bluuebunny/crossref_metadata_2025 huggingface dataset:
Arrhythmogene rechtsventrikuläre Kardiomyopathie / Dysplasie: Pathogenese, Diagnose und Therapie
Authors: Akdis Deniz , Duru Firat
Published: May 2017

Zusammenfassung. Die arrhythmogene rechtsventrikuläre Kardiomyopathie / Dysplasie beschreibt eine genetische Erkrankung welche zu einer Umwandlung des Herzmuskels in Fett-und Bindegewebe, typischerweise im rechten Ventrikel führt. Biventrikuläre und linksventrikuläre Subtypen stellen zudem klinische Manifestationen dar. Mutationen in desmosomalen und nicht-desmosomalen Proteinen führen zu elektrischer und mechanischer Instabilität welche sich klinisch als initial als Rhythmusstörungen zeigen. Da die Erkrankung insbesondere junge Sportler betrifft, sind die Frühdiagnose und die adäquate Therapie von grosser Bedeutung, da die Erkrankung auch zum plötzlichen Herztod führen kann.
New Technique Reveals Iceberg Calving Process
Authors: Kornei Katherine
Published: May 2017

Researchers used unmanned aerial vehicle data to model the growth of a fracture that broke a 1-kilometer-long iceberg off a Greenland glacier.
TORC1 coordinates the conversion of Sic1 from a target to an inhibitor of cyclin-CDK-Cks1
Authors: Moreno-Torres Marta , Jaquenoud Malika , Péli-Gulli Marie-Pierre , Nicastro Raffaele , De Virgilio Claudio
Published: May 2017

Eukaryotic cell cycle progression through G1–S is driven by hormonal and growth-related signals that are transmitted by the target of rapamycin complex 1 (TORC1) pathway. In yeast, inactivation of TORC1 restricts G1–S transition due to the rapid clearance of G1 cyclins (Cln) and the stabilization of the B-type cyclin (Clb) cyclin-dependent kinase (CDK) inhibitor Sic1. The latter mechanism remains mysterious but requires the phosphorylation of Sic1-Thr173 by Mpk1 and inactivation of the Sic1-pThr173-targeting phosphatase (PP2ACdc55) through greatwall kinase-activated endosulfines. Here we show that the Sic1-pThr173 residue serves as a specific docking site for the CDK phospho-acceptor subunit Cks1 that sequesters, together with a C-terminal Clb5-binding motif in Sic1, Clb5-CDK-Cks1 complexes, thereby preventing them from flagging Sic1 for ubiquitin-dependent proteolysis. Interestingly, this functional switch of Sic1 from a target to an inhibitor of cyclin-CDK-Cks1 also operates in proliferating cells and is coordinated by the greatwall kinase, which responds to both Cln-CDK-dependent cell-cycle and TORC1-mediated nutritional cues.
T‐cell activation RhoGTPase‐activating protein plays an important role in TH17‐cell differentiation
Authors: Tamehiro Norimasa , Nishida Kyoko , Yanobu‐Takanashi Reiko , Goto Motohito , Okamura Tadashi , Suzuki Harumi
Published: May 2017

T‐cell activation RhoGTPase‐activating protein (TAGAP) is a GTPase‐activating protein specific for RhoA that is exclusively expressed in activated T cells. Genome‐wide association studies and metagenome SNPs analyses have indicated that TAGAP is associated with the pathogenesis of multiple autoimmune diseases, including psoriasis, rheumatoid arthritis, Crohn's disease, celiac disease and multiple sclerosis. However, the precise function of TAGAP remains unclear. Because TH17 cells contribute to TAGAP‐associated autoimmune diseases, we hypothesized that TAGAP plays key roles in the differentiation and/or function of TH17 cells. To evaluate this hypothesis, we analyzed the effect of TAGAP on TH17 differentiation in vitro and established a line of TAGAP‐deficient mice. We found that TAGAP was required for TH17 differentiation in vitro and that the loss of TAGAP in mice ameliorated the clinical features of experimental autoimmune encephalomyelitis, indicating that TAGAP is critical for disease progression. We also demonstrated that TAGAP interacts with RhoH, an adapter protein that interacts with lck and ZAP70 in proximal TCR signaling. TAGAP competes with ZAP70 for RhoH binding, thereby inhibiting TCR‐associated signal transduction. Consistent with these findings, TCR‐induced ERK activation was increased in TAGAP‐deficient T cells. Because the upregulation of TCR signaling inhibits Th17 differentiation, TAGAP may prevent TCR signaling activity from reaching the limit of the induction of TH17 cells. Collectively, our findings indicate that TAGAP is a novel factor required for TH17‐cell differentiation and that TAGAP potentially represents a novel target of autoimmune disease therapies.
Subnanometre-resolution structure of the doublet microtubule reveals new classes of microtubule-associated proteins
Authors: Ichikawa Muneyoshi , Liu Dinan , Kastritis Panagiotis L. , Basu Kaustuv , Hsu Tzu Chin , Yang Shunkai , Bui Khanh Huy
Published: May 2017

