Publications by authors named "Yu-Jin Kim"

467 Publications

Association of the duration of on-scene advanced life support with good neurological recovery in out-of-hospital cardiac arrest.

Am J Emerg Med 2021 Sep 6;50:486-491. Epub 2021 Sep 6.

Department of Emergency Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea; Department of Emergency Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address:

Background: As advanced life support (ALS) provided by emergency medical services (EMS) on scene becomes more common, the scene time interval (STI) for which EMS providers stay on scene tends to lengthen. We investigated the relationship between the STI and neurological outcome of patients at hospital discharge when ALS was provided by EMS on scene.

Methods: We conducted a retrospective analysis of prospectively collected out-of-hospital cardiac arrest (OHCA) data between August 2015 and December 2018. A restricted cubic spline curve was used to investigate the relationship between the STI and neurologic outcome, and patients were divided into two groups based on the cut-off value obtained through receiver operating characteristic (ROC) analysis. Comparisons of outcomes between the two groups were performed before and after propensity score matching.

Results: 4548 patients were included in the analysis. In ROC analysis, the optimal cut-off value for STI was 19 min. For the group with an STI <19 min, survival admission, survival discharge, and good neurologic outcome at hospital discharge were all higher than for the group with STI ≥19 min before and after propensity score matching. The multivariable model also showed that the STI ≥19 min was significantly associated with poor neurologic outcome at hospital discharge compared with the STI <19 min (adjusted odds ratio, 2.00; 95% CI, 1.40-2.88).

Conclusions: A duration of on-scene ALS more than 19 min was associated with a poor neurologic outcome of patients at hospital discharge in OHCA.
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http://dx.doi.org/10.1016/j.ajem.2021.09.006DOI Listing
September 2021

A Systemic View of Carbohydrate Metabolism in Rice to Facilitate Productivity.

Plants (Basel) 2021 Aug 17;10(8). Epub 2021 Aug 17.

Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea.

Carbohydrate metabolism is an important biochemical process related to developmental growth and yield-related traits. Due to global climate change and rapid population growth, increasing rice yield has become vital. To understand whole carbohydrate metabolism pathways and find related clues for enhancing yield, genes in whole carbohydrate metabolism pathways were systemically dissected using meta-transcriptome data. This study identified 866 carbohydrate genes from the MapMan toolkit and the Kyoto Encyclopedia of Genes and Genomes database split into 11 clusters of different anatomical expression profiles. Analysis of functionally characterized carbohydrate genes revealed that source activity and eating quality are the most well-known functions, and they each have a strong correlation with tissue-preferred clusters. To verify the transcriptomic dissection, three pollen-preferred cluster genes were used and found downregulated in the mutant. Finally, we summarized carbohydrate metabolism as a conceptual model in gene clusters associated with morphological traits. This systemic analysis not only provided new insights to improve rice yield but also proposed novel tissue-preferred carbohydrate genes for future research.
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http://dx.doi.org/10.3390/plants10081690DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401045PMC
August 2021

Development of a Multi-Layer Skin Substitute Using Human Hair Keratinic Extract-Based Hybrid 3D Printing.

Polymers (Basel) 2021 Aug 4;13(16). Epub 2021 Aug 4.

Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea.

Large-sized or deep skin wounds require skin substitutes for proper healing without scar formation. Therefore, multi-layered skin substitutes that mimic the genuine skin anatomy of multiple layers have attracted attention as suitable skin substitutes. In this study, a novel skin substitute was developed by combining the multi-layer skin tissue reconstruction method with the combination of a human-derived keratinic extract-loaded nano- and micro-fiber using electrospinning and a support structure using 3D printing. A polycaprolactone PCL/keratin electrospun scaffold showed better cell adhesion and proliferation than the keratin-free PCL scaffold, and keratinocytes and fibroblasts showed better survival, adhesion, and proliferation in the PCL/keratin electrospun nanofiber scaffold and microfiber scaffold, respectively. In a co-culture of keratinocytes and fibroblasts using a multi-layered scaffold, the two cells formed the epidermis and dermal layer on the PCL/keratin scaffold without territorial invasion. In the animal study, the PCL/keratin scaffold caused a faster regeneration of new skin without scar formation compared to the PCL scaffold. Our study showed that PCL/keratin scaffolds co-cultured with keratinocytes and fibroblasts promoted the regeneration of the epidermal and dermal layers in deep skin defects. Such finding suggests a new possibility for artificial skin production using multiple cells.
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http://dx.doi.org/10.3390/polym13162584DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401121PMC
August 2021

Inhibitors of anti-apoptotic Bcl-2 family proteins exhibit potent and broad-spectrum anti-mammarenavirus activity via cell cycle arrest at G0/G1 phase.

bioRxiv 2021 Aug 17. Epub 2021 Aug 17.

Targeting host factors is a promising strategy to develop broad-spectrum antiviral drugs. Drugs targeting anti-apoptotic Bcl-2 family proteins that were originally developed as tumor suppressors have been reported to inhibit multiplication of different types of viruses. However, the mechanisms whereby Bcl-2 inhibitors exert their antiviral activity remain poorly understood. In this study, we have investigated the mechanisms by which obatoclax (OLX) and ABT-737 Bcl-2 inhibitors exhibited a potent antiviral activity against the mammarenavirus lymphocytic choriomeningitis virus (LCMV). OLX and ABT-737 potent anti-LCMV activity was not associated with their pro-apoptotic properties, but rather their ability of inducing cell arrest at G0/G1 phase. OLX and ABT-737 mediated inhibition of Bcl-2 correlated with reduced expression levels of thymidine kinase 1 (TK1), cyclin A2 (CCNA2), and cyclin B1 (CCNB1) cell cycle regulators. In addition, siRNA-mediated knock down of TK1, CCNA2, and CCNB1 resulted in reduced levels of LCMV multiplication. The antiviral activity exerted by Bcl-2 inhibitors correlated with reduced levels of viral RNA synthesis at early times of infection. Importantly, ABT-737 exhibited moderate efficacy in a mouse model of LCMV infection, and Bcl-2 inhibitors displayed broad-spectrum antiviral activities against different mammarenaviruses and SARS-CoV-2. Our results suggest that Bcl-2 inhibitors, actively being explored as anti-cancer therapeutics, might be repositioned as broad-spectrum antivirals.

