17 results on '"Geng S"'
Search Results
2. Highly potent and broadly neutralizing anti-CD4 trimeric nanobodies inhibit HIV-1 infection by inducing CD4 conformational alteration.
- Author
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Zhu L, Huang B, Wang X, Ni F, Ao M, Wang R, Zheng B, Chen C, Xue J, Zhu L, Yang C, Shi L, Geng S, Hu J, Yang M, Zhang D, Yang P, Li M, Li Y, Hu Q, Ye S, Zheng P, Wei H, Wu Z, Zhang L, Wang Y, Liu Y, and Wu X
- Subjects
- Animals, Humans, Mice, Antibodies, Neutralizing immunology, Antibodies, Neutralizing pharmacology, Protein Conformation, Female, Virus Internalization drug effects, HEK293 Cells, Anti-HIV Agents pharmacology, Anti-HIV Agents therapeutic use, Antibodies, Monoclonal, HIV-1 immunology, HIV-1 drug effects, Single-Domain Antibodies pharmacology, Single-Domain Antibodies immunology, CD4 Antigens immunology, CD4 Antigens metabolism, HIV Infections immunology, HIV Infections drug therapy, HIV Infections virology, Camelids, New World immunology, HIV Antibodies immunology, HIV Antibodies pharmacology
- Abstract
Despite advancements in antiretroviral therapy (ART) suppressing HIV-1 replication, existing antiviral drugs pose limitations, including lifelong medication, frequent administration, side effects and viral resistance, necessitating novel HIV-1 treatment approaches. CD4, pivotal for HIV-1 entry, poses challenges for drug development due to neutralization and cytotoxicity concerns. Nevertheless, Ibalizumab, the sole approved CD4-specific antibody for HIV-1 treatment, reignites interest in exploring alternative anti-HIV targets, emphasizing CD4's potential value for effective drug development. Here, we explore anti-CD4 nanobodies, particularly Nb457 from a CD4-immunized alpaca. Nb457 displays high potency and broad-spectrum activity against HIV-1, surpassing Ibalizumab's efficacy. Strikingly, engineered trimeric Nb457 nanobodies achieve complete inhibition against live HIV-1, outperforming Ibalizumab and parental Nb457. Structural analysis unveils Nb457-induced CD4 conformational changes impeding viral entry. Notably, Nb457 demonstrates therapeutic efficacy in humanized female mouse models. Our findings highlight anti-CD4 nanobodies as promising HIV-1 therapeutics, with potential implications for advancing clinical treatment against this global health challenge., (© 2024. The Author(s).)
- Published
- 2024
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3. Single-atom Mo-tailored high-entropy-alloy ultrathin nanosheets with intrinsic tensile strain enhance electrocatalysis.
- Author
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He L, Li M, Qiu L, Geng S, Liu Y, Tian F, Luo M, Liu H, Yu Y, Yang W, and Guo S
- Abstract
The precise structural integration of single-atom and high-entropy-alloy features for energy electrocatalysis is highly appealing for energy conversion, yet remains a grand challenge. Herein, we report a class of single-atom Mo-tailored PdPtNiCuZn high-entropy-alloy nanosheets with dilute Pt-Pt ensembles and intrinsic tensile strain (Mo
1 -PdPtNiCuZn) as efficient electrocatalysts for enhancing the methanol oxidation reaction catalysis. The as-made Mo1 -PdPtNiCuZn delivers an extraordinary mass activity of 24.55 A mgPt -1 and 11.62 A mgPd+Pt -1 , along with impressive long-term durability. The planted oxophilic Mo single atoms as promoters modify the electronic structure of isolated Pt sites in the high-entropy-alloy host, suppressing the formation of CO adsorbates and steering the reaction towards the formate pathway. Meanwhile, Mo promoters and tensile strain synergistically optimize the adsorption behaviour of intermediates to achieve a more energetically favourable pathway and minimize the methanol oxidation reaction barrier. This work advances the design of atomically precise catalytic sites by creating a new paradigm of single atom-tailored high-entropy alloys, opening an encouraging pathway to the design of CO-tolerance electrocatalysts., (© 2024. The Author(s).)- Published
- 2024
- Full Text
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4. High-strength and crack-free welding of 2024 aluminium alloy via Zr-core-Al-shell wire.
