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Abstract Background Chronic hepatitis B virus (HBV) infection remains a serious health issue, and determining the optimal time for antiviral therapy is challenging. We aimed to assess liver histological changes in patients with HBeAg-positive chronic hepatitis B (CHB) and those with HBeAg-negative CHB who had persistently normal alanine aminotransferase and to determine the association between significant liver injury and various clinical parameters. Methods We retrospectively included, in this study, 339 treatment-naïve patients with chronic HBV infections who had persistently normal alanine aminotransferase and underwent liver biopsy from 2013 to 2023. Histologic assessment was based on the Metavir scoring system to evaluate the association between clinical characteristics and the severity of liver inflammation and fibrosis. Results Among the included participants, 138 were HBeAg-positive and 201 were HBeAg-negative. Lower hepatitis B surface antigen (HBsAg) (P = 0.003) and higher aspartate aminotransferase (AST) (P = 0.002) levels were associated with significant necroinflammation, whereas increasing age (P = 0.004) and lower HBV DNA (P

Background: Hepatic macrophages play an indispensable role in liver pathophysiology, serving as key orchestrators of both liver injury and repair processes. ATG16L1 (autophagy‐related 16 like 1) has emerged as a novel and critical autophagy marker. In macrophages, ATG16L1 assumes a particularly crucial role. The current understanding of how macrophage ATG16L1 regulates liver inflammation in the context of liver fibrosis is unclear. Methods: This study included clinical patient samples of liver fibrosis and established a murine model with myeloid‐specific Atg16l1 knockout, creating a mouse model of liver fibrosis. Employing RNA sequencing, we sought to elucidate the mechanisms of macrophage ATG16L1 in liver fibrosis by identifying critical signaling pathways. To assess the influence of macrophage ATG16L1 on hepatocyte apoptosis and hepatic stellate cell (HSC) activation, we constructed a dedicated culture system. Ultimately, the introduction of mice with myeloid‐specific Atg16l1 knock‐in substantiated the protective role of myeloid‐specific Atg16l1 against inflammatory signaling, hepatocyte apoptosis, and activation of HSCs. Results: An upregulation of the ATG16L1 signal was observed in the liver tissues of patients with liver fibrosis and in fibrotic mice, predominantly localized to hepatic macrophages. In Atg16l1ΔMφ mice afflicted with liver fibrosis, we detected exacerbated liver damage, evidenced by heightened inflammatory signal expression, increased hepatocyte apoptosis, and enhanced activation of HSCs. The absence of macrophage Atg16l1 was found to result in elevated TNF receptor‐associated factor 1 (TRAF1) signaling, triggering inflammatory activation, intensifying hepatocyte apoptosis, and facilitating HSC activation through the transforming growth factor beta 1 (TGF‐β1) signaling. The detrimental effects of macrophage Atg16l1 depletion were demonstrated to be mitigated upon Atg16l1 reintroduction. Conclusions: This research delved into the mechanisms by which the macrophage ATG16L1 signal influences inflammatory signaling, hepatocyte apoptosis, and activation of HSCs in liver fibrosis. Consequently, it offers theoretical substantiation and an experimental groundwork for the identification of biological targets for therapeutic intervention in liver fibrosis. [ABSTRACT FROM AUTHOR]

Gaudichaudione H (GH) is a natural small molecular compound isolated from Garcinia oligantha Merr. (Clusiaceae). Being an uncommon rare caged polyprenylated xanthone, the potential pharmacological functions of GH remain to be fully elucidated currently. In this study, we primarily focused on identifying potential bioavailable targets and elucidating related therapeutic actions. Herein, the network pharmacology analysis, metabolomics analysis and genome-wide mRNA transcription assay were performed firstly to predict the major pharmacological action and potential targets of GH. To confirm the hypothesis, gene knockout model was created using CRISPR/Cas9 method. The pharmacological action of GH was evaluated in vitro and in vivo. Firstly, our results of network pharmacology analysis and omics assay indicated that GH significantly activated NRF2 signaling pathway, and the function could be associated with liver disease treatment. Then, the pharmacological action of GH was evaluated in vitro and in vivo. The treatment with GH significantly increased the protein levels of NRF2 and promoted the transcription of NRF2 downstream genes. Further analysis suggested that GH regulated NRF2 through an autophagy-mediated non-canonical mechanism. Additionally, the administration of GH effectively protected the liver from carbon tetrachloride (CCl 4)-induced liver fibrosis and inflammation, which depended on the activation of NRF2 in hepatic stellate cells and inflammatory cells respectively. Collectively, our findings underscore the potential therapeutic effect of GH on alleviating hepatic fibrosis and inflammation through the augmentation of NRF2 signaling pathway, providing a promising avenue for the treatment of liver fibrosis and inflammation in clinical settings. [Display omitted] • GH is identified as a functional NRF2 activator in vitro and in vivo. • GH enhances NRF2 signaling via autophagy-mediated non-canonical pathway. • GH alleviates hepatic fibrosis and inflammation in a NRF2-depedent manner. [ABSTRACT FROM AUTHOR]

ABSTRACT Aims Methods Results Conclusions Since its discovery, the patatin‐like phospholipase domain containing 3 (PNPLA3) (rs738409 C>G p.I148M) variant has been studied extensively to unravel its molecular function. Although several studies proved a causal relationship between the PNPLA3 I148M variant and MASLD development and particularly fibrosis, the pathological mechanisms promoting this phenotype have not yet been fully clarified.We summarise the latest data regarding the PNPLA3 I148M variant in hepatic stellate cells (HSCs) activation and macrophage biology or the path to inflammation‐induced fibrosis.Elegant but contradictory studies have ascribed PNPLA3 a hydrolase or an acyltransferase function. The PNPLA3 I148M results in hepatic lipid accumulation, which predisposes the hepatocyte to lipotoxicity and lipo‐apoptosis, producing DAMPs, cytokines and chemokines leading to recruitment and activation of macrophages and HSCs, propagating fibrosis. Recent studies showed that the PNPLA3 I148M variant alters HSCs biology via attenuation of PPARγ, AP‐1, LXRα and TGFβ activity and signalling.The advent of refined techniques in isolating HSCs has made PNPLA3's direct role in HSCs for liver fibrosis development more apparent. However, many other mechanisms still need detailed investigations. [ABSTRACT FROM AUTHOR]

Background: Chronic hepatitis B virus (HBV) infection remains a serious health issue, and determining the optimal time for antiviral therapy is challenging. We aimed to assess liver histological changes in patients with HBeAg-positive chronic hepatitis B (CHB) and those with HBeAg-negative CHB who had persistently normal alanine aminotransferase and to determine the association between significant liver injury and various clinical parameters. Methods: We retrospectively included, in this study, 339 treatment-naïve patients with chronic HBV infections who had persistently normal alanine aminotransferase and underwent liver biopsy from 2013 to 2023. Histologic assessment was based on the Metavir scoring system to evaluate the association between clinical characteristics and the severity of liver inflammation and fibrosis. Results: Among the included participants, 138 were HBeAg-positive and 201 were HBeAg-negative. Lower hepatitis B surface antigen (HBsAg) (P = 0.003) and higher aspartate aminotransferase (AST) (P = 0.002) levels were associated with significant necroinflammation, whereas increasing age (P = 0.004) and lower HBV DNA (P < 0.001) levels were associated with significant fibrosis in HBeAg-positive patients with normal ALT levels. Higher HBV-DNA (P = 0.001) and AST levels(P < 0.001) were associated with significant necroinflammation, and higher AST(P < 0.001) levels were associated with significant fibrosis in HBeAg-negative patients. Conclusions: A substantial proportion of patients with HBV infection who had normal ALT presented significant liver injury. HBsAg and AST were independent predictive factors for evaluating inflammation, while HBV DNA load and age were independent predictive factors for evaluating fibrosis in the HBeAg-positive group. HBV DNA load and AST were independent predictive factors for evaluating inflammation, while AST were independent predictive factors for evaluating fibrosis in the HBeAg-negative group. [ABSTRACT FROM AUTHOR]

Magnetic resonance elastography (MRE) is recognized as the most precise imaging technology for assessing liver fibrosis in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD). We aimed to investigate the clinical factors and pathological characteristics that may impact LSM in MASLD patients. This cross-sectional study recruited 124 patients who concurrently performed MRE, MRI-PDFF, and biopsy-proven MASLD. Linear regression models, Spearman's correlation, and subgroup analysis were employed to identify the variables affecting LSM. The AUROC (95 % CI) of MRE for diagnosing fibrosis stage ≥ 1, 2, 3, and 4 was 0.80 (0.70–0.90), 0.76 (0.66–0.85), 0.92 (0.86–0.99), and 0.99 (0.99–1.00), with corresponding cutoffs of 2.56, 2.88, 3.35, and 4.76 kPa, respectively. Multivariate analyses revealed that AST was the only independent clinical variable significantly correlated with LSM. Furthermore, LSM exhibited a notable association with the grade of lobular inflammation and hepatocellular ballooning. Subgroup analysis showed that when AST ≥ 2 ULN or inflammation grade ≥ 2, LSM of patients with early fibrosis stages showed a slight but significant increase. MRE demonstrates significant diagnostic accuracy in predicting liver fibrosis stages for MASLD patients, especially for advanced liver fibrosis and cirrhosis. However, elevated AST and the severity of liver inflammation may impact its accuracy in staging early liver fibrosis. [ABSTRACT FROM AUTHOR]

