BACKGROUND: The global prevalence of autoimmune hepatitis (AIH) is increasing due in part to the lack of effective pharmacotherapies. Growing evidence suggests that fibroblast growth factor 4 (FGF4) is crucial for diverse aspects of liver pathophysiology. However, its role in AIH remains unknown. Therefore, we investigated whether FGF4 can regulate M1 macrophage and thereby help treat liver inflammation in AIH.
METHODS: We obtained transcriptome-sequencing and clinical data for patients with AIH. Mice were injected with concanavalin A to induce experimental autoimmune hepatitis (EAH). The mechanism of action of FGF4 was examined using macrophage cell lines and bone marrow-derived macrophages.
RESULTS: We observed higher expression of markers associated with M1 and M2 macrophages in patients with AIH than that in individuals without AIH. EAH mice showed greater M1-macrophage polarization than control mice. The expression of M1-macrophage markers correlated positively with FGF4 expression. The loss of hepatic Fgf4 aggravated hepatic inflammation by increasing the abundance of M1 macrophages. In contrast, the pharmacological administration of FGF4 mitigated hepatic inflammation by reducing M1-macrophage levels. The efficacy of FGF4 treatment was compromised following the in vivo clearance of macrophage populations. Mechanistically, FGF4 treatment activated the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT)-signal pathway in macrophages, which led to reduced M1 macrophages and hepatic inflammation.
CONCLUSIONS: We identified FGF4 as a novel M1/M2 macrophage-phenotype regulator that acts through the PI3K-AKT-signaling pathway, suggesting that FGF4 may represent a novel target for treating inflammation in patients with AIH.

Autoimmune hepatitis (AIH) is a chronic liver disease characterized by immune dysregulation and hepatocyte damage. FKBP38, a member of the immunophilin family, has been implicated in immune regulation and the modulation of intracellular signaling pathways; however, its role in AIH pathogenesis remains poorly understood. In this study, we aimed to investigate the effects of hepatic FKBP38 deletion on AIH using a hepatic FKBP38 knockout (LKO) mouse model created via cre-loxP technology. We compared the survival rates, incidence, and severity of AIH in LKO mice with those in control mice. Our findings revealed that hepatic FKBP38 deletion resulted in an unfavorable prognosis in LKO mice with AIH. Specifically, LKO mice exhibited heightened liver inflammation and extensive hepatocyte damage compared to control mice, with a significant decrease in anti-apoptotic proteins and a marked increase in pro-apoptotic proteins. Additionally, transcriptional and translational levels of pro-inflammatory cytokines and chemokines were significantly increased in LKO mice compared to control mice. Immunoblot analysis showed that MCP-1 expression was significantly elevated in LKO mice. Furthermore, the phosphorylation of p38 was increased in LKO mice with AIH, indicating that FKBP38 deletion promotes liver injury in AIH by upregulating p38 phosphorylation and increasing MCP-1 expression. Immune cell profiling demonstrated elevated populations of T, NK, and B cells, suggesting a dysregulated immune response in LKO mice with AIH. Overall, our findings suggest that FKBP38 disruption exacerbates AIH severity by augmenting the immune response by activating the MCP-1/p38 signaling pathway.

UNASSIGNED: The effect of the functionally unknown gene C6orf120 on autoimmune hepatitis was investigated on C6orf120 knockout rats ( C6orf120 -/- ) and THP-1 cells.
UNASSIGNED: Six-eight-week-old C6orf120 -/- and wild-type (WT) SD rats were injected with Con A (16 mg/kg), and euthanized after 24 h. The sera, livers, and spleens were collected. THP-1 cells and the recombinant protein (rC6ORF120) were used to explore the mechanism in vitro. The frequency of M1 and M2 macrophages was analyzed using flow cytometry. Western blotting and PCR were used to detect macrophage polarization-associated factors.
UNASSIGNED: C6orf120 knockout attenuated Con A-induced autoimmune hepatitis. Flow cytometry indicated that the proportion of CD68 +CD86 +M1 macrophages from the liver and spleen in the C6orf120 -/- rats decreased. C6orf120 knockout induced downregulation of CD86 protein and the mRNA levels of related inflammatory factors TNF-α, IL-1β, and IL-6 in the liver. C6orf120 knockout did not affect the polarization of THP-1 cells. However, rC6ORF120 promoted the THP-1 cells toward CD68 +CD80 +M1 macrophages and inhibited the CD68 +CD206 +M2 phenotype.
UNASSIGNED: C6orf120 knockout alleviates Con A-induced autoimmune hepatitis by inhibiting macrophage polarization toward M1 macrophages and reducing the expression of related inflammatory factors in C6orf120 -/- rats.

