Metabolic dysfunction-associated steatotic liver disease (MASLD) comprises a spectrum of liver injuries, including steatosis to steatohepatitis (MASH), liver fibrosis, cirrhosis, and relevant complications. The liver mainly comprises hepatocytes, liver sinusoidal endothelial cells (LSECs), Kupffer cells (KCs), immune cells (T cells, B cells), and hepatic stellate cells (HSCs). Crosstalk among these different liver cells, endogenous aberrant glycolipid metabolism, and altered gut dysbiosis are involved in the pathophysiology of MASLD. This review systematically examines advances in understanding the molecular pathogenesis of MASLD, with a focus on emerging therapeutic targets and translational clinical trials. We first delineate the crucial regulatory mechanisms involving diverse liver cells and the gut-liver axis in MASLD development. These cell-specific pathogenic insights offer valuable perspectives for advancing precision medicine approaches in MASLD treatment. Furthermore, we evaluate potential therapeutic targets and summarize clinical trials currently underway. By comprehensively updating the MASLD pathophysiology and identifying promising strategies, this review aims to facilitate the development of novel pharmacotherapies for this increasingly prevalent condition.
Humans ; Fatty Liver/therapy* ; Animals ; Liver/pathology* ; Kupffer Cells/metabolism* ; Hepatocytes/metabolism* ; Hepatic Stellate Cells/metabolism*

Liver fibrosis is a dynamic wound-healing response characterized by the agglutination of the extracellular matrix (ECM). Si-Wu-Tang (SWT), a traditional Chinese medicine (TCM) formula, is known for treating gynecological diseases and liver fibrosis. Our previous studies demonstrated that long non-coding RNA H19 (H19) was markedly upregulated in fibrotic livers while its deficiency markedly reversed fibrogenesis. However, the mechanisms by which SWT influences H19 remain unclear. Thus, we established a bile duct ligation (BDL)-induced liver fibrosis model to evaluate the hepatoprotective effects of SWT on various cells in the liver. Our results showed that SWT markedly improved ECM deposition and bile duct reactions in the liver. Notably, SWT relieved liver fibrosis by regulating the transcription of genes involved in the cytoskeleton remodeling, primarily in hepatic stellate cells (HSCs), and influencing cytoskeleton-related angiogenesis and hepatocellular injury. This modulation collectively led to reduced ECM deposition. Through extensive bioinformatics analyses, we determined that H19 acted as a miRNA sponge and mainly inhibited miR-200, miR-211, and let7b, thereby regulating the above cellular regulatory pathways. Meanwhile, SWT reversed H19-related miRNAs and signaling pathways, diminishing ECM deposition and liver fibrosis. However, these protective effects of SWT were diminished with the overexpression of H19 in vivo. In conclusion, our study elucidates the underlying mechanisms of SWT from the perspective of H19-related signal networks and proposes a potential SWT-based therapeutic strategy for the treatment of liver fibrosis.
Humans ; RNA, Long Noncoding/genetics* ; Liver Cirrhosis/genetics* ; Liver/metabolism* ; Hepatic Stellate Cells/pathology* ; MicroRNAs/metabolism* ; Extracellular Matrix/metabolism* ; Drugs, Chinese Herbal

