Article added to library!
x
Pubchase is a service of protocols.io - free, open access, crowdsourced protocols repository. Explore protocols.
Sign in
Reset password
or connect with
Facebook
By signing in you are agreeing to our
Terms Of Service and Privacy Policy
Biochemistry
Immunogene therapy with fusogenic nanoparticles modulates macrophage response to Staphylococcus aureus.
May 23, 2018   Nature Communications
Kim B, Pang HB, Kang J, Park JH, Ruoslahti E, Sailor MJ
Immunogene therapy with fusogenic nanoparticles modulates macrophage response to Staphylococcus aureus.
May 23, 2018
Nature Communications
The incidence of adverse effects and pathogen resistance encountered with small molecule antibiotics is increasing. As such, there is mounting focus on immunogene therapy to augment the immune system's response to infection and accelerate healing. A major obstacle to in vivo gene delivery is that the primary uptake pathway, cellular endocytosis, results in extracellular excretion and lysosomal degradation of genetic material. Here we show a nanosystem that bypasses endocytosis and achieves potent gene knockdown efficacy. Porous silicon nanoparticles containing an outer sheath of homing peptides and fusogenic liposome selectively target macrophages and directly introduce an oligonucleotide payload into the cytosol. Highly effective knockdown of the proinflammatory macrophage marker IRF5 enhances the clearance capability of macrophages and improves survival in a mouse model of Staphyloccocus aureus pneumonia.
Effects of ethanol on the anticancer function of doxorubicin in JJ012 cells.
Jun 05, 2018   Future Oncology (London, England)
Huang H, Li Y, Wu M, Luo J, Nie J, Hou B, He Q, Diao Y, Qi L, Zhao Y, Liu Y, Yang D, Zhou L
Effects of ethanol on the anticancer function of doxorubicin in JJ012 cells.
Jun 05, 2018
Future Oncology (London, England)
AIM: Chondrosarcoma is difficult to treat because of resistance to conventional chemotherapy and radiotherapy. This study evaluated the effects of ethanol in combination with doxorubicin in chondrosarcoma cells. MATERIALS & METHODS: JJ012, was treated with doxorubicin alone or in combination with ethanol. Effects on cellular proliferation, migration, invasion, apoptosis, and the cell cycle were evaluated. RESULTS: Treatment of JJ012 cells with 100 mM ethanol and doxorubicin resulted in reduced cell growth, invasion, and migration. In addition, doxorubicin uptake into the nucleus was enhanced and p53 mRNA expression was upregulated in JJ012 cells. CONCLUSION: Ethanol combined with doxorubicin increased doxorubicin uptake in the nucleus and enhanced the effects of doxorubicin in JJ012 cells.
Molecular characterization of physis tissue by RNA sequencing.
Jun 13, 2018   Gene
Paradise CR, Galeano-Garces C, Galeano-Garces D, Dudakovic A, Milbrandt TA, Saris DBF, Krych AJ, Karperien M, Ferguson GB, Evseenko D, Riester SM, van Wijnen AJ, Noelle Larson A
Molecular characterization of physis tissue by RNA sequencing.
Jun 13, 2018
Gene
The physis is a well-established and anatomically distinct cartilaginous structure that is crucial for normal long-bone development and growth. Abnormalities in physis function are linked to growth plate disorders and other pediatric musculoskeletal diseases. Understanding the molecular pathways operative in the physis may permit development of regenerative therapies to complement surgically-based procedures that are the current standard of care for growth plate disorders. Here, we performed next generation RNA sequencing on mRNA isolated from human physis and other skeletal tissues (e.g., articular cartilage and bone; n = 7 for each tissue). We observed statistically significant enrichment of gene sets in the physis when compared to the other musculoskeletal tissues. Further analysis of these upregulated genes identified physis-specific networks of extracellular matrix proteins including collagens (COL2A1, COL6A1, COL9A1, COL14A1, COL16A1) and matrilins (MATN1, MATN2, MATN3), and signaling proteins in the WNT pathway (WNT10B, FZD1, FZD10, DKK2) or the FGF pathway (FGF10, FGFR4). Our results provide further insight into the gene expression networks that contribute to the physis' unique structural composition and regulatory signaling networks. Physis-specific expression profiles may guide ongoing initiatives in tissue engineering and cell-based therapies for treatment of growth plate disorders and growth modulation therapies. Furthermore, our findings provide new leads for therapeutic drug discovery that would permit future intervention through pharmacological rather than surgical strategies.
Ultrastructural Characterization of Corticotropin-Releasing Factor and Neuropeptide Y in the Rat Locus Coeruleus: Anatomical Evidence for Putative Interactions.
Jun 19, 2018   Neuroscience
Theisen CC, Reyes BAS, Sabban EL, Van Bockstaele EJ
Ultrastructural Characterization of Corticotropin-Releasing Factor and Neuropeptide Y in the Rat Locus Coeruleus: Anatomical Evidence for Putative Interactions.
