Low dose of the liver X receptor agonist, AZ876, reduces atherosclerosis in APOE*3Leiden mice without affecting liver or plasma triglyceride levels.
van der Hoorn Jwa,Lindén D,Lindahl U,Bekkers Mea,Voskuilen M,Nilsson R,Oscarsson J,Lindstedt El,Princen Hmg
British journal of pharmacology
BACKGROUND AND PURPOSE:Liver X receptor (LXR) agonists are atheroprotective but often induce hypertriglyceridaemia and liver steatosis. We investigated the effect of a novel high-affinity LXR activator, AZ876, on plasma lipids, inflammation and atherosclerosis, and compared the effects with another LXR agonist, GW3965. EXPERIMENTAL APPROACH:APOE*3Leiden mice were fed an atherogenic diet alone or supplemented with either AZ876 (5 or 20µmol·kg(-1) ·day(-1) ) or GW3965 (17µmol·kg(-1) ·day(-1) ) for 20 weeks. Total cholesterol and triglyceride levels were measured using commercial kits. Plasma cytokines were determined by using bead-based multiplex suspension array kits with the Luminex technology. Atherosclerosis was assessed histochemically and lesion composition was assessed by immunohistochemical methods. KEY RESULTS:Low-dose AZ876 had no effect on plasma or liver lipids, whereas high-dose AZ876 increased plasma triglycerides (+110%) and reduced cholesterol (-16%) compared with controls. GW3965 increased plasma triglycerides (+70%). Low-dose AZ876 reduced lesion area (-47%); and high-dose AZ876 strongly decreased lesion area (-91%), lesion number (-59%) and severity. In either dose, AZ876 did not affect lesion composition. GW3965 reduced atherosclerosis and collagen content of lesions (-23%; P < 0.01). High-dose AZ876 and GW3965, but not low-dose AZ876, reduced inflammation as reflected by lower cytokine levels and vessel wall activation. CONCLUSIONS AND IMPLICATIONS:We have identified a novel LXR agonist that when given in a low dose inhibits the progression of atherosclerosis without inducing anti-inflammatory effects, liver steatosis or hypertriglyceridaemia. Therefore, the primary protective action of a low-dose AZ876 is likely to be an increased reverse cholesterol transport.
10.1111/j.1476-5381.2010.01168.x
A NO-releasing derivative of acetaminophen spares the liver by acting at several checkpoints in the Fas pathway.
Fiorucci Stefano,Antonelli Elisabetta,Mencarelli Andrea,Palazzetti Barbara,Alvarez-Miller Lorena,Muscara Marcelo,del Soldato Piero,Sanpaolo Laura,Wallace John L,Morelli Antonio
British journal of pharmacology
NCX-701 is a nitric oxide (NO)-releasing acetaminophen (APAP) derivative. In the present study we demonstrated that NCX-701 is as effective as APAP in controlling body temperature in a rat model of endotoxin-induced fever. Liver toxicity is a major complication of APAP overdosing. To investigate whether NCX-701 is hepatotoxic, BALB/C mice were injected with 100 - 500 mg kg(-1) APAP or NCX-701 alone or in combination (i.e. 500 mg kg(-1) of both compounds). Our results demonstrated that although APAP caused a dose-dependent liver injury, NCX-701 was completely devoid of liver toxicity. At the dose of 500 mg kg(-1) APAP caused an approximately 40 fold increase of AST plasma levels and extensive centrilobular necrosis. APAP and NCX-701 share the same metabolic pathway as demonstrated by the time-course of APAP-glucuronide concentrations in plasma and liver. NCX-701 was safe in mice with pre-existing chronic liver disease. Indeed, while C57BL6 transgenic mice expressing the hepatitis B virus (HBV) at the age of 8 months were significantly more susceptible to liver damage induced by APAP (500 mg kg(-1)) than their congenic littermates, treating HBV-transgenic mice with NCX-701, 500 mg kg(-1), caused no damage. Co-administration of NCX-701 at the dose 500 mg kg(-1) to mice treated with APAP, 500 mg kg(-1), completely protected against liver damage induced by APAP. APAP, but not NCX-701, upregulated liver Fas and Fas Ligand mRNA expression in vivo. Incubating mouse hepatocytes with APAP, but not with NCX-701, increased cell surface Fas expression and sensitized hepatocytes to death induced by challenge with a Fas-agonistic antibody. Collectively, these observations suggest that APAP toxicity is Fas mediated and that NCX-701 spares the liver by acting at several checkpoints in the Fas pathway.
10.1038/sj.bjp.0704500
A new histone deacetylase inhibitor improves liver fibrosis in BDL rats through suppression of hepatic stellate cells.
