Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
2,219 result(s) for "Park, Kyong"
Sort by:
Enhancement of therapeutic potential of mesenchymal stem cell-derived extracellular vesicles
After the initial investigations into applications of mesenchymal stem cells (MSCs) for cell therapy, there was increased interest in their secreted soluble factors. Following studies of MSCs and their secreted factors, extracellular vesicles (EVs) released from MSCs have emerged as a new mode of intercellular crosstalk. MSC-derived EVs have been identified as essential signaling mediators under both physiological and pathological conditions, and they appear to be responsible for many of the therapeutic effects of MSCs. In several in vitro and in vivo models, EVs have been observed to have supportive functions in modulating the immune system, mainly mediated by EV-associated proteins and nucleic acids. Moreover, stimulation of MSCs with biophysical or biochemical cues, including EVs from other cells, has been shown to influence the contents and biological activities of subsequent MSC-derived EVs. This review provides on overview of the contents of MSC-derived EVs in terms of their supportive effects, and it provides different perspectives on the manipulation of MSCs to improve the secretion of EVs and subsequent EV-mediated activities. In this review, we discuss the possibilities for manipulating MSCs for EV-based cell therapy and for using EVs to affect the expression of elements of interest in MSCs. In this way, we provide a clear perspective on the state of the art of EVs in cell therapy focusing on MSCs, and we raise pertinent questions and suggestions for knowledge gaps to be filled.
Adjuvant Capecitabine for Breast Cancer after Preoperative Chemotherapy
Patients who complete neoadjuvant chemotherapy for breast cancer without a pathological complete response have a high risk of relapse. A randomized trial comparing capecitabine with no additional adjuvant therapy showed that capecitabine prolonged disease-free and overall survival. Patients who have residual invasive breast cancer after the receipt of neoadjuvant chemotherapy have a high risk of relapse. 1 The rate of complete response as assessed on pathological testing (hereafter, pathological complete response) ranges from 13 to 22% among patients with human epidermal growth factor receptor 2 (HER2)–negative primary breast cancer. 1 Patients who do not have a pathological complete response after the receipt of neoadjuvant taxane and anthracycline chemotherapy have a 20 to 30% risk of relapse. 2 Patients with HER2-negative cancer who receive neoadjuvant chemotherapy often receive postoperative radiation therapy, whereas endocrine therapy is administered to patients with hormone-receptor–positive disease . . .
Mesenchymal stromal cell-derived nanovesicles ameliorate bacterial outer membrane vesicle-induced sepsis via IL-10
Background Sepsis remains a source of high mortality in hospitalized patients despite proper antibiotic approaches. Encouragingly, mesenchymal stromal cells (MSCs) and their produced extracellular vesicles (EVs) have been shown to elicit anti-inflammatory effects in multiple inflammatory conditions including sepsis. However, EVs are generally released from mammalian cells in relatively low amounts, and high-yield isolation of EVs is still challenging due to a complicated procedure. To get over these limitations, vesicles very similar to EVs can be produced by serial extrusions of cells, after which they are called nanovesicles (NVs). We hypothesized that MSC-derived NVs can attenuate the cytokine storm induced by bacterial outer membrane vesicles (OMVs) in mice, and we aimed to elucidate the mechanism involved. Methods NVs were produced from MSCs by the breakdown of cells through serial extrusions and were subsequently floated in a density gradient. Morphology and the number of NVs were analyzed by transmission electron microscopy and nanoparticle tracking analysis. Mice were intraperitoneally injected with Escherichia coli -derived OMVs to establish sepsis, and then injected with 2 × 10 9 NVs. Innate inflammation was assessed in peritoneal fluid and blood through investigation of infiltration of cells and cytokine production. The biodistribution of NVs labeled with Cy7 dye was analyzed using near-infrared imaging. Results Electron microscopy showed that NVs have a nanometer-size spherical shape and harbor classical EV marker proteins. In mice, NVs inhibited eye exudates and hypothermia, signs of a systemic cytokine storm, induced by intraperitoneal injection of OMVs. Moreover, NVs significantly suppressed cytokine release into the systemic circulation, as well as neutrophil and monocyte infiltration in the peritoneum. The protective effect of NVs was significantly reduced by prior treatment with anti-interleukin (IL)-10 monoclonal antibody. In biodistribution study, NVs spread to the whole mouse body and localized in the lung, liver, and kidney at 6 h. Conclusions Taken together, these data indicate that MSC-derived NVs have beneficial effects in a mouse model of sepsis by upregulating the IL-10 production, suggesting that artificial NVs may be novel EV-mimetics clinically applicable to septic patients.