Jun 19, 2018
Neuroscience
As a neurochemical mediator of stress resilience, NPY has been shown to oppose excitatory effects of the pro-stress neuropeptide corticotropin-releasing factor (CRF). Previous studies have described the anatomical organization of NPY and CRF in the central nucleus of the amygdala, which sends CRF projections to the locus coeruleus (LC), activating LC norepinephrine release. However, the cellular substrates for interactions between NPY and CRF in the LC remain unknown. In this study, we investigated these anatomical substrates in the male rat LC, using immunocytochemistry, confocal microscopy, and immunoelectron microscopy to detect NPY and CRF, as well as CRF and Y1 or Y2 receptors (Y1R or Y2R). Immunofluorescence and electron microscopy revealed both co-localization of NPY and CRF in LC axon terminals, as well as separately labeled terminals, suggesting NPY and CRF may serve as co-transmitters in a subset of terminals. Semi-quantitative analysis showed that 32.4% of CRF-labeled terminals contained NPY, while 58.2% (152/261) of NPY-labeled terminals contained CRF. With respect to Y1R and CRF, dual immunoelectron microscopy showed that 23.3% (67/288) of CRF-labeled axon terminals directly contacted Y1R-labeled dendrites, while only 6.3% (18/288) of CRF-labeled axon terminals co-localized with Y1R. Dual immunoelectron microscopy also showed Y2R co-localized with 30.4% (103/339) CRF-labeled terminals, but only with 16.2% (55/339) of dendrites post-synaptic to CRF-labeled axon terminals in the LC. Taken together, these findings indicate multiple sites of interaction between CRF and NPY in the LC and suggest that conditions or drugs that modulate the NPY:CRF balance in the LC may promote stress resilience.
Enhanced Sampling of Interdomain Motion Using Map-Restrained Langevin Dynamics and NMR: Application to Pin1.
Jun 17, 2018   Journal Of Molecular Biology
Bouchard JJ, Xia J, Case DA, Peng JW
Enhanced Sampling of Interdomain Motion Using Map-Restrained Langevin Dynamics and NMR: Application to Pin1.
Jun 17, 2018
Journal Of Molecular Biology
Many signaling proteins consist of globular domains connected by flexible linkers that allow for substantial domain motion. Because these domains often serve as complementary functional modules, the possibility of functionally important domain motions arises. To explore this possibility, we require knowledge of the ensemble of protein conformations sampled by interdomain motion. Measurements of NMR residual dipolar couplings (RDCs) of backbone HN bonds offer a per-residue characterization of interdomain dynamics, as the couplings are sensitive to domain orientation. A challenge in reaching this potential is the need to interpret the RDCs as averages over dynamic ensembles of domain conformations. Here, we address this challenge by introducing an efficient protocol for generating conformational ensembles appropriate for flexible, multi-domain proteins. The protocol uses map-restrained self-guided Langevin dynamics simulations to promote collective, interdomain motion while restraining the internal domain motion to near rigidity. Critically, the simulations retain an all-atom description for facile inclusion of site-specific NMR RDC restraints. The result is the rapid generation of conformational ensembles consistent with the RDC data. We illustrate this protocol on human Pin1, a two-domain peptidyl-prolyl isomerase relevant for cancer and Alzheimer's disease. The results include the ensemble of domain orientations sampled by Pin1, as well as those of a dysfunctional variant, I28A-Pin1. The differences between the ensembles corroborate our previous spin relaxation results that showed weakened interdomain contact in the I28A variant relative to wild type. Our protocol extends our abilities to explore the functional significance of protein domain motions.
Structure of Telomerase with Telomeric DNA.
Jun 13, 2018   Cell
Jiang J, Wang Y, Sušac L, Chan H, Basu R, Zhou ZH, Feigon J
Structure of Telomerase with Telomeric DNA.
Jun 13, 2018
Cell
Telomerase is an RNA-protein complex (RNP) that extends telomeric DNA at the 3' ends of chromosomes using its telomerase reverse transcriptase (TERT) and integral template-containing telomerase RNA (TER). Its activity is a critical determinant of human health, affecting aging, cancer, and stem cell renewal. Lack of atomic models of telomerase, particularly one with DNA bound, has limited our mechanistic understanding of telomeric DNA repeat synthesis. We report the 4.8 Å resolution cryoelectron microscopy structure of active Tetrahymena telomerase bound to telomeric DNA. The catalytic core is an intricately interlocked structure of TERT and TER, including a previously structurally uncharacterized TERT domain that interacts with the TEN domain to physically enclose TER and regulate activity. This complete structure of a telomerase catalytic core and its interactions with telomeric DNA from the template to telomere-interacting p50-TEB complex provides unanticipated insights into telomerase assembly and catalytic cycle and a new paradigm for a reverse transcriptase RNP.
Correlating Transcription Initiation and Conformational Changes by a Single-Subunit RNA Polymerase with Near Base-Pair Resolution.
Jun 06, 2018   Molecular Cell
Koh HR, Roy R, Sorokina M, Tang GQ, Nandakumar D, Patel SS, Ha T
Correlating Transcription Initiation and Conformational Changes by a Single-Subunit RNA Polymerase with Near Base-Pair Resolution.
Jun 06, 2018
Molecular Cell
We provide a comprehensive analysis of transcription in real time by T7 RNA Polymerase (RNAP) using single-molecule fluorescence resonance energy transfer by monitoring the entire life history of transcription initiation, including stepwise RNA synthesis with near base-pair resolution, abortive cycling, and transition into elongation. Kinetically branching pathways were observed for abortive initiation with an RNAP either recycling on the same promoter or exchanging with another RNAP from solution. We detected fast and slow populations of RNAP in their transition into elongation, consistent with the efficient and delayed promoter release, respectively, observed in ensemble studies. Real-time monitoring of abortive cycling using three-probe analysis showed that the initiation events are stochastically branched into productive and failed transcription. The abortive products are generated primarily from initiation events that fail to progress to elongation, and a majority of the productive events transit to elongation without making abortive products.
