RESUMO
A fundamental challenge in developing treatments for autism spectrum disorders is the heterogeneity of the condition. More than one hundred genetic mutations confer high risk for autism, with each individual mutation accounting for only a small fraction of cases1-3. Subsets of risk genes can be grouped into functionally related pathways, most prominently those involving synaptic proteins, translational regulation, and chromatin modifications. To attempt to minimize this genetic complexity, recent therapeutic strategies have focused on the neuropeptides oxytocin and vasopressin4-6, which regulate aspects of social behaviour in mammals7. However, it is unclear whether genetic risk factors predispose individuals to autism as a result of modifications to oxytocinergic signalling. Here we report that an autism-associated mutation in the synaptic adhesion molecule Nlgn3 results in impaired oxytocin signalling in dopaminergic neurons and in altered behavioural responses to social novelty tests in mice. Notably, loss of Nlgn3 is accompanied by a disruption of translation homeostasis in the ventral tegmental area. Treatment of Nlgn3-knockout mice with a new, highly specific, brain-penetrant inhibitor of MAP kinase-interacting kinases resets the translation of mRNA and restores oxytocin signalling and social novelty responses. Thus, this work identifies a convergence between the genetic autism risk factor Nlgn3, regulation of translation, and oxytocinergic signalling. Focusing on such common core plasticity elements might provide a pragmatic approach to overcoming the heterogeneity of autism. Ultimately, this would enable mechanism-based stratification of patient populations to increase the success of therapeutic interventions.
Assuntos
Transtorno Autístico/metabolismo , Transtorno Autístico/psicologia , Modelos Animais de Doenças , Ocitocina/metabolismo , Comportamento Social , Animais , Moléculas de Adesão Celular Neuronais/deficiência , Moléculas de Adesão Celular Neuronais/genética , Fator de Iniciação 4E em Eucariotos/metabolismo , Masculino , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Área Tegmentar Ventral/citologia , Área Tegmentar Ventral/efeitos dos fármacosRESUMO
Acute heart failure (AHF) is a major burden disease, with a complex physiopathology, unsatisfactory diagnosis, treatment and a very poor prognosis. In the last two decades, a number of drugs have progressed from preclinical to early and late clinical development, but only a few of them have been approved and added to a stagnant pharmacological armamentarium. We have reviewed the data published on drugs developed for AHF since early 2000s, trying to recognise factors that have worked for a successful approval or for the stoppage of the program, in an attempt to delineate future trajectories for AHF drug development. Our review has identified limitations at both preclinical and clinical levels. At the preclinical level, the major shortcoming is represented by animal models looking at short-term endpoints which do not recapitulate the complexity of the human disease. At the clinical level, the main weakness is given by the disconnect between short-term endpoints assessed in the early stage of drug development, and medium-long-term endpoints requested in Phase 3 for regulatory approval. This is further amplified by the lack of validation and standardisation of short- and long-term endpoints; absence of predictive biomarkers; conduct of studies on heterogeneous populations; and use of different eligibility criteria, time of assessments, drug schedules and background therapies. Key goals remain a better understanding of AHF and the construction of a successful drug development program. A reasonable way to move forward resides in a strong collaboration between main stakeholders of therapeutic innovation: scientific community, industry and regulatory agencies.
Assuntos
Cardiotônicos/uso terapêutico , Desenvolvimento de Medicamentos/métodos , Insuficiência Cardíaca/tratamento farmacológico , Doença Aguda , Aprovação de Drogas , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Humanos , Peptídeo Natriurético Encefálico/uso terapêutico , Simendana/uso terapêuticoRESUMO
In the last decade, drug development has tackled substantial challenges to improve efficiency and facilitate access to innovative medicines. Integrated clinical protocols and the investigation of targeted oncology drugs in healthy volunteers (HVs) have emerged as modalities with an increase in scope and complexity of early clinical studies and first-in-human (FIH) studies in particular. However, limited work has been done to explore the impact of these two modalities, alone or in combination, on the scientific value and on the implementation of such articulated studies. We conducted an FIH study in HVs with an oncology targeted drug, an Mnk 1/2 small molecule inhibitor. In this article, we describe results, advantages, and limitations of an integrated clinical protocol with an oncology drug. We further discuss and indicate points to consider when designing and conducting similar scientifically and operationally demanding FIH studies.
