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The aberrant expression of forkhead box P3 (FOXP3) leads to the formation of malignant tumors. FOXP3 expression levels are also elevated in hepatocellular carcinoma (HCC). The aim of the present study was to investigate the effects of FOXP3 silencing on cell proliferation, migration, apoptosis and chemokine/chemokine receptor expression in the MHCC-97H HCC cell line. Three FOXP3 short hairpin (sh)RNA constructs were designed: Sh-FOXP3-1-pGreenPuro, sh-FOXP3-2-pGreenPuro, and sh-FOXP3-3-pGreenPuro. MHCC-97H cells were transfected with shRNA-FOXP3, and the mRNA and protein expression levels of C-X-C motif chemokine (CXC) ligand 12 (CXCL12), CXCL11, CXC receptor 4 (CXCR4) and CXCR7 were measured. Cell Counting Kit-8, terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling and Transwell assays were used to evaluate cell proliferation, apoptosis and migration, respectively. Of the three FOXP3 lentivirus carriers constructed, sh-FOXP3-1 significantly reduced FOXP3 expression levels and was chosen for further experiments. sh-FOXP3-1 inhibited cell proliferation, promoted apoptosis and inhibited cell migration compared with the negative control. The mRNA and protein expression levels of CXCL12, CXCL11, CXCR4 and CXCR7 were decreased significantly in response to FOXP3 silencing. FOXP3 silencing may therefore inhibit cell growth, induce apoptosis and inhibit migration in HCC cells, possibly by impairing the chemokine/chemokine receptor axes.

With the popularity of Small Private Online Courses (SPOCs) in higher education, a plentiful of discussion data has been increasingly generated in SPOC forums. With 752 undergraduates’ discussion posts, this study aims to investigate students’ engagement patterns within SPOC forums in terms of engagement behaviors and emotions. Firstly, we designed a behavioral code rule to identify posting- and content-level behaviors, and examined their association with course performance. Secondly, we built an emotion lexicon including positivity, negativity and confusion word sets, and adopted an emotion calculation approach to visualize emotional evolutionary trends and to examine emotional differences in registration types and course performance. The results show that, (1) the high-performing group was more active in the most engagement behaviors except for interactive postings. (2) The registered group delivered more threads and wrote richer vocabulary in post content. (3) Whether students were registered for a course or not did not have a significant effect on their emotional expressions, but the registered group exhibited more confusion in forum interactions at the end of the semester. (4) Positive emotion was prevailing for the entire population. Furthermore, compared with the low-achieving group, the high-performing group had higher emotion densities in three types of emotions.

Inter-turn short circuit of field windings (ISCFW) is a common generator fault which can result in serious safety accidents for power systems, if the fault is not eliminated in time. Taking advantage of the electrical and mechanical characteristics of the generator after a fault as a fault criterion is a new idea for fault monitoring, so finding out the frequency and amplitude frequency characteristics of rotor unbalanced magnetic pull (UMP)—the vibration excitation source of the fault—is the basis and key of the research. Taking a six-pole generator as an example, the effects of harmonic magnetic motive force (MMF) interaction on rotor UMP, as well as the frequency characteristics of rotor UMP after generator faults in different stator windings, are obtained based on the analysis of the air-gap MMF of the generator after a fault, and the results of theoretical analysis are verified by simulation. Based on the above results, the simulation calculation on rotor UMP of generators with three stator winding forms under different operating conditions has been achieved, to get the relation between rotor UMP amplitude and active power and field current, and to find out the mechanism of rotor UMP amplitude change along with operating conditions and effect of stator winding forms on UMP amplitude by theoretical analysis. The conclusions are of important significance for studying fault mechanical characteristics of generators and lay a foundation for online monitoring on ISCFW by integrating mechanical and electrical information.

Objective: This study was conducted to investigate the relationship between SLC22A1 and SLC22A4 gene polymorphisms and genetic susceptibility to type 2 diabetes in Chinese Han population. Methods: The research group comprised 110 patients with type 2 diabetes in Chinese Han population, while and the control group consisted of 110 healthy volunteers. The polymorphisms of SLC22A1 gene rs628031 and rs2282143 loci and SLC22A4 gene rs2073838 and rs272893 loci were detected in the subjects in the two groups. Genotype distributions and allele frequencies of the two genes were compared between the research and control groups. Results: Statistically significant differences were identified in the genotype distributions of SLC22A1 gene rs628031 and rs2282143 loci between the research and control groups (P SLC22A1 gene rs628031 locus and the T allele frequency of rs2282143 locus were higher in the research group than in the control group; these differences were statistically significant (P SLC22A4 gene rs2073838 locus exhibited no significant difference between the research and control groups (P>0.05). However, the genotype distributions of rs272893 locus showed a significant difference between the research and control groups (P

In this study, the complete mitochondrial genome of Graphium doson was recovered through Illumina sequencing data. This complete mitochondrial genome of G. doson is 15,285 bp in length and has a ba...

The phylum Chaetognatha (arrow worms) comprises a group of small marine predators that constitute a critical component of the zooplankton community throughout the world's oceans. Various phylogenetic affiliations have been proposed for the Chaetognatha, for which there are at least nine possible phylogenetic positions. Resolving the phylogenetic position of the chaetognaths is a key in understanding the fundamental developmental features of bilaterians. In comparison with the typical gene content of metazoan mitogenomes, two protein-coding genes (atp6 and atp8) are absent from all chaetognaths. The two mitogenomes sequenced from Sagitta crassa and Zonosagitta nagae in this study nevertheless contain two and four tRNA genes, respectively, in contrast to those of the other five chaetognaths reported where only one tRNA gene (trnMet) is present, thus invalidating the view that all chaetognath mitogenomes have a single tRNA gene. A conserved major gene order shared by all chaetognaths could be partially identified in many protostome mitogenomes, but not in any ancestral mitogenome gene arrangement of the four deuterostome groups. Phylogenetic analysis of the deduced amino acid sequences of protein-coding genes from 85 mitogenomes of 19 groups suggests the Chaetognatha to be a sister group to the protostomes, a result consistent with evidences from the developmental pattern and other molecular analyses.

