Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
1.
Genes Dev ; 35(1-2): 117-132, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33334825

RESUMO

The p53 tumor suppressor protein is a potent activator of proliferative arrest and cell death. In normal cells, this pathway is restrained by p53 protein degradation mediated by the E3-ubiquitin ligase activity of MDM2. Oncogenic stress releases p53 from MDM2 control, so activating the p53 response. However, many tumors that retain wild-type p53 inappropriately maintain the MDM2-p53 regulatory loop in order to continuously suppress p53 activity. We have shown previously that single point mutations in the human MDM2 RING finger domain prevent the interaction of MDM2 with the E2/ubiquitin complex, resulting in the loss of MDM2's E3 activity without preventing p53 binding. Here, we show that an analogous mouse MDM2 mutant (MDM2 I438K) restrains p53 sufficiently for normal growth but exhibits an enhanced stress response in vitro. In vivo, constitutive expression of MDM2 I438K leads to embryonic lethality that is rescued by p53 deletion, suggesting MDM2 I438K is not able to adequately control p53 function through development. However, the switch to I438K expression is tolerated in adult mice, sparing normal cells but allowing for an enhanced p53 response to DNA damage. Viewed as a proof of principle model for therapeutic development, our findings support an approach that would inhibit MDM2 E3 activity without preventing MDM2/p53 binding as a promising avenue for development of compounds to activate p53 in tumors with reduced on-target toxicities.


Assuntos
Desenvolvimento Embrionário/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Animais , Antineoplásicos Hormonais/farmacologia , Proliferação de Células/genética , Células Cultivadas , Embrião de Mamíferos/enzimologia , Ativação Enzimática/efeitos dos fármacos , Feminino , Masculino , Camundongos , Mutação , Tamoxifeno/farmacologia
2.
Nucleic Acids Res ; 51(4): e21, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36617985

RESUMO

Transposon screens are powerful in vivo assays used to identify loci driving carcinogenesis. These loci are identified as Common Insertion Sites (CISs), i.e. regions with more transposon insertions than expected by chance. However, the identification of CISs is affected by biases in the insertion behaviour of transposon systems. Here, we introduce Transmicron, a novel method that differs from previous methods by (i) modelling neutral insertion rates based on chromatin accessibility, transcriptional activity and sequence context and (ii) estimating oncogenic selection for each genomic region using Poisson regression to model insertion counts while controlling for neutral insertion rates. To assess the benefits of our approach, we generated a dataset applying two different transposon systems under comparable conditions. Benchmarking for enrichment of known cancer genes showed improved performance of Transmicron against state-of-the-art methods. Modelling neutral insertion rates allowed for better control of false positives and stronger agreement of the results between transposon systems. Moreover, using Poisson regression to consider intra-sample and inter-sample information proved beneficial in small and moderately-sized datasets. Transmicron is open-source and freely available. Overall, this study contributes to the understanding of transposon biology and introduces a novel approach to use this knowledge for discovering cancer driver genes.


Assuntos
Elementos de DNA Transponíveis , Neoplasias , Software , Humanos , Sequência de Bases , Carcinogênese , Mutagênese Insercional , Oncogenes , Neoplasias/genética
4.
Anal Chem ; 95(23): 8825-8833, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37259796

RESUMO

Protein O-glycosylation is one of the most diverse post-translational modifications. A critical step in the analysis of O-glycomes is the release of glycans from glycoconjugates. Current release methods rely mainly on ß-elimination, which can result in peeling reactions and loss of base-sensitive functionalities leading to misidentification of glycans. To address this challenge, well-defined synthetic glycopeptides were used to establish a robust workflow for the oxidative release of O-glycans suitable for glycomics. Treatment of O-glycopeptides with neutralized hypochlorite resulted in the selective formation of lactic/glycolic acid glycosides, thereby retaining unique information of the parent amino acid (serine/threonine) that is lost by ß-elimination. It locks the glycan in a closed ring configuration, thereby preventing peeling, and furthermore, the carboxylate of the anomeric tag promotes ionization in negative ion mode mass spectrometry, thereby increasing signal intensities. Labile modifications such as sialic acids, sulfates, and acetyl esters are maintained during the release procedure. The promise of the approach was demonstrated by the analysis of O-glycans from bovine submaxillary mucin, which identified mono- and di-O-acetylated sialoglycans as well as previously undetected tri-O-acetylated and sulfated glycans. The use of well-defined glycopeptide standards made it also possible to identify reaction intermediates, which in turn allowed us to postulate a reaction mechanism for oxidative O-glycan release under neutral conditions.


