Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Science ; 373(6554): 541-547, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34326236

RESUMO

Repurposing drugs as treatments for COVID-19, the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has drawn much attention. Beginning with sigma receptor ligands and expanding to other drugs from screening in the field, we became concerned that phospholipidosis was a shared mechanism underlying the antiviral activity of many repurposed drugs. For all of the 23 cationic amphiphilic drugs we tested, including hydroxychloroquine, azithromycin, amiodarone, and four others already in clinical trials, phospholipidosis was monotonically correlated with antiviral efficacy. Conversely, drugs active against the same targets that did not induce phospholipidosis were not antiviral. Phospholipidosis depends on the physicochemical properties of drugs and does not reflect specific target-based activities-rather, it may be considered a toxic confound in early drug discovery. Early detection of phospholipidosis could eliminate these artifacts, enabling a focus on molecules with therapeutic potential.


Assuntos
Antivirais/farmacologia , COVID-19/tratamento farmacológico , Reposicionamento de Medicamentos , Lipidoses/induzido quimicamente , Fosfolipídeos/metabolismo , SARS-CoV-2/efeitos dos fármacos , Células A549 , Animais , Antivirais/química , Antivirais/uso terapêutico , Antivirais/toxicidade , COVID-19/virologia , Cátions , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Feminino , Humanos , Camundongos , Testes de Sensibilidade Microbiana , SARS-CoV-2/fisiologia , Tensoativos/química , Tensoativos/farmacologia , Tensoativos/toxicidade , Células Vero , Replicação Viral/efeitos dos fármacos
2.
Pharmaceuticals (Basel) ; 14(3)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800393

RESUMO

eTRANSAFE is a research project funded within the Innovative Medicines Initiative (IMI), which aims at developing integrated databases and computational tools (the eTRANSAFE ToxHub) that support the translational safety assessment of new drugs by using legacy data provided by the pharmaceutical companies that participate in the project. The project objectives include the development of databases containing preclinical and clinical data, computational systems for translational analysis including tools for data query, analysis and visualization, as well as computational models to explain and predict drug safety events.

3.
ALTEX ; 38(2): 187-197, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33637997

RESUMO

Pre-competitive data sharing can offer the pharmaceutical industry significant benefits in terms of reducing the time and costs involved in getting a new drug to market through more informed testing strategies and knowledge gained by pooling data. If sufficient data is shared and can be co-analyzed, then it can also offer the potential for reduced animal usage and improvements in the in silico prediction of toxicological effects. Data sharing benefits can be further enhanced by applying the FAIR Guiding Principles, reducing time spent curating, transforming and aggregating datasets and allowing more time for data mining and analysis. We hope to facilitate data sharing by other organizations and initiatives by describing lessons learned as part of the Enhancing TRANslational SAFEty Assessment through Integrative Knowledge Management (eTRANSAFE) project, an Innovative Medicines Initiative (IMI) partnership which aims to integrate publicly available data sources with proprietary preclinical and clinical data donated by pharmaceutical organizations. Methods to foster trust and overcome non-technical barriers to data sharing such as legal and IPR (intellectual property rights) are described, including the security requirements that pharmaceutical organizations generally expect to be met. We share the consensus achieved among pharmaceutical partners on decision criteria to be included in internal clearance pro­cedures used to decide if data can be shared. We also report on the consensus achieved on specific data fields to be excluded from sharing for sensitive preclinical safety and pharmacology data that could otherwise not be shared.

4.
ALTEX ; 37(3): 343-349, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32242633

RESUMO

Sharing legacy data from in vivo toxicity studies offers the opportunity to analyze the variability of control groups stratified for strain, age, duration of study, vehicle and other experimental conditions. Historical animal control group data may lead to a repository, which could be used to construct virtual control groups (VCGs) for toxicity studies. VCGs are an established concept in clinical trials, but the idea of replacing living beings with virtual data sets has so far not been introduced into the design of regulatory animal studies. The use of VCGs has the potential of a 25% reduction in animal use by replacing the control group animals with existing randomized data sets. Prerequisites for such an approach are the availability of large and well-structured control data sets as well as thorough statistical evaluations. the foundation of data sharing has been laid within the Innovative Medicines Initiatives projects eTOX and eTRANSAFE. For a proof of principle participating companies have started to collect control group data for subacute (4-week) GLP studies with Wistar rats (the strain preferentially used in Europe) and are characterizing these data for its variability. In a second step, the control group data will be shared among the companies and cross-company variability will be investigated. In a third step, a set of studies will be analyzed to assess whether the use of VCG data would have influenced the outcome of the study compared to the real control group.

