Exosomal lncRNA NEAT1 Inhibits NK-Cell Activity to Promote Multiple Myeloma Cell Immune Escape via an EZH2/PBX1 Axis.

Exosomal long noncoding RNAs (lncRNA) derived from cancer cells are implicated in various processes, including cancer cell proliferation, metastasis, and immunomodulation. We investigated the role and underlying mechanism of exosome-transmitted lncRNA NEAT1 in the immune escape of multiple myeloma cells from natural killer (NK) cells. Multiple myeloma cells and samples from patients with multiple myeloma were obtained. The effects of multiple myeloma cell-derived exosomes (multiple myeloma exosomes) and exosomal NEAT1 on the functions of NK cells were evaluated using EdU staining, CCK-8, flow cytometry, and ELISA. Chromatin and RNA immunoprecipitation were performed to identify interactions between NEAT1, enhancer of Zeste Homolog 2 (EZH2), and pre-B-cell leukemia transcription factor 1 (PBX1). A xenograft tumor model was constructed to verify the effects of exosomal NEAT1 on tumor growth. qRT-PCR, Western blot analysis, and IHC were conducted to detect related genes. NEAT1 levels were upregulated in multiple myeloma tumor tissues, multiple myeloma cells, and multiple myeloma exosomes. Multiple myeloma exosomes suppressed cell proliferation, promoted apoptosis, reduced natural killer group 2, member D (NKG2D)-positive cells, and the production of TNFα) and interferon-gamma (IFN-γ) in NK cells, whereas NEAT1-silenced exosomes had little effect. NEAT1 silenced PBX1 by recruiting EZH2. PBX1 knockdown abrogated the effects of NEAT1-silenced exosomes on NK and multiple myeloma cells. NEAT1-silenced exosomes inhibited tumor growth in mice, decreased Ki67 and PD-L1, and increased NKG2D, TNFα, and IFNγ in tumor tissues. In summary, multiple myeloma cell-derived exosomal NEAT1 suppressed NK-cell activity by downregulating PBX1, promoting multiple myeloma cell immune escape. This study suggests a potential strategy for treating multiple myeloma. IMPLICATIONS: This study reveals that exosomal NEAT1 regulates EZH2/PBX1 axis to inhibit NK-cell activity, thereby promoting multiple myeloma cell immune escape, which offers a novel therapeutic potential for multiple myeloma.

Effects of Fiber Loading on Mechanical Properties of Kenaf Nanocellulose Reinforced Nanohybrid Dental Composite Made of Rice Husk Silica.

The innovation of nanocellulose as reinforcement filler in composites has been a topic of interest in the development of new biomaterials. The objective of this study was to investigate the mechanical properties of a nanohybrid dental composite made of rice husk silica and loaded with different percentages of kenaf nanocellulose. Kenaf cellulose nanocrystals (CNC) were isolated and characterized using a transmission electron microscope (TEM) (Libra 120, Carl Zeiss, Germany). The experimental composite was fabricated with fiber loadings of 1 wt%, 2 wt%, 3 wt%, 4 wt%, and 6 wt% silane-treated kenaf CNC, and subjected to a flexural and compressive strength test (n = 7) using an Instron Universal Testing Machine (Shimadzu, Kyoto, Japan), followed by a scanning electron microscopic assessment of the flexural specimen's fracture surface using a scanning electron microscope (SEM) (FEI Quanta FEG 450, Hillsborough, OR, USA). Commercial composites Filtek Z350XT (3M ESPE, St. Paul, MN, USA), Neofil (Kerr Corporation, Orange, CA, USA) and Ever-X Posterior (GC Corporation, Tokyo, Japan) were used as a comparison. The average diameter of kenaf CNC under TEM was 6 nm. For flexural and compressive strength tests, one-way ANOVA showed a statistically significant difference (p < 0.05) between all groups. Compared to the control group (0 wt%), the incorporation of kenaf CNC (1 wt%) into rice husk silica nanohybrid dental composite showed a slight improvement in mechanical properties and modes of reinforcement, which was reflected in SEM images of the fracture surface. The optimum dental composite reinforcement made of rice husk was 1 wt% kenaf CNC. Excessive fiber loading results in a decline in mechanical properties. CNC derived from natural sources may be a viable alternative as a reinforcement co-filler at low concentrations.