Cyanea nozakii and Nemopilema nomurai are two major giant jellyfish species frequently blooming in East Asian waters in recent decades. In order to inspect their asexual reproduction performance in climate regimes associated with global warming, variations of podocyst reproduction and strobilation were investigated at five different temperature regimes (approximate simulation of summer in warm years and cold years: temperature increased from 18 to 25A degrees C and then decreased to 18 and 10A degrees C in three months, respectively; approximate simulation of autumn in warm years and cold years: temperature decreased from 18 to 10A degrees C in two and three months, respectively; control: constant 18A degrees C), and three food frequencies (once per 3d, once per 6d, and unfed). Strobilation in C. nozakii occurred at warmer temperature (a parts per thousand yen18A degrees C) but lower temperature (a parts per thousand currency sign18A degrees C) in N. nomurai. More than 90% of ephyrae of C. nozakii and N. nomurai were released in the thermal ranges of 22-25A degrees C and 10-13A degrees C, respectively. Higher percentages of polyps produced podocysts, and increased podocyst production was observed at warmer temperature (> 18A degrees C) and more food supplies in both species. The numbers of ephyrae in C. nozakii and podocysts in N. nomurai were significantly increased by prolonged duration of 18-25A degrees C in summer during warm years. Simultaneously, prolonged duration of 10-18A degrees C significantly increased strobilation percentage, ephyra, and podocyst production in N. nomurai in the autumn. More polyps of N. nomurai strobilating in the autumn proved adverse to outbreaks of medusae in the following summer. The results of this study indicate that the response of asexual reproduction to ocean warming appears species specific. Increased ephyra production in C. nozakii but higher podocyst reproduction in N. nomurai is expected in summer and autumn during warm years.

In East Asian waters, concern about giant jellyfish blooms, including Nemopilema nomurai (Cnidaria: Scyphozoa: Rhizostomeae), has increased in recent decades. Based on surveys in 2012 and 2013, as a part of the Chinese Jellyfish 973 Program, we investigated the life cycle in situ of the planktonic stages of this species in the Yellow Sea and the East China Sea. We found the following results: (1) Offshore of the Changjiang River is one of its principal breeding places, and is the area where the pelagic stages of N. nomurai appear earliest in the YS and ECS. (2) The general distribution pattern of pelagic stages of N. nomurai described previously in the YS and ECS is confirmed from the 2012 and 2013 surveys: From this small area (31.50–33.00°N, 122.00–122.75°E) usually in late May and early June, it expanded into the 31.5–36°N sea area (aggregating in 32–34°N) in June, then continued to expand northward and southward to 30–37°N by August, and then shrank to 34–37°N in October. (3) The biomass and abundance of N. nomurai in 2012 both in June and August were higher than those in 2013. (4) We confirmed that almost all pelagic stages of N. nomurai in the YS and ECS were confined north of 30°N. The breeding places, population dynamics, and mechanism of formation of the distribution pattern of N. nomurai in the YS and ECS in recent years are presented.

The aim of this paper is to develop a boundary control for attenuating the vibration of a flexible beam and string system in the presence of input restriction. To this end, a boundary control is developed to attenuate the vibration and mitigate the effect of the restricted input employing smooth hyperbolic tangent function. Under the proposed control, the stability of the controlled system is achieved through rigorous analysis without resorting to discretization of the system infinite-dimensional model, and the controlled system is ensured to be asymptotically stable. Finally, the simulations verify the results.

Background/Aims: Long noncoding RNAs (lncRNAs) are key regulators of cancer initiation and progression. In this study, we investigated the clinical value and functional role of LncRNA DQ786243 (LncDQ) in the pathogenesis of hepatocellular carcinoma (HCC). Methods: To investigate the expression level of LncDQ in HCC, we performed quantitative real-time PCR using total RNA extracted from HCC tumor tissues and their matched non-neoplastic counterparts, as well as from the serum of HCC patients and healthy volunteers. The correlation of LncDQ expression with clinicopathologic features and prognosis was analyzed. The functional role of LncDQ in cell proliferation, migration, and invasion were evaluated by MTT cell viability, wound healing, and transwell assays in vitro and in vivo. RNA immunoprecipitation and chromatin immunoprecipitation assays were performed to analyze the potential mechanism of LncDQ in HCC cells. Results: LncDQ was upregulated in both HCC tissue samples and serum and was correlated with low survival rate and adverse clinical pathological characteristics. Multivariate analysis demonstrated that LncDQ expression was an independent prognostic factor for HCC. The area under the receiver operating characteristic curve was 0.804 with a sensitivity of 0.72 and a specificity of 0.8. Knockdown of LncDQ induced inhibition of cell proliferation, migration, and invasion in vitro and in vivo. Mechanistically, LncDQ regulated the epithelial–mesenchymal transition pathway by interacting with EZH2, to epigenetically repress the expression of E-cadherin in HCC cells. Conclusions: Taken together, the results of our study indicate that LncDQ plays a critical role in HCC progression, and may serve as a potential diagnostic and prognostic biomarker for HCC.

Inter-turn short circuit of field windings (ISCFW) may cause the field current of a generator to increase, output reactive power to decrease, and unit vibration to intensify, seriously affecting its safe and stable operation. Full integration of mechanical and electrical characteristics can improve the sensitivity of online monitoring, and detect the early embryonic period fault of small turns. This paper studies the calculations and variations of unbalanced magnetic pull (UMP), of which the excitation source of rotor vibration is the basis and key to online fault monitoring. In grid load operation, ISCFW are first calculated with the multi-loop method, so as to obtain the numerical solutions of the stator and the rotor currents during the fault. Next, the air-gap magnetic field of the ISCFW is analyzed according to the actual composition modes of the motor loops in the fault, so as to obtain the analytic expressions of the air-gap magnetic motive force (MMF) and magnetic density. The UMP of the rotor is obtained by solving the integral of the Maxwell stress. The correctness of the electric quantity calculation is verified by the ISCFW experiment, conducted in a one pair-pole non-salient pole model machine. On this basis, comparing the simulation analysis with the calculation results of the model in this paper not only verifies the accuracy of the electromagnetic force calculation, but also proves that the latter has the advantages of a short time consumption and high efficiency. Finally, the influencing factors and variation law of UMP are analyzed by means of an analytic model. This develops a base for the online monitoring of ISCFW with the integration of mechanical and electrical information.

