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1.
J Med Chem ; 64(3): 1454-1480, 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33492963

RESUMO

Sphingosine-1-phosphate (S1P) binds to a family of sphingosine-1-phosphate G-protein-coupled receptors (S1P1-5). The interaction of S1P with these S1P receptors has a fundamental role in many physiological processes in the vascular and immune systems. Agonist-induced functional antagonism of S1P1 has been shown to result in lymphopenia. As a result, agonists of this type hold promise as therapeutics for autoimmune disorders. The previously disclosed differentiated S1P1 modulator BMS-986104 (1) exhibited improved preclinical cardiovascular and pulmonary safety profiles as compared to earlier full agonists of S1P1; however, it demonstrated a long pharmacokinetic half-life (T1/2 18 days) in the clinic and limited formation of the desired active phosphate metabolite. Optimization of this series through incorporation of olefins, ethers, thioethers, and glycols into the alkyl side chain afforded an opportunity to reduce the projected human T1/2 and improve the formation of the active phosphate metabolite while maintaining efficacy as well as the improved safety profile. These efforts led to the discovery of 12 and 24, each of which are highly potent, biased agonists of S1P1. These compounds not only exhibited shorter in vivo T1/2 in multiple species but are also projected to have significantly shorter T1/2 values in humans when compared to our first clinical candidate. In models of arthritis, treatment with 12 and 24 demonstrated robust efficacy.

2.
ACS Med Chem Lett ; 11(9): 1766-1772, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32944145

RESUMO

Efforts aimed at increasing the in vivo potency and reducing the elimination half-life of 1 and 2 led to the identification of aryl ether and thioether-derived bicyclic S1P1 differentiated modulators 3-6. The effects of analogs 3-6 on lymphocyte reduction in the rat (desired pharmacology) along with pulmonary- and cardiovascular-related effects (undesired pharmacology) are described. Optimization of the overall properties in the aryl ether series yielded 3d, and the predicted margin of safety against the cardiovascular effects of 3d would be large enough for human studies. Importantly, compared to 1 and 2, compound 3d had a better profile in both potency (ED50 < 0.05 mg/kg) and predicted human half-life (t 1/2 ∼ 5 days).

3.
Semin Nephrol ; 39(2): 159-175, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30827339

RESUMO

The kidney plays a critical role in the elimination of many xenobiotics, and drug-induced kidney injury is a risk factor in drug discovery and development. In addition, accumulation of nephrotoxic compounds, a process often controlled by xenobiotic transporters, is often a prerequisite to kidney injury. Such adverse events are dependent on many transporters, particularly those in the solute carrier and adenosine triphosphate-binding cassette superfamilies. This review details the current understanding of how kidney transporters contribute to toxic outcomes and highlights critical knowledge gaps regarding species differences that account for some lack of predictivity between preclinical animal models and human beings. The basic classification, physiological roles, and species differences of solute carrier and adenosine triphosphate-binding cassette transporters is reviewed, along with mechanistic details for drug-induced kidney injury involving transporters. The use of preclinical data (in vitro and in vivo), clinical data, and conventional as well as emerging tools for studying kidney transporter function are summarized. Finally, we highlight some challenges and opportunities to improve experimental approaches to support preclinical and clinical studies of kidney transporters and their role in nephrotoxicity.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Lesão Renal Aguda/induzido quimicamente , Insuficiência Renal Crônica/induzido quimicamente , Proteínas Carreadoras de Solutos/metabolismo , Lesão Renal Aguda/metabolismo , Humanos , Túbulos Renais/metabolismo , Insuficiência Renal Crônica/metabolismo , Xenobióticos
4.
J Med Chem ; 62(5): 2265-2285, 2019 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-30785748

