• 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.

• 대한수의학회지
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• 제51권3호
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• pp.239-241
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• 2011

In this study, we investigated the kinetics of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6 and high mobility group box 1 (HMGB1) concentrations in a 48-h model of canine endotoxemia by lipopolysaccharide (LPS) injection. Four healthy beagles were slowly administered 1 mg/kg of LPS diluted in normal saline, while two others were administered normal saline as controls. Blood collection was performed at 0 h (baseline), 1 h and 3 h (for TNF-${\alpha}$), 6 h, 12 h, 24 h and 48 h of the experiment, and cytokine levels were determined using the sandwich ELISA method. Early increments of TNF-${\alpha}$ and IL-6 were observed (< 3 h), but HMGB1 levels increased the most at 12 h of the experiment and gradually decreased until 48 h. During the whole experiment, IL-6 and HMGB1 were sustained over 12 h of LPS injection, whereas TNF-${\alpha}$ decreased within 6 h of LPS injection. Taken together, canine HMGB1 levels increase relatively late (< 12 h) and sustained longer than TNF-${\alpha}$ and IL-6 in response to endotoxin. This is the first study to evaluate canine HMGB1 cytokine from endotoxemia in dogs.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.5789-5795
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• 2013

Background: The high mobility group box 1 (HMGB1) protein is a widespread nuclear protein present in most cell types. It typically locates in the nucleus and functions as a nuclear cofactor in transcription regulation. However, HMGB1 can also localize in the cytoplasm and be released into extracellular matrix, where it plays critical roles in carcinogenesis and inflammation. However, it remains elusive whether HMGB1 is relocated to cytoplasm in clear cell renal cell carcinoma (ccRCC). Methods: Nuclear and cytoplasmic proteins were extracted by different protocols from 20 ccRCC samples and corresponding adjacent renal tissues. Western blotting and immunohistochemistry were used to identify the expression of HMGB1 in ccRCC. To elucidate the potential mechanism of HMGB1 cytoplasmic translocation, HMGB1 proteins were enriched by immunoprecipitation and analyzed by mass spectrometry (MS). Results: The HMGB1 protein was overexpressed and partially localized in cytoplasm in ccRCC samples (12/20, 60%, p<0.05). Immunohistochemistry results indicated that ccRCC of high nuclear grade possess more HMGB1 relocation than those with low grade (p<0.05). Methylation of HMGB1 at lysine 112 in ccRCC was detected by MS. Bioinformatics analysis showed that post-translational modification might affect the binding ability to DNA and mediate its translocation. Conclusion: Relocation of HMGB1 to cytoplasm was confirmed in ccRCC. Methylation of HMGB1 at lysine 112 might the redistribution of this cofactor protein.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• 제15권12호
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• pp.4865-4869
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• 2014

Objective: This study evaluated the expression level of high mobility group box-B1 (HMGB-1) and matrix metalloproteinase-9 (MMP-9) in non-small cell lung cancer (NSCLC) inmorder to reveal any relation with development and prognosis. Methods: NSCLC and normal tissues were selected from 30 patients at age of 30-73, and used for RT-PCR and Western blot analyses of HMGB-1. A total of 100 paraffin embedded NSCLC tissues were also isolated from patients through surgical resection, and used for detection of HMGB-1 by immunohistochemistry. In addition, 50 samples were also applied for MMP-9 detection, and 30 normal tissues were considered as controls. Correlation analysis of HMGB-1 and MMP-9 was carried out by Pearsons correlation coefficient. Results: The average expression level of HMGB-1 in NSCLC patients was significantly higher than in normal lung tissues. In addition, patients in III-IV period exhibit significantly higher positive rate of HMGB-1 when compared with I-II period cases. Furthermore, a positive correlation with HMGB-1 was found in the expression of MPP-9. Conclusion: HMGB-1 was highly expressed in NSCLC, which may become a prognostic and predictive marker for NSCLC. Besides, MPP-9 was positively correlated with HMGB-1.

• IMMUNE NETWORK
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• 제12권4호
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• pp.148-154
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• 2012

Previously, we have reported that high mobility group box 1 (HMGB1), a proinflammatory mediator in sepsis, is released via the IFN-${\beta}$-mediated JAK/STAT pathway. However, detailed mechanisms are still unclear. In this study, we dissected upstream signaling pathways of HMGB1 release using various molecular biology methods. Here, we found that calcium/calmodulin-dependent protein kinase (CaM kinase, CaMK) is involved in HMGB1 release by regulating IFN-${\beta}$ production. CaMK inhibitor, STO609, treatment inhibits LPS-induced IFN-${\beta}$ production, which is correlated with the phosphorylation of interferon regulatory factor 3 (IRF3). Additionally, we show that CaMK-I plays a major role in IFN-${\beta}$ production although other CaMK members also seem to contribute to this event. Furthermore, the CaMK inhibitor treatment reduced IFN-${\beta}$ production in a murine endotoxemia. Our results suggest CaMKs contribute to HMGB1 release by enhancing IFN-${\beta}$ production in sepsis.

