Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by peptide and protein misfolding and aggregation, in part due to the presence of excess metal ions such as copper. Aggregation and cytotoxicity of amyloid-? (A?) peptide with copper ion have been investigated extensively; however, the effects of metalation on tau are less known. Here, we presented the effects of Cu(+) and Cu(2+) on aggregation and neurotoxicity of the second repeat unit of the microtubule-binding domain of tau (tau-R2). Tau-R2 was demonstrated to bind 0.44 Cu(2+) and 0.34 Cu(+) per monomer with dissociation constants of 1.1 nM and 0.2 pM, respectively. Copper in both oxidation states stimulated the aggregation, ROS production, and neuronal cytotoxicity of tau-R2. We showed that copper-associated tau-R2 aggregates, decreased protein levels of microtubule-associated protein 2 (MAP-2), and synaptophysin in the primarily cultured cortical neurons, reduced mitochondrial density and mobility in the axon and, as a consequence, impaired the growth and probably also the function of neurons. Previously, we reported that the His-rich domain of selenoprotein P (SelP-H) inhibited metal-induced aggregation and toxicity of A?, due to its metal chelation ability. Here we demonstrated that SelP-H not only inhibited copper-mediated tau aggregation but also interfered with the ongoing aggregation and reversed the already formed aggregates. More intriguing, SelP-H significantly attenuated Cu(2+)/Cu(+)-tau-R2-induced intracellular ROS production and the impairments of synapse and mitochondrial movement in neurons. This work implies that the surface-exposed His-rich domain of SelP makes it capable of modulating Cu(+)/Cu(2+)-mediated aggregation and neurotoxicity of both Aß and tau and may play important roles in the prevention of AD progression.
The enzymes cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the two key reduction reactions in the conversion of cinnamic acid derivatives into monolignol building blocks for lignin polymers in plant cell walls. Here, we describe detailed functional and structural analyses of CCRs from Medicago truncatula and Petunia hybrida and of an atypical CAD (CAD2) from M. truncatula. These enzymes are closely related members of the short-chain dehydrogenase/reductase (SDR) superfamily. Our structural studies support a reaction mechanism involving a canonical SDR catalytic triad in both CCR and CAD2 and an important role for an auxiliary cysteine unique to CCR. Site-directed mutants of CAD2 (Phe226Ala and Tyr136Phe) that enlarge the phenolic binding site result in a 4- to 10-fold increase in activity with sinapaldehyde, which in comparison to the smaller coumaraldehyde and coniferaldehyde substrates is disfavored by wild-type CAD2. This finding demonstrates the potential exploitation of rationally engineered forms of CCR and CAD2 for the targeted modification of monolignol composition in transgenic plants. Thermal denaturation measurements and structural comparisons of various liganded and unliganded forms of CCR and CAD2 highlight substantial conformational flexibility of these SDR enzymes, which plays an important role in the establishment of catalytically productive complexes of the enzymes with their NADPH and phenolic substrates.
BackgroundPhosphoinositide 3-kinases (PI3Ks) are relatively conserved and important intracellular lipid kinases involved in signalling and other biological pathways. In the free-living nematode Caenorhabditis elegans, the heterodimeric form of PI3K consists of catalytic (AGE-1) and regulatory (AAP-1) subunits. These subunits are key components of the insulin-like signalling pathway and play roles in the regulation of the entry into and exit from dauer. Although, in parasitic nematodes, similar components are proposed to regulate the transition from free-living or arrested stages to parasitic larvae, nothing is known about PI3Ks in relation to the transition of third-stage larvae (L3s) to parasitism in Haemonchus contortus.MethodsAn integrated molecular approach was used to investigate age-1 and aap-1 of H. contortus (Hc-age-1 and Hc-aap-1) in C. elegans. ResultsThe two genes Hc-age-1 and Hc-aap-1 were transcribed in all life stages, with the highest levels in the egg, infective L3 and adult female. The expression of these genes was localized to the intestine, contrasting the pattern of their orthologues in C. elegans (where they are expressed in both head neurons and the intestine). The yeast two-hybrid analysis demonstrated that the adaptor-binding domain of Hc-AGE-1 interacted strongly with the Hc-AAP-1; however, this complex did not rescue the function of its orthologue in age-1-deficient C. elegans.ConclusionsThis is the first time that the PI3K-encoding genes have been characterized from a strongylid parasitic nematode. The findings provide insights into the role of the PI3K heterodimer represented by Hc-age-1 and Hc-aap-1 in the developmental biology of H. contortus.
Enhancing natural attenuation of benzene, toluene, ethylbenzene, and xylene (BTEX) in groundwater is a potential remediation technology. This study focused on selecting appropriate electron acceptors to promote BTEX degradation in a nitrate-reducing environment. Nitrate-reducing soil was obtained from simulated BTEX-contaminated column. Enhancing experiments were conducted in the microcosm with nitrate-reducing material and simulated BTEX-polluted groundwater to investigate the promoting feasibility of adding dissolved oxygen (DO), nitrate, chelated Fe(III), and sulphate as electron acceptors. The concentrations of BTEX, electron acceptors, and their reducing products were measured. The order of promoting BTEX degradation with four electron acceptors was nitrate>sulphate>chelated Fe(III)>DO, and the first-order decay coefficients were 0.0432, 0.0333, 0.0240, and 0.0155, respectively. Nitrate, sulphate, and chelated Fe(III) enhanced attenuation. Nitrate was the most effective electron acceptor under nitrate-reducing conditions. Selecting proper electron acceptor is significant in promoting BTEX degradation according to the biogeochemical characteristics of local underground environment.
?-Secretase is an intramembrane protease responsible for the generation of amyloid-? (A?) peptides. Aberrant accumulation of A? leads to the formation of amyloid plaques in the brain of patients with Alzheimer's disease. Nicastrin is the putative substrate-recruiting component of the ?-secretase complex. No atomic-resolution structure had been identified on ?-secretase or any of its four components, hindering mechanistic understanding of ?-secretase function. Here we report the crystal structure of nicastrin from Dictyostelium purpureum at 1.95-Å resolution. The extracellular domain of nicastrin contains a large lobe and a small lobe. The large lobe of nicastrin, thought to be responsible for substrate recognition, associates with the small lobe through a hydrophobic pivot at the center. The putative substrate-binding pocket is shielded from the small lobe by a lid, which blocks substrate entry. These structural features suggest a working model of nicastrin function. Analysis of nicastrin structure provides insights into the assembly and architecture of the ?-secretase complex.