Total and differential WBC counts are related with coronary artery atherosclerosis and increase the risk for cardiovascular disease in Koreans
Inflammation is a key mechanism of atherosclerosis. White blood cells (WBCs) play a pivotal role in the inflammatory process. We investigated the relationships between total and differential WBC counts and multi-detector cardiac computed tomography (MDCT) findings, as well as the risk of cardiovascular disease in asymptomatic patients in Korea. We recruited asymptomatic men (n = 7274) and women (n = 5478) aged ≥30 years who were free of known coronary heart disease. All patients underwent MDCT during a routine health check-up in the Seoul National University Bundang Hospital between 2006 and 2007, and were followed-up for 5.6 years. We reviewed medical records for cardiovascular diseases (CVDs) and covariates. In covariate-adjusted logistic regression models for MDCT findings, subjects within the third tertile of all WBC subtypes had a higher risk for significant stenosis and noncalcified plaques compared with the first tertile of each subtype. In Cox proportional hazard regression models for the risk of CVDs, subjects within the third tertiles of lymphocytes and monocytes were at an increased risk of CVDs (total WBC, HR = 1.22 [1.02-1.44]; lymphocyte, HR = 1.47 [1.25-1.74]; monocytes, HR = 1.26 [1.02-1.35]) even after further adjustment for covariates and coronary artery stenosis. Total WBC counts were related with the severity of coronary artery disease, and higher WBC counts increased the risk of CVDs in asymptomatic Koreans mainly by virtue of monocytes.
Unraveling the complexity of faba bean (Vicia faba L.) transcriptome to reveal cold-stress-responsive genes using long-read isoform sequencing technology
Faba bean ( Vicia faba L.), a globally important grain legume providing a stable source of dietary protein, was one of the earliest plant cytogenetic models. However, the lack of draft genome annotations and unclear structural information on mRNA transcripts have impeded its genetic improvement. To address this, we sequenced faba bean leaf transcriptome using the PacBio single-molecule long-read isoform sequencing platform. We identified 28,569 nonredundant unigenes, ranging from 108 to 9669 bp, with a total length of 94.5 Mb. Many unigenes (3597, 12.5%) had 2–20 isoforms, indicating a highly complex transcriptome. Approximately 96.5% of the unigenes matched sequences in public databases. The predicted proteins and transcription factors included NB-ARC , Myb_domain , C3H , bHLH , and heat shock proteins, implying that this genome has an abundance of stress resistance genes. To validate our results, we selected WCOR413-15785, DHN2-12403, DHN2-14197, DHN2-14797, COR15-14478, and HVA22-15 unigenes from the ICE-CBF-COR pathway to analyze their expression patterns in cold-treated samples via qRT-PCR. The expression of dehydrin-related genes was induced by cold stress. The assembled data provide the first insights into the deep sequencing of full-length RNA from faba bean at the single-molecule level. This study provides an important foundation to improve gene modeling and protein prediction.
Centrifugation-free extraction of circulating nucleic acids using immiscible liquid under vacuum pressure
Extraction of cell-free DNA (cfDNA), which exists at an extremely low concentration in plasma, is a critical process for either targeted-sensing or massive sequencing of DNAs. However, such small amount of DNA cannot be fully obtained without high-speed centrifugation (<20,000 g). Here, we developed a centrifugation-free cfDNA extraction method and system that utilizes an immiscible solvent under single low vacuum pressure throughout the entire process. It has been named Pressure and Immiscibility-Based EXtraction (PIBEX). The amounts of extracted cfDNA by PIBEX were compared with those extracted by the conventional gold standards such as QIAGEN using quantitative PCR (qPCR). The PIBEX system showed equal performance regarding extraction amount and efficiency compared to the existing method. Because the PIBEX eliminates the troublous and repetitive centrifugation processes in DNA extraction, it can be further utilized in microfluidic-sample preparation systems for circulating nucleic acids, which would lead to an integrated sample-to-answer system in liquid biopsies.
Effect of Rhizopus nigricans (Rhizopus stolonifera)-based novel starter culture on quality and safety attributes of doenjang, a traditional Korean soybean fermented food product
We aimed to develop a consortium of starter culture of effective microorganisms to prepare doenjang , a traditional Korean fermented food. Different ratios of Bacillus subtilis TKSP 24 (B), Aspergillus oryzae complex (A), Rhizopus nigricans (also named as Rhizopus stolonifera ) (R), and Mucor racemosus 15 (M15) were selected as meju starter cultures to produce doenjang with improved quality. Microbial strain combinations (B: A: R and B: M15: R) were mixed separately at three different ratios [1:1:1 (w/w), 1:0.5:1.5 (w/w), and 1:1.5:0.5 (w/w)] to prepare BAR-1, BAR-2, BAR-3, BM15R-1, BM15R-2, and BM15R-3 doenjang samples. Quantitative analyses included free amino acids, free sugar, volatile and non-volatile organic acids, cellular antioxidant activity along with the presence of biogenic amines and aflatoxins, and microbial counts. Total free amino acids responsible for the sweet taste of doenjang were highest in BAR-2 (322.50 mg/100 g) and BM15R-3 (320.07 mg/100 g). Total volatile organic acid was highest in BAR-1 compared to other preparations. All doenjang samples had biogenic amines, especially histamine, below the toxicity level (500 mg/kg). Also, the aflatoxin and hazardous microbial count in the tested doenjang samples were below the level of toxicity. The findings suggest that use of multiple microbial strains in combination with R. nigricans as a starter culture could be a novel and effective approach to improve the nutrition and safety of fermented soybean food products of doenjang .
Extracellular vesicle surface engineering with integrins (ITGAL & ITGB2) to specifically target ICAM-1-expressing endothelial cells
Extracellular vesicles (EVs) are taken up by most cells, however specific or preferential cell targeting remains a hurdle. This study aims to develop an EV that targets cells involved in inflammation, specifically those expressing intercellular adhesion molecule-1 (ICAM-1). To target these cells, we overexpress the ICAM-1 binding receptor “lymphocyte function-associated antigen-1” (LFA-1) in HEK293F cells, by sequential transfection of plasmids of the two LFA-1 subunits, ITGAL and ITGB2 (CD11a and CD18). The LFA-1 receptor was strongly overexpressed on the EVs released by the transfected cells. We further loaded these EVs with a therapeutic peptide, targeting myeloid differentiation primary response 88 (Myd88; EV Myd88 ), through a developed EV open-and-close procedure. Myd88 is a downstream common intracellular messenger for most TLR-receptors. EV expression of LFA-1 increases EV binding to ICAM-1-expressing cells, an effect that was dose-dependently inhibited by a specific neutralizing ICAM-1 antibody. Further, activated human endothelial cells treated with LFA-1 EV Myd88 had increased uptake of these EVs, resulting in dose-dependent inhibition of induced release of IL-8, presumably by targeting Myd88. We conclude that LFA-1-expressing EV Myd88 may be a candidate suitable for delivering therapeutic peptides in inflammatory diseases associated with TLR-activation. Graphical Abstract
Escherichia coli outer membrane vesicles can contribute to sepsis induced cardiac dysfunction
Sepsis induced cardiac dysfunction (SIC) is a severe complication to sepsis which significantly worsens patient outcomes. It is known that bacteria have the capacity to release outer membrane vesicles (OMVs), which are nano-sized bilayered vesicles composed of lipids and proteins, that can induce a fatal inflammatory response. The aim of this study was to determine whether OMVs from a uropathogenic Escherichia coli strain can induce cardiac dysfunction, and to elucidate any mechanisms involved. OMVs induced irregular Ca 2+ oscillations with a decreased frequency in cardiomyocytes through recordings of intracellular Ca 2+ dynamics. Mice were intraperitoneally injected with bacteria-free OMVs, which resulted in increased concentration of pro-inflammatory cytokine levels in blood. Cytokines were increased in heart lysates, and OMVs could be detected in the heart after OMVs injection. Troponin T was significantly increased in blood, and echocardiography showed increased heart wall thickness as well as increased heart rate. This study shows that E. coli OMVs induce cardiac injury in vitro and in vivo , in the absence of bacteria, and may be a causative microbial signal in SIC. The role of OMVs in clinical disease warrant further studies, as bacterial OMVs in addition to live bacteria may be good therapeutic targets to control sepsis.
A Non‐Centrifugation Method to Concentrate and Purify Extracellular Vesicles Using Superabsorbent Polymer Followed by Size Exclusion Chromatography
ABSTRACT Extracellular vesicles (EVs) can be isolated and purified from cell cultures and biofluids using different methodologies. Here, we explored a novel EV isolation approach by combining superabsorbent polymers (SAP) in a dialysis membrane with size exclusion chromatography (SEC) to achieve high concentration and purity of EVs without the use of ultracentrifugation (UC). Suspension HEK293 cells transfected with CD63 coupled with Thermo Luciferase were used to quantify the EV yield and purity. The 500 mL conditioned medium volume was initially reduced by pressure ultrafiltration, followed by UC, SAP or a centrifugal filter unit (CFU). Using either of these methods, the EVs were concentrated to a final volume of approximately 1 mL, with retained functionality. The yield, quantified by luciferase activity, was highest with UC (70%–80%), followed by SAP (60%–70%) and CFU (50%–60%). Further purification of the EVs was performed by iodixanol density cushion (IDC) or SEC (Sepharose CL‐2B or 6B, in either 10 or 20 mL columns). Although the IDC and Sepharose CL‐2B (10 mL) achieved the highest yields, the purity was slightly higher (30%) with IDC. In conclusion, combining SAP concentration with CL‐2B SEC is an alternative and efficient way to isolate EVs without using UC.