Assessing the combined impact of fatty liver-induced TGF-β1 and LPS-activated macrophages in fibrosis through a novel 3D serial section methodology

Non-alcoholic steatohepatitis (NASH), caused by fat buildup, can lead to liver inflammation and damage. Elucidation of the spatial distribution of fibrotic tissue in the fatty liver in NASH can be immensely useful to understand its pathogenesis. Thus, we developed a novel serial section-3D (SS3D) technique that combines high-resolution image acquisition with 3D construction software, which enabled highly detailed analysis of the mouse liver and extraction and quantification of stained tissues. Moreover, we studied the underexplored mechanism of fibrosis progression in the fatty liver in NASH by subjecting the mice to a high-fat diet (HFD), followed by lipopolysaccharide (LPS) administration. The HFD/LPS (+) group showed extensive fibrosis compared with control; additionally, the area of these fibrotic regions in the HFD/LPS (+) group was almost double that of control using our SS3D technique. LPS administration led to an increase in Tnfα and Il1β mRNA expression and the number of macrophages in the liver. On the other hand, transforming growth factor-β1 (Tgfβ1) mRNA increased in HFD group compared to that of control group without LPS-administration. In addition, COL1A1 levels increased in hepatic stellate cell (HSC)-like XL-2 cells when treated with recombinant TGF-β1, which attenuated with recombinant latency-associated protein (rLAP). This attenuation was rescued with LPS-activated macrophages. Therefore, we demonstrated that fatty liver produced "latent-form" of TGF-β1, which activated by macrophages via inflammatory cytokines such as TNFα and IL1β, resulting in activation of HSCs leading to the production of COL1A1. Moreover, we established the effectiveness of our SS3D technique in creating 3D images of fibrotic tissue, which can be used to study other diseases as well.

Artifact reduction in low and ultra-low dose chest computed tomography for patients with pacemaker: A phantom study

INTRODUCTION

Implanted pacemakers (PM) would decrease the detection of lung nodules in chest computed tomography (CT) due to the metal artifact. This study aimed to explore the computer-aided diagnosis (CAD) detectability of pulmonary nodules for the patients implanted with PMs in low- and ultra-low-dose chest CT screening.

METHODS

Four different sizes of artificial nodules were placed in an anthropomorphic chest phantom with two alternative diameters utilized. A commercially available PM was placed on the surface of the left chest wall of the phantom. The image acquisitions were performed with 120 kV and 150 kV with a dedicated selective photon shield made of tin filter (Sn150 kV) at low- and ultra-low- radiation doses (1.0 and 0.5 mGy of volume CT dose index), and reconstructed with and without Iterative Metal Artifact Reduction (iMAR, Siemens Healthineers, Erlangen, Germany). The relative artifact index (AIr) was calculated as an index of metal artifacts, and the nodule detectability was evaluated with a CAD system.

RESULTS

Sn150 kV reduced AIr in all acquisitions when comparing 120 kV and Sn150 kV. Although PM reduced the detectability of nodules, Sn150 kV showed higher detectability compared to 120 kV. The use of iMAR showed inconsistent results in nodule detectability.

CONCLUSION

Sn150 kV reduced PM-induced metal artifacts and improved nodule detectability with CAD compared to 120 kV acquisition in many conditions including low and ultra-low doses and large phantoms, but iMAR did not improve the detectability.

IMPLICATIONS FOR PRACTICE

Based on the results of the current phantom study, low and ultra-low dose with Sn150 kV acquisition reduced PM-induced metal artifacts and improved nodule detectability.

The effect of nano hydroxyapatite coating implant surfaces on gene expression and osseointegration

BACKGROUND

Hierarchical micro-nano structured topography along with surface chemistry modifications of dental implants have been suggested to positively contribute to the osseointegration process. However, the effect of such surface modifications on the molecular response as well as bone formation rate and quality are still unclear, especially in the early healing period. This study aimed to evaluate the effect of coating a double acid etched (DAE) implant surface with nano-sized (20 nm) hydroxyapatite (Nano) with respect to gene expression, histologic parameters, and nanomechanical properties when compared to DAE control at 1 and 2 weeks after implant placement in a rodent femur model.

MATERIAL AND METHODS

Expression of bone-related genes was determined by qRT-PCR (Col-I, Runx-2, Osx, Opn, Ocn, Alp). Histomorphometric evaluation of bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) within implant threads was performed using photomicrographs after histologic processing. Mechanical properties, reduced elastic modulus and hardness, were determined through nanoindentation.

RESULTS

At 1 week, the Nano group demonstrated significantly higher expression of Col-I and Ocn compared to the DAE group, indicating upregulation of osteoprogenitor and osteoblast differentiation genes. At 2 weeks, Nano surface further exhibited enhanced gene expression of Col-I and Osx in comparison to the DAE surface, suggesting an increased mineralization of the newly formed bone. Nanoindentation analysis revealed that the Nano group presented no significant difference on the ranks of reduced elastic modulus and hardness compared to DAE for both timepoints. Histomorphometric analysis yielded no significant difference in the percentage of BIC and BAFO between the Nano and DAE surfaces at 1 and 2 weeks. However, Nano implants did present a higher mean value, ~50%, of BIC compared to DAE, ~30%, after 2 weeks in vivo.

CONCLUSIONS

While no significant differences were observed in the amount and mechanical properties of newly formed bone, Nano surface positively and significantly increased the expression osteogenic genes compared to DAE surface at early healing periods.