Assuntos
Glicoproteínas , Polissacarídeos , Animais , Bovinos , Glicoproteínas/química , Polissacarídeos/química , Glicosilação , Glicopeptídeos/química , Estresse Oxidativo
5.
Learn Mem ; 26(11): 424-435, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31615854

RESUMO

Adjusting behavior to changed environmental contingencies is critical for survival, and reversal learning provides an experimental handle on such cognitive flexibility. Here, we investigate reversal learning in larval Drosophila Using odor-taste associations, we establish olfactory reversal learning in the appetitive and the aversive domain, using either fructose as a reward or high-concentration sodium chloride as a punishment, respectively. Reversal learning is demonstrated both in differential and in absolute conditioning, in either valence domain. In differential conditioning, the animals are first trained such that an odor A is paired, for example, with the reward whereas odor B is not (A+/B); this is followed by a second training phase with reversed contingencies (A/B+). In absolute conditioning, odor B is omitted, such that the animals are first trained with paired presentations of A and reward, followed by unpaired training in the second training phase. Our results reveal "true" reversal learning in that the opposite associative effects of both the first and the second training phase are detectable after reversed-contingency training. In what is a surprisingly quick, one-trial contingency adjustment in the Drosophila larva, the present study establishes a simple and genetically easy accessible study case of cognitive flexibility.


Assuntos
Aprendizagem por Associação/fisiologia , Comportamento Animal/fisiologia , Condicionamento Psicológico/fisiologia , Drosophila/fisiologia , Larva/fisiologia , Reversão de Aprendizagem/fisiologia , Animais , Comportamento Apetitivo/fisiologia , Aprendizagem da Esquiva/fisiologia , Percepção Olfatória/fisiologia , Recompensa , Percepção Gustatória/fisiologia
6.
BMC Oral Health ; 19(1): 68, 2019 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-31035974

RESUMO

BACKGROUND: Many countries offer systematic group prevention programs in kindergarten and school in order to promote children's oral health. Little is known, however, about the actual toothbrushing abilities of children when group prevention programs end. METHODS: In Germany, all children take advantage from a nationwide group prevention program (called "Gruppenprophylaxe") lasting from kindergarten up to sixth grade (12 years of age). Standardized recommendations are given concerning brushing systematics and brushing movements. N = 174 children at the age of 12 were thus randomly selected from two German towns and were asked to perform toothbrushing to the best of their abilities in front of a mirror which also served as a camera. Brushing behavior was analyzed by video analysis. RESULTS: Children brushed their teeth for an average of 200 s ± 80.48 s (mean ± SD). Still, more than 55% missed at least one sextant when brushing inner surfaces, 16% missed them all. Only 7.5% of the children brushed both inner and outer surfaces by the intended movements (vertical movements on the inner surfaces and circular movements on the outer surfaces) for at least 90% of the respective brushing time. Instead, horizontal brushing was very common on the lateral surfaces. CONCLUSIONS: The present analysis indicates that children have low efficiency to adopt the tooth-brushing recommendations given in prevention programs. This is surprising as great endeavors are made to help children internalize the recommendations. Future research is needed to better understand which factors impede adoption of toothbrushing recommendations in children and which efforts are necessary to improve their toothbrushing abilities.