Importance: Anti-apoptotic Bcl-2 inhibitors have been shown to exert potent antiviral activities against various types of viruses via mechanisms that are currently poorly understood. This study has revealed that Bcl-2 inhibitors mediated cell cycle arrest at the G0/G1 phase, rather than their pro-apoptotic activity, plays a critical role in blocking mammarenavirus multiplication in cultured cells. In addition, we show that Bcl-2 inhibitor ABT-737 exhibited moderate anti-mammarenavirus activity , and that Bcl-2 inhibitors displayed broad-spectrum antiviral activities against different mammarenaviruses and SARS-CoV-2. Our results suggest that Bcl-2 inhibitors, actively being explored as anti-cancer therapeutics, might be repositioned as broad-spectrum antivirals.
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http://dx.doi.org/10.1101/2021.08.16.456587DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8382120PMC
August 2021

Predictive biomarkers for 5-fluorouracil and oxaliplatin-based chemotherapy in gastric cancers via profiling of patient-derived xenografts.

Nat Commun 2021 08 10;12(1):4840. Epub 2021 Aug 10.

Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea.

Gastric cancer (GC) is commonly treated by chemotherapy using 5-fluorouracil (5-FU) derivatives and platinum combination, but predictive biomarker remains lacking. We develop patient-derived xenografts (PDXs) from 31 GC patients and treat with a combination of 5-FU and oxaliplatin, to determine biomarkers associated with responsiveness. When the PDXs are defined as either responders or non-responders according to tumor volume change after treatment, the responsiveness of PDXs is significantly consistent with the respective clinical outcomes of the patients. An integrative genomic and transcriptomic analysis of PDXs reveals that pathways associated with cell-to-cell and cell-to-extracellular matrix interactions enriched among the non-responders in both cancer cells and the tumor microenvironment (TME). We develop a 30-gene prediction model to determine the responsiveness to 5-FU and oxaliplatin-based chemotherapy and confirm the significant poor survival outcomes among cases classified as non-responder-like in three independent GC cohorts. Our study may inform clinical decision-making when designing treatment strategies.
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http://dx.doi.org/10.1038/s41467-021-25122-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8355375PMC
August 2021

Optimization of Protein Isolation and Label-Free Quantitative Proteomic Analysis in Four Different Tissues of Korean Ginseng.

Plants (Basel) 2021 Jul 9;10(7). Epub 2021 Jul 9.

Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang 50463, Korea.

Korean ginseng is one of the most valuable medicinal plants worldwide. However, our understanding of ginseng proteomics is largely limited due to difficulties in the extraction and resolution of ginseng proteins because of the presence of natural contaminants such as polysaccharides, phenols, and glycosides. Here, we compared four different protein extraction methods, namely, TCA/acetone, TCA/acetone-MeOH/chloroform, phenol-TCA/acetone, and phenol-MeOH/chloroform methods. The TCA/acetone-MeOH/chloroform method displayed the highest extraction efficiency, and thus it was used for the comparative proteome profiling of leaf, root, shoot, and fruit by a label-free quantitative proteomics approach. This approach led to the identification of 2604 significantly modulated proteins among four tissues. We could pinpoint differential pathways and proteins associated with ginsenoside biosynthesis, including the methylerythritol 4-phosphate (MEP) pathway, the mevalonate (MVA) pathway, UDP-glycosyltransferases (UGTs), and oxidoreductases (CYP450s). The current study reports an efficient and reproducible method for the isolation of proteins from a wide range of ginseng tissues and provides a detailed organ-based proteome map and a more comprehensive view of enzymatic alterations in ginsenoside biosynthesis.
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http://dx.doi.org/10.3390/plants10071409DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8309323PMC
July 2021

Comparison of Effectiveness and Associated Complications Between Conventional Subdermal Excision and Hydrosurgery (Versajet) for Osmidrosis.

Aesthetic Plast Surg 2021 Aug 5. Epub 2021 Aug 5.

Department of plastic and reconstructive surgery, Gachon University Gil Medical Center, 21 Namdong-daero 774beon-gil, Namdong-gu, Incheon, 21565, Republic of Korea.

Background: Recent studies have shown hydrosurgery (Versajet TM II) is a simple and effective tool with reduced complications in surgical treatment of osmidrosis. Since then, hydrosurgery has been widely used for osmidrosis. However, we have experienced that some complications often occur in patients treated with hydrosurgery.

Objective: We hypothesized that using a hydrosurgery could lead to excessive resection of the tightly attached apocrine glands and thus more complications. We aimed at evaluating the effectiveness and associated complications of the hydrosurgery method for osmidrosis were compared with those of conventional methods with two parallel incisions.

Methods & Materials: We retrospectively analyzed 31 and 16 patients who underwent conventional and hydrosurgery methods, respectively, for osmidrosis from 2010 to 2020. Two parallel long incisions were identical in both groups. Early complications (hematoma, seroma, wound dehiscence, skin necrosis, revision, scar contracture), late complications (scar, pigmentation, comedones/milia, and sebaceous cysts), and effectiveness (subjective satisfaction, malodor elimination, reduced hair growth, and sweating elimination) were evaluated.

Results: Skin necrosis was significantly more frequent in the hydrosurgery group than in the conventional group (p = 0.036). No other significant differences were found between the two groups in terms of other complications and effectiveness. As a result of comparing effectiveness, subjective satisfaction (p = 0.306), malodor elimination (p = 1.000), reduced hair growth (p=1.000), and sweating elimination (p = 0.742) did not show any significant difference between the two groups.

Conclusion: Osmidrosis treatment with the use of VERSAJET™ Hydrosurgery System yielded similar and satisfactory results as the conventional subdermal excision method. The incidence of skin necrosis was higher in the hydrosurgery group than in the conventional group with two parallel incisions.

Level Of Evidence Iii: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
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http://dx.doi.org/10.1007/s00266-021-02485-zDOI Listing
August 2021

Phytochemistry of ginsenosides: Recent advancements and emerging roles.

Crit Rev Food Sci Nutr 2021 Jul 19:1-28. Epub 2021 Jul 19.

Department of Botany, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India.

