300 research outputs found
Proximity effect in a ferromagnetic semiconductor with spin-orbit interactions
We study theoretically the proximity effect in a ferromagnetic semiconductor
with Rashba spin-orbit interaction. The exchange potential generates
opposite-spin-triplet Cooper pairs which are transformed into
equal-spin-triplet pairs by the spin-orbit interaction. In the limit of strong
spin-orbit interaction, symmetry of the dominant Cooper pair depends on the
degree of disorder in a ferromagnet. In the clean limit, spin-singlet -wave
Cooper pairs are the most dominant because the spin-momentum locking stabilizes
a Cooper pair consisting of a time-reversal partner. In the dirty limit, on the
other hand, equal-spin-triplet -wave pairs are dominant because random
impurity potentials release the locking. We also discuss the effects of the
spin-orbit interaction on the Josephson current.Comment: 9 pages, 12 figure
Expression of SARS‐CoV‐2 entry factors in human oral tissue
The distribution of cells expressing SARS‐CoV‐2 entry factor angiotensin‐converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) in human oral tissues were tested. The investigation was conducted with normal flesh tissue and paraffin‐embedded specimens. The ACE2 and TMPRSS2 expression was detected with all subjects in the normal mucosa of the keratinized stratified squamous epithelia of the tongue and non‐keratinized stratified squamous epithelia of the lip and cheek. It was found that ACE2 is expressed in the cytoplasm and on the cell membrane mainly in the stratum granulosum of the epithelia while the TMPRSS2 is strongly expressed on the cell membrane mainly in the stratum granulosum and stratum spinosum, but not in the stratum basale. Antibodies’ reactions for ACE2 and TMPRSS2 were not observed in the nuclei or keratin layer. The expression of ACE2 and TMPRSS2 in the oral epithelia appears to be general, and the expression was also observed in the mucous and serous acini of the labial glands. The SARS‐CoV‐2 may transiently attach to the oral mucosa and the minor salivary glands which are present under all of the oral mucosa. The oral cavity can be considered an important organ for SARS‐CoV‐2 attachment and may provide a preventive medical avenue to guard against COVID‐19 by preventing saliva from scattering
TGF-β receptor kinase inhibitor enhances growth and integrity of embryonic stem cell–derived endothelial cells
Recent findings have shown that embryonic vascular progenitor cells are capable of differentiating into mural and endothelial cells. However, the molecular mechanisms that regulate their differentiation, proliferation, and endothelial sheet formation remain to be elucidated. Here, we show that members of the transforming growth factor (TGF)-β superfamily play important roles during differentiation of vascular progenitor cells derived from mouse embryonic stem cells (ESCs) and from 8.5–days postcoitum embryos. TGF-β and activin inhibited proliferation and sheet formation of endothelial cells. Interestingly, SB-431542, a synthetic molecule that inhibits the kinases of receptors for TGF-β and activin, facilitated proliferation and sheet formation of ESC-derived endothelial cells. Moreover, SB-431542 up-regulated the expression of claudin-5, an endothelial specific component of tight junctions. These results suggest that endogenous TGF-β/activin signals play important roles in regulating vascular growth and permeability
Differential interferon signaling in cells in liver lobules and portal areas under treatment for chronic hepatitis C
金沢大学医薬保健研究域医学系Background & Aims: The mechanisms of treatment resistance to interferon (IFN) and ribavirin (Rib) combination therapy for hepatitis C virus (HCV) infection are not known. This study aims to gain insight into these mechanisms by exploring hepatic gene expression before and during treatment. Methods: Liver biopsy was performed in 50 patients before therapy and repeated in 30 of them 1 week after initiating combination therapy. The cells in liver lobules (CLL) and the cells in portal areas (CPA) were obtained from 12 patients using laser capture microdissection (LCM). Results: Forty-three patients were infected with genotype 1 HCV, 20 of who were viral responders (genotype 1-Rsp) with treatment outcome of SVR or TR, while 23 were non-responders (genotype 1-nonRsp) with NR. Only seven patients were infected with genotype 2. Before treatment, the expression of IFN and Rib-stimulated genes (IRSGs), apoptosis-associated genes, and immune reaction gene pathways was greater in genotype 1-nonRsp than in Rsp. During treatment, IRSGs were induced in genotype 1-Rsp, but not in nonRsp. IRSG induction was irrelevant in genotype 2-Rsp and was mainly impaired in CLL but not in CPA. Pathway analysis revealed that many immune regulatory pathways were induced in CLL from genotype 1-Rsp, while growth factors related to angiogenesis and fibrogenesis were more induced in CPA from genotype 1-nonRsp. Conclusions: Impaired IRSGs induction in CLL reduces the sensitivity to treatment for genotype 1 HCV infection. CLL and CPA in the liver might be differentially involved in treatment resistance. These findings could be useful for the improvement of therapy for HCV infection. © 2010 European Association for the Study of the Liver