OBJECTIVE: To explore the effect and mechanism of Dahuang Zhechong Pill (DHZCP) on liver fibrosis. METHODS: Liver fibrosis cell model was induced by transforming growth factor-β (TGF-β) in hepatic stellate cells (HSC-T6). DHZCP medicated serum (DMS) was prepared in rats. HSC-T6 cells were divided into the control (15% normal blank serum culture), TGF-β (15% normal blank serum + 5 ng/mL TGF-β), DHZCP (15% DMS + 5 ng/mL TGF-β), DHZCP+PDTC [15% DMS + 4 mmol/L ammonium pyrrolidine dithiocarbamate (PDTC)+ 5 ng/mL TGF-β], and PDTC groups (4 mmol/L PDTC + 5 ng/mL TGF-β). Cell activity was detected by cell counting kit 8 and levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the cell supernatant were determined by enzyme-linked immunosorbnent assay. Western blot was used to measure the expressions of p38 mitogen-activated protein kinase/nuclear factor kappa B/transforming growth factor-β1 (p38 MAPK/NF-κ B/TGF-β1) pathway related proteins, and the localization and expressions of these proteins were observed by immunofluorescence staining. RESULTS: DHZCP improves the viability of cells damaged by TGF-β and reduces inflammatory cytokines and ALT and AST levels in the supernatant of HSC-T6 cells induced with TGF-β (P<0.05 or P<0.01). Compared with the TGF-β group, NF-κ B p65 levels in the DHZCP group were decreased (P<0.05). p38 MAPK and NF-κ B p65 levels in the DHZCP+PDTC were also reduced (P<0.01). Compared with the TGF-β group, the protein expression of Smad2 showed a downward trend in the DHZCP, DHZCP+PDTC, and PDTC groups (all P<0.01), and the decreasing trend of Samd3 was statistically significant only in DHZCP+PDTC group (P<0.01), whereas Smad7 was increased (P<0.05 or P<0.01). CONCLUSION DHZCP can inhibit the process of HSC-T6 cell fibrosis by down-regulating the expression of p38 MAPK/NF-κ B/TGF-β1 pathway.
Animals ; Liver Cirrhosis/pathology* ; Drugs, Chinese Herbal/therapeutic use* ; p38 Mitogen-Activated Protein Kinases/metabolism* ; NF-kappa B/metabolism* ; Transforming Growth Factor beta1/metabolism* ; Male ; Signal Transduction/drug effects* ; Rats ; Disease Progression ; Cell Line ; Hepatic Stellate Cells/pathology* ; Rats, Sprague-Dawley

OBJECTIVE: To establish a visual reporting system for evaluating the activity of collagen Ⅰ α 1 chain (COL1A1) gene promoter in immortalized human hepatic stellate cells, so as to estimate the activation status of the cells and provide a new cell model for the screening and study of anti-hepatic fibrosis drugs. METHODS: The promoter sequence of human COL1A1 was amplified from the genomic DNA of human hepatocarcinoma cell line HepG2. Based on the pLVX-AcGFP1-N1 plasmid, the recombinant plasmid pLVX-COL1A1-enhanced green fluorescent protein (EGFP) was constructed, in which the enhanced green fluorescent protein gene expression was regulated by the COL1A1 promoter. The monoclonal cell line was acquired by stably transfecting pLVX-COL1A1-EGFP into the immortalized human hepatic stellate cell line LX-2 by the lentivirus packaging system and screening. The cell line was treated with transforming growth factor-β1 (TGF-β1) or co-treated with TGF-β1 and drugs with potential anti-hepatic fibrosis effects. The EGFP fluorescence intensity in cells was analyzed by the fluorescence microscope and ImageJ 1.49 software using a semi-quantitative method. The COL1A1 and EGFP mRNA were detected by reverse transcription real-time quantitative PCR (RT-qPCR), and corresponding proteins were detected by Western blot. RESULTS: The recombinant plasmid pLVX-COL1A1-EGFP with the expression of EGFP regulated by COL1A1 promoter was successfully constructed. Kozak sequence was added to enhance the expression of EGFP, which was identified by double digestion and sequencing. The LX-2 monoclonal cell line LX-2-CE stably transfected with pLVX-COL1A1-EGFP was obtained. After co-treatment with TGF-β1 and 5 μmol/L dihydrotanshinone Ⅰ with potential anti-hepatic fibrosis effect for 24 h, the total fluorescence intensity and the average fluorescence intensity of LX-2-CE were lower than those in TGF-β1 single treatment group (P < 0.05), the intracellular mRNA and protein levels of COL1A1 and EGFP were also lower than those in the TGF-β1 single treatment group (P < 0.05). CONCLUSION A reporter system for estimating activation of hepatic stellate cells based on COL1A1 promoter regulated EGFP expression is successfully constructed, which could visually report the changes in COL1A1 expression, one of the activation-related markers of hepatic stellate cells, in vitro. It provides a new cell model for the screening and study of anti-hepatic fibrosis drugs.
Humans ; Transforming Growth Factor beta1/pharmacology* ; Hepatic Stellate Cells/pathology* ; Liver Cirrhosis/genetics* ; Collagen Type I/pharmacology* ; RNA, Messenger/metabolism*