Tryptophan dimers (TDs) are an important class of natural products with diverse bioactivities and share conserved biosynthetic pathways. We report the identification of a partial gene cluster (spm) responsible for the biosynthesis of a class of unusual TDs with non-planar skeletons including spiroindimicins (SPMs), indimicins (IDMs), and lynamicins (LNMs) from the deep-sea derived Streptomyces sp. SCSIO 03032. Bioinformatics analysis, targeted gene disruptions, and heterologous expression studies confirmed the involvement of the spm gene cluster in the biosynthesis of SPM/IDM/LNMs, and revealed the indispensable roles for the halogenase/reductase pair SpmHF, the amino acid oxidase SpmO, and the chromopyrrolic acid (CPA) synthase SpmD, as well as the positive regulator SpmR and the putative transporter SpmA. However, the spm gene cluster was unable to confer a heterologous host the ability to produce SPM/IDM/LNMs. In addition, the P450 enzyme SpmP and the monooxygenase SpmX2 were found to be non-relevant to the biosynthesis of SPM/IDM/LNMs. Sequence alignment and structure modeling suggested the lack of key conserved amino acid residues in the substrate-binding pocket of SpmP. Furthermore, feeding experiments in the non-producing ΔspmO mutant revealed several biosynthetic precursors en route to SPMs, indicating that key enzymes responsible for the biosynthesis of SPMs should be encoded by genes outside of the identified spm gene cluster. Finally, the biosynthetic pathways of SPM/IDM/LNMs are proposed to lay a basis for further insights into their intriguing biosynthetic machinery.

Background. Transplantation of islets is a promising alternative to treat type 1 diabetes (T1D), but graft rejection is the major obstacle to its application in clinical practice. We evaluated the effects of mesenchymal stem cells (MSCs) and immature dendritic cells (imDCs) on islet transplantation in diabetic model. Methods. The streptozotocin T1D model was established in BABL/c mice. Rat islets were isolated and identified with dithizone (DTZ) staining. MSCs and imDCs were isolated from bone marrow of syngenic mice. Islets, alone or along with MSCs and/or imDCs, were transplanted to the left kidney capsule of diabetic mice. The blood glucose levels and glycosylated hemoglobin levels after transplantation were monitored. Results. Cotransplantation significantly decreased blood glucose and glycosylated hemoglobin levels in the diabetes mice. Transplantation of 200 islets + 2 × 105 MSCs + 2 × 105 imDCs could not only restore normal blood glucose levels, but also significantly prolong graft survival for 12.6±3.48 days. Conclusions. Cotransplantation of allogenic islets with imDCs and/or MSCs can significantly promote graft survival, reverse hyperglycemia, and effectively control the glycosylated hemoglobin levels.

Because jellyfish are sensitive to the availability of prey, their distribution likely is linked to the distribution pattern of zooplankton functional groups. We studied the regional and interannual variations of zooplankton functional groups in the Yellow Sea using data from six cruises conducted in June between 2000 and 2009. We compared these data to previously collected data on giant jellyfish distribution and biomass. Our results indicate that different zooplankton functional groups have their own relatively fixed distribution patterns and that the distribution of zooplankton can affect the distribution of the jellyfish community. Giant crustaceans and large copepods were found to be mainly distributed offshore, small copepods and small jellyfish tended to be located in the coastal region, and chaetognaths were mainly sampled along the 50 m isobath. Sea bottom temperature and salinity, determined by the Yellow Sea Cold Water Mass, are shown to have been major factors affecting the distribution of zooplankton functional groups. Among zooplankton functional groups, small copepods and giant jellyfish show similar distribution patterns, suggesting that the abundance of small copepods is feeding that of giant jellyfish. The observed interannual biomass of small copepod was positively related to temperature, and we suggest that this relationship may explain the rarity of giant jellyfish outbreaks in cold years.

Summary: Transcription factors and chromatin-remodeling complexes are key determinants of embryonic stem cell (ESC) identity. Here, we demonstrate that BRD4, a member of the bromodomain and extraterminal domain (BET) family of epigenetic readers, regulates the self-renewal ability and pluripotency of ESCs. BRD4 inhibition resulted in induction of epithelial-to-mesenchymal transition (EMT) markers and commitment to the neuroectodermal lineage while reducing the ESC multidifferentiation capacity in teratoma assays. BRD4 maintains transcription of core stem cell genes such as OCT4 and PRDM14 by occupying their super-enhancers (SEs), large clusters of regulatory elements, and recruiting to them Mediator and CDK9, the catalytic subunit of the positive transcription elongation factor b (P-TEFb), to allow Pol-II-dependent productive elongation. Our study describes a mechanism of regulation of ESC identity that could be applied to improve the efficiency of ESC differentiation. : Di Micco et al. now dissect the mechanisms by which BRD4 regulates embryonic stem cell (ESC) identity by binding to super-enhancers of core pluripotency genes and recruiting active transcription complexes. BRD4 inhibition results in defective elongation of super-enhancer-associated gene transcripts, loss of ESC self-renewal/pluripotency, and commitment to the neuroectodermal lineage.

The criteria used for successful drug discovery involves high throughput screening for preclinical evaluation and its interaction with target enzymes. In silico approach resulting in the creation of drug like library and identification of essential reactions and pathways spreads across several parts of metabolism. The aim of the present study was to evaluate the preclinical property and interaction to various drug target enzymes for spiroindimicins A-D and lynamicin A and D isolated from deep marine sea derived Streptomyces sp. SCSIO 03032 with 7 selected drug target enzymes. The preclinical and molecular docking simulation was performed using In silico pharmacology and docking tool. Drug likeliness, ADME and toxicity testing findings suggested the compounds with oral drug candidate's probability. Interaction of isolated compounds against drug target enzymes was satisfactory with Spiroindimicins C, D and Lynamicin D emerging as most potent Topoisomerase II, Cathepsin K, Cytochrome P4503A4, Aromatase P450, protein kinase and histone deacetylase inhibitors. Our results suggest that In silico approach in drug discovery procedure in later stage of development can ease up making lead molecules library.