Liver diseases have a global prevalence of 25%, accounting for 4% of all deaths worldwide, and are associated with a 36% increased risk of fatal and nonfatal cardiovascular events. Metabolic dysfunction-associated steatotic liver disease constitutes the liver expression of metabolic syndrome and represents the primary type of liver disease. Microscopical analysis of biopsies, which allows the evaluation of a small portion of tissue with inferences made to the entire organ, is considered the gold standard for determining the presence of liver diseases. However, potential sampling errors in liver biopsies are conceivable because the obtained tissue represents only a tiny fraction of the entire liver mass and may not accurately reflect the true pathological state. Studies have demonstrated the existence of sampling errors in liver biopsies, particularly concerning the severity of inflammation, degree of fibrosis, and the presence of cirrhosis. Also, clinical studies have shown that histopathological abnormalities are better detected in humans when liver samples are collected from both the right and the left lobes. However, a gap exists in clinical investigation to clarify the role of differences between these lobes in improving the diagnostic and prognostic for liver diseases. Building upon the heterogeneous nature of pathological alterations observed in liver lobes, this perspective review provided recommendations to enhance the precision of diagnosis and prognostic accuracy of liver diseases. [ABSTRACT FROM AUTHOR]

Abstract The chemokine (CCL)-chemokine receptor (CCR2) interaction, importantly CCL2-CCR2, involved in the intrahepatic recruitment of monocytes upon liver injury promotes liver fibrosis. CCL2-CCR2 antagonism using Cenicriviroc (CVC) showed promising results in several preclinical studies. Unfortunately, CVC failed in phase III clinical trials due to lack of efficacy to treat liver fibrosis. Lack of efficacy could be attributed to the fact that macrophages are also involved in disease resolution by secreting matrix metalloproteinases (MMPs) to degrade extracellular matrix (ECM), thereby inhibiting hepatic stellate cells (HSCs) activation. HSCs are the key pathogenic cell types in liver fibrosis that secrete excessive amounts of ECM causing liver stiffening and liver dysfunction. Knowing the detrimental role of intrahepatic monocyte recruitment, ECM, and HSCs activation during liver injury, we hypothesize that combining CVC and MMP (MMP1) could reverse liver fibrosis. We evaluated the effects of CVC, MMP1 and CVC + MMP1 in vitro and in vivo in CCl4-induced liver injury mouse model. We observed that CVC + MMP1 inhibited macrophage migration, and TGF-β induced collagen-I expression in fibroblasts in vitro. In vivo, MMP1 + CVC significantly inhibited normalized liver weights, and improved liver function without any adverse effects. Moreover, MMP1 + CVC inhibited monocyte infiltration and liver inflammation as confirmed by F4/80 and CD11b staining, and TNFα gene expression. MMP1 + CVC also ameliorated liver fibrogenesis via inhibiting HSCs activation as assessed by collagen-I staining and collagen-I and α-SMA mRNA expression. In conclusion, we demonstrated that a combination therapeutic approach by combining CVC and MMP1 to inhibit intrahepatic monocyte recruitment and increasing collagen degradation respectively ameliorate liver inflammation and fibrosis.

The chemokine (CCL)-chemokine receptor (CCR2) interaction, importantly CCL2-CCR2, involved in the intrahepatic recruitment of monocytes upon liver injury promotes liver fibrosis. CCL2-CCR2 antagonism using Cenicriviroc (CVC) showed promising results in several preclinical studies. Unfortunately, CVC failed in phase III clinical trials due to lack of efficacy to treat liver fibrosis. Lack of efficacy could be attributed to the fact that macrophages are also involved in disease resolution by secreting matrix metalloproteinases (MMPs) to degrade extracellular matrix (ECM), thereby inhibiting hepatic stellate cells (HSCs) activation. HSCs are the key pathogenic cell types in liver fibrosis that secrete excessive amounts of ECM causing liver stiffening and liver dysfunction. Knowing the detrimental role of intrahepatic monocyte recruitment, ECM, and HSCs activation during liver injury, we hypothesize that combining CVC and MMP (MMP1) could reverse liver fibrosis. We evaluated the effects of CVC, MMP1 and CVC + MMP1 in vitro and in vivo in CCl4-induced liver injury mouse model. We observed that CVC + MMP1 inhibited macrophage migration, and TGF-β induced collagen-I expression in fibroblasts in vitro. In vivo, MMP1 + CVC significantly inhibited normalized liver weights, and improved liver function without any adverse effects. Moreover, MMP1 + CVC inhibited monocyte infiltration and liver inflammation as confirmed by F4/80 and CD11b staining, and TNFα gene expression. MMP1 + CVC also ameliorated liver fibrogenesis via inhibiting HSCs activation as assessed by collagen-I staining and collagen-I and α-SMA mRNA expression. In conclusion, we demonstrated that a combination therapeutic approach by combining CVC and MMP1 to inhibit intrahepatic monocyte recruitment and increasing collagen degradation respectively ameliorate liver inflammation and fibrosis. [ABSTRACT FROM AUTHOR]

Background: The relationship between liver fibrosis and inflammation and Mac-2-binding protein glycosylation isomer (M2BPGi) in patients with chronic liver disease (CLD) other than hepatitis C remains uncertain, owing to the limitations of qualitative methods. Here, we evaluated the influence of liver fibrosis and inflammation on quantitative M2BPGi (M2BPGi-Qt) in CLD, considering each etiology. Methods: We recruited 1373 patients with CLD. To evaluate the influence of liver fibrosis and inflammation on M2BPGi-Qt levels, we assessed M2BPGi-Qt levels at each fibrosis and activity stage within different etiologies of CLD based on pathological findings. Subsequently, we evaluated if the accuracy of fibrosis staging based on M2BPGi-Qt could be improved by considering the influence of liver inflammation. Results: In patients with viral hepatitis, non-alcoholic fatty liver disease, and primary biliary cholangitis, the median M2BPGi-Qt levels increased liver fibrosis progression. Median M2BPGi-Qt levels were not associated with the degree of fibrosis in patients with autoimmune hepatitis (AIH). Median M2BPGi-Qt levels increased with the progression of liver activity in all etiologies. A significant difference was found at each stage in AIH. Considering the liver inflammation, we established an algorithm, M2BPGi-Qt, to determine the alanine aminotransferase-to-platelet ratio (MAP-R) in liver cirrhosis (LC). The area under the receiver operating characteristic curve (AUC) of MAP-R was higher than that of the M2BPGi-Qt for detecting LC (AUC MAP-R = 0.759 and M2BPGi-Qt = 0.700, p < 0.001). Conclusions: The quantitative measurement system for M2BPGi depends on liver fibrosis and inflammation, regardless of etiology. Liver inflammation complicates the interpretation of M2BPGi-Qt results when assessing the fibrosis stage. [ABSTRACT FROM AUTHOR]

Background: Water T1 of the liver has been shown to be promising in discriminating the progressive forms of fatty liver diseases, inflammation, and fibrosis, yet proper correction for iron and lipid is required. Purpose: To examine the feasibility of an empirical approach for iron and lipid correction when measuring imaging‐based T1 and to validate this approach by spectroscopy on in vivo data. Study Type: Retrospective. Population: Next to mixed lipid‐iron phantoms, individuals with different hepatic lipid content were investigated, including people with type 1 diabetes (N = 15, %female = 15.6, age = 43.5 ± 14.0), or type 2 diabetes mellitus (N = 21, %female = 28.9, age = 59.8 ± 9.7) and healthy volunteers (N = 9, %female = 11.1, age = 58.0 ± 8.1). Field Strength/Sequences: 3 T, balanced steady‐state free precession MOdified Look‐Locker Inversion recovery (MOLLI), multi‐ and dual‐echo gradient echo Dixon, gradient echo magnetic resonance elastography (MRE). Assessment: T1 values were measured in phantoms to determine the respective correction factors. The correction was tested in vivo and validated by proton magnetic resonance spectroscopy (1H‐MRS). The quantification of liver T1 based on automatic segmentation was compared to the T1 values based on manual segmentation. The association of T1 with MRE‐derived liver stiffness was evaluated. Statistical Tests: Bland–Altman plots and intraclass correlation coefficients (ICCs) were used for MOLLI vs. 1H‐MRS agreement and to compare liver T1 values from automatic vs. manual segmentation. Pearson's r correlation coefficients for T1 with hepatic lipids and liver stiffness were determined. A P‐value of 0.05 was considered statistically significant. Results: MOLLI T1 values after correction were found in better agreement with the 1H‐MRS‐derived water T1 (ICC = 0.60 [0.37; 0.76]) in comparison with the uncorrected T1 values (ICC = 0.18 [−0.09; 0.44]). Automatic quantification yielded similar liver T1 values (ICC = 0.9995 [0.9991; 0.9997]) as with manual segmentation. A significant correlation of T1 with liver stiffness (r = 0.43 [0.11; 0.67]) was found. A marked and significant reduction in the correlation strength of T1 with liver stiffness (r = 0.05 [−0.28; 0.38], P = 0.77) was found after correction for hepatic lipid content. Data Conclusion: Imaging‐based correction factors enable accurate estimation of water T1 in vivo. Level of Evidence: 1 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]

