Interleukin-1 and inflammasomes in alcoholic liver disease/acute alcoholic hepatitis and nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

The Critical Role of Regulatory T Cells in Immune Tolerance and Rejection Following Liver Transplantation: Interactions With the Gut Microbiome

Liver transplantation (LT) is the ultimate treatment for patients with end-stage liver disease or early hepatocellular carcinoma. In the context of LT, because of the unique immunological characteristics of human liver allograft, 5%-20% of selected LT recipients can achieve operational tolerance. Nonetheless, there remains a risk of rejection in LT patients. Maintaining immune homeostasis is thus crucial for improving clinical outcomes in these patients. In mechanism, several immune cells, including dendritic cells, Kupffer cells, myeloid-derived suppressor cells, hepatic stellate cells, regulatory B cells, and CD4 + regulatory T cells (Treg), contribute to achieving tolerance following LT. In terms of Treg, it plays a role in successfully minimizing immunosuppression or achieving tolerance post-LT while also reducing the risk of rejection. Furthermore, the gut microbiome modulates systemic immune functions along the gut-liver axis. Recent studies have explored changes in the microbiome and its metabolites under various conditions, including post-LT, acute rejection, and tolerance. Certain functional microbiomes and metabolites exhibit immunomodulatory functions, such as the augmentation of Treg, influencing immune homeostasis. Therefore, understanding the mechanisms of tolerance in LT, the role of Treg in tolerance and rejection, as well as their interactions with gut microbiome, is vital for the management of LT patients.

p-Cymene inhibits pro-fibrotic and inflammatory mediators to prevent hepatic dysfunction

This study evaluated the hepatoprotective potential of p-cymene (p-CYM) against two models of liver damage: ethanol (EtOH)-induced hepatocellular injury and diethylnitrosamine-carbon tetrachloride (DEN-CCl4)-induced liver fibrosis (LF). HepG2 cells were treated with p-CYM or silymarin (SIL) before exposure to 10% EtOH in order to induce cellular injury. LF was induced in Sprague-Dawley rats using a single dose of DEN followed by increasing doses of CCl4 over 60 days. Rats were treated twice weekly with p-CYM or SIL from day 21 to day 60. Results showed that p-CYM effectively mitigated EtOH-induced cell death in HepG2 cells by enhancing the activity of superoxide dismutase and glutathione reductase. In vivo findings revealed that p-CYM attenuated DEN- CCl4-induced liver damage by preventing weight loss, improving serum biomarkers (e.g., aspartate transaminase, alanine aminotransferase, alkaline phosphatase, and bilirubin), and reducing liver fibrotic changes. It also decreased the expression of pro-inflammatory and pro-fibrotic markers such as TNF-α, IL-1β, IL-6, TGF-β1, COL1A1, and TIMP-1. Molecular docking further supported the experimental findings, showing strong interactions between p-CYM and the target proteins. These results indicate that the hepatoprotective effects of p-CYM are likely due to its combined antioxidant, anti-inflammatory, and anti-fibrotic properties.

Adipokines: masterminds of metabolic inflammation

Adipose tissue is an immunologically active organ that controls host physiology, partly through the release of mediators termed adipokines. In obesity, adipocytes and infiltrating leukocytes produce adipokines, which include the hormones adiponectin and leptin and cytokines such as tumour necrosis factor and IL-1β. These adipokines orchestrate immune responses that are collectively referred to as metabolic inflammation. Consequently, metabolic inflammation characterizes metabolic disorders and promotes distinct disease aspects, such as insulin resistance, metabolic dysfunction-associated liver disease and cardiovascular complications. In this unifying concept, adipokines participate in the immunological cross-talk that occurs between metabolically active organs in metabolic diseases, highlighting the fundamental role of adipokines in obesity and their potential for therapeutic intervention. Here, we summarize how adipokines shape metabolic inflammation in mice and humans, focusing on their contribution to metabolic disorders in the setting of obesity and discussing their value as therapeutic targets.

IL-1 Signal Inhibition in Alcohol-Related Hepatitis: A Randomized, Double-Blind, Placebo-Controlled Trial of Canakinumab

BACKGROUND AND AIMS

Short-term mortality in alcohol-related hepatitis (AH) is high, and no current therapy results in durable benefit. A role for interleukin (IL)-1β has been demonstrated in the pathogenesis of alcohol-induced steatohepatitis. This study explored the safety and efficacy of canakinumab (CAN), a monoclonal antibody targeting IL-1β, in the treatment of patients with AH.

METHODS

Participants with biopsy-confirmed AH and discriminant function ≥32 but Model for End-Stage Liver Disease ≤27 were randomly allocated 1:1 to receive either CAN 3 mg/kg or placebo (PBO). Liver biopsies were taken before and 28 days after treatment. The primary endpoint was the overall histological improvement in inflammation analyzed by the modified intention-to-treat principle.

RESULTS

Fifty-seven participants were randomized: 29 to CAN and 28 to PBO. Two participants had histology that did not corroborate the clinical diagnosis. Of the remaining 55 participants, paired histology data were evaluable from 48 participants. In CAN-treated participants, 14 (58%) of 24 demonstrated histological improvement compared with 10 (42%) of 24 in the PBO group (P = .25). There was no improvement in prognostic scores of liver function. Four (7%) of the 55 participants died within 90 days, 2 in each group. The number of serious adverse events was similar between CAN vs PBO. In post hoc exploratory analyses after adjustment for baseline prognostic factors, CAN therapy was associated with overall histological improvement (P = .04).

CONCLUSIONS

CAN therapy in severe AH participants with Model for End-Stage Liver Disease ≤27 did not alter biochemical or clinical outcomes compared with PBO. Nonsignificant histological improvements did not translate into clinical benefit. EudraCT, Number: 2017-003724-79; ClinicalTrials.gov, Number: NCT03775109.

Chronic Cr(VI) exposure-induced biotoxicity involved in liver microbiota-gut axis disruption in Phoxinus lagowskii Dybowski based on multi-omics technologies

Cr(VI) is widely used in industry and has high toxicity, making it one of the most common environmental pollutants. Long-term exposure to Cr(VI) can cause metabolic disorders and tissue damage. However, the effects of Cr(VI) on liver and gut microbes in fish have rarely been reported. In this study, 240 fish were randomly divided into 3 groups: the control group, low-dose Cr(VI) group (0.5 mg/L), and high-dose Cr(VI) group (2 mg/L). The mechanism by which Cr(VI) affects the enterohepatic axis of common carp was elucidated via multiomic analysis, serology, histomorphology, and physiological and biochemical indices. The results revealed that Cr(VI) stress led to hepatocyte damage, nuclear lysis, inflammatory cell infiltration, and vacuolated degeneration. The structure of the intestinal villi was severely damaged, and the length and width of the intestinal villi were significantly reduced. We also found that the accumulation of Cr(VI) in tissues increased in a concentration-dependent manner, and the content of Cr(VI) in each tissue increased in the order of gut > gill > liver > muscle. Multiple omics studies have revealed that chronic Cr(VI) stress leads to disturbances in the intestinal flora, with a significant reduction in the abundance of the beneficial bacterium Akkermansia and a significant increase in the abundance of the harmful bacterium Escherichia/Shigella. Intestinal injury and dysbiosis lead to an increase in blood LPS levels, further inducing metabolic disorders in the liver. The metabolites in the liver, including geniposide, leucine, C17 sphingosine, and 9,10-DiHODE, were significantly increased, whereas the beneficial metabolites, such as carnitine propionate and palmitoyl ethanolamide, were significantly reduced. In conclusion, our results suggest that chronic Cr(VI) stress leads to disturbances in gut microbial homeostasis and disturbed fatty acid and amino acid metabolism in the liver. LPS released into the bloodstream reaches the liver through the portal circulation, further exacerbating Cr(VI) stress-induced hepatotoxicity. This study revealed the mechanism of Cr(VI) toxicity to the liver-microbiota-gut axis of common carp. Our study provides new insights into the effects of Cr(VI) on the liver-microbiota-gut axis.

