Cellular stress in the pathogenesis of nonalcoholic steatohepatitis and liver fibrosis

Advances in fluorescent probes of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the predominant chronic liver disease worldwide, with 20-30 % of individuals going on to develop non-alcoholic steatohepatitis (NASH), which could result in serious complications such as fibrosis, liver cirrhosis, and hepatocellular carcinoma. Since NAFLD is reversible in its early stages, early diagnosis is necessary. By using particular structural and functional designs, fluorescent probes can be made to detect NAFLD-related chemicals or biological processes with a high degree of sensitivity and selectivity. In this work, we summarize the existing fluorescent probes for identifying biomarkers in NAFLD, including microenvironment (viscosity, polarity), ROS, RNS, RSS, metal ions, enzymes, and RNA. Furthermore, future directions are envisioned to inform the creation of more accurate and reliable fluorescent probes for NAFLD diagnosis, emphasizing the benefits and challenges of fluorescence probes.

AMPK activator ATX-304 reduces oxidative stress and improves MASLD via metabolic switching

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide for which there is only one approved treatment. Adenosine monophosphate-activated protein kinase (AMPK) is an interesting therapeutic target since it acts as a central regulator of cellular metabolism. Despite efforts to target AMPK, no direct activators have yet been approved for treatment of this disease. This study investigated the effect of the AMPK activator ATX-304 in a preclinical mouse model of progressive fatty liver disease. The data demonstrated that ATX-304 diminishes body fat mass, lowers blood cholesterol levels, and mitigates general liver steatosis and the development of liver fibrosis, but with pronounced local heterogeneities. The beneficial effects of ATX-304 treatment were accompanied by a shift in the liver metabolic program, including increased fatty acid oxidation, reduced lipid synthesis, as well as remodeling of cholesterol and lipid transport. We also observed variations in lipid distribution among liver lobes in response to ATX-304, and a shift in the zonal distribution of lipid droplets upon treatment. Taken together, our data suggested that ATX-304 holds promise as a potential treatment for MASLD.

Inflammation and cancer: molecular mechanisms and clinical consequences

Inflammation, a hallmark of cancer, has been associated with tumor progression, transition into malignant phenotype and efficacy of anticancer treatments in cancer. It affects all stages of cancer, from the initiation of carcinogenesis to metastasis. Chronic inflammation induces immunosup-pression, providing an environment conducive to carcinogenesis, whereas acute inflammation induces an antitumor immune response, leading to tumor suppression. Solid tumors have an inflammatory tumor microenvironment (TME) containing cancer cells, immune cells, stromal cells, and soluble molecules, which plays a key role in tumor progression and therapy response. Both cancer cells and stromal cells in the TME are highly plastic and constantly change their phenotypic and functional properties. Cancer-associated inflammation, the majority of which consists of innate immune cells, plays an important role in cancer cell plasticity, cancer progression and the development of anticancer drug resistance. Today, with the combined used of advanced technologies, such as single-cell RNA sequencing and spatial molecular imaging analysis, the pathways linking chronic inflammation to cancer have been largely elucidated. In this review article, we highlighted the molecular and cellular mechanisms involved in cancer-associated inflammation and its effects on cancer progression and treatment response. We also comprehensively review the mechanisms linking chronic inflammation to cancer in the setting of GI cancers.

MEOX1-mediated transcriptional regulation of circABHD3 exacerbates hepatic fibrosis through promoting m6A/YTHDF2-dependent YPEL3 mRNA decay to activate β-catenin signaling

BACKGROUND

Hepatic fibrosis may progress to liver cirrhosis and eventually cause death. Epithelial-mesenchymal transition (EMT) of hepatocytes plays critical roles in hepatic fibrosis. Exploring the mechanisms underlying EMT is crucial for a better understanding of hepatic fibrosis pathogenesis.

METHODS

Hepatocyte EMT wad induced with TGF-β1 and evaluated by Western blotting and immunofluorescence staining. Methylated RNA immunoprecipitation (MeRIP) was applied to assess N6-methyladenosine (m6A) modification. RIP and RNA pull-down assays were performed to analyze the interaction between circABHD3, YTHDF2 and YPEL3 mRNA. MEOX1-mediated transcription of ABHD3 was examined by luciferase and chromatin immunoprecipitation (ChIP). Mice were intraperitoneally injected with CCl4 or treated with bile duct ligation (BDL) surgery for hepatic fibrosis induction. Liver injury and collagen deposition were examined with hematoxylin and eosin (HE), Masson, and Sirius Red staining. Alanine transaminase (ALT), aspartate transaminase (AST) and hydroxyproline (HYP) were examined using ELISA.

