当前位置: 首页 >> 检索结果
共有 146687 条符合本次的查询结果, 用时 7.4752968 秒

381. Human Embryonic Stem Cells Do Not Change Their X Inactivation Status during Differentiation.

作者: Sanjeet Patel.;Giancarlo Bonora.;Anna Sahakyan.;Rachel Kim.;Constantinos Chronis.;Justin Langerman.;Sorel Fitz-Gibbon.;Liudmilla Rubbi.;Rhys J P Skelton.;Reza Ardehali.;Matteo Pellegrini.;William E Lowry.;Amander T Clark.;Kathrin Plath.
来源: Cell Rep. 2017年18卷1期54-67页
Applications of embryonic stem cells (ESCs) require faithful chromatin changes during differentiation, but the fate of the X chromosome state in differentiating ESCs is unclear. Female human ESC lines either carry two active X chromosomes (XaXa), an Xa and inactive X chromosome with or without XIST RNA coating (XiXIST+Xa;XiXa), or an Xa and an eroded Xi (XeXa) where the Xi no longer expresses XIST RNA and has partially reactivated. Here, we established XiXa, XeXa, and XaXa ESC lines and followed their X chromosome state during differentiation. Surprisingly, we found that the X state pre-existing in primed ESCs is maintained in differentiated cells. Consequently, differentiated XeXa and XaXa cells lacked XIST, did not induce X inactivation, and displayed higher X-linked gene expression than XiXa cells. These results demonstrate that X chromosome dosage compensation is not required for ESC differentiation. Our data imply that XiXIST+Xa ESCs are most suited for downstream applications and show that all other X states are abnormal byproducts of our ESC derivation and propagation method.

382. Novel androgen-induced activity of an antimicrobial β-defensin: Regulation of Wolffian duct morphogenesis.

作者: Camilla M Ribeiro.;Lucas G A Ferreira.;Daniel S Thimoteo.;Lee B Smith.;Barry T Hinton.;Maria Christina W Avellar.
来源: Mol Cell Endocrinol. 2017年442卷142-152页
The Wolffian duct (WD) undergoes morphological changes induced by androgens to form the epididymis, which is an organ essential for sperm maturation. Androgen action in WD epithelium involves paracrine factors of mesenchymal origin that function by still poorly understood mechanisms. Here we studied the antimicrobial β-defensin SPAG11C as a new player in duct morphogenesis, localized prenatally in the WD mesenchyme. Organotypic culture of rat WDs and tissues from Androgen Receptor (AR) knockout mice (ARKO) were used. Our results show that androgen/AR signaling differentially regulated SPAG11C expression at mRNA and protein levels in the developing WD. WDs incubated with recombinant human SPAG11C were shorter and less coiled as a result of reduced epithelial cell proliferation, but not increased apoptosis. Our results suggested β-defensin SPAG11C as an androgen-target required for WD morphogenesis. This highlights the multifunctional repertoire of the β-defensin protein family and their potential contribution to the in utero environment that determines male reproductive success.

383. Unpredicted Downregulation of RAD51 Suggests Genome Instability Induced by Tetrachlorobenzoquinone.

作者: Xiufang Song.;Qiong Shi.;Zixuan Liu.;Yawen Wang.;Yuxin Wang.;Erqun Song.;Yang Song.
来源: Chem Res Toxicol. 2016年29卷12期2184-2193页
We previously demonstrated that halogenated quinone induces DNA double strand breaks (DSBs) in a ROS-dependent manner, which coordinates with downstream repair cascade including nonhomologous end joining, base excision repair, and nucleotide excision repair. However, these error-prone processes may cause the potential risk of genome instability, and current has no information on how faithful repair route, such as homologous recombination (HR), was affected. RAD51 is a key protein in the HR pathway of DSBs repair. Here, we found that tetrachlorobenzoquinone (TCBQ) causes a time-dependent reverse U-shape biphasic trend of RAD51 expression. An increase in the early stage and a following decrease of RAD51 expression were found in both 12.5 and 25 μM TCBQ groups, wherein higher concentration faced a faster response. The upregulated RAD51 in the early phase suggested the attempting to repair TCBQ-induced DNA damage; however, the downregulation of RAD51 in the late phase implicated that the rescue probably be abandoned with severe DNA damage. This phenomenon is a general toxic manner of TCBQ regardless of cell type. Surprisingly, TCBQ showed minimum effect on RAD51 mRNA (or protein) synthesis as well as RAD51 degradation. Specific inhibition of RAD51 by siRNA amplified TCBQ-induced DNA damage and cytotoxicity, while cells with enhanced RAD51 expression resisted TCBQ-induced toxicity. The modulation of RAD51 is correlated with p53 level, which suggests p53 has a role in TCBQ-induced RAD51 clearance. Together, our data suggested that TCBQ increases genome instability and cell death through a unique mechanism of inducing DNA damage and inhibiting DNA repair.