RESUMO

Recently, our research group reported the identification of BMS-986104 (2) as a differentiated S1P1 receptor modulator. In comparison to fingolimod (1), a full agonist of S1P1 currently marketed for the treatment of relapse remitting multiple sclerosis (RRMS), 2 offers several potential advantages having demonstrated improved safety multiples in preclinical evaluations against undesired pulmonary and cardiovascular effects. In clinical trials, 2 was found to exhibit a pharmacokinetic half-life ( T1/2) longer than that of 1, as well as a reduced formation of the phosphate metabolite that is required for activity against S1P1. Herein, we describe our efforts to discover highly potent, partial agonists of S1P1 with a shorter T1/2 and increased in vivo phosphate metabolite formation. These efforts culminated in the discovery of BMS-986166 (14a), which was advanced to human clinical evaluation. The pharmacokinetic/pharmacodynamic (PK/PD) relationship as well as pulmonary and cardiovascular safety assessments are discussed. Furthermore, efficacy of 14a in multiple preclinical models of autoimmune diseases are presented.


Assuntos
Ensaios Clínicos como Assunto , Naftalenos/farmacologia , Receptores de Esfingosina-1-Fosfato/agonistas , Tetra-Hidronaftalenos/farmacologia , Animais , Líquido da Lavagem Broncoalveolar , Relação Dose-Resposta a Droga , Meia-Vida , Humanos , Naftalenos/química , Naftalenos/farmacocinética , Ratos , Ratos Endogâmicos Lew , Tetra-Hidronaftalenos/química , Tetra-Hidronaftalenos/farmacocinética
5.
Obesity (Silver Spring) ; 25(6): 1069-1076, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28452429

RESUMO

OBJECTIVE: Characteristic pathological changes define the progression of steatosis to nonalcoholic steatohepatitis (NASH) and are correlated to metabolic pathways. A common rodent model of NASH is the methionine and choline deficient (MCD) diet. The objective of this study was to perform full metabolomic analyses on liver samples to determine which pathways are altered most pronouncedly in this condition in humans, and to compare these changes to rodent models of nonalcoholic fatty liver disease (NAFLD). METHODS: A principal component analysis for all 91 metabolites measured indicated that metabolome perturbation is greater and less varied for humans than for rodents. RESULTS: Metabolome changes in human and rat NAFLD were greatest for the amino acid and bile acid metabolite families (e.g., asparagine, citrulline, gamma-aminobutyric acid, lysine); although, in many cases, the trends were reversed when compared between species (cholic acid, betaine). CONCLUSIONS: Overall, these results indicate that metabolites of specific pathways may be useful biomarkers for NASH progression, although these markers may not correspond to rodent NASH models. The MCD model may be useful when studying certain end points of NASH; however, the metabolomics results indicate important differences between humans and rodents in the biochemical pathogenesis of the disease.


Assuntos
Metabolômica/métodos , Obesidade/complicações , Animais , Dieta , Progressão da Doença , Humanos , Fígado/patologia , Masculino , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ratos , Ratos Sprague-Dawley
6.
Toxicol Sci ; 155(2): 379-388, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28025230

RESUMO

The objective of this work was to investigate the mechanisms of hepatobiliary toxicity caused by thienopyrimidone MCHR1 antagonists using BMS-773174 as a tool molecule. Co-administration of the pan CYP inhibitor 1-aminobenzotriazole with BMS-773174 prevented hepatobiliary damage, and direct delivery of the diol metabolite BMS-769750 caused hepatobiliary toxicity, identifying the diol and possibly its downstream hydroxyacid (BMS-800754) metabolite as the toxic species. Rat liver gene expression revealed treatment-related changes in hepatic transporters and induction of oval cell-specific genes including deleted malignant tumor 1 (Dmbt1). The metabolites did not alter hepatic transporter activities, suggesting that transporter-mediated cholestasis was not involved. Because injury to biliary epithelium can result in adaptive hyperplasia, rat biliary epithelial cells (BECs) were isolated and exposed to the oxidative metabolites. BMS-769750 was cytotoxic to BECs, but not rat hepatocytes, suggesting a role of the diol in biliary epithelial injury. BMS-800754 was cytotoxic to rat hepatocytes therefore its contribution to hepatocyte injury in rats is a possibility. Induction of Dmbt1 in rat BECs was investigated because of its role in hepatic progenitor cell differentiation/proliferation during injury. Dmbt1 mRNA was induced by BMS-769750, but not BMS-800754 in BECs; this induction and cellular injury was confirmed with diol metabolites formed by other compounds with the same hepatobiliary liability. In conclusion, hepatobiliary injury by thienopyrimidinone MCHR1 antagonists was driven through a CYP-mediated bioactivation pathway. Induction of Dmbt1 mRNA coupled with cellular injury suggests that injury of biliary epithelium may be the first step toward an adaptive proliferative response causing BDH by these compounds.