The studies investigating the effects of green tea on blood pressure (BP) have generated inconsistent results. The aim of this study is to quantitatively evaluate the effects of green tea on BP control. PubMed, Embase, and the Cochrane Library (updated to March 2014) were searched for randomized controlled trials evaluating the effects of green tea on BP. Pooled effect of green tea consumption on BP was evaluated using fixed-effects or random-effects model. Thirteen trials comprising a total of 1,367 subjects were included in the current meta-analysis. The overall outcome of the meta-analysis suggested that green tea consumption significantly decrease systolic blood pressure (SBP) level by -1.98 mmHg (95% CI: -2.94, -1.01 mmHg; P < 0.001). Compared with the control group, green tea also showed a significant lowering effect on diastolic blood pressure (DBP) in treatment group (-1.92 mmHg; 95% CI: -3.17, -0.68 mmHg; P = 0.002). Subgroup analyses further suggested that the positive effect of green tea polyphenols on BP was only showed in studies using a low-dose green tea polyphenol, with the long-term intervention duration or ruling out the confounding effects of caffeine. The meta-analysis suggested that green tea consumption had a favorable effect on decrease of BP.
An electrofluorochromic (EFC) conjugated copolymer (PEFC) containing carbazole and benzothiadiazole (BTD) moieties is synthesized through Suzuki coupling followed by electrochemical polymerization, resulting in a nanoporous EFC polymer electrode. The electrode exhibits high sensitivity and selectivity in the EFC detection of cyanide anions (CN(-)) in largely aqueous electrolyte (67?vol?% water) because electrochemical oxidation of PEFC leads to significant fluorescence quenching, and the presence of different concentrations (1 to 100??M) of CN(-) in the electrolyte can weaken the oxidative quenching to substantially different extents. Although PEFC is hydrophobic in the neutral state, it is converted to radical cation/dication states upon oxidation, rendering the PEFC some hydrophilicity. Moreover, its nanoporous morphology provides a large surface area and short diffusion distance, facilitating the movement of CN(-) in the electrolyte into the PEFC film to interact with receptors. Density functional theory calculations show that the noncovalent interaction between electron-deficient BTD and nucleophilic CN(-) is energy favorable in the oxidized states in both aqueous and organic media, suggesting that the specific ?(-)-?(+) interaction plays the main role in the CN(-) detection.
The intestinal microbiota plays an important role in the pathogenesis of inflammatory bowel disease (IBD), and geographical and genetic backgrounds impact the composition of the intestinal microbiota. However, there is a lack of evidence regarding the overall changes and characteristics of fecal-associated microbiota (FAM) and mucosa-associated microbiota (MAM) in Chinese patients with IBD. We recruited 26 patients with Crohn's disease (CD), 46 patients with ulcerative colitis (UC), and 21 healthy individuals; we collected matched fresh fecal and mucosal samples from the same subjects. The microbial communities were studied by 454-pyrosequencing. Community-wide changes in FAM and MAM were observed in patients with IBD. The proportion of several butyrate-producing bacteria, such as of the genera Roseburia, Coprococcus, and Ruminococcus were significantly reduced, whereas the pathogens Escherichia-Shigella and Enterococcus were prevalent in patients with IBD. FAM and MAM were similar between CD and UC. FAM differed from MAM in healthy individuals and patients with UC. In conclusion, the compositions of FAM and MAM were altered in patients with IBD. The reduction of butyrate-producing bacteria and the increase in opportunistic pathogens might be associated with the pathogenesis of IBD.
Research on the migration and transformation of phenol with space and temporal variability in the vadose zone is hindered by monitoring technology in field experiments. Four column experiments were conducted to investigate the effect of porous media size, volatilization, biological effects, and oxidation on the transport of phenol in the vadose zone. The initial inflow phenol concentration of each column was 500 mg/L, and the final outflow concentrations were 0, 348, 240, and 365 mg/L, More than 90% of reduction of phenol concentration occurred at the top of the simulation column. Results show that volatilization and oxidation are the main factors that could lead to the decrease of phenol concentration in an open system. However, these two processes cannot be accurately separated. The migration rate of phenol was larger in coarse sands (6.06 cm/d) than in fine sands (4.55 cm/d). Phenol biodegradation did not occur under experimental conditions. However, mercury (as biological inhibitor) could react with phenol to generate a mercury-phenol complex, which could lead to the reduction of phenol concentration to 21.6% in the simulation experiment.
Interferon-inducible transmembrane proteins 1, 2 and 3 (IFITM1, IFITM2 and IFITM3) have recently been identified as potent antiviral effectors that function to suppress the entry of a broad range of enveloped viruses and modulate cellular tropism independent of viral receptor expression. However, the antiviral effect and mechanisms of IFITMs in response to viral infections remain incompletely understood and characterized. In this work, we focused our investigation on the function of the extracellular IFITM3 protein. In cell models of DENV-2 infection, we found that IFITM3 contributed to both the baseline and interferon-induced inhibition of DENV entry. Most importantly, our study for the first time demonstrated the presence of IFITM-containing exosome in the extracellular environment, and identified an ability of cellular exosome to intercellularly deliver IFITM3 and thus transmit its antiviral effect from infected to non-infected cells. Thus, our findings provide new insights in the basic mechanisms underlying the actions of IFITM3, which might lead to future development of exosome-mediated anti-viral strategies using IFITM3 as a therapeutic agent. Conceivably, variations in the basal and inducible levels of IFITMs, as well as in intracellular and extracellular levels of IFITMs, might predict the severity of dengue virus infections among individuals or across species.
Growing evidence has shown that coagulation processes play an important role in disease pathogenesis and/or disease progression in patients with inflammatory bowel disease. However, no study has ever focused on the possible influence of infliximab (IFX) therapy on the coagulation status in patients with Crohn's disease (CD).
To analyze the short monosyllabic list of Mandarin speech test materials (MSTMs) which have been evaluated the equivalence of difficulty, and to establish the performance-intensity function (P-I function) for people with normal hearing as clinical reference of hearing recovery and individuals ability to perceive and process speech.
The aim of this study was to analyze the relationship between low bone mineral density (BMD) and conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia in a Chinese cohort.
Cryptosporidium spp. is a protozoan parasite that infects the gastrointestinal epithelium and causes diarrhoeal disease worldwide. It is one of the most common pathogens responsible for moderate to severe diarrhoea in children younger than 2 years. Because of the 'minimally invasive' nature of Cryptosporidium infection, mucosal epithelial cells are critical to the host's anti-Cryptosporidium immunity. Gastrointestinal epithelial cells not only provide the first and most rapid defence against Cryptosporidium infection, they also mobilize immune effector cells to the infection site to activate adaptive immunity. Recent advances in genomic research have revealed the existence of a large number of non-protein-coding RNA transcripts, so called non-coding RNAs (ncRNAs), in mammalian cells. Some ncRNAs may be key regulators for diverse biological functions, including innate immune responses. Specifically, ncRNAs may modulate epithelial immune responses at every step of the innate immune network following Cryptosporidium infection, including production of antimicrobial molecules, expression of cytokines/chemokines, release of epithelial cell-derived exosomes, and feedback regulation of immune homoeostasis. This review briefly summarizes the current science on ncRNA regulation of innate immunity to Cryptosporidium, with a focus on microRNA-associated epithelial immune responses.
