RESUMO
Phosphodiesterase 5 (PDE5) is a cyclic guanosine monophosphate-degrading enzyme involved in numerous biological pathways. Inhibitors of PDE5 are important therapeutics for the treatment of neurodegenerative diseases, including Alzheimer's disease (AD). We previously reported the first generation of quinoline-based PDE5 inhibitors for the treatment of AD. However, the short in vitro microsomal stability rendered them unsuitable drug candidates. Here we report a series of new quinoline-based PDE5 inhibitors. Among them, compound 4b, 8-cyclopropyl-3-(hydroxymethyl)-4-(((6-methoxypyridin-3-yl)methyl)amino)quinoline-6-carbonitrile, shows a PDE5 IC50 of 20 nM and improved in vitro microsomal stability (t1/2 = 44.6 min) as well as excellent efficacy in restoring long-term potentiation, a type of synaptic plasticity to underlie memory formation, in electrophysiology experiments with a mouse model of AD. These results provide an insight into the development of a new class of PDE5 inhibitors for the treatment of AD.
Assuntos
Doença de Alzheimer , Quinolinas , Camundongos , Animais , Inibidores da Fosfodiesterase 5/farmacologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Plasticidade Neuronal , Doença de Alzheimer/tratamento farmacológico , Quinolinas/farmacologia , Quinolinas/uso terapêuticoRESUMO
Phosphoinositide 3-kinase (PI3K) and the proteasome pathway are both involved in activating the mechanistic target of rapamycin (mTOR). Because mTOR signaling is required for initiation of messenger RNA translation, we hypothesized that cotargeting the PI3K and proteasome pathways might synergistically inhibit translation of c-Myc. We found that a novel PI3K δ isoform inhibitor TGR-1202, but not the approved PI3Kδ inhibitor idelalisib, was highly synergistic with the proteasome inhibitor carfilzomib in lymphoma, leukemia, and myeloma cell lines and primary lymphoma and leukemia cells. TGR-1202 and carfilzomib (TC) synergistically inhibited phosphorylation of the eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1), leading to suppression of c-Myc translation and silencing of c-Myc-dependent transcription. The synergistic cytotoxicity of TC was rescued by overexpression of eIF4E or c-Myc. TGR-1202, but not other PI3Kδ inhibitors, inhibited casein kinase-1 ε (CK1ε). Targeting CK1ε using a selective chemical inhibitor or short hairpin RNA complements the effects of idelalisib, as a single agent or in combination with carfilzomib, in repressing phosphorylation of 4E-BP1 and the protein level of c-Myc. These results suggest that TGR-1202 is a dual PI3Kδ/CK1ε inhibitor, which may in part explain the clinical activity of TGR-1202 in aggressive lymphoma not found with idelalisib. Targeting CK1ε should become an integral part of therapeutic strategies targeting translation of oncogenes such as c-Myc.
Assuntos
Caseína Quinase 1 épsilon/antagonistas & inibidores , Neoplasias Hematológicas , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-myc/biossíntese , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Camundongos , Oligopeptídeos/farmacologia , Biossíntese de Proteínas , Distribuição Aleatória , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We have previously identified and reported several potent piperidine-derived amide inhibitors of the human soluble epoxide hydrolase (sEH) enzyme. The inhibition of this enzyme leads to elevated levels of epoxyeicosatrienoic acids (EETs), which are known to possess anti-inflammatory, vasodilatory, and anti-fibrotic effects. Herein, we report the synthesis of 9 analogs of the lead sEH inhibitor and the follow-up structure-activity relationship and liver microsome stability studies. Our findings show that isosteric modifications that lead to significant alterations in the steric and electronic properties at a specific position in the molecule can reduce the efficacy by up to 75-fold. On the other hand, substituting hydrogen with deuterium produces a notable increase (â¼30%) in the molecules' half-lives in both rat and human microsomes, while maintaining sEH inhibition potency. These data highlight the utility of isosteric replacement for improving bioavailability, and the newly-synthesized inhibitor structures may thus, serve as a starting point for preclinical development. Our docking study reveals that in the catalytic pocket of sEH, these analogs are in proximity of the key amino acids involved in hydrolysis of EETs.
