[Advances in the role of extracellular histones in the inflammatory process of liver injury].

Histones are important structural proteins of chromatin in the nucleus, which can regulate gene transcription, and can be released from the nucleus to the outside of the cell under injury and inflammatory stimulations, thereby causing cytotoxicity and immune stimulation, and aggravating tissue damage. Extracellular histones are involved in the occurrence and development of many diseases, including sepsis, autoimmune diseases, liver injury, and acute lung injury. Therefore, its application not only can be used as a body's biomarker of inflammation, but also it is expected to become a molecular target for the treatment of diseases. This article reviews the role of extracellular histones in the inflammatory process of liver injury.

[Protective effect of the histone deacetylase inhibitor ACY1215 against brain edema in mice with acute liver failure].

Objective: To investigate the protective effect of ACY1215 (Rocilinostat), a histone deacetylase inhibitor, against brain edema in mice with acute liver failure. Methods: Lipopolysaccharide combined with D-galactosamine was used to establish a mouse model of acute liver failure, and ACY1215 was used for intervention. The effect of ACY1215 on histopathological changes of the liver was observed after 24 hours, as well as the changes in alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood ammonia, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), brain water content, blood-brain barrier structure, NF-κB-p65, histone, acetylated histone, and TNF-α mRNA in brain tissue. Results: The mice with acute liver failure had marked pathological damage in liver tissue, as well as significant increases in the levels of ALT, AST, blood ammonia, TNF-α, and IFN-γ (t≥5.367, all P < 0.05). ACY1215 significantly improved the pathological damage in liver tissue and reduced the serum levels of ALT, AST, blood ammonia, TNF-α, and IFN-γ (t≤-3.515, all P < 0.05). ACY1215 also significantly reduced the expression of NF-κB-p65 (t = -5.871, P = 0.004) and the mRNA expression of TNF-α (t = -11.913, P < 0.01) in brain tissue and brain water content (t = -2.355, P < 0.01). According to the results of electron microscopy, the model group had an abnormal blood-brain barrier structure, and the ACY1215 group had slighter damage than the model group. Compared with the normal group, the model group had significant increases in the acetylation level of histone H3 and H4 in brain tissue (t≥3.009, both P < 0.05), while ACY1215 further upregulated the acetylation levels of histone H3 and H4 (t≥6.682, both P < 0.05). Conclusion: ACY1215 exerts a protective effect against brain edema in mice with acute liver failure, possibly by regulating histone acetylation and inhibiting inflammation.