EP300-Mediated Lysine 2-Hydroxyisobutyrylation Regulates Glycolysis.
May 26, 2018   Molecular Cell
Huang H, Tang S, Ji M, Tang Z, Shimada M, Liu X, Qi S, Locasale JW, Roeder RG, Zhao Y, Li X
EP300-Mediated Lysine 2-Hydroxyisobutyrylation Regulates Glycolysis.
May 26, 2018
Molecular Cell
Lysine 2-hydroxyisobutyrylation (Khib) is an evolutionarily conserved and widespread histone mark like lysine acetylation (Kac). Here we report that EP300 functions as a lysine 2-hyroxyisobutyryltransferase to regulate glycolysis in response to nutritional cues. We discovered that EP300 differentially regulates Khib and Kac on distinct lysine sites, with only 6 of the 149 EP300-targeted Khib sites overlapping with the 693 EP300-targeted Kac sites. We demonstrate that diverse cellular proteins, particularly glycolytic enzymes, are targeted by EP300 for Khib, but not for Kac. Specifically, deletion of EP300 significantly reduces Khib levels on several EP300-dependent, Khib-specific sites on key glycolytic enzymes including ENO1, decreasing their catalytic activities. Consequently, EP300-deficient cells have impaired glycolysis and are hypersensitive to glucose-depletion-induced cell death. Our study reveals an EP300-catalyzed, Khib-specific molecular mechanism that regulates cellular glucose metabolism and further indicate that EP300 has an intrinsic ability to select short-chain acyl-CoA-dependent protein substrates.
Pseudomonas aeruginosa type IV minor pilins and PilY1 regulate virulence by modulating FimS-AlgR activity.
Jun 17, 2018   PLoS Pathogens
Marko VA, Kilmury SLN, MacNeil LT, Burrows LL
Pseudomonas aeruginosa type IV minor pilins and PilY1 regulate virulence by modulating FimS-AlgR activity.
Jun 17, 2018
PLoS Pathogens
Type IV pili are expressed by a wide range of prokaryotes, including the opportunistic pathogen Pseudomonas aeruginosa. These flexible fibres mediate twitching motility, biofilm maturation, surface adhesion, and virulence. The pilus is composed mainly of major pilin subunits while the low abundance minor pilins FimU-PilVWXE and the putative adhesin PilY1 prime pilus assembly and are proposed to form the pilus tip. The minor pilins and PilY1 are encoded in an operon that is positively regulated by the FimS-AlgR two-component system. Independent of pilus assembly, PilY1 was proposed to be a mechanosensory component that-in conjunction with minor pilins-triggers up-regulation of acute virulence phenotypes upon surface attachment. Here, we investigated the link between the minor pilins/PilY1 and virulence. pilW, pilX, and pilY1 mutants had reduced virulence towards Caenorhabditis elegans relative to wild type or a major pilin mutant, implying a role in pathogenicity that is independent of pilus assembly. We hypothesized that loss of specific minor pilins relieves feedback inhibition on FimS-AlgR, increasing transcription of the AlgR regulon and delaying C. elegans killing. Reporter assays confirmed that FimS-AlgR were required for increased expression of the minor pilin operon upon loss of select minor pilins. Overexpression of AlgR or its hyperactivation via a phosphomimetic mutation reduced virulence, and the virulence defects of pilW, pilX, and pilY1 mutants required FimS-AlgR expression and activation. We propose that PilY1 and the minor pilins inhibit their own expression, and that loss of these proteins leads to FimS-mediated activation of AlgR that suppresses expression of acute-phase virulence factors and delays killing. This mechanism could contribute to adaptation of P. aeruginosa in chronic lung infections, as mutations in the minor pilin operon result in the loss of piliation and increased expression of AlgR-dependent virulence factors-such as alginate-that are characteristic of such infections.
Treadmilling analysis reveals new insights into dynamic FtsZ ring architecture.
Jun 17, 2018   PLoS Biology
Ramirez-Diaz DA, García-Soriano DA, Raso A, Mücksch J, Feingold M, Rivas G, Schwille P
Treadmilling analysis reveals new insights into dynamic FtsZ ring architecture.
Jun 17, 2018
PLoS Biology
FtsZ, the primary protein of the bacterial Z ring guiding cell division, has been recently shown to engage in intriguing treadmilling dynamics along the circumference of the division plane. When coreconstituted in vitro with FtsA, one of its natural membrane anchors, on flat supported membranes, these proteins assemble into dynamic chiral vortices compatible with treadmilling of curved polar filaments. Replacing FtsA by a membrane-targeting sequence (mts) to FtsZ, we have discovered conditions for the formation of dynamic rings, showing that the phenomenon is intrinsic to FtsZ. Ring formation is only observed for a narrow range of protein concentrations at the bilayer, which is highly modulated by free Mg2+ and depends upon guanosine triphosphate (GTP) hydrolysis. Interestingly, the direction of rotation can be reversed by switching the mts from the C-terminus to the N-terminus of the protein, implying that the filament attachment must have a perpendicular component to both curvature and polarity. Remarkably, this chirality switch concurs with previously shown inward or outward membrane deformations by the respective FtsZ mutants. Our results lead us to suggest an intrinsic helicity of FtsZ filaments with more than one direction of curvature, supporting earlier hypotheses and experimental evidence.