Assuntos
Comportamentos Relacionados com a Saúde , Escovação Dentária/estatística & dados numéricos , Criança , Alemanha , Humanos
7.
Br J Cancer ; 118(9): 1217-1228, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29610456

RESUMO

BACKGROUND: Septin 9 (SEPT9) and short stature homeobox 2 (SHOX2) methylation in circulating cell-free DNA (ccfDNA) are powerful biomarkers for colorectal cancer (CRC) screening, as well as head and neck squamous cell carcinoma staging and monitoring. In the present study, we investigated SEPT9 and SHOX2 ccfDNA methylation as auxiliary pre and post-therapeutic staging parameters in CRC patients. METHODS: ccfDNA methylation was quantified in 184 prospectively enrolled patients prior to and 3-10 days after surgery, and biomarker levels were associated with clinico-pathological parameters. RESULTS: Pre-therapeutic levels of SHOX2 and SEPT9 ccfDNA methylation were strongly associated with Union for International Cancer Control (UICC) stages, tumour (T), nodal (N), and metastasis (M) categories, and histological grade (all P ≤ 0.001), as well as lymphatic invasion and extracapsular lymph node extension (all P< 0.05). Post-therapeutic SHOX2 and SEPT9 ccfDNA methylation levels correlated with UICC stage (all P <0.01). SEPT9 ccfDNA methylation further allowed for an accurate pre- and post-therapeutic detection of distant metastases (AUCpre-therapeutic = 0.79 (95%CI 0.69-0.89), AUCpost-therapeutic = 0.93 (95% CI 0.79-1.0)). CONCLUSIONS: DNA methylation analysis in plasma is a powerful pre and post-therapeutic diagnostic tool for CRC and may add valuable information to current TNM staging, thereby holding the potential to assist in the development of individually tailored treatment protocols.


Assuntos
Adenocarcinoma/sangue , DNA Tumoral Circulante/metabolismo , Neoplasias Colorretais/sangue , Metilação de DNA , Proteínas de Homeodomínio , Septinas , Adenocarcinoma/diagnóstico , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Estudos de Coortes , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Detecção Precoce de Câncer/métodos , Feminino , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias/métodos , Septinas/genética , Septinas/metabolismo
8.
Org Biomol Chem ; 16(12): 2043-2048, 2018 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-29465119

RESUMO

The Fusarium metabolite culmorin (1) is receiving increased attention as an "emerging mycotoxin". It co-occurs with trichothecene mycotoxins and potentially influences their toxicity. Its ecological role and fate in plants is unknown. We synthesized sulfated and glucosylated culmorin conjugates as potential metabolites, which are expected to be formed in planta, and used them as reference compounds. An efficient procedure for the synthesis of culmorin sulfates was developed. Diastereo- and regioselective glucosylation of culmorin (1) was achieved by exploiting or preventing unexpected acyl transfer when using different glucosyl donors. The treatment of a wheat suspension culture with culmorin (1) revealed an in planta conversion of culmorin into culmorin-8-glucoside (6) and culmorin acetate, but no sulfates or culmorin-11-glucoside (7) was found. The treatment of wheat cells with the fungal metabolite 11-acetylculmorin (2) revealed its rapid deacetylation, but also showed the formation of 11-acetylculmorin-8-glucoside (8). These results show that plants are capable of extensively metabolizing culmorin.


Assuntos
Sesquiterpenos/síntese química , Sesquiterpenos/farmacologia , Triticum/efeitos dos fármacos , Células Cultivadas , Fusarium/metabolismo , Glucose/química , Glicosilação , Espectroscopia de Ressonância Magnética , Micotoxinas/farmacologia , Sesquiterpenos/metabolismo , Estereoisomerismo , Sulfatos/química , Triticum/citologia
9.
European J Org Chem ; 2018(20-21): 2701-2706, 2018 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-29937688

RESUMO

The synthesis of (2-nitrophenyl)acetyl (NPAc)-protected glucosyl donors is described that were designed for the neighboring-group assisted glucosylation of base-labile natural products also being sensitive to hydrogenolysis. Glycosylation conditions were optimized using a trichloroacetimidate glucosyl donor, and cyclohexylmethanol and (+)-menthol as model acceptors. The approach was then extended to a one-pot procedure for the synthesis of 1,2-trans-glycosides. This method was finally applied for improved synthesis of the masked mycotoxin T2-O-ß,d-glucoside.