Yiqi formula (YF), a traditional herbal prescription, has long been used to treat triple-negative breast cancer (TNBC) patients. The present study aims to investigate the effects and the related mechanism of YF for treatment of TNBC xenografts. MDA-MB-231 (human TNBC) cells were subcutaneously injected into the second mammary fat pad of 40 female nude mice, which were divided into four groups: control, erlotinib (an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor), YF, and combination (YF plus erlotinib). All treatments were administered orally for 30 days. Inhibition rate of tumor weight by erlotinib, YF, and the combination was 26.47%, 17.24%, and 39.15%, respectively. Western blotting showed that YF, erlotinib, and the combination downregulated p-EGFR (P < 0.01) and p-Akt1 (pT308) (P < 0.05) and upregulated PTEN compared with control, and the combination was more efficacious than erlotinib alone (P < 0.05). Similar results were detected by immunohistochemistry. Real-time quantitative PCR showed that YF, erlotinib, and the combination increased PTEN mRNA (P < 0.05, P < 0.01) compared with control, and the combination was more efficacious than erlotinib alone (P < 0.05). In conclusion, YF can regulate the main components of the PI3K/Akt pathway in TNBC xenografts. When YF was used in combination with erlotinib, it enhanced the antitumor effects of erlotinib on TNBC xenografts. These findings suggest that YF is suitable to use for the treatment of TNBC patients.
RNA interference (RNAi) triggered by synthetic long double-stranded RNAs (dsRNAs) has been applied in many Drosophila cell lines to study the functions of individual genes or for genome-wide scans. One contributor to the popularity of this approach is that many fly cell lines spontaneously take up dsRNAs from media, obviating the need for assisted uptake methods such as transfection. In this protocol, RNAi is induced in Drosophila S2 cells by soaking with dsRNA. Cell lines other than S2 can also be used, although the ability of each line to passively take up dsRNA does vary. Therefore, the efficiency of passive uptake should be carefully verified for each line.
Much of the difficulty in elucidating the precise function of S100 protein family has been attributed to functional redundancy and compensation by its conserved family members. In this study, we showed that seven S100 family members were almost totally undetectable in HepG2.2.15 cells, while all of them were highly expressed in its parental HepG2 cells. Re-expression of S100 proteins in HepG2.2.15 cells can partially rescue their defects in cell protrusion and migration through the regulation of cytoskeletons and adhesions. Thus, HepG2.2.15 can serve as a useful model for studying cell protrusion and migration regulated by S100 proteins.
The ?-secretase complex, comprising presenilin 1 (PS1), PEN-2, APH-1 and nicastrin, is a membrane-embedded protease that controls a number of important cellular functions through substrate cleavage. Aberrant cleavage of the amyloid precursor protein (APP) results in aggregation of amyloid-?, which accumulates in the brain and consequently causes Alzheimer's disease. Here we report the three-dimensional structure of an intact human ?-secretase complex at 4.5 Å resolution, determined by cryo-electron-microscopy single-particle analysis. The ?-secretase complex comprises a horseshoe-shaped transmembrane domain, which contains 19 transmembrane segments (TMs), and a large extracellular domain (ECD) from nicastrin, which sits immediately above the hollow space formed by the TM horseshoe. Intriguingly, nicastrin ECD is structurally similar to a large family of peptidases exemplified by the glutamate carboxypeptidase PSMA. This structure serves as an important basis for understanding the functional mechanisms of the ?-secretase complex.
While a high osmolarity medium activates Cpx signaling and causes CpxR to repress csgD expression, and efflux protein TolC protein plays an important role in biofilm formation in Escherichia coli, whether TolC also responds to an osmolarity change to regulate biofilm formation in extraintestinal pathogenic E. coli (ExPEC) remains unknown. In this study, we constructed ?tolC mutant and complement ExPEC strains to investigate the role of TolC in the retention of biofilm formation and curli production capability under different osmotic conditions. The ?tolC mutant showed significantly decreased biofilm formation and lost the ability to produce curli fimbriae compared to its parent ExPEC strain PPECC42 when cultured in M9 medium or 1/2 M9 medium of increased osmolarity with NaCl or sucrose at 28°C. However, biofilm formation and curli production levels were restored to wild-type levels in the ?tolC mutant in 1/2 M9 medium. We propose for the first time that TolC protein is able to form biofilm even under high osmotic stress. Our findings reveal an interplay between the role of TolC in ExPEC biofilm formation and the osmolarity of the surrounding environment, thus providing guidance for the development of a treatment for ExPEC biofilm formation.
We present experimentally and analytically the phase noise characterization of an externally injected gain switched comb source. The results reveal the residual high frequency FM noise in the comb lines, which stays unnoticed in the optical linewidth value but leads to an increased phase-error variance. The potential impact of the residual phase noise is investigated in a 10.7 GBaud optical DQPSK system where a 2 dB power penalty is recorded at BER of 10(-9). In a 10.7 GBaud digital coherent QPSK system no penalty is observed but with 5 GBaud 16-QAM format a 3 dBpenalty exists at the FEC limit of 4.4e-3.
A novel approach to toughen epoxy resin with lignin, a common waste material from the pulp and paper industry, is presented in this article. First, carboxylic acid-functionalized alkali lignin (AL-COOH) was prepared and subsequently incorporated into anhydride-cured epoxy networks via a one-pot method. The results of mechanical tests show that covalent incorporation of rigid AL-COOH into epoxy networks can significantly toughen the epoxy matrix without deteriorating its tensile strength and modulus. The addition of 1.0 wt % AL-COOH gives increases of 68 and 164% in the critical stress intensity factor (K(IC)) and critical strain energy release rate (G(IC)), respectively, relative to that of neat epoxy. This article opens up the possibility of utilizing low-cost and renewable lignin feedstocks as effective toughening agents for thermoset polymers.
The results of human clinical trials investigating the effects of resveratrol on glucose control and insulin sensitivity are inconsistent.OBJECTIV: e: We aimed to quantitatively evaluate the effects of resveratrol on glucose control and insulin sensitivity.DESIGN: We performed a strategic literature search of PubMed, Embase, MEDLINE, and the Cochrane Library (updated to March 2014) for randomized controlled trials that estimated the effects of resveratrol on glucose control and insulin sensitivity. Study quality was assessed by using the Jadad scale. Weighted mean differences were calculated for net changes in glycemic measures by using fixed-effects or random-effects models. We performed prespecified subgroup and sensitivity analyses to evaluate potential heterogeneity. Meta-regression analyses were conducted to investigate dose effects of resveratrol on fasting glucose and insulin concentrations in nondiabetic subjects.RESULTS: Eleven studies comprising a total of 388 subjects were included in this meta-analysis. Resveratrol consumption significantly reduced fasting glucose, insulin, glycated hemoglobin, and insulin resistance (measured by using the homeostatic model assessment) levels in participants with diabetes. No significant effect of resveratrol on glycemic measures of nondiabetic participants was found in the meta-analysis. Subgroup and sensitivity analyses indicated that the pooled effects of resveratrol on fasting glucose and insulin concentrations in nondiabetic participants were not affected by body mass index, study design, resveratrol dose, study duration, or Jadad score.CONCLUSIONS: Resveratrol significantly improves glucose control and insulin sensitivity in persons with diabetes but does not affect glycemic measures in nondiabetic persons. Additional high-quality studies are needed to further evaluate the potential benefits of resveratrol in humans.
microRNAs (miRNAs) have been documented playing a critical role in cancer development and progression. In this study, we investigated the role of miR-548l in non-small cell lung cancer (NSCLC) migration and invasion.