Establishment of a Cell Culture Model Permissive for Infection by Hepatitis B and C Viruses

Compared with each monoinfection, coinfection with hepatitis B virus (HBV) and hepatitis C virus (HCV) is well known to increase the risks of developing liver cirrhosis and hepatocellular carcinoma. However, the mechanism by which HBV/HCV coinfection is established in hepatocytes is not well understood. Common cell culture models for coinfection are required to examine viral propagation. In this study, we aimed to establish a cell line permissive for both HBV and HCV infection. We first prepared a HepG2 cell line expressing sodium taurocholate cotransporting polypeptide, an HBV receptor, and then selected a cell line highly permissive for HBV infection, G2/NT18-B. After transduction with a lentivirus-encoding microRNA-122, the cell line harboring the highest level of replicon RNA was selected and then treated with anti-HCV compounds to eliminate the replicon RNA. The resulting cured cell line was transduced with a plasmid-encoding CD81. The cell line permissive for HCV infection was cloned and then designated the G2BC-C2 cell line, which exhibited permissiveness for HBV and HCV propagation. JAK inhibitor I potentiated the HCV superinfection of HBV-infected cells, and fluorescence-activated cell-sorting analysis indicated that HBV/HCV double-positive cells accounted for approximately 30% of the coinfected cells. Among several host genes tested, cyclooxygenase-2 showed synergistic induction by coinfection compared with each monoinfection. Conclusion: These data indicate that our in vitro HBV/HCV coinfection system provides an easy-to-use platform for the study of host and viral responses against coinfection and the development of antiviral agents targeting HBV and HCV.

Lipidome-based rapid diagnosis with machine learning for detection of TGF-β signalling activated area in head and neck cancer

Background

Several pro-oncogenic signals, including transforming growth factor beta (TGF-β) signalling from tumour microenvironment, generate intratumoural phenotypic heterogeneity and result in tumour progression and treatment failure. However, the precise diagnosis for tumour areas containing subclones with cytokine-induced malignant properties remains clinically challenging.

Methods

We established a rapid diagnostic system based on the combination of probe electrospray ionisation-mass spectrometry (PESI-MS) and machine learning without the aid of immunohistological and biochemical procedures to identify tumour areas with heterogeneous TGF-β signalling status in head and neck squamous cell carcinoma (HNSCC). A total of 240 and 90 mass spectra were obtained from TGF-β-unstimulated and -stimulated HNSCC cells, respectively, by PESI-MS and were used for the construction of a diagnostic system based on lipidome.

Results

This discriminant algorithm achieved 98.79% accuracy in discrimination of TGF-β1-stimulated cells from untreated cells. In clinical human HNSCC tissues, this approach achieved determination of tumour areas with activated TGF-β signalling as efficiently as a conventional histopathological assessment using phosphorylated-SMAD2 staining. Furthermore, several altered peaks on mass spectra were identified as phosphatidylcholine species in TGF-β-stimulated HNSCC cells.

Conclusions

This diagnostic system combined with PESI-MS and machine learning encourages us to clinically diagnose intratumoural phenotypic heterogeneity induced by TGF-β.

Visualization of Nigrosome 1 from the Viewpoint of Anatomic Structure

BACKGROUND AND PURPOSE

Parkinson disease is related to neurodegeneration and iron deposition in the substantia nigra pars compacta and nigrosome 1. However, visualization of nigrosome 1 via MR imaging is poor owing to the bilateral asymmetry, regardless of whether it is healthy. We focused on the magic angle and susceptibility effect and evaluated the anatomic slant structure of nigrosome 1 by tilting subjects' heads in the B₀ direction.

MATERIALS AND METHODS

To investigate the effectiveness of the magic angle, we tilted the volunteers' heads to the right and left in the B₀ direction or not at all for evaluating correlations between the degree of head tilting and visualization of the right nigrosome 1 and left nigrosome 1 using 3D spoiled gradient-echo sequences with multiecho acquisitions. We evaluated the susceptibility of nigrosome 1 and the local field using quantitative susceptibility mapping to assess static magnetic field inhomogeneity.

RESULTS

The heads tilted to the right and left showed significantly higher contrasts of nigrosome 1 and the substantia nigra pars compacta than the nontilted heads. No significant differences were observed in the visualization and susceptibility between the right nigrosome 1 and left nigrosome 1 for each head tilt. The effect of the magic angle was remarkable in the nontilted heads. This finding was supported by quantitative susceptibility mapping because the anatomic slant structure of nigrosome 1 was coherent between the axis of nigrosome 1 and the magic angle.

CONCLUSIONS

The asymmetric visualization of nigrosome 1 is affected by the magic angle and susceptibility. The anatomic slant structure of nigrosome 1 causes these challenges in visualization.

Potential Risk of Virus Carryover by Fabrics of Personal Protective Gowns

Personal protective gowns and coveralls are classified based on barrier efficiency that validates protection from fluid penetration under certain pressures. Materials standardized in this system have been found suitable for emergency medical practices confronting highly contagious diseases. Nevertheless, adhesion of blood, and body fluids from virus-infected patients to the surface of protective clothing still imposes a risk of pathogen transmission in the process of doffing, or undressing. We performed a small-scale experiment to test the possibility of infectious virus carryover on the surface of different fabrics used in commercially available protective gowns. Application of a lentivirus vector that expresses green fluorescent protein allowed easy monitoring of infectious viral loads on fabrics. Results indicate that fabrics of level-3 surgical gowns serve better to reduce virus transmission compared to fabrics of chemical protective clothing with the same or higher barrier efficiency. Analysis of sliding angles provided indexes of fluid repellency, which were inversely related to virus carryover potentials. Droplets of infectious body fluids may easily roll off fabrics with water-repellent finishing. Thus, virus carryover is a measurable risk factor to be considered for better choice of personal protective clothing.

Sustained rescue of prefrontal circuit dysfunction by antidepressant-induced spine formation

The neurobiological mechanisms underlying the induction and remission of depressive episodes over time are not well understood. Through repeated longitudinal imaging of medial prefrontal microcircuits in the living brain, we found that prefrontal spinogenesis plays a critical role in sustaining specific antidepressant behavioral effects and maintaining long-term behavioral remission. Depression-related behavior was associated with targeted, branch-specific elimination of postsynaptic dendritic spines on prefrontal projection neurons. Antidepressant-dose ketamine reversed these effects by selectively rescuing eliminated spines and restoring coordinated activity in multicellular ensembles that predict motivated escape behavior. Prefrontal spinogenesis was required for the long-term maintenance of antidepressant effects on motivated escape behavior but not for their initial induction.