384. AhDGR2, an amaranth abiotic stress-induced DUF642 protein gene, modifies cell wall structure and composition and causes salt and ABA hyper-sensibility in transgenic Arabidopsis.

作者: Paola A Palmeros-Suárez.;Julio A Massange-Sánchez.;Lino Sánchez-Segura.;Norma A Martínez-Gallardo.;Eduardo Espitia Rangel.;Juan F Gómez-Leyva.;John P Délano-Frier.
来源: Planta. 2017年245卷3期623-640页
An amaranth DGR gene, induced under abiotic stress, modifies cell wall structure and causes hypersensitivity to ABA and salt when overexpressed in Arabidopsis. DUF642 is a highly conserved plant-specific family of unknown cell wall-associated proteins. The AhDGR2 gene, coding for a DUF642 protein, was significantly induced in grain amaranth (Amaranthus hypochondriacus) plants subjected to water-deficit and salinity stress, thereby suggesting its participation in abiotic stress tolerance in this plant. A role in development was also inferred from the higher AhDGR2 expression rates detected in young tissues. Subsequent overexpression of AhDGR2 in transgenic Arabidopsis plants (OE-AhDGR2) supported its possible role in development processes. Thus, OE-AhDGR2 plants generated significantly longer roots when grown in normal MS medium. However, they showed a hypersensitivity to increasing concentrations of abscisic acid or NaCl in the medium, as manifested by shorter root length, smaller and slightly chlorotic rosettes, as well as highly reduced germination rates. Contrary to expectations, OE-AhDGR2 plants were intolerant to abiotic stress. Moreover, cell walls in transgenic plants were thinner, in leaves, and more disorganized, in roots, and had significantly modified pectin levels. Lower pectin methylesterase activity detected in leaves of OE-AhDGR2 plants, but not in roots, was contrary to previous reports associating DUF642 proteins and decreased pectin esterification levels in cell walls. Nonetheless, microarray data identified candidate genes whose expression levels explained the phenotypes observed in leaves of OE-AhDGR2 plants, including several involved in cell wall integrity and extension, growth and development, and resistance to abiotic stress. These results support the role of DUF642 proteins in cell wall-related processes and offer novel insights into their possible role(s) in plants.

385. Insights on wood combustion generated proinflammatory ultrafine particles (UFP).

作者: Emanuela Corsini.;Senem Ozgen.;Angela Papale.;Valentina Galbiati.;Giovanni Lonati.;Paola Fermo.;Lorenza Corbella.;Gianluigi Valli.;Vera Bernardoni.;Manuela Dell'Acqua.;Silvia Becagli.;Donatella Caruso.;Roberta Vecchi.;Corrado L Galli.;Marina Marinovich.
来源: Toxicol Lett. 2017年266卷74-84页
This study aimed to collect, characterize ultrafine particles (UFP) generated from the combustion of wood pellets and logs (softwood and hardwood) and to evaluate their pro-inflammatory effects in THP-1 and A549 cells. Both cell lines responded to UFP producing interleukin-8 (IL-8), with wood log UFP being more active compared to pellet UFP. With the exception of higher effect observed with beech wood log UFP in THP-1, the ability of soft or hard woods to induce IL-8 release was similar. In addition, on weight mass, IL-8 release was similar or lower compared to diesel exhaust particles (DEP), arguing against higher biological activity of smaller size particles. UFP-induced IL-8 could be reduced by SB203580, indicating a role of p38MAPK activation in IL-8 production. The higher activity of beech wood log UFP in THP-1 was not due to higher uptake or endotoxin contamination. Qualitatively different protein adsorption profiles were observed, with less proteins bound to beech UFP compared to conifer UFP or DEP, which may provide higher intracellular availability of bioactive components, i.e. levoglucosan and galactosan, toward which THP-1 were more responsive compared to A549 cells. These results contribute to our understanding of particles emitted by domestic appliances and their biological effects.

