Extracellular matrix degradation and the role of hepatic stellate cells

Immunomodulatory activities and biomedical applications of melittin and its recent advances

Melittin (MLT), a peptide containing 26 amino acids, is a key constituent of bee venom. It comprises ∼40%-60% of the venom's dry weight and is the main pricing index for bee venom, being the causative factor of pain. The unique properties of MLT extracted from bee venom have made it a very valuable active ingredient in the pharmaceutical industry as this cationic and amphipathic peptide has propitious effects on human health in diverse biological processes. It has the ability to strongly impact the membranes of cells and display hemolytic activity with anticancer characteristics. However, the clinical application of MLT has been limited by its severe hemolytic activity, which poses a challenge for therapeutic use. By employing more efficient mechanisms, such as modifying the MLT sequence, genetic engineering, and nano-delivery systems, it is anticipated that the limitations posed by MLT can be overcome, thereby enabling its wider application in therapeutic contexts. This review has outlined recent advancements in MLT's nano-delivery systems and genetically engineered cells expressing MLT and provided an overview of where the MLTMLT's platforms are and where they will go in the future with the challenges ahead. The focus is on exploring how these approaches can overcome the limitations associated with MLT's hemolytic activity and improve its selectivity and efficacy in targeting cancer cells. These advancements hold promise for the creation of innovative and enhanced therapeutic approaches based on MLT for the treatment of cancer.

Novel protein C6ORF120 promotes liver fibrosis by activating hepatic stellate cells through the PI3K/Akt/mTOR pathway

BACKGROUND AND AIM

The role of C6ORF120 in promoting CCL4-induced hepatic fibrosis and its possible mechanisms were explored in C6orf120 knockout rats (C6orf120-/-) and LX-2 cells (a type of human hepatic stellate cell line).

METHODS

In vivo experiments, wild-type and C6orf120-/- rats were used to investigate the function of C6ORF120. In the in vitro experiments, C6ORF120 recombinant protein (rC6ORF120) at a concentration of 200 ng/mL was used to stimulate LX-2 cells. Sirius Red staining, Masson staining, western blotting, polymerase chain reaction, immunohistochemistry, and immunofluorescence were used to explore fibrosis-associated factors.

RESULTS

C6orf120-/- rats showed mild fibrosis and liver injury in the CCL4-induced liver fibrosis model. Furthermore, RNA-seq revealed that C6orf120-/- rats had less extracellular matrix deposition and activated stellate cells. Consistent with the in vivo, the rC6ORF120 induced LX-2 cell activation. Moreover, mechanistic studies revealed that the p-PI3K/PI3K, p-Akt/Akt, and p-mTOR/mTOR levels were significantly elevated and LY294002 (a PI3K/Akt/mTOR typical pathway inhibitor) reversed the function of C6ORF120 in activating LX-2 cells.

CONCLUSION

C6ORF120 could activate hepatic stellate cells and promote hepatic fibrosis via the PI3K/Akt/mTOR signaling pathway.

Targeting necroptosis in fibrosis

Necroptosis, a type of programmed cell death that resembles necrosis, is now known to depend on a different molecular mechanism from apoptosis, according to several recent studies. Many efforts have reported the possible influence of necroptosis in human disorders and concluded the crucial role in the pathophysiology of various diseases, including liver diseases, renal injuries, cancers, and others. Fibrosis is the most common end-stage pathological cascade of several chronic inflammatory disorders. In this review, we explain the impact of necroptosis and fibrosis, for which necroptosis has been demonstrated to be a contributing factor. We also go over the inhibitors of necroptosis and how they have been applied to fibrosis models. This review helps to clarify the role of necroptosis in fibrosis and will encourage clinical efforts to target this pathway of programmed cell death.

Binding of berberine to PEBP1 synergizes with sorafenib to induce the ferroptosis of hepatic stellate cells

Hepatic stellate cell (HSC) activation is the key process in hepatic fibrosis (HF) development. Targeted death of HSCs could be effective in the prevention and treatment of HF. Phosphatidylethanolamine-binding protein (PEBP)1 can trigger ferroptosis by mediating peroxide production, but how it modulates HSC ferroptosis is not known. We screened natural small molecules that could bind with PEBP1, and investigated the mechanism by which it promotes HSC ferroptosis. The maximum binding energy of berberine with PEBP1 was - 8.51 kcal/mol, indicating that berberine could bind strongly with PEBP1. Berberine binding to PEBP1 could promote HSC ferroptosis via synergy of its actions with those of sorafenib, but it could not induce ferroptosis alone. Combined administration of berberine enhanced the ferroptotic effects of low-dose sorafenib upon HSCs. Herein, we revealed that PEBP1 might be a target that could enhance the effects of sorafenib, which could provide a new therapeutic approach for HF treatment.

Primary human hepatocytes-laden scaffolds for the treatment of acute liver failure

Cell-based liver therapies based on retrieving and steadying failed metabolic function(s) for acute and chronic diseases could be a valuable substitute for liver transplants, even though they are limited by the low engraftment capability and reduced functional quality of primary human hepatocytes (PHH). In this paper we propose the use of gelatin-hyaluronic acid (Gel-HA) scaffolds seeded with PHH for the treatment of liver failure. We first optimized the composition using Gel-HA hydrogels, looking for the mechanical properties closer to the human liver and determining HepG2 cells functionality. Gel-HA scaffolds with interconnected porosity (pore size 102 μm) were prepared and used for PHH culture and evaluation of key hepatic functions. PHH cultured in Gel-HA scaffolds exhibited increased albumin and urea secretion and metabolic capacity (CYP and UGT activity levels) compared to standard monolayer cultures. The transplant of the scaffold containing PHH led to an improvement in liver function (transaminase levels, necrosis) and ameliorated damage in a mouse model of acetaminophen (APAP)-induced liver failure. The study provided a mechanistic understanding of APAP-induced liver injury and the impact of transplantation by analyzing cytokine production and oxidative stress induction to find suitable biomarkers of cell therapy effectiveness.

Mechanosensory feedback loops during chronic inflammation

Epithelial tissues are crucial to maintaining healthy organization and compartmentalization in various organs and act as a first line of defense against infection in barrier organs such as the skin, lungs and intestine. Disruption or injury to these barriers can lead to infiltration of resident or foreign microbes, initiating local inflammation. One often overlooked aspect of this response is local changes in tissue mechanics during inflammation. In this mini-review, we summarize known molecular mechanisms linking disruption of epithelial barrier function to mechanical changes in epithelial tissues. We consider direct mechanisms, such as changes in the secretion of extracellular matrix (ECM)-modulating enzymes by immune cells as well as indirect mechanisms including local activation of fibroblasts. We discuss how these mechanical changes can modulate local immune cell activity and inflammation and perturb epithelial homeostasis, further dysregulating epithelial barrier function. We propose that this two-way relationship between loss of barrier function and altered tissue mechanics can lead to a positive feedback loop that further perpetuates inflammation. We discuss this cycle in the context of several chronic inflammatory diseases, including inflammatory bowel disease (IBD), liver disease and cancer, and we present the modulation of tissue mechanics as a new framework for combating chronic inflammation.

A review of liver fibrosis and cirrhosis regression

Cirrhosis has traditionally been considered an irreversible process of end-stage liver disease. With new treatments for chronic liver disease, there is regression of fibrosis and cirrhosis, improvement in clinical parameters (i.e. liver function and hemodynamic markers, hepatic venous pressure gradient), and survival rates, demonstrating that fibrosis and fibrolysis are a dynamic process moving in two directions. Microscopically, hepatocytes push into thinning fibrous septa with eventual perforation leaving behind delicate periportal spikes in the portal tracts and loss of portal veins. Obliterated portal veins during progressive fibrosis and cirrhosis due to parenchymal extinction, vascular remodeling and thrombosis often leave behind a bile duct and hepatic artery within the portal tract. Traditional staging classification systems focused on a linear, progressive process; however, the Beijing classification system incorporates both the bidirectional nature for the progression and regression of fibrosis. However, even with regression, vascular lesions/remodeling, parenchymal extinction and a cumulative mutational burden place patients at an increased risk for developing hepatocellular carcinoma and should continue to undergo active clinical surveillance. It is more appropriate to consider cirrhosis as another stage in the evolution of chronic liver disease as a bidirectional process rather than an end-stage, irreversible state.