Identification of an Essential Cytoplasmic Region of Interleukin-7 Receptor α Subunit in B-Cell Development

Interleukin-7 (IL-7) is essential for lymphocyte development. To identify the functional subdomains in the cytoplasmic tail of the IL-7 receptor (IL-7R) α chain, here, we constructed a series of IL-7Rα deletion mutants. We found that IL-7Rα-deficient hematopoietic progenitor cells (HPCs) gave rise to B cells both in vitro and in vivo when a wild-type (WT) IL-7Rα chain was introduced; however, no B cells were observed under the same conditions from IL-7Rα-deficient HPCs with introduction of the exogenous IL-7Rα subunit, which lacked the amino acid region at positions 414⁻441 (d414⁻441 mutant). Signal transducer and activator of transcription 5 (STAT5) was phosphorylated in cells with the d414⁻441 mutant, similar to that in WT cells, in response to IL-7 stimulation. In contrast, more truncated STAT5 (tSTAT5) was generated in cells with the d414⁻441 mutant than in WT cells. Additionally, the introduction of exogenous tSTAT5 blocked B lymphopoiesis but not myeloid cell development from WT HPCs in vivo. These results suggested that amino acids 414⁻441 in the IL-7Rα chain formed a critical subdomain necessary for the supportive roles of IL-7 in B-cell development.

Modeling and simulation of bone mineral density in Japanese osteoporosis patients treated with zoledronic acid using tartrate-resistant acid phosphatase 5b, a bone resorption marker

Annual intravenous administration of zoledronic acid is used in the treatment of osteoporosis. A mathematical model was developed to predict bone mineral density up to 2 years after two annual doses of zoledronic acid from the early values of a bone resorption marker in osteoporosis patients.

INTRODUCTION

The measurement of bone mineral density (BMD) has been used as a surrogate marker instead of the observation of incident fractures to detect the efficacy of treatment. However, this method requires a long time to obtain significant changes. On the other hand, bone resorption markers respond to bone resorption inhibitors within a few weeks. Therefore, the aim of this study was to develop a mathematical model predicting long-term BMD after two annual doses of zoledronic acid (ZOL) using the early response of a bone resorption marker in osteoporosis patients.

METHODS

The model was constructed using 3410 tartrate-resistant acid phosphatase 5b (TRACP-5b) serum concentrations and 1146 lumbar spine (L2-L4) BMD values from 306 patients with primary osteoporosis. A mathematical model was developed to describe the time-dependent profiles of TRACP-5b and BMD.

RESULTS

The percentage changes from baseline of the BMD (%BMD) at up to 2 years were predicted from patients' baseline BMD and baseline and 12-week TRACP-5b values by the model obtained. The simulated 90% prediction interval almost covered the observed %BMD distribution at each time point, and the predictions were comparable to the observed %BMD.

CONCLUSIONS

This is the first model to predict BMD for up to 2 years following two annual doses of ZOL using patients' background characteristics and the early response of TRACP-5b. This model allows us to inform patients at the initial stage of ZOL treatment of their predicted response to treatment.

Efficacy and safety of trastuzumab, lapatinib, and paclitaxel neoadjuvant treatment with or without prolonged exposure to anti-HER2 therapy, and with or without hormone therapy for HER2-positive primary breast cancer: a randomised, five-arm, multicentre, open-label phase II trial

Background

Dual blockade of HER2 promises increased pathological complete response (pCR) rate compared with single blockade in the presence of chemotherapy for HER2-positive (+) primary breast cancer. Many questions remain regarding optimal duration of treatment and combination impact of endocrine therapy for luminal HER2 disease.

Methods

We designed a randomised phase II, five-arm study to evaluate the efficacy and safety of lapatinib and trastuzumab (6 weeks) followed by lapatinib and trastuzumab plus weekly paclitaxel (12 weeks) with/without prolongation of anti-HER2 therapy prior to chemotherapy (18 vs. 6 weeks), and with/without endocrine therapy in patients with HER2+ and/or oestrogen receptor (ER)+ disease. The primary endpoint was comprehensive pCR (CpCR) rate. Among the secondary endpoints, pCR (yT0-isyN0) rate, safety, and clinical response were evaluated.

Results

In total, 215 patients were enrolled; 212 were included in the full analysis set (median age 53.0 years; tumour size = T2, 65%; and tumour spread = N0, 55%). CpCR was achieved in 101 (47.9%) patients and was significantly higher in ER− patients than in ER+ patients (ER− 63.0%, ER+ 36.1%; P = 0.0034). pCR with pN0 was achieved in 42.2% of patients (ER− 57.6%, ER+ 30.3%). No significant difference was observed in pCR rate between prolonged exposure groups and standard groups. Better clinical response outcomes were obtained in the prolongation phase of the anti-HER2 therapy. No surplus was detected in pCR rate by adding endocrine treatment. No major safety concern was recognised by prolonging the anti-HER2 treatment or adding endocrine therapy.

Conclusions

This study confirmed the therapeutic impact of lapatinib, trastuzumab, and paclitaxel therapy for each ER− and ER+ subgroup of HER2+ patients. Development of further strategies and tools is required, particularly for luminal HER2 disease.

Electronic supplementary material

The online version of this article (10.1007/s12282-018-0839-7) contains supplementary material, which is available to authorized users.

