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1.
Sci Rep ; 10(1): 4813, 2020 Mar 16.
Article in English | MEDLINE | ID: mdl-32179784

ABSTRACT

Nitrogen-vacancy (NV) centers in diamond have been used as platforms for quantum information, magnetometry and imaging of microwave (MW) fields. The spatial distribution of the MW fields used to drive the electron spin of NV centers plays a key role for these applications. Here, we report a system for the control and characterization of MW magnetic fields used for the NV spin manipulation. The control of the MW field in the vicinity of a diamond surface is mediated by an exchangeable lumped resonator, coupled inductively to a MW planar ring antenna. The characterization of the MW fields in the near-field is performed by an FFT imaging of Rabi oscillations, by using an ensemble of NV centers. We have found that the Rabi frequency over a lumped resonator is enhanced 22 times compared to the Rabi frequency without the presence of the lumped resonator. Our system may find applications in quantum information and magnetometry where a precise and controlled spin manipulation is required, showing NV centers as good candidates for imaging MW fields and characterization of MW devices.

2.
Opt Express ; 27(20): 28091-28103, 2019 Sep 30.
Article in English | MEDLINE | ID: mdl-31684567

ABSTRACT

In this study, we demonstrate the switching of the direction of the photocurrent in an n-type GaAs/Al0.3Ga0.7As modulation-doped quantum well using a polarization pulse-shaping apparatus containing a 4f setup. The right- and left-polarization-twisting pulses with a polarization rotation frequency in the THz-regime are incident on a modulation-doped quantum well. The results show that the sign of the photovoltage is dependent on the direction of rotation of the polarization-twisting pulses, which can be explained by the circular photogalvanic effect combined with the production of a classical edge photocurrent from the acceleration of free electrons in the vicinity of the sample edge by the incident optical electric field. The wide range over which the polarization-rotation frequency may be tuned makes this method a powerful tool to investigate the response of an extensive variety of materials in the THz-regime.

3.
PLoS One ; 11(9): e0162672, 2016.
Article in English | MEDLINE | ID: mdl-27611322

ABSTRACT

BACKGROUND: Asthma is a chronic inflammatory disease of airways, but an ideal biomarker that accurately reflects ongoing airway inflammation has not yet been established. The aim of this study was to examine the potential of sputum leucine-rich alpha-2 glycoprotein (LRG) as a new biomarker for airway inflammation in asthma. METHODS: We obtained induced sputum samples from patients with asthma (N = 64) and healthy volunteers (N = 22) and measured LRG concentration by sandwich enzyme-linked immunosorbent assay (ELISA). Ovalbumin (OVA)-induced asthma model mice were used to investigate the mechanism of LRG production during airway inflammation. The LRG concentrations in the bronchoalveolar lavage fluid (BALF) obtained from mice were determined by ELISA and mouse lung sections were stained with anti-LRG antibody and periodic acid-Schiff (PAS) reagent. RESULTS: Sputum LRG concentrations were significantly higher in patients with asthma than in healthy volunteers (p = 0.00686). Consistent with patients' data, BALF LRG levels in asthma model mice were significantly higher than in control mice (p = 0.00013). Immunohistochemistry of lung sections from asthma model mice revealed that LRG was intensely expressed in a subpopulation of bronchial epithelial cells, which corresponded with PAS-positive mucus producing cells. CONCLUSION: These findings suggest that sputum LRG is a promising biomarker of local inflammation in asthma.


