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991.
Jun Zhang Zanchao Liu Yuanyuan Pei Wen Yang Chicu Xie Shiqi Long 《Neurochemical research》2018,43(3):736-744
Brain-derived neurotrophic factor (BDNF) is a crucial regulator to support synaptic plasticity and neuronal survival, its significant decrease is a pathophysiological hallmark in Alzheimer’s disease (AD) brains and accounts for poor prognosis. MicroRNAs (miRNAs) interfere with the translation of target mRNAs and control a variety of physiological and pathological processes. MiR-322 is the rodent homologue of human miR-424, it is involved in the modulation of cell differentiation, proliferation, apoptosis and metabolic activities in diverse tissues and organs. However, the roles and potential mechanisms of miR-322 remain elusive in AD pathogenesis. Here we observed miR-322 is significantly increased along with BDNF decrease in AD mouse brain. Bioinformatics prediction implicated that BDNF 3′-untranslated region (3′-UTR) possesses the putative target sequence of miR-322. Luciferase reporter assay identified that miR-322 can directly conjugate to BDNF 3′-UTR. The functional research showed that MiR-322 input deregulates BDNF expression at either mRNA or protein levels, whereas miR-322 silence restores BDNF expression in vitro. Furthermore, we found miR-322 promotes Tau phosphorylation via negatively controlling BDNF–TrkB receptor activation, otherwise MiR-322 silence restores TrkB activation and attenuates tau phosphorylation. Collectively, this study demonstrated a novel miRNA-dependent manner of BDNF degradation in AD pathogenesis, it may drive a miRNAs- or BDNF based therapeutic strategies against Alzheimer’s disease. 相似文献
992.
Michael D Kennedy Mark J Haykowsky Carol A Boliek Ben TA Esch Jessica M Scott Darren ER Warburton 《Dynamic medicine : DM》2006,5(1):8
Background
Near infrared spectroscopy (NIRS) is used to assess muscle oxygenation (MO) within skeletal muscle at rest and during aerobic exercise. Previous investigations have used a single probe placement to measure MO during various forms of exercise. However, regional MO differences have been shown to exist within the same muscle which suggests that different areas of the same muscle may have divergent MO. Thus, the aim of this study was to examine whether regional differences in MO exist within the same muscle during different types of incremental (rest, 25, 50, 75, 100 % of maximum) exercise (1 leg knee extension (KE), 2 leg KE, or cycling).Methods
Nineteen healthy active males (Mean ± SD: Age 27 ± 4 yrs; VO2max: 55 ± 11 mL/kg/min) performed incremental exercise to fatigue using each mode of exercise. NIRS probes were placed on the distal and proximal portion of right leg vastus lateralis (VL). Results were analyzed with a 3-way mixed model ANOVA (probe × intensity × mode).Results
Differences in MO exist within the VL for each mode of exercise, however these differences were not consistent for each level of intensity. Comparison of MO revealed that the distal region of VL was significantly lower throughout KE exercise (1 leg KE proximal MO – distal MO = 9.9 %; 2 leg KE proximal MO – distal MO = 13 %). In contrast, the difference in MO between proximal and distal regions of VL was smaller in cycling and was not significantly different at heavy workloads (75 and 100 % of maximum).Conclusion
MO is different within the same muscle and the pattern of the difference will change depending on the mode and intensity of exercise. Future investigations should limit conclusions on MO to the area under assessment as well as the type and intensity of exercise employed.993.
Quillaguamán J Doan-Van T Guzmán H Guzmán D Martín J Everest A Hatti-Kaul R 《Applied microbiology and biotechnology》2008,78(2):227-232
High poly(3-hydroxybutyrate) (PHB) content and volumetric productivity were achieved by fed-batch culture of Halomonas boliviensis using a defined medium. Initial shake flask cultivations in a minimal medium revealed that the growth of H. boliviensis was supported only when the medium was supplemented with aspartic acid, glycine, or glutamine. Addition of 0.1% (w/v) glutamine in the medium resulted in the highest cell dry weight (CDW; 3.9 g l−1). Glutamine was replaced by the less expensive monosodium glutamate (MSG) in the medium without any notable change in the
final cell density. Effect of initial concentrations of NH4Cl and K2HPO4 on cell growth and PHB accumulation by H. boliviensis was then analyzed using a fed-batch fermentation system. The best conditions for PHB production by H. boliviensis were attained using 0.4% (w/v) NH4Cl and 0.22% (w/v) K2HPO4 and adding MSG intermittently to the fermentor. Poly(3-hydroxybutyrate) content and CDW reached 90 wt.% and 23 g l−1, respectively, after 18 h of cultivation. In order to increase CDW and PHB content, MSG, NH4Cl, and K2HPO4 were initially fed to the fermentor to maintain their concentrations at 2%, 0.4%, and 0.22% (w/v), respectively, and subsequently their feed was suppressed. This resulted in a CDW of 44 g l−1, PHB content of 81 wt.%, and PHB volumetric productivity of 1.1 g l−1 h−1. 相似文献
994.