Liver fibrosis incidence and adverse outcomes are high; however, there are no known chemical drugs or biological agents that are specific and effective for treatment. The paucity of a robust and realistic in vitro model for liver fibrosis is one of the major causes hindering anti-liver fibrosis drug development. This article summarizes the latest progress in the development of in vitro cell models for liver fibrosis, with a focus based on the analysis of induction and activation of hepatic stellate cells, cell co-culture, and 3D model co-construction, as well as concurrent potential methods based on hepatic sinusoidal endothelial cell establishment.
Humans ; Liver Cirrhosis/pathology* ; Hepatic Stellate Cells ; Cell Culture Techniques ; Endothelial Cells

Objective: To explore the pathogenic mechanism of the miR-340/high mobility group box 1 (HMGB1) axis in the formation of liver fibrosis. Methods: A rat liver fibrosis model was established by injecting CCl(4) intraperitoneally. miRNAs targeting and validating HMGB1 were selected with gene microarrays after screening the differentially expressed miRNAs in rats with normal and hepatic fibrosis. The effect of miRNA expressional changes on HMGB1 levels was detected by qPCR. Dual luciferase gene reporter assays (LUC) was used to verify the targeting relationship between miR-340 and HMGB1. The proliferative activity of the hepatic stellate cell line HSC-T6 was detected by thiazolyl blue tetrazolium bromide (MTT) assay after co-transfection of miRNA mimics and HMGB1 overexpression vector, and the expression of extracellular matrix (ECM) proteins type I collagen and α-smooth muscle actin (SMA) was detected by western blot. Statistical analysis was performed by analysis of variance and the LSD-t test. Results: Hematoxylin-eosin and Masson staining results showed that the rat model of liver fibrosis was successfully established. Gene microarray analysis and bioinformatics prediction had detected eight miRNAs possibly targeting HMGB1, and animal model validation had detected miR-340. qPCR detection results showed that miR-340 had inhibited the expression of HMGB1, and a luciferase complementation assay suggested that miR-340 had targeted HMGB1. Functional experiments results showed that HMGB1 overexpression had enhanced cell proliferation activity and the expression of type I collagen and α-SMA, while miR-340 mimics had not only inhibited cell proliferation activity and the expression of HMGB1, type I collagen, and α-SMA, but also partially reversed the promoting effect of HMGB1 on cell proliferation and ECM synthesis. Conclusion: miR-340 targets HMGB1 to inhibit the proliferation and ECM deposition in hepatic stellate cells and plays a protective role during the process of liver fibrosis.
Animals ; Rats ; Cell Proliferation ; Collagen Type I/metabolism* ; Fibrosis ; Hepatic Stellate Cells ; HMGB1 Protein/genetics* ; Liver Cirrhosis/pathology* ; MicroRNAs/metabolism*

An effective therapeutic regimen for hepatic fibrosis requires a deep understanding of the pathogenesis mechanism. Hepatic fibrosis is characterized by activated hepatic stellate cells (aHSCs) with an excessive production of extracellular matrix. Although promoted activation of HSCs by M2 macrophages has been demonstrated, the molecular mechanism involved remains ambiguous. Herein, we propose that the vitamin D receptor (VDR) involved in macrophage polarization may regulate the communication between macrophages and HSCs by changing the functions of exosomes. We confirm that activating the VDR can inhibit the effect of M2 macrophages on HSC activation. The exosomes derived from M2 macrophages can promote HSC activation, while stimulating VDR alters the protein profiles and reverses their roles in M2 macrophage exosomes. Smooth muscle cell-associated protein 5 (SMAP-5) was found to be the key effector protein in promoting HSC activation by regulating autophagy flux. Building on these results, we show that a combined treatment of a VDR agonist and a macrophage-targeted exosomal secretion inhibitor achieves an excellent anti-hepatic fibrosis effect. In this study, we aim to elucidate the association between VDR and macrophages in HSC activation. The results contribute to our understanding of the pathogenesis mechanism of hepatic fibrosis, and provide potential therapeutic targets for its treatment.
Humans ; Hepatic Stellate Cells/pathology* ; Receptors, Calcitriol ; Liver Cirrhosis/pathology* ; Macrophages/metabolism*

OBJECTIVE: Huangqi Decoction (HQD), a classical traditional Chinese medicine formula, has been used as a valid treatment for alleviating liver fibrosis; however, the underlying molecular mechanism is still unknown. Although our previous studies showed that microRNA-663a (miR-663a) suppresses the proliferation and activation of hepatic stellate cells (HSCs) and the transforming growth factor-β/small mothers against decapentaplegic (TGF-β/Smad) pathway, whether long noncoding RNAs (lncRNAs) are involved in HSC activation via the miR-663a/TGF-β/Smad signaling pathway has not yet reported. The present study aimed to investigate the roles of lncRNA lnc-C18orf26-1 in the activation of HSCs and the mechanism by which HQD inhibits hepatic fibrosis. METHODS: The expression levels of lnc-C18orf26-1, miR-663a and related genes were measured by quantitative reverse transcription-polymerase chain reaction. HSCs were transfected with the miR-663a mimic or inhibitor and lnc-C18orf26-1 small interfering RNAs. The water-soluble tetrazolium salt-1 assay was used to assess the proliferation rate of HSCs. Changes in lncRNA expression were evaluated in miR-663a-overexpressing HSCs by using microarray to identify miR-663a-regulated lncRNAs. RNA hybrid was used to predict the potential miR-663a binding sites on lncRNAs. Luciferase reporter assays further confirmed the interaction between miR-663a and the lncRNA. The expression levels of collagen α-2(I) chain (COL1A2), α-smooth muscle actin (α-SMA) and TGF-β/Smad signaling pathway-related proteins were determined using Western blotting. RESULTS: Lnc-C18orf26-1 was upregulated in TGF-β1-activated HSCs and competitively bound to miR-663a. Knockdown of lnc-C18orf26-1 inhibited HSC proliferation and activation, downregulated TGF-β1-stimulated α-SMA and COL1A2 expression, and inhibited the TGF-β1/Smad signaling pathway. HQD suppressed the proliferation and activation of HSCs. HQD increased miR-663a expression and decreased lnc-C18orf26-1 expression in HSCs. Further studies showed that HQD inhibited the expression of COL1A2, α-SMA, TGF-β1, TGF-β type I receptor (TGF-βRI) and phosphorylated Smad2 (p-Smad2) in HSCs, and these effects were reversed by miR-663a inhibitor treatment. CONCLUSION Our study identified lnc-C18orf26-1 and miR-663a as promising therapeutic targets for hepatic fibrosis. HQD inhibits HSC proliferation and activation at least partially by regulating the lnc-C18orf26-1/miR-663a/TGF-β1/TGF-βRI/p-Smad2 axis.
Humans ; Transforming Growth Factor beta/pharmacology* ; Transforming Growth Factor beta1/metabolism* ; RNA, Long Noncoding/pharmacology* ; Drugs, Chinese Herbal/pharmacology* ; MicroRNAs/genetics* ; Hepatic Stellate Cells/pathology* ; Liver Cirrhosis/metabolism* ; Cell Proliferation ; Transforming Growth Factors/pharmacology*

The purpose of this study was to investigate the effect of Geniposide on hepatic fibrosis and activation of hepatic stellate cells (HSCs) and to explore possible underlying mechanism. Human HSCs (LX-2) were treated with 5 ng/mL transforming growth factor-β1 (TGF-β1), followed by co-culture with Geniposide at various concentrations (0, 1, 2.5, 5, 10, 20, 40, 60, 80, 100 μmol/L). Cell viability was determined by MTT assay. Then, LX-2 cells were divided into control, TGF-β1 (5 ng/mL) and TGF-β1 + Geniposide (20 μmol/L) groups, and the gene and protein expression of collagen I, fibronectin, α-smooth muscle actin (α-SMA), p-Smad2 and p-Smad3 was detected by qPCR and Western blot, respectively. BALB/c mice were treated with CCl₄ (25%, 1 mL/kg) to generate a model of hepatic fibrosis (CCl₄ group), and the control group and CCl₄ + Geniposide group were administered with olive oil and CCl₄ + 40 mg/kg Geniposide, respectively. After 4 weeks of treatment, the liver function and serum hepatic fibrosis indexes of mice were detected, histological observation was performed by HE and Masson staining, and α-SMA expression in the tissue was analyzed by immunohistochemistry. Western blot was utilized for the determination of the protein expression of α-SMA, TGF-β1, p-Smad2 and p-Smad3. The results showed that Geniposide inhibited LX-2 cell proliferation. In addition, Geniposide significantly downregulated the gene and protein expression of collagen I, fibronectin and α-SMA and the expression of TGF-β1/Smad signaling-related proteins induced by TGF-β1 in vitro. Histological observations showed that Geniposide significantly inhibited CCl₄-induced hepatic fibrosis, HSC activation and expression of TGF-β1/Smad signaling-related proteins in mice. In summary, Geniposide prevents the hepatic fibrosis and HSC activation possibly through the inhibition of the TGF-β1/Smad signaling pathway.
Animals ; Collagen Type I/metabolism* ; Fibronectins ; Hepatic Stellate Cells/pathology* ; Iridoids ; Liver Cirrhosis/pathology* ; Mice ; Signal Transduction ; Smad Proteins/pharmacology* ; Transforming Growth Factor beta1/metabolism*

OBJECTIVE: To investigate the molecular mechanism underlying the anti-hepatic fibrosis activity of ethyl acetate fraction Dicliptera chinensis (L.) Juss. (EDC) in human hepatic stellate cells (HSCs) in vitro and in a carbon tetrachloride (CCl₄)-induced hepatic fibrosis mouse model in vivo. METHODS: For in vitro study, HSCs were pre-treated with platelet-derived growth factor (10 ng/mL) for 2 h to ensure activation and treated with EDC for 24 h and 48 h, respectively. The effect of EDC on HSCs was assessed using cell counting kit-8 assay, EdU staining, transmission electron microscopy, immunofluorescence staining, and Western blot, respectively. For in vivo experiments, mice were intraperitoneally injected with CCl₄ (2 ° L/g, adjusted to a 25% concentration in olive oil), 3 times per week for 6 weeks, to develop a hepatic fibrosis model. Forty 8-week-old male C57BL/6 mice were divided into 4 groups using a random number table (n=10), including control, model, positive control and EDC treatment groups. Mice in the EDC and colchicine groups were intragastrically administered EDC (0.5 g/kg) or colchicine (0.2 mg/kg) once per day for 6 weeks. Mice in the control and model groups received an equal volume of saline. Biochemical assays and histological examinations were used to assess liver damage. Protein expression levels of α -smooth muscle actin (α -SMA) and microtubule-associated protein light chain 3B (LC3B) were measured by Western blot. RESULTS: EDC reduced pathological damage associated with liver fibrosis, downregulated the expression of α -SMA and upregulated the expression of LC3B (P<0.05), both in HSCs and the CCl₄-induced liver fibrosis mouse model. The intervention of bafilomycin A1 and rapamycin in HSCs strongly supported the notion that inhibition of autophagy enhanced α -SMA protein expression levels (P<0.01). The results also found that the levels of phosphoinositide (PI3K), p-PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR), p-mTOR, and p-p70S6K all decreased after EDC treatment (P<0.05). CONCLUSIONS EDC has anti-hepatic fibrosis activity by inducing autophagy and might be a potential drug to be further developed for human liver fibrosis therapy.
Acetates ; Animals ; Autophagy ; Carbon Tetrachloride ; Hepatic Stellate Cells ; Liver/pathology* ; Liver Cirrhosis/pathology* ; Male ; Mice ; Mice, Inbred C57BL ; Phosphatidylinositol 3-Kinases ; Proto-Oncogene Proteins c-akt/metabolism* ; Ribosomal Protein S6 Kinases, 70-kDa ; Signal Transduction ; TOR Serine-Threonine Kinases/metabolism*