Role of the IL-33/ST2 Activation Pathway in the Development of the Hepatic Fibrosis Induced by Schistosoma mansoni Granulomas in Mice

Schistosoma mansoni eggs retained in host tissues induce innate cytokine release, contributing to the induction of Type-2 immune responses and granuloma formation, important to restrain cytotoxic antigens, but leading to fibrosis. Interleukin(IL)-33 participates in experimental models of inflammation and chemically induced fibrosis, but its role in S. mansoni-induced fibrosis is still unknown. To explore the role of the IL-33/suppressor of the tumorigenicity 2 (ST2) pathway, serum and liver cytokine levels, liver histopathology, and collagen deposition were comparatively evaluated in S. mansoni-infected wild-type (WT) and IL-33-receptor knockout (ST2-/-) BALB/c mice. Our data show similar egg counts and hydroxyproline in the livers of infected WT and ST2-/- mice; however, the extracellular matrix in ST2-/- granulomas was loose and disorganised. Pro-fibrotic cytokines, such as IL-13 and IL-17, and the tissue-repairing IL-22 were significantly lower in ST2-/- mice, especially in chronic schistosomiasis. ST2-/- mice also showed decreased α-smooth muscle actin (α-SMA) expression in granuloma cells, in addition to reduced Col III and Col VI mRNA levels and reticular fibres. Therefore, IL-33/ST2 signalling is essential for tissue repairing and myofibroblast activation during S. mansoni infection. Its disruption results in inappropriate granuloma organisation, partly due to the reduced type III and VI collagen and reticular fibre formation.

Placental nanoparticle gene therapy normalizes gene expression changes in the fetal liver associated with fetal growth restriction in a fetal sex-specific manner

Fetal growth restriction (FGR) is associated with increased risk of developing non-communicable diseases. We have a placenta-specific nanoparticle gene therapy protocol that increases placental expression of human insulin-like growth factor 1 (hIGF1), for the treatment of FGR in utero. We aimed to characterize the effects of FGR on hepatic gluconeogenesis pathways during early stages of FGR establishment, and determine whether placental nanoparticle-mediated hIGF1 therapy treatment could resolve differences in the FGR fetus. Female Hartley guinea pigs (dams) were fed either a Control or Maternal Nutrient Restriction (MNR) diet using established protocols. At GD30-33, dams underwent ultrasound guided, transcutaneous, intraplacental injection of hIGF1 nanoparticle or PBS (sham) and were sacrificed 5 days post-injection. Fetal liver tissue was fixed and snap frozen for morphology and gene expression analysis. In female and male fetuses, liver weight as a percentage of body weight was reduced by MNR, and not changed with hIGF1 nanoparticle treatment. In female fetal livers, expression of hypoxia inducible factor 1 (Hif1α) and tumor necrosis factor (Tnfα) were increased in MNR compared to Control, but reduced in MNR + hIGF1 compared to MNR. In male fetal liver, MNR increased expression of Igf1 and decreased expression of Igf2 compared to Control. Igf1 and Igf2 expression was restored to Control levels in the MNR + hIGF1 group. This data provides further insight into the sex-specific mechanistic adaptations seen in FGR fetuses and demonstrates that disruption to fetal developmental mechanisms may be returned to normal by treatment of the placenta.

In Vivo and In Vitro Models to Study Liver Fibrosis: Mechanisms and Limitations

Liver fibrosis is a common result of liver injury owing to various kinds of chronic liver diseases. A deeper understanding of the pathophysiology of liver fibrosis and identifying potential therapeutic targets of liver fibrosis is important because liver fibrosis may progress to advanced liver diseases, such as cirrhosis and hepatocellular carcinoma. Despite numerous studies, the underlying mechanisms of liver fibrosis remain unclear. Mechanisms of the development and progression of liver fibrosis differ according to etiologies. Therefore, appropriate liver fibrosis models should be selected according to the purpose of the study and the type of underlying disease. Many in vivo animal and in vitro models have been developed to study liver fibrosis. However, there are no perfect preclinical models for liver fibrosis. In this review, we summarize the current in vivo and in vitro models for studying liver fibrosis and highlight emerging in vitro models, including organoids and liver-on-a-chip models. In addition, we discuss the mechanisms and limitations of each model.

Deleterious liver-adipose crosstalk in obesity: Hydroethanolic extract of Lampaya medicinalis Phil. (Verbenaceae) counteracts fatty acid-induced fibrotic marker expression in human hepatocytes

Elevated circulating fatty acids in obesity may induce hepatic steatosis, leading to liver inflammation, fibrosis and nonalcoholic fatty liver disease (NAFLD). On the other hand, impaired communication between hepatocytes and adipose tissue (AT) in obesity influences adipose lipolysis and fibrosis, negatively affecting metabolic function. Infusions of Lampaya medicinalis Phil. (Verbenaceae) are used in Chilean folk medicine to treat inflammatory diseases. Hydroethanolic extract of lampaya (HEL) contains flavonoids that may explain its anti-inflammatory effect, but it is unknown whether HEL modulates fibrogenic processes in hepatocytes. We studied lipolysis and expression of fibrosis markers after exposure of visceral AT explants from subjects with obesity to HepG2-secreted factors. In addition, we evaluated the effect of HEL on palmitic acid (PA, C16:0) and oleic acid (OA; C18:1)-induced fibrotic marker expression in HepG2 hepatocytes. Results: Exposure to HepG2-secreted factors increased visceral AT lipolysis and expression of CTGF and collagen I. Exposure to OA/PA elevated collagen I, CTGF, fibronectin, α-smooth muscle actin, MMP-2 and MMP-9 expression in HepG2 cells, and these effects were prevented by HEL co-treatment. Conclusion: HEL effect counteracting OA/PA-induced fibrotic marker expression in HepG2 hepatocytes may represent a preventive approach against hepatic fibrosis and deleterious liver-adipose crosstalk in obesity.

Lipocalin-2 activates hepatic stellate cells and promotes nonalcoholic steatohepatitis in high-fat diet-fed Ob/Ob mice

BACKGROUND AND AIMS

In obesity and type 2 diabetes mellitus, leptin promotes insulin resistance and contributes to the progression of NASH via activation of hepatic stellate cells (HSCs). However, the pathogenic mechanisms that trigger HSC activation in leptin-deficient obesity are still unknown. This study aimed to determine how HSC-targeting lipocalin-2 (LCN2) mediates the transition from simple steatosis to NASH.

APPROACH AND RESULTS

Male wild-type (WT) and ob/ob mice were fed a high-fat diet (HFD) for 20 weeks to establish an animal model of NASH with fibrosis. Ob/ob mice were subject to caloric restriction or recombinant leptin treatment. Double knockout (DKO) mice lacking both leptin and lcn2 were also fed an HFD for 20 weeks. In addition, HFD-fed ob/ob mice were treated with gadolinium trichloride to deplete Kupffer cells. The LX-2 human HSCs and primary HSCs from ob/ob mice were used to investigate the effects of LCN2 on HSC activation. Serum and hepatic LCN2 expression levels were prominently increased in HFD-fed ob/ob mice compared with normal diet-fed ob/ob mice or HFD-fed WT mice, and these changes were closely linked to liver fibrosis and increased hepatic α-SMA/matrix metalloproteinase 9 (MMP9)/signal transducer and activator of transcription 3 (STAT3) protein levels. HFD-fed DKO mice showed a marked reduction of α-SMA protein compared with HFD-fed ob/ob mice. In particular, the colocalization of LCN2 and α-SMA was increased in HSCs from HFD-fed ob/ob mice. In primary HSCs from ob/ob mice, exogenous LCN2 treatment induced HSC activation and MMP9 secretion. By contrast, LCN2 receptor 24p3R deficiency or a STAT3 inhibitor reduced the activation and migration of primary HSCs.

CONCLUSIONS

LCN2 acts as a key mediator of HSC activation in leptin-deficient obesity via α-SMA/MMP9/STAT3 signaling, thereby exacerbating NASH.

