ObjectiveTo investigate the role of DEAD-box helicase 3 X-linked （DDX3X） in immune-mediated liver injury （ILI）， and to clarify its mechanism by regulating endoplasmic reticulum stress （ERS）-dependent apoptotic pathway and its association with the clinical progression of hepatitis B. MethodsMice were given injection of concanavalin A （ConA） via the caudal vein to establish a model of ILI， PBS （control group） and different concentrations of ConA were injected into the tail vein of hepatocyte-specific DDX3X-knockout mice （DDX3X^ΔHep and DDX3X-flox mice （DDX3X^fl/fl）， respectively.. The log-rank survival analysis， measurement of the serum levels of aspartate aminotransferase （AST） and alanine aminotransferase （ALT）， and HE staining of liver tissue were performed to assess liver injury， and qRT-PCR and Western Blot were used to measure the mRNA and protein expression levels of glucose-regulated protein 78 （GRP78）， CCAAT/enhancer-binding protein homologous protein （CHOP）， and DDX3X in liver tissue. Intraperitoneal injection of 4-phenylbutyric acid （4-PBA， 100 mg/kg） was performed to inhibit ERS. Serum samples （n=30） and liver tissue samples （n=6） were collected from healthy controls， chronic hepatitis B （CHB） patients， and hepatitis B virus-associated liver failure （HBV-LF） patients； ELISA was used to measure the serum level of DDX3X， and qRT-PCR/Western Blot was used to analyze the expression of targets in liver tissue. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the control group of mice， the expression of DDX3X in the liver of mice induced by ConA was significantly increased after liver injury （P<0.05）， and hepatocyte-specific DDX3X knockout increased the 72-hour survival rate of mice by 55% （compared with 20% in the DDX3X^fl/fl group）， with significant reductions in the serum levels of ALT and AST （P<0.000 1） and the expression levels of the ERS markers GRP78 and CHOP （P<0.05）. After ERS was inhibited by 4-PBA， there was alleviation of liver injury （with reductions in ALT and AST， P <0.001） and a reduction in DDX3X expression （P<0.01）. The analysis of clinical samples showed that the mRNA and protein expression levels of liver DDX3X in CHB patients and HBV-LF patients were significantly higher than those in healthy controls （all P<0.01）， and there was a significant increase in the serum level of DDX3X in HBV-LF patients （P<0.000 1）. ConclusionDDX3X exacerbates ILI by regulating the ERS-dependent apoptotic pathway （GRP78/CHOP）， and its expression is associated with the progression of hepatitis B. Therefore， it can be used as a potential therapeutic target.

Liver regeneration plays a crucial role in the recovery after liver injury induced by N-acetyl-p-aminophenol(APAP).After APAP overdose,the degree of regeneration increases with the extent of liver injury,leading to the resolution of liver injury and spontaneous recovery in most cases.However,severe APAP overdose can impair liver regeneration and result in uncontrolled liver injury,even failure to recover or death in severe cases.Following APAP-induced liver injury,interactions between cells in the liver are essential for regenerative response.Liver regeneration is jointly regulated by multiple proliferative signaling pathways,involving various kinases,nuclear receptors,transcription factors,and coactivators.Severe APAP overdose can inhibit the activation of proliferative signaling pathways,thereby causing cell cycle arrest and impairing liver regeneration.Although liver regeneration plays a critical role in the repair of APAP-induced liver injury,the underlying mechanisms remain unclear.This article reviews the research advances in the role of liver regeneration in APAP-induced liver injury,in order to provide a reference for further basic research in this area.