• 한국자기공명학회논문지
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• 제25권2호
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• pp.17-23
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• 2021

High mobility group protein B1 (HMGB1) is a highly conserved, non-histone, chromatin associated nuclear protein encoded by HMGB1 gene. HMGB1 proteins may be general co-factors in Hox-mediated transcriptional activation that facilitate the access of Hox proteins to specific DNA targets. It is unclear that the exact binding interface of Hoxc9DBD and HMGB1. To identify the interface and binding affinity of Hoxc9DBD and HMGB1 A-box, the paramagnetic probe, MTSL was used in NMR titration experiment. It is attached to the N-terminal end of HMGB1 A-box by reaction with thiol groups. The backbone assignment of HMGB1 A-box was achieved with 3D NMR techinques. The ¹⁵N-labeled HMGB1 A-box was titrated with MTSL-labeled Hoxc9DBD respectively. Based on the chemical shift changes we can identify the interacting residues and further map out the binding sites on the protein structure. The NMR titration result showed that the binding interface of HMGB1 A-box is around loop-1 between helix-1 and helix-2. In addition, the additional contacts were found in N- and C-terminus. The N-terminal arm region of Hoxc9DBD is the major binding region and the loop between helix1 and helix2 is the minor binding region.

• Tuberculosis and Respiratory Diseases
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• 제62권4호
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• pp.299-307
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• 2007

배경: HMGB1은 염증반응의 후기에 분비되는 중요한 염증유발물질 중 하나이다. 본 연구에서는 기존에 염증유발물질로 잘 알려진 LPS와 새롭게 염증유발물질로 관심을 받고 있는 HMGB1의 염증유발작용을 생체 외 및 생체 내 실험을 통해 비교하고자 하였다. 또한 HMGB1의 자극에 의한 IL-8 promoter region의 활성화에 중요한 역할을 수행하는 전사인자들을 확인하고자 하였다. 방법: RAW264.7 세포에 LPS(100 ng/ml) 또는 HMGB1(500 ng/ml)을 투여하고 각각 0, 2, 4, 8, 12 그리고 24시간 뒤에 세포상층액의 $TNF-{\alpha}$, MIP-2 그리고 $IL-1{\beta}$의 농도를 ELISA법으로 측정하였다. 생쥐의 복강에 LPS(5 mg/kg) 또는 HMGB1(2.5 mg/kg)을 주입하여 급성폐손상을 유발한 후에 폐의 사이토카인의 발현과 MPO 활성도를 측정하였다(LPS는 4시간 뒤, HMGB1은 24 시간 뒤). IL-8 promoter 부위에 있는 NF-IL6, $NF-{\kappa}B$ 그리고 AP-1에 대한 결합부위에 대해 돌연변이를 일으킨 후에 각각의 돌연변이체를 pIL-6luc에 결합시킨 뒤 RAW264.7 세포에 삽입하였다. 이 세포들을 36시간 배양한 후에 HMGB1(500 ng/ml)으로 자극하고, 한 시간 뒤에 세포를 녹인 후 luciferase 활성도를 측정하였다. 결과: LPS 투여 후에 RAW264.7 세포 배양상층액의 $TNF-{\alpha}$농도는 24시간 뒤에, MIP-2 농도는 8시간 뒤에 최고치를 보였다. 한편 HMGB1 투여 후에는 $TNF-{\alpha}$와 MIP-2 농도 모두 24시간 뒤에 최고치를 나타내었다. LPS 복강 내 투여 후 4시간 뒤에 생쥐의 폐의 $TNF-{\alpha}$, MIP-2 그리고 $IL-1{\beta}$의 농도는 대조군에 비해 현저히 증가하였으나, HMGB1 복강 내 투여 후 24시간 뒤에 생쥐의 폐에서는 $IL-1{\beta}$의 농도만 약간 증가하였다. MPO 활성도는 LPS와 HMGB1 투여 후에 모두 증가하였으며, LPS 투여 후가 더 의미있게 증가하였다. $NF-{\kappa}B$ 돌연변이체와 AP-1 돌연변이체에서 luciferase 활성도가 의미있게 감소하였다. 결론: 이상의 결과를 살펴볼 때 HMGB1은 염증유발효과는 LPS에 비해 강도가 떨어지나 지속시간은 오래 계속되는 것으로 보이며, HMGB1에 의한 IL-8의 활성화에 $NF-{\kappa}B$ 뿐만 아니라 AP-1도 중요한 역할을 수행하는 것으로 판단된다.

• BMB Reports
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• 제49권2호
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• pp.99-104
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• 2016

The nuclear non-histone protein high mobility group box (HMGB) 1 is known to having an inhibitory effect on the repair of DNA damaged by the antitumor drug cisplatin in vitro. To investigate the role of HMGB1 in living cells, we studied the DNA repair of cisplatin damages in mouse fibroblast cell line, NIH-3T3. We evaluated the effect of the post-synthetic acetylation and C-terminal domain of the protein by overexpression of the parental and mutant GFP fused forms of HMGB1. The results revealed that HMGB1 had also an inhibitory effect on the repair of cisplatin damaged DNA in vivo. The silencing of HMGB1 in NIH-3T3 cells increased the cellular DNA repair potential. The increased levels of repair synthesis could be "rescued" and returned to less than normal levels if the knockdown cells were transfected with plasmids encoding HMGB1 and HMGB1 K2A. In this case, the truncated form of HMGB1 also exhibited a slight inhibitory effect.