The aim of this study is to review and analyze the pleiotropic effects of TGF-β in physiological and pathological conditions of the liver, with particular emphasis on its role in immune suppression, wound healing, regulation of cell growth and differentiation, and liver cell apoptosis. A literature review was conducted, including 52 studies, comprising review articles, in vitro and in vivo studies, and meta-analyses. Only studies published in peer-reviewed scientific journals were included in the analysis. TGF-β is a pleiotropic growth factor that is crucial for the liver, both in physiology and pathophysiology. Although its functions are complex and diverse, TGF-β plays a constant role in immune suppression, wound healing, and the regulation of cell growth and differentiation. In concentrations exceeding the norm, it can induce the apoptosis of liver cells. Increased TGF-β levels are observed in many liver diseases, such as fibrosis, inflammation, and steatosis. TGF-β has been shown to play a key role in many physiological and pathological processes of the liver, and its concentration may be a potential diagnostic and prognostic marker in liver diseases. [ABSTRACT FROM AUTHOR]

Biliary atresia (BA) is characterized by a progressive fibroinflammatory cholangiopathy in early infants with unknown etiology. Although innate immune disorder is involved in its mechanism, role of NLRP3 inflammasome in BA remains largely undefined. To explore the role of NLRP3 inflammasome in BA. The expressions of NLRP3 inflammasome-related genes were determined in BA patients. Role of NLRP3 inflammasome was evaluated using MCC950 in experimental BA. Furthermore, gadolinium chloride, a macrophage scavenger, was applied to validate the inflammasome's cellular localization. Finally, the effects of NLRP3 inflammasome activation on liver fibrosis were explored in vivo and vitro in experimental BA. The components of NLRP3 inflammasome were up-regulated in BA patients. Inflammasome-related genes showed positively correlated with liver inflammation and fibrosis in BA patients. In experimental BA, inflammasome-related genes were up-regulated, and their expressions were inhibited by MCC950, which promoted mice growth, protected liver function, alleviated obstructive jaundice, inhibited liver inflammation, and reduced serum IL-1β level. NLRP3 inflammasome was expressed in macrophages, and macrophage elimination exerted the same protective roles as MCC950 did in BA. Additionally, NLRP3 inflammasome activation promoted liver fibrosis in experimental BA. NLRP3 inflammasome activation in macrophages promoted liver inflammation and fibrosis in experimental BA. [ABSTRACT FROM AUTHOR]

BackgroundObesity, non-alcoholic fatty liver disease (NAFLD) and its more advanced form non-alcoholic steatohepatitis (NASH) are important causes of morbidity and mortality worldwide. Bile acid dysregulation is a pivotal part in their pathogenesis. The aim of this study was to evaluate the bile acid sequestrant colesevelam in a microbiome-humanized mouse model of diet-induced obesity and steatohepatitis.MethodsGerm-free C57BL/6 mice were associated with stool from patients with NASH and subjected to 20 weeks of Western diet feeding with and without colesevelam.ResultsColesevelam reduced Western diet-induced body and liver weight gain in microbiome-humanized mice compared with controls. It ameliorated Western diet-induced hepatic inflammation, steatosis, fibrosis and insulin resistance. Colesevelam increased de novo bile acid synthesis and decreased hepatic cholesterol content in microbiome-humanized mice fed a Western diet. It further induced the gene expression of the antimicrobials Reg3g and Reg3b in the distal small intestine and decreased plasma levels of LPS.ConclusionsColesevelam ameliorates Western diet-induced steatohepatitis and obesity in microbiome-humanized mice.

Liver damage caused by various factors results in fibrosis and inflammation, leading to cirrhosis and cancer. Fibrosis results in the accumulation of extracellular matrix components. The role of STAT proteins in mediating liver inflammation and fibrosis has been well documented; however, approved therapies targeting STAT3 inhibition against liver disease are lacking. This study investigated the anti-fibrotic and anti-inflammatory effects of STAT3 decoy oligodeoxynucleotides (ODN) in hepatocytes and liver fibrosis mouse models. STAT3 decoy ODN were delivered into cells using liposomes and hydrodynamic tail vein injection into 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-fed mice in which liver injury was induced. STAT3 target gene expression changes were verified using qPCR and Western blotting. Liver tissue fibrosis and bile duct proliferation were assessed in animal experiments using staining techniques, and macrophage and inflammatory cytokine distribution was verified using immunohistochemistry. STAT3 decoy ODN reduced fibrosis and inflammatory factors in liver cancer cell lines and DDC-induced liver injury mouse model. These results suggest that STAT3 decoy ODN may effectively treat liver fibrosis and must be clinically investigated. [ABSTRACT FROM AUTHOR]

Background: Nonalcoholic fatty liver disease (NAFLD) is increasing worldwide and is a growing cause of liver cirrhosis and cancer. The performance of the magnetic resonance elastography (MRE) visco‐elastic parameters in diagnosing progressive forms of NAFLD, including nonalcoholic steatohepatitis (NASH) and substantial fibrosis (F ≥ 2), needs to be clarified. Purpose: To assess the value of three‐dimensional MRE visco‐elastic parameters as markers of NASH and substantial fibrosis in mice with NAFLD. Study Type: Prospective. Animal Model: Two mouse models of NAFLD were induced by feeding with high fat diet or high fat, choline‐deficient, amino acid‐defined diet. Field Strength/Sequence: 7T/multi‐slice multi‐echo spin‐echo MRE at 400 Hz with motion encoding in the three spatial directions. Assessment: Hepatic storage and loss moduli were calculated. Histological analysis was based on the NASH Clinical Research Network criteria. Statistical Tests: Mann–Whitney, Kruskal–Wallis tests, Spearman rank correlations and multiple regressions were used. Diagnostic performance was assessed with areas under the receiver operating characteristic curves (AUCs). P value <0.05 was considered significant. Results: Among the 59 mice with NAFLD, 21 had NASH and 20 had substantial fibrosis (including 8 mice without and 12 mice with NASH). The storage and loss moduli had similar moderate accuracy for diagnosing NASH with AUCs of 0.67 and 0.66, respectively. For diagnosing substantial fibrosis, the AUC of the storage modulus was 0.73 and the AUC of the loss modulus was 0.81, indicating good diagnostic performance. Using Spearman correlations, histological fibrosis, inflammation and steatosis, but not ballooning, were significantly correlated with the visco‐elastic parameters. Using multiple regression, fibrosis was the only histological feature independently associated with the visco‐elastic parameters. Conclusion: MRE in mice with NAFLD suggests that the storage and loss moduli have good diagnostic performance for detecting progressive NAFLD defined as substantial fibrosis rather than NASH. Evidence Level: 1 Technical Efficacy Stage: 2 [ABSTRACT FROM AUTHOR]

Summary: The process of dead cell clearance by phagocytic cells, called efferocytosis, prevents inflammatory cell necrosis and promotes resolution and repair. Defective efferocytosis contributes to the progression of numerous diseases in which cell death is prominent, including liver disease. Many gaps remain in our understanding of how hepatic macrophages carry out efferocytosis and how this process goes awry in various types of liver diseases. Thus far, studies have suggested that, upon liver injury, liver-resident Kupffer cells and infiltrating monocyte-derived macrophages clear dead cells, limit inflammation, and, through macrophage reprogramming, repair liver damage. However, in unusual settings, efferocytosis can promote liver disease. In this review, we will focus on efferocytosis in various types of acute and chronic liver diseases, including metabolic dysfunction-associated steatohepatitis. Understanding the mechanisms and consequences of efferocytosis by hepatic macrophages has the potential to shed new light on liver disease pathophysiology and to guide new treatment strategies to prevent disease progression.