The formation of colonies and the evolution of coloniality have been suggested to be a by-product of the use of public information
to select breeding habitats. In this study we performed an experimental test to investigate whether the Lesser Kestrel (Falco naumanni) uses breeding success of conspecifics as a source of public information to select a breeding colony. We considered four
potential cues based on reproductive performance of conspecifics in each colony: mean and variance of breeding success measured
in both all pairs (TRS, total reproductive success), and only successful pairs (PRS, partial reproductive success). Both mean
PRS and mean TRS could be predictive cues of the future reproductive output at a given site, because they varied among colonies
and were autocorrelated from one year to the next. To dissociate any relationship between habitat quality and reproductive
success we manipulated the mean brood sizes by transferring chicks among ten colonies. In five colonies, all the broods with
at least two nestlings were reduced in one chick and in other five colonies all broods were enlarged by one chick. In the
following year, we found that the number of adult immigrant kestrels settled at a colony was only explained by mean PRS in
the previous year. We also examined the settlement of yearlings, which lack of information on breeding success in previous
years. Unlike adult immigrant kestrels, yearlings tended to settle more frequently in those colonies with low mean PRS in
the previous year, probably because of the lower pressure for occupation in those colonies. A multiple regression analysis
showed that the growth of colonies was positively dependent on the mean PRS in the experimental year, and negatively on the
number of predated nests. This study provides a solid support to the hypothesis that colonial species can use mean breeding
success of successful pairs as a source of public information to make settlement decisions. 相似文献
995.
996.
We have examined the relationship between the history of fluvial disturbance and understory vegetation in a riparian forest.
The study site was divided into three sites, by use of aerial photographs and topographical maps, with different histories
of fluvial disturbance: (1) Fagus-type on land that has not been flooded for the last 39 years, at least; (2) Populus-type on land that has not been flooded since debris flow occurred 34 years ago; and (3) Salix-type on land that has been flooded periodically from an abandoned channel since debris flow occurred 34 years ago. Species
richness in the Salix-type was significantly higher than in the other types. Detrended correspondence analysis revealed obvious floristic differences
among the three canopy types. Canonical correspondence analysis showed that herbaceous species were mainly found on lower
plots with high moss cover, implying that moss layers may capture seeds transported by the stream. Tall herbs occurred in
less shaded plots and on higher plots, suggesting that their rapid growth prevented the occurrence of other species. Fagus-type was dominated by species with ingested fruits which depended on animals for their dispersal. Populus and Salix-types were dominated by species with wind dispersal or no dispersal mechanism, which depended on physical phenomena for dispersal.
Attributes of current understory vegetation were connected with historical events, suggesting that riparian vegetation reflects
the history of fluvial disturbance. 相似文献
997.
Ji Hyun Kim Yae Jin Yoon Jaewook Lee Eun-Jeong Choi Namwoo Yi Kyong-Su Park Jaesung Park Jan L?tvall Yoon-Keun Kim Yong Song Gho 《PloS one》2013,8(3)
Escherichia coli, as one of the gut microbiota, can evoke severe inflammatory diseases including peritonitis and sepsis. Gram-negative bacteria including E. coli constitutively release nano-sized outer membrane vesicles (OMVs). Although E. coli OMVs can induce the inflammatory responses without live bacteria, the effect of E. coli OMVs in vivo on endothelial cell function has not been previously elucidated. In this study, we show that bacteria-free OMVs increased the expression of endothelial intercellular adhesion molecule-1 (ICAM-1), E-selectin and vascular cell adhesion molecule-1, and enhanced the leukocyte binding on human microvascular endothelial cells in vitro. Inhibition of NF-κB and TLR4 reduced the expression of cell adhesion molecules in vitro. OMVs given intraperitoneally to the mice induced ICAM-1 expression and neutrophil sequestration in the lung endothelium, and the effects were reduced in ICAM-1-/- and TLR4-/- mice. When compared to free lipopolysaccharide, OMVs were more potent in inducing both ICAM-1 expression as well as leukocyte adhesion in vitro, and ICAM-1 expression and neutrophil sequestration in the lungs in vivo. This study shows that OMVs potently up-regulate functional cell adhesion molecules via NF-κB- and TLR4-dependent pathways, and that OMVs are more potent than free lipopolysaccharide. 相似文献
998.
