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Hsu-Feng Lu Jai-Sing Yang Kuang-Chi Lai Shu-Chun Hsu Shu-Ching Hsueh Yuan-Liang Chen Jo-Hua Chiang Chi-Cheng Lu Chyi Lo Mei-Due Yang Jing-Gung Chung 《Neurochemical research》2009,34(8):1491-1497
Curcumin is reported to be a potent inhibitor of the initiation and promotion of many cancer cells. We investigated to examine
whether or not curcumin induce DNA damage in mouse–rat hybrid retina ganglion cell line N18 cells. The Comet assay showed
that incubation of N18 cells with 10, 25 and 30 μM of curcumin led to a longer DNA migration smear (Comet tail). The DNA gel
electrophoresis showed that 20 μM of curcumin for 24 and 48 h treatment induced DNA damage and fragments in N18 cells. The
real time PCR analysis showed that 20 μM of curcumin for 48 h treatment decreased ATM, ATR, BRCA1, 14-3-3σ, DNA-PK and MGMT
mRNA, and ATM and MGMT mRNA expression were inhibited in a time-dependent manner. Our results indicate that curcumin caused
DNA damage and inhibited DNA repair genes which may be the factors for curcumin-inhibited cell growth.
H.-F. Lu and J.-S. Yang are contributed equally to this study. 相似文献
995.
Lai Hong Fu Yansong Miao Sze Wan Lo Tai Chi Seto Samuel S.M. Sun Zeng-Fu Xu Sabine Clemens Lorne A. Clarke Allison R. Kermode Liwen Jiang 《Plant science》2009,177(6):668-675
Lysosomal storage diseases (LSDs), that collectively represent over 50 disorders, are amenable to enzyme replacement therapies. However, the current methods used to commercially produce recombinant lysosomal enzymes for this purpose, most commonly Chinese Hamster Ovary cells and human fibroblasts, are prohibitively costly. Plant bioreactors hold great promise for economic production of functional human α-l-iduronidase (hIDUA; glycosaminoglycan α-l-iduronohydrolase; EC 3.2.1.76), the enzyme deficient in the human LSD, Mucopolysaccharidosis I. We have developed and tested an expression system using transgenic tobacco BY-2 cells to produce high amounts of active hIDUA. A plant signal peptide was essential for proper expression and secretion of the 78 kDa glycosylated hIDUA into the cultured media of transgenic BY-2 cells. The yield and activity of the secreted hIDUA from long-term cultures of transgenic BY-2 cell lines were as high as 10 μg/mL media and 53,000 pmol/min/mg proteins, respectively. Thus, this transgenic BY-2 cell line presents an attractive platform for economic production and easy downstream purification of hIDUA for enzyme replacement therapy. Furthermore, this system can be used for the production and purification of other human lysosomal enzymes or pharmaceuticals. 相似文献
996.
Sunil S. Adav Duu-Jong Lee Juin-Yih Lai 《Applied microbiology and biotechnology》2009,84(6):1181-1189
Efficient nitrification and denitrification of wastewater containing 1,700 mgl−1 of ammonium-nitrogen was achieved using aerobic granular sludge cultivated at medium-to-high organic loading rates. The cultivated
granules were tested in a sequencing batch reactor (SBR) fed with 6.4 or 10.2 kg NH4+-N m−3 day−1, a loading significantly higher than that reported in literature. With alternating 2 h oxic and 2 h anoxic operation (OA)
modes, removal rate was 45.5 mg NH4+-N g−1 volatile suspended solids−1 h−1 at 6.4 kg NH4+-N m−3 day−1 loading and 41.3 ± 2.0 at 10.2 kg NH4+-N m−3 day−1 loading. Following the 60 days SBR test, granules were intact. The fluorescence in situ hybridization and confocal laser
scanning microscopy results indicate that the SBR-OA granules have a distribution with nitrifers outside and heterotrophs
outside that can effectively expose functional strains to surrounding substrates at high concentrations with minimal mass
transfer limit. This microbial alignment combined with the smooth granule surface achieved nitrification–denitrification of
wastewaters containing high-strength ammonium using aerobic granules. Conversely, the SBR continuous aeration mode yielded
a distribution with nitrifers outside and heterotrophs inside with an unsatisfactory denitrification rate and floating granules
as gas likely accumulated deep in the granules. 相似文献
997.