- Author
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Jin J, Geng S, Shu L, Jiang P, Shao X, Han C, Ren L, Li Y, Yang L, and Wang X
- Abstract
The 2000 series aluminium alloys are qualified for widespread use in lightweight structures, but solidification cracking during fusion welding has been a long-standing issue. Here, we create a zirconium (Zr)-core-aluminium (Al)-shell wire (ZCASW) and employ the oscillating laser-arc hybrid welding technique to control solidification during welding, and ultimately achieve reliable and crack-free welding of 2024 aluminium alloy. We select Zr wires with an ideal lattice match to Al based on crystallographic information and wind them by the Al wires with similar chemical components to the parent material. Crack-free, equiaxed (where the length, width and height of the grains are roughly equal), fine-grained microstructures are acquired, thereby considerably increasing the tensile strength over that of conventional fusion welding joints, and even comparable to that of friction stir welding joints. This work has important engineering application value in welding of high-strength aluminum alloys., (© 2024. The Author(s).)
- Published
- 2024
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5. A rechargeable Ca/Cl 2 battery.
- Author
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Geng S, Zhao X, Xu Q, Yuan B, Wang Y, Liao M, Ye L, Wang S, Ouyang Z, Wu L, Wang Y, Ma C, Zhao X, and Sun H
- Abstract
Rechargeable calcium (Ca) metal batteries are promising candidates for sustainable energy storage due to the abundance of Ca in Earth's crust and the advantageous theoretical capacity and voltage of these batteries. However, the development of practical Ca metal batteries has been severely hampered by the current cathode chemistries, which limit the available energy and power densities, as well as their insufficient capacity retention and low-temperature capability. Here, we describe the rechargeable Ca/Cl
2 battery based on a reversible cathode redox reaction between CaCl2 and Cl2 , which is enabled by the use of lithium difluoro(oxalate)borate as a key electrolyte mediator to facilitate the dissociation and distribution of Cl-based species and Ca2+ . Our rechargeable Ca/Cl2 battery can deliver discharge voltages of 3 V and exhibits remarkable specific capacity (1000 mAh g-1 ) and rate capability (500 mA g-1 ). In addition, the excellent capacity retention (96.5% after 30 days) and low-temperature capability (down to 0 °C) allow us to overcome the long-standing bottleneck of rechargeable Ca metal batteries., (© 2024. The Author(s).)- Published
- 2024
- Full Text
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6. Hydrogel dressing integrating FAK inhibition and ROS scavenging for mechano-chemical treatment of atopic dermatitis.
- Author
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Jia Y, Hu J, An K, Zhao Q, Dang Y, Liu H, Wei Z, Geng S, and Xu F
- Subjects
- Mice, Animals, Reactive Oxygen Species, Pruritus complications, Hydrogels adverse effects, Focal Adhesion Protein-Tyrosine Kinases, Skin, Inflammation complications, Bandages, Dermatitis, Atopic drug therapy
- Abstract
Atopic dermatitis (AD) is a chronic skin disease caused by skin immune dyshomeostasis and accompanied by severe pruritus. Although oxidative stress and mechanical scratching can aggravate AD inflammation, treatment targeting scratching is often overlooked, and the efficiency of mechano-chemically synergistic therapy remains unclear. Here, we find that enhanced phosphorylation of focal adhesion kinase (FAK) is associated with scratch-exacerbated AD. We then develop a multifunctional hydrogel dressing that integrates oxidative stress modulation with FAK inhibition to synergistically treat AD. We show that the adhesive, self-healing and antimicrobial hydrogel is suitable for the unique scratching and bacterial environment of AD skin. We demonstrate that it can scavenge intracellular reactive oxygen species and reduce mechanically induced intercellular junction deficiency and inflammation. Furthermore, in mouse AD models with controlled scratching, we find that the hydrogel alleviates AD symptoms, rebuilds the skin barrier, and inhibits inflammation. These results suggest that the hydrogel integrating reactive oxygen species scavenging and FAK inhibition could serve as a promising skin dressing for synergistic AD treatment., (© 2023. The Author(s).)