Atomic resolution mechanism of ligand binding to a solvent inaccessible cavity in T4 lysozyme.
Jun 18, 2018   PLoS Computational Biology
Mondal J, Ahalawat N, Pandit S, Kay LE, Vallurupalli P
Atomic resolution mechanism of ligand binding to a solvent inaccessible cavity in T4 lysozyme.
Jun 18, 2018
PLoS Computational Biology
Ligand binding sites in proteins are often localized to deeply buried cavities, inaccessible to bulk solvent. Yet, in many cases binding of cognate ligands occurs rapidly. An intriguing system is presented by the L99A cavity mutant of T4 Lysozyme (T4L L99A) that rapidly binds benzene (~106 M-1s-1). Although the protein has long served as a model system for protein thermodynamics and crystal structures of both free and benzene-bound T4L L99A are available, the kinetic pathways by which benzene reaches its solvent-inaccessible binding cavity remain elusive. The current work, using extensive molecular dynamics simulation, achieves this by capturing the complete process of spontaneous recognition of benzene by T4L L99A at atomistic resolution. A series of multi-microsecond unbiased molecular dynamics simulation trajectories unequivocally reveal how benzene, starting in bulk solvent, diffuses to the protein and spontaneously reaches the solvent inaccessible cavity of T4L L99A. The simulated and high-resolution X-ray derived bound structures are in excellent agreement. A robust four-state Markov model, developed using cumulative 60 μs trajectories, identifies and quantifies multiple ligand binding pathways with low activation barriers. Interestingly, none of these identified binding pathways required large conformational changes for ligand access to the buried cavity. Rather, these involve transient but crucial opening of a channel to the cavity via subtle displacements in the positions of key helices (helix4/helix6, helix7/helix9) leading to rapid binding. Free energy simulations further elucidate that these channel-opening events would have been unfavorable in wild type T4L. Taken together and via integrating with results from experiments, these simulations provide unprecedented mechanistic insights into the complete ligand recognition process in a buried cavity. By illustrating the power of subtle helix movements in opening up multiple pathways for ligand access, this work offers an alternate view of ligand recognition in a solvent-inaccessible cavity, contrary to the common perception of a single dominant pathway for ligand binding.
Masses and β-Decay Spectroscopy of Neutron-Rich Odd-Odd ^{160,162}Eu Nuclei: Evidence for a Subshell Gap with Large Deformation at N=98.
May 21, 2018   Physical Review Letters
Hartley DJ, Kondev FG, Orford R, Clark JA, Savard G,   . . . . . .   , Seweryniak D, Sharma KS, Zhang H, Zhu S, Zhu Y
Masses and β-Decay Spectroscopy of Neutron-Rich Odd-Odd ^{160,162}Eu Nuclei: Evidence for a Subshell Gap with Large Deformation at N=98.
May 21, 2018
Physical Review Letters
The structure of deformed neutron-rich nuclei in the rare-earth region is of significant interest for both the astrophysics and nuclear structure fields. At present, a complete explanation for the observed peak in the elemental abundances at A∼160 eludes astrophysicists, and models depend on accurate quantities, such as masses, lifetimes, and branching ratios of deformed neutron-rich nuclei in this region. Unusual nuclear structure effects are also observed, such as the unexpectedly low energies of the first 2^{+} levels in some even-even nuclei at N=98. In order to address these issues, mass and β-decay spectroscopy measurements of the ^{160}Eu_{97} and ^{162}Eu_{99} nuclei were performed at the Californium Rare Isotope Breeder Upgrade radioactive beam facility at Argonne National Laboratory. Evidence for a gap in the single-particle neutron energies at N=98 and for large deformation (β_{2}∼0.3) is discussed in relation to the unusual phenomena observed at this neutron number.
Integrative Epigenetic Analysis Reveals Therapeutic Targets to the DNA Methyltransferase Inhibitor SGI-110 in Hepatocellular Carcinoma.
May 31, 2018   Hepatology (Baltimore, Md.)
Liu M, Zhang L, Li H, Hinoue T, Zhou W, Ohtani H, El-Khoueiry A, Daniels J, O'Connell C, Dorff TB, Lu Q, Weisenberger DJ, Liang G
Integrative Epigenetic Analysis Reveals Therapeutic Targets to the DNA Methyltransferase Inhibitor SGI-110 in Hepatocellular Carcinoma.
May 31, 2018
Hepatology (Baltimore, Md.)