RESULTS

CircABHD3 was upregulated in in vitro and in vivo models of hepatic fibrosis and patients. Knockdown of circABHD3 inhibited TGF-β1-induced expression of fibrosis markers, EMT and mitochondrial impairment in hepatocytes. MEOX1 could directly bind to the promoter of ABHD3 to facilitate its transcription and subsequent circABHD3 generation. Knockdown of MEOX1 suppressed TGF-β1-induced EMT and mitochondrial impairment through suppression of circABHD3. CircABHD3 destabilized YPEL3 mRNA via promoting YTHDF2-dependent recognition of m6A-modified YPEL3 mRNA to trigger β-catenin signaling activation. Furthermore, circABHD3 silencing-mediated inhibition of EMT and mitochondrial impairment was counteracted by YPEL3 knockdown and activation of β-catenin signaling. Depletion of circABHD3 significantly reduced EMT, mitochondrial impairment and hepatic fibrosis via promoting YPEL3 expression and suppressing β-catenin signaling in vivo.

CONCLUSION

MEOX1-mediated generation of circABHD3 promotes EMT and mitochondrial impairment by enhancing YTHDF2-mediated degradation of YPEL3 mRNA and activating downstream β-catenin signaling, thus exacerbating hepatic fibrosis.

Liver-Secreted Extracellular Vesicles Promote Cirrhosis-Associated Skeletal Muscle Injury Through mtDNA-cGAS/STING Axis

Skeletal muscle atrophy (sarcopenia) is a serious complication of liver cirrhosis, and chronic muscle inflammation plays a pivotal role in its pathologenesis. However, the detailed mechanism through which injured liver tissues mediate skeletal muscle inflammatory injury remains elusive. Here, it is reported that injured hepatocytes might secrete mtDNA-enriched extracellular vesicles (EVs) to trigger skeletal muscle inflammation by activating the cGAS-STING pathway. Briefly, injured liver secreted increased amounts of EVs into circulation, which are then engulfed primarily by macrophages in skeletal muscle and subsequently induce cGAS-STING signaling and its-mediated inflammatory response in muscles. In contrast, suppression of hepatic EV secretion or STING signaling significantly alleviated cirrhosis-induced skeletal muscle inflammation and muscle atrophy in vivo. Circulating EVs from cirrhotic patients showed higher levels of mtDNA, and the levels of EV-mtDNA positively correlated with the severity of liver injury. In injured hepatocytes, mitochondrial damage promoted the release of cytosolic mtDNA and the subsequent secretion of mtDNA-enriched EVs. This study reveals that injured hepatocyte-derived EVs induce skeletal muscle inflammation via the mtDNA‒STING axis, while targeted blockade of liver EV secretion or STING signaling represents a potential therapeutic approach for preventing cirrhosis-associated skeletal muscle atrophy.

An Integration of RNA Sequencing and Network Pharmacology Approaches Predicts the Molecular Mechanisms of the Huo-Xue-Shen Formula in the Treatment of Liver Fibrosis

Background: Liver fibrosis is a prevalent, chronic inflammatory condition characterized by the excessive accumulation of extracellular matrix components and, primarily, collagen in the liver. Huo-xue-shen (HXS) has proven effective for the treatment of liver fibrosis. However, the mechanism is yet to be deciphered. Methods: Network pharmacology, machine learning algorithms and RNA-seq were used to predict the immune-treated targets and mechanisms associated with HXS in liver fibrosis. Molecular docking was employed to screen for effective agents based on the drug-compound-hub gene network in HXS, aiming to identify the most critical bioactive compound in HXS for the treatment of liver fibrosis. Results: A total of 100 immune-treated targets (ITTs) of HXS were found to significantly regulate the PI3K-Akt signaling pathway and the MAPK signaling pathway. Among these, CDKN1A, NR1I3, and TUBB1, which can concurrently interact with quercetin, were associated with the prognosis of liver fibrosis, indicating that HXS may inhibit or reverse HSC activation primarily by suppressing neutrophil extracellular trap formation, stimulating oxidative phosphorylation and promoting thyroid hormone synthesis in the regulation of the liver microenvironment. Conclusions: Our study suggests that HXS may delay the progression of liver fibrosis by targeting multiple pathways, as shown by the network pharmacology and transcriptome profiling used to examine the liver immune environment. Quercetin, its key ingredient, likely plays an important role by mediating the CDKN1A, NR1I3, and TUBB1 signaling pathways. Overall, our findings provide a new perspective on the potential biological mechanisms of this traditional Chinese medicine formula.

