STAT3: A key regulator in liver fibrosis

Advances in the treatment of liver injury based on mesenchymal stem cell-derived exosomes

Mesenchymal stem cells (MSCs) have shown a great potential role in treating liver injury. MSCs can promote liver regeneration by differentiating into hepatocytes, and can also secrete exosomes to participate in the repair of liver injury. Increasing evidence has shown that mesenchymal stem cell-derived exosomes (MSC-EXOs) play an important role in treating liver injury. In this review, the biogenesis and function of exosomes and the characteristics of MSC-EXOs were analyzed based on recent research results. MSC-EXOs are significant in liver injuries such as liver fibrosis, liver failure, hepatocellular carcinoma, oxidative stress, and lipid steatosis, and participate in the process of liver regeneration.

Pirfenidone Downregulates eIF6, P311, and TGF-β Expression and Improves Liver Fibrosis Induced by Bile Duct Ligation in Wistar Rats: Evidence for Liver Regeneration

Liver fibrosis (LF) is a clinical disorder characterized by inflammation and excessive accumulation of extracellular matrix (ECM). This study investigates the effects of the antifibrotic compound pirfenidone (PFD) on improving LF through histological changes and modulation of eukaryotic translation initiation factor 6 (eIF6), P311, and transforming growth factor beta (TGF-β) in rats with bile duct ligation (BDL)-induced LF. Rats received daily doses of PFD (200 and 500 mg/kg) for 4 weeks. The study encompassed biochemical, pathological, and immunohistochemical (IHC) analyses. mRNA levels of eIF6, P311, TGF-β, ECM deposition, hepatic stellate cell (HSC) activation, and inflammatory mediator genes were measured by RT-qPCR. Protein levels of eIF6, P311, and TGF-β were detected by western blotting. Compared with the BDL group, PFD dose-dependently reduced hydroxyproline content, liver index, biochemical parameters, fibrosis score, and fibrosis area. PFD also modulated BDL-induced hepatic inflammation, ECM accumulation, and HSC activation. IHC staining of Ki-67 and hepatocyte paraffin-1 revealed that PFD enhanced liver regeneration. The research confirmed that PFD gradually downregulated elevated eIF6, P311, and TGF-β levels in BDL-induced LF. These findings suggest that PFD could be a potential treatment for LF, as it may help attenuate fibrosis and enhance liver regeneration, possibly through the modulation of these specific markers.

FOXA1 knockdown alleviates inflammation and enhances osteogenic differentiation of periodontal ligament stem cells via STAT3 pathway

BACKGROUND

Evidence has confirmed that forkhead box protein A1 (FOXA1) inhibits the osteogenic differentiation of bone marrow mesenchymal stem cells. However, whether FOXA1 regulates the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) to participate in periodontitis process is unclear.

METHODS

Lipopolysaccharide (LPS) was used to treat hPDLSCs to mimic inflammation environments. FOXA1 expression was examined by quantitative real-time PCR and western blot. The levels of IL-6 and TNF-α were evaluated by quantitative real-time PCR, ELISA and immunohistochemistry staining. hPDLSCs osteogenic differentiation was assessed by measuring alkaline phosphatase activity, alizarin red S intensity and the levels of osteogenic differentiation-related markers. Besides, the expression of signal transducer and activator of transcription 3 (STAT3) pathway-related markers were examined by western blot and immunofluorescence staining.

RESULTS

FOXA1 was upregulated in the periodontal ligament tissues of periodontitis patients, and its knockdown enhanced osteogenic differentiation of hPDLSCs. Besides, downregulation of FOXA1 suppressed inflammation levels in LPS-induced hPDLSCs. Also, FOXA1 silencing promoted the osteogenic differentiation of LPS-induced hPDLSCs by the inactivation of STAT3 pathway.

CONCLUSION

Our data confirmed that knockdown of FOXA1 attenuated inflammation and enhanced osteogenic differentiation of LPS-induced hPDLSCs by regulating STAT3 pathway, indicating that FOXA1 might be a target for periodontitis treatment.

Novel Compound HJC0416 Attenuates Hepatic Fibrosis via HSP90/NF-κB-Associated Mechanism

INTRODUCTION

Chronic liver disease is driven by a prolonged wound healing response leading to fibrogenesis, potentially progressing to cirrhosis. Hepatic stellate cells (HSCs) are the primary cells driving hepatic fibrosis because they are major producers of extracellular matrix. The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ΚB) pathway is a key regulator of inflammatory signaling, and survival of activated HSCs has been found to be NF-KB dependent. Our team previously synthesized HJC0416-a signal transducer and activator of transcription three inhibitor with potent anti-inflammatory effects. In HSCs, HJC0416 reduced cell viability, extracellular matrix production, and-notably-NF-KB activation. However, HJC0416's antifibrogenetic mechanism remains unknown. This study examined the effects of HJC0416 on NF-KB and its associate factor HSP-90 in HSCs.

METHODS

The activated human HSC line LX-2 was treated with either HJC0416 or 17-AAG, then exposed to TNFα as indicated. Nuclear and cytosolic proteins were isolated for Western blot or immunofluorescence assay.

RESULTS

HJC0416 significantly attenuated TNFα-induced IκBα phosphorylation, NF-KBp65 nuclear translocation, and DNA binding activity. Endogenous and TNFα-induced p65 phosphorylation of S536 was suppressed by HJC0416. Notably, HJC0416 dose-dependently attenuated the expression of FAK, IKKα, and signal transducer and activator of transcription three which are Heat Shock Protein 90 (HSP90) interacting proteins. The expression of other HSP90 interacting proteins-RIP1, AKT, FAK, and cyclin-dependent kinase nine-were decreased. HSP90-specific inhibitor 17-AAG significantly attenuated TNFα-induced IκBα phosphorylation and degradation, p65 nuclear translocation, DNA binding, and production of collagen type I and fibronectin.

CONCLUSIONS

The HSP90 chaperone protein may be a key intermediary linking HJC0416's ability to inhibit NF-κB activity. HJC0416 may be a promising drug candidate for liver fibrosis.

Active Targets and Potential Mechanisms of Erhuang Quzhi Formula in Treating NAFLD: Network Analysis and Experimental Assessment

The purpose of this research was to investigate the main active components, potential targets of action, and pharmacological mechanisms of Erhuang Quzhi Formula (EHQZF) against NAFLD using network pharmacology, molecular docking, and experimental validation. The main active chemical components of EHQZF and the potential targets for treating NAFLD were extracted and analyzed. The PPI network diagram of "Traditional Chinese Medicine-Active Ingredients-Core Targets" was constructed and the GO, KEGG, and molecular docking analysis were carried out. Identification of components in traditional Chinese medicine compounds was conducted by LC-MS. NAFLD models were established and relevant pathologic indicators and Western blot were analyzed in vivo and ex vivo. Totally 8 herbs attributed to the liver meridian and 20 corresponding targets of NAFLD were obtained from EHQZF. Flavonoids and phenolic acids as the main components of EHQZF treated NAFLD through the MAPK/AKT signaling pathway. Pathway enrichment analysis focused on the MAPK/AKT signaling pathway and apoptosis signaling pathway. Molecular docking showed that Quercetin and Luteolin had stable binding structures with AKT1, STAT3, and other targets. Experiments showed that EHQZF reduced lipid accumulation, regulated changes in adipose tissue, inhibited the MAPK/AKT signaling pathway and exert multiple components, several targets, and multiple pathway interactions to treat NAFLD.

The overlooked impact of cadmium on the progression of chronic hepatitis and the onset of renal failure in advanced cirrhosis

The mechanism of hepatocyte destruction in chronic hepatitis is not completely understood, while renal failure in individuals with advanced cirrhosis is a significant concern. It is well known that smokers who are chronically infected with hepatitis B and C viruses (HBV, HCV) have a poor prognosis. In the present review, we propose a novel hypothesis that environmental exposure to a nephrotoxic metal pollutant, cadmium (Cd) may contribute to hepatocyte destruction and, subsequently, affect the duration of chronic hepatitis. The metal binding protein, metallothionein (MT) sequesters cadmium as CdMT complexes, and effectively neutralize its adverse effects. Cadmium can cause the damage to hepatocytes, only when it is in an unbound form. In addition to its ability to bind cadmium, MT can act as a scavenger of reactive oxygen species (ROS). However, the cellular MT levels may decrease, when ROS is excessively produced under the pathologic chronic viral hepatitis conditions, especially while the cellular levels of zinc may also be low. Zinc is an endogenous inducer of MT, and is required for maximal MT expression. High ROS levels in the hepatocytes diminishes MT binding to metals. Consequently, the proportion of unbound Cd is increased and thus there is more hepatic damage. Hepatic damage leads to a copious release of CdMT into the circulation. This significant cadmium load, which occurs after hepatic damage, and in some cases, muscle atrophy, induces kidney damage with resultant renal failure in advanced cirrhosis.

Pharmacotherapeutic potential of bilobetin to combat chromium induced hepatotoxicity via regulating TLR-4, Nrf-2/Keap-1, JAK1/STAT3 and NF-κB pathway: A pharmacokinetic and molecular dynamic approach

BACKGROUND

Chromium (Cr) is one of the top-notch noxious heavy metals that is documented to exert deleterious effects on various body organs including the liver. Bilobetin (BLB) is a natural flavonoid which exhibits a wide range of medicinal properties.