There is an urgent need for developing more effective therapies for hepatocellular carcinoma (HCC) because of its aggressiveness. Guadecitabine (SGI-110) is a second-generation DNA methyltransferase inhibitor (DNMTi) currently in clinical trials for HCC and shows greater stability and performance over first generation DNMTis. In order to identify potential therapeutic targets of SGI-110 for clinical trials, HCC cell lines (SNU398, HepG2 and SNU475) were used to evaluate effects of transient SGI-110 treatment by an integrative analysis of DNA methylation, nucleosome accessibility, gene expression profiles and its clinical relevance by comparisons to TCGA HCC clinical data. Each HCC cell lines represents a different DNA methylation subtype of primary HCC tumors based on TCGA data. After SGI-110 treatment, all cell lines were sensitive to SGI-110 with prolonged anti-proliferation effects. Expression of up-regulated genes, including tumor suppressors, were positively correlated with nucleosome accessibility and negatively correlated with gene promoter DNA methylation. Alternatively, expression of down-regulated genes, such as oncogenes, were negatively correlated with nucleosome accessibility and positively correlated with gene body DNA methylation. SGI-110 can also act as dual inhibitor to down-regulate PRC2 complex genes by demethylating their gene bodies, resulting in re-activation of PRC2 repressed genes without involvement of DNA methylation. Furthermore, it can up-regulate endogenous retroviruses (ERVs) to reactivate immune pathways. Finally, about 48% of frequently altered genes in primary HCC tumors can be reversed by SGI-110 treatment.CONCLUSION: our integrative analysis has successfully linked the anti-tumor effects of SGI-110 to detailed epigenetic alterations in HCC cells, identified potential therapeutic targets, and provided rationale for combination treatments of SGI-110 with immune checkpoint therapies. This article is protected by copyright. All rights reserved.
Light-induced formation of partially reduced oxygen species limits the lifetime of photosystem 1-based biocathodes.
May 22, 2018   Nature Communications
Zhao F, Hardt S, Hartmann V, Zhang H, Nowaczyk MM, Rögner M, Plumeré N, Schuhmann W, Conzuelo F
Light-induced formation of partially reduced oxygen species limits the lifetime of photosystem 1-based biocathodes.
May 22, 2018
Nature Communications
Interfacing photosynthetic proteins specifically photosystem 1 (PS1) with electrodes enables light-induced charge separation processes for powering semiartificial photobiodevices with, however, limited long-term stability. Here, we present the in-depth evaluation of a PS1/Os-complex-modified redox polymer-based biocathode by means of scanning photoelectrochemical microscopy. Focalized local illumination of the bioelectrode and concomitant collection of H2O2 at the closely positioned microelectrode provide evidence for the formation of partially reduced oxygen species under light conditions. Long-term evaluation of the photocathode at different O2 concentrations as well as after incorporating catalase and superoxide dismutase reveals the particularly challenging issue of avoiding the generation of reactive species. Moreover, the evaluation of films prepared with inactivated PS1 and free chlorophyll points out additional possible pathways for the generation of oxygen radicals. To avoid degradation of PS1 during illumination and hence to enhance the long-term stability, the operation of biophotocathodes under anaerobic conditions is indispensable.
The distinct structural preferences of tau protein repeat domains.
Jun 06, 2018   Chemical Communications (Cambridge, England)
Li X, Dong X, Wei G, Margittai M, Nussinov R, Ma B
The distinct structural preferences of tau protein repeat domains.
Jun 06, 2018
Chemical Communications (Cambridge, England)
The tau fibrillar structures from the brain of an Alzheimer's patient have a core with a C-shaped motif of the third and fourth repeat domains (R3-R4). Our simulations indicated that the C-shaped motif is only stable for R3-R4, while R1-R2 tends to be linear in shape. These two structural motifs appear in the most stable K18 protofilament. Heparin can further stabilize the C-shaped R3-R4 motif, but not other repeats.
Mannan-induced Nos2 in macrophages enhances IL-17-driven psoriatic arthritis by innate lymphocytes.
May 20, 2018   Science Advances
Zhong J, Scholz T, Yau ACY, Guerard S, Hüffmeier U, Burkhardt H, Holmdahl R
Mannan-induced Nos2 in macrophages enhances IL-17-driven psoriatic arthritis by innate lymphocytes.
May 20, 2018
Science Advances
Previous identification of the inducible nitric oxide synthase (NOS2) gene as a risk allele for psoriasis (Ps) and psoriatic arthritis (PsA) suggests a possible pathogenic role of nitric oxide (NO). Using a mouse model of mannan-induced Ps and PsA (MIP), where macrophages play a regulatory role by releasing reactive oxygen species (ROS), we found that NO was detectable before disease onset in mice, independent of a functional nicotinamide adenine dinucleotide phosphate oxidase 2 complex. MIP was suppressed by either deletion of Nos2 or inhibition of NO synthases with NG-nitro-l-arginine methyl ester, demonstrating that Nos2-derived NO is pathogenic. NOS2 expression was also up-regulated in lipopolysaccharide- and interferon-γ-stimulated monocyte subsets from patients with PsA compared to healthy controls. Nos2-dependent interleukin-1α (IL-1α) release from skin macrophages was essential for arthritis development by promoting IL-17 production of innate lymphoid cells. We conclude that Nos2-derived NO by tissue macrophages promotes MIP, in contrast to the protective effect by ROS.
The fission yeast Stn1-Ten1 complex limits telomerase activity via its SUMO-interacting motif and promotes telomeres replication.
May 20, 2018   Science Advances
Matmati S, Vaurs M, Escandell JM, Maestroni L, Nakamura TM, Ferreira MG, Géli V, Coulon S
The fission yeast Stn1-Ten1 complex limits telomerase activity via its SUMO-interacting motif and promotes telomeres replication.
