• Bulletin of the Korean Chemical Society
• /
• v.34 no.12
• /
• pp.3665-3670
• /
• 2013

The R3V6 peptide includes a hydrophilic arginine stretch and a hydrophobic valine stretch. In previous studies, the R3V6 peptide was evaluated as a gene carrier and was found to have low cytotoxicity. However, the transfection efficiency of R3V6 was lower than that of poly-L-lysine (PLL) in N2A neuroblastoma cells. In this study, the transfection efficiency of R3V6 was improved in combination with high mobility group box 1A domain (HMGA). HMGA is originated from the nuclear protein and has many positively-charged amino acids. Therefore, HMGA binds to DNA via charge interaction. In addition, HMGA has a nuclear localization signal peptide and may increase the delivery efficiency of DNA into the nucleus. The ternary complex with HMGA, R3V6, and DNA was prepared and evaluated as a gene carrier. First, the HMGA/DNA complex was prepared with a negative surface charge. Then, R3V6 was added to the complex to coat the negative charges of the HMGA/DNA complex, forming the ternary complex of HMGA, R3V6, and DNA. A physical characterization study showed that the ternary complex was more stable than the PLL/DNA complex. The HMGA/R3V6/DNA complex had a higher transfection efficiency than the PLL/DNA, HMGA/DNA, or R3V6/DNA complexes in N2A cells. Furthermore, the HMGA/R3V6/DNA complex was not toxic to cells. Therefore, the HMGA/R3V6/DNA complex may be a useful gene delivery carrier.

• The Korean Journal of Physiology and Pharmacology
• /
• v.24 no.4
• /
• pp.311-317
• /
• 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.

• Korean Journal of Veterinary Research
• /
• v.51 no.3
• /
• pp.239-241
• /
• 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.

• IMMUNE NETWORK
• /
• v.12 no.4
• /
• pp.148-154
• /
• 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.

• IMMUNE NETWORK
• /
• v.8 no.2
• /
• pp.39-45
• /
• 2008

Background: Down regulation of major histocompatibility complex class II transactivator (CIITA) has been identified as a major factor of immunosuppression in sepsis and the level of CIITA expression inversely correlates with the degree of severity. However, it has not been fully elucidated whether the lower expression of CIITA is a cause of disease process or a just associated sign. Here we determined whether the CIITA deficiency decreased survival rate using murine sepsis model. Methods: Major histocompatibility complex class II (MHC-II) deficient, CIITA deficient and wild type B6 mice were subjected to cecal ligation puncture (CLP) surgery. CIITA and recombination activation gene (RAG)-1 double deficient mice were generated to test the role of lymphocytes in CIITA-associated sepsis progression. Results: Sepsis mortality was enhanced in CIITA deficient mice, not by impaired bacterial clearance resulted from CD4 T cell depletion, but hyper-inflammatory response such as excessive release of a pro-inflammatory cytokine, high-mobility group box 1 (HMGB1). Conclusion: Our results demonstrate that CIITA deficiency affects the course of sepsis via the unexpected function of CIITA, regulation of cytokine release.

• Journal of the Korean Magnetic Resonance Society
• /
• v.25 no.2
• /
• pp.17-23
• /
• 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.

• Molecules and Cells
• /
• v.41 no.4
• /
• pp.362-372
• /
• 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
• /
• v.14 no.10
• /
• pp.5789-5795
• /
• 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.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.4
• /
• pp.1365-1370
• /
• 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.

• Journal of Life Science
• /
• v.29 no.1
• /
• pp.9-17
• /
• 2019

As tumors develop, they encounter microenvironmental stress, such as hypoxia and glucose depletion, due to poor vascular function, thereby leading to necrosis, which is observed in solid tumors. Necrotic cells are known to release cellular cytoplasmic contents, such as high mobility group box 1 (HMGB1), into the extracellular space. The release of HMGB1, a proinflammatory and tumor-promoting cytokine, plays an important role in promoting inflammation and metabolism during tumor development. Recently, HMGB1 was shown to induce the epithelial-mesenchymal transition (EMT) and metastasis. However, the underlying mechanism of the HMGB1-induced EMT, invasion, and metastasis is unclear. In this study, we showed that noninvasive breast cancer cells MCF-7 formed tightly packed, rounded spheroids and that the cells in the inner regions of a multicellular tumor spheroid (MTS), an in vitro model of a solid tumor, led to necrosis due to an insufficient supply of O2 and glucose. In addition, after 7 d of MTS culture, the EMT was induced via the transcription factor Snail. We also showed that HMGB1 receptors, including RAGE, TLR2, and TLR4, were induced by MTS culture. RAGE, TLR2, and TLR4 shRNA inhibited MTS growth, supporting the idea that RAGE/TLR2/TLR4 play critical roles in MTS growth. They also prevented MTS culture-induced Snail expression, pointing to RAGE/TLR2/TLR4-dependent Snail expression. RAGE, TLR2, and TLR4 shRNA suppressed the MTS-induced EMT. In human cancer tissues, high levels of RAGE, TLR2, and TLR4 were detected. These findings demonstrated that the HMGB-RAGE/TLR2/TLR4-Snail axis played a crucial role in the growth of the MTS and MTS culture-induced EMT.