Ginsenosides, a group of tetracyclic saponins, accounts for the nutraceutical and pharmaceutical relevance of the ginseng () herb. Owing to the associated therapeutic potential of ginsenosides, their demand has been increased significantly in the last two decades. However, a slow growth cycle, low seed production, and long generation time of ginseng have created a gap between the demand and supply of ginsenosides. The biosynthesis of ginsenosides involves an intricate network of pathways with multiple oxidation and glycosylation reactions. However, the exact functions of some of the associated genes/proteins are still not completely deciphered. Moreover, ginsenoside estimation and extraction using analytical techniques are not feasible with high efficiency. The present review is a step forward in recapitulating the comprehensive aspects of ginsenosides including their distribution, structural diversity, biotransformation, and functional attributes in both plants and animals including humans. Moreover, ginsenoside biosynthesis in the potential plant sources and their metabolism in the human body along with major regulators and stimulators affecting ginsenoside biosynthesis have also been discussed. Furthermore, this review consolidates biotechnological interventions to enhance the biosynthesis of ginsenosides in their potential sources and advancements in the development of synthetic biosystems for efficient ginsenoside biosynthesis to meet their rising industrial demands.
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http://dx.doi.org/10.1080/10408398.2021.1952159DOI Listing
July 2021

Truncated Neogenin Promotes Hippocampal Neuronal Death after Acute Seizure.

Neuroscience 2021 08 7;470:78-87. Epub 2021 Jul 7.

Department of Pharmacology, Department of Biomedicine & Health Sciences, Catholic Neuroscience Institute, Institute of Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address:

Protecting hippocampal neurons from death after seizure activity is critical to prevent an alteration of neuronal circuitry and hippocampal function. Here, we present a novel target, a truncated form of neogenin that is associated with seizure-induced hippocampal necroptosis, and novel use of the γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) as a pharmacological regulator of neogenin truncation. We show that 3 days after pilocarpine-induced status epilepticus in mice, when hippocampal cell death is detected, the level of truncated neogenin is increased, while that of full-length neogenin is decreased. Moreover, phosphorylation of mixed lineage kinase domain-like pseudokinase, a crucial marker of necroptosis, was also markedly upregulated at 3 days post-status epilepticus. In cultured hippocampal cells, kainic acid treatment significantly reduced the expression of full-length neogenin. Notably, treatment with DAPT prevented neogenin truncation and protected cultured neurons from N-methyl-D-aspartate (NMDA)-induced death. These data suggest that seizure-induced hippocampal necroptosis is associated with the generation of truncated neogenin, and that prevention of this by DAPT treatment can protect against NMDA-induced excitotoxicity.
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http://dx.doi.org/10.1016/j.neuroscience.2021.06.039DOI Listing
August 2021

Progress in Anti-Mammarenavirus Drug Development.

Viruses 2021 06 22;13(7). Epub 2021 Jun 22.

Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA.

Mammarenaviruses are prevalent pathogens distributed worldwide, and several strains cause severe cases of human infections with high morbidity and significant mortality. Currently, there is no FDA-approved antiviral drugs and vaccines against mammarenavirus and the potential treatment option is limited to an off-label use of ribavirin that shows only partial protective effect and associates with side effects. For the past few decades, extensive research has reported potential anti-mammarenaviral drugs and their mechanisms of action in host as well as vaccine candidates. This review describes current knowledge about mammarenavirus virology, progress of antiviral drug development, and technical strategies of drug screening.
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http://dx.doi.org/10.3390/v13071187DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8310104PMC
June 2021

Subclinical Infection and Transmission of Clade 2.3.4.4 H5N6 Highly Pathogenic Avian Influenza Virus in Mandarin Duck () and Domestic Pigeon ().

Viruses 2021 06 4;13(6). Epub 2021 Jun 4.

Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea.

Since 2014, H5Nx clade 2.3.4.4 highly pathogenic avian influenza viruses (HPAIV) have caused outbreaks in wild birds and poultry in multiple continents, including Asia, Europe, Africa, and North America. Wild birds were suspected to be the sources of the local and global spreads of HPAIV. This study evaluated the infectivity, pathogenicity, and transmissibility of clade 2.3.4.4 H5N6 HPAIV in mandarin ducks ) and domestic pigeons (). None of the birds used in this study, 20 mandarin ducks or 8 pigeons, showed clinical signs or mortality due to H5N6 HPAI infection. Two genotypes of H5N6 HPAIV showed replication and transmission by direct and indirect contact between mandarin ducks. H5N6 HPAIV replicated and transmitted by direct contact between pigeons, although the viral shedding titer and duration were relatively lower and shorter than those in mandarin ducks. Influenza virus antigen was detected in various internal organs of infected mandarin ducks and pigeons, indicating systemic infection. Therefore, our results indicate mandarin ducks and pigeons can be subclinically infected with clade 2.3.4.4 H5N6 HPAIV and transfer the virus to adjacent birds. The role of mandarin ducks and pigeons in the spread and prevalence of clade 2.3.4.4 H5N6 viruses should be carefully monitored.
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http://dx.doi.org/10.3390/v13061069DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8227613PMC
June 2021

OsMTD2-mediated reactive oxygen species (ROS) balance is essential for intact pollen-tube elongation in rice.

Plant J 2021 Aug 20;107(4):1131-1147. Epub 2021 Jul 20.

Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin, Republic of Korea.

The highly specialized haploid male gametophyte-pollen consist of two sperm cells and a large vegetative cell. Successful fertilization requires proper growth timing and rupture of the pollen tube until it delivers sperm cells, which occur immediately after a pollen grain hydrates. Although a tight regulation on polar cell-wall expansion of the pollen tube is fundamentally important, the underlying molecular mechanism remains largely unknown, especially in crop plants. Here, we characterized the function of male-gene transfer defective 2 (OsMTD2) gene in rice (Oryza sativa), which belongs to the plant-specific receptor-like kinase, the CrRLK1L family. We demonstrated that OsMTD2 is an essential male factor participating in pollen-tube elongation based on genetic evidence and physiological observations. Because of unavailability of homozygous mutant via conventional methods, we used CRISPR-Cas9 system to obtain homozygous knockout mutant of OsMTD2. We were able to identify phenotypic changes including male sterility due to early pollen-tube rupture in the mutant. We observed that the production of reactive oxygen species (ROS) was dramatically reduced in mutants of OsMTD2 pollen grain and tubes with defective pectin distribution. Transcriptome analysis of osmtd2-2 versus wild-type anthers revealed that genes involved in defense responses, metabolic alteration, transcriptional and protein modification were highly upregulated in the osmtd2-2 mutant. Through yeast-two-hybrid screening, we found that OsMTD2 kinase interacts with E3 ligase SPL11. Taken together, we propose that OsMTD2 has crucial functions in promoting pollen-tube elongation through cell-wall modification, possibly by modulating ROS homeostasis during pollen-tube growth.
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http://dx.doi.org/10.1111/tpj.15373DOI Listing
August 2021

Delivery of a spheroids-incorporated human dermal fibroblast sheet increases angiogenesis and M2 polarization for wound healing.