Assuntos
Amidas , Inibidores Enzimáticos , Epóxido Hidrolases , Metabolismo dos Lipídeos/efeitos dos fármacos , Simulação de Acoplamento Molecular , Piperidinas , Amidas/química , Amidas/farmacologia , Animais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/química , Epóxido Hidrolases/metabolismo , Feminino , Humanos , Masculino , Piperidinas/química , Piperidinas/farmacologia , RatosRESUMO
Venous thrombosis (VT) is a common vascular disease associated with reduced survival and a high recurrence rate. Previous studies have shown that the accumulation of platelets and neutrophils at sites of endothelial cell activation is a primary event in VT, but a role for platelet αIIbß3 in the initiation of venous thrombosis has not been established. This task has been complicated by the increased bleeding linked to partial agonism of current αIIbß3 inhibitory drugs such as tirofiban (Aggrastat ® ). Here, we show that m-tirofiban, an engineered version of tirofiban, is not a partial agonist of αIIbß3. This is based on its cryo-EM structure in complex with human full-length αIIbß3 and its inability to increase expression of an activation-sensitive epitope on platelet αIIbß3. m-tirofiban abolished agonist-induced platelet aggregation ex vivo at concentrations that preserved clot retraction and markedly suppressed the accumulation of platelets, neutrophils, and fibrin on thrombin-activated endothelium in real-time using intravital microscopy in a mouse model of venous thrombogenesis. Unlike tirofiban, however, m-tirofiban did not increase bleeding at the thrombosis-inhibitory dose. These findings establish a key role for αIIbß3 in the initiation of VT, provide a guiding principle for designing potentially safer inhibitors for other integrins, and suggest that pure antagonists of αIIbß3 like m-tirofiban merit further consideration as potential thromboprophylaxis agents in patients at high-risk for VT and hemorrhage.
RESUMO
A series of potent amide non-urea inhibitors of soluble epoxide hydrolase (sEH) is disclosed. The inhibition of soluble epoxide hydrolase leads to elevated levels of epoxyeicosatrienoic acids (EETs), and thus inhibitors of sEH represent one of a novel approach to the development of vasodilatory and anti-inflammatory drugs. Structure-activities studies guided optimization of a lead compound, identified through high-throughput screening, gave rise to sub-nanomolar inhibitors of human sEH with stability in human liver microsomal assay suitable for preclinical development.
Assuntos
Epóxido Hidrolases/antagonistas & inibidores , Piperidinas/síntese química , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Domínio Catalítico , Humanos , Concentração Inibidora 50 , Microssomos Hepáticos/enzimologia , Modelos Moleculares , Estrutura Molecular , Piperidinas/química , Piperidinas/farmacologia , Inibidores de Proteases/farmacologia , Solubilidade , Relação Estrutura-Atividade , Ureia/química , Ureia/farmacologia , Vasodilatadores/síntese química , Vasodilatadores/química , Vasodilatadores/farmacologiaRESUMO
Accumulated evidence indicates that the interconversion of iron between ferric (Fe(3+)) and ferrous (Fe(2+)) can be realized through interaction with reactive oxygen species in the Fenton and Haber-Weiss reactions and thereby physiologically effects redox cycling. The imbalance of iron and ROS may eventually cause tissue damage such as renal proximal tubule injury and necrosis. Many approaches were exploited to ameliorate the oxidative stress caused by the imbalance. (-)-Epigallocatechin-3-gallate, the most active and most abundant catechin in tea, was found to be involved in the protection of a spectrum of renal injuries caused by oxidative stress. Most of studies suggested that EGCG works as an antioxidant. In this paper, Multivariate analysis of the LC-MS data of tea extracts and binding assays showed that the tea polyphenol EGCG can form stable complex with iron through the protein Ngal, a biomarker of acute kidney injury. UV-Vis and Luminescence spectrum methods showed that Ngal can inhibit the chemical reactivity of iron and EGCG through forming an Ngal-EGCG-iron complex. In thinking of the interaction of iron and ROS, we proposed that EGCG may work as both antioxidant and Ngal binding siderphore in protection of kidney from injuries.
