保护作用及机制研究

目的:研究吡咯喹啉醌(pyrroloquinoline quinine,PQQ)对UVA诱导人皮肤成纤维细胞衰老的保护作用及其机制?方法:体外使用6孔板培养人皮肤成纤维细胞(human skin fibroblasts,HSF),予以9 J/cm2照射,照射前后实验组加入80 ng/ml的8-甲氧基补骨脂(8-methoxypsoralan,8-MOP)和浓度为50?100?200 ng/ml的PQQ?UVA照射72 h后,对细胞进行衰老β-半乳糖苷酶染色?JC-1染色荧光显微镜检测线粒体膜电位变化?JC-1染色流式细胞仪检测线粒体膜去极化状况?real-time PCR检测衰老相关基因mmp1?mmp3的表达?结果:低剂量PQQ(50 ng/ml)实验组β-半乳糖苷酶染色呈阴性,JC-1染色后低剂量PQQ(50 ng/ml)实验组细胞线粒体膜电位改变的趋势有回转,JC-1染色后流式细胞仪检测PQQ对UVA诱导的衰老细胞线粒体去极化有保护作用,而且低剂量PQQ(50 ng/ml)实验组衰老相关基因mmp1?mmp3的表达也有明显降低?结论:吡咯喹啉醌对由UVA诱导的人皮肤成纤维细胞衰老有保护作用,而且这一作用可能是通过线粒体途径发挥作用的?