scholarly journals Deficiency of the novel high mobility group protein HMGXB4 protects against systemic inflammation-induced endotoxemia in mice

2021 ◽  
Vol 118 (7) ◽  
pp. e2021862118
Author(s):  
Xiangqin He ◽  
Kunzhe Dong ◽  
Jian Shen ◽  
Guoqing Hu ◽  
Jinhua Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Critical Role ◽  
Cecal Ligation ◽  
High Mobility ◽  
High Mobility Group ◽  
No Production ◽  
High Mobility Group Protein ◽  
Pulmonary Vascular Permeability ◽  
Proinflammatory Gene

Sepsis is a major cause of mortality in intensive care units, which results from a severely dysregulated inflammatory response that ultimately leads to organ failure. While antibiotics can help in the early stages, effective strategies to curtail inflammation remain limited. The high mobility group (HMG) proteins are chromosomal proteins with important roles in regulating gene transcription. While HMGB1 has been shown to play a role in sepsis, the role of other family members including HMGXB4 remains unknown. We found that expression of HMGXB4 is strongly induced in response to lipopolysaccharide (LPS)-elicited inflammation in murine peritoneal macrophages. Genetic deletion of Hmgxb4 protected against LPS-induced lung injury and lethality and cecal ligation and puncture (CLP)-induced lethality in mice, and attenuated LPS-induced proinflammatory gene expression in cultured macrophages. By integrating genome-wide transcriptome profiling and a publicly available ChIP-seq dataset, we identified HMGXB4 as a transcriptional activator that regulates the expression of the proinflammatory gene, Nos2 (inducible nitric oxide synthase 2) by binding to its promoter region, leading to NOS2 induction and excessive NO production and tissue damage. Similar to Hmgxb4 ablation in mice, administration of a pharmacological inhibitor of NOS2 robustly decreased LPS-induced pulmonary vascular permeability and lethality in mice. Additionally, we identified the cell adhesion molecule, ICAM1, as a target of HMGXB4 in endothelial cells that facilitates inflammation by promoting monocyte attachment. In summary, our study reveals a critical role of HMGXB4 in exacerbating endotoxemia via transcriptional induction of Nos2 and Icam1 gene expression and thus targeting HMGXB4 may be an effective therapeutic strategy for the treatment of sepsis.

scholarly journals Role of High-Mobility Group Box-1 in Liver Pathogenesis

2019 ◽  
Vol 20 (21) ◽  
pp. 5314 ◽  
Author(s):  
Bilon Khambu ◽  
Shengmin Yan ◽  
Nazmul Huda ◽  
Xiao-Ming Yin
Keyword(s):  
Liver Disease ◽  
Critical Role ◽  
High Mobility ◽  
High Mobility Group ◽  
Sterile Inflammation ◽  
Contributing Factors ◽  
Drug Induced ◽  
Ductular Reaction ◽  
Alcoholic Fatty Liver

High-mobility group box 1 (HMGB1) is a highly abundant DNA-binding protein that can relocate to the cytosol or undergo extracellular release during cellular stress or death. HMGB1 has a functional versatility depending on its cellular location. While intracellular HMGB1 is important for DNA structure maintenance, gene expression, and autophagy induction, extracellular HMGB1 acts as a damage-associated molecular pattern (DAMP) molecule to alert the host of damage by triggering immune responses. The biological function of HMGB1 is mediated by multiple receptors, including the receptor for advanced glycation end products (RAGE) and Toll-like receptors (TLRs), which are expressed in different hepatic cells. Activation of HMGB1 and downstream signaling pathways are contributing factors in the pathogenesis of non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), and drug-induced liver injury (DILI), each of which involves sterile inflammation, liver fibrosis, ductular reaction, and hepatic tumorigenesis. In this review, we will discuss the critical role of HMGB1 in these pathogenic contexts and propose HMGB1 as a bona fide and targetable DAMP in the setting of common liver diseases.

α-Chemokine receptor blockade reduces high mobility group box 1 protein-induced lung inflammation and injury and improves survival in sepsis

2005 ◽  
Vol 289 (4) ◽  
pp. L583-L590 ◽  
Author(s):  
Xinchun Lin ◽  
Huan Yang ◽  
Tohru Sakuragi ◽  
Maowen Hu ◽  
Lin L. Mantell ◽  
...  
Keyword(s):  
Lung Injury ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Critical Role ◽  
High Mobility ◽  
High Mobility Group ◽  
Receptor Blockade ◽  
Inflammatory Injury ◽  
Receptor Inhibition

High mobility group box 1 (HMGB1) protein, a late mediator of lethality in sepsis, can induce acute inflammatory lung injury. Here, we identify the critical role of α-chemokine receptors in the HMGB1-induced inflammatory injury and show that α-chemokine receptor inhibition increases survival in sepsis, in a clinically relevant time frame. Intratracheal instillation of recombinant HMGB1 induces a neutrophilic leukocytosis, preceded by alveolar accumulation of the α-chemokine macrophage inflammatory protein-2 and accompanied by injury and increased inflammatory potential within the air spaces. To investigate the role of α-chemokine receptors in the injury, we instilled recombinant HMGB1 (0.5 μg) directly into the lungs and administered a subcutaneous α-chemokine receptor inhibitor, Antileukinate (200 μg). α-Chemokine receptor blockade reduced HMGB1-induced inflammatory injury (neutrophils: 2.9 ± 3.2 vs. 8.1 ± 2.4 × 104cells; total protein: 120 ± 48 vs. 311 ± 129 μg/ml; reactive nitrogen species: 2.3 ± 0.3 vs. 3.5 ± 1.3 μM; and macrophage migration inhibitory factor: 6.4 ± 4.2 vs. 37.4 ± 15.9 ng/ml) within the bronchoalveolar lavage fluid, indicating that HMGB1-induced inflammation and injury are α-chemokine mediated. Because HMGB1 can mediate late septic lethality, we administered Antileukinate to septic mice and observed increased survival (from 58% in controls to 89%) even when the inhibitor treatment was initiated 24 h after the induction of sepsis. These data demonstrate that α-chemokine receptor inhibition can reduce HMGB1-induced lung injury and lethality in established sepsis and may provide a novel treatment in this devastating disease.