Assuntos
Antineoplásicos/efeitos adversos , Doenças Cardiovasculares/diagnóstico , Protocolos Clínicos , Inibidores de Proteínas Quinases/efeitos adversos , Projetos de Pesquisa , Administração Oral , Adulto , Antineoplásicos/administração & dosagem , Doenças Cardiovasculares/induzido quimicamente , Eletrocardiografia , Voluntários Saudáveis , Neoplasias Hematológicas/tratamento farmacológico , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Masculino , Oncologia/métodos , Pessoa de Meia-Idade , Monitorização Ambulatorial/métodos , Inibidores de Proteínas Quinases/administração & dosagem , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Adulto JovemRESUMO
Bacterial tRNA modification synthesis pathways are critical to cell survival under stress and thus represent ideal mechanism-based targets for antibiotic development. One such target is the tRNA-(N1G37) methyltransferase (TrmD), which is conserved and essential in many bacterial pathogens. Here we developed and applied a widely applicable, radioactivity-free, bioluminescence-based high-throughput screen (HTS) against 116350 compounds from structurally diverse small-molecule libraries to identify inhibitors of Pseudomonas aeruginosa TrmD ( PaTrmD). Of 285 compounds passing primary and secondary screens, a total of 61 TrmD inhibitors comprised of more than 12 different chemical scaffolds were identified, all showing submicromolar to low micromolar enzyme inhibitor constants, with binding affinity confirmed by thermal stability and surface plasmon resonance. S-Adenosyl-l-methionine (SAM) competition assays suggested that compounds in the pyridine-pyrazole-piperidine scaffold were substrate SAM-competitive inhibitors. This was confirmed in structural studies, with nuclear magnetic resonance analysis and crystal structures of PaTrmD showing pyridine-pyrazole-piperidine compounds bound in the SAM-binding pocket. Five hits showed cellular activities against Gram-positive bacteria, including mycobacteria, while one compound, a SAM-noncompetitive inhibitor, exhibited broad-spectrum antibacterial activity. The results of this HTS expand the repertoire of TrmD-inhibiting molecular scaffolds that show promise for antibiotic development.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/farmacologia , Metiltransferases/antagonistas & inibidores , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , RNA de Transferência/metabolismo , Antibacterianos/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Descoberta de Drogas , Inibidores Enzimáticos/química , Cinética , Metiltransferases/química , Metiltransferases/genética , Metiltransferases/metabolismo , Pseudomonas aeruginosa/genética , Especificidade por SubstratoRESUMO
[This corrects the article DOI: 10.1021/acsmedchemlett.9b00170.].
RESUMO
SMYD3 is a histone methyltransferase that regulates gene transcription, and its overexpression is associated with multiple human cancers. A novel class of tetrahydroacridine compounds which inhibit SMYD3 through a covalent mechanism of action is identified. Optimization of these irreversible inhibitors resulted in the discovery of 4-chloroquinolines, a new class of covalent warheads. Tool compound 29 exhibits high potency by inhibiting SMYD3's enzymatic activity and showing antiproliferative activity against HepG2 in 3D cell culture. Our findings suggest that covalent inhibition of SMYD3 may have an impact on SMYD3 biology by affecting expression levels, and this warrants further exploration.
RESUMO
Non-profit organizations (NPO) play an increasingly important role in drug discovery and development for diseases that are neglected by the pharmaceutical industry because of low or absent commercial incentives. Governments and major private foundations such as the Wellcome Trust and the Bill & Melinda Gates Foundation increasingly step in to provide strategic direction, communication platforms and major resources, motivated by the fact that major healthcare problems remain unsolved. Drug discovery in the field of neglected diseases is fraught with complexities since, in many cases, important tools are lacking including readily available diagnostics, molecular epidemiology, appropriate model systems, representative strain collections, biomarkers, up-to-date trial methodologies and regulatory strategies. On top of this, the high hurdles addressing novel drug targets must be cleared.
Assuntos
Desenho de Fármacos , Indústria Farmacêutica/organização & administração , Organizações sem Fins Lucrativos/organização & administração , Indústria Farmacêutica/economia , Humanos , Inovação Organizacional , Organizações sem Fins Lucrativos/economia , Terapias em EstudoRESUMO
Cell mediated immunity plays a vital role in defense against influenza infection in humans. Less is known about the role of vaccine-induced cell mediated immunity and the cytokine responses elicited. We measured CD4+ and CD8+ T-cell reactivity in human subjects following vaccination with licensed trivalent influenza vaccine and a novel virus-like particle based vaccine. We detected influenza-specific CD4+ T-cell responses following vaccination with the licensed trivalent influenza vaccine and found that these correlated with antibody measurements. Administration of the novel virus-like particle based vaccine elicited influenza-specific CD4+ and CD8+ T-cell responses and the induction of the cytokines IFN-γ, IL-17A, IL17F, IL-5, IL-13, IL-9, IL-10 and IL-21. Pre-existing cytokine responses influenced the profile of the cytokine response elicited by vaccination. In a subset of individuals the VLP vaccine changed pre-vaccination production of type 2 cytokines such as IL-5 and IL-13 to a post-vaccination type 1 cytokine signature characterized by IFN-γ. A transcriptional signature to vaccination was found to correlate with antibody titer, IFN-γ production by T-cells and expression of a putative RNA helicase, DDX17, on the surface of immune cells.