386. The anti-tumor effects of the recombinant toxin protein rLj-RGD3 from Lampetra japonica on pancreatic carcinoma Panc-1 cells in nude mice.

作者: Yue Wang.;Yuanyuan Zheng.;Zuoyu Tu.;Yongguo Dai.;Hong Xu.;Li Lv.;Jihong Wang.
来源: Peptides. 2017年88卷8-17页
Recombinant Lampetra japonica RGD peptide (rLj-RGD3) is a soluble toxin protein with three RGD (Arg-Gly-Asp) motifs and a molecular weight of 13.5kDa. The aim of this study was to investigate the effects and mechanisms of rLj-RGD3 on tumor growth and survival in pancreatic carcinoma Panc-1 cell-bearing mice. A Panc-1 human pancreatic carcinoma-bearing nude mouse model was successfully generated, and the animals were treated with different doses of rLj-RGD3 for 3 weeks. The volume and weight of the subcutaneous tumors, the survival of the nude mice, histopathological changes, the intratumoral MVD, the number of apoptotic Panc-1 cells, and apoptosis-related proteins and gene expressions were determined. rLj-RGD3 significantly decreased the tumor volumes and weights, and the maximum tumor volume and weight IR values were 53.2% (p<0.001) and 55.9% (p<0.001), respectively. The life expectancy of Panc-1-bearing nude mice treated with rLj-RGD3 was increased by 56.3% (p<0.001). Meanwhile, rLj-RGD3 promoted the expression of Bax, caspase-3, and caspase-9 and inhibited Bcl-2 and VEGF expression. In addition, rLj-RGD3 did not change FAK, PI3K and Akt expression, but p-FAK, p-PI3K and p-Akt, levels were down-regulated. These results show that rLj-RGD3 induced potent anti-tumor activity in vivo and suppressed the growth of transplanted Panc-1 cells in a nude mouse model, implying that rLj-RGD3 may serve as a potent clinical therapeutic agent for human pancreatic carcinoma.

387. The effects of urotensin II on migration and invasion are mediated by NADPH oxidase-derived reactive oxygen species through the c-Jun N-terminal kinase pathway in human hepatoma cells.

作者: Ying-Ying Li.;Zheng-Ming Shi.;Xiao-Tong Yu.;Ping Feng.;Xue-Jiang Wang.
来源: Peptides. 2017年88卷106-114页
Urotensin II (UII) is a vasoactive neuropeptide involved in migration and invasion in various cell types. However, the effects of UII on human hepatoma cells still remain unclear. The aim of this study was to investigate the role and mechanism of UII on migration and invasion in human hepatoma cells.

388. Incorporation of silver and strontium in hydroxyapatite coating on titanium surface for enhanced antibacterial and biological properties.

作者: Zhen Geng.;Renfeng Wang.;Xianglong Zhuo.;Zhaoyang Li.;Yongcan Huang.;Lili Ma.;Zhenduo Cui.;Shengli Zhu.;Yanqin Liang.;Yunde Liu.;Huijing Bao.;Xue Li.;Qianyu Huo.;Zhili Liu.;Xianjin Yang.
来源: Mater Sci Eng C Mater Biol Appl. 2017年71卷852-861页
Implant-related infection in primary total joint prostheses has attracted considerable research attention. As a measure to improve the antimicrobial properties of implant materials, silver (Ag) was incorporated into calcium phosphate (CaP) coatings on Titanium (Ti) via a hydrothermal method. Further, strontium (Sr) was added as a binary dopant to reduce the cytotoxicity of Ag in the coatings. Results showed that the CaP coatings were uniformly deposited on Ti with enhanced hydrophilicity and nanoscale surface roughness. Moreover, cell adhesion, proliferation, and differentiation were improved after the CaP coating deposition. The antibacterial properties of the coatings were distinctly improved by the incorporation of Ag, but the cell proliferation and differentiation were significantly decreased. Owing to the incorporation of Sr, the Ag-CaP coatings were able to effectively counteract the negative effects of Ag while maintaining good antibacterial properties. In summary, hydrothermally deposited CaP coatings doped with Ag and Sr exhibit excellent biocompatibility and antimicrobial activity. Thus, such co-doped CaP coatings have considerable potential for orthopaedic implant modification.