- Published
- 2023
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7. Multifunctional solvent molecule design enables high-voltage Li-ion batteries.
- Author
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Zhang J, Zhang H, Weng S, Li R, Lu D, Deng T, Zhang S, Lv L, Qi J, Xiao X, Fan L, Geng S, Wang F, Chen L, Noked M, Wang X, and Fan X
- Abstract
Elevating the charging cut-off voltage is one of the efficient approaches to boost the energy density of Li-ion batteries (LIBs). However, this method is limited by the occurrence of severe parasitic reactions at the electrolyte/electrode interfaces. Herein, to address this issue, we design a non-flammable fluorinated sulfonate electrolyte by multifunctional solvent molecule design, which enables the formation of an inorganic-rich cathode electrolyte interphase (CEI) on high-voltage cathodes and a hybrid organic/inorganic solid electrolyte interphase (SEI) on the graphite anode. The electrolyte, consisting of 1.9 M LiFSI in a 1:2 v/v mixture of 2,2,2-trifluoroethyl trifluoromethanesulfonate and 2,2,2-trifluoroethyl methanesulfonate, endows 4.55 V-charged graphite||LiCoO
2 and 4.6 V-charged graphite||NCM811 batteries with capacity retentions of 89% over 5329 cycles and 85% over 2002 cycles, respectively, thus resulting in energy density increases of 33% and 16% compared to those charged to 4.3 V. This work demonstrates a practical strategy for upgrading the commercial LIBs., (© 2023. The Author(s).)- Published
- 2023
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8. Tumor-intrinsic YTHDF1 drives immune evasion and resistance to immune checkpoint inhibitors via promoting MHC-I degradation.
- Author
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Lin W, Chen L, Zhang H, Qiu X, Huang Q, Wan F, Le Z, Geng S, Zhang A, Qiu S, Chen L, Kong L, and Lu JJ
- Subjects
- Histocompatibility Antigens Class I metabolism, HLA Antigens, RNA-Binding Proteins genetics, RNA-Binding Proteins metabolism, Animals, Immune Checkpoint Inhibitors pharmacology, Immune Evasion, Neoplasms drug therapy, Neoplasms genetics
- Abstract
The recently described role of RNA methylation in regulating immune cell infiltration into tumors has attracted interest, given its potential impact on immunotherapy response. YTHDF1 is a versatile and powerful m6A reader, but the understanding of its impact on immune evasion is limited. Here, we reveal that tumor-intrinsic YTHDF1 drives immune evasion and immune checkpoint inhibitor (ICI) resistance. Additionally, YTHDF1 deficiency converts cold tumors into responsive hot tumors, which improves ICI efficacy. Mechanistically, YTHDF1 deficiency inhibits the translation of lysosomal genes and limits lysosomal proteolysis of the major histocompatibility complex class I (MHC-I) and antigens, ultimately restoring tumor immune surveillance. In addition, we design a system for exosome-mediated CRISPR/Cas9 delivery to target YTHDF1 in vivo, resulting in YTHDF1 depletion and antitumor activity. Our findings elucidate the role of tumor-intrinsic YTHDF1 in driving immune evasion and its underlying mechanism., (© 2023. The Author(s).)
- Published
- 2023
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9. STAG2 regulates interferon signaling in melanoma via enhancer loop reprogramming.
