237 research outputs found

    5′-Triphosphate-RNA-independent activation of RIG-I via RNA aptamer with enhanced antiviral activity

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    RIG-I is a cytosolic receptor for non-self RNA that mediates immune responses against viral infections through IFNα/β production. In an attempt to identify novel tools that modulate IFNα/β production, we used SELEX technology to screen RNA aptamers that specifically target RIG-I protein. Most of the selected RIG-I aptamers contained polyU motifs in the second half regions that played critical roles in the activation of RIG-I-mediated IFNβ production. Unlike other known ligands, RIG-I aptamer bound and activated RIG-I in a 5′-triphosphate-independent manner. The helicase and RD domain of RIG-I were used for aptamer binding, but intact RIG-I protein was required to exert aptamer-mediated signaling activation. Furthermore, replication of NDV, VSV and influenza virus in infected host cells was efficiently blocked by pre- or post-treatment with RIG-I aptamer. Based on these data, we propose that RIG-I aptamer has strong potential to be an antiviral agent that specifically boosts the RIG-I-dependent signaling cascade

    The Traditional Herbal Medicine, Dangkwisoo-San, Prevents Cerebral Ischemic Injury through Nitric Oxide-Dependent Mechanisms

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    Dangkwisoo-San (DS) is an herbal extract that is widely used in traditional Korean medicine to treat traumatic ecchymosis and pain by promoting blood circulation and relieving blood stasis. However, the effect of DS in cerebrovascular disease has not been examined experimentally. The protective effects of DS on focal ischemic brain were investigated in a mouse model. DS stimulated nitric oxide (NO) production in human brain microvascular endothelial cells (HBMECs). DS (10–300 μg/mL) produced a concentration-dependent relaxation in mouse aorta, which was significantly attenuated by the nitric oxide synthase (NOS) inhibitor L-NAME, suggesting that DS causes vasodilation via a NO-dependent mechanism. DS increased resting cerebral blood flow (CBF), although it caused mild hypotension. To investigate the effect of DS on the acute cerebral injury, C57/BL6J mice received 90 min of middle cerebral artery occlusion followed by 22.5 h of reperfusion. DS administered 3 days before arterial occlusion significantly reduced cerebral infarct size by 53.7% compared with vehicle treatment. However, DS did not reduce brain infarction in mice treated with the relatively specific endothelial NOS (eNOS) inhibitor, N5-(1-iminoethyl)-L-ornithine, suggesting that the neuroprotective effect of DS is primarily endothelium-dependent. This correlated with increased phosphorylation of eNOS in the brains of DS-treated mice. DS acutely improves CBF in eNOS-dependent vasodilation and reduces infarct size in focal cerebral ischemia. These data provide causal evidence that DS is cerebroprotective via the eNOS-dependent production of NO, which ameliorates blood circulation

    Compositional assessment of carotenoid-biofortified rice using substantial equivalence

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    One important aspect in assessing the safety of genetically modified (GM) crops for human consumption is characterizing their nutrient composition. A β-carotene-biofortified rice was generated by inserting phytoene synthase (Psy) and carotene desaturase (Crtl) genes isolated from Capsicum and Pantoea into the genome of a conventional variety of rice (Nakdongbyeo). Nutrients (proximates, amino acids, fatty acids, minerals, and vitamins), anti-nutritive components (trypsin inhibitors and phytic acid), and ferulic acid in GM rice were compared with those in the parent line Nakdongbyeo. Statistical comparisons to test for equivalence showed that all of the analyzed components in the GM plants were equivalent to those in its non-transgenic counterpart, and most nutritional components fell within the range of values reported for other commercial lines, indicating the safety of the GM plant.Key words: Genetically modified crop, β-Carotene, Transgenic rice, Nutrient, Substantial equivalence