Five new bisindole alkaloids, indimicins A-E (1-5), bearing a unique 1',3'-dimethyl-2'-hydroindole moiety, were isolated from the marine-derived Streptomyces sp. SCSIO 03032, along with two new compounds, lynamicins F and G (6 and 7). Their planar structures were elucidated by detailed interpretation of their MS and NMR spectroscopic data, and the absolute configurations were determined by X-ray crystallographic analysis (for 1), comparison of CD spectra (for 2-4), and quantum chemical calculations (for 5). Indimicin B (2) exhibited moderate cytotoxic activity toward the MCF-7 cell line.

Lysine acetylation regulates gene expression through modulating protein-protein interactions in chromatin. Chemical inhibition of acetyl-lysine binding bromodomains of the major chromatin regulators BET (bromodomain and extra-terminal domain) proteins, has been shown to effectively block cell proliferation in cancer and inflammation. However, whether selective inhibition of individual BET bromodomains has distinctive functional consequences, remains only partially understood. In this study, we show that selective chemical inhibition of the first bromodomain of BET proteins using our newly designed small molecule inhibitor, Olinone, accelerated the progression of mouse primary oligodendrocyte progenitors towards differentiation, while inhibition of both bromodomains of BET proteins hindered differentiation. This effect was target-specific, as it was not detected in cells treated with inactive analogues and independent of any effect on proliferation. Therefore, selective chemical modulation of individual bromodomains, rather than use of broad-based inhibitors may enhance regenerative strategies in disorders characterized by myelin loss such as aging and neurodegeneration.

Ikarugamycin is a member of the polycyclic tetramate macrolactams (PTMs) family of natural products with diverse biological activities. The biochemical mechanisms for the formation of polycyclic ring systems in PTMs remain elusive. The enzymatic mechanism of constructing an inner five-membered ring in ikarugamycin is reported. A three-gene-cassette ikaABC from the marine-derived Streptomyces sp. ZJ306 is sufficient for conferring ikarugamycin production in a heterologous host. IkaC catalyzes a reductive cyclization reaction to form the inner five-membered ring by a Michael addition-like reaction. This study provides the first biochemical evidence for polycycle formation in PTMs and suggests a reductive cyclization strategy which may be potentially applicable in general to the corresponding ring formation in other PTMs.

Three new macrolactams, heronamides D-F (1-3), were isolated from the deep-sea-derived Streptomyces sp. SCSIO 03032 upon changing cultivation conditions. The planar structures of heronamides D-F (1-3) were elucidated by extensive MS and NMR spectroscopic analyses and comparisons with the closely related heronamides A-C. The relative configurations of 1-3 were deduced by detailed analysis of (3)JHH values and NOESY data. The absolute configurations of 1 and 2 were determined by chemical modifications and application of the modified Mosher's method. None of the compounds exhibited obvious antimicrobial or cytotoxic activities.

Cancer stem cells are associated with chemoresistance and rapid recurrence of malignant tumors including glioblastoma (GBM). Although temozolomide (TMZ) is the most effective drug against GBM to date, GBM cells acquire resistance and become refractory to TMZ during treatment. Therefore, glioma stem cell (GSC)-targeted therapy and TMZ enhancing therapy may be effective approaches to improve prognosis of GBM. Many drugs that suppress the signaling pathway related to maintain GSC or enhance the effect of TMZ have been reported. However, there are no established therapies. Here, we screened drug libraries that are composed of 1,301 existing drugs using cell viability assay using GSCs, then extracted Kenpaullone, a kinase inhibitor, as a TMZ enhancer targeting GSCs. Kenpaullone efficiently suppressed activity of glycogen synthase kinase (GSK)3β. Combination therapy of Kenpaullone and TMZ demonstrated suppression of stem cell properties and proliferation of both GSCs and glioma cell lines. Combination therapy for the mouse models significantly prolonged survival time compared with TMZ monotherapy. Taken together, Kenpaullone is a promising drug for the treatment of GBM by targeting GSCs and overcoming chemoresistance against TMZ.

Metastatic melanoma remains a mostly incurable disease. Although newly approved targeted therapies are efficacious in a subset of patients, resistance and relapse rapidly ensue. Alternative therapeutic strategies to manipulate epigenetic regulators and disrupt the transcriptional program that maintains tumor cell identity are emerging. Bromodomain and extraterminal domain (BET) proteins are epigenome readers known to exert key roles at the interface between chromatin remodeling and transcriptional regulation. Here, we report that BRD4, a BET family member, is significantly upregulated in primary and metastatic melanoma tissues compared with melanocytes and nevi. Treatment with BET inhibitors impaired melanoma cell proliferation in vitro and tumor growth and metastatic behavior in vivo, effects that were mostly recapitulated by individual silencing of BRD4. RNA sequencing of BET inhibitor–treated cells followed by Gene Ontology analysis showed a striking impact on transcriptional programs controlling cell growth, proliferation, cell-cycle regulation, and differentiation. In particular, we found that, rapidly after BET displacement, key cell-cycle genes (SKP2, ERK1, and c-MYC) were downregulated concomitantly with the accumulation of cyclin-dependent kinase (CDK) inhibitors (p21 and p27), followed by cell-cycle arrest. Importantly, BET inhibitor efficacy was not influenced by BRAF or NRAS mutational status, opening the possibility of using these small-molecule compounds to treat patients for whom no effective targeted therapy exists. Collectively, our study reveals a critical role for BRD4 in melanoma tumor maintenance and renders it a legitimate and novel target for epigenetic therapy directed against the core transcriptional program of melanoma. Cancer Res; 73(20); 6264–76. ©2013 AACR.

The Yellow Sea Cold Water Mass (YSCWM) was suggested as an over-summering site of the dominant copepod species Calanus sinicus in coastal Chinese seas. Population abundance and structure were investigated by monthly sampling along three transects across the northern boundary of the YSCWM during 2009–2010. Results show that thermal stratification existed from June to October and that the vertical thermal difference increased with depth. Generally, total abundance was lowest in October and highest in June, and the female/male sex ratio was highest in February and lowest in August. Evident spatial differences in abundance were observed during the existence of the YSCWM. In June, total abundance averaged 158.8 ind/m3 at well-stratified stations, and 532.1 ind/m3 at other stations. Similarly, high abundances of 322.0 and 324.4 ind/m 3 were recorded from July to August inside the YSCWM, while the abundance decreased from 50.4 to 1.9 ind/m3 outside the water mass. C. sinicus distribution tended to even out over the study area in September when the YSCWM disappeared. We believe that the YSCWM may retard population recruitment in spring and preserve abundant cohorts in summer. The summer population was transported to neritic waters in autumn. In addition to low temperatures, stable vertical structure was also an essential condition for preservation of the summer population. C. sinicus can survive the summer in marginal areas in high abundance, but the population structure is completely different in terms of C5 proportion and sex ratio.