- Author
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Chu Z, Gu L, Hu Y, Zhang X, Li M, Chen J, Teng D, Huang M, Shen CH, Cai L, Yoshida T, Qi Y, Niu Z, Feng A, Geng S, Frederick DT, Specht E, Piris A, Sullivan RJ, Flaherty KT, Boland GM, Georgopoulos K, Liu D, Shi Y, and Zheng B
- Subjects
- Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Genome, Humans, Interferons genetics, Chromosomal Proteins, Non-Histone genetics, Chromosomal Proteins, Non-Histone metabolism, Melanoma genetics
- Abstract
The cohesin complex participates in the organization of 3D genome through generating and maintaining DNA loops. Stromal antigen 2 (STAG2), a core subunit of the cohesin complex, is frequently mutated in various cancers. However, the impact of STAG2 inactivation on 3D genome organization, especially the long-range enhancer-promoter contacts and subsequent gene expression control in cancer, remains poorly understood. Here we show that depletion of STAG2 in melanoma cells leads to expansion of topologically associating domains (TADs) and enhances the formation of acetylated histone H3 lysine 27 (H3K27ac)-associated DNA loops at sites where binding of STAG2 is switched to its paralog STAG1. We further identify Interferon Regulatory Factor 9 (IRF9) as a major direct target of STAG2 in melanoma cells via integrated RNA-seq, STAG2 ChIP-seq and H3K27ac HiChIP analyses. We demonstrate that loss of STAG2 activates IRF9 through modulating the 3D genome organization, which in turn enhances type I interferon signaling and increases the expression of PD-L1. Our findings not only establish a previously unknown role of the STAG2 to STAG1 switch in 3D genome organization, but also reveal a functional link between STAG2 and interferon signaling in cancer cells, which may enhance the immune evasion potential in STAG2-mutant cancer., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
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10. A top-down strategy for amorphization of hydroxyl compounds for electrocatalytic oxygen evolution.
- Author
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Liu S, Geng S, Li L, Zhang Y, Ren G, Huang B, Hu Z, Lee JF, Lai YH, Chu YH, Xu Y, Shao Q, and Huang X
- Abstract
Amorphous materials have attracted increasing attention in diverse fields due to their unique properties, yet their controllable fabrications still remain great challenges. Here, we demonstrate a top-down strategy for the fabrications of amorphous oxides through the amorphization of hydroxides. The versatility of this strategy has been validated by the amorphizations of unitary, binary and ternary hydroxides. Detailed characterizations indicate that the amorphization process is realized by the variation of coordination environment during thermal treatment, where the M-OH octahedral structure in hydroxides evolves to M-O tetrahedral structure in amorphous oxides with the disappearance of the M-M coordination. The optimal amorphous oxide (FeCoSn(OH)
6 -300) exhibits superior oxygen evolution reaction (OER) activity in alkaline media, where the turnover frequency (TOF) value is 39.4 times higher than that of FeCoSn(OH)6 . Moreover, the enhanced OER performance and the amorphization process are investigated with density functional theory (DFT) and molecule dynamics (MD) simulations. The reported top-down fabrication strategy for fabricating amorphous oxides, may further promote fundamental research into and practical applications of amorphous materials for catalysis., (© 2022. The Author(s).)- Published
- 2022
- Full Text
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11. Iridium metallene oxide for acidic oxygen evolution catalysis.
- Author
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Dang Q, Lin H, Fan Z, Ma L, Shao Q, Ji Y, Zheng F, Geng S, Yang SZ, Kong N, Zhu W, Li Y, Liao F, Huang X, and Shao M
- Abstract
Exploring new materials is essential in the field of material science. Especially, searching for optimal materials with utmost atomic utilization, ideal activities and desirable stability for catalytic applications requires smart design of materials' structures. Herein, we report iridium metallene oxide: 1 T phase-iridium dioxide (IrO
2 ) by a synthetic strategy combining mechanochemistry and thermal treatment in a strong alkaline medium. This material demonstrates high activity for oxygen evolution reaction with a low overpotential of 197 millivolt in acidic electrolyte at 10 milliamperes per geometric square centimeter (mA cmgeo ). Together, it achieves high turnover frequencies of 4.2 s-2 (3.0 sUPD -1 (3.0 sBET -1 ) at 1.50 V vs. reversible hydrogen electrode. Furthermore, 1T-IrO2 also shows little degradation after 126 hours chronopotentiometry measurement under the high current density of 250 mA cmgeo -2 in proton exchange membrane device. Theoretical calculations reveal that the active site of Ir in 1T-IrO2 provides an optimal free energy uphill in *OH formation, leading to the enhanced performance. The discovery of this 1T-metallene oxide material will provide new opportunities for catalysis and other applications., (© 2021. The Author(s).)- Published
- 2021
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12. Simultaneous Zn 2+ tracking in multiple organelles using super-resolution morphology-correlated organelle identification in living cells.
