• Molecules and Cells
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• v.45 no.6
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• pp.403-412
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• 2022

Hypoxia leads to significant cellular stress that has diverse pathological consequences such as cardiovascular diseases and cancers. MicroRNAs (miRNAs) are one of regulators of the adaptive pathway in hypoxia. We identified a hypoxia-induced miRNA, miR-34c, that was significantly upregulated in hypoxic human umbilical cord vein endothelial cells (HUVECs) and in murine blood vessels on day 3 of hindlimb ischemia (HLI). miR-34c directly inhibited BCL2 expression, acting as a toggle switch between apoptosis and autophagy in vitro and in vivo. BCL2 repression by miR-34c activated autophagy, which was evaluated by the expression of LC3-II. Overexpression of miR-34c inhibited apoptosis in HUVEC as well as in a murine model of HLI, and increased cell viability in HUVEC. Importantly, the number of viable cells in the blood vessels following HLI was increased by miR-34c overexpression. Collectively, our findings show that miR-34c plays a protective role in hypoxia, suggesting a novel therapeutic target for hypoxic and ischemic diseases in the blood vessels.

• Journal of the Korean Institute of Oriental Medical Informatics
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• v.18 no.1
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• pp.116-137
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• 2012

The topic of this study is to ask and answer about 'What matters most in medicine'. And the purpose of this study is to establish paradigm which guarantee 'the original principles of science in medicine' and 'the safety of human life in medicine'. The organized characteristics of this study is as follows. 1. 'The harmony of nature (heaven, earth and human)' is the base of medicine. Because medicine control life directly and all life is 'the son of nature'. 2. 'The harmony of Eum and Yang' is the essential power of universe and the key of metabolism of all life including human, animals and plants. Because 'the nature of universe' and all 'Life field' is 'electro-magnetic field'. 3. The Convergence of Oriental medicine and Western medicine orients 'the harmony of Eum and Yang'.

• Molecules and Cells
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• v.42 no.9
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• pp.672-685
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• 2019

Currently, liver transplantation is the only available remedy for patients with end-stage liver disease. Conservation of transplanted liver graft is the most important issue as it directly related to patient survival. Carbonyl reductase 1 (CBR1) protects cells against oxidative stress and cell death by inactivating cellular membrane-derived lipid aldehydes. Ischemia-reperfusion (I/R) injury during living-donor liver transplantation is known to form reactive oxygen species. Thus, the objective of this study was to investigate whether CBR1 transcription might be increased during liver I/R injury and whether such increase might protect liver against I/R injury. Our results revealed that transcription factor Nrf2 could induce CBR1 transcription in liver of mice during I/R. Pre-treatment with sulforaphane, an activator of Nrf2, increased CBR1 expression, decreased liver enzymes such as aspartate aminotransferase and alanine transaminase, and reduced I/R-related pathological changes. Using oxygen-glucose deprivation and recovery model of human normal liver cell line, it was found that oxidative stress markers and lipid peroxidation products were significantly lowered in cells overexpressing CBR1. Conversely, CBR1 knockdown cells expressed elevated levels of oxidative stress proteins compared to the parental cell line. We also observed that Nrf2 and CBR1 were overexpressed during liver transplantation in clinical samples. These results suggest that CBR1 expression during liver I/R injury is regulated by transcription factor Nrf2. In addition, CBR1 can reduce free radicals and prevent lipid peroxidation. Taken together, CBR1 induction might be a therapeutic strategy for relieving liver I/R injury during liver transplantation.

• BMB Reports
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• v.56 no.6
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• pp.359-364
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• 2023

KAI1/CD82, a membrane tetraspanin protein, can prevent various cancers and retinal disorders through its anti-angiogenic and anti-metastatic capacity. However, little is known about its anti-inflammatory effect and molecular mechanism. Therefore, the present study aimed to inLPSvestigate effect of a recombinant protein of the large extracellular domain of human KAI1 (Gly 111-Leu 228, rhKAI1) on lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage-like cells and mouse bone marrow-derived macrophages (BMDM) and to identify its underlying mechanism. Our data showed that rhKAI1 suppressed expression levels of classically macrophages (M1) phenotype-related surface markers F4/80+CD86+ in LPS-stimulated BMDM and RAW264.7 cells. In addition, LPS markedly increased mRNA expression and release levels of pro-inflammatory cytokines and mediators such as interleukin (IL)-1β, IL-6, tumor necrosis factor-α, cyclooxygenase-2, nitric oxide and prostaglandin E2, whereas these increases were substantially down-regulated by rhKAI1. Furthermore, LPS strongly increased expression of NF-κB p65 in the nuclei and phosphorylation of ERK, JNK, and p38 MAPK. However, nuclear translocation of NF-κB p65 and phosphorylation of JNK were greatly reversed in the presence of rhKAI1. Especially, rhKAI1 markedly suppressed expression of toll-like receptor (TLR4) and prevented binding of LPS with TLR4 through molecular docking predict analysis. Importantly, Glu 214 of rhKAI1 residue strongly interacted with Lys 360 of TLR4 residue, with a binding distance of 2.9 Å. Taken together, these findings suggest that rhKAI1 has an anti-inflammatory effect on LPS-polarized macrophages by interacting with TLR4 and down-regulating the JNK/NF-κB signaling pathway.

