• Journal of Life Science
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• v.26 no.10
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• pp.1214-1217
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• 2016

Rebamipide is a mucosal-protective antiulcer drug, but its mechanism of action in gastric cancer remains elusive. CagA, a major virulence factor of Helicobacter pylori (H. pylori), is associated with the risk of gastric cancer. CagA protein is injected into gastric epithelial cells and deregulates a variety of cellular signaling molecules. CagA from H. pylori induces phospholipase D1 (PLD1) expression through NFκB activation in gastric epithelial cells, followed by invasion and proliferation of gastric epithelial cancer cells. Infection with cagA-positive H. pylori and expression of CagA enhances the binding of NFκB to the PLD1 promoter. Rebamipide abolishes H. pylori cagA-induced PLD1 expression via inhibition of binding of NFκB to the PLD1 promoter and also inhibits PLD activity. Moreover, rebamipide abolishes H. pylori CagA-induced β-catenin and the expression of a target cancer stem cell (CSC) marker gene via upregulation of miRNA-320a and -4496, followed by attenuation of self-renewal capacity of H. pylori CagA-infected gastric CSCs. In addition, rebamipide increases the chemosensitivity of CagA-expressed gastric CSCs and suppresses gastric carcinogenesis. Thus, it is speculated that rebamipide might show a potent efficacy as chemotherapeutic drug against gastric cancer cells. In this review, we summarizes recent results regarding the novel insights for the efficacy of rebamipide in gastric cancer cells.

• Journal of Ginseng Research
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• v.42 no.3
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• pp.370-378
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• 2018

Background: Ginseng has been the subject of many experimental and clinical studies to uncover the diverse biological activities of its constituent compounds. It is a traditional medicine that has been used for its immunostimulatory, antithrombotic, antioxidative, anti-inflammatory, and anticancer effects. Ginseng may interact with concomitant medications and alter metabolism and/or drug transport, which may alter the known efficacy and safety of a drug; thus, the role of ginseng may be controversial when taken with other medications. Methods: We extensively assessed the effects of Korean Red Ginseng (KRG) in rats on the expression of enzymes responsible for drug metabolism [cytochrome p450 (CYP)] and transporters [multiple drug resistance (MDR) and organic anion transporter (OAT)] in vitro and on the pharmacokinetics of two probe drugs, midazolam and fexofenadine, after a 2-wk repeated administration of KRG at different doses. Results: The results showed that 30 mg/kg KRG significantly increased the expression level of CYP3A11 protein in the liver and 100 mg/kg KRG increased both the mRNA and protein expression of OAT1 in the kidney. Additionally, KRG significantly increased the mRNA and protein expression of OAT1, OAT3, and MDR1 in the liver. Although there were no significant changes in the metabolism of midazolam to its major metabolite, 1'-hydroxymidazolam, KRG significantly decreased the systemic exposure of fexofenadine in a dose-dependent manner. Conclusion: Because KRG is used as a health supplement, there is a risk of KRG overdose; thus, a clinical trial of high doses would be useful. The use of KRG in combination with P-glycoprotein substrate drugs should also be carefully monitored.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.195-202
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• 2018

Hyperglycemia is one of the major risk factors for stroke. Hyperglycemia can lead to a more extensive infarct volume, aggravate neuronal damage after cerebral ischemia. ${\alpha}$-Synuclein is especially abundant in neuronal tissue, where it underlies the etiopathology of several neurodegenerative diseases. This study investigated whether hyperglycemic conditions regulate the expression of ${\alpha}$-synuclein in middle cerebral artery occlusion (MCAO)-induced cerebral ischemic injury. Male Sprague-Dawley rats were treated with streptozotocin (40 mg/kg) via intraperitoneal injection to induce hyperglycemic conditions. MCAO were performed four weeks after streptozotocin injection to induce focal cerebral ischemia, and cerebral cortex tissues were obtained 24 hours after MCAO. We confirmed that MCAO induced neurological functional deficits and cerebral infarction, and these changes were more extensive in diabetic animals compared to non-diabetic animals. Moreover, we identified a decrease in ${\alpha}$-synuclein after MCAO injury. Diabetic animals showed a more serious decrease in ${\alpha}$-synuclein than non-diabetic animals. Western blot and reverse-transcription PCR analyses confirmed more extensive decreases in ${\alpha}$-synuclein expression in MCAO-injured animals with diabetic condition than these of non-diabetic animals. It is accepted that ${\alpha}$-synuclein modulates neuronal cell death and exerts a neuroprotective effect. Thus, the results of this study suggest that hyperglycemic conditions cause more serious brain damage in ischemic brain injuries by decreasing ${\alpha}$-synuclein expression.