Park Ki Cheong,Park Ji Hyun,Jeon Jeong Yong,Kim Sang Yong,Kim Jung Min,Lim Chang Yong,Lee Tae Hyung,Kim Hyung Kwan,Lee Hyun Gyu,Kim Sung Min,Kwon Ho Jeong,Suh Jin Suck,Kim Seung Won,Choi Seung Hoon
British journal of pharmacology
BACKGROUND AND PURPOSE:Activation of hepatic stellate cells (HSCs) is a crucial step in the pathogenesis of hepatic fibrosis. Histone deacetylase (HDAC) is an attractive target in liver fibrosis because it plays a key role in gene expression and cell differentiation. We have developed a HDAC inhibitor, N-hydroxy-7-(2-naphthylthio)heptanomide (HNHA), and investigated the anti-fibrotic activity of HNHA in vitro and in vivo. EXPERIMENTAL APPROACH:We investigated the anti-fibrotic effect of HNHA on mouse and human HSC activation in vitro and in the liver of bile duct-ligated (BDL) rats in vivo using cell proliferation assays, cell cycle analysis, biochemical assay, immunohistochemistry and Western blots. Liver pathology was assessed with histochemical techniques. KEY RESULTS:HNHA inhibited proliferation and arrested the cell cycle via p21 induction in HSCs. In addition, HNHA induced apoptosis of HSCs, which was correlated with reduced COX-2 expression, NF-κB activation and cell death signals. HNHA restored liver function and decreased the accumulation of extracellular matrix in the liver via suppression of HSC activation in BDL rats in vivo. HNHA administration also increased survival in BDL rats. CONCLUSIONS AND IMPLICATIONS:HNHA improved liver function, suppressed liver fibrosis and increased survival of BDL rats, accompanied by reduction of cell growth, activation and survival of HSCs. These findings show that HNHA may be a potent anti-fibrosis agent against hepatic fibrosis because of its multi-targeted inhibition of HSC activity in vivo and in vitro.
10.1111/bph.12590
Inhibition of TGF-beta signaling by an ALK5 inhibitor protects rats from dimethylnitrosamine-induced liver fibrosis.
de Gouville Anne-Charlotte,Boullay Valerie,Krysa Gael,Pilot Julia,Brusq Jean-Marie,Loriolle Florence,Gauthier Jean-Michel,Papworth Stephen A,Laroze Alain,Gellibert Françoise,Huet Stephane
British journal of pharmacology
1 Chronic liver disease is characterized by an exacerbated accumulation of matrix, causing progressive fibrosis, which may lead to cirrhosis. Transforming growth factor beta (TGF-beta), a well-known profibrotic cytokine, transduces its signal through the ALK5 ser/thr kinase receptor, and increases transcription of different genes including PAI-1 and collagens. The identification of GW6604 (2-phenyl-4-(3-pyridin-2-yl-1H-pyrazol-4-yl)pyridine), an ALK5 inhibitor, allowed us to evaluate the therapeutic potential of inhibiting TGF-beta pathway in different models of liver disease. 2 A cellular assay was used to identify GW6604 as a TGF-beta signaling pathway inhibitor. This ALK5 inhibitor was then tested in a model of liver hepatectomy in TGF-beta-overexpressing transgenic mice, in an acute model of liver disease and in a chronic model of dimethylnitrosamine (DMN)-induced liver fibrosis. 3 In vitro, GW6604 inhibited autophosphorylation of ALK5 with an IC(50) of 140 nM and in a cellular assay inhibited TGF-beta-induced transcription of PAI-1 (IC(50): 500 nM). In vivo, GW6604 (40 mg kg(-1) p.o.) increased liver regeneration in TGF-beta-overexpressing mice, which had undergone partial hepatectomy. In an acute model of liver disease, GW6604 reduced by 80% the expression of collagen IA1. In a chronic model of DMN-induced fibrosis where DMN was administered for 6 weeks and GW6604 dosed for the last 3 weeks (80 mg kg(-1) p.o., b.i.d.), mortality was prevented and DMN-induced elevations of mRNA encoding for collagen IA1, IA2, III, TIMP-1 and TGF-beta were reduced by 50-75%. Inhibition of matrix genes overexpression was accompanied by reduced matrix deposition and reduction in liver function deterioration, as assessed by bilirubin and liver enzyme levels. 4 Our results suggest that inhibition of ALK5 could be an attractive new approach to treatment of liver fibrotic diseases by both preventing matrix deposition and promoting hepatocyte regeneration.
10.1038/sj.bjp.0706172
The peripheral CB receptor antagonist JD5037 attenuates liver fibrosis via a CB receptor/β-arrestin1/Akt pathway.