Biomaterials 2021 08 7;275:120954. Epub 2021 Jun 7.

School of Chemical Engineering, Sungkyunkwan University, Suwon, Gyeonggi, 16419, Republic of Korea. Electronic address:

Low cell engraftment is a major problem in tissue engineering. Although various methods related with cell sheets have been attempted to resolve the issue, low cell viability due to oxygen and nutrient depletion remains an obstacle toward advanced therapeutic applications. Cell therapy using fibroblasts is thought of as a good alternative due to the short doubling times of fibroblasts together with their immunomodulatory properties. Furthermore, three-dimensional (3D) fibroblasts exhibit unique angiogenic and inflammation-manipulating properties that are not present in two-dimensional (2D) forms. However, the therapeutic effect of 3D fibroblasts in tissue regeneration has not been fully elucidated. Macrophage polarization has been widely studied, as it stimulates the transition from the inflammation to the proliferation phase of wound healing. Although numerous strategies have been developed to achieve better polarization of macrophages, the low efficacy of these strategies and safety issues remain problematic. To this end, we introduced a biocompatible flat patch with specifically designed holes that form a spheroids-incorporated human dermal fibroblast sheet (SIS) to mediate the activity of inflammatory cytokines for M2 polarization and increase angiogenic efficacy. We further confirmed in vivo enhancement of wound healing with an SIS-laden skin patch (SISS) compared to conventional cell therapy.
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http://dx.doi.org/10.1016/j.biomaterials.2021.120954DOI Listing
August 2021

Antiangiogenic and antitumor potential of berbamine, a natural CaMKIIγ inhibitor, against glioblastoma.

Biochem Biophys Res Commun 2021 Aug 11;566:129-134. Epub 2021 Jun 11.

Department of Pharmaceutical Engineering and Biotechnology, Sun Moon University, Asan, South Chungcheong, 31460, Republic of Korea. Electronic address:

Glioblastoma (GBM) is one of the most malignant brain tumors and requires the formation of new blood vessels, called angiogenesis, for its growth and metastasis. Several proangiogenic factors, including vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF), stimulate GBM angiogenesis. Accordingly, blocking the angiogenesis induced by angiogenic factors represents a promising modality for the treatment of GBM. In this study, we evaluated the inhibitory effects of berbamine, a plant-derived compound, on the angiogenesis induced by VEGF and BDNF in human umbilical vein endothelial cells (HUVECs). Berbamine effectively inhibited the angiogenic features stimulated by VEGF (such as proliferation, adhesion, invasion, tube formation, and reactive oxygen species (ROS) generation in HUVECs) as well as those by BDNF, at concentrations that do not affect endothelial cell viability. The antiangiogenic effects of berbamine were associated with the downregulation of VEGF/VEGF receptor 2 (VEGFR2)/Ca/calmodulin-dependent protein kinase IIγ (CaMKIIγ) and BDNF/tropomyosin receptor kinase B (TrkB)/CaMKIIγ signaling pathways. In addition, berbamine suppressed the expression of a key regulator of tumor angiogenesis, hypoxia-inducible factor-1α (HIF-1α), and its transcriptional target, VEGF, in U87MG GBM cells. Furthermore, berbamine significantly inhibited in vivo neovascularization as well as U87MG tumor growth in a chick embryo chorioallantoic membrane (CAM) model. All these findings suggest that berbamine may be utilized as a new antiangiogenic agent for the treatment of malignant brain tumors.
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http://dx.doi.org/10.1016/j.bbrc.2021.06.025DOI Listing
August 2021

Catalyst- and Solvent-Free Synthesis of a Chemically Stable Aza-Bridged Bis(phenanthroline) Macrocycle-Linked Covalent Organic Framework.

Angew Chem Int Ed Engl 2021 Jul 26;60(31):17191-17197. Epub 2021 Jun 26.

School of Energy and Chemical Engineering, Center for Dimension Controllable Organic Frameworks, Ulsan National Institute of Science and Technology, South Korea.

Developing new linkage-based covalent organic frameworks (COFs) is one of the major topics in reticular chemistry. Electrically conductive COFs have enabled applications in energy storage and electrochemical catalysis, which are not feasible using insulating COFs. Despite significant advances, the construction of chemically stable conductive COFs by the formation of new linkages remains relatively unexplored and challenging. Here we report the solvent- and catalyst-free synthesis of a two-dimensional aza-bridged bis(phenanthroline) macrocycle-linked COF (ABBPM-COF) from the thermally induced poly-condensation of a tri-topic monomer and ammonia gas. The ABBPM-COF structure was elucidated using multiple techniques, including X-ray diffraction analysis combined with structural simulation, revealing its crystalline nature with an ABC stacking mode. Further experiments demonstrated its excellent chemical stability in acid/base solutions. Electrical-conductivity measurements showed that the insulating ABBPM-COF becomes a semiconducting material after exposure to iodine vapor.
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http://dx.doi.org/10.1002/anie.202106389DOI Listing
July 2021

Interaction of OsRopGEF3 Protein With OsRac3 to Regulate Root Hair Elongation and Reactive Oxygen Species Formation in Rice ().

Front Plant Sci 2021 25;12:661352. Epub 2021 May 25.

Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin, South Korea.

