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951.
Changjie Lou Fayun Zhang Ming Yang Juan Zhao Wenfeng Zeng Xiaocui Fang Yanqiao Zhang Chunling Zhang Wei Liang 《PloS one》2012,7(12)
Epithelial to mesenchymal transition (EMT) promotes cellular motility, invasiveness and metastasis during embryonic development and tumorigenesis. Transforming growth factor-β (TGF-β) signaling pathway is a key regulator of EMT. A lot of evidences suggest that this process is Smad3-dependent. Herein we showed that exposure of aspc-1 and panc-1 pancreatic cancer cells to TGF-β1 resulted in characteristic morphological alterations of EMT, and enhancement of cell motility and gemcitabine (Gem) resistance along with an up-regulation of EMT markers genes such as vimentin, N-cadherin, MMP2 and MMP9. Naringenin (Nar) down-regulated EMT markers expression in both mRNA and protein levels by inhibiting TGF-β1/Smad3 signal pathway in the pancreatic cancer cells. Consequently, Nar suppressed the cells migration and invasion and reversed their resistance to Gem. 相似文献
952.
Estes JD Gordon SN Zeng M Chahroudi AM Dunham RM Staprans SI Reilly CS Silvestri G Haase AT 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(10):6798-6807
Primate lentiviruses are typically apathogenic in their evolutionarily coadapted host species but can be lethal when transferred to new host species. Why such infections are pathogenic in humans and rhesus macaques (RMs) but not in sooty mangabeys (SMs), a natural host, remains unclear. Studies of chronically infected animals point to the importance of diminished immune activation in response to the infection in SMs. In this study, we sought the causes and timing of the differences in immune activation in a comparative study of acute SIV infection in RMs and SMs. Surprisingly, we show that in acute infection immune activation is comparable in SMs and RMs but thereafter, SMs quickly resolve immune activation, whereas RMs did not. Early resolution of immune activation in SMs correlated with increased expression of PD-1 and with preservation of CD4(+) T cell counts and lymphatic tissue architecture. These findings point to early control of immune activation by host immunoregulatory mechanisms as a major determinant of the different disease outcomes in SIV infection of natural vs non-natural hosts. 相似文献
953.
Piracetam is the derivate of gamma-aminobutyric acid, which improves the cognition,memory,consciousness, and is widely applied
in the clinical treatment of brain dysfunction. In the present experiments, we study the effects of piracetam on chronic cerebral
hypoperfused rats and observe its influence on amino acids, synaptic plasticity in the Perforant path-CA3 pathway and apoptosis
in vivo. Cerebral hypoperfusion for 30 days by occlusion of bilateral common carotid arteries induced marked amnesic effects
along with neuron damage, including: (1) spatial learning and memory deficits shown by longer escape latency and shorter time
spent in the target quadrant; (2) significant neuronal loss and nuclei condensation in the cortex and hippocampus especially
in CA1 region; (3) lower induction rate of long term potentiation, overexpression of BAX and P53 protein, and lower content
of excitatory and inhibitory amino acids in hippocampus. Oral administration of piracetam (600 mg/kg, once per day for 30 days)
markedly improved the memory impairment, increased the amino acid content in hippocampus, and attenuated neuronal damage.
The ability of piracetam to attenuate memory deficits and neuronal damage after hypoperfusion may be beneficial in cerebrovascular
type dementia. 相似文献
954.
C. -W. Zhu J. -G. Zhu G. Liu Q. Zeng Z. -B. Xie J. Pang Z. -Z. Feng H. -Y. Tang L. Wang 《Photosynthetica》2008,46(2):318-320
Net photosynthetic rate (P
N) of ear and flag leaf during grain filling stage and grain yield of plants with non-darkened or darkened flag leaf or darkened
ear were examined in two different CO2 concentrations: ambient (AC) and AC+200 μmol mol−1 (EC). Ear showed much higher enhancement (56 %) of P
N than flag leaf (23 %) under EC. Moreover, CO2 enrichment shortened the photosynthetic duration of flag leaf relative to ear. In this way the ratio of ear to flag leaf
contribution to grain yield increased from 1.18 (AC) to 1.39 (EC). 相似文献
955.
956.
Ferritins are a class of iron storage protein spheres found mainly in the liver and spleen, which have attracted many research interests due to their unique structural features and biological properties. Recently, ferritin and apoferritin (ferritin devoid of the iron core), have been employed as chemically addressable nanoscale building blocks for functional materials development. However, the reactive residues of apoferritin or ferritin have never been specified and it is still unclear about the chemoselectivity of apoferritin towards different kinds of bioconjugation reagents. In this work, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry combined with enzymatic digestion analysis was used to identify the reactive lysine residues of horse spleen apoferritin when conjugated with N-hydroxysuccinimide reagents. The result demonstrated that among all the lysine residues, K97, K83, K104, K67 and K143 are the reactive ones that can be addressed. 相似文献
957.
Quan-Ying Cai Ce-Hui Mo Qiao-Yun Zeng Qi-Tang Wu Jean-François Férard Blanca Antizar-Ladislao 《Environmental and Experimental Botany》2008,62(3):205-211
Five different genotypic cultivars of Ipomoea aquatica commonly grown in Southeast Asia were cultivated to investigate their accumulation variation of di-n-butyl phthalate (DBP) and their potential for phytoremediation of three soils contaminated with DBP (4.5, 10.3 and 22.5 mg kg?1). The results indicated different cultivar tolerance to DBP. DBP concentration in the shoots of the cultivars and residual DBP concentration in the soil were proportional to initial DBP concentrations in the soil and significantly different with different genotypic cultivars, indicating that the removal of DBP is cultivar-specific. DBP removal in the soil with indigenous DBP was higher than that in freshly DBP-spiked soils. The cultivars of local white-skin I. aquatica (cultivar V5) and Taiwan filiform-leaf I. aquatica (cultivar V1) presented the highest phytoremediation potential in the soil containing indigenous DBP and in freshly DBP-spiked soil, respectively. The translocation factor (TF, DBP concentration ratio of the shoots to the roots) and bioconcentration factor (BCF, DBP concentration ratio of the plant to the soil) also significantly varied with different cultivars, and they did not follow distribution profiles correlated to DBP removal indicating that phytoextraction was not the dominant DBP removal mechanism. Finally, the potential ability of different cultivars of enhancing biodegradation varied widely. 相似文献
958.
Many Streptomyces species harbor circular plasmids (8 to 31 kb) as well as linear plasmids (12 to 1,700 kb). We report the characterization of two newly detected circular plasmids, pFP11 (35,139 bp) and pFP1 (39,360 bp). As on linear plasmids, their replication loci comprise repA genes and adjacent iterons, to which RepA proteins bind specifically in vitro. Plasmids containing the minimal iterons plus the repA locus of pFP11 were inherited extremely unstably; par and additional loci were required for stable inheritance. Surprisingly, plasmids containing replication loci from pFP11 or Streptomyces circular plasmid SCP2 but not from pFP1, SLP1, or pIJ101 propagated in a stable linear mode when the telomeres of a linear plasmid were attached. These results indicate bidirectional replication for pFP11 and SCP2. Both pFP11 and pFP1 contain, for plasmid transfer, a major functional traB gene (encoding a DNA translocase typical for Streptomyces plasmids) as well as, surprisingly, a putative traA gene (encoding a DNA nickase, characteristic of single-stranded DNA transfer of gram-negative plasmids), but this did not appear to be functional, at least in isolation. 相似文献
959.
spata3是一个在睾丸中特异性表达的基因,可能与精子发生或生精细胞凋亡相关.为了进一步研究Spata3的功能,将spata3克隆入经修饰的pcDNA5/FRT/TO表达载体,应用Flp-InTMT-RExTM-293 细胞系作为拗飨赴? 成功地构建了可被四环素或 Doxycline 诱导的稳定表达 Flp-InTMT-RExTM-sptat3 的细胞系.该细胞系在spata3基因 的3'端有2×FLAG tag和2×Histag,在缺乏可利用的spata3或其抗体的情况下,也能够很容易地应用商品化的FLAG抗体检测到spata3全长蛋白的表达.这种可诱导的稳定表达Flp-InTMT-Rex TM-spata3 的细胞系的建立,不仅有利于spata3的分析鉴定和功能研究,而且对于其他蛋白质的分离纯化和功能研究也有很好的借鉴作用. 相似文献
960.