Induction of premature senescence and a less-fibrogenic phenotype by programmed cell death 4 knockdown in the human hepatic stellate cell line Lieming Xu-2

Although programmed cell death 4 (PDCD4) was initially reported as a tumor suppressor and has been shown to inhibit cancer cell growth and metastasis, recent studies have demonstrated that loss of PDCD4 expression also induces growth inhibition by inducing apoptosis and/or cellular senescence. At present, the roles of PDCD4 in the activation and profibrogenic properties of myofibroblasts, which are critically involved in organ fibrosis, such as that in the liver, are unclear. We, therefore, investigated the roles of PDCD4 in myofibroblasts using human hepatic stellate cell line Lieming Xu-2 (LX-2). PDCD4 knockdown inhibited LX-2 proliferation and induced a senescent phenotype with increased β-galactosidase staining and p21 expression in a p53-independent manner together with downregulation of the notch signaling mediator RBJ-κ/CSL. During PDCD4 knockdown, alpha smooth muscle actin (α-SMA; an activation marker of myofibroblasts), matrix metalloproteinases MMP-1 and MMP-9, and collagen IV were upregulated, but the expression of collagen1α1 and collagen III was markedly downregulated without any marked change in the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1). These results demonstrated that knockdown of PDCD4 induced the cellular senescence phenotype and activated myofibroblasts while suppressing the profibrogenic phenotype, suggesting roles of PDCD4 in cellular senescence and fibrogenesis in the liver.

Enzymes of Fibrosis in Chronic Liver Disease

Introduction: Liver fibrosis has been extensively studied at the cellular and molecular level, but very few data exist on the final enzymatic stages of collagen synthesis (prolyl hydroxylase, PH) and degradation (matrix metalloproteinases, MMPs), particularly in primary biliary cholangitis (PBC). Aim: We studied enzyme activities in liver tissue from patients with chronic liver diseases and compared them to normal livers. Patients: Eighteen patients with PBC of early and late stages (Ludwig’s classification) and seven on treatment with ursodeoxycholate (UDCA) were studied and compared to 34 patients with alcoholic liver disease (ALD), 25 patients with chronic viral liver disease and five normal biopsies. Sera were available from a total of 140 patients. Methods: The tritiated water released from the tritiated proline was measured in PH assessment. 14C intact and heat-denatured collagen substrates were used to measure collagenase and gelatinases, respectively. 3H Elastin was the substrate for elastase. In serum, ELISAs were used for MMP-1, TIMP-1, and TIMP-2 measurements while MMP-2 and MMP-9 were estimated by zymography. Results: PH was significantly increased in early and late PBC. Collagenase was reduced only in the late stages (p < 0.01), where the ratio PH/collagenase was increased. UDCA treatment restored values to almost normal. Gelatinases were reduced in late stages (p < 0.05). In contrast to PBC and ALD fibrosis, collagen synthesis is not increased in viral fibrosis. The balance shifted towards collagen deposition due to reduced degradation. Interestingly, gelatinolytic activity is not impaired in ALD. Elastase was similar to controls in all diseases studied. TIMP-1 was reduced in early PBC and viral and alcoholic hepatitis and cirrhosis (p < 0.001). Conclusions: (1) There is evidence that collagen synthesis increases in the early stages of PBC, but the collagenolytic mechanism may compensate for the increased synthesis. (2) In viral disease, fibrosis may be due to decreased degradation rather than increased synthesis. (3) The final biochemical stages of liver fibrosis may be quantitatively different according to underlying etiology.

Patch grafting of organoids of stem/progenitors into solid organs can correct genetic-based disease states

Patch grafting, a novel strategy for transplantation of stem/progenitor organoids into porcine livers, has been found successful also for organoid transplantation into other normal or diseased solid organs in pigs and mice. Each organoid contained ∼100 cells comprised of biliary tree stem cells (BTSCs), co-hepato/pancreatic stem/progenitors, and partnered with early lineage stage mesenchymal cells (ELSMCs), angioblasts and precursors to endothelia and stellate cells. Patch grafting enabled transplantation into livers or pancreases of ≥108th (pigs) or ≥106th-7th (mice) organoids/patch. Graft conditions fostered expression of multiple matrix-metalloproteinases (MMPs), especially secretory isoforms, resulting in transient loss of the organ's matrix-dictated histological features, including organ capsules, and correlated with rapid integration within a week of organoids throughout the organs and without emboli or ectopic cell distribution. Secondarily, within another week, there was clearance of graft biomaterials, followed by muted expression of MMPs, restoration of matrix-dictated histology, and maturation of donor cells to functional adult fates. The ability of patch grafts of organoids to rescue hosts from genetic-based disease states was demonstrated with grafts of BTSC/ELSMC organoids on livers, able to rescue NRG/FAH-KO mice from type I tyrosinemia, a disease caused by absence of fumaryl acetoacetate hydrolase. With the same grafts, if on pancreas, they were able to rescue NRG/Akita mice from type I diabetes, caused by a mutation in the insulin 2 gene. The potential of patch grafting for cell therapies for solid organs now requires translational studies to enable its adaptation and uses for clinical programs.

Concentration of Serum Matrix Metalloproteinase-3 in Patients With Primary Biliary Cholangitis

Background and Aims

Metalloproteinases (MMPs) are involved in many distinct processes in the liver. Matrix metalloproteinase-3 (MMP-3) plays an important role in connective tissue remodeling, degradation of collagen (types II, III, IV, IX, and X), proteoglycans, fibronectin, laminin, and elastin. In addition, MMP-3 can also activate other MMPs such as MMP-1, MMP-7, and MMP-9. Primary biliary cholangitis (PBC) is a cholestatic, autoimmune liver disease, characterized by the progressive destruction of intrahepatic bile ducts, leading to cholestasis, fibrosis, cirrhosis, and liver failure. Fibrosis is the result of an imbalance between production and degradation of the extracellular matrix surrounding hepatocytes. Our aim in the present study was to determine whether the measurement of serum MMP-3 is clinically useful for assessing ongoing liver fibrosis in patients with PBC.

Methods

The MMP-3 concentration was determined in 182 PBC patients and 80 non-PBC controls using a commercially available ELISA kit.

Results

Higher concentrations of MMP-3 were found in 61% of PBC patients. PBC subjects had greater MMP-3 levels than controls: 68.9 ± 62.6 vs 21.3 ± 7.4 ng/mL, p &lt; 0.001 for healthy subjects; 68.9 ± 62.6 vs 22.7 ± 7.6 ng/mL, p = 0.022 for autoimmune hepatitis controls; and 68.9 ± 62.6 vs 37.2 ± 17.4 ng/mL, p = 0.002 for primary sclerosing cholangitis controls. The serum MMP-3 concentration was significantly elevated in patients with higher bilirubin concentration (107.6 ± 85.8 vs 61.6 ± 46.1 ng/mL, p &lt; 0.001) and was correlated with the level of antimitochondrial antibodies specific for PBC. The concentration of MMP-3 in sera of PBC patients was also found to correlate with the state of liver fibrosis (OR = 4.3; p &lt; 0.01).

Conclusions

Our study demonstrated significantly higher MMP-3 levels in PBC patients than in healthy and pathological controls. Increased MMP-3 concentrations were positively correlated with various clinical and immunological parameters, and advanced liver fibrosis. The level of MMP-3 was associated with hepatic dysfunction and could play a role in the pathophysiology of hepatic fibrosis in PBC.

Hydrogels derived from decellularized liver tissue support the growth and differentiation of cholangiocyte organoids

Human cholangiocyte organoids are promising for regenerative medicine applications, such as repair of damaged bile ducts. However, organoids are typically cultured in mouse tumor-derived basement membrane extracts (BME), which is poorly defined, highly variable and limits the direct clinical applications of organoids in patients. Extracellular matrix (ECM)-derived hydrogels prepared from decellularized human or porcine livers are attractive alternative culture substrates. Here, the culture and expansion of human cholangiocyte organoids in liver ECM(LECM)-derived hydrogels is described. These hydrogels support proliferation of cholangiocyte organoids and maintain the cholangiocyte-like phenotype. The use of LECM hydrogels does not significantly alter the expression of selected genes or proteins, such as the cholangiocyte marker cytokeratin-7, and no species-specific effect is found between human or porcine LECM hydrogels. Proliferation rates of organoids cultured in LECM hydrogels are lower, but the differentiation capacity of the cholangiocyte organoids towards hepatocyte-like cells is not altered by the presence of tissue-specific ECM components. Moreover, human LECM extracts support the expansion of ICO in a dynamic culture set up without the need for laborious static culture of organoids in hydrogel domes. Liver ECM hydrogels can successfully replace tumor-derived BME and can potentially unlock the full clinical potential of human cholangiocyte organoids.