Macroporous Ti with macropores of 50-400 ?m size is prepared by sintering Ti microbeads with different diameters of 100, 200, 400, and 600 ?m. Bioactive microarc oxidation (MAO) coatings with micropores of 2-5 ?m size are prepared on the macroporous Ti. The MAO coatings are composed of a few TiO2 nanocrystals and lots of amorphous phases with Si, Ca, Ti, Na, and O elements. Compared to compact Ti, the MC3T3-E1 cell attachment is prolonged on macroporous Ti without and with MAO coatings; however, the cell proliferation number increases. These results are contributed to the effects of the space structure of macroporous Ti and the surface chemical feature and element dissolution of the MAO coatings during the cell culture. Macroporous Ti both without and with MAO coatings does not cause any adverse effects in vivo. The new bone grows well into the macropores and micropores of macroporous Ti with MAO coatings, showing good mechanical properties in vivo compared to Ti, MAO-treated Ti, and macroporous Ti because of its excellent osseointegration. Moreover, the MAO coatings not only show a high interface bonding strength with new bones but also connect well with macroporous Ti. Furthermore, the pushing out force for macroporous Ti with MAO coatings increases significantly with increasing microbead diameter.
Dragon's blood (DB) possesses great medicinal values due to the presence of several phenolic compounds. This study was designed to investigate the effects of DB and its extracts (DBEs) on oxidative stress in mice exposed to whole body (60)Co-? irradiation (4 Gy). DB and DBEs were intragastrically administered to mice for 5 d prior to radiation. The antioxidant activities, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels in liver and spleen were measured using kits. Furthermore, DB and DBE effects were determined by organ indices and histology of liver and spleen. Our results indicated that the DB and DBE-treated groups showed a significant decrease (P < 0.05) in levels of MDA in liver and spleen compared with the irradiation-only group. Moreover, the activity of SOD, CAT and the level of GSH in liver and spleen tissue were enhanced significantly (P < 0.05) in the DB and DBE groups. DB and DBE also had a significant effect on the recovery of thymus indices. The histological observations of groups having treatment with DB and DBE indicated significant reduction in the radiation-induced damage to the liver and spleen, together with improvement in the morphology of the liver and spleen. These results suggest that DB and DBE treatment prevents radiation-induced oxidative stress injury and restores antioxidant status and histopathological changes in the liver and spleen, but there is need for further study to explore the precise molecular mechanism and strategy for optimal practical application of DB and DBE.
A water-soluble polysaccharide fraction (LP1) was prepared from Dimocarpus longan Lour. by hot water extraction, DEAE-cellulose and Sephadex G-100 chromatography. Its sulfated derivative (LP1-S) was prepared by the sulfuric acid method. Preliminary tests in vitro showed LP1 and LP1-S could stimulate murine lymphocytes proliferation, increase pinocytic activity of murine macrophages and production of nitric oxide (NO), interleukin 6 (IL-6), IL-1? and tumor necrosis factor-alpha (TNF-?) in macrophages. Furthermore, LP1-S exhibited higher antiproliferative activity against human nasopharyngeal carcinoma HONE1 cells in vitro than LP1, which might be caused by the sulfate group in its structures. These results indicated that the LP1-S might be useful for developing safe antitumor drugs or health food.
The phenolic composition of the free phenolic extract from Sphallerocarpus gracilis seeds was analyzed by HPLC-MS and predominant compounds were chlorogenic acid, di-caffeoylquinic acid glucoside and luteolin-7-O-glucoside. The free phenolic extract was evaluated for DNA damage protective activity induced by ROO and OH radicals and hepatoprotective effect in vivo and in vitro. Results revealed that the free phenolic extract exhibited significant protective activity against both ROO and OH radical-induced DNA damage and the phenolic extract exerted more potent inhibitory activity against OH radical-induced damage than against that induced by ROO radicals. In vivo experimental results showed that the phenolic extract significantly prevented the increase of serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities and hepatic malondialdehyde level caused by CCl4 in rats, and markedly increased hepatic superoxide dismutase, catalase and glutathione peroxidase levels. Histopathological examinations further confirmed that the phenolic extract could protect the liver from CCl4-induced damage. In vitro experimental results showed that the phenolic extract could reduce BRL hepatocyte apoptosis and damage induced by CCl4. These findings indicate that the S. gracilis seed could be developed as a medicinal herb for the therapy and prevention of hepatic injury.
As the outmost coating of cells, the pericellular matrix (PCM) involved in various cellular functions has been exploited previously to be able to accumulate 120 nm Au nanoparticles (NPs), adjust their diffusion coefficient similar to that of membrane receptors, and enhance their uptake efficiency. In this study, the interactions between PCM and NPs with different sizes and materials were systematically investigated. We found that PCM can selectively enhance the retention and cellular uptake of NPs with diameters from 50 to 180 nm, but has no enhancement effect for 20 nm NPs. Identical behaviors of PCM was observed for both Au NPs and polystyrene NPs, indicating that this unique phenomenon is more related to the dimensions of the NPs. The study of single-particle tracking of 50-180 nm NPs on the surface of thick PCM cells revealed that PCM actively adjusts the diffusion coefficient of NPs to ?0.1 ?m(2)/s regardless of their sizes. By blocking the receptor-mediated endocytosis (RME) pathway with four different inhibitors, this active role of PCM can be effectively suppressed, further confirming that the trapping and retention of NPs by PCM is an inherent biological function. These findings provided new insights for better understanding of the RME pathway and may have promising NP-based applications for controlled drug delivery and therapy in biomedicine.
Infective L3s (iL3s) of parasitic nematodes share common behavioural, morphological and developmental characteristics with the developmentally arrested (dauer) larvae of the free-living nematode Caenorhabditis elegans. It is proposed that similar molecular mechanisms regulate entry into or exit from the dauer stage in C. elegans, and the transition from free-living to parasitic forms of parasitic nematodes. In C. elegans, one of the key factors regulating the dauer transition is the insulin-like receptor (designated Ce-DAF-2) encoded by the gene Ce-daf-2. However, nothing is known about DAF-2 homologues in most parasitic nematodes. Here, using a PCR-based approach, we identified and characterised a gene (Hc-daf-2) and its inferred product (Hc-DAF-2) in Haemonchus contortus (a socioeconomically important parasitic nematode of ruminants). The sequence of Hc-DAF-2 displays significant sequence homology to insulin receptors (IR) in both vertebrates and invertebrates, and contains conserved structural domains. A sequence encoding an important proteolytic motif (RKRR) identified in the predicted peptide sequence of Hc-DAF-2 is consistent with that of the human IR, suggesting that it is involved in the formation of the IR complex. The Hc-daf-2 gene was transcribed in all life stages of H. contortus, with a significant up-regulation in the iL3 compared with other stages. To compare patterns of expression between Hc-daf-2 and Ce-daf-2, reporter constructs fusing the Ce-daf-2 or Hc-daf-2 promoter to sequence encoding GFP were microinjected into the N2 strain of C. elegans, and transgenic lines were established and examined. Both genes showed similar patterns of expression in amphidial (head) neurons, which relate to sensation and signal transduction. Further study by heterologous genetic complementation in a daf-2-deficient strain of C. elegans (CB1370) showed partial rescue of function by Hc-daf-2. Taken together, these findings provide a first insight into the roles of Hc-daf-2/Hc-DAF-2 in the biology and development of H. contortus, particularly in the transition to parasitism.
The newly developed transcription activator-like effector protein (TALE) and clustered regularly interspaced short palindromic repeats/Cas9 transcription factors (TF) offered a powerful and precise approach for modulating gene expression. In this article, we systematically investigated the potential of these new tools in activating the stringently silenced pluripotency gene Oct4 (Pou5f1) in mouse and human somatic cells. First, with a number of TALEs and sgRNAs targeting various regions in the mouse and human Oct4 promoters, we found that the most efficient TALE-VP64s bound around -120 to -80 bp, while highly effective sgRNAs targeted from -147 to -89-bp upstream of the transcription start sites to induce high activity of luciferase reporters. In addition, we observed significant transcriptional synergy when multiple TFs were applied simultaneously. Although individual TFs exhibited marginal activity to up-regulate endogenous gene expression, optimized combinations of TALE-VP64s could enhance endogenous Oct4 transcription up to 30-fold in mouse NIH3T3 cells and 20-fold in human HEK293T cells. More importantly, the enhancement of OCT4 transcription ultimately generated OCT4 proteins. Furthermore, examination of different epigenetic modifiers showed that histone acetyltransferase p300 could enhance both TALE-VP64 and sgRNA/dCas9-VP64 induced transcription of endogenous OCT4. Taken together, our study suggested that engineered TALE-TF and dCas9-TF are useful tools for modulating gene expression in mammalian cells.
Dysbiosis in the intestinal microbiota of persons with inflammatory bowel disease (IBD) has been described, but there are still varied reports on changes in the abundance of Bifidobacterium and Lactobacillus organisms in patients with IBD. The aim of this investigation was to compare the compositions of mucosa-associated and fecal bacteria in patients with IBD and in healthy controls (HCs). Fecal and biopsy samples from 21 HCs, 21 and 15 Crohn's disease (CD) patients, and 34 and 29 ulcerative colitis (UC) patients, respectively, were analyzed by quantitative real-time PCR targeting the 16S rRNA gene. The bacterial numbers were transformed into relative percentages for statistical analysis. The proportions of bacteria were uniformly distributed along the colon regardless of the disease state. Bifidobacterium was significantly increased in the biopsy specimens of active UC patients compared to those in the HCs (4.6% versus 2.1%, P = 0.001), and the proportion of Bifidobacterium was significantly higher in the biopsy specimens than in the fecal samples in active CD patients (2.7% versus 2.0%, P = 0.012). The Lactobacillus group was significantly increased in the biopsy specimens of active CD patients compared to those in the HCs (3.4% versus 2.3%, P = 0.036). Compared to the HCs, Faecalibacterium prausnitzii was sharply decreased in both the fecal and biopsy specimens of the active CD patients (0.3% versus 14.0%, P < 0.0001 for fecal samples; 0.8% versus 11.4%, P < 0.0001 for biopsy specimens) and the active UC patients (4.3% versus 14.0%, P = 0.001 for fecal samples; 2.8% versus 11.4%, P < 0.0001 for biopsy specimens). In conclusion, Bifidobacterium and the Lactobacillus group were increased in active IBD patients and should be used more cautiously as probiotics during the active phase of IBD. Butyrate-producing bacteria might be important to gut homeostasis.
Bioactive amorphous phase/TiO2 nanocrystal (APTN) composite coatings were fabricated by microarc oxidation (MAO) on Ti. The APTN coatings are composed of much amorphous phase with Si, Na, Ca, Ti and O elements and a few TiO2 nanocrystals. With increasing applied voltage, the micropore density of the APTN coating decreases and the micropore size of the APTN coating increases. The results indicate that less MC3T3-E1 cells attach on the APTN coatings as compared to Ti. However, the APTN coatings greatly enhance the cell proliferation ability and the activity of alkaline phosphatase. The amorphous phase and the concentrations of the released Ca and Si from the APTN coatings during cell culture have significant effects on the cell response.
We have prepared enzyme-mimic Au-Pt nanocomposites (NCs) for catalyzing the decomposition of reactive oxygen species. After surface modification, the Au-Pt NCs can be readily internalized and retained by human skin cells and also can effectively reduce cellular oxidative stress. We have demonstrated that the active and biocompatible Au-Pt nanocomposites can be applied for preventing cell damages by scavenging cellular reactive oxygen species induced by ultraviolet irradiation, indicating potential uses for the prevention and therapy of ROS-mediated diseases.
Improving the cell penetration and enhancing the cell selectivity of drugs have been approved for overcoming the major drawbacks of chemotherapeutic agents: the toxicity to normal cells and the drug resistance in tumors. In this paper, lysine dendrimers (G1-G3) were chosen as novel cell-penetrating carriers for anti-cancer drugs based on the internalization mechanism of cell-penetrating peptides and the characteristics of dendritic peptides. After labeling with fluorescein isothiocyanate (FITC), the cell-penetrable capacity of lysine dendrimers was certified by flow cytometric analysis. In a preliminary biological evaluation, the conjugates of lysine dendrimers and 5-fluorouracil showed the expected advantages: stable drug release, low toxicity to normal cells, and moderate inhibition of tumor cells. These results imply that cell-penetrable lysine dendrimers could be potential carriers in drug delivery of anti-cancer medicine.
The convenient, high yielding and diastereoselective synthesis of ?-amino-?-substituted-?,?-disubstituted butyric acid derivatives was carried out by a three-component tandem reaction of a chiral equivalent of nucleophilic glycine. The reaction was performed smoothly under mild conditions and enabled the construction of two or three adjacent chiral centers in one step, thus affording a novel and convenient route to ?-amino-?-substituted-?,?-disubstituted butyric acid derivatives.
The amorphous phase/TiO2 nanocrystals (APTN) composited coatings were prepared on Ti implants for biomedical applications. The Ti implants without and with the APTN composited coatings both do not cause any adverse effects after implantation into the rabbit tibia. The osseointegration of Ti implants after covering the APTN coatings is improved pronouncedly, greatly increasing the interface bonding strength between the implants and newly formed bones. In addition, it is interesting that the newly formed bone tissues appear in the micro-pores of the APTN coatings, promoting the interface bonding between the implants and new bones by the mechanical interlock. Moreover, the Ti implant with the APTN coatings formed at higher applied voltage exhibit higher shear strength and displacement during the pushing out experiment probably due to its better osseointegration.
The basal forebrain (BF) plays a crucial role in cortical activation [1, 2]. However, the exact role of cholinergic BF (ch-BF) neurons in the sleep-wake cycle remains unclear [3, 4]. We demonstrated that photostimulation of ch-BF neurons genetically targeted with channelrhodopsin 2 (ChR2) was sufficient to induce an immediate transition to waking or rapid eye movement (REM) sleep from slow-wave sleep (SWS). Light stimulation was most likely to induce behavioral arousal during SWS, but not during REM sleep, a result in contrast to the previously reported photostimulation of noradrenergic or hypocretin neurons that induces wake transitions from both SWS and REM sleep. Furthermore, the ratio of light-induced transitions from SWS to wakefulness or to REM sleep did not significantly differ from that of natural transitions, suggesting that activation of ch-BF neurons facilitates the transition from SWS but does not change the direction of the transition. Excitation of ch-BF neurons during wakefulness or REM sleep sustained the cortical activation. Stimulation of these neurons for 1 hr induced a delayed increase in the duration of wakefulness in the subsequent inactive period. Our results suggest that activation of ch-BF neurons alone is sufficient to suppress SWS and promote wakefulness and REM sleep.
A novel, sensitive chemiluminescence (CL) immunoassay for Escherichia coli O157:H7 detection with signal dual-amplification using glucose oxidase (GOx) and laccase was investigated. The method was based on the characterization of a luminol-H2O2-laccase reaction. Compared with the horseradish peroxidase-based biosensor, laccase exhibited high catalytic activity in strong alkaline medium, which was compatible with the luminol system. The capture antibody was immobilized onto the magnetic bead (MB) surfaces. The detection antibody was linked with GOx through biotin-avidin recognition. Accordingly, the bioconjugation of MB-caputure antibody- E. coli O157:H7-detection antibody-GOx catalyzed the substrate glucose, thereby generating H2O2. E. coli O157:H7 was then detected by measuring the CL intensity after H2O2 formation. Under optimal conditions, the calibration plot obtained for E. coli O157:H7 was approximately linear from 4.3 × 10(3) colony-forming unit (CFU) mL(-1) to 4.3 × 10(5) CFU mL(-1), and the total assay time was <2.0 h without any enrichment. The limit of detection for the assay was 1.2 × 10(3) CFU mL(-1) (3?), which was considerably lower than that of enzyme-linked immunosorbent assay method (1.0 × 10(5) CFU mL(-1)) (3?). A series of repeatability measurements of using 1.7 × 10(4) CFU mL(-1) E. coli O157:H7 exhibited reproducible results with a relative standard deviation (RSD) of 3.5% (n = 11). Moreover, the proposed method was successfully used to detect E. coli O157:H7 in synthetic samples (spring water, apple juice, and skim milk), which indicated its potential practical application. This protocol can be applied in various fields of study.
Actinobacillus pleuropneumoniae is an important porcine respiratory pathogen causing great economic losses in the pig industry worldwide. Oxygen deprivation is a stress that A. pleuropneumoniae will encounter during both early infection and the later, persistent stage. To understand modulation of A. pleuropneumoniae gene expression in response to the stress caused by anaerobic conditions, gene expression profiles under anaerobic and aerobic conditions were compared in this study. The microarray results showed that 631 genes (27.7% of the total ORFs) were differentially expressed in anaerobic conditions. Many genes encoding proteins involved in glycolysis, carbon source uptake systems, pyruvate metabolism, fermentation and the electron respiration transport chain were up-regulated. These changes led to an increased amount of pyruvate, lactate, ethanol and acetate in the bacterial cells as confirmed by metabolite detection. Genes encoding proteins involved in cell surface structures, especially biofilm formation, peptidoglycan biosynthesis and lipopolysaccharide biosynthesis were up-regulated as well. Biofilm formation was significantly enhanced under anaerobic conditions. These results indicate that induction of central metabolism is important for basic survival of A. pleuropneumoniae after a shift to an anaerobic environment. Enhanced biofilm formation may contribute to the persistence of this pathogen in the damaged anaerobic host tissue and also in the early colonization stage. These discoveries give new insights into adaptation mechanisms of A. pleuropneumoniae in response to environmental stress.
To investigate the vehicle induced air pollution situations both inside and outside the tunnel, the field measurement of the pollutants concentrations and its diurnal variations was performed inside and outside the Xiangyin tunnel in Shanghai from 13:00 on April 24th to 13:00 on April 25th, 2013. The highest hourly average concentrations of pollutants were quantified that CO, NO, NO2 and NOX inside the tunnel were 13.223 mg/m3, 1.829 mg/m3, 0.291 mg/m3 and 3.029 mg/m3, respectively, while the lowest ones were 3.086 mg/m3, 0.344 mg/m3, 0.080 mg/m3 and 0.619 mg/m3. Moreover, the concentrations of pollutants were higher during the daytime, and lower at night, which is relevant to the traffic conditions inside the tunnel. Pollutants concentrations inside the tunnel were much higher than those outside the tunnel. Then in a case of slow wind, the effect of wind is much smaller than the impact of pollution sources. Additionally, the PM2.5 concentrations climbed to the peak sharply (468.45 µg/m3) during the morning rush hours. The concentrations of organic carbon (OC) and elemental carbon (EC) in PM2.5 inside the tunnel were 37.09-99.06 µg/m3 and 22.69-137.99 µg/m3, respectively. Besides, the OC/EC ratio ranged from 0.72 to 2.19 with an average value of 1.34. Compared with the results of other tunnel experiments in Guangzhou and Shenzhen, China, it could be inferred that the proportion of HDVs through the Xiangyin tunnel is relatively lower.
Genetic variants make some contributions to inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). More than 100 susceptibility loci were identified in Western IBD studies, but susceptibility gene has not been found in Chinese IBD patients till now. Sequencing of individuals with an IBD family history is a powerful approach toward our understanding of the genetics and pathogenesis of IBD. The aim of this study, which focuses on a Han Chinese CD family, is to identify high-risk variants and potentially novel loci using whole exome sequencing technique.