The antibacterial and antiviral agent amicetin is a disaccharide nucleoside antibiotic featuring a unique α-(1→4)-glycoside bond between amosamine and amicetose, characteristic of a retaining glycosylation. In this study, two key steps for amosamine biosynthesis were investigated: the N-methyltransferase AmiH was demonstrated to be requisite for the dimethylation in amosamine, and the glycosyltransferase AmiG was shown to be necessary for amosaminylation. Biochemical and kinetic characterization of AmiG revealed for the first time the catalytic reversibility of a retaining glycosyltransferase involved in secondary metabolite biosynthesis. AmiG displayed substrate flexibility by utilizing five additional sugar nucleotides as surrogate donors. AmiG was also amenable to sugar and aglycon exchange reactions. This study indicates that AmiG is a potential catalyst for diversifying nucleoside antibiotics and paves the way for mechanistic studies of a natural-product retaining glycosyltransferase.

Nutrient and Chlorophyll-a (Chl-a) concentrations were investigated monthly along three transects extending from a mariculture area to open waters around the Zhangzi Island area from July to December 2009. The objective of this study is to illustrate food availability to the bottom-sowed scallop Patinopecten yessoensis under the influences of the Yellow Sea Cold Water Mass (YSCWM), freshwater input and feedbacks of cultivated scallops. Significant thermal stratification was present in open waters from July to October, and salinity decreased in July and August in surface layers in the mariculture area. Nutrient concentrations increased with depth in both areas in summer, but were similar through water column in November and December. On average, nutrient increased from summer to autumn in all components except ammonia. Nutrient concentrations lower than the minimum thresholds for phytoplankton growth were present only in upper layers in summer, but stoichiometric nitrogen limitation existed in the entire investigation period. Column-averaged Chl-a concentration was lower in open waters than in mariculture area in all months. It increased significantly in mariculture area in August and October, and was less variable in open waters. Our results show that nutrients limitation to phytoplankton growth is present mainly in upper layer in association with stratification caused by YSCWM in summer. Freshwater input and upwelling of nutrients accumulated in YSCWM can stimulate phytoplankton production in mariculture area. Farming activities may change stoichiometric nutrient ratios but have less influence on Chl-a concentration.

The identification of a lobophorin biosynthetic gene cluster from the deep-sea derived Streptomyces sp. SCSIO 01127 reveals a paradigm of three glycosyltransferases (GTs) LobG1-LobG3 being responsible for appending four sugars. Characterization of five differentially glycosylated metabolites from three GT gene-inactivation mutants allowed the assignment of GT functions and the implication of LobG3 as an iterative GT to attach two digitoxoses.

An increase in marine artificial constructions has been proposed as a major cause of jellyfish blooms, because these constructions provide additional substrates for organisms at the benthic stage (polyps), which proliferate asexually and release a large amount of free-swimming medusae. These hard surfaces are normally covered by fouling communities, the components of which have the potential to impede the proliferation of polyps. In this study, we report an in situ experiment of polyp survival of four large scyphozoan species found in East Asian marginal seas that were exposed to biofouling, a universal phenomenon occurring on marine artificial constructions. Our results showed that the polyps of three species (Nemopilema nomurai, Cyanea nozaki, and Rhopilema esculentum) attached to the artificial surfaces were completely eliminated by biofouling within 7-8months, and only those of moon jellyfish (Aurelia sp.1) in the upper layers could multiply on both artificial materials and other organisms (e.g., ascidians and bryozoans). Fouling-associated competition and predation and suppressed asexual reproduction of podocysts were observed to contribute to the loss of polyps. This study shows that the natural distribution of polyps is defined by the biofouling community that colonizes the surfaces of artificial constructions. Consequently, the contribution of marine constructions to jellyfish bloom is limited only to the ability of the jellyfish species to reproduce asexually through budding and inhabit solid surfaces of fouling organisms in addition to inhabiting original artificial materials. We anticipate that fragile polyps will colonize and proliferate in harsh environments that are deleterious to biofouling, and we propose special attention to polyps in antifouling practices for excluding the possibility that they occupy the available ecological space.

Tintinnids are planktonic ciliates that play an important role in marine ecosystem. According to their distribution in the world oceans, tintinnid genera were divided into several biogeographical types such as boreal, warm water, austral and neritic. Therefore, the oceanic tintinnid assemblage could be correspondingly divided into boreal assemblage, warm water assemblage and austral assemblage. The purpose of this study was to investigate the characteristics of boreal tintinnid assemblage in the Northwest Pacific and the Arctic, and to identify the connection between boreal tintinnid assemblage and neighboring assemblages. Surface water samples were collected along a transect from the East China Sea to the Chukchi Sea in summer 2014. According to the presence of boreal genera and warm water genera, three tintinnid assemblages (the East China Sea neritic assemblage, the Japan Sea warm water assemblage, and the boreal assemblage) were identified along the transect. The boreal assemblage extended from the Chukchi Sea to the waters north of the Soya Strait. Densities peaks occurred at stations in the two branches of the Alaska Current and decreased both northward and southward. The densities were

Vibration signal of rotating machinery is often submerged in a large amount of noise, leading to the decrease of fault diagnosis accuracy. In order to improve the denoising effect of the vibration signal, an adaptive redundant second-generation wavelet (ARSGW) denoising method is proposed. In this method, a new index for denoising result evaluation (IDRE) is constructed first. Then, the maximum value of IDRE and the genetic algorithm are taken as the optimization objective and the optimization algorithm, respectively, to search for the optimal parameters of the ARSGW. The obtained optimal redundant second-generation wavelet (RSGW) is used for vibration signal denoising. After that, features are extracted from the denoised signal and then input into the support vector machine method for fault recognition. The application result indicates that the proposed ARSGW denoising method can effectively improve the accuracy of rotating machinery fault diagnosis.

