Carbon Tetrachloride Research Articles

Effects of elafibranor on liver fibrosis and gut barrier function in a mouse model of alcohol-associated liver disease.

Alcohol-associated liver disease (ALD) is a leading cause of liver-related morbidity and mortality, but there are no therapeutic targets and modalities to prevent ALD-related liver fibrosis. Peroxisome proliferator activated receptor (PPAR) α and δ play a key role in lipid metabolism and intestinal barrier homeostasis, which are major contributors to the pathological progression of ALD. Meanwhile, elafibranor (EFN), which is a dual PPARα and PPARδ agonist, has reached a phase III clinical trial for the treatment of metabolic dysfunction-associated steatotic liver disease and primary biliary cholangitis. However, the benefits of EFN for ALD treatment is unknown. To evaluate the inhibitory effects of EFN on liver fibrosis and gut-intestinal barrier dysfunction in an ALD mouse model. ALD-related liver fibrosis was induced in female C57BL/6J mice by feeding a 2.5% ethanol (EtOH)-containing Lieber-DeCarli liquid diet and intraperitoneally injecting carbon tetrachloride thrice weekly (1 mL/kg) for 8 weeks. EFN (3 and 10 mg/kg/day) was orally administered during the experimental period. Histological and molecular analyses were performed to assess the effect of EFN on steatohepatitis, fibrosis, and intestinal barrier integrity. The EFN effects on HepG2 lipotoxicity and Caco-2 barrier function were evaluated by cell-based assays. The hepatic steatosis, apoptosis, and fibrosis in the ALD mice model were significantly attenuated by EFN treatment. EFN promoted lipolysis and β-oxidation and enhanced autophagic and antioxidant capacities in EtOH-stimulated HepG2 cells, primarily through PPARα activation. Moreover, EFN inhibited the Kupffer cell-mediated inflammatory response, with blunted hepatic exposure to lipopolysaccharide (LPS) and toll like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling. EFN improved intestinal hyperpermeability by restoring tight junction proteins and autophagy and by inhibiting apoptosis and proinflammatory responses. The protective effect on intestinal barrier function in the EtOH-stimulated Caco-2 cells was predominantly mediated by PPARδ activation. EFN reduced ALD-related fibrosis by inhibiting lipid accumulation and apoptosis, enhancing hepatocyte autophagic and antioxidant capacities, and suppressing LPS/TLR4/NF-κB-mediated inflammatory responses by restoring intestinal barrier function.

Atmospheric CFC-11 and CCl4: A free calibration standard for PTR-MS

Proton-transfer-reaction mass spectrometry (PTR-MS) is an analytical technique used to monitor volatile organic compounds in real-time. For quantitative analysis, compounds of interest are typically calibrated using gas standards, but PTR-MS is quantitative to uncalibrated compounds if the mass-dependent transmission is well defined. However, long-term measurements are challenging due to the drift in transmission over time. Performing frequent calibrations helps, but the methods are time-consuming and tedious, often leading to instruments being under-calibrated. Here we show the use of long-lived and globally monitored compounds in the atmosphere as a tool to constrain the transmission between calibrations. The major ion of trichlorofluromethane (CFC-11) and carbon tetrachloride (CCl4) is found at the mass-to-charge ratio (m/z) 116.9, which we propose using to retrieve the transmission of a PTR-MS. We determined the pseudo-reaction rate constants of CFC-11 and CCl4 to be 0.82 × 10−9 ± 0.05 × 10−9 cm3 s−1 molecule−1, and 1.65 × 10−9 ± 0.08 × 10−9 cm3 s−1 molecule−1, respectively. The method introduced here can improve data quality and accuracy, especially for long-term atmospheric measurements.

Transcriptome Analyses of Liver Sinusoidal Endothelial Cells Reveal a Consistent List of Candidate Genes Associated with Endothelial Dysfunction and the Fibrosis Progression.

Liver fibrosis is an important step in the transformation of chronic liver disease into cirrhosis and liver cancer, and structural changes and functional disorders of liver sinusoidal endothelial cells (LSECs) are early events in the occurrence of liver fibrosis. Therefore, it is necessary to identify the key regulatory genes of endothelial dysfunction in the process of liver fibrosis to provide a reference for the diagnosis and treatment of liver fibrosis. In this study, we identified 230 common differentially expressed genes (Co-DEGs) by analyzing transcriptomic data of primary LSECs from three different liver fibrosis mouse models (carbon tetrachloride; choline-deficient, l-amino acid-defined diet; and nonalcoholic steatohepatitis). Enrichment analysis revealed that the Co-DEGs were mainly involved in regulating the inflammatory response, immune response, angiogenesis, formation and degradation of the extracellular matrix, and mediating chemokine-related pathways. A Venn diagram analysis was used to identify 17 key genes related to the progression of liver cirrhosis. Regression analysis using the Lasso-Cox method identified genes related to prognosis among these key genes: SOX4, LGALS3, SERPINE2, CD52, and LPXN. In mouse models of liver fibrosis (bile duct ligation and carbon tetrachloride), all five key genes were upregulated in fibrotic livers. This study identified key regulatory genes for endothelial dysfunction in liver fibrosis, namely SOX4, LGALS3, SERPINE2, CD52, and LPXN, which will provide new targets for the development of therapeutic strategies targeting endothelial dysfunction in LSECs and liver fibrosis.

Copper sulfate and carbon tetrachloride induces a uniform response at the level of the redox system and the nature of this response depends on age

The concept of oxidative stress, which is a development of D. Harman’s idea of random harmful tissue damage by free radicals, remains one of the most popular in the study of pathological processes, including age-dependent chronic changes. The work tested the hypothesis according to which, a shift in equilibrium towards pro-oxidants, i.e. oxidative stress, is the primary adaptive response of the body to exogenous toxic environmental factors. To test this, a number of indicators of the redox system were determined as a response to hepatotoxic compounds of different nature (copper sulfate and carbon tetrachloride) in young and old animals. The amount of lipid hydroperoxides and the activity of a number of antioxidant enzymes were determined in the blood serum of young (3 months) and old (20 months) rats before exposure (initial level) and after repeated sequential injections (3 injections) of copper sulfate at a dose of 1 mg/100 g body weight and carbon tetrachloride in a dose of 0.1 mL in 50% vegetable oil. It was found that in intact (initial level) old animals, the indicators of the redox system are shifted towards antioxidants. After three consecutive administrations of various hepatotoxic compounds, with an interval of 48 hours between administrations, the balance shifted towards pro-oxidants, regardless of the inducer, however, this effect was more pronounced in old animals compared to young ones, relative to their initial level. Such different reactivity of redox system indicators in animals of different ages led to the “evening out” of the initially different redox system indicators. We came to the conclusion that changing the balance in the pro-oxidant-antioxidant system is a universal, primary reaction of the body to endogenous or exogenous factors that perform regulatory functions and, depending on the temporal and functional characteristics of the body, are “transformed” into specific physiological manifestations.

Lipid nanoparticle-mediated hepatocyte delivery of siRNA and silibinin in metabolic dysfunction-associated steatotic liver disease

Lipid nanoparticle-mediated co-delivery of siRNA and small molecule holds a great potential to treat metabolic dysfunction-associated steatotic liver disease (MASLD). However, targeted delivery of therapeutics to hepatocytes remains challenging. Taking the advantage of rising low density lipoprotein receptor/very-low density lipoprotein receptor (LDLR/VLDR) levels in MASLD, the biological fate of dinonylamine-ethylene glycol chlorophosphate-1-nonanol (DNNA-COP-NA) based lipid nanoparticles (LNPs) was oriented to liver tissues via apolipoprotein E (ApoE)-LDLR/VLDLR pathway. We then adopted a three-round screening strategy to optimize the formulation with both high potency and selectivity to deliver siRNA-HIF-1α (siHIF1α) and silibinin (SLB) payloads to hepatocytes. The optimized SLB/siHIF1α-LNPs mediates great siRNA delivery and transfection of hepatocytes. In high fat diet (HFD)- and carbon tetrachloride (CCl4)-induced mouse models of MASLD, SLB/siHIF1α-LNPs enabled the silencing of hypoxia inducible factor-1α (HIF-1α), a therapeutic target primarily expressed by hepatocytes, leading to significantly reduced inflammation and liver fibrosis synergized with SLB. Moreover, it is demonstrated the hepatocyte-targeting delivery of SLB/siHIF1α-LNPs has the potential to restore the immune homeostasis by modulating the population of Tregs and cytotoxic T cells in spleen. This proof-of-concept study enable siRNA and small molecule co-delivery to hepatocytes through intrinsic variation of targeting receptors for MASLD therapy.

Protective Effects of Hepatocyte Stress Defenders, Nrf1 and Nrf2, against MASLD Progression.

Progression of metabolic dysfunction-associated steatites liver disease (MASLD) to steatohepatitis (MASH) is driven by stress-inducing lipids that promote liver inflammation and fibrosis, and MASH can lead to cirrhosis and hepatocellular carcinoma. Previously, we showed coordinated defenses regulated by transcription factors, nuclear factor erythroid 2-related factor-1 (Nrf1) and -2 (Nrf2), protect against hepatic lipid stress. Here, we investigated protective effects of hepatocyte Nrf1 and Nrf2 against MASH-linked liver fibrosis and tumorigenesis. Male and female mice with flox alleles for genes encoding Nrf1 (Nfe2l1), Nrf2 (Nfe2l2), or both were fed a MASH-inducing diet enriched with high fat, fructose, and cholesterol (HFFC) or a control diet for 24-52 weeks. During this period, hepatocyte Nrf1, Nrf2, or combined deficiency for ~7 days, ~7 weeks, and ~35 weeks was induced by administering mice hepatocyte-targeting adeno-associated virus (AAV) expressing Cre recombinase. The effects on MASH, markers of liver fibrosis and proliferation, and liver tumorigenesis were compared to control mice receiving AAV-expressing green fluorescent protein. Also, to assess the impact of Nrf1 and Nrf2 induction on liver fibrosis, HFFC diet-fed C57bl/6J mice received weekly injections of carbon tetrachloride, and from week 16 to 24, mice were treated with the Nrf2-activating drug bardoxolone, hepatocyte overexpression of human NRF1 (hNRF1), or both, and these groups were compared to control. Compared to the control diet, 24-week feeding with the HFFC diet increased bodyweight as well as liver weight, steatosis, and inflammation. It also increased hepatocyte proliferation and a marker of liver damage, p62. Hepatocyte Nrf1 and combined deficiency increased liver steatosis in control diet-fed but not HFFC diet-fed mice, and increased liver inflammation under both diet conditions. Hepatocyte Nrf1 deficiency also increased hepatocyte proliferation, whereas combined deficiency did not, and this also occurred for p62 level in control diet-fed conditions. In 52-week HFFC diet-fed mice, 35 weeks of hepatocyte Nrf1 deficiency, but not combined deficiency, resulted in more liver tumors in male mice, but not in female mice. In contrast, hepatocyte Nrf2 deficiency had no effect on any of these parameters. However, in the 15-week CCL4-exposed and 24-week HFFC diet-fed mice, Nrf2 induction with bardoxolone reduced liver steatosis, inflammation, fibrosis, and proliferation. Induction of hepatic Nrf1 activity with hNRF1 enhanced the effect of bardoxolone on steatosis and may have stimulated liver progenitor cells. Physiologic Nrf1 delays MASLD progression, Nrf2 induction alleviates MASH, and combined enhancement synergistically protects against steatosis and may facilitate liver repair.

Ameliorative effects of sildenafil against carbon tetrachloride induced hepatic fibrosis in rat model through downregulation of osteopontin gene expression

The liver carries out many essential tasks, such as synthesising cholesterol, controlling the body’s storage of glycogen, and detoxifying metabolites, in addition to performing, and regulating homeostasis. Hepatic fibrosis is a pathological state characterized by over accumulation of extracellular matrix (ECM) including collagen fibers. Sildenafil (a selective inhibitor of type 5 phosphodiesterase) has anti-inflammatory, antioxidant and anti-apoptotic properties. It is commonly used to treat erectile dysfunction in male. The purpose of the current investigation was to evaluate sildenafil’s hepatoprotective potential against liver fibrosis in rats that was caused by carbon tetrachloride (CCl4). Liver enzymes and oxidative markers as well as profibrotic genes were determined. The findings showed that sildenafil alleviates the hepatic dysfunctions caused by CCl4 by restoring normal levels of ALT, AST, and GGT as well as by restoring the antioxidant status demonstrated by increased glutathione (GSH), and catalase. In addition, a significantly down-regulated the mRNA expressions of profibrotic genes [collagen-1α, IL-1β, osteopontin (OPN), and transforming growth factor-β (TGF-β)]. Additionally, sildenafil lessens the periportal fibrosis between hepatic lobules, congestion and dilatation in the central vein, and the inflammatory cell infiltrations. As a result, it is hypothesized that sildenafil may be helpful in the management of hepatotoxicity brought on by CCl4 through suppressing OPN.

Single-cell RNA sequencing reveals reduced intercellular adhesion molecule crosstalk between activated hepatic stellate cells and neutrophils alleviating liver fibrosis in hepatitis B virus transgenic mice post menstrual blood-derived mesenchymal stem cell transplantation.

Liver fibrosis can cause hepatitis B virus (HBV)-associated hepatocellular carcinoma. Menstrual blood-derived mesenchymal stem cells (MenSCs) can ameliorate liver fibrosis through paracrine. Single-cell RNA sequencing (scRNA-seq) may be used to explore the roadmap of activated hepatic stellate cell (aHSC) inactivation to target liver fibrosis. This study established HBV transgenic (HBV-Tg) mouse model of carbon tetrachloride (CCl4)-induced liver fibrosis and demonstrated that MenSCs migrated to the injured liver to improve serological indices and reduce fibrotic accumulation. RNA-bulk analysis revealed that MenSCs mediated extracellular matrix accumulation and cell adhesion. Liver parenchymal cells and nonparenchymal cells were identified by scRNA-seq in the control, CCl4, and MenSC groups, revealing the heterogeneity of fibroblasts/HSCs. A CellChat analysis revealed that diminished intercellular adhesion molecule (ICAM) signaling is vital for MenSC therapy. Specifically, Icam1 in aHSCs acted on Itgal/Itgb2 and Itgam/Itgb2 in neutrophils, causing decreased adhesion. The expression of Itgal, Itgam, and Itgb2 was higher in CCl4 group than in the control group and decreased after MenSC therapy in neutrophil clusters. The Lcn2, Pglyrp1, Wfdc21, and Mmp8 had high expression and may be potential targets in neutrophils. This study highlights interacting cells, corresponding molecules, and underlying targets for MenSCs in treating HBV-associated liver fibrosis.

The activity of glutathione reductase under impaired liver function and regulation by the Krebs cycle intermediates of the catalytic action of the enzyme isolated by chromatographic methods

The aim of the study was to determine the activity of glutathione reductase (GR, EC 1.6.4.2) in the blood serum of patients with alcoholic hepatitis (AH) and in the blood serum and livers of rats with experimental toxic hepatitis (ETH), as well as to develop a scheme for the purification of the enzyme from the liver of experimental animals using chromatographic methods. In the experiment, we used the blood serum of apparently healthy individuals with normal indices of general and biochemical blood tests (control group of patients), people diagnosed with alcoholic hepatitis (AH), as well as the serum and livers of rats in the control group and rats with ETG. The pathological state in experimental animals was modelled by oral administration of carbon tetrachloride, an organ-specific toxin with hepatotropic effect, as a 33% solution in paraffin oil at the rate of 64 µl of toxin per 100 g of animal weight. The animals were slaughtered on the 4th day after administration of the toxic agent. The control animals were injected with the corresponding aliquot of paraffin oil. The activity of GR was determined spectrophotometrically using a spectrophotometer SF-46 at a wavelength of 340 nm. The total amount of protein was determined by the Lowry method. To study the regulatory properties of the enzyme, it was purified from the livers of the control rats and those with induced toxic hepatitis using the protein separation by ammonium sulphate, as well as gel filtration through Sephadex G-25 and ion-exchange chromatography on DEAE-cellulose. As a result, we obtained 54.5 and 49.1 times purified GR enzyme preparations from the livers of the control rats and animals with ETG. We determined that in the process of ion-exchange chromatography using a column with DEAE-cellulose, the enzyme from the livers of the studied groups of animals was desorbed as a single peak at a KCl concentration of 100 mM. Using the obtained enzyme preparations, we detected differences in the regulation of GR activity under the action of Krebs cycle intermediates. They are obviously associated with conformational modifications of the enzyme molecules under oxidative stress developing during pathology.

Pituitary-derived small extracellular vesicles promote liver repair by its cargo miR-143-3p

The small Extracellular vesicles (sEV) has been recognized to be significant for intercellular communication due to their ability to transfer important cellular cargoes like miRNAs through circulation. The pituitary gland has not been clearly known about the role of its secreted sEV under normal physiological conditions. And Liver disease is a global public health burden. The present study is the first to investigate the effect of pituitary sEV on the liver. Sequencing and qRT-PCR revealed miR-143-3p is one of the richest in the pituitary sEV. MiR-143 Knockout (KO) mice resulted in a remarkable decrease in insulin-like growth factor 1 (IGF-1) levels and a significant increase in insulin-like growth factor binding protein 5 (IGFBP5) levels along with a reduction in liver primary cell growth. More importantly, compared with miR-143-KO-sEV, WT-sEV possesses a more robust capacity to improve miR-143 KO mice liver repair through the Wnt/β-catenin pathway after an acute injury caused by carbon tetrachloride (CCl4). Our results indicate that pituitary-derived sEV promotes hepatocyte proliferation and liver repair by its cargo miR-143-3p and provides new insight into the regulation mechanism of the pituitary-liver axis, and open a new window for endocrine regulation by using sEV.

Hepatoprotective and Antioxidant Activities of Polyphenolic Extract of Pyrus communis Leaf in Carbon tetrachloride–Treated Albino Wistar Rats

Polyphenols are active plant compounds that are reportedly capable of eliminating or limiting the deleterious side effects of free radicals and consequently restoring the functional integrity of important organs such as the liver. This study investigated the liver-protecting and antioxidant activities of PEP.c (Polyphenol leaf extract of Pyrus communis) against carbon tetrachloride-induced hepatotoxicity in Wistar rats. Liver damage was induced via intraperitoneal (i.p.) injection of 1.5 mL/kg body weight (b.w.) of 50% carbon tetrachloride (CCl4) in olive oil on the 7th day of extract/drug administration. In-duction of CCl4 significantly (P < 0.05) increased the activities of serum gam-ma-glutamyl transferase (GGT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) as well as a significant decrease (P < 0.05) in the serum level of total protein and the activity of superoxide dismutase and glutathione in the liver tissue with a concomitant increase in malondialdehyde (MDA) level. Oral administration of PEP.c (50, 100, and 250 mg/kg b.w.) for 7 days, significantly (P < 0.05) reduced the elevated serum levels of serum GGT, AST, ALT, ALP and increased the level of total protein as compared to CCl4-induced hepatotoxic-untreated group. However, administration of PEP.c significantly (P < 0.05) decreased concentration of malondialdehyde and increased the activity of the superoxide dismutase (SOD) as well as enhanced glutathione (GSH) level in the liver tissue. Results were compared to N-acetylcysteine, a known liver-protecting agent. Results from histopathological evaluation also supported the hepatoprotective-city of PEP.c in the CCl4-induced albino Wistar rats. The results of this study suggested that PEP.c can be used as a safe and alternative drug for the prevention and management of liver injury.

Exploring the Hepatoprotective Potential of Plants: A Comprehensive Review

The liver is an important organ that aids in the metabolism and elimination of xenobiotics from the body. Liver injury or malfunction is a serious public health issue that affects not only doctors and nurses, but also the pharmaceutical business and drug regulatory bodies. Excessive alcohol use, toxic chemicals (particular antibiotics, chemotherapeutic drugs, carbon tetrachloride (CCL4), thioacetamide (TAA), and microorganisms all induce liver cell harm. In this scenario, the current synthetic medications to treat liver problems promote more liver damage. As a result, herbal drugs have grown in popularity and are widely used. For a long time, herbal remedies have been utilized to treat liver problems. There are a variety of herbal preparations on the market. The goal of this review is to compile information on promising phytochemicals from medicinal plants that have been investigated in hepatotoxicity models utilizing cutting-edge scientific methods.

Erythrocyte Antioxidants and Hexokinase Activity Alterations in CCl4-Induced Cirrhotic Rats Through Naltrexone Treatment

Cirrhosis is the consequence of chronic liver injury Considering the crucial role of oxidative stress in the progression of liver cirrhosis, we aimed to investigate the ameliorative effect of NTX against oxidative stress in carbon tetrachloride (CCl4)-induced cirrhotic rats. Eighty-four male Wistar rats were randomly assigned into 4 groups (21 rats /group I) receiving CCl4; (II) NTX+CCl4; (III) mineral oil (M) (as the control); (IV) NTX+M. The animals in each group were sacrificed in 3 different time-points 2 weeks, 6 weeks (early cirrhosis) and 8 weeks (advanced cirrhosis). Liver function tests, NO metabolites, GSH level, as well as the activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione peroxides (GPX), and hexokinase (HK) were assessed. NTX was able to ameliorate liver injury, revealed by attenuation of ALT activity, which was significantly enhanced due to cirrhosis induction, as well as pathological evaluation. HK was also increased significantly after treatment with CCl₄ while NTX moderated this increase. Although CCl4 treatment did not have a significant effect on GSH levels, NTX was able to considerably increase GSH in blood. The activity of CAT and SOD as well as NO levels were all augmented by NTX in CCl4-treated rats. Naltrexone demonstrates antioxidative effects in liver cirrhosis and may confer a protective effect against hepatic cirrhosis through modulation of oxidative stress.

Glycyrrhizic acid ameliorates hepatic fibrosis by inhibiting oxidative stress via AKR7A2

BackgroundHepatic fibrosis is a reversible pathological phenomenon caused by the abnormal proliferation of connective tissues in the liver for self-repair after persistent liver injury. Among these tissues, the activation status of hepatic stellate cells (HSCs) is crucial. Glycyrrhizic acid (GA) agents have been proven to have excellent anti-fibrosis effects, but their targets are unclear. PurposeTo investigate the anti-hepatic fibrosis effect of GA and its target in activated HSCs. MethodsA mouse model of hepatic fibrosis was prepared with 20 % carbon tetrachloride (CCl4) and GA was administered continuously for 4 weeks. Subsequently, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), type Ⅲ procollagen peptide (P III P), laminin (LN), hyaluronic acid (HA), and type Ⅳ collagen (Col Ⅳ) were measured. Liver tissues were subjected to hematoxylin and eosin (HE), Masson, and Sirius red staining and proteome sequencing analysis. Based on LX-2 cells, activity-based protein profiling (ABPP) was used to investigate the potential targets of GA, which was further validated by the cellular thermal shift assay (CETSA), immunofluorescence co-localization, molecular docking, small interfering RNA (siRNA) and western blot (WB) assays. ResultsIn vivo, GA significantly reduced serum ALT, AST, HA, P III P, Col IV, and LN levels. HE, Masson, and Sirius red staining showed that GA significantly ameliorated hepatic inflammatory response and collagen deposition in CCl4-treated mice. Proteome sequencing results showed that GA mainly regulated glutathione S-transferase family members involved in glutathione metabolism. In vitro, GA significantly inhibited LX-2 cell proliferation and reduced reactive oxygen species accumulation. ABPP suggested that aldo-keto reductase family 7 member A2 (AKR7A2) was the major binding protein of GA in LX-2 cells. CETSA, fluorescence co-localization, molecular docking, and surface plasmon resonance further validated GA binding to AKR7A2. The WB results showed that GA up-regulated AKR7A2 expression both in vitro and in vivo and was corroborated by siRNA experiments. ConclusionGA targeted AKR7A2 in LX-2 cells to defend against sustained oxidative stress injury, thereby inhibiting the proliferation of activated HSCs and reversing hepatic fibrosis.

On the Choice of Variable for Quantization of Conformal GR

The possibility of using spin connection components as basic quantization variables of a conformal version of general relativity is studied. The considered model contains gravitational degrees of freedom and a scalar dilaton field. The standard tetrad formalism is applied. Properties of spin connections in this model are analyzed. Secondary quantization of the chosen variables is performed. The gravitational part of the model action turns out to be quadratic with respect to the spin connections. So at the quantum level, the model looks trivial, i.e., without quantum self-interactions. Meanwhile the correspondence to general relativity is preserved at the classical level.

Discovery of Sophoridine α-Aryl Propionamide Derivative ZM600 as a Novel Antihepatic Fibrosis Agent.

Hepatic stellate cells (HSCs) activation is a key event in the development of liver fibrosis, and blockage of the activation of HSCs has been shown to alleviate liver fibrosis. Sophoridine, a bioactive alkaloid found in many Chinese herbs, exhibits a broad spectrum of pharmacological effects, but its activities are not strong. In this study, a series of structurally modified derivatives of sophoridine were designed and synthesized. Among them, sophoridine α-aryl propionamide derivative ZM600 displayed a significant inhibitory effect on the activation of HSCs. The in vivo experiment demonstrated that ZM600 markedly ameliorated carbon tetrachloride (CCl4) and bile duct ligation (BDL)-induced liver fibrosis with a significant improvement of extracellular matrix deposition. Mechanism investigations revealed that ZM600 specifically inhibited the activation of NF-κB, PI-3K/AKT, and TGF-β/Smads signaling pathways. These results suggest that ZM600 has a protective effect on liver fibrosis, which provides a new candidate for the treatment of liver fibrosis.

Yes-associated protein inhibition ameliorates carbon tetrachloride-induced acute liver injury in mice by reducing VDR

Carbon tetrachloride (CCl4) has a wide range of toxic effects, especially causing acute liver injury (ALI), in which rapid compensation for hepatocyte loss ensures liver survival, but proliferation of surviving hepatocytes (known as endoreplication) may imply impaired residual function. Yes-associated protein (YAP) drives hepatocytes to undergo endoreplication and ploidy, the underlying mechanisms of which remain a mystery. In the present study, we uncover during CCl4-mediated ALI accompanied by increased hepatocytes proliferation and YAP activation. Notably, bioinformatics analyses elucidate that hepatic-specific deletion of YAP substantially ameliorated CCl4-induced hepatic proliferation, effectively decreased the vitamin D receptor (VDR) expression. Additionally, a mouse model of acute liver injury substantiated that inhibition of YAP could suppress hepatocytes proliferation via VDR. Furthermore, we also disclosed that the VDR agonist nullifies CCl4-induced ALI alleviated by the YAP inhibitor in vivo. Importantly, hepatocytes were isolated from mice, and it was spotlighted that the anti-proliferative impact of the YAP inhibitor was abolished by the activation of VDR within these hepatocytes. Similarly, primary hepatic stellate cells (HSCs) were isolated and it was manifested that YAP inhibitor suppressed HSC activation via VDR during acute liver injury. Our findings further elucidate the YAP's role in ALI and may provide new avenues for protection against CCl4-drived acute liver injury.

Deletion of GPR81 activates CREB/Smad7 pathway and alleviates liver fibrosis in mice

BackgroundEnhanced glycolysis is a crucial metabolic event that drives the development of liver fibrosis, but the molecular mechanisms have not been fully understood. Lactate is the endproduct of glycolysis, which has recently been identified as a bioactive metabolite binding to G-protein-coupled receptor 81 (GPR81). We then questioned whether GPR81 is implicated in the development of liver fibrosis.MethodsThe level of GPR81 was determined in mice with carbon tetrachloride (CCl4)-induced liver fibrosis and in transforming growth factor beta 1 (TGF-β1)-activated hepatic stellate cells (HSCs) LX-2. To investigate the significance of GPR81 in liver fibrosis, wild-type (WT) and GPR81 knockout (KO) mice were exposed to CCl4, and then the degree of liver fibrosis was determined. In addition, the GPR81 agonist 3,5-dihydroxybenzoic acid (DHBA) was supplemented in CCl4-challenged mice and TGF-β1-activated LX-2 cells to further investigate the pathological roles of GPR81 on HSCs activation.ResultsCCl4 exposure or TGF-β1 stimulation significantly upregulated the expression of GPR81, while deletion of GPR81 alleviated CCl4-induced elevation of aminotransferase, production of pro-inflammatory cytokines, and deposition of collagen. Consistently, the production of TGF-β1, the expression of alpha-smooth muscle actin (α-SMA) and collagen I (COL1A1), as well as the elevation of hydroxyproline were suppressed in GPR81 deficient mice. Supplementation with DHBA enhanced CCl4-induced liver fibrogenesis in WT mice but not in GPR81 KO mice. DHBA also promoted TGF-β1-induced LX-2 activation. Mechanistically, GPR81 suppressed cAMP/CREB and then inhibited the expression of Smad7, a negative regulator of Smad3, which resulted in increased phosphorylation of Smad3 and enhanced activation of HSCs.ConclusionGPR81 might be a detrimental factor that promotes the development of liver fibrosis by regulating CREB/Smad7 pathway.

Enhancing indoor air quality: Examination of formaldehyde adsorption efficiency of portable air cleaner fitted with chemically-treated activated carbon filters

The pursuit of salubrious living environments necessitates a holistic approach to assuring indoor air quality. This entails considering not only particulate matter but also gaseous pollutants, particularly formaldehyde – a carcinogenic and prevalent pollutant in household environment. In addressing the persistent challenge in balancing efficiency, operating costs and environmental impact in formaldehyde removal, our study pioneers to empirically explore and compare the relationship between Carbon Tetrachloride Activity (CTC), Clean Air Delivery Rate (CADR), and Cumulate Clean Mass (CCM) in the context of formaldehyde adsorption, using both raw and 2-Imidazolidone-treated activated carbon (AC) filters fitted in a Portable Air Cleaner (PAC). Our experimental results show that the formaldehyde CADRs of an air cleaner with chemically-treated CTC70 and CTC100 filters were about 251 m3/h and 286 m3/h respectively, representing an increase of 1.52 and 2.5 times over untreated filters, with the treated CTC100 AC filters outperforming the CTC70 filters by approximately 12 percent under new condition. While the precise mechanisms by which 2-Imidazolidone enhances the performance of AC filters are still unknown, these findings provide an first-of-its-kind directive for future research on the interplay among the parameters (CTC, CADR and CCM) of PACs, casting a foundation for further investigations that aim at optimizing the performance of AC filters, thereby making significant strides in the enhancement of indoor air quality.

Exploring Fibrosis Pathophysiology in Lean and Obese Metabolic-Associated Fatty Liver Disease: An In-Depth Comparison.

While obesity-related nonalcoholic fatty liver disease (NAFLD) is linked with metabolic dysfunctions such as insulin resistance and adipose tissue inflammation, lean NAFLD more often progresses to liver fibrosis even in the absence of metabolic syndrome. This review aims to summarize the current knowledge regarding the mechanisms of liver fibrosis in lean NAFLD. The most commonly used lean NAFLD models include a methionine/choline-deficient (MCD) diet, a high-fat diet with carbon tetrachloride (CCl4), and a high-fructose and high-cholesterol diet. The major pro-fibrogenic mechanisms in lean NAFLD models include increased activation of the extracellular signal-regulated kinase (ERK) pathway, elevated expression of α-smooth muscle actin (α-SMA), collagen type I, and TGF-β, and modulation of fibrogenic markers such as tenascin-X and metalloproteinase inhibitors. Additionally, activation of macrophage signaling pathways promoting hepatic stellate cell (HSC) activation further contributes to fibrosis development. Animal models cannot cover all clinical features that are evident in patients with lean or obese NAFLD, implicating the need for novel models, as well as for deeper comparisons of clinical and experimental studies. Having in mind the prevalence of fibrosis in lean NAFLD patients, by addressing specific pathways, clinical studies can reveal new targeted therapies along with novel biomarkers for early detection and enhancement of clinical management for lean NAFLD patients.