Rice apoplastic CBM1-interacting protein counters blast pathogen invasion by binding conserved carbohydrate binding module 1 motif of fungal proteins
いもち病からイネを守る細胞外タンパク質 (CBMIP) の発見 --CBMIPはイネの細胞壁を守り、いもち病菌の感染を抑える--. 京都大学プレスリリース. 2022-09-30.When infecting plants, fungal pathogens secrete cell wall-degrading enzymes (CWDEs) that break down cellulose and hemicellulose, the primary components of plant cell walls. Some fungal CWDEs contain a unique domain, named the carbohydrate binding module (CBM), that facilitates their access to polysaccharides. However, little is known about how plants counteract pathogen degradation of their cell walls. Here, we show that the rice cysteine-rich repeat secretion protein OsRMC binds to and inhibits xylanase MoCel10A of the blast fungus pathogen Magnaporthe oryzae, interfering with its access to the rice cell wall and degradation of rice xylan. We found binding of OsRMC to various CBM1-containing enzymes, suggesting that it has a general role in inhibiting the action of CBM1. OsRMC is localized to the apoplast, and its expression is strongly induced in leaves infected with M. oryzae. Remarkably, knockdown and overexpression of OsRMC reduced and enhanced rice defense against M. oryzae, respectively, demonstrating that inhibition of CBM1-containing fungal enzymes by OsRMC is crucial for rice defense. We also identified additional CBM-interacting proteins (CBMIPs) from Arabidopsis thaliana and Setaria italica, indicating that a wide range of plants counteract pathogens through this mechanism
Label-free metabolic imaging of non-alcoholic-fatty-liver-disease (NAFLD) liver by volumetric dynamic optical coherence tomography
Label-free metabolic imaging of non-alcoholic fatty liver disease (NAFLD)
mouse liver is demonstrated ex vivo by dynamic optical coherence tomography
(OCT). The NAFLD mouse is a methionine choline-deficient (MCD)-diet model, and
two mice fed MCD diet for 1 and 2 weeks are involved in addition to a
normal-diet mouse. The dynamic OCT is based on repeating raster scan and
logarithmic intensity variance (LIV) analysis which enables volumetric
metabolic imaging with a standard-speed (50,000 A-lines/s) OCT system.
Metabolic domains associated with lipid droplet accumulation and inflammation
are clearly visualized three-dimensionally. Particularly, the normal-diet liver
exhibits highly metabolic vessel-like structures of peri-vascular hepatic
zones. The 1-week MCD-diet liver shows ring-shaped highly metabolic structures
formed with lipid droplets. The 2-week MCD-diet liver exhibits fragmented
vessel-like structures associated with inflammation. These results imply that
volumetric LIV imaging is useful for visualizing and assessing NAFLD
abnormalities
Hepatic interferon-stimulated genes are differentially regulated in the liver of chronic hepatitis C patients with different interleukin-28B genotypes
Pretreatment up-regulation of hepatic interferon (IFN)-stimulated genes (ISGs) has a stronger association with the treatment-resistant interleukin (IL)28B minor genotype (MI; TG/GG at rs8099917) than with the treatment-sensitive IL28B major genotype (MA; TT at rs8099917). We compared the expression of ISGs in the liver and blood of 146 patients with chronic hepatitis C who received pegylated IFN and ribavirin combination therapy. Gene expression profiles in the liver and blood of 85 patients were analyzed using an Affymetrix GeneChip (Affymetrix, Santa Clara, CA). ISG expression was correlated between the liver and blood of the MA patients, whereas no correlation was observed in the MI patients. This loss of correlation was the result of the impaired infiltration of immune cells into the liver lobules of MI patients, as demonstrated by regional gene expression analysis in liver lobules and portal areas using laser capture microdissection and immunohistochemical staining. Despite having lower levels of immune cells, hepatic ISGs were up-regulated in the liver of MI patients and they were found to be regulated by multiple factors, namely, IL28A/B, IFN-λ4, and wingless-related MMTV integration site 5A (WNT5A). Interestingly, WNT5A induced the expression of ISGs, but also increased hepatitis C virus replication by inducing the expression of the stress granule protein, GTPase-activating protein (SH3 domain)-binding protein 1 (G3BP1), in the Huh-7 cell line. In the liver, the expression of WNT5A and its receptor, frizzled family receptor 5, was significantly correlated with G3BP1. Conclusions: Immune cells were lost and induced the expression of other inflammatory mediators, such as WNT5A, in the liver of IL28B minor genotype patients. This might be related to the high level of hepatic ISG expression in these patients and the treatment-resistant phenotype of the IL28B minor genotype. © 2014 by the American Association for the Study of Liver Diseases.This article has Supplemental materrial and methods
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