• Molecules and Cells
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• 제41권4호
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• pp.362-372
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• 2018

High mobility group box 2 (HMGB2) is an abundant, chromatin-associated, non-histone protein involved in transcription, chromatin remodeling, and recombination. Recently, the HMGB2 gene was found to be significantly downregulated during senescence and shown to regulate the expression of senescent-associated secretory proteins. Here, we demonstrate that HMGB2 transcription is repressed by p21 during radiation-induced senescence through the ATM-p53-p21 DNA damage signaling cascade. The loss of p21 abolished the downregulation of HMGB2 caused by ionizing radiation, and the conditional induction of p21 was sufficient to repress the transcription of HMGB2. We also showed that the p21 protein binds to the HMGB2 promoter region, leading to sequestration of RNA polymerase and transcription factors E2F1, Sp1, and p300. In contrast, NF-Y, a CCAAT box-binding protein complex, is required for the expression of HMGB2, but NF-Y binding to the HMGB2 promoter was unaffected by either radiation or p21 induction. A proximity ligation assay results confirmed that the chromosome binding of E2F1 and Sp1 was inhibited by p21 induction. As HMGB2 have been shown to regulate premature senescence by IR, targeting the p21-mediated repression of HMGB2 could be a strategy to overcome the detrimental effects of radiation-induced senescence.

• 한국식품저장유통학회지
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• 제19권2호
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• pp.287-293
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• 2012

본 연구에서는 HMGB1 의해 증가되는 각종 염증관련물질에 대해 라이코펜이 가지는 저해 역할을 규명하고 하였다. 라이코펜은 HMGB1에 의해 증가되는 MCP-1, IL-8, sPLA2-IIA, PGE2의 발현을 NF-${\kappa}B$ 그리고 TNF-${\alpha}$의 활성를 저해함으로써 감소시켰다. 특히, 1 mM에서 그 효능이 통계적으로 유효하였다. 결론적으로 HMGB1에 의해서 발생하는 각종 혈관염증질환에서 라이코펜은 증가하는 각종 염증관련물질을 저해하였고, 결국 라이코펜이 패혈증을 포함하는 염증질환을 효과적으로 치료할 수 있는 방법에 있어 많은 방향성을 제시할 것으로 기대한다.

• 생명과학회지
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• 제29권11호
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• pp.1179-1191
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• 2019

암세포는 epithelial mesenchymal transition (EMT)를 통해 tumor invasion과 metastasis가 일어나며, 또한 정상세포와 다른 oncogenic metabolic phenotypes 획득 즉, glycolytic switch 등이 암 발생과 진행에 깊이 연관되어 있음이 잘 알려져 있다. High-mobility group box 1 (HMGB1)은 chromatin-associated nuclear protein으로 알려져 있으나, dying cells 또는 immune cells로부터 방출되기도 한다. 방출된 HMGB1은 damage-associated molecular pattern (DAMP)로서 작용하여 EMT 및 invasion, metastasis를 유도함으로서 tumor progression에 기여한다고 알려졌다. 본 연구에서 HMGB1에 의해 EMT와 glycolytic switch 유도되며, 이 과정은 Snail 의존적임을 확인하였다. 또한 HMGB1/Snail cascade는 COX subunits인 COXVIIa와 COXVIIc의 발현 억제를 통해 mitochondrial repression과 cytochrome c oxidase (COX) inhibition을 유도하였다. HMGB1은 Snail를 통해 glycolytic switch의 주요 효소인 hexokinase 2 (HK2), phosphofructokinase-2/fructose-2,6-bisphosphatase 2 (PFKFB2), phosphoglycerate mutase 1 (PGAM1)의 발현을 증가시켰다. 이들 효소는 glycolytic switch에 중요하게 관여하는 것으로 알려져 있다. 이들 해당과정의 효소들을 knockdown한 결과 HMGB1에 의한 EMT를 억제함으로써 glycolysis와 HMGB1-induced EMT가 밀접하게 연관되어 있을 제시하였다. 이상의 연구 결과들은 HMGB1/Snail cascade가 EMT 및 glycolytic switch, mitochondrial repression에 중요하게 작용할 것임을 시사한다.