May 20, 2018
Science Advances
Mammalian CST (CTC1-STN1-TEN1) complex fulfills numerous functions including rescue of the stalled replication forks and termination of telomerase action. In fission yeast lacking the CTC1 ortholog, the Stn1-Ten1 complex restricts telomerase action via its sumoylation-mediated interaction with Tpz1TPP1. We identify a small ubiquitin-like modifier (SUMO)-interacting motif (SIM) in the carboxyl-terminal part of Stn1 and show that this domain is crucial for SUMO and Tpz1-SUMO interactions. Point mutations in the SIM (Stn1-226) lead to telomere elongation, impair Stn1-Ten1 recruitment to telomeres, and enhance telomerase binding, revealing that Stn1 SIM domain contributes to the inhibition of telomerase activity at chromosome ends. Our results suggest that Stn1-Ten1 promotes DNA synthesis at telomeres to limit single-strand DNA accumulation. We further demonstrate that Stn1 functions in the replication of telomeric and subtelomeric regions in a Taz1-independent manner. Genetic analysis reveals that misregulation of origin firing and/or telomerase inhibition circumvents the replication defects of the stn1-226 mutant. Together, our results show that the Stn1-Ten1 complex has a dual function at telomeres by limiting telomerase action and promoting chromosome end replication.
Long non-coding RNAs AC026904.1 and UCA1: a "one-two punch" for TGF-β-induced SNAI2 activation and epithelial-mesenchymal transition in breast cancer.
May 20, 2018   Theranostics
Li GY, Wang W, Sun JY, Xin B, Zhang X, Wang T, Zhang QF, Yao LB, Han H, Fan DM, Yang AG, Jia LT, Wang L
Long non-coding RNAs AC026904.1 and UCA1: a "one-two punch" for TGF-β-induced SNAI2 activation and epithelial-mesenchymal transition in breast cancer.
May 20, 2018
Theranostics
Transforming growth factor-β (TGF-β) has received much attention as a major inducer of epithelial-mesenchymal transition (EMT) during cancer progression, mainly by activating a set of pleiotropic transcription factors including SNAI2/Slug. However, the involvement of long non-coding RNAs (lncRNAs) in TGF-β-induced Slug activation and EMT remains largely unknown. Methods: In this study, we used microarray analysis to compare lncRNA expression profiles between TGF-β treated and untreated breast cancer cells. Then, the clinical significance of lncRNAs in breast cancer was investigated by qPCR and Kaplan-Meier survival analysis. The molecular mechanisms and EMT-promoting effects in vitro were analyzed by confocal laser microscopy, Western blotting, chromosome conformation capture (3C), chromatin isolation by RNA purification (ChIRP), ChIP, luciferase reporter assay and transwell migration assay. Lastly, the pro-metastatic effects in vivo were evaluated by bioluminescent imaging and hematoxylin and eosin (H&E) staining. Results: We observed that TGF-β induced genome-wide changes in lncRNA levels in breast cancer cells, among which AC026904.1 and UCA1 were highly expressed in metastatic breast cancer and closely associated with poor prognosis. Mechanistic study revealed that AC026904.1 and UCA1 were upregulated by non-canonical and canonical TGF-β pathways, respectively. Further analysis showed that AC026904.1 functions as an enhancer RNA in the nucleus, whereas UCA1 exerts a competitive endogenous RNA (ceRNA) activity in the cytoplasm. In addition, the biological functions of these two lncRNAs converged on the activation and maintenance of Slug, constituting a one-two punch in promoting EMT and tumor metastasis. Conclusion: These findings uncover for the first time that AC026904.1 and UCA1 could cooperatively upregulate Slug expression at both transcriptional and post-transcriptional levels, exerting critical roles in TGF-β-induced EMT. The present work provides new evidence that lncRNAs function as key regulators of EMT and hold great promise to be used as novel biomarkers and therapeutic targets for metastatic breast cancer.
NEDD9 promotes oncogenic signaling, a stem/mesenchymal gene signature, and aggressive ovarian cancer growth in mice.
May 26, 2018   Oncogene
Gabbasov R, Xiao F, Howe CG, Bickel LE, O'Brien SW, Benrubi D, Do TV, Zhou Y, Nicolas E, Cai KQ, Litwin S, Seo S, Golemis EA, Connolly DC
NEDD9 promotes oncogenic signaling, a stem/mesenchymal gene signature, and aggressive ovarian cancer growth in mice.
May 26, 2018
Oncogene
Neural precursor cell expressed, developmentally downregulated 9 (NEDD9) supports oncogenic signaling in a number of solid and hematologic tumors. Little is known about the role of NEDD9 in ovarian carcinoma (OC), but available data suggest elevated mRNA and protein expression in advanced stage high-grade cancers. We used a transgenic MISIIR-TAg mouse OC model combined with genetic ablation of Nedd9 to investigate its action in the development and progression of OC. A Nedd9-/- genotype delayed tumor growth rate, reduced incidence of ascites, and reduced expression and activation of signaling proteins including SRC, STAT3, E-cadherin, and AURKA. Cell lines established from MISIIR-TAg;Nedd9-/- and MISIIR-TAg;Nedd9+/+ mice exhibited altered migration and invasion. Growth of these cells in a syngeneic allograft model indicated that systemic Nedd9 loss in the microenvironment had little impact on tumor allograft growth, but in a Nedd9 wild-type background Nedd9-/- allografts exhibited significantly reduced growth, dissemination, and oncogenic signaling compared to Nedd9+/+ allografts. Gene expression analysis revealed that Nedd9+/+ tumors exhibited more mesenchymal "stem-like" transcriptional program, including increased expression of Aldh1a1 and Aldh1a2. Conversely, loss of Nedd9 resulted in increased expression of differentiation genes, including fallopian tube markers Foxj1, Ovgp1, and Pax8. Collectively, these data suggest that tumor cell-intrinsic Nedd9 expression promotes OC development and progression by broad induction of oncogenic protein signaling and stem/mesenchymal gene expression.