Cilia are ubiquitous, hair-like appendages found in eukaryotic cells that carry out functions of cell motility and sensory reception. Cilia contain an intriguing cytoskeletal structure, termed the axoneme that consists of nine doublet microtubules radially interlinked and longitudinally organized in multiple specific repeat units. Little is known, however, about how the axoneme allows cilia to be both actively bendable and sturdy or how it is assembled. To answer these questions, we used cryo-electron microscopy to structurally analyse several of the repeating units of the doublet at sub-nanometre resolution. This structural detail enables us to unambiguously assign α- and β-tubulins in the doublet microtubule lattice. Our study demonstrates the existence of an inner sheath composed of different kinds of microtubule inner proteins inside the doublet that likely stabilizes the structure and facilitates the specific building of the B-tubule.
Facile access to potent antiviral quinazoline heterocycles with fluorescence properties via merging metal-free domino reactions
Authors: Held Felix E. , Guryev Anton A. , Fröhlich Tony , Hampel Frank , Kahnt Axel , Hutterer Corina , Steingruber Mirjam , Bahsi Hanife , von Bojničić-Kninski Clemens , Mattes Daniela S. , Foertsch Tobias C. , Nesterov-Mueller Alexander , Marschall Manfred , Tsogoeva Svetlana B.
Published: May 2017

Most of the known approved drugs comprise functionalized heterocyclic compounds as subunits. Among them, non-fluorescent quinazolines with four different substitution patterns are found in a variety of clinically used pharmaceuticals, while 4,5,7,8-substituted quinazolines and those displaying their own specific fluorescence, favourable for cellular uptake visualization, have not been described so far. Here we report the development of a one-pot synthetic strategy to access these 4,5,7,8-substituted quinazolines, which are fluorescent and feature strong antiviral properties (EC50 down to 0.6±0.1 μM) against human cytomegalovirus (HCMV). Merging multistep domino processes in one-pot under fully metal-free conditions leads to sustainable, maximum efficient and high-yielding organic synthesis. Furthermore, generation of artesunic acid–quinazoline hybrids and their application against HCMV (EC50 down to 0.1±0.0 μM) is demonstrated. Fluorescence of new antiviral hybrids and quinazolines has potential applications in molecular imaging in drug development and mechanistic studies, avoiding requirement of linkage to external fluorescent markers.
Identification and characterization of a heterotrimeric archaeal DNA polymerase holoenzyme
Authors: Yan Jiangyu , Beattie Thomas R. , Rojas Adriana L. , Schermerhorn Kelly , Gristwood Tamzin , Trinidad Jonathan C. , Albers Sonja V. , Roversi Pietro , Gardner Andrew F. , Abrescia Nicola G. A. , Bell Stephen D.
Published: May 2017

Since their initial characterization over 30 years ago, it has been believed that the archaeal B-family DNA polymerases are single-subunit enzymes. This contrasts with the multi-subunit B-family replicative polymerases of eukaryotes. Here we reveal that the highly studied PolB1 from Sulfolobus solfataricus exists as a heterotrimeric complex in cell extracts. Two small subunits, PBP1 and PBP2, associate with distinct surfaces of the larger catalytic subunit and influence the enzymatic properties of the DNA polymerase. Thus, multi-subunit replicative DNA polymerase holoenzymes are present in all three domains of life. We reveal the architecture of the assembly by a combination of cross-linking coupled with mass spectrometry, X-ray crystallography and single-particle electron microscopy. The small subunits stabilize the holoenzyme assembly and the acidic tail of one small subunit mitigates the ability of the enzyme to perform strand-displacement synthesis, with important implications for lagging strand DNA synthesis.
Payoff information hampers the evolution of cooperation
Authors: Huck Steffen , Leutgeb Johannes , Oprea Ryan
Published: May 2017

Human cooperation has been explained through rationality as well as heuristics-based models. Both model classes share the feature that knowledge of payoff functions is weakly beneficial for the emergence of cooperation. Here, we present experimental evidence to the contrary. We let human subjects interact in a competitive environment and find that, in the long run, access to information about own payoffs leads to less cooperative behaviour. In the short run subjects use naive learning heuristics that get replaced by better adapted heuristics in the long run. With more payoff information subjects are less likely to switch to pro-cooperative heuristics. The results call for the development of two-tier models for the evolution of cooperation.
Conserved and species-specific molecular denominators in mammalian skeletal muscle aging
Authors: Mercken Evi M. , Capri Miriam , Carboneau Bethany A. , Conte Maria , Heidler Juliana , Santoro Aurelia , Martin-Montalvo Alejandro , Gonzalez-Freire Marta , Khraiwesh Husam , González-Reyes José A. , Moaddel Ruin , Zhang Yongqing , Becker Kevin G. , Villalba José M. , Mattison Julie A. , Wittig Ilka , Franceschi Claudio , de Cabo Rafael
Published: May 2017

Aging is a complex phenomenon involving functional decline in multiple physiological systems. We undertook a comparative analysis of skeletal muscle from four different species, i.e. mice, rats, rhesus monkeys, and humans, at three different representative stages during their lifespan (young, middle, and old) to identify pathways that modulate function and healthspan. Gene expression profiling and computational analysis revealed that pathway complexity increases from mice to humans, and as mammals age, there is predominantly an upregulation of pathways in all species. Two downregulated pathways, the electron transport chain and oxidative phosphorylation, were common among all four species in response to aging. Quantitative PCR, biochemical analysis, mitochondrial DNA measurements, and electron microscopy revealed a conserved age-dependent decrease in mitochondrial content, and a reduction in oxidative phosphorylation complexes in monkeys and humans. Western blot analysis of key proteins in mitochondrial biogenesis discovered that (i) an imbalance toward mitochondrial fusion occurs in aged skeletal muscle and (ii) mitophagy is not overtly affected, presumably leading to the observed accumulation of abnormally large, damaged mitochondria with age. Select transcript expression analysis uncovered that the skeletal inflammatory profile differentially increases with age, but is most pronounced in humans, while increased oxidative stress (as assessed by protein carbonyl adducts and 4-hydroxynonenal) is common among all species. Expression studies also found that there is unique dysregulation of the nutrient sensing pathways among the different species with age. The identification of conserved pathways indicates common molecular mechanisms intrinsic to health and lifespan, whereas the recognition of species-specific pathways emphasizes the importance of human studies for devising optimal therapeutic modalities to slow the aging process.
The effect of cognitive remediation in individuals at ultra-high risk for psychosis: a systematic review
Authors: Glenthøj Louise Birkedal , Hjorthøj Carsten , Kristensen Tina Dam , Davidson Charlie Andrew , Nordentoft Merete
Published: May 2017