389. Apoptotic and anti-apoptotic genes transcripts patterns of graphene in mice.

作者: Hossein Ahmadian.;Ehsan Hashemi.;Omid Akhavan.;Mehdi Shamsara.;Mehrdad Hashemi.;Abbas Farmany.;Morteza Daliri Joupari.
来源: Mater Sci Eng C Mater Biol Appl. 2017年71卷460-464页
Recent studies showed that a large amount of graphene oxide accumulated in kidney and liver when it injected intravenously. Evaluation of lethal and apoptosis gene expression in these tissues, which are under stress is very important. In this paper the in vivo dose-dependent effects of graphene oxide and reduced graphene oxide nanoplatelets on kidney and liver of mice were studied. Balb/C mice were treated by 20mg/kg body weight of nanoplatelets. Molecular biology analysis showed that graphene nanoplatelets injected intravenously lead to overexpression of BAX gene in both kidney and liver tissues (P≥0.01). In addition these nanoparticles significantly increase BCL2 gene expression in both kidney and liver tissues (P≥0.05). Graphene significantly increase level of SGPT in groups 1 (220.64±13), 2 (164.44±9.3) in comparison to control group (P≤0.05). Also in comparison with control group (148.11±10.4), (P≤0.05), the level of SGOT in groups 1(182.01±12.6) and 2 (178.2±2.2) significantly increased.

390. [Effect of type 1 sphingosine-1-phosphate receptor siRNA on human salivary gland cells].

作者: Q Li.;Z F Chang.;G A Yang.;C Y Pang.;Y F Wang.
来源: Beijing Da Xue Xue Bao Yi Xue Ban. 2016年48卷6期987-993页
To construct sphingosine 1-phosphate receptor-1 (S1P1)-small interfering RNA (siRNA) lentiviral vectors and infect human salivary gland cells (HSG), and to investigate its possible therapy on Sjogren's syndrome.

391. [Analgesic effects of ionotropic glutamate receptor antagonists MK-801 and NBQX on collagen-induced arthritis rats].

作者: H Zhu.;R Zhu.;Z D Deng.;Y C Feng.;H L Shen.
来源: Beijing Da Xue Xue Bao Yi Xue Ban. 2016年48卷6期977-981页
The ionotropic glutamate receptorantagonists include two types: MK-801, antagonist of N-methyl-D-asparticacid (NMDA) receptor, and NBQX, antagonist of non-NMDA receptor.The above-mentioned ionotropic antagonists can block the glutamate and its corresponding receptor binding to produce analgesic effect. The objective of this research was to study two antagonists in analgesic effect on rat behavior,as well as to investigate the down-regulation and up-regulation of cyclooxygenase-2 (COX-2) and Janus-activated kinase (Jak3) in collagen-induced arthritis (CIA) rat serum and tissue fluid after the application of these antagonists, that is, the effect on molecular biology.

392. Clobetasol propionate causes immunosuppression in zebrafish (Danio rerio) at environmentally relevant concentrations.