5.
J Pharmacol Exp Ther ; 369(3): 428-442, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30894455

RESUMO

The colony-stimulating factor-1 (CSF-1) receptor pathway has been implicated in a variety of diseases, and CSF-1-dependent mechanisms are also involved in bloodborne protein clearance. Lacnotuzumab is a novel, high-affinity, humanized, anti-CSF-1 monoclonal antibody that prevents CSF-1-mediated receptor activation. This phase 1, two-part, double-blind study in healthy volunteers assessed the safety and tolerability of lacnotuzumab and its pharmacokinetics (PK) and pharmacodynamic properties. Part A (n = 36) was a single, ascending-dose assessment of eight lacnotuzumab doses (0.01-20 mg/kg); in part B (n = 16), lacnotuzumab was administered at either 5 or 10 mg/kg. In each study cohort, individuals were randomized 3:1 to lacnotuzumab or placebo. Lacnotuzumab was generally well tolerated. At higher doses (10 and 20 mg/kg), creatine kinase (CK) elevations (>5× the upper limit of normal, but asymptomatic and reversible) and mild transient periorbital swelling were reported. Most adverse events (AEs) were low-grade, no unexpected or novel AEs were observed, and there were no discontinuations for AEs. Free, unbound lacnotuzumab serum concentration-time profiles showed nonlinear PK across doses from 0.01 to 20 mg/kg, with faster apparent elimination at lower doses or concentrations; this finding was consistent with apparent target-mediated drug disposition. Lacnotuzumab also showed dose-dependent, on-target effects on multiple downstream biomarkers. Preclinical investigations of the CK elevation and periorbital swelling observed after lacnotuzumab administration suggest that these are reversible, nonpathological events linked to inhibition of the CSF-1 pathway. These data support further evaluation of lacnotuzumab in clinical studies.

6.
ALTEX ; 36(2): 289-313, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30570669

RESUMO

Investigative Toxicology describes the de-risking and mechanistic elucidation of toxicities, supporting early safety decisions in the pharmaceutical industry. Recently, Investigative Toxicology has contributed to a shift in pharmaceutical toxicology, from a descriptive to an evidence-based, mechanistic discipline. This was triggered by high costs and low throughput of Good Laboratory Practice in vivo studies, and increasing demands for adhering to the 3R (Replacement, Reduction and Refinement) principles of animal welfare. Outside the boundaries of regulatory toxicology, Investigative Toxicology has the flexibility to embrace new technologies, enhancing translational steps from in silico, in vitro to in vivo mechanistic understanding to eventually predict human response. One major goal of Investigative Toxicology is improving preclinical decisions, which coincides with the concept of animal-free safety testing. Currently, compounds under preclinical development are being discarded due to the use of inappropriate animal models. Progress in Investigative Toxicology could lead to humanized in vitro test systems and the development of medicines less reliant on animal tests. To advance this field a group of 14 European-based leaders from the pharmaceutical industry founded the Investigative Toxicology Leaders Forum (ITLF), an open, non-exclusive and pre-competitive group that shares knowledge and experience. The ITLF collaborated with the Centre for Alternatives to Animal Testing Europe (CAAT-Europe) to organize an "Investigative Toxicology Think-Tank", which aimed to enhance the interaction with experts from academia and regulatory bodies in the field. Summarizing the topics and discussion of the workshop, this article highlights Investigative Toxicology's position by identifying key challenges and perspectives.


Assuntos
Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos/tendências , Toxicologia/tendências , Alternativas aos Testes com Animais , Animais , Simulação por Computador , Indústria Farmacêutica , Europa (Continente) , Humanos , Técnicas In Vitro , Medição de Risco
7.
Arch Toxicol ; 92(5): 1877-1891, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29556671