Assuntos
Proteínas de Fase Aguda/química , Antioxidantes/química , Catequina/análogos & derivados , Ferro/química , Lipocalinas/química , Proteínas Proto-Oncogênicas/química , Antioxidantes/isolamento & purificação , Catequina/química , Catequina/isolamento & purificação , Cloretos , Cromatografia Líquida , Compostos Férricos , Compostos Ferrosos , Lipocalina-2 , Espectrometria de Massas , Oxirredução , Extratos Vegetais/química , Ligação Proteica , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/química , Proteínas Recombinantes/química , Chá/químicaRESUMO
The lipocalins are secreted proteins that bind small organic molecules. Scn-Ngal (also known as neutrophil gelatinase associated lipocalin, siderocalin, lipocalin 2) sequesters bacterial iron chelators, called siderophores, and consequently blocks bacterial growth. However, Scn-Ngal is also prominently expressed in aseptic diseases, implying that it binds additional ligands and serves additional functions. Using chemical screens, crystallography and fluorescence methods, we report that Scn-Ngal binds iron together with a small metabolic product called catechol. The formation of the complex blocked the reactivity of iron and permitted its transport once introduced into circulation in vivo. Scn-Ngal then recycled its iron in endosomes by a pH-sensitive mechanism. As catechols derive from bacterial and mammalian metabolism of dietary compounds, the Scn-Ngal-catechol-Fe(III) complex represents an unforeseen microbial-host interaction, which mimics Scn-Ngal-siderophore interactions but instead traffics iron in aseptic tissues. These results identify an endogenous siderophore, which may link the disparate roles of Scn-Ngal in different diseases.
Assuntos
Proteínas de Fase Aguda/metabolismo , Catecóis/metabolismo , Ferro/sangue , Rim/metabolismo , Lipocalinas/metabolismo , Proteínas Oncogênicas/metabolismo , Proteínas de Fase Aguda/química , Animais , Catecóis/sangue , Catecóis/química , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Biologia Computacional , Cristalografia por Raios X , Endossomos/metabolismo , Corantes Fluorescentes , Humanos , Ferro/química , Quelantes de Ferro/metabolismo , Ligantes , Lipocalina-2 , Lipocalinas/sangue , Lipocalinas/química , Camundongos , Proteínas Oncogênicas/sangue , Proteínas Oncogênicas/química , Ligação Proteica , Proteínas Recombinantes/química , Sideróforos/metabolismoRESUMO
Inhibition of soluble epoxide hydrolase (sEH) has been proposed as a new pharmaceutical approach for treating hypertension and vascular inflammation. The most potent sEH inhibitors reported in literature to date are urea derivatives. However, these compounds have limited pharmacokinetic profiles. We investigated non-urea amide derivatives as sEH inhibitors and identified a potent human sEH inhibitor 14-34 having potency comparable to urea-based inhibitors.