- Author
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Fang H, Geng S, Hao M, Chen Q, Liu M, Liu C, Tian Z, Wang C, Takebe T, Guan JL, Chen Y, Guo Z, He W, and Diao J
- Subjects
- Autophagosomes metabolism, Autophagy, Carbonyl Cyanide m-Chlorophenyl Hydrazone pharmacology, Cell Survival, Endoplasmic Reticulum metabolism, Fluorescent Dyes metabolism, HeLa Cells, Humans, Induced Pluripotent Stem Cells metabolism, Intracellular Space metabolism, Lysosomes metabolism, Molecular Probes chemistry, Molecular Probes metabolism, Naphthalimides metabolism, Organoids metabolism, Spectrometry, Fluorescence, Cell Tracking, Organelles metabolism, Zinc metabolism
- Abstract
Zn
2+ plays important roles in metabolism and signaling regulation. Subcellular Zn2+ compartmentalization is essential for organelle functions and cell biology, but there is currently no method to determine Zn2+ signaling relationships among more than two different organelles with one probe. Here, we report simultaneous Zn2+ tracking in multiple organelles (Zn-STIMO), a method that uses structured illumination microscopy (SIM) and a single Zn2+ fluorescent probe, allowing super-resolution morphology-correlated organelle identification in living cells. To guarantee SIM imaging quality for organelle identification, we develop a new turn-on Zn2+ fluorescent probe, NapBu-BPEA, by regulating the lipophilicity of naphthalimide-derived Zn2+ probes to make it accumulate in multiple organelles except the nucleus. Zn-STIMO with this probe shows that CCCP-induced mitophagy in HeLa cells is associated with labile Zn2+ enhancement. Therefore, direct organelle identification supported by SIM imaging makes Zn-STIMO a reliable method to determine labile Zn2+ dynamics in various organelles with one probe. Finally, SIM imaging of pluripotent stem cell-derived organoids with NapBu-BPEA demonstrates the potential of super-resolution morphology-correlated organelle identification to track biospecies and events in specific organelles within organoids.- Published
- 2021
- Full Text
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13. A dual-labeling probe to track functional mitochondria-lysosome interactions in live cells.
- Author
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Chen Q, Fang H, Shao X, Tian Z, Geng S, Zhang Y, Fan H, Xiang P, Zhang J, Tian X, Zhang K, He W, Guo Z, and Diao J
- Subjects
- Fluorescence Recovery After Photobleaching methods, Fluorescent Dyes chemistry, HeLa Cells, Humans, Lysosomes chemistry, Microscopy, Fluorescence methods, Mitochondria chemistry, Molecular Probe Techniques, Photobleaching, Intravital Microscopy methods, Lysosomes metabolism, Mitochondria metabolism, Mitophagy, Molecular Probes chemistry
- Abstract
Mitochondria-lysosome interactions are essential for maintaining intracellular homeostasis. Although various fluorescent probes have been developed to visualize such interactions, they remain unable to label mitochondria and lysosomes simultaneously and dynamically track their interaction. Here, we introduce a cell-permeable, biocompatible, viscosity-responsive, small organic molecular probe, Coupa, to monitor the interaction of mitochondria and lysosomes in living cells. Through a functional fluorescence conversion, Coupa can simultaneously label mitochondria with blue fluorescence and lysosomes with red fluorescence, and the correlation between the red-blue fluorescence intensity indicates the progress of mitochondria-lysosome interplay during mitophagy. Moreover, because its fluorescence is sensitive to viscosity, Coupa allowed us to precisely localize sites of mitochondria-lysosome contact and reveal increases in local viscosity on mitochondria associated with mitochondria-lysosome contact. Thus, our probe represents an attractive tool for the localization and dynamic tracking of functional mitochondria-lysosome interactions in living cells.