Assuntos
Sistema Biliar/efeitos dos fármacos , Compostos Heterocíclicos com 2 Anéis/farmacologia , Fígado/efeitos dos fármacos , Receptores de Somatostatina/antagonistas & inibidores , Animais , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Compostos Heterocíclicos com 2 Anéis/química , Fígado/metabolismo , Masculino , Microscopia Eletrônica de Transmissão , Ratos , Ratos Sprague-Dawley
7.
Medchemcomm ; 8(4): 725-729, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30108791

RESUMO

Recently, our research group reported the identification of prodrug amino-alcohol 2 as a potent and efficacious S1P1 receptor modulator. This molecule is differentiated preclinically over the marketed drug fingolimod (Gilenya 1), whose active phosphate metabolite is an S1P1 full agonist, in terms of pulmonary and cardiovascular safety. S1P1 partial agonist 2, however, has a long half-life in rodents and was projected to have a long half-life in humans. The purpose of this communication is to disclose highly potent partial agonists of S1P1 with shorter half-lives relative to the clinical compound 2. PK/PD relationships as well as their preclinical pulmonary and cardiovascular safety assessment are discussed.

8.
Anal Chim Acta ; 945: 57-66, 2016 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-27968716

RESUMO

LC-MS/MS has been widely applied to the quantitative analysis of tissue samples. However, one key remaining issue is that the extraction recovery of analyte from spiked tissue calibration standard and quality control samples (QCs) may not accurately represent the "true" recovery of analyte from incurred tissue samples. This may affect the accuracy of LC-MS/MS tissue bioanalysis. Here, we investigated whether the recovery determined using tissue QCs by LC-MS/MS can accurately represent the "true" recovery from incurred tissue samples using two model compounds: BMS-986104, a S1P1 receptor modulator drug candidate, and its phosphate metabolite, BMS-986104-P. We first developed a novel acid and surfactant assisted protein precipitation method for the extraction of BMS-986104 and BMS-986104-P from rat tissues, and determined their recoveries using tissue QCs by LC-MS/MS. We then used radioactive incurred samples from rats dosed with 3H-labeled BMS-986104 to determine the absolute total radioactivity recovery in six different tissues. The recoveries determined using tissue QCs and incurred samples matched with each other very well. The results demonstrated that, in this assay, tissue QCs accurately represented the incurred tissue samples to determine the "true" recovery, and LC-MS/MS assay was accurate for tissue bioanalysis. Another aspect we investigated is how the tissue QCs should be prepared to better represent the incurred tissue samples. We compared two different QC preparation methods (analyte spiked in tissue homogenates or in intact tissues) and demonstrated that the two methods had no significant difference when a good sample preparation was in place. The developed assay showed excellent accuracy and precision, and was successfully applied to the quantitative determination of BMS-986104 and BMS-986104-P in tissues in a rat toxicology study.


Assuntos
Modelos Químicos , Animais , Cromatografia Líquida , Ratos , Padrões de Referência , Espectrometria de Massas em Tandem
9.
J Med Chem ; 59(24): 11138-11147, 2016 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-28002964

RESUMO

We describe a highly efficient route for the synthesis of 4a (BMS-986104). A key step in the synthesis is the asymmetric hydroboration of trisubstituted alkene 6. Particularly given the known difficulties involved in this type of transformation (6 → 7), the current methodology provides an efficient approach to prepare this class of compounds. In addition, we disclose the efficacy of 4a in a mouse EAE model, which is comparable to 4c (FTY720). Mechanistically, 4a exhibited excellent remyelinating effects on lysophosphatidylcholine (LPC) induced demyelination in a three-dimensional brain cell culture assay.