Assuntos
Química Farmacêutica/métodos , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Amidas/química , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Corantes Fluorescentes/farmacologia , Humanos , Ligação de Hidrogênio , Hipertensão/tratamento farmacológico , Inflamação/tratamento farmacológico , Concentração Inibidora 50 , Microscopia de Fluorescência/métodos , Modelos Químicos , Solubilidade , Relação Estrutura-AtividadeRESUMO
The lymphoid tyrosine phosphatase (LYP), encoded by the PTPN22 gene, has recently been identified as a promising drug target for human autoimmunity diseases. Like the majority of protein-tyrosine phosphatases LYP can adopt two functionally distinct forms determined by the conformation of the WPD-loop. The WPD-loop plays an important role in the catalytic dephosphorylation by protein-tyrosine phosphatases. Here we investigate the binding modes of two chemotypes of small molecule LYP inhibitors with respect to both protein conformations using computational modeling. To evaluate binding in the active form, we built a LYP protein structure model of high quality. Our results suggest that the two different compound classes investigated, bind to different conformations of the LYP phosphatase domain. Binding to the closed form is facilitated by an interaction with Asp195 in the WPD-loop, presumably stabilizing the active conformation. The analysis presented here is relevant for the design of inhibitors that specifically target either the closed or the open conformation of LYP in order to achieve better selectivity over phosphatases with similar binding sites.
Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 22/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 22/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Domínio Catalítico , Humanos , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Proteína Tirosina Fosfatase não Receptora Tipo 22/químicaRESUMO
BK channels are composed of alpha-subunits, which form a voltage- and Ca(2+)-gated potassium channel, and of modulatory beta-subunits. The beta1-subunit is expressed in smooth muscle, where it renders the BK channel sensitive to [Ca(2+)](i) in a voltage range near the smooth-muscle resting potential and slows activation and deactivation. BK channel acts thereby as a damped feedback regulator of voltage-dependent Ca(2+) channels and of smooth muscle tone. We explored the contacts between alpha and beta1 by determining the extent of endogenous disulfide bond formation between cysteines substituted just extracellular to the two beta1 transmembrane (TM) helices, TM1 and TM2, and to the seven alpha TM helices, consisting of S1-S6, conserved in all voltage-dependent potassium channels, and the unique S0 helix, which we previously concluded was partly surrounded by S1-S4. We now find that the extracellular ends of beta1 TM2 and alpha S0 are in contact and that beta1 TM1 is close to both S1 and S2. The extracellular ends of TM1 and TM2 are not close to S3-S6. In almost all cases, cross-linking of TM2 to S0 or of TM1 to S1 or S2 shifted the conductance-voltage curves toward more positive potentials, slowed activation, and speeded deactivation, and in general favored the closed state. TM1 and TM2 are in position to contribute, in concert with the extracellular loop and the intracellular N- and C-terminal tails of beta1, to the modulation of BK channel function.
Assuntos
Canais de Potássio Ativados por Cálcio de Condutância Alta/química , Modelos Moleculares , Músculo Liso/metabolismo , Estrutura Terciária de Proteína , Cisteína/química , Dissulfetos/química , Eletrofisiologia , Canais de Potássio Ativados por Cálcio de Condutância Alta/fisiologiaRESUMO
During exercise, defects in calcium (Ca2+) release have been proposed to impair muscle function. Here, we show that during exercise in mice and humans, the major Ca2+ release channel required for excitation-contraction coupling (ECC) in skeletal muscle, the ryanodine receptor (RyR1), is progressively PKA-hyperphosphorylated, S-nitrosylated, and depleted of the phosphodiesterase PDE4D3 and the RyR1 stabilizing subunit calstabin1 (FKBP12), resulting in "leaky" channels that cause decreased exercise tolerance in mice. Mice with skeletal muscle-specific calstabin1 deletion or PDE4D deficiency exhibited significantly impaired exercise capacity. A small molecule (S107) that prevents depletion of calstabin1 from the RyR1 complex improved force generation and exercise capacity, reduced Ca2+-dependent neutral protease calpain activity and plasma creatine kinase levels. Taken together, these data suggest a possible mechanism by which Ca2+ leak via calstabin1-depleted RyR1 channels leads to defective Ca2+ signaling, muscle damage, and impaired exercise capacity.