Root hairs are tip-growing cells that emerge from the root epidermis and play a role in water and nutrient uptake. One of the key signaling steps for polar cell elongation is the formation of Rho-GTP by accelerating the intrinsic exchange activity of the Rho-of-plant (ROP) or the Rac GTPase protein; this step is activated through the interaction with the plant Rho guanine nucleotide exchange factor (RopGEFs). The molecular players involved in root hair growth in rice are largely unknown. Here, we performed the functional analysis of , which is highly expressed in the root hair tissues among the family genes in rice. To reveal the role of OsRopGEF3, we analyzed the phenotype of loss-of-function mutants of , which were generated using the CRISPR-Cas9 system. The mutants had reduced root hair length and increased root hair width. In addition, we confirmed that reactive oxygen species (ROS) were highly reduced in the root hairs of the mutant. The pairwise yeast two-hybrid experiments between OsRopGEF3 and OsROP/Rac proteins in rice revealed that the OsRopGEF3 protein interacts with OsRac3. This interaction and colocalization at the same subcellular organelles were again verified in tobacco leaf cells and rice root protoplasts via bimolecular functional complementation (BiFC) assay. Furthermore, among the three respiratory burst oxidase homolog (OsRBOH) genes that are highly expressed in rice root hair cells, we found that OsRBOH5 can interact with OsRac3. Our results demonstrate an interaction network model wherein OsRopGEF3 converts the GDP of OsRac3 into GTP, and OsRac3-GTP then interacts with the N-terminal of OsRBOH5 to produce ROS, thereby suggesting OsRopGEF3 as a key regulating factor in rice root hair growth.
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http://dx.doi.org/10.3389/fpls.2021.661352DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8185220PMC
May 2021

Inhibitory Effects of Gyeji-Tang on MMP-9 Activity and the Expression of Adhesion Molecules in IL-4- and TNF-α-Stimulated BEAS-2B Cells.

Plants (Basel) 2021 May 10;10(5). Epub 2021 May 10.

Herbal Medicine Research Division, Korea Institute of Oriental Medicine, 1672 Yuseong-daero, Yuseong-gu, Daejeon 34054, Korea.

Gyeji-tang (GJT), a traditional herbal formula composed of five herbal medicines, is commonly used to treat the common cold, exogenous febrile disease, fever and headaches in Korea, China and Japan. Although various pharmacological activities of GJT have been reported in several studies, the effect of GJT water extract (GJTWE) on airway inflammation has not yet been investigated. This study aimed to evaluate the effects of GJTWE on airway inflammation-related factors using human bronchial epithelial BEAS-2B cells, and to identify the phytochemicals in GJTWE by ultra-performance liquid chromatography-diode array detector-tandem mass spectrometry (UPLC-DAD-MS/MS) analysis. GJTWE significantly decreased the production of chemokines, including eotaxin-3, eotaxin-1, regulated on activation normal T-cell expressed and secreted (RANTES), and matrix metalloproteinase-9, and the expression of the adhesion molecules, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, in interleukin-4 + tumor necrosis factor-α (IT)-stimulated BEAS-2B cells. In the UPLC-DAD-MS/MS analysis, 21 phytochemicals, including six flavonoids, two chalcones, five terpenoids, six phenolics, one phenylpropanoid and one coumarin, were identified in GJTWE. The findings suggested that GJTWE might exhibit anti-inflammatory effects on airway inflammation by regulating the expression of inflammatory response-related factors in IT-stimulated BEAS-2B cells; further studies are required to determine the bioactive compounds involved in the inhibition of airway inflammation.
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http://dx.doi.org/10.3390/plants10050951DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8151808PMC
May 2021

Multiplex PCR-Based Nanopore Sequencing and Epidemiological Surveillance of in , Republic of Korea.

Viruses 2021 05 6;13(5). Epub 2021 May 6.

BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul 02841, Korea.

Whole-genome sequencing of infectious agents enables the identification and characterization of emerging viruses. The MinION device is a portable sequencer that allows real-time sequencing in fields or hospitals. (Hantaan virus, HTNV), harbored by , causes hemorrhagic fever with renal syndrome (HFRS) and poses a critical public health threat worldwide. In this study, we aimed to evaluate the feasibility of using nanopore sequencing for whole-genome sequencing of HTNV from samples having different viral copy numbers. Amplicon-based next-generation sequencing was performed in lung tissues collected from the Republic of Korea. Genomic sequences of HTNV were analyzed based on the viral RNA copy numbers. Amplicon-based nanopore sequencing provided nearly full-length genomic sequences of HTNV and showed sufficient read depth for phylogenetic analysis after 8 h of sequencing. The average identity of the HTNV genome sequences for the nanopore sequencer compared to those of generated from Illumina MiSeq revealed 99.8% (L and M segments) and 99.7% (S segment) identities, respectively. This study highlights the potential of the portable nanopore sequencer for rapid generation of accurate genomic sequences of HTNV for quicker decision making in point-of-care testing of HFRS patients during a hantavirus outbreak.
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http://dx.doi.org/10.3390/v13050847DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8148566PMC
May 2021

MIT-001 Restores Human Placenta-Derived Mesenchymal Stem Cells by Enhancing Mitochondrial Quiescence and Cytoskeletal Organization.

Int J Mol Sci 2021 May 11;22(10). Epub 2021 May 11.

Department of Biomedical Science, College of Life Science, CHA University, Pocheon 11160, Korea.

Inflammation is a major cause of several chronic diseases and is reported to be recovered by the immuno-modulation of mesenchymal stem cells (MSCs). While most studies have focussed on the anti-inflammatory roles of MSCs in stem cell therapy, the impaired features of MSCs, such as the loss of homeostasis by systemic aging or pathologic conditions, remain incompletely understood. In this study, we investigated whether the altered phenotypes of human placenta-derived MSCs (hPD-MSCs) exposed to inflammatory cytokines, including TNF-α and IFN-γ, could be protected by MIT-001, a small anti-inflammatory and anti-necrotic molecule. MIT-001 promoted the spindle-like shape and cytoskeletal organization extending across the long cell axis, whereas hPD-MSCs exposed to TNF-α/IFN-γ exhibited increased morphological heterogeneity with an abnormal cell shape and cytoskeletal disorganization. Importantly, MIT-001 improved mitochondrial distribution across the cytoplasm. MIT-001 significantly reduced basal respiration, ATP production, and cellular ROS levels and augmented the spare respiratory capacity compared to TNF-α/IFN-γ-exposed hPD-MSCs, indicating enhanced mitochondrial quiescence and homeostasis. In conclusion, while TNF-α/IFN-γ-exposed MSCs lost homeostasis and mitochondrial quiescence by becoming over-activated in response to inflammatory cytokines, MIT-001 was able to rescue mitochondrial features and cellular phenotypes. Therefore, MIT-001 has therapeutic potential for clinical applications to treat mitochondrion-related inflammatory diseases.
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http://dx.doi.org/10.3390/ijms22105062DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8151078PMC
May 2021

BCG Cell Wall Skeleton As a Vaccine Adjuvant Protects Both Infant and Old-Aged Mice from Influenza Virus Infection.