Hepatocellular carcinoma: signaling pathways and therapeutic advances

Liver cancer represents a major global health concern, with projections indicating that the number of new cases could surpass 1 million annually by 2025. Hepatocellular carcinoma (HCC) constitutes around 90% of liver cancer cases and is primarily linked to factors incluidng aflatoxin, hepatitis B (HBV) and C (HCV), and metabolic disorders. There are no obvious symptoms in the early stage of HCC, which often leads to delays in diagnosis. Therefore, HCC patients usually present with tumors in advanced and incurable stages. Several signaling pathways are dis-regulated in HCC and cause uncontrolled cell propagation, metastasis, and recurrence of HCC. Beyond the frequently altered and therapeutically targeted receptor tyrosine kinase (RTK) pathways in HCC, pathways involved in cell differentiation, telomere regulation, epigenetic modification and stress response also provide therapeutic potential. Investigating the key signaling pathways and their inhibitors is pivotal for achieving therapeutic advancements in the management of HCC. At present, the primary therapeutic approaches for advanced HCC are tyrosine kinase inhibitors (TKI), immune checkpoint inhibitors (ICI), and combination regimens. New trials are investigating combination therapies involving ICIs and TKIs or anti-VEGF (endothelial growth factor) therapies, as well as combinations of two immunotherapy regimens. The outcomes of these trials are expected to revolutionize HCC management across all stages. Here, we provide here a comprehensive review of cellular signaling pathways, their therapeutic potential, evidence derived from late-stage clinical trials in HCC and discuss the concepts underlying earlier clinical trials, biomarker identification, and the development of more effective therapeutics for HCC.

Acetylation of proximal cysteine-lysine pairs by alcohol metabolism

Alcohol consumption induces hepatocyte damage through complex processes involving oxidative stress and disrupted metabolism. These factors alter proteomic and epigenetic marks, including alcohol-induced protein acetylation, which is a key post-translational modification (PTM) that regulates hepatic metabolism and is associated with the pathogenesis of alcohol-associated liver disease (ALD). Recent evidence suggests lysine acetylation occurs when a proximal cysteine residue is within ∼15 Å of a lysine residue, referred to as a cysteine-lysine (Cys-Lys) pair. Here, acetylation can occur through the transfer of an acetyl moiety via an S → N transfer reaction. Alcohol-mediated redox stress is known to occur coincidentally with lysine acetylation, yet the biochemical mechanisms related to cysteine and lysine crosstalk within ALD remain unexplored. A murine model of ALD was employed to quantify hepatic cysteine redox changes and lysine acetylation, revealing that alcohol metabolism significantly reduced the cysteine thiol proteome and increased protein acetylation. Interrogating both cysteine redox and lysine acetylation datasets, 1280 protein structures generated by AlphaFold2 represented by a 3D spatial matrix were used to quantify the distances between 557,815 cysteine and lysine residues. Our analysis revealed that alcohol metabolism induces redox changes and acetylation selectively on proximal Cys-Lys pairs with an odds ratio of 1.88 (p < 0.0001). Key Cys-Lys redox signaling hubs were impacted in metabolic pathways associated with ALD, including lipid metabolism and the electron transport chain. Proximal Cys-Lys pairs exist as sets with four major motifs represented by the number of Cys and Lys residues that are pairing (Cys1:Lys1, Cysx:Lys1, Cys1:Lysx and Cysx:Lysx) each with a unique microenvironment. The motifs are composed of functionally relevant Cys-Ly altered within ALD, identifying potential therapeutic targets. Furthermore, these unique Cys-Lys redox signatures are translationally relevant as revealed by orthologous comparison with severe alcohol-associated hepatitis (SAH) explants, revealing numerous pathogenic thiol redox signals in these patients.

Gut microbiota of patients insusceptible to olanzapine-induced fatty liver disease relieves hepatic steatosis in rats

Olanzapine-induced fatty liver disease continues to pose vital therapeutic challenges in the treatment of psychiatric disorders. In addition, we observed that some patients were less prone to hepatic steatosis induced by olanzapine. Therefore, we aimed to investigate the role and the underlying mechanism of the intestinal flora in olanzapine-mediated hepatic side effects and explore the possible countermeasures. Our results showed that patients with different susceptibilities to olanzapine-induced fatty liver disease had different gut microbial diversity and composition. Furthermore, we performed fecal microbiota treatment (FMT), and confirmed that the gut microbiome of patients less prone to the fatty liver caused by olanzapine exhibited an alleviation against fatty liver disease in rats. In terms of mechanism, we revealed that the cross talk of leptin with the gut-short-chain fatty acid (SCFA)-liver axis play a critical role in olanzapine-related fatty degeneration in liver. These findings propose a promising strategy for overcoming the issues associated with olanzapine application and will hopefully inspire future in-depth research of fecal microbiota-based therapy in olanzapine-induced fatty liver disease.NEW & NOTEWORTHY Patients who were less inclined to have olanzapine-induced fatty liver had different gut microbiota profiles than did those in the susceptible cohort. Lachnospiraceae, Ruminococcaceae, Oscillospiraceae, Butyricicoccaceae, and Christensenellaceae were enriched in patients who were less prone to fatty liver disease caused by olanzapine. Fecal microbiota treatment (FMT) with these fecal samples promoted short-chain fatty acid (SCFA) production, which attenuated the circulating leptin and inhibited FASN and ACC1, thereby suppressing lipid synthesis in the liver, ultimately leading to alleviation of hepatic steatosis.

Emerging trends and hotspots in intestinal microbiota research in sepsis: bibliometric analysis

Background

The association between the gut microbiota and sepsis has garnered attention in the field of intestinal research in sepsis. This study utilizes bibliometric methods to visualize and analyze the literature on gut microbiota research in sepsis from 2011 to 2024, providing a scientific foundation for research directions and key issues in this domain.

Methods

Original articles and reviews of gut microbiota research in sepsis, which published in English between 2011 and 2024, were obtained from the Web of Science Core Collection on June 21, 2024. Python, VOSviewer, and CiteSpace software were used for the visual analysis of the retrieved data.

Results

A total of 1,031 articles were analyzed, originating from 72 countries or regions, 1,614 research institutions, and 6,541 authors. The articles were published in 434 different journals, covering 89 different research fields. The number of publications and citations in this research area showed a significant growth trend from 2011 to 2024, with China, the United States, and the United Kingdom being the main research forces. Asada Leelahavanichkul from Thailand was identified as the most prolific author, making him the most authoritative expert in this field. "Nutrients" had the highest number of publications, while "Frontiers in Cellular and Infection Microbiology," "Frontiers in Immunology" and "the International Journal of Molecular Sciences" have shown increasing attention to this field in the past 2 years. Author keywords appearing more than 100 times included "gut microbiota (GM)," "sepsis" and "microbiota." Finally, this study identified "lipopolysaccharides (LPS)," "short-chain fatty acids (SCFAs)," "probiotics," "fecal microbiota transplantation (FMT)" and "gut-liver axis" as the research hotspots and potential frontier directions in this field.

Conclusion

This bibliometric study summarizes current important perspectives and offers comprehensive guidance between sepsis and intestinal microbiota, which may help researchers choose the most appropriate research directions.

Linking Antibodies Against Apolipoprotein A-1 to Metabolic Dysfunction-Associated Steatohepatitis in Mice

Metabolic dysfunction-associated fatty liver disease (MASLD) is a common liver and health issue associated with heightened cardiovascular disease (CVD) risk, with Cytokeratin 18 (CK-18) as a marker of liver injury across the MASLD to cirrhosis spectrum. Autoantibodies against apolipoprotein A-1 (AAA-1s) predict increased CVD risk, promoting atherosclerosis and liver steatosis in apoE-/- mice, though their impact on liver inflammation and fibrosis remains unclear. This study examined AAA-1s' impact on low-grade inflammation, liver steatosis, and fibrosis using a MASLD mouse model exposed to AAA-1s passive immunization (PI). Ten-week-old male C57BL/6J mice under a high-fat diet underwent PI with AAA-1s or control antibodies for ten days. Compared to controls, AAA-1-immunized mice showed higher plasma CK-18 (5.3 vs. 2.1 pg/mL, p = 0.031), IL-6 (13 vs. 6.9 pg/mL, p = 0.035), IL-10 (27.3 vs. 9.8 pg/mL, p = 0.007), TNF-α (32.1 vs. 24.2 pg/mL, p = 0.032), and liver steatosis (93.4% vs. 73.8%, p = 0.007). Transcriptomic analyses revealed hepatic upregulation of pro-fibrotic mRNAs in AAA-1-recipient mice, though histological changes were absent. In conclusion, short-term AAA-1 PI exacerbated liver steatosis, inflammation, and pro-fibrotic gene expression, suggesting that AAA-1s may play a role in MASLD progression. Further research with prolonged AAA-1 exposure is warranted to clarify their potential role in liver fibrosis and associated complications.

Post-translational modifications drive the effects of HMGB1 in alcohol-associated liver disease

BACKGROUND

We previously identified that high-mobility group box-1 (HMGB1) is increased and undergoes post-translational modifications (PTMs) in response to alcohol consumption. Here, we hypothesized that specific PTMs, occurring mostly in hepatocytes and myeloid cells, could contribute to the pathogenesis of alcohol-associated liver disease (AALD).