Assuntos
Adaptação Fisiológica , Canais de Cálcio/metabolismo , Exercício Físico , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologiaRESUMO
Large-conductance, voltage- and Ca(2+)-gated potassium (BK) channels control excitability in a number of cell types. BK channels are composed of alpha subunits, which contain the voltage-sensor domains and the Ca(2+)- sensor domains and form the pore, and often one of four types of beta subunits, which modulate the channel in a cell-specific manner. beta 4 is expressed in neurons throughout the brain. Deletion of beta 4 in mice causes temporal lobe epilepsy. Compared with channels composed of alpha alone, channels composed of alpha and beta 4 activate and deactivate more slowly. We inferred the locations of the two beta 4 transmembrane (TM) helices TM1 and TM2 relative to the seven alpha TM helices, S0-S6, from the extent of disulfide bond formation between cysteines substituted in the extracellular flanks of these TM helices. We found that beta 4 TM2 is close to alpha S0 and that beta 4 TM1 is close to both alpha S1 and S2. At least at their extracellular ends, TM1 and TM2 are not close to S3-S6. In six of eight of the most highly crosslinked cysteine pairs, four crosslinks from TM2 to S0 and one each from TM1 to S1 and S2 had small effects on the V(50) and on the rates of activation and deactivation. That disulfide crosslinking caused only small functional perturbations is consistent with the proximity of the extracellular ends of TM2 to S0 and of TM1 to S1 and to S2, in both the open and closed states.
Assuntos
Canais de Potássio Ativados por Cálcio de Condutância Alta/química , Canais de Potássio Ativados por Cálcio de Condutância Alta/genética , Modelos Moleculares , Domínios e Motivos de Interação entre Proteínas/fisiologia , Estrutura Terciária de Proteína , Sequência de Aminoácidos , Animais , Biotinilação/métodos , Linhagem Celular Transformada , Cisteína/genética , Humanos , Potenciais da Membrana/genética , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida/métodos , Técnicas de Patch-Clamp/métodos , Relação Estrutura-Atividade , Transfecção/métodosRESUMO
Nitric oxide (NO) is a gaseous molecule that plays a multifactorial role in several cellular processes. In the central nervous system, the NO dual nature in neuroprotection and neurotoxicity has been explored to unveil its involvement in Alzheimer's disease (AD). A growing body of research shows that the activation of the NO signaling pathway leading to the phosphorylation of the transcription factor cyclic adenine monophosphate responsive element binding protein (CREB) (so-called NO/cGMP/PKG/CREB signaling pathway) ameliorates altered neuroplasticity and memory deficits in AD animal models. In addition to NO donors, several other pharmacological agents, such as phosphodiesterase 5 (PDE5) inhibitors have been used to activate the pathway and rescue memory disorders. PDE5 inhibitors, including sildenafil, tadalafil and vardenafil, are marketed for the treatment of erectile dysfunction and arterial pulmonary hypertension due to their vasodilatory properties. The ability of PDE5 inhibitors to interfere with the NO/cGMP/PKG/CREB signaling pathway by increasing the levels of cGMP has prompted the hypothesis that PDE5 inhibition might be used as an effective therapeutic strategy for the treatment of AD. To this end, newly designed PDE5 inhibitors belonging to different chemical classes with improved pharmacologic profile (e.g. higher potency, improved selectivity, and blood-brain barrier penetration) have been synthesized and evaluated in several animal models of AD. In addition, recent medicinal chemistry effort has led to the development of agents concurrently acting on the PDE5 enzyme and a second target involved in AD. Both marketed and investigational PDE5 inhibitors have shown to reverse cognitive defects in young and aged wild type mice as well as transgenic mouse models of AD and tauopathy using a variety of behavioral tasks. These studies confirmed the therapeutic potential of PDE5 inhibitors as cognitive enhancers. However, clinical studies assessing cognitive functions using marketed PDE5 inhibitors have not been conclusive. Drug discovery efforts by our group and others are currently directed towards the development of novel PDE5 inhibitors tailored to AD with improved pharmacodynamic and pharmacokinetic properties. In summary, the present perspective reports an overview of the correlation between the NO signaling and AD, as well as an outline of the PDE5 inhibitors used as an alternative approach in altering the NO pathway leading to an improvement of learning and memory. The last two sections describe the preclinical and clinical evaluation of PDE5 inhibitors for the treatment of AD, providing a comprehensive analysis of the current status of the AD drug discovery efforts involving PDE5 as a new therapeutic target.