作者: Anita O Hidasi.;Ksenia J Groh.;Marc J-F Suter.;Kristin Schirmer.
来源: Ecotoxicol Environ Saf. 2017年138卷16-24页
Synthetic glucocorticoids (GCs) are potential endocrine disrupting compounds that have been detected in the aquatic environment around the world in the low ng/L (nanomolar) range. GCs are used as immunosuppressants in medicine. It is of high interest whether clobetasol propionate (CP), a highly potent GC, suppresses the inflammatory response in fish after exposure to environmentally relevant concentrations. Bacterial lipopolysaccharide (LPS) challenge was used to induce inflammation and thus mimic pathogen infection. Zebrafish embryos were exposed to ≤1000nM CP from ~1h post fertilization (hpf) to 96 hpf, and CP uptake, survival after LPS challenge, and expression of inflammation-related genes were examined. Our initial experiments were carried out using 0.001% DMSO as a solvent vehicle, but we observed that DMSO interfered with the LPS challenge assay, and thus masked the effects of CP. Therefore, DMSO was not used in the subsequent experiments. The internal CP concentration was quantifiable after exposure to ≥10nM CP for 96h. The bioconcentration factor (BCF) of CP was determined to be between 16 and 33 in zebrafish embryos. CP-exposed embryos showed a significantly higher survival rate in the LPS challenge assay after exposure to ≥0.1nM in a dose dependent manner. This effect is an indication of immunosuppression. Furthermore, the regulation pattern of several genes related to LPS challenge in mammals supported our results, providing evidence that LPS-mediated inflammatory pathways are conserved from mammals to teleost fish. Anxa1b, a GC-action related anti-inflammatory gene, was significantly down-regulated after exposure to ≥0.05nM CP. Our results show for the first time that synthetic GCs can suppress the innate immune system of fish at environmentally relevant concentrations. This may reduce the chances of fish to survive in the environment, as their defense against pathogens is weakened.

393. The Antinociceptive Effect of a Tapentadol-Ketorolac Combination in a Mouse Model of Trigeminal Pain is Mediated by Opioid Receptors and ATP-Sensitive K+ Channels.

作者: Israel Barreras-Espinoza.;José Alberto Soto-Zambrano.;Nicolás Serafín-Higuera.;Ramón Zapata-Morales.;Ángel Alonso-Castro.;Ronell Bologna-Molina.;Vinicio Granados-Soto.;Mario A Isiordia-Espinoza.
来源: Drug Dev Res. 2017年78卷1期63-70页
Preclinical Research The aim of the present study was to evaluate the antinoceptive interaction between the opioid analgesic, tapentadol, and the NSAID, ketorolac, in the mouse orofacial formalin test. Tapentadol or ketorolac were administered ip 15 min before orofacial formalin injection. The effect of the individual drugs was used to calculate their ED50 values and different proportions (tapentadol-ketorolac in 1:1, 3:1, and 1:3) were assayed in the orofacial test using isobolographic analysis and interaction index to evaluate the interaction between the drugs. The combination showed antinociceptive synergistic and additive effects in the first and second phase of the orofacial formalin test. Naloxone and glibenclamide were used to evaluate the possible mechanisms of action and both partially reversed the antinociception produced by the tapentadol-ketorolac combination. These data suggest that the mixture of tapentadol and ketorolac produces additive or synergistic interactions via opioid receptors and ATP-sensitive K+ channels in the orofacial formalin-induced nociception model in mice. Drug Dev Res 78 : 63-70, 2017. © 2016 Wiley Periodicals, Inc.

394. Immunomodulatory Properties of Filamentous Fungi Cultivated through Solid-State Fermentation on Rapeseed Meal.

作者: Stéphanie Sutter.;France Thevenieau.;Anne Bourdillon.;Joëlle De Coninck.
来源: Appl Biochem Biotechnol. 2017年182卷3期910-924页
Water extracts from solid-state fermentation (SSF) on rapeseed meal using filamentous fungi exhibit interesting immunomodulatory activities in vitro. Immunomodulation was determined by the capacity of the compounds to activate blood neutrophils and to influence cytokine production in human peripheral blood mononuclear cells (PBMC) and mouse bone marrow-derived macrophages (BMDM). Among the strains tested, Aspergillus sojae mycelium and SSF extracts were the most promising in terms of enhancing the immune response. The filamentous fungus was also successfully cultivated in a pre-pilot bioreactor with forced aeration. The results indicated that the extracts not only activated blood neutrophils but also significantly modulated IL-1β cytokine levels with lipopolysaccharide (LPS)-stimulated PBMC and BMDM without any cytotoxicity in immune cells. IL-1β was down-regulated in a dose-dependent manner in the presence of A. sojae crude mycelium and SSF extract with PBMC, which indicated that there was an anti-inflammatory activity, whereas IL-1β secretion was up-regulated in the presence of stimulated BMDM with the highest concentration that was tested (100 μg/mL). The non-fermented rapeseed had no effect at the same concentration. SSF culture, as a natural product, may be a good source for the development of functional feed with an immunostimulating effect or could potentially be used in medicinal applications.

395. Enhancing tolerance of rice (Oryza sativa) to simulated acid rain by exogenous abscisic acid.

作者: Xi Wu.;Chanjuan Liang.
来源: Environ Sci Pollut Res Int. 2017年24卷5期4860-4870页
Abscisic acid (ABA) regulates much important plant physiological and biochemical processes and induces tolerance to different stresses. Here, we studied the regulation of exogenous ABA on adaptation of rice seedlings to simulated acid rain (SAR) stress by measuring biomass dry weight, stomatal conductance, net photosynthesis rate, nutrient elements, and endogenous hormones. The application of 10 μM ABA alleviated the SAR-induced inhibition on growth, stomatal conductance, net photosynthesis rate, and decreases in contents of nutrient (K, Mg, N, and P) and hormone (auxin, gibberellins, and zeatin). Moreover, 10 μM ABA could stimulate the Ca content as signaling molecules under SAR stress. Contrarily, the application of 100 μM ABA aggravated the SAR-induced inhibition on growth, stomatal conductance, net photosynthesis rate, and contents of nutrient and hormone. The results got after a 5-day recovery (without SAR) show that exogenous 10 μM ABA can promote self-restoration process in rice whereas 100 μM ABA hindered the restoration by increasing deficiency of nutrients and disturbing the balance of hormones. These results confirmed that exogenous ABA at proper concentration could enhance the tolerance of rice to SAR stress.

396. Omega-3 fatty acids and mood stabilizers alter behavioral and oxidative stress parameters in animals subjected to fenproporex administration.

作者: Lara M Gomes.;Milena Carvalho-Silva.;Letícia J Teixeira.;Joyce Rebelo.;Isabella T Mota.;Rafaela Bilesimo.;Monique Michels.;Camila O Arent.;Edemilson Mariot.;Felipe Dal-Pizzol.;Giselli Scaini.;João Quevedo.;Emilio L Streck.
来源: Metab Brain Dis. 2017年32卷2期519-528页
Studies have shown that oxidative stress is involved in the pathophysiology of bipolar disorder (BD). It is suggested that omega-3 (ω3) fatty acids are fundamental to maintaining the functional integrity of the central nervous system. The animal model used in this study displayed fenproporex-induced hyperactivity, a symptom similar to manic BD. Our results showed that the administration of fenproporex, in the prevent treatment protocol, increased lipid peroxidation in the prefrontal cortex (143%), hippocampus (58%) and striatum (181%), and ω3 fatty acids alone prevented this change in the prefrontal cortex and hippocampus, whereas the co-administration of ω3 fatty acids with VPA prevented the lipoperoxidation in all analyzed brain areas, and the co-administration of ω3 fatty acids with Li prevented this increase only in the prefrontal cortex and striatum. Moreover, superoxide dismutase (SOD) activity was decreased in the striatum (54%) in the prevention treatment, and the administration of ω3 fatty acids alone or in combination with Li and VPA partially prevented this inhibition. On the other hand, in the reversal treatment protocol, the administration of fenproporex increased carbonyl content in the prefrontal cortex (25%), hippocampus (114%) and striatum (91%), and in prefrontal coxter the administration of ω3 fatty acids alone or in combination with Li and VPA reversed this change, whereas in the hippocampus and striatum only ω3 fatty acids alone or in combination with VPA reversed this effect. Additionally, the administration of fenproporex resulted in a marked increase of TBARS in the hippocampus and striatum, and ω3 fatty acids alone or in combination with Li and VPA reversed this change. Finally, fenproporex administration decreased SOD activity in the prefrontal cortex (85%), hippocampus (52%) and striatum (76%), and the ω3 fatty acids in combination with VPA reversed this change in the prefrontal cortex and striatum, while the co-administration of ω3 fatty acids with Li reversed this inhibition in the hippocampus and striatum. In conclusion, our results support other studies showing the importance of ω3 fatty acids in the brain and the potential for these fatty acids to aid in the treatment of BD.

397. Characterization of a vacuolar H+-ATPase G subunit gene from Juglans regia (JrVHAG1) involved in mannitol-induced osmotic stress tolerance.

作者: Zhenggang Xu.;Yunlin Zhao.;Yu Ge.;Jiao Peng.;Meng Dong.;Guiyan Yang.
来源: Plant Cell Rep. 2017年36卷3期407-418页
JrVHAG1 is an important candidate gene for plant osmotic tolerance regulation. Vacuolar H+-ATPase (V-ATPase) is important for plant responses to abiotic stress; the G subunit is a vital part of V-ATPase. In this study, a G subunit of V-ATPase was cloned from Juglans regia (JrVHAG1) and functionally characterized. JrVHAG1 transcription was induced by mannitol that increasing 17.88-fold in the root at 12 h and 19.16-fold in the leaf at 96 h compared to that under control conditions. JrVHAG1 was overexpressed in Arabidopsis and three lines (G2, G6, and G9) with highest expression levels were selected for analysis. The results showed that under normal conditions, the transgenic and wild-type (WT) plants displayed similar germination, biomass accumulation, reactive oxygen species (ROS) level, and physiological index. However, when treated with mannitol, the fresh weight, root length, water-holding ability, and V-ATPase, superoxide dismutase, and peroxidase activity of G2, G6, and G9 were significantly higher than those of WT. In contrast, the ROS and cell damage levels of the transgenic seedlings were lower than those of WT. Furthermore, the transcription levels of V-ATPase subunits, ABF, DREB, and NAC transcription factors (TFs), all of which are factors of ABA signaling pathway, were much higher in JrVHAG1 transgenic plants than those in WT. The positive induction of JrVHAG1 gene under abscisic acid (ABA) treatments in root and leaf tissues indicates that overexpression of JrVHAG1 improves plant tolerance to osmotic stress relating to the ABA signaling pathway, which is transcriptionally activated by ABF, DREB, and NAC TFs, and correlated to ROS scavenging and V-ATPase activity.

398. Comprehensive characterization of a theophylline riboswitch reveals two pivotal features of Shine-Dalgarno influencing activated translation property.

作者: Wenjing Cui.;Jintao Cheng.;Shengnan Miao.;Li Zhou.;Zhongmei Liu.;Junling Guo.;Zhemin Zhou.
来源: Appl Microbiol Biotechnol. 2017年101卷5期2107-2120页
Tuneable gene expression controlled by synthetic biological elements is of great importance to biotechnology and synthetic biology. The synthetic riboswitch is a pivotal type of elements that can easily control the heterologous gene expression in diverse bacteria. In this study, the theophylline-dependent synthetic riboswitch and the corresponding variants with varied spacings between Shine-Dalgarno (SD) sequence and start codon were employed to comprehensively characterize the induction and regulation properties through combining a strong promoter aprE in Bacillus subtilis. Amongst the sets of newly constructed expression elements, the expression element with 9-bp spacing exhibited the higher expression level, a superior induction fold performance, and a considerably lower leaky expression than those with longer or shorter spacings. The riboswitch expression element with 9-bp spacing showed an approximately linear dose dependence from 0 to 8 mM of theophylline. Modification of the SD sequence through the insertion of a single A base prior to the native sequence enables the increase of the expression level post induction while decreasing the induction fold as a result of the elevated leaky level. The riboswitch elements with the engineered SD and the optimal 9-bp spacing exhibit an altered dose dependency in which the approximately linear range shifts to 0-4 mM, although it has a similar profile to the induction process. These results not only provide comprehensive data for the induced expression by a theophylline riboswitch combined with a strong native promoter from B. subtilis but also provide the two pivotal features of SD essential to the modular design of other synthetic riboswitches.

399. A Case-Matched Gender Comparison Transcriptomic Screen Identifies eIF4E and eIF5 as Potential Prognostic Markers in Male Breast Cancer.