AIM

This trial was executed to investigate the pharmacotherapeutic potential of BLB to avert Cr instigated hepatotoxicity via modulating TLR4, JAK1/STAT3, Nrf-2/Keap-1 and NF-κB pathway.

RESEARCH LAYOUT

Our trial was executed on thirty-six male albino rats that were segregated into four equal groups including the control, Cr (10 mg/kg), Cr (10 mg/kg) + BLB (12 mg/kg) and BLB (12 mg/kg) alone treated group. Various biochemical parameters were assessed by using qRT-PCR, molecular docking, molecular dynamic simulation and histological approaches.

FINDINGS

Our results revealed that Cr administration significantly impaired the health of hepatic tissues by reducing the gene expression of Nrf-2 and its downregulating genes while promoting the levels of oxidative stress markers (ROS and MDA). Moreover, Cr administration upregulated the hepatic enzymes including ALT, GGT, AST, and ALP while concurrently decreasing the levels of total protein and albumin. Cr exposure also elevated the gene expression of pro-inflammatory cytokines including toll-like receptor 4 (TLR4), high mobility group box 1 (HMGB1) nuclear factor kappa B (NF-κB), Janus kinase 1 (JAK1), signal transducer and activator of transcription 3 (STAT3), tumor necrosis factor alpha (TNF-α), C-reactive proteins, interferon-gamma inducible protein-10 (IP-10), Interleukin beta-1(IL-1β), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2). Hepatic apoptosis was observed to be elevated following the Cr intoxication. Nonetheless, BLB treatment remarkably alleviated the hepatic damages via regulating the biochemical as well as histological profile of liver. Our findings are further endorsed by molecular docking analysis that demonstrated that BLB exhibit strong binding affinity to Keap-1 and STAT3 thus supporting its efficient hepatoprotective potential.

CONCLUSION

BLB protected the hepatic tissues via regulating Cr induced impairments. These findings were confirmed by molecular docking and molecular dynamic simulation analysis.

Artesunate: A potential drug for the prevention and treatment from hepatitis to hepatocellular carcinoma

Liver cancer represents a multifactorial, multistage, and intricately progressive malignancy. Over the past decade, artesunate (ART), initially renowned for its anti-malarial efficacy, has been the focus of over 3000 studies uncovering its diverse pharmacological actions, including anti-inflammatory, immunoregulatory, metabolic regulatory, anti-fibrotic, and anti-cancer properties. This review highlights ART's role in the multistep progression from hepatitis to cancer and its underlying regulatory mechanisms, revealing signal transducer and activator of transcription 3 (STAT3) and ferroptosis (a novel form of programmed cell death) as promising therapeutic targets. ART demonstrates efficacy in inhibiting hepatitis virus infections, modulating inflammation, and facilitating recovery from inflammatory processes. During stages of hepatic fibrosis or cirrhosis, ART reverses fibrotic and cirrhotic changes by suppressing hepatic stellate cell activity, regulating inflammatory pathways, inhibiting hematopoietic stem cell proliferation, and inducing ferroptosis. Additionally, ART hinders hepatocellular carcinoma (HCC) cell proliferation, invasion, and metastasis, induces apoptosis and autophagy, combats drug resistance, and enhances chemosensitivity. Collectively, ART exhibits multi-step actions across multiple targets and signaling pathways, highlighting its potential as a clinical candidate for the prevention and treatment of liver cancer, from hepatitis and hepatic fibrosis to advanced HCC.

Upadacitinib counteracts hepatic lipid deposition via the repression of JAK1/STAT3 signaling and AMPK/autophagy-mediated suppression of ER stress

Upadacitinib (UPA) has been utilized to treat conditions such as rheumatoid arthritis, psoriatic arthritis, atopic dermatitis, ulcerative colitis, Crohn's disease, ankylosing spondylitis, and axial spondyloarthritis by modulating inflammation via the JAK pathway. However, its impact on hepatic lipogenesis remains insufficiently studied. This research evaluated protein expression through Western blotting, lipid accumulation with oil red O staining, autophagosomes in hepatocytes via MDC staining, and hepatic apoptosis via cell viability and caspase 3 activity assays. This study aimed to explore the effects of UPA on hepatic lipogenesis and the underlying molecular mechanisms in in vitro models of hepatic steatosis. These findings demonstrated that UPA reduced lipid deposition, apoptosis, and ER stress in palmitate-treated hepatocytes. UPA treatment inhibited phosphorylated JAK1 and STAT3 while promoting the expression of phosphorylated AMPK and autophagy markers. AMPK siRNA negated the effects of UPA on lipogenic lipid deposition, apoptosis, JAK1/STAT3 phosphorylation, and ER stress. These results reveal that UPAmitigates ER stress through the JAK1/STAT3/AMPK pathway, thereby reducing lipid deposition and apoptosis in hyperlipidemic hepatocytes, supporting its potential as a therapeutic strategy for treating hepatic steatosis in obese individuals.

Mechanistic Studies of Cyclooxygenase-2 (COX-2) in Skeletal Muscle Cells During Rotator Cuff Injury: An In Vitro Study

The mechanism of rotator cuff injury remains to be elucidated. And COX-2 plays a dual role in skeletal muscle injury and regeneration, would be associated with the development of rotator cuff injury. Therefore, we chose human skeletal muscle cells (HSKMC) as an in vitro muscle tissue model and transfected lentivirus with overexpressed COX-2 to simulate the in vitro environment of rotator cuff injury. To investigate the specific molecular biological mechanism of COX-2, transcriptome sequencing (RNA-Seq) was used to analyze the differentially expressed mRNAs in HSKMC overexpressing COX-2. Enrichment analysis was performed to analyze these differentially expressed genes and real-time quantitative PCR (RT-qPCR) was used to examine the mRNA levels of genes induced by overexpression. Subsequently, the role of COX-2 in cell proliferation was confirmed by cell counting kit-8 (CCK-8), and focal adhesion kinase (FAK) and signal transducer and activator of transcription 3 (STAT3) phosphorylation induced by COX-2 was utilized by western blotting (WB). The results showed that total of 30,759 differentially expressed genes were obtained, and the expression of CYP4F3 and GPR87 was significantly increased. COX-2 could bind CYP4F3 and GPR87 and co-localize with them in the cytoplasm. Finally, COX-2 promoted the proliferation of human skeletal muscle cells by activating the FAK and STAT3 pathways.

Landscape of extrachromosomal circular DNAs, transcriptome, and proteome analysis reveals insights into alcoholic liver cirrhosis

Alcoholic liver cirrhosis (ALC) is a result of excessive and chronic alcohol consumption. Because alchol can cause DNA damage, extrachromosomal circular DNA (eccDNA) was investigated in ALC liver due to it can be a result of DNA damage. Considering eccDNA has ability to lead to genomic instability as an enhancer of gene transcription, we utilized Circle-Seq to identify differences in eccDNA profiles and gene expression patterns in liver samples obtained from ALC patients (n = 3) and healthy controls (n = 3) to investigate the role of eccDNA in the development of ALC. The abundance of eccDNA in ALC (mean = 13,349) were higher than the healthy control (mean = 11,557) without significant difference (pvalue = 0.6530). We observed 1,032 eccDNA containing genes showed higher expression in ALC patients compared to healthy controls (p < 0.05, log2FC > 1). Notably, we discovered seven genes that exhibited a significant positive correlation between eccDNA abundance and gene expression levels. These genes include A disintegrin and metalloproteinase with thrombospondin motifs 2 (ADAMTS2), Voltage-dependent L-type calcium channel subunit alpha-1C (CACNA1C), Protein TANC1 (TANC1), Integrin alpha-2 (ITGA2), EH domain-containing protein 4 (EHD4), Phosphofurin acidic cluster sorting protein 1 (PACS1), and Neuron navigator 2 (NAV2). Through mass spectrometry proteomics, ITGA2 were found to have significantly higher abbudance in ALC. Integrins are a family of proteins plays key roles in the fibrosis development of liver. Thus, our study opens a new perspective for liver fibrosis development.

STAT3-specific nanocarrier for shRNA/drug dual delivery and tumor synergistic therapy

Non-small cell lung cancer (NSCLC) is a major disease with high incidence, low survival rate and prone to develop drug resistance to chemotherapy. The mechanism of secondary drug resistance in NSCLC chemotherapy is very complex, and studies have shown that the abnormal activation of STAT3 (Signal Transducer and Activator of Transcription 3) plays an important role in it. In this study, the pGPU6/GFP/Neo STAT3-shRNA recombinant plasmid was constructed with STAT3 as the precise target. By modifying hydrophilic and hydrophobic blocks onto chitosan, a multifunctional vitamin E succinate-chitosan-polyethylene glycol monomethyl ether histidine (VES-CTS-mPEG-His) micelles were synthesized. The micelles could encapsulate hydrophobic drug doxorubicin through self-assembly, and load the recombinant pGPU6/GFP/Neo STAT3-shRNA (pDNA) through positive and negative charges to form dual-loaded nanoparticles DOX/VCPH/pDNA. The co-delivery and synergistic effect of DOX and pDNA could up-regulate the expression of PTEN (Phosphatase and Tensin Homolog), down-regulate the expression of CD31, and induce apoptosis of tumor cells. The results of precision targeted therapy showed that DOX/VCPH/pDNA could significantly down-regulate the expression level of STAT3 protein, further enhancing the efficacy of chemotherapy. Through this study, precision personalized treatment of NSCLC could be effectively achieved, reversing its resistance to chemotherapy drugs, and providing new strategies for the treatment of drug-resistant NSCLC.