Cognitive deficits are prominent features of the ultra-high risk state for psychosis that are known to impact functioning and course of illness. Cognitive remediation appears to be the most promising treatment approach to alleviate the cognitive deficits, which may translate into functional improvements. This study systematically reviewed the evidence on the effectiveness of cognitive remediation in the ultra-high risk population. The electronic databases MEDLINE, PsycINFO, and Embase were searched using keywords related to cognitive remediation and the UHR state. Studies were included if they were peer-reviewed, written in English, and included a population meeting standardized ultra-high risk criteria. Six original research articles were identified. All the studies provided computerized, bottom-up-based cognitive remediation, predominantly targeting neurocognitive function. Four out of five studies that reported a cognitive outcome found cognitive remediation to improve cognition in the domains of verbal memory, attention, and processing speed. Two out of four studies that reported on functional outcome found cognitive remediation to improve the functional outcome in the domains of social functioning and social adjustment. Zero out of the five studies that reported such an outcome found cognitive remediation to affect the magnitude of clinical symptoms. Research on the effect of cognitive remediation in the ultra-high risk state is still scarce. The current state of evidence indicates an effect of cognitive remediation on cognition and functioning in ultra-high risk individuals. More research on cognitive remediation in ultra-high risk is needed, notably in large-scale trials assessing the effect of neurocognitive and/or social cognitive remediation on multiple outcomes.
Neural correlates of distraction and conflict resolution for nonverbal auditory events
Authors: Stewart Hannah J. , Amitay Sygal , Alain Claude
Published: May 2017

In everyday situations auditory selective attention requires listeners to suppress task-irrelevant stimuli and to resolve conflicting information in order to make appropriate goal-directed decisions. Traditionally, these two processes (i.e. distractor suppression and conflict resolution) have been studied separately. In the present study we measured neuroelectric activity while participants performed a new paradigm in which both processes are quantified. In separate block of trials, participants indicate whether two sequential tones share the same pitch or location depending on the block’s instruction. For the distraction measure, a positive component peaking at ~250 ms was found – a distraction positivity. Brain electrical source analysis of this component suggests different generators when listeners attended to frequency and location, with the distraction by location more posterior than the distraction by frequency, providing support for the dual-pathway theory. For the conflict resolution measure, a negative frontocentral component (270–450 ms) was found, which showed similarities with that of prior studies on auditory and visual conflict resolution tasks. The timing and distribution are consistent with two distinct neural processes with suppression of task-irrelevant information occurring before conflict resolution. This new paradigm may prove useful in clinical populations to assess impairments in filtering out task-irrelevant information and/or resolving conflicting information.
Biochar amendment reduces paddy soil nitrogen leaching but increases net global warming potential in Ningxia irrigation, China
Authors: Wang Yongsheng , Liu Yansui , Liu Ruliang , Zhang Aiping , Yang Shiqi , Liu Hongyuan , Zhou Yang , Yang Zhengli
Published: May 2017

The efficacy of biochar as an environmentally friendly agent for non-point source and climate change mitigation remains uncertain. Our goal was to test the impact of biochar amendment on paddy rice nitrogen (N) uptake, soil N leaching, and soil CH4 and N2O fluxes in northwest China. Biochar was applied at four rates (0, 4.5, 9 and13.5 t ha−1 yr−1). Biochar amendment significantly increased rice N uptake, soil total N concentration and the abundance of soil ammonia-oxidizing archaea (AOA), but it significantly reduced the soil NO3−-N concentration and soil bulk density. Biochar significantly reduced NO3−-N and NH4+-N leaching. The C2 and C3 treatments significantly increased the soil CH4 flux and reduced the soil N2O flux, leading to significantly increased net global warming potential (GWP). Soil NO3−-N rather than NH4+-N was the key integrator of the soil CH4 and N2O fluxes. Our results indicate that a shift in abundance of the AOA community and increased rice N uptake are closely linked to the reduced soil NO3−-N concentration under biochar amendment. Furthermore, soil NO3−-N availability plays an important role in regulating soil inorganic N leaching and net GWP in rice paddies in northwest China.
In silico evaluation of DNA Damage Inducible Transcript 4 gene (DDIT4) as prognostic biomarker in several malignancies
Authors: Pinto Joseph A. , Rolfo Christian , Raez Luis E. , Prado Alexandra , Araujo Jhajaira M. , Bravo Leny , Fajardo Williams , Morante Zaida D. , Aguilar Alfredo , Neciosup Silvia P. , Mas Luis A. , Bretel Denisse , Balko Justin M. , Gomez Henry L.
Published: May 2017