- Published
- 2020
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14. Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO 4+δ .
- Author
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Li J, Pan F, Geng S, Lin C, Palatinus L, Allix M, Kuang X, Lin J, and Sun J
- Abstract
CeNbO
4+δ , a family of oxygen hyperstoichiometry materials with varying oxygen content (CeNbO4 , CeNbO4.08 , CeNbO4.25 , CeNbO4.33 ) that shows mixed electronic and oxide ionic conduction, has been known for four decades. However, the oxide ionic transport mechanism has remained unclear due to the unknown atomic structures of CeNbO4.08 and CeNbO4.33 . Here, we report the complex (3 + 1)D incommensurately modulated structure of CeNbO4.08 , and the supercell structure of CeNbO4.33 from single nanocrystals by using a three-dimensional electron diffraction technique. Two oxide ion migration events are identified in CeNbO4.08 and CeNbO4.25 by molecular dynamics simulations, which was a synergic-cooperation knock-on mechanism involving continuous breaking and reformation of Nb2 O9 units. However, the excess oxygen in CeNbO4.33 hardly migrates because of the high concentration and the ordered distribution of the excess oxide ions. The relationship between the structure and oxide ion migration for the whole series of CeNbO4+δ compounds elucidated here provides a direction for the performance optimization of these compounds.- Published
- 2020
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15. Regulation of FT splicing by an endogenous cue in temperate grasses.
- Author
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Qin Z, Wu J, Geng S, Feng N, Chen F, Kong X, Song G, Chen K, Li A, Mao L, and Wu L
- Subjects
- 14-3-3 Proteins genetics, 14-3-3 Proteins metabolism, Brachypodium metabolism, Florigen metabolism, Flowers metabolism, Hordeum genetics, Hordeum metabolism, Plant Proteins metabolism, Plants, Genetically Modified, Protein Binding, Protein Isoforms genetics, Protein Isoforms metabolism, RNA Splicing, Time Factors, Transcription Factors genetics, Transcription Factors metabolism, Triticum genetics, Triticum metabolism, Brachypodium genetics, Flowers genetics, Gene Expression Regulation, Plant, Plant Proteins genetics
- Abstract
Appropriate flowering timing is crucial for plant reproductive success. The florigen, FLOWERING LOCUS T (FT), interacts with 14-3-3 proteins and the bZIP transcription factor FD, functioning at core nodes in multiple flowering pathways. There are two FT homologues, FT1 and FT2, in Brachypodium distachyon. Here we show that FT2 undergoes age-dependent alternative splicing (AS), resulting in two splice variants (FT2α and FT2β). The FT2β-encoded protein cannot interact with FD or 14-3-3s but is able to form heterodimers with FT2α and FT1, thereby interfering with the florigen-mediated assembly of the flowering initiation complex. Notably, transgenic plants overproducing FT2β exhibit delayed flowering, while transgenic plants in which FT2β is silenced by an artificial microRNA display accelerated flowering, demonstrating a dominant-negative role of FT2β in flowering induction. Furthermore, we show that the AS splicing of FT2 is conserved in important cereal crops, such as barley and wheat. Collectively, these findings reveal a novel posttranscriptional mode of FT regulation in temperate grasses., Competing Interests: The authors declare no competing financial interests.
- Published
- 2017
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16. The persistence of low-grade inflammatory monocytes contributes to aggravated atherosclerosis.