• Journal of Chest Surgery
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• v.54 no.1
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• pp.9-16
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• 2021

Background: The deposition of monomeric C-reactive protein (mCRP) in the myocardium aggravates ischemia-reperfusion injury (IRI) and myocardial infarction. Ischemic preconditioning (IPC) is known to protect the myocardium against IRI. Methods: We evaluated the effects of IPC on myocardium upon which mCRP had been deposited due to IRI in a rat model. Myocardial IRI was induced via ligation of the coronary artery. Direct IPC was applied prior to IRI using multiple short direct occlusions of the coronary artery. CRP was infused intravenously after IRI. The study included sham (n=3), IRI-only (n=5), IRI+CRP (n=9), and IPC+IRI+CRP (n=6) groups. The infarcted area and the area at risk were assessed using Evans blue and 2,3,5-triphenyltetrazolium staining. Additionally, mCRP immunostaining and interleukin-6 (IL-6) mRNA reverse transcription-polymerase chain reaction were performed. Results: In the IRI+CRP group, the infarcted area and the area of mCRP deposition were greater, and the level of IL-6 mRNA expression was higher, than in the IRI-only group. However, in the IPC+IRI+CRP group relative to the IRI+CRP group, the relative areas of infarction (20% vs. 34%, respectively; p=0.079) and mCRP myocardial deposition (21% vs. 44%, respectively; p=0.026) were lower and IL-6 mRNA expression was higher (fold change: 407 vs. 326, respectively; p=0.376), although the difference in IL-6 mRNA expression was not statistically significant. Conclusion: IPC was associated with significantly decreased deposition of mCRP and with increased expression of IL-6 in myocardium damaged by IRI. The net cardioprotective effect of decreased mCRP deposition and increased IL-6 levels should be clarified in a further study.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.284-290
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• 2022

Oral squamous cell carcinoma (OSCC) is mostly diagnosed at an advanced stage, with local and/or distal metastasis. Thus, locoregional and/or local control of the primary tumor is crucial for a better prognosis in patients with OSCC. Platelets have long been considered major players in cancer metastasis. Traditional antiplatelet agents, such as aspirin, are thought to be potential chemotherapeutics, but they need to be used with caution because of the increased bleeding risk. Podoplanin (PDPN)-expressing cancer cells can activate platelets and promote OSCC metastasis. However, the reciprocal effect of platelets on PDPN expression in OSCC has not been investigated. In this study, we found that direct contact with platelets upregulated PDPN and integrin β1 at the protein level and promoted invasiveness of human OSCC Ca9.22 cells that express low levels of PDPN. In another human OSCC HSC3 cell line that express PDPN at an abundant level, silencing of the PDPN gene reduced cell invasiveness. Analysis of the public database further supported the co-expression of PDPN and integrin β1 and their increased expression in metastatic tissues compared to normal and tumor tissues of the oral cavity. Taken together, these data suggest that PDPN is a potential target to regulate platelet-tumor interaction and metastasis for OSCC treatment, which can overcome the limitations of traditional antiplatelet drugs.

• Molecules and Cells
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• v.45 no.5
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• pp.306-316
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• 2022

Chronic stress contributes to the risk of developing depression; the habenula, a nucleus in epithalamus, is associated with many neuropsychiatric disorders. Using genome-wide gene expression analysis, we analyzed the transcriptome of the habenula in rats exposed to chronic restraint stress for 14 days. We identified 379 differentially expressed genes (DEGs) that were affected by chronic stress. These genes were enriched in neuroactive ligand-receptor interaction, the cAMP (cyclic adenosine monophosphate) signaling pathway, circadian entrainment, and synaptic signaling from the Kyoto Encyclopedia of Genes and Genomes pathway analysis and responded to corticosteroids, positive regulation of lipid transport, anterograde trans-synaptic signaling, and chemical synapse transmission from the Gene Ontology analysis. Based on protein-protein interaction network analysis of the DEGs, we identified neuroactive ligand-receptor interactions, circadian entrainment, and cholinergic synapse-related subclusters. Additionally, cell type and habenular regional expression of DEGs, evaluated using a recently published single-cell RNA sequencing study (GSE137478), strongly suggest that DEGs related to neuroactive ligand-receptor interaction and trans-synaptic signaling are highly enriched in medial habenular neurons. Taken together, our findings provide a valuable set of molecular targets that may play important roles in mediating the habenular response to stress and the onset of chronic stress-induced depressive behaviors.

• The Korea Journal of Herbology
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• v.28 no.3
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• pp.69-74
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• 2013