DDIT4 gene encodes a protein whose main action is to inhibit mTOR under stress conditions whilst several in vitro studies indicate that its expression favors cancer progression. We have previously described that DDIT4 expression is an independent prognostic factor for tripe negative breast cancer resistant to neoadjuvant chemotherapy. We herein report that high DDIT4 expression is related to the outcome (recurrence-free survival, time to progression and overall survival) in several cancer types. We performed in silico analysis in online platforms, in pooled datasets from KM Plotter and meta-analysis of individual datasets from SurvExpress. High levels of DDIT4 were significantly associated with a worse prognosis in acute myeloid leukemia, breast cancer, glioblastoma multiforme, colon, skin and lung cancer. Conversely, a high DDIT4 expression was associated with an improved prognostic in gastric cancer. DDIT4 was not associated with the outcome of ovarian cancers. Analysis with data from the Cell Miner Tool in 60 cancer cell lines indicated that although rapamycin activity was correlated with levels of MTOR, it is not influenced by DDIT4 expression. In summary, DDIT4 might serve as a novel prognostic biomarker in several malignancies. DDIT4 activity could be responsible for resistance to mTOR inhibitors and is a potential candidate for the development of targeted therapy.
Diffusion Kurtosis Imaging of Microstructural Alterations in the Brains of Paediatric Patients with Congenital Sensorineural Hearing Loss
Authors: Zheng Wenbin , Wu Chunxiao , Huang Lexing , Wu Renhua
Published: May 2017

Our aim was to assess microstructural alterations in the cerebrums of paediatric patients with congenital sensorineural hearing loss (SNHL) using diffusion kurtosis imaging (DKI). Seventy-two paediatric SNHL patients and 38 age-matched healthy volunteers were examined via DKI using a 3.0 T magnetic resonance (MR) imager. Fractional anisotropy (FA) and mean kurtosis (MK) values were computed for 12 cerebral regions in both the controls and the SNHL patients. Compared with patients below age 3, patients in the older age group were found to have more significant differences in MK than in FA, and these appeared in more major areas of the brain. In contrast, in 1- to 3-year-old children, a few major brain areas exhibited differences in FA, but none exhibited appreciable differences in MK. There were significant decreases in the FA or MK values (P < 0.05, all) in more areas of the brain in patients with lesions than in patients with normal-appearing brains. DKI offers comprehensive measurements for quantitative evaluation of age-related microstructural changes in both white and grey matter in SNHL patients. DKI scans of children with SNHL exhibiting significant decreases in MK might play an important role in evaluating the severity of developmental delay.
Variability in multiple paternity rates for grey reef sharks (Carcharhinus amblyrhynchos) and scalloped hammerheads (Sphyrna lewini)
Authors: Green M. E. , Appleyard S. A. , White W. , Tracey S. , Ovenden J.
Published: May 2017

This study assessed the presence and prevalence of multiple paternity (MP) in litters of grey reef sharks (Carcharhinus amblyrhynchos) and scalloped hammerheads (Sphyrna lewini) opportunistically caught in Papua New Guinea (PNG). Litter size between species were significantly different with an average of 3.3 pups for grey reef sharks and 17.2 pups for scalloped hammerhead. Using 14 and 10 microsatellite loci respectively, we identified MP in 66% of grey reef sharks (4 out of 6 litters) and 100% MP in scalloped hammerheads (5 litters). We found high paternal skew (the uneven contribution of sires per litter) and a positive correlation between female adult size and litter size in scalloped hammerheads but not in grey reef sharks. Differences in the frequency of MP between species and the identification of paternal skew may be linked with mating strategies and post-copulatory mechanisms. Multiple paternity is thought to benefit populations by enhancing genetic diversity therefore increasing the population’s genetic resilience to extrinsic pressures. The identification of MP in two shark species reported here, further elucidates the complex breeding strategies elasmobranchs undertake.
Hydration effects on the efficacy of the Epidermal growth factor receptor kinase inhibitor afatinib
Authors: Kannan Srinivasaraghavan , Pradhan Mohan R. , Tiwari Garima , Tan Wei-Chong , Chowbay Balram , Tan Eng Huat , Tan Daniel Shao-Weng , Verma Chandra
Published: May 2017

Small molecules targeting the EGFR tyrosine kinase domain have been used with some success at treating patients with non-small cell lung cancer driven by activating mutations in the kinase domain. The initial class of inhibitors displaced ATP noncovalently but were rendered ineffective due to the development of resistance mutations in the kinase domain. These were overcome by the development of covalent inhibitors such as afatinib which also bind in the ATP pocket. However pooled analysis of two recent clinical trials LUX-3 and LUX-6 demonstrated an unprecedented overall survival benefit of afatinib over chemotherapy for the EGFR
19del
, but not the EGFR
L858R
. In the current study we use modelling and simulations to show that structural constraints in EGFR
19del
deletion result in significantly attenuated flexibilities in the binding pocket resulting in strong hydrogen and halogen bonds with afatinib in the EGFR
19del
; these constraints are modulated by buried water and result in the differential affinities of afatinib for the different mutants. SNP analysis of residues surrounding the buried water points to the likelihood of further differential effects of afatinib and provides a compelling case for investigating the effects of the SNPs towards further stratification of patients for ensuring the most effective use of afatinib.
An injectable non-cross-linked hyaluronic-acid gel containing therapeutic spheroids of human adipose-derived stem cells
Authors: Feng Jingwei , Mineda Kazuhide , Wu Szu-Hsien , Mashiko Takanobu , Doi Kentaro , Kuno Shinichiro , Kinoshita Kahori , Kanayama Koji , Asahi Rintaro , Sunaga Ataru , Yoshimura Kotaro
Published: May 2017

