Glycocholic acid aggravates liver fibrosis by promoting the up-regulation of connective tissue growth factor in hepatocytes

Exploring bile acid transporters as key players in cancer development and treatment: Evidence from preclinical and clinical studies

Bile acid transporters (BATs) are integral membrane proteins belonging to various families, such as solute carriers, organic anion transporters, and ATP-binding cassette families. These transporters play a crucial role in bile acid transportation within the portal and systemic circulations, with expression observed in tissues, including the liver, kidney, and small intestine. Bile acids serve as signaling molecules facilitating the absorption and reabsorption of fats and lipids. Dysregulation of bile acid concentration has been implicated in tumorigenesis, yet the role of BATs in this process remains underexplored. Emerging evidence suggests that BATs may modulate various stages of cancer progression, including initiation, development, proliferation, metastasis, and tumor microenvironment regulation. Targeting BATs using siRNAs, miRNAs, and small compound inhibitors in preclinical models and their polymorphisms are well-studied for transporters like BSEP, MDR1, MRP2, OATP1A2, etc., and have shed light on their involvement in tumorigenesis, particularly in cancers such as those affecting the liver and gastrointestinal tract. While BATs' role in diseases like Alagille syndrome, biliary atresia, and cirrhosis have been extensively studied, their implications in cancer warrant further investigation. This review highlights the expression and function of BATs in cancer development and emphasizes the potential of targeting these transporters as a novel therapeutic strategy for various malignancies.

Tamoxifen upregulates the peroxisomal β-oxidation enzyme Enoyl CoA hydratase and 3-hydroxyacyl CoA hydratase ameliorating hepatic lipid accumulation in mice

Tamoxifen is an estrogen receptor modulator that has been reported to alleviate hepatic lipid accumulation in mice, but the mechanism is still unclear. Peroxisome fatty acid β-oxidation is the main metabolic pathway for the overload of long-chain fatty acids. As long-chain fatty acids are a cause of hepatic lipid accumulation, the activation of peroxisome fatty acid β-oxidation might be a novel therapeutic strategy for metabolic associated fatty liver disease. In this study, we investigated the mechanism of tamoxifen against hepatic lipid accumulation based on the activation of peroxisome fatty acid β-oxidation. Tamoxifen reduced liver long-chain fatty acids and relieved hepatic lipid accumulation in high fat diet mice without sex difference. In vitro, tamoxifen protected primary hepatocytes against palmitic acid-induced lipotoxicity. Mechanistically, the RNA-sequence of hepatocytes isolated from the liver revealed that peroxisome fatty acid β-oxidation was activated by tamoxifen. Protein and mRNA expression of enoyl CoA hydratase and 3-hydroxyacyl CoA hydratase were significantly increased in vivo and in vitro. Small interfering RNA enoyl CoA hydratase and 3-hydroxyacyl CoA hydratase in primary hepatocytes abolished the therapeutic effects of tamoxifen in lipid accumulation. In conclusion, our results indicated that tamoxifen could relieve hepatic lipid accumulation in high fat diet mice based on the activation of enoyl CoA hydratase and 3-hydroxyacyl CoA hydratase-mediated peroxisome fatty acids β-oxidation.

Group 1 innate lymphoid cell activation via recognition of NKG2D and liver resident macrophage MULT-1: Collaborated roles in triptolide induced hepatic immunotoxicity in mice

Triptolide (TP) is the major bioactive component of traditional Chinese medicine Tripterygium wilfordii Hook. F., a traditional Chinese medicinal plant categorized within the Tripterygium genus of the Celastraceae family. It is recognized for its therapeutic potential in addressing a multitude of diseases. Nonetheless, TP is known to exhibit multi-organ toxicity, notably hepatotoxicity, which poses a significant concern for the well-being of patients undergoing treatment. The precise mechanisms responsible for TP-induced hepatotoxicity remain unresolved. In our previous investigation, it was determined that TP induces heightened hepatic responsiveness to exogenous lipopolysaccharide (LPS). Additionally, natural killer (NK) cells were identified as a crucial effector responsible for mediating hepatocellular damage in this context. However, associated activating receptors and the underlying mechanisms governing NK cell represented innate lymphoid cell (ILC) activation remained subjects of inquiry and were not yet investigated. Herein, activating receptor Killer cell lectin like receptor K1 (NKG2D) of group 1 ILCs was specifically upregulated in TP- and LPS-induced acute liver failure (ALF), and in vivo blockade of NKG2D significantly reduced group 1 ILC mediated cytotoxicity and mitigated TP- and LPS-induced ALF. NKG2D ligand UL16-binding protein-like transcript 1 (MULT-1) was found upregulated in liver resident macrophages (LRMs) after TP administration, and LRMs did exhibit NK cell activating effect. Furthermore, M1 polarization of LRMs cells was observed, along with an elevation in intracellular tumor necrosis factor (TNF)-α levels. In vivo neutralization of TNF-α significantly alleviated TP- and LPS-induced ALF. In conclusion, the collaborative role of group 1 ILCs and LRMs in mediating hepatotoxicity was confirmed in TP- and LPS-induced ALF. TP-induced MULT-1 expression in LRMs was the crucial mechanism in the activation of group 1 ILCs via MULT-1-NKG2D signal upon LPS stimulation, emphasizing the importance of infection control after TP administration.

