Publications by authors named "Ki C Chang"

In this study, thiol-functionalized ladder-like polysesquioxanes end-capped with methyl and phenyl groups were synthesized via a simple sol-gel method and characterized through gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and thermogravimetric analysis (TGA). Additionally, epoxy blends of different formulations were prepared. Their structural, flame-retardant, thermal, and mechanical properties, as well as volatile organic compound (VOC) emissions, were determined using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), TGA, scanning electron microscopy (SEM), limiting oxygen index (LOI), cone calorimetry, and a VOC analyzer.

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A novel thiol-functionalized polysilsesqioxane containing hydroxyl and methyl groups was synthesized using a simple acid-catalyzed sol-gel method to develop an epoxy hardener with low odor, low volatile organic compound (VOC) emissions, and fast curing at low temperatures. The synthesized thiol-based hardeners were characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, thermogravimetric analysis (TGA), and gel permeation chromatography and compared with commercially available hardeners in terms of odor intensity and VOC emissions using the air dilution olfaction method and VOC analysis. The curing behavior and thermal and mechanical properties of the epoxy compounds prepared with the synthesized thiol-based hardeners were also evaluated.

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Berberine is reported to have multiple biological effects, including antimicrobial, anti-inflammatory, and antitumor activities, and 13-alkyl-substituted berberines show higher activity than berberine against certain bacterial species and human cancer cell lines. In particular, 13-ethylberberine (13-EBR) was reported to have anti-inflammatory effects in endotoxin-activated macrophage and septic mouse models. Thus, in this study, we aimed to examine the anticancer effects of 13-EBR and its mechanisms in radiotherapy-resistant (RT-R) MDA-MB-231 cells derived from the highly metastatic MDA-MB-231 cells.

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Previous studies suggest that cancer stem cells (CSCs) exist in solid tumors, and contribute to therapeutic resistance and disease recurrence. Therefore, the present study aimed to investigate whether radioresistant (RT‑R) breast cancer cells derived from breast cancer cells increase the number of CSCs, and whether these CSCs are responsible to increased invasiveness and therapeutic resistance. MCF‑7, T47D and MDA‑MB‑231 cells were irradiated 25 times (2 Gy each; 50 Gy total) to generate radioresistant breast cancer cells (RT‑R‑MCF‑7, RT‑R‑T47D and RT‑R‑MDA‑MB‑231).

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High mobility group box 1 (HMGB1) has been proposed as crucial in the pathogenesis of many diseases including sepsis. Acetylation of HMGB1 prevents its entry into the nucleus and leads to its secretion from the cell where it can trigger inflammation. We hypothesized that histone deacetylase 4 (HDAC4) controls the acetylation of HMGB1 in lipopolysaccharide (LPS)-stimulated RAW264.

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Excessive inflammation plays a detrimental role in endotoxemia. A recent study indicated that alarmins such as high mobility group box 1 (HMGB1) have drawn attention as therapeutic targets of sepsis. Post-translational modification (i.

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Activation of the α7 nicotinic acetylcholine receptor (α7nAChR) has been shown to attenuate excessive inflammation by inhibiting proinflammatory cytokines during ischemia-reperfusion (IR) injury; however, the underlying kidney-specific molecular mechanisms remain unclear. The protective action of α7nAChR against renal IR injury was investigated using a selective α7nAChR agonist and antagonist. α7nAChR activation reduced plasma creatinine levels and tubular cell damage, whereas α7nAChR inhibition aggravated the IR-induced phenotype.

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Objective: Although luteolin has shown to have anti-inflammatory action, no report is available whether luteolin inhibits HMGB1 and protects acute lung injury (ALI) in endotoxin rodents. We hypothesized that HO-1 induction by luteolin might play a crucial role for inhibition of pro-inflammatory mediators including HMGB1 through MAPK signaling in LPS-induced RAW264.7 cells, and it ameliorates ALI of endotoxin mice.

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Background And Aims: High mobility group box 1 (HMGB1) plays an important role as a pro-inflammatory cytokine that regulates inflammation in various diseases. We hypothesized that hemin might reduce HMGB1 release through the induction of HO-1 in UVB-induced HaCaTs.

Methods: The effects of hemin on the release of HMGB1 in UVB exposure were evaluated.

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Tetrahydroisoquinoline alkaloids (THIs) have shown to increase survival and beneficial effect on animal model of sepsis, partly due to heme oxygenase-1 (HO-1) induction. Here, we aimed to compare a limited series of synthesized THIs on HO-1 induction and inhibitory effect of iNOS and COX-2 expression in lipopolysaccharide (LPS)-activated RAW264.7 cells.

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High mobility group box 1 (HMGB1), a highly conserved non-histone DNA-binding protein, plays an important role in the pathogenesis of sepsis. Previously, the authors reported 13-ethylberberine (13-EBR) has anti-inflammatory and antibacterial effects. However, the effect of 13-EBR on HMGB1 release was not investigated.

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High mobility group box 1 (HMGB1), a cytokine present in the late phase of sepsis, may be a potential target for the treatment of sepsis. For HMGB1 to be actively secreted from macrophages during infections, it must be post-translationally modified. Although ethyl pyruvate (EP), a simple aliphatic ester derived from pyruvic acid, has been shown to inhibit the release of HMGB1 in lipopolysaccharide (LPS)-treated RAW 264.

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High mobility group box 1 (HMGB1), a late phase cytokine of sepsis, is viewed as a potential target for the treatment of sepsis. The authors considered that 13-methylberberine (13-MB) might reduce circulating HMGB1 levels and increase survival in a mouse model of sepsis by activating AMP-activated protein kinase (AMPK). Western blot analysis and vascular contraction testing were performed using RAW264.

