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991.
O. V. Avercheva E. M. Bassarskaya T. V. Zhigalova Yu. A. Berkovich S. O. Smolyanina M. R. Leont’eva A. N. Erokhin 《Russian Journal of Plant Physiology》2010,57(3):382-391
Leaf mesostructure, photochemical activity, and chloroplast photophosphorylation (PP) in the fourth true leaf of 28-day-old
Chinese cabbage (Brassica chinensis L.) plants were investigated. Plants were grown under a light source based on red (650 nm) and blue (470 nm) light-emitting
diodes (LED) with red/blue photon flux ratio of 7: 1 and under illumination with high-pressure sodium lamp (HPSL) at photon
flux densities of 391 ± 24 μmol/(m2 s) (“normal irradiance”) and 107 ± 9 μmol/(m2 s) (“low irradiance”) in photosynthetically active range. At normal irradiance, the leaf area in plants grown under HPSL
was twofold higher than in LED-illuminated plants; other parameters of leaf mesostructure were little affected by spectral
quality of incident light. The lowering of growth irradiance reduced the majority of leaf mesostructure parameters in plants
grown under illumination with HPSL, whereas in LED-illuminated plants the lowered irradiance reduced only specific leaf weight
but increased the leaf thickness and dimensions of mesophyll cells and chloroplasts. The photochemical activity of isolated
chloroplasts was almost independent of growth irradiance and light spectral quality. Light quality and intensity used for
plant growing had a considerable impact on PP in chloroplasts. At normal light intensity, the highest activity of noncyclic
PP in chloroplasts was observed for plants grown under HPSL; at low light intensity the highest rates of PP were noted for
plants grown under LED. The P/2e− ratio, which characterizes the degree of PP coupling to electron transport in the chloroplast electron transport chain, showed
a similar pattern. Thus, the narrow-band spectrum of the light source had little influence on leaf mesostructure and electron
transport rates. However, this spectrum significantly affected the chloroplast PP activity. The PP patterns at low and normal
light intensities were opposite for plants grown under LED and HPSL light sources. We suppose that growing plants under LED
array at normal light intensity disturbed the chloroplast coupling system, thus preventing the effective use of light energy
for ATP synthesis. At low light intensity, chloroplast PP activity was significantly higher under LED illumination, but plant
growth was suppressed because of impaired adaptation to low light intensity. 相似文献
992.
993.
Xiaoxing You Liangzhuan Liu Yanhua Zeng Ranhui Li Jun He Xiaohua Ma Chuanhao Jiang Cuiming Zhu Liesong Chen Minjun Yu Guangli Ou Yimou Wu 《PloS one》2014,9(7)
Aims
This study is to investigate the mechanisms by which macrophage-activating lipopeptide-2 (MALP-2) induces heme oxygenase (HO)-1, a cytoprotective enzyme that catalyzes the degradation of heme, in human monocytes.Methods
Human monocytic THP-1 cells were cultured for transient transfection with plasmids and stimulation with MALP-2 for indicative time intervals. After incubation with MALP-2, cells were collected and disrupted, before being tested for promoter activity using luciferase assay. For analysis of proteins, immunoreactive bands were detected using an enhanced chemiluminescence Western blotting system, and the band intensity was measured by densitometryic analysis. For the detection of co-immunoprecipitation, SDS-PAGE was performed and the membranes were probed using respective antibodies. To investigate the cellular localization of NF-E2-related factor 2 (Nrf2), cells underwent immunofluorescence staining and confocal microscopy, and were analyzed using electrophoretic mobility shift assay.Results
MALP-2-induced HO-1 expression and promoter activity were abrogated by transfection with dominant negative (DN) plasmids of TLR2 and TLR6, or their neutralizing antibodies. However, inhibition of MyD88 or transfection with the DN-MyD88 was insufficient to attenuate HO-1 expression. In contrast, mutation or silencing of MyD88 adapter-like (Mal) by DN-Mal or siRNA almost completely blocked HO-1 induction. Btk, c-Src and PI3K were also involved in MALP-2-induced HO-1 expression, as revealed by specific inhibitors LFM-A13, PP1 and , or by transfection with siRNA of c-Src. MALP-2-induced activation of PI3K was attenuated by transfection with DN mutant of Mal, and by pretreatment with LFM-A13 or PP1. Furthermore, MALP-2 stimulated the translocation of Nrf2 from the cytosol to the nucleus and Nrf2 binding to the ARE site in the HO-1 promoter, which could also be inhibited by pretreatment with a PI3K inhibitor, LY294002. LY294002Conclusions
These results indicated that MALP-2 required TLR2/6, Btk, Mal and c-Src to activate PI3K, which in turn initiated the activation of Nrf2 for efficient HO-1 induction. 相似文献994.