C5a induces A549 cell proliferation of non-small cell lung cancer via GDF15 gene activation mediated by GCN5-dependent KLF5 acetylation.
May 18, 2018   Oncogene
Zhao C, Li Y, Qiu W, He F, Zhang W, Zhao D, Zhang Z, Zhang E, Ma P, Liu Y, Ma L, Yang F, Wang Y, Shu Y
C5a induces A549 cell proliferation of non-small cell lung cancer via GDF15 gene activation mediated by GCN5-dependent KLF5 acetylation.
May 18, 2018
Oncogene
Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, and multiple evidence has confirmed that C5a production is elevated in NSCLC microenvironment. Although NSCLC cell proliferation induced by C5a has been reported, the involved mechanism has not been elucidated. In this study, we examined the proliferation-related genes (i.e., KLF5, GCN5, and GDF15) and C5a receptor (C5aR) expression in tumor tissues as well as C5a concentration in plasma of NSCLC patients, and then determined the roles of KLF5, GCN5, and GDF15 in C5a-triggered NSCLC cell proliferation and the related mechanism both in vitro and in vivo. Our results found that the expression of KLF5, GCN5, GDF15, C5aR, and C5a was significantly upregulated in NSCLC patients. Mechanistic exploration in vitro revealed that C5a could facilitate A549 cell proliferation through increasing KLF5, GCN5, and GDF15 expression. Besides, KLF5 and GCN5 could form a complex, binding to GDF15 promoter in a KLF5-dependent manner and leading to GDF15 gene transcription. More importantly, GCN5-mediated KLF5 acetylation contributing to GDF15 gene transcription and cell proliferation upon C5a stimulation, the region (-103 to +58 nt) of GDF15 promoter which KLF5 could bind to, and two new KLF5 lysine sites (K335 and K391) acetylated by GCN5 were identified for the first time. Furthermore, our experiment in vivo demonstrated that the growth of xenograft tumors in BALB/c nude mice was greatly suppressed by the silence of KLF5, GCN5, or GDF15. Collectively, these findings disclose that C5a-driven KLF5-GCN5-GDF15 axis had a critical role in NSCLC proliferation and might serve as targets for NSCLC therapy.
AICAR inhibits NFκB DNA binding independently of AMPK to attenuate LPS-triggered inflammatory responses in human macrophages.
May 25, 2018   Scientific Reports
Kirchner J, Brüne B, Namgaladze D
AICAR inhibits NFκB DNA binding independently of AMPK to attenuate LPS-triggered inflammatory responses in human macrophages.
May 25, 2018
Scientific Reports
5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) is an established pharmacological activator of AMP-activated protein kinase (AMPK). Both, AICAR and AMPK were reported to attenuate inflammation. However, AICAR is known for many AMPK-independent effects, although the mechanisms remain incompletely understood. Here we report a potent suppression of lipopolysaccharide (LPS)-induced inflammatory gene expression by AICAR in primary human macrophages, which occurred independently of its conversion to AMPK-activating 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranosyl monophosphate. Although AICAR did not interfere with activation of cytosolic signalling cascades and nuclear translocation of nuclear factor - κB (NFκB) by LPS, it prevented the recruitment of NFκB and RNA polymerase II to target gene promoters. AICAR also inhibited signal transducer and activator of transcription 3 (STAT3)-dependent induction of interleukin (IL) IL-6 and IL-10 targets, while leaving STAT6 and HIF1α-dependent gene expression in IL-4 and dimethyloxalylgylcine-treated macrophages intact. This points to a transcription factor-specific mode of action. Attenuated gene expression correlated with impaired NFκB and STAT3, but not HIF-binding in electrophoretic mobility shift assays in vitro. Conclusively, AICAR interferes with DNA binding of NFκB and STAT3 to modulate inflammatory responses.
Single Nucleotide Polymorphisms in the G-Protein Coupled Receptor Kinase 5 (GRK5) Gene are associated with Plasma LDL-Cholesterol Levels in Humans.
May 25, 2018   Scientific Reports
Lutz SZ, Falcenberg M, Machicao F, Peter A, Kächele M,   . . . . . .   , Fritsche A, Stefan N, Häring HU, Staiger H, Kantartzis K
Single Nucleotide Polymorphisms in the G-Protein Coupled Receptor Kinase 5 (GRK5) Gene are associated with Plasma LDL-Cholesterol Levels in Humans.
