658 research outputs found
Texture zeros realization in a three-loop radiative neutrino mass model from modular symmetry
We derive verifiable two-zero textures in the framework of a three-loop
induced neutrino mass model applying a modular symmetry for the lepton
sector. Interestingly, the neutrino mass structure is determined by assignments
of the right-handed charged-lepton particles only. We show all the possible
texture patterns and demonstrate their analytical and numerical analyses.
Finally, we mention a possibility of detection for doubly-charged boson via
colliders that decays into specific modes due to the flavor symmetry.Comment: 15 pages, 3 figure
Flavor, CP and Metaplectic Modular Symmetries in Type IIB Chiral Flux Vacua
We examine symmetries of chiral four-dimensional vacua of Type IIB flux
compactifications with vanishing superpotential . We find that the supersymmetric MSSM-like and Pati-Salam vacua possess enhanced discrete
symmetries in the effective action below the mass scale of stabilized complex
structure moduli and dilaton. Furthermore, a generation number of
quarks/leptons is small on these vacua where the flavor, CP and metaplectic
modular symmetries are described in the framework of eclectic flavor symmetry.Comment: 30 pages, 5 figure
Highly sensitive chiral analysis in capillary electrophoresis with large-volume sample stacking with an electroosmotic flow pump.
To improve the sensitivity in chiral analysis by capillary electrophoresis without loss of optical resolution, application of large-volume sample stacking with an electroosmotic flow pump (LVSEP) was investigated. Effects of the addition of cyclodextrin (CD) into a running solution on the LVSEP preconcentration was theoretically studied, where the preconcentration efficiency and effective separation length would be slightly increased if the effective electrophoretic velocity (v(ep, eff, BGS)) of the analytes was decreased by interacting with CD. In LVSEP-CD-modified capillary zone electrophoresis (CDCZE) and LVSEP-CD electrokinetic chromatography with reduced v(ep, eff, BGS), up to 1000-fold sensitivity increases were achieved with almost no loss of resolution. In LVSEP-CD-modified micellar electrokinetic chromatography of amino acids with increased v(ep, eff, BGS), a 1300-fold sensitivity increase was achieved without much loss of resolution, indicating the versatile applicability of LVSEP to many separation modes. An enantio-excess (EE) assay was also carried out in LVSEP-CDCZE, resulting in successful analyses of up to 99.6% EE. Finally, we analyzed ibuprofen in urine by desalting with a C(18) solid-phase extraction column. As a typical result, 250ppb ibuprofen was well concentrated and optically resolved with 84.0-86.6% recovery in LVSEP-CDCZE, indicating the applicability of LVSEP to real samples containing a large amount of unnecessary background salts
Novel moduli space in modular flavor models : a case study for modular seesaw model with hidden gauge symmetry
We study flavor phenomenologies in a basis of a double covering of modular
group with a hidden symmetry, in which we work on regions at
nearby two fixed points and three special points. These special points of
moduli space are statistically favored in flux
compactifications of Type IIB string theory. Neutrino masses are approximately
obtained by using the seesaw mechanism due to our two additional symmetries. We
perform chi square numerical analysis for each of the fixed/special points in
the normal and inverted hierarchies and demonstrate predictions for each case.
Then, we briefly discuss the possible signature of hidden gauge bosons at
collider experiments from the hidden symmetry.Comment: 28 pages, 10 figures, 2 table
A human transporter protein that mediates the final excretion step for toxic organic cations
In mammals, toxic electrolytes of endogenous and exogenous origin are excreted through the urine and bile. Before excretion, these compounds cross numerous cellular membranes in a transporter-mediated manner. However, the protein transporters involved in the final excretion step are poorly understood. Here, we show that MATE1, a human and mouse orthologue of the multidrug and toxin extrusion (MATE) family conferring multidrug resistance on bacteria, is primarily expressed in the kidney and liver, where it is localized to the luminal membranes of the urinary tubules and bile canaliculi. When expressed in HEK293 cells, MATE1 mediates H+-coupled electroneutral exchange of tetraethylammonium (TEA) and 1-methyl-4-phenylpyridinium (MPP). Its substrate specificity is similar to those of renal and hepatic H+-coupled organic cations (OCs) export. Thus, MATE1 appears to be the long searched for polyspecific OC exporter that directly transports toxic OCs into urine and bile.</p
Localization of cyclophilin A and cyclophilin C mRNA in murine kidney using RT-PCR
Localization of cyclophilin A and cyclophilin C mRNA in murine kidney using RT-PCR. Cyclosporin A (CsA), which is widely used as an immunosuppressant, has a nephrotoxic side effect. The mechanism of this nephrotoxicity is not well understood; however, recent studies suggest that cyclophilin (cyp) is responsible for mediating the immunosuppressive action of CsA through the interaction with the Ca2+ - and calmodulin-dependent phosphatase, calcineurin. While cyp A mRNA is expressed ubiquitously, cyp C mRNA has been shown to be topically expressed, including in the kidney. We examined: (1) distribution of cyp A and cyp C mRNA in microdissected murine nephron segments, using a combination of reverse transcription and polymerase chain reaction (RT-PCR) techniques, and (2) the effect of CsA administration on cyp C mRNA expression in proximal convoluted tubule. Among the nephron segments examined, large signals for cyp C PCR product were detected in proximal convoluted tubule and proximal straight tubule. Our data showed that the distribution of cyp C mRNA was uneven, and it mainly existed in segments that are relatively sensitive to CsA toxicity. In contrast, cyp A mRNA was found to be distributed almost equally along the nephron segments examined. By CsA administration, the signal for cyp C mRNA PCR product was increased. These results suggest that cyp C may play some role in the renal tubular disorder observed in CsA nephrotoxicity
Role of orexin in exercise-induced leptin sensitivity in the mediobasal hypothalamus of mice
Orexin is known as an important neuropeptide in the regulation of energy metabolism. However, the role of orexin in exercise-induced leptin sensitivity in the hypothalamus has been unclear. In this study, we determined the effect of transient treadmill exercise on leptin sensitivity in the mediobasal hypothalamus (MBH) of mice and examined the role of orexin in post-exercise leptin sensitivity. Treadmill running for 45 min increased the orexin neuron activity in mice. Intraperitoneal injection of a submaximal dose of leptin after exercise stimulated the phosphorylation of signal transducer and activator of transcription 3 (STAT3) in MBH of mice post-exercise compared with that in non-exercised mice, although intracerebroventricular (icv) injection of leptin did not enhance STAT3 phosphorylation, even after exercise. Icv injection of an orexin receptor antagonist, SB334867 reduced STAT3 phosphorylation, which was enhanced by icv injection of orexin but not by direct injection of orexin into MBH. Exercise increased the phosphorylation of extracellular signal-regulated kinases (ERKs) in the MBH of mice, while ERK phosphorylation was reduced by SB334867. Leptin injection after exercise increased the leptin level in MBH, whereas icv injection of SB334867 suppressed the increase in the leptin level in MBH of mice. These results indicate that the activation of orexin neurons by exercise may contribute to the enhancement of leptin sensitivity in MBH. This effect may be mediated by increased transportation of circulating leptin into MBH, with the involvement of ERK phosphorylation
The EZH2 inhibitor tazemetostat upregulates the expression of CCL17/TARC in B‐cell lymphoma and enhances T‐cell recruitment
An inhibitor of the histone methyltransferase enhancer of zeste homologue 2 (EZH2), tazemetostat, has been developed for the treatment of B-cell lymphoma, but its mechanisms of action are not fully elucidated. We screened for genes targeted by tazemetostat in eleven B-cell lymphoma cell lines and found that tazemetostat significantly increased the expression of chemokine (C-C motif) ligand 17 (CCL17)/thymus- and activation-regulated chemokine (TARC) in all, which codes for a chemokine that is a hallmark of Hodgkin/Reed-Sternberg (H/RS) cells in Hodgkin lymphoma. Notably, gene set enrichment analysis demonstrated a positive correlation between the genes upregulated by tazemetostat in five follicular lymphoma (FL) cell lines and those reported to be overexpressed in H/RS cells. The CCL17 promoter region was enriched in repressive histone modification H3K27me3, and tazemetostat induced H3K27 demethylation and activated gene transcription. CCL17 protein secretion was also induced by EZH2 inhibition, which was further enhanced by concurrent CpG stimulation. In vitro transwell migration assay demonstrated that CCL17 produced by tazemetostat-treated B cells enhanced the recruitment of T cells, which had the potential to exert antilymphoma response. Analysis of publicly available human lymphoma databases showed that CCL17 gene expression was inversely correlated with the EZH2 activation signature and significantly paralleled the CD4⁺ and CD8⁺ T-cell–rich signature in FL and germinal center B-cell–like diffuse large B-cell lymphoma. Our findings indicate that tazemetostat can potentially activate antilymphoma response by upregulating CCL17 expression in B-cell lymphoma cells and promote T-cell recruitment, which provides a rationale for its combination with immunotherapy
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