METHODS

We used the Lieber-DeCarli (LD) model of early alcohol-induced liver injury, combined with engineered viral vectors and genetic approaches to regulate the expression of HMGB1, its PTMs (reduced [H], oxidized [O], acetylated [Ac], both [O + Ac]), and its receptors (RAGE, TLR4) in a cell-specific manner (hepatocytes and/or myeloid cells).

RESULTS

Hmgb1 ablation in hepatocytes or myeloid cells partially protected, while ablation in both prevented steatosis, inflammation, IL1B production, and alcohol-induced liver injury. Hepatocytes were a major source of [H], [O], and [Ac] HMGB1, whereas myeloid cells produced only [H] and [Ac] HMGB1. Neutralization of HMGB1 prevented, whereas injection of [H] HMGB1 increased AALD, which was worsened by injection of [O] HMGB1. While [O] HMGB1 induced liver injury, [Ac] HMGB1 protected and counteracted the effects of [O] HMGB1 in AALD. [O] HMGB1 stimulated macrophage (MF) migration, activation, IL1B production, and secretion. Ethanol-fed RageΔMye but not Tlr4ΔMye, RageΔHep, or Tlr4ΔHep mice were protected from AALD, indicating a crucial role of RAGE in myeloid cells for AALD. [O] HMGB1 recruited and activated myeloid cells through RAGE and contributed to steatosis, inflammation, and IL1B production in AALD.

CONCLUSIONS

These results provide evidence for targeting [O] HMGB1 of hepatocyte origin as a ligand for RAGE signaling in myeloid cells and a driver of steatosis, inflammatory cell infiltration, and IL1B production in AALD. Importantly, we reveal that [Ac] HMGB1 offsets the noxious effects of [O] HMGB1 in AALD.

Liver fibrosis is associated with left ventricular remodeling: insight into the liver-heart axis

OBJECTIVE

In nonalcoholic fatty liver disease (NAFLD), liver fibrosis is the strongest predictor of adverse outcomes. We sought to investigate the relationship between liver fibrosis and cardiac remodeling in participants from the general population using magnetic resonance imaging (MRI), as well as explore potential mechanistic pathways by analyzing circulating cardiovascular biomarkers.

METHODS

In this cross-sectional study, we prospectively included participants with type 2 diabetes and individually matched controls from the SCAPIS (Swedish CArdioPulmonary bioImage Study) cohort in Linköping, Sweden. Between November 2017 and July 2018, participants underwent MRI at 1.5 Tesla for quantification of liver proton density fat fraction (spectroscopy), liver fibrosis (stiffness from elastography), left ventricular (LV) structure and function, as well as myocardial native T1 mapping. We analyzed 278 circulating cardiovascular biomarkers using a Bayesian statistical approach.

RESULTS

In total, 92 participants were enrolled (mean age 59.5 ± 4.6 years, 32 women). The mean liver stiffness was 2.1 ± 0.4 kPa. 53 participants displayed hepatic steatosis. LV concentricity increased across quartiles of liver stiffness. Neither liver fat nor liver stiffness displayed any relationships to myocardial tissue characteristics (native T1). In a regression analysis, liver stiffness was related to increased LV concentricity. This association was independent of diabetes and liver fat (Beta = 0.26, p = 0.0053), but was attenuated (Beta = 0.17, p = 0.077) when also adjusting for circulating levels of interleukin-1 receptor type 2.

CONCLUSION

MRI reveals that liver fibrosis is associated to structural LV remodeling, in terms of increased concentricity, in participants from the general population. This relationship could involve the interleukin-1 signaling.

CLINICAL RELEVANCE STATEMENT

Liver fibrosis may be considered a cardiovascular risk factor in patients without cirrhosis. Further research on the mechanisms that link liver fibrosis to left ventricular concentricity may reveal potential therapeutic targets in patients with non-alcoholic fatty liver disease (NAFLD).

KEY POINTS

Previously, studies on liver fibrosis and cardiac remodeling have focused on advanced stages of liver fibrosis. Liver fibrosis is associated with left ventricular (LV) concentricity and may relate to interleukin-1 receptor type 2. Interleukin-1 signaling is a potential mechanistic interlink between early liver fibrosis and LV remodeling.

Neutrophil extracellular traps activate hepatic stellate cells and monocytes via NLRP3 sensing in alcohol-induced acceleration of MASH fibrosis

OBJECTIVE

Alcohol use in metabolic dysfunction-associated steatohepatitis (MASH) is associated with an increased risk of fibrosis and liver-related death. Here, we aimed to identify a mechanism through which repeated alcohol binges exacerbate liver injury in a high fat-cholesterol-sugar diet (MASH diet)-induced model of MASH.

DESIGN

C57BL/6 mice received either chow or the MASH diet for 3 months with or without weekly alcohol binges. Neutrophil infiltration, neutrophil extracellular traps (NETs) and fibrosis were evaluated.

RESULTS

We found that alcohol binges in MASH increase liver injury and fibrosis. Liver transcriptomic profiling revealed differential expression of genes involved in extracellular matrix reorganisation, neutrophil activation and inflammation compared with alcohol or the MASH diet alone. Alcohol binges specifically increased NET formation in MASH livers in mice, and NETs were also increased in human livers with MASH plus alcohol use. We discovered that cell-free NETs are sensed via Nod-like receptor protein 3 (NLRP3). Furthermore, we show that cell-free NETs in vitro induce a profibrotic phenotype in hepatic stellate cells (HSCs) and proinflammatory monocytes. In vivo, neutrophil depletion using anti-Ly6G antibody or NET disruption with deoxyribonuclease treatment abrogated monocyte and HSC activation and ameliorated liver damage and fibrosis. In vivo, inhibition of NLRP3 using MCC950 or NLRP3 deficiency attenuated NET formation, liver injury and fibrosis in MASH plus alcohol diet-fed mice (graphical abstract).

CONCLUSION

Alcohol binges promote liver fibrosis via NET-induced activation of HSCs and monocytes in MASH. Our study highlights the potential of inhibition of NETs and/or NLRP3, as novel therapeutic strategies to combat the profibrotic effects of alcohol in MASH.

The Pathophysiology of Portal Hypertension

This article reviews the pathophysiology of portal hypertension that includes multiple mechanisms internal and external to the liver. This article starts with a review of literature describing the cellular and molecular mechanisms of portal hypertension, microvascular thrombosis, sinusoidal venous congestion, portal angiogenesis, vascular hypocontractility, and hyperdynamic circulation. Mechanotransduction and the gut-liver axis, which are newer areas of research, are reviewed. Dysfunction of this axis contributes to chronic liver injury, inflammation, fibrosis, and portal hypertension. Sequelae of portal hypertension are discussed in subsequent studies.

Global research trends on gut microbiota and metabolic dysfunction-associated steatohepatitis: Insights from bibliometric and scientometric analysis

Background

Metabolic dysfunction-associated steatohepatitis (MASH) is an inflammatory subtype of metabolic dysfunction-associated steatotic liver disease (MASLD) has recently been proposed as a replacement term for NAFLD, a common, multifactorial and poorly understood liver disease whose incidence is increasing worldwide. In recent years, there has been increasing scientific interest in exploring the relationship between gut microbiota and MASH. To learn more about the gut microbiota in MASH, this study aims to provide a comprehensive analysis of the knowledge structure and research hotspots from a bibliometric perspective.

Methods

We searched the Web of Science Core Collection for articles and reviews that covered the connections between gut microbiota and MASH over the last decade. The Online Analysis Platforms, VOSviewer, CiteSpace, the R tool "bibliometrix" were used to analyzed existing publications trends and hotspots.

Results

A total of 4,069 documents related to the interaction between gut microbiota and MASH were retrieved from 2014 to 2023. The number of annual publications increased significantly over the last decade, particularly in the United States and China. The University of California-San Diego was the most productive institution, while researcher Rohit Loomba published the most papers in the field. Younossi ZM was ranked as the first co-cited author and largest contributor of highly cited articles in the field. Gastroenterology and hepatology were the most common specialty category. The most cited journal in the last decade was Hepatology. The Keyword Bursts analysis highlighted the importance of studying the association between gut microbiota and MASH, as well as related factors such as metabolic syndrome, insulin resistance, endotoxemia and overgrowth of gut bacteria. Keyword clusters with co-citation were used to illustrate important topics including intestinal permeability, insulin sensitivity and liver immunology. The most common keywords include insulin resistance, obesity, dysbiosis, inflammation and oxidative stress, which are current hotspots.