- Author
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Geng S, Chen K, Yuan R, Peng L, Maitra U, Diao N, Chen C, Zhang Y, Hu Y, Qi CF, Pierce S, Ling W, Xiong H, and Li L
- Subjects
- Animals, Atherosclerosis metabolism, Base Sequence, Cell Polarity, Disease Progression, Endotoxemia metabolism, Homeostasis, Inflammation metabolism, Interleukin-1 Receptor-Associated Kinases deficiency, Interleukin-1 Receptor-Associated Kinases metabolism, Lipopolysaccharides, Mice, Inbred C57BL, MicroRNAs metabolism, Monocytes metabolism, Scavenger Receptors, Class B metabolism, Smad4 Protein metabolism, Atherosclerosis pathology, Endotoxemia pathology, Inflammation pathology, Monocytes pathology
- Abstract
Sustained low-grade inflammation mediated by non-resolving inflammatory monocytes has long been suspected in the pathogenesis of atherosclerosis; however, the molecular mechanisms responsible for the sustainment of non-resolving inflammatory monocytes during atherosclerosis are poorly understood. Here we observe that subclinical endotoxemia, often seen in humans with chronic inflammation, aggravates murine atherosclerosis through programming monocytes into a non-resolving inflammatory state with elevated Ly6C, CCR5, MCP-1 and reduced SR-B1. The sustainment of inflammatory monocytes is due to the disruption of homeostatic tolerance through the elevation of miR-24 and reduction of the key negative-feedback regulator IRAK-M. miR-24 reduces the levels of Smad4 required for the expression of IRAK-M and also downregulates key lipid-processing molecule SR-B1. IRAK-M deficiency in turn leads to elevated miR-24 levels, sustains disruption of monocyte homeostasis and aggravates atherosclerosis. Our data define an integrated feedback circuit in monocytes and its disruption may lead to non-resolving low-grade inflammation conducive to atherosclerosis.
- Published
- 2016
- Full Text
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17. Myeloid cell-derived inducible nitric oxide synthase suppresses M1 macrophage polarization.
- Author
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Lu G, Zhang R, Geng S, Peng L, Jayaraman P, Chen C, Xu F, Yang J, Li Q, Zheng H, Shen K, Wang J, Liu X, Wang W, Zheng Z, Qi CF, Si C, He JC, Liu K, Lira SA, Sikora AG, Li L, and Xiong H
- Subjects
- Animals, Cell Polarity drug effects, Disease Models, Animal, Interferon Regulatory Factors metabolism, Lysine analogs & derivatives, Lysine pharmacology, Macrophage Activation, Macrophages cytology, Macrophages drug effects, Mice, Mice, Inbred C57BL, Mice, Knockout, Myeloid Cells cytology, Myeloid Cells immunology, Myeloid Cells metabolism, Nitric Oxide Donors pharmacology, Nitric Oxide Synthase antagonists & inhibitors, Nitric Oxide Synthase Type II genetics, Nitric Oxide Synthase Type II metabolism, Phenotype, S-Nitroso-N-Acetylpenicillamine pharmacology, Cell Polarity genetics, Macrophages immunology, Nitric Oxide Synthase Type II immunology, Shock, Septic immunology
- Abstract
Here we show that iNOS-deficient mice display enhanced classically activated M1 macrophage polarization without major effects on alternatively activated M2 macrophages. eNOS and nNOS mutant mice show comparable M1 macrophage polarization compared with wild-type control mice. Addition of N6-(1-iminoethyl)-L-lysine dihydrochloride, an iNOS inhibitor, significantly enhances M1 macrophage polarization while S-nitroso-N-acetylpenicillamine, a NO donor, suppresses M1 macrophage polarization. NO derived from iNOS mediates nitration of tyrosine residues in IRF5 protein, leading to the suppression of IRF5-targeted M1 macrophage signature gene activation. Computational analyses corroborate a circuit that fine-tunes the expression of IL-12 by iNOS in macrophages, potentially enabling versatile responses based on changing microenvironments. Finally, studies of an experimental model of endotoxin shock show that iNOS deficiency results in more severe inflammation with an enhanced M1 macrophage activation phenotype. These results suggest that NO derived from iNOS in activated macrophages suppresses M1 macrophage polarization.
- Published
- 2015
- Full Text
- View/download PDF
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