Assuntos
Encefalomielite Autoimune Experimental/tratamento farmacológico , Naftalenos/farmacologia , Receptores de Lisoesfingolipídeo/agonistas , Animais , Células Cultivadas , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Células HEK293 , Humanos , Linfócitos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Estrutura Molecular , Naftalenos/síntese química , Naftalenos/química , Relação Estrutura-Atividade
10.
J Med Chem ; 59(21): 9837-9854, 2016 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-27726358

RESUMO

Fingolimod (1) is the first approved oral therapy for the treatment of relapsing remitting multiple sclerosis. While the phosphorylated metabolite of fingolimod was found to be a nonselective S1P receptor agonist, agonism specifically of S1P1 is responsible for the peripheral blood lymphopenia believed to be key to its efficacy. Identification of modulators that maintain activity on S1P1 while sparing activity on other S1P receptors could offer equivalent efficacy with reduced liabilities. We disclose in this paper a ligand-based drug design approach that led to the discovery of a series of potent tricyclic agonists of S1P1 with selectivity over S1P3 and were efficacious in a pharmacodynamic model of suppression of circulating lymphocytes. Compound 10 had the desired pharmacokinetic (PK) and pharmacodynamic (PD) profile and demonstrated maximal efficacy when administered orally in a rat adjuvant arthritis model.


Assuntos
Desenho de Fármacos , Cloridrato de Fingolimode/farmacologia , Compostos Heterocíclicos com 3 Anéis/farmacologia , Receptores de Lisoesfingolipídeo/agonistas , Animais , Artrite Experimental/tratamento farmacológico , Artrite Experimental/imunologia , Cães , Relação Dose-Resposta a Droga , Cloridrato de Fingolimode/administração & dosagem , Cloridrato de Fingolimode/química , Adjuvante de Freund/administração & dosagem , Compostos Heterocíclicos com 3 Anéis/administração & dosagem , Compostos Heterocíclicos com 3 Anéis/química , Ligantes , Linfócitos/efeitos dos fármacos , Macaca fascicularis , Masculino , Camundongos , Estrutura Molecular , Mycobacterium/efeitos dos fármacos , Ratos , Ratos Endogâmicos Lew , Relação Estrutura-Atividade , Distribuição Tecidual
11.
ACS Med Chem Lett ; 7(3): 283-8, 2016 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-26985316

RESUMO

Clinical validation of S1P receptor modulation therapy was achieved with the approval of fingolimod (Gilenya, 1) as the first oral therapy for relapsing remitting multiple sclerosis. However, 1 causes a dose-dependent reduction in the heart rate (bradycardia), which occurs within hours after first dose. We disclose the identification of clinical compound BMS-986104 (3d), a novel S1P1 receptor modulator, which demonstrates ligand-biased signaling and differentiates from 1 in terms of cardiovascular and pulmonary safety based on preclinical pharmacology while showing equivalent efficacy in a T-cell transfer colitis model.

12.
Amino Acids ; 47(3): 603-15, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25534430

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is a globally widespread disease of increasing clinical significance. The pathological progression of the disease from simple steatosis to nonalcoholic steatohepatitis (NASH) has been well defined, however, the contribution of altered branched chain amino acid metabolomic profiles to the progression of NAFLD is not known. The three BCAAs: leucine, isoleucine and valine are known to mediate activation of several important hepatic metabolic signaling pathways ranging from insulin signaling to glucose regulation. The purpose of this study is to profile changes in hepatic BCAA metabolite levels with transcriptomic changes in the progression of human NAFLD to discover novel mechanisms of disease progression. Metabolomic and transcriptomic data sets representing the spectrum of human NAFLD (normal, steatosis, NASH fatty, and NASH not fatty livers) were utilized for this study. During the transition from steatosis to NASH, increases in the levels of leucine (127% of normal), isoleucine (139%), and valine (147%) were observed. Carnitine metabolites also exhibited significantly elevated profiles in NASH fatty and NASH not fatty samples and included propionyl, hexanoyl, lauryl, acetyl and butyryl carnitine. Amino acid and BCAA metabolism gene sets were significantly enriched among downregulated genes during NASH. These cumulative alterations in BCAA metabolite and amino acid metabolism gene profiles represent adaptive physiological responses to disease-induced hepatic stress in NASH patients.