    Interleukin-13 Increases Podocyte Apoptosis in Cultured Human Podocytes

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    Purpose Podocytes are important architectures that maintain the crucial roles of glomerular filtration barrier functions. Despite this structural importance, however, the mechanisms of the changes in podocytes that can be an important pathogenesis of minimal change nephrotic syndrome (MCNS) are not clear yet. The aim of this study was to investigate whether apoptosis is induced by interleukin (IL)-13 in cultured human podocytes. Methods Human podocytes were treated with different IL-13 doses and apoptotic cells were analyzed using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL assay) and fluorescence-activated cell sorting (FACS). Results The IL-13 increased the number of TUNEL-positive cells in a dose-dependent manner at 6 and 18 hours (P <0.05 and P <0.05, respectively). The apoptosis rate was appeared to be increased slightly in the IL-13-stimulated podocytes (8.63%, 13.02%, and 14.46%; 3, 10 and 30 ng/mL, respectively) than in the control cells (7.66%) at 12 hours by FACS assay. Conclusion Our study revealed that IL-13 expression may increase podocyte apoptosis. Blocking the IL-13 signal pathway can potentially play an important role in regulating the apoptosis of podocytes

    A Korean Female Patient with Thiamine-responsive Pyruvate Dehydrogenase Complex Deficiency Due to a Novel Point Mutation (Y161C)in the PDHA1 Gene

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    Pyruvate dehydrogenase complex (PDHC) deficiency is mostly due to mutations in the X-linked E1α subunit gene (PDHA1). Some of the patients with PDHC deficiency showed clinical improvements with thiamine treatment. We report the results of biochemical and molecular analysis in a female patient with lactic acidemia. The PDHC activity was assayed at different concentrations of thiamine pyrophosphate (TPP). The PDHC activity showed null activity at low TPP concentration (1×10-3 mM), but significantly increased at a high TPP concentration (1 mM). Sequencing analysis of PDHA1 gene of the patient revealed a substitution of cysteine for tyrosine at position 161 (Y161C). Thiamine treatment resulted in reduction of the patient's serum lactate concentration and dramatic clinical improvement. Biochemical, molecular, and clinical data suggest that this patient has a thiamine-responsive PDHC deficiency due to a novel mutation, Y161C. Therefore, to detect the thiamine responsiveness it is necessary to measure activities of PDHC not only at high but also at low concentration of TPP

    A Role of Canonical Transient Receptor Potential 5 Channel in Neuronal Differentiation from A2B5 Neural Progenitor Cells

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    Store-operated Ca2+ entry (SOCE) channels are the main pathway of Ca2+ entry in non-excitable cells such as neural progenitor cells (NPCs). However, the role of SOCE channels has not been defined in the neuronal differentiation from NPCs. Here, we show that canonical transient receptor potential channel (TRPC) as SOCE channel influences the induction of the neuronal differentiation of A2B5+ NPCs isolated from postnatal-12-day rat cerebrums. The amplitudes of SOCE were significantly higher in neural cells differentiated from proliferating A2B5+ NPCs and applications of SOCE blockers, 2-aminoethoxy-diphenylborane (2-APB), and ruthenium red (RR), inhibited their rise of SOCE. Among TRPC subtypes (TRPC1-7), marked expression of TRPC5 and TRPC6 with turned-off TRPC1 expression was observed in neuronal cells differentiated from proliferating A2B5+ NPCs. TRPC5 small interfering RNA (siRNA) blocked the neuronal differentiation from A2B5+ NPCs and reduced the rise of SOCE. In contrast, TRPC6 siRNA had no significant effect on the neuronal differentiation from A2B5+ NPCs. These results indicate that calcium regulation by TRPC5 would play a key role as a switch between proliferation and neuronal differentiation from NPCs

    Level of professional ethics awareness and medical ethics competency of dental hygienists and dental hygiene students: the need to add ethics items to the Korean Dental Hygienist Licensing Examination