Conclusion

Our analysis highlights key aspects of this field and emphasizes multiorgan crosstalk in MASLD/MASH pathogenesis. In particular, the central role of the gut-liver axis and the significant influence of gut microbiota dysbiosis on disease progression are highlighted. Furthermore, our results highlight the transformative potential of microbiota-specific therapies and cover the way for innovative healthcare and pharmaceutical strategies.

Elevated PINK1/Parkin-Dependent Mitophagy and Boosted Mitochondrial Function Mediate Protection of HepG2 Cells from Excess Palmitic Acid by Hesperetin

Deregulation of mitochondrial functions in hepatocytes contributes to many liver diseases, such as nonalcoholic fatty liver disease (NAFLD). Lately, it was referred to as MAFLD (metabolism-associated fatty liver disease). Hesperetin (Hst), a bioactive flavonoid constituent of citrus fruit, has been proven to attenuate NAFLD. However, a potential connection between its preventive activities and the modulation of mitochondrial functions remains unclear. Here, our results showed that Hst alleviates palmitic acid (PA)-triggered NLRP3 inflammasome activation and cell death by inhibition of mitochondrial impairment in HepG2 cells. Hst reinstates fatty acid oxidation (FAO) rates measured by seahorse extracellular flux analyzer and intracellular acetyl-CoA levels as well as intracellular tricarboxylic acid cycle metabolites levels including NADH and FADH2 reduced by PA exposure. In addition, Hst protects HepG2 cells against PA-induced abnormal energetic profile, ATP generation reduction, overproduction of mitochondrial reactive oxygen species, and collapsed mitochondrial membrane potential. Furthermore, Hst improves the protein expression involved in PINK1/Parkin-mediated mitophagy. Our results demonstrate that it restores PA-impaired mitochondrial function and sustains cellular homeostasis due to the elevation of PINK1/Parkin-mediated mitophagy and the subsequent disposal of dysfunctional mitochondria. These results provide therapeutic potential for Hst utilization as an effective intervention against fatty liver disease.

Gut-liver axis: Potential mechanisms of action of food-derived extracellular vesicles

Food-derived extracellular vesicles (FEVs) are nanoscale membrane vesicles obtained from dietary materials such as breast milk, plants and probiotics. Distinct from other EVs, FEVs can survive the harsh degrading conditions in the gastrointestinal tract and reach the intestines. This unique feature allows FEVs to be promising prebiotics in health and oral nanomedicine for gut disorders, such as inflammatory bowel disease. Interestingly, therapeutic effects of FEVs have recently also been observed in non-gastrointestinal diseases. However, the mechanisms remain unclear or even mysterious. It is speculated that orally administered FEVs could enter the bloodstream, reach remote organs, and thus exert therapeutic effects therein. However, emerging evidence suggests that the amount of FEVs reaching organs beyond the gastrointestinal tract is marginal and may be insufficient to account for the significant therapeutic effects achieved regarding diseases involving remote organs such as the liver. Thus, we herein propose that FEVs primarily act locally in the intestine by modulating intestinal microenvironments such as barrier integrity and microbiota, thereby eliciting therapeutic impact remotely on the liver in non-gastrointestinal diseases via the gut-liver axis. Likewise, drugs delivered to the gastrointestinal system through FEVs may act via the gut-liver axis. As the liver is the main metabolic hub, the intestinal microenvironment may be implicated in other metabolic diseases. In fact, many patients with non-alcoholic fatty liver disease, obesity, diabetes and cardiovascular disease suffer from a leaky gut and dysbiosis. In this review, we provide an overview of the recent progress in FEVs and discuss their biomedical applications as therapeutic agents and drug delivery systems, highlighting the pivotal role of the gut-liver axis in the mechanisms of action of FEVs for the treatment of gut disorders and metabolic diseases.

Circulating total and H-specific GDF15 levels are elevated in subjects with MASLD but not in hyperlipidemic but otherwise metabolically healthy subjects with obesity

BACKGROUND

Growth differentiation factor 15 (GDF15) is a mitokine, the role of which, total or H-specific, in modulating energy metabolism and homeostasis in obesity-related diseases, such as metabolic dysfunction associated steatotic liver disease (MASLD), has not been fully elucidated in adult humans. We aimed to investigate the fasting and stimulated levels of GDF15, total and H-specific, glucose-dependent insulinotropic polypeptide (GIP) and C-peptide, in two physiology interventional studies: one focusing on obesity, and the other on MASLD.

METHODS

Study 1 investigated individuals with normal weight or with obesity, undergoing a 3-h mixed meal test (MMT); and study 2, examined adults with MASLD and controls undergoing a 120-min oral glucose tolerance test (OGTT). Exploratory correlations of total and H-specific GDF15 with clinical, hormonal and metabolomic/lipidomic parameters were also performed.

RESULTS

In study 1, 15 individuals were included per weight group. Fasting and postprandial total and H-specific GDF15 were similar between groups, whereas GIP was markedly higher in leaner individuals and was upregulated following a MMT. Baseline and postprandial C-peptide were markedly elevated in people with obesity compared with lean subjects. GIP was higher in leaner individuals and was upregulated after a MMT, while C-peptide and its overall AUC after a MMT was markedly elevated in people with obesity compared with lean subjects. In study 2, 27 individuals were evaluated. Fasting total GDF15 was similar, but postprandial total GDF15 levels were significantly higher in MASLD patients compared to controls. GIP and C-peptide remained unaffected. The postprandial course of GDF15 was clustered among those of triglycerides and molecules of the alanine cycle, was robustly elevated under MASLD, and constituted the most notable differentiating molecule between healthy and MASLD status. We also present robust positive correlations of the incremental area under the curve of total and H-specific GDF15 with a plethora of lipid subspecies, which remained significant after adjusting for confounders.

CONCLUSION

Serum GDF15 levels do not differ in relation to weight status in hyperlipidemic but otherwise metabolically healthy individuals. In contrast, GDF15 levels are significantly increased in MASLD patients at baseline and they remain significantly higher compared to healthy participants during OGTT, pointing to a role for GDF15 as a mitokine with important roles in the pathophysiology and possibly therapeutics of MASLD. Trial registration ClinicalTrials.gov NCT03986684, NCT04430946.

Randomized trial of anakinra plus zinc vs. prednisone for severe alcohol-associated hepatitis

BACKGROUND & AIMS

Severe alcohol-associated hepatitis (SAH) is associated with high 90-day mortality. Glucocorticoid therapy for 28 days improves 30- but not 90-day survival. We assessed the efficacy and safety of a combination of anakinra, an IL-1 antagonist, plus zinc (A+Z) compared to prednisone using the Day-7 Lille score as a stopping rule in patients with SAH.

METHODS

In this phase IIb double-blind randomized trial in adults with SAH and MELD scores of 20-35, participants were randomized to receive either daily anakinra 100 mg subcutaneously for 14 days plus daily zinc sulfate 220 mg orally for 90 days, or daily prednisone 40 mg orally for 30 days. Prednisone or prednisone placebo was stopped if Day-7 Lille score was >0.45. All study drugs were stopped for uncontrolled infection or ≥5 point increase in MELD score. The primary endpoint was overall survival at 90 days.

RESULTS

Seventy-three participants were randomized to prednisone and 74 to A+Z. The trial was stopped early after a prespecified interim analysis showed prednisone was associated with higher 90-day overall survival (90% vs. 70%; hazard ratio for death = 0.34, 95% CI 0.14-0.83, p = 0.018) and transplant-free survival (88% vs. 64%; hazard ratio for transplant or death = 0.30, 95% CI 0.13-0.69, p = 0.004) than A+Z. Acute kidney injury was more frequent with A+Z (45%) than prednisone (22%) (p = 0.001), but rates of infection were similar (31% in A+Z vs. 27% in prednisone, p = 0.389).

CONCLUSIONS

Participants with SAH treated with prednisone using the Day-7 Lille score as a stopping rule had significantly higher overall and transplant-free 90-day survival and lower incidence of acute kidney injury than those treated with A+Z.

IMPACT AND IMPLICATIONS

There is no approved treatment for severe alcohol-associated hepatitis (SAH). In this double-blind randomized trial, patients with SAH treated with prednisone using the Lille stopping rule on Day 7 had higher 90-day overall and transplant-free survival and lower rates of acute kidney injury compared to patients treated with a combination of anakinra and zinc. The data support continued use of glucocorticoids for patients with SAH, with treatment discontinuation for those with a Lille score >0.45 on Day 7.

TRIAL REGISTRATION

NCT04072822.