Tan Siwei,Liu Huiling,Ke Bilun,Jiang Jie,Wu Bin
British journal of pharmacology
BACKGROUND AND PURPOSE:Liver fibrosis is a serious cause of morbidity and mortality worldwide and has no adequate treatment. Accumulating evidence suggests that cannabinoid CB receptors regulate a variety of physiological and pathological processes in the liver, and blockage of CB receptor signalling shows promise as a new therapy for several liver diseases. The aim of this study was to investigate the potential therapeutic effects of CB receptors and a peripheral CB receptor antagonist JD5037 in liver fibrogenesis. EXPERIMENTAL APPROACH:Liver samples from both humans and mouse models were investigated. The peripheral CB receptor antagonist JD5037, β-arr1 wild type (β-arr1-WT) and β-arr1 knockout (β-arr1-KO) littermate models, and primary hepatic stellate cells (HSCs) were also used. The mechanisms underlying CB receptor-regulated HSCs activation in fibrosis and the therapeutic potential of JD5037 were further analysed. KEY RESULTS:CB receptors were induced in samples from patients with liver fibrosis and from mouse models. These receptors promoted activation of HSCs in liver fibrosis via recruiting β-arrestin1 and Akt signalling, while blockage of CB receptors with JD5037 attenuated CB receptor-regulated HSCs activation and liver fibrosis by suppressing β-arrestin1/Akt signalling. CONCLUSIONS AND IMPLICATIONS:CB receptors promote the activation of HSCs and liver fibrosis via the β-arrestin1/Akt signalling pathway. The peripheral CB receptor antagonist JD5037 blocked this pathway, the activation of HSCs and liver fibrosis. This compound and the associated pathway may be a novel approach to the treatment of liver fibrosis.
10.1111/bph.15010
Cortistatin regulates fibrosis and myofibroblast activation in experimental hepatotoxic- and cholestatic-induced liver injury.
British journal of pharmacology
BACKGROUND AND PURPOSE:Liver fibrosis induced by chronic hepatic injury remains a major cause of morbidity and mortality worldwide. Identification of susceptibility/prognosis factors and new therapeutic tools for treating hepatic fibrotic disorders are urgent medical needs. Cortistatin is a neuropeptide with potent anti-inflammatory and anti-fibrotic activities in lung that binds to receptors that are expressed in liver fibroblasts and hepatic stellate cells. We evaluated the capacity of cortistatin to regulate liver fibrosis. EXPERIMENTAL APPROACH:We experimentally induced liver fibrosis in mice by chronic CCl exposure and bile duct ligation and evaluated the histopathological signs and fibrotic markers. KEY RESULTS:Hepatic expression of cortistatin inversely correlated with liver fibrosis grade in mice and humans with hepatic disorders. Cortistatin-deficient mice showed exacerbated signs of liver damage and fibrosis and increased mortality rates when challenged by hepatotoxic and cholestatic injury. Compared with wild-type mice, non-parenchymal liver cells isolated from cortistatin-deficient mice showed increased presence of cells with activated myofibroblast phenotypes and a differential genetic signature that is indicative of activated hepatic stellate cells and periportal fibroblasts and of myofibroblasts with active contractile apparatus. Cortistatin treatment reversed in vivo and in vitro these exaggerated fibrogenic phenotypes and protected from progression to severe liver fibrosis in response to hepatic injury. CONCLUSION AND IMPLICATIONS:We identify cortistatin as an endogenous molecular brake on liver fibrosis and its deficiency as a potential poor-prognosis marker for chronic hepatic disorders that link with fibrosis. Cortistatin-based therapies emerge as attractive strategies for ameliorating severe hepatic fibrosis of various aetiologies.
10.1111/bph.15752
Morin, a novel liver X receptor α/β dual antagonist, has potent therapeutic efficacy for nonalcoholic fatty liver diseases.
Gu Ming,Zhang Yu,Liu Chuhe,Wang Dongshan,Feng Li,Fan Shengjie,Yang Baican,Tong Qingchun,Ji Guang,Huang Cheng
British journal of pharmacology
BACKGROUND AND PURPOSE:Morin is a natural occurring flavonoid in many dietary plants and has a wide range of beneficial effects on metabolism; however, the mechanism underlying its action remains elusive. EXPERIMENTAL APPROACH:A reporter assay and the time-resolved FRET assay were used to identify morin as a dual antagonist of liver X receptor (LXR)-α and -β. Morin (100 mg 100 g diet) was administered to high-fat diet-induced obese or LXRβ mice. The pharmacological effects and mechanism of action of morin were evaluated by Western blot and RT-PCR analyses. KEY RESULTS:From the in vitro assays, morin was shown to be a dual antagonist of LXRα and LXRβ. In vivo, morin blunted the development of liver hepatic steatosis, reduced body weight gains, lowered triglyceride levels and improved glucose and insulin tolerance in mice fed a high-fat diet. Mechanistically, morin inhibited 3T3-L1 adipocyte differentiation and lipid formation in human hepatic HepG2 cells and suppressed the mRNA expression of genes downstream of LXR. Consistently, the effects of morin on metabolic disorders were attenuated in LXRβ mice. CONCLUSION AND IMPLICATIONS:Our data reveal that morin is a dual antagonist of LXRα and LXRβ and suggest that morin may alleviate hepatic steatosis and other associated metabolic disorders via the suppression of LXR signalling and, therefore, shows promise as a novel therapy or nutraceutical for nonalcoholic fatty liver disease.