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    Purpose This study aimed to evaluate the level of professional ethics awareness and medical ethics competency in order to assess the potential need for ethics items to be included on the Korean Dental Hygienist Licensing Examination. Methods In total, 358 clinical dental hygienists and dental hygiene students completed a structured questionnaire to evaluate their level of ethical awareness and medical ethics competency. The sub-factors of medical ethics were classified into relationships with patients, medical and social relations, and individual specialized fields. Results Only 32.1% of participants indicated that they had taken a course on professional ethics in the university curriculum, but 95.2% of respondents considered professional ethics to be important. The overall score for medical ethics competency was average (3.37 out of 5). The score for relationships with patients was 3.75 points, followed by medical and social relations (3.19 points) and individual specialized fields (3.16 points). The level of professional ethics awareness was higher among participants who had taken a course on professional ethics than among those who had not done so or who did not remember whether they had done so. Conclusion Dental hygienists were aware of the importance of professional ethics, but their medical ethics competency was moderate. Therefore, medical ethics should be treated as a required subject in the university curriculum, and medical ethics competency evaluations should be strengthened by adding ethics items to the Korean Dental Hygienist Licensing Examination

    The presence of high level soluble herpes virus entry mediator in sera of gastric cancer patients

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    The development of gastric cancer (GC) is closely related to chronic inflammation caused by Helicobacter pylori infection, and herpes virus entry mediator (HVEM) is a receptor expressed on the surface of leukocytes that mediates potent inflammatory responses in animal models. However, the role of HVEM in human GC has not been studied. Previously, we showed that the interaction of HVEM on human leukocytes with its ligand LIGHT induces intracellular calcium mobilization, which results in inflammatory responses including induction of proinflammatory cytokine production and anti-bacterial activities. In this study, we report that leukocytes from GC patients express lower levels of membrane HVEM (mHVEM) and have lower LIGHT-induced bactericidal activities than those from healthy controls (HC). In contrast, levels of soluble HVEM (sHVEM) in the sera of GC patients were significantly higher than in those of HC. We found that monocyte membrane-bound HVEM is released into the medium when cells are activated by proinflammatory cytokines such as TNF-α and IL-8, which are elevated in the sera of GC patients. mHVEM level dropped in parallel with the release of sHVEM, and release was completely blocked by the metalloprotease inhibitor, GM6001. We also found that the low level of mHVEM on GC patient leukocytes was correlated with low LIGHT-induced bactericidal activities against H. pylori and S. aureus and production of reactive oxygen species. Our results indicate that mHVEM on leukocytes and sHVEM in sera may contribute to the development and/or progression of GC

    Consensus Subtypes of Hepatocellular Carcinoma Associated With Clinical Outcomes and Genomic Phenotypes

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    BACKGROUND AND AIMS: Although many studies revealed transcriptomic subtypes of HCC, concordance of the subtypes are not fully examined. We aim to examine a consensus of transcriptomic subtypes and correlate them with clinical outcomes. APPROACH AND RESULTS: By integrating 16 previously established genomic signatures for HCC subtypes, we identified five clinically and molecularly distinct consensus subtypes. STM (STeM) is characterized by high stem cell features, vascular invasion, and poor prognosis. CIN (Chromosomal INstability) has moderate stem cell features, but high genomic instability and low immune activity. IMH (IMmune High) is characterized by high immune activity. BCM (Beta-Catenin with high Male predominance) is characterized by prominent β-catenin activation, low miRNA expression, hypomethylation, and high sensitivity to sorafenib. DLP (Differentiated and Low Proliferation) is differentiated with high hepatocyte nuclear factor 4A activity. We also developed and validated a robust predictor of consensus subtype with 100 genes and demonstrated that five subtypes were well conserved in patient-derived xenograft models and cell lines. By analyzing serum proteomic data from the same patients, we further identified potential serum biomarkers that can stratify patients into subtypes. CONCLUSIONS: Five HCC subtypes are correlated with genomic phenotypes and clinical outcomes and highly conserved in preclinical models, providing a framework for selecting the most appropriate models for preclinical studies
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