Natural killer T (NKT) cells share phenotypic and functional properties with both conventional natural killer cells and T cells. These cells might have an important role in the pathogenesis of ulcerative colitis (UC). The interaction of chemokine ligand 25 (CCL25) with chemokine receptor 9 (CCR9) is involved in gut-specific migration of leukocytes and induces regulatory T cells (Tregs) to migrate to the intestine in chronic ileitis.
Fractures are associated with cardiovascular diseases in the elderly. The purpose of the present study was to investigate the association between aortic calcification (AC) and the risk of vertebral fractures in postmenopausal Chinese women.
Methanol has become an alternative fuel for gasoline, which is facing a rapidly rising world demand with a limited oil supply. Methanol-gasoline has been used in China, but phase stability and vapor lock still need to be resolved in methanol-gasoline applications. In this paper, a series of tartaric esters were synthesized and used as phase stabilizers and saturation vapor pressure depressors for methanol-gasoline.
Of the many direct numerical methods, the pseudospectral method serves as an effective tool to solve the reentry trajectory optimization for hypersonic vehicles. However, the traditional pseudospectral method is time-consuming due to large number of discretization points. For the purpose of autonomous and adaptive reentry guidance, the research herein presents a multistage trajectory control strategy based on the pseudospectral method, capable of dealing with the unexpected situations in reentry flight. The strategy typically includes two subproblems: the trajectory estimation and trajectory refining. In each processing stage, the proposed method generates a specified range of trajectory with the transition of the flight state. The full glide trajectory consists of several optimal trajectory sequences. The newly focused geographic constraints in actual flight are discussed thereafter. Numerical examples of free-space flight, target transition flight, and threat avoidance flight are used to show the feasible application of multistage pseudospectral method in reentry trajectory optimization.
The authors report on the downlink performance of a 10??Gb/s long-reach and ultra-dense wavelength-division multiplexed passive optical network, based on a multicarrier transmitter realized by using an externally injected gain-switched distributed-feedback laser diode. Each of the comb channels, spaced by 10 GHz, is modulated with a 3 Gbaud dual polarization quadrature phase shift keying signal that included a 20% overhead for forward error correction. Frequency selectivity and enhanced receiver sensitivity is achieved by employing a digital coherent receiver to receive the signal. Experimental results achieved in a back-to-back and 100 km transmission scenarios show an excellent worst case receiver sensitivity of -44??dBm.
To evaluate the diagnostic utility of platelet count (PLT), mean platelet volume (MPV), and red cell distribution width (RDW) in patients with active Crohns disease (CD) and intestinal tuberculosis (ITB).
Primary alcohol-functionalized ?-diketones (bdks) are successfully synthesized via facile one-step Claisen condensation between aromatic monoketones and ?-caprolactone (?-CL). To demonstrate application potentials, these bdk alcohols are used to chelate with various Lewis acids, including Tb (III), Eu (III), and B (III). It is discovered that the resulting Tb (III) and Eu (III) diketonate complexes can serve as both catalysts and initiators for ring-opening polymerization (ROP) under solvent-free conditions, using lactide monomer as an example. The polylactides (PLAs) thus obtained exhibit luminescence properties characteristic of Tb (III) and Eu (III), respectively. On the other hand, boron-chelated diketone can initiate ROP of lactide in the presence of Sn(oct)2 , and affords a PLA material with dual-emission, i.e., fluorescence and room temperature phosphorescence. The synthesis described here represents a shortcut for the preparation of bdk-based macroligands and subsequent functional materials.
Abstract The past two decades have seen an explosion in research on non-coding RNAs and their physiological and pathological functions. Several classes of small (20-30 nucleotides) and long (>200 nucleotides) non-coding RNAs have been firmly established as key regulators of gene expression in myriad processes ranging from embryonic development to innate immunity. In this review, we focus on our current understanding of the molecular mechanisms underlying the biogenesis and function of small interfering RNAs (siRNAs), microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs). In addition, we briefly review the relevance of small and long non-coding RNAs to human physiology and pathology and their potential to be exploited as therapeutic agents.
RNAi is an evolutionarily conserved gene regulatory process that operates in a wide variety of organisms. During RNAi, long double-stranded RNA precursors are processed by Dicer proteins into ?21-nt siRNAs. Subsequently, siRNAs are incorporated into the RNA-induced silencing complexes (RISCs) that contain Argonaute-family proteins and guide RISC to target RNAs via complementary base pairing, leading to posttranscriptional gene silencing. Select pre-mRNA splicing factors have been implicated in RNAi in fission yeast, worms, and flies, but the underlying molecular mechanisms are not well understood. Here, we show that SmD1, a core component of the Drosophila small nuclear ribonucleoprotein particle implicated in splicing, is required for RNAi and antiviral immunity in cultured cells and in vivo. SmD1 interacts with both Dicer-2 and dsRNA precursors and is indispensable for optimal siRNA biogenesis. Depletion of SmD1 impairs the assembly and function of the small interfering RISC without significantly affecting the expression of major canonical siRNA pathway components. Moreover, SmD1 physically and functionally associates with components of the small interfering RISC, including Argonaute 2, both in flies and in humans. Notably, RNAi defects resulting from SmD1 silencing can be uncoupled from defects in pre-mRNA splicing, and the RNAi and splicing machineries are physically and functionally distinct entities. Our results suggest that Drosophila SmD1 plays a direct role in RNAi-mediated gene silencing independently of its pre-mRNA splicing activity and indicate that the dual roles of splicing factors in posttranscriptional gene regulation may be evolutionarily widespread.
It has been widely demonstrated that endothelial progenitor cells are involved in several diseases and that they have therapeutic implications. In order to define the altered pulmonary vascular homeostasis in chronic obstructive pulmonary disease, we sought to observe the level and functions of circulating endothelial progenitor cells in patients with chronic obstructive pulmonary disease.
This paper describes the design, modeling, and testing of a novel flexure-based microgripper for a large jaw displacement with high resolution. Such a microgripper is indispensable in micro?nano manipulation. In achieving a large jaw displacement, double amplification mechanisms, namely, Scott-Russell mechanism and leverage mechanism arranged in series, are utilized to overcome the limited output of microgrippers driven by piezoelectric actuators. The mechanical performance of the microgripper is analyzed using the pseudo rigid body model approach. Finite element analysis is conducted to evaluate the performance and validate the established models for further optimum design of the microgripper. The prototype of the developed microgripper is fabricated, with which experimental tests are carried out. The experimental results show that the developed microgripper is capable of handling various sized micro-objects with a maximum jaw displacement of 134 ?m and a high amplification ratio of 15.5.