Assuntos
Isoleucina/metabolismo , Leucina/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Valina/metabolismo , Carnitina/genética , Carnitina/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Isoleucina/genética , Leucina/genética , Masculino , Metabolômica , Hepatopatia Gordurosa não Alcoólica/genética , Transdução de Sinais/genética , Valina/genética
13.
Dig Dis Sci ; 59(2): 365-74, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24048683

RESUMO

BACKGROUND: The worldwide prevalences of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are estimated to range from 30 to 40 % and 5-17 %, respectively. Hepatocellular carcinoma (HCC) is primarily caused by hepatitis B infection, but retrospective data suggest that 4-29 % of NASH cases will progress to HCC. Currently the connection between NASH and HCC is unclear. AIMS: The purpose of this study was to identify changes in expression of HCC-related genes and metabolite profiles in NAFLD progression. METHODS: Transcriptomic and metabolomic datasets from human liver tissue representing NAFLD progression (normal, steatosis, NASH) were utilized and compared to published data for HCC. RESULTS: Genes involved in Wnt signaling were downregulated in NASH but have been reported to be upregulated in HCC. Extracellular matrix/angiogenesis genes were upregulated in NASH, similar to reports in HCC. Iron homeostasis is known to be perturbed in HCC and we observed downregulation of genes in this pathway. In the metabolomics analysis of hepatic NAFLD samples, several changes were opposite to what has been reported in plasma of HCC patients (lysine, phenylalanine, citrulline, creatine, creatinine, glycodeoxycholic acid, inosine, and alpha-ketoglutarate). In contrast, multiple acyl-lyso-phosphatidylcholine metabolites were downregulated in NASH livers, consistent with observations in HCC patient plasma. CONCLUSIONS: These data indicate an overlap in the pathogenesis of NAFLD and HCC where several classes of HCC related genes and metabolites are altered in NAFLD. Importantly, Wnt signaling and several metabolites are different, thus implicating these genes and metabolites as mediators in the transition from NASH to HCC.


Assuntos
Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Carcinoma Hepatocelular/patologia , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Análise por Conglomerados , Bases de Dados Genéticas , Fígado Gorduroso/patologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologia , Metabolômica , Hepatopatia Gordurosa não Alcoólica , Transdução de Sinais/genética
14.
BMC Genomics ; 14: 575, 2013 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-23981290

RESUMO

BACKGROUND: The eyes and skin are obvious retinoid target organs. Vitamin A deficiency causes night blindness and retinoids are widely used to treat acne and psoriasis. However, more than 90% of total body retinol is stored in liver stellate cells. In addition, hepatocytes produce the largest amount of retinol binding protein and cellular retinoic acid binding protein to mobilize retinol from the hepatic storage pool and deliver retinol to its receptors, respectively. Furthermore, hepatocytes express the highest amount of retinoid x receptor alpha (RXRα) among all the cell types. Surprisingly, the function of endogenous retinoids in the liver has received very little attention. RESULTS: Based on the data generated from chromatin immunoprecipitation followed by sequencing, the global DNA binding of transcription factors including retinoid x receptor α (RXRα) along with its partners i.e. retinoic acid receptor α (RARα), pregnane x receptor (PXR), liver x receptor (LXR), farnesoid x receptor (FXR), and peroxisome proliferator-activated receptor α (PPARα) has been established. Based on the binding, functional annotation illustrated the role of those receptors in regulating hepatic lipid homeostasis. To correlate the DNA binding data with gene expression data, the expression patterns of 576 genes that regulate lipid homeostasis were studied in wild type and liver RXRα-null mice treated with and without RA. The data showed that RA treatment and RXRα-deficiency had opposite effects in regulating lipid homeostasis. A subset of genes (114), which could clearly differentiate the effect of ligand treatment and receptor deficiency, were selected for further functional analysis. The expression data suggested that RA treatment could produce unsaturated fatty acids and induce triglyceride breakdown, bile acid secretion, lipolysis, and retinoids elimination. In contrast, RXRα deficiency might induce the synthesis of saturated fatty acids, triglyceride, cholesterol, bile acids, and retinoids. In addition, DNA binding data indicated extensive cross-talk among RARα, PXR, LXR, FXR, and PPARα in regulating those RA/RXRα-dependent gene expression levels. Moreover, RA reduced serum cholesterol, triglyceride, and bile acid levels in mice. CONCLUSIONS: We have characterized the role of hepatic RA for the first time. Hepatic RA mediated through RXRα and its partners regulates lipid homeostasis.