Astaxanthin (ASX) is an oxygen-containing non-vitamin A carotenoid pigment. However, the role of ASX in autoimmune hepatitis (AIH) remains unclear. In this study, a mouse model of AIH is established induced by concanavalin A (ConA). Mass cytometry and single-cell RNA sequencing (scRNA-seq) are used to analyze the potential role of ASX in regulating the immune microenvironment of AIH. ASX treatment effectively alleviated liver damage induced by ConA and downregulated pro-inflammatory cytokines production in mice. Mass cytometry and scRNA-seq analyses revealed a significant increase in the number of CD8+ T cells following ASX treatment. Functional markers of CD8+ T cells, such as CD69, MHC II, and PD-1, are significantly downregulated. Additionally, specific CD8+ T cell subclusters (subclusters 4, 13, 24, and 27) are identified, each displaying distinct changes in marker gene expression after ASX treatment. This finding suggests a modulation of CD8+ T cell function by ASX. Finally, the key transcription factors for four subclusters of CD8+ T cells are predicted and constructed a cell-to-cell communication network based on receptor-ligand interactions probability. In conclusion, ASX holds the potential to ameliorate liver damage by regulating the number and function of CD8+ T cells.

OBJECTIVE: This study aimed to use Mendelian randomization (MR) to investigate the potential causal association between inflammatory bowel disease (IBD) and autoimmune hepatitis (AIH).
METHODS: Two-sample MR was performed to estimate the causal effect of IBD on AIH. The primary analysis employed the inverse variance weighted (IVW) method in univariable MR analysis, supplemented by additional methods including MR-Egger, weighted median, simple mode, and weighted mode. The p values were adjusted by FDR p-value adjustment. In the replication analysis, the primary IVW analysis was repeated and then pooled by meta-analysis. Sensitivity analyses were performed using Cochran\'s Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out, and funnel plot analysis to evaluate the robustness of the MR findings. Additionally, multivariable MR (MVMR) was employed to estimate the direct causal effect of IBD on the risk of AIH.
RESULTS: In univariable MR analysis, a significant positive causal association was observed between IBD (both Crohn\'s disease (CD) or ulcerative colitis (UC)) and the risk of AIH (for CD and AIH, the IVW odds ratio (OR) = 1.10, 95% confidence interval (CI) = 1.00-1.16, P = 0.045, FDR P = 0.045; for UC and AIH, the IVW OR = 1.07, 95% CI = 1.00-1.13, P = 0.038, FDR P = 0.076). Furthermore, no significant positive correlation between IBD and the risk of AIH (OR = 1.13, 95% CI = 0.94-1.35, P = 0.194). Sensitivity analysis revealed no pleiotropic bias. MVMR analysis further confirmed the direct causal effect of CD or UC on the risk of AIH after adjusting for the common risk factors (cigarettes per day and osteoporosis). In the replication analysis, the positive causal association between UC and the risk of AIH remain significant (the IVW odds ratio (OR) = 1.32, 95% CI = 1.18-1.48, P = 2.90E-06). While no significant positive association was observed between CD or IBD and the risk of AIH in the replication analysis, a suggestive positive association between the identified risk factors (UC, CD, and IBD) and the risk of AIH was detected in the meta-analysis (OR = 1.09, 95% CI = 1.05-1.13, P<0.0001).
CONCLUSIONS: This MR study revealed a positive impact of the identified risk factors (CD, UC and IBD) on the risk of AIH within the European population.

自身免疫性肝炎是以自身免疫紊乱导致肝细胞炎症受损为主要特点的肝实质病变，近年来发病率逐渐升高。临床起病隐匿，个体差异较大，可表现为乏力、食欲下降、黄疸、肝区不适等，主要特征有高IgG血症、自身抗体阳性，伴随血清转氨酶升高，肝组织病理表现主要为门静脉周围碎片状坏死或界板性肝炎，可进展为肝硬化或终末期肝衰竭。本文对自身免疫性肝炎的诊治原则及研究进展进行阐述。.