作者: Matthew P Humphries.;Sreekumar Sundara Rajan.;Alastair Droop.;Charlotte A B Suleman.;Carmine Carbone.;Cecilia Nilsson.;Hedieh Honarpisheh.;Gabor Cserni.;Jo Dent.;Laura Fulford.;Lee B Jordan.;J Louise Jones.;Rani Kanthan.;Maria Litwiniuk.;Anna Di Benedetto.;Marcella Mottolese.;Elena Provenzano.;Sami Shousha.;Mark Stephens.;Rosemary A Walker.;Janina Kulka.;Ian O Ellis.;Margaret Jeffery.;Helene H Thygesen.;Vera Cappelletti.;Maria G Daidone.;Ingrid A Hedenfalk.;Marie-Louise Fjällskog.;Davide Melisi.;Lucy F Stead.;Abeer M Shaaban.;Valerie Speirs.
来源: Clin Cancer Res. 2017年23卷10期2575-2583页
Purpose: Breast cancer affects both genders, but is understudied in men. Although still rare, male breast cancer (MBC) is being diagnosed more frequently. Treatments are wholly informed by clinical studies conducted in women, based on assumptions that underlying biology is similar.Experimental Design: A transcriptomic investigation of male and female breast cancer was performed, confirming transcriptomic data in silico Biomarkers were immunohistochemically assessed in 697 MBCs (n = 477, training; n = 220, validation set) and quantified in pre- and posttreatment samples from an MBC patient receiving everolimus and PI3K/mTOR inhibitor.Results: Gender-specific gene expression patterns were identified. eIF transcripts were upregulated in MBC. eIF4E and eIF5 were negatively prognostic for overall survival alone (log-rank P = 0.013; HR = 1.77, 1.12-2.8 and P = 0.035; HR = 1.68, 1.03-2.74, respectively), or when coexpressed (P = 0.01; HR = 2.66, 1.26-5.63), confirmed in the validation set. This remained upon multivariate Cox regression analysis [eIF4E P = 0.016; HR = 2.38 (1.18-4.8), eIF5 P = 0.022; HR = 2.55 (1.14-5.7); coexpression P = 0.001; HR = 7.04 (2.22-22.26)]. Marked reduction in eIF4E and eIF5 expression was seen post BEZ235/everolimus, with extended survival.Conclusions: Translational initiation pathway inhibition could be of clinical utility in MBC patients overexpressing eIF4E and eIF5. With mTOR inhibitors that target this pathway now in the clinic, these biomarkers may represent new targets for therapeutic intervention, although further independent validation is required. Clin Cancer Res; 23(10); 2575-83. ©2016 AACR.

400. Propofol attenuates pancreatic cancer malignant potential via inhibition of NMDA receptor.

作者: Xiangyuan Chen.;Qichao Wu.;Li You.;Sisi Chen.;Minmin Zhu.;Changhong Miao.
来源: Eur J Pharmacol. 2017年795卷150-159页
Propofol is a commonly used intravenous anesthetic, and could attenuate cancer cells malignant potential via inhibiting hypoxia-inducible factor-1α (HIF-1α) expression. However, the mechanism is still inclusive. In the present study, we mainly focus on the mechanism by which propofol down-regulated HIF-1α expression and malignant potential in pancreatic cancer cells. Human pancreatic cancer cells (Miapaca-2 and Panc-1) in vitro and murine pancreatic cancer cell (Panc02) in vivo were used to assess the effect of propofol on vascular endothelial growth factor (VEGF) expression and migration of pancreatic cancer cells. Propofol inhibited cells migration, expression of VEGF and HIF-1α, phosphorylation of extracellular regulated protein kinases (ERK), AKT, Ca2+/calmodulin dependent protein kinases II (CaMK II), and Ca2+ concentration in a concentration-dependent manner (5, 25, 50, 100μM). Furthermore, MK801, an inhibitor of NMDA receptor, and KN93, an inhibitor of CaMK II, could inhibit the expression of VEGF, HIF-1a, p-AKT, p-ERK, p-CaMK II in vitro, growth of tumor and VEGF expression in vivo, which were similar to the effect of propofol. In addition, the anti-tumor effect of propofol could be counteracted by rapastinel, an activator of NMDA receptor. Our study indicated that propofol suppressed VEGF expression and migration ability of pancreatic cancer cells in vitro and in vivo, probably via inhibiting NMDA receptor.
共有 146687 条符合本次的查询结果, 用时 7.4752968 秒