Design by Nature: Emerging Applications of Native Liver Extracellular Matrix for Cholangiocyte Organoid-Based Regenerative Medicine

Organoid technology holds great promise for regenerative medicine. Recent studies show feasibility for bile duct tissue repair in humans by successfully transplanting cholangiocyte organoids in liver grafts during perfusion. Large-scale expansion of cholangiocytes is essential for extending these regenerative medicine applications. Human cholangiocyte organoids have a high and stable proliferation capacity, making them an attractive source of cholangiocytes. Commercially available basement membrane extract (BME) is used to expand the organoids. BME allows the cells to self-organize into 3D structures and stimulates cell proliferation. However, the use of BME is limiting the clinical applications of the organoids. There is a need for alternative tissue-specific and clinically relevant culture substrates capable of supporting organoid proliferation. Hydrogels prepared from decellularized and solubilized native livers are an attractive alternative for BME. These hydrogels can be used for the culture and expansion of cholangiocyte organoids in a clinically relevant manner. Moreover, the liver-derived hydrogels retain tissue-specific aspects of the extracellular microenvironment. They are composed of a complex mixture of bioactive and biodegradable extracellular matrix (ECM) components and can support the growth of various hepatobiliary cells. In this review, we provide an overview of the clinical potential of native liver ECM-based hydrogels for applications with human cholangiocyte organoids. We discuss the current limitations of BME for the clinical applications of organoids and how native ECM hydrogels can potentially overcome these problems in an effort to unlock the full regenerative clinical potential of the organoids.

Cell-to-Cell Communications in Alcohol-Associated Liver Disease

This review covers some important new aspects of the alcohol-induced communications between liver parenchymal and non-parenchymal cells leading to liver injury development. The information exchange between various cell types may promote end-stage liver disease progression and involves multiple mechanisms, such as direct cell-to-cell interactions, extracellular vesicles (EVs) or chemokines, cytokines, and growth factors contained in extracellular fluids/cell culture supernatants. Here, we highlighted the role of EVs derived from alcohol-exposed hepatocytes (HCs) in activation of non-parenchymal cells, liver macrophages (LM), and hepatic stellate cells (HSC). The review also concentrates on EV-mediated crosstalk between liver parenchymal and non-parenchymal cells in the settings of HIV- and alcohol co-exposure. In addition, we overviewed the literature on the crosstalk between cell death pathways and inflammasome activation in alcohol-activated HCs and macrophages. Furthermore, we covered highly clinically relevant studies on the role of non-inflammatory factors, sinusoidal pressure (SP), and hepatic arterialization in alcohol-induced hepatic fibrogenesis. We strongly believe that the review will disclose major mechanisms of cell-to-cell communications pertained to alcohol-induced liver injury progression and will identify therapeutically important targets, which can be used for alcohol-associated liver disease (ALD) prevention.

Molecular Mechanisms and Potential New Therapeutic Drugs for Liver Fibrosis

Liver fibrosis is the pathological process of excessive extracellular matrix deposition after liver injury and is a precursor to cirrhosis, hepatocellular carcinoma (HCC). It is essentially a wound healing response to liver tissue damage. Numerous studies have shown that hepatic stellate cells play a critical role in this process, with various cells, cytokines, and signaling pathways engaged. Currently, the treatment targeting etiology is considered the most effective measure to prevent and treat liver fibrosis, but reversal fibrosis by elimination of the causative agent often occurs too slowly or too rarely to avoid life-threatening complications, especially in advanced fibrosis. Liver transplantation is the only treatment option in the end-stage, leaving us with an urgent need for new therapies. An in-depth understanding of the mechanisms of liver fibrosis could identify new targets for the treatment. Most of the drugs targeting critical cells and cytokines in the pathogenesis of liver fibrosis are still in pre-clinical trials and there are hardly any definitive anti-fibrotic chemical or biological drugs available for clinical use. In this review, we will summarize the pathogenesis of liver fibrosis, focusing on the role of key cells, associated mechanisms, and signaling pathways, and summarize various therapeutic measures or drugs that have been trialed in clinical practice or are in the research stage.

High throughput interrogation of human liver stellate cells reveals microenvironmental regulation of phenotype

Liver fibrosis is a common feature of progressive liver disease and is manifested as a dynamic series of alterations in both the biochemical and biophysical properties of the liver. Hepatic stellate cells (HSCs) reside within the perisinusoidal space of the liver sinusoid and are one of the main drivers of liver fibrosis, yet it remains unclear how changes to the sinusoidal microenvironment impact HSC phenotype in the context of liver fibrosis. Cellular microarrays were used to examine and deconstruct the impacts of bio-chemo-mechanical changes on activated HSCs in vitro. Extracellular matrix (ECM) composition and stiffness were found to act individually and in combination to regulate HSC fibrogenic phenotype and proliferation. Hyaluronic acid and collagen III promoted elevated collagen I expression while collagen IV mediated a decrease. Previously activated HSCs exhibited reduced lysyl oxidase (Lox) expression as array substrate stiffness increased, with less dependence on ECM composition. Collagens III and IV increased HSC proliferation, whereas hyaluronic acid had the opposite effect. Meta-analysis performed on these data revealed distinct phenotypic clusters (e.g. low fibrogenesis/high proliferation) as a direct function of their microenvironmental composition. Notably, soft microenvironments mimicking healthy tissue (1 kPa), promoted higher levels of intracellular collagen I and Lox expression in activated HSCs, compared to stiff microenvironments mimicking fibrotic tissue (25 kPa). Collectively, these data suggest potential HSC functional adaptations in response to specific bio-chemo-mechanical changes relevant towards the development of therapeutic interventions. These findings also underscore the importance of the microenvironment when interrogating HSC behavior in healthy, disease, and treatment settings. STATEMENT OF SIGNIFICANCE: In this work we utilized high-throughput cellular microarray technology to systematically interrogate the complex interactions between HSCs and their microenvironment in the context of liver fibrosis. We observed that HSC phenotype is regulated by ECM composition and stiffness, and that these phenotypes can be classified into distinct clusters based on their microenvironmental context. Moreover, the range of these phenotypic responses to microenvironmental stimuli is substantial and a direct consequence of the combinatorial pairing of ECM protein and stiffness signals. We also observed a novel role for microenvironmental context in affecting HSC responses to potential fibrosis therapeutics.

Intestinal Barrier and Permeability in Health, Obesity and NAFLD

The largest surface of the human body exposed to the external environment is the gut. At this level, the intestinal barrier includes luminal microbes, the mucin layer, gastrointestinal motility and secretion, enterocytes, immune cells, gut vascular barrier, and liver barrier. A healthy intestinal barrier is characterized by the selective permeability of nutrients, metabolites, water, and bacterial products, and processes are governed by cellular, neural, immune, and hormonal factors. Disrupted gut permeability (leaky gut syndrome) can represent a predisposing or aggravating condition in obesity and the metabolically associated liver steatosis (nonalcoholic fatty liver disease, NAFLD). In what follows, we describe the morphological-functional features of the intestinal barrier, the role of major modifiers of the intestinal barrier, and discuss the recent evidence pointing to the key role of intestinal permeability in obesity/NAFLD.

Human Liver Stem Cell Transplantation Alleviates Liver Fibrosis in a Rat Model of CCl4-Induced Liver Fibrosis

Background and Objectives

Mesenchymal stem cells (MSCs) elicit therapeutic effects against liver fibrosis in animal models. Human liver stem cells (HLSCs) are cells isolated from human liver tissue that have mesenchymal morphology and express MSC markers. HLSCs also possess intrahepatic stem cell properties. We introduce a rat model of liver fibrosis and trans-portal transplantation of HLSC to demonstrate alleviation of liver fibrosis.

Methods and Results

Liver fibrosis was induced by intraperitoneal injection of Carbon tetrachloride (CCl₄). Sprague Dawley rats underwent simultaneous partial hepatectomy of the left hepatic lobe and HLSC transplantation via the portal vein. Gross appearance of the liver observed following CCl₄ injection showed cholestasis and surface nodularity. Sirius red staining revealed deposition of collagen fibers in the extracellular matrix (ECM). Following HLSC transplantation, human albumin secreting cells were detected by immunohistochemistry in liver specimens. Quantitative measurements of fibrosis area stained by Sirius red were compared between baseline and post-HLSC transplant (1×10⁷ cells) following 10 weeks of CCl₄ treatment liver specimens. Fibrosis area (p<0.05), serum markers of liver inflammation and fibrosis (AST, ALT levels and APRI, p<0.05) significantly decreased from baseline after HLSC transplantation. RNA expression in liver tissues revealed significant decrease in tissue inhibitor of matrix metalloproteinase 1 (TIMP1), TIMP2 expression and increase in hepatocyte growth factor expression following HLSC transplantation (p<0.05).

Conclusions

HLSC transplantation effectively reduced the area of liver fibrosis with increased expression of factors promoting ECM degradation. These findings suggest the potential therapeutic role of HLSCs in various liver diseases presenting with liver fibrosis.

Schisandrin B Attenuates Hepatic Stellate Cell Activation and Promotes Apoptosis to Protect against Liver Fibrosis

The activation of hepatic stellate cells (HSC) plays a key role in the progression of hepatic fibrosis, it is essential to remove activated HSC through apoptosis to reverse hepatic fibrosis. Schisandrin B (Sch B) is the main chemical component of schisandrin lignan, and it has been reported to have good hepatoprotective effects. However, Schisandrin B on HSC apoptosis remains unclear. In our study, we stimulated the HSC-T6 and LX-2 cell lines with TGF-β1 to induce cell activation, and the proliferation and apoptosis of the activated HSC-T6 and LX-2 cells were detected after treatment with different doses of Schisandrin B. Flow cytometry results showed that Sch B significantly reduced the activity of activated HSC-T6 and LX-2 cells and significantly induced apoptosis. In addition, the cleaved-Caspase-3 levels were increased, the Bax activity was increased, and the Bcl-2 expression was decreased in HSC-T6 and LX-2 cells treated with Sch B. Our study showed that Sch B inhibited the TGF-β1-induced activity of hepatic stellate cells by promoting apoptosis.

Molecular and pathobiological involvement of fetuin-A in the pathogenesis of NAFLD

The liver acts as a manufacturing unit for the production of fetuin-A, which is essential for various physiological characteristics. Scientific research has shown that a moderate upward push in fetuin-A serum levels is associated with a confirmed non-alcoholic fatty liver disease (NAFLD) diagnosis. Fetuin-A modulation is associated with a number of pathophysiological variables that cause liver problems, including insulin receptor signaling deficiencies, adipocyte dysfunction, hepatic inflammation, fibrosis, triacylglycerol production, macrophage invasion, and TLR4 activation. The focus of the present review is on the various molecular pathways, and genetic relevance of mRNA expression of fetuin-A which is correlated with progression of NAFLD. The other major area of exploration in the present review is based on the new targets for the modulation of fetuin-A, like calorie restriction and novel pharmacological agents, such as rosuvastatin, metformin, and pioglitazone which are successfully implicated in the management of various liver-related complications.

Thioacetamide-induced norepinephrine production by hepatocytes is associated with hepatic stellate cell activation and liver fibrosis

BACKGROUND

Collagen production by activated hepatic stellate cells (HSCs) to encapsulate injury is part of the natural wound-healing response in injured liver. However, persistent activation of HSCs can lead to pathological fibrogenesis. Such persistent HSC activation could be mediated by norepinephrine (NE), a reaction product of dopamine beta-hydroxylase (DBH).

OBJECTIVE

To investigate the potential paracrine role of NE in hepatotoxin thioacetamide (TAA)-induced liver fibrosis.

METHODS/RESULTS

In TAA-treated mice, fibrotic liver tissue showed significant increases in the mRNA expression of DBH up to 14-fold and collagen up to 7-fold. Immunohistochemical staining showed increased DBH protein expression in fibrotic liver tissue. Parenchymal hepatocyte cell line HepG2 expressed DBH and secreted NE, and the conditioned medium of HepG2 cells promoted collagenesis in nonparenchymal HSC cell line LX-2. TAA treatment increased DBH expression by 170% in HepG2 cells, as well as increased NE by 120% in the conditioned medium of HepG2 cells. The conditioned medium of TAA-treated HepG2 cells was used to culture LX-2 cells, and was found to increase collagen expression by 80% in LX-2 cells. Collagen expression was reduced by pre-treating HepG2 cells with siRNA targeting DBH or by adding NE antagonists to the conditioned medium. Finally, TAA-induced oxidative stress in HepG2 cells was associated with induction of DBH expression.

CONCLUSION

Collectively, our results suggest a potential role for DBH/NE-mediated crosstalk between hepatocytes and HSCs in fibrogenesis. From a therapeutic standpoint, antagonism of DBH/NE induction in hepatocytes might be a useful strategy to suppress pathological fibrogenesis.

Two-stage Cox-nnet: biologically interpretable neural-network model for prognosis prediction and its application in liver cancer survival using histopathology and transcriptomic data

Pathological images are easily accessible data with the potential of prognostic biomarkers. Moreover, integration of heterogeneous data types from multi-modality, such as pathological image and gene expression data, is invaluable to help predicting cancer patient survival. However, the analytical challenges are significant. Here, we take the hepatocellular carcinoma (HCC) pathological image features extracted by CellProfiler, and apply them as the input for Cox-nnet, a neural network-based prognosis prediction model. We compare this model with the conventional Cox proportional hazards (Cox-PH) model, CoxBoost, Random Survival Forests and DeepSurv, using C-index and log-rank P-values. The results show that Cox-nnet is significantly more accurate than Cox-PH and Random Survival Forests models and comparable with CoxBoost and DeepSurv models, on pathological image features. Further, to integrate pathological image and gene expression data of the same patients, we innovatively construct a two-stage Cox-nnet model, and compare it with another complex neural-network model called PAGE-Net. The two-stage Cox-nnet complex model combining histopathology image and transcriptomic RNA-seq data achieves much better prognosis prediction, with a median C-index of 0.75 and log-rank P-value of 6e-7 in the testing datasets, compared to PAGE-Net (median C-index of 0.68 and log-rank P-value of 0.03). Imaging features present additional predictive information to gene expression features, as the combined model is more accurate than the model with gene expression alone (median C-index 0.70). Pathological image features are correlated with gene expression, as genes correlated to top imaging features present known associations with HCC patient survival and morphogenesis of liver tissue. This work proposes two-stage Cox-nnet, a new class of biologically relevant and interpretable models, to integrate multiple types of heterogenous data for survival prediction.

Taxifolin, Extracted from Waste Larix olgensis Roots, Attenuates CCl4-Induced Liver Fibrosis by Regulating the PI3K/AKT/mTOR and TGF-β1/Smads Signaling Pathways

Purpose

Taxifolin is a kind of dihydroflavone and is usually used as a food additive and health food for its antioxidant, anti-inflammatory, and anti-tumor activities. The purpose of this research is to probe into the hepatoprotective activity and the molecular mechanism of taxifolin.

Materials and Methods

The liver fibrosis model was established by intraperitoneal injection of 5 mL/kg body weight of CCl₄ (20% CCl₄ peanut oil solution), and taxifolin was dissolved with 0.9% physiological saline and administered intragastrically to mice.

Results

The results indicated that CCl₄-induced significantly increased the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in mice. Histopathological examination showed severe hepatocyte necrosis and hepatic tissue lesion. Immunohistochemical staining and rt-PCR analysis demonstrated that the expressions of inducible nitric oxide synthetase (iNOS), cyclooxygenase-2 (COX-2), IL-1β, IL-6, and TNF-α were increased. These changes were significantly reversed when treated with taxifolin. In addition, TUNEL staining and Bcl-2/Bax pathway confirmed that taxifolin significantly inhibited hepatocyte apoptosis. Besides, the research confirmed that taxifolin also inhibited the activation of hepatic stellate cells and the production of extracellular matrix (ECM) by regulating PI3K/AKT/mTOR and TGF-β1/Smads pathways.

Conclusion

Taxifolin inhibited inflammation, and attenuated CCl₄-induced oxidative stress and cell apoptosis by regulating PI3K/AKT/mTOR and TGF-β1/Smads pathways, which might in part contributed to taxifolin anti-hepatic fibrosis, further demonstrating that taxifolin may be an efficient hepatoprotective agent.

Landscape of extracellular vesicles in the tumour microenvironment: Interactions with stromal cells and with non-cell components, and impacts on metabolic reprogramming, horizontal transfer of neoplastic traits, and the emergence of therapeutic resistance

Extracellular vesicles (EVs) are increasingly recognised as a pivotal player in cell-cell communication, an attribute of EVs that derives from their ability to transport bioactive cargoes between cells, resulting in complex intercellular signalling mediated by EVs, which occurs under both physiological and pathological conditions. In the context of cancer, recent studies have demonstrated the versatile and crucial roles of EVs in the tumour microenvironment (TME). Here, we revisit EV biology, and focus on EV-mediated interactions between cancer cells and stromal cells, including fibroblasts, immune cells, endothelial cells and neurons. In addition, we focus on recent reports indicating interactions between EVs and non-cell constituents within the TME, including the extracellular matrix. We also review and summarise the intricate cancer-associated network modulated by EVs, which promotes metabolic reprogramming, horizontal transfer of neoplastic traits, and therapeutic resistance in the TME. We aim to provide a comprehensive and updated landscape of EVs in the TME, focusing on oncogenesis, cancer progression and therapeutic resistance, together with our future perspectives on the field.

Transcriptional regulation of alcohol induced liver fibrosis in a translational porcine hepatocellular carcinoma model

Hepatocellular carcinoma (HCC) is the 5th most common and 2nd deadliest cancer worldwide. HCC risk factors include alcohol induced liver cirrhosis, which prompts hepatic inflammation, cell necrosis, and fibrosis deposition. As 25% of HCC cases are associated with alcohol induced liver disease, understanding the effects of the cirrhotic liver microenvironment on HCC tumor biology and therapeutic responses are critical. This study utilized the Oncopig Cancer Model-a transgenic pig model that recapitulates human HCC through induced expression of KRAS^G12D and TP53^R167H driver mutations-to investigate the molecular mechanisms underlying alcohol induced liver disease. Oncopigs (n = 5) underwent fibrosis induction via infusion of ethanol and ethiodized oil (1:3 v/v dosed at 0.75 mL/kg) into the hepatic arterial circulation. Eight-weeks post induction, liver tissue samples from fibrotic and age-matched control (n = 5) Oncopigs were collected for histological evaluation and transcriptional profiling. Increased hepatic inflammation and fibrosis was observed in fibrotic Oncopigs via pathological assessment. Transcriptional profiling (RNA-seq) resulted in the identification of 4387 differentially expressed genes between Oncopig fibrotic and control livers. GO term enrichment analysis identified pathway alterations associated with cirrhosis progression in humans, including cell proliferation, angiogenesis, extracellular matrix deposition, and oxidation-reduction. Key alterations include activation of hepatic stellate cells, increased matrix metalloproteinase production, and altered expression of ABC and SLC transporter genes involved in transport of anticancer drugs.These results demonstrate Oncopig liver fibrosis recapitulates transcriptional hallmarks of human cirrhosis, making the Oncopig an ideal model for studying the effects of the cirrhotic liver microenvironment on HCC tumor biology and therapeutic response.

Pathogenesis of NASH and Promising Natural Products

Nonalcoholic steatohepatitis (NASH) is a common clinical condition that can lead to advanced liver diseases. The mechanism of the diaease progression, which is lacking effective therapy, remains obsure. Therefore, there is a need to understand the pathogenic mechanisms responsible for disease development and progression in order to develop innovative therapies. To accomplish this goal, experimental animal models that recapitulate the human disease are necessary. Currently, an increasing number of studies have focused on natural constituents from medicinal plants which have been emerged as a new hope for NASH. This review summarized the pathogenesis of NASH, animal models commonly used, and the promising targets for therapeutics. We also reviewed the natural constituents as potential NASH therapeutic agents.

The Role of RECK in Hepatobiliary Neoplasia Reveals Its Therapeutic Potential in NASH

Non-alcoholic fatty liver disease (NAFLD) is a multimorbidity disorder ranging from excess accumulation of fat in the liver (steatosis) to steatohepatitis (NASH) and end-stage cirrhosis, and the development of hepatocellular carcinoma (HCC) in a subset of patients. The defining features of NASH are inflammation and progressive fibrosis. Currently, no pharmaceutical therapies are available for NAFLD, NASH and HCC; therefore, developing novel treatment strategies is desperately needed. Reversion Inducing Cysteine Rich Protein with Kazal motifs (RECK) is a well-known modifier of the extracellular matrix in hepatic remodeling and transition to HCC. More recently, its role in regulating inflammatory and fibrogenic processes has emerged. Here, we summarize the most relevant findings that extend our current understanding of RECK as a regulator of inflammation and fibrosis, and its induction as a potential strategy to blunt the development and progression of NASH and HCC.

A Review of Liver Fibrosis and Emerging Therapies

With the increasing burden of liver cirrhosis, the most advanced stage of hepatic fibrosis, there is a need to better understand the pathological processes and mechanisms to target specific treatments to reverse or cease fibrosis progression. Antiviral therapy for hepatitis B and C has effectively treated underlying causes of chronic liver disease and has induced fibrosis reversal in some; however, this has not been targeted for the majority of aetiologies for cirrhosis including alcohol or nonalcoholic steatohepatitis. Fibrosis, characterised by the accumulation of extracellular matrix proteins, is caused by chronic injury from toxic, infectious, or metabolic causes. The primary event of fibrogenesis is increased matrix production and scar formation mediated by the hepatic stellate cell, which is the principal cell type involved. Experimental models using rodent and human cell lines of liver injury have assisted in better understanding of fibrogenesis, especially in recognising the role of procoagulant factors. This has led to interventional studies using anticoagulants in animal models with reversal of fibrosis as the primary endpoint. Though these trials have been encouraging, no antifibrotic therapies are currently licenced for human use. This literature review discusses current knowledge in the pathophysiology of hepatic fibrosis, including characteristics of the extracellular matrix, signalling pathways, and hepatic stellate cells. Current types of experimental models used to induce fibrosis, as well as up-to-date anticoagulant therapies and agents targeting the hepatic stellate cell that have been trialled in animal and human studies with antifibrotic properties, are also reviewed.

Vitamin D alleviates liver fibrosis by inhibiting histidine-rich calcium binding protein (HRC)

BACKGROUND

Liver fibrosis may progress toward cirrhosis and cancer without effective therapy. Here, we investigated the underlying mechanism of Vitamin D as a therapeutic approach.

METHODS

Carbon tetrachloride (CCL4)-induced mice model and transforming growth factor-β1 (TGF-β1) induced human hepatic stellate cell line LX-2 were used in vivo and in vitro. The fibrotic profiles, degree of liver injury and HRC expression were assessed by histology, Western blot, immunohistochemistry and Real-Time PCR. The proliferation of cells transfected with HRC ^+/+ and HRC^-/- plasmids was detected by MTS and cell cycle methods.

RESULTS

Vitamin D significantly suppressed the expression of HRC in liver fibrosis model both in vivo and in vitro (P < 0.01). The cell with overexpression of HRC significantly increased TGF-β1/Smad3 expressions and the percentage of the S peak in cell cycle (P < 0.05). However, Vitamin D can significantly reverse the levels of TGF-β1, Smad3 and p-smad3 caused by HRC in vitro. Furthermore, the overexpression of HRC in cell lines can attenuate the function of Vitamin D, suggesting that VD played a role by regulating HRC. Mechanically, HRC as the target of VDR is detected by CHIP method.

CONCLUSIONS

Vitamin D can delay hepatic fibrosis by reducing activation of hepatic stellate cells and TGF-β/Smad signaling through negative regulation of HRC. The findings revealed the important regulatory effect of Vitamin D in hepatic stellate cells and provided new insights into the therapeutic function of Vitamin D on liver fibrosis.

Highly specific recognition of denatured collagen by fluorescent peptide probes with the repetitive Gly-Pro-Pro and Gly-Hyp-Hyp sequences

Denatured collagen is a key biomarker for various critical diseases such as cancer. Peptide probes with the repetitive (Gly-Pro-Hyp)n sequences have recently been found to selectively target denatured collagen; however, thermal or UV pretreatment is required to drive the peptides into the monomer conformation, which poses a substantial challenge for clinical applications. We herein construct two peptide probes, FAM-GOO and FAM-GPP, consisting of the repetitive (Gly-Hyp-Hyp)8 and (Gly-Pro-Pro)8 sequences, respectively. The CD, fluorescence and colorimetric studies have consistently revealed that FAM-GOO showed strong capability of forming the triple helical structure, while FAM-GPP pronouncedly displayed the single stranded conformation at temperatures as low as 4 °C. The binding experiments have indicated that both peptide probes could recognize denatured collagen with high specificity, and FAM-GPP remarkably did not need the preheating treatment. The tissue staining results have shown that preheated FAM-GOO and unheated FAM-GPP could target denatured collagen in a wide variety of rat frozen and human FFPE tissue sections. Compared with antibodies specific for a certain type of collagen, both FAM-GOO and FAM-GPP act as broad-spectrum probes for the selective detection of denatured collagen of different types and from different species. Importantly, FAM-GPP possessed the unique capability of maintaining the monomer conformation by itself, thus avoiding the potential risks of the thermal or UV pretreatment. This novel peptide probe provides a handy and versatile biosensor for specifically targeting denatured collagen, which has attractive potential in the diagnosis and therapeutics of collagen-involved diseases.

Effects of intraperitoneal injection of magnetic graphene oxide on the improvement of acute liver injury induced by CCl4

Background

Liver failure is usually associated with the inflammation and oxidation of hepatocytes. Due to their unique properties, graphene and graphene-based nanostructures such as magnetic graphene oxide (MGO) are useful in biomedicine and engineering. In this study, synthesized MGO was used to improve the liver failure induced by carbon tetrachloride (CCl₄). The hepatoprotective effects of intraperitoneal injection of MGO on the rat model of CCl₄-induced acute liver failure were investigated.

Materials and methods

In order to provide a rat model of acute liver failure, male rats were intraperitoneally injected with 2 ml/kg body weight CCl₄. In the experimental groups, rats received 2 ml/kg CCl₄ and 300 mg/kg MGO body weight simultaneously. Four days after injection, symptoms of acute liver failure appeared. The control, sham, CCl₄, and CCl₄ + MGO groups were compared and analyzed both histologically and biochemically.

Results

The results indicated that the MGO injection reduced all CCl₄-induced liver failure such as necrosis, fibrosis, inflammation, aspartate transaminase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) in the experimental groups of the rat model of acute liver failure.

Conclusion

The hepatoprotective effects of MGO might be due to histopathological suppression and inflammation inhibition in the liver.

Liver Steatosis, Gut-Liver Axis, Microbiome and Environmental Factors. A Never-Ending Bidirectional Cross-Talk

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide and parallels comorbidities such as obesity, metabolic syndrome, dyslipidemia, and diabetes. Recent studies describe the presence of NAFLD in non-obese individuals, with mechanisms partially independent from excessive caloric intake. Increasing evidences, in particular, point towards a close interaction between dietary and environmental factors (including food contaminants), gut, blood flow, and liver metabolism, with pathways involving intestinal permeability, the composition of gut microbiota, bacterial products, immunity, local, and systemic inflammation. These factors play a critical role in the maintenance of intestinal, liver, and metabolic homeostasis. An anomalous or imbalanced gut microbial composition may favor an increased intestinal permeability, predisposing to portal translocation of microorganisms, microbial products, and cell wall components. These components form microbial-associated molecular patterns (MAMPs) or pathogen-associated molecular patterns (PAMPs), with potentials to interact in the intestine lamina propria enriched in immune cells, and in the liver at the level of the immune cells, i.e., Kupffer cells and stellate cells. The resulting inflammatory environment ultimately leads to liver fibrosis with potentials to progression towards necrotic and fibrotic changes, cirrhosis. and hepatocellular carcinoma. By contrast, measures able to modulate the composition of gut microbiota and to preserve gut vascular barrier might prevent or reverse NAFLD.

Decreased overall mortality rate with Chinese herbal medicine usage in patients with decompensated liver cirrhosis in Taiwan

Background

Liver cirrhosis is one of the main causes of the morbidity and mortality in liver diseases. Chinese herbal medicine (CHM) has long been used for the clinical treatment of liver diseases. This study was designed to explore the usage frequency and prescription patterns of CHM for patients with decompensated liver cirrhosis and to evaluate the long-term effects of CHM on overall mortality.

Methods

Two thousand four hundred sixty-seven patients with decompensated liver cirrhosis (ICD-9-CM code: 571.2, 571.5, and 571.6) diagnosed between 2000 and 2009 in Taiwan were identified from the registry for catastrophic illness patients. Of these, 149 CHM users and 298 CHM non-users were matched for age, gender, and Charlson comorbidity index score. The chi-squared test, paired Student’s t-test, Cox proportional hazard model, and Kaplan–Meier method were applied for various comparisons between these groups of patients.

Results

CHM-treated patients showed a lower overall mortality risk compared with non-treated patients (Multivariable: p < 0.0001; HR: 0.54, 95% CI: 0.42–0.69). The cumulative incidence of overall mortality was lower in the CHM-treated group (stratified log-rank test, p = 0.0002). The strongest CHM co-prescription pattern- Yin-Chen-Hao-Tang (YCHT) → Long-Dan-Xie-Gan-Tang (LDXGT) had the highest support, followed by Zhi-Zi (ZZ) → Yin-Chen-Wu-Ling-San (YCWLS) and Bai-Hua-She-She-Cao (BHSSC) → Da-Huang (DaH).

Conclusion

CHM, as adjunct therapy, might decrease the risk of overall mortality in patients with decompensated liver cirrhosis. CHM co-prescription patterns and network analysis showed that comprehensive herbal medicines have a protective role against liver fibrosis. Further studies are required to enhance the knowledge of safety and efficacy of CHM in patients with decompensated liver cirrhosis.

The Role of Autophagy and NLRP3 Inflammasome in Liver Fibrosis

Liver fibrosis is an intrinsic repair process of chronic injury with excessive deposition of extracellular matrix. As an early stage of various liver diseases, liver fibrosis is a reversible pathological process. Therefore, if not being controlled in time, liver fibrosis will evolve into cirrhosis, liver failure, and liver cancer. It has been demonstrated that hepatic stellate cells (HSCs) play a crucial role in the formation of liver fibrosis. In particular, the activation of HSCs is a key step for liver fibrosis. Recent researches have suggested that autophagy and inflammasome have biological effect on HSC activation. Herein, we review current studies about the impact of autophagy and NOD-like receptors containing pyrin domain 3 (NLRP3) inflammasome on liver fibrosis and the underlying mechanisms.

Anti-fibrotic activity of gold and platinum complexes - Au(I) compounds as a new class of anti-fibrotic agents

Molecular gold(I) and platinum(II) species were examined for the inhibition of liver fibrosis and the hepatitis C virus (HCV). Determination of inhibition efficiency was conducted via morphological analysis, cell viability, western blot analysis, and quantitative reverse transcription polymerase chain reaction (RT-PCR). Auranofin and Ph₃PAuCl demonstrated the greatest inhibition of liver fibrosis amongst the tested gold species in human hepatic stellate LX-2 cells. Western blot analysis indicated that auranofin and Ph₃PAuCl prevent signal transducer and activator of transcription 3 (STAT3) phosphorylation, which may be a key connection to fibrosis and inflammation. Auranofin and Ph₃PAuCl also reduced expression of HCV-nonstructural protein 3 (NS3) and HCV-NS5a proteins in a HCV subgenomic replicon system. These results demonstrate significant promise for the use of gold compounds in treating liver diseases such as HCV.

A review of the clinical utility of the Enhanced Liver Fibrosis test in multiple aetiologies of chronic liver disease

The rising incidence of chronic liver disease continues to be an increasing health burden. The morbidity and mortality associated with chronic liver disease typically occur in patients with advanced fibrosis. Hence, early identification of those at-risk is of vital importance to ensure appropriate ongoing management. Currently, tools for appropriate risk stratification remain limited. Increasing awareness of the limitations of liver biopsy has driven research into alternative non-invasive methods of fibrosis assessment including serological markers assessing functional changes. One such biomarker, the Enhanced Liver Fibrosis test, was initially validated in a cohort of 1021 patients with mixed aetiology chronic liver disease and shown to perform well. Since this pathfinder study, it has been independently validated in cohorts of hepatitis C, non-alcoholic fatty liver disease, alcoholic liver disease, primary biliary cirrhosis and primary sclerosing cholangitis. In addition to performing well as a diagnostic tool, the Enhanced Liver Fibrosis test has been shown to outperform liver biopsy in prognostic studies and is the only non-invasive marker to do so. However, questions remain regarding the use of this test, particularly regarding the possible effect age and alcohol may have on test scores. This review examines the current literature published in relation to the Enhanced Liver Fibrosis test and its clinical utility and highlights areas requiring further study.

Intestinal permeability in the pathogenesis of liver damage: From non-alcoholic fatty liver disease to liver transplantation

The intimate connection and the strict mutual cooperation between the gut and the liver realizes a functional entity called gut-liver axis. The integrity of intestinal barrier is crucial for the maintenance of liver homeostasis. In this mutual relationship, the liver acts as a second firewall towards potentially harmful substances translocated from the gut, and is, in turn, is implicated in the regulation of the barrier. Increasing evidence has highlighted the relevance of increased intestinal permeability and consequent bacterial translocation in the development of liver damage. In particular, in patients with non-alcoholic fatty liver disease recent hypotheses are considering intestinal permeability impairment, diet and gut dysbiosis as the primary pathogenic trigger. In advanced liver disease, intestinal permeability is enhanced by portal hypertension. The clinical consequence is an increased bacterial translocation that further worsens liver damage. Furthermore, this pathogenic mechanism is implicated in most of liver cirrhosis complications, such as spontaneous bacterial peritonitis, hepatorenal syndrome, portal vein thrombosis, hepatic encephalopathy, and hepatocellular carcinoma. After liver transplantation, the decrease in portal pressure should determine beneficial effects on the gut-liver axis, although are incompletely understood data on the modifications of the intestinal permeability and gut microbiota composition are still lacking. How the modulation of the intestinal permeability could prevent the initiation and progression of liver disease is still an uncovered area, which deserves further attention.

Curcumin and α/β-Adrenergic Antagonists Cotreatment Reverse Liver Cirrhosis in Hamsters: Participation of Nrf-2 and NF-κB

Liver cirrhosis is the result of an uncontrolled fibrogenetic process, due to the activation and subsequent differentiation into myofibroblasts of the hepatic stellate cells (HSC). It is known that HSC express adrenoreceptors (AR), and the use of AR antagonists protects experimental animals from cirrhosis. However, several studies suggest that the toxicity generated by metabolism of these antagonists would hinder its use in cirrhotic patients. In addition, liver fibrosis may be associated with a decrease of the antioxidant response of the nuclear factor erythroid 2-related factor 2 (Nrf-2) and the overregulation of the proinflammatory pathway of nuclear factor kappa B (NF-κB). Therefore, in the present work, the capacity of doxazosin (α1 antagonist), carvedilol (nonselective beta-adrenoceptor blocker with alpha 1-blocking properties), and curcumin (antioxidant and anti-inflammatory compound) to reverse liver cirrhosis and studying the possible modulation of Nrf-2 and NF-κB were evaluated. Hamsters received CCl4 for 20 weeks, and then treatments were immediately administered for 4 weeks more. The individual administration of doxazosin or carvedilol showed less ability to reverse cirrhosis in relation to concomitantly curcumin administration. However, the best effect was the combined effect of doxazosin, carvedilol, and curcumin, reversing liver fibrosis and decreasing the amount of collagen I (Sirius red stain) without affecting the morphology of hepatocytes (hematoxylin and eosin stain), showing normal hepatic function (glucose, albumin, AST, ALT, total bilirubin, and total proteins). In addition, carvedilol treatment and the combination of doxazosin with curcumin increased Nrf-2/NF-κB mRNA ratio and its protein expression in the inflammatory cells in the livers, possibly as another mechanism of hepatoprotection. Therefore, these results suggest for the first time that α/β adrenergic blockers with curcumin completely reverse hepatic damage, possibly as a result of adrenergic antagonism on HSC and conceivably by the increase of Nrf-2/NF-κB mRNA ratio.

Evaluation of Plasma Urokinase-Type Plasminogen Activator Receptor (UPAR) in Patients With Chronic Hepatitis B, C and Non-Alcoholic Fatty Liver Disease (NAFLD) as Serological Fibrosis Marker

BACKGROUND/AIMS

Progressive hepatic fibrosis is the main predictor of outcome and prognosis in chronic liver diseases. The importance of the coagulation cascade has been defined in liver fibrosis; however, the role of the fibrinolytic pathway has not been clear yet. We aimed to evaluate the association between the plasma levels of soluble urokinase Plasminogen Activator Receptor (uPAR) and the severity of liver fibrosis in chronic hepatitis B, C and Non-Alcoholic Fatty Liver Disease (NAFLD).

METHODS

96 chronic hepatitis B, 22 chronic hepatitis C and 11 NAFLD patients together with 47 healthy controls were enrolled in the study. uPAR plasma levels were detected by Enzyme-Linked Immunosorbent Assay (ELISA) method.

RESULTS

The plasma levels of uPAR in patients with chronic hepatitis B and C significantly exceeded those of healthy controls (P < 0.001) while mean uPAR levels in patients with NAFLD were not different from healthy controls. Mean uPAR levels in chronic viral hepatitis patients with F1-F3 fibrosis and F4-F6 fibrosis were higher than those of control group (P < 0.001). Mean uPAR level in patients with F4-F6 fibrosis was significantly higher than that of patients with F1-F3 fibrosis (P < 0.001).

CONCLUSION

This is the first study that investigated uPAR as a fibrosis marker in NAFLD and chronic hepatitis B patients. It is suggested that plasma levels of uPAR are closely related to the fibrosis stage in chronic hepatitis B and C and that uPAR might be a noninvasive marker of liver fibrosis.

Anti-hepatofibrosis effect of Allium senescens in activated hepatic stellate cells and thioacetamide-induced fibrosis rat model

CONTEXT

Allium senescens Linn. (Liliaceae) (ASL) has been traditionally used in Korea and other Asian countries for improving digestive and liver functions.

OBJECTIVE

The anti-hepatofibrosis effect of ASL ethanol extract in cellular and experimental fibrosis rat model was investigated.

MATERIALS AND METHODS

In vitro cell viability, cell cycle and apoptosis in hepatic stellate cells (HSCs) were studied using MTT assay, flow cytometry and Annexin V-FITC/PI staining. Thioacetamide (TAA; 200 mg/kg, i.p.)-induced liver fibrosis model using Sprague Dawley rats (n = 10) was developed in vivo by injecting TAA twice per week for 13 weeks. ASL (25 and 100 mg/kg) and silymarin (50 mg/kg) were administered through oral gavage 2 times per week from 7th to 13th week. Specific fibrotic-related biomarkers such as aspartate transaminase (AST), alanine transaminase (ALT), glutathione and hydroxyproline levels in serum were analyzed by spectrophotometer using commercial kits. Morphological, histopathological and fibrotic-related gene expression such as TGF-β, Col1α1 and α-SMA in liver tissues was estimated by hematoxylin and eosin staining, Picrosirius red stain and quantitative real-time polymerase chain reaction, respectively.

RESULTS

ASL (0.1 mg/mL) and silymarin (0.05 mg/mL) treatment induced apoptosis (4.06% and 8.67%) in activated HSC-T6 cells, compared with control group (3.7%). The altered morphology in activated primary HSCs was also restored by ASL (0.1 mg/mL) treatment. Further, ASL (100 and 25 mg/kg) ameliorated the TAA-induced altered fibrotic-related biomarkers, histopathological changes and fibrotic-related gene expression significantly (p < 0.05 ∼ p < 0.001).

CONCLUSIONS

ASL can potentially be developed as a therapeutic agent in the treatment of hepatic fibrosis.