Subject(s)
Asthma/complications , Asthma/metabolism , Glycoproteins/metabolism , Pneumonia/complications , Pneumonia/metabolism , Sputum/metabolism , Animals , Asthma/blood , Asthma/pathology , Biomarkers/blood , Bronchi/pathology , Bronchoalveolar Lavage Fluid , Cell Count , Disease Models, Animal , Epithelial Cells/metabolism , Female , Glycoproteins/blood , Humans , Male , Mice, Inbred C57BL , Middle Aged , Pneumonia/blood , Pneumonia/pathology , Up-Regulation
4.
Adv Mater ; 28(14): 2777-81, 2016 Apr 13.
Article in English | MEDLINE | ID: mdl-26865384

ABSTRACT

Ultrapure blue-fluorescent molecules based on thermally activated delayed fluorescence are developed. Organic light-emitting diode (OLED) devices employing the new emitters exhibit a deep blue emission at 467 nm with a full-width at half-maximum of 28 nm, CIE coordinates of (0.12, 0.13), and an internal quantum efficiency of ≈100%, which represent record-setting performance for blue OLED devices.

5.
Sci Rep ; 5: 15097, 2015 Oct 13.
Article in English | MEDLINE | ID: mdl-26459874

ABSTRACT

Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field.

6.
Angew Chem Int Ed Engl ; 54(46): 13581-5, 2015 Nov 09.
Article in English | MEDLINE | ID: mdl-26380959

ABSTRACT

The development of a one-step borylation of 1,3-diaryloxybenzenes, yielding novel boron-containing polycyclic aromatic compounds, is reported. The resulting boron-containing compounds possess high singlet-triplet excitation energies as a result of localized frontier molecular orbitals induced by boron and oxygen. Using these compounds as a host material, we successfully prepared phosphorescent organic light-emitting diodes exhibiting high efficiency and adequate lifetimes. Moreover, using the present one-step borylation, we succeeded in the synthesis of an efficient, thermally activated delayed fluorescence emitter and boron-fused benzo[6]helicene.

7.
Exp Eye Res ; 140: 53-64, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26297802

ABSTRACT

Recently, a number of biologics have been used in the treatment of autoimmune diseases. However, in the treatment of severe autoimmune uveitis, only TNF-alpha inhibitors are preferably used and the effect of other biologics such as interleukin-6 (IL-6) signaling blockade or cytotoxic T-lymphocyte antigen-4-immunoglobulin fusion protein (CTLA4-Ig) has not been well studied. Previously, we reported that IL-6 blockade effectively suppresses the development of experimental autoimmune uveitis (EAU), a mouse model for uveitis, by inhibiting Th17 cell development. In this study, we investigated the effect of CTLA4-Ig on EAU development and compared it with the effect of anti-IL-6 receptor monoclonal antibody (MR16-1). C57BL/6J mice were immunized with interphotoreceptor retinoid-binding protein (IRBP) and treated once with CTLA4-Ig or MR16-1. Both CTLA4-Ig and MR16-1 administered in the induction phase (the same day as immunization) significantly reduced the clinical and histopathological scores of EAU. Fluorescence-activated cell sorting studies using draining lymph node (LN) cells from EAU mice 10 days after immunization showed that CTLA4-Ig can suppress early T-helper cell activation. CTLA4-Ig administered in the effector phase of the disease (one week after immunization), when IRBP-reactive T cells have been primed, also significantly reduced the clinical and histopathological scores of EAU. In contrast, MR16-1 administered in the effector phase did not ameliorate EAU. To investigate the differences between these biologics in the effector phase, in vitro restimulation analysis of LN cells obtained from EAU mice one week after immunization was performed and revealed that CTLA4-Ig, but not MR16-1, added to culture media could inhibit the proliferation of IRBP-specific CD4(+) T cells which possessed capacities of producing IFN-gamma and/or IL-17. Collectively, CTLA4-Ig ameliorated EAU through preventing initial T-cell activation in the induction phase and suppressing proliferation of IRBP-specific T cells in the effector phase. Blockade of IL-6 signaling did not have such inhibitory effects after T-cell priming. CTLA4-Ig may have therapeutic effects on human chronic uveitis.


Subject(s)
Abatacept/pharmacology , Autoimmune Diseases/prevention & control , Disease Models, Animal , Immunosuppressive Agents/pharmacology , Interleukin-6/antagonists & inhibitors , Uveitis/prevention & control , Animals , Antibodies, Blocking/pharmacology , Autoimmune Diseases/chemically induced , Autoimmune Diseases/immunology , CD4-Positive T-Lymphocytes/immunology , Cell Proliferation/drug effects , Enzyme-Linked Immunosorbent Assay , Eye Proteins , Female , Flow Cytometry , Interferon-gamma/metabolism , Interleukin-17/metabolism , Lymph Nodes , Lymphocyte Activation/drug effects , Mice , Mice, Inbred C57BL , Peptide Fragments , Receptors, Interleukin-6/immunology , Retinol-Binding Proteins , Uveitis/chemically induced , Uveitis/immunology
8.
PLoS One ; 10(8): e0135836, 2015.
Article in English | MEDLINE | ID: mdl-26284361

ABSTRACT

Human dynactin-associated protein (dynAP) is a transmembrane protein that promotes AktSer473 phosphorylation. Here, we report the oncogenic properties of dynAP. In contrast to control NIH3T3 cells expressing LacZ (NIH3T3LacZ), NIH3T3dynAP cells vigorously formed foci in two-dimensional culture, colonies on soft agar, and spheroids in anchorage-deficient three-dimensional culture. NIH3T3dynAP cells injected into nude mice produced tumors with abundant blood vessels and weak cell-cell contacts. Expression of dynAP elevated the level of rictor (an essential subunit of mTORC2) and promoted phosphorylation of FOXO3aSer253. FOXO3a is a transcriptional factor that stimulates expression of pro-apoptotic genes and phosphorylation of FOXO3a abrogates its function, resulting in promoted cell survival. Knockdown of rictor in NIH3T3dynAP cells reduced AktSer473 phosphorylation and formation of foci, colony in soft agar and spheroid, indicating that dynAP-induced activation of the mTORC2/AktSer473 pathway for cell survival contributes to cell transformation. E-cadherin and its mRNA were markedly reduced upon expression of dynAP, giving rise to cells with higher motility, which may be responsible for the weak cell-cell adhesion in tumors. Thus, dynAP could be a new oncoprotein and a target for cancer therapy.


Subject(s)
Cell Communication , Cell Transformation, Neoplastic , Microtubule-Associated Proteins/genetics , Neoplasms/blood supply , Neoplasms/pathology , Neovascularization, Pathologic/genetics , Animals , Dynactin Complex , Female , Humans , Lac Operon/genetics , Mice , NIH 3T3 Cells , Neoplasms/genetics , Up-Regulation
9.
Oncotarget ; 6(13): 11009-22, 2015 May 10.
Article in English | MEDLINE | ID: mdl-25826092

ABSTRACT

Leucine-rich α2-glycoprotein (LRG) is an approximately 50-kDa glycoprotein that has been found to be elevated in the sera of patients with several types of cancer. LRG directly binds to transforming growth factor beta 1 (TGFß1) and modulates TGFß1 signaling in endothelial cells; however, the precise function of LRG in cancer remains unclear. This study aimed to investigate the role of LRG in cancer. Lewis lung carcinoma (LLC) cells hardly expressed LRG. The growth of LLC tumors allografted in the LRG knockout (KO) mice was significantly increased compared with wild-type (WT) mice. Conversely, overexpression of LRG significantly inhibited the growth of LLC tumors in WT mice. In the presence of LRG, TGFß1 significantly inhibited the proliferation of LLC cells and human hepatocellular carcinoma Hep3B cells in vitro by inducing apoptosis via the potent activation of smad2 and its downstream signaling pathway. Furthermore, administration of a TGFßR1 inhibitor (SB431542) significantly enhanced the growth of LLC tumors in WT mice compared with LRG KO mice via inhibition of apoptosis. We propose that LRG potentiates the effect of TGFß1 in cancer cells whose growth is suppressed in the presence of TGFß1.


Subject(s)
Apoptosis , Carcinoma, Hepatocellular/prevention & control , Carcinoma, Lewis Lung/prevention & control , Glycoproteins/physiology , Liver Neoplasms/prevention & control , Transforming Growth Factor beta1/metabolism , Animals , Blotting, Western , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Carcinoma, Lewis Lung/genetics , Carcinoma, Lewis Lung/pathology , Cell Proliferation , Female , Humans , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Transforming Growth Factor beta1/genetics , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
10.
Nano Lett ; 15(4): 2417-21, 2015 Apr 08.
Article in English | MEDLINE | ID: mdl-25727460

ABSTRACT

We have successfully developed a circularly polarized near-field scanning optical microscope (NSOM) that enables us to irradiate circularly polarized light with spatial resolution below the diffraction limit. As a demonstration, we perform real-space mapping of the quantum Hall chiral edge states near the edge of a Hall-bar structure by injecting spin polarized electrons optically at low temperature. The obtained real-space mappings show that spin-polarized electrons are injected optically to the two-dimensional electron layer. Our general method to locally inject spins using a circularly polarized NSOM should be broadly applicable to characterize a variety of nanomaterials and nanostructures.


Subject(s)
Circular Dichroism/instrumentation , Magnetic Fields , Materials Testing/instrumentation , Microscopy, Scanning Probe/instrumentation , Quantum Theory , Radiometry/instrumentation , Equipment Design , Equipment Failure Analysis , Reproducibility of Results , Sensitivity and Specificity , Spin Labels
11.
Pigment Cell Melanoma Res ; 27(4): 630-9, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24674392

ABSTRACT

Given no reliable therapy for advanced malignant melanoma, it is important to elucidate the molecular mechanisms underlying the disease progression. Using a quantitative proteomics approach, the 'isobaric tags for relative and absolute quantitation (iTRAQ)' method, we identified that the extracellular matrix protein, periostin (POSTN), was highly expressed in invasive melanoma compared with normal skin. An immunohistochemical analysis showed that POSTN was expressed in all invasive melanoma (n = 20) and metastatic lymph node (n = 5) tissue samples, notably restricted in their stroma. In terms of the intercellular regulation of POSTN, we found that there was upregulation of POSTN when melanoma cells and normal human dermal fibroblasts (NHDFs) were cocultured, with restricted expression of TGF-ß1 and TGF-ß3. In a functional analyses, recombinant and NHDF-derived POSTN significantly accelerated melanoma cell proliferation via the integrin/mitogen-activated protein kinase (MAPK) signaling pathway in vitro. The size of implanted melanoma tumors was significantly suppressed in POSTN/Rag2 double knockout mice compared with Rag2 knock-out mice. These results indicate that NHDF-derived POSTN accelerates melanoma progression and might be a promising therapeutic target for malignant melanoma.


Subject(s)
Cell Adhesion Molecules/metabolism , MAP Kinase Signaling System , Melanoma/metabolism , Neoplasm Proteins/metabolism , Tumor Microenvironment , Animals , Cell Adhesion Molecules/genetics , Cell Line, Tumor , Heterografts , Humans , Male , Melanoma/genetics , Melanoma/pathology , Mice , Mice, Knockout , Neoplasm Proteins/genetics , Neoplasm Transplantation
12.
Opt Express ; 22(2): 1997-2006, 2014 Jan 27.
Article in English | MEDLINE | ID: mdl-24515209

ABSTRACT

Low-temperature photoluminescence (PL) spectra of electron-hole systems in Si nanowires (NWs) prepared by thermal oxidization of Si fin structures were studied. Mapping of PL reveals that NWs with uniform width are formed over a large area. Annealing temperature dependence of PL peak intensities was maximized at 400 °C for each NW type, which are consistent with previous reports. Our results confirmed that the micro-PL demonstrated here is one of the important methods for characterizations of the interface defects in Si NWs.

13.
Cancer Sci ; 104(11): 1483-91, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23962256

ABSTRACT

Lung cancer (LC) is the major cause of death by cancer and the number of LC patients is increasing worldwide. This study investigated the therapeutic potential of gene delivery using suppressor of cytokine signaling 1 (SOCS-1), an endogenous inhibitor of intracellular signaling pathways, for the treatment of LC. To examine the antitumor effect of SOCS-1 overexpression on non-small-cell lung cancer (NSCLC) cells, NSCLC cells (A549, LU65, and PC9) were infected with adenovirus-expressing SOCS-1 vector. The cell proliferation assay showed that A549 and LU65, but not PC9, were sensitive to SOCS-1 gene-mediated suppression of cell growth. Although JAK inhibitor I could also inhibit proliferation of A549 and LU65 cells, SOCS-1 gene delivery appeared to be more potent as SOCS-1 could suppress focal adhesion kinase and epidermal growth factor receptor, as well as the JAK/STAT3 signaling pathway. Enhanced phosphorylation of the p53 protein was detected by means of phospho-kinase array in SOCS-1 overexpressed A549 cells compared with control cells, whereas no phosphorylation of p53 was observed when JAK inhibitor I was used. Furthermore, treatment with adenoviral vector AdSOCS-1 in vivo significantly suppressed NSCLC proliferation in a xenograft model. These results suggest that the overexpression of SOCS-1 gene is effective for antitumor therapy by suppressing the JAK/STAT, focal adhesion kinase, and epidermal growth factor receptor signaling pathways and enhancing p53-mediated antitumor activity in NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung/therapy , Lung Neoplasms/therapy , Suppressor of Cytokine Signaling Proteins/genetics , Adenoviridae/genetics , Animals , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Proliferation , Cell Survival , ErbB Receptors/genetics , ErbB Receptors/metabolism , Female , Focal Adhesion Kinase 1/genetics , Focal Adhesion Kinase 1/metabolism , Gene Expression Regulation, Neoplastic , Genetic Therapy , Humans , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice , Mice, Inbred ICR , Mice, Nude , Neoplasm Transplantation , Signal Transduction , Suppressor of Cytokine Signaling 1 Protein , Suppressor of Cytokine Signaling Proteins/biosynthesis , Transduction, Genetic , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
14.
Carbohydr Polym ; 98(1): 611-7, 2013 Oct 15.
Article in English | MEDLINE | ID: mdl-23987389

ABSTRACT

In this study, we investigated the preparation of polysaccharide supramolecular films through the formation of inclusion complexes by amylose in vine-twining polymerization using carboxymethyl cellulose-graft-poly(ε-caprolactone) (CMC-g-PCL) as a new guest polymer. First, hydrogels were prepared by phosphorylase-catalyzed enzymatic polymerization in the presence of CMC-g-PCL according to the vine-twining polymerization manner. The XRD result of a powdered sample obtained by lyophilization of the resulting hydrogel indicated the presence of inclusion complexes of amylose with the PCL graft-chains between intermolecular (CMC-g-PCL)s, which acted as supramolecular cross-linking points for the hydrogelation. Then, the supramolecular films were obtained by adding water to the powdered samples, followed by drying. The mechanical properties of the selected films examined by tensile testing were superior to those of a CMC film. The effect of the supramolecular cross-linking structures on the mechanical properties of the films was evaluated further by several investigations.


Subject(s)
Polymerization , Polysaccharides/chemistry , Carboxymethylcellulose Sodium/chemistry , Green Chemistry Technology , Hydrogels/chemistry , Polyesters/chemistry
15.
Int J Cancer ; 132(2): 459-71, 2013 Jan 15.
Article in English | MEDLINE | ID: mdl-22532243

ABSTRACT

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis for which an effective therapy remains to be established. This study investigated the therapeutic potential of gene delivery using suppressor of cytokine signaling 1 (SOCS-1), an endogenous inhibitor of intracellular signaling pathways, for the treatment of MPM. We infected MPM cells (MESO-4, H28 and H226) with adenovirus-expressing SOCS-1 vector to examine the effect of SOCS-1 overexpression on MPM cells. We evaluated the antitumor effect of SOCS-1 gene delivery combined with cisplatin plus pemetrexed by cell proliferation, apoptosis and invasion assay. We also investigated the regulation of NF-κB and STAT3 signaling related to apoptotic pathways. Furthermore, we evaluated the inhibition of tumor growth by SOCS-1 gene delivery combined with cisplatin plus pemetrexed in vivo. SOCS-1 gene delivery cooperated with cisplatin plus pemetrexed to inhibit cell proliferation, invasiveness and induction of apoptosis in MPM cells. SOCS-1 regulated NF-κB and STAT3 signaling to induce apoptosis in MESO-4 and H226 cells. Furthermore, SOCS-1 gene delivery cooperated with cisplatin plus pemetrexed to regulate NF-κB signaling and significantly inhibit tumor growth of MPM in vivo. These results suggest that SOCS-1 gene delivery has a potent antitumor effect against MPM and a potential for clinical use in combination with cisplatin plus pemetrexed.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Mesothelioma/therapy , Pleural Neoplasms/therapy , Suppressor of Cytokine Signaling Proteins/genetics , Adenoviridae/genetics , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Apoptosis , Cell Line, Tumor , Cell Movement , Cell Proliferation/drug effects , Cell Survival/drug effects , Cisplatin/administration & dosage , Combined Modality Therapy , Enzyme Activation , Female , Gene Expression , Genetic Therapy , Genetic Vectors , Glutamates/administration & dosage , Guanine/administration & dosage , Guanine/analogs & derivatives , Humans , Inhibitor of Apoptosis Proteins/metabolism , Interferon-gamma/pharmacology , Interferon-gamma/physiology , Mesothelioma/pathology , Mice , Mice, Inbred ICR , Mice, Nude , NF-kappa B/metabolism , Neoplasm Invasiveness , Pemetrexed , Pleural Neoplasms/pathology , STAT3 Transcription Factor/metabolism , Signal Transduction , Suppressor of Cytokine Signaling 1 Protein , Suppressor of Cytokine Signaling Proteins/metabolism , Tumor Burden/drug effects , Xenograft Model Antitumor Assays
16.
PLoS One ; 7(11): e48933, 2012.
Article in English | MEDLINE | ID: mdl-23152823

ABSTRACT

Embryo implantation is a highly orchestrated process that involves blastocyst-uterine interactions. This process is confined to a defined interval during gestation referred to as the "window of embryo implantation receptivity". In mice this receptive period is controlled by ovarian estrogen and involves a coordination of blastocyst adhesion competence and uterine receptivity. Mechanisms coordinating the acquisition of blastocyst adhesion competence and uterine receptivity are largely unknown. Here, we show that ovarian estrogen indirectly regulates blastocyst adhesion competence. Acquisition of blastocyst adhesion competence was attributed to integrin activation (e.g. formation of adhesion complexes) rather than de novo integrin synthesis. Osteopontin (OPN) was identified as an estrogen-dependent uterine endometrial gland secretory factor responsible for activating blastocyst adhesion competence. Increased adhesion complex assembly in OPN-treated blastocysts was mediated through focal adhesion kinase (FAK)- and phosphatidylinositol 3-kinase (PI3K)-dependent signaling pathways. These findings define for the first time specific regulatory components of an estrogen-dependent pathway coordinating blastocyst adhesion competence and uterine receptivity.


Subject(s)
Blastocyst/metabolism , Estrogens/metabolism , Osteopontin/metabolism , Uterus/metabolism , Animals , Blastocyst/cytology , Cell Adhesion , Decidua/physiology , Female , Fibronectins/metabolism , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Gene Expression Regulation , Humans , Integrins/metabolism , Mice , Osteopontin/genetics , Phosphatidylinositol 3-Kinases/metabolism , Signal Transduction
17.
Opt Express ; 20(20): 21847-59, 2012 Sep 24.
Article in English | MEDLINE | ID: mdl-23037335

ABSTRACT

We investigated the dynamic response of a cascaded-ring-resonator-loaded Mach-Zehnder modulator (CRR-MZM), in which a number of cascaded ring resonators (RRs) are loaded in the interferometer as phase modulators. The analytical form is derived for the small-signal response of CRR-MZM using temporal-coupled-mode (TCM) theory, and its validity is confirmed by numerical calculations. It is revealed that the bandwidth of the CRR-MZM is maximized by setting proper delays in driving signals between neighboring RRs; the optimized delay is twice the photon lifetime of each RR. The calculated performances of CRR-MZMs are compared with those of standard modulators based on a single-ring-resonator (SRR) without interferometer, in terms of the modulation depth and bandwidth. For a given degree of the refractive index change in a waveguide, CRR-MZM can provide a larger modulation depth than a SRR-type modulator in frequency ranges exceeding 25 GHz.


Subject(s)
Interferometry/instrumentation , Optical Devices , Refractometry/instrumentation , Telecommunications/instrumentation , Equipment Design , Equipment Failure Analysis , Microwaves
18.
Invest Ophthalmol Vis Sci ; 52(6): 3264-71, 2011 May 17.
Article in English | MEDLINE | ID: mdl-21330657

ABSTRACT

PURPOSE. Both Th17 and Th1 cells contribute to experimental autoimmune uveoretinitis (EAU). Interleukin-6 (IL-6) blockade inhibits Th17 differentiation in EAU and potently suppresses ocular inflammation, although its effect on Th1 cells is unknown. To clarify the mechanism of IL-6 blockade, the authors investigated T helper cells with particular focus on Th1 and regulatory T cells (Treg) in EAU of IL-6 gene knockout (KO) mice. METHODS. EAU was induced in wild-type (WT) mice and in mice lacking IL-6 (IL-6KO), IL-17 (IL-17KO), and IFN-γ (GKO) on a C57BL/6 background. Clinical scores of EAU, cytokine levels in supernatants from ocular tissue homogenates, and T helper cell differentiation in lymph nodes in each mouse were examined. To study the roles of Treg cells, EAU was induced in IL-6KO mice treated with anti-CD25 monoclonal antibody (mAb) to deplete Treg cells in vivo. RESULTS. Inflammation was comparable between WT, IL-17KO, and GKO mice but was absent in IL-6KO mice. Th17 and interphotoreceptor retinoid binding protein (IRBP)-specific Th1 cells were increased in GKO and IL-17KO mice, respectively, whereas both populations were reduced in IL-6KO mice. Th1-dominant EAU in IL-17KO mice was suppressed by anti-IL-6R mAb treatment. Treg cell depletion in vivo induced EAU in IL-6KO mice. CONCLUSIONS. After the induction of EAU, IL-6 deficiency resulted in the inhibition of the IRBP-specific Th1 response and enhanced the generation of IRBP-specific Treg cells. Furthermore, Treg was needed to inhibit Th1 responses and ocular inflammation in IL-6KO mice. Protective effects of IL-6 signaling blockade in EAU involve not only Th17 cell inhibition but also IRBP-specific Treg cell promotion.


Subject(s)
Autoimmune Diseases/prevention & control , Eye Proteins/immunology , Interleukin-6/physiology , Retinitis/prevention & control , Retinol-Binding Proteins/immunology , T-Lymphocytes, Regulatory/immunology , Th1 Cells/immunology , Th17 Cells/immunology , Uveitis/prevention & control , Animals , Autoimmune Diseases/immunology , Cells, Cultured , Cytokines/metabolism , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Lymphocyte Depletion , Mice , Mice, Inbred C57BL , Mice, Knockout , Retinitis/immunology , Signal Transduction/physiology , Uveitis/immunology
19.
Int J Cancer ; 129(4): 1005-17, 2011 Aug 15.
Article in English | MEDLINE | ID: mdl-20949562

ABSTRACT

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis for which an effective therapy remains to be established. Our study investigated the therapeutic potential of the suppressor of cytokine signaling 3 (SOCS3), an endogenous inhibitor of intracellular signaling pathways, for treatment of MPM. We infected MPM cells (H226, EHMES-1, MESO-1 and MESO-4) with an adenovirus-expressing SOCS3 (AdSOCS3) to examine the effect of SOCS3 overexpression on MPM cells. SOCS3 overexpression reduced MPM proliferation and induced apoptosis and partial G0/G1 arrest. SOCS3 also inhibited the proliferation of MPM cells via multiple signaling pathways including Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), extracellular signal-regulated kinase (ERK), focal adhesion kinase (FAK) and p53 pathways. Notably, AdSOCS3 treatment inhibited tumor growth in an MPM pleural xenograft model. These findings demonstrate that overexpression of SOCS3 has a potent antitumor effect against MPM both in vitro and in vivo and indicate the potential for clinical use of SOCS3 for MPM treatment.


Subject(s)
Mesothelioma/prevention & control , Pleural Neoplasms/prevention & control , Suppressor of Cytokine Signaling Proteins/metabolism , Adenoviridae/genetics , Animals , Apoptosis , Blotting, Western , Cell Cycle , Cell Line, Tumor , Cell Proliferation , Female , Humans , Immunoenzyme Techniques , Mesothelioma/metabolism , Mesothelioma/pathology , Mice , Mice, Inbred ICR , Mice, Nude , Pleural Neoplasms/metabolism , Pleural Neoplasms/pathology , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Xenograft Model Antitumor Assays
20.
J Immunol ; 186(1): 32-40, 2011 Jan 01.
Article in English | MEDLINE | ID: mdl-21106853

ABSTRACT

IL-6 is a proinflammatory cytokine and its overproduction is implicated in a variety of inflammatory disorders. Recent in vitro analyses suggest that IL-6 is a key cytokine that determines the balance between Foxp3(+) regulatory T cells (Tregs) and Th17 cells. However, it remains unclear whether excessive IL-6 production in vivo alters the development and function of Foxp3(+) Tregs. In this study, we analyzed IL-6 transgenic (Tg) mice in which serum IL-6 levels are constitutively elevated. Interestingly, in IL-6 Tg mice, whereas peripheral lymphoid organs were enlarged, and T cells exhibited activated phenotype, Tregs were not reduced but rather increased compared with wild-type mice. In addition, Tregs from Tg mice normally suppressed proliferation of naive T cells in vitro. Furthermore, Tregs cotransferred with naive CD4 T cells into SCID-IL-6 Tg mice inhibited colitis as successfully as those transferred into control SCID mice. These results indicate that overproduction of IL-6 does not inhibit development or function of Foxp3(+) Tregs in vivo. However, when naive CD4 T cells alone were transferred, Foxp3(+) Tregs retrieved from SCID-IL-6 Tg mice were reduced compared with SCID mice. Moreover, the Helios(-) subpopulation of Foxp3(+) Tregs, recently defined as extrathymic Tregs, was significantly reduced in IL-6 Tg mice compared with wild-type mice. Collectively, these results suggest that IL-6 overproduced in vivo inhibits inducible Treg generation from naive T cells, but does not affect the development and function of natural Tregs.


Subject(s)
Cell Differentiation/immunology , Forkhead Transcription Factors/biosynthesis , Interleukin-6/biosynthesis , T-Lymphocytes, Regulatory/immunology , Adoptive Transfer , Animals , Cell Differentiation/genetics , Cells, Cultured , Coculture Techniques , Colitis/immunology , Colitis/pathology , Colitis/prevention & control , Disease Models, Animal , Forkhead Transcription Factors/physiology , Humans , Interleukin-6/blood , Interleukin-6/physiology , Lymphocyte Count , Mice , Mice, Inbred BALB C , Mice, SCID , Mice, Transgenic , T-Lymphocytes, Regulatory/cytology , T-Lymphocytes, Regulatory/transplantation
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