10.
Proc Natl Acad Sci U S A ; 112(45): 13982-7, 2015 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-26508638

RESUMO

Here, we show CRISPR/Cas9-based targeted somatic multiplex-mutagenesis and its application for high-throughput analysis of gene function in mice. Using hepatic single guide RNA (sgRNA) delivery, we targeted large gene sets to induce hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). We observed Darwinian selection of target genes, which suppress tumorigenesis in the respective cellular/tissue context, such as Pten or Cdkn2a, and conversely found low frequency of Brca1/2 alterations, explaining mutational spectra in human ICC/HCC. Our studies show that multiplexed CRISPR/Cas9 can be used for recessive genetic screening or high-throughput cancer gene validation in mice. The analysis of CRISPR/Cas9-induced tumors provided support for a major role of chromatin modifiers in hepatobiliary tumorigenesis, including that of ARID family proteins, which have recently been reported to be mutated in ICC/HCC. We have also comprehensively characterized the frequency and size of chromosomal alterations induced by combinatorial sgRNA delivery and describe related limitations of CRISPR/Cas9 multiplexing, as well as opportunities for chromosome engineering in the context of hepatobiliary tumorigenesis. Our study describes novel approaches to model and study cancer in a high-throughput multiplexed format that will facilitate the functional annotation of cancer genomes.


Assuntos
Sistemas CRISPR-Cas/genética , Carcinoma Hepatocelular/genética , Modelos Animais de Doenças , Genômica/métodos , Ensaios de Triagem em Larga Escala , Neoplasias Hepáticas/genética , Mutagênese/genética , Animais , Sequência de Bases , Marcação de Genes , Técnicas Histológicas , Fígado/metabolismo , Camundongos , Dados de Sequência Molecular , Seleção Genética/genética
11.
Unfallchirurg ; 121(3): 223-229, 2018 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-28105481

RESUMO

BACKGROUND: Severely injured children and adolescents in clinical practice are rare. For adequate treatment of these patients, detailed knowledge of anatomical and physiological peculiarities, as well as abundant injury patterns, are indispensable. Traumatic brain injuries are known to lead to an unfavorable outcome. In addition, thoracic trauma is regarded as prognostically unfavorable. OBJECTIVES: This study depicts epidemiology and injury patterns of severely injured children and adolescents focusing on peculiarities in the severely injured with associated thoracic injuries. MATERIALS AND METHODS: A retrospective analysis of underaged patients with suspicion of severe injuries who obtained emergency-room treatment in our level-one trauma center during a four-year time period was performed. The data was collected prospectively using the TraumaRegister® of the German Trauma Society as well as an extended house-internal dataset including data of daily clinical routine. The patients were divided into subgroups with (TT) and without (KT) thoracic trauma based on whether a thoracic injury was present or not. For further analysis, four age groups were established. RESULTS: In all, 256 patients younger than 18 years were eligible. Of these, 46 patients revealed thoracic injuries. The mean age of patients with thoracic trauma (12.4 ± 4.9 years) was significantly higher than for patients without thoracic trauma (8.0 ± 5.2 years). In both subgroups, most patients were male (TT: 69.9%, KT: 64.8%). Patients with concomitant thoracic trauma showed a significantly higher injury severity score (ISS) than patients without thoracic trauma (ISS: TT: 26.7 ± 15.8 vs. KT: 8.1 ± 6.8 points). Mortality was higher for TT as well (TT: 6.9% vs. KT: 1.9%). For both groups, traffic accidents were the most common cause of injury. Of patients with thoracic injuries, 52.2% developed at least one complication during their hospital stay (KT: 12.9%). CONCLUSIONS: Thoracic trauma is a relevant factor in children with regard to the severity of total injury and complications. Particular attention should therefore be paid to early diagnosis and treatment.