Assuntos
Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Transcriptoma , Tretinoína/fisiologia , Animais , Ácidos e Sais Biliares/sangue , Sítios de Ligação , Colesterol/sangue , Regulação da Expressão Gênica , Genoma , Homeostase/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligação Proteica , Receptores Citoplasmáticos e Nucleares/metabolismo , Tretinoína/farmacologia , Triglicerídeos/sangue
15.
Biochem Pharmacol ; 86(3): 437-45, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23747753

RESUMO

Organic anion transporting polypeptides (human: OATPs; rodent: Oatps) were thought to have important functions in bile acid (BA) transport. Oatp1a1, 1a4, and 1b2 are the three major Oatp1 family members in rodent liver. Our previous studies have characterized the BA homeostasis in Oatp1a1-null and Oatp1b2-null mice. The present study investigated the physiological role of Oatp1a4 in BA homeostasis by using Oatp1a4-null mice. Oatp1a4 expression is female-predominant in livers of mice, and thereby it was expected that female Oatp1a4-null mice will have more prominent changes than males. Interestingly, the present study demonstrated that female Oatp1a4-null mice had no significant alterations in BA concentrations in serum or liver, though they had increased mRNA of hepatic BA efflux transporters (Mrp4 and Ostα/ß) and ileal BA transporters (Asbt and Ostα/ß). In contrast, male Oatp1a4-null mice showed significantly altered BA homeostasis, including increased concentrations of deoxycholic acid (DCA) in serum, liver and intestinal contents. After feeding a DCA-supplemented diet, male but not female Oatp1a4-null mice had higher concentrations of DCA in serum and livers than their WT controls. This suggested that Oatp1a4 is important for intestinal absorption of secondary BAs in male mice. Furthermore, loss of Oatp1a4 function did not decrease BA accumulation in serum or livers of bile-duct-ligated mice, suggesting that Oatp1a4 is not likely a BA uptake transporter. In summary, the present study for the first time demonstrates that Oatp1a4 does not appear to mediate the hepatic uptake of BAs, but plays an important male-predominant role in secondary BA metabolism in mice.


Assuntos
Ácidos e Sais Biliares/metabolismo , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Animais , Ácidos e Sais Biliares/sangue , Feminino , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fatores Sexuais
16.
Toxicol Appl Pharmacol ; 268(2): 132-40, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23391614

RESUMO

Bile acids (BAs) have many physiological roles and exhibit both toxic and protective influences within the liver. Alterations in the BA profile may be the result of disease induced liver injury. Nonalcoholic fatty liver disease (NAFLD) is a prevalent form of chronic liver disease characterized by the pathophysiological progression from simple steatosis to nonalcoholic steatohepatitis (NASH). The hypothesis of this study is that the 'classical' (neutral) and 'alternative' (acidic) BA synthesis pathways are altered together with hepatic BA composition during progression of human NAFLD. This study employed the use of transcriptomic and metabolomic assays to study the hepatic toxicologic BA profile in progressive human NAFLD. Individual human liver samples diagnosed as normal, steatosis, and NASH were utilized in the assays. The transcriptomic analysis of 70 BA genes revealed an enrichment of downregulated BA metabolism and transcription factor/receptor genes in livers diagnosed as NASH. Increased mRNA expression of BAAT and CYP7B1 was observed in contrast to decreased CYP8B1 expression in NASH samples. The BA metabolomic profile of NASH livers exhibited an increase in taurine together with elevated levels of conjugated BA species, taurocholic acid (TCA) and taurodeoxycholic acid (TDCA). Conversely, cholic acid (CA) and glycodeoxycholic acid (GDCA) were decreased in NASH liver. These findings reveal a potential shift toward the alternative pathway of BA synthesis during NASH, mediated by increased mRNA and protein expression of CYP7B1. Overall, the transcriptomic changes of BA synthesis pathway enzymes together with altered hepatic BA composition signify an attempt by the liver to reduce hepatotoxicity during disease progression to NASH.


Assuntos
Ácidos e Sais Biliares/metabolismo , Fígado Gorduroso/metabolismo , Fígado/efeitos dos fármacos , Ácidos e Sais Biliares/análise , Ácidos e Sais Biliares/genética , Ácidos e Sais Biliares/toxicidade , Análise por Conglomerados , Progressão da Doença , Perfilação da Expressão Gênica , Humanos , Metabolômica , Hepatopatia Gordurosa não Alcoólica
17.
J Clin Transl Hepatol ; 1(1): 51-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26357607

RESUMO

Since the first approval of interferon for the treatment of chronic hepatitis B virus (HBV) infection in 1992, six additional antivirals have been developed: pegylated interferon-alfa2a, and the oral antivirals lamivudine, adefovir, telbivudine, entecavir and tenofovir. The availability of animal models for HBV infection and hepatocyte cell culture led to the discovery and development of oral antivirals targeted at HBV polymerase and reverse transcriptase, which inhibit viral replication. The discovery and development of entecavir, the first oral anti-HBV drug with both potent antiviral activity and a high genetic barrier to resistance, took more than 10 years before it was first approved in the USA. Since then, multiple real-life studies have provided data consistent with the findings of the registration trials and the long-term rollover study in terms of efficacy, resistance, and safety. Data from the long-term follow-up of patients enrolled in the registration studies showed that treatment with entecavir can lead to significant improvements in liver histopathology, and recent cohort studies have demonstrated that treatment with entecavir may reduce disease progression and the development of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B. In addition, real-life studies suggest that entecavir may reduce HCC recurrence and increase survival rates in patients with HBV-related HCC post-surgical resection.

18.
Toxicol Sci ; 131(2): 447-57, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23042729

RESUMO

The mouse embryonic stem cell test (EST) is a 10-day screen for teratogenic potential developed to reduce animal use for embryotoxicity testing of chemicals (Spielmann, 2005; Spielmann et al., 1997). In this study, we used the cytotoxicity IC(50) values and transcriptional expression changes as primary endpoints in a shorter 4-day version of the EST, the molecular embryonic stem cell assay. Mouse D3 embryonic stem cells were used for cytotoxicity assessment (monolayers) or grown as embryoid bodies in low attachment plates for transcriptional profiling. Sixty-five compounds with known in vivo teratogenicity (33 teratogens and 32 nonteratogens) were evaluated to develop a model for classifying compounds with teratogenic potential. The expression of 12 developmentally regulated gene targets (nanog, fgf5, gsc, cd34, axin2, apln, chst7, lhx1, fgf8, sox17, foxa2, and cxcr4) was measured following exposure of embryoid bodies to a single compound concentration (0.1 × the cytotoxicity IC(20)) for 4 days. In the decision-tree model, compounds with IC(50) values < 22 µM were categorized as teratogens, whereas compounds in the two groups with IC(50) values between 22-200 µM and > 200 µM were categorized as teratogens if ≥ 8 and 12 genes, respectively, were deregulated by at least 10%. Forty-seven of 65 compounds of the training set were correctly identified (72% total concordance). In a test set of 12 additional compounds (5 teratogens, 7 nonteratogens), 10 were correctly classified by this approach (83% concordance). The false positive rate in the training and test sets was 24 and 0%, respectively, indicating that this assay has potential to identify teratogens.


Assuntos
Células-Tronco Embrionárias/efeitos dos fármacos , Teratogênios/toxicidade , Animais , Diferenciação Celular , Linhagem Celular , DNA Complementar/genética , Concentração Inibidora 50 , Camundongos , Modelos Teóricos , Reação em Cadeia da Polimerase
19.
PLoS One ; 7(4): e34522, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22496825

RESUMO

Organic anion transporting polypeptide 1a1 (Oatp1a1) is predominantly expressed in liver and is able to transport bile acids (BAs) in vitro. Male Oatp1a1-null mice have increased concentrations of taurodeoxycholic acid (TDCA), a secondary BA generated by intestinal bacteria, in both serum and livers. Therefore, in the present study, BA concentrations and intestinal bacteria in wild-type (WT) and Oatp1a1-null mice were quantified to investigate whether the increase of secondary BAs in Oatp1a1-null mice is due to alterations in intestinal bacteria. The data demonstrate that Oatp1a1-null mice : (1) have similar bile flow and BA concentrations in bile as WT mice; (2) have a markedly different BA composition in the intestinal contents, with a decrease in conjugated BAs and an increase in unconjugated BAs; (3) have BAs in the feces that are more deconjugated, desulfated, 7-dehydroxylated, 3-epimerized, and oxidized, but less 7-epimerized; (4) have 10-fold more bacteria in the small intestine, and 2-fold more bacteria in the large intestine which is majorly due to a 200% increase in Bacteroides and a 30% reduction in Firmicutes; and (5) have a different urinary excretion of bacteria-related metabolites than WT mice. In conclusion, the present study for the first time established that lack of a liver transporter (Oatp1a1) markedly alters the intestinal environment in mice, namely the bacteria composition.


Assuntos
Bactérias/crescimento & desenvolvimento , Ácidos e Sais Biliares/metabolismo , Intestinos/microbiologia , Intestinos/patologia , Proteínas de Transporte de Cátions Orgânicos/fisiologia , Animais , Bactérias/genética , Bactérias/metabolismo , DNA Bacteriano/genética , DNA Ribossômico/genética , Fezes/microbiologia , Mucosa Intestinal/metabolismo , Fígado/citologia , Fígado/metabolismo , Masculino , Metaboloma , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase
20.
Toxicol Sci ; 127(2): 331-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22461448

RESUMO

Toxicology and careers in toxicology, as well as many other scientific disciplines, are undergoing rapid and dramatic changes as new discoveries, technologies, and hazards advance at a blinding rate. There are new and ever increasing demands on toxicologists to keep pace with expanding global economies, highly fluid policy debates, and increasingly complex global threats to public health. These demands must be met with new paradigms for multidisciplinary, technologically complex, and collaborative approaches that require advanced and continuing education in toxicology and associated disciplines. This requires paradigm shifts in educational programs that support recruitment, development, and training of the modern toxicologist, as well as continued education and retraining of the midcareer professional to keep pace and sustain careers in industry, government, and academia. The Society of Toxicology convened the Toxicology Educational Summit to discuss the state of toxicology education and to strategically address educational needs and the sustained advancement of toxicology as a profession. The Summit focused on core issues of: building for the future of toxicology through educational programs; defining education and training needs; developing the "Total Toxicologist"; continued training and retraining toxicologists to sustain their careers; and, finally, supporting toxicology education and professional development. This report summarizes the outcomes of the Summit, presents examples of successful programs that advance toxicology education, and concludes with strategies that will insure the future of toxicology through advanced educational initiatives.


Assuntos
Educação Profissionalizante/tendências , Toxicologia/educação , Toxicologia/tendências , Comportamento Cooperativo , Currículo/tendências , Bolsas de Estudo/tendências , Previsões , Humanos , Relações Interinstitucionais , Determinação de Necessidades de Cuidados de Saúde/tendências , Competência Profissional , Apoio à Pesquisa como Assunto/tendências
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