RESUMO

A high incidence of hemangiosarcoma (HSA) was observed in mice treated for 2 years with siponimod, a sphingosine-1-phosphate receptor 1 (S1P1) functional antagonist, while no such tumors were observed in rats under the same treatment conditions. In 3-month rat (90 mg/kg/day) and 9-month mouse (25 and 75 mg/kg/day) in vivo mechanistic studies, vascular endothelial cell (VEC) activation was observed in both species, but VEC proliferation and persistent increases in circulating placental growth factor 2 (PLGF2) were only seen in the mouse. In mice, these effects were sustained over the 9-month study duration, while in rats increased mitotic gene expression was present at day 3 only and PLGF2 was induced only during the first week of treatment. In the mouse, the persistent VEC activation, mitosis induction, and PLGF2 stimulation likely led to sustained neo-angiogenesis which over life-long treatment may result in HSA formation. In rats, despite sustained VEC activation, the transient mitotic and PLGF2 stimuli did not result in the formation of HSA. In vitro, the mouse and rat primary endothelial cell cultures mirrored their respective in vivo findings for cell proliferation and PLGF2 release. Human VECs, like rat cells, were unresponsive to siponimod treatment with no proliferative response and no release of PLGF2 at all tested concentrations. Hence, it is suggested that the human cells also reproduce a lack of in vivo response to siponimod. In conclusion, the molecular mechanisms leading to siponimod-induced HSA in mice are considered species specific and likely irrelevant to humans.


Assuntos
Azetidinas/efeitos adversos , Compostos de Benzil/efeitos adversos , Células Endoteliais/efeitos dos fármacos , Hemangiossarcoma/induzido quimicamente , Testes de Toxicidade Crônica/métodos , Administração Oral , Animais , Azetidinas/administração & dosagem , Compostos de Benzil/administração & dosagem , Células Cultivadas , Endotélio Vascular/citologia , Hemangiossarcoma/genética , Humanos , Masculino , Camundongos Endogâmicos , Fator de Crescimento Placentário/metabolismo , Ratos Sprague-Dawley , Ratos Wistar , Receptores de Lisoesfingolipídeo/antagonistas & inibidores , Receptores de Lisoesfingolipídeo/metabolismo , Especificidade da Espécie , Toxicocinética , Transcriptoma/efeitos dos fármacos
8.
Toxicol Sci ; 163(1): 265-278, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29432567

RESUMO

The FGF19- fibroblast growth factor receptor (FGFR4)-ßKlotho (KLB) pathway plays an important role in the regulation of bile acid (BA) homeostasis. Aberrant activation of this pathway has been described in the development and progression of a subset of liver cancers including hepatocellular carcinoma, establishing FGFR4 as an attractive therapeutic target for such solid tumors. FGF401 is a highly selective FGFR4 kinase inhibitor being developed for hepatocellular carcinoma, currently in phase I/II clinical studies. In preclinical studies in mice and dogs, oral administration of FGF401 led to induction of Cyp7a1, elevation of its peripheral marker 7alpha-hydroxy-4-cholesten-3-one, increased BA pool size, decreased serum cholesterol and diarrhea in dogs. FGF401 was also associated with increases of serum aminotransferases, primarily alanine aminotransferase (ALT), in the absence of any observable adverse histopathological findings in the liver, or in any other organs. We hypothesized that the increase in ALT could be secondary to increased BAs and conducted an investigative study in dogs with FGF401 and coadministration of the BA sequestrant cholestyramine (CHO). CHO prevented and reversed FGF401-related increases in ALT in dogs in parallel to its ability to reduce BAs in the circulation. Correlation analysis showed that FGF401-mediated increases in ALT strongly correlated with increases in taurolithocholic acid and taurodeoxycholic acid, the major secondary BAs in dog plasma, indicating a mechanistic link between ALT elevation and changes in BA pool hydrophobicity. Thus, CHO may offer the potential to mitigate elevations in serum aminotransferases in human subjects that are caused by targeted FGFR4 inhibition and elevated intracellular BA levels.


Assuntos
Alanina Transaminase/sangue , Ácidos e Sais Biliares/sangue , Resina de Colestiramina/farmacologia , Fígado/efeitos dos fármacos , Inibidores de Proteínas Quinases/toxicidade , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Alanina Transaminase/biossíntese , Animais , Ácidos e Sais Biliares/biossíntese , Cães , Relação Dose-Resposta a Droga , Feminino , Fígado/enzimologia , Masculino , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/sangue , Piridinas/farmacologia , Testes de Toxicidade , Toxicocinética
9.
Basic Clin Pharmacol Toxicol ; 123 Suppl 5: 29-36, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29316298