May 25, 2018
Scientific Reports
Genetically modified mice models suggest an important role for G-protein-coupled receptor kinase 5 (GRK5) in the pathophysiology of obesity and related disorders. We investigated whether single nucleotide polymorphisms (SNPs) in the gene encoding GRK5 affect cardiometabolic traits in humans. We genotyped 3 common SNPs in intron 1 (rs1980030, rs10466210, rs9325562) and one SNP in intron 3 (rs10886471) of GRK5 in 2332 subjects at risk for type 2 diabetes. Total- and visceral fat mass were measured by magnetic resonance (MR) tomography and liver fat content by 1H-MR spectroscopy. Insulin secretion and sensitivity were estimated during an OGTT and measured during the euglycemic, hyperinsulinemic clamp (n = 498). Carriers of the minor allele of rs10466210 and rs1980030 had higher total- and LDL-cholesterol levels (p = 0.0018 and p = 0.0031, respectively, for rs10466210; p = 0.0035 and p = 0.0081, respectively, for rs1980030), independently of gender, age, BMI and lipid-lowering drugs. The effects of rs10466210 withstood Bonferroni correction. Similar associations were observed with apolipoprotein B levels (p = 0.0034 and p = 0.0122, respectively). Carriers of the minor allele of rs10466210 additionally displayed a trend for higher intima-media thickness of the carotid artery (p = 0.075). GRK5 may represent a novel target for strategies aiming at lowering LDL-cholesterol levels and at modifying cardiovascular risk.
Quantitative SUMO proteomics reveals the modulation of several PML nuclear body associated proteins and an anti-senescence function of UBC9.
May 25, 2018   Scientific Reports
McManus FP, Bourdeau V, Acevedo M, Lopes-Paciencia S, Mignacca L, Lamoliatte F, Rojas Pino JW, Ferbeyre G, Thibault P
Quantitative SUMO proteomics reveals the modulation of several PML nuclear body associated proteins and an anti-senescence function of UBC9.
May 25, 2018
Scientific Reports
Several regulators of SUMOylation have been previously linked to senescence but most targets of this modification in senescent cells remain unidentified. Using a two-step purification of a modified SUMO3, we profiled the SUMO proteome of senescent cells in a site-specific manner. We identified 25 SUMO sites on 23 proteins that were significantly regulated during senescence. Of note, most of these proteins were PML nuclear body (PML-NB) associated, which correlates with the increased number and size of PML-NBs observed in senescent cells. Interestingly, the sole SUMO E2 enzyme, UBC9, was more SUMOylated during senescence on its Lys-49. Functional studies of a UBC9 mutant at Lys-49 showed a decreased association to PML-NBs and the loss of UBC9's ability to delay senescence. We thus propose both pro- and anti-senescence functions of protein SUMOylation.
X-ray structure of a carpet-like antimicrobial defensin-phospholipid membrane disruption complex.
May 22, 2018   Nature Communications
Järvå M, Lay FT, Phan TK, Humble C, Poon IKH, Bleackley MR, Anderson MA, Hulett MD, Kvansakul M
X-ray structure of a carpet-like antimicrobial defensin-phospholipid membrane disruption complex.
May 22, 2018
Nature Communications
Defensins are cationic antimicrobial peptides expressed throughout the plant and animal kingdoms as a first line of defense against pathogens. Membrane targeting and disruption is a crucial function of many defensins, however the precise mechanism remains unclear. Certain plant defensins form dimers that specifically bind the membrane phospholipids phosphatidic acid (PA) and phosphatidylinositol 4,5-bisphosphate, thereby triggering the assembly of defensin-lipid oligomers that permeabilize cell membranes. To understand this permeabilization mechanism, here we determine the crystal structure of the plant defensin NaD1 bound to PA. The structure reveals a 20-mer that adopts a concave sheet- or carpet-like topology where NaD1 dimers form one face and PA acyl chains form the other face of the sheet. Furthermore, we show that Arg39 is critical for PA binding, oligomerization and fungal cell killing. These findings identify a putative defensin-phospholipid membrane attack configuration that supports a longstanding proposed carpet mode of membrane disruption.
Effectiveness of a flow-based device using riboflavin photochemistry in damaging blood-borne viral nucleic acids.
May 26, 2018   Journal Of Photochemistry And Photobiology. B, Biology
Zhu L, Tong H, Wang S, Yu Y, Liu Z, Li C, Wang D
Effectiveness of a flow-based device using riboflavin photochemistry in damaging blood-borne viral nucleic acids.
May 26, 2018
Journal Of Photochemistry And Photobiology. B, Biology
BACKGROUND: Effectiveness of a flow-based treatment device using riboflavin photochemistry was demonstrated by cytopathic effect method using indicator viruses. However, inactivation efficacy against real blood-borne viruses needs to be evaluated, especially at nucleic acid level. MATERIAL AND METHODS: Special plasma samples with varying concentrations of blood-borne virus were selected using a strict blood selection procedure and were treated with device treatment (DT). Nucleic acid test (NAT) using polymerase chain reaction fluorescence method was used to detect virus copies. RESULTS: The NAT value of 4325 in plasma with high Hepatitis B Virus (HBV) concentrations decreased to 1330 with DT. After 100-fold dilution, the NAT value was below the NAT detection limits with DT compared with 23.0 that without DT. The NAT value of 61.9 in plasma with medium HBV concentrations decreased to 37.8 with DT, and after 10-fold dilution, the NAT value was below the NAT detection limits with DT compared with below 20 that without DT. The Ct values of plasma with low concentrations of blood-borne viruses were below the NAT detection limits with DT. CONCLUSION: There was a dose effect with DT which was effective in blood-borne viruses damaging nucleic acids to a level below the NAT detection limits.

The link you entered does not seem to be valid

Please make sure the link points to nature.com contains a valid shared_access_token

Downloading PDF to your library...

Uploading PDF...

PDF uploading

Delete tag: