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991.
Xiuli Zhang Dan Liang Baolei Guo Lixia Sun Zhi-Hong Chi Yuan Cai Lining Wang Jianfei Ma 《Biological trace element research》2013,151(1):138-147
Zinc (Zn) is an essential micronutrient and cytoprotectant involved in preventing many types of epithelial-to-mesenchymal transition (EMT)-driven fibrosis in vivo. The zinc-transporter family SLC30A (ZnT) is a pivotal factor in the regulation of Zn homeostasis. However, its function in EMT in peritoneal mesothelial cells (PMCs) remains unknown. This study explored the regulation of zinc transporters and the role they play in cell EMT, particularly in rat peritoneal mesothelial cells (RPMCs), surrounding glucose concentrations and the molecular mechanism involved. The effects of high glucose (HG) on zinc transporter gene expression were measured in RPMCs by real-time PCR. We explored ZnT7 (Slc30A7): the effect of ZnT7 over-expression and siRNA-mediated knock-down on HG-induced EMT was investigated as well as the underlying molecular mechanisms. Over-expression of ZnT7 resulted in significantly inhibited HG-induced EMT in RPMCs, while inhibition of ZnT7 expression using a considerable siRNA-mediated knock-down of RPMCs increased the levels of EMT. Furthermore, over-expression of ZnT7 is accompanied by down-regulation of TGF-β/Smad pathway, phospho-Smad3,4 expression levels. The finding suggests that the zinc-transporting system in RPMCs is influenced by the exposure to HG. The ZnT7 may account for the inhibition of HG-induced EMT in RPMCs, likely through targeting TGF-β/Smad signaling. 相似文献
992.
Q. Li X. Z. Li T. Wang L. W. Zhou H. Q. Feng L. Gao J. R. Pei C. Lin C. X. Jiang 《Biological trace element research》2013,151(1):14-17
The aim of the present study was to explore the role of selenoprotein P (SePP) in the etiology of the endemic sudden cardiac death in Yunnan, China. The levels of SePP of 124 subjects and glutathione peroxidase (GPx) of 119 subjects were measured. The subjects were from the old and new endemic areas and non-endemic areas. The levels of SePP and GPx of the subjects of the old endemic area were significantly higher than those of the subjects of the new endemic area and the non-endemic areas, respectively. The Pearson’s correlation among SePP, GPx, and the number of the incident cases of the disease were statistically significant. These correlations show that there is an inverse relationship among the number of patients and the levels of SePP (r? = ?? 0.9800, P ?= ?0.0200) and GPx (r? = ?? 0.961, P ?= ?0.009). The results show that selenium deficiency might play an important role in the incidence of the disease. 相似文献
993.
Jinming Luo Xiongrui Yin Yajie Ya Yongjie Wang Shuying Zang Xia Zhou 《Biological trace element research》2013,156(1-3):134-143
Pb and Cd concentrations in the habitat and preys of the red-crowned crane (i.e., reed rhizomes and three typical aquatic animal families (Perccottus glehni Dybowski, Carassius auratus Linnaeus, and Viviparidae)) were analyzed to examine the impact of these hazards on red-crowned cranes in northeastern China. Results indicated that Pb and Cd concentrations in the preys of the red-crowned cranes were elevated via food chain. Most of the detected Pb and Cd contents in the sediments were above the natural background level, ranging from 9.85 to 129.72 ppm and 1.23 to 10.63 ppm (dry weight), respectively. Cd geo-accumulation index at all sites were larger than 3, even reached 5.22, suggesting serious pollution in this region. Three common water animal families were detected to contain heavy metals, following the order of increasing concentrations: primary consumers (i.e., Viviparidae and Carassius auratus Linnaeus)?<?secondary consumers (i.e., Perccottus glehni Dybowski). Pb and Cd concentrations in the buffer zone are significantly higher than in the core area and being elevated in the food chain. The molten feathers of the red-crowned cranes showed the highest toxic metal concentrations of Pb (2.09 to 5.81 ppm) and Cd (1.42 to 3.06 ppm) compared with the feces produced by cranes and residual eggshell left by water fowls. Exceptionally high Pb and Cd concentrations in the cranes and their preys were thought to be associated with their habitat. 相似文献
994.