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Obesity-associated non-alcoholic fatty liver disease (NAFLD) increases coagulation and inflammation. We hypothesized that (S)YS-51, an agent found to be beneficial in animal models of sepsis, may reduce NAFLD in high-fat diet (HFD) mice by reducing coagulation and inflammation. C57BL/6 mice were fed either a chow diet or HFD and each was supplemented with or without (S)YS-51 (10mg/kg, daily, i.

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Objective: Retinoic acid (RA) is the active vitamin A derivative and has diverse immunomodulatory actions. We hypothesized that RA reduces prothrombotic mediators such as tissue factor (TF) in endothelial cells during inflammatory conditions via an AMPK-dependent pathway, which attenuates cardiovascular complications.

Results: RA significantly increased AMPK and Akt phosphorylation in a time- and concentration-dependent manner in endothelial cells (EC).

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Introduction: Inflammation and coagulation play important roles in the pathogenesis of sepsis. Anticoagulants with anti-inflammatory action draw attention as therapeutic agent in sepsis.

Objective: Whether cilostazol (6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2-(1H)-quinolinone), anticoagulant, protects mice against sepsis and underlying mechanism(s) were investigated.

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Article Synopsis
  • Tumor metastasis is a leading cause of cancer-related deaths, prompting research into the differences between highly and low metastatic breast cancer cells, specifically comparing MDA-MB-231 and MCF-7 cell lines.
  • The study found that MDA-MB-231 cells released more ATP and had greater P2Y2R activity, which contributed to a microenvironment conducive to metastasis through various signaling pathways.
  • Researchers discovered that the invasive behavior of MDA-MB-231 and SK-BR-3 cells is linked to over-activated ERK and PKC signaling pathways, which can be inhibited by targeting P2Y2R or using specific inhibitors.
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Article Synopsis
  • * The study found that VSMCs treated with IL-1β showed increased proliferation and migration when stimulated with ATP or UTP, indicating that these receptors play a significant role in these processes.
  • * Specific signaling pathways (ERK, AKT, PKC, Rac-1, and ROCK2) were activated in the presence of IL-1β, enhancing cell activities and secretion of factors that contribute to atherosclerosis,
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High mobility group box 1 (HMGB1) is now recognized as a late mediator of sepsis. We tested hypothesis that ascorbic acid (AscA) induces heme oxygenase (HO)-1 which inhibits HMGB1 release in lipopolysaccharide (LPS)-stimulated cells and increases survival of septic mice. AscA increased HO-1 protein expression in a concentration- and time-dependent manner via Nrf2 activation in RAW 264.

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High mobility group box 1 (HMGB1) is now recognized as a late mediator of sepsis. Although glycyrrhizin was known as inhibitor of HMGB1, it is not yet clear underlying mechanism(s). We found that glycyrrhizin activates translocation of Nrf2 from cytosol to nucleus and induces heme oxygenase (HO)-1 expression in RAW 264.

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Honokiol is a bioactive neolignan compound isolated from the species of Magnolia. This study was designed to elucidate the cellular mechanism by which honokiol alleviates the development of non-alcoholic steatosis. HepG2 cells were treated with honokiol for 1h, and then exposed to 1mM free fatty acid (FFA) for 24h to simulate non-alcoholic steatosis in vitro.

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CKD-712, a newly synthesized tetrahydroisoquinoline (THI) and an enantiomer (S form) of YS 49 (a derivative of higenamine) has been reported to suppress nuclear factor-κB (NF-κB) activity in normal cells. In the present study, we investigated the anticancer effects of THI at a low concentration where CKD-712 did not induce cell death in normal cells. At the range of concentrations used, CKD-712 induced cell growth arrest, and inhibited the invasion and motility of A549 cells as determined by cell cycle analysis, a Matrigel-coated chamber assay, and a wound-healing assay, respectively.

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Ethnopharmacological Relevance: Magnolia officinalis (MO) is a traditional Chinese herbal medicine that has been used in clinical practice to treat liver disease. The aim of this study is to examine the effects of MO on the development of nonalcoholic fatty liver in hepatocytes.

Materials And Methods: Human hepatoma-derived HepG2 cells and mouse normal FL83B hepatocytes were exposed to 0.

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Article Synopsis
  • Tumor hypoxia leads to increased HIF-1α expression, which promotes the release of lysyl oxidase (LOX) that facilitates cancer cell metastasis by crosslinking collagen in distant tissues.
  • ATP or UTP released from hypoxia-treated MDA-MB-231 breast cancer cells activates the P2Y2 receptor (P2Y2R), enhancing HIF-1α and LOX production, with reduced effects observed in cells lacking P2Y2R.
  • In experiments with nude mice, MDA-MB-231 cells showed increased LOX, collagen crosslinking, and immune cell recruitment in the lungs, while P2Y2R-depleted cells failed to produce these changes,
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Article Synopsis
  • Extracellular nucleotides, particularly ATP and UTP, play a significant role in activating the P2Y2 receptor, which is involved in inflammatory responses such as cell migration and proliferation; the study focuses on understanding its role in cancer metastasis, especially in highly metastatic breast cancer cells like MDA-MB-231.
  • The research compared the activity of P2Y2R and ATP release levels between highly metastatic MDA-MB-231 cells and low metastatic MCF-7 cells, investigating the interaction between these cancer cells and endothelial cells (ECs) both in vitro and in vivo.
  • Results showed that MDA-MB-231 cells had increased ATP release, P2Y2R activity, and
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