Serum ECM1 is a promising biomarker for staging and monitoring fibrosis in patients with chronic hepatitis B

It is critical to assess the extent and progression of liver fibrosis for patients to receive suitable treatments, but its diagnostic methods remain unmet. Extracellular matrix protein 1 (ECM1) has previously been reported to be a key factor in the induction and progression of liver fibrosis. However, little is known about the use of ECM1 as a biomarker to evaluate fibrosis. In a CCl4-induced mouse model of liver fibrosis, the present study demonstrated that ECM1 decreased with gradually increasing fibrosis. Using biopsy as a reference, the serum ECM1 levels decreased with increasing fibrosis stage in 247 patients with liver fibrosis, but there were no significant changes between fibrosis stage 2 and stage 0-1. To improve the performance of ECM1, age, platelet count, and ECM1 concentration were combined to calculate an EPA (ECM1-platelet-age) score (ranging from 0 to 10). The areas under the receiver operating characteristic curve of the EPA scores for the detection of F⩾2, F⩾3, and F4 were 0.6801, 0.7377, and 0.8083, respectively, which showed a comparable or significantly greater diagnostic performance for assessing fibrosis than that of the AST/ALT ratio, APRI score, or FIB-4 score. In HBV patients following antiviral treatment, the dynamics of the EPA score depended on the status of liver fibrosis development. The accuracy of the EPA score in predicting fibrosis regression and progression was 66.00% and 71.43%, respectively, while that of the LSM, another useful method for monitoring hepatic fibrosis changes during treatment, was only 52.00% and 7.14%, respectively. Compared with healthy controls, there were lower levels of serum ECM1 in HBV patients and individuals with HCV infection, MAFLD, ALD, PBC, and DILI. These findings suggested that individuals with reduced ECM1 levels may have a risk of developing liver injury, and further examinations or medical care are needed. In conclusion, the ECM1-containing EPA score is a valuable noninvasive test for staging fibrosis and predicting the progression of liver fibrosis. Additionally, ECM1 alone is an indicator for distinguishing patients with liver injury from healthy controls.

IRG1/Itaconate inhibits hepatic stellate cells ferroptosis and attenuates TAA-induced liver fibrosis by regulating SLC39A14 expression

This study aimed to elucidate the protective roles of Immune Response Gene-1 (IRG1) and exogenous itaconate in murine models of hepatic fibrosis and to delineate the underlying mechanistic pathways using both wild-type and IRG1-deficient (IRG1-/-) mice. Primary murine stellate cells (mHSC) and bone marrow-derived macrophages (BMDM) were isolated and cocultured. Hepatocellular fibrosis was induced in vitro using Transforming Growth Factor-beta (TGF-β) to evaluate the protective efficacy of IRG1/itaconate. Histopathological damage in the hepatic tissues was assessed using Hematoxylin and Eosin (H&E), Masson's trichrome, and Sirius red staining, followed by hepatic fibrosis scoring. The levels of released inflammatory cytokines were quantified using enzyme-linked immunosorbent assay (ELISA) kits. Immunohistochemistry was used to detect 4-Hydroxynonenal (4-HNE) levels and Perls staining was used to assess ferroptosis. RNA sequencing and gene enrichment analyses were performed to identify implicated molecular entities and signaling pathways. IRG1 and SLC39A14 knockdown and overexpression cell lines were generated. Quantitative real-time PCR (qRT-PCR) and western blotting (WB) were used to measure the mRNA and protein expression levels in hepatic tissues and cells. Kits were used to assess reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and the concentrations of liver enzymes, iron, GSH, and GSSG within hepatic tissues and cells.4-octyl itaconate (4-OI) significantly attenuated the histopathological damage in hepatic tissues, preserved the normal hepatic function, effectively reduced the release of inflammatory cytokines, and mitigated oxidative stress markers such as ROS and MDA in Thioacetamide (TAA)-induced fibrotic mice. Notably, this study is the first to reveal the pivotal role of SLC39A14 in the pathogenesis of hepatic fibrosis in murine models and elucidate how IRG1/itaconate mediates downstream ferroptosis-related signaling pathways by targeting SLC39A14, thereby inhibiting ferroptosis-induced hepatic fibrosis. IRG1/itaconate can alleviate the TAA-induced hepatic fibrosis in mice by regulating the expression of SLC39A14, consequently suppressing hepatic stellate cell ferroptosis.

NLRP3 inflammasome constrains liver regeneration through impairing MerTK-mediated macrophage efferocytosis

The NOD-like receptor protein 3 (NLRP3) inflammasome plays a crucial role in human acute and chronic liver diseases. However, the role and cell-specific contribution of NLRP3 in liver regeneration remains unclear. Here, we found that NLRP3 was highly activated during the early stage of liver regeneration via 70% partial hepatectomy (PHx) mice model and clinical data. Global NLRP3 depletion or pharmacologically blocking NLRP3 significantly enhanced liver regeneration, while NLRP3 overexpression impaired it after PHx. Furthermore, mice with myeloid-specific knockout of Nlrp3 (Nlrp3Δmye), rather than hepatocyte-specific knockout (Nlrp3Δhep), showed improved liver regeneration compared to control (Nlrp3fl/fl). Mechanistically, deficiency of Nlrp3 promoted myeloid-epithelial-reproductive tyrosine kinase (MerTK)-mediated efferocytosis, thereby inducing macrophages toward a pro-reparative Ly6Clo phenotype. Notably, NLRP3 inhibition by MCC950 effectively reversed the impairment of liver regeneration after PHx in mice fed a high-fat diet. Our findings provide a potential therapeutic strategy for the prevention and treatment of post-hepatectomy liver failure.

