Farnesoid X Receptor Overexpression Decreases the Migration, Invasion and Angiogenesis of Human Bladder Cancers via AMPK Activation and Cholesterol Biosynthesis Inhibition

Bladder cancer is one of the most prevailing cancers worldwide. Although treatments for urothelial carcinoma have improved, the rate of recurrence observed in the clinic is still high. The aim of this study was to evaluate whether cholesterol biosynthesis is involved in the effect of Farnesoid X Receptor (FXR) on bladder cancers. FXR overexpression contributed to activation of 5' AMP-activated protein kinase (AMPK) and decreased cholesterol levels. FXR overexpression reduced cholesterol biosynthesis and secretion by downregulating Sterol Regulatory Element Binding Protein 2 (SREBP2) and 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGCR) expression. In addition, an AMPK inhibitor, dorsomorphin, reversed the inhibition of migration, invasion and angiogenesis by FXR overexpression. In a metastatic xenograft animal study, FXR overexpression suppressed bladder cancer lung metastasis by decreasing matrix metalloproteinase-2 (MMP2), SREBP2 and HMGCR expression. Moreover, FXR overexpression combined with atorvastatin treatment further enhanced the downregulation of the migratory, adhesive, invasive and angiogenic properties in human urothelial carcinoma. In clinical observations, statin administration was associated with better survival rates of early-stage bladder cancer patients. Our results may provide guidance for improving therapeutic strategies for the treatment of urothelial carcinoma.

Enhancement of Farnesoid X Receptor Inhibits Migration, Adhesion and Angiogenesis through Proteasome Degradation and VEGF Reduction in Bladder Cancers

(1) Background: Bladder cancer is a malignant tumor mainly caused by exposure to environmental chemicals, with a high recurrence rate. NR1H4, also known as Farnesoid X Receptor (FXR), acts as a nuclear receptor that can be activated by binding with bile acids, and FXR is highly correlated with the progression of cancers. The aim of this study was to verify the role of FXR in bladder cancer cells. (2) Methods: A FXR overexpressed system was established to investigate the effect of cell viability, migration, adhesion, and angiogenesis in low-grade TSGH8301 and high-grade T24 cells. (3) Results: After FXR overexpression, the ability of migration, adhesion, invasion and angiogenesis of bladder cancer cells declined significantly. Focal adhesive complex, MMP2, MMP9, and angiogenic-related proteins were decreased, while FXR was overexpressed in bladder cancer cells. Moreover, FXR overexpression reduced vascular endothelial growth factor mRNA and protein expression and secretion in bladder cancer cells. After treatment with the proteosome inhibitor MG132, the migration, adhesion and angiogenesis caused by FXR overexpression were all reversed in bladder cancer cells. (4) Conclusions: These results may provide evidence on the role of FXR in bladder cancer, and thus may improve the therapeutic efficacy of urothelial carcinoma in the future.

Substance P Hinders Bile Acid-Induced Hepatocellular Injury by Modulating Oxidative Stress and Inflammation

Liver failure is an outcome of chronic liver disease caused by steatohepatitis and cholestatic injury. This study examined substance P (SP) effect on liver injury due to cholestatic stress caused by excessive bile acid (BA) accumulation. Chenodeoxycholic acid (CDCA) was added to HepG2 cells to induce hepatic injury, and cellular alterations were observed within 8 h. After confirming BA-mediated cellular injury, SP was added, and its restorative effect was evaluated through cell viability, reactive oxygen species (ROS)/inflammatory cytokines/endothelial cell media expression, and adjacent liver sinusoidal endothelial cell (LSEC) function. CDCA treatment provoked ROS production, followed by IL-8 and ICAM-1 expression in hepatocytes within 8 h, which accelerated 24 h post-treatment. Caspase-3 signaling was activated, reducing cell viability and promoting alanine aminotransferase release. Interestingly, hepatocyte alteration by CDCA stress could affect LSEC activity by decreasing cell viability and disturbing tube-forming ability. In contrast, SP treatment reduced ROS production and blocked IL-8/ICAM-1 in CDCA-injured hepatocytes. SP treatment ameliorated the effect of CDCA on LSECs, preserving cell viability and function. Collectively, SP could protect hepatocytes and LSECs from BA-induced cellular stress, possibly by modulating oxidative stress and inflammation. These results suggest that SP can be used to treat BA-induced liver injury.

Nuclear Receptors as Multiple Regulators of NLRP3 Inflammasome Function

Nuclear receptors are important bridges between lipid signaling molecules and transcription responses. Beside their role in several developmental and physiological processes, many of these receptors have been shown to regulate and determine the fate of immune cells, and the outcome of immune responses under physiological and pathological conditions. While NLRP3 inflammasome is assumed as key regulator for innate and adaptive immune responses, and has been associated with various pathological events, the precise impact of the nuclear receptors on the function of inflammasome is hardly investigated. A wide variety of factors and conditions have been identified as modulators of NLRP3 inflammasome activation, and at the same time, many of the nuclear receptors are known to regulate, and interact with these factors, including cellular metabolism and various signaling pathways. Nuclear receptors are in the focus of many researches, as these receptors are easy to manipulate by lipid soluble molecules. Importantly, nuclear receptors mediate regulatory mechanisms at multiple levels: not only at transcription level, but also in the cytosol via non-genomic effects. Their importance is also reflected by the numerous approved drugs that have been developed in the past decade to specifically target nuclear receptors subtypes. Researches aiming to delineate mechanisms that regulate NLRP3 inflammasome activation draw a wide range of attention due to their unquestionable importance in infectious and sterile inflammatory conditions. In this review, we provide an overview of current reports and knowledge about NLRP3 inflammasome regulation from the perspective of nuclear receptors, in order to bring new insight to the potentially therapeutic aspect in targeting NLRP3 inflammasome and NLRP3 inflammasome-associated diseases.

In-silico therapeutic investigations of arjunic acid and arjungenin as an FXR agonist and validation in 3T3-L1 adipocytes

The present study was to illustrate the agonistic property of arjungenin and arjunic acid towards farnesoid X receptor protein (FXR).The pharmacokinetic properties like molecular interactions, absorption, distribution, metabolism, elimination and toxicity (ADMET) of the ligands were checked through in-silico studies. Protein-ligand docking was carried out using autodock software. Molecular docking analysis confirmed strong binding energy and interaction of arjungenin and arjunic acid with the target protein and the ADMET profiles identified for both compounds were promising.Further in vitro studies were performed in 3T3-L1 adipocyte to verify the agonistic property of arjungenin and arjunic acid. Oil red O staining was done to check differentiation induction. Adiponectin, leptin, triglycerides and total cholesterol levels were quantified. The mRNA expression of FXR, Cyp7a1, PPAR-γ and SREBP-1c were quantified using fluorescent real-time PCR. Cytotoxicity assay was confirmed that up to 150 μM concentration there is no significant cell death on treatment with arjunic acid and arjungenin. Treatment with arjungenin and arjunic acid confirms increased differentiation of the cells with significant (P < 0.05) increase in adiponectin (118.07% and 132.92%) and leptin (133.52% and 149.74%) protein levels compared to the negative control group. After treatment with arjungenin and arjunic acid in 3T3-L1 preadipocytes the mRNA expression of FXR, PPAR-γ and SREBP-1c were significantly (P < 0.01) increased and cyp7a1 was significantly (P < 0.01) decreased when compared with the negative control group. Overall, our results suggest that arjungenin and arjunic acid acts as an FXR agonist and may be useful for rational therapeutic strategies as a novel drug to treat cholesterol mediated metabolic syndrome and insulin resistance.