Kyeong Min Min Young Gi Bae Jong Seob Lee Young Hee Choi Young Ryun Cha Sung Ho Cho 《Journal of Plant Biology》1997,40(4):234-239
Aminoalcoholphosphotransferase is the enzyme that catalyzes the synthesis of phosphatidylcholine and phosphatidylethanolamine from diacylglycerol using CDP-aminoalcohol such as CDP-choline and CDP-ethanolamine. To determine its cDNA structure from roots of Chinese cabbage,Brassica campestris L. ssp.pekinensis, degenerate primers were designed from the regions showing high amino acid homology between yeastCPT1 and soybeanAAPT1 and used for PCR amplification of Chinese cabbage DNA. Chinese cabbage aminoalcoholphosphotransferase cDNA (AAPT) contains an open reading frame of 1,167 bp coding for a protein of 389 amino acids. It shared 81% identity and 94% similarity with soybeanAAPT1 at the predicted amino acid level. Hydropathy profile analysis suggested that the predicted protein structure of Chinese cabbage aminoalcoholphosphotransferase was very similar to the soybean enzyme, showing an overall hydrophobicity and having the same number of predicted transmembrane domains. Southern analysis indicated that there might be close isoforms of the enzyme.AAPT was expressed equally well in young shoots and roots. 相似文献
999.
Serotoninergic modulation of GABAergic synaptic transmission in developing rat CA3 pyramidal neurons
Choi IS Cho JH Kim JT Park EJ Lee MG Shin HI Choi BJ Jang IS 《Journal of neurochemistry》2007,103(6):2342-2353
Serotoninergic modulation of GABAergic mIPSCs was investigated in immature (postnatal 12–16-days old) rat CA3 pyramidal neurons using a conventional whole-cell patch clamp technique. Serotonin or 5-hydroxytryptamine (5-HT) (10 μmol/L) transiently and explosively increased mIPSC frequency with a small increase in the current amplitude. However, 5-HT did not affect the GABA-induced postsynaptic currents, indicating that 5-HT acts presynaptically to facilitate the probability of spontaneous GABA release. The 5-HT action on GABAergic mIPSC frequency was completely blocked by 100 nmol/L MDL72222, a selective 5-HT3 receptor antagonist, and mimicked by mCPBG, a selective 5-HT3 receptor agonist. The 5-HT action on GABAergic mIPSC frequency was completely occluded either in the presence of 200 μmol/L Cd2+ or in the Na+ -free external solution, suggesting that the 5-HT3 receptor-mediated facilitation of mIPSC frequency requires a Ca2+ influx passing through voltage-dependent Ca2+ channels from the extracellular space, and that presynaptic 5-HT3 receptors are less permeable to Ca2+ . The 5-HT action on mIPSC frequency in the absence or presence of extracellular Na+ gradually increased with postnatal development. Such a developmental change in the 5-HT3 receptor-mediated facilitation of GABAergic transmission would play important roles in the regulation of excitability as well as development in CA3 pyramidal neurons. 相似文献
1000.
Woo-Jong Yim Selvaraj Poonguzhali Munusamy Madhaiyan Pitchai Palaniappan M. A. Siddikee Tongmin Sa 《Journal of microbiology (Seoul, Korea)》2009,47(2):147-155
Diazotrophic bacteria isolated from the rhizosphere of Chinese cabbage were assessed for other plant growth promoting characteristics
viz., production of IAA, ethylene, ACC deaminase, phosphate solubilization, and gnotobiotic root elongation. Their effect on inoculation
to Chinese cabbage was also observed under growth chamber conditions. A total of 19 strains that showed higher nitrogenase
activity identified by 16S rRNA gene sequence analysis were found to be the members of the genera Pseudomonas and Agrobacterium belonging to α- and γ-Proteobacteria groups. These strains were also efficient in producing IAA and ACC deaminase though they produced low levels of ethylene
and no phosphate solubilization. In addition, inoculation of selected diazotrophic bacterial strains significantly increased
seedling length, dry weight, and total nitrogen when compared to uninoculated control. The colonization of crop plants by
diazotrophic bacteria can be affected by many biotic and abiotic factors, and further studies are oriented towards investigating
the factors that could influence the establishment of a selected bacterial community. 相似文献