Samuel Rommelaere Virginie Millet Thien-Phong Vu Manh Thomas Gensollen Pierre Andreoletti Mustapha Cherkaoui-Malki Christophe Bourges Bertrand Escalière Xin Du Yu Xia Jean Imbert Bruce Beutler Yoshiakira Kanai Bernard Malissen Marie Malissen Anne Tailleux Bart Staels Franck Galland Philippe Naquet 《PloS one》2014,9(8)
995.
Hengxiu Yu Mo Wang Ding Tang Kejian Wang Fuli Chen Zhiyun Gong Minghong Gu Zhukuan Cheng 《Chromosoma》2010,119(6):625-636
Spo11 is a homolog of a subunit of archaebacterial topoisomerase, which catalyzes DNA double-strand breaks and initiates homologous
chromosome recombination. In the present study, we silenced the SPO11-1 gene in rice (Oryza sativa) using RNAi. Rice plants with loss-of-function of OsSPO11-1 have no apparent growth defects during vegetative development,
but homologous chromosome pairing and recombination are significantly obstructed. Telomeres can be assembled as bouquet during
the zygotene stage of the OsSPO11-1-deficient plants, just as that in wild type. Although the two axial-associated proteins,
REC8 and PAIR2, are loaded onto the chromosomes, the depletion of PAIR2 from the chromosomes is much later than in wild type.
The central element of the synaptonemal complex (SC), ZEP1, does not load onto the chromosomes normally, implying that SC
formation is disturbed severely. The crossover protein, MER3, isn't efficiently assembled onto chromosomes and the lack of
bivalent suggests that crossovers are also affected in the absence of OsSPO11-1. Thus, OsSPO11-1 is essential for both homologous
chromosomes pairing and crossover formation during meiosis in rice. 相似文献
996.
Murugan Loganathan Subbiyan Maruthasalam Ling Yin Shiu Wei Ching Lien Wen Hwei Hsu Pei Fang Lee Chih Wen Yu Chin Ho Lin 《In vitro cellular & developmental biology. Plant》2010,46(3):265-273
We describe here a simple and efficient system of soybean (Glycine max L. Merrill) regeneration through direct somatic embryogenesis by using immature embryonic shoot tips (IEST) as explants.
The cultivar Kaohsiung 10 (cv. K10) used in this study did not show embryogenic response either from mature seed-derived explants
(cotyledon, embryonic tip, leaf, shoot and root) or immature cotyledons. However, it showed a high percentage (55.8%) of somatic
embryo (SEm) formation from the IEST excised 2–3 wk after flowering, thus indicating the crucial roles of type and age of
explants. The IEST put forth primary SEm after 2 mo of culturing on Murashige and Skoog (MS) medium supplemented with 6% sucrose,
164.8 μM 2,4-dichlorophenoxyacetic acid (2,4-D), 5 mM asparagine and 684 μM glutamine. Subsequently, secondary SEm were developed
1 mo after culturing on MS medium containing 123.6 μM 2,4-D and 3% sucrose. Cotyledonary embryos were induced on MS medium
supplemented with 0.5% activated charcoal after 1 mo. The embryos were desiccated for 72–96 h on sterile Petri dishes and
regenerated on hormone-free MS medium. Plantlets with well-developed shoots and roots were obtained within 5–6 mo of culturing
of IEST. The SEm-derived plants were morphologically normal and fertile. Various parameters thought to be responsible for
efficient regeneration of soybean through somatic embryogenesis are discussed. To our knowledge, this is the first report
to employ IEST as explants for successful direct somatic embryogenesis in soybean. 相似文献
997.