A crucial role of a high mobility group protein HMGA2 in cardiogenesis

2008 ◽  
Vol 10 (5) ◽  
pp. 567-574 ◽  
Author(s):  
Koshiro Monzen ◽  
Yuzuru Ito ◽  
Atsuhiko T. Naito ◽  
Hiroki Kasai ◽  
Yukio Hiroi ◽  
...  
Keyword(s):  
Crucial Role ◽  
High Mobility ◽  
High Mobility Group ◽  
High Mobility Group Protein ◽  
Group Protein

scholarly journals Functional roles of the transcription factor Oct-2A and the high mobility group protein I/Y in HLA-DRA gene expression.

1995 ◽  
Vol 182 (2) ◽  
pp. 487-500 ◽  
Author(s):  
S A Abdulkadir ◽  
S Krishna ◽  
D Thanos ◽  
T Maniatis ◽  
J L Strominger ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
High Mobility ◽  
High Mobility Group ◽  
High Mobility Group Protein ◽  
Ifn Gamma ◽  
Group Protein

The class II major histocompatibility complex gene HLA-DRA is expressed in B cells, activated T lymphocytes, and in antigen-presenting cells. In addition, HLA-DRA gene expression is inducible in a variety of cell types by interferon-gamma (IFN-gamma). Here we show that the lymphoid-specific transcription factor Oct-2A plays a critical role in HLA-DRA gene expression in class II-positive B cell lines, and that the high mobility group protein (HMG) I/Y binds to multiple sites within the DRA promoter, including the Oct-2A binding site. Coexpression of HMG I/Y and Oct-2 in cell lines lacking Oct-2 results in high levels of HLA-DRA gene expression, and in vitro DNA-binding studies reveal that HMG I/Y stimulates Oct-2A binding to the HLA-DRA promoter. Thus, Oct-2A and HMG I/Y may synergize to activate HLA-DRA expression in B cells. By contrast, Oct-2A is not involved in the IFN-gamma induction of the HLA-DRA gene in HeLa cells, but antisense HMG I/Y dramatically decreases the level of induction. We conclude that distinct sets of transcription factors are involved in the two modes of HLA-DRA expression, and that HMG I/Y may be important for B cell-specific expression, and is essential for IFN-gamma induction.

scholarly journals Critical Role of cRel Subunit of NF-κB in Sepsis Survival

2011 ◽  
Vol 79 (5) ◽  
pp. 1848-1854 ◽  
Author(s):  
Emilie Courtine ◽  
Frédéric Pène ◽  
Nicolas Cagnard ◽  
Julie Toubiana ◽  
Catherine Fitting ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Critical Role ◽  
Cecal Ligation ◽  
Gene Expression Profiles ◽  
Severe Infection ◽  
A Genome ◽  
Underlying Mechanisms ◽  
Pathogen Clearance

ABSTRACTNF-κB is a critical regulator of gene expression during severe infections. NF-κB comprises homo- and heterodimers of proteins from the Rel family. Among them, p50 and p65 have been clearly implicated in the pathophysiology of sepsis. In contrast, the role of cRel in sepsis is still controversial and has been poorly studied in single-pathogen infections. We aimed to investigate the consequences of cRel deficiency in a cecal ligation and puncture (CLP) model of sepsis. We have approached the underlying mechanisms of host defense by analyzing bacterial clearance, systemic inflammation, and the distribution of spleen dendritic cell subsets. Moreover, by using a genome-wide technology, we have also analyzed the CLP-induced modifications in gene expression profiles both in wild-type (wt) and inrel−/−mice. The absence of cRel enhances mortality due to polymicrobial sepsis. Despite normal pathogen clearance, cRel deficiency leads to an altered systemic inflammatory response associated with a sustained loss of the spleen lymphoid dendritic cells. Furthermore, a whole-blood microarray study reveals that the differential outcome between wt andrel−/−mice during sepsis is preceded by remarkable changes in the expression of hundreds of genes involved in aspects of host-pathogen interaction, such as host survival and lipid metabolism. In conclusion, cRel is a key NF-κB member required for host antimicrobial defenses and a regulatory transcription subunit that controls the inflammatory and immune responses in severe infection.

scholarly journals Role of the Acidic Tail of High Mobility Group Protein B1 (HMGB1) in Protein Stability and DNA Bending

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e79572 ◽  
Author(s):  
Fabricio S. Belgrano ◽  
Isabel C. de Abreu da Silva ◽  
Francisco M. Bastos de Oliveira ◽  
Marcelo R. Fantappié ◽  
Ronaldo Mohana-Borges
Keyword(s):  
Protein Stability ◽  
Dna Bending ◽  
High Mobility ◽  
High Mobility Group ◽  
High Mobility Group Protein ◽  
Group Protein
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