• BMB Reports
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• 제51권10호
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• pp.508-513
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• 2018

Fibronectin fragments found in the synovial fluid of patients with osteoarthritis (OA) induce the catabolic responses in cartilage. Nuclear high-mobility group protein Box 1 (HMGB1), a damage-associated molecular pattern, is responsible for the regulation of signaling pathways related to cell death and survival in response to various stimuli. In this study, we investigated whether changes induced by 29-kDa amino-terminal fibronectin fragment (29-kDa FN-f) in HMGB1 expression influences the pathogenesis of OA via an HMGB1-modulated autophagy signaling pathway. Human articular chondrocytes were enzymatically isolated from articular cartilage. The level of mRNA was measured by quantitative real-time PCR. The expression of proteins was examined by western blot analysis, immnunofluorescence assay, and enzyme-linked immunosorbent assay. Interaction of proteins was evaluated by immunoprecipitation. The HMGB1 level was significantly lower in human OA cartilage than in normal cartilage. Although 29-kDa FN-f significantly reduced the HMGB1 expression at the mRNA and protein levels 6 h after treatment, the cytoplasmic level of HMGB1 was increased in chondrocytes treated with 29-kDa FN-f, which significantly inhibited the interaction of HMGB1 with Beclin-1, increased the interaction of Bcl-2 with Beclin-1, and decreased the levels of Beclin-1 and phosphorylated Bcl-2. In addition, the level of microtubule-associated protein 1 light chain 3-II, an autophagy marker, was down-regulated in chondrocytes treated with 29-kDa FN-f, whereas the effect was antagonized by mTOR knockdown. Furthermore, prolonged treatment with 29-kDa FN-f significantly increased the release of HMGB1 into the culture medium. These results demonstrated that 29-kDa FN-f inhibits chondrocyte autophagy by modulating the HMGB1 signaling pathway.

• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.2955-2962
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• 2014

Asian ginseng is used as a treatment for cardiovascular diseases, ischemia, and cancers. High mobility group box 1 (HMGB1) protein acts as a late mediator of severe vascular inflammatory conditions. However, the effect of ginsenosides from Asian ginseng on HMGB1-induced inflammatory responses has not been studied. We addressed this question by monitoring the effects of ginsenoside treatment on lipopolysaccharide (LPS) and cecal ligation and puncture (CLP)-mediated release of HMGB1, and HMGB1-mediated regulation of proinflammatory responses. Ginsenoside treatment suppressed LPS-mediated release of HMGB1 and HMGB1-mediated cytoskeletal rearrangements. Ginsenosides also inhibited HMGB1-mediated inflammatory responses. In addition, ginsenosides inhibited the production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and activation of protein kinase B (Akt), nuclear factor-${\kappa}B$ (NF-${\kappa}B$), and extracellular-regulated kinases (ERK) 1/2 by HMGB1. Ginsenosides also decreased CLP-induced release of HMGB1, production of interleukin (IL) $1{\beta}/6$, and mortality. These results suggested that ginsenosides may be potential therapeutic agents for treatment of vascular inflammatory diseases through inhibition of the HMGB1 signaling pathway.

• IMMUNE NETWORK
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• 제23권3호
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• pp.25.1-25.17
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• 2023

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces excessive pro-inflammatory cytokine release and cell death, leading to organ damage and mortality. High-mobility group box 1 (HMGB1) is one of the damage-associated molecular patterns that can be secreted by pro-inflammatory stimuli, including viral infections, and its excessive secretion levels are related to a variety of inflammatory diseases. Here, the aim of the study was to show that SARS-CoV-2 infection induced HMGB1 secretion via active and passive release. Active HMGB1 secretion was mediated by post-translational modifications, such as acetylation, phosphorylation, and oxidation in HEK293E/ACE2-C-GFP and Calu-3 cells during SARS-CoV-2 infection. Passive release of HMGB1 has been linked to various types of cell death; however, we demonstrated for the first time that PANoptosis, which integrates other cell death pathways, including pyroptosis, apoptosis, and necroptosis, is related to passive HMGB1 release during SARS-CoV-2 infection. In addition, cytoplasmic translocation and extracellular secretion or release of HMGB1 were confirmed via immunohistochemistry and immunofluorescence in the lung tissues of humans and angiotensin-converting enzyme 2-overexpressing mice infected with SARS-CoV-2.

• BMB Reports
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• 제50권11호
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• pp.590-595
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• 2017

High-mobility group box-1 (HMGB-1) is expressed in almost all cells, and its dysregulated expression correlates with inflammatory diseases, ischemia, and cancer. Some of these conditions accompany HMGB-1-mediated abnormal angiogenesis. Thus far, the mechanism of HMGB-1-induced angiogenesis remains largely unknown. In this study, we performed time-dependent DNA microarray analysis of endothelial cells (ECs) after HMGB-1 or VEGF treatment. The pathway analysis of each gene set upregulated by HMGB-1 or VEGF showed that most HMGB-1-induced angiogenic pathways were also activated by VEGF, although the activation time and gene sets belonging to the pathways differed. In addition, HMGB-1 upregulated some VEGFR signaling-related angiogenic factors including EGR1 and, importantly, novel angiogenic factors, such as ABL2, CEACAM1, KIT, and VIPR1, which are reported to independently promote angiogenesis under physiological and pathological conditions. Our findings suggest that HMGB-1 independently induces angiogenesis by activating HMGB-1-specific angiogenic factors and also functions as an accelerator for VEGF-mediated conventional angiogenesis.