Matrix metalloproteinases in liver injury, repair and fibrosis

Interrelation of adipose tissue macrophages and fibrosis in obesity

Obesity is characterized by adipose tissue expansion, extracellular matrix remodelling and unresolved inflammation that contribute to insulin resistance and fibrosis. Adipose tissue macrophages represent the most abundant class of immune cells in adipose tissue inflammation and could be key mediators of adipocyte dysfunction and fibrosis in obesity. Although macrophage activation states are classically defined by the M1/M2 polarization nomenclature, novel studies have revealed a more complex range of macrophage phenotypes in response to external condition or the surrounding microenvironment. Here, we discuss the plasticity of adipose tissue macrophages (ATMs) in response to their microenvironment in obesity, with special focus on macrophage infiltration and polarization, and their contribution to adipose tissue fibrosis. A better understanding of the role of ATMs as regulators of adipose tissue remodelling may provide novel therapeutic strategies against obesity and associated metabolic diseases.

Alcohol-induced epigenetic changes prevent fibrosis resolution after alcohol cessation in miceresolution

BACKGROUND AND AIMS

Alcohol-associated liver disease is a major cause of alcohol-associated mortality. Recently, we identified hepatic demethylases lysine demethylase (KDM)5B and KDM5C as important epigenetic regulators of alcohol response in the liver. In this study, we aimed to investigate the role of KDM5 demethylases in alcohol-associated liver disease resolution.

APPROACH AND RESULTS

We showed that alcohol-induced liver steatosis rapidly resolved after alcohol cessation. In contrast, fibrosis persisted in the liver for up to 8 weeks after the end of alcohol exposure. Defects in fibrosis resolution were in part due to alcohol-induced KDM5B and KDM5C-dependent epigenetic changes in hepatocytes. Using cell-type-specific knockout mice, we found that adeno-associated virus-mediated knockout of KDM5B and KDM5C demethylases in hepatocytes at the time of alcohol withdrawal promoted fibrosis resolution. Single-cell ATAC sequencing analysis showed that during alcohol-associated liver disease resolution epigenetic cell states largely reverted to control conditions. In addition, we found unique epigenetic cell states distinct from both control and alcohol states and identified associated transcriptional regulators, including liver X receptor (LXR) alpha (α). In vitro and in vivo analysis confirmed that knockout of KDM5B and KDM5C demethylases promoted LXRα activity, likely through regulation of oxysterol biosynthesis, and this activity was critical for the fibrosis resolution process. Reduced LXR activity by small molecule inhibitors prevented fibrosis resolution in KDM5-deficient mice.

CONCLUSIONS

In summary, KDM5B and KDM5C demethylases prevent liver fibrosis resolution after alcohol cessation in part through suppression of LXR activity.

Advances in Noninvasive Molecular Imaging Probes for Liver Fibrosis Diagnosis

Liver fibrosis is a wound-healing response to chronic liver injury, which may lead to cirrhosis and cancer. Early-stage fibrosis is reversible, and it is difficult to precisely diagnose with conventional imaging modalities such as magnetic resonance imaging, positron emission tomography, single-photon emission computed tomography, and ultrasound imaging. In contrast, probe-assisted molecular imaging offers a promising noninvasive approach to visualize early fibrosis changes in vivo, thus facilitating early diagnosis and staging liver fibrosis, and even monitoring of the treatment response. Here, the most recent progress in molecular imaging technologies for liver fibrosis is updated. We start by illustrating pathogenesis for liver fibrosis, which includes capillarization of liver sinusoidal endothelial cells, cellular and molecular processes involved in inflammation and fibrogenesis, as well as processes of collagen synthesis, oxidation, and cross-linking. Furthermore, the biological targets used in molecular imaging of liver fibrosis are summarized, which are composed of receptors on hepatic stellate cells, macrophages, and even liver collagen. Notably, the focus is on insights into the advances in imaging modalities developed for liver fibrosis diagnosis and the update in the corresponding contrast agents. In addition, challenges and opportunities for future research and clinical translation of the molecular imaging modalities and the contrast agents are pointed out. We hope that this review would serve as a guide for scientists and students who are interested in liver fibrosis imaging and treatment, and as well expedite the translation of molecular imaging technologies from bench to bedside.

Simultaneous fingerprinting of multiplex collagen biomarkers in connective tissues by multicolor quantum dots-based peptide probes

The accurate detection of multiplex collagen biomarkers is vital for diagnosing and treating various critical diseases such as tumors and fibrosis. Despite the attractive optical properties of quantum dots (QDs), it remains technically challenging to create stable and specific QDs-based probes for multiplex biological imaging. We report for the first time the construction of multi-color QDs-based peptide probes for the simultaneous fingerprinting of multiplex collagen biomarkers in connective tissues. A bipeptide system composed of a glutathione (GSH) host peptide and a collagen-targeting guest peptide (CTP) has been developed, yielding CTP-QDs probes that exhibit exceptional luminescence stability when exposed to ultraviolet irradiation and mildly acidic conditions. The versatile bipeptide system allows for facile one-pot synthesis of high-quality multicolor CTP-QDs probes, exhibiting superior selectivity in targeting critical collagen biomarkers including denatured collagen, type I collagen, type II collagen, and type IV collagen. The multicolor CTP-QDs probes have demonstrated remarkable efficacy in simultaneously fingerprinting multiple collagen types in diverse connective tissues, irrespective of their status, whether affected by injury, diseases, or undergoing remodeling processes. The innovative multicolor CTP-QDs probes offer a robust toolkit for the multiplex fingerprinting of the collagen suprafamily, demonstrating significant potential in the diagnosis and treatment of collagen-related diseases.

Optimized combination of Cervus nippon (Sika deer), Angelica (Dangui), and Rehmannia (Suk-jihwang) mitigates LPS-induced inflammation: exploring signaling pathways through plasma metabolomics

This study aimed to determine the optimal combination of three anti-inflammatory materials [i.e., Cervus nippon Temminck (CT), Angelica gigas Nakai (AN), and Rehmannia glutinosa (RG)] for the strongest anti-inflammatory potential. Eighteen combinations of the three materials were tested in LPS-stimulated RAW264.7 cells via assessing nitric oxide (NO). The best combination from in vitro studies was administered to LPS-treated C57BL/6J mice for five days. Subsequently, plasma metabolites were profiled by bioinformatics analyses and validations. As results, 2, 20, and 50 µg/mL of CT, AN, and RG (TM) were the most effective combination suppressing inflammation. In mice, TM mitigated hepatic inflammatory markers. Similarly, the metabolomics indicated that TM may suppress NF-κB signaling pathway, thereby alleviating hepatic inflammation. TM also decreased systemic and hepatic pro-inflammatory cytokines. Collectively, we found the optimal combination of TM for mitigating inflammation; thus further studies on safety, mechanisms, and clinical models are warranted for human applications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01476-x.

Serum biomarkers for liver fibrosis assessment

Liver fibrosis is the result of chronic liver injury of different etiologies produced by an imbalance between the synthesis and degeneration of the extracellular matrix and dysregulation of physiological mechanisms. Liver has a high regenerative capacity in the early stage of chronic diseases so a prompt liver fibrosis detection is important. Consequently, an easy and economic tool that could identify patients with liver fibrosis at the initial stages is needed. To achieve this, many non-invasive serum direct, such as hyaluronic acid or metalloproteases, and indirect biomarkers have been proposed to evaluate liver fibrosis. Also, there have been developed formulas that combine these biomarkers, some of them also introduce clinical and/or demographic parameters, like FIB-4, non-alcoholic fatty liver disease fibrosis score (NFS), enhance liver fibrosis (ELF) or Hepamet fibrosis score (HFS). In this manuscript we critically reviewed different serum biomarkers and formulas for their utility in the diagnosis and progression of liver fibrosis.

Biomarcadores séricos para la evaluación de la fibrosis hepática

La fibrosis hepática se desarrolla como respuesta a la presencia de daño hepático crónico de diferentes etiologías, provocando un desequilibrio entre la síntesis y degeneración de la matriz extracelular y la desregulación de diversos mecanismos fisiológicos. En los estadios iniciales de las patologías crónicas, el hígado posee una elevada capacidad de regeneración, por lo que la detección temprana de la fibrosis hepática resulta esencial. En este contexto, es preciso contar con herramientas sencillas y económicas que permitan detectar la fibrosis hepática en sus fases iniciales. Para evaluar la fibrosis hepática, se han propuesto multitud de biomarcadores séricos no invasivos, tanto directos, como el ácido hialurónico o las metaloproteasas, como indirectos. Así mismo, se han desarrollado diversas fórmulas que combinan dichos biomarcadores junto con parámetros demográficos, como el índice FIB-4, el índice de fibrosis en la enfermedad de hígado graso no alcohólico (NFS, por sus siglas en inglés), la prueba ELF o el score de fibrosis Hepamet (HFS, por sus siglas en inglés). En el presente manuscrito, realizamos una revisión crítica del valor diagnóstico y pronóstico de los diferentes biomarcadores séricos y fórmulas actualmente existentes.

3D microscaffolds with triple-marker sensitive nanoprobes for studying fatty liver disease in vitro

Non-alcoholic fatty liver disease (NAFLD) is a heterogeneous condition that encompasses a wide range of liver diseases that progresses from simple hepatic steatosis to the life-threatening state of cirrhosis. However, due to the heterogeneity of this disease, comprehensive analysis of several physicochemical and biological factors that drive its progression is necessary. Therefore, an in vitro platform is required that would enable real-time monitoring of these changes to better understand the progression of these diseases. The earliest stage of NAFLD, i.e. hepatic steatosis, is characterised by triglyceride accumulation in the form of lipid vacuoles in the cytosol of hepatocytes. This fatty acid accumulation is usually accompanied by hepatic inflammation, leading to tissue acidification and dysregulated expression of certain proteases such as matrix metalloproteinases (MMPs). Taking cues from the biological parameters of the disease, we report here a 3D in vitro GelMA/alginate microscaffold platform encapsulating a triple-marker (pH, MMP-3 and MMP-9) sensitive fluorescent nanoprobe for monitoring, and hence, distinguishing the fatty liver disease (hepatic steatosis) from healthy livers on the basis of pH change and MMP expression. The nanoprobe consists of a carbon nanoparticle (CNP) core, which exhibits intrinsic pH-dependent fluorescence properties, decorated either with an MMP-3 (NpMMP3) or MMP-9 (NpMMP9) sensitive peptide substrate. These peptide substrates are flanked with a fluorophore-quencher pair that separates on enzymatic cleavage, resulting in fluorescence emission. The cocktail of these nanoprobes generated multiple fluorescence signals corresponding to slightly acidic pH (blue) and overexpression of MMP-3 (green) and MMP-9 (red) enzymes in a 3D in vitro fatty liver model, whereas no/negligible fluorescence signals were observed in a healthy liver model. Moreover, this platform enabled us to mimic fatty liver disease in a more realistic manner. Therefore, this 3D in vitro platform encapsulating triple-marker sensitive fluorescent nanoprobes would facilitate the monitoring of the changes in pH and MMP expression, thereby enabling us to distinguish a healthy liver from a diseased liver and to study liver disease stages on the basis of these markers.

LP340, a novel histone deacetylase inhibitor, decreases liver injury and fibrosis in mice: role of oxidative stress and microRNA-23a

Effective therapy for liver fibrosis is lacking. Here, we examined whether LP340, the lead candidate of a new-generation of hydrazide-based HDAC1,2,3 inhibitors (HDACi), decreases liver fibrosis. Liver fibrosis was induced by CCl4 treatment and bile duct ligation (BDL) in mice. At 6 weeks after CCl4, serum alanine aminotransferase increased, and necrotic cell death and leukocyte infiltration occurred in the liver. Tumor necrosis factor-α and myeloperoxidase markedly increased, indicating inflammation. After 6 weeks, α-smooth muscle actin (αSMA) and collagen-1 expression increased by 80% and 575%, respectively, indicating hepatic stellate cell (HSC) activation and fibrogenesis. Fibrosis detected by trichrome and Sirius-red staining occurred primarily in pericentral regions with some bridging fibrosis in liver sections. 4-Hydroxynonenal adducts (indicator of oxidative stress), profibrotic cytokine transforming growth factor-β (TGFβ), and TGFβ downstream signaling molecules phospho-Smad2/3 also markedly increased. LP340 attenuated indices of liver injury, inflammation, and fibrosis markedly. Moreover, Ski-related novel protein-N (SnoN), an endogenous inhibitor of TGFβ signaling, decreased, whereas SnoN expression suppressor microRNA-23a (miR23a) increased markedly. LP340 (0.05 mg/kg, ig., daily during the last 2 weeks of CCl4 treatment) decreased 4-hydroxynonenal adducts and miR23a production, blunted SnoN decreases, and inhibited the TGFβ/Smad signaling. By contrast, LP340 had no effect on matrix metalloproteinase-9 expression. LP340 increased histone-3 acetylation but not tubulin acetylation, indicating that LP340 inhibited Class-I but not Class-II HDAC in vivo. After BDL, focal necrosis, inflammation, ductular reactions, and portal and bridging fibrosis occurred at 2 weeks, and αSMA and collagen-1 expression increased by 256% and 560%, respectively. LP340 attenuated liver injury, ductular reactions, inflammation, and liver fibrosis. LP340 also decreased 4-hydroxynonenal adducts and miR23a production, prevented SnoN decreases, and inhibited the TGFβ/Smad signaling after BDL. In vitro, LP340 inhibited immortal human hepatic stellate cells (hTERT-HSC) activation in culture (αSMA and collagen-1 expression) as well as miR23a production, demonstrating its direct inhibitory effects on HSC. In conclusions, LP340 is a promising therapy for both portal and pericentral liver fibrosis, and it works by inhibiting oxidative stress and decreasing miR23a.

Lactoferrin as a therapeutic agent for attenuating hepatic stellate cell activation in thioacetamide-induced liver fibrosis

Liver fibrosis is a chronic liver disease caused by prolonged liver injuries. Excessive accumulation of extracellular matrix replaces the damaged hepatocytes, leading to fibrous scar formation and fibrosis induction. Lactoferrin (LF) is a glycoprotein with a conserved, monomeric signal polypeptide chain, exhibiting diverse physiological functions, including antioxidant, anti-inflammatory, antibacterial, antifungal, antiviral, and antitumoral activities. Previous study has shown LF's protective role against chemically-induced liver fibrosis in rats. However, the mechanisms of LF in liver fibrosis are still unclear. In this study, we investigated LF's mechanisms in thioacetamide (TAA)-induced liver fibrosis in rats and TGF-β1-treated HSC-T6 cells. Using ultrasonic imaging, H&E, Masson's, and Sirius Red staining, we demonstrated LF's ability to improve liver tissue damage and fibrosis induced by TAA. LF reduced the levels of ALT, AST, and hydroxyproline in TAA-treated liver tissues, while increasing catalase levels. Additionally, LF treatment decreased mRNA expression of inflammatory factors such as Il-1β and Icam-1, as well as fibrogenic factors including α-Sma, Collagen I, and Ctgf in TAA-treated liver tissues. Furthermore, LF reduced TAA-induced ROS production and cell death in FL83B cells, and decreased α-SMA, Collagen I, and p-Smad2/3 productions in TGF-β1-treated HSC-T6 cells. Our study highlights LF's ability to ameliorate TAA-induced hepatocyte damage, oxidative stress, and liver fibrosis in rats, potentially through its inhibitory effect on HSC activation. These findings suggest LF's potential as a therapeutic agent for protecting against liver injuries and fibrosis.

A novel fluorescence probe for simultaneous detection of mitochondrial viscosity in hepatic ischemia reperfusion injury models

Acute liver failure caused by hepatic ischemia reperfusion injury (HIRI) poses a severe threat to life, emphasizing the urgent need for precise and timely early diagnosis. Viscosity, a key parameter reflecting active analyte levels at the cellular level, remains underexplored in relation to HIRI. To address this gap, we have developed a groundbreaking near-infrared molecule rotator, PN, exhibiting exceptional characteristics. PN demonstrates remarkable sensitivity, with a 32-fold change in response to viscosity, ranging from PBS to glycerol solution. PN's distinctive features include maximum emission wavelength 790 nm, as well as an impressive Stokes shift 190 nm. Moreover, PN exhibits the ability to sensitively and selectively differentiate nystatin-induced viscosity changes within living cells, and can be used for the detection of viscosity changes in the HIRI mouse model. This capability enhances our understanding of cellular responses, opening avenues for potential applications within disease models. The versatility of PN extends to its potential role in guiding timely monitoring and imaging of viscosity, offering valuable insights into disease progression.

Silicone implant surface microtopography modulates inflammation and tissue repair in capsular fibrosis

Excessive fibrous capsule formation around silicone mammary implants (SMI) involves immune reactions to silicone. Capsular fibrosis, a common SMI complication linked to host responses, worsens with specific implant topographies. Our study with 10 patients investigated intra- and inter-individually, reduced surface roughness effects on disease progression, wound responses, chronic inflammation, and capsular composition. The results illuminate the significant impact of surface roughness on acute inflammatory responses, fibrinogen accumulation, and the subsequent fibrotic cascade. The reduction of surface roughness to an average roughness of 4 μm emerges as a promising approach for mitigating detrimental immune reactions, promoting healthy wound healing, and curbing excessive fibrosis. The identified proteins adhering to rougher surfaces shed light on potential mediators of pro-inflammatory and pro-fibrotic processes, further emphasizing the need for meticulous consideration of surface design. The composition of the implant capsule and the discovery of intracapsular HSP60 expression highlight the intricate web of stress responses and immune activation that can impact long-term tissue outcomes.

Therapeutic potential of AAV-FL-Klotho in obesity: Impact on weight loss and lipid metabolism in mice

Klotho, an anti-aging protein, has gained attention for its protective effects against various diseases, including metabolic disorders, through recombinant Klotho administration. However, the potential of Klotho as a target for gene therapy requires further exploration, as it remains relatively understudied in the context of metabolic disorders. In this study, we demonstrate that AAV-full length(FL)-Klotho administration induces weight loss in mice and provides protection against high-fat diet (HFD)-induced obesity and hepatic steatosis, concurrently reducing the weights of white adipose tissue and liver. AAV-FL-Klotho administration also enhanced thermogenic gene expression in brown adipose tissue (BAT) and improved the morphology of interscapular BAT. The weight loss effect of AAV-FL-Klotho was found to be, at least in part, mediated by UCP1-dependent thermogenesis in brown adipocytes, potentially influenced by hepatokines secreted from AAV-FL-Klotho-transduced hepatocytes. These findings suggest that AAV-FL-Klotho is an attractive candidate for gene therapy to combat obesity. Nevertheless, unbiased experiments have also revealed disturbances in lipid metabolism due to AAV-FL-Klotho, as evidenced by the emergence of lipomas and increased expression of hepatic lipogenic proteins.

Two sides of the same coin: Non-alcoholic fatty liver disease and atherosclerosis

The prevalence of non-alcoholic fatty liver disease (NAFLD) and atherosclerosis remain high, which is primarily due to widespread adoption of a western diet and sedentary lifestyle. NAFLD, together with advanced forms of this disease such as non-alcoholic steatohepatitis (NASH) and cirrhosis, are closely associated with atherosclerotic-cardiovascular disease (ASCVD). In this review, we discussed the association between NAFLD and atherosclerosis and expounded on the common molecular biomarkers underpinning the pathogenesis of both NAFLD and atherosclerosis. Furthermore, we have summarized the mode of function and potential clinical utility of existing drugs in the context of these diseases.

Effects of Addition of Lanthanum and Zinc Oxides on the Biological Properties of TiO2-SiO2-P2O5/CaO on Ion Exchange Resin for Bone Implantation

The spherical materials TiO2-SiO2-P2O5/CaO, TiO2-SiO2-P2O5/La2O3, and TiO2-SiO2-P2O5/ZnO deposited on the Tokem-250 cation exchanger have been synthesized with an alcoholic solution by the sol-gel method. The macroporous cation exchanger Tokem-250, which has high Ca2+, Zn2+, and La3+ ion selectivity, was used in the present study. This material has the ability to precipitate and mineralize calcium phosphates on its surface in biological media, since it has high porosity, a homogeneous structure with a uniform variation of elements, and the presence of active centers (Si4+, Ti4+) on the surface. The effect of lanthanum and zinc additives on biological properties has been studied. It was established that accumulation of Ca2+ and Mg2+ occurs faster on the surface of TiO2-SiO2-P2O5/ZnO in the SBF (simulated body fluid) model solution, showing higher reaction capacity. The amount of calcium and phosphorus ions on the surface of sample TiO2-SiO2-P2O5/La2O3 is greater due to the ability of lanthanum to coordinate a large number of ions (lanthanum coordination number is 10). The presence of zinc ions in the system causes the partial hemoglobin release from erythrocytes into the supernatant fluid. The samples with lanthanum ions reduce the amount of protein in plasma after incubation, which has a positive effect on the practical application.

Unveiling the immune symphony: decoding colorectal cancer metastasis through immune interactions

Colorectal cancer (CRC), known for its high metastatic potential, remains a leading cause of cancer-related death. This review emphasizes the critical role of immune responses in CRC metastasis, focusing on the interaction between immune cells and tumor microenvironment. We explore how immune cells, through cytokines, chemokines, and growth factors, contribute to the CRC metastasis cascade, underlining the tumor microenvironment's role in shaping immune responses. The review addresses CRC's immune evasion tactics, especially the upregulation of checkpoint inhibitors like PD-1 and CTLA-4, highlighting their potential as therapeutic targets. We also examine advanced immunotherapies, including checkpoint inhibitors and immune cell transplantation, to modify immune responses and enhance treatment outcomes in CRC metastasis. Overall, our analysis offers insights into the interplay between immune molecules and the tumor environment, crucial for developing new treatments to control CRC metastasis and improve patient prognosis, with a specific focus on overcoming immune evasion, a key aspect of this special issue.

Research progress on rodent models and its mechanisms of liver injury

The liver is the most important organ for biological transformation in the body and is crucial for maintaining the body's vital activities. Liver injury is a serious pathological condition that is commonly found in many liver diseases. It has a high incidence rate, is difficult to cure, and is prone to recurrence. Liver injury can cause serious harm to the body, ranging from mild to severe fatty liver disease. If the condition continues to worsen, it can lead to liver fibrosis and cirrhosis, ultimately resulting in liver failure or liver cancer, which can seriously endanger human life and health. Therefore, establishing an rodent model that mimics the pathogenesis and severity of clinical liver injury is of great significance for better understanding the pathogenesis of liver injury patients and developing more effective clinical treatment methods. The author of this article summarizes common chemical liver injury models, immune liver injury models, alcoholic liver injury models, drug-induced liver injury models, and systematically elaborates on the modeling methods, mechanisms of action, pathways of action, and advantages or disadvantages of each type of model. The aim of this study is to establish reliable rodent models for researchers to use in exploring anti-liver injury and hepatoprotective drugs. By creating more accurate theoretical frameworks, we hope to provide new insights into the treatment of clinical liver injury diseases.

FXR agonists INT-787 and OCA increase RECK and inhibit liver steatosis and inflammation in diet-induced ob/ob mouse model of NASH

BACKGROUND AND AIMS

We have previously shown in a model of hepatic ischaemia/reperfusion injury that the farnesoid X receptor (FXR) agonist obeticholic acid (OCA) restores reversion-inducing-cysteine-rich protein with Kazal motifs (RECK), an inverse modulator of metalloproteases (MMPs) and inhibitor of the sheddases ADAM10 and ADAM17 involved in inflammation and fibrogenesis. Here, the effects of FXR agonists OCA and INT-787 on hepatic levels of RECK, MMPs, ADAM10 and ADAM17 were compared in a diet-induced ob/ob mouse model of non-alcoholic steatohepatitis (NASH).

METHODS

Lep ob/ob NASH mice fed a high-fat diet (HFD) or control diet (CD) for 9 weeks (wks) were treated with OCA or INT-787 0.05% dosed via HFD admixture (30 mg/kg/day) or HFD for further 12 wks. Serum alanine transaminase (ALT) and inflammatory cytokines, liver RECK, MMP-2 and MMP-9 activity as well as ADAM10, ADAM17, collagen deposition (Sirius red), hepatic stellate cell activation (α-SMA) and pCK+ reactive biliary cells were quantified.

RESULTS

Only INT-787 significantly reduced serum ALT, IL-1β and TGF-β. A downregulation of RECK expression and protein levels observed in HFD groups (at 9 and 21 wks) was counteracted by both OCA and INT-787. HFD induced a significant increase in liver MMP-2 and MMP-9; OCA administration reduced both MMP-2 and MMP-9 while INT-787 markedly reduced MMP-2 expression. OCA and INT-787 reduced both ADAM10 and ADAM17 expression and number of pCK+ cells. INT-787 was superior to OCA in decreasing collagen deposition and α-SMA levels.

CONCLUSION

INT-787 is superior to OCA in controlling specific cell types and clinically relevant anti-inflammatory and antifibrotic molecular mechanisms in NASH.

Antioxidant therapy against TGF-β/SMAD pathway involved in organ fibrosis

Fibrosis refers to excessive build-up of scar tissue and extracellular matrix components in different organs. In recent years, it has been revealed that different cytokines and chemokines, especially Transforming growth factor beta (TGF-β) is involved in the pathogenesis of fibrosis. It has been shown that TGF-β is upregulated in fibrotic tissues, and contributes to fibrosis by mediating pathways that are related to matrix preservation and fibroblasts differentiation. There is no doubt that antioxidants protect against different inflammatory conditions by reversing the effects of nitrogen, oxygen and sulfur-based reactive elements. Oxidative stress has a direct impact on chronic inflammation, and as results, prolonged inflammation ultimately results in fibrosis. Different types of antioxidants, in the forms of vitamins, natural compounds or synthetic ones, have been proven to be beneficial in the protection against fibrotic conditions both in vitro and in vivo. In this study, we reviewed the role of different compounds with antioxidant activity in induction or inhibition of TGF-β/SMAD signalling pathway, with regard to different fibrotic conditions such as gastro-intestinal fibrosis, cardiac fibrosis, pulmonary fibrosis, skin fibrosis, renal fibrosis and also some rare cases of fibrosis, both in animal models and cell lines.

Expression of Matrix Metalloproteinases in Human Cystic Echinococcosis

BACKGROUND

Cystic echinococcosis (CE) is a zoonotic disease caused by the Echinococcus granulosus senso lato (E. granulosus s.l.) larval stages. Parasitederived products have been shown to regulate host matrix metalloproteinases (MMPs), contributing to CE pathogenesis and progressive liver fibrosis in intermediate hosts. The current study aimed to investigate the potential role of MMP1, 7, 8, and 13 in E. granulosus s.l-induced liver fibrosis.

METHODS

Thirty CE patients with active, transitional, or inactive hydatid cysts were enrolled in this study to determine the inductive effects of E. granulosus on the expression of MMP-1, MMP-7, MMP-8, and MMP-13 in healthy liver tissue and fibrotic liver tissue using qRT-PCR.

RESULTS

According to the WHO-IWGE classification, patients with functional cysts (CE1 and CE2) had the highest percentage (46.6%). MMP-1, MMP-7, MMP-8, and MMP-13 expression levels were significantly higher in fibrotic liver than in normal liver tissue. MMP-13 and MMP-1 had the highest and lowest expression levels among MMPs. Compared to the normal group, the fold change for MMP-13 in the fibrotic group was greater than 12 and had the highest AUC value (AUC= 0.8283).

CONCLUSION

Our findings suggest that E. granulosus-derived products might be involved in regulating host MMPs. Thus, MMPs may be considered potential biomarkers for predicting CE prognosis. Because of the non-normal distribution of our patients' CE types, further research, particularly on circulation MMPs, is needed to confirm the potential role of MMPs in CE pathogenesis and to follow up on CE patients.

Ultra-high-performance liquid chromatography-quadrupole-time of flight-mass spectrometry combined with network pharmacology for analysis of potential quality markers of three processed products of Qingpi

Qingpi, a well-known traditional Chinese medicine for qi-regulating and commonly processed into three types of pieces, has been widely used in the clinical application of liver disease for thousands of years. In this study, an ultra-high-performance liquid chromatography-quadrupole-time of flight-mass spectrometry approach along with multivariate statistical analysis was developed to assess and characterize the differentiations of three processed products and confirm the potential quality markers of Qingpi. In addition, a systematic analysis combined with network pharmacology and molecular docking was performed to clarify the potential mechanism of Qingpi for the treatment of liver disease. As a result, 18 components were identified and an integrated network of Qingpi-Components-Target-Pathway-Liver Disease was constructed. Eight compounds were finally screened out as the potential quality markers acting on ten main targets and pathways of liver disease. Molecular docking analysis results indicated that the quality markers had a good binding activity with the targets. Overall, this work preliminarily identified the potential quality markers of three processed products of Qingpi, and predicted its targets in the prevention and treatment of liver disease, which can provide supporting information for further study of the pharmacodynamic substances and mechanisms of Qingpi.

Synthesis and evaluation of novel pleuromutilin derivatives targeting the 50S ribosomal subunit for antibacterial ability

Multidrug-resistant bacteria, particularly methicillin-resistant Staphylococcus aureus, have become a major global public health concern. Therefore, developing new antibiotics that do not possess cross-resistance for the currently available antibiotics is critical. Herein, we synthesized a novel class of pleuromutilin derivatives containing substituted triazine with improved antibacterial activity. Among these derivatives, 6d, which contains 4-dimethylamino-1,3,5-triazine in the side chain of pleuromutilin, exhibited highly promising antimicrobial activity and mitigated antibiotic resistance. The high antibacterial potency of 6d was further supported by docking model analysis and green fluorescent protein inhibition assay. Additionally, cytotoxicity and acute oral toxicity evaluation and in vivo mouse systemic infection experiments revealed that 6d possessed tolerable toxicity and promising therapeutic efficacy.

Triptolide attenuates CCL4-induced liver fibrosis by regulating the differentiation of CD4+ T cells in mice

Liver fibrosis is a major global health issue, and immune dysregulation is a main contributor. Triptolide is a natural immunosuppressive agent with demonstrated effectiveness in ameliorating liver fibrosis, but whether it exerts anti-liver fibrotic effects via immunoregulation remains obscure. In this study, first, by employing a CCL4-induced liver fibrosis mouse model, we demonstrated that triptolide could alleviate pathological damage to liver tissue and attenuate liver function damaged by CCL4. In addition, triptolide inhibited the expression of liver fibrotic markers such as hydroxyproline, collagen type IV, hyaluronidase, laminin, and procollagen type III, and the protein expression of α-SMA in CCL4-induced liver fibrosis. Second, with the help of network pharmacology, we predicted that triptolide's anti-liver fibrotic effects might occur through the regulation of Th17, Th1, and Th2 cell differentiation, which indicated that triptolide might mitigate liver fibrosis via immunoregulation. Finally, multiplex immunoassays and flow cytometry were adopted to verify this prediction. The results suggested that triptolide could reverse the aberrant expression of inflammatory cytokines caused by CCL4 and regulate the differentiation of Th1, Th2, Th17, and Treg cells. In conclusion, triptolide could attenuate CCL4-induced liver fibrosis by regulating the differentiation of CD4+ T cells. The results obtained in this study extended the application of triptolide and introduced a new mechanism of triptolide's anti-liver fibrotic effects.

The role of ischaemia-reperfusion injury and liver regeneration in hepatic tumour recurrence

The risk of cancer recurrence after liver surgery mainly depends on tumour biology, but preclinical and clinical evidence suggests that the degree of perioperative liver injury plays a role in creating a favourable microenvironment for tumour cell engraftment or proliferation of dormant micro-metastases. Understanding the contribution of perioperative liver injury to tumour recurrence is imperative, as these pathways are potentially actionable. In this review, we examine the key mechanisms of perioperative liver injury, which comprise mechanical handling and surgical stress, ischaemia-reperfusion injury, and parenchymal loss leading to liver regeneration. We explore how these processes can trigger downstream cascades leading to the activation of the immune system and the pro-inflammatory response, cellular proliferation, angiogenesis, anti-apoptotic signals, and release of circulating tumour cells. Finally, we discuss the novel therapies under investigation to decrease ischaemia-reperfusion injury and increase regeneration after liver surgery, including pharmaceutical agents, inflow modulation, and machine perfusion.

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

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

S-nitrosylation of EMMPRIN influences the migration of HSCs and MMP activity in liver fibrosis

The mechanism of extracellular matrix metalloproteinase inducer (EMMPRIN) in the regulation of liver fibrosis has not been clarified. This study aims to investigate the role of EMMPRIN S-nitrosylation (SNO) in the regulation of hepatic stellate cell (HSC) migration and matrix metalloproteinase (MMP) activities in liver fibrosis. The results from the tissue microarrays and rat/mouse liver tissues suggest that EMMPRIN mRNA and protein levels in the fibrotic livers are lower than those in the corresponding normal control livers, but higher SNO level of EMMPRIN in fibrotic liver area was shown by immunohistochemistry, immunofluorescence staining, and biotin-switch assay conversely in vivo. Primary EMMPRIN comes from hepatocytes and liver sinus epithelial cells (LSECs) rather than quiescent HSCs. To mimic the uptake of extrinsic EMMPRIN, supernatants from mouse primary hepatocytes/293 cells transfected with EMMPRIN wild-type plasmids (WT) and EMMPRIN SNO site (cysteine 87) mutation plasmids (MUT) were collected and added to JS-1/LX2 cell medium. The MUT EMMPRIN diminishes SNO successfully, enhances the activities of MMP2 and MMP9, and subsequently increases HSC migration. In conclusion, SNO of EMMPRIN influences HSC migration and MMP activities in liver fibrosis. This finding may shed light on the possible regulatory mechanism of MMPs in ECM accumulation in liver fibrosis.

Panic at the Bile Duct: How Intrahepatic Cholangiocytes Respond to Stress and Injury

In the liver, biliary epithelial cells (BECs) line intrahepatic bile ducts (IHBDs) and are primarily responsible for modifying and transporting hepatocyte-produced bile to the digestive tract. BECs comprise only 3% to 5% of the liver by cell number but are critical for maintaining choleresis through homeostasis and disease. To this end, BECs drive an extensive morphologic remodeling of the IHBD network termed ductular reaction (DR) in response to direct injury or injury to the hepatic parenchyma. BECs are also the target of a broad and heterogenous class of diseases termed cholangiopathies, which can present with phenotypes ranging from defective IHBD development in pediatric patients to progressive periductal fibrosis and cancer. DR is observed in many cholangiopathies, highlighting overlapping similarities between cell- and tissue-level responses by BECs across a spectrum of injury and disease. The following core set of cell biological BEC responses to stress and injury may moderate, initiate, or exacerbate liver pathophysiology in a context-dependent manner: cell death, proliferation, transdifferentiation, senescence, and acquisition of neuroendocrine phenotype. By reviewing how IHBDs respond to stress, this review seeks to highlight fundamental processes with potentially adaptive or maladaptive consequences. A deeper understanding of how these common responses contribute to DR and cholangiopathies may identify novel therapeutic targets in liver disease.

Matrix metalloproteinase 1 is a poor prognostic biomarker for patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains an incurable malignancy despite the treatment methods being continually updated. Matrix metalloproteinases (MMPs) promote the progression of HCC; however, no consensus exists on which MMP plays the predominant role in HCCs. In the present study, we analyzed differentially expressed genes in HCCs, especially MMPs, compared with adjacent tissues using the Cancer Genome Atlas database. The KEGG enrichment pathway using differentially expressed genes included extracellular matrix-receptor interaction, which was correlated with MMPs. We found that among the MMP family, only MMP1, MMP3, MMP8, MMP9, MMP11, MMP12, MMP14, MMP15, MMP20, MMP21, and MMP24 significantly increased in HCCs compared with adjacent tissues. Crucially, survival and univariate analyses indicated that only MMPs 1, 9, 12, and 14 predict poor overall survival; however, multivariate Cox analysis and a nomogram demonstrated that only MMP1 is a poor prognostic biomarker for HCCs. In addition, we observed significant enrichment of uncharacterized cells but decreased macrophages in HCC tissues. Consistent with decreased macrophages in HCCs, MMP1 was negatively associated with macrophages but positively correlated with uncharacterized cells, indicating that the main producer of MMP1 is uncharacterized cells. Furthermore, MMP1 expression was negatively correlated with immune responses of HCCs. Taken together, our findings indicated that MMP1 is a poor and predominant prognostic biomarker for patients with HCC and that anti-MMP1 may be a novel therapy that is worth studying in depth.

Characterization and verification of MMP family members as potential biomarkers in kidney clear cell renal carcinoma

Renal cell carcinoma can arise from lesions in the renal epithelium. This particular type of cancer is prevalent in the realm of renal cancers and is associated with an unfavorable prognosis. Among these cases, over 70% are classified as kidney renal clear cell carcinoma (KIRC). Since the underlying causes of KIRC haven't been fully understood, there is an urgent need for deeper investigation into its pathogenesis. Various tools, software, and molecular analysis was used, including Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), Cytoscape, University of ALabama at Birmingham CANcer data analysis Portal (UALCAN), muTarget, Gene Expression Profiling Interactive Analysis (GEPIA), OncoDB, Human Protein Atlas (HPA), cBioPortal, Kaplan-Meier (KM) plotter, Gene Set Enrichment Analysis (GSEA), Tumor IMmune Estimation Resource (TIMER), Encyclopedia of RNA Interactomes (ENCORI), DrugBank, Encyclopedia of RNA Interactomes (RT-qPCR), targeted bisulfide sequencing (bisulfide-seq), and receiver operating curve (ROC) to matrix metallopeptidase (MMP) gene family constituents, with the precise objective of identifying a small set of hub genes. These hub genes hold the potential to be harnessed as molecular biomarkers for KIRC. By performing STRING and CytoHubba analyses of the 24 MMP gene family members, MMP2 (matrix metallopeptidase 2), MMP9 (matrix metallopeptidase 9), MMP14 (matrix metallopeptidase 14), and MMP16 (matrix metallopeptidase 16) were recognized as hub genes having highest degree scores. After conducting an in-depth expression analysis of MMP2, MMP9, MMP14, and MMP16 using various The Cancer Genome Atlas (TCGA) databases and RT-qPCR techniques, these displayed a significant increase in expression at both the mRNA and protein levels within KIRC samples when compared to control samples. The impact of the over expression of MMP2, MMP9, MMP14, and MMP16 also left a distinct mark on the worst overall survival (OS) rates of KIRC patients. Furthermore, a targeted bisulfide-seq investigation unveiled a correlation between promoter hypomethylation patterns and the up-regulation of these key genes in KIRC patients. Additionally, hub genes were involved in various diverse oncogenic pathways. In conclusion, four MMP gene family members, including MMP2, MMP9, MMP14, and MMP16 may serve as therapeutic target and molecular biomarker in KIRC.

Concentration-Dependent Attenuation of Pro-Fibrotic Responses after Cannabigerol Exposure in Primary Rat Hepatocytes Cultured in Palmitate and Fructose Media

Hepatic fibrosis is a consequence of liver injuries, in which the overproduction and progressive accumulation of extracellular matrix (ECM) components with the simultaneous failure of matrix turnover mechanisms are observed. The aim of this study was to investigate the concentration-dependent influence of cannabigerol (CBG, Cannabis sativa L. component) on ECM composition with respect to transforming growth factor beta 1 (TGF-β1) changes in primary hepatocytes with fibrotic changes induced by palmitate and fructose media. Cells were isolated from male Wistar rats' livers in accordance with the two-step collagenase perfusion technique. This was followed by hepatocytes incubation with the presence or absence of palmitate with fructose and/or cannabigerol (at concentrations of 1, 5, 10, 15, 25, 30 µM) for 48 h. The expression of ECM mRNA genes and proteins was determined using PCR and Western blot, respectively, whereas media ECM level was evaluated using ELISA. Our results indicated that selected low concentrations of CBG caused a reduction in TGF-β1 mRNA expression and secretion into media. Hepatocyte exposure to cannabigerol at low concentrations attenuated collagen 1 and 3 deposition. The protein and/or mRNA expressions and MMP-2 and MMP-9 secretion were augmented using CBG. Considering the mentioned results, low concentrations of cannabigerol treatment might expedite fibrosis regression and promote regeneration.

Targeting collagen homeostasis for the treatment of liver fibrosis: Opportunities and challenges

Liver fibrosis is an excessive production, aberrant deposition, and deficit degradation of extracellular matrix (ECM). Patients with unresolved fibrosis ultimately undergo end-stage liver diseases. To date, the effective and safe strategy to cease fibrosis progression remains an unmet clinical need. Since collagens are the most abundant ECM protein which play an essential role in fibrogenesis, the suitable regulation of collagen homeostasis could be an effective strategy for the treatment of liver fibrosis. Therefore, this review provides a brief overview on the dysregulation of ECM homeostasis, focusing on collagens, in the pathogenesis of liver fibrosis. Most importantly, promising therapeutic mechanisms related to biosynthesis, deposition and extracellular interactions, and degradation of collagens, together with preclinical and clinical antifibrotic evidence of drugs affecting each target are orderly criticized. In addition, challenges for targeting collagen homeostasis in the treatment of liver fibrosis are discussed.

Interleukin-19 Gene-Deficient Mice Promote Liver Fibrosis via Enhanced TGF-β Signaling, and the Interleukin-19-CCL2 Axis Is Important in the Direction of Liver Fibrosis

IL-19 is a cytokine discovered by homologous searching with IL-10 and is produced by non-immune cells, such as keratinocytes, in addition to immune cells, such as macrophages. Liver fibrosis results from the inflammation and activation of hepatic stellate cells via chronic liver injury. However, the participation of IL-19 in liver fibrosis remains to be sufficiently elucidated. Our group studied the immunological function of IL-19 in a mouse model of carbon tetrachloride (CCl₄)-induced liver fibrosis. IL-19 gene-deficient (KO) mice and body weight-matched wild-type (WT) mice were used. A liver fibrosis mouse model was created via CCl₄ administration (two times per week) for 8 weeks. In CCl₄-induced liver fibrosis, serum analysis revealed that IL-19 KO mice had higher ALT levels compared to WT mice. IL-19 KO mice had worse fibrosis, as assessed by morphological evaluation of total area stained positive with Azan and Masson trichrome. In addition, the expression of α-SMA was increased in liver tissues of IL-19 KO mice compared to WT mice. Furthermore, mRNA expression levels of TGF-β and α-SMA were enhanced in IL-19 KO mice compared to WT mice. In vitro assays revealed that IL-19-high expressing RAW264.7 cells inhibited the migration of NIH3T3 cells via the inhibited expression of CCL2 in the presence of CCl₄ and IL-4. These findings indicate that IL-19 plays a critical role in liver fibrosis by affecting TGF-β signaling and the migration of hepatic stellate cells during liver injury. Enhancement of the IL-19 signaling pathway is a potential treatment for liver fibrosis.

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.

RNA methylations in hepatic fibrosis, a gradually emerging new treatment strategy

BACKGROUND

Hepatic fibrosis (HF) is a pathological process caused by excessive accumulation of extracellular matrix caused by a series of causes, leading to the formation of fiber scar. RNA methylation is a newly discovered epigenetic modification that exists widely in eukaryotes and prokaryotes and plays a crucial role in the pathogenesis of many diseases.

RESULTS

The occurrence and development of HF are regulated by many factors, including excessive deposition of extracellular matrix, activation of hepatic stellate cells, inflammation, and oxidative stress. RNA methylations of different species have become a crucial regulatory mode of transcript expression, And participate in the pathogenesis of tumors, nervous system diseases, autoimmune diseases, and other diseases. In addition, there are five common types of RNA methylation, but only m6A plays a crucial regulatory role in HF. The pathophysiological regulation of m6A on HF is achieved by the combination of the methylated transferase, demethylated enzyme, and methylated reading protein.

CONCLUSIONS

RNA methylated methyltransferase, demethylase, and reading protein extensively affect the pathological mechanism of HF, which may be a new therapeutic and diagnostic target, representing a new class of therapeutic strategies.

Magnesium and Liver Metabolism Through the Lifespan

Within the organism, the liver is the main organ responsible for metabolic homeostasis and xenobiotic transformation. To maintain an adequate liver weight-to-bodyweight ratio, this organ has an extraordinary regenerative capacity and is able to respond to an acute insult or partial hepatectomy. Maintenance of hepatic homeostasis is crucial for the proper functioning of the liver, and in this context, adequate nutrition with macro- and micronutrient intake is mandatory. Among all known macro-minerals, magnesium has a key role in energy metabolism and in metabolic and signaling pathways that maintain liver function and physiology throughout its life span. In the present review, the cation is reported as a potential key molecule during embryogenesis, liver regeneration, and aging. The exact role of the cation during liver formation and regeneration is not fully understood due to its unclear role in the activation and inhibition of those processes, and further research in a developmental context is needed. As individuals age, they may develop hypomagnesemia, a condition that aggravates the characteristic alterations. Additionally, risk of developing liver pathologies increases with age, and hypomagnesemia may be a contributing factor. Therefore, magnesium loss must be prevented by adequate intake of magnesium-rich foods such as seeds, nuts, spinach, or rice to prevent age-related hepatic alterations and contribute to the maintenance of hepatic homeostasis. Since magnesium-rich sources include a variety of foods, a varied and balanced diet can meet both macronutrient and micronutrient needs.

Loss of CEACAM1 in endothelial cells causes hepatic fibrosis

OBJECTIVES

Hepatocytic CEACAM1 plays a critical role in NASH pathogenesis, as bolstered by the development of insulin resistance, visceral obesity, steatohepatitis and fibrosis in mice with global Ceacam1 (Cc1) deletion. In contrast, VECadCre+Cc1fl/fl mice with endothelial loss of Cc1 manifested insulin sensitivity with no visceral obesity despite elevated NF-κB signaling and increased systemic inflammation. We herein investigated whether VECadCre+Cc1fl/fl male mice develop hepatic fibrosis and whether this is mediated by increased production of endothelin1 (ET1), a transcriptional NF-κB target.

METHODS

VECadCre+Et1.Cc1fl/fl mice with combined endothelial loss of Cc1/Et1 genes were generated. Histological and immunohistochemical analyses were conducted on their livers and on liver tissue biopsies from adult patients undergoing bariatric surgery or from patients with NASH diagnosis receiving liver transplant.

RESULTS

Hepatic fibrosis and inflammatory infiltration developed in VECadCre+Cc1fl/fl liver parenchyma. This was preceded by increased ET1 production and reversed with combined endothelial loss of Et1. Conditioned media from VECadCre+Cc1fl/fl, but not VECadCre+Et1.Cc1fl/fl primary liver endothelial cells activated wild-type hepatic stellate cells; a process inhibited by bosentan, an ETAR/ETBR dual antagonist. Consistently, immunohistochemical analysis of liver biopsies from patients with NASH showed a decline in endothelial CEACAM1 in parallel with increased plasma endothelin1 levels and progression of hepatic fibrosis stage.

CONCLUSIONS

The data demonstrated that endothelial CEACAM1 plays a key role in preventing hepatic fibrogenesis by reducing autocrine endothelin1 production.

Elastography of the Liver in Wilson's Disease

Staging of liver fibrosis is of special significance in Wilson's disease as it determines the patient's prognosis and treatment. Histopathological examination is a standard method for fibrosis assessment; however, non-invasive methods like transient elastography and share wave elastography are believed to be reliable and repetitive and are expected to replace liver biopsy in Wilson's disease. This article presents a short description of available elastography techniques and the results of the most recent studies on elastography of the liver in patients with Wilson's disease.

The effect of ginsenosides on liver injury in preclinical studies: a systematic review and meta-analysis

Background: Liver injury is a severe liver lesion caused by various etiologies and is one of the main areas of medical research. Panax ginseng C.A. Meyer has traditionally been used as medicine to treat diseases and regulate body functions. Ginsenosides are the main active components of ginseng, and their effects on liver injury have been extensively reported. Methods: Preclinical studies meeting the inclusion criteria were retrieved from PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and Wan Fang Data Knowledge Service Platforms. The Stata 17.0 was used to perform the meta-analysis, meta-regression, and subgroup analysis. Results: This meta-analysis included ginsenosides Rb1, Rg1, Rg3, and compound K (CK), in 43 articles. The overall results showed that multiple ginsenosides significantly reduced alanine aminotransferase (ALT) and aspartate aminotransferase (AST), affected oxidative stress-related indicators, such as superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GSH-Px), and catalase (CAT), and reduced levels of inflammatory factor, such as factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6). Additionally, there was a large amount of heterogeneity in the meta-analysis results. Our predefined subgroup analysis shows that the animal species, the type of liver injury model, the duration of treatment, and the administration route may be the sources of some of the heterogeneity. Conclusion: In a word, ginsenosides have good efficacy against liver injury, and their potential mechanisms of action target antioxidant, anti-inflammatory and apoptotic-related pathways. However, the overall methodological quality of our current included studies was low, and more high-quality studies are needed to confirm their effects and mechanisms further.

Temporal analysis of paracetamol-induced hepatotoxicity

Paracetamol-induced hepatotoxicity (APAP) causes severe damage that may be irreversible. Understanding the evolution of liver injury caused by overdose of the drug is important to assist in the treatment. In the present study, we evaluated the acute intoxication by APAP (500 mg/kg) in periods of 3 and 12 hours in C57BL/6 mice through biochemical, histological, inflammatory parameters, and the redox status. The results showed that in the 3-hour period there was an increase in creatinine dosage and lipid peroxidation (TBARS) compared to the control group. In the period of 12 hours after APAP intoxication all parameters evaluated were altered; there was an increase of ALT, AST, and necrosis, besides the increase of redox status biomarkers as carbonylated protein, TBARS, and MMP-9. We also observed activation of the inflammasome pathway as well as a reduction in the regenerative capacity of hepatocytes with a decrease in binucleated liver cells. In cytochrome gene expression, the mRNA level increased in CYP2E1 isoenzyme and reduced CYP1A2 expression. This study indicated that early treatment is necessary to mitigate APAP-induced acute liver injury, and alternative therapies capable of controlling the progression of intoxication in the liver are needed.

Matrix metalloproteinases induce extracellular matrix degradation through various pathways to alleviate hepatic fibrosis

Liver fibrosis is the common consequence of various chronic liver injuries and is mainly characterized by the imbalance between the production and degradation of extracellular matrix, which leads to the accumulation of interstitial collagen and other matrix components. Matrix metalloproteinases (MMPs) and their specific inhibitors, that is, tissue inhibitors of metalloproteinases (TIMPs), play a crucial role in collagen synthesis and lysis. Previous in vivo and in vitro studies of our laboratory found repressing extracellular matrix (ECM) accumulation by restoring the balance between MMPs and TIMPs can alleviate liver fibrosis. We conducted a review of articles published in PubMed and Science Direct in the last decade until February 1, 2023, which were searched for using these words "MMPs/TIMPs" and "Hepatic Fibrosis." Through a literature review, this article reviews the experimental studies of liver fibrosis based on MMPs/TIMPs, summarizes the components that may exert an anti-liver fibrosis effect by affecting the expression or activity of MMPs/TIMPs, and attempts to clarify the mechanism of MMPs/TIMPs in regulating collagen homeostasis, so as to provide support for the development of anti-liver fibrosis drugs. We found the MMP-TIMP-ECM interaction can result in better understanding of the pathogenesis and progression of hepatic fibrosis from a different angle, and targeting this interaction may be a promising therapeutic strategy for hepatic fibrosis. Additionally, we summarized and analyzed the drugs that have been found to reduce liver fibrosis by changing the ratio of MMPs/TIMPs, including medicine natural products.

Extracellular matrix-regulator MMPA is required for the orderly proliferation of neoblasts and differentiation of ectodermal progenitor cells in the planarian Dugesia japonica

Matrix metalloproteinases (MMPs) are members of a family of zinc-dependent metallopeptidase proteins that are widely found in plants, animals, and microorganisms. As the regulators of the extracellular matrix and basement membrane, MMPs play an important role in embryogenesis, development, innate immunity, and regeneration. However, the function of MMP family in planarian, a model for regeneration research, is still ambiguous. Here, we cloned 5 MMPs genes from Dugesia japonica and found that DjMMPA was associated with the process of regeneration, neoblasts cell maintenance confusion and destruction. Loss of DjMMPA led to homeostasis confusion and eventually death, owing to neoblasts proliferation disorder. Additionally, DjMMPA RNAi-treated animals had impaired regeneration after amputation. Furthermore, knockdown of DjMMPA had noticeable defects in cell differentiation of ectoderm, especially in eyes and neural progenitor cells, possibly by inhibiting Wnt signaling. Our results suggest that extracellular matrix-regulator MMPA is required for the orderly proliferation of neoblasts and differentiation of ectodermal progenitor cells in the planarian, which provide valuable information for further explorations into the molecular mechanism of MMPS, stem cells, and regeneration.

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.

Exploring the constituent mechanisms of hepatitis: a dynamical systems approach

Hepatitis is the term used to describe inflammation in the liver. It is associated with a high rate of mortality, but the underlying disease mechanisms are not completely understood and treatment options are limited. We present a mathematical model of hepatitis that captures the complex interactions between hepatocytes (liver cells), hepatic stellate cells (cells in the liver that produce hepatitis-associated fibrosis) and the immune components that mediate inflammation. The model is in the form of a system of ordinary differential equations. We use numerical techniques and bifurcation analysis to characterize and elucidate the physiological mechanisms that dominate liver injury and its outcome to a healthy or unhealthy, chronic state. This study reveals the complex interactions between the multiple cell types and mediators involved in this complex disease and highlights potential problems in targeting inflammation in the liver therapeutically.

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.

Sterile liver injury induces a protective tissue-resident cDC1-ILC1 circuit through cDC1-intrinsic cGAS-STING-dependent IL-12 production

Tissue-resident immune cells are critical to the initiation and potentiation of inflammation. However, the tissue-protective cellular communication networks initiated by resident immunity during sterile inflammation are not well understood. Using single-cell transcriptomic analysis, we show the liver-resident cell connectome and signalome during acute liver injury. These analyses identify Il12b as a central regulator of liver injury-associated changes in gene expression. Interleukin (IL)-12 produced by conventional type 1 dendritic cells (cDC1s) is required for protection during acute injury through activation of interferon (IFN)-γ production by liver-resident type 1 innate lymphoid cells (ILC1s). Using a targeted in vivo CRISPR-Cas9 screen of innate immune sensing pathways, we find that cDC1-intrinsic cGAS-STING signaling acts upstream of IL-12 production to initiate early protective immune responses. Our study identifies the core communication hubs initiated by tissue-resident innate immune cells during sterile inflammation in vivo and implicates cDC1-derived IL-12 as an important regulator of this process.

Effect of Percutaneous Biliary Drainage on Enzyme Activity of Serum Matrix Metalloproteinase-9 in Patients with Malignant Hilar Obstructive Hyperbilirubinemia

Background and Objectives. Cholestasis activates complex mechanisms of liver injury and as a result has an increased production of matrix metalloproteinases (MMP). Depending on the stage of liver disease, different matrix metalloproteinases expressions have been detected and could serve as indirect biomarkers as well as therapeutic targets. MMP-9 proteolytic activity has a proven role in both liver regeneration and neoplastic cell invasion in various malignancies. The purpose of this prospective cohort study was to evaluate the effect of external biliary drainage on enzyme activity of MMP-9 in the serum of patients with malignant hilar biliary obstruction. Materials and Methods. Between November 2020 and April 2021, 45 patients with malignant hilar biliary obstruction underwent percutaneous biliary drainage following determination of serum MMP-9 enzyme activity (before treatment and 4 weeks after the treatment) by gelatin zymography. Results. MMP-9 values decreased statistically significantly 4 weeks after percutaneous biliary drainage (p = 0.028) as well as the value of total bilirubin (p < 0.001), values of direct bilirubin (p < 0.001), aspartate aminotransferase (AST) (p < 0.001), alanine transaminase (ALT) (p < 0.001), and gamma-glutamyl transferase (GGT) (p < 0.001). Conclusions. In patients with malignant hilar biliary obstruction treated by external percutaneous biliary drainage for cholestasis resolution, a significant reduction in MMP-9 serum values was noted 4 weeks after the treatment.

Regulatory T cells (Tregs) in liver fibrosis

The ability of the human liver to both synthesize extracellular matrix(ECM), as well as regulate fibrogenesis, are integral functions to maintaining homoeostasis. Chronic liver injury stimulates fibrogenesis in response to the imbalance between ECM accumulation and fibrosis resolution. Liver disease that induces fibrogenesis is associated with multiple risk factors like hepatitis infection, schistosomiasis, alcohol, certain drugs, toxicants and emerging aetiology like diabetes and obesity. The activation of hepatic stellate cells (HSCs), whose function is to generate and accumulate ECM, is a pivotal event in liver fibrosis. Simultaneously, HSCs selectively promote regulatory T-cells (Tregs) in an interleukin-2-dependent pattern that displays a dual relationship. On the one hand, Tregs can protect HSCs from NK cell attack, while on the other hand, they demonstrate an inhibitory effect on HSCs. This paper reviews the dual role of Tregs in liver fibrogenesis which includes its promotion of immunosuppression, as well as its activation of fibrosis. In particular, the balance between Tregs and the Th17 cell population, which produce interleukin (IL)-17 and IL-22, is explored to demonstrate their key role in maintaining homoeostasis and immunoregulation. The contradictory roles of Tregs in liver fibrosis in different immune microenvironments and molecular pathways need to be better understood if they are to be deployed to manage this disease.

Optical Biomedical Imaging Reveals Criteria for Violated Liver Regenerative Potential

To reduce the risk of post-hepatectomy liver failure in patients with hepatic pathologies, it is necessary to develop an approach to express the intraoperative assessment of the liver's regenerative potential. Traditional clinical methods do not enable the prediction of the function of the liver remnant. Modern label-free bioimaging, using multiphoton microscopy in combination with second harmonic generation (SHG) and fluorescence lifetime imaging microscopy (FLIM), can both expand the possibilities for diagnosing liver pathologies and for assessing the regenerative potential of the liver. Using multiphoton and SHG microscopy, we assessed the structural state of liver tissue at different stages of induced steatosis and fibrosis before and after 70% partial hepatectomy in rats. Using FLIM, we also performed a detailed analysis of the metabolic state of the hepatocytes. We were able to determine criteria that can reveal a lack of regenerative potential in violated liver, such as the presence of zones with reduced NAD(P)H autofluorescence signals. Furthermore, for a liver with pathology, there was an absence of the jump in the fluorescence lifetime contributions of the bound form of NADH and NADPH the 3rd day after hepatectomy that is characteristic of normal liver regeneration. Such results are associated with decreased intensity of oxidative phosphorylation and of biosynthetic processes in pathological liver, which is the reason for the impaired liver recovery. This modern approach offers an effective tool that can be successfully translated into the clinic for express, intraoperative assessment of the regenerative potential of the pathological liver of a patient.

Hepatoprotective Efficacy of Cycloastragenol Alleviated the Progression of Liver Fibrosis in Carbon-Tetrachloride-Treated Mice

The continuous death of hepatocytes induced by various etiologies leads to an aberrant tissue healing process and promotes the progression of liver fibrosis and ultimately chronic liver diseases. To date, effective treatments to delay this harmful process remain an unmet clinical need. Cycloastragenol is an active phytochemical substance isolated from Astragalus membranaceus, a plant used in traditional Chinese medicine to protect the liver. Therefore, our study aimed to elucidate the efficacy of cycloastragenol on carbon-tetrachloride (CCl₄)-induced liver fibrosis in mice. We found that cycloastragenol at 200 mg/kg dosage exhibited anti-fibrotic efficacy as demonstrated by a decrease in collagen deposition, downregulation of mRNA expression of collagen type 1, and a reduction in the content of total collagens. In addition, cycloastragenol further augmented the levels of anti-fibrotic matrix metalloproteinases (Mmps), that is, Mmp8, proMmp9, and Mmp12, which play a pivotal role in fibrosis resolution. According to histological analysis and serum markers of hepatotoxicity, cycloastragenol protected the livers from damage and mitigated the increment of serum alanine aminotransferase and bilirubin implicating hepatoprotective efficacy against CCl₄. Moreover, cycloastragenol upregulated the mRNA expression of interleukin 6, a pleiotropic cytokine plays a vital role in the promotion of hepatocyte regeneration. In conclusion, cycloastragenol alleviated the progression of liver fibrosis in CCl₄-treated mice and its anti-fibrotic efficacy was mainly due to the hepatoprotective efficacy.