Immune complexes induce TNF-α and BAFF production from U937 cells by HMGB1 and RAGE

OBJECTIVE

This study investigated the effects of immune complexes (ICs) on tumor necrosis factor α (TNF-α) and B cell-activating factor (BAFF) production from U937 cells and further explored the mechanism.

MATERIALS AND METHODS

U937 cells were incubated with necrosis supernatant or systemic lupus erythematosus (SLE) sera alone, or their combination. The expression of TNF-α and BAFF was determined by Real-time polymerase chain reaction and enzyme-linked immunosorbent assay. High mobility group box protein 1(HMGB1) A-box was produced by gene recombination. HMGB1 A-box and anti-receptor for advanced glycation end products (RAGE) antibody were adopted in the blocking experiments. The importance of DNA for cytokine induction was investigated by DNase treatment.

RESULTS

The combination of necrosis supernatant and SLE sera induced the expression of TNF-α and BAFF significantly increased compared to necrosis supernatant or SLE sera alone. Recombinant HMGB1 A-box protein was purified, and TNF-α and BAFF production, which were induced by this combination, was blocked via HMGB1 A-box and anti-RAGE antibody. Moreover, we found that DNA component is important for the immunostimulatory activity of this combination.

CONCLUSIONS

ICs containing DNA can promote TNF-α and BAFF production in U937 cells, and this process can be mediated by HMGB1 and RAGE. One possible mechanism of increasing BAFF production in SLE is proposed in this study whereby B cell activation, antibody production and ICs stimulated monocytes may create a vicious cycle that leads to B cell hyperactivity, which can be of importance for SLE etiopathogenesis.

Cirmtuzumab inhibits Wnt5a-induced Rac1 activation in chronic lymphocytic leukemia treated with ibrutinib

Signaling via the B cell receptor (BCR) plays an important role in the pathogenesis and progression of chronic lymphocytic leukemia (CLL). This is underscored by the clinical effectiveness of ibrutinib, an inhibitor of Bruton's tyrosine kinase (BTK) that can block BCR-signaling. However, ibrutinib cannot induce complete responses (CR) or durable remissions without continued therapy, suggesting alternative pathways also contribute to CLL growth/survival that are independent of BCR-signaling. ROR1 is a receptor for Wnt5a, which can promote activation of Rac1 to enhance CLL-cell proliferation and survival. In this study, we found that CLL cells of patients treated with ibrutinib had activated Rac1. Moreover, Wnt5a could induce Rac1 activation and enhance proliferation of CLL cells treated with ibrutinib at concentrations that were effective in completely inhibiting BTK and BCR-signaling. Wnt5a-induced Rac1 activation could be blocked by cirmtuzumab (UC-961), an anti-ROR1 mAb. We found that treatment with cirmtuzumab and ibrutinib was significantly more effective than treatment with either agent alone in clearing leukemia cells in vivo. This study indicates that cirmtuzumab may enhance the activity of ibrutinib in the treatment of patients with CLL or other ROR1⁺ B-cell malignancies.

Technical note: The effect of carcass deboning technique on the meat quality of cattle

The objective of this study was to evaluate the effects of the suspended carcass deboning technique on the meat attributes of electrically stimulated cattle ( = 10). A carcass deboning technique that removes the main bones without breakdown of the entire carcass was applied to suspended sides soon after slaughter. After 3 d of aging at 4°C, the shear force of the rectus femoris, longissimus lumborum, and supraspinatus muscles of the suspended carcass deboning technique was reduced by 27%, 29%, and 23% ( < 0.05), respectively. The carcass deboning technique increased the sarcomere length by 14%, 10%, and 16% ( < 0.05), and the myofibril fragmentation index was increased by 10%, 5%, and 13% ( < 0.05), respectively, for the same 3 muscles. There was no difference in the pH, color, or cooking loss between the treatment and the control ( > 0.05). The carcass deboning technique could be a viable approach to improve beef tenderness with a relatively short aging duration.

The metabolic responses of HepG2 cells to the exposure of mycotoxin deoxynivalenol

As the number of reported deoxynivalenol (DON) contamination incidents increased steadily over the past decades, there has been a widespread interest in understanding the cellular mechanisms of the toxicological effects of DON using in vitro systems and omics technologies. The present investigation was conducted to understand the metabolomic changes in human hepatocellular carcinoma cells (HepG2) exposed to 10 μM DON for short term (4 h) and long term (12 h) periods, using a non-targeted metabolomics approach. Our results revealed a remarkable metabolic shift from short term to long term exposure to DON in HepG2 cells. Our metabolomics data also confirmed the role of DON induced oxidative stress in DON toxicity. Coupled with pattern recognition and pathway analysis, effects of DON on redox homeostasis, energy balance, lipid metabolism, and potential toxicological mechanisms were discussed, which would facilitate further studies on the risk assessment of the dietary mycotoxin DON.

The potential protective role of hepatitis B virus infection in pristane-induced lupus in mice

OBJECTIVE

The objective of this study was to investigate whether hepatitis B virus (HBV) infection plays a role in the regulation of autoimmunity for systemic lupus erythematosus (SLE).

METHOD

A total of 21 female BALB/c mice and 21 female HBV transgenic BALB/c mice aged two months were randomly divided into four groups: BALB/c mice, HBV(Tg) mice, pristane-injected BALB/c mice, and pristane-injected HBV(Tg) mice. BALB/c mice and HBV(Tg) mice were given an intraperitoneal injection of 0.5 ml normal saline, and the mice in the other two groups were given an intraperitoneal injection of 0.5 ml pristane. ANA and anti-dsDNA levels in serum were detected by indirect immunofluorescence. Interleukin 2 (IL-2), IL-4, IL-6, IL-17, and TNF-α were measured by Luminex technology. The serum BAFF level was measured using an Elisa kit. Twenty-four weeks after pristane administration, kidneys were removed, dissected, and stained with hematoxylin and eosin and periodic-acid Schiff.

RESULT

At six months after injecting, the ANA titers in pristane-injected HBV(Tg) mice were significantly lower than pristane-injected BALB/c mice. IL-17, TNF-α, and BAFF levels were significantly higher in pristane-injected BALB/c mice than BALB/c mice and pristane-injected HBV(Tg) mice. IL-2, IL-4, and IL-6 levels were much higher in pristane-injected HBV(Tg) mice than pristane-injected BALB/c mice. In pristane-injected HBV(Tg) mice and HBV(Tg) mice, fewer glomerulonephritis changes were found in the kidneys.

CONCLUSIONS

Our results showed that the incidence of SLE was much lower in HBV(Tg) mice, and that HBV infection helped the SLE mice survive high levels of inflammatory cytokines and severe renal damage. All these findings demonstrated the protective role of HBV in SLE patients via the immunoregulatory networks of the cytokines.

Intrinsic Two-Dimensional Organic Topological Insulators in Metal-Dicyanoanthracene Lattices

We predict theoretical existence of intrinsic two-dimensional organic topological insulator (OTI) states in Cu-dicyanoanthracene (DCA) lattice, a system that has also been grown experimentally on Cu substrate, based on first-principle density functional theory calculations. The pz-orbital Kagome bands having a Dirac point lying exactly at the Fermi level are found in the freestanding Cu-DCA lattice. The tight-binding model analysis, the calculated Chern numbers, and the semi-infinite Dirac edge states within the spin-orbit coupling gaps all confirm its intrinsic topological properties. The intrinsic TI states are found to originate from a proper number of electrons filling of the hybridized bands from Cu atomic and DCA molecular orbitals based on which similar lattices containing noble metal atoms (Au and Cu) and those molecules with two CN groups (DCA and cyanogens) are all predicted to be intrinsic OTIs.

Self-medication practices with antibiotics among Chinese university students

OBJECTIVES

Self-medication with antibiotics (SMA) is a serious global health problem. We sought to investigate SMA behaviors and risk factors among Chinese university students, and further explore the association between SMA practices and adverse drug events (ADEs).

STUDY DESIGN

Cross-sectional study.

METHODS

An online survey was conducted at Jiangsu University (JSU) in eastern China in July 2011 using a pretested questionnaire.

RESULTS

Out of 2608 website visitors, 1086 participated in the survey (response rate: 41.6%), 426 respondents were excluded for not being a JSU student or repeat participation, 660 (2.2% of JSU students) were included in analysis, and 316 students (47.9%) had a lifetime history of SMA. Among self-treated students, 43.5% believed that antibiotic was suitable for viral infections, 65.9% had more than one SMA episode in the previous year, 73.5% self-medicated with at least two different antibiotics, 57.1% and 64.4% changed antibiotic dosage and antibiotics during the course, respectively. Female gender, older age, and prior knowledge of antibiotics (PKA) were identified as independent risk factors of SMA. There was no difference between students with and without PKA regarding SMA frequency, use of polyantibiotics, and switching antibiotic dosage or antibiotics. ADEs happened to 13.3% of self-medicated students. Frequent change of dosage and simultaneous use of the same antibiotic with different names were independent risk practices associated with an ADE.

CONCLUSIONS

Our findings substantiate high SMA prevalence among Chinese university students. Older age and PKA are independent SMA risk factors common to Chinese university students and female gender is exclusive SMA risk factor for JSU students. Poor SMA practices are associated with ADEs. Strict regulations on antibiotic sales and public education reinforced by further health care reform are recommended.

Tilt engineering of exchange coupling at G-type SrMnO3/(La,Sr)MnO3 interfaces

With the recent realization of hybrid improper ferroelectricity and room-temperature multiferroic by tilt engineering, "functional" octahedral tilting has become a novel concept in multifunctional perovskite oxides, showing great potential for property manipulation and device design. However, the control of magnetism by octahedral tilting has remained a challenging issue. Here a qualitative and quantitative tilt engineering of exchange coupling, one of the magnetic properties, is demonstrated at compensated G-type antiferromagnetic/ferromagnetic (SrMnO3/La2/3Sr1/3MnO3) interfaces. According to interfacial Hamiltonian, exchange bias (EB) in this system originates from an in-plane antiphase rotation (a(-)) in G-type antiferromagnetic layer. Based on first-principles calculation, tilt patterns in SrMnO3 are artificially designed in experiment with different epitaxial strain and a much stronger EB is attained in the tensile heterostructure than the compressive counterpart. By controlling the magnitude of octahedral tilting, the manipulation of exchange coupling is even performed in a quantitative manner, as expected in the theoretical estimation. This work realized the combination of tilt engineering and exchange coupling, which might be significant for the development of multifunctional materials and antiferromagnetic spintronics.

Unconventional resistive switching behavior in ferroelectric tunnel junctions

An unconventional resistive switching behavior is observed in ferroelectric tunnel junctions, which builds a bridge between ferroelectric tunnel junctions and resistive random access memory devices.

Metal-carbonyl organometallic polymers, PFpP, as resists for high-resolution positive and negative electron beam lithography

Metal-carbonyl organometallic polymers, PFpP, can function as high-resolution resists for electron beam lithography.

Strain engineering induced interfacial self-assembly and intrinsic exchange bias in a manganite perovskite film

The control of complex oxide heterostructures at atomic level generates a rich spectrum of exotic properties and unexpected states at the interface between two separately prepared materials. The frustration of magnetization and conductivity of manganite perovskite at surface/interface which is inimical to their device applications, could also flourish in tailored functionalities in return. Here we prove that the exchange bias (EB) effect can unexpectedly emerge in a (La,Sr)MnO₃ (LSMO) “single” film when large compressive stress imposed through a lattice mismatched substrate. The intrinsic EB behavior is directly demonstrated to be originating from the exchange coupling between ferromagnetic LSMO and an unprecedented LaSrMnO₄-based spin glass, formed under a large interfacial strain and subsequent self-assembly. The present results not only provide a strategy for producing a new class of delicately functional interface by strain engineering, but also shed promising light on fabricating the EB part of spintronic devices in a single step.

Tuning the entanglement between orbital reconstruction and charge transfer at a film surface

The interplay between orbital, charge, spin, and lattice degrees of freedom is at the core of correlated oxides. This is extensively studied at the interface of heterostructures constituted of two-layer or multilayer oxide films. Here, we demonstrate the interactions between orbital reconstruction and charge transfer in the surface regime of ultrathin (La,Sr)MnO₃, which is a model system of correlated oxides. The interactions are manipulated in a quantitative manner by surface symmetry-breaking and epitaxial strain, both tensile and compressive. The established charge transfer, accompanied by the formation of oxygen vacancies, provides a conceptually novel vision for the long-term problem of manganites—the severe surface/interface magnetization and conductivity deterioration. The oxygen vacancies are then purposefully tuned by cooling oxygen pressure, markedly improving the performances of differently strained films. Our findings offer a broad opportunity to tailor and benefit from the entanglements between orbit, charge, spin, and lattice at the surface of oxide films.

The beam diagnostic instruments in Beijing radioactive ion-beam facilities isotope separator on-line

The beam diagnostic instruments for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line are introduced [B. Q. Cui, Z. H. Peng, Y. J. Ma, R. G. Ma, B. Tang, T. Zhang, and W. S. Jiang, Nucl. Instrum. Methods 266, 4113 (2008); T. J. Zhang, X. L. Guan, and B. Q. Cui, in Proceedings of APAC 2004, Gyeongju, Korea, 2004, http://www.jacow.org, p. 267]. For low intensity ion beam [30-300 keV/1 pA-10 μA], the beam profile monitor, the emittance measurement unit, and the analyzing slit will be installed. For the primary proton beam [100 MeV/200 μA], the beam profile scanner will be installed. For identification of the nuclide, a beam identification unit will be installed. The details of prototype of the beam diagnostic units and some experiment results will be described in this article.

An ion source module for the Beijing Radioactive Ion-beam Facility

An ion source module is developed for Beijing Radioactive Ion-beam Facility. The ion source module is designed to meet the requirements of remote handling. The connection and disconnection of the electricity, cooling and vacuum between the module and peripheral units can be executed without on-site manual work. The primary test of the target ion source has been carried out and a Li(+) beam has been extracted. Details of the ion source module and its primary test results are described.

The development of the high intensity electron cyclotron resonance ion source at China Institute of Atomic Energy

High-current microwave ion source has been under development over 15 years for accelerator driven sub-critical system research at China Institute of Atomic Energy, and the beam intensity higher than 140 mA proton beam is produced by this ion source with long lifetime and high reliability. The emittance of high intensity continue-wave and pulse beam is measured on a test-bench in the laboratory. Based on the good performance of this proton ion source, a new 120 mA deuterium ion source is proposed for a high intensity neutron generator. The ion source details and status will be presented.

Tuning of uniaxial magnetic anisotropy in amorphous CoFeB films

We demonstrate that the uniaxial magnetic anisotropy (UMA) of amorphous CoFeB films can be tuned by crystallinity and orbital moment ratio, combining the results of magnetization reversal and ferromagnetic resonance with high-resolution transmission electron microscopy, x-ray-absorption near-edge structure and x-ray magnetic circular dichroism. Isotropic polycrystalline buffers of tungsten (W), tantalum (Ta), and copper (Cu) between CoFeB and Si(100) substrates have direct and crucial bearing on the interfacial microstructure and orbital moment ratio. Compared with Ta and Cu buffer, CoFeB with W buffer exhibits obvious UMA and has lower crystallinity at the interface and higher orbital moment. Amorphous phase distributed homogeneously in CoFeB film grown on W buffer contributes to improve the easy-axis squareness with a sharp magnetization reversal. Our demonstrations not only realize effective tuning of UMA in amorphous CoFeB, but also provide an appealing alternative buffer (W) for CoFeB-based magnetic tunnel junctions.

Room-temperature perpendicular exchange coupling and tunneling anisotropic magnetoresistance in an antiferromagnet-based tunnel junction

We investigate the exchange coupling between perpendicular anisotropy (PMA) Co/Pt and IrMn in-plane antiferromagnets (AFMs), as well as tunneling anisotropic magnetoresistance (TAMR) in [Pt/Co]/IrMn/AlO_{x}/Pt tunnel junctions, where Co/Pt magnetization drives rotation of AFM moments with the formation of exchange-spring twisting. When coupled with a PMA ferromagnet, the AFM moments partially rotate with out-of-plane magnetic fields, in contrast with being pinned along the easy direction of IrMn for in-plane fields. Because of the superior thermal tolerance of perpendicular exchange coupling and the stability of moments in ~6 nm-thick IrMn, TAMR gets significantly enhanced up to room temperature. Their use would advance the process towards practical AFM spintronics.

The plasma level of soluble receptor for advanced glycation end products is decreased in patients with systemic lupus erythematosus

In recent years, the role of high mobility group box-1 (HMGB1) protein and its receptors in autoimmune diseases has received increasing attention. It has been documented that HMGB1 is associated with disease activity in patients with systemic lupus erythematosus (SLE). This study was undertaken to determine the potential role of receptor for advanced glycation end products (RAGE), one receptor for HMGB1, in the pathogenesis of SLE. Plasma levels of soluble RAGE (sRAGE) from 105 patients with clinical diagnosis of SLE and 43 healthy controls were determined by ELISA. Associations between sRAGE levels and clinical, laboratory characteristics were assessed. The data showed that plasma levels of sRAGE in patients with SLE were significantly lower than those in healthy controls (HC) (P = 0.003). Plasma sRAGE in patients receiving short-period treatment showed an immediate decrease compared with the untreated patients (P = 0.023). In contrast, plasma sRAGE in patients receiving long-period treatment were significantly increased compared to those with short-period treatment (P = 0.000) and comparable with those in HC (P = 0.305). The significant decreased levels of sRAGE in patients with SLE suggest the potential association of RAGE signalling and SLE clinical pathology, whereas, long-period antilupus treatment may counteract the decreased sRAGE levels in patients with SLE.