RESUMO

The application of read-across and in silico tools for regulatory decision-making has been limited for pharmaceutical compounds to the assessment of genotoxic impurity. In contrast, the broad availability of toxicity data for industrial chemicals has triggered regulatory frameworks for read-across (e.g. ECHA Read-Across Assessment Framework), software tools and public databases for an automated process of gap filling in the context of safety assessment. This MiniReview provides an overview of the currently existing in silico and read-across approaches for chemicals together with recent developments for pharmaceutical compounds in these areas. It also highlights the differences and commonalities in the in silico safety assessment of industrial chemicals and drug candidates. Whereas toxicity data collection and sharing is now common practice for chemicals falling under the European REACH regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals), the biggest hurdle for establishing preclinical safety databases for pharmaceutical compounds is the unwillingness to share proprietary data and lack of published data sets. In a recent consortium approach, thirteen pharmaceutical companies, eleven academic partners and six small to medium size enterprises (SMEs) of the bioinformatics sector joined forces over the last 7 years within the European Innovative Medicines Initiative project eTOX ('electronic toxicity') to design and implement a strategy for leveraging these preclinical data for small molecules and sharing them across project partners. The eTOX database has evolved as the largest preclinical toxicity database for drugs and drug candidates and currently contains more than 1900 different chemical structures and more than 8000 in vivo toxicity study data sets. It can be foreseen that the development and application of such databases for drugs or drug candidates will in the future also cross-fertilize the read-across and the in silico assessment of industrial or consumer chemicals particularly as soon as human safety data from clinical trials are integrated too.


Assuntos
Biologia Computacional , Simulação por Computador , Avaliação Pré-Clínica de Medicamentos/normas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Animais , Bases de Dados Factuais , Avaliação Pré-Clínica de Medicamentos/métodos , Guias como Assunto , Humanos , Medição de Risco/métodos , Medição de Risco/normas , Software
11.
Bioinformatics ; 33(1): 148-149, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27605099

RESUMO

The lack of controlled terminology and ontology usage leads to incomplete search results and poor interoperability between databases. One of the major underlying challenges of data integration is curating data to adhere to controlled terminologies and/or ontologies. Finding subject matter experts with the time and skills required to perform data curation is often problematic. In addition, existing tools are not designed for continuous data integration and collaborative curation. This results in time-consuming curation workflows that often become unsustainable. The primary objective of OntoBrowser is to provide an easy-to-use online collaborative solution for subject matter experts to map reported terms to preferred ontology (or code list) terms and facilitate ontology evolution. Additional features include web service access to data, visualization of ontologies in hierarchical/graph format and a peer review/approval workflow with alerting. AVAILABILITY AND IMPLEMENTATION: The source code is freely available under the Apache v2.0 license. Source code and installation instructions are available at http://opensource.nibr.com This software is designed to run on a Java EE application server and store data in a relational database. CONTACT: philippe.marc@novartis.com.


Assuntos
Ontologias Biológicas , Curadoria de Dados/métodos , Bases de Dados Factuais/normas , Revisão por Pares/métodos , Software , Vocabulário Controlado
12.
Toxicol In Vitro ; 40: 55-65, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27923774

RESUMO

Arctigenin has previously been identified as a potential anti-tumor treatment for advanced pancreatic cancer. However, the mechanism of how arctigenin kills cancer cells is not fully understood. In the present work we studied the mechanism of toxicity by arctigenin in the human pancreatic cell line, Panc-1, with special emphasis on the mitochondria. A comparison of Panc-1 cells cultured in glucose versus galactose medium was applied, allowing assessments of effects in glycolytic versus oxidative phosphorylation (OXPHOS)-dependent Panc-1 cells. For control purposes, the mitochondrial toxic response to treatment with arctigenin was compared to the anti-cancer drug, sorafenib, which is a tyrosine kinase inhibitor known for mitochondrial toxic off-target effects (Will et al., 2008). In both Panc-1 OXPHOS-dependent and glycolytic cells, arctigenin dissipated the mitochondrial membrane potential, which was demonstrated to be due to inhibition of the mitochondrial complexes II and IV. However, arctigenin selectively killed only the OXPHOS-dependent Panc-1 cells. This selective killing of OXPHOS-dependent Panc-1 cells was accompanied by generation of ER stress, mitochondrial membrane permeabilization and caspase activation leading to apoptosis and aponecrosis.


