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41.
Jing Fang Heng Yin Zhixiang Zheng Panpan Zhu Xi Peng Zhicai Zuo Hengmin Cui Yi Zhou Ping Ouyang Yi Geng Junliang Deng 《Biological trace element research》2018,181(1):142-153
Aflatoxin B1 (AFB1) is the most toxic among the mycotoxins and causes detrimental health effects on human and animals. Selenium (Se) plays an important role in chemopreventive, antioxidant, anticarcinogen, and detoxification and involved in cell cycle regulation. The aim of this study was to explore the molecular mechanisms of selenium involved in inhibition of G2/M cell cycle arrest of broiler’s jejunum. A total of 240 one-day-old healthy Cobb broilers were randomly divided into four groups and fed with basal diet (control group), 0.6 mg/kg AFB1 (AFB1 group), 0.4 mg/kg Se (+Se group), and 0.6 mg/kg AFB1 + 0.4 mg/kg Se (AFB1 + Se group) for 21 days, respectively. The histological observation and morphological analysis revealed that 0.4 mg/kg Se prevented the AFB1-associated lesions of jejunum including the shedding of the apical region of villi, the decreased villus height, and villus height/crypt ratio. The cell cycle analysis by flow cytometry showed that 0.4 mg/kg Se ameliorated the AFB1-induced G2/M phase arrest in jejunal cells. Moreover, the expressions of ATM, Chk2, p53, Mdm2, p21, PCNA, Cdc25, cyclin B, and Cdc2 analyzed by immunohistochemistry and qRT-PCR demonstrated that 0.4 mg/kg Se restored these parameters to be close to those in the control group. In conclusion, Se promoted cell cycle recovery from the AFB1-induced G2/M phase arrest by the molecular regulation of ATM pathway in the jejunum of broilers. The outcomes from the present study may lead to a better understanding of the nature of selenium’s essentiality and its protective roles against AFB1. 相似文献
42.
Zou T Rao JN Liu L Xiao L Cui YH Jiang Z Ouyang M Donahue JM Wang JY 《American journal of physiology. Cell physiology》2012,303(1):C102-C111
Polyamines regulate multiple signaling pathways and are implicated in many aspects of cellular functions, but the exact molecular processes governed by polyamines remain largely unknown. In response to environmental stress, repression of translation is associated with the assembly of stress granules (SGs) that contain a fraction of arrested mRNAs and are thought to function as mRNA storage. Here we show that polyamines modulate the assembly of SGs in normal intestinal epithelial cells (IECs) and that induced SGs following polyamine depletion are implicated in the protection of IECs against apoptosis. Increasing the levels of cellular polyamines by ectopic overexpression of the ornithine decarboxylase gene decreased cytoplasmic levels of SG-signature constituent proteins eukaryotic initiation factor 3b and T-cell intracellular antigen-1 (TIA-1)-related protein and repressed the assembly of SGs induced by exposure to arsenite-induced oxidative stress. In contrast, depletion of cellular polyamines by inhibiting ornithine decarboxylase with α-difluoromethylornithine increased cytoplasmic eukaryotic initiation factor 3b and TIA-1 related protein abundance and enhanced arsenite-induced SG assembly. Polyamine-deficient cells also exhibited an increase in resistance to tumor necrosis factor-α/cycloheximide-induced apoptosis, which was prevented by inhibiting SG formation with silencing SG resident proteins Sort1 and TIA-1. These results indicate that the elevation of cellular polyamines represses the assembly of SGs in normal IECs and that increased SGs in polyamine-deficient cells are crucial for increased resistance to apoptosis. 相似文献
43.
Bret Wankel Jiangyong Ouyang Xuemei Guo Krassimira Hadjiolova Jeremy Miller Yi Liao Daniel Kai Long Tham Rok Romih Leonardo R. Andrade Iwona Gumper Jean-Pierre Simon Rakhee Sachdeva Tanya Tolmachova Miguel C. Seabra Mitsunori Fukuda Nicole Schaeren-Wiemers Wan Jin Hong David D. Sabatini Xue-Ru Wu Xiangpeng Kong Gert Kreibich Michael J. Rindler Tung-Tien Sun 《Molecular biology of the cell》2016,27(10):1621-1634
Uroplakins (UPs) are major differentiation products of urothelial umbrella cells and play important roles in forming the permeability barrier and in the expansion/stabilization of the apical membrane. Further, UPIa serves as a uropathogenic Escherichia coli receptor. Although it is understood that UPs are delivered to the apical membrane via fusiform vesicles (FVs), the mechanisms that regulate this exocytic pathway remain poorly understood. Immunomicroscopy of normal and mutant mouse urothelia show that the UP-delivering FVs contained Rab8/11 and Rab27b/Slac2-a, which mediate apical transport along actin filaments. Subsequently a Rab27b/Slp2-a complex mediated FV–membrane anchorage before SNARE-mediated and MAL-facilitated apical fusion. We also show that keratin 20 (K20), which forms a chicken-wire network ∼200 nm below the apical membrane and has hole sizes allowing FV passage, defines a subapical compartment containing FVs primed and strategically located for fusion. Finally, we show that Rab8/11 and Rab27b function in the same pathway, Rab27b knockout leads to uroplakin and Slp2-a destabilization, and Rab27b works upstream from MAL. These data support a unifying model in which UP cargoes are targeted for apical insertion via sequential interactions with Rabs and their effectors, SNAREs and MAL, and in which K20 plays a key role in regulating vesicular trafficking. 相似文献
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45.
Exposure to high glutamate concentration activates aerobic glycolysis but inhibits ATP‐linked respiration in cultured cortical astrocytes 下载免费PDF全文
Yao Shen Yueyang Tian Xiaojie Shi Jianbo Yang Li Ouyang Jieqiong Gao Jianxin Lu 《Cell biochemistry and function》2014,32(6):530-537
Astrocytes play a key role in removing the synaptically released glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. However, high concentration of glutamate leads to toxicity in astrocytes, and the underlying mechanisms are unclear. The purpose of this study was to investigate whether energy metabolism disorder, especially impairment of mitochondrial respiration, is involved in the glutamate‐induced gliotoxicity. Exposure to 10‐mM glutamate for 48 h stimulated glycolysis and respiration in astrocytes. However, the increased oxygen consumption was used for proton leak and non‐mitochondrial respiration, but not for oxidative phosphorylation and ATP generation. When the exposure time extended to 72 h, glycolysis was still activated for ATP generation, but the mitochondrial ATP‐linked respiration of astrocytes was reduced. The glutamate‐induced astrocyte damage can be mimicked by the non‐metabolized substrate d ‐aspartate but reversed by the non‐selective glutamate transporter inhibitor TBOA. In addition, the glutamate toxicity can be partially reversed by vitamin E. These findings demonstrate that changes of bioenergetic profile occur in cultured cortical astrocytes exposed to high concentration of glutamate and highlight the role of mitochondria respiration in glutamate‐induced gliotoxicity in cortical astrocytes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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48.
Plant regeneration through organogenesis from callus induced from mature zygotic embryos of loblolly pine 总被引:7,自引:1,他引:7
Mature zygotic embryos from three seed sources of loblolly pine were cultured on callus induction medium containing 10 mg
l–1
α-naphthaleneacetic acid, 4 mg l–1 benzyladenine (BA), 400 mg l–1 casein hydrolysate, and 400 mg l–1 glutamine for 6 weeks. Light-yellow, loose, glossy, globular callus was formed, and the highest frequency was 35.7%. The
highest differentiation frequency of callus on adventitious bud induction medium was 62.1%. After culture of calli with adventitious
buds on elongation medium for 6 weeks, adventitious shoots more than 1.0 cm in height were selected for rooting. On rooting
medium supplemented with 0.1 mg l–1 indole-3-butyric acid, 1 mg l–1 BA, and 0.5 mg l–1 gibberellic acid, the highest rooting frequency of adventitious shoots was 46% in a culture period of 6 weeks. Established
plants survived following transfer to soil at a frequency of 71%.
Received: 14 May 1997 / Revision received: 25 September 1997 / Accepted: 11 October 1997 相似文献
49.
The surface pressure-area (-A) isotherms ofN-hexadecyl-8-hydroxy-2-quinolinecarboxamide (HHQ) monolayers at an air-water interface on subphases with different pH values were investigated. The monolayer of HHQ was expanded and unstable on acidic subphases, while it was condensed and stable on basic subphases. The acid-base equilibrium of HHQ was investigated in an aqueous dioxane solution and at the air-water interface. The association-dissociation of HHQ with H+ ions in the interfacial region was very different from that in the aqueous dioxane solution. Some information regarding the packing density, phase transition and degree of ionization of the head group under different experimental conditions has been obtained. 相似文献
50.
Willem Rensink Amy Hart Jia Liu Shu Ouyang Victoria Zismann C Robin Buell 《Génome》2005,48(4):598-605