The vitamin D receptor (VDR) is a nuclear transcription factor that acts as the main transducer in response to vitamin D (VD), regulating about 3% of the gene expression in the human genome. This study investigated the expression of VDR in the liver of patients with chronic hepatitis B virus (HBV) infection and determined its correlation with liver inflammation and fibrosis. We evaluated the effects of HBV infection on the expression of VDR in vivo and in vitro and further investigate the potential mechanism. Subsequently, the associations between hepatic VDR expression with liver inflammation and fibrosis were statistically analyzed. Results showed that hepatic VDR expression was significantly decreased in patients with chronic HBV infection as compared to healthy individuals. Similarly, in vitro experiments further confirmed that HBV infection could inhibit the expression of VDR in hepatocytes. Mechanistically, HBV was able to directly induce the expression of miR-125a which inhibited the mRNA and protein levels of VDR. Statistical analysis showed that hepatic VDR expression was significantly negatively correlated with liver inflammation and fibrosis in patients. We conclude that inhibition of hepatic vitamin D receptor expression by HBV/miR-125a is negatively associated with liver inflammation and fibrosis in patients with chronic HBV infection. [ABSTRACT FROM AUTHOR]

Chronic liver diseases can lead to fibrotic changes that may progress to the development of cirrhosis, which poses a significant risk for morbidity and increased mortality rates. Metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol-associated liver disease (ALD), and viral hepatitis are prevalent liver diseases that may lead to cirrhosis. The advanced stages of cirrhosis can be further complicated by cancer development or end-stage liver disease and liver failure. Hence, early detection and diagnosis of liver fibrosis is crucial for preventing the progression to cirrhosis and improving patient outcomes. Traditionally, invasive liver biopsy has been considered the gold standard for diagnosing and staging liver fibrosis. In the last decade, research has focused on non-invasive methods, known as liquid biopsies, which involve the identification of disease-specific biomarkers in human fluids, such as blood. Among these alternative approaches, extracellular vesicles (EVs) have emerged as promising diagnostic and therapeutic tools for various diseases, including chronic liver diseases. EVs are released from stressed or damaged cells and can be isolated and quantified. Moreover, EVs facilitate cell-to-cell communication by transporting various cargo, and they have shown the potential to reduce the expression of profibrogenic markers, making them appealing tools for novel anti-fibrotic treatments. This review focuses on the impact of EVs in chronic liver diseases and exploring their potential applications in innovative therapeutic and diagnostic approaches. [ABSTRACT FROM AUTHOR]

Liver fibrosis is a disease largely driven by resident and recruited macrophages. The phenotypic switch of hepatic macrophages can be achieved by chemo-attractants and cytokines. During a screening of plants traditionally used to treat liver diseases in China, paeoniflorin was identified as a potential drug that affects the polarization of macrophages. The aim of this study was to evaluate the therapeutic effects of paeoniflorin in an animal model of liver fibrosis and explore its underlying mechanisms. Liver fibrosis was induced in Wistar rats via an intraperitoneal injection of CCl4. In addition, the RAW264.7 macrophages were cultured in the presence of CoCl2 to simulate a hypoxic microenvironment of fibrotic livers in vitro. The modeled rats were treated daily with either paeoniflorin (100, 150, and 200 mg/kg) or YC-1 (2 mg/kg) for 8 weeks. Hepatic function, inflammation and fibrosis, activation of hepatic stellate cells (HSC), and extracellular matrix (ECM) deposition were assessed in the in vivo and in vitro models. The expression levels of M1 and M2 macrophage markers and the NF- κ B/HIF-1 α pathway factors were measured using standard assays. Paeoniflorin significantly alleviated hepatic inflammation and fibrosis, as well as hepatocyte necrosis in the CCl4-induced fibrosis model. Furthermore, paeoniflorin also inhibited HSC activation and reduced ECM deposition both in vivo and in vitro. Mechanistically, paeoniflorin restrained M1 macrophage polarization and induced M2 polarization in the fibrotic liver tissues as well as in the RAW264.7 cells grown under hypoxic conditions by inactivating the NF- κ B/HIF-1 α signaling pathway. In conclusion, paeoniflorin exerts its anti-inflammatory and anti-fibrotic effects in the liver by coordinating macrophage polarization through the NF- κ B/HIF-1 α pathway. [ABSTRACT FROM AUTHOR]

The aim of this study is to review and analyze the pleiotropic effects of TGF-β in physiological and pathological conditions of the liver, with particular emphasis on its role in immune suppression, wound healing, regulation of cell growth and differentiation, and liver cell apoptosis. A literature review was conducted, including 52 studies, comprising review articles, in vitro and in vivo studies, and meta-analyses. Only studies published in peer-reviewed scientific journals were included in the analysis. TGF-β is a pleiotropic growth factor that is crucial for the liver, both in physiology and pathophysiology. Although its functions are complex and diverse, TGF-β plays a constant role in immune suppression, wound healing, and the regulation of cell growth and differentiation. In concentrations exceeding the norm, it can induce the apoptosis of liver cells. Increased TGF-β levels are observed in many liver diseases, such as fibrosis, inflammation, and steatosis. TGF-β has been shown to play a key role in many physiological and pathological processes of the liver, and its concentration may be a potential diagnostic and prognostic marker in liver diseases.

Over 240 million people worldwide are chronically infected with Hepatitis B Virus (HBV), a hepatotropic DNA virus with an evolutionary root of over 400 million years. Persistent HBV infection exhibits distinct and diverse phases of disease, from minimal liver pathology to fulminant Hepatitis, that vary in duration and severity among individuals. Although huge progress has been made in HBV research which has yielded an effective prophylactic vaccine and potent antiviral therapy, our understanding of its virology and immunobiology is still far from complete. For example, the recent re-discovery of serum HBV RNA in chronic Hepatitis B (CHB) patients has led to the proposal of noncanonical viral particles such as RNA virion and capsid-derived immune complex (Capsid-Antibody-Complexes, CACs) that contradict long-established basic theory. Furthermore, the existence of capsid-derived immune complex may hint at novel mechanism of HBV-induced liver disease. Here, we summarize the past and recent literature on HBV-induced immune complex. We propose that the release of capsid-derived particles by HBV has its deep evolutionary origin, and the associated complement activation serves as an indispensable trigger for intrahepatic damage and a catalyst for further cell-mediated immunopathology. [ABSTRACT FROM AUTHOR]

The placenta contains multiple biologically active substances, which exert antioxidation, anti-inflammatory, immunomodulatory, and delayed aging effects. Its extract can improve hepatic morphology and function: on the one hand, it can reduce liver interstitial collagen deposition, lipogenesis, and inflammatory cell infiltration and improve fibrosis; on the other hand, it can prevent hepatocellular degeneration by scavenging reactive oxygen species (ROS) and inhibiting inflammatory cytokine production, further improve hepatocyte apoptosis and necrosis, and promote hepatocyte regeneration, making it a promising liver-protective agent. Current research on placenta extract (PE) mainly focuses on treating a specific type of liver injury, and there are no systematic reports. Therefore, this review comprehensively summarizes the treatment reports of PE on liver injury and analyzes its mechanism of action. [ABSTRACT FROM AUTHOR]

Background and aims: Effective hepatic blood flow (EHBF) decreases with liver disease progression, and identifying liver pathology is critical for patients with liver disease. This study was designed to elucidate the correlation between EHBF and liver pathology and explore the potential of EHBF for predicting the degree of liver pathology. Methods: In this study, 207 patients with hepatitis B virus (HBV) who underwent liver biopsy and indocyanine green (ICG) clearance tests were enrolled. EHBF was measured using the ICG clearance test, and liver tissue was histologically analyzed to determine the pathological stage according to the Scheuer scoring system. Demographic data, biochemical indexes, and FibroScan data were collected for statistical analysis. Results: EHBF levels decreased as the liver histological stages of inflammation and fibrosis increased (P

Chronic liver diseases can lead to fibrotic changes that may progress to the development of cirrhosis, which poses a significant risk for morbidity and increased mortality rates. Metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol-associated liver disease (ALD), and viral hepatitis are prevalent liver diseases that may lead to cirrhosis. The advanced stages of cirrhosis can be further complicated by cancer development or end-stage liver disease and liver failure. Hence, early detection and diagnosis of liver fibrosis is crucial for preventing the progression to cirrhosis and improving patient outcomes. Traditionally, invasive liver biopsy has been considered the gold standard for diagnosing and staging liver fibrosis. In the last decade, research has focused on non-invasive methods, known as liquid biopsies, which involve the identification of disease-specific biomarkers in human fluids, such as blood. Among these alternative approaches, extracellular vesicles (EVs) have emerged as promising diagnostic and therapeutic tools for various diseases, including chronic liver diseases. EVs are released from stressed or damaged cells and can be isolated and quantified. Moreover, EVs facilitate cell-to-cell communication by transporting various cargo, and they have shown the potential to reduce the expression of profibrogenic markers, making them appealing tools for novel anti-fibrotic treatments. This review focuses on the impact of EVs in chronic liver diseases and exploring their potential applications in innovative therapeutic and diagnostic approaches.

Mucosal-associated invariant T cells or MAIT cells are an abundant cell type in humans and especially so in the liver. MAIT cells are a subset of T lymphocytes that sit at a bridge between innate and adaptive immunity, so-called innate-like or "unconventional" T cells. The specificity of their antigen receptor (T cell receptor or TCR) is for the conserved major histocompatibility complex (MHC)-related molecule MR1, which presents a modified bacterial metabolite from the vitamin B2 biosynthesis pathway – this allows them to respond in the presence of many bacteria or yeast. MAIT cells also possess an array of cytokine receptors, which allows triggering independently of the TCR. The combination of such signals drives their functionality – this means they can respond to a range of stimuli and likely play a role not only in infection or inflammation, but also under homeostatic conditions. In this review, we will look at the question of what MAIT cells are doing in the normal liver and how they behave in the setting of disease. These questions are of relevance because MAIT cells are such a distinctive cell type enriched in the liver under normal conditions, and their modulation could be of therapeutic benefit. The recent discovery that they appear to be involved in liver fibrosis is particularly of interest in this context. [ABSTRACT FROM AUTHOR]

Liver fibrosis is the most significant prognostic factor in chronic liver disease (CLD). Clinical practice guidelines recommend the use of non-invasive techniques, such as two-dimensional shear-wave elastography (2D-SWE), to assess liver stiffness as a marker of fibrosis. Several other factors influence liver stiffness in addition to liver fibrosis. It is presumed that changes due to necro-inflammation modify the propagation of shear waves (dispersion). Therefore, new imaging techniques that investigate the dispersion properties of shear waves have been developed, which can serve as an indirect method of measuring liver viscosity (Vi PLUS). Defining the reference values in healthy subjects among different age groups and genders and analyzing the factors that influence these values is essential. However, published data on liver viscosity are still limited. This is the first study that aimed to assess the normal range of liver viscosity values in subjects with healthy livers and analyze the factors that influence them. One hundred and thirty-one consecutive subjects with healthy livers were enrolled in this prospective study. The results showed that Vi PLUS is a highly feasible method. Liver stiffness, age and BMI influenced the liver viscosity values. The mean liver viscosity by Vi PLUS in subjects with healthy livers was 1.59 Pa·s. [ABSTRACT FROM AUTHOR]

Background & aimsLiver fibrosis is the most worrisome feature of non-alcoholic steatohepatitis (NASH). Growing evidence supports a link between hepatocyte apoptosis and liver fibrogenesis. Our aim was to determine the therapeutic efficacy and safety of liver Bid, a key pro-apoptotic molecule, suppression using RNA interference (RNAi) for the treatment of fibrosis.MethodsFirst, we optimized the delivery system for Bid siRNA in mice using ten different stealth RNAi siRNAs and two lipid formulations -Invivofectamine2.0 and a newly developed Invivofectamine3.0 - that have been designed for high efficacy accumulation in the liver, assessed via real-time PCR of Bid mRNA. Next, C57BL/6 mice were placed on a choline-deficient L-amino acid defined (CDAA) diet. After 19weeks of the CDAA diet, a time point that results in severe fibrotic NASH, mice were injected with the selected Bid siRNA-Invivofectamine3.0 biweekly for three weeks. Additionally hepatocyte-specific Bid deficient (Bid(Δhep)) mice were placed on CDAA diet for 20weeks.ResultsA maximum Bid knockdown was achieved at 1.5mg/kg siRNA with Invivofectamine3.0, whereas it was at 7mg/kg with Invivofectamine2.0. In NASH mice, after 3weeks of treatment, BID protein was reduced to 10% and this was associated with an improvement in liver fibrosis and inflammation associated with a marked reduction in TUNEL positive cells, caspase 3 activation, and a reduction in mitochondrial BAX and BAK. Bid(Δhep) mice showed similar protection from fibrotic changes.ConclusionOur data demonstrate that liver Bid suppression by RNAi technology, as well as hepatocyte-specific Bid deficiency, improves liver fibrosis coupled with a reduction of inflammation in experimental NASH. These findings are consistent with existing evidence that hepatocyte apoptosis triggers hepatic stellate cell activation and liver fibrosis and suggest that Bid inhibition may be useful as an antifibrotic NASH therapy.

Chronic liver injury results in immune-driven progressive fibrosis, with risk of cirrhosis development and impact on morbidity and mortality. Persistent liver cell damage and death causes immune cell activation and inflammation. Patients with advanced cirrhosis additionally experience pathological bacterial translocation, exposure to microbial products and chronic engagement of the immune system. Bacterial infections have a high incidence in cirrhosis, with spontaneous bacterial peritonitis being the most common, while the subsequent systemic inflammation, organ failure and immune dysregulation increase the mortality risk. Tissue-resident and recruited macrophages play a central part in the development of inflammation and fibrosis progression. In the liver, adipose tissue, peritoneum and intestines, diverse macrophage populations exhibit great phenotypic and functional plasticity determined by their ontogeny, epigenetic programming and local microenvironment. These changes can, at different times, promote or ameliorate disease states and therefore represent potential targets for macrophage-directed therapies. In this review, we discuss the evidence for macrophage phenotypic and functional alterations in tissue compartments during the development and progression of chronic liver failure in different aetiologies and highlight the potential of macrophage modulation as a therapeutic strategy for liver disease.

Background: Recent studies have suggested that several types of toxic bile acids (BAs) are involved in the pathogenesis of non-alcoholic steatohepatitis (NASH). In the present study, we aimed to determine whether elobixibat, an ileal bile acid transporter (IBAT) inhibitor, would ameliorate NASH in mice. Methods: C57BL/6N mice were fed a methionine and choline-deficient (MCD) to induce NASH or standard diet as control for 8 weeks (n = 5 per group). The MCD diet-fed mice were administered elobixibat 5 days a week for 4 weeks by gavage (n = 5). The effects of the treatments on liver histopathology, proinflammatory cytokine concentrations, intestinal epithelial tight junctions, and the intestinal microbial composition were then assessed. Results: In MCD-fed mice, hepatic fibrosis and inflammatory cell infiltration developed, and the serum aspartate transaminase activity and BA concentration were higher than the control. In addition, the proinflammatory cytokine concentrations were high in the liver and mesenteric lymph nodes (MLN), and the expression of intestinal epithelium tight junction proteins, claudin1, was increased. In the intestinal microbial composition, the abundance of the Lachnospiraceae and Ruminococcaeae were decreased, whereas that of the Enterobacteriaceae was increased. Treatment with elobixibat reduced the serum BA and increased the fecal BA concentration, and ameliorated the liver inflammation and fibrosis. It also reduced the expression of proinflammatory cytokines in the liver and MLNs, and transforming growth factor-β expression in the liver. Finally, elobixibat normalized intestinal tight junction protein level and the composition of the intestinal microbiota. Conclusion: Elobixibat ameliorates NASH-related histopathology, reduces cytokine expression, and normalizes the intestinal microbial composition in MCD-fed mice, which suggests that it may represent a promising candidate for the therapy of NASH. [ABSTRACT FROM AUTHOR]

Chronic liver injury results in immune-driven progressive fibrosis, with risk of cirrhosis development and impact on morbidity and mortality. Persistent liver cell damage and death causes immune cell activation and inflammation. Patients with advanced cirrhosis additionally experience pathological bacterial translocation, exposure to microbial products and chronic engagement of the immune system. Bacterial infections have a high incidence in cirrhosis, with spontaneous bacterial peritonitis being the most common, while the subsequent systemic inflammation, organ failure and immune dysregulation increase the mortality risk. Tissue-resident and recruited macrophages play a central part in the development of inflammation and fibrosis progression. In the liver, adipose tissue, peritoneum and intestines, diverse macrophage populations exhibit great phenotypic and functional plasticity determined by their ontogeny, epigenetic programming and local microenvironment. These changes can, at different times, promote or ameliorate disease states and therefore represent potential targets for macrophage-directed therapies. In this review, we discuss the evidence for macrophage phenotypic and functional alterations in tissue compartments during the development and progression of chronic liver failure in different aetiologies and highlight the potential of macrophage modulation as a therapeutic strategy for liver disease. [ABSTRACT FROM AUTHOR]

Foxp3+ regulatory T (Treg) cells are pivotal in maintaining immunological self-tolerance and tissue homeostasis; however, it remains unclear how tissue Treg cells respond to liver injury and regulate chronic inflammation, which can cause liver fibrosis. We report here that hepatic Treg cells play a critical role in preventing liver pathology by suppressing inflammatory cellular immunity that can promote liver damage and fibrosis. Chronic liver inflammation induced by injections of carbon tetrachloride (CCl4) led to preferential expansion of hepatic Treg cells that prevented liver fibrosis. In contrast, depletion of Treg cells in the CCl4-induced liver fibrosis model exacerbated the severity of liver pathology. Treg depletion unleashed tissue cellular immunity and drove the activation and expansion of the pro-fibrotic IL-4-producing T helper 2 cells, as well as CCR2high Ly-6Chigh inflammatory monocytes/macrophages in the inflamed liver. Although Treg expression of amphiregulin plays a key role in tissue remodeling and repair in various inflammation models, amphiregulin from hepatic Treg cells, the largest producer among liver immune cells, was dispensable for maintaining liver homeostasis and preventing liver fibrosis during CCl4-induced chronic inflammation. Our results indicate that Treg cells control chronic liver inflammation and fibrosis by regulating the aberrant activation and functions of immune effector cells. Harnessing Treg functions, which effectively regulate tissue cellular immunity, may be a therapeutic strategy for preventing and treating liver fibrosis.

Foxp3+ regulatory T (Treg) cells are pivotal in maintaining immunological self-tolerance and tissue homeostasis; however, it remains unclear how tissue Treg cells respond to liver injury and regulate chronic inflammation, which can cause liver fibrosis. We report here that hepatic Treg cells play a critical role in preventing liver pathology by suppressing inflammatory cellular immunity that can promote liver damage and fibrosis. Chronic liver inflammation induced by injections of carbon tetrachloride (CCl4) led to preferential expansion of hepatic Treg cells that prevented liver fibrosis. In contrast, depletion of Treg cells in the CCl4-induced liver fibrosis model exacerbated the severity of liver pathology. Treg depletion unleashed tissue cellular immunity and drove the activation and expansion of the pro-fibrotic IL-4-producing T helper 2 cells, as well as CCR2high Ly-6Chigh inflammatory monocytes/macrophages in the inflamed liver. Although Treg expression of amphiregulin plays a key role in tissue remodeling and repair in various inflammation models, amphiregulin from hepatic Treg cells, the largest producer among liver immune cells, was dispensable for maintaining liver homeostasis and preventing liver fibrosis during CCl4-induced chronic inflammation. Our results indicate that Treg cells control chronic liver inflammation and fibrosis by regulating the aberrant activation and functions of immune effector cells. Harnessing Treg functions, which effectively regulate tissue cellular immunity, may be a therapeutic strategy for preventing and treating liver fibrosis. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. This study aimed to evaluate the performance of four ultrasound-based techniques for the non-invasive multiparametric (MPUS) assessment of liver fibrosis (LF), steatosis (HS), and inflammation in patients with NAFLD. We included 215 consecutive adult patients with NAFLD (mean age: 54.9 ± 11.7; 54.5% were male), in whom LF, HS, and viscosity were evaluated in the same session using four new ultrasound-based techniques embedded on the Aixplorer MACH 30 system: ShearWave Elastography (2D-SWE.PLUS), Sound Speed Plane-wave UltraSound (SSp.PLUS), Attenuation Plane-wave UltraSound (Att.PLUS), and Viscosity Plane-wave UltraSound (Vi.PLUS). Transient Elastography (TE) with Controlled Attenuation Parameter (CAP) (FibroScan) were considered as control. All elastographic measurements were performed according to guidelines. Valid liver stiffness measurements (LSM) were obtained in 98.6% of patients by TE, in 95.8% of patients by 2D-SWE.PLUS/Vi.PLUS, and in 98.1% of patients by Att.PLUS/SSp.PLUS, respectively. Therefore, 204 subjects were included in the final analysis. A strong correlation between LSMs by 2D-SWE.PLUS and TE (r = 0.89) was found. The best 2D-SWE.PLUS cut-off value for the presence of significant fibrosis (F ≥ 2) was 7 kPa. Regarding steatosis, SSp.PLUS correlated better than Att.PLUS with CAP values: (r = −0.74) vs. (r = 0.45). The best SSp.PLUS cut-off value for predicting the presence of significant steatosis was 1524 m/s. The multivariate regression analysis showed that Vi.PLUS values were associated with BMI and LSM by 2D-SWE.PLUS. In conclusion, MPUS was useful for assessing fibrosis, steatosis, and inflammation in a single examination in patients with NAFLD.

Recent evidence implicates adaptive immunity as a key player in the mechanisms supporting hepatic inflammation during the progression of nonalcoholic fatty liver disease (NAFLD). In these settings, patients with NAFLD often show an increase in the circulating levels of antibodies against oxidative stress-derived epitopes (OSE). Nonetheless, the actual role of humoral immunity in NAFLD is still unclear. This study investigates the contribution of B-lymphocytes to NAFLD evolution. B-lymphocyte immunostaining of liver biopsies from NAFLD patients showed that B-cells were evident within cell aggregates rich in T-lymphocytes. In these subjects, B/T-lymphocyte infiltration positively correlated with both circulating IgG targeting oxidative stress-derived epitopes (OSE) and interferon-γ (IFN-γ) levels. Furthermore, high prevalence of lymphocyte aggregates identified patients with more severe lobular inflammation and fibrosis. In mouse models of NAFLD, the onset of steatohepatitis was characterized by hepatic B2-lymphocytes maturation to plasma cells and by an elevation in circulating anti-OSE IgG titers. B-cell responses preceded T-cell activation and were accompanied by the up-regulation in the hepatic expression of B-cell Activating Factor (BAFF). Selective B2-cell depletion in mice over-expressing a soluble form of the BAFF/APRIL receptor Transmembrane Activator and Cyclophilin Ligand Interactor (TACI-Ig) prevented plasma cell maturation and Th-1 activation of liver CD4 + T-lymphocytes. Furthermore, TACI-Ig mice showed milder steatohepatitis and a decreased progression to fibrosis. Similarly, mice treatment with the BAFF-neutralizing monoclonal antibody Sandy-2 prevented hepatic B2-cell responses and ameliorated steatohepatitis. From these data we conclude that B2-lymphocyte activation is an early event in NAFLD evolution and contributes to the disease progression through the interaction with T-cells. Furthermore, combined clinical and experimental data suggest that elevated circulating anti-OSE IgG can identify a subset of NAFLD patients in whom adaptive immunity has a relevant role in the disease evolution toward fibrosis. [ABSTRACT FROM AUTHOR]

Inflammation has been known to be an important driver of fibrogenesis in the liver and onset of hepatic fibrosis. It starts off as a process meant to protect the liver from further damage, but it can become the main promoter of liver fibrosis. There are many inflammation-related pathways activated during liver fibrosis that lead to hepatic stellate cells (HSCs) activation and collagen-deposition in the liver. Such events are mostly modulated upstream of HSCs and involve signals from hepatocytes and innate immune cells. One particular event is represented by cell death during liver injury that generates multiple inflammatory signals that further trigger sterile inflammation and enhancement of inflammatory response. The assembly of inflammasome that responds to danger-associated molecular patterns (DAMPs) stimulates the release of pro-inflammatory cytokines and at the same time, initiates programmed cell death called pyroptosis. This review focuses on cellular and molecular mechanisms responsible for initiation and progress of inflammation in the liver.

Nonalcoholic fatty liver disease (NAFLD) caused by fat accumulation in the liver is globally the most common cause of chronic liver disease. Simple steatosis can progress to nonalcoholic steatohepatitis (NASH), a more severe form of NAFLD. The most potent driver for NASH is hepatocyte death induced by lipotoxicity, which triggers inflammation and fibrosis, leading to cirrhosis and/or liver cancer. Despite the significant burden of NAFLD, there is no therapy for NAFLD/NASH. Accumulating evidence indicates gender-related NAFLD progression. A higher incidence of NAFLD is found in men and postmenopausal women than premenopausal women, and the experimental results, showing protective actions of estradiol in liver diseases, suggest that estrogen, as the main female hormone, is associated with the progression of NAFLD/NASH. However, the mechanism explaining the functions of estrogen in NAFLD remains unclear because of the lack of reliable animal models for NASH, the imbalance between the sexes in animal experiments, and subsequent insufficient results. Herein, we reviewed the pathogenesis of NAFLD/NASH focused on gender and proposed a feasible association of estradiol with NAFLD/NASH based on the findings reported thus far. This review would help to expand our knowledge of the gender differences in NAFLD and for developing gender-based treatment strategies for NAFLD/NASH.

Abstract: The antioxidant and anti‐inflammatory effects of selenium‐enriched yeast (SY) and Gum Arabic (GA) have been reported. This study aimed to determine the hepatoprotective effect of SY and GA combination on carbon tetrachloride (CCl4)‐induced chronic liver injury in rats and to explore their synergistic mechanisms of action. Forty adult male Wistar rats randomly allotted to 5 groups: (A) worked as control, (B) was administered CCl4, (C‐E) were fed daily by GA, SY, and GA+SY respectively after mixing with basal diet, following CCl4‐intoxication. GA and SY combination significantly ameliorated CCl4‐induced reduction in serum total protein with elevation in aspartate transaminase (AST) and alanine transaminase (ALT) in addition to restoring the histopathological changes and hepatic content of hydroxyproline. GA and SY combination was also effective in reducing lipid peroxidation (MDA), consistent with an increase in total antioxidant capacity (T‐AOC), glutathione (GSH), superoxide dismutase (SOD) activities, indicating the suppression of liver oxidative stress. Furthermore, liver inflammation was ameliorated by GA and SY combination through inhibition of nuclear factor‐kappa (NF‐κB), tumor necrosis factor‐alpha (TNF‐α), cyclooxygenase‐2(COX‐2), monocyte chemotactic protein‐1 (MCP‐1), and toll‐like receptor 4(TLR‐4) over expression in the liver. Moreover, the up‐regulation of proliferating cell nuclear antigen (PCNA) expression by GA and SY combination enhanced the regeneration of liver tissue after CCl4‐administration. The expression of Collagen1, alpha‐smooth muscle actin (α‐SMA), and transforming growth factor‐beta1 (TGFβ1), was obviously ameliorated by GA and SY combination, suggesting the amelioration of profibrotic response of the liver. Taken together, our current study suggests that GA and SY combination exhibit a significant hepatoprotective activity, which more efficient than GA or SY alone. Practical Application: Chronic liver diseases are the serious health problems, which increase the morbidity and mortality in the world today. Selenium‐enriched yeast (SY) and Gum Arabic (GA) combination might be potential dietary agents could obviously ameliorate chronic liver damage, higher than GA and SY alone. They act to suppress the inflammation and inhibit the profibrotic response as well as support the liver regeneration. [ABSTRACT FROM AUTHOR]

Purpose: Hepatocellular carcinoma (HCC) cases are closely associated with chronic inflammation and fibrosis which is known as hepatic inflammation-fibrosis-cancer (IFC) axis. The aim of this study is to elucidate the development characteristics of the rat HCC model based on IFC axis. Methods: The diethylnitrosamine (DEN)-induced rat HCC, which presents a stepwise histopathological progression that is similar to human HCC, was used to analyze the features of the different stages (inflammation, fibrosis, cancer). Rats were injected DEN at a dose of 30 mg/kg body weight twice a week for 11 weeks and the animals were observed until week 20. Time series sera and organ samples from the DEN animal model were collected to evaluate the dynamic changes. Results: It was found that serum biochemical indicators (AST, ALT, ALP, TP, T-BIL, IL-6, TNF-α) from DEN-treated group were higher than that from control group. Fibrosis-related index in serum and live tissue were increased, respectively, from week 4 after DEN treatment. The expression of TGF-β1 and α-SMA in DEN-treated group was higher than that in control group. JAK2/STAT3 signaling was significantly up-regulated in DEN-treated group compared to that in control group. The histological examination confirmed that the hepatocarcinogenesis model was successfully established, and 100% of the animals in the DEN-exposed group developed liver tumors at 20 weeks. According to the pathological changes, the model characterized resulted in three stages: the inflammation stage (week 2-6), the fibrosis stage (week 8-12), and the HCC stage (week 14-20). Conclusions: The results suggested that the HCC development was associated with IFC axis. The serial progression of hepatocarcinogenesis was according to the sequence of hepatic inflammation, fibrosis and then hepatic tumor. [ABSTRACT FROM AUTHOR]

Trillin is an active ingredient isolated fromDioscorea nipponicaMakino. This study investigated the anti-inflammatory and anti-fibrosis effects of trillin on CCl4-induced hepatotoxicity in C57BL/6 mice. Chronic inflammation and fibrosis were induced by intraperitoneal administration of CCl40.5 μL/g of body weight twice a week for 6 weeks. Trillin (50 mg/kg, 100 mg/kg) was administered by gavage for 12 days before finishing the CCl4induction. Aspartate amino-transferase (AST) and glutamic-pyruvic transaminase (ALT) in serum were determined by AST and ALT kits. Superoxidase dismutase (SOD) activity and malondialdehyde (MDA) levels in serum were assayed by SOD and MDA kits. Meanwhile, the levels of inflammatory mediators including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in serum were detected by enzyme-linked immunosorbent assay (ELISA) method. Pathological changes were observed by hematoxylin-eosin (HE) staining. The proteins of the NF-κB pathway and the TGF-β/Smad pathway were measured by western blot. The trillin-treated group exhibited reduced AST, ALT, MDA, IL-6, TNF-α, and IL-1β, and increased SOD. Histological analyses of the trillin-treated group exhibited reduced inflammatory process and prevented liver fibrosis. Western blot analyses of the trillin-treated group showed reduced NF-κB pathway and TGF-β/Smad pathway. Significance: Based on the results of the present study, trillin can be used as a potential anti-inflammatory drug for chronic hepatic inflammation. [ABSTRACT FROM PUBLISHER]

Summary: Hepatic macrophages are central in the pathogenesis of chronic liver injury and have been proposed as potential targets in combatting fibrosis. Recent experimental studies in animal models revealed that hepatic macrophages are a remarkably heterogeneous population of immune cells that fulfill diverse functions in homeostasis, disease progression, and regression from injury. These range from clearance of pathogens or cellular debris and maintenance of immunological tolerance in steady state conditions; central roles in initiating and perpetuating inflammation in response to injury; promoting liver fibrosis via activating hepatic stellate cells in chronic liver damage; and, finally, resolution of inflammation and fibrosis by degradation of extracellular matrix and release of anti-inflammatory cytokines. Cellular heterogeneity in the liver is partly explained by the origin of macrophages. Hepatic macrophages can either arise from circulating monocytes, which are recruited to the injured liver via chemokine signals, or from self-renewing embryo-derived local macrophages, termed Kupffer cells. Kupffer cells appear essential for sensing tissue injury and initiating inflammatory responses, while infiltrating Ly-6C+ monocyte-derived macrophages are linked to chronic inflammation and fibrogenesis. In addition, proliferation of local or recruited macrophages may possibly further contribute to their accumulation in injured liver. During fibrosis regression, monocyte-derived cells differentiate into Ly-6C (Ly6C, Gr1) low expressing ‘restorative’ macrophages and promote resolution from injury. Understanding the mechanisms that regulate hepatic macrophage heterogeneity, either by monocyte subset recruitment, by promoting restorative macrophage polarization or by impacting distinctive macrophage effector functions, may help to develop novel macrophage subset-targeted therapies for liver injury and fibrosis. [Copyright &y& Elsevier]

Growing evidence indicates that NF-KB (nuclear factor ?B) activation contributes to the pathogenesis of NASH (non-alcoholic steatohepatisis). Among the NF-KB subunits, p50/NF-KB1 has regulatory activities down-modulating NF-KB-mediated responses. In the present study, we investigated the effects of NF-KB1 deficiency on the progression of NASH induced by feeding mice on an MCD (methionine/choline-deficient) diet. Following 4 weeks on the MCD diet, steatosis, ALT (alanine aminotransferase) release, hepatocyte apoptosis, lobular inflammation and TNFa (tumour necrosis factor a) production were higher in NF-KB1-/- (NF-KB1-knockout) mice than in WT (wild-type) mice. NF-KB1-/- mice also showed appreciable centrilobular collagen deposition, an increased number of activated hepatic stellate cells and higher type-I procollagen-a and TIMP-1 (tissue inhibitor of metalloproteases-1) mRNA expression. Although NF-KB p50 homodimers regulate macrophage activation, the number of hepatic macrophages and liver mRNAs for iNOS (inducible NO synthase), IL (interleukin)-12p40, CCL2 (CC chemokine ligand 2) and CXCL10 (CXC chemokine ligand 10) were comparable in the two strains. NASH was associated with an increase in liver infiltrating T-cells that was more evident in MCD-fed NF-KB1-/- than in similarly treated WT mice. Flow cytorimetry showed that T-cell recruitment involved effector CD8+ T-cells without changes in the helper CD4+ T-cell fraction. Furthermore, although NASH lowered hepatic NKT cells [NK (natural killer) T-cells] in WT mice, the NKT cell pool was selectively increased in the livers of MCD-fed NF-KB1-/- mice. Such NKT cell recruitment was associated with an early overexpression of IL-15, a cytokine controlling NKT cell survival and maturation. In the livers of MCD-fed NF-KB1-/- mice, but not in those of WT littermates, we also observed an up-regulation in the production of NKT-related cytokines IFN (interferon)-? and osteopontin. Taken together, these results indicate that NF-KB1 down-modulation enhanced NASH progression to fibrosis by favouring NKT cell recruitment, stressing the contribution of NKT cells in the pathogenesis of NASH. [ABSTRACT FROM AUTHOR]

Abstract: Chlorogenic acid (CGA) is a type of polyphenol with anti-inflammatory, antioxidant activities. Our previous studies showed CGA could efficiently inhibit carbon tetrachloride (CCl4)-induced liver fibrosis in rats. However, the specific underlying mechanism remains unclear. The aim of this study is to investigate the effects of CGA on liver inflammation and fibrosis induced by CCl4 and whether they are related to inhibition of toll-like receptor 4 (TLR4) signaling pathway. Male Sprague-Dawley (SD) rats were administrated CCl4 together with or without CGA for 8 weeks. Histopathological and biochemical analyses were carried out. The mRNA and protein expression levels of proinflammatory and profibrotic mediators were detected by RT-PCR and Western blot, respectively. The levels of serum proinflammatory cytokines were detected by ELISA. CGA significantly attenuated CCl4-induced liver damage and symptoms of liver fibrosis, accompanied by reduced serum transaminase levels, collagen I and α-smooth muscle actin (α-SMA) expression. As compared with the CCl4-treated group, the expression levels of TLR4, myeloid differentiation factor 88 (MyD88), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were reduced in the treatment group of CCl4 and CGA, whereas bone morphogenetic protein and activin membrane-bound inhibitor (Bambi) expression was increased. CGA also suppressed CCl4 induced nuclear factor-κB (NF-κB) activation. Moreover, the hepatic mRNA expression and serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were significantly increased in CCl4-treated rats and attenuated by co-treatment with CGA. Our data indicate that CGA can efficiently inhibit CCl4-induced liver fibrosis in rats and the protective effect may be due to the inhibition of TLR4/MyD88/NF-κB signaling pathway. [Copyright &y& Elsevier]

Background: The possibility of extracting RNA and measuring RNA expression from paraffin sections can allow extensive investigations on stored paraffin samples obtained from diseased livers and could help with studies of the natural history of liver fibrosis and inflammation, and in particular, correlate basic mechanisms to clinical outcomes. Results: To address this issue, a pilot study of multiplex gene expression using branched-chain DNA technology was conducted to directly measure mRNA expression in formalin-fixed paraffin-embedded needle biopsy samples of human liver. Twenty-five genes were selected for evaluation based on evidence obtained from human fibrotic liver, a rat BDL model and in vitro cultures of immortalized human hepatic stellate cells. The expression levels of these 25 genes were then correlated with liver fibrosis and inflammation activity scores. Statistical analysis revealed that three genes (COL3A1, KRT18, and TUBB) could separate fibrotic from non-fibrotic samples and that the expression of ten genes (ANXA2, TIMP1, CTGF, COL4A1, KRT18, COL1A1, COL3A1, ACTA2, TGFB1, LOXL2) were positively correlated with the level of liver inflammation activity. Conclusion: This is the first report describing this multiplex technique for liver fibrosis and has provided the proof of concept of the suitability of RNA extracted from paraffin sections for investigating the modulation of a panel of proinflammatory and profibrogenic genes. This pilot study suggests that this technique will allow extensive investigations on paraffin samples from diseased livers and possibly from any other tissue. Using identical or other genes, this multiplex expression technique could be applied to samples obtained from extensive patient cohorts with stored paraffin samples in order to correlate gene expression with valuable clinically relevant information. This method could be used to provide a better understanding of the mechanisms of liver fibrosis and inflammation, its progression, and help development of new therapeutic approaches for this indication. [ABSTRACT FROM AUTHOR]

Abstract: The anti-inflammatory and antioxidant effects of epigallocatechin-3-gallate (EGCG) are considered important forces in attenuate liver injury and fibrosis. The aim of the study was to investigate the effect of EGCG on the expression of fibrogenic factors and whether EGCG attenuates the severity of oxidative stress and inflammatory response in chronic liver injury. Mice were administered with CCl4 together with or without EGCG for 8 weeks (n =6–8 per group). Histopathological and biochemical analyses were carried out. The mRNA expression levels of TNF-α, COX-2, iNOS, α-smooth muscle actin (α-SMA), transforming growth factor (TGF-β1), pro-collagen-I, matrix metalloproteinases (MMP-2, -9) and their inhibitors (TIMP-1, -2) were determined by RT-PCR. The collagen deposited in the liver was detected by Sirius Red staining. The formation of nitrotyrosine was measured as a marker of oxidative stress. The activity level of NF-κB and the expression level of C/EBP were also assessed. Chronic CCl4 treatment caused liver injury, oxidative stress and nitrosative stress, and collagen accumulation in the liver. The expression levels of pro-inflammatory and pro-fibrotic mediators and the activity of NF-κB were increased. Treatment with EGCG significantly reduced liver injury, oxidative stress and the inflammatory response. EGCG also significantly reduced the formation of collagen in the liver, the expression of α-SMA and all of the assayed pro-fibrogenic markers except TIMP-2 and MMP-9. EGCG significantly attenuated the severity of CCl4-induced liver injury and the progression of liver fibrosis. The protective effect of EGCG may in part be a consequence of the reduction in oxidative stress and the pro-inflammatory response. [Copyright &y& Elsevier]

Curcumin and saikosaponin A as antioxidants improve antioxidant status. This study investigated the anti-inflammatory and antifibrotic actions of curcumin and saikosaponin A on CCl4-induced liver damage. Sprague-Dawley rats were randomly divided into control, CCl4, CCl4+ curcumin (0.005%; CU), CCl4 + saikosaponin A (0.004%; SS), and CCl4 + curcumin + saikosaponin A (0.005% + 0.004%; CU + SS) groups. Carbon tetrachloride (40% in olive oil) at a dose of 0.75 ml/kg was injected intraperitoneally once a week. Curcumin and saikosaponin A were supplemented alone or in combination with diet 1 week before CCl4 injection for 8 weeks. After 8-week supplementation, histopathological results showed hepatic collagen deposition was significantly reduced in the CU and SS groups, and activated nuclear factor-κ B expression induced by CCl4 in the liver was significantly inhibited by curcumin and/or saikosaponin A. Hepatic proinflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 were significantly inhibited, and anti-inflammatory cytokine interleukin-10 was significantly increased by supplementation with curcumin and/or saikosaponin A. Additionally, curcumin and/or saikosaponin A significantly reduced the increased levels of hepatic transforming growth factor-β1 and hydroxyproline after CCl4 treatment. Therefore, supplementation with curcumin and/or saikosaponin A suppress inflammation and fibrogenesis in rats with CCl4-induced liver injury. However, the combination has no additive effects on anti-inflammation and antifibrosis. [ABSTRACT FROM AUTHOR]

Background: Activated hepatic stellate cells (HSC) and other fibrogenic cell types are frequently found around hepatocellular carcinoma. It is unknown whether hepatocarcinoma cells regulate the biological functions of HSC. Aims: This study aimed to investigate the paracrine effects of hepatocarcinoma cells on human HSC using a co-culture system. Methods: Huh7 or HepG2 cells, human hepatocarcinoma cell lines, were co-cultured with primary human HSC. Intracellular calcium mobilization, proliferation, migration, expression of pro-angiogenic and fibrogenic genes, smooth muscle α-actin (α-SMA) protein expression, inflammatory properties (nuclear factor kappa B activation and interleukin 8 secretion) and intracellular signalling pathways (AKT and ERK) were analysed in HSC. Results: Culture of HSC with Huh7 cells for 24 h stimulated HSC proliferation, migration and expression of pro-angiogenic genes. The migration effect was corroborated with HepG2 cells. The effects of Huh7 cells on cell proliferation and migration were mediated mainly by PI3K/AKT activation. Moreover, Huh7 cells reduced the expression of genes involved in fibrogenesis, while they did not modify the inflammatory properties of HSC. The expression of α-SMA was induced by Huh7 cells. Because hepatitis C virus (HCV) infection is a major cause of hepatocarcinoma, we next investigated whether these effects are regulated by the expression of HCV in hepatocarcinoma cells. Expression of a subgenomic replicon expressing HCV nonstructural proteins (NS3–NS5) in Huh7 cells did not affect paracrine actions in HSC (cell proliferation and migration). Conclusions: These results suggested that there is a cross-talk between hepatocarcinoma cells and HSC. Activated HSC may be stimulated by cancer cells to accumulate and express angiogenic genes. [ABSTRACT FROM AUTHOR]