For chronic wounds, the delivery of stem cells in spheroidal structures can enhance graft survival and stem cell potency. We describe an easy method for the 3D culture of adipose-derived stem/stromal cells (ASCs) to prepare a ready-to-use injectable. We transferred suspensions of monolayer-cultured ASCs to a syringe containing hyaluronic acid (HA) gel, and then incubated the syringe as a 3D culture vessel. Spheroids of cells formed after 12 h. We found that 6 × 106 ASCs/ml in 3% HA gel achieved the highest spheroid density with appropriate spheroid sizes (20–100 µm). Immunocytology revealed that the stem cell markers, NANOG, OCT3/4, SOX-2, and SSEA-3 were up-regulated in the ASC spheroids compared with those in nonadherent-dish spheroids or in monolayer cultured ASCs. In delayed wound healing mice models, diabetic ulcers treated with ASC spheroids demonstrated faster wound epithelialization with thicker dermis than those treated with vehicle alone or monolayer cultured ASCs. In irradiated skin ulcers in immunodeficient mice, ASC spheroids exhibited faster healing and outstanding angiogenic potential partly by direct differentiation into α-SMA+ pericytes. Our method of 3D in-syringe HA gel culture produced clinically relevant amounts of ready-to-inject human ASC microspheroids that exhibited superior stemness in vitro and therapeutic efficacy in pathological wound repair in vivo.
Molecular floating-gate single-electron transistor
Authors: Yamamoto Makoto , Azuma Yasuo , Sakamoto Masanori , Teranishi Toshiharu , Ishii Hisao , Majima Yutaka , Noguchi Yutaka
Published: May 2017

We investigated reversible switching behaviors of a molecular floating-gate single-electron transistor (MFG-SET). The device consists of a gold nanoparticle-based SET and a few tetra-tert-butyl copper phthalocyanine (ttbCuPc) molecules; each nanoparticle (NP) functions as a Coulomb island. The ttbCuPc molecules function as photoreactive floating gates, which reversibly change the potential of the Coulomb island depending on the charge states induced in the ttbCuPc molecules by light irradiation or by externally applied voltages. We found that single-electron charging of ttbCuPc leads to a potential shift in the Coulomb island by more than half of its charging energy. The first induced device state was sufficiently stable; the retention time was more than a few hours without application of an external voltage. Moreover, the device exhibited an additional state when irradiated with 700 nm light, corresponding to doubly charged ttbCuPc. The life time of this additional state was several seconds, which is much shorter than that of the first induced state. These results clearly demonstrate an alternative method utilizing the unique functionality of the single molecule in nanoelectronics devices, and the potential application of MFG-SETs for investigating molecular charging phenomena.
The Brillouin gain of vector modes in a few-mode fiber
Authors: Pradhan Prabin , Sengupta Dipankar , Wang Lixian , Tremblay Christine , LaRochelle Sophie , Ung Bora
Published: May 2017

In this work, we demonstrate the measurement of the Brillouin gain spectra of vector modes in a few-mode fiber for the first time using a simple heterodyne detection technique. A tunable long period fiber grating is used to selectively excite the vector modes supported by the few-mode fiber. Further, we demonstrate the non-destructive measurement of the absolute effective refractive indices (n
eff
) of vector modes with ~10−4 accuracy based on the acquired Brillouin frequency shifts of the modes. The proposed technique represents a new tool for probing and controlling vector modes as well as modes carrying orbital angular momentum in optical fibers with potential applications in advanced optical communications and multi-parameter fiber-optic sensing.
Expression proteomics study to determine metallodrug targets and optimal drug combinations
Authors: Lee Ronald F. S. , Chernobrovkin Alexey , Rutishauser Dorothea , Allardyce Claire S. , Hacker David , Johnsson Kai , Zubarev Roman A. , Dyson Paul J.
Published: May 2017

The emerging technique termed functional identification of target by expression proteomics (FITExP) has been shown to identify the key protein targets of anti-cancer drugs. Here, we use this approach to elucidate the proteins involved in the mechanism of action of two ruthenium(II)-based anti-cancer compounds, RAPTA-T and RAPTA-EA in breast cancer cells, revealing significant differences in the proteins upregulated. RAPTA-T causes upregulation of multiple proteins suggesting a broad mechanism of action involving suppression of both metastasis and tumorigenicity. RAPTA-EA bearing a GST inhibiting ethacrynic acid moiety, causes upregulation of mainly oxidative stress related proteins. The approach used in this work could be applied to the prediction of effective drug combinations to test in cancer chemotherapy clinical trials.
2-benzothiazoleacetonitrile based two-photon fluorescent probe for hydrazine and its bio-imaging and environmental applications
Authors: Wang Jian-Yong , Liu Zhan-Rong , Ren Mingguang , Lin Weiying
Published: May 2017

A novel turn-on two-photon fluorescent probe NS-N
2
H
4
was developed with the 2-benzothiazoleacetonitrile as a new recognition site for the detection of hydrazine (N2H4). The two-photon probe exhibited favorable properties including high selectivity, low cytotoxicity and almost 16-fold fluorescence enhancement in the presence of N2H4 in solution. The probe could be used to image hydrazine in the living cells. Notably, we also used the two-photon fluorescent probe to image hydrazine in the tissue imaging for the first time. Furthermore, by the way of probe-loaded TLC plate, we further monitored vapor of hydrazine. Therefore, the novel two-photon probe is expected to be employed to detect N2H4 in biosamples and environmental pollution and the new recognition site will be widely applied to construct fluorescent probes for the detection of N2H4.
Monocytic microRNA profile associated with coronary collateral artery function in chronic total occlusion patients
Authors: Hakimzadeh Nazanin , Elias Joëlle , Wijntjens Gilbert W. M. , Theunissen Ruud , van Weert Angela , Smulders Martijn W. , van den Akker Nynke , Moerland Perry D. , Verberne Hein J. , Hoebers Loes P. , Henriques Jose P. S. , van der Laan Anja M. , Ilhan Mustafa , Post Mark , Bekkers Sebastiaan C. A. M. , Piek Jan J.
Published: May 2017