The species range of Calanus sinicus along the Chinese coast extends from the Bohai Sea and the Yellow Sea in the north to the northern part of the South China Sea in the south. The subtropical seas along the southern coast of China mark the southern edge of the range of C. sinicus. In coastal seas off eastern Hong Kong, C. sinicus appears first in December, but densities comparable to those in the Yellow Sea and the East China Sea are reached only in January and February when temperature is 25°C. The average prosome length of females collected in February is comparable to that of females from the Yellow Sea, but females collected after mid-March are smaller than the smallest females from the Yellow Sea. Reproduction occurred mainly between January and March. Rapid decline of the population in April and the absence of a summer population suggest that the local population is derived from individuals advected from the north by ocean currents. Eggs produced locally probably did not hatch or develop into adults.

Gene transcriptional activation of the human genome in response to physiological and environmental stimuli requires chromatin structure changes defined by enzymes that modify chromatin and directed by proteins that interact with chromatin in a modification-sensitive manner. This highly complex system operates with a large number of chemical modifications on chromatin (both DNA and histones) and transcription-associated proteins.1 Of these, lysine acetylation functions to facilitate chromatin opening and productive transcriptional machinery assembly required for gene activation. These activities are directed by the acetyl-lysine binding activity of the bromodomain (BrD), a fundamental molecular mechanism for gene transcriptional activation that was discovered in the structural biology study of the histone acetyltransferase (HAT) transcriptional co-activator PCAF.2 The human genome encodes a total of 61 bromodomains in 46 chromatin regulator proteins, some of which comprise multiple bromodomains.2 As a key epigenome reader, the bromodomain is almost solely responsible for binding to acetylated-lysine in histones and transcription-associated proteins, thereby orchestrating gene transcription in chromatin in an ordered fashion.2 Recent studies show that pharmacological small molecule modulation of the acetyl-lysine binding activity of BrD proteins such as the BET (Bromodomain and Extra-Terminal domain) family protein BRD4 and the HAT co-activator CBP/p300 dictates gene transcription outcome in disease models3 such as multiple myeloma, lymphoma, acute myeloid leukemia, mixed lineage leukemia, HIV-associated kidney disease, and ischemia, indicating these bromodomains as attractive drug targets for diseases including cancer and inflammation.

River discharge can deliver nutrients to the coastal zone and change the hydrologic properties of the water column. Soon after a flash flood from the Yalu River (Northeast China) in August 2010, we investigated the salinity and nutrient concentrations, as well as other environmental conditions in the Changshan Archipelago area, located approximately 100 km west of the river mouth in the northern Yellow Sea. Diluted water was mainly observed in the upper layers shallower than 15 m, with surface salinity between 18.13 and 30.44 in the eastern study area and between 28.16 and 29.72 in the western area. Surface salinity showed a significant negative correlation with concentrations of dissolved nutrients (P < 0.05), but not with that of Chlorophyll-a (Chl-a), dissolved oxygen (DO), particulate materials or pH. The average concentrations of nitrite, nitrate, and silicic acid decreased from the surface layer to bottom layer and were significantly higher in the east area than in the west area (P < 0.05). In contrast, average ammonium and phosphate concentrations were highest in the bottom layer of both areas, with no significant spatial differences. DO varied between 6.06 and 8.25 mg L-1 in the surface layer, and was significantly higher in the eastern area than in the western area in the surface and middle layers. Chl-a concentration was constantly below 4.09 mu g L-1. Our work demonstrated the strong influences of Yalu River on proportions of various nutrient components in the Changshan Archipelago area. Silicic acid and total inorganic nitrogen levels were significantly elevated comparing to phosphate in the eastern area. Such changes can potentially induce phosphate limit to phytoplankton growth.

The biosynthetic gene cluster for caerulomycin A (1) was cloned and characterized from the marine actinomycete Actinoalloteichus cyanogriseus WH1-2216-6, which revealed an unusual hybrid polyketide synthase (PKS)/nonribosomal peptide synthetase (NRPS) system. The crmL disruption mutant accumulated caerulomycin L (2) with an extended L-leucine at C-7, implicating an amidohydrolase activity for CrmL. The leucine-removing activity was confirmed for crude CrmL enzymes. Heterologous expression of the 1 gene cluster led to 1 production in Streptomyces coelicolor.

Better sources of drying oils for coatings and conjugated linoleic acid (CLA) for potential health benefits are of continuing interest. Iodine under photochemical conditions in hexanesB at reflux temperatures was investigated as a catalyst for conjugating soybean oil (SBO) for use as drying oils and as a potential source of CLA. Variations in catalyst loading, SBO, light source, free radical catalyst, solvent and temperature strongly affected the efficiency of the process. Changes in fatty acid isomer distributions in conjugated SBO (CSBO) influenced drying properties of CSBO. Conjugated dienes formed were predominantly trans-9,trans-11, which contrasts distributions found with catalysts such as strong base and metal compounds. Drying times of some of the CSBOs were superior to that of raw linseed oil. Iodine was partially recovered.

Mass occurrence of Salpa fusiformis was observed in the Southern Yellow Sea in May and June 2007. In order to investigate its population recruitment and environmental adaptation, temporal variation of abundance, diel vertical migration (DVM) and length frequency distribution of both aggregate and solitary forms were studied with samples collected from eight months during September 2006 to August 2007. S. fusiformis presented in six months other than September and October 2006, and average abundance of aggregate and solitary forms peaked in June and May, respectively. In December, aggregate forms were absent in the bottom layer and performed irregular DVM from surface to 50 m depth, while solitary forms was too scarce to perform diel vertical distribution analysis. Both aggregate and solitary forms presented reverse DVM in May and June. They migrated upwards during daytime and concentrated in surface layer at sunset. The bimodal distribution of aggregate forms was found in April and the average size was largest in this month. In other months, the smaller aggregate forms (1–5 mm) dominated in populations except for May, when the modal size ranged from 2 to 8 mm. The average size of solitary forms was largest in December, followed by April. The skewed nomal distribution of solitary forms was found in May and June, with the modal size of 2–7 mm and 5–13 mm, respectively.