Integrated network toxicology, transcriptomics and gut microbiomics reveals hepatotoxicity mechanism induced by benzo[a]pyrene exposure in mice

Benzo[a]pyrene (BaP) is a ubiquitous environmental pollutant posing various toxicity effects on organisms. Previous studies demonstrated that BaP could induce hepatotoxicity, while the underlying mechanism remains incompletely elucidated. In this study, a comprehensive strategy including network toxicology, transcriptomics and gut microbiomics was applied to investigate the hepatotoxicity and the associated mechanism of BaP exposure in mice. The results showed that BaP induced liver damage, liver oxidative stress and hepatic lipid metabolism disorder. Mechanistically, BaP may disrupt hepatic lipid metabolism through increasing the uptake of free fatty acid (FFA), promoting the synthesis of FA and triglyceride (TG) in the liver and suppressing lipid synthesis in white adipose tissue. Moreover, integrated network toxicology and hepatic transcriptomics revealed that BaP induced hepatotoxicity by acting on several core targets, such as signal transducer and activator of transcription 1 (STAT1), C-X-C motif chemokine ligand 10 (CXCL10) and toll-like receptor 2 (TLR2). Further analysis suggested that BaP inhibited JAK2-STAT3 signaling pathway, as supported by molecular docking and western blot. The 16S rRNA sequencing showed that BaP changed the composition of gut microbiota which may link to the hepatotoxicity based on the correlation analysis. Taken together, this study demonstrated that BaP caused liver injury, hepatic lipid metabolism disorder and gut microbiota dysbiosis, providing novel insights into the hepatotoxic mechanism induced by BaP exposure.

BRUCE liver-deficiency potentiates MASLD/MASH in PTEN liver-deficient background by impairment of mitochondrial metabolism in hepatocytes and activation of STAT3 signaling in hepatic stellate cells

Metabolic dysfunction-associated steatotic liver disease (MASLD) is currently the most common liver disease, affecting up to 25% of people worldwide, featuring excessive fat accumulation in hepatocytes. Its advanced form, metabolic dysfunction-associated steatohepatitis (MASH), is a serious disease with hepatic inflammation and fibrosis, increasing the need for liver transplants. However, the pathogenic mechanism of MASLD and MASH is not fully understood. We reported that BRUCE ( BIRC6) is a liver cancer suppressor and is downregulated in MASLD/MASH patient liver specimens, though the functional role of BRUCE in MASLD/MASH remains to be elucidated. To this end, we generated liver-specific double KO (DKO) mice of BRUCE and PTEN, a major tumor suppressor and MASLD/MASH suppressor. By comparing liver histopathology among 2-3-month-old mice, there were no signs of MASLD or MASH in BRUCE liver-KO mice and only onset of steatosis in PTEN liver-KO mice. Interestingly, DKO mice had developed robust hepatic steatosis with inflammation and fibrosis. Further analysis of mitochondrial function with primary hepatocytes found moderate reduction of mitochondrial respiration, ATP production and fatty acid oxidation in BRUCE KO and the greatest reduction in DKO hepatocytes. Moreover, aberrant activation of pro-fibrotic STAT3 signaling was found in hepatic stellate cells (HSCs) in DKO mice which was prevented by administered STAT3-specific inhibitor (TTI-101). Collectively, the data demonstrates by maintaining mitochondrial metabolism BRUCE works in concert with PTEN to suppress the pro-fibrogenic STAT3 activation in HSCs and consequentially prevent MASLD/MASH. The findings highlight BRUCE being a new co-suppressor of MASLD/MASH.

Ursolic acid improves necroptosis via STAT3 signaling in intestinal ischemia/reperfusion injury

Intestinal ischemia/reperfusion injury (IRI) poses a serious threat to human survival and quality of life with high mortality and morbidity rates. The current absence of effective treatments for intestinal IRI highlights the urgent need to identify new therapeutic targets. Ursolic acid (UA), a pentacyclic triterpene natural compound, has been shown to possess various pharmacological properties including intestinal protection. However, its potential protective efficacy on intestinal IRI remains elusive. This study aimed to investigate the effect of UA on intestinal IRI and explore the underlying mechanisms. To achieve this, we utilized network pharmacology to analyze the mechanism of UA in intestinal IRI and assessed UA's effects on intestinal IRI using a mouse model of superior mesenteric artery occlusion/reperfusion and an in vitro model of oxygen-glucose deprivation and reperfusion-induced IEC-6 cells. Our results demonstrated that UA improved necroptosis through the RIP1/RIP3/MLKL pathway, reduced necroinflammation via the HMGB1/TLR4/NF-κB pathway, attenuated morphological damage, and enhanced intestinal barrier function. Furthermore, UA pretreatment downregulated the phosphorylation level of signal transducer and activator of transcription 3 (STAT3). The effects of UA were attenuated by the STAT3 agonist Colivelin. In conclusion, our study suggests that UA can improve intestinal IRI by inhibiting necroptosis in enterocytes via the suppression of STAT3 activation. These results provide a theoretical basis for UA treatment of intestinal IRI and related clinical diseases.

Hepatocellular Interactions of Potential Nutraceuticals in the Management of Inflammatory NAFLD

Numerous studies highlight the potential of natural antioxidants, such as those found in foods and plants, to prevent or treat nonalcoholic fatty liver disease (NAFLD). Inflammation is a key factor in the progression from high-fat diet-induced NAFLD to nonalcoholic steatohepatitis (NASH). Injured liver cells and immune cells release inflammatory cytokines, activating hepatic stellate cells. These cells acquire a profibrogenic phenotype, leading to extracellular matrix accumulation and fibrosis. Persistent fibrosis can progress to cirrhosis. Fatty infiltration, oxidative stress, and inflammation exacerbate fatty liver diseases. Thus, many plant-derived antioxidants, like silymarin, silibinin, curcumin, resveratrol, berberine, and quercetin, have been extensively studied in experimental models and clinical patients with NAFLD. Experimentally, these compounds have shown beneficial effects in reducing lipid accumulation, oxidative stress, and inflammatory markers by modulating the ERK, NF-κB, AMPKα, and PPARγ pathways. They also help decrease metabolic endotoxemia, intestinal permeability, and gut inflammation. Clinically, silymarin and silibinin have been found to reduce transaminase levels, while resveratrol and curcumin help alleviate inflammation in NAFLD patients. However, these phytocompounds exhibit poor water solubility, leading to low oral bioavailability and hindering their biological efficacy. Additionally, inconclusive clinical results highlight the need for further trials with larger populations, longer durations, and standardized protocols.

Hydroxysafflor yellow A ameliorates alcohol-induced liver injury through PI3K/Akt and STAT3/NF-κB signaling pathways

BACKGROUND

Alcohol-associated liver disease (ALD) is a prevalent liver ailment. It has escalated into a significant public health issue, imposing substantial burdens on medical, economic, and social domains. Currently, oxidative stress, inflammation, and apoptosis are recognized as crucial culprits in improving ALD. Consequently, mitigating these issues has emerged as a promising avenue for enhancing ALD. Hydroxysafflor yellow A (HSYA) is the main ingredient in safflower, showing excellent antioxidative stress, anti-inflammatory, and anti-apoptosis traits. However, there are limited investigations into the mechanisms by which HSYA ameliorates ALD PURPOSE: We investigated whether HSYA, a significant constituent of Asteraceae safflower, exerts antioxidant stress and attenuates inflammation and anti-apoptotic effects through PI3K/Akt and STAT3/NF-κB pathways, thereby ameliorating ALD METHODS: We established two experimental models: an ethanol-induced liver damage mouse model in vivo and a HepG2 cell alcohol injury model in vitro RESULTS: The results demonstrated that HSYA effectively ameliorated liver tissue damage, reduced levels of ALT, AST, LDL-C, TG, TC, and MDA, enhanced HDL-C levels, SOD and GSH activities, reduced ROS accumulation in cells, and activated the Nrf2 pathway, a transcription factor involved in antioxidant defense. By regulating the PI3K/Akt and STAT3/NF-κB pathways, HSYA exhibits notable antioxidative stress, anti-inflammatory, and anti-apoptotic effects, effectively impeding ALD's advancement. To further confirm the regulatory effect of HSYA on PI3K/Akt and downstream signaling pathways, the PI3K activator 740 Y-P was used and was found to reverse the downregulation of PI3K by HSYA CONCLUSION: This study supports the effectiveness of HSYA in reducing ALD by regulating the PI3K/Akt and STAT3/NF-κB pathways, indicating its potential medicinal value.

Ginsenoside RD prevents acute liver injury in mice by inhibiting STAT3-mediated NLRP3/GSDMD activation

We investigated the role and mechanism of ginsenoside RD (GRD) in acute liver injury. Network pharmacology was used to analyze the correlations among GRD-liver injury-pyroptosis targets. A mouse model of acute liver injury was established by lipopolysaccharide + d-galactose（LPS + d/Gal). After pretreatment with GRD, the changes in mouse liver function were detected. The histopathological changes were assayed by hematoxylin and eosin and Masson staining, the tissue expressions of inflammatory cytokines were detected by enzyme-linked immunosorbent assay, and the protein expressions were assayed by immunohistochemical staining and Western blotting. Meanwhile, mechanism research was conducted using STAT3-knockout transgenic mice and STAT3-IN13, a STAT3 inhibitor. GRD inhibited liver injury, mitigated tissue inflammation, and suppressed STAT3-mediated pyroptosis in mice. After applying STAT3-knockout mouse model or STAT3-IN13, GRD did not further inhibit the liver injury. GRD can resist liver injury by inhibiting the STAT3-mediated pyroptosis, which is one of the hepatoprotective mechanisms of GRD.