An expansive collateral artery network is correlated with improved survival in case of adverse cardiac episodes. We aimed to identify cellular microRNAs (miRNA; miR) important for collateral artery growth. Chronic total occlusion (CTO) patients (n = 26) were dichotomized using pressure-derived collateral flow index (CFIp) measurements; high collateral capacity (CFIp > 0.39; n = 14) and low collateral (CFIp < 0.39; n = 12) capacity. MiRNA profiling via next generation sequencing from various monocyte phenotypes (freshly isolated monocytes, monocytes cultured without stimulant, or stimulation with lipopolysaccharide, interleukin 4, transforming growth factor beta-1, or interferon gamma) revealed significantly different miRNA expression patterns between high versus low collateral capacity patients. Validation by real-time polymerase chain reaction demonstrated significantly decreased expression of miR339-5p in all stimulated monocyte phenotypes of low collateral capacity patients. MiR339-5p showed significant correlation with CFIp values in stimulated monocytes. Ingenuity pathway analysis of predicted gene targets of miR339-5p and differential gene expression data from high versus low CFIp patients (n = 20), revealed significant association with STAT3 pathway, and also suggested a possible regulatory role for this signaling pathway. These results identify a novel association between miR339-5p and coronary collateral function. Future work examining modulation of miR339-5p and downstream effects on the STAT3 pathway and subsequent collateral vessel growth are warranted.
Predicting influenza antigenicity from Hemagglutintin sequence data based on a joint random forest method
Authors: Yao Yuhua , Li Xianhong , Liao Bo , Huang Li , He Pingan , Wang Fayou , Yang Jiasheng , Sun Hailiang , Zhao Yulong , Yang Jialiang
Published: May 2017

Timely identification of emerging antigenic variants is critical to influenza vaccine design. The accuracy of a sequence-based antigenic prediction method relies on the choice of amino acids substitution matrices. In this study, we first compared a comprehensive 95 substitution matrices reflecting various amino acids properties in predicting the antigenicity of influenza viruses by a random forest model. We then proposed a novel algorithm called joint random forest regression (JRFR) to jointly consider top substitution matrices. We applied JRFR to human H3N2 seasonal influenza data from 1968 to 2003. A 10-fold cross-validation shows that JRFR outperforms other popular methods in predicting antigenic variants. In addition, our results suggest that structure features are most relevant to influenza antigenicity. By restricting the analysis to data involving two adjacent antigenic clusters, we inferred a few key amino acids mutation driving the 11 historical antigenic drift events, pointing to experimentally validated mutations. Finally, we constructed an antigenic cartography of all H3N2 viruses with hemagglutinin (the glycoprotein on the surface of the influenza virus responsible for its binding to host cells) sequence available from NCBI flu database, and showed an overall correspondence and local inconsistency between genetic and antigenic evolution of H3N2 influenza viruses.
Metabolic discrimination of sea buckthorn from different Hippophaë species by 1H NMR based metabolomics
Authors: Liu Yue , Fan Gang , Zhang Jing , Zhang Yi , Li Jingjian , Xiong Chao , Zhang Qi , Li Xiaodong , Lai Xianrong
Published: May 2017

Sea buckthorn (Hippophaë; Elaeagnaceae) berries are widely consumed in traditional folk medicines, nutraceuticals, and as a source of food. The growing demand of sea buckthorn berries and morphological similarity of Hippophaë species leads to confusions, which might cause misidentification of plants used in natural products. Detailed information and comparison of the complete set of metabolites of different Hippophaë species are critical for their objective identification and quality control. Herein, the variation among seven species and seven subspecies of Hippophaë was studied using proton nuclear magnetic resonance (1H NMR) metabolomics combined with multivariate data analysis, and the important metabolites were quantified by quantitative 1H NMR (qNMR) method. The results showed that different Hippophaë species can be clearly discriminated and the important interspecific discriminators, including organic acids, L-quebrachitol, and carbohydrates were identified. Statistical differences were found among most of the Hippophaë species and subspecies at the content levels of the aforementioned interspecific discriminators via qNMR and one-way analysis of variance (ANOVA) test. These findings demonstrated that 1H NMR-based metabolomics is an applicable and effective approach for simultaneous metabolic profiling, species differentiation and quality assessment.
Electrophysiological Properties and Viability of Neonatal Rat Ventricular Myocyte Cultures with Inducible ChR2 Expression
Authors: Li Qince , Ni Rong , Hong Huixian , Goh Kah Yong , Rossi Michael , Fast Vladimir G. , Zhou Lufang
Published: May 2017