Caerulomycin A (CRM A 1) belongs to a family of natural products containing a 2,2'-bipyridyl ring core structure and is currently under development as a potent novel immunosuppressive agent. Herein, we report the functional characterization, kinetic analysis, substrate specificity, and structure insights of an aminotransferase CrmG in 1 biosynthesis. The aminotransferase CrmG was confirmed to catalyze a key transamination reaction to convert an aldehyde group to an amino group in the 1 biosynthetic pathway, preferring l-glutamate and l-glutamine as the amino donor substrates. The crystal structures of CrmG in complex with the cofactor 5'-pyridoxal phosphate (PLP) or 5'-pyridoxamine phosphate (PMP) or the acceptor substrate were determined to adopt a canonical fold-type I of PLP-dependent enzymes with a unique small additional domain. The structure guided site-directed mutagenesis identified key amino acid residues for substrate binding and catalytic activities, thus providing insights into the transamination mechanism of CrmG.

Chk2 (checkpoint kinase 2) is a serine/threonine kinase that participates in a series of signaling networks responsible for maintaining genomic integrity and responding to DNA damage. The development of selective Chk2 inhibitors has recently attracted much interest as a means of sensitizing cancer cells to current DNA-damaging agents used in the treatment of cancer. Additionally, selective Chk2 inhibitors may reduce p53-mediated apoptosis in normal tissues, thereby helping to mitigate adverse side effects from chemotherapy and radiation. Thus far, relatively few selective inhibitors of Chk2 have been described and none have yet progressed into clinical trials. Here, we report crystal structures of the catalytic domain of Chk2 in complex with a novel series of potent and selective small molecule inhibitors. These compounds exhibit nanomolar potencies and are selective for Chk2 over Chk1. The structures reported here elucidate the binding modes of these inhibitors to Chk2 and provide information that can be exploited for the structure-assisted design of novel chemotherapeutics.

Bacterial community structure on the surface of Ulva prolifera thalli and in seawater in an Ulva blooming region in Jiaozhou Bay was investigated by methods of denaturing gradient gel electrophoresis and 16S rDNA clone libraries. Statistical analysis on the clone libraries indicated that bacterial community structure presented no significant differences between two algal samples. Thallus-surface bacterial communities identified by 16S rDNA clone library were dominated by Alteromonadales, Flavobacteriales, and Rhodobacterales. Sequences affiliated with Gammaproteobacteria, Alphaproteobacteria and CFB were detected in all the four seawater samples. However, their different distribution frequencies among the four samples and the presence of some specific bacterial clusters in some samples indicated changes in the bacterial community composition over the course of the bloom. The dominant bacterial clades changed from Alteromonadales and Rickettsiales in A-SW, to Flavobacteriales and Alteromonadales in B-SW, to Alteromonadales and Campylobacterales in C-SW, and to Rickettsiales, Rhodobacterales and Flavobacteriales in D-SW. Some specific dominant bacterial assemblages were present in some seawater samples, such as Campylobacterales in C-SW and Actinobacteria in D-SW. Our results give an insight into the changes in the bacterial community composition in seawater in blooming region during the course of macroalgal Ulva bloom.

Distribution, egg production rate (EPR) and abundances of four small copepods in genera Paracalanus and Acartia were studied monthly from October 2005 to September 2006 in and outside Jiaozhou Bay, China. Biomass and secondary production also were calculated to show the importance of these small copepods. As predominant species, Paracalanus parvus and Acartia bifilosa, occurred continuously in this bay throughout the year, with large abundance peaks from late spring to early summer. Acartia pacifica occurred sporadically in May, but in July, it reached higher maximum abundance than the other species. Parvocalanus crassirostris was relatively rare and occurred seasonally. Spatial distributions of these species differed according to the environmental variation inside and outside the bay. Egg production for each species mainly occurred in the warming period. The average female growth rates were higher for species with seasonal occurrence than those that were present continuously. The total secondary production rate of these four species was highest in June and lowest in April. These small copepods made greater contributions to the annual secondary production rate than did larger copepod species in Jiaozhou Bay. Comparisons are also made with other similar coastal waters worldwide.

Tolo Harbour is a poorly flushed bay in the northeastern corner of Hong Kong. Eutrophication caused by discharge of untreated and secondarily treated sewage into the bay was first detected during the 1970s. Increased nutrient input led to a noticeable increase in algal biomass and algal bloom occurrences. Nutrient reduction measures, including the construction of a pipeline to export all sewage effluents from Tolo Harbour, were introduced during the late 1980s. Decline in nutrient levels and decrease in the number of algal blooms have been recorded since 1998 when all nutrient reduction measures became fully operational. Zooplankton samples collected during 2003–2004 revealed that Tolo Harbour still contained a higher density and lower diversity of planktonic copepods compared to Mirs Bay, a less-polluted sea area outside Tolo Harbour. A comparison between data collected in this study to those collected during 1988–1990, several years before nutrient reduction measures were to be fully implemented, showed a decrease in copepod densities and an increase in copepod diversity. Small copepods, notably species of Paracalanus and Oithona, dominated the copepod communities in both periods, but there was an increase in species evenness during 2003–2004, caused by an increase in the number of dominant species. These observations confirm that eutrophication may lead to increases in copepod densities accompanied by increased dominance of small species.

Niemann-Pick type C disease (NPC) is a lysosomal storage disorder causing accumulation of unesterified cholesterol in lysosomal storage organelles. Recent studies have shown that hydroxypropyl-β-cyclodextrin injections in npc1 −/− mice are partially effective in treating this disease. Using cultured fibroblasts, we have investigated the cellular mechanisms responsible for reduction of cholesterol accumulation. We show that decreased levels of cholesterol accumulation are maintained for several days after removal of cyclodextrin from the culture medium. This suggests that endocytosed cyclodextrin can reduce the cholesterol storage by acting from inside endocytic organelles rather than by removing cholesterol from the plasma membrane. To test this further, we incubated both NPC1 and NPC2 mutant cells with cholesterol-loaded cyclodextrin for 1 h, followed by chase in serum-containing medium. Although the cholesterol content of the treated cells increased after the 1-h incubation, the cholesterol levels in the storage organelles were later reduced significantly. We covalently coupled cyclodextrin to fluorescent dextran polymers. These cyclodextrin–dextran conjugates were delivered to cholesterol-enriched lysosomal storage organelles and were effective at reducing the cholesterol accumulation. We demonstrate that methyl-β-cyclodextrin is more potent than hydroxypropyl-β-cyclodextrin in reducing both cholesterol and bis(monoacylglycerol) phosphate accumulation in NPC mutant fibroblasts. Brief treatment of cells with cyclodextrins causes an increase in cholesterol esterification by acyl CoA:cholesterol acyl transferase, indicating increased cholesterol delivery to the endoplasmic reticulum. These findings suggest that cyclodextrin-mediated enhanced cholesterol transport from the endocytic system can reduce cholesterol accumulation in cells with defects in either NPC1 or NPC2.