Inflammation in Alcohol-Associated Hepatitis: Pathogenesis and Therapeutic Targets

Alcohol-associated hepatitis (AH) is an acute-on-chronic liver injury that occurs in patients with chronic alcohol-associated liver disease (ALD). Patients with severe AH have high short-term mortality and lack effective pharmacologic therapies. Inflammation is believed to be one of the key factors promoting AH progression and has been actively investigated as therapeutic targets over the last several decades, but no effective inflammatory targets have been identified so far. In this review, we discuss how inflammatory cells and the inflammatory mediators produced by these cells contribute to the development and progression of AH, with focus on neutrophils and macrophages. The crosstalk between inflammatory cells and liver nonparenchymal cells in the pathogenesis of AH is elaborated. We also deliberate the application of recent cutting-edge technologies in characterizing liver inflammation in AH. Finally, the potential therapeutic targets of inflammatory mediators for AH are briefly summarized.

Implications of Kynurenine Pathway Metabolism for the Immune System, Hypothalamic-Pituitary-Adrenal Axis, and Neurotransmission in Alcohol Use Disorder

In recent years, there has been a marked increase in interest in the role of the kynurenine pathway (KP) in mechanisms associated with addictive behavior. Numerous reports implicate KP metabolism in influencing the immune system, hypothalamic-pituitary-adrenal (HPA) axis, and neurotransmission, which underlie the behavioral patterns characteristic of addiction. An in-depth analysis of the results of these new studies highlights interesting patterns of relationships, and approaching alcohol use disorder (AUD) from a broader neuroendocrine-immune system perspective may be crucial to better understanding this complex phenomenon. In this review, we provide an up-to-date summary of information indicating the relationship between AUD and the KP, both in terms of changes in the activity of this pathway and modulation of this pathway as a possible pharmacological approach for the treatment of AUD.

Mitochondrial dynamics, quality control, and mtDNA in alcohol-associated liver disease and liver cancer

Mitochondria are intracellular organelles responsible for energy production, glucose and lipid metabolism, cell death, cell proliferation, and innate immune response. Mitochondria are highly dynamic organelles that constantly undergo fission, fusion, and intracellular trafficking, as well as degradation and biogenesis. Mitochondrial dysfunction has been implicated in a variety of chronic liver diseases including alcohol-associated liver disease, metabolic dysfunction-associated steatohepatitis, and HCC. In this review, we provide a detailed overview of mitochondrial dynamics, mitophagy, and mitochondrial DNA-mediated innate immune response, and how dysregulation of these mitochondrial processes affects the pathogenesis of alcohol-associated liver disease and HCC. Mitochondrial dynamics and mitochondrial DNA-mediated innate immune response may thereby represent an attractive therapeutic target for ameliorating alcohol-associated liver disease and alcohol-associated HCC.

Innate Immunity and MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as the most common liver disease worldwide in recent years. MASLD commonly presents as simple hepatic steatosis, but ~25% of patients develop liver inflammation, progressive fibrosis, liver cirrhosis and related hepatocellular carcinoma. Liver inflammation and the degree of fibrosis are key determinants of the prognosis. The pathophysiology of liver inflammation is incompletely understood and involves diverse factors and specifically innate and adaptive immune responses. More specifically, diverse mediators of innate immunity such as proinflammatory cytokines, adipokines, inflammasomes and various cell types like mononuclear cells, macrophages and natural killer cells are involved in directing the inflammatory process in MASLD. The activation of innate immunity is driven by various factors including excess lipids and lipotoxicity, insulin resistance and molecular patterns derived from gut commensals. Targeting pathways of innate immunity might therefore appear as an attractive therapeutic strategy in the future management of MASLD and possibly its complications.

Inflammatory liver diseases and susceptibility to sepsis

Patients with inflammatory liver diseases, particularly alcohol-associated liver disease and metabolic dysfunction-associated fatty liver disease (MAFLD), have higher incidence of infections and mortality rate due to sepsis. The current focus in the development of drugs for MAFLD is the resolution of non-alcoholic steatohepatitis and prevention of progression to cirrhosis. In patients with cirrhosis or alcoholic hepatitis, sepsis is a major cause of death. As the metabolic center and a key immune tissue, liver is the guardian, modifier, and target of sepsis. Septic patients with liver dysfunction have the highest mortality rate compared with other organ dysfunctions. In addition to maintaining metabolic homeostasis, the liver produces and secretes hepatokines and acute phase proteins (APPs) essential in tissue protection, immunomodulation, and coagulation. Inflammatory liver diseases cause profound metabolic disorder and impairment of energy metabolism, liver regeneration, and production/secretion of APPs and hepatokines. Herein, the author reviews the roles of (1) disorders in the metabolism of glucose, fatty acids, ketone bodies, and amino acids as well as the clearance of ammonia and lactate in the pathogenesis of inflammatory liver diseases and sepsis; (2) cytokines/chemokines in inflammatory liver diseases and sepsis; (3) APPs and hepatokines in the protection against tissue injury and infections; and (4) major nuclear receptors/signaling pathways underlying the metabolic disorders and tissue injuries as well as the major drug targets for inflammatory liver diseases and sepsis. Approaches that focus on the liver dysfunction and regeneration will not only treat inflammatory liver diseases but also prevent the development of severe infections and sepsis.

The Role of Cytokines in the Pathogenesis and Treatment of Alcoholic Liver Disease

Alcoholic liver disease (ALD) is a major cause of chronic liver disease. This term covers a broad spectrum of liver lesions, from simple steatosis to alcoholic hepatitis and cirrhosis. The pathogenesis of ALD is multifactorial and not fully elucidated due to complex mechanisms related to direct ethanol toxicity with subsequent hepatic and systemic inflammation. The accumulation of pro-inflammatory cytokines and the reduction of anti-inflammatory cytokines promote the development and progression of ALD. To date, there are no targeted therapies to counter the progression of chronic alcohol-related liver disease and prevent acute liver failure. Corticosteroids reduce mortality by acting on the hepatic-systemic inflammation. On the other hand, several studies analyzed the effect of inhibiting pro-inflammatory cytokines and stimulating anti-inflammatory cytokines as potential therapeutic targets in ALD. This narrative review aims to clarify the role of the main cytokines involved in the pathogenesis and treatment of ALD.

Dual-Stimuli-Responsive Gut Microbiota-Targeting Nitidine Chloride-CS/PT-NPs Improved Metabolic Status in NAFLD

Background and Purpose

Nitidine chloride (NC) is a botanical drug renowned for its potent anti-inflammatory, antimalarial, and hepatocellular carcinoma-inhibiting properties; however, its limited solubility poses challenges to its development and application. To address this issue, we have devised a colon-targeted delivery system (NC-CS/PT-NPs) aimed at modulating the dysbiosis of the gut microbiota by augmenting the interaction between NC and the intestinal microbiota, thereby exerting an effect against nonalcoholic fatty liver disease.

Methods

The NC-CS/PT-NPs were synthesized using the ion gel method. Subsequently, the particle size distribution, morphology, drug loading efficiency, and release behavior of the NC-CS/PT-NPs were characterized. Furthermore, the impact of NC-CS/PT-NPs on non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet (HFD) in mice was investigated through serum biochemical analysis, ELISA, and histochemical staining. Additionally, the influence of NC-CS/PT-NPs on intestinal microbiota was analyzed using 16S rDNA gene sequencing.

Results

The nanoparticles prepared in this study have an average particle size of (255.9±5.10) nm, with an encapsulation rate of (72.83±2.13) % and a drug loading of (4.65±0.44) %. In vitro release experiments demonstrated that the cumulative release rate in the stomach and small intestine was lower than 22.0%, while it reached 66.75% in the colon. In vivo experiments conducted on HFD-induced NAFLD mice showed that treatment with NC-CS/PT-NPs inhibited weight gain, decreased serum aspartate aminotransferase (AST), Alanine aminotransferase (ALT) and lipid levels, improved liver and intestinal inflammation, and altered the diversity of gut microbiota in mice.

Conclusion

This study provides new evidence for the treatment of NAFLD through the regulation of gut microbiota using active ingredients from traditional Chinese medicine.

Bacillus coagulans regulates gut microbiota and ameliorates the alcoholic-associated liver disease in mice

Introduction

Alcoholic-associated liver diseases (ALD) are now widespread issues worldwide. Alcoholic-induced chronic dysbiosis of the gut microbiota is one of the factors in the pathophysiology of ALD.

Methods

In this work, we employed a chronic-binge ethanol feeding mice model, as described in a previous report.