Assuntos
Linfócitos T CD4-Positivos/fisiologia , Linfócitos T CD8-Positivos/fisiologia , Citocinas/metabolismo , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Ativação Linfocitária/imunologia , Adulto , Formação de Anticorpos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Proliferação de Células , Estudos de Coortes , Feminino , Humanos , Imunidade Celular/imunologia , Influenza Humana/imunologia , Influenza Humana/metabolismo , Masculino , Pessoa de Meia-Idade , Vacinação , Adulto JovemRESUMO
Chronic myeloid leukemia (CML) is a myeloproliferative disease caused by bcr-abl1, a constitutively active tyrosine kinase fusion gene responsible for an abnormal proliferation of leukemic stem cells (LSCs). Inhibition of BCR-ABL1 kinase activity offers long-term relief to CML patients. However, for a proportion of them, BCR-ABL1 inhibition will become ineffective at treating the disease, and CML will progress to blast crisis (BC) CML with poor prognosis. BC-CML is often associated with excessive phosphorylated eukaryotic translation initiation factor 4E (eIF4E), which renders LSCs capable of proliferating via self-renewal, oblivious to BCR-ABL1 inhibition. In vivo, eIF4E is exclusively phosphorylated on Ser209 by MNK1/2. Consequently, a selective inhibitor of MNK1/2 should reduce the level of phosphorylated eIF4E and re-sensitize LSCs to BCR-ABL1 inhibition, thus hindering the proliferation of BC LSCs. We report herein the structure-activity relationships and pharmacokinetic properties of a selective MNK1/2 inhibitor clinical candidate, ETC-206, which in combination with dasatinib prevents BC-CML LSC self-renewal in vitro and enhances dasatinib antitumor activity in vivo.
Assuntos
Crise Blástica/tratamento farmacológico , Proliferação de Células , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Crise Blástica/patologia , Feminino , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Camundongos , Camundongos SCID , Modelos Moleculares , Estrutura Molecular , Conformação Proteica , Inibidores de Proteínas Quinases/química , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
In the early 1980s, it became apparent that the work of pioneers such as Robert Weinberg, Mariano Barbacid and many others in identifying cancer-causing genes in humans was opening the door to a new era in anticancer research. Motivated by this, and by dissatisfaction with the limited efficacy and tolerability of available anticancer modalities, a drug discovery programme was initiated with the aim of rationally developing targeted anticancer therapies. Here, we describe how this programme led to the discovery and continuing development of Glivec (Gleevec in the United States), the first selective tyrosine-kinase inhibitor to be approved for the treatment of a cancer.
Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-kit/efeitos dos fármacos , Pirimidinas/farmacologia , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Animais , Benzamidas , Proteínas de Fusão bcr-abl , Humanos , Mesilato de Imatinib , Piperazinas/química , Piperazinas/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/química , Pirimidinas/uso terapêuticoRESUMO
Protein tyrosine kinases (PTKs) have been recognized as attractive cell-signaling targets for drug discovery in the treatment of cancer and other diseases. Most of the PTK inhibitors are small molecules, designed to compete for, or nearby, the ATP-binding site, and are currently in phase I-III clinical trials, mainly for oncological indications. Recent efforts focused on the synthesis of selective PTK inhibitors have generated several promising clinical candidates, which recently culminated in the approval of Gleevec, the first kinase inhibitor registered for the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Inibidores Enzimáticos/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Animais , Benzamidas , Ensaios Clínicos como Assunto/estatística & dados numéricos , Sistemas de Liberação de Medicamentos/tendências , Inibidores Enzimáticos/administração & dosagem , Humanos , Mesilato de Imatinib , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Piperazinas/administração & dosagem , Piperazinas/uso terapêutico , Proteínas Tirosina Quinases/metabolismo , Pirimidinas/administração & dosagem , Pirimidinas/uso terapêuticoRESUMO
This review starts with a brief history of drug discovery & development, and the place of Asia in this worldwide effort discussed. The conditions and constraints of a successful translational R&D involving academic basic research and clinical research are discussed and the Singapore model for pursuit of open R&D described. The importance of well-characterized, validated drug targets for the search for novel targeted anti-cancer agents is emphasized, as well as a structured, high quality translational R&D. Furthermore, the characteristics of an attractive preclinical development drug candidate are discussed laying the foundation of a successful preclinical development. The most frequent sources of failures are described and risk management at every stage is highly recommended. Organizational factors are also considered to play an important role. The factors to consider before starting a new drug discovery & development project are described, and an example is given of a successful clinical project that has had its roots in local universities and was carried through preclinical development into phase I clinical trials.