Channelrhodopsin-2 (ChR2)-based optogenetic technique has been increasingly applied to cardiovascular research. However, the potential effects of ChR2 protein overexpression on cardiomyocytes are not completely understood. The present work aimed to examine how the doxycycline-inducible lentiviral-mediated ChR2 expression may affect cell viability and electrophysiological property of neonatal rat ventricular myocyte (NRVM) cultures. Primary NVRMs were infected with lentivirus containing ChR2 or YFP gene and subjected to cytotoxicity analysis. ChR2-expressing cultures were then paced electrically or optically with a blue light-emitting diode, with activation spread recorded simultaneously using optical mapping. Results showed that ChR2 could be readily transduced to NRVMs by the doxycycline-inducible lentiviral system; however, high-level ChR2 (but not YFP) expression was associated with substantial cytotoxicity, which hindered optical pacing. Application of bromodeoxyuridine significantly reduced cell damage, allowing stimulation with light. Simultaneous optical Vm mapping showed that conduction velocity, action potential duration, and dVm/dtmax were similar in ChR2-expressing and control cultures. Finally, the ChR2-expressing cultures could be optically paced at multiple sites, with significantly reduced overall activation time. In summary, we demonstrated that inducible lentiviral-mediated ChR2 overexpression might cause cytotoxicity in NRVM cultures, which could be alleviated without impairing electrophysiological function, allowing simultaneous optical pacing and Vm mapping.
Pattern analysis of laser-tattoo interactions for picosecond- and nanosecond-domain 1,064-nm neodymium-doped yttrium-aluminum-garnet lasers in tissue-mimicking phantom
Authors: Ahn Keun Jae , Zheng Zhenlong , Kwon Tae Rin , Kim Beom Joon , Lee Hye Sun , Cho Sung Bin
Published: May 2017

During laser treatment for tattoo removal, pigment chromophores absorb laser energy, resulting in fragmentation of the ink particles via selective photothermolysis. The present study aimed to outline macroscopic laser-tattoo interactions in tissue-mimicking (TM) phantoms treated with picosecond- and nanosecond-domain lasers. Additionally, high-speed cinematographs were captured to visualize time-dependent tattoo-tissue interactions, from laser irradiation to the formation of photothermal and photoacoustic injury zones (PIZs). In all experimental settings using the nanosecond or picosecond laser, tattoo pigments fragmented into coarse particles after a single laser pulse, and further disintegrated into smaller particles that dispersed toward the boundaries of PIZs after repetitive delivery of laser energy. Particles fractured by picosecond treatment were more evenly dispersed throughout PIZs than those fractured by nanosecond treatment. Additionally, picosecond-then-picosecond laser treatment (5-pass-picosecond treatment + 5-pass-picosecond treatment) induced greater disintegration of tattoo particles within PIZs than picosecond-then-nanosecond laser treatment (5-pass-picosecond treatment + 5-pass-nanosecond treatment). High-speed cinematography recorded the formation of PIZs after repeated reflection and propagation of acoustic waves over hundreds of microseconds to a few milliseconds. The present data may be of use in predicting three-dimensional laser-tattoo interactions and associated reactions in surrounding tissue.
Regulation of CHK1 by mTOR contributes to the evasion of DNA damage barrier of cancer cells
Authors: Zhou Xinhui , Liu Weijin , Hu Xing , Dorrance Adrienne , Garzon Ramiro , Houghton Peter J. , Shen Changxian
Published: May 2017

Oncogenic transformation leads to dysregulated cell proliferation, nutrient deficiency, and hypoxia resulting in metabolic stress and increased DNA damage. In normal cells, such metabolic stress leads to inhibition of signaling through the mammalian Target of Rapamycin Complex 1 (mTORC1), reduction of protein translation, cell cycle arrest, and conservation of energy. In contrast, negative regulation of mTORC1 signaling by DNA damage is abrogated in many cancer cells, thus mTORC1 signaling remains active under microenvironmental conditions that potentially promote endogenous DNA damage. Here we report that mTORC1 signaling suppresses endogenous DNA damage and replication stress. Pharmacological inhibition of mTOR signaling resulted in phosphorylation of H2AX concomitant with the decrease of CHK1 levels both in cell culture and mouse rhadomyosarcoma xenografts. Further results demonstrated that mTORC1-S6K1 signaling controls transcription of CHK1 via Rb-E2F by upregulating cyclin D and E. Consistent with these results, downregulation of CHK1 by inhibition of mTOR kinase resulted in defects in the slow S phase progression following DNA damage. These results indicate that, under stressful conditions, maintained mTORC1 signaling in cancer cells promotes survival by suppressing endogenous DNA damage, and may control cell fate through the regulation of CHK1.
A molecular beacon-based approach for live-cell imaging of RNA transcripts with minimal target engineering at the single-molecule level
Authors: Chen Mingming , Ma Zhao , Wu Xiaotian , Mao Shiqi , Yang Yantao , Tan Jie , Krueger Christopher J. , Chen Antony K.
Published: May 2017

Analysis of RNA dynamics and localization at the single-molecule level in living cells has been predominantly achieved by engineering target RNAs with large insertions of tandem repeat sequences that are bound by protein-based or oligonucleotide-based fluorescent probes. Thus, individual RNAs are tagged by multiple fluorescent probes, making them detectable by fluorescence microscopy. Since large insertions may affect RNA processes including trafficking and localization, here we present a strategy to visualize single RNA transcripts in living cells using molecular beacons (MBs) - fluorogenic oligonucleotide probes - with minimal target engineering. The MBs are composed of 2′-O-methyl RNAs with a fully phosphorothioate-modified loop domain (2Me/PSLOOP MBs), an architecture that elicits marginal levels of nonspecific signals in cells. We showed that MBs can detect single transcripts containing as few as 8 target repeat sequences with ~90% accuracy. In both the nucleus and the cytoplasm, mRNAs harboring 8 repeats moved faster than those with 32 repeats, suggesting that intracellular activities are less impeded by smaller engineered insertions. We then report the first MB-based imaging of intracellular dynamics and localization of single long noncoding RNAs (lncRNAs). We envision the proposed minimally-engineered, MB-based technology for live-cell single-molecule RNA imaging could facilitate new discoveries in RNA research.
DNA Methyltransferase1 (DNMT1) Isoform3 methylates mitochondrial genome and modulates its biology
Authors: Saini Sunil Kumar , Mangalhara Kailash Chandra , Prakasam Gopinath , Bamezai R. N. K.
Published: May 2017