Yuan Lu Hongxin Zhao Chong Zhang Qiheng Lai Xi Wu Xin-Hui Xing 《Biotechnology letters》2009,31(10):1525-1530
An expression system for NAD+-dependent formate dehydrogenase gene (fdh1), from Candida boidinii, was constructed and cloned into Enterobacter aerogenes IAM1183. With the fdh1 expression, the total H2 yield was attributed to a decrease in activity of the lactate pathway and an increase of the formate pathway flux due to
the NADH regeneration. Analysis of the redox state balance and ethanol-to-acetate ratio in the fdhl-expressed strain showed that increased reducing power arose from the reconstruction of NADH regeneration pathway from formate
thereby contributing to the improved H2 production. 相似文献
998.
Stratigraphy and palaeoenvironmental implications of Pleistocene and Holocene aeolian sediments in the Lhasa area,southern Tibet (China) 总被引:2,自引:0,他引:2
Knut Kaiser Zhongping Lai Birgit Schneider Christoph Reudenbach Georg Miehe Helmut Brückner 《Palaeogeography, Palaeoclimatology, Palaeoecology》2009,271(3-4):329-342
Along the middle and lower reaches of the Kyichu River and its tributaries (Lhasa area, southern Tibet), a multidisciplinary study was carried out in order to investigate the areal distribution, sedimentological properties, ages and palaeoenvironmental implications of aeolian deposits including intercalated palaeosols. This research was initiated to investigate to what extent southern Tibet is influenced by past human activity, as even recent evaluations perceive the present treeless desertic environment as natural. Fifteen profiles were recorded at an altitude of 3540–4580 m a.s.l. with subsequent sedimentological, geochronological (OSL, AMS 14C) and palaeobotanical (charcoal) analyses. Sediment properties of both loesses and aeolian sands reveal an origin from aeolian sorting of nearby fluvial deposits. The calculated ages are the oldest obtained thus far on aeolian sediments from southern and interior Tibet, revealing natural aeolian sedimentation before and around the Last Glacial Maximum (c. 20 ka). However, a distinct portion of Late Holocene sandy aeolian sediments also occurs. Both the evidence for the aeolian dynamics (widespread Pleistocene loess and aeolian sand deposition, local Late Holocene aeolian sand deposition, modern reactivation of widespread Pleistocene aeolian sands) and the palaeobotanical findings (Late Holocene vegetation change from a tree-bearing to a widely treeless landscape) provide evidence that the Lhasa area was strongly influenced by human activity since at least the Late Neolithic (c. 4200 cal yrs BP). Thus the present-day desertic environment might not primarily be a result of the semiarid climate or the high-altitude conditions, but rather of activities of the humans and their collateral effects. However, once established, this semi-natural ecosystem persisted, controlled by strong grazing, firewood extraction, erosion and harsh edaphic conditions, preventing the recovery of trees. 相似文献
999.
Duen-Suey Chou George Hsiao Yan-An Lai Yan-Jyu Tsai Joen-Rong Sheu 《Free radical biology & medicine》2009,46(8):1197-1203
In a previous study, we demonstrated that baicalein induces hydroxyl radical formation in human platelets but the mechanisms are unclear. Herein, we show, using an electron spin resonance technique, that baicalein also induces hydroxyl radical formation in B16F10 melanoma cells in a dose-dependent manner. Baicalein produced superoxide anions in the presence of an iron chelator and superoxide dismutase (SOD) inhibitor. We suggest that superoxide anions produced by baicalein were promptly converted to hydroxyl radicals through SOD and the Fenton reaction in B16F10 melanoma cells. According to Western blotting results, the 12-LOX protein was expressed in B16F10 melanoma cells, but baicalein had no effect on 12-LOX expression. Decreases in 12-LOX protein expression and hydroxyl radical signals occurred in a 12-LOX small interfering RNA knockdown protein group compared with the baicalein control. In the MTT assay, we also found that baicalein caused a reduction in cellular viability, which was reversed by the addition of ROS scavengers. On the basis of these data, we conclude that ROS formation catalyzed by 12-LOX is one possible mechanism of growth inhibition by baicalein in B16F10 melanoma cells. 相似文献
1000.