本文报道了1例原发性胆汁性胆管炎-自身免疫性肝炎重叠综合征（PBC-AIH OS）合并下肢软组织感染患者的诊治经过。患者为老年女性，因肝功能异常就诊入院，在完善肝穿刺病理后确诊PBC-AIH OS。治疗过程中出现下肢软组织感染，及时停用免疫抑制剂并针对副作用进行积极治疗后，创面愈合良好，在后续随访中再次使用免疫抑制剂未发现不良反应，目前复查肝功能、免疫指标均正常。本文通过该病例的诊治经过回顾总结该病的临床特点和联合免疫抑制治疗过程中处理、预防不良事件的经验，希望能提高我们对该病的认识和处理药物不良反应的经验。.

BACKGROUND: Autoimmune hepatitis (AIH), primarily mediated by T cells, is characterized by liver inflammation. Despite the advancements in understanding its pathogenesis, effective therapeutic options are limited. Naringin, a flavonoid abundant in citrus fruits, is recognized for its anti-inflammatory properties and ability to protect against various inflammatory diseases, including drug-induced liver injury. However, the exact effects of naringin on AIH and the mechanisms involved remain poorly understood.
OBJECTIVE: We aim to determine the role of naringin in AIH, exploring its targets and actions in this disease.
METHODS: Network pharmacology, molecular docking, and molecular dynamics simulations were utilized to predict the HUB targets connecting naringin, T cell-mediated autoimmune disorders, and AIH. Cellular thermal shift assays were used to determine the binding abilities of naringin with the HUB targets. An in vivo experiment confirmed the impact of naringin treatment on AIH development and underlying mechanisms.
RESULTS: Naringin demonstrated therapeutic effects on ConA-induced AIH. There were 455 shared targets between naringin, T cell-mediated autoimmune diseases, and AIH. Ten HUB genes (AKT1, ALB, IL-6, IL-1β, CTNNB1, TNF, TP53, MAPK3, VEGFA, and JUN) were identified through the PPI network. Gene ontology analysis revealed involvement in gene expression regulation, lipopolysaccharide-mediated signaling, and I-kappa kinase/NFκB signaling. Pathway analysis suggested TNF, Th1/Th2 cell differentiation, and Toll-like receptor pathways, with favorable naringin-HUB gene binding. Molecular docking confirmed albumin (ALB), IL-1β, IL-6, and TNF as primary targets for naringin. Molecular dynamics simulations showed stable binding in ALB-naringin, TNF-naringin, and IL-1β-naringin complexes. Naringin\'s hepatoprotective effect on AIH was supported by increased serum ALB and decreased hepatic inflammatory cytokines including IL-1β, IL-6, and TNF-α.
CONCLUSIONS: Our data underscore the potential of naringin as a preventive or therapeutical agent in T cell-mediated autoimmune diseases including AIH.

Yinchenhao Decoction (YCHD) is a classic prescription in traditional Chinese medicine (TCM). It appears to play an important role in anti-inflammation and autoimmunity protection. As one of the key active ingredients in YCHD, quercetin is a novel anti-inflammatory metabolite that exerts protective effects in many autoimmune diseases. However, its role in autoimmune hepatitis (AIH)-related hepatic injury has not been studied. The aim of this study was to reveal the hepatocyte protective mechanism of quercetin. In this study, we used Concanavalin A (Con A) to establish an in vitro hepatocyte injury-associated AIH model. Brl3a hepatocyte injury was induced by the supernatant of J774A.1 cells treated with Con A. We found that quercetin mitigated Con A-induced via macrophage-mediated Brl3a hepatocyte injury. Quercetin administration reduced the levels of alanine transaminase (ALT) and aspartate transaminase (AST) in the supernatant of Con A-treated Brl3a cells and attenuated the infiltration of J774A.1 macrophages induced by Con A. Moreover, quercetin effectively inhibited the expression of proinflammatory cytokines including interleukin-1β (IL-1β) by Con A. Furthermore, quercetin decreased hepatocyte apoptosis and ferroptosis levels in the macrophage-induced hepatocyte injury model. In conclusion, our study indicates that quercetin alleviates macrophage-induced hepatocyte damage by reducing the inflammatory response, apoptosis and ferroptosis. Our work suggests that quercetin might be a potential therapeutic strategy for AIH.

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