Transcription factor Klf9 controls bile acid reabsorption and enterohepatic circulation in mice via promoting intestinal Asbt expression.

Bile acid (BA) homeostasis is regulated by the extensive cross-talk between liver and intestine. Many bile-acid-activated signaling pathways have become attractive therapeutic targets for the treatment of metabolic disorders. In this study we investigated the regulatory mechanisms of BA in the intestine. We showed that the BA levels in the gallbladder and faeces were significantly increased, whereas serum BA levels decreased in systemic Krüppel-like factor 9 (Klf9) deficiency (Klf9-/-) mice. These phenotypes were also observed in the intestine-specific Klf9-deleted (Klf9vil-/-) mice. In contrast, BA levels in the gallbladder and faeces were reduced, whereas BA levels in the serum were increased in intestinal Klf9 transgenic (Klf9Rosa26+/+) mice. By using a combination of biochemical, molecular and functional assays, we revealed that Klf9 promoted the expression of apical sodium-dependent bile acid transporter (Asbt) in the terminal ileum to enhance BA absorption in the intestine. Reabsorbed BA affected liver BA synthetic enzymes by regulating Fgf15 expression. This study has identified a previously neglected transcriptional pathway that regulates BA homeostasis.

Thermal Decomposition of Nanostructured Bismuth Subcarbonate.

Nanostructured (BiO)2CO3 samples were prepared, and their thermal decomposition behaviors were investigated by thermogravimetric analysis under atmospheric conditions. The method of preparation and Ca2+ doping could affect the morphologies of products and quantity of defects, resulting in different thermal decomposition mechanisms. The (BiO)2CO3 nanoplates decomposed at 300-500 °C with an activation energy of 160-170 kJ/mol. Two temperature zones existed in the thermal decomposition of (BiO)2CO3 and Ca-(BiO)2CO3 nanowires. The first one was caused by the decomposition of (BiO)4(OH)2CO3 impurities and (BiO)2CO3 with surface defects, with an activation energy of 118-223 kJ/mol, whereas the second one was attributed to the decomposition of (BiO)2CO3 in the core of nanowires, with an activation energy of 230-270 kJ/mol for the core of (BiO)2CO3 nanowires and 210-223 kJ/mol for the core of Ca-(BiO)2CO3 nanowires. Introducing Ca2+ ions into (BiO)2CO3 nanowires improved their thermal stability and accelerated the decomposition of (BiO)2CO3 in the decomposition zone.

Unraveling the coordination structure-performance relationship in Pt1/Fe2O3 single-atom catalyst.

Heterogeneous single-atom catalyst (SAC) opens a unique entry to establishing structure-performance relationship at the molecular level similar to that in homogeneous catalysis. The challenge lies in manipulating the coordination chemistry of single atoms without changing single-atom dispersion. Here, we develop an efficient synthetic method for SACs by using ethanediamine to chelate Pt cations and then removing the ethanediamine by a rapid thermal treatment (RTT) in inert atmosphere. The coordination chemistry of Pt single atoms on a Fe2O3 support is finely tuned by merely adjusting the RTT temperature. With the decrease in Pt-O coordination number, the oxidation state of Pt decreases, and consequently the hydrogenation activity increases to a record level without loss of chemoselectivity. The tunability of the local coordination chemistry, oxidation states of the metal, and the catalytic performance of single atoms reveals the unique role of SACs as a bridge between heterogeneous and homogeneous catalysis.

Autophagy is positively associated with the accumulation of myeloid­derived suppressor cells in 4­nitroquinoline­1­oxide­induced oral cancer.

It has previously been demonstrated that autophagy and inflammation act synergistically to promote carcinogenesis. However, the precise roles of autophagy in multistep oral carcinogenesis are still unclear, particularly regarding its association with tumor inflammation. The present study established a 4NQO­induced oral cancer mouse model and investigated autophagy status in the multistep process of oral carcinogenesis using immunohistochemistry, western blotting and immunofluorescence staining. Furthermore, the number of Gr­1+CD11b+ myeloid derived suppressor cells (MDSCs) and CD4+ Foxp3+ regulatory T cells (Tregs) during oral carcinogenesis and the association with autophagy status was also examined. The results revealed that the expression of autophagy biomarkers, including dihydrosphingosine 1-phosphate phosphatase LCB3 (LC3B), p62/SQSTM1 (p62) and Beclin 1 increased during 4NQO­induced carcinogenesis and in human oral cancer. The number of MDSCs and Tregs also increased during oral carcinogenesis. Furthermore, the expression of LC3B and p62 significantly correlated with the accumulation of MDSCs and the expression of Beclin 1 correlated with the increase of Tregs. These data indicated that autophagy may be activated by the tumor inflammation microenvironment during oral carcinogenesis.

The effect of defects on the catalytic activity of single Au atom supported carbon nanotubes and reaction mechanism for CO oxidation.

The mechanism of CO oxidation by O2 on a single Au atom supported on pristine, mono atom vacancy (m), di atom vacancy (di) and the Stone Wales defect (SW) on single walled carbon nanotube (SWCNT) surface is systematically investigated theoretically using density functional theory. We determine that single Au atoms can be trapped effectively by the defects on SWCNTs. The defects on SWCNTs can enhance both the binding strength and catalytic activity of the supported single Au atom. Fundamental aspects such as adsorption energy and charge transfer are elucidated to analyze the adsorption properties of CO and O2 and co-adsorption of CO and O2 molecules. It is found that CO binds stronger than O2 on Au supported SWCNT. We clearly demonstrate that the defected SWCNT surface promotes electron transfer from the supported single Au atom to O2 molecules. On the other hand, this effect is weaker for pristine SWCNTs. It is observed that the high density of spin-polarized states are localized in the region of the Fermi level due to the strong interactions between Au (5d orbital) and the adjacent carbon (2p orbital) atoms, which influence the catalytic performance. In addition, we elucidate both the Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms of CO oxidation by O2. For the LH pathway, the barriers of the rate-limiting step are calculated to be 0.02 eV and 0.05 eV for Au/m-SWCNT and Au/di-SWCNT, respectively. To regenerate the active sites, an ER-like reaction occurs to form a second CO2 molecule. The ER pathway is observed on Au/m-SWCNT, Au/SW-SWCNT and Au/SWCNT in which the Au/m-SWCNT has a smaller barrier. The comparison with a previous study (Lu et al., J. Phys. Chem. C, 2009, 113, 20156-20160.) indicates that the curvature effect of SWCNTs is important for the catalytic property of the supported single Au. Overall, Au/m-SWCNT is identified as the most active catalyst for CO oxidation compared to pristine SWCNT, SW-SWCNT and di-SWCNT. Our findings give a clear description on the relationship between the defects in the support and the catalytic properties of Au and open a new avenue to develop carbon nanomaterial-based single atom catalysts for application in environmental and energy related fields.

Long noncoding RNAs: emerging regulators of tumor angiogenesis.

Long noncoding RNAs (lncRNAs) participate in multiple biological processes especially human diseases, of which, tumor seems to be one of the most significant. Angiogenesis has been deemed to have a pivotal role in a series of tumor biological behaviors in tumorigenesis, progression and prognosis. Emerging evidences suggested that lncRNAs are involved in tumor angiogenesis and lncRNAs have already been verified to be potential biomarkers and promising therapeutic targets. This review summarized emerging angiogenesis-related lncRNAs, discussed their mechanisms interacting with cytokines, cancer stem cells, miRNAs and tumor hypoxia microenvironment, and demonstrated if lncRNAs could be new candidate targets of antiangiogenesis therapy.

The role of tumor microenvironment in collective tumor cell invasion.

For many cancer types, cancer cells invade into surrounding tissues by collective movement of cell groups that remain connected via cell-cell junctions. This migration is completely distinguished from single-cell migration, in which cancer cells disrupt the tight intercellular junctions and gain a mesenchymal phenotype. Recently, emerging evidence has revealed that collective cell invasion depends on not only cell-intrinsic mechanisms but also on extracellular mechanisms by bidirectional interplay between the tumor cell and the tumor environment. Herein, in this review we discuss the role and underline mechanisms of tumor microenvironment in collective tumor cell invasion, particularly focusing on extracellular matrix remodeling and cross-talk between tumor and stromal cells.

Bio-inspired Construction of Advanced Fuel Cell Cathode with Pt Anchored in Ordered Hybrid Polymer Matrix.

The significant use of platinum for catalyzing the cathodic oxygen reduction reactions (ORRs) has hampered the widespread use of polymer electrolyte membrane fuel cells (PEMFCs). The construction of well-defined electrode architecture in nanoscale with enhanced utilization and catalytic performance of Pt might be a promising approach to address such barrier. Inspired by the highly efficient catalytic processes in enzymes with active centers embedded in charge transport pathways, here we demonstrate for the first time a design that allocates platinum nanoparticles (Pt NPs) at the boundaries with dual-functions of conducting both electrons by aid of polypyrrole and protons via Nafion(®) ionomer within hierarchical nanoarrays. By mimicking enzymes functionally, an impressive ORR activity and stability is achieved. Using this brand new electrode architecture as the cathode and the anode of a PEMFC, a high mass specific power density of 5.23 W mg(-1)Pt is achieved, with remarkable durability. These improvements are ascribed to not only the electron decoration and the anchoring effects from the Nafion(®) ionomer decorated PPy substrate to the supported Pt NPs, but also the fast charge and mass transport facilitated by the electron and proton pathways within the electrode architecture.

[Postoperative infection bacteria and drug resistance in patients with oral and maxillofacial tumors].

PURPOSE: To evaluate postoperative infection patterns of patients suffering from oral and maxillofacial neoplasms. The risk factors giving rise to postoperative infections were analyzed. Infection bacteria and antibiotic resistance were investigated. METHODS: Fifty-three cases suffering from postoperative infection were selected during 2007.12-2012.12 at the Department of Oral & Maxillofacial Surgery, West China College of Stomatology. The relationship between infections and factors including patients' sex, age, type of tumor, operation time and methods were evaluated with Excel and SPSS 21.0 software package, putting emphasis on infection bacteria and drug-resistance. RESULTS: Postoperative infection mainly occurred in patients with oral malignant tumors. Operation types and time had important influence on postoperative infection. The infection bacteria included gram-positive (59.5%) and gram-negative ones (40.5%). Streptococcus pyogenes accounted for the majority of G- bacteria, which was very sensitive to ß-lactam antibiotics. Pseudomonas aeruginosa were multi-drug resistant G- bacteria, which brought difficulties to the treatment of the infection. CONCLUSIONS: Integrant bacterial culture and drug sensitivity test should be performed to choose appropriate antibiotics, and monitor multi-drug resistant bacteria, so as to improve the control rates of postoperative infection.

Macroporous 'bubble' graphene film via template-directed ordered-assembly for high rate supercapacitors.

A three-dimensional bubble graphene film, with controllable and uniform macropores and tailorable microstructure, was fabricated by a facile hard templating strategy and exhibit extraordinary electrochemical capacitance with high rate capability (1.0 V s(-1)).

Supported Au nanoparticles as efficient catalysts for aerobic homocoupling of phenylboronic acid.

Au nanoparticles with small sizes (1-4 nm) were effectively formed on Mg-Al mixed oxides (Au/MAO), which showed superior catalytic performances and good recyclability in aerobic homocoupling of phenylboronic acid.

Release characteristics of alkali and alkaline earth metallic species during biomass pyrolysis and steam gasification process.

Investigating the release characteristics of alkali and alkaline earth metallic species (AAEMs) is of potential interest because of AAEM's possible useful service as catalysts in biomass thermal conversion. In this study, three kinds of typical Chinese biomass were selected to pyrolyse and their chars were subsequently steam gasified in a designed quartz fixed-bed reactor to investigate the release characteristics of alkali and alkaline earth metallic species (AAEMs). The results indicate that 53-76% of alkali metal and 27-40% of alkaline earth metal release in pyrolysis process, as well as 12-34% of alkali metal and 12-16% of alkaline earth metal evaporate in char gasification process, and temperature is not the only factor to impact AAEMs emission. The releasing characteristics of AAEMs during pyrolysis and char gasification process of three kinds of biomass were discussed in this paper.

{4-Dimethyl-amino-N'-[1-(2-oxidophen-yl)ethyl-idene]benzohydrazidato}(methano-lato)oxidovanadium(V).

The title oxidovanadium(V) complex, [V(C(17)H(17)N(3)O(2))(CH(3)O)O], was obtained by the reaction of 2-acetyl-phenol, 4-dimethyl-amino-benzohydrazide and vanadyl sulfate in methanol. The V(V) atom is five-coordinated by N,O,O'-donor atoms of the Schiff base ligand, one meth-oxy O atom and one oxide O atom, forming a square-pyramidal geometry.

(Methanol-κO)(methano-lato-κO)oxido{N'-[1-(2-oxidonaphthalen-1-yl-κO)ethyl-idene]nicotinohydrazidato-κN',O}vanadium(V).

The title oxovanadium(V) complex, [V(C(18)H(13)N(3)O(2))(CH(3)O)O(CH(3)OH)], was obtained by the reaction of 1-(2-hy-droxy-naphthalen-1-yl)ethanone, nicotinohydrazide and vanadyl sulfate in methanol. The V(V) atom is six-coordinated by the N,N,O-tridentate Schiff base ligand, one methano-late O atom, one methanol O atom and one oxide O atom, forming a distorted octa-hedral geometry. The methanol O atom lies trans to the V=O group. The dihedral angle between the pyridine ring and the naphthalene ring system is 31.52 (10)°. In the crystal, inversion dimers linked by pairs of O-H⋯N hydrogen bonds occur.

(Methano-lato-κO)[N'-(3-meth-oxy-2-oxidobenzyl-idene-κO)-4-nitro-benzo-hydrazidato-κN',O]oxidovanadium(V).

The title oxidovanadium(V) complex, [V(C(15)H(11)N(3)O(5))(CH(3)O)O], was obtained by the reaction of 2-hy-droxy-3-meth-oxy-benzaldehyde, 4-nitro-benzohydrazide and vanadyl sulfate in methanol. The V(V) atom is five-coordinated by the two O and one N donor atoms of the Schiff base ligand, one methano-late O atom and one oxido O atom, forming a distorted square-pyramidal geometry.

Controllable synthesis of vertically aligned ZnO nanorod arrays in aqueous solution.

High-density well-aligned ZnO nanorod array was successfully synthesized on a large-area magnetron sputtering deposited Al doped ZnO film-coated Si (AZO/Si) substrate via a convenient solution method. X-ray diffraction and scanning electron microscopy show that the nanorods are well-oriented perpendicular to the substrate. The influences of the reaction temperature, time, on the size and shapes of the as-prepared ZnO nanorods (ZNs) samples have been studied. The length and diameter of the nanorods became bigger when a longer reaction time was used. When the temperature is elevated to 130 degrees C, a new conical ZNs was synthesized. Room-temperature photoluminescence (PL) spectra of all the ZnO products showed a strong ultraviolet (UV) emission. The photoluminescence from free excitons of the ZNs synthesized at higher temperature reflects the high purity and nearly defect free structure of nanorods. The well-aligned feature of the nanorod array is attributed to the nanorods' epitaxial growth from the AZO films.