Alantolactone alleviates epithelial-mesenchymal transition by regulating the TGF-β/STAT3 signaling pathway in renal fibrosis

Objective

The epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (RTECs) plays a crucial role in renal interstitial fibrosis and inflammation, which are key components of chronic kidney disease (CKD). Alantolactone, a selective inhibitor of signal transducer and activator of transcription 3 (STAT3), is used in Chinese herbal medicine. Despite its use, the effects of alnatolactone on EMT of RTECs has not been fully elucidated.

Methods

In this study, we investigated the potential of alantolactone to EMT in vivo and in vitro. Our experiments were performed using a unilateral ureteral obstruction (UUO) models and HK-2 cells, RTECs, treated with transforming growth factor (TGF-β).

Results

Alantolactone decreased tubular injury and reduced the expression of vimentin, a key EMT marker, while increasing E-cadherin expression in UUO kidneys. Similarly, in RTECs, alantolactone inhibited TGF-β-induced EMT and its markers. Furthermore, alantolactone attenuated UUO- and TGF-β-induced STAT3 phosphorylation both in vivo and in vitro, and inhibited the expression of TWIST, an EMT transcription factor, in both models.

Conclusion

Alantolactone improves EMT in RTECs by inhibiting STAT3 phosphorylation and Twist expression, suggesting its potential as a therapeutic agent for kidney fibrosis.

Mechanism Study of Xiaoyao San against Nonalcoholic Steatohepatitis-Related Liver Fibrosis Based on a Combined Strategy of Transcriptome Analysis and Network Pharmacology

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of liver disease worldwide. Nonalcoholic steatohepatitis (NASH) is an advanced form of NAFLD. The livers of patients with NASH are more likely to develop fibrosis. Xiaoyao San (XYS) is a classic traditional Chinese medicine (TCM) formula that has been widely used in treating liver diseases. In this study, we elucidated the effects and mechanism of XYS in treating NASH-related liver fibrosis by combining high-throughput sequencing-based high-throughput screening with network pharmacology analysis. Our work revealed that XYS may play a role in preventing NASH-related liver fibrosis by regulating biological functions related to the extracellular matrix (ECM), inflammation, and metabolism. Additionally, Bupleuri Radix, Poria, Zingiberis Rhizoma Recens, and Paeoniae Radix Alba are the key herbs of XYS that could partially represent the functions of XYS. These regulatory effects are mediated by targeting signal transducer and activator of transcription 3 (STAT3), nuclear factor kappa B (NFκB), and peroxisome proliferator-activated receptor gamma (PPARγ) signaling. Narcissin, casuarictin, and γ-sitosterol were identified as representative active compounds in XYS targeting STAT3, NFκB, and PPARγ, respectively. Taken together, our findings provide a novel strategy for investigating the pharmacological effects and biological mechanisms of a TCM formula.

Cryptotanshinone alleviates liver fibrosis via inhibiting STAT3/CPT1A-dependent fatty acid oxidation in hepatic stellate cells

Hepatic stellate cells (HSCs) are a major source of fibrogenic cells and play a central role in liver fibrogenesis. HSC activation depends on metabolic activation, for which it is well established that fatty acid oxidation (FAO) sustains their rapid proliferative rate. Studies have indicated that tanshinones inhibit HSC activation, however, the anti-fibrosis mechanisms of tanshinones are remain unclear. Herein, we reported that cryptotanshinone (CTS), a lipid-soluble ingredient of Salvia miltiorrhiza Bunge, exhibited the strongest inhibitory effects on HSC-LX2 proliferation and activation. CTS could induce lipocyte phenotype in mouse primary HSC and HSC-LX2. Transcriptomic sequencing and qPCR revealed that CTS regulated fatty acid metabolism and inhibited CPT1A and CPT1B expression. Target prediction suggested CTS regulates lipid metabolism by targeting STAT3. Mechanistically, the level of ATP and acetyl-CoA were reduced by the treatment of CTS, indicating that CTS could inhibit the level of FAO. Furthermore, CTS could inhibit the phosphorylation and nuclear translocation of STAT3. Additionally, CPT1A overexpression reversed the efficacy of CTS. Finally, CTS (40 mg/kg/day) attenuated CCl4-induced liver fibrosis and inhibited collagen production and HSC activation. Moreover, the results of immunofluorescence showed that α-SMA and p-STAT3 were co-located, and CTS could reduce the levels of p-STAT3 and α-SMA. In summary, CTS alleviated liver fibrosis by inhibiting the p-STAT3/CPT1A-dependent FAO both in vitro and in vivo, making it a potential candidate drug for the treatment of liver fibrosis.

Graveoline attenuates D-GalN/LPS-induced acute liver injury via inhibition of JAK1/STAT3 signaling pathway

Graveoline exhibits various biological activities. However, only limited studies have focused on its hepatoprotective properties. This study evaluated the anti-inflammatory and hepatoprotective activities of graveoline, a minor 2-phenylquinolin-4-one alkaloid isolated from Ruta graveolens L., in a liver injury model in vitro and in vivo. A network pharmacology approach was used to investigate the potential signaling pathway associated with the hepatoprotective activity of graveoline. Subsequently, biological experiments were conducted to validate the findings. Topological analysis of the KEGG pathway enrichment revealed that graveoline mediates its hepatoprotective activity through genes associated with the hepatitis B viral infection pathway. Biological experiments demonstrated that graveoline effectively reduced the levels of alanine transaminase and aspartate transaminase in lipopolysaccharide (LPS)-induced HepG2 cells. Graveoline exerted antihepatitic activity by inhibiting the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and elevated the anti-inflammatory cytokines interleukin-4 (IL-4) and interleukin-10 (IL-10) in vitro and in vivo. Additionally, graveoline exerted its hepatoprotective activity by inhibiting JAK1 and STAT3 phosphorylation both in vitro and in vivo. In summary, graveoline can attenuate acute liver injury by inhibiting the TNF-α inflammasome, activating IL-4 and IL-10, and suppressing the JAK1/STAT3 signaling pathway. This study sheds light on the potential of graveoline as a promising therapeutic agent for treating liver injury.

A First Metabolite Analysis of Norfolk Island Pine Resin and Its Hepatoprotective Potential to Alleviate Methotrexate (MTX)-Induced Hepatic Injury

Drug-induced liver injury (DILI) represents a significant clinical challenge characterized by hepatic dysfunction following exposure to diverse medications. Methotrexate (MTX) is a cornerstone in treating various cancers and autoimmune disorders. However, the clinical utility of MTX is overshadowed by its ability to induce hepatotoxicity. The current study aims to elucidate the hepatoprotective effect of the alcoholic extract of Egyptian Araucaria heterophylla resin (AHR) on MTX-induced liver injury in rats. AHR (100 and 200 mg/kg) significantly decreased hepatic markers (AST, ALT, and ALP), accompanied by an elevation in the antioxidant's markers (SOD, HO-1, and NQO1). AHR extract also significantly inhibited the TGF-β/NF-κB signaling pathway as well as the downstream cascade (IL-6, JAK, STAT-3, and cyclin D). The extract significantly reduced the expression of VEGF and p38 with an elevation in the BCL2 levels, in addition to a significant decrease in the IL-1β and TNF-α levels, with a prominent effect at a high dose (200 mg/kg). Using LC-HRMS/MS analysis, a total of 43 metabolites were tentatively identified, and diterpenes were the major class. This study presents AHR as a promising hepatoprotective agent through inhibition of the TGF-β/NF-κB and JAK/STAT3 pathways, besides its antioxidant and anti-inflammatory effects.

Endothelial POFUT1 controls injury-induced liver fibrosis by repressing fibrinogen synthesis

BACKGROUND & AIMS

NOTCH signaling in liver sinusoidal endothelial cells (LSECs) regulates liver fibrosis, a pathological feature of chronic liver diseases. POFUT1 is an essential regulator of NOTCH signaling. Here, we investigated the role of LSEC-expressed POFUT1 in liver fibrosis.

METHODS

Endothelial-specific Pofut1 knockout mice were generated and experimental liver fibrosis was induced by chronic carbon tetrachloride exposure or common bile duct ligation. Liver samples were assessed by ELISA, histology, electron microscopy, immunostaining and RNA in situ hybridization. LSECs and hepatic stellate cells (HSCs) were isolated for gene expression analysis by RNA sequencing, qPCR, and western blotting. Signaling crosstalk between LSECs and HSCs was investigated by treating HSCs with supernatant from LSEC cultures. Liver single-cell RNA sequencing datasets from patients with cirrhosis and healthy individuals were analyzed to evaluate the clinical relevance of gene expression changes observed in mouse studies.

RESULTS

POFUT1 loss promoted injury-induced LSEC capillarization and HSC activation, leading to aggravated liver fibrosis. RNA sequencing analysis revealed that POFUT1 deficiency upregulated fibrinogen expression in LSECs. Consistently, fibrinogen was elevated in LSECs of patients with cirrhosis. HSCs treated with supernatant from LSECs of Pofut1 null mice showed exacerbated activation compared to those treated with supernatant from control LSECs, and this effect was attenuated by knockdown of fibrinogen or by pharmacological inhibition of fibrinogen receptor signaling, altogether suggesting that LSEC-derived fibrinogen induced the activation of HSCs. Mechanistically, POFUT1 loss augmented fibrinogen expression by enhancing NOTCH/HES1/STAT3 signaling.

CONCLUSIONS

Endothelial POFUT1 prevents injury-induced liver fibrosis by repressing the expression of fibrinogen, which functions as a profibrotic paracrine signal to activate HSCs. Therapies targeting the POFUT1/fibrinogen axis offer a promising strategy for the prevention and treatment of fibrotic liver diseases.

IMPACT AND IMPLICATIONS

Paracrine signals produced by liver vasculature play a major role in the development of liver fibrosis, which is a pathological hallmark of most liver diseases. Identifying those paracrine signals is clinically relevant in that they may serve as therapeutic targets. In this study, we discovered that genetic deletion of Pofut1 aggravated experimental liver fibrosis in mouse models. Moreover, fibrinogen was identified as a downstream target repressed by Pofut1 in liver endothelial cells and functioned as a novel paracrine signal that drove liver fibrosis. In addition, fibrinogen was found to be relevant to cirrhosis and may serve as a potential therapeutic target for this devastating human disease.

Hepatoprotective effects of paeonol by suppressing hepatic stellate cell activation via inhibition of SMAD2/3 and STAT3 pathways

Hepatic stellate cell (HSC) activation is a key event in extracellular matrix accumulation, causing hepatic fibrosis. Therefore, identifying chemicals that inhibit HSC activation is an important therapeutic strategy for hepatic fibrosis. The aim of this study was to investigate the therapeutic effects of paeonol on HSC activation. In LX-2 cells, paeonol inhibited the expression of collagen and decreased the expression of HSC activation markers. In mice with thioacetamide-induced liver fibrosis, paeonol treatment decreased the serum levels of aspartate aminotransferase and alanine transaminase and mRNA expression of α-smooth muscle actin, platelet-derived growth factor-β, and connective-tissue growth factor. Investigation of the underlying molecular mechanism of paeonol showed that paeonol inhibits the SMAD2/3 and STAT3 signaling pathways that are important for HSC activation. On the basis of these results, paeonol should be investigated and developed further for hepatic fibrosis treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01440-9.

The antiprotozoal drug nitazoxanide improves experimental liver fibrosis in mice

Nitazoxanide is an FDA-approved antiprotozoal drug. Our previous studies find that nitazoxanide and its metabolite tizoxanide affect AMPK, STAT3, and Smad2/3 signals which are involved in the pathogenesis of liver fibrosis, therefore, in the present study, we examined the effect of nitazoxanide on experimental liver fibrosis and elucidated the potential mechanisms. The in vivo experiment results showed that oral nitazoxanide (75, 100 mg·kg-1) significantly improved CCl4- and bile duct ligation-induced liver fibrosis in mice. Oral nitazoxanide activated the inhibited AMPK and inhibited the activated STAT3 in liver tissues from liver fibrosis mice. The in vitro experiment results showed that nitazoxanide and its metabolite tizoxanide activated AMPK and inhibited STAT3 signals in LX-2 cells (human hepatic stellate cells). Nitazoxanide and tizoxanide inhibited cell proliferation and collagen I expression and secretion of LX-2 cells. Nitazoxanide and tizoxanide inhibited transforming growth factor-β1 (TGF-β1)- and IL-6-induced increases of cell proliferation, collagen I expression and secretion, inhibited TGF-β1- and IL-6-induced STAT3 and Smad2/3 activation in LX-2 cells. In mouse primary hepatic stellate cells, nitazoxanide and tizoxanide also activated AMPK, inhibited STAT3 and Smad2/3 activation, inhibited cell proliferation, collagen I expression and secretion. In conclusion, nitazoxanide inhibits liver fibrosis and the underlying mechanisms involve AMPK activation, and STAT3 and Smad2/3 inhibition.

Hepatokine ITIH3 protects against hepatic steatosis by downregulating mitochondrial bioenergetics and de novo lipogenesis

Recent studies demonstrate that liver secretory proteins, also known as hepatokines, regulate normal development, obesity, and simple steatosis to non-alcoholic steatohepatitis (NASH) progression. Using a panel of ∼100 diverse inbred strains of mice and a cohort of bariatric surgery patients, we found that one such hepatokine, inter-trypsin inhibitor heavy chain 3 (ITIH3), was progressively lower in severe non-alcoholic fatty liver disease (NAFLD) disease states highlighting an inverse relationship between Itih3/ITIH3 expression and NAFLD severity. Follow-up animal and cell culture models demonstrated that hepatic ITIH3 overexpression lowered liver triglyceride and lipid droplet accumulation, respectively. Conversely, ITIH3 knockdown in mice increased the liver triglyceride in two independent NAFLD models. Mechanistically, ITIH3 reduced mitochondrial respiration and this, in turn, reduced liver triglycerides, via downregulated de novo lipogenesis. This was accompanied by increased STAT1 signaling and Stat3 expression, both of which are known to protect against NAFLD/NASH. Our findings indicate hepatokine ITIH3 as a potential biomarker and/or treatment for NAFLD.

The role of interleukin-20 in liver disease: Functions, mechanisms and clinical applications

Liver disease is a severe public health concern worldwide. There is a close relationship between the liver and cytokines, and liver inflammation from a variety of causes leads to the release and activation of cytokines. The functions of cytokines are complex and variable, and are closely related to their cellular origin, target molecules and mode of action. Interleukin (IL)-20 has been studied as a pro-inflammatory cytokine that is expressed and regulated in some diseases. Furthermore, accumulating evidences has shown that IL-20 is highly expressed in clinical samples from patients with liver disease, promoting the production of pro-inflammatory molecules involved in liver disease progression, and antagonists of IL-20 can effectively inhibit liver injury and produce protective effects. This review highlights the potential of targeting IL-20 in liver diseases, elucidates the potential mechanisms of IL-20 inducing liver injury, and suggests multiple viable strategies to mitigate the pro-inflammatory response to IL-20. Genomic CRISPR/Cas9-based screens may be a feasible way to further explore the signaling pathways and regulation of IL-20 in liver diseases. Nanovector systems targeting IL-20 offer new possibilities for the treatment and prevention of liver diseases.

Effect of Calebin-A on Critical Genes Related to NAFLD: A Protein-Protein Interaction Network and Molecular Docking Study

Background

Calebin-A is a minor phytoconstituent of turmeric known for its activity against inflammation, oxidative stress, cancerous, and metabolic disorders like Non-alcoholic fatty liver disease(NAFLD). Based on bioinformatic tools. Subsequently, the details of the interaction of critical proteins with Calebin-A were investigated using the molecular docking technique.

Methods

We first probed the intersection of genes/ proteins between NAFLD and Calebin-A through online databases. Besides, we performed an enrichment analysis using the ClueGO plugin to investigate signaling pathways and gene ontology. Next, we evaluate the possible interaction of Calebin-A with significant hub proteins involved in NAFLD through a molecular docking study.

Results

We identified 87 intersection genes Calebin-A targets associated with NAFLD. PPI network analysis introduced 10 hub genes (TP53, TNF, STAT3, HSP90AA1, PTGS2, HDAC6, ABCB1, CCT2, NR1I2, and GUSB). In KEGG enrichment, most were associated with Sphingolipid, vascular endothelial growth factor A (VEGFA), C-type lectin receptor, and mitogen-activated protein kinase (MAPK) signaling pathways. The biological processes described in 87 intersection genes are mostly concerned with regulating the apoptotic process, cytokine production, and intracellular signal transduction. Molecular docking results also directed that Calebin-A had a high affinity to bind hub proteins linked to NAFLD.

Conclusion

Here, we showed that Calebin-A, through its effect on several critical genes/ proteins and pathways, might repress the progression of NAFLD.

CDK4/6 inhibitors in drug-induced liver injury: a pharmacovigilance study of the FAERS database and analysis of the drug-gene interaction network

Objective

The aim of this study was to investigate the potential risk of drug-induced liver injury (DILI) caused by the CDK4/6 inhibitors (CDK4/6is abemaciclib, ribociclib, and palbociclib by comprehensively analyzing the FDA Adverse Event Reporting System (FAERS) database. Moreover, potential toxicological mechanisms of CDK4/6is-related liver injury were explored via drug-gene network analysis.

Methods

In this retrospective observational study, we collected reports of DILI associated with CDK4/6i use from the FAERS dated January 2014 to March 2023. We conducted disproportionality analyses using the reporting odds ratio (ROR) with a 95% confidence interval (CI). Pathway enrichment analysis and drug-gene network analyses were subsequently performed to determine the potential mechanisms underlying CDK4/6i-induced liver injury.

Results

We found positive signals for DILI with ribociclib (ROR = 2.60) and abemaciclib (ROR = 2.37). DILIs associated with liver-related investigations, signs, and symptoms were confirmed in all three reports of CDK4/6is. Moreover, ascites was identified as an unlisted hepatic adverse effect of palbociclib. We isolated 189 interactive target genes linking CDK4/6 inhibitors to hepatic injury. Several key genes, such as STAT3, HSP90AA1, and EP300, were revealed via protein-protein analysis, emphasizing their central roles within the network. KEGG pathway enrichment of these genes highlighted multiple pathways.

Conclusion

Our study revealed variations in hepatobiliary toxicity among the different CDK4/6 inhibitors, with ribociclib showing the highest risk of liver injury, followed by abemaciclib, while palbociclib appeared relatively safe. Our findings emphasize the need for cautious use of CDK4/6 inhibitors, and regular liver function monitoring is recommended for long-term CDK4/6 inhibitor use.

UBE2J1 promotes ALV-A proviral DNA synthesis through the STAT3/IRF1 signaling pathway

The ubiquitin-binding enzyme E2J1 is located on the endoplasmic reticulum membrane. It plays a role in transport throughout the process of ubiquitination. In mammals, UBE2J1 can promote RNA virus replication. However, the biological function of chicken UBE2J1 is unclear. In this study, chicken UBE2J1 was cloned for the first time, and UBE2J1 overexpression and shRNA knockdown plasmids were constructed. In chicken embryo fibroblasts, overexpression of UBE2J1 promoted the replication of subtype A avian leukosis virus, while knockdown of UBE2J1 inhibited the replication of ALV-A virus. In addition, we divided virus replication into virus adsorption and invasion into DF-1 cells, synthesis of proviral DNA, and release of viral particles. UBE2J1 promoted the replication of ALV-A virus by promoting the synthesis of proviral DNA. This result was caused by UBE2J1 inhibiting the production of interferon by inhibiting the STAT3/IRF1 pathway. We mutated ser at position 184 of UBE2J1 to Gly and found that this site plays a role as the phosphorylation site of UBE2J1. We confirmed that UBE2J1 promotes ALV-A replication in chicken embryo fibroblasts by inhibiting the STAT3/IRF1 pathway. This study provides new ideas and insights into ubiquitin-related proteins and antiviral immunity.

Mechanisms and therapeutic prospect of the JAK-STAT signaling pathway in liver cancer

Liver cancer (LC) poses a significant global health challenge due to its high incidence and poor prognosis. Current systemic treatment options, such as surgery, chemotherapy, radiofrequency ablation, and immunotherapy, have shown limited effectiveness for advanced LC patients. Moreover, owing to the heterogeneous nature of LC, it is crucial to uncover more in-depth pathogenic mechanisms and develop effective treatments to address the limitations of the existing therapeutic modalities. Increasing evidence has revealed the crucial role of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway in the pathogenesis of LC. The specific mechanisms driving the JAK-STAT pathway activation in LC, participate in a variety of malignant biological processes, including cell differentiation, evasion, anti-apoptosis, immune escape, and treatment resistance. Both preclinical and clinical investigations on the JAK-STAT pathway inhibitors have exhibited potential in LC treatment, thereby opening up avenues for the development of more targeted therapeutic strategies for LC. In this study, we provide an overview of the JAK-STAT pathway, delving into the composition, activation, and dynamic interplay within the pathway. Additionally, we focus on the molecular mechanisms driving the aberrant activation of the JAK-STAT pathway in LC. Furthermore, we summarize the latest advancements in targeting the JAK-STAT pathway for LC treatment. The insights presented in this review aim to underscore the necessity of research into the JAK-STAT signaling pathway as a promising avenue for LC therapy.

Palmatine alleviates cardiac fibrosis by inhibiting fibroblast activation through the STAT3 pathway

Cardiac fibrosis, the hallmark of cardiovascular disease, is characterized by excessive deposition of extracellular matrix in the heart. Emerging evidence indicates that cardiac fibroblasts (CFs) play pivotal roles in driving cardiac fibrosis. However, due to incomplete insights into CFs, there are limited effective approaches to prevent or reverse cardiac fibrosis currently. Palmatine, a protoberberine alkaloid extracted from traditional Chinese botanical remedies, possesses diverse biological effects. This study investigated the potential therapeutic value and mechanism of palmatine against cardiac fibrosis. Adult male C57BL/6 mice were treated with vehicle, isoproterenol (ISO), or ISO plus palmatine for one week. After echocardiography assessment, mice hearts were collected for histopathology, real-time polymerase chain reaction, and Western blot analyses. Primary rat CFs were utilized in vitro. Compared to control, ISO-treated mice exhibited cardiac hypertrophy and structural abnormalities; however, treatment with palmatine ameliorated these effects of ISO. Moreover, palmatine treatment mitigated ISO-induced cardiac fibrosis. Network pharmacology and molecular docking analysis showed that palmatine strongly binds the regulators of cardiac fibrosis including signal transducer and activator of transcription 3 (STAT3) and mammalian target of rapamycin. Furthermore, palmatine reduced the elevated fibrotic factor expressions and overactivated STAT3 induced by ISO, Transformed growth factor β1 (TGF-β1), or interleukin-6 both in vivo and in vitro. Additionally, blocking STAT3 suppressed the TGF-β1-induced CF activation. Collectively, these data demonstrated that palmatine attenuated cardiac fibrosis partly by inhibiting fibroblast activation through the STAT3 pathway. This provides an experimental basis for the clinical treatment of cardiac fibrosis with palmatine.

Identification of STAT3 as a biomarker for cellular senescence in liver fibrosis: A bioinformatics and experimental validation study

BACKGROUND

Cellular senescence is associated with a dysregulated inflammatory response, which is an important driver of the development of liver fibrosis (LF). This study aimed to investigate the effect of cellular senescence on LF and identify potential key biomarkers through bioinformatics analysis combined with validation experiments in vivo and in vitro.

METHODS

The Gene Expression Omnibus (GEO) database and GeneCards database were used to download the LF dataset and the aging-related gene set, respectively. Functional enrichment analysis of differential genes was then performed using GO and KEGG. Hub genes were further screened using Cytoscape's cytoHubba. Diagnostic values for hub genes were evaluated with a receiver operating characteristic (ROC) curve. Next, CIBERSORTx was used to estimate immune cell types and ratios. Finally, in vivo and in vitro experiments validated the results of the bioinformatics analysis. Moreover, molecular docking was used to simulate drug-gene interactions.

RESULTS

A total of 44 aging-related differentially expressed genes (AgDEGs) were identified, and enrichment analysis showed that these genes were mainly enriched in inflammatory and immune responses. PPI network analysis identified 6 hub AgDEGs (STAT3, TNF, MMP9, CD44, TGFB1, and TIMP1), and ROC analysis showed that they all have good diagnostic value. Immune infiltration suggested that hub AgDEGs were significantly associated with M1 macrophages or other immune cells. Notably, STAT3 was positively correlated with α-SMA, COL1A1, IL-6 and IL-1β, and was mainly expressed in hepatocytes (HCs). Validation experiments showed that STAT3 expression was upregulated and cellular senescence was increased in LF mice. A co-culture system of HCs and hepatic stellate cells (HSCs) further revealed that inhibiting STAT3 reduced HCs senescence and suppressed HSCs activation. In addition, molecular docking revealed that STAT3 was a potential drug therapy target.

CONCLUSIONS

STAT3 may be involved in HCs senescence and promote HSCs activation, which in turn leads to the development of LF. Our findings suggest that STAT3 could be a potential biomarker for LF.

Ferulic acid protects against gamma-radiation induced liver injury via regulating JAK/STAT/Nrf2 pathways

This study aims to evaluate the effect and underlying mechanism of ferulic acid (FA) in alleviating the acute liver injury by ionizing radiation (IR) in vivo. Rats were divided into 4groups (Groups: control, 6Gy irradiated (IRR), FA (50 mg/kg) and FA + IRR). The results showed that FA can effectively inhibit liver damage and restore the structure and function of the liver. In mechanism, FA prevented IR-induced liver fibrosis and blocked the JAK/STAT signaling pathway to effectively inhibit the hepatic inflammatory response; and inhibited IR-induced oxidative stress (OS) by upregulating the Nrf2 signaling pathway and promoting the synthesis of several antioxidants. Moreover, FA inhibited ferroptosis in the liver by stimulating the expression of GPX4 and SLC7A11. FA reduced lipid peroxidation by downregulation of the reactive oxygen species (ROS) production and iron aggregation, thus inhibiting ferroptosis and alleviating IR-induced liver injury. In conclusion, the current study suggests the potential complex mechanisms underlying the mitigating impact of FA in IR-induced ferroptotic liver damage.

Hepatocellular Carcinoma: Old and Emerging Therapeutic Targets

Liver cancer, predominantly hepatocellular carcinoma (HCC), globally ranks sixth in incidence and third in cancer-related deaths. HCC risk factors include non-viral hepatitis, alcohol abuse, environmental exposures, and genetic factors. No specific genetic alterations are unequivocally linked to HCC tumorigenesis. Current standard therapies include surgical options, systemic chemotherapy, and kinase inhibitors, like sorafenib and regorafenib. Immunotherapy, targeting immune checkpoints, represents a promising avenue. FDA-approved checkpoint inhibitors, such as atezolizumab and pembrolizumab, show efficacy, and combination therapies enhance clinical responses. Despite this, the treatment of hepatocellular carcinoma (HCC) remains a challenge, as the complex tumor ecosystem and the immunosuppressive microenvironment associated with it hamper the efficacy of the available therapeutic approaches. This review explores current and advanced approaches to treat HCC, considering both known and new potential targets, especially derived from proteomic analysis, which is today considered as the most promising approach. Exploring novel strategies, this review discusses antibody drug conjugates (ADCs), chimeric antigen receptor T-cell therapy (CAR-T), and engineered antibodies. It then reports a systematic analysis of the main ligand/receptor pairs and molecular pathways reported to be overexpressed in tumor cells, highlighting their potential and limitations. Finally, it discusses TGFβ, one of the most promising targets of the HCC microenvironment.

Perilipin 5 deletion protects against nonalcoholic fatty liver disease and hepatocellular carcinoma by modulating lipid metabolism and inflammatory responses

The molecular mechanisms underlying the transition from nonalcoholic fatty liver disease (NAFLD) to hepatocellular carcinoma (HCC) are incompletely understood. During the development of NAFLD, Perilipin 5 (PLIN5) can regulate lipid metabolism by suppressing lipolysis and preventing lipotoxicity. Other reports suggest that the lack of PLIN5 decreases hepatic injury, indicating a protective role in NAFLD pathology. To better understand the role of PLIN5 in liver disease, we established mouse models of NAFLD and NAFLD-induced HCC, in which wild-type and Plin5 null mice were exposed to a single dose of acetone or 7,12-dimethylbenz[a]anthracene (DMBA) in acetone, followed by a 30-week high-fat diet supplemented with glucose/fructose. In the NAFLD model, RNA-seq revealed significant changes in genes related to lipid metabolism and immune response. At the intermediate level, pathways such as AMP-activated protein kinase (AMPK), signal transducer and activator of transcription 3 (STAT3), c-Jun N-terminal kinase (JNK), and protein kinase B (AKT) were blunted in Plin5-deficient mice (Plin5-/-) compared to wild-type mice (WT). In the NAFLD-HCC model, only WT mice developed liver tumors, while Plin5-/- mice were resistant to tumorigenesis. Furthermore, only 32 differentially expressed genes associated with NALFD progession were identified in Plin5 null mice. The markers of mitochondrial function and immune response, such as the peroxisome proliferator-activated receptor-γ, coactivator 1-α (PGC-1α) and phosphorylated STAT3, were decreased. Lipidomic analysis revealed differential levels of some sphingomyelins between WT and Plin5-/- mice. Interestingly, these changes were not detected in the HCC model, indicating a possible shift in the metabolism of sphingomelins during carcinogenesis.

A single-nucleus transcriptomic atlas of primate liver aging uncovers the pro-senescence role of SREBP2 in hepatocytes

Aging increases the risk of liver diseases and systemic susceptibility to aging-related diseases. However, cell type-specific changes and the underlying mechanism of liver aging in higher vertebrates remain incompletely characterized. Here, we constructed the first single-nucleus transcriptomic landscape of primate liver aging, in which we resolved cell type-specific gene expression fluctuation in hepatocytes across three liver zonations and detected aberrant cell-cell interactions between hepatocytes and niche cells. Upon in-depth dissection of this rich dataset, we identified impaired lipid metabolism and upregulation of chronic inflammation-related genes prominently associated with declined liver functions during aging. In particular, hyperactivated sterol regulatory element-binding protein (SREBP) signaling was a hallmark of the aged liver, and consequently, forced activation of SREBP2 in human primary hepatocytes recapitulated in vivo aging phenotypes, manifesting as impaired detoxification and accelerated cellular senescence. This study expands our knowledge of primate liver aging and informs the development of diagnostics and therapeutic interventions for liver aging and associated diseases.

STAT3 Decoy Oligodeoxynucleotides Suppress Liver Inflammation and Fibrosis in Liver Cancer Cells and a DDC-Induced Liver Injury Mouse Model

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.

Synergistic Differential DNA Demethylation Activity of Danshensu (Salvia miltiorrhiza) Associated with Different Probiotics in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a major hepatic disorder occurring in non-alcohol-drinking individuals. Salvianic acid A or Danshensu (DSS, 3-(3, 4-dihydroxyphenyl)-(2R)-lactic acid), derived from the root of Danshen (Salvia miltiorrhiza), has demonstrated heart and liver protective properties. In this work, we investigated the antioxidant activity and hepatoprotective activity of Danshensu alone and in combination with different agents, such as probiotic bacteria (Lactobacillus casei and Lactobacillus acidophilus), against several assays. The inhibition mechanism of the methylation gene biomarkers, such as DNMT-1, MS, STAT-3, and TET-1, against DSS was evaluated by molecular docking and RT-PCR techniques. The physicochemical and pharmacokinetic ADMET properties of DSS were determined by SwissADME and pkCSM. The results indicated that all lipid blood test profiles, including cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), were reduced after the oral administration of Danshensu combined with probiotics (L. casei and L. acidophilus) that demonstrated good, efficient free radical scavenging activity, measured using anti-oxidant assays. ADMET and drug-likeness properties certify that the DSS could be utilized as a feasible drug since DSS showed satisfactory physicochemical and pharmacokinetic ADMET properties.

Corosolic acid enhances oxidative stress-induced apoptosis and senescence in pancreatic cancer cells by inhibiting the JAK2/STAT3 pathway

BACKGROUND

Pancreatic cancer (PC) is a fatal human malignancy with a poor prognosis. Corosolic acid (CRA) is a triterpenoid, has been reported to have inhibitory effects on tumor growth. However, the role of CRA on PC has not been explored. Here, we aimed to uncover the molecular mechanisms of CRA in PC progression.

METHODS

Cell viability, lactate dehydrogenase (LDH) release, cell apoptosis and senescence were detected by cell counting kit-8 (CCK-8), LDH, flow cytometry and senescence associated-β-galactosidase (SA-β-gal) assay. Levels of relevant proteins and oxidative stress (OS) markers were evaluated by Western blot and enzyme-linked immunosorbent assay (ELISA). A xenograft tumor model was established to explore the in vivo effects of CRA on PC.

RESULTS

We found that CRA inhibited PC cell viability and promoted LDH release in a dose-dependent manner, but had no significant effect on human normal pancreatic ductal epithelial cells HPDE6C7. CRA increased OS-induced cell apoptosis and senescence in HAPC and SW1990 cells. And CRA decreased the levels of anti-apoptotic protein Bcl-2, and elevated the expression of pro-apoptotic protein Bax and senescence-associated proteins P21 and P53. Besides, CRA decreased tumor growth in xenograft models. Furthermore, CRA inactivated the Janus kinase-2 (JAK2)/Signal Transducer and Activator of Transcription 3 (STAT3) signaling pathway in HAPC and SW1990 cells. Functional experiments demonstrated that activation of the JAK2/STAT3 pathway by the JAK2 activator coumermycin A1 (C-A1) or the STAT3 activator colivelin (col) reduced the contribution effect of OS, apoptosis and senescence by CRA.

CONCLUSION

Taken together, our findings indicated that CRA exerted anti-cancer effects in PC by inhibiting the JAK2/STAT3 pathway.

A New Frontier in Phytotherapy: Harnessing the Therapeutic Power of Medicinal Herb-derived miRNAs

Medicinal herbs have been utilized in the treatment of various pathologic conditions, including neoplasms, organ fibrosis, and diabetes mellitus. However, the precise pharmacological actions of plant miRNAs in animals remain to be fully elucidated, particularly in terms of their therapeutic efficacy and mechanism of action. In this review, some important miRNAs from foods and medicinal herbs are presented. Plant miRNAs exhibit a range of pharmacological properties, such as anti-cancer, anti-fibrosis, anti-viral, anti-inflammatory effects, and neuromodulation, among others. These results have not only demonstrated a cross-species regulatory effect, but also suggested that the miRNAs from medicinal herbs are their bioactive components. This shows a promising prospect for plant miRNAs to be used as drugs. Here, the pharmacological properties of plant miRNAs and their underlying mechanisms have been highlighted, which can provide new insights for clarifying the therapeutic mechanisms of medicinal herbs and suggest a new way for developing therapeutic drugs.

Antirheumatic drugs and the risk of nonalcoholic fatty liver disease in patients with rheumatoid arthritis: A nationwide, population-based cohort study

OBJECTIVES

To assess the association between antirheumatic drugs and of the risk of nonalcoholic fatty liver disease (NAFLD) in a nationwide rheumatoid arthritis (RA) cohort.

METHODS

Using claim data from the 2000-2020 National Health Insurance Research Database, we identified 21 457 incident patients with RA from 2002 to 2020 without prior liver diseases. A time-varying multivariable Cox regression model was applied to estimate for the association of NAFLD with the use of antirheumatic drugs after adjusting potential confounders, show as adjusted hazard ratios (aHRs) with 95% confidence interval (CIs). Subgroup analyses were conducted based on age-, sex-, and obesity-related comorbidities.

RESULTS

Multivariable time-dependent Cox regression analyses showed that defined daily dose (DDD) of NSAID (aHR, 1.03; 95% CI: 1.02-1.05) and prednisolone equivalent dose >5 mg/day (aHR, 2.39; 95% CI: 1.85-3.09) were risk factors of NAFLD in patients with RA, while prednisolone equivalent dose ≤5 mg/day (aHR of 0.53; 95% CI: 0.40-0.71) and HCQ use (aHR of 0.75; 95% CI: 0.60-0.93) were associated with a decreased risk of NAFLD. In addition, a history of hospitalizations, number of outpatient visits, age, male, and leflunomide use were associated with the development of NAFLD in some subgroups.

CONCLUSION

This study reveals that NSAID use and prednisolone equivalent dose >5 mg/day were associated with an increased risk of NAFLD in patients with RA, while the use of HCQ and prednisolone equivalent dose ≤5 mg/day decreased the risk of NAFLD.

Mitochondrial-mediated nuclear remodeling and macrophage polarizations: A key switch from liver fibrosis to HCC progression

Liver fibrosis is a significant health burden worldwide and has emerged as the leading cause of Hepatocellular carcinoma (HCC) incidence. Mitochondria are the dynamic organelles that regulate the differentiation, survival, and polarization of macrophages. Nuclear-DNA-associated proteins, micro-RNAs, as well as macrophage polarization are essential for maintaining intracellular and extra-cellular homeostasis in the liver parenchyma. Dysregulated mitochondrial coding genes (ETS complexes I, II, III, IV, and V), non-coding RNAs (mitomiRs), and nuclear alteration lead to the production of reactive oxygen species (ROS) and inflammation which are implicated in the transition of liver fibrosis into HCC. Recent findings indicated the protecting effect of E74-like factor 3/peroxisome proliferator-activated receptor-γ (Elf-3/PPAR-γ). HDAR-y inhibits the deacetylation of PPAR-y and maintains the PPAR-y pathway. Elf-3 plays a tumor suppressive role through epithelial-mesenchymal transition-related gene and zinc finger E-box binding homeobox 2 (ZEB-2) domain. Additionally, the development of HCC includes the PI3K/Akt/mTOR and transforming Growth Factor β (TGF-β) pathway that promotes the Epithelial-mesenchymal transition (EMT) through Smad/Snail/Slug signaling cascade. In contrast, the TLR2/NOX2/autophagy axis promotes M2 polarization in HCC. Thus, a thorough understanding of the mitochondrial and nuclear reciprocal relationship related to macrophage polarization could provide new research opportunities concerning diseases with a significant impact on liver parenchyma towards developing liver fibrosis or liver cancer. Moreover, this knowledge can be used to develop new therapeutic strategies to treat liver diseases.

Rucker L, Johnson J, Ghosh S. Transcriptomics of MASLD Pathobiology in African American Patients in the Washington DC Area †

Metabolic-dysfunction-associated steatotic liver disease (MASLD) is becoming the most common chronic liver disease worldwide and is of concern among African Americans (AA) in the United States. This pilot study evaluated the differential gene expressions and identified the signature genes in the disease pathways of AA individuals with MASLD. Blood samples were obtained from MASLD patients (n = 23) and non-MASLD controls (n = 24) along with their sociodemographic and medical details. Whole-blood transcriptomic analysis was carried out using Affymetrix Clarion-S Assay. A validation study was performed utilizing TaqMan Arrays coupled with Ingenuity Pathway Analysis (IPA) to identify the major disease pathways. Out of 21,448 genes in total, 535 genes (2.5%) were significantly (p < 0.05) and differentially expressed when we compared the cases and controls. A significant overlap in the predominant differentially expressed genes and pathways identified in previous studies using hepatic tissue was observed. Of note, TGFB1 and E2F1 genes were upregulated, and HMBS was downregulated significantly. Hepatic fibrosis signaling is the top canonical pathway, and its corresponding biofunction contributes to the development of hepatocellular carcinoma. The findings address the knowledge gaps regarding how signature genes and functional pathways can be detected in blood samples ('liquid biopsy') in AA MASLD patients, demonstrating the potential of the blood samples as an alternative non-invasive source of material for future studies.

Identification of novel STAT3 inhibitors for liver fibrosis, using pharmacophore-based virtual screening, molecular docking, and biomolecular dynamics simulations

The signal transducer and activator of transcription 3 (STAT3) plays a fundamental role in the growth and regulation of cellular life. Activation and over-expression of STAT3 have been implicated in many cancers including solid blood tumors and other diseases such as liver fibrosis and rheumatoid arthritis. Therefore, STAT3 inhibitors are be coming a growing and interesting area of pharmacological research. Consequently, the aim of this study is to design novel inhibitors of STAT3-SH3 computationally for the reduction of liver fibrosis. Herein, we performed Pharmacophore-based virtual screening of databases including more than 19,481 commercially available compounds and in-house compounds. The hits obtained from virtual screening were further docked with the STAT3 receptor. The hits were further ranked on the basis of docking score and binding interaction with the active site of STAT3. ADMET properties of the screened compounds were calculated and filtered based on drug-likeness criteria. Finally, the top five drug-like hit compounds were selected and subjected to molecular dynamic simulation. The stability of each drug-like hit in complex with STAT3 was determined by computing their RMSD, RMSF, Rg, and DCCM analyses. Among all the compounds Sa32 revealed a good docking score, interactions, and stability during the entire simulation procedure. As compared to the Reference compound, the drug-like hit compound Sa32 showed good docking scores, interaction, stability, and binding energy. Therefore, we identified Sa32 as the best small molecule potent inhibitor for STAT3 that will be helpful in the future for the treatment of liver fibrosis.

Extracellular matrix turnover: phytochemicals target and modulate the dual role of matrix metalloproteinases (MMPs) in liver fibrosis

Extracellular matrix (ECM) resolution by matrix metalloproteinases (MMPs) is a well-documented mechanism. MMPs play a dual and complex role in modulating ECM degradation at different stages of liver fibrosis, depending on the timing and levels of their expression. Increased MMP-1 combats disease progression by cleaving the fibrillar ECM. Activated hepatic stellate cells (HSCs) increase expression of MMP-2, -9, and -13 in different chemicals-induced animal models, which may alleviate or worsen disease progression based on animal models and the stage of liver fibrosis. In the early stage, elevated expression of certain MMPs may damage surrounding tissue and activate HSCs, promoting fibrosis progression. At the later stage, downregulation of MMPs can facilitate ECM accumulation and disease progression. A number of phytochemicals modulate MMP activity and ECM turnover, alleviating disease progression. However, the effects of phytochemicals on the expression of different MMPs are variable and may depend on the disease models and stage, and the dosage, timing and duration of phytochemicals used in each study. Here, we review the most recent advances in the role of MMPs in the effects of phytochemicals on liver fibrogenesis, which indicates that further studies are warranted to confirm and define the potential clinical efficacy of these phytochemicals.

Metformin regulates the LIN28B‑mediated JNK/STAT3 signaling pathway through miR‑140‑3p in subretinal fibrosis

Subretinal fibrosis (SF) is an important cause of submacular neovascularization that leads to permanent vision loss, but has no effective clinical treatment. The present study examined the influence of metformin on SF, and investigated whether the mechanism involves the microRNA (miR)-140-3p/LIN28B/JNK/STAT3-mediated regulation of oxidative stress, angiogenesis and fibrosis-associated indicators. A mouse model of laser-induced SF was established. In addition, an ARPE-19 fibrotic cell model was established using TGF-β1. A Cell Counting Kit-8 assay was used to examine cell viability. Flow cytometry was used to measure reactive oxygen species levels, and western blotting was used to detect the levels of proteins associated with epithelial-mesenchymal transition (EMT), signaling and fibrosis. The levels of superoxide dismutase, malondialdehyde, glutathione-peroxidase and catalase were measured using kits. Scratch assays and Transwell assays were used to assess cell migration and invasion, respectively, and reverse transcription-quantitative PCR was used to determine the levels of miR-140-3p and LIN28B. Dual-luciferase assays were used to verify the targeting relationship between miR-140-3p and LIN28B, and coimmunoprecipitation was used to confirm the interaction between LIN28B and JNK. Masson staining and hematoxylin and eosin staining were used to examine collagenous fibers and the histopathology of eye tissue. In ARPE-19 cells induced by TGF-β1, metformin promoted miR-140-3p expression and inhibited LIN28B expression and JNK/STAT3 pathway activation, thereby inhibiting oxidative stress, EMT and fibrosis in ARPE-19 cells. The overexpression of LIN28B or treatment with the JNK/STAT3 agonist anisomycin partially reversed the inhibitory effect of metformin on oxidative stress and fibrosis in ARPE-19 cells. The dual-luciferase reporter assay and coimmunoprecipitation assay showed that miR-140-3p targeted the 3' untranslated region of LIN28B mRNA and inhibited LIN28B expression. LIN28B targeted and bound to JNK and regulated the JNK/STAT3 pathway. Therefore, it may be concluded that metformin can promote miR-140-3p expression, inhibit LIN28B and then inhibit the JNK/STAT3 pathway to alleviate SF.

Interaction between estrogen receptor-α and PNPLA3 p.I148M variant drives fatty liver disease susceptibility in women

Fatty liver disease (FLD) caused by metabolic dysfunction is the leading cause of liver disease and the prevalence is rising, especially in women. Although during reproductive age women are protected against FLD, for still unknown and understudied reasons some develop rapidly progressive disease at the menopause. The patatin-like phospholipase domain-containing 3 (PNPLA3) p.I148M variant accounts for the largest fraction of inherited FLD variability. In the present study, we show that there is a specific multiplicative interaction between female sex and PNPLA3 p.I148M in determining FLD in at-risk individuals (steatosis and fibrosis, P < 10-10; advanced fibrosis/hepatocellular carcinoma, P = 0.034) and in the general population (P < 10-7 for alanine transaminase levels). In individuals with obesity, hepatic PNPLA3 expression was higher in women than in men (P = 0.007) and in mice correlated with estrogen levels. In human hepatocytes and liver organoids, PNPLA3 was induced by estrogen receptor-α (ER-α) agonists. By chromatin immunoprecipitation and luciferase assays, we identified and characterized an ER-α-binding site within a PNPLA3 enhancer and demonstrated via CRISPR-Cas9 genome editing that this sequence drives PNPLA3 p.I148M upregulation, leading to lipid droplet accumulation and fibrogenesis in three-dimensional multilineage spheroids with stellate cells. These data suggest that a functional interaction between ER-α and PNPLA3 p.I148M variant contributes to FLD in women.