Targeted quantitative lipidomic uncovers lipid biomarkers for predicting the presence of compensated cirrhosis and discriminating decompensated cirrhosis from compensated cirrhosis

OBJECTIVES

This study aimed to characterize serum lipid metabolism and identify potential biomarkers for compensated cirrhosis (CC) predicting and decompensated cirrhosis (DC) discrimination using targeted quantitative lipidomics and machine learning approaches.

METHODS

Serum samples from a cohort of 120 participants was analyzed, including 90 cirrhosis patients (45 CC patients and 45 DC patients) and 30 healthy individuals. Lipid metabolic profiling was performed using targeted LC-MS/MS. Two machine learning methods, least absolute shrinkage and selection operator (LASSO), and random forest (RF) were applied to screen for candidate metabolite biomarkers.

RESULTS

The metabolic profiling analysis showed a significant disruption in patients with CC and DC. Compared to the CC group, the DC group exhibited a significant upregulation in the abundance of glycochenodeoxycholic acid (GCDCA), glyco-ursodeoxycholic acid (GUDCA), glycocholic acid (GCA), phosphatidylethanolamine (PE), N-acyl-lyso-phosphatidylethanolamine (LNAPE), and triglycerides (TG), and a significant downregulation in the abundance of ceramides (Cer) and lysophosphatidylcholines (LPC). Machine learning identified 11 lipid metabolites (abbreviated as BMP11) as potential CC biomarkers with excellent prediction performance, with an AUC of 0.944, accuracy of 94.7 %, precision of 95.6 %, and recall of 95.6 %. For DC discrimination, eight lipids (abbreviated as BMP8) were identified, demonstrating strong efficacy, with an AUC of 0.968, accuracy of 92.2 %, precision of 88.0 %, and recall of 97.8 %.

CONCLUSIONS

This study unveiled distinct lipidomic profiles in CC and DC patients and established robust lipid-based models for CC predicting and DC discrimination.

Molecular mechanisms of hepatoprotective effect of tectorigenin against ANIT-induced cholestatic liver injury: Role of FXR and Nrf2 pathways

Cholestatic liver injury is caused by toxic action or allergic reaction, resulting in abnormality of bile formation and excretion. Few effective therapies have become available for the treatment of cholestasis. Herein, we found that tectorigenin (TG), a natural isoflavone, showed definite protective effects on alpha-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury, significantly reversing the abnormality of plasma alanine/aspartate aminotransferase, total/direct bilirubin and alkaline phosphatase, as well as hepatic reactive oxygen species, catalase and superoxide dismutase. Importantly, the targeted metabolomic determination found that BA homeostasis could be well maintained in TG-treated cholestatic mice, especially the levels of glycocholic acid, tauromuricholic acid, taurocholic acid, taurolithocholic acid, tauroursodeoxycholic acid and taurodeoxycholic acid. Overall, primary/secondary and amidated/unamidated bile acid (BA) levels were significantly altered upon ANIT stimulation but could be restored by TG intervention to certain extents. In addition, TG boosted the expression of farnesoid x receptor (FXR), which in turn upregulated multidrug resistance protein 2 (MRP2) and bile salt export pump (BSEP) to accelerate the excretion of BA. Meanwhile, TG enhanced the expression of Nrf2 and its upstream genes PI3K/Akt and downstream target genes HO-1, NQO1, GCLC and GCLM to strengthen the antioxidant capacity. Taken together, TG plays a vital role in maintaining BA homeostasis and ameliorating cholestatic liver injury through regulating FXR-mediated BA efflux and Nrf2-mediated antioxidative pathways.

Investigation of the Therapeutic Effect of Total Alkaloids of Corydalis saxicola Bunting on CCl4-Induced Liver Fibrosis in Rats by LC/MS-Based Metabolomics Analysis and Network Pharmacology

Liver fibrosis is a pathological result of liver injury that usually leads to a pathophysiological wound healing response. The total alkaloids of Corydalis saxicola Bunting (TACS) have been used for hepatoprotective effects on the liver. However, its exact therapeutic mechanisms of liver fibrosis are not yet well understood. To explore the potential anti-fibrosis mechanism of TACS, metabolomics coupled with network pharmacology were applied to reveal the underlying mechanisms. Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) combined with multivariate statistical analyses were performed to estimate changes in metabolic profiles. As a result, a total of 23 metabolites in rats with liver fibrosis were altered; of these, 11 had been downregulated and 12 had been upregulated compared with the control group. After TACS treatment, the levels of 13 metabolites were significantly restored compared with the CCl₄-treated group, of which 4 metabolites were up-regulated and 9 metabolites were down-regulated. Many of these metabolites are involved in the bile acid metabolism, glutathione metabolism, tryptophan metabolism and purine metabolism. Then, three key targets, including cytochrome P450 family1 subfamily A member 1 (CYP1A1), ornithine decarboxylase 1 (OCD1) and monoamine oxidase Type B (MAOB) were predicted as potential therapeutic targets of TACS against liver fibrosis through network pharmacology analysis. Finally, palmatine, tetrahydropalmatine and dehydrocavidine were screened as potential active compounds responsible for the anti-fibrosis effect of TACS by molecular docking analysis. This study reveals that TACS exerted anti-fibrosis effects by regulating the liver metabolic pathway with multiple components and multiple targets, which is helpful to further clarify the hepatoprotective mechanisms of natural plant extracts.