Biomedicines 2021 May 5;9(5). Epub 2021 May 5.

Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30302, USA.

Bacillus Calmette-Guerin (BCG) and the cell wall skeleton (CWS) derived from BCG are known to enhance nonspecific immune activation and anti-cancer immunity; however, their roles as a vaccine adjuvant are largely unknown. Here, we report that BCG-CWS acts as a strong immune adjuvant by promoting the protective immune responses in mouse models with influenza vaccination. The different aged mice immunized with inactivated split vaccine with or without BCG-CWS were challenged with an influenza pandemic virus. When protective immune responses were compared, even a single immunization of adult mice with a BCG-CWS-adjuvanted vaccine showed significantly enhanced humoral immune responses with increased IgG1 and IgG2a isotype antibodies. Importantly, the protective effects by the BCG-CWS adjuvant for influenza vaccination upon humoral and cellular immunogenicity were comparable between infants (6 days and 2 weeks old) and aged (20 months old) mice. Moreover, BCG-CWS dramatically augmented vaccine-mediated protective responses, including decreased viral loads, lung damage, and airway resistance, as well as increased mouse survival, amelioration of weight loss, and proinflammatory cytokine expression in all experimental groups including infant, adults, and old aged mice. We further provided the evidence that the BCG-CWS adjuvant effects were mediated through Toll-like receptors (TLR) 2 and TLR4 signaling pathways. Together, these data suggest that BCG-CWS can be promising as a potential influenza vaccine adjuvant in both young and old aged population through TLR2/4-mediated immune-boosting activities.
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http://dx.doi.org/10.3390/biomedicines9050516DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8148143PMC
May 2021

Evaluation of the image quality and dose reduction in digital radiography with an advanced spatial noise reduction algorithm in pediatric patients.

Eur Radiol 2021 May 26. Epub 2021 May 26.

Department of Radiology & Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-Gu, Seoul, 06351, South Korea.

Objectives: To evaluate whether the advanced spatial noise reduction (ASNR) algorithm installed in a digital radiography system generates acceptable images at a lower dose than a conventional denoising algorithm in pediatric patients.

Methods: Nine sets of 30 images of pediatric patients, classified under three protocols and three age groups, were retrospectively selected. Different levels of low-dose image sets of these 270 images were generated by a noise simulation tool after validation testing using phantoms. Each image set was obtained with both the ASNR and conventional algorithm, and grouped randomly and blinded. Three experienced pediatric radiologists were asked to pick the "image with optimum dose" among images of different dose levels with an ALARA (as low as reasonably achievable) perspective. Dose reduction rates for each protocol and age group were calculated, and entrance skin exposure (ESE) was calculated using the values of kVp and mAs, assuming a standard body depth for each age group.

Results: With the ASNR algorithm, estimated dose reduction rates were highest for abdominal radiographs (45.0%, 27.3%, and 24.3% in infants, children, and adolescents, respectively, p < 0.001). The mean dose reductions for all age groups in the abdominal, chest, and skull radiographs were 32.8%, 12.9%, and 23.2%, respectively (p < 0.001). Average of the calculated ESE was lower with the ASNR algorithm than with the conventional algorithm group (p < 0.001).

Conclusions: The ASNR algorithm facilitated optimization of image quality with a higher reduction in radiation dose than the conventional algorithm, making it more acceptable for use in pediatric patients.

Key Points: •ASNR algorithm in DR system improves image quality via enhanced contrast and noise removal by estimating actual noise distribution based on a multi-scale noise covariance and frequency processing. •Noise simulation tool (NST) generating images of different dose levels can be used for evaluation of the optimum dose without unnecessary additional radiation exposure to pediatric patients. •Retrospective clinical study using NST showed that the ASNR algorithm enabled a higher reduction in radiation dose than the conventional algorithm in pediatric patients.
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http://dx.doi.org/10.1007/s00330-021-07942-6DOI Listing
May 2021

Association between menopausal hormone therapy and risk of neurodegenerative diseases: Implications for precision hormone therapy.

Alzheimers Dement (N Y) 2021 13;7(1):e12174. Epub 2021 May 13.

Center for Innovation in Brain Science University of Arizona Tucson Arizona USA.

Introduction: The impact of menopausal hormone therapy (HT) on age-associated Alzheimer's and neurodegenerative diseases (NDDs) remains unresolved. To determine the effect of HT, formulation, type, and duration on risk of NDDs, a retrospective analysis was performed using a 10-year Humana claims dataset.

Methods: Study population included women aged 45 years or older with or without claim records of HT medications. Patients diagnosed with NDDs including Alzheimer's disease (AD), Parkinson's disease (PD), dementia, multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS) were identified. Relative risk (RR) ratios and 95% confidence intervals (CI) for combined NDDs, or AD, PD, dementia, MS, and ALS were determined. Cumulative hazard ratios were determined to investigate the association between HT and NDDs at different age groups.

Results: In 379,352 women with or without claim records of HT, use of HT was associated with significantly reduced risk for combined NDDs (RR 0.42, 95% CI 0.40-0.43,  < 0.001). Average follow-up time was 5.1 [2.3] years. Formulations containing natural steroids 17β-estradiol and/or progesterone were associated with greater reduction in NDD risk. Oral- HT users showed significantly reduced RRs (0.42, 0.41-0.44,  < 0.001) for combined NDDs compared to non-HT users. The RRs for transdermal-HT users were significantly decreased for all-cause dementia (0.73, 0.60-0.88,  = 0.001) and MS (0.55, 0.36-0.84,  = 0.005). Greatest reduction in risk of NDD, AD, and dementia emerged in patients aged 65 years or older. Further, the protective effect of long-term therapy (>1 year) on combined NDDs, AD, PD, and dementia was greater compared to short-term therapy (≤1 year).

Discussion: HT was associated with reduced risk of all NDDs including AD and dementia, with greater duration of therapy and natural steroid formulations associated with greater efficacy. These findings advance precision HT to prevent NDDs including AD.
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http://dx.doi.org/10.1002/trc2.12174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8118114PMC
May 2021

Thunb. Leaves Ameliorate Cognitive Deficit and Neuronal Damage in a Mouse Model of Amyloid-β-Induced Alzheimer's Disease.

Front Pharmacol 2021 15;12:607403. Epub 2021 Apr 15.

Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon, South Korea.

Alzheimer's disease (AD) pathogenesis is linked to amyloid plaque accumulation, neuronal loss, and brain inflammation. Thunb. is a food and medicinal plant used to treat inflammatory diseases. Here, we investigated the neuroprotective effects of Thunb. against cognitive deficit and neuronal damage in a mouse model of amyloid-β (Aβ)-induced AD. First, we confirmed the inhibitory effects of ethanol extracts of (EEFE) leaves on Aβ aggregation and . Next, behavioral tests (passive avoidance task and Morris water maze test) revealed EEFE markedly improved cognitive impairment in Aβ-injected mice. Furthermore, EEFE reduced neuronal loss and the expression of neuronal nuclei (NeuN), a neuronal marker, in brain tissues of Aβ-injected mice. EEFE significantly reversed Aβ-induced suppression of cAMP response element-binding protein (CREB) phosphorylation and brain-derived neurotrophic factor (BDNF) expression, indicating neuroprotection was mediated by the CREB/BDNF signaling. Moreover, EEFE significantly suppressed the inflammatory cytokines interleukin 1beta (IL-1β) and tumor necrosis factor alpha (TNF-α), and expression of ionized calcium-binding adaptor molecule 1 (Iba-1), a marker of microglial activation, in brain tissues of Aβ-injected mice, suggesting anti-neuroinflammatory effects. Taken together, EEFE protects against cognitive deficit and neuronal damage in AD-like mice via activation of the CREB/BDNF signaling and upregulation of the inflammatory cytokines.
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http://dx.doi.org/10.3389/fphar.2021.607403DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8082460PMC
April 2021

Global Identification of Genes Involved in Rice Pollen Germination and Functional Characterization of a Key Member, OsANTH3.

Front Plant Sci 2021 13;12:609473. Epub 2021 Apr 13.

Department of Life Science and Environmental Biochemistry, Life and Industry Convergence Research Institute, Pusan National University, Miryang, South Korea.

Pollen in angiosperms plays a critical role in double fertilization by germinating and elongating pollen tubes rapidly in one direction to deliver sperm. In this process, the secretory vesicles deliver cell wall and plasma membrane materials, and excessive materials are sequestered via endocytosis. However, endocytosis in plants is poorly understood. AP180 N-terminal homology (ANTH) domain-containing proteins function as adaptive regulators for clathrin-mediated endocytosis in eukaryotic systems. Here, we identified 17 ANTH domain-containing proteins from rice based on a genome-wide investigation. Motif and phylogenomic analyses revealed seven asparagine-proline-phenylalanine (NPF)-rich and 10 NPF-less subgroups of these proteins, as well as various clathrin-mediated endocytosis-related motifs in their C-terminals. To investigate their roles in pollen germination, we performed meta-expression analysis of all genes encoding ANTH domain-containing proteins in ( genes) in anatomical samples, including pollen, and identified five mature pollen-preferred genes. The subcellular localization of four OsANTH proteins that were preferentially expressed in mature pollen can be consistent with their role in endocytosis in the plasma membrane. Of them, OsANTH3 represented the highest expression in mature pollen. Functional characterization of using T-DNA insertional knockout and gene-edited mutants revealed that a mutation in decreased seed fertility by reducing the pollen germination percentage in rice. Thus, our study suggests OsANTH3-mediated endocytosis is important for rice pollen germination.
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http://dx.doi.org/10.3389/fpls.2021.609473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8076639PMC
April 2021

Simultaneous Quantification of Four Marker Compounds in Extract and Their Potential Inhibitory Effects on Alzheimer's Disease Biomarkers.

Plants (Basel) 2021 Apr 6;10(4). Epub 2021 Apr 6.

Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.

is a tropical woody plant widely distributed in Vietnam and Unnan in southern China. Although many studies have shown the biological activities of extracts from various other species in the genus, no studies have investigated the effects of extracts on biological systems. In the present study, a quantitative analysis of four marker compounds of ethanol extracts of branches (EEBC) was performed using the high performance liquid chromatography (HPLC)-photodiode array (PDA) method. Among gallic acid, (+)-catechin, ellagic acid, and quercitrin contained in EEBC, the most abundant compound was (+)-catechin (18.736 mg/g). In addition, we investigated the EEBC on neuroprotection, antioxidation, and Alzheimer's disease (AD) marker molecules, acetylcholinesterase (AChE), and amyloid-β (Aβ). EEBC significantly inhibited hydrogen peroxide (HO)-induced cell death in a HT22 neuronal cell line and increased 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl scavenging activity markedly. EEBC also inhibited AChE and Aβ aggregation. Among the four compounds, gallic acid exhibited strong inhibitory effects against AChE activation. In the Aβ aggregation assay, the four marker compounds exhibited inhibitory effects lower than 30%. According to the results, EEBC could exert anti-AChE activation and Aβ aggregation activities based on the interactive effects of the marker compounds. Our findings suggest that EEBC are sources of therapeutic candidates for application in the development of AD medication based on AChE and Aβ dual targeting.
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http://dx.doi.org/10.3390/plants10040702DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8067434PMC
April 2021

Predictive Role of Lung Injury Prediction Score in the Development of Acute Respiratory Distress Syndrome in Korea.

Yonsei Med J 2021 May;62(5):417-423

Division of Pulmonology, Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Korea.

Purpose: Early recognition and therapeutic intervention are important in patients at high risk of acute respiratory distress syndrome (ARDS). The lung injury prediction score (LIPS) has been used to predict ARDS development; however, it was developed based on the previous definition of ARDS. We investigated the predictive role of LIPS in ARDS development according to its Berlin definition in the Korean population.

Materials And Methods: This was a retrospective study that enrolled adult patients admitted to the intensive care unit (ICU) at a single university-affiliated hospital in Korea from September 1, 2018, to August 31, 2019. LIPS at the time of ICU admission and the development of ARDS were evaluated.

Results: Of the 548 enrolled patients, 33 (6.0%) fulfilled the Berlin ARDS definition. The LIPS for non-ARDS and ARDS groups were 4.96±3.05 and 8.53±2.45, respectively (<0.001); it was significantly associated with ARDS development (odds ratio 1.48, 95% confidence interval, 1.29-1.69; <0.001). LIPS >6 predicted the development of ARDS with a sensitivity of 84.8% and a specificity of 67.2% [area under the curve (AUC)=0.82]. A modified LIPS model adjusted for age and severity at ICU admission predicted ICU mortality in patients with ARDS (AUC=0.80), but not in those without ARDS (AUC=0.54).

Conclusion: LIPS predicted the development of ARDS as diagnosed by the Berlin definition in the Korean population. LIPS provides useful information for managing patients with ARDS.
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http://dx.doi.org/10.3349/ymj.2021.62.5.417DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8084702PMC
May 2021

Korean traditional herbal formula Soshiho-tang attenuates memory impairment and neuronal damage in mice with amyloid-beta-induced Alzheimer's disease.

Integr Med Res 2021 Sep 30;10(3):100723. Epub 2021 Mar 30.

Clinical Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea.

Background: Soshiho-tang (SST), also known as Xiaochaihu-tang in China and Sho-saiko-to in Japan, is an Oriental herbal formula traditionally used to treat febrile diseases. Recently, several and studies have reported the anti-cancer, anti-liver disease, and anti-inflammatory activities of SST. However, there is little evidence of its effects on neurological diseases. We previously reported the inhibitory effects of SST on acetylcholinesterase (AChE) activation and amyloid-β (Aβ) aggregation, which are crucial hallmarks of Alzheimer's disease (AD). In the present study, we report that SST has preventive effects on memory impairment and neuronal cell changes in an Aβ-induced AD-like mouse model.

Methods: Male mice underwent injection of Aβ aggregates and administered SST (500, 1,000, or 2,000 mg/kg/day) for 20 days. Behavioral tests (passive avoidance task [PAT] and Morris water maze [MWM] test) were conducted. Lastly, brain sections were obtained from sacrificed mice for quantitative analysis.

Results: Intracerebroventricular (ICV) injection of Aβ aggregates significantly decreased the latency time in the PAT and MWM test compared to normal control. In contrast, SST administration markedly reversed the latency caused by Aβ injection. Additionally, our data revealed that SST-mediated improvements in memory impairment are related to its neuroprotective and anti-neuroinflammatory effects. On histological analysis, SST treatment protected neuronal loss and damage as well as microglial activation, and ameliorated amount of Aβ in brain of mouse model of AD.

Conclusion: Our findings suggest that SST may be a promising candidate for the development of novel drugs for AD.
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http://dx.doi.org/10.1016/j.imr.2021.100723DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8059063PMC
September 2021

Daily Life Changes and Life Satisfaction among Korean School-Aged Children in the COVID-19 Pandemic.

Int J Environ Res Public Health 2021 03 23;18(6). Epub 2021 Mar 23.

Department of Child Development and Family Studies, College of Human Ecology, Seoul National University, Seoul 08826, Korea.

The recent COVID-19 pandemic has been disrupting the daily lives of people across the world, causing a major concern for psychological well-being in children. This study aimed to examine (1) how life satisfaction and its potential predictors have been affected by the pandemic among school-aged children in Korea, and (2) which factors would predict their life satisfaction during the pandemic. We surveyed 166 fourth-graders in the Seoul metropolitan area to assess their psychological well-being and potentially related variables during the pandemic. The data were compared with those available from two pre-COVID-19 surveys, the 2018 Korean Children and Youth Panel Survey ( = 1236) and the 2019 Korean Children and Youth Well-being Index Survey ( = 334). Higher levels of stress were observed in children during the COVID-19 pandemic; however, the level of their life satisfaction remained unchanged when compared with data from the pre-COVID-19 surveys. The pandemic also affected peer relationship quality and susceptibility to smartphone addiction, but not perceived parenting style nor academic engagement. Interestingly, peer relationship quality no longer predicted life satisfaction during the pandemic; perceived parenting styles and parent-child conversation time predicted life satisfaction. The results suggest a central role of parent-child relationship in supporting the psychological well-being of school-aged children during the pandemic.
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http://dx.doi.org/10.3390/ijerph18063324DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8004811PMC
March 2021

Role of RGMc as a Neogenin Ligand in Follicular Development in the Ovary.

Biomedicines 2021 Mar 10;9(3). Epub 2021 Mar 10.

CHA Fertility Center Seoul Station, Seoul 04637, Korea.

There is currently no cure for infertility in women with a poor ovarian response (POR). Neogenin is reported to be abundantly expressed in the ovary; however, its role in mammalian follicular development is unclear and its ligand and signaling pathway remain uncertain. We systematically investigated the role of neogenin and the ligand repulsive guidance molecule c (RGMc) during follicular development. We treated hyperstimulated mouse ovaries with RGMc and analyzed follicular development. Furthermore, we investigated clusters of up/downregulated genes in RGMc-treated ovaries using whole-transcriptome next-generation sequencing (NGS). In addition, we investigated whether expression of up/downregulated factors identified by NGS was also altered in cumulus cells (CCs) of patients with a POR. The number of oocytes was 40% higher in RGMc-treated ovaries than in control ovaries. NGS data indicated that prostaglandin D2 (PGD2) was involved in the RGMc signaling pathway during follicular development. RGMc treatment significantly elevated the PGD2 level in culture medium of CCs obtained from patients with a POR. Our results demonstrate that RGMc as neogenin ligand promotes follicular development in ovaries via the PGD2 signaling pathway. Therefore, it may be possible to use RGMc for ovarian stimulation in patients with a POR.
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http://dx.doi.org/10.3390/biomedicines9030280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7999520PMC
March 2021
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