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Modelos Animais de Doenças , Inibidores da Fosfodiesterase 5/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Doença de Alzheimer/enzimologia , Doença de Alzheimer/metabolismo , Animais , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Humanos , Óxido Nítrico/metabolismoRESUMO
We previously identified the N-quinoline-benzenesulfonamide (NQBS) scaffold as a potent inhibitor of nuclear factor-κB (NF-κB) translocation. Now, we report the structure-activity relationship of compounds with the NQBS scaffold in models of diffuse large B-cell lymphoma (DLBCL). We identified CU-O42, CU-O47, and CU-O75 as NQBS analogs with the most potent cytotoxic activity in DLBCL lines. Their anti-lymphoma effect was mediated by NF-κB sequestration to the cytoplasm of DLBCL cells. Internal Coordinates Mechanics analysis suggested direct binding between CU-O75 and IκBα/p50/p65 which leads to the stabilization of the NF-κB trimer. A whole cellular thermal shift assay confirmed direct binding of the NQBS to IκBα, an inhibitory component of the IκBα/p50/p65 trimer. Lymphoma cell line sequencing revealed CU-O75 induced downregulation of NF-κB-dependent genes and DeMAND analysis identified IκBα as one of the top protein targets for CU-O75. CU-O42 was potent in inhibiting tumor growth in two mouse models of aggressive lymphomas.
RESUMO
Enhancing stress resilience in at-risk populations could significantly reduce the incidence of stress-related psychiatric disorders. We have previously reported that the administration of (R,S)-ketamine prevents stress-induced depressive-like behavior in male mice, perhaps by altering α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated transmission in hippocampal CA3. However, it is still unknown whether metabolites of (R,S)-ketamine can be prophylactic in both sexes. We administered (R,S)-ketamine or its metabolites (2R,6R)-hydroxynorketamine ((2R,6R)-HNK) and (2S,6S)-hydroxynorketamine ((2S,6S)-HNK) at various doses 1 week before one of a number of stressors in male and female 129S6/SvEv mice. Patch clamp electrophysiology was used to determine the effect of prophylactic drug administration on glutamatergic activity in CA3. To examine the interaction between ovarian hormones and stress resilience, female mice also underwent ovariectomy (OVX) surgery and a hormone replacement protocol prior to drug administration. (2S,6S)-HNK and (2R,6R)-HNK protected against distinct stress-induced behaviors in both sexes, with (2S,6S)-HNK attenuating learned fear in male mice, and (2R,6R)-HNK preventing stress-induced depressive-like behavior in both sexes. (R,S)-ketamine and (2R,6R)-HNK, but not (2S,6S)-HNK, attenuated large-amplitude AMPAR-mediated bursts in hippocampal CA3. All three compounds reduced N-methyl-D-aspartate receptor (NMDAR)-mediated currents 1 week after administration. Furthermore, ovarian-derived hormones were necessary for and sufficient to restore (R,S)-ketamine- and (2R,6R)-HNK-mediated prophylaxis in female mice. Our data provide further evidence that resilience-enhancing prophylactics may alter AMPAR-mediated glutamatergic transmission in CA3. Moreover, we show that prophylactics against stress-induced depressive-like behavior can be developed in a sex-specific manner and demonstrate that ovarian hormones are necessary for the prophylactic efficacy of (R,S)-ketamine and (2R,6R)-HNK in female mice.
Assuntos
Ketamina , Animais , Fenômenos Eletrofisiológicos , Feminino , Hipocampo/metabolismo , Ketamina/análogos & derivados , Ketamina/farmacologia , Masculino , Camundongos , Receptores de N-Metil-D-Aspartato/metabolismoRESUMO
A quinazoline that decreases polyglutamine aggregate burden in a cell-based assay was identified from a high-throughput screen of a chemical-compound library, provided by the NIH Molecular Libraries Small Molecule Repository (MLSMR). A structure and activity study yielded leads with submicromolar potency.