Several Mycobacterium tuberculosis strains, Mycobacterium leprae, and other mycobacterial pathogens produce a group of small-molecule virulence factors called phenolic glycolipids (PGLs). PGLs play key roles in pathogenicity and host-pathogen interaction. Thus, elucidation of the PGL biosynthetic pathway will not only expand our understanding of natural product biosynthesis, but may also illuminate routes to novel therapeutics to afford alternative lines of defense against mycobacterial infections. In this study, we report an investigation of the enzymatic requirements for the production of long-chain p-hydroxyphenylalkanoate intermediates of PGL biosynthesis. We demonstrate a functional cooperation between a coenzyme A-independent stand-alone didomain initiation module (FadD22) and a 6-domain reducing iterative type I polyketide synthase (Pks15/1) for production of p-hydroxyphenylalkanoate intermediates in in vitro and in vivo FadD22-Pks15/1 reconstituted systems. Our results suggest that Pks15/1 is an iterative type I polyketide synthase with a relaxed control of catalytic cycle iterations, a mechanistic property that explains the origin of a characteristic alkyl chain length variability seen in mycobacterial PGLs. The FadD22-Pks15/1 reconstituted systems lay an initial foundation for future efforts to unveil the mechanism of iterative catalysis control by which the structures of the final products of Pks15/1 are defined, and to scrutinize the functional partnerships of the FadD22-Pks15/1 system with downstream enzymes of the PGL biosynthetic pathway.

Chk2 is a checkpoint kinase involved in the ataxia telangiectasia mutated pathway, which is activated by genomic instability and DNA damage, leading to either cell death (apoptosis) or cell cycle arrest. Chk2 provides an unexplored therapeutic target against cancer cells. We recently reported 4,4′-diacetyldiphenylurea-bis(guanylhydrazone) (NSC 109555) as a novel chemotype Chk2 inhibitor. We have now synthesized a derivative of NSC 109555, PV1019 (NSC 744039) [7-nitro-1H-indole-2-carboxylic acid {4-[1-(guanidinohydrazone)-ethyl]-phenyl}-amide], which is a selective submicromolar inhibitor of Chk2 in vitro. The cocrystal structure of PV1019 bound in the ATP binding pocket of Chk2 confirmed enzymatic/biochemical observations that PV1019 acts as a competitive inhibitor of Chk2 with respect to ATP. PV1019 was found to inhibit Chk2 in cells. It inhibits Chk2 autophosphorylation (which represents the cellular kinase activation of Chk2), Cdc25C phosphorylation, and HDMX degradation in response to DNA damage. PV1019 also protects normal mouse thymocytes against ionizing radiation-induced apoptosis, and it shows synergistic antiproliferative activity with topotecan, camptothecin, and radiation in human tumor cell lines. We also show that PV1019 and Chk2 small interfering RNAs can exert antiproliferative activity themselves in the cancer cells with high Chk2 expression in the NCI-60 screen. These data indicate that PV1019 is a potent and selective inhibitor of Chk2 with chemotherapeutic and radiosensitization potential.

Bisubstrate analog inhibitors in which a nicotinamide mimic is attached to a series of structurally diversified guanidines (arginine mimics) were synthesized and evaluated for inhibition of cholera toxin. The mechanism-based bisubstrate inhibitors were up to 1400-fold more potent than the natural substrate NAD+ and 400-fold more potent than the artificial substrate diethylamino (benzylidine-amino) guanidine (DEABAG) in an assay toward an intrinsically active mutant of wild-type cholera toxin.

Amyloid beta-peptide (Abeta) is implicated as the major causative agent in Alzheimer's disease (AD). Abeta is produced by the processing of the amyloid precursor protein (APP) by BACE1 (beta-secretase) and gamma-secretase. Many inhibitors have been developed for the secretases. However, the inhibitors will interfere with the processing of not only APP but also of other secretase substrates. In this study, we describe the development of inhibitors that prevent production of Abeta by specific binding to the beta-cleavage site of APP. We used the hydropathic complementarity (HC) approach for the design of short peptide inhibitors. Some of the HC peptides were bound to the substrate peptide (Sub W) corresponding to the beta-cleavage site of APP and blocked its cleavage by recombinant human BACE1 (rhBACE1) in vitro. In addition, HC peptides specifically inhibited the cleavage of Sub W, and not affecting other BACE1 substrates. Chemical modification allowed an HC peptide (CIQIHF) to inhibit the processing of APP as well as the production of Abeta in the treated cells. Such novel APP-specific inhibitors will provide opportunity for the development of drugs that can be used for the prevention and treatment of AD with minimal side effects.

We have observed that Calanus sinicus retreated from neritic areas in the Yellow Sea and concentrated in the Yellow Sea Cold Bottom Water (YSCBW) area in summer. To investigate the summer reproductive strategy of C. sinicus in this situation, effects of high temperature on reproduction and hatching, as well as geographical variation of in situ egg production rate, were studied by onboard incubation in August 2001. Diel vertical migration (DVM) of females was investigated within and outside the YSCBW, respectively. Onboard incubation at 27 degrees C (i.e. surface temperature) resulted in lower fecundities than that at 9.8 and 12 degrees C (i.e. bottom temperature inside and outside the YSCBW) together with decreased hatching rates and increased naupliar malformation. Egg production was more active at stations outside the YSCBW than inside, where chlorophyll-a concentration was also relatively low. Females inside the YSCBW underwent DVM although they rarely entered the surface layer, but DVM was not observed outside the YSCBW. We conclude that surface temperature in summer has deleterious effects on C. sinicus egg production and hatching, and that it cannot reproduce successfully over the whole area. Inside the YSCBW, egg production is depressed by low food availability, while females outside suffer from high temperatures because of strong vertical mixing.