There is considerable debate over the capacity of the cell wall polymer lignin to incorporate unnatural monomer units. We have identified Tnt1 retrotransposon insertion mutants of barrel medic (Medicago truncatula) that show reduced lignin autofluorescence under UV microscopy and red coloration in interfascicular fibers. The phenotype is caused by insertion of retrotransposons into a gene annotated as encoding cinnamyl alcohol dehydrogenase, here designated M. truncatula CAD1. NMR analysis indicated that the lignin is derived almost exclusively from coniferaldehyde and sinapaldehyde and is therefore strikingly different from classical lignins, which are derived mainly from coniferyl and sinapyl alcohols. Despite such a major alteration in lignin structure, the plants appear normal under standard conditions in the greenhouse or growth chamber. However, the plants are dwarfed when grown at 30 °C. Glycome profiling revealed an increased extractability of some xylan and pectin epitopes from the cell walls of the cad1-1 mutant but decreased extractability of others, suggesting that aldehyde-dominant lignin significantly alters cell wall structure.
Interleukin-23/T-helper 17 (IL-23/Th17) pathway plays a key role in the pathogenesis of inflammatory bowel disease (IBD), but little is known about its expression in Chinese population. In this study, we investigated the mRNA and protein levels of IL-12p40, tumor necrosis factor-like cytokine 1A (TL1A), Janus kinase 2 (JAK2), and IL-23R both locally and systemically in Chinese IBD patients. Our results indicated that the mRNA levels of IL-12p40 and TL1A were increased in ulcerative colitis (UC) patients. Furthermore, serum IL-12p40 and TL1A levels were higher in active UC patients, especially in patients with disease course less than 1.25 years or initial onset. No correlation was found between the genotype and serum levels of IL-12p40 or TL1A in UC patients. Additionally, the mRNA and protein expression of JAK2 and IL-23R were increased in UC and Crohns disease (CD) patients. Taken together, our results provided evidence that IL-23/Th17 pathway genes may represent important biomarkers of active stage of IBD and serve as novel therapeutic targets for IBD in Chinese population.
The results of studies investigating the effect of green tea on glucose control and insulin sensitivity in humans are inconsistent. Objective: We aimed to quantitatively evaluate the effect of green tea on glucose control and insulin sensitivity.
A series of solvent-free ionic liquid (IL)-based polymer electrolytes composed of amorphous and biodegradable poly(propylene carbonate) (PPC) host, LiClO4, and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM(+)BF4(-)) were prepared and characterized for the first time. FTIR studies reveal that the interaction between PPC chains and imidazolium cations weakens the complexation between PPC chains and Li(+) ions. Thermal analysis (DSC and TGA) results show that the incorporation of BMIM(+)BF4(-) into PPC/LiClO4 remarkably decreases the glass transition temperature and improves the thermal stability of the electrolytes. AC impedance results show that the ionic conductivities of the electrolytes are significantly increased with the increase of BMIM(+)BF4(-) amount, the ambient ionic conductivity of the electrolyte at a PPC/LiClO4/BMIM(+)BF4(-) weight ratio of 1/0.2/3 is 1.5 mS/cm, and the ionic transport behavior follows the Arrhenius equation. Both PPC/LiClO4/BMIM(+)BF4(-) and PPC/BMIM(+)BF4(-) electrolytes were applied in electrochromic devices with polyaniline as the electrochromic layer. The PPC/LiClO4/BMIM(+)BF4(-)-based device exhibits much better electrochromic performance in terms of optical contrast and switching time due to the presence of much smaller cations.
PYR1/PYL/RCAR family proteins (PYLs) are well-characterized abscisic acid (ABA) receptors. Among the 14 PYL members in Arabidopsis thaliana, PYL13 is ABA irresponsive and its function has remained elusive. Here, we show that PYL13 selectively inhibits the phosphatase activity of PP2CA independent of ABA. The crystal structure of PYL13-PP2CA complex, which was determined at 2.4 Å resolution, elucidates the molecular basis for the specific recognition between PP2CA and PYL13. In addition to the canonical interactions between PYLs and PP2Cs, an extra interface is identified involving an element in the vicinity of a previously uncharacterized CCCH zinc-finger (ZF) motif in PP2CA. Sequence blast identified another 56 ZF-containing PP2Cs, all of which are from plants. The structure also reveals the molecular determinants for the ABA irresponsiveness of PYL13. Finally, biochemical analysis suggests that PYL13 may hetero-oligomerize with PYL10. These two PYLs antagonize each other in their respective ABA-independent inhibitions of PP2Cs. The biochemical and structural studies provide important insights into the function of PYL13 in the stress response of plant and set up a foundation for future biotechnological applications of PYL13.
As a transcription factor, c-Myc exerts significant influence in cancer development by regulating transcription of a large number of target genes including microRNAs. However, details of regulatory networks composed of Myc, microRNAs, and microRNA target genes are still unclear. Here, at system level, we built a comprehensive Myc-regulated miRNAs (Myc-miRNAs) regulatory network through the integration of experimentally validated high-throughput data and computational predictions. Using miRNA genomic information with ChIP-PET, we identified 30 Myc-miRNAs and found most of these Myc-miRNAs target genes were significantly enriched in cell cycle, apoptosis, cell proliferation GO terms and Myc-regulated signaling pathways, using gene sets enrichment analysis. We found most Myc-miRNAs involved in Myc-related cancer pathways expressed abnormally in Myc-associated tumors through the integration of diverse types of experimental data. Based upon Myc target genes identified by ChIP-chip assays, we identified that 1031 Myc-miRNAs feed-forward loops (FFLs) were significantly different from those obtained by chance; also, 11 high-quality FFLs were extracted from experimentally validated interactions. Finally, we built the miRNA-protein interaction network of experimentally validated Myc-miRNAs and discussed the more complex network composed of several FFLs networks. As shown in this study, we performed comprehensive analysis of the Myc-miRNAs regulatory network and provided potential Myc-miRNAs target genes which were involved in Myc pathway and cancer-related biological processes.
Previously a disease of the West and rarely seen in China, inflammatory bowel disease (IBD) is now increasing in incidence in China. However, its true incidence is unknown. The incidence of IBD in Wuhan, a major city in central China, was investigated using population-based methods.
In Drosophila cells, RNA interference (RNAi) can be triggered by synthetic long double-stranded RNAs (dsRNAs). For many Drosophila cell lines and cell types, passive dsRNA uptake is inefficient. More complete silencing responses can often be obtained in Drosophila S2 cells using transfection, perhaps because higher levels of intracellular dsRNA are achieved. In this protocol, S2 cells are transfected with dsRNA using QIAGENs Effectene reagent, which has proven to be reliable for many investigators. A plasmid DNA can also be included in the transfection mix to provide additional functionality. The plasmid DNA can encode, for example, a reporter of the activity of a pathway or specific transcription factor, or a marker that allows visualization of some cellular behavior or structure. It is also useful to include a plasmid that encodes a fluorescent protein simply to monitor transfection efficiency.
Mycoplasma columbinum is a member of nonglycolytic Mycoplasma species which can hydrolyze arginine. Increasingly research has revealed that M. columbinum is associated with respiratory disease of pigeons and that the respiratory disease symptoms could be eliminated via the use of mycoplasma treatment medicine. Here we report the genome sequence of M. columbinum strain SF7, which is the first genome report for M. columbinum.
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