Objectives : Since hypopigmentation is known to increase the risk of skin cancer, melanogenesis in the skin needs to be regulated. Here, we evaluated the melanogenesis stimulatory effects of a modified Goagium herbal remedy (HR) and HR+ox bile (Bos taurus domesticus) extract (OBE) to address hypopigmentation disorders. Methods : B16F10 melanoma cells were treated with different dosages of HR and HR+OBE for 24 to 48 h after 1 h of 10 nM ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH). After the treatment, cell viability, tyrosinase activity, melanin synthesis and the expression of genes related to melanin synthesis were measured and the regulation of the ${\alpha}$-MSH signalling through cAMP responding element binding protein (CREB) was determined. Results : HR and HR+OBE with the ranges of $15{\sim}100{\mu}g/mL$ did not affect cell viability in melanoma cells. The 1 h treatment of HR+OBE (50 and $100{\mu}g/mL$) potentiated the phosphorylation of CREB by enhancing ${\alpha}$-MSH signaling and its 24 h treatment increased CREB expression. Consistent with CREB potentiation, their treatment for 24 h, the expression of microphthalmia-associated transcription factor (MIFT), tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 were increased in realtime PCR. Ultimately, the 48 h treatment of HR+OBE (50 and $100{\mu}g/mL$) increased tyrosniase activity and melanin contents in the melanoma cells in comparison to the control. Conclusions : HR+OBE (50 and $100{\mu}g/mL$) increases melanin synthesis in B16F10 melanoma cells via the stimulation of tyrosinase activity and expression of MIFT, tyrosinase, TRP-1 and TRP-2. HR+OBE can be used as the a possible treatment for hypopigmentation of the skin.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.218-225
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• 2022

High levels of proinflammatory cytokines have been observed in obese pregnancies. Obesity during pregnancy may increase the risk of various pregnancyrelated complications, with pathogenesis resulting from excessive inflammation. Palmitic acid (PA) is a saturated fatty acid that circulates in high levels in obese women. In our previous study, we found that PA inhibited the proliferation of trophoblasts developing into the placenta, induced apoptosis, and regulated the number of cleaved halves derived from transfer RNAs (tRNAs). However, it is not known how the expression of tRNA-derived stress-induced RNAs (tiRNAs) changes in response to PA treatment at concentrations that induce inflammation in human trophoblasts. We selected concentrations that did not affect cell viability after dose-dependent treatment of HTR8/SVneo cells, a human trophoblast cell line. PA (200 μM) did not affect the expression of apoptotic proteins in HTR8/SVneo cells. PA significantly increased the expression of inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α. In addition, 200 μM PA significantly increased the expression of tiRNAs compared to 800 μM PA treatment. These results suggest that PA impairs placental development during early pregnancy by inducing an inflammatory response in human trophoblasts. In addition, this study provides a basis for further research on the association between PA-induced inflammation and tiRNA generation.

• Journal of Ginseng Research
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• v.47 no.4
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• pp.524-533
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• 2023

Background: Obesity is a risk factor for aging and many diseases, and the disorder of lipid metabolism makes it prominent. This study aims to investigate the effect of ginsenoside Rg1 on aging, lipid metabolism and stress resistance Methods: Rg1 was administered to Caenorhabditis elegans (C. elegans) cultured in NGM or GNGM. The lifespan, locomotory activity, lipid accumulation, cold and heat stress resistance and related mRNA expression of the worms were examined. Gene knockout mutants were used to clarify the effect on lipid metabolism of Rg1. GFP-binding mutants were used to observe the changes in protein expression Results: We reported that Rg1 reduced lipid accumulation and improved stress resistance in C. elegans. Rg1 significantly reduced the expression of fatty acid synthesis-related genes and lipid metabolism-related genes in C. elegans. However, Rg1 did not affect the fat storage in fat-5/fat-6 double mutant or nhr-49 mutant. Combined with network pharmacology, we clarified the possible pathways and targets of Rg1 in lipid metabolism. In addition, Rg1-treated C. elegans showed a higher expression of anti-oxidative genes and heat shock proteins, which might contribute to stress resistance Conclusion: Rg1 reduced fat accumulation by regulating lipid metabolism via nhr-49 and enhanced stress resistance by its antioxidant effect in C. elegans.

• Molecules and Cells
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• v.46 no.4
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• pp.245-255
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• 2023

This study aimed to exploring the pathophysiological mechanism of 7α,25-dihydroxycholesterol (7α,25-DHC) in osteoarthritis (OA) pathogenesis. 7α,25-DHC accelerated the proteoglycan loss in ex vivo organ-cultured articular cartilage explant. It was mediated by the decreasing extracellular matrix major components, including aggrecan and type II collagen, and the increasing expression and activation of degenerative enzymes, including matrix metalloproteinase (MMP)-3 and -13, in chondrocytes cultured with 7α,25-DHC. Furthermore, 7α,25-DHC promoted caspase-dependent chondrocyte death via extrinsic and intrinsic pathways of apoptosis. Moreover, 7α,25-DHC upregulated the expression of inflammatory factors, including inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E₂, via the production of reactive oxygen species via increase of oxidative stress in chondrocytes. In addition, 7α,25-DHC upregulated the expression of autophagy biomarkers, including beclin-1 and microtubule-associated protein 1A/1B-light chain 3 via the modulation of p53-Akt-mTOR axis in chondrocytes. The expression of CYP7B1, caspase-3, and beclin-1 was elevated in the degenerative articular cartilage of mouse knee joint with OA. Taken together, our findings suggest that 7α,25-DHC is a pathophysiological risk factor of OA pathogenesis that is mediated a chondrocyte death via oxiapoptophagy, which is a mixed mode of apoptosis, oxidative stress, and autophagy.