Nano-encapsulation of drugs to target hepatic stellate cells: Toward precision treatments of liver fibrosis

Liver fibrosis is characterized by excessive extracellular matrix (ECM) deposition triggered by hepatic stellate cells (HSCs). As central players in fibrosis progression, HSCs are the most important therapeutic targets for antifibrotic therapy. However, owing to the limitations of systemic drug administration, there is still no suitable and effective clinical treatment. In recent years, nanosystems have demonstrated expansive therapeutic potential and evolved into a clinical modality. In liver fibrosis, nanosystems have undergone a paradigm shift from targeting the whole liver to locally targeted modifying processes. Nanomedicine delivered to HSCs has significant potential in managing liver fibrosis, where optimal management would benefit from targeted delivery, personalized therapy based on the specific site of interest, and minor side effects. In this review, we present a brief overview of the role of HSCs in the pathogenesis of liver fibrosis, summarize the different types of nanocarriers and their specific delivery applications in liver fibrosis, and highlight the biological barriers associated with the use of nanosystems to target HSCs and approaches available to solve this issue. We further discuss in-depth all the molecular target receptors overexpressed during HSC activation in liver fibrosis and their corresponding ligands that have been used for drug or gene delivery targeting HSCs.

Abrus cantoniensis Hance: Ethnopharmacology, phytochemistry and pharmacology of a promising traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Abrus cantoniensis Hance (ACH), known as Jigucao (Chinese: ) has been used in ethnopharmacology for a long history with therapeutic effects for clearing heat, soothing the liver, especially in treating acute and chronic hepatitis which was very effective. In southern China, such as Guangdong and Guangxi, people often use ACH in soup or herbal tea as dietetic therapy.

AIM OF THE REVIEW

This paper aims to review ACH's ethnopharmacology, phytochemistry, and pharmacological activity systematically, at the same time, we also hope to provide more research avenues between traditional uses and pharmacological properties.

MATERIAL AND METHODS

Through PubMed, Wan Fang Database, CNKI, Web of Science, EBSCO Database, and Google Scholar search for relevant literature in both Chinese and English, the keywords "Abrus cantoniensis, Abrus cantoniensis Hance, Jigucao, pharmacology, chemical constituents, clinical application, network pharmacology" were used alone or combination.

RESULTS

Traditionally, ACH was believed to have the effect of soothing the liver, clearing heat, and detoxifying, often used to treat diseases of the liver and inflammation. Modern pharmacological research indicates that ACH has liver protection, anti-inflammation, anti-oxidant, immunomodulation, anti-tumor effects and so on. Whether it was a single chemical compound or an extract from ACH, studies have found that it has abundant pharmacological activities, these were the fundamental sources of traditional uses, like liver protection and anti-inflammation.

CONCLUSIONS

A systematic review found that modern phytochemistry and pharmacodynamic research reports on ACH are closely related to its traditional uses, especially its hepatoprotective and anti-inflammatory effects. Modern research has also further explored and expanded the effects of ACH, such as its anti-tumor effect. And all these efforts are gradually filling the gap between traditional uses and modern pharmacology. In general, the current research on the pharmacodynamic mechanism of ACH still needs further in-depth research, and the strategies adopted must also be further strengthened.

Knockdown of hepatic mitochondrial calcium uniporter mitigates MASH and fibrosis in mice

BACKGROUND

Mitochondrial calcium uniporter (MCU) plays pleiotropic roles in cellular physiology and pathology that contributes to a variety of diseases, but the role and potential mechanism of MCU in the pathogenesis of metabolic dysfunction-associated steatohepatitis (MASH) remain poorly understood.

METHODS AND RESULTS

Here, hepatic knockdown of MCU in C57BL/6J mice was achieved by tail vein injection of AAV8-mediated the CRISPR/Cas9. Mice were fed a Choline-deficient, L-amino acid-defined high-fat diet (CDAHFD) for 8 weeks to induce MASH and fibrosis. We find that expression of MCU enhanced in MASH livers of humans and mice. MCU knockdown robustly limits lipid droplet accumulation, steatosis, inflammation, and hepatocyte apoptotic death during MASH development both in vivo in mice and in vitro in cellular models. MCU-deficient mice strikingly mitigate MASH-related fibrosis. Moreover, the protective effects of MCU knockdown against MASH progression are accompanied by a reduced level of mitochondrial calcium, limiting hepatic oxidative stress, and attenuating mitochondrial dysfunction. Mechanically, RNA sequencing analysis and protein immunoblotting indicate that knockdown MCU inhibited the Hippo/YAP pathway activation and restored the AMP-activated protein kinase (AMPK) activity during MASH development both in vitro and in vivo.

CONCLUSIONS

MCU is up-regulated in MASH livers in humans and mice; and hepatic MCU knockdown protects against diet-induced MASH and fibrosis in mice. Thus, targeting MCU may represent a novel therapeutic strategy for MASH and fibrosis.

Natural history and progression of metabolic dysfunction-associated steatotic liver disease

The natural history of metabolic dysfunction-associated steatotic liver disease (MASLD), previously referred to as non-alcoholic fatty liver disease (NAFLD), is complex and long. A minority of patients develop inflammation and risk progressive fibrosis that can result in cirrhosis. Progression to cirrhosis occurs in 3-5% of patients and often takes more than 20 years. This narrative review presents an update on the natural history of MASLD, discussing studies and risk estimates for progression to severe outcomes, such as decompensated cirrhosis or hepatocellular carcinoma. We highlight the dynamic progression of liver damage, how to identify patients whose disease progresses over time, and how risk factors might be mitigated to reduce the risk for disease progression.

Phenylethanol Glycoside from Cistanche tubulosa Attenuates BSA-Induced Liver Fibrosis in Rats by Modulating the Gut Microbiota-Liver Axis

This study aimed to investigate the effect of phenylethanol glycoside from Cistanche tubulosa (CPhGs) on the prevention of bovine serum albumin (BSA)-induced hepatic fibrosis in rats. Investigation of the mechanisms of the anti-hepatic fibrosis effect was focused on CPhGs' influence on the "gut-liver" regulation, including the gut microbiota, intestinal barrier, systemic lipopolysaccharide (LPS) concentration, and LPS-related signaling pathway. The results show that CPhGs restored the diversity of gut microbiota, increased the relative abundance of Bacteroidetes, and decreased the relative abundance of Firmicutes and Proteobacteria in the fibrotic rats. In addition, CPhGs promoted the enrichment of probiotics such as Blautia, Oscillospira, Ruminococcus, Odoribacter, Bacteroides, and Parabacteroides in intestines of these rats. Furthermore, CPhGs reduced histopathological injury in the intestine and restored the tight junctions of the intestine by increasing the expression of ZO-1, occludin, and E-cadherin. CPhGs efficiently reduced serum LPS and liver lipopolysaccharide-binding protein (LBP) levels and inhibited the LPS-TLR4/MyD88/NF-κB pathway, which is related to protein expression in the liver. Correlation analysis confirmed that these beneficial bacteria were negatively associated with pathological damage, while LPS and harmful bacteria were positively associated with liver injury. Our fecal microbiota transplantation (FMT) experiment confirmed that gut microbiota is an important part of disease progression and that CPhGs is useful for the prevention and treatment of hepatic fibrosis. Our data demonstrate that the anti-hepatic fibrosis mechanism of CPhGs was mediated by regulation of the "gut-liver" axis. These results can stimulate consideration for its use in clinical practices.

Smart Microneedle Arrays Integrating Cell-Free Therapy and Nanocatalysis to Treat Liver Fibrosis

Liver fibrosis is a chronic pathological condition lacking specific clinical treatments. Stem cells, with notable potential in regenerative medicine, offer promise in treating liver fibrosis. However, stem cell therapy is hindered by potential immunological rejection, carcinogenesis risk, efficacy variation, and high cost. Stem cell secretome-based cell-free therapy offers potential solutions to address these challenges, but it is limited by low delivery efficiency and rapid clearance. Herein, an innovative approach for in situ implantation of smart microneedle (MN) arrays enabling precisely controlled delivery of multiple therapeutic agents directly into fibrotic liver tissues is developed. By integrating cell-free and platinum-based nanocatalytic combination therapy, the MN arrays can deactivate hepatic stellate cells. Moreover, they promote excessive extracellular matrix degradation by more than 75%, approaching normal levels. Additionally, the smart MN arrays can provide hepatocyte protection while reducing inflammation levels by ≈70-90%. They can also exhibit remarkable capability in scavenging almost 100% of reactive oxygen species and alleviating hypoxia. Ultimately, this treatment strategy can effectively restrain fibrosis progression. The comprehensive in vitro and in vivo experiments, supplemented by proteome and transcriptome analyses, substantiate the effectiveness of the approach in treating liver fibrosis, holding immense promise for clinical applications.

Liver Fibrosis: From Basic Science towards Clinical Progress, Focusing on the Central Role of Hepatic Stellate Cells

The burden of chronic liver disease is globally increasing at an alarming rate. Chronic liver injury leads to liver inflammation and fibrosis (LF) as critical determinants of long-term outcomes such as cirrhosis, liver cancer, and mortality. LF is a wound-healing process characterized by excessive deposition of extracellular matrix (ECM) proteins due to the activation of hepatic stellate cells (HSCs). In the healthy liver, quiescent HSCs metabolize and store retinoids. Upon fibrogenic activation, quiescent HSCs transdifferentiate into myofibroblasts; lose their vitamin A; upregulate α-smooth muscle actin; and produce proinflammatory soluble mediators, collagens, and inhibitors of ECM degradation. Activated HSCs are the main effector cells during hepatic fibrogenesis. In addition, the accumulation and activation of profibrogenic macrophages in response to hepatocyte death play a critical role in the initiation of HSC activation and survival. The main source of myofibroblasts is resident HSCs. Activated HSCs migrate to the site of active fibrogenesis to initiate the formation of a fibrous scar. Single-cell technologies revealed that quiescent HSCs are highly homogenous, while activated HSCs/myofibroblasts are much more heterogeneous. The complex process of inflammation results from the response of various hepatic cells to hepatocellular death and inflammatory signals related to intrahepatic injury pathways or extrahepatic mediators. Inflammatory processes modulate fibrogenesis by activating HSCs and, in turn, drive immune mechanisms via cytokines and chemokines. Increasing evidence also suggests that cellular stress responses contribute to fibrogenesis. Recent data demonstrated that LF can revert even at advanced stages of cirrhosis if the underlying cause is eliminated, which inhibits the inflammatory and profibrogenic cells. However, despite numerous clinical studies on plausible drug candidates, an approved antifibrotic therapy still remains elusive. This state-of-the-art review presents cellular and molecular mechanisms involved in hepatic fibrogenesis and its resolution, as well as comprehensively discusses the drivers linking liver injury to chronic liver inflammation and LF.

Association between triglyceride to high-density lipoprotein cholesterol ratio and nonalcoholic fatty liver disease and liver fibrosis in American adults: an observational study from the National Health and Nutrition Examination Survey 2017-2020

Objective

This study investigated the link between triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio and nonalcoholic fatty liver disease (NAFLD) and liver fibrosis in American adults.

Methods

Information for 6495 participants from the National Health and Nutrition Examination Survey (NHANES) 2017-2020.03 was used for this cross-sectional study. The link between TG/HDL-C ratios and NAFLD and liver fibrosis was assessed by multiple linear regression before evaluating nonlinear correlations based on smoothed curve fitting models. Stratification analysis was then applied to confirm whether the dependent and independent variables displayed a stable association across populations.

Results

TG/HDL-C ratios were positively correlated with NAFLD, with higher ratios being linked to increased prevalence of NAFLD. After adjusting for potential confounders, the odds ratios (OR) for NAFLD patients in the fourth TG/HDL-C quartile were 3.61 (95% confidence interval [CI], 2.94-4.38) (P for trend < 0.001) in comparison with those in the first quartile after adjusting for clinical variables. However, no statistical significance was noted for the ratio for liver fibrosis after adjusting for potential confounders (P for trend = 0.07). A nonlinear correlation between TG/HDL-C ratios and NAFLD was observed based on smoothed curve fitting models. However, a nonlinear relationship between the ratios and liver fibrosis was not established. In subgroup analyses, there was an interaction between smoking status and TG/HDL-C ratio in relation to the prevalence of liver fibrosis (P for interaction < 0.001).

Conclusions

Among American adults, the TG/HDL-C ratio was noted to be nonlinearly positively associated with the prevalence of NAFLD; however, this relationship was not present in liver fibrosis.

Unveiling the role of ferroptosis in the progression from NAFLD to NASH: recent advances in mechanistic understanding

Non-alcoholic fatty liver disease (NAFLD) is a prevalent and significant global public health issue. Nonalcoholic steatohepatitis (NASH) represents an advanced stage of NAFLD in terms of pathology. However, the intricate mechanisms underlying the progression from NAFLD to NASH remain elusive. Ferroptosis, characterized by iron-dependent cell death and distinguished from other forms of cell death based on morphological, biochemical, and genetic criteria, has emerged as a potential participant with a pivotal role in driving NAFLD progression. Nevertheless, its precise mechanism remains poorly elucidated. In this review article, we comprehensively summarize the pathogenesis of NAFLD/NASH and ferroptosis while highlighting recent advances in understanding the mechanistic involvement of ferroptosis in NAFLD/NASH.

Ginsenoside Rb1 induces hepatic stellate cell ferroptosis to alleviate liver fibrosis via the BECN1/SLC7A11 axis

Liver fibrosis is primarily driven by the activation of hepatic stellate cells (HSCs), a process associated with ferroptosis. Ginsenoside Rb1 (GRb1), a major active component extracted from Panax ginseng, inhibits HSC activation. However, the potential role of GRb1 in mediating HSC ferroptosis remains unclear. This study examined the effect of GRb1 on liver fibrosis both in vivo and in vitro, using CCl4-induced liver fibrosis mouse model and primary HSCs, LX-2 cells. The findings revealed that GRb1 effectively inactivated HSCs in vitro, reducing alpha-smooth muscle actin (α-SMA) and Type I collagen (Col1A1) levels. Moreover, GRb1 significantly alleviated CCl4-induced liver fibrosis in vivo. From a mechanistic standpoint, the ferroptosis pathway appeared to be central to the antifibrotic effects of GRb1. Specifically, GRb1 promoted HSC ferroptosis both in vivo and in vitro, characterized by increased glutathione depletion, malondialdehyde production, iron overload, and accumulation of reactive oxygen species (ROS). Intriguingly, GRb1 increased Beclin 1 (BECN1) levels and decreased the System Xc-key subunit SLC7A11. Further experiments showed that BECN1 silencing inhibited GRb1-induced effects on HSC ferroptosis and mitigated the reduction of SLC7A11 caused by GRb1. Moreover, BECN1 could directly interact with SLC7A11, initiating HSC ferroptosis. In conclusion, the suppression of BECN1 counteracted the effects of GRb1 on HSC inactivation both in vivo and in vitro. Overall, this study highlights the novel role of GRb1 in inducing HSC ferroptosis and promoting HSC inactivation, at least partly through its modulation of BECN1 and SLC7A11.

Engineered liposomes targeting hepatic stellate cells overcome pathological barriers and reverse liver fibrosis

Dual pathological barriers, including capillarized liver sinusoidal endothelial cells (LSECs) and deposited extracellular matrix (ECM), result in insufficient drug delivery, significantly compromising the anti-fibrosis efficacy. Additionally, excessive reactive oxygen species (ROS) in the hepatic microenvironment are crucial factors contributing to the progression of liver fibrosis. Hence, hyaluronic acid (HA) modified liposomes co-delivering all-trans retinoic acid (RA) and L-arginine (L-arg) were constructed to reverse hepatic fibrosis. By exhibiting exceptional responsiveness to the fibrotic microenvironment, our cleverly constructed liposomes efficiently disrupted the hepatic sinus pathological barrier, leading to enhanced accumulation of liposomes in activated hepatic stellate cells (HSCs) and subsequent induction of HSCs quiescence. Specially, excessive ROS in liver fibrosis promotes the conversion of loaded L-arg to nitric oxide (NO). The ensuing NO serves to reestablish the fenestrae structure of capillarized LSECs, thereby augmenting the likelihood of liposomes reaching the hepatic sinus space. Furthermore, subsequent oxidation of NO by ROS into peroxynitrite activates pro-matrix metalloproteinases into matrix metalloproteinases, which further disrupts the deposited ECM barrier. Consequently, this NO-induced cascade process greatly amplifies the accumulation of liposomes within activated HSCs. More importantly, the released RA could induce quiescence of activated HSCs by significantly downregulating the expression of myosin light chain-2, thereby effectively mitigating excessive collagen synthesis and ultimately leading to the reversal of liver fibrosis. Overall, this integrated systemic strategy has taken a significant step forward in advancing the treatment of liver fibrosis.

Genetic Ablation of STE20-Type Kinase MST4 Does Not Alleviate Diet-Induced MASLD Susceptibility in Mice

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its advanced subtype, metabolic dysfunction-associated steatohepatitis (MASH), have emerged as the most common chronic liver disease worldwide, yet there is no targeted pharmacotherapy presently available. This study aimed to investigate the possible in vivo function of STE20-type protein kinase MST4, which was earlier implicated in the regulation of hepatocellular lipotoxic milieu in vitro, in the control of the diet-induced impairment of systemic glucose and insulin homeostasis as well as MASLD susceptibility. Whole-body and liver-specific Mst4 knockout mice were generated by crossbreeding conditional Mst4fl/fl mice with mice expressing Cre recombinase under the Sox2 or Alb promoters, respectively. To replicate the environment in high-risk subjects, Mst4-/- mice and their wild-type littermates were fed a high-fat or a methionine-choline-deficient (MCD) diet. Different in vivo tests were conducted in obese mice to describe the whole-body metabolism. MASLD progression in the liver and lipotoxic damage to adipose tissue, kidney, and skeletal muscle were analyzed by histological and immunofluorescence analysis, biochemical assays, and protein and gene expression profiling. In parallel, intracellular fat storage and oxidative stress were assessed in primary mouse hepatocytes, where MST4 was silenced by small interfering RNA. We found that global MST4 depletion had no effect on body weight or composition, locomotor activity, whole-body glucose tolerance or insulin sensitivity in obese mice. Furthermore, we observed no alterations in lipotoxic injuries to the liver, adipose, kidney, or skeletal muscle tissue in high-fat diet-fed whole-body Mst4-/- vs. wild-type mice. Liver-specific Mst4-/- mice and wild-type littermates displayed a similar severity of MASLD when subjected to an MCD diet, as evidenced by equal levels of steatosis, inflammation, hepatic stellate cell activation, fibrosis, oxidative/ER stress, and apoptosis in the liver. In contrast, the in vitro silencing of MST4 effectively protected primary mouse hepatocytes against ectopic lipid accumulation and oxidative cell injury triggered by exposure to fatty acids. In summary, these results suggest that the genetic ablation of MST4 in mice does not mitigate the initiation or progression of MASLD and has no effect on systemic glucose or insulin homeostasis in the context of nutritional stress. The functional compensation for the genetic loss of MST4 by yet undefined mechanisms may contribute to the apparent discrepancy between in vivo and in vitro phenotypic consequences of MST4 silencing.

Silymarin and Inflammation: Food for Thoughts

Inflammation is a vital defense mechanism, creating hostile conditions for pathogens, preventing the spread of tissue infection and repairing damaged tissues in humans and animals. However, when inflammation resolution is delayed or compromised as a result of its misregulation, the process proceeds from the acute phase to chronic inflammation, leading to the development of various chronic illnesses. It is proven that redox balance disturbances and oxidative stress are among major factors inducing NF-κB and leading to over-inflammation. Therefore, the anti-inflammatory properties of various natural antioxidants have been widely tested in various in vitro and in vivo systems. Accumulating evidence indicates that silymarin (SM) and its main constituent silibinin/silybin (SB) have great potential as an anti-inflammation agent. The main anti-inflammatory mechanism of SM/SB action is attributed to the inhibition of TLR4/NF-κB-mediated signaling pathways and the downregulated expression of pro-inflammatory mediators, including TNF-α, IL-1β, IL-6, IL-12, IL-23, CCL4, CXCL10, etc. Of note, in the same model systems, SM/SB was able to upregulate anti-inflammatory cytokines (IL-4, IL-10, IL-13, TGF-β, etc.) and lipid mediators involved in the resolution of inflammation. The inflammatory properties of SM/SB were clearly demonstrated in model systems based on immune (macrophages and monocytes) and non-immune (epithelial, skin, bone, connective tissue and cancer) cells. At the same time, the anti-inflammatory action of SM/SB was confirmed in a number of in vivo models, including toxicity models, nonalcoholic fatty liver disease, ischemia/reperfusion models, stress-induced injuries, ageing and exercising models, wound healing and many other relevant model systems. It seems likely that the anti-inflammatory activities of SM/SB are key elements on the health-promoting properties of these phytochemicals.

Role of the immune system in liver transplantation and its implications for therapeutic interventions

Liver transplantation (LT) stands as the gold standard for treating end-stage liver disease and hepatocellular carcinoma, yet postoperative complications continue to impact survival rates. The liver's unique immune system, governed by a microenvironment of diverse immune cells, is disrupted during processes like ischemia-reperfusion injury posttransplantation, leading to immune imbalance, inflammation, and subsequent complications. In the posttransplantation period, immune cells within the liver collaboratively foster a tolerant environment, crucial for immune tolerance and liver regeneration. While clinical trials exploring cell therapy for LT complications exist, a comprehensive summary is lacking. This review provides an insight into the intricacies of the liver's immune microenvironment, with a specific focus on macrophages and T cells as primary immune players. Delving into the immunological dynamics at different stages of LT, we explore the disruptions after LT and subsequent immune responses. Focusing on immune cell targeting for treating liver transplant complications, we provide a comprehensive summary of ongoing clinical trials in this domain, especially cell therapies. Furthermore, we offer innovative treatment strategies that leverage the opportunities and prospects identified in the therapeutic landscape. This review seeks to advance our understanding of LT immunology and steer the development of precise therapies for postoperative complications.

Chronic metabolic stress drives developmental programs and loss of tissue functions in non-transformed liver that mirror tumor states and stratify survival

Under chronic stress, cells must balance competing demands between cellular survival and tissue function. In metabolic dysfunction-associated steatotic liver disease (MASLD, formerly NAFLD/NASH), hepatocytes cooperate with structural and immune cells to perform crucial metabolic, synthetic, and detoxification functions despite nutrient imbalances. While prior work has emphasized stress-induced drivers of cell death, the dynamic adaptations of surviving cells and their functional repercussions remain unclear. Namely, we do not know which pathways and programs define cellular responses, what regulatory factors mediate (mal)adaptations, and how this aberrant activity connects to tissue-scale dysfunction and long-term disease outcomes. Here, by applying longitudinal single-cell multi -omics to a mouse model of chronic metabolic stress and extending to human cohorts, we show that stress drives survival-linked tradeoffs and metabolic rewiring, manifesting as shifts towards development-associated states in non-transformed hepatocytes with accompanying decreases in their professional functionality. Diet-induced adaptations occur significantly prior to tumorigenesis but parallel tumorigenesis-induced phenotypes and predict worsened human cancer survival. Through the development of a multi -omic computational gene regulatory inference framework and human in vitro and mouse in vivo genetic perturbations, we validate transcriptional (RELB, SOX4) and metabolic (HMGCS2) mediators that co-regulate and couple the balance between developmental state and hepatocyte functional identity programming. Our work defines cellular features of liver adaptation to chronic stress as well as their links to long-term disease outcomes and cancer hallmarks, unifying diverse axes of cellular dysfunction around core causal mechanisms.