Qingyu Lang Haoxing Zhang Jie Li Fang Xie Yifeng Zhang Bo Wan Long Yu 《Molecular biology reports》2010,37(3):1577-1583
The Aurora kinases play a critical role in mitosis and have been suggested as promising targets for cancer therapy due to
their frequent overexpression in a variety of tumors. Compared with established inhibitors of cell division such as the anti-tubulins,
novel agents target mitotic enzymes and show similar efficacy but with fewer side effects. Several small-molecule inhibitors
of Aurora kinases have been developed as anticancer agents, some of which have progressed to early clinical evaluation. Here
we identified 3-hydroxyflavone as a novel Aurora B inhibitor through high throughput screening. 3-Hydroxyflavone showed potent
inhibition to Aurora B with the IC50 on a nanomolar basis in the enzyme-based kinase activity assay. In the cell-based western blotting analysis, 3-hydroxyflavone
dramatically decreased the phosphorylation level of Histone H3 on the site of serine 10, demonstrating the potent endogenous
Aurora B activity inhibition in cell level. The followed cell image analysis provided the consist result. To make it clear
whether 3-hydroxyflavone inhibited Aurora B by direct binding or not, SPR analysis was carried out to measure the affinity
of interaction between Aurora B protein and 3-hydroxyflavone and the result proved the binding with high affinity. Usually
Aurora activity suppression induced cancer cell proliferation inhibition. Colony formation and cell viability with/without
treatment of 3-hydroxyflavone were measured using CCK-8. The growth suppression under 3-hydroxyflavone present and the growth
recovery after being released gave strong evidence that presence of 3-hydroxyflavone efficiently inhibited the fast growth
of cancer cells. 相似文献
998.
Ji-Yeon Yu Ji-Hae Kim Tae-Geum Kim Beom-Tae Kim Yong-Suk Jang Jeong-Chae Lee 《Molecules and cells》2010,30(4):303-310
Growing interest in the beneficial effects of antioxidants has inspired the synthesis of new phenolic acid phenethyl ureas
(PAPUs) with enhanced antioxidant potential. We have previously shown the capacity of one PAPU compound, (E)-1-(3,4-dihydroxyphenethyl)-3-styrylurea (PAPU1), to induce caspase-dependent apoptosis in melanoma cells. In the present
study, we examined the anti-proliferative effects of PAPU compounds on MCF-7 human breast cancer cells and determined the
molecular mechanisms involved. Treatment with PAPU compounds inhibited predominantly proliferation in these cells, where the
PAPU1 was the most efficient form. Flow cytometric analysis showed that PAPU1 blocked cell cycle progression in the G0/G1 phase, and reduced the proportion of cells in G2/M phase. This was related to the inhibition of cell cycle regulatory factors, including cyclin D/E and cyclin-dependent kinase
(CDK) 2/4, through induction of p21Cip1. PAPU1 also induced the mitochondrial-mediated and caspase-dependent apoptosis in MCF-7 cells. This was evidenced by cellular
changes in the levels of Bcl-2 and Bax, loss of the mitochondrial membrane potential, release of cytochrome c into the cytosol, and caspase-9 activation. Collectively, our results suggest that G1 cell cycle regulatory proteins and mitochondrial pathways are the crucial targets of PAPU1 in the chemoprevention of breast
cancer cells. 相似文献
999.
Yu. N. Litvinov N. T. Erzhanov N. V. Lopatina T. Zh. Abylkhasanov 《Contemporary Problems of Ecology》2010,3(5):593-596
Small mammals were studied in the Kazakh Uplands in the spring and fall of 2008. The trapping studies revealed 10 species. Abundances of the animals were low in the four main distinct characteristic biotopes of Bayanaul National Park, but those of biotope dominants were high. In the Kazakh Uplands, rodents and insectivores are clearly restricted to certain biotopes. Biodiversity indices for small mammal communities are low, indicating that the community structure is disturbed. 相似文献
1000.
Lowering the extracellular pH (from 7.2 to 6.3) or intracellular acidification in isolated murine peritoneal macrophages before
UV-irradiating them to 9 J/cm2 (λmax = 306 nm) diminish the percentage of cells with damaged membranes. Extracellular pH 8.4 or intracellular alkalization have
an opposite effect. After transient hypoosmotic swelling, the UV-induced membrane damage is fully pronounced regardless of
external pH. In cells that survive UV-irradiation to 8 and 10 J/cm2 (λmax = 297 nm), the intracellular pH is 0.2 and 0.25 unit lower than in nonirradiated cells. 相似文献