Here we demonstrate localization of the isoform3 of DNA Methyltransferase1 (DNMT1) enzyme to mitochondria, instead of isoform1 as reported earlier. The fused DNMT1-isoform1, reported earlier to localize in mitochondria, surprisingly showed its exclusive presence inside the nucleus after its ectopic expression; and failed to localize in mitochondria. On the other hand, ectopically expressed DNMT1-isoform3 targeted itself to mitochondria and subsequently methylated CpG regions in the mitochondrial genome. In addition, overexpression of DNMT1-isoform3 affected mitochondrial biology and regulated its function. Under different conditions of oxidative and nutritional stress, this isoform was down-regulated, resulting in hypomethylation of mitochondrial genome. Our study reveals how DNMT1-isoform3, instead of isoform1, is responsible for mtDNA methylation, influencing its biology.
Characterizing microglia activation: a spatial statistics approach to maximize information extraction
Authors: Davis Benjamin M. , Salinas-Navarro Manual , Cordeiro M. Francesca , Moons Lieve , De Groef Lies
Published: May 2017

Microglia play an important role in the pathology of CNS disorders, however, there remains significant uncertainty about the neuroprotective/degenerative role of these cells due to a lack of techniques to adequately assess their complex behaviour in response to injury. Advancing microscopy techniques, transgenic lines and well-characterized molecular markers, have made histological assessment of microglia populations more accessible. However, there is a distinct lack of tools to adequately extract information from these images to fully characterise microglia behaviour. This, combined with growing economic pressures and the ethical need to minimise the use of laboratory animals, led us to develop tools to maximise the amount of information obtained. This study describes a novel approach, combining image analysis with spatial statistical techniques. In addition to monitoring morphological parameters and global changes in microglia density, nearest neighbour distance, and regularity index, we used cluster analyses based on changes in soma size and roundness to yield novel insights into the behaviour of different microglia phenotypes in a murine optic nerve injury model. These methods should be considered a generic tool to quantitatively assess microglia activation, to profile phenotypic changes into microglia subpopulations, and to map spatial distributions in virtually every CNS region and disease state.
Total fecal microbiota transplantation alleviates high-fat diet-induced steatohepatitis in mice via beneficial regulation of gut microbiota
Authors: Zhou Da , Pan Qin , Shen Feng , Cao Hai-xia , Ding Wen-jin , Chen Yuan-wen , Fan Jian-gao
Published: May 2017

Non-alcoholic steatohepatitis (NASH) is an epidemic metabolic disease with limited therapeutic strategies. Cumulative data support the pivotal role of gut microbiota in NASH. Here, we investigated the hypothesis regarding whether fecal microbiota transplantation (FMT) is effective in attenuating high-fat diet (HFD)-induced steatohepatitis in mice. Mice were randomized into control, HFD and HFD + FMT groups. After an 8-week HFD, FMT treatment was initiated and carried out for 8 weeks. The gut microbiota structure, butyrate concentrations of the cecal content, liver pathology and intrahepatic lipid and cytokines were examined. Our results showed that after FMT, the gut microbiota disturbance was corrected in HFD-fed mice with elevated abundances of the beneficial bacteria Christensenellaceae and Lactobacillus. FMT also increased butyrate concentrations of the cecal content and the intestinal tight junction protein ZO-1, resulting in relief of endotoxima in HFD-fed mice. Steatohepatitis was alleviated after FMT, as indicated by a significant decrease in intrahepatic lipid accumulation (reduced Oli-red staining, decreased intrahepatic triglyceride and cholesterol), intrahepatic pro-inflammatory cytokines, and the NAS score. Accordingly, intrahepatic IFN-γ and IL-17 were decreased, but Foxp3, IL-4 and IL-22 were increased after FMT intervention. These data indicate that FMT attenuated HFD-induced steatohepatitis in mice via a beneficial effect on the gut microbiota.
Improved thermostability of an acidic xylanase from Aspergillus sulphureus by combined disulphide bridge introduction and proline residue substitution
Authors: Yang Wenhan , Yang Yongzhi , Zhang Lingdi , Xu Hang , Guo Xiaojing , Yang Xu , Dong Bing , Cao Yunhe
Published: May 2017

As a feed additive, xylanase has been widely applied in the feed of monogastric animals, which contains multiple plant polysaccharides. However, during feed manufacture, the high pelleting temperatures challenge wild-type xylanases. The aim of this study was to improve the thermostability of Aspergillus sulphureus acidic xylanase. According to the predicted protein structure, a series of disulphide bridges and proline substitutions were created in the xylanase by PCR, and the mutants were expressed in Pichia pastoris. Enzyme properties were evaluated following chromatographic purification. All the recombinant enzymes showed optima at pH 3.0 and 50 °C or 55 °C and better resistance to some chemicals except for CuSO4. The specific activity of the xylanase was decreased by introduction of the mutations. Compared to the wild-type enzyme, a combined mutant, T53C-T142C/T46P, with a disulphide bond at 53–142 and a proline substitution at 46, showed a 22-fold increase of half-life at 60 °C. In a 10-L fermentor, the maximal xylanase activity of T53C-T142C/T46P reached 1,684 U/mL. It was suggested that the T53C-T142C/T46P mutant xylanase had excellent thermostability characteristics and could be a prospective additive in feed manufacture.