RESUMO
METHODS: A novel, fully bacterially produced recombinant virus-like particle (VLP) based influenza vaccine (gH1-Qbeta) against A/California/07/2009(H1N1) was tested in a double-blind, randomized phase I clinical trial at two clinical sites in Singapore. The trial evaluated the immunogenicity and safety of gH1-Qbeta in the presence or absence of alhydrogel adjuvant. Healthy adult volunteers with no or low pre-existing immunity against A/California/07/2009 (H1N1) were randomized to receive two intramuscular injections 21 days apart, with 100µg vaccine, containing 42µg hemagglutinin antigen. Antibody responses were measured before and 21 days after each immunization by hemagglutination inhibition (HAI) assays. The primary endpoint was seroconversion on Day 42, defined as percentage of subjects which reach a HAI titer ≥40 or achieve an at least 4-fold rise in HAI titer (with pre-existing immunity). The co-secondary endpoints were safety and seroconversion on Day 21. RESULTS: A total of 84 Asian volunteers were enrolled in this study and randomized to receive the adjuvanted (n=43) or the non-adjuvanted (n=41) vaccine. Of those, 43 and 37 respectively (95%) completed the study. There were no deaths or serious adverse events reported during this trial. A total of 535 adverse events occurred during treatment with 49.5% local solicited symptoms, of mostly (76.4%) mild severity. The most common treatment-related systemic symptom was fatigue. The non-adjuvanted vaccine met all primary and secondary endpoints and showed seroconversion in 62.2% and 70.3% of participants respectively on Day 21 and Day 42. While the adjuvanted vaccine showed an increased seroconversion from 25.5% (Day 21) to 51.2% (Day 42), it did not meet the immunogenicity endpoint. CONCLUSION: In summary, non-adjuvanted gH1-Qbeta showed similar antibody mediated immunogenicity and a comparable safety profile in healthy humans to commercially available vaccines. These results warrant the consideration of this VLP vaccine platform for the vaccination against influenza infection (HSA CTC1300092).
Assuntos
Formação de Anticorpos , Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza/uso terapêutico , Influenza Humana/prevenção & controle , Adjuvantes Imunológicos/administração & dosagem , Adulto , Hidróxido de Alumínio/administração & dosagem , Anticorpos Antivirais/sangue , Método Duplo-Cego , Determinação de Ponto Final , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Masculino , Pessoa de Meia-Idade , Singapura , Vacinas de Partículas Semelhantes a Vírus/uso terapêutico , Adulto JovemRESUMO
Influenza pandemics can spread quickly and cost millions of lives; the 2009 H1N1 pandemic highlighted the shortfall in the current vaccine strategy and the need for an improved global response in terms of shortening the time required to manufacture the vaccine and increasing production capacity. Here we describe the pre-clinical assessment of a novel 2009 H1N1 pandemic influenza vaccine based on the E. coli-produced HA globular head domain covalently linked to virus-like particles derived from the bacteriophage Qß. When formulated with alum adjuvant and used to immunize mice, dose finding studies found that a 10 µg dose of this vaccine (3.7 µg globular HA content) induced antibody titers comparable to a 1.5 µg dose (0.7 µg globular HA content) of the licensed 2009 H1N1 pandemic vaccine Panvax, and significantly reduced viral titers in the lung following challenge with 2009 H1N1 pandemic influenza A/California/07/2009 virus. While Panvax failed to induce marked T cell responses, the novel vaccine stimulated substantial antigen-specific interferon-γ production in splenocytes from immunized mice, alongside enhanced IgG2a antibody production. In ferrets the vaccine elicited neutralizing antibodies, and following challenge with influenza A/California/07/2009 virus reduced morbidity and lowered viral titers in nasal lavages.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Células Th1/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Adjuvantes Imunológicos , Compostos de Alúmen , Animais , Especificidