Anti-inflammatory, anti-oxidative stress and novel therapeutic targets for cholestatic liver injury

A metabolomics study on the mechanisms of Gardeniae fructus against α-naphthylisothiocyanate-induced cholestatic liver injury

Gardeniae fructus (GF) is known for its various beneficial effects on cholestatic liver injury (CLI). However, the biological mechanisms through which GF regulates CLI have not been fully elucidated. This study aimed to explore the potential mechanisms of GF against α-naphthylisothiocyanate (ANIT)-induced CLI. First, HPLC technology was used to analyze the chemical profile of the GF extract. Second, the effects of GF on serum biochemical indicators and liver histopathology were examined. Lastly, metabolomics was utilized to study the changes in liver metabolites and clarify the associated metabolic pathways. In chemical analysis, 10 components were identified in the GF extract. GF treatment regulated serum biochemical indicators in ANIT-induced CLI model rats and alleviated liver histological damage. Metabolomics identified 26 endogenous metabolites as biomarkers of ANIT-induced CLI, with 23 biomarkers returning to normal levels, particularly involving primary bile acid biosynthesis, glycerophospholipid metabolism, tryptophan metabolism, and arachidonic acid metabolism. GF shows promise in alleviating ANIT-induced CLI by modulating multiple pathways.

Nicorandil attenuates lithocholic acid-induced hepatotoxicity in mice through impeding oxidative stress, inflammation and apoptosis

This study was performed to explore the beneficial protective impact of nicorandil (Nico) against lithocholic acid (LCA)-induced hepatotoxicity.

MATERIALS AND METHODS

Mice received Nico (50 and 100 mg/kg. orally) for 7 days and LCA (125 mg/kg, i.p.) was injected for the last 4 days two times daily.

RESULTS

Nico improved both structural and functional abnormalities induced by LCA. Nico significantly decreased serum levels of transaminases, ALP, GGT and markedly elevated albumin levels. Additionally, Nico mitigated oxidative stress; it decreased contents of MDA and NO and increased GSH level and SOD activity. Moreover, Nico markedly decreased the elevated levels of TNF-α, JNK, Bax, Caspase-3 and iNOS, and increased the levels of eNOS in hepatic tissues. Furthermore, Nico substantially decreased the expression of NFκBp65 in hepatic tissues. Histopathological and transmission electron microscopy findings further supported these biomarkers.

CONCLUSION

Nico might be used as an adjuvant medication to prevent LCA-induced hepatotoxicity, pending further clinical research, through impeding oxidative stress, inflammation and apoptosis.

Pirfenidone ameliorates ANIT-induced cholestatic liver injury via modulation of FXR, NF-кB/TNF-α, and Wnt/GSK-3β/β-catenin signaling pathways

Cholestasis is a hepatobiliary disorder characterized by the excessive accumulation of toxic bile acids in hepatocytes, leading to cholestatic liver injury (CLI) through multiple pathogenic inflammatory pathways. Currently, there are limited therapeutic options for the management of cholestasis and associated CLI; therefore, new options are urgently needed. Pirfenidone (PF), an oral bioavailable pyridone analog, is used for the treatment of idiopathic pulmonary fibrosis. PF has recently demonstrated diverse potential therapeutic activities against different pathologies. Accordingly, the present study adopted the α-naphthyl isothiocyanate (ANIT)-induced CLI model in mice to explore the potential protective impact of PF and investigate the underlying mechanisms of action. PF intervention markedly reduced the serum levels of ALT, AST, LDH, total bilirubin, and total bile acids, which was accompanied by a remarkable amelioration of histopathological lesions induced by ANIT. PF also protected the mice against ANIT-induced redox imbalance in the liver, represented by reduced MDA levels and elevated GSH and SOD activities. Mechanistically, PF inhibited ANIT-induced downregulated expressions of the farnesoid X receptor (FXR), as well as the bile salt export pump (BSEP) and the multidrug resistance-associated protein 2 (MRP2) bile acid efflux channels. PF further repressed ANIT-induced NF-κB activation and TNF-α and IL-6 production. These beneficial effects were associated with its ability to dose-dependently inhibit Wnt/GSK-3β/β-catenin/cyclin D1 signaling. Collectively, PF protects against ANIT-induced CLI in mice, demonstrating powerful antioxidant and anti-inflammatory activities as well as an ability to oppose BA homeostasis disorder. These protective effects are primarily mediated by modulating the interplay between FXR, NF-κB/TNF-α/IL-6, and Wnt/β-catenin signaling pathways.

Anti-inflammatory and anti-angiogenic effects of Withania somnifera extract on liver toxicity induced by silver nanoparticles in vivo

The liver is a critical organ in the human body and is frequently exposed to numerous exogenous toxic substances, including silver nanoparticles (AgNPs). This study aimed to examine the anti-inflammatory, anti-angiogenic, and hepatoprotective effects of Withania somnifera (W. somnifera) extract on AgNP-induced liver toxicity in Swiss mice. Fifty mice were divided into five groups. Group I (negative control) consisted of ten mice. Group II received oral W. somnifera extracts (80 mg/kg/bw) for 14 days. Group III was injected intraperitoneally (i.p.) with AgNPs at a daily dose of 35 mg/kg/bw for 3 days. Group IV received i.p. AgNPs for 3 days, followed by saline for 14 days. Group V received i.p. AgNPs for 3 days, followed by oral W. somnifera (80 mg/kg/bw) for 14 days. Liver function tests, pro and anti-inflammatory cytokines, antioxidant activities, protein carbonyl (PC) levels, liver histopathological analysis, immunohistochemical expressions of transcription factor (NF-κB), and vascular endothelial growth factor (VEGF) were examined. Group III had elevated levels of liver function, a significant increase of pro and anti-inflammatory cytokines, antioxidant activity, and PC levels. Histological observations revealed congested sinusoids filled with red blood cells (RBCs) and hepatocyte necrosis. Also, positive expressions of NF-κB and VEGF were detected compared with Group I. However, the administration of W. somnifera to Group V revealed significant changes with evident improvements in liver function biomarkers, pro and anti-inflammatory cytokines, antioxidant activities, oxidative stress markers (PC), and histopathological and immunohistochemical parameters compared to Group III. The results revealed that W. somnifera has promising and potential hepatoprotective, anti-inflammatory, and anti-angiogenic effects against liver toxicity. Further detailed studies are recommended to explore the potential of W. somnifera as a treatment for human liver ailments.

Exploring the effect and mechanism of cucurbitacin B on cholestatic liver injury based on network pharmacology and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Cholestatic liver injury (CLI) is a pathologic process with the impairment of liver and bile secretion and excretion, resulting in an excessive accumulation of bile acids within the liver, which leads to damage to both bile ducts and hepatocytes. This process is often accompanied by inflammation. Cucumis melo L is a folk traditional herb for the treatment of cholestasis. Cucurbitacin B (CuB), an important active ingredient in Cucumis melo L, has significant anti-inflamamatory effects and plays an important role in diseases such as neuroinflammation, skin inflammation, and chronic hepatitis. Though numerous studies have confirmed the significant therapeutic effect of CuB on liver diseases, the impact of CuB on CLI remains uncertain. Consequently, the objective of this investigation is to elucidate the therapeutic properties and potential molecular mechanisms underlying the effects of CuB on CLI.

AIM OF THE STUDY

The aim of this paper was to investigate the potential protective mechanism of CuB against CLI.

METHODS

First, the corresponding targets of CuB were obtained through the SwissTargetPrediction and SuperPre online platforms. Second, the DisGeNET database, GeneCards database, and OMIM database were utilized to screen therapeutic targets for CLI. Then, protein-protein interaction (PPI) was determined using the STRING 11.5 data platform. Next, the OmicShare platform was employed for the purpose of visualizing the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The molecular docking technique was then utilized to evaluate the binding affinity existing between potential targets and CuB. Subsequently, the impacts of CuB on the LO2 cell injury model induced by Lithocholic acid (LCA) and the CLI model induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) were determined by evaluating inflammation in both in vivo and in vitro settings. The potential molecular mechanism was explored by real-time quantitative polymerase chain reaction (RT-qPCR) and western blot (WB) techniques.

RESULTS

A total of 122 CuB targets were collected and high affinity targets were identified through the PPI network, namely TLR4, STAT3, HIF1A, and NFKB1. GO and KEGG analyses indicated that the treatment of CLI with CuB chiefly involved the inflammatory pathway. In vitro study results showed that CuB alleviated LCA-induced LO2 cell damage. Meanwhile, CuB reduced elevated AST and ALT levels and the release of inflammatory factors in LO2 cells induced by LCA. In vivo study results showed that CuB could alleviate DDC-induced pathological changes in mouse liver, inhibit the activity of serum transaminase, and suppress the liver and systemic inflammatory reaction of mice. Mechanically, CuB downregulated the IL-6, STAT3, and HIF-1α expression and inhibited STAT3 phosphorylation.

CONCLUSION

By combining network pharmacology with in vivo and in vitro experiments, the results of this study suggested that CuB prevented the inflammatory response by inhibiting the IL-6/STAT3/HIF-1α signaling pathway, thereby demonstrating potential protective and therapeutic effects on CLI. These results establish a scientific foundation for the exploration and utilization of natural medicines for CLI.

Vitamin D Receptor Activation Reduces Hepatic Inflammation via Enhancing Macrophage Autophagy in Cholestatic Mice

Macrophage autophagy dysfunction aggravates liver injury by activating inflammasomes, which can cleave pro-IL-1β to its active, secreted form. We investigated whether the vitamin D/vitamin D receptor (VDR) axis could up-regulate macrophage autophagy function to inhibit the activation of inflammasome-dependent IL-1β during cholestasis. Paricalcitol (PAL; VDR agonist) was intraperitoneally injected into bile duct-ligated mice for 5 days. Up-regulation of VDR expression by PAL reduced liver injury by reducing the oxidative stress-induced inflammatory reaction in macrophages. Moreover, PAL inhibited inflammasome-dependent IL-1β generation. Mechanistically, the knockdown of VDR increased IL-1β generation, whereas VDR overexpression exerted the opposite effect following tert-butyl hydroperoxide treatment. The inflammasome antagonist glyburide, the caspase-1-specific inhibitor YVAD, and the reactive oxygen species (ROS) scavenger N-acetyl-l-cysteine (NAC) blocked the increase in Vdr shRNA-induced IL-1β production. Interestingly, up-regulation of VDR also enhanced macrophage autophagy. Autophagy reduction impaired the up-regulation of VDR-inhibited macrophage inflammasome-generated IL-1β, whereas autophagy induction showed a synergistic effect with VDR overexpression through ROS-p38 mitogen-activated protein kinase (MAPK) pathway. This result was confirmed by p38 MAPK inhibitor, MAPK activator, and ROS inhibitor NAC. Collectively, PAL triggered macrophage autophagy by suppressing activation of the ROS-p38 MAPK pathway, which, in turn, suppressed inflammasome-generated cleaved, active forms of IL-1β, eventually leading to reduced inflammation. Thus, triggering the VDR may be a potential target for the anti-inflammatory treatment of cholestatic liver disease.

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.

Jujuboside B alleviates acetaminophen-induced hepatotoxicity in mice by regulating Nrf2-STING signaling pathway

BACKGROUND

Jujuboside B (JuB) is the main bioactive saponin component of Chinese anti-insomnia herbal medicine Ziziphi Spinosae Semen, which has been reported to possess varied pharmacological functions. Even though it has been traditionally used to treat inflammation- and toxicity-related diseases, the effects of JuB on acetaminophen (APAP) overdose-induced hepatotoxicity have not been determined yet.

METHODS

C57BL/6 J mice were pre-treated with JuB (20 or 40 mg/kg) for seven days before APAP (400 mg/kg) injection. After 24 h of APAP treatment, serum, and liver tissues were collected to evaluate the therapeutic effects. To investigate whether the Nrf2-STING signaling pathway is involved in the protective effects of JuB against APAP-induced hepatotoxicity, the mice received the DMXAA (the specific STING agonist) or ML385 (the specific Nrf2 inhibitor) during the administration of JuB, and Hematoxylin-eosin staining, Real-time PCR, immunohistochemical, and western blot were performed.

RESULTS

JuB pretreatment reversed APAP-induced CYP2E1 accumulations and alleviated APAP-induced acute liver injury. Furthermore, JuB treatment significantly inhibited oxidative stress and the pro-inflammatory cytokines, as well as alleviated hepatocyte apoptosis induced by APAP. Besides, our result also demonstrated that JuB treatment upregulated the levels of total Nrf2, facilitated its nuclear translocation, upregulated the expression of HO-1 and NQO-1, and inhibited the APAP-induced STING pathway activation. Finally, we verified that the beneficial effects of JuB were weakened by DMXAA and ML385.

CONCLUSION

Our study suggested that JuB could ameliorate APAP-induced hepatic damage and verified a previously unrecognized mechanism by which JuB prevented APAP-induced hepatotoxicity through adjusting the Nrf2-STING pathway.

Gut microbiota and metabolites in estrus cycle and their changes in a menopausal transition rat model with typical neuroendocrine aging

Background

Neuroendocrine alterations in the mid-life hypothalamus coupled with reproductive decline herald the initiation of menopausal transition. The certain feature and contribution of gut microflora and metabolites to neuroendocrine changes in the menopausal transition remain largely unknown.

Methods

Fecal samples of rats experiencing different reproductive stages were collected and processed for 16S rRNA and liquid chromatography-mass spectrometry sequencing. The differences of gut microbiota and metabolites between young and middle-aged rats during proestrus and diestrus were analyzed, and their relationships to neuroendocrine aging were then examined.

Results

At the genus level, Anaeroyorax, Rikenella, Tyzzerella_3, and Atopostipes were abundant at proestrus, while Romboutsia, Turicibacter, Clostridium_sensu_stricto_1, Ruminococcaceae_NK4A214_group, CHKCI002, Ruminococcaceae_UCG-010, Staphylococcus, Family_XII_AD3011_group, Ruminococcaceae UCG-011, and Christensenellaceae_R_7_group were enriched in the diestrus of middle-aged rats. DNF00809, Phocea, and Lachnospiraceae_UCG-006 were found abundant during proestrus instead, while Bacteroides, Lactobacillus, Erysipelatoclostridium, Anaeroplasma, Anaerofustis, Parasutterella, and Enterococcus were enriched at the diestrus of young female individuals. Discriminatory metabolites were identified involving 90 metabolic pathways among the animal sets, which were enriched for steroid hormone biosynthesis, arachidonic metabolism, primary bile acid synthesis, and ovarian steroidogenesis. A total of 21 metabolites lacking in hormone-associated changes in middle-aged female individuals presented positive or negative correlations with the circulating luteinizing hormone, bile acid, fibroblast growth factor 19, and gut hormones. Moreover, close correlations were detected between the intestinal bacteria and their metabolites.

Conclusion

This study documents specific gut microbial composition changes and concomitant shifting trends of metabolites during menopausal transition, which may initiate the gut-brain dysfunction in neuroendocrine aging.

The Role of Inflammation in Cholestatic Liver Injury

Cholestasis is a common clinical event in which bile formation and excretion are blocked, leading to retention of bile acids or bile salts; whether it occurs intra- or extrahepatically, primary or secondary, its pathogenesis is still unclear and is influenced by a combination of factors. In a variety of inflammatory and immune cells such as neutrophils, macrophages (intrahepatic macrophages are also known as Kupffer cells), mast cells, NK cells, and even T cells in humoral immunity and B cells in cellular immunity, inflammation can be a "second strike" against cholestatic liver injury. These cells, stimulated by a variety of factors such as bile acids, inflammatory chemokines, and complement, can be activated and accumulate in the cholestatic liver, and with the involvement of inflammatory mediators and modulation by cytokines, can lead to destruction of hepatocytes and bile duct epithelial cells and exacerbate (and occasionally retard) the progression of cholestatic liver disease. In this paper, we summarized the new research advances proposed so far regarding the relationship between inflammation and cholestasis, aiming to provide reference for researchers and clinicians in the field of cholestatic liver injury research.

Integrated 16 S rRNA gene sequencing and serum metabolomics approaches to decipher the mechanism of Qingre Lidan decoction in the treatment of cholestatic liver injury

BACKGROUND

Cholestasis is a commonly occurring disorder induced by impaired bile flow, for which there is no effective treatment so far. Qingre Lidan decoction (QRLD) is a clinically used herbal compound for the long-term treatment of bile circulation disorders arising from inflammation and obstruction in the gallbladder and bile ducts. The objective of this study was to investigate the protective effect of QRLD on cholestatic liver injury and its possible mechanism.

METHODS

α-Naphthyl isothiocyanate (ANIT) was used to induce cholestatic liver injury in rats. Liver histopathology and serum biochemical markers were used to assess QRLD's protective impact. The possible biomarkers and mechanism of the therapeutic benefits of QRLD were investigated using a UHPLC-based Q-Exactive Orbitrap MS / MS untargeted serum metabolomics technique together with 16 S rRNA microbiota profiling. Afterwards, using RT-qPCR as well as Western Blot techniques, the expression of pertinent indicators was determined.

RESULTS

The intervention effect of QRLD was stronger at medium and high dosages than at low doses, and it dramatically decreased the levels of serum biochemical markers in cholestatic rats reflecting alterations in liver function and relieving ANIT-induced abnormalities in the liver's histopathology. Serum metabolomics showed that QRLD could affect the metabolic profile of cholestatic rats, mainly related to glycerophospholipid metabolism, taurine and hypotaurine metabolism, alanine, aspartate and glutamate metabolism, and histidine metabolic pathway. Additionally, analysis of 16 S rRNA gene sequencing indicated that QRLD could moderate ANIT-induced microbiota disorders, particularly Romboutsia, Bifidobacterium, Fusicatenibacter, Prevotella_9, Prevotellaceae_NK3B31_group and Prevotella_1. Other experimental results showed that QRLD significantly upregulated the mRNA and protein expression of PPARα, CYP7A1 and NTCP in the liver, inhibited the expression of p-IκBα, p-p65 and TNFα while increasing the anti-inflammatory factor IL-10, and downregulated the expression of MDA (a peroxidation product) and D-lactic acid (an intestinal barrier indicator) while increasing the expression of SOD and GSH.

CONCLUSIONS

QRLD can effectively regulate endogenous metabolites and microbiota disorders in cholestatic rats that are correlated with the attenuation of inflammation and oxidative stress.

Gallic acid improves liver cirrhosis by reducing oxidative stress and fibrogenesis in the liver of rats induced by bile duct ligation

Disturbance in the production and excretion of bile acid causes cholestatic liver disease. Liver cirrhosis is a disease that occurs if cholestasis continues. This study evaluated the protective effect of gallic acid (GA) on liver damage caused by biliary cirrhosis. Rats were randomly divided into 4 groups, each with 8 subjects: 1) control, 2) BDL, 3) BDL + GA 20, and 4) BDL + GA 30. The rats were anesthetized 28 days after the BDL, followed by collecting their blood and excising their liver. Their serum was used to measure liver enzymes, and the liver was used for biochemical analysis, gene expression, and histopathological analysis. Serum levels of liver enzymes, total bilirubin, liver Malondialdehyde level (MDA), expression of inflammatory cytokines and caspase-3, necrosis of hepatocytes, bile duct proliferation, lymphocytic infiltration, and liver fibrosis showed an increase in the BDL group compared to the control group (p < 0.05). In addition, BDL decreased the activity of liver antioxidant enzymes and glutathione (GSH) levels compared to the control group (p < 0.05). The groups receiving GA indicated a decrease in liver enzymes, total bilirubin, MDA, the expression of inflammatory cytokines and caspase-3, and a reduction in liver tissue damage compared to the BDL group (p < 0.05). The level of GSH in the BDL + GA 20 group showed a significant increase compared to the BDL group (p < 0.05). Moreover, it was found that GA, with its anti-fibrotic and anti-inflammatory properties, reduces liver damage caused by biliary cirrhosis.

Hypericum perforatum L. and the Underlying Molecular Mechanisms for Its Choleretic, Cholagogue, and Regenerative Properties

Any defects in bile formation, secretion, or flow may give rise to cholestasis, liver fibrosis, cirrhosis, and hepatocellular carcinoma. As the pathogenesis of hepatic disorders is multifactorial, targeting parallel pathways potentially increases the outcome of therapy. Hypericum perforatum has been famed for its anti-depressive effects. However, according to traditional Persian medicine, it helps with jaundice and acts as a choleretic medication. Here, we will discuss the underlying molecular mechanisms of Hypericum for its use in hepatobiliary disorders. Differentially expressed genes retrieved from microarray data analysis upon treatment with safe doses of Hypericum extract and intersection with the genes involved in cholestasis are identified. Target genes are located mainly at the endomembrane system with integrin-binding ability. Activation of α5β1 integrins, as osmo-sensors in the liver, activates a non-receptor tyrosine kinase, c-SRC, which leads to the insertion of bile acid transporters into the canalicular membrane to trigger choleresis. Hypericum upregulates CDK6 that controls cell proliferation, compensating for the bile acid damage to hepatocytes. It induces ICAM1 to stimulate liver regeneration and regulates nischarin, a hepatoprotective receptor. The extract targets the expression of conserved oligomeric Golgi (COG) and facilitates the movement of bile acids toward the canalicular membrane via Golgi-derived vesicles. In addition, Hypericum induces SCP2, an intracellular cholesterol transporter, to maintain cholesterol homeostasis. We have also provided a comprehensive view of the target genes affected by Hypericum's main metabolites, such as hypericin, hyperforin, quercitrin, isoquercitrin, quercetin, kaempferol, rutin, and p-coumaric acid to enlighten a new scope in the management of chronic liver disorders. Altogether, standard trials using Hypericum as a neo-adjuvant or second-line therapy in ursodeoxycholic-acid-non-responder patients define the future trajectories of cholestasis treatment with this product.

Oxidative stress in Wernicke's encephalopathy

Wernicke's encephalopathy (WE) is a severe life-threatening disease that occurs due to vitamin B1 (thiamine) deficiency (TD). It is characterized by acute mental disorder, ataxia, and ophthalmoplegia. TD occurs because of the following reasons: insufficient intake, increased demand, and long-term drinking due to corresponding organ damage or failure. Recent studies showed that oxidative stress (OS) can damage organs and cause TD in the brain, which further leads to neurodegenerative diseases, such as WE. In this review, we discuss the effects of TD caused by OS on multiple organ systems, including the liver, intestines, and brain in WE. We believe that strengthening the human antioxidant system and reducing TD can effectively treat WE.

Obeticholic acid improved triptolide/lipopolysaccharide-induced hepatotoxicity by inhibiting caspase-11-GSDMD pyroptosis pathway

This study was designed to investigate the potential role of farnesoid X receptor (FXR) in abnormal bile acid metabolism and pyroptosis during the pathogenesis of triptolide (TP)/lipopolysaccharide (LPS)-induced hepatotoxicity. Moreover, the protective effect of obeticholic acid (OCA) was explored under this condition. In vivo, female C57BL/6 mice were administrated with OCA (40 mg/kg bw, intragastrical injection) before (500 μg/kg bw, intragastrical injection)/LPS (0.1 mg/kg bw, intraperitoneal injection) administration. In vitro, AML12 cells were treated with TP (50 nM) and TNF-α (50 ng/ml) to induce hepatotoxicity; GW4064 (5 μM) and cholestyramine (CHO) (0.1 mg/ml and 0.05 mg/ml) were introduced to explain the role of FXR/total bile acid (TBA) in it. Serum TBA level was significantly elevated, which was induced by FXR suppression. And both GW4064 and CHO intervention presented remarkable protective effects against TP/TNF-α-induced NLRP3 upregulation and pyroptosis pathway activation. Pre-administration of FXR agonist OCA successfully attenuated TP/LPS-induced severe liver injury by reducing serum bile acids accumulation and inhibiting the activation of caspase-11-GSDMD (gasdermin D) pyroptosis pathway. We have drawn conclusions that TP aggravated liver hypersensitivity to LPS and inhibited FXR-SHP (small heterodimer partner) axis, which was served as endogenous signals to activate caspase-11-GSDMD-mediated pyroptosis contributing to liver injury. OCA alleviated TP/LPS-induced liver injury accompanied by inhibiting caspase-11-GSDMD-mediated pyroptosis pathway and decreased serum TBA level. The results indicated that FXR might be an attractive therapeutic target for TP/LPS-induced hepatotoxicity, providing an effective strategy for drug-induced liver injury.

Gut-Microbiota-Derived Metabolites Maintain Gut and Systemic Immune Homeostasis

The gut microbiota, including bacteria, archaea, fungi, viruses and phages, inhabits the gastrointestinal tract. This commensal microbiota can contribute to the regulation of host immune response and homeostasis. Alterations of the gut microbiota have been found in many immune-related diseases. The metabolites generated by specific microorganisms in the gut microbiota, such as short-chain fatty acids (SCFAs), tryptophan (Trp) and bile acid (BA) metabolites, not only affect genetic and epigenetic regulation but also impact metabolism in the immune cells, including immunosuppressive and inflammatory cells. The immunosuppressive cells (such as tolerogenic macrophages (tMacs), tolerogenic dendritic cells (tDCs), myeloid-derived suppressive cells (MDSCs), regulatory T cells (Tregs), regulatory B cells (Breg) and innate lymphocytes (ILCs)) and inflammatory cells (such as inflammatory Macs (iMacs), DCs, CD4 T helper (Th)1, CD4Th2, Th17, natural killer (NK) T cells, NK cells and neutrophils) can express different receptors for SCFAs, Trp and BA metabolites from different microorganisms. Activation of these receptors not only promotes the differentiation and function of immunosuppressive cells but also inhibits inflammatory cells, causing the reprogramming of the local and systemic immune system to maintain the homeostasis of the individuals. We here will summarize the recent advances in understanding the metabolism of SCFAs, Trp and BA in the gut microbiota and the effects of SCFAs, Trp and BA metabolites on gut and systemic immune homeostasis, especially on the differentiation and functions of the immune cells.

Hepatocytic AP-1 and STAT3 contribute to chemotaxis in alphanaphthylisothiocyanate-induced cholestatic liver injury

The development of cholestatic liver injury (CLI) involves inflammation, but the dominant pathway mediating the chemotaxis is not yet established. This work explored key signaling pathway mediating chemotaxis in CLI and the role of Kupffer cells in the inflammatory liver injury. Probe inhibitors T-5224 (100 mg/kg) for AP-1 and C188-9 (100 mg/kg) for STAT3 were used to validate key inflammatory pathways in alpha-naphthylisothiocyanate (ANIT, 100 mg/kg)-induced CLI. Two doses of GdCl₃ (10 mg/kg and 40 mg/kg) were used to delete Kupffer cells and explore their role in CLI. Serum and liver samples were collected for biochemical and mechanism analysis. The liver injury in ANIT-treated mice were significantly increased supported by biochemical and histopathological changes, and neutrophils gathering around the necrotic loci. Inhibitor treatments down-regulated liver injury biomarkers except the level of total bile acid. The chemokine Ccl2 increased by 170-fold and to a less degree Cxcl2 by 45-fold after the ANIT treatment. p-c-Jun and p-STAT3 were activated in the group A but inhibited by the inhibitors in western blot analysis. The immunofluorescence results showed AP-1 not STAT3 responded to inhibitors in ANIT-induced CLI. With or without GdCl₃, there was no significant difference in liver injury among the CLI groups. In necrotic loci in CLI, CXCL2 colocalized with hepatocyte biomarker Albumin, not with the F4/80 in Kupffer cells. Conclusively, AP-1 played a more critical role in the inflammation cascade than STAT3 in ANIT-induced CLI. Hepatocytes, not the Kupffer cells released chemotactic factors mediating the chemotaxis in CLI.

Vitamin D Receptor Activation Targets ROS-Mediated Crosstalk Between Autophagy and Apoptosis in Hepatocytes in Cholestasic Mice

BACKGROUND & AIMS

Observational epidemiologic studies have associated vitamin D deficiency with cholestasis. We reported previously that activation of the vitamin D/vitamin D receptor (VDR) axis in cholangiocytes mitigates cholestatic liver injury by remodeling the damaged bile duct. However, the function of VDR in hepatocytes during cholestasis remains unclear.

METHODS

Paricalcitol (VDR agonist, 200 ng/kg) was injected intraperitoneally into bile duct-ligated mice every other day for 5 days. Primary hepatocytes and HepG2 hepatoma cells were transfected with Vdr short hairpin RNA, control short hairpin RNA, Vdr plasmid, control vector, Atg5 small interfering RNA (siRNA), and control siRNA. Liver histology, cell proliferation, and autophagy were evaluated.

RESULTS

Treatment with the VDR agonist paricalcitol improved liver injury in bile duct-ligated mice by up-regulating VDR expression in hepatocytes, which in turn reduced hepatocyte apoptosis by inhibiting reactive oxygen species (ROS) generation via suppressing the Ras-related C3 botulinum toxin substrate 1/reduced nicotinamide adenine dinucleotide phosphate oxidase 1 pathway. Mechanistically, upon exposure to an ROS-inducing compound, Vdr siRNA contributed to apoptosis, whereas the Vdr overexpression caused resistance to apoptosis. Interestingly, up-regulated VDR expression also increased the generation of autophagosomes and macroautophagic/autophagic flux, which was the underlying mechanism for reduced apoptosis following VDR activation. Autophagy depletion impaired the positive effects of VDR overexpression, whereas autophagy induction was synergystic with VDR overexpression. Importantly, up-regulation of VDR promoted autophagy activation by suppressing the activation of the extracellular signal-regulated kinase (ERK)/p38 mitogen-activated protein kinase (p38MAPK) pathway. Thus, a p38MAPK inhibitor abrogated the Vdr siRNA-induced decrease in autophagy and the Vdr siRNA-induced increase in apoptosis. In contrast, a Mitogen-activated protein kinase kinase (MEK)/ERK activator prevented the enhancement of autophagy and decreased apoptosis following Vdr overexpression. Moreover, the ROS inhibitor N-acetylcystein (NAC) blocked Vdr siRNA-enhanced activation of the ERK/p38MAPK pathway.

CONCLUSIONS

VDR activation mitigated liver cholestatic injury by reducing autophagy-dependent hepatocyte apoptosis and suppressing the activation of the ROS-dependent ERK/p38MAPK pathway. Thus, VDR activation may be a potential target for the treatment of cholestatic liver disease.

Single-cell profiling of peripheral blood and muscle cells reveals inflammatory features of juvenile dermatomyositis

Introduction: Juvenile dermatomyositis (JDM) is a rare yet serious childhood systemic autoimmune condition that primarily causes skin rashes and inflammatory myopathy of the proximal muscles. Although the associated immune response involves the innate and adaptive arms, a detailed analysis of the pertinent immune cells remains to be performed. This study aims to investigate the dynamic changes of cell type, cell composition and transcriptional profiles in peripheral blood and muscle tissues, and in order to clarify the involvement of immune cells in the pathogenesis of JDM and provide a theoretical reference for JDM. Methods: Single-cell RNA sequencing combined with bioinformatic analyses were used to investigate the dynamic changes in cell composition and transcriptional profiles. Results: Analysis of 45,859 cells revealed nine and seven distinct cell subsets in the peripheral blood and muscle tissues respectively. IFITM2+ and CYP4F3+ monocytes were largely produced, and CD74⁺ smooth muscle cells (SMCs) and CCL19+ fibroblasts were identified as inflammatory-related cell subtypes in JDM patients, exhibiting patient-specific cell population heterogeneity.The dynamic gene expression patterns presented an enhanced type I interferon response in peripheral blood monocytes and T-cells, and SMCs and fibroblasts in muscle of untreated JDM patients. EGR1 and IRF7 may play central roles in the inflammation in both CD74⁺ SMCs and CCL19+ fibroblasts. Moreover, inflammatory-related monocytes could regulate T-cells, and the interaction between immune cells and SMCs or fibroblasts in muscle was enhanced under the inflammatory state. Conclusions: Immune dysregulation is one of the key pathogenic factors of JDM, and type I interferon responses are significantly enhanced in peripheral blood Monos and T cells as well as SMCs and fibroblasts. EGR1 and IRF7 may play central roles in the inflammation and are considered as potential therapeutic targets for JDM.

Kuhuang alleviates liver fibrosis by modulating gut microbiota-mediated hepatic IFN signaling and bile acid synthesis

Background: Liver fibrosis is a common outcome of the pathological progression of chronic liver disease; however, no specific and effective therapeutic agent has been approved for its treatment. We investigated the effects of Kuhuang on liver fibrosis and the underlying mechanisms of action. Materials and methods: To induce hepatic fibrosis, either 3,5-diethoxycarbonyl-1,4-dihydro-collidine (DDC) diet was administered, or bile duct ligation (BDL) surgery was performed on C57BL/6 mice. Kuhuang was orally administered to mice for 7 days before and after bile duct ligation or 4 weeks with a DDC diet. Hematoxylin and eosin, Sirius red staining, and immunohistochemical analyses were performed to evaluate hepatic pathology. Hepatic interferon-β (IFN-β) levels were measured using an enzyme-linked immunosorbent assay. RNA sequencing was performed to examine the gene expression profiles of liver tissues. The mRNA expression of inflammatory, profibrotic, and bile acid (BA)-related genes was further validated by qRT-PCR. A targeted metabolomics assay revealed the alteration of the hepatic bile acid (BA) composition. The composition of the gut microbiota was determined via 16S rRNA sequencing. Results: Treatment with Kuhuang attenuated liver fibrosis and reduced the inflammatory response in bile duct ligation and DDC mouse models. In addition, the hepatic IFN signaling pathway was activated following Kuhuang treatment. Kuhuang treatment also significantly decreased hepatic levels of both primary and secondary BAs. In addition, Kuhuang treatment altered gut microbiota composition, with an increased abundance of interferon-inducing Akkermansia and decreased abundance of bile salt hydrolase-producing Lactobacillus, Clostridium, and Bifidobacterium. Furthermore, the abundance of Akkermansia was positively correlated with the hepatic mRNA expression levels of Ifna4, Ifnb, and Isg15, whereas that of Lactobacillus, Clostridium _- sensu _- stricto _- 1, and Bifidobacterium was positively correlated with levels of bile acid synthesis-related genes. Conclusion: Our results suggest that Kuhuang plays a protective role during the progression of liver fibrosis, potentially by altering the composition of the gut microbiota, which consequently activates interferon signaling and inhibits bile acid synthesis in the liver.

Dietary carbon loaded with nano-ZnO alters the gut microbiota community to mediate bile acid metabolism and potentiate intestinal immune function in fattening beef cattle

BACKGROUND

To our knowledge, carbon loaded with nano-ZnO (NZnOC) represents a new nutritional additive for the animal husbandry industry. However, the mechanism by which NZnOC mediates beef cattle growth and intestinal health is not fully understood. This study aimed to investigate the effects of carbon loaded with nano-ZnO (NZnOC) supplementation on growth performance, gut microbiota, bile acid (BAs) metabolism and intestinal immunity in fattening cattle. Twenty cattle (16 ± 0.95 months) were randomly assigned to two dietary groups: CON (control, without feed additive) and NZnOC (diet supplemented with 80 mg NZnOC/kg diet dry matter basic) for 60 d. The colon digesta microbiota composition and BAs concentration were determined by microbiota metagenomics and gas chromatography methods, respectively.

RESULTS

The results showed that the NZnOC-supplemented cattle had greater final weight, average daily gain and gain-to-feed ratio than those in the CON group. Cattle fed the NZnOC diet had a higher relative abundance of the secondary BAs synthesizing phyla Firmicutes, Tenericutes and Actinobacteria than those fed the CON diet. Dietary supplementation with NZnOC increased the relative abundance of the secondary BAs synthesis microbiota genera Clostridium, Ruminococcus, Eubacterium, and Brevibacillus in colon digesta. Cattle fed the NZnOC diet had increased activities of 3α-hydroxysteroid dehydrogenase (EC: 1.1.1.52) and bile acid-CoA ligase BaiB (EC: 6.2.1.7) in the colon digesta compared with those fed the CON diet. The primary BAs taurocholic acid, taurochenodeoxycholic acid and taurodeoxycholate acid were significantly decreased by dietary NZnOC supplementation, while the secondary BAs deoxycholic acid, taurolithocholic acid, beta-muricholic acid, 12-ketolithocholic acid and ursodeoxycholic acid were significantly increased. Dietary supplementation with NZnOC increased the mRNA abundance of G protein-coupled bile acid receptor 1, protein kinase cAMP-activated catalytic subunit alpha, cyclic-AMP response element binding protein 1 and interleukin (IL)-10 in the colon mucosa of cattle, while the mRNA abundance of tumor necrosis factor and IL-1β were significantly decreased.

CONCLUSIONS

In summary, dietary supplementation with NZnOC can facilitate the growth performance and intestinal immune function of cattle by improving BAs metabolism. NZnOC can be supplemented in the diet as a safe regulator of gut microbiota and as a feed additive in the ruminants industry.

Mechanism of interventional effect and targets of Zhuyu pill in regulating and suppressing colitis and cholestasis

Zhuyu pill (ZYP) is a traditional Chinese medicine prescription composed of two drugs, Coptis chinensis Franch. and Tetradium ruticarpum (A. Jussieu) T. G. Hartley, and is commonly used in the clinical treatment of diseases of the digestive system. However, the mechanism underlying the effect of ZYP on colitis remains unclear. In this study, a colitis rat model was induced with 2,4,6-trinitro-benzenesulfonic acid (TNBS, 100 mg/kg) and treated with ZYP (low dose: 0.6 g/kg, high dose: 1.2 g/kg). Disease activity index, colonic weight index, and weight change ratio were used to evaluate the model and efficacy. LC-MS and 16S rRNA gene sequencing were used to measure differences in fecal metabolism and microorganism population among the control, model, low-dose ZYP, and high-dose ZYP groups. To elucidate the mechanism of interventional effect of ZYP, Spearman correlation analysis was used to analyze the correlation between fecal metabolism and fecal microbial number. High-dose and low-dose ZYP both exhibited significant interventional effects on colitis rat models, and high-dose ZYP produced a better interventional effect compared with low-dose ZYP. Based on a metabolomics test of fecal samples, significantly altered metabolites in the model and high-dose ZYP treatment groups were identified. In total, 492 metabolites were differentially expressed. Additionally, sequencing of the 16S rRNA gene in fecal samples revealed that the high-dose ZYP could improve TNBS-induced fecal microbiota dysbiosis. Ultimately, changes in tryptophan metabolism and Firmicutes and Gammaproteobacteria populations were detected after ZYP treatment in both colitis and cholestasis. Therefore, we conclude that tryptophan metabolism and Firmicutes and Gammaproteobacteria populations are the core targets of the anti-inflammatory effect of ZYP. These findings provide a scientific basis for further investigation of the anti-inflammatory mechanism of ZYP in the future.

Empagliflozin Exhibits Hepatoprotective Effects Against Bile Duct Ligation-induced Liver Injury in Rats: A Combined Molecular Docking Approach to In Vivo Studies

BACKGROUND

Cholestatic liver damage is a chronic disease caused by dysfunction of the hepaticbiliary system. Oxidative stress and inflammation are essential factors in the pathogenesis of cholestasis. Thus, the current study was designed to examine the effect of empagliflozin on bile duct ligation-induced liver damage in rats.

METHODS

This study was done on male Wistar rats, which were randomly assigned to the four experimental groups: sham control (SC), bile duct ligation (BDL), SC plus empagliflozin (SC+EMPA) (receiving 10 mg of EMPA orally for 7 days), BDL plus empagliflozin 10 mg/kg (BDL+ EMPA). At the end of the study, the rats were sacrificed, and serum and tissue samples were collected to analyze biochemical parameters, biomarkers of oxidative stress, inflammatory markers, and histopathological changes. The molecular docking technique was performed to elucidate the interaction of EMPA and Cu/Zn-superoxide dismutase (SOD1).

RESULTS

The results showed that BDL elevated the serum activity of ALT, AST, ALP, and levels of TBIL and TPro. BDL also intensifies the oxidative stress state in rats, which was confirmed by augmenting lipid peroxidation (MDA), protein oxidation (PCO), and altering antioxidant defense parameters through decreased SOD, catalase (CAT), and glutathione peroxidase (GPX) levels. Furthermore, the histopathological changes in the liver demonstrated the aggravation of inflammation and oxidative stress. In contrast, treatment with EMPA has shown anti-inflammatory and anti-oxidant effects by reducing TNF-α and IL-6 pro-inflammatory marker proteins, restoring the antioxidant status (increased SOD and GPX), reducing ALT, AST, ALP, TBIL levels, and protein oxidation, and improving the histopathological alterations through reducing bile duct proliferation, fibrosis, focal and portal inflammation. According to the attained findings, the SOD1 activity can be regulated by the EMPA. Our documentation presents direct evidence at the molecular level related to the ability of EMPA to exert its antioxidant performance through certain measures in a particular molecular route.

CONCLUSION

The results showed EMPA to have hepatic protective effects in rats against cholestatic liver injury, an effect mediated by its antioxidant and anti-inflammatory properties.

Promising traditional Chinese medicine for the treatment of cholestatic liver disease process (cholestasis, hepatitis, liver fibrosis, liver cirrhosis)

ETHNOPHARMACOLOGICAL RELEVANCE

Cholestatic liver disease (CLD) is mainly characterized by cholestasis. If not treated, it will deteriorate to cholestatic hepatitis, liver fibrosis, liver cirrhosis, and even liver failure. CLD has a high clinical incidence, and limited treatment with single therapy. In the long-term clinical exploration, traditional Chinese medicine (TCM) has been corroborated with unique therapeutic effects on the CLD process.

AIM OF THIS REVIEW

This paper summarizes the effective single and compound TCMs for the treatment of CLD. According to 4 important clinical stages of CLD: cholestasis, hepatitis, liver fibrosis, liver cirrhosis, pharmacological effects and mechanisms of 5 typical TCM examples are reviewed, aims to provide basis for clinical drug selection in different processes of CLD.

MATERIALS AND METHODS

Relevant scientific articles regarding therapeutic effects of TCM for the CLD were collected from different databases. We collated three single herbs including Artemisia scoparia Waldst. et Kit. or Artemisia capillaris Thunb. (Artemisiae Scopariae Herba, Yin Chen in Chinese), Paeonia lactiflora Pall. or Paeonia veitchii Lynch. (Paeoniae radix rubra, Chi Shao in Chinese), Poria cocos (Schw.) Wolf (Poria, Fu Ling in Chinese), and two compound herbs of Huang Qi Decoction (HQD) and Yin Chen Hao Decoction (YCHD) to studied and analyzed.

RESULTS

We proposed five promising TCMs treatments for the important developmental stages of CLD. Among them, Yin Chen is an essential medicine for protecting liver and gallbladder, and its TCM prescription is also a promising strategy for cholestasis. Based on clinical evidence, high-dose application of Chi Shao is a clinical special treatment of cholestasis hepatitis. Fu Ling can regulate immune cells and increase antibody levels in serum, which is expected to be an emerging therapy to prevent cholestatic liver fibrosis to cirrhosis. HQD can be used as routine clinical medicine for liver fibrosis. In addition, YCHD can exert better comprehensive advantages with multiple components, can treat the whole course of CLD and prevent it from developing to the end-stage.

CONCLUSION

Yin Chen, Chi Shao, Fu Ling, HQD and YCHD have shown good clinical efficacy in controlling the development of CLD. Clinically, it is easier to curb the development of CLD by adopting graded diagnosis and treatment measures. We suggest that CLD should be risk stratified in clinical treatment to ensure personalized treatment for patients, so as to slow down the development of the disease.

Association of Low-Density Lipoprotein Cholesterol Levels During Statin Treatment With Cardiovascular and Renal Outcomes in Patients With Moderate Chronic Kidney Disease

Background The benefit of low-density lipoprotein cholesterol (LDL-C) levels in chronic kidney disease populations remains unclear. This study evaluated the cardiovascular and renal outcomes in patients with stage 3 chronic kidney disease with different LDL-C levels during statin treatment. Methods and Results There were 8500 patients newly diagnosed as having stage 3 chronic kidney disease under statin treatment who were identified from the Chang Gung Research Database and divided into 3 groups according to their first LDL-C level after the index date: <70 mg/dL, 70 to 100 mg/dL, and >100 mg/dL. Inverse probability of treatment weighting was performed to balance baseline characteristics. Compared with the LDL-C ≥100 mg/dL group, the 70≤LDL-C<100 mg/dL group exhibited significantly lower risks of major adverse cardiac and cerebrovascular events (6.8% versus 8.8%; subdistribution hazard ratio [SHR], 0.76 [95% CI, 0.64-0.91]), intracerebral hemorrhage (0.23% versus 0.51%; SHR, 0.44 [95% CI, 0.25-0.77]), and new-onset end-stage renal disease requiring chronic dialysis (7.6% versus 9.1%; SHR, 0.82 [95% CI, 0.73-0.91]). By contrast, the LDL-C <70 mg/dL group exhibited a marginally lower risk of major adverse cardiac and cerebrovascular events (7.3% versus 8.8%; SHR, 0.82 [95% CI, 0.65-1.02]) and a significantly lower risk of new-onset end-stage renal disease requiring chronic dialysis (7.1% versus 9.1%; SHR, 0.76 [95% CI, 0.67-0.85]). Conclusions Among patients with stage 3 chronic kidney disease, statin users with 70≤LDL-C<100 mg/dL and with LDL-C <70 mg/dL had similar beneficial effect in the reduction of risks of major adverse cardiac and cerebrovascular events and new-onset end-stage renal disease compared with those with LDL-C >100 mg/dL. Moreover, the 70≤LDL-C<100 mg/dL group seemed to have a lowest risk of intracerebral hemorrhage, although the incidence was low.

An effective method for preventing cholestatic liver injury of Aucklandiae Radix and Vladimiriae Radix: Inflammation suppression and regulate the expression of bile acid receptors

ETHNOPHARMACOLOGICAL RELEVANCE

Aucklandiae Radix (AR) and Vladimiriae Radix (VR) were used to treat gastrointestinal, liver and gallbladder diseases at practice. In most conditions, VR was used to be a substitute of AR or a local habit may attribute to the same main active ingredients Costunolide and Dehydrocostus lactone, which presented many similar pharmacological activities. However, other different lactone compounds in AR and VR also play a role in disease treatment, so the difference in therapeutic effects of AR and VR in related diseases needs to be further studied.

AIMS OF THE STUDY

Revealing the differences between the chemical compounds of the total lactone extracts of AR and VR (TLE of AR and VR) and the differences in the protective effects of cholestatic liver injury to ensure rational use of AR and VR.

STUDY DESIGN AND METHODS

The macroporous adsorption resin was used to purify and enrich the lactone compounds to obtain the total lactone extracts of AR and VR. HPLC-PDA was used to obtain the data to establish chemical fingerprint and chemometric analysis to compare similarities and differences between TLE of AR and VR. The pharmacodynamic experiment revealed how TLE of AR and VR to show protect effects on cholestatic liver injury.

RESULTS

Similarity analysis results showed TLE of AR and VR had a high similarity (>0.9). Nevertheless, difference analysis results showed 4 compounds, Costunolide, Dehydrocostus lactone, 3β-acetoxy-11β-guaia-4 (15), 10 (14)-diene-12,6α-olide and vladinol F may contribute to the differences between them. The pharmacodynamics experiments results showed the TLE of AR and VR affected the different liver cholate-associated transporters mRNA expression (TLE of AR up-regulated CYP7A1, TLE of VR down-regulated FXR and BSEP), the TLE of AR and VR had an effect to regulate biochemical indicators (AST, ALT, ALP, TBA) of liver function, and TLE of VR was better than TLE of AR in reducing the expression of inflammatory factors (IL-6 and IL-1β).

CONCLUSION

The liver protection of AR and VR have been confirmed, but the differences of material basis and mechanism of drug efficacy needed further study to guarantee formulation research and provide theoretical references for clinical rational applications of AR and VR.

Oleanolic acid alleviates ANIT-induced cholestatic liver injury by activating Fxr and Nrf2 pathways to ameliorate disordered bile acids homeostasis

BACKGROUND

Cholestasis is a clinical syndrome with high incidence and few effective treatments. Oleanolic acid (OA) is a triterpenoid compound with anti-cholestatic effects. Studies using bile duct ligation or lithocholic acid modeling have shown that the alleviating effect of OA on cholerosis is related to the regulation of nuclear factor erythroid 2 related factor (Nrf2) or farnesoid X receptor (Fxr).

PURPOSE

This study aims to investigate the underlying mechanism of OA against alpha-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury based on Nrf2 and Fxr dual signaling pathways.

METHODS

The ANIT-induced rats model was used with or without OA treatment. Serum biochemical indexes, liver histopathological changes and glutathione level were examined. Bile acids (BAs) targeted metabolomics based on UHPLC-MS/MS were performed. siRNA, RT-qPCR and western blot analysis were used to prove the role of Fxr and Nrf2 pathway in OA's anti-cholestatic liver injury in vivo and in vitro.

RESULTS

OA significantly alleviated ANIT-induced liver injury in rats, reduced primary bile acids, accelerated metabolism of BAs and reduced the intrahepatic accumulation of BAs. The expressions of bile salt export pump (Bsep), Na+-taurocholic cotransport polypeptide (Ntcp), UDP-glucuronyl transferase 1a1 (Ugt1a1) and Fxr in rat liver were markedly up-regulated, the activation of Nrf2 was promoted, and the expression of cholesterol 7α-hydroxylase (Cyp7a1) was decreased after OA treatment. Moreover, Fxr or Nrf2 silencing attenuated the regulation of OA on BAs homeostasis related transporters and enzymes in rat primary hepatocytes.

CONCLUSION

OA may regulate BAs-related transporters and metabolic enzymes by activating Fxr and Nrf2 pathways, thus alleviating the cholestatic liver injury induced by ANIT.

PPARα: A potential therapeutic target of cholestasis

The accumulation of bile acids in the liver leads to the development of cholestasis and hepatocyte injury. Nuclear receptors control the synthesis and transport of bile acids in the liver. Among them, the farnesoid X receptor (FXR) is the most common receptor studied in treating cholestasis. The activation of this receptor can reduce the amount of bile acid synthesis and decrease the bile acid content in the liver, alleviating cholestasis. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) have a FXR excitatory effect, but the unresponsiveness of some patients and the side effect of pruritus seriously affect the results of UDCA or OCA treatment. The activator of peroxisome proliferator-activated receptor alpha (PPARα) has emerged as a new target for controlling the synthesis and transport of bile acids during cholestasis. Moreover, the anti-inflammatory effect of PPARα can effectively reduce cholestatic liver injury, thereby improving patients’ physiological status. Here, we will focus on the function of PPARα and its involvement in the regulation of bile acid transport and metabolism. In addition, the anti-inflammatory effects of PPARα will be discussed in some detail. Finally, we will discuss the application of PPARα agonists for cholestatic liver disorders.

Sphingosine 1-phosphate receptor, a new therapeutic direction in different diseases

Sphingosine 1-phosphate receptor (S1PR), as a kind of G protein-coupled receptor, has five subtypes, including S1PR1, S1PR2, S1PR3, S1PR4, and S1PR5. Sphingosine 1-phosphate receptor (S1P) and S1PR regulate the trafficking of neutrophils and some cells, which has great effects on immune systems, lung tissue, and liver tissue. Presently, many related reports have proved that S1PR has a strong effect on the migration of lymphocytes, tumor cells, neutrophils, and many other cells via the regulation of signals, pathways, and enzymes. In this way, S1PR can regulate the relative response of the organism. Thus, S1PR has become a possible target for the treatment of autoimmune diseases, pulmonary disease, liver disease, and cancer. In this review, we mainly focus on the research of the S1PR for the new therapeutic directions of different diseases and is expected to assist support in the clinic and drug use.

Advances of natural activators for Nrf2 signaling pathway on cholestatic liver injury protection: a review

Cholestasis is a common manifestation of obstruction of bile flow in various liver diseases. If the bile acid accumulation is not treated in time, it will further lead to hepatocyte damage, liver fibrosis and ultimately to cirrhosis, which seriously affects human life. The pathogenesis of cholestatic liver injury is very complicated, mainly including oxidative stress and inflammation. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important transcription factor responsible for upregulating expression of various genes with cytoprotective functions. Nrf2 activation has been proved to inhibit oxidative stress and inflammatory reaction, modulate bile acid homeostasis, and alleviate fibrosis during cholestasis. Therefore, Nrf2 emerges as a potential therapeutic target for cholestatic liver injury. In recent years, natural products with various biological activities including anti-inflammatory, anti-oxidant, anti-tumor and anti-fibrotic effects have received growing attention for being hepatoprotective agents. Natural products like asiatic acid, diosmin, rutin, and so forth have shown significant potential in activating Nrf2 pathway which can lead to attenuate cholestatic liver injury. Therefore, this paper emphasizes the effect of Nrf2 signaling pathway on alleviating cholestasis, and summarizes recent evidence about natural Nrf2 activators with hepatoprotective effect in various models of cholestatic liver injury, thus providing theoretical reference for the development of anti-cholestatic drug.

A UPLC-MS/MS-based metabolomics analysis of the pharmacological mechanisms of rabdosia serra against cholestasis

BACKGROUND

Rabdosia Serra, the dried aerial parts of Rabdosia serra (Maxim.) Hara (RS) from the Labiatae family, is a traditional Chinese herbal medicine called Xihuangcao. Although RS has been found to exert a therapeutic effect on cholestasis, the underlying molecular mechanism remains unclear.

PURPOSE

This study was designed to investigate the pharmacological effect and mechanism of RS on cholestatic rats using metabolomics platform.

METHODS

Histopathology and biochemical evaluations were performed to determine the therapeutic effect of RS and developed a rapid metabolite detection technology method based on UPLC-MS/MS to perform metabolomics research. Further, quantitative real-time polymerase chain reaction (RT-qPCR) was used to study the effect of RS on the bile acid metabolism pathway at the transcriptional level.

RESULTS

RS significantly reduced the bile flow rates in cholestatic rats and decreased the levels of ALT, AST, TBA, T-BIL, and LDH, which were increased in the model group. Histological analysis showed that RS alleviated the liver injury induced by ANIT. Serum metabolomics results revealed 33 of the 37 biomarkers were found to be significantly altered by ANIT, and 26 were considerably changed following treatment with RS. Metabolic pathway analysis revealed four pathways such as primary bile acid biosynthesis, biosynthesis of unsaturated fatty acids, and arachidonic acid and tryptophan metabolism. The bile acid secretion process and the inflammation and oxidative stress processes are the major biochemical reactions following treatment with ANIT and RS. Bile acid-targeted metabolomics study showed that TCA, GCA, GCDCA, and GDCA might be sensitive biomarkers that induced liver injury. we found that treatment with RS regulated the levels of bile acid in the serum and liver and restored the proportion of bile acids, especially CA and conjugated bile acids, such as TCA and GCA, in the bile duct. RS increased the mRNA expression levels of FXR, SHP, BSEP, and MRP2 in livers, and IBABP, OST-α, and OST-β in the ileum.

CONCLUSION

In this study, RS was found to protect the liver by regulating multiple metabolic pathways and promoting the excretion of bile acids. Simultaneously, RS played an essential role in reversing the imbalance of bile acids and protected against cholestasis by regulating the expression of transporters associated with bile acids. We demonstrated the correlation between molecular mechanisms and metabolites, provide a reference for the fabrication of extracts that can be used to treat cholestasis.

Kinsenoside Alleviates 17α-Ethinylestradiol-Induced Cholestatic Liver Injury in Rats by Inhibiting Inflammatory Responses and Regulating FXR-Mediated Bile Acid Homeostasis

Cholestasis is an important predisposing factor of liver diseases, such as hepatocyte necrosis, liver fibrosis and primary biliary cirrhosis. In this study, we aimed to investigate the effects of Kinsenoside (KD), a natural active ingredient of Anoectochilus roxburghii, on estrogen-induced cholestatic liver injury in Sprague-Dawley rats and the underlying mechanism. The rats were randomly divided into six groups: control group, model group, low-dose KD group (50 mg/kg body weight, KD-L), medium-dose KD group (100 mg/kg body weight, KD-M), high-dose KD group (200 mg/kg body weight, KD-H) and ursodeoxycholic acid group (40 mg/kg body weight, UDCA). 17α-Ethinylestradiol (EE) was used to establish an experimental animal model of estrogen-induced cholestasis (EIC). The results demonstrated that KD alleviated liver pathologic damage, serum biochemical status and inhibited hepatocellular microstructure disorder and bile duct hyperplasia in EE-induced cholestatic rats. Mechanically, KD alleviated EE-induced cholestatic liver injury by inhibiting inflammatory responses and regulating bile acid homeostasis. Concretely, KD reduced the expression of IL-1β and IL-6 by inhibiting NF-κB p65 to suppress EE-mediated inflammation in rat liver. KD enhanced the expression of FXR and inhibited EE-mediated reduction of FXR in vitro and in vivo. It was the potential mechanism that KD mitigates cholestasis by increasing efflux and inhibiting uptake of bile acids via FXR-mediated induction of bile salt export pump (BSEP) and reduction of Na⁺-dependent taurocholate cotransport peptide (NTCP) to maintain bile acid homeostasis. Moreover, KD repressed the bile acid synthesis through reducing the expression of synthetic enzyme (CYP7A1), thereby normalizing the expression of metabolic enzyme (SULT2A1) of bile acid. In conclusion, our results revealed that KD may be an effective drug candidate for the treatment of cholestasis.

Impact of Cholestasis on the Sensitivity of Percutaneous Transluminal Forceps Biopsy in 93 Patients with Suspected Malignant Biliary Stricture

PURPOSE

The aim of this study was to determine the effect of hyperbilirubinemia in the sensitivity of percutaneous transluminal forceps biopsy (PTFB) in patients with suspected malignant biliary stricture.

MATERIALS AND METHODS

Ninety-three patients with suspicion of malignant biliary stricture underwent percutaneous transhepatic cholangiography followed by PTFB. Sensitivity, specificity and predictive values were analysed based on the presence or absence of hyperbilirubinemia, defined as total bilirubin equal to, or higher than 5 mg/dL. Variables included demographic and clinical features, laboratory, tumour type and localization, stricture length, therapeutic approach and histopathology. Additionally, major morbidity and mortality were assessed.

RESULTS

The overall sensitivity, specificity, positive predictive value and accuracy of PTFB were 61.1%, 100%, 100%, and 62.4%, respectively. Hyperbilirubinemia affected 57% of patients at the time of PTFB. There were 35 (37%) false negative results, none of them related to tumour type or localization, stricture length, or previous biliary intervention (i.e. PBBD (percutaneous biliary balloon dilatation), ERCP (endoscopic retrograde cholangiopancreatography)) (p > 0.05). However, when bilirubin was < 5 mg/dL, false negative results decreased globally (p = 0.024) and sensitivity increased significantly for intrahepatic and hilar localization, as well as for colorectal metastasis, gallbladder carcinoma, and pancreatic carcinoma. No major morbidity occurred.

CONCLUSION

The sensitivity of percutaneous transluminal biopsy for diagnosis of malignant stricture may significantly increase if samples are obtained in the absence of hyperbilirubinemia, without adding morbidity to the procedure.

LEVEL OF EVIDENCE

Level 3, Case- Control studies.

Knockout of calpain-1 protects against high-fat diet-induced liver dysfunction in mouse through inhibiting oxidative stress and inflammation

The present study was designed to investigate the significance of calpain-1 in the high-fat diet (HFD)-induced liver dysfunction and to explore the possible mechanism. C57 mice and calpain-1 knockout (KO) mice were fed with standard diet (SD) or HFD, respectively, for 16 weeks. The activities of calpain, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and superoxide dismutase (SOD) in serum and/or liver of mouse were measured. Lipid profiles in the serum and liver were examined. Contents of oxidized low-density lipoprotein (oxLDL), malondialdehyde (MDA), tumor necrosis factor (TNF-α), and interleukin-6 (IL-6) in serum or/and liver were detected. The results showed that compared with C57 mice fed with SD, HFD-fed C57 mice showed the increased activities of AST and ALT in the serum, which was decreased in calpain-1 KO mice fed with HFD. In addition, knockout of calpain-1 decreased the contents of oxLDL, MDA, TNF-α, and IL-6, while increased SOD activity, in serum and/or liver. However, knockout of calpain-1 had no effects on lipid profiles in both serum and liver. When fed with SD, all these parameters of C57 and calpain-1 KO mice were comparable except for decreased calpain activity in the liver of calpain-1 KO mice. The results suggested that knockout of calpain-1 protects against HFD-induced liver dysfunction through inhibiting oxidative stress and inflammation.

Identification of atypical mitogen-activated protein kinase MAPK4 as a novel regulator in acute lung injury

Background

Acute lung injury (ALI) is a serious disease with highly morbidity and mortality that causes serious health problems worldwide. Atypical mitogen activated protein kinases (MAPKs) play critical roles in the development of tissues and have been proposed as promising therapeutic targets for various diseases. However, the potential role of atypical MAPKs in ALI remains elusive. In this study, we investigated the role of atypical MAPKs family member MAPK4 in ALI using LPS-induced murine ALI model.

Results

We found that MAPK4 deficiency mice exhibited prolonged survival time after LPS challenge, accompanied by alleviated pathology in lung tissues, decreased levels of pro-inflammatory cytokines and altered composition of immune cells in BALF. Furthermore, the transduction of related signaling pathways, including MK5, AKT, JNK, and p38 MAPK pathways, was reduced obviously in LPS-treated MAPK4^−/− mice. Notably, the expression of MAPK4 was up-regulated in lung tissues of ALI model, which was not related with MAPK4 promoter methylation, but negatively orchestrated by transcriptional factors NFKB1 and NR3C1. Further studies have shown that the expression of MAPK4 was also increased in LPS-treated macrophages. Meanwhile, MAPK4 deficiency reduced the expression of related pro-inflammatory cytokines in macrophage in response to LPS treatment. Finally, MAPK4 knockdown using shRNA pre-treatment could ameliorate the pathology of lung tissues and prolong the survival time of mice after LPS challenge.

Conclusions

Collectively, these findings reveal an important biological function of atypical MAPK in mediating the pathology of ALI, indicating that MAPK4 might be a novel potential therapeutic target for ALI treatment.

Studies on the potential link between antidepressant effect of Xiaoyao San and its pharmacological activity of hepatoprotection based on multi-platform metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine (TCM) theory, depression is considered to be "liver qi stagnation", and relieving "liver qi stagnation" is regarded as an effective method for treating depression. Xiaoyao San (XYS) is a well-known TCM formula for the treatment of depression by relieving "liver qi stagnation". This formula consists of Radix Paeoniae Alba (Paeonia lactiflora Pall.), Radix Bupleuri (Bupleurum chinense DC.), Poria (Poria cocos (Schw.) Wolf), Rhizoma Atractylodis Macrocephalae (Atractylodes macrocephala Koidz.), Radix Angelicae Sinensis (Angelica sinensis (Oliv.) Diels), Radix Glycyrrhizae (Glycyrrhiza uralensis Fisch.), Rhizoma Zingiberis Recens (Zingiber officinale Roscoe) and Herba Menthae Haplocalycis (Mentha haplocalyx Briq.).

AIM OF THE STUDY

Several studies have suggested that depression is associated with liver injury. XYS was a well-known TCM formula for the treatment of depression and liver stagnancy. However, it was still unknown whether the antidepressant effect of XYS is related to the pharmacological activity of hepatoprotection. The aim of this study was to elucidate the potential link between the antidepressant and hepatoprotective effect of XYS.

MATERIALS AND METHODS

A depression rat model was established by the CUMS (chronic unpredictable mild stress) procedure. The antidepressant effect of XYS was assessed by the behavioral indicators, and the hepatoprotective effect of XYS was evaluated through biochemical assays. ¹H-NMR and LC/MS-based liver metabolomics were performed to discover key metabolic pathways involved in the antidepressant and hepatoprotective effects of XYS. Further, the key pathway was validated using commercial kits.

RESULTS

The results demonstrated that XYS pretreatment could significantly improve the depressive symptom induced by CUMS. More importantly, the results demonstrated that liver injury was observed in the CUMS model rats, and XYS had a hepatoprotective effect by reducing the activities of AST and ALT in serum, increasing the levels of SOD and GSH-Px and reducing the contents of MDA, IL-6, and IL-1β in the liver. In addition, the NMR and LC/MS-based metabolomics results indicated that XYS improved 23 of the 35 perturbed potential liver biomarkers that were induced by CUMS. Among them, 9 biomarkers were significantly correlated with both depression and liver pathology, according to Pearson correlation analysis. Metabolic pathway analyses of these 9 biomarkers showed that glutamine and glutamate metabolism were the most important metabolic pathways. Furthermore, to verify glutamine and glutamate metabolism, the levels of glutamine and glutamate, and the activity of glutamine synthetase (GS) and glutaminase (GLS) were quantitatively determined in the liver by commercial kits, and these results were consistent with the metabolomics results.

CONCLUSIONS

XYS could significantly improve the depressive and liver injury symptoms induced by CUMS. The metabolomics results indicate that the regulation of glutamine and glutamate metabolism to maintain the balance of ammonia and promote energy metabolism is a potential junction between the antidepressant and hepatoprotective effects of XYS.

Single-Cell Transcriptomes Reveal Characteristic Features of Mouse Hepatocytes with Liver Cholestatic Injury

Hepatocytes are the main parenchymal cells of the liver and play important roles in liver homeostasis and disease process. The heterogeneity of normal hepatocytes has been reported, but there is little knowledge about hepatocyte subtype and distinctive functions during liver cholestatic injury. Bile duct ligation (BDL)-induced mouse liver injury model was employed, and single-cell RNA sequencing was performed. Western blot and qPCR were used to study gene expression. Immunofluoresence was employed to detect the expressions of marker genes in hepatocytes. We detected a specific hepatocyte cluster (BDL-6) expressing extracellular matrix genes, indicating these hepatocytes might undergo epithelia-mesenchymal transition. Hepatocytes of BDL-6 also performed tissue repair functions (such as angiogenesis) during cholestatic injury. We also found that four clusters of cholestatic hepatocytes (BDL-2, BDL-3, BDL-4, and BDL-5) were involved in inflammatory process in different ways. To be specific, BDL-2/3/5 were inflammation-regulated hepatocytes, while BDL-4 played a role in cell chemotaxis. Among these four clusters, BDL-5 was special. because the hepatocytes of BDL-5 were proliferating hepatocytes. Our analysis provided more knowledge of hepatocyte distinctive functions in injured liver and gave rise to future treatment aiming at hepatocytes.

In silico Identification and Mechanism Exploration of Hepatotoxic Ingredients in Traditional Chinese Medicine

BACKGROUNDS AND AIMS

Recently, a growing number of hepatotoxicity cases aroused by Traditional Chinese Medicine (TCM) have been reported, causing increasing concern. To date, the reported predictive models for drug induced liver injury show low prediction accuracy and there are still no related reports for hepatotoxicity evaluation of TCM systematically. Additionally, the mechanism of herb induced liver injury (HILI) still remains unknown. The aim of the study was to identify potential hepatotoxic ingredients in TCM and explore the molecular mechanism of TCM against HILI.

MATERIALS AND METHODS

In this study, we developed consensus models for HILI prediction by integrating the best single classifiers. The consensus model with best performance was applied to identify the potential hepatotoxic ingredients from the Traditional Chinese Medicine Systems Pharmacology database (TCMSP). Systems pharmacology analyses, including multiple network construction and KEGG pathway enrichment, were performed to further explore the hepatotoxicity mechanism of TCM.

RESULTS

16 single classifiers were built by combining four machine learning methods with four different sets of fingerprints. After systematic evaluation, the best four single classifiers were selected, which achieved a Matthews correlation coefficient (MCC) value of 0.702, 0.691, 0.659, and 0.717, respectively. To improve the predictive capacity of single models, consensus prediction method was used to integrate the best four single classifiers. Results showed that the consensus model C-3 (MCC = 0.78) outperformed the four single classifiers and other consensus models. Subsequently, 5,666 potential hepatotoxic compounds were identified by C-3 model. We integrated the top 10 hepatotoxic herbs and discussed the hepatotoxicity mechanism of TCM via systems pharmacology approach. Finally, Chaihu was selected as the case study for exploring the molecular mechanism of hepatotoxicity.

CONCLUSION

Overall, this study provides a high accurate approach to predict HILI and an in silico perspective into understanding the hepatotoxicity mechanism of TCM, which might facilitate the discovery and development of new drugs.