10.1111/bph.13933
Upregulation of cytochromes P450 2B in rat liver by orphenadrine.
British journal of pharmacology
1 The alkylamine drug orphenadrine (ORPH) is an inducer and inhibitor of the microsomal cytochrome P450 (CYP) system in mammals. This study evaluated the selectivity of CYP induction by ORPH in rat liver. 2 Immunoblot analysis indicated that ORPH was a selective inducer of the phenobarbitone (PB)-inducible CYP2B in rat liver. CYP2B protein was increased to approximately 14-fold of levels in untreated rat liver. By comparison PB increased CYP2B expression 40-fold. Corresponding increases in the activity of CYP2B-dependent androstenedione 16beta-hydroxylation were measured in microsomes from ORPH and PB-induced rats. 3 Northern analysis indicated that CYP2B1/2 mRNA was increased in ORPH-induced rat liver. Consistent with this finding, ORPH was found to activate a PB-responsive enhancer module in constitutive androstane receptor (CAR)-transfected Hep G2 cells. 4 Other alkylamines like troleandomycin impair CYP turnover. We tested whether ORPH induction of CYP2B may include a post-translational component. In PB-pretreated animals ORPH administration delayed the loss of CYP2B after PB withdrawal, but no evidence for altered turnover was found. 5 These studies establish ORPH as a selective inducer of CYP2B in rat liver. Induction appears to be mediated pretranslationally by CAR activation of CYP2B gene transcription. Post-translational stabilisation by an ORPH metabolite does not elicit induction. Induction of CYP2B may influence pharmacokinetic interactions involving ORPH.
10.1038/sj.bjp.0705305
Liver delivery of NO by NCX-1000 protects against acute liver failure and mitochondrial dysfunction induced by APAP in mice.
Fiorucci Stefano,Antonelli Elisabetta,Distrutti Eleonora,Mencarelli Andrea,Farneti Silvana,Del Soldato Piero,Morelli Antonio
British journal of pharmacology
1. NCX-1000, (3alpha, 5beta, 7beta)-3,7-dihydroxycholan-24oic acid[2-methoxy-4-[3-[4-(nitroxy)butoxy]-3-oxo-1-propenyl]phenyl ester, is a nitric oxide (NO)-derivative of ursodeoxyxholic acid (UDCA) that selectively release NO in the liver. 2. Here, we demonstrated that administering mice with 40 micromol kg(-1) NCX-1000, but not UDCA, improves liver histopathology and reduces mortality caused by 330 micromol kg(-1) APAP from 60 to 25% (P<0.01). Administration of NCX-1000, in a therapeutic manner, that is, 2 h after acetaminophen (APAP) intoxication reduced mortality, improved liver histopathology and prevented liver IFN-gamma, TNF-alpha, Fas/Fas ligand and inducible nitric oxide synthase (iNOS) mRNA accumulation caused by APAP. 3. In vitro exposure of primary cultures of mouse hepatocytes to APAP, 6.6 mm, resulted in apoptosis followed by necrosis. Loss of cell viability correlates with early mitochondrial membrane potential (Deltapsi(m)) hyperpolarization followed by depolarization and cytochrome c translocation from mitochondria to cytosol. APAP-induced apoptosis associated with procaspase-3 and -9 cleavage, appearance of truncated Bid and activation of poly(ADP-ribose) polymerase (PARP). 4. Treating primary culture of hepatocytes with 5 microm cyclosporine and 10 microm trifluoperazine for eight resulted in significant reduction of apoptosis induced by APAP suggesting that loss of Deltapsim was mechanistically involved in apoptosis induced by APAP in vitro. 5. NCX-1000, but not UDCA, concentration-dependently (ED(50)=16 microm) protected against Deltapsi(m) depolarization and reduced transition from apoptosis to necrosis caused by 6.6 mm APAP. 6. Treating primary cultures of hepatocytes with the NO-donor DETA-NO, 100 microm, reduced apoptosis induced by APAP and prevented caspase activation. 7. In conclusion, NCX-1000 is effective in protecting against APAP-induced hepatotoxicity when administered in a therapeutic manner. This protection may involve the inhibition of apoptosis and the maintenance of mitochondrial integrity.
10.1038/sj.bjp.0705780