Results

Our findings demonstrate that hepatic inflammatory injury damage and accumulation of fat can be effectively reduced in mice with ALD by altering the gut microbiota utilizing Bacillus coagulans. Treatment with B. coagulans significantly modulates the levels of TNF-α, IL-1β, and IL-22 cytokines while maintaining tight junction proteins and mucin protein expressions to support intestinal barrier function restoration. Treatment with B. coagulans also alters the composition of the gut microbiota and increases the production of short-chain fatty acids (SCFAs).

Discussion

This is mostly due to B. coagulans promotes the growth of bacteria that produce SCFAs, such as Ruminococcus species and Akkermansia, while inhibiting the growth of pathogenic bacteria like Escherichia Shigella. Moreover, treatment with B. coagulans causes levels of 2-Ketobutyric acid, ketoleucine, and indoleacetic acid increase while homovanillic acid and 3'-O-Methylguanosine metabolites decrease significantly. This study facilitates the development of therapeutic and preventive strategies for ALD using lactic acid bacteria.

Optimization of Microwave-Assisted Extraction Process of Total Flavonoids from Salicornia bigelovii Torr. and Its Hepatoprotective Effect on Alcoholic Liver Injury Mice

The objective of this study was to determine the optimal extraction conditions for total flavonoids from S. bigelovii using microwave-assisted extraction and to analyze the protective effect of total flavonoids from S. bigelovii on alcoholic liver injury in mice. The optimization of the process conditions for the microwave-assisted extraction of total flavonoids from S. bigelovii was performed using response surface methodology, and an alcohol-induced acute liver injury model in mice was used to investigate the effects of different doses of total flavonoids (100 mg/kg, 200 mg/kg, and 400 mg/kg) on the levels and activities of serum alanine aminotransferase kits (ALT), glutamic oxaloacetic transaminase kits (AST), superoxide dismutase kits (SOD), glutathione peroxidase kits (GSH-Px), and malondialdehyde (MDA). We performed hematoxylin-eosin (H&E) staining analysis on pathological sections of mouse liver tissue, and qRT-PCR technology was used to detect the expression levels of the inflammatory factors IL-1 β, IL-6, and TNF-α. The results revealed that the optimal extraction process conditions for total flavonoids in S. bigelovii were a material-to-liquid ratio of 1:30 (g/mL), an ethanol concentration of 60%, an extraction temperature of 50 °C, an ultrasound power of 250 W, and a yield of 5.71 ± 0.28 mg/g. Previous studies have demonstrated that the flavonoids of S. bigelovii can significantly inhibit the levels of ALT and AST in the serum (p < 0.001), reduce MDA levels (p < 0.001), increase the activity of the antioxidant enzymes SOD and GSH-Px (p < 0.001), and inhibit the IL-1 β, IL-6, and TNF-α gene expression levels (p < 0.001) of inflammatory factors. The total flavonoids of S. bigelovii exert a protective effect against alcoholic liver injury by reducing the levels of inflammation, oxidative stress, and lipid peroxidation caused by alcohol. The results of this study lay the foundation for the high-value utilization of S. bigelovii and provide new resources for the development of liver-protective drugs.

Endotoxin Inflammatory Action on Cells by Dysregulated-Immunological-Barrier-Linked ROS-Apoptosis Mechanisms in Gut-Liver Axis

Our study highlighted the immune changes by pro-inflammatory biomarkers in the gut-liver-axis-linked ROS-cell death mechanisms in chronic and acute inflammations when gut cells are exposed to endotoxins in patients with hepatic cirrhosis or steatosis. In duodenal tissue samples, gut immune barrier dysfunction was analyzed by pro-inflammatory biomarker expressions, oxidative stress, and cell death by flow cytometry methods. A significant innate and adaptative immune system reaction was observed as result of persistent endotoxin action in gut cells in chronic inflammation tissue samples recovered from hepatic cirrhosis with the A-B child stage. Instead, in patients with C child stage of HC, the endotoxin tolerance was installed in cells, characterized by T lymphocyte silent activation and increased Th1 cytokines expression. Interesting mechanisms of ROS-cell death were observed in chronic and acute inflammation samples when gut cells were exposed to endotoxins and immune changes in the gut-liver axis. Late apoptosis represents the chronic response to injury induction by the gut immune barrier dysfunction, oxidative stress, and liver-dysregulated barrier. Meanwhile, necrosis represents an acute and severe reply to endotoxin action on gut cells when the immune system reacts to pro-inflammatory Th1 and Th2 cytokines releasing, offering protection against PAMPs/DAMPs by monocytes and T lymphocyte activation. Flow cytometric analysis of pro-inflammatory biomarkers linked to oxidative stress-cell death mechanisms shown in our study recommends laboratory techniques in diagnostic fields.

Mouse Type-I Interferon-Mannosylated Albumin Fusion Protein for the Treatment of Chronic Hepatitis

Although a lot of effort has been put into creating drugs and combination therapies against chronic hepatitis, no effective treatment has been established. Type-I interferon is a promising therapeutic for chronic hepatitis due to its excellent anti-inflammatory effects through interferon receptors on hepatic macrophages. To develop a type-I IFN equipped with the ability to target hepatic macrophages through the macrophage mannose receptor, the present study designed a mouse type-I interferon-mannosylated albumin fusion protein using site-specific mutagenesis and albumin fusion technology. This fusion protein exhibited the induction of anti-inflammatory molecules, such as IL-10, IL-1Ra, and PD-1, in RAW264.7 cells, or hepatoprotective effects on carbon tetrachloride-induced chronic hepatitis mice. As expected, such biological and hepatoprotective actions were significantly superior to those of human fusion proteins. Furthermore, the repeated administration of mouse fusion protein to carbon tetrachloride-induced chronic hepatitis mice clearly suppressed the area of liver fibrosis and hepatic hydroxyproline contents, not only with a reduction in the levels of inflammatory cytokine (TNF-α) and fibrosis-related genes (TGF-β, Fibronectin, Snail, and Collagen 1α2), but also with a shift in the hepatic macrophage phenotype from inflammatory to anti-inflammatory. Therefore, type-I interferon-mannosylated albumin fusion protein has the potential as a new therapeutic agent for chronic hepatitis.

What are the common downstream molecular events between alcoholic and nonalcoholic fatty liver?

Liver fat storage, also called hepatic steatosis, is increasingly common and represents a very frequent diagnosis in the medical field. Excess fat is not without consequences. In fact, hepatic steatosis contributes to the progression toward liver fibrosis. There are two main types of fatty liver disease, alcoholic fatty liver disease (AFLD) and nonalcoholic fatty liver disease (NAFLD). Although AFLD and NAFLD are similar in their initial morphological features, both conditions involve the same evolutive forms. Moreover, there are various common mechanisms underlying both diseases, including alcoholic liver disease and NAFLD, which are commonalities. In this Review, the authors explore similar downstream signaling events involved in the onset and progression of the two entities but not completely different entities, predominantly focusing on the gut microbiome. Downstream molecular events, such as the roles of sirtuins, cytokeratins, adipokines and others, should be considered. Finally, to complete the feature, some new tendencies in the therapeutic approach are presented.

GRP/GRPR enhances alcohol-associated liver injury through the IRF1-mediated Caspase-1 inflammasome and NOX2-dependent ROS pathway

BACKGROUND AND AIMS

The common characteristics of alcohol-associated liver injury (ALI) include abnormal liver function, infiltration of inflammatory cells, and generation of oxidative stress. The gastrin-releasing peptide receptor (GRPR) is activated by its neuropeptide ligand, gastrin-releasing peptide (GRP). GRP/GRPR appears to induce the production of cytokines in immune cells and promotes neutrophil migration. However, the effects of GRP/GRPR in ALI are unknown.

APPROACH AND RESULTS

We found high GRPR expression in the liver of patients with alcohol-associated steatohepatitis and increased pro-GRP levels in peripheral blood mononuclear cells of these patients compared with that of the control. Increased expression of GRP may be associated with histone H3 lysine 27 acetylation induced by alcohol, which promotes the expression of GRP and then GRPR binding. Grpr-/- and Grprflox/floxLysMCre mice alleviated ethanol-induced liver injury with relieved steatosis, lower serum alanine aminotransferase, aspartate aminotransferase, triglycerides, malondialdehyde, and superoxide dismutase levels, reduced neutrophil influx, and decreased expression and release of inflammatory cytokines and chemokines. Conversely, the overexpression of GRPR showed opposite effects. The pro-inflammatory and oxidative stress roles of GRPR might be dependent on IRF1-mediated Caspase-1 inflammasome and NOX2-dependent reactive oxygen species pathway, respectively. In addition, we verified the therapeutic and preventive effects of RH-1402, a novel GRPR antagonist, for ALI.