• BMB Reports
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• v.53 no.6
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• pp.311-316
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• 2020

Cholestasis is a condition in which the bile duct becomes narrowed or clogged by a variety of factors and bile acid is not released smoothly. Bile acid-induced liver injury is facilitated by necrotic cell death, neutrophil infiltration, and inflammation. Metformin, the first-line treatment for type 2 diabetes, is known to reduce not only blood glucose but also inflammatory responses. In this study, we investigated the effects of metformin on liver injury caused by cholestasis with bile acid-induced hepatocyte injury. Static bile acid-induced liver injury is thought to be related to endoplasmic reticulum (ER) stress, inflammatory response, and chemokine expression. Metformin treatment reduced liver injury caused by bile acid, and it suppressed ER stress, inflammation, chemokine expression, and neutrophil infiltration. Similar results were obtained in mouse primary hepatocytes exposed to bile acid. Hepatocytes treated with tauroursodeoxycholic acid, an ER stress inhibitor, showed inhibition of ER stress, as well as reduced levels of inflammation and cell death. These results suggest that metformin may protect against liver injury by suppressing ER stress and inflammation and reducing chemokine expression.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.335-344
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• 2019

Obesity causes inflammation and impairs thermogenic functions in brown adipose tissue (BAT). The adipokine lipocalin 2 (LCN2) has been implicated in inflammation and obesity. Herein, we investigated the protective effects of caloric restriction (CR) on LCN2-mediated inflammation and oxidative stress in the BAT of high-fat diet (HFD)-fed mice. Mice were fed a HFD for 20 weeks and then either continued on the HFD or subjected to CR for the next 12 weeks. CR led to the browning of the white fat-like phenotype in HFD-fed mice. Increased expressions of LCN2 and its receptor in the BAT of HFD-fed mice were significantly attenuated by CR. Additionally, HFD+CR-fed mice had fewer neutrophils and macrophages expressing LCN2 and iron-positive cells than HFD-fed mice. Further, oxidative stress and mitochondrial fission induced by a HFD were also significantly attenuated by CR. Our findings indicate that the protective effects of CR on inflammation and oxidative stress in the BAT of obese mice may be associated with regulation of LCN2.

• Korean Medical Education Review
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• v.19 no.2
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• pp.114-114
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• 2017

• Clinical Endoscopy
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• v.51 no.6
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• pp.503-504
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• 2018

• Herbal Formula Science
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• v.32 no.1
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• pp.99-109
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• 2024

Objectives : In this study, we investigated the cytoprotective effect of Eriobotrya japonica L. (EJ) extract against Arachidonic acid (AA)+iron-induced oxidative stress. Methods : To confirm the cytoprotective effect of EJ against AA+iron-induced oxidative stress in HepG2 cells, it was evaluated by MTT assay, immunoblot anaylsis, and Calcein-AM/propidium iodide (PI) staining. Additionally, the mechanism of action of the cytoprotective effect was evaluated through molecular mechanisms. Results : EJ (100 ㎍/mL) inhibited Arachidonic acid (AA)+iron-induced cell death in a concentration-dependent manner. It also inhibited AA+iron-induced mitochondrial dysfunction and ROS production. EJ activated the LKB1-AMPK signaling pathway. Conclusions : In conclusion, EJ has the ability to protect liver cells from oxidative stress, indicating that it is related to AMPK-LKB1 signaling pathways.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.2
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• pp.146-154
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• 2020

Selective installation of proteins using chemical reagents is important for the development of potential biomaterials for the treatment of human diseases. However, modification in a chemo- and regioselective manner under physiological conditions is a great challenge due to the presence of multiple reactive centers in the protein. Currently, the majority of conjugations are limited to lysine (Lys)- and cysteine (Cys)-selective reagents. Thus, they have been extensively studied. Apart from Lys and Cys, widespread site selectivity has been recently achieved through most of the 20 naturally occurring amino acid-bearing reactive functional groups. Consequently, this review focused on several recent achievements in site-selective modification of the rarest amino acid backbones (e.g., methionine, serine, glutamic acid, and tyrosine).