Assuntos
Antineoplásicos/farmacologia , Furanos/farmacologia , Lignanas/farmacologia , Trifosfato de Adenosina/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Glicólise , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Necrose , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos
13.
Toxicol Sci ; 155(1): 283-297, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27742868

RESUMO

The aim of this study was to determine the relative safety of 4 antiviral drugs (telbivudine, tenofovir, adefovir, and entecavir) against hepatitis B virus with respect to kidney function and toxicity in male Sprague Dawley rats. The antiviral drugs were administered once daily for 4 weeks by oral gavage at ∼10 and 25-40 times the human equivalent dose. Main assessments included markers of renal toxicity in urine, magnetic resonance imaging (MRI) of kidney function, histopathology, and electron microscopic examination. Administration of adefovir at 11 and 28 mg/kg for 4 weeks caused functional and morphological kidney alterations in a time- and dose-dependent manner, affecting mainly the proximal tubules and suggesting a mechanism of toxicity related to mitochondrial degeneration/depletion. Of note, the observed adefovir-induced reduction of kidney function was not detected by the standard method of glomerular filtration rate (GFR) measurements (clearance rate of the endogenous marker, creatinine), thereby emphasizing the superiority of MRI in terms of sensitive detection of GFR in rats. For the low dose of 300 mg/kg of tenofovir, minor kidney effects such as nuclear enlargement in the tubular epithelium, and hyaline droplets accumulation were detected, which was also observed for the low dose (11 mg/kg) of adefovir. No assessments could be done at the higher dose of 600/1000 mg/kg tenofovir due to gastrointestinal tract toxicity which prevented treatment of the animals for longer than 1 week. Entecavir at 1 and 3 mg/kg and telbivudine at 600 and 1600 mg/kg caused no toxicologically relevant effects on the kidney.


Assuntos
Antivirais/efeitos adversos , Hepatite B/tratamento farmacológico , Rim/efeitos dos fármacos , Animais , Antivirais/uso terapêutico , Rim/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Ratos , Ratos Sprague-Dawley
14.
Biomed Res Int ; 2016: 9737920, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27689095

RESUMO

Drug-induced liver injury (DILI) is a major cause of late-stage clinical drug attrition, market withdrawal, black-box warnings, and acute liver failure. Consequently, it has been an area of focus for toxicologists and clinicians for several decades. In spite of considerable efforts, limited improvements in DILI prediction have been made and efforts to improve existing preclinical models or develop new test systems remain a high priority. While prediction of intrinsic DILI has improved, identifying compounds with a risk for idiosyncratic DILI (iDILI) remains extremely challenging because of the lack of a clear mechanistic understanding and the multifactorial pathogenesis of idiosyncratic drug reactions. Well-defined clinical diagnostic criteria and risk factors are also missing. This paper summarizes key data interpretation challenges, practical considerations, model limitations, and the need for an integrated risk assessment. As demonstrated through selected initiatives to address other types of toxicities, opportunities exist however for improvement, especially through better concerted efforts at harmonization of current, emerging and novel in vitro systems or through the establishment of strategies for implementation of preclinical DILI models across the pharmaceutical industry. Perspectives on the incorporation of newer technologies and the value of precompetitive consortia to identify useful practices are also discussed.

15.
Clin Res Hepatol Gastroenterol ; 40(3): 257-266, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26874804

RESUMO

Bile acid research has gained great momentum since the role of bile acids as key signaling molecules in the enterohepatic circulation was discovered. Their physiological function in regulating their own homeostasis, as well as energy and lipid metabolism make them interesting targets for the pharmaceutical industry in the context of diseases such as bile acid induced diarrhea, bile acid induced cholestasis or nonalcoholic steatohepatitis. Changes in bile acid homeostasis are also linked to various types of drug-induced liver injury (DILI). However, the key question whether bile acids are surrogate markers for monitoring DILI or key pathogenic players in the onset and progression of DILI is under intense investigation. The purpose of this review is to summarize the different facets of bile acids in the context of normal physiology, hereditary defects of bile acid transport and DILI.


Assuntos
Ácidos e Sais Biliares/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Ductos Biliares/citologia , Transporte Biológico/fisiologia , Biomarcadores/metabolismo , Colestase Intra-Hepática/induzido quimicamente , Colestase Intra-Hepática/fisiopatologia , Circulação Êntero-Hepática/fisiologia , Homeostase , Humanos
16.
Adv Drug Deliv Rev ; 86: 101-11, 2015 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-25794480

RESUMO

The use of in silico tools within the drug development process to predict a wide range of properties including absorption, distribution, metabolism, elimination and toxicity has become increasingly important due to changes in legislation and both ethical and economic drivers to reduce animal testing. Whilst in silico tools have been used for decades there remains reluctance to accept predictions based on these methods particularly in regulatory settings. This apprehension arises in part due to lack of confidence in the reliability, robustness and applicability of the models. To address this issue we propose a scheme for the verification of in silico models that enables end users and modellers to assess the scientific validity of models in accordance with the principles of good computer modelling practice. We report here the implementation of the scheme within the Innovative Medicines Initiative project "eTOX" (electronic toxicity) and its application to the in silico models developed within the frame of this project.


Assuntos
Modelos Teóricos , Simulação por Computador , Humanos , Projetos Piloto , Reprodutibilidade dos Testes
17.
Toxicol Pathol ; 43(5): 694-703, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25630683

RESUMO

Sphingosine-1-phosphate (S1P) lyase is considered as a drug target in autoimmune diseases based on the protective effect of reducing activity of the enzyme in animal models of inflammation. Since S1P lyase deficiency in mice causes a severe, lethal phenotype, it was of interest to investigate any pathological alterations associated with only partially reduced activity of S1P lyase as may be encountered upon pharmacological inhibition. Both genetic reduction of S1P lyase activity in mice and inhibition of S1P lyase with a low-molecular-weight compound in rats consistently resulted in podocyte-based kidney toxicity, which is the most severe finding. In addition, skin irritation and platelet activation were observed in both instances. The similarity of the findings in both the genetic model and the pharmacological study supports the value of analyzing inducible partially target-deficient mice for safety assessment. If the findings described in rodents translate to humans, target-related toxicity, particularly podocyte dysfunction, may limit chronic systemic treatment of autoimmune diseases with S1P lyase inhibitors. Furthermore, partial deficiency or inhibition of S1P lyase appears to provide an in vivo rodent model to enable studies on the mechanism of podocyte dysfunction.


Assuntos
Aldeído Liases/antagonistas & inibidores , Aldeído Liases/metabolismo , Ativação Plaquetária/fisiologia , Podócitos/enzimologia , Proteinúria/enzimologia , Aldeído Liases/genética , Animais , Feminino , Rim/enzimologia , Rim/patologia , Masculino , Camundongos , Proteinúria/sangue , Ratos , Pele/enzimologia , Pele/patologia , Tamoxifeno/farmacologia
18.
Toxicol In Vitro ; 30(1 Pt A): 79-94, 2015 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-24933330

RESUMO

DILI is a major safety issue during drug development and one of the leading causes for market withdrawal. Despite many efforts made in the past, the prediction of DILI using in vitro models remains very unreliable. In the present study, the well-established hepatocyte Collagen I-Matrigel™ sandwich culture was used, mimicking chronic drug treatment after multiple incubations for 14 days. Ten drugs associated with different types of specific preclinical and clinical liver injury were evaluated at non-cytotoxic concentrations. Mrp2-mediated transport, intracellular accumulation of neutral lipids and phospholipids were selected as functional endpoints by using Cellomics™ Arrayscan® technology and assessed at five timepoints (day 1, 3, 7, 10, 14). Liver specific functional impairments after drug treatment were enhanced over time and could be monitored by HCI already after few days and before cytotoxicity. Phospholipidosis-inducing drugs Chlorpromazine and Amiodarone displayed the same response as in vivo. Cyclosporin A, Chlorpromazine, and Troglitazone inhibited Mrp2-mediated biliary transport, correlating with in vivo findings. Steatosis remained difficult to be reproduced under the current in vitro testing conditions, resulting into false negative and positive responses. The present results suggest that the repeated long-term treatment of rat hepatocytes in the Collagen I-Matrigel™ sandwich configuration might be a suitable tool for safety profiling of the potential to induce phospholipidosis and impair Mrp2-mediated transport processes, but not to predict steatosis.