CONCLUSIONS

A knockout or antagonist of GRPR during excess alcohol intake could have anti-inflammatory and antioxidative roles, as well as provide a platform for histone modification-based therapy for ALI.

Improving survival in alcohol-related hepatitis: what's new?

Alcohol-related hepatitis (AH) is the most florid presentation of alcohol-related liver disease and carries a high short-term and long-term mortality rate. Specific treatment options remain inadequate. The current management approach for AH focuses on early identification, careful screening and treatment of infection, as well as identification of those patients who may benefit from corticosteroid therapy based on validated prognostic scoring systems. In recent years, there has been growing interest in exploring novel therapies for AH, which may offer alternative treatment options beyond the traditional approaches. Additionally, early liver transplantation (LT) has emerged as a promising option in selected cases with growing evidence supporting its role. In this review, we will discuss the current evidence base for the assessment and treatment of AH, and how these advances are shaping practice to improve outcomes in the UK.

Obesity-associated Airway Hyperresponsiveness: Mechanisms Underlying Inflammatory Markers and Possible Pharmacological Interventions

Obesity is rapidly becoming a global health problem affecting about 13% of the world's population affecting women and children the most. Recent studies have stated that obese asthmatic subjects suffer from an increased risk of asthma, encounter severe symptoms, respond poorly to anti-asthmatic drugs, and ultimately their quality-of-life decreases. Although, the association between airway hyperresponsiveness (AHR) and obesity is a growing concern among the public due to lifestyle and environmental etiologies, however, the precise mechanism underlying this association is yet to establish. Apart from aiming at the conventional antiasthmatic targets, treatment should be directed towards ameliorating obesity pathogenesis too. Understanding the pathogenesis underlying the association between obesity and AHR is limited, however, a plethora of obesity pathologies have been reported viz., increased pro-inflammatory and decreased anti-inflammatory adipokines, depletion of ROS controller Nrf2/HO-1 axis, NLRP3 associated macrophage polarization, hypertrophy of WAT, and down-regulation of UCP1 in BAT following down-regulated AMPKα and melanocortin pathway that may be correlated with AHR. Increased waist circumference (WC) or central obesity was thought to be related to severe AHR, however, some recent reports suggest body mass index (BMI), not WC tends to exaggerate airway closure in AHR due to some unknown mechanisms. This review aims to co-relate the above-mentioned mechanisms that may explain the copious relation underlying obesity and AHR with the help of published reports. A proper understanding of these mechanisms discussed in this review will ensure an appropriate treatment plan for patients through advanced pharmacological interventions.

Atherosclerotic plaque development in mice is enhanced by myeloid ZEB1 downregulation

Accumulation of lipid-laden macrophages within the arterial neointima is a critical step in atherosclerotic plaque formation. Here, we show that reduced levels of the cellular plasticity factor ZEB1 in macrophages increase atherosclerotic plaque formation and the chance of cardiovascular events. Compared to control counterparts (Zeb1WT/ApoeKO), male mice with Zeb1 ablation in their myeloid cells (Zeb1∆M/ApoeKO) have larger atherosclerotic plaques and higher lipid accumulation in their macrophages due to delayed lipid traffic and deficient cholesterol efflux. Zeb1∆M/ApoeKO mice display more pronounced systemic metabolic alterations than Zeb1WT/ApoeKO mice, with higher serum levels of low-density lipoproteins and inflammatory cytokines and larger ectopic fat deposits. Higher lipid accumulation in Zeb1∆M macrophages is reverted by the exogenous expression of Zeb1 through macrophage-targeted nanoparticles. In vivo administration of these nanoparticles reduces atherosclerotic plaque formation in Zeb1∆M/ApoeKO mice. Finally, low ZEB1 expression in human endarterectomies is associated with plaque rupture and cardiovascular events. These results set ZEB1 in macrophages as a potential target in the treatment of atherosclerosis.

An update: is there a relationship between H. pylori infection and nonalcoholic fatty liver disease? why is this subject of interest?

Helicobacter pylori (H. pylori) infection is thought to impact various extragastric diseases, including nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease. Meanwhile, the pathogenesis of NAFLD needs further research, and effective treatment for this disease remains elusive. In this mini-review, we enumerate and ponder on the evidence demonstrating an association between H. pylori infection and NAFLD. Primarily, we delve into high-quality meta-analyses and clinical randomized controlled trials focusing on the association studies between the two. We also discuss clinical studies that present opposite conclusions. In addition, we propose a mechanism through which H. pylori infection aggravates NAFLD: inflammatory cytokines and adipocytokines, insulin resistance, lipid metabolism, intestinal barrier and microbiota, H. pylori outer membrane vesicles and H. pylori-infected cell-extracellular vesicles. This mini-review aims to further explore NAFLD pathogenesis and extragastric disease mechanisms caused by H. pylori infection.

Astragaloside IV ameliorate acute alcohol-induced liver injury in mice via modulating gut microbiota and regulating NLRP3/caspase-1 signaling pathway

PURPOSE

Astragaloside IV (AS-IV) is a natural saponin substance extracted from the plant Radix Astragali with anti-inflammatory, antioxidant, anti-apoptotic, and liver-protecting effects. This study was to evaluate the liver protection effect of AS-IV on mice after acute alcohol stimulation.

MATERIALS AND METHODS

Mice were orally administrated with AS-IV (50, 150, and 500 mg/kg, respectively), and sodium carboxymethyl cellulose (CMC, 50 mg/kg) daily for 7 days, before giving five alcohol-intragastric injections.

RESULTS

Results suggested that the levels of serum ALT and AST, liver SOD, GSH-PX, 4-HNE, and MDA, serum and liver TNF-α, IL-1β, and IL-6, serum lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP), diamine oxidase (DAO) and Myeloperoxidase (MPO), the mRNA and protein expression of hepatic NLRP3, Caspase-1, IL-1β, and IL-18 were significantly decreased in AS-IV-treated mice compared with the model group. Moreover, the effect of AS-IV on histopathology of liver tissue confirmed its protective function. Furthermore, AS-IV ameliorated the gut microbiota imbalance and adjusted the abundance of the following dysfunctional bacteria closer to the control group: Butyricicoccus, Turicibacter, Akkermansia, Anaerotruncus, and Mucispirillum. A strong correlation between intestinal bacteria and potential biomarkers was found.

CONCLUSION

Together, our findings indicated that AS-IV exert the hepatoprotective effect by modulating the gut microbiota imbalance and regulating NLRP3/Caspase-1 signaling pathway.

Gut microbiota in obesity and related complications: Unveiling the complex interplay

In recent years, the obesity epidemic has escalated into a serious public health catastrophe that is only getting worse. However, research into the pathophysiological pathways behind the obesity development and the illnesses that it is associated with is ongoing. In the last decades, it is now clear that the gut microbiota plays a significant role in the genesis and progression of obesity and obesity-related illnesses, particularly changes in its metabolites and composition as obesity progresses. Here, we provide a summary of the processes by which variations in gut metabolite levels and the composition of gut microbiota affect obesity and associated disorders. The bacteria residing in the gut release several chemicals that influence the appetite control, metabolism, and other systems. Since it can either encourage or restrict the deposition of fat in several different ways, the gut microbiota's role in obesity is debatable. Additionally, we go over potential therapeutic approaches that could be utilized to alter gut microbiota composition and focus on the important metabolic pathways associated with obesity and metabolic disorders linked to obesity.

Probiotic Pediococcus pentosaceus Li05 Improves Cholestasis through the FXR-SHP and FXR-FGF15 Pathways

Primary sclerosing cholangitis (PSC), a rare chronic cholestatic liver disease, is characterized by intrahepatic or extrahepatic strictures accompanied by biliary fibrosis. So far, there are no effective therapies to slow down the progression of this disease. Farnesoid X receptors (FXRs) are ligand-activated transcription factors involved in the control of bile acid (BA) synthesis and enterohepatic circulation. Therefore, targeting FXRs holds promise as a potential approach for treating PSC. Pediococcus pentosaceus Li05 is a probiotic that was isolated from healthy volunteers and has previously been shown to have an anti-inflammatory effect in DSS-induced colitis. In this study, we established a 3,5-diethoxycarbonyl-1,4-Dihydrocollidine (DDC)-induced cholestasis mouse model and investigated the effects of Pediococcus pentosaceus Li05 on PSC. Our findings revealed that administration of Li05 significantly attenuated liver damage, hepatic inflammation, and fibrosis, as well as bile duct hyperplasia. Li05 activated the hepatic FXR-SHP and ileal FXR-FGF15 signaling pathways to decrease the expression of Cyp7a1. In addition, the Li05-modulated gut microbiota structure especially improved the abundance of 7α-dehydroxylation bacteria like Eubacterium. The intervention of Li05 also improved the intestinal barrier and reduced bacterial endotoxin translocation. Based on these findings, Li05 shows promise for future application as a therapeutic strategy for cholestasis.

Advances in the understanding and management of alcohol-related liver disease

Alcohol-related liver disease (ALD) is a major cause of liver-related morbidity and mortality. Epidemiological trends indicate recent and predicted increases in the burden of disease. Disease progression is driven by continued alcohol exposure on a background of genetic predisposition together with environmental cofactors. Most individuals present with advanced disease despite a long history of excessive alcohol consumption and multiple missed opportunities to intervene. Increasing evidence supports the use of non-invasive tests to screen for and identify disease at earlier stages. There is a definite role for public health measures to reduce the overall burden of disease. At an individual level, however, the ability to influence subsequent disease course by modifying alcohol consumption or the underlying pathogenic mechanisms remains limited due to a comparative lack of effective, disease-modifying medical interventions. Abstinence from alcohol is the key determinant of outcome in established ALD and the cornerstone of clinical management. In those with decompensated ALD, liver transplant has a clear role. There is consensus that abstinence from alcohol for an arbitrary period should not be the sole determinant in a decision to transplant. An increasing understanding of the mechanisms by which alcohol causes liver disease in susceptible individuals offers the prospect of new therapeutic targets for disease-modifying drugs. Successful translation will require significant public and private investment in a disease area which has traditionally been underfunded when compared to its overall prevalence.

Therapeutic modulation of the liver immune microenvironment

Inflammation is a hallmark of progressive liver diseases such as chronic viral or immune-mediated hepatitis, alcohol-associated liver disease, and NAFLD. Preclinical and clinical studies have provided robust evidence that cytokines and related cellular stress sensors in innate and adaptive immunity orchestrate hepatic disease processes. Unresolved inflammation and liver injury result in hepatic scarring, fibrosis, and cirrhosis, which may culminate in HCC. Liver diseases are accompanied by gut dysbiosis and a bloom of pathobionts, fueling hepatic inflammation. Anti-inflammatory strategies are extensively used to treat human immune-mediated conditions beyond the liver, while evidence for immunomodulatory therapies and cell therapy-based strategies in liver diseases is only emerging. The development and establishment of novel immunomodulatory therapies for chronic liver diseases has been dampened by several clinical challenges, such as invasive monitoring of therapeutic efficacy with liver biopsy in clinical trials and risk of DILI in several studies. Such aspects prevented advancements of novel medical therapies for chronic inflammatory liver diseases. New concepts modulating the liver immune environment are studied and eagerly awaited to improve the management of chronic liver diseases in the future.

24-Norursodeoxycholic acid ameliorates experimental alcohol-related liver disease and activates hepatic PPARγ

Background & Aims

Alcohol-related liver disease (ALD) is a global healthcare challenge with limited treatment options. 24-Norursodeoxycholic acid (NorUDCA) is a synthetic bile acid with anti-inflammatory properties in experimental and human cholestatic liver diseases. In the present study, we explored the efficacy of norUDCA in experimental ALD.

Methods

NorUDCA was tested in a preventive and therapeutic setting in an experimental ALD model (Lieber-DeCarli diet enriched with ethanol). Liver disease was phenotypically evaluated using histology and biochemical methods, and anti-inflammatory properties and peroxisome proliferator-activated receptor gamma activation by norUDCA were evaluated in cellular model systems.

Results

NorUDCA administration ameliorated ethanol-induced liver injury, reduced hepatocyte death, and reduced the expression of hepatic pro-inflammatory cytokines including tumour necrosis factor (Tnf), Il-1β, Il-6, and Il-10. NorUDCA shifted hepatic macrophages towards an anti-inflammatory M2 phenotype. Further, norUDCA administration altered the composition of the intestinal microbiota, specifically increasing the abundance of Roseburia, Enterobacteriaceae, and Clostridum spp. In a therapeutic model, norUDCA also ameliorated ethanol-induced liver injury. Moreover, norUDCA suppressed lipopolysaccharide-induced IL-6 expression in human peripheral blood mononuclear cells and evoked peroxisome proliferator-activated receptor gamma activation.

Conclusions

NorUDCA ameliorated experimental ALD, protected against hepatic inflammation, and affected gut microbial commensalism. NorUDCA could serve as a novel therapeutic agent in the future management of patients with ALD.

Impact and implications

Alcohol-related liver disease is a global healthcare concern with limited treatment options. 24-Norursodeoxycholic acid (NorUDCA) is a modified bile acid, which was proven to be effective in human cholestatic liver diseases. In the present study, we found a protective effect of norUDCA in experimental alcoholic liver disease. For patients with ALD, norUDCA could be a potential new treatment option.

Heat stress exposure cause alterations in intestinal microbiota, transcriptome, and metabolome of broilers

Introduction

Heat stress can affect the production of poultry through complex interactions between genes, metabolites and microorganisms. At present, it is unclear how heat stress affects genetic, metabolic and microbial changes in poultry, as well as the complex interactions between them.

Methods

Thus, at 28  days of age a total of 200 Arbor Acres broilers with similar body weights were randomly divided into the control (CON) and heat stress treatment (HS). There were 5 replicates in CON and HS, respectively, 20 per replication. From the 28-42  days, the HS was kept at 31 ± 1°C (9:00-17:00, 8 h) and other time was maintained at 21 ± 1°C as in the CON. At the 42nd day experiment, we calculated the growth performance (n = 8) of broilers and collected 3 and 6 cecal tissues for transcriptomic and metabolomic investigation and 4 cecal contents for metagenomic investigation of each treatment.

Results and discussion

The results indicate that heat stress significantly reduced the average daily gain and body weight of broilers (value of p < 0.05). Transcriptome KEGG enrichment showed that the differential genes were mainly enriched in the NF-kB signaling pathway. Metabolomics results showed that KEGG enrichment showed that the differential metabolites were mainly enriched in the mTOR signaling pathway. 16S rDNA amplicon sequencing results indicated that heat stress increased the relative abundance of Proteobacteria decreased the relative abundance of Firmicutes. Multi-omics analysis showed that the co-participating pathway of differential genes, metabolites and microorganisms KEGG enrichment was purine metabolism. Pearson correlation analysis found that ornithine was positively correlated with SULT1C3, GSTT1L and g_Lactobacillus, and negatively correlated with CALB1. PE was negatively correlated with CALB1 and CHAC1, and positively with g_Alistipes. In conclusion, heat stress can generate large amounts of reactive oxygen and increase the types of harmful bacteria, reduce intestinal nutrient absorption and antioxidant capacity, and thereby damage intestinal health and immune function, and reduce growth performance indicators. This biological process is manifested in the complex regulation, providing a foundational theoretical basis for solving the problem of heat stress.

Swertia bimaculata moderated liver damage in mice by regulating intestine microbiota

Swertia bimaculata (SB) is a medicinal herb in China having an array of therapeutic and biological properties. This study aimed to explore the attenuating effect of SB on carbon tetrachloride (CCl4) induced hepato-toxicity by regulation of gut microbiome in ICR mice. For this purpose, CCl4 was injected intraperitoneally in different mice groups (B, C, D and E) every 4th day for a period of 47 days. Additionally, C, D, and E groups received a daily dose (50 mg/kg, 100 mg/kg, and 200 mg/kg respectively) of Ether extract of SB via gavage for the whole study period. The results of serum biochemistry analysis, ELISA, H&E staining, and sequencing of the gut microbiome, indicated that SB significantly alleviates the CCl4-induced liver damage and hepatocyte degeneration. The serum levels of alanine transaminase, aspartate aminotransferase, malondialdehyde, interleukin 1 beta and tumor necrosis factor-alpha were significantly lower in SB treated groups compared to control while levels of glutathione peroxidase were raised. Also, the sequencing data indicate that supplementation with SB could restore the microbiome and its function in CCl4-induced variations in intestinal microbiome of mice by significantly downregulating the abundances of pathogenic intestinal bacteria species including Bacteroides, Enterococcus, Eubacterium, Bifidobacterium while upregulating the levels of beneficial bacteria like Christensenella in the gut. In conclusion, we revealed that SB depicts a beneficial effect against hepatotoxicity induced by CCl4 in mice through the remission of hepatic inflammation and injury, through regulation of oxidative stress, and by restoring gut microbiota dysbiosis.