Assuntos
Química Farmacêutica/métodos , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas Nucleares/antagonistas & inibidores , Quinazolinas/química , Técnicas de Química Combinatória , Desenho de Fármacos , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , Humanos , Proteína Huntingtina , Concentração Inibidora 50 , Modelos Químicos , Estrutura Molecular , Peptídeos/química , Relação Estrutura-AtividadeRESUMO
Soluble epoxide hydrolase (sEH) is a novel target for the treatment of hypertension and vascular inflammation. A new class of potent non-urea sEH inhibitors was identified via high throughput screening (HTS) and chemical modification. IC(50)s of the most potent compounds range from micromolar to low nanomolar.
Assuntos
Descoberta de Drogas/métodos , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/metabolismo , Ureia/metabolismo , Humanos , Solubilidade , Relação Estrutura-Atividade , Ureia/química , Ureia/classificação , Ureia/farmacologiaRESUMO
An IKKbeta inhibitor reported to block NF-kappaB transcriptional activities in Jurkat T cells, was found to enhance NF-kappaB translocation in HUVEC cells. These studies suggested a noncanonical NF-kappaB signaling pathway independent of IKKbeta in HUVEC cells.
Assuntos
NF-kappa B/metabolismo , Quinazolinas/síntese química , Quinazolinas/farmacologia , Técnicas de Química Combinatória , Humanos , Células Jurkat , Leupeptinas/química , Leupeptinas/farmacologia , Estrutura Molecular , NF-kappa B/efeitos dos fármacos , Nitrilas/química , Nitrilas/farmacologia , Quinazolinas/química , Sulfonas/química , Sulfonas/farmacologia , Sulfóxidos/química , Sulfóxidos/farmacologia , Tetrazóis/química , Tetrazóis/farmacologiaRESUMO
BACKGROUND: Soluble aggregates of oligomeric forms of tau protein (oTau) have been associated with impairment of synaptic plasticity and memory in Alzheimer's disease. However, the molecular mechanisms underlying the synaptic and memory dysfunction induced by elevation of oTau are still unknown. METHODS: This work used a combination of biochemical, electrophysiological and behavioral techniques. Biochemical methods included analysis of phosphorylation of the cAMP-responsive element binding (CREB) protein, a transcriptional factor involved in memory, histone acetylation, and expression immediate early genes c-Fos and Arc. Electrophysiological methods included assessment of long-term potentiation (LTP), a type of synaptic plasticity thought to underlie memory formation. Behavioral studies investigated both short-term spatial memory and associative memory. These phenomena were examined following oTau elevation. RESULTS: Levels of phospho-CREB, histone 3 acetylation at lysine 27, and immediate early genes c-Fos and Arc, were found to be reduced after oTau elevation during memory formation. These findings led us to explore whether up-regulation of various components of the nitric oxide (NO) signaling pathway impinging onto CREB is capable of rescuing oTau-induced impairment of plasticity, memory, and CREB phosphorylation. The increase of NO levels protected against oTau-induced impairment of LTP through activation of soluble guanylyl cyclase. Similarly, the elevation of cGMP levels and stimulation of the cGMP-dependent protein kinases (PKG) re-established normal LTP after exposure to oTau. Pharmacological inhibition of cGMP degradation through inhibition of phosphodiesterase 5 (PDE5), rescued oTau-induced LTP reduction. These findings could be extrapolated to memory because PKG activation and PDE5 inhibition rescued oTau-induced memory impairment. Finally, PDE5 inhibition re-established normal elevation of CREB phosphorylation and cGMP levels after memory induction in the presence of oTau. CONCLUSIONS: Up-regulation of CREB activation through agents acting on the NO cascade might be beneficial against tau-induced synaptic and memory dysfunctions.