Assuntos
Hepatócitos/efeitos dos fármacos , Amiodarona/administração & dosagem , Amiodarona/toxicidade , Animais , Células Cultivadas , Clorpromazina/administração & dosagem , Clorpromazina/toxicidade , Cromanos/administração & dosagem , Cromanos/toxicidade , Técnicas de Cultura , Ciclosporina/administração & dosagem , Ciclosporina/toxicidade , Antagonistas de Dopamina/administração & dosagem , Antagonistas de Dopamina/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/toxicidade , Imunossupressores/administração & dosagem , Imunossupressores/toxicidade , Masculino , Bloqueadores dos Canais de Potássio/administração & dosagem , Bloqueadores dos Canais de Potássio/toxicidade , Ratos , Ratos Wistar , Tiazolidinedionas/administração & dosagem , Tiazolidinedionas/toxicidade , Troglitazona
19.
Drug Metab Dispos ; 43(1): 126-39, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25339109

RESUMO

Although skin is the largest organ of the human body, cutaneous drug metabolism is often overlooked, and existing experimental models are insufficiently validated. This proof-of-concept study investigated phase II biotransformation of 11 test substrates in fresh full-thickness human skin explants, a model containing all skin cell types. Results show that skin explants have significant capacity for glucuronidation, sulfation, N-acetylation, catechol methylation, and glutathione conjugation. Novel skin metabolites were identified, including acyl glucuronides of indomethacin and diclofenac, glucuronides of 17ß-estradiol, N-acetylprocainamide, and methoxy derivatives of 4-nitrocatechol and 2,3-dihydroxynaphthalene. Measured activities for 10 µM substrate incubations spanned a 1000-fold: from the highest 4.758 pmol·mg skin(-1)·h(-1) for p-toluidine N-acetylation to the lowest 0.006 pmol·mg skin(-1)·h(-1) for 17ß-estradiol 17-glucuronidation. Interindividual variability was 1.4- to 13.0-fold, the highest being 4-methylumbelliferone and diclofenac glucuronidation. Reaction rates were generally linear up to 4 hours, although 24-hour incubations enabled detection of metabolites in trace amounts. All reactions were unaffected by the inclusion of cosubstrates, and freezing of the fresh skin led to loss of glucuronidation activity. The predicted whole-skin intrinsic metabolic clearances were significantly lower compared with corresponding whole-liver intrinsic clearances, suggesting a relatively limited contribution of the skin to the body's total systemic phase II enzyme-mediated metabolic clearance. Nevertheless, the fresh full-thickness skin explants represent a suitable model to study cutaneous phase II metabolism not only in drug elimination but also in toxicity, as formation of acyl glucuronides and sulfate conjugates could play a role in skin adverse reactions.


Assuntos
Catecóis/metabolismo , Glutationa/metabolismo , Desintoxicação Metabólica Fase II/fisiologia , Pele/metabolismo , Acetilação , Adulto , Idoso , Biotransformação/fisiologia , Diclofenaco/metabolismo , Feminino , Glucuronídeos/metabolismo , Humanos , Fígado/metabolismo , Masculino , Metilação , Pessoa de Meia-Idade , Naftóis/metabolismo , Sulfatos/metabolismo
20.
Int J Mol Sci ; 15(11): 21136-54, 2014 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-25405742

RESUMO

The high-quality in vivo preclinical safety data produced by the pharmaceutical industry during drug development, which follows numerous strict guidelines, are mostly not available in the public domain. These safety data are sometimes published as a condensed summary for the few compounds that reach the market, but the majority of studies are never made public and are often difficult to access in an automated way, even sometimes within the owning company itself. It is evident from many academic and industrial examples, that useful data mining and model development requires large and representative data sets and careful curation of the collected data. In 2010, under the auspices of the Innovative Medicines Initiative, the eTOX project started with the objective of extracting and sharing preclinical study data from paper or pdf archives of toxicology departments of the 13 participating pharmaceutical companies and using such data for establishing a detailed, well-curated database, which could then serve as source for read-across approaches (early assessment of the potential toxicity of a drug candidate by comparison of similar structure and/or effects) and training of predictive models. The paper describes the efforts undertaken to allow effective data sharing intellectual property (IP) protection and set up of adequate controlled vocabularies) and to establish the database (currently with over 4000 studies contributed by the pharma companies corresponding to more than 1400 compounds). In addition, the status of predictive models building and some specific features of the eTOX predictive system (eTOXsys) are presented as decision support knowledge-based tools for drug development process at an early stage.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Preparações Farmacêuticas/química , Simulação por Computador , Mineração de Dados , Bases de Dados de Produtos Farmacêuticos , Descoberta de Drogas , Humanos , Modelos Biológicos , Vocabulário Controlado
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...