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

Xiangqin He, Kunzhe Dong, Jian Shen, Guoqing Hu, Jinhua Liu, Xiuhua Kang, Liang Wang, Reem T. Atawia, Islam Osman, Robert W. Caldwell, Meixiang Xiang, Wei Zhang, Zeqi Zheng, Liwu Li, David J.R. Fulton, Keyu Deng, Hongbo Xin, Jiliang Zhou

Research output: Contribution to journalArticlepeer-review

Abstract

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.

Original languageEnglish (US)
Article numbere2021862118
JournalProceedings of the National Academy of Sciences of the United States of America
Volume118
Issue number7
DOIs
StatePublished - Feb 16 2021

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Deficiency of the novel high mobility group protein HMGXB4 protects against systemic inflammation-induced endotoxemia in mice'. Together they form a unique fingerprint.

Cite this