• Tuberculosis and Respiratory Diseases
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• 제80권2호
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• pp.153-158
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• 2017

Background: Recently, increased levels of high-mobility group box 1 protein (HMGB1) have been identified in various inflammatory conditions and infections. However, no studies have evaluated the HMGB1 level in nontuberculous mycobacterial (NTM) lung disease, and compared it to mycobacterial lung disease. Methods: A total of 60 patients newly diagnosed with NTM lung disease, 44 culture-positive pulmonary tuberculosis (TB) patients, and 34 healthy controls, were included in this study. The serum HMGB1 concentrations were quantified using HMGB1 enzyme-linked immunosorbent assay kits. Results: Serum HMGB1 level in patients with pulmonary TB or NTM lung disease, was significantly lower than that of the healthy controls. In addition, the serum HMGB1 level in TB patients was significantly lower than patients with NTM lung disease. However, the levels in NTM patient subgroups did not differ according to the causative species, disease progression, and disease phenotype. Conclusion: Although low levels of serum HMGB1 has the potential to be a marker of mycobacterial lung disease, these levels were unable to differentiate disease progression and disease phenotype in NTM lung diseases.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1365-1370
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• 2012

The high mobility group box-1 (HMGB1) protein and NALP3 inflammasome have been identified to play important roles in inflammation and cancer pathogenesis, but the relationships between the two and cancer remain unclear. The current study investigated the relationship between HMGB1 and the NALP3 inflammasome in THP-1 macrophages. HMGB1 was found unable to activate the NALP3 inflammasome and failed to induce the release of the IL-$1{\beta}$ and IL-18 in THP-1 macrophages. HMGB1 was also found significantly enhanced the activity of ATP to induce IL-$1{\beta}$ and IL-18 by the induction of increased expression of pro-IL-$1{\beta}$ and pro-IL-18. This process was dependent on activation of RAGE, MAPK p38 and NF-${\kappa}B$ signaling pathway. These results demonstrate that HMGB1 promotes the synthesis of pro-IL-$1{\beta}$ and pro-IL-18 in THP-1 macrophages by the activation of p38 MAPK and NF-${\kappa}B$ through RAGE. HMGB1 likely plays an important role in the first step of the release of the IL-$1{\beta}$ and IL-18, preparing for other cytokines to induce excessive release of IL-$1{\beta}$ and IL-18 which promote inflammation and cancer progression.

• The Korean Journal of Physiology and Pharmacology
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• 제24권4호
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• pp.311-317
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• 2020

In the present experimental study, cecal ligation and puncture significantly increased the myocardial injury assessed in terms of excess release of creative kinase-MB (CK-MB), cardiac troponin I (cTnI), interleukin (IL)-6 and decrease of IL-10 in the blood following 12 h of laparotomy procedure as compared to normal control. Also, a significant increase in protein expression levels of high-mobility group box 1 (HMGB1) and decreased phosphorylation of glycogen synthase kinase-3β (GSK-3β) was observed in the myocardial tissue as compared to normal control. A single independent administration of telmisartan (2 and 4 mg/kg) and AR-A014418 (1 and 2 mg/kg) substantially reduced sepsis-induced myocardial injury in terms of decrease levels of CK-MB, cTnI and IL-6, HMGB1, GSK-3β and increase in IL-10 and p-GSK-3β in the blood in sepsis- subjected rats. The effects of telmisartan at dose 4 mg/kg and AR-A014418 at a dose of 2 mg/kg were significantly higher than the telmisartan at a dose of 2 mg/kg and AR-A014418 1 mg/kg respectively. Further, no significant effects on different parameters were observed in the sham control group in comparison to normal. Therefore it is plausible to suggest that sepsis may increase the levels of angiotensin II to trigger GSK-3β-dependent signaling to activate the HMGB1/receptors for advanced glycation end products, which may promote inflammation and myocardial injury in sepsis-subjected rats.

• 생명과학회지
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• 제29권1호
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• pp.9-17
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• 2019

암조직의 내부에서 hypoxia와 glucose depletion 등의 microenvironmental stress를 받게 되면 necrosis가 유도되고, 실제로 암 조직 내부에서 necrotic core 형성이 관찰된다. Necrotic cells은 high mobility group box 1(HMGB1)를 extracellular space로 방출하는 것으로 알려져 있다. 방출된 HMGB1은 tumor-promoting cytokine으로 작용함으로써 tumor development 시 inflammation, metabolism 및 metastasis에 기여한다. 본 연구에서 non-invasive breast cancer cells MCF-7이 solid tumor의 in vitro model인 multicellular tumor spheroid (MTS) 배양을 통해 완전한 구형의 MTS를 형성하며 MTS가 성장함에 따라 inner region에 necrosis가 유도됨을 밝혔다. 또한 MCF-7 세포의 MTS 배양은 Snail 의존적으로 epithelial-mesenchymal transition (EMT)를 유도함을 관찰하였다. HMGB1의 cell surface receptors인 RAGE, TLR2, TLR4 발현이 MTS 배양에 의해 증가됨을 발견하였다. RAGE, TLR2, TLR4 를 knockdown한 결과 MTS 성장을 억제할 뿐만 아니라 MTS에 의해 증가되는 Snail 발현을 억제함을 밝혔다. 이는 MTS-induced Snail 발현이 RAGE/TLR2/TLR4의존적으로 조절되며 RAGE/TLR2/TLR4-Snail이 MTS 성장에 관여하는 것으로 보인다. 또한 Snail, RAGE, TLR2, TLR4 shRNA는 MTS 배양에 의해 유도되는 EMT를 억제함을 밝혔다. 실제 인간 암조직에서 정상조직에 비해 RAGE, TLR2, TLR4 유전자의 발현이 높음을 관찰하였다. 따라서 HMGB1이 RAGE/TLR2/4-Snail axis를 통해 MTS 배양에 따른 성장 및 EMT에 중요하게 작용할 것으로 예상된다.