Zhenying Zhao Yongqiang Yin Zengyong Wang Runping Fang Hong Wu Min Jiang Gang Bai Guo’an Luo 《Biological trace element research》2013,156(1-3):181-187
Arctigenin, a lignan extract from Arctium lappa (L.), exhibits anti-inflammation, antioxidation, vasodilator effects, etc. However, the effects of arctigenin on bronchus relaxation are not well investigated. This study aimed to investigate how arctigenin regulates bronchus tone and calcium ion (Ca2+) flow. Trachea strips of guinea pigs were prepared for testing the relaxation effect of arctigenin to acetylcholine, histamine, KCl, and CaCl2, respectively. Furthermore, l-type calcium channel currents were detected by patch–clamp, and intracellular Ca2+ concentration was detected by confocal microscopy. The results showed that arctigenin exhibited relaxation effect on tracheae to different constrictors, and this was related to decreasing cytoplasmic Ca2+ concentration by inhibiting Ca2+ influx partly through l-type calcium channel as well as promoting Ca2+ efflux. In summary, this study provides new insight into the mechanisms by which arctigenin exhibits relaxation effect on bronchus and suggests its potential use for airway disease therapy. 相似文献
995.
To obtain bacteria with arsenic accumulation potential that can be used to remove arsenic from contaminated waters, experiments were made to investigate the tolerance and accumulation to arsenic of an indigenous bacterium XZM002 isolated from aquifer sediments of Datong Basin, northern China. The results showed that strain XZM002 belongs to the genus Bacillus and has evolved defense mechanisms to reduce arsenic injury: the change of cellular shape from initial rod to oval and then to round with increment of arsenic toxicity. The effect of arsenate or arsenite on the bacterial growth was also investigated. Results showed that growth of the strain was inhibited under As(III) and high concentration As(V) (over 1200 μg l?1) conditions in the first 2 days and promoted under low concentration As(V) (under 400 μg l?1) condition. Its arsenic bioaccumulation potential was surveyed by monitoring the concentration changes of total arsenic and arsenic speciation in the medium and in the cytoplasm, and those of total arsenic on the membrane. Methylated arsenic species were not detected throughout the experiment. The results indicated that 11.5% of arsenic was removed from liquid medium into the bacterial cells and 9.22% of As(V) in the medium was transformed gradually to As(III) during 4 d of incubation. Approximately 80% of the total accumulated arsenic was adsorbed onto the membrane instead of into cytoplasm; and the arsenic accumulation almost approached saturation after incubation for 72 h. 相似文献
996.
Chao Peng Hongchen Jiang Liuqin Huang Weiguo Hou Jian Yang Shang Wang 《Geomicrobiology journal》2013,30(6):530-539
The cold springs underlain by gas hydrates on the Qinghai-Tibet Plateau (QTP) are similar to deep-sea cold seeps with respect to methane biogeochemistry. Previous studies have shown that ammonia oxidizing bacteria (AOB) and archaea (AOA) are actively present and play important roles in the carbon/nitrogen cycles in cold seeps. Studying AOA and AOB communities in the QTP cold springs will be of great importance to our understanding of carbon and nitrogen cycling dynamics related to the underlying gas hydrates on the QTP. Thus, the abundance and diversity of AOB and AOA in sediments of four cold springs underlain by gas hydrates on the QTP were determined by using quantitative polymerase chain reaction and amoA gene (encoding ammonia monooxygenase involved in ammonia oxidation) phylogenetic analysis. The results showed that the AOB and AOA amoA gene abundances were at 103–104 copies per gram of the sediments in the investigated cold springs. The AOB population consisted of Nitrosospira and Nitrosomonas in contrast with the mere presence of Nitrosospira in marine cold seeps. The AOB diversity was higher in cold springs than in cold seeps. The AOA population was mainly composed of Nitrososphaera, in contrast with the dominance of Nitrosopumilus in cold seeps. The terrestrial origin and high level of dissolved oxygen of the cold springs may be the main factors accounting for the observed differences in AOB and AOA populations between the QTP cold springs and marine cold seeps. 相似文献
997.
Ruimin Mu Yujie He Sixiu Liu Xiangrong Wang Zhengqiu Fan 《Geomicrobiology journal》2013,30(7):516-521
One strain of algicidal bacterium which can inhibit Harmful algal blooms (HABs), FDT5, was isolated from activated sludge and found to have good algicidal effects on Microcystis aeruginosa. It was revealed that: The FDT5 was a Gram-negative bacterium and identified as Ochrobactrum sp.; The greater the initial bacterial cell density, the faster the degradation of chlorophyll a.; The algicidal efficiency was evaluated at the most favorable conditions which were a temperature of 30–35°C, a pH of 7.6 and complete darkness; The FDT5 strain lysed Microcystis aeruginosa not directly but by secreting metabolites which could withstand high temperatures and pressure. 相似文献
998.
Bin Liu Guangbin Ye Fengpin Wang Ryan Bell John Noakes Tim Short 《Geomicrobiology journal》2013,30(6):363-369
Microorganisms play fundamental roles in the ecosystem of the Gulf of Mexico (GOM), yet their vertical distributions along the depth continuum of water column are not well known. In this study, we presented the 16S rDNA sequences and lipid profiles in the context of water chemistry to characterize the archaeal community structure above a gas hydrate mound (MC 118) in GOM. Our results showed that all archaeal sequences were related to unknown species of Crenarchaeota or Euryarchaeota. Phylogenetically, group II –β Euryarchaeota dominated the surface water and mid-depth (400-m) water (74% and 58% of total archaeal species, respectively) whereas the marine group I-γ Crenarchaeota dominated the bottom (869 m) water (61% of total archaeal species). Estimates of the Shannon index showed the highest diversity of planktonic Archaea at the 400 m depth. Glycerol dialkyl glycerol tetraether (GDGT) lipids were detected from the 400- and 869-m depths only and characterized by relatively high abundances of GDGT-5 (crenarchaeol) and GDGT-0. Our studies suggested a possible zonation of archaeal community in the water column, which did not seem to be affected by the possible venting of hydrocarbons from the hydrate location in GOM. 相似文献
999.
Bacillus cereus strain XZM002 isolated from high arsenic aquifer sediments of Datong Basin was applied to examine the effects of arsenate stress on antioxidant enzyme activities, lipid peroxidation levels and cell growth inhibition rate. After 2 d exposure, the cell growth inhibition rate enhanced with an increase of As(V) concentrations (0, 800, 1600 μg/l). Reactive oxygen species and glutathione contents, lipid peroxidation levels, and antioxidant enzymes (glutathione peroxidase, and other three) activities of the treated cells were significantly higher than those of the controls during 3 d exposure (p < 0.05). Besides, the levels of nine parameters reached maximum after 2 d exposure and increased significantly with increasing arsenate stress (p < 0.05). However, they returned to levels similar to those of the control on the fourth day of exposure. The results suggested that the antioxidant defense system in B. cereus strain XZM002 could protect the cells from oxidative damage induced by arsenate. 相似文献
1000.
Xiao K. Wang Qiu F. Ma Wei Jiang Jing Lv Wei D. Pan Tao Song 《Geomicrobiology journal》2013,30(6):296-303
Magnetotactic bacteria synthesize intracellular magnetic particles, magnetosomes, which arrange in chain(s) and confer on cell a magnetic dipolar moment. To explore the function of geomagnetic field to magnetotactic bacteria, the effects of hypomagnetic field on magnetosome formation in Magnetospirillum magneticum AMB-1 were studied. Cells were cultivated in a specially designed device where geomagnetic field was reduced by about 100-fold to less than 500nT. AMB-1 cultures were incubated in hypomagnetic field or geomagnetic field. Results showed that hypomagnetic field had no significant effects on the average number of magnetic particles per bacterium and bacterial iron depletion. However, the growth (OD) of cell at stationary-phase was lower and cellular magnetism (R mag) at exponential growth phase was higher than that of bacteria cultivated in geomagnetic field. Statistic results on transmission electron microscopy (TEM) micrographs showed that the average size of magnetic particles in AMB-1 cells in hypomagnetic field group was larger than that of in geomagnetic field group and more ratio of larger-size magnetic particles (>50 nm) was observed when cultivated 16 h under hypomagnetic field. Furthermore, the influences of hypomagnetic field on gene expression were studied in AMB-1 cells. Quantitative RT-PCR results showed that hypomagnetic field up-regulated mms13, down-regulated mms6 and had no effect on magA. Together, the results showed that hypomagnetic field could affect the growth of AMB-1 at the stationary-phase, the crystallization process of magnetosomes, and mms13, mms6 expressions. In addition, our results suggested that the geomagnetic field plays an important role in the biomineralization of magnetosomes. 相似文献