Hepatitis B virus prevents excessive viral production via reduction of cell death-inducing DFF45-like effectors

The relationship between hepatitis B virus (HBV) infection and lipid accumulation remains largely unknown. In this study, we investigated the effect of HBV propagation on lipid droplet growth in HBV-infected cells and HBV-producing cell lines, HepG2.2.15 and HBV-inducible Hep38.7-Tet. The amount of intracellular triglycerides was significantly reduced in HBV-infected and HBV-producing cells compared with HBV-lacking control cells. Electron and immunofluorescent microscopic analyses showed that the average size of a single lipid droplet (LD) was significantly less in the HBV-infected and HBV-producing cells than in the HBV-lacking control cells. Cell death-inducing DFF45-like effectors (CIDEs) B and C (CIDEB and CIDEC), which are involved in LD expansion for the improvement of lipid storage, were expressed at a significantly lower level in HBV-infected or HBV-producing cells than in HBV-lacking control cells, while CIDEA was not detected in those cells regardless of HBV production. The activity of the CIDEB and CIDEC gene promoters was impaired in HBV-infected or HBV-producing cells compared to HBV-lacking control cells, while CIDEs potentiated HBV core promoter activity. The amount of HNF4α, that can promote the transcription of CIDEB was significantly lower in HBV-producing cells than in HBV-lacking control cells. Knockout of CIDEB or CIDEC significantly reduced the amount of supernatant HBV DNA, intracellular viral RNA and nucleocapsid-associated viral DNA, while the expression of CIDEB or CIDEC recovered HBV production in CIDEB- or CIDEC-knockout cells. These results suggest that HBV regulates its own viral replication via CIDEB and CIDEC.

Cinnamic acid derivatives inhibit hepatitis C virus replication via the induction of oxidative stress

Several cinnamic acid derivatives have been reported to exhibit antiviral activity. In this study, we prepared 17 synthetic cinnamic acid derivatives and screened them to identify an effective antiviral compound against hepatitis C virus (HCV). Compound 6, one of two hit compounds, suppressed the viral replications of genotypes 1b, 2a, 3a, and 4a with EC₅₀ values of 1.5-8.1 μM and SI values of 16.2-94.2. The effect of compound 6 on the phosphorylation of Tyr⁷⁰⁵ in signal transducer and activator of transcription 3 (STAT3) was investigated because a cinnamic acid derivative AG490 was reported to suppress HCV replication and the activity of Janus kinase (JAK) 2. Compound 6 potently suppressed HCV replication, but it did not inhibit the JAK1/2-dependent phosphorylation of STAT3 Tyr⁷⁰⁵ at the same concentration. Furthermore, a pan-JAK inhibitor tofacitinib potently impaired phosphorylation of STAT3 Tyr ⁷⁰⁵, but it did not inhibit HCV replication in the replicon cells and HCV-infected cells at the same concentration, supporting the notion that the phosphorylated state of STAT3 Tyr⁷⁰⁵ is not necessarily correlated with HCV replication. The production of reactive oxygen species (ROS) was induced by treatment with compound 6, whereas N-acetyl-cysteine restored HCV replication and impaired ROS production in the replicon cells treated with compound 6. These data suggest that compound 6 inhibits HCV replication via the induction of oxidative stress.

Inhibitory effect of presenilin inhibitor LY411575 on maturation of hepatitis C virus core protein, production of the viral particle and expression of host proteins involved in pathogenicity

Hepatitis C virus (HCV) core protein is responsible for the formation of infectious viral particles and induction of pathogenicity. The C-terminal transmembrane region of the immature core protein is cleaved by signal peptide peptidase (SPP) for maturation of the core protein. SPP belongs to the family of presenilin-like aspartic proteases. Some presenilin inhibitors are expected to suppress HCV infection and production; however, this anti-HCV effect has not been investigated in detail. In this study, presenilin inhibitors were screened to identify anti-HCV compounds. Of the 13 presenilin inhibitors tested, LY411575 was the most potent inhibitor of SPP-dependent cleavage of HCV core protein. Production of intracellular core protein and supernatant infectious viral particles from HCV-infected cells was significantly impaired by LY411575 in a dose-dependent manner (half maximum inhibitory concentration = 0.27 μM, cytotoxic concentration of the extracts to cause death to 50% of viable cells > 10 μM). No effect of LY411575 on intracellular HCV RNA in the subgenomic replicon cells was detected. LY411575 synergistically promoted daclatasvir-dependent inhibition of viral production, but not that of viral replication. Furthermore, LY411575 inhibited HCV-related production of reactive oxygen species and expression of NADPH oxidases and vascular endothelial growth factor. Taken together, our data suggest that LY411575 suppresses HCV propagation through SPP inhibition and impairs host gene expressions related to HCV pathogenicity.

CO-induced Pd segregation and the effect of subsurface Pd on CO adsorption on CuPd surfaces

We report results of our study on the adsorption of CO on CuPd surfaces with bulk stoichiometric and nonstoichiometric layers using density functional theory (DFT). We found that the presence of Pd atoms in the subsurface layer promotes the adsorption of CO. We also observed CO-induced Pd segregation on the CuPd surface and we attribute this to the strong CO-Pd interaction. Lastly, we showed that the adsorption of CO promotes Pd-Pd interaction as compared to the pristine surface which promotes strong Cu-Pd interaction. These results indicate that CO adsorption on CuPd surfaces can be tuned by taking advantage of the CO-induced segregation and by considering the role of subsurface Pd atoms.

A novel mechanism of spin-orientation dependence of O2 reactivity from first principles methods

A novel mechanism of oxygen reaction on a metal surface beyond the present charge transfer or hybridization mechanism, spin-orientation dependence via a coupling mechanism due to the finite spin moment of O₂ at the transition state, is obtained using a combination of spin density functional theory (SDFT) and constrained DFT.

Repression of Wnt/β-catenin response elements by p63 (TP63)

Submitted: TP63 (p63), a member of the tumor suppressor TP53 (p53) gene family, is expressed in keratinocyte stem cells and well-differentiated squamous cell carcinomas to maintain cellular potential for growth and differentiation. Controversially, activation of the Wnt/β-catenin signaling by p63 (Patturajan M. et al., 2002, Cancer Cells) and inhibition of the target gene expression (Drewelus I. et al., 2010, Cell Cycle) have been reported. Upon p63 RNA-silencing in squamous cell carcinoma (SCC) lines, a few Wnt target gene expression substantially increased, while several target genes moderately decreased. Although ΔNp63α, the most abundant isoform of p63, appeared to interact with protein phosphatase PP2A, neither GSK-3β phosphorylation nor β-catenin nuclear localization was altered by the loss of p63. As reported earlier, ΔNp63α enhanced β-catenin-dependent luc gene expression from pGL3-OT having 3 artificial Wnt response elements (WREs). However, this activation was detectable only in HEK293 cells examined so far, and involved a p53 family-related sequence 5' to the WREs. In Wnt3-expressing SAOS-2 cells, ΔNp63α rather strongly inhibited transcription of pGL3-OT. Importantly, ΔNp63α repressed WREs isolated from the regulatory regions of MMP7. ΔNp63α-TCF4 association occurred in their soluble forms in the nucleus. Furthermore, p63 and TCF4 coexisted at a WRE of MMP7 on the chromatin, where β-catenin recruitment was attenuated. The combined results indicate that ΔNp63α serves as a repressor that regulates β-catenin-mediated gene expression.

Acetylation Modulates IL-2 Receptor Signaling in T Cells

Ligand binding to the cognate cytokine receptors activates intracellular signaling by recruiting protein tyrosine kinases and other protein modification enzymes. However, the roles of protein modifications other than phosphorylation remain unclear. In this study, we examine a novel regulatory mechanism of Stat5, based on its acetylation. As for phosphorylation, IL-2 induces the acetylation of signaling molecules, including Stat5, in the murine T cell line CTLL-2. Stat5 is acetylated in the cytoplasm by CREB-binding protein (CBP). Acetylated Lys⁶⁹⁶ and Lys⁷⁰⁰ on Stat5 are critical indicators for limited proteolysis, which leads to the generation of a truncated form of Stat5. In turn, the truncated form of Stat5 prevents transcription of the full-length form of Stat5. We also demonstrate that CBP physically associates with the IL-2 receptor β-chain. CBP, found in the nucleus in resting CTLL-2 cells, relocates to the cytoplasm after IL-2 stimulation in an MEK/ERK pathway-dependent manner. Thus, IL-2-mediated acetylation plays an important role in the modulation of cytokine signaling and T cell fate.

Association of the clinical efficacy of vancomycin with the novel pharmacokinetic parameter area under the trough level (AUTL) in elderly patients with hospital-acquired pneumonia

WHAT IS KNOWN AND OBJECTIVE

The pharmacokinetic-pharmacodynamic parameter that best predicts the efficacy of vancomycin is the ratio of the area under the concentration versus time curve (AUC) to the minimum inhibitory concentration (MIC). A 24-h AUC (AUC24 )/MIC ratio ≥ 400 was recommended in an American consensus review, but vancomycin treatment occasionally fails despite maintenance of AUC24 /MIC ≥ 400. We evaluated the association between clinical efficacy of vancomycin and two novel pharmacokinetic parameters, the 'area under the trough level' (AUTL) and the 'area above the trough level' (AATL), in hospitalized elderly patients with methicillin-resistant Staphylococcus aureus (MRSA) pneumonia.

METHODS

The subjects were hospitalized elderly patients who were administered vancomycin for treatment of MRSA pneumonia between 2006 and 2012 at Sasebo Chuo Hospital (Nagasaki, Japan). Pharmacokinetic parameters of vancomycin were estimated for each patient by Bayesian analysis using population pharmacokinetic parameters for Japanese patients. Based on the patient-specific parameters thus obtained, AUC24 values were calculated as the vancomycin dosage divided by vancomycin clearance. AUTL was calculated as the trough serum concentration multiplied by 24 h, whereas AATL was calculated by subtracting AUTL from AUC24 .

RESULTS AND DISCUSSION

Logistic regression analysis demonstrated that efficacy of vancomycin was more strongly associated with AUTL than AUC24 . The optimal cut-off value of AUTL was 331 μg∙h/mL, which means that the optimal cut-off value of the trough serum concentration was 13·8 μg/mL.

WHAT IS NEW AND CONCLUSION

Efficacy of vancomycin was associated with AUTL, a novel pharmacokinetic parameter. Determining the target AUTL or trough concentration may enhance the efficacy of vancomycin therapy in elderly patients with MRSA pneumonia. Given that nephrotoxicity may increase with a Ctrough in excess of 15 μg/mL, this level should ideally not be exceeded.

A DFT+U study on the contribution of 4f electrons to oxygen vacancy formation and migration in Ln-doped CeO2

The variable occupancy of empty 4f orbitals is important typically for early Ln elements to produce the covalent interactions that essentially affect the formation and migration of oxygen vacancy.

Hepatitis B virus efficiently infects non-adherent hepatoma cells via human sodium taurocholate cotransporting polypeptide

Sodium taurocholate cotransporting polypeptide (NTCP) has been reported as a functional receptor for hepatitis B virus (HBV) infection. However, HBV could not efficiently infect HepG2 cells expressing NTCP (NTCP-HepG2 cells) under adherent monolayer-cell conditions. In this study, NTCP was mainly detected in the basolateral membrane region, but not the apical site, of monolayer NTCP-HepG2 cells. We hypothesized that non-adherent cell conditions of infection would enhance HBV infectivity. Non-adherent NTCP-HepG2 cells were prepared by treatment with trypsin and EDTA, which did not degrade NTCP in the membrane fraction. HBV successfully infected NTCP-HepG2 cells at a viral dose 10 times lower in non-adherent phase than in adherent phase. Efficient infection of non-adherent NTCP-HepG2 cells with blood-borne or cell-culture-derived HBV was observed and was remarkably impaired in the presence of the myristoylated preS1 peptide. HBV could also efficiently infect HepaRG cells under non-adherent cell conditions. We screened several compounds using our culture system and identified proscillaridin A as a potent anti-HBV agent with an IC₅₀ value of 7.2 nM. In conclusion, non-adherent host cell conditions of infection augmented HBV infectivity in an NTCP-dependent manner, thus providing a novel strategy to identify anti-HBV drugs and investigate the mechanism of HBV infection.

Involvement of FKBP6 in hepatitis C virus replication

The chaperone system is known to be exploited by viruses for their replication. In the present study, we identified the cochaperone FKBP6 as a host factor required for hepatitis C virus (HCV) replication. FKBP6 is a peptidyl prolyl cis-trans isomerase with three domains of the tetratricopeptide repeat (TPR), but lacks FK-506 binding ability. FKBP6 interacted with HCV nonstructural protein 5A (NS5A) and also formed a complex with FKBP6 itself or FKBP8, which is known to be critical for HCV replication. The Val¹²¹ of NS5A and TPR domains of FKBP6 were responsible for the interaction between NS5A and FKBP6. FKBP6 was colocalized with NS5A, FKBP8, and double-stranded RNA in HCV-infected cells. HCV replication was completely suppressed in FKBP6-knockout hepatoma cell lines, while the expression of FKBP6 restored HCV replication in FKBP6-knockout cells. A treatment with the FKBP8 inhibitor N-(N′, N′-dimethylcarboxamidomethyl)cycloheximide impaired the formation of a homo- or hetero-complex consisting of FKBP6 and/or FKBP8, and suppressed HCV replication. HCV infection promoted the expression of FKBP6, but not that of FKBP8, in cultured cells and human liver tissue. These results indicate that FKBP6 is an HCV-induced host factor that supports viral replication in cooperation with NS5A.

Identification of Antiviral Agents Targeting Hepatitis B Virus Promoter from Extracts of Indonesian Marine Organisms by a Novel Cell-Based Screening Assay

The current treatments of chronic hepatitis B (CHB) face a limited choice of vaccine, antibody and antiviral agents. The development of additional antiviral agents is still needed for improvement of CHB therapy. In this study, we established a screening system in order to identify compounds inhibiting the core promoter activity of hepatitis B virus (HBV). We prepared 80 extracts of marine organisms from the coral reefs of Indonesia and screened them by using this system. Eventually, two extracts showed high inhibitory activity (>95%) and low cytotoxicity (66% to 77%). Solvent fractionation, column chromatography and NMR analysis revealed that 3,5-dibromo-2-(2,4-dibromophenoxy)-phenol (compound 1) and 3,4,5-tribromo-2-(2,4-dibromophenoxy)-phenol (compound 2), which are classified as polybrominated diphenyl ethers (PBDEs), were identified as anti-HBV agents in the extracts. Compounds 1 and 2 inhibited HBV core promoter activity as well as HBV production from HepG2.2.15.7 cells in a dose-dependent manner. The EC₅₀ values of compounds 1 and 2 were 0.23 and 0.80 µM, respectively, while selectivity indexes of compound 1 and 2 were 18.2 and 12.8, respectively. These results suggest that our cell-based HBV core promoter assay system is useful to determine anti-HBV compounds, and that two PBDE compounds are expected to be candidates of lead compounds for the development of anti-HBV drugs.

Hindered rotational physisorption states of H2 on Ag(111) surfaces

We have investigated the physisorption states of H2 on Ag(111) surfaces. To clarify the accurate adsorption properties of H2 on Ag(111), we performed first-principles calculations based on spin-polarized density functional theory (DFT) with the semiempirical DFT-D2 method and the newly-developed exchange functional with the non-local correlation functional vdW-DF2 (rev-vdW-DF2). We constructed exhaustive potential energy surfaces, and revealed that non-negligible out-of-plane potential anisotropy with a perpendicular orientation preference exists even for H2 physisorption on planar Ag(111), as predicted by previous results of resonance-enhanced multiphoton ionization spectroscopy and temperature-programmed desorption experiments. Therefore, the molecular rotational ground states of ortho-H2 split into two energy levels in the anisotropic potential. The obtained adsorption energy and the number of bound states, including the zero-point energies and the rotational energy shift, agree with diffractive and rotationally mediated selective adsorption scattering resonance measurements. The origin of the potential anisotropy on Ag(111) is a combination of the London dispersion interaction and the virtual transition of the metal electron to the unoccupied molecular state.

Long-term imipramine treatment increases N-methyl-d-aspartate receptor activity and expression via epigenetic mechanisms

Imipramine, a major antidepressant, is known to inhibit reuptake of serotonin and norepinephrine, which contributes to recovery from major depressive disorder. It has recently been reported that acute imipramine treatment inhibits N-methyl-d-aspartate (NMDA) receptor activity. However, the mechanisms underlying long-term effects of imipramine have not been identified. We tested these distinct effects in mouse cortical neurons and found that acute (30s) imipramine treatment decreased Ca(2+) influx through NMDA receptors, whereas long-term treatment (48h) increased Ca(2+) influx via the same receptors. Furthermore, long-term treatment increased NMDA receptor 2B (NR2B) subunit expression via epigenetic changes, including increased acetylation of histones H3K9 and H3K27 in the NR2B promoter and decreased activity of histone deacetylase 3 (HDAC3) and HDAC4. These results suggest that the long-term effects of imipramine on NMDA receptors are quite different from its acute effects. Furthermore, increased NR2B expression via epigenetic alterations might be a part of the mechanism responsible for this long-term effect.

Interstitial impurity-induced magnetism in α-PbO surface

We have investigated the effects of 3d transition metal (TM) and non-magnetic interstitial impurities in α-PbO (0 0 1) surface using ab-initio calculations. The calculated impurity-induced magnetic moments are 2.25 μB, 3.11 μB and 0.94 μB for Fe, Mn and Pb interstitials respectively. In the bonding process, TM's lower energy lying d(z2) states form overlaps with nearest neighbour oxygen atoms' p(z) states, with other non-bonding spin split d states situated near or at the Fermi level. These spin split orbitals introduce spin polarised p impurity states of oxygen atoms near the surface.

Effects of plasmon energetics on light emission induced by scanning tunneling microscopy

A theoretical model of plasmon and molecular luminescence induced by scanning tunneling microscopy using a molecule-covered tip on clean metal surfaces is developed. The effects of coupling between molecular exciton and interface plasmon on the luminescence spectra are investigated for variable energy of plasmon modes by means of the nonequilibrium Green's function method. It is found that spectral features arising from interference between the processes of energy absorption by the molecule and interface plasmons appear near the energy of the excitonic mode. For the energy of plasmon above (below) the energy of excitonic mode, an additional peak structure appears in the energy range slightly below (above) the energy of the excitonic mode. Prominent peak and dip structures observed in recent luminescence experiments are interpreted by the developed theory whereby its utility in the fields of plasmonics and nanophotonics is demonstrated.

Enhanced diacylglycerol production by phospholipase D activation is responsible for abnormal increase in concanavalin A cap formation in polymorphonuclear leukocytes from Chediak-Higashi syndrome (beige) mice

We previously reported that enhanced ceramide production induces calpain-mediated proteolysis of protein kinase C (PKC) in leukocytes from Chediak-Higashi syndrome (CHS). In the present study, we demonstrated that phospholipase D (PLD) inhibitors ameliorated abnormal increases in concanavalin A (Con A) cap formation in polymorphonuclear leukocytes (PMNs) from beige mouse, an animal model of CHS. PLD activity in PMNs from beige mice enhanced at 30 to 60s after Con A stimulation. In Con A-stimulated beige PMNs, both neutral sphingomyelinase (N-SMase) and acidic sphingomyelinase (A-SMase) activities enhanced, and ceramide levels are also increased. We found that ceramide levels were reversed by the treatment of beige PMNs with propranolol which inhibits phosphatidic acid phosphohydrolase. In addition, we showed that diacylgycerol (DAG) analogs enhance both N-SMase and A-SMase activities in PMNs from normal mice. We subsequently examined the association of CHS1 with PLD, and showed that expression of a truncated mutant of CHS1 in 293T cells induced abnormally rapid activation of PLD after phorbol ester stimulation. Moreover, we showed that specific inhibitors of 14-3-3 proteins, which interact with CHS1/LYST and bind PKC, did not affect abnormal increases in Con A cap formation in beige PMNs. These results suggest that the enhanced DAG production via the PLD pathway is associated with abnormal increases in Con A cap formation in beige PMNs, and that CHS1 may be involved in the regulation of PLD activity.

Inactivation of koi-herpesvirus in water using bacteria isolated from carp intestines and carp habitats

Since its first outbreak in Japan in 2003, koi-herpesvirus (KHV) remains a challenge to the carp Cyprinus carpio L. breeding industry. In this study, inactivation of KHV in water from carp habitats (carp habitat water) was investigated with the aim of developing a model for rapidly inactivating the pathogen in aquaculture effluent. Experiments with live fish showed that, in carp habitat water, KHV lost its infectivity within 3 days. Indications were that inactivation of KHV was caused by the antagonistic activity of bacteria (anti-KHV bacteria) in the water from carp habitats. Carp habitat water and the intestinal contents of carp were therefore screened for anti-KHV bacteria. Of 581 bacterial isolates, 23 showed anti-KHV activity. An effluent treatment model for the disinfection of KHV in aquaculture effluent water using anti-KHV bacteria was developed and evaluated. The model showed a decrease in cumulative mortality and in the number of KHV genome copies in kidney tissue of fish injected with treated effluent compared with a positive control. It is thought that anti-KHV bacteria isolated from the intestinal contents of carp and from carp habitat water can be used to control KHV outbreaks.

Microglia release ATP by exocytosis

Microglia survey the brain environment by sensing several types of diffusible molecules, among which extracellular nucleotides released/leaked from damaged cells have central roles. Microglia sense ATP or other nucleotides by multiple P2 receptors, after which they change into several different phenotypes. However, so far, it is largely unknown whether microglia themselves release ATP and, if so, by what mechanism. Here we show that exocytosis is the mechanism by which microglia release ATP. When we stimulated microglia with ionomycin, they released ATP and the release was dependent on Ca²⁺, vesicular H⁺-ATPase, or SNAREs but independent of connexin/pannexin hemichannels. VNUT was found to be expressed in microglia and exhibited no colocalization with lysosome. We also visualized the exocytosis of ATP by a quinacrine-based fluorescent time-lapse imaging. Moreover, we found that lipopolysaccharide increased the ionomycin-induced release of ATP, which was dependent on the increase in VNUT. Taken together, our data suggested that exocytosis is the mechanism of ATP release from microglia. When activated, they would release ATP by increasing VNUT-dependent exocytotic mechanisms.

Analysis of structural and electronic properties of Pr2NiO4 through first-principles calculations

The structural and electronic properties of bulk Pr(2)NiO(4+δ) (δ = 0 and 0.031) were analyzed using first-principles calculations based on the density functional theory (DFT) for application to electrode materials in solid-oxide fuel cells (SOFCs). Two structures of Pr(2)NiO(4) were analyzed: one in space group I4/mmm associated with the high temperature tetragonal (HTT) structure, and the other in Bmab with the low temperature orthorhombic (LTO) structure. The main difference between the two structures is the pronounced tilting of the nickelate octahedra found in the Bmab structure. Here, we will show that the difference in the electronic properties between the two structures, i.e. half-metallic for the I4/mmm structure and metallic for the Bmab structure, is attributed to the tilting of the nickelate octahedra. Furthermore, we found that the presence of interstitial O atoms at the Pr(2)O(2) bilayers is responsible for the tilting of the octahedra and thus is a dominant factor in the transition from the I4/mmm structure to the Bmab structure. These results would be of great significance to materials design related to the enhancement of O diffusivity in this material.

NO dissociation on Cu(111) and Cu2O(111) surfaces: a density functional theory based study

NO dissociation on Cu(111) and Cu(2)O(111) surfaces is investigated using spin-polarized density functional theory. This is to verify the possibility of using Cu-based catalyst for NO dissociation which is the rate limiting step for the NO(x) reduction process. The dissociation of molecularly adsorbed NO on the surface is activated for both cases. However, from the reaction path of the NO-Cu(2)O(111) system, the calculated transition state lies below the reference energy which indicates the possibility of dissociation. For the NO-Cu(111) system, the reaction path shows that NO desorption is more likely to occur. The geometric and electronic structure of the Cu(2)O(111) surface indicates that the surface Cu atoms stabilize themselves with reference to the O atom in the subsurface. The interaction results in modification of the electronic structure of the surface Cu atoms of Cu(2)O(111) which greatly affects the adsorption and dissociation of NO. This phenomenon further explains the obtained differences in the dissociation pathways of NO on the surfaces.

Delta-ADC (apparent diffusion coefficient) analysis in patients with idiopathic normal pressure hydrocephalus

We have developed the delta-apparent diffusion coefficient (ADC), a new parameter of the water dynamics of brain tissue using MRI. Delta-ADC is the changes in regional ADC values of the brain during the cardiac cycle. The study included 6 idiopathic normal pressure hydrocephalus (iNPH) patients (iNPH group) and 12 healthy volunteers (control group). ECG-triggered single-shot diffusion echo planar imaging (b = 0 and 1,000 s/mm(2)) was used on a 1.5-T MRI. The delta-ADC image was calculated from the maximum minus the minimum ADC value of all cardiac phase images (20 phases) on a pixel-by-pixel basis. Delta-ADC values in the white matter of the frontal, temporal, and occipital lobe were obtained. Delta-ADC values in the iNPH group were significantly higher than those in the control group in all regions. ADC values in the iNPH were also significantly higher than those in the control group, but the differences in the ADC between the groups in each region were much lower than those for the delta-ADC. Although the changes in the delta-ADC and ADC values were similar, there was no significant correlation between the delta-ADC and the ADC. These results suggest that the ADC and the delta-ADC may reflect different kinds of water dynamics. The ADC depends on the water content in brain tissue. On the other hand, delta-ADC depends on not only the water content, but also on the degree of the fluctuation of the water molecules. Delta-ADC analysis makes it possible to obtain non-invasively new and more detailed information on the regional brain condition in iNPH.

Surface magnetism in O2 dissociation-from basics to application

First-principles calculations were performed to investigate magnetic phenomena in surface reactions involving O(2). We present two magnetized surface cases: (1) oxidation of paramagnetic Ag, and magnetic properties of the high coverage oxide phase, which correspond to a magnetic impurity superlattice on paramagnetic surfaces and (2) oxidation of ferromagnetic Pt, represented by the Pt layer on M (M = Fe and Co) relevant to the oxidation reduction reaction (ORR) on Pt, in relation to both fundamental and application interests. In the first case, we found that the dissociative adsorption of O(2), resulting in oxide phases in Ag(111), reveals interesting magnetic interactions. We note that the magnetic states are induced by the ferromagnetic superexchange interactions and Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions. Specifically, the superlattice structures with short O-O distances have an effective ferromagnetic superexchange and RKKY interaction. In the second case, we found that a magnetic moment is induced on the Pt layer by the M substrate. The spin polarization of Pt-d states is due to hybridization with M-d states. The d-band center (ε(d)) of Pt (on M), is shifted downwards with respect to pure Pt. However, because of the spin polarization, the otherwise filled spin-down d(zz) orbital in paramagnetic pure Pt is shifted towards the Fermi level. This promotes π(z↑)-d(zz↓) interactions, which influences the O(2)-Pt interaction at O(2) far from the surface. Details and mechanisms of these two magnetic phenomena are discussed.

Deletion of Ia-2 and/or Ia-2β in mice decreases insulin secretion by reducing the number of dense core vesicles

AIMS/HYPOTHESIS

Islet antigen 2 (IA-2) and IA-2β are dense core vesicle (DCV) transmembrane proteins and major autoantigens in type 1 diabetes. The present experiments were initiated to test the hypothesis that the knockout of the genes encoding these proteins impairs the secretion of insulin by reducing the number of DCV.

METHODS

Insulin secretion, content and DCV number were evaluated in islets from single knockout (Ia-2 [also known as Ptprn] KO, Ia-2β [also known as Ptprn2] KO) and double knockout (DKO) mice by a variety of techniques including electron and two-photon microscopy, membrane capacitance, Ca(2+) currents, DCV half-life, lysosome number and size and autophagy.

RESULTS

Islets from single and DKO mice all showed a significant decrease in insulin content, insulin secretion and the number and half-life of DCV (p < 0.05 to 0.001). Exocytosis as evaluated by two-photon microscopy, membrane capacitance and Ca(2+) currents supports these findings. Electron microscopy of islets from KO mice revealed a marked increase (p < 0.05 to 0.001) in the number and size of lysosomes and enzymatic studies showed an increase in cathepsin D activity (p < 0.01). LC3 protein, an indicator of autophagy, also was increased in islets of KO compared with wild-type mice (p < 0.05 to 0.01) suggesting that autophagy might be involved in the deletion of DCV.

CONCLUSIONS/INTERPRETATION

We conclude that the decrease in insulin content and secretion, resulting from the deletion of Ia-2 and/or Ia-2β, is due to a decrease in the number of DCV.

Ferromagnetic domain nucleation and growth in colossal magnetoresistive manganite

Colossal magnetoresistance is a dramatic decrease in resistivity caused by applied magnetic fields, and has been the focus of much research because of its potential for magnetic data storage using materials such as manganites. Although extensive microscopy and theoretical studies have shown that colossal magnetoresistance involves competing insulating and ferromagnetic conductive phases, the mechanism underlying the effect remains unclear. Here, by directly observing magnetic domain walls and flux distributions using cryogenic Lorentz microscopy and electron holography, we demonstrate that an applied magnetic field assists nucleation and growth of an ordered ferromagnetic phase. These results provide new insights into the evolution dynamics of complex domain structures at the nanoscale, and help to explain anomalous phase separation phenomena that are relevant for applications. Our approach can also be used to determine magnetic parameters of nanoscale regions, such as magnetocrystalline anisotropy and exchange stiffness, without bulk magnetization results or neutron scattering data.