Assuntos
Escala de Gravidade do Ferimento , Traumatismo Múltiplo/epidemiologia , Traumatismos Torácicos/epidemiologia , Acidentes de Trânsito/estatística & dados numéricos , Adolescente , Criança , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Traumatismo Múltiplo/diagnóstico , Traumatismo Múltiplo/mortalidade , Traumatismo Múltiplo/terapia , Sistema de Registros/estatística & dados numéricos , Estudos Retrospectivos , Traumatismos Torácicos/diagnóstico , Traumatismos Torácicos/mortalidade , Traumatismos Torácicos/terapia , Centros de Traumatologia/estatística & dados numéricos
12.
Am J Med Genet A ; 170(9): 2394-9, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27255444

RESUMO

Interstitial deletions including chromosome region 1q23.3q24.1 are rare. Only eight patients with molecularly characterized deletions have been reported to date. Their phenotype included intellectual disability/developmental delay, growth retardation, microcephaly, congenital heart disease, and renal malformations. We report on a female patient with mild developmental delay, congenital heart disease, and bilateral renal hypoplasia in whom an interstitial de novo deletion of approximately 2.7 Mb in 1q23.3q24.1 was detected by array CGH. This is the smallest deletion described in this region so far. Genotype-phenotype comparison with previously published patients allowed us to propose LMX1A and RXRG as potential candidate genes for intellectual disability, PBX1 as a probable candidate gene for renal malformation, and enabled us to narrow down a chromosome region associated with microcephaly. © 2016 Wiley Periodicals, Inc.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 3 , Cardiopatias Congênitas/genética , Deficiência Intelectual/genética , Rim/anormalidades , Fenótipo , Anormalidades Múltiplas/genética , Pré-Escolar , Hibridização Genômica Comparativa , Deficiências do Desenvolvimento/genética , Ecocardiografia , Fácies , Feminino , Estudos de Associação Genética , Cardiopatias Congênitas/diagnóstico , Humanos , Hibridização in Situ Fluorescente , Deficiência Intelectual/diagnóstico , Ultrassonografia
13.
J Nanosci Nanotechnol ; 16(2): 1354-62, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27433586

RESUMO

The association of vegetable products to nanostructured systems has attracted the attention of researchers due to several advantages, such as drug photoprotection, as well as the improvement of the pharmacological and therapeutic activities because of synergistic action, which can provide their topical application. In this work, lipid-core nanocapsules containing borage oil as oil core and betamethasone dipropionate were developed, and nanocapsules without the drug were prepared for comparison. The suspensions were characterized in relation to mean particle size, zeta potential, pH, drug content, and encapsulation efficiency. A photodegradation study was carried out and the in vitro release profile as well as the irritation potential of the drug after nanoencapsulation were also evaluated. In addition, the antiproliferative activity of the free borage oil as well as loaded in nanocapsules was studied. Lipid-core nanocapsules showed nanometric mean size (185-210 nm); polydispersity index below 0.10; negative zeta potential and pH slightly acid (6.0-6.2). Moreover, the drug content was close to theoretical concentration (0.50 +/- 0.03 mg/ml of betamethasone), and the encapsulation efficiency was approximately 100%. The study of the antiproliferative activity of borage oil showed ability to reduce cell growth of Allium cepa. The nanoencapsulation of betamethasone dipropionate provided greater protection against UVC light and decreased the irritation potential of the drug. The release profile of betamethasone dipropionate from nanocapsules followed monoexponential model.


Assuntos
Betametasona/análogos & derivados , Nanopartículas/química , Cebolas/crescimento & desenvolvimento , Óleos de Plantas , Ácido gama-Linolênico , Betametasona/química , Betametasona/farmacologia , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Ácido gama-Linolênico/química , Ácido gama-Linolênico/farmacologia
14.
Drug Dev Ind Pharm ; 42(1): 19-27, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25775013

RESUMO

CONTEXT: Our group previously reported the photoinstability of some desonide topical commercial formulations under direct exposure to UVA radiation. OBJECTIVE: This study aimed to prepare and characterize a gel-cream containing desonide, with greater photostability than the commercial gel-cream (C-GC). Benzophenone-3 (BP-3) was used as a photostabilizing agent. METHODS: The gel-cream developed (D-GC) containing BP-3 at 0.1% was prepared and characterized regarding its pH, drug content, spreadability, viscosity, in vitro drug release and in vitro permeation. The in vivo anti-inflammatory effect was assessed by ear edema measurement, croton oil-induced acute skin inflammation and myeloperoxidase assay. RESULTS AND DISCUSSION: D-GC presented characteristics compatible with topical application, appropriate drug content and good spreadability, and non-Newtonian behavior with pseudoplastic flow. D-GC showed a good photostability profile, presenting a desonide content of 95.70% after 48 h of exposure to UVA radiation, and stability under room conditions during 60 days. The amount of desonide released from D-GC and C-GC was 57.8 and 51.7 µg/cm2, respectively, measured using the vertical Franz cell. The in vitro skin permeation showed that desonide reached the site of action of the topical corticosteroids, from both formulations; however, the desonide amount retained in the dermis was lower with D-GC. The in vivo evaluation of topical anti-inflammatory activity indicated that D-GC presented the same biological effect as C-GC. CONCLUSION: D-GC represents a promising approach to treat dermatological disorders, since it presented satisfactory physicochemical characteristics, the same biological activity as C-GC and superior photostability, conferred by the addition of BP-3 at 0.1%.


Assuntos
Benzofenonas/química , Dermatite de Contato/tratamento farmacológico , Desonida/química , Desonida/farmacologia , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Química Farmacêutica , Óleo de Cróton/toxicidade , Fármacos Dermatológicos/química , Fármacos Dermatológicos/farmacologia , Modelos Animais de Doenças , Orelha , Géis , Glucocorticoides/química , Glucocorticoides/farmacologia , Humanos , Masculino , Camundongos , Pele/efeitos dos fármacos , Creme para a Pele/química , Creme para a Pele/farmacologia , Raios Ultravioleta
15.
J Chem Inf Model ; 55(2): 207-13, 2015 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-25629725

RESUMO

VAMMPIRE-LORD (lead optimization by rational design) describes an innovative strategy to improve the binding affinity of a defined lead compound using 3D matched molecular pairs (3D-MMPs). 3D-MMPs are defined as pairs of molecules that differ in exactly one structural transformation and have a known bioactive conformation. We developed a novel atom-pair descriptor (LORD_FP) that represents the ligand-as well as the receptor environment-of a chemical transformation and built a predictive model based on 17602 3D-MMPs. We demonstrate that the created model is able to extrapolate the knowledge of a chemical transformation and the associated effect on ligand affinity to any similar system. VAMMPIRE-LORD was implemented as a web server that guides the user step-by-step through the optimization process of a defined lead compound.


Assuntos
Bases de Dados de Compostos Químicos , Descoberta de Drogas/métodos , Internet/instrumentação , Algoritmos , Inibidores de Ciclo-Oxigenase 2/química , Inibidores de Ciclo-Oxigenase 2/farmacologia , Descoberta de Drogas/instrumentação , Previsões , Ligantes , Modelos Moleculares , Conformação Molecular , Software , Relação Estrutura-Atividade
16.
Bioorg Med Chem ; 23(3): 499-514, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25583100

RESUMO

Nuclear receptors, especially the peroxisome proliferator activated receptors (PPARs) and the farnesoid X receptor (FXR) fulfill crucial roles in metabolic balance. Their activation offers valuable therapeutic potential which has high clinical relevance with the fibrates and glitazones as PPAR agonistic drugs. With growing knowledge about the various functions of nuclear receptors in many disorders, new selective or dual ligands of these pharmaceutical targets are however still required. Here we report the class of anthranilic acid derivatives as novel selective PPAR or dual FXR/PPAR ligands. We identified distinct molecular determinants that govern selectivity for each PPAR subtype or FXR as well as the amplitude of activation of the respective receptors. We thereby discovered several lead compounds for further optimization and developed a highly potent dual PPARα/FXR partial agonist that might have a beneficial synergistic effect on lipid homeostasis by simultaneous activation of two nuclear receptors involved in lipid metabolism.


Assuntos
Receptores Ativados por Proliferador de Peroxissomo/agonistas , Receptores Citoplasmáticos e Nucleares/agonistas , ortoaminobenzoatos/farmacologia , Animais , Células COS , Chlorocebus aethiops , Ligantes , Metabolismo dos Lipídeos/efeitos dos fármacos , Receptores Ativados por Proliferador de Peroxissomo/química , Receptores Citoplasmáticos e Nucleares/química , Relação Estrutura-Atividade , ortoaminobenzoatos/química
17.
Bioorg Med Chem ; 22(19): 5354-67, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25150091

RESUMO

Sphingosine kinases (SphK1, SphK2) are main regulators of sphingosine-1-phosphate (S1P), which is a pleiotropic lipid mediator involved in numerous physiological and pathophysiological functions. SphKs are targets for novel anti-cancer and anti-inflammatory agents that can promote cell apoptosis and modulate autoimmune diseases. Herein, we describe the design, synthesis and evaluation of an aminothiazole class of SphK inhibitors. Potent inhibitors have been discovered through a series of modifications using the known SKI-II scaffold to define structure-activity relationships. We identified N-(4-methylthiazol-2-yl)-(2,4'-bithiazol)-2'-amine (24, ST-1803; IC50 values: 7.3 µM (SphK1), 6.5 µM (SphK2)) as a promising candidate for further in vivo investigations and structural development.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Desenho de Fármacos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Tiazóis/síntese química , Tiazóis/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Relação Dose-Resposta a Droga , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Conformação Molecular , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade , Tiazóis/química
18.
Tetrahedron ; 70(34): 5260-5266, 2014 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-25170180

RESUMO

The synthesis of several sulfates of trichothecene mycotoxins is presented. Deoxynivalenol (DON) and its acetylated derivatives were synthesized from 3-acetyldeoxynivalenol (3ADON) and used as substrate for sulfation in order to reach a series of five different DON-based sulfates as well as T2-toxin-3-sulfate. These substances are suspected to be formed during phase-II metabolism in plants and humans. The sulfation was performed using a sulfuryl imidazolium salt, which was synthesized prior to use. All protected intermediates and final products were characterized via NMR and will serve as reference materials for further investigations in the fields of toxicology and bioanalytics of mycotoxins.

19.
Beilstein J Org Chem ; 10: 1129-34, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24991263

RESUMO

The development of a reliable procedure for the synthesis of the 16-glucoside and 16-sulfate of the resorcylic acid lactone (RAL) type compound zearalenone is presented. Different protective group strategies were considered and applied to enable the preparation of glucosides and sulfates that are difficult to access up to now. Acetyl and p-methoxybenzyl protection led to undesired results and were shown to be inappropriate. Finally, triisopropylsilyl-protected zearalenone was successfully used as intermediate for the first synthesis of the corresponding mycotoxin glucoside and sulfate that are highly valuable as reference materials for further studies in the emerging field of masked mycotoxins. Furthermore, high stability was observed for aryl sulfates prepared as tetrabutylammonium salts. Overall, these findings should be applicable for the synthesis of similar RAL type and natural product conjugates.

20.
Eur J Psychol ; 20(1): 25-40, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38487601

RESUMO

Interventions can foster personal growth. However, our understanding of the specific mechanisms for change and the types of interventions driving this growth process remains limited. In this study, we focused on emotion regulation ability as a potential mechanism. We examined the effects of an affirmation coaching intervention on changes in emotion regulation ability, an important facet of personality. In this coaching intervention, participants created a personal mantra/goal derived from a selected image and positive associations linked to this image (motto goals). This is considered to enhance emotion regulation abilities by internalizing self-stabilizing value. We assigned sixty-six participants to either this affirmation coaching intervention or one of two control coaching interventions: specific-goal versus indulgence coaching. Before and after each intervention, participants completed questionnaires. Only the affirmation coaching intervention significantly increased in adaptive aspects of personality. Notably, the affirmation coaching intervention increased emotion regulation ability, and this effect persisted even when controlling for extraversion and neuroticism. Furthermore, exploratory analysis showed that extraversion increased following the affirmation coaching, while neuroticism remained unchanged. Our results suggest that emotion regulation ability might be the key factor in personality growth. It could be more malleable and/or respond more strongly to short-term coaching, compared to neuroticism. Thus, the malleability of personality traits may not be an all-or-nothing phenomenon; rather, it could depend on the facet of emotion regulation ability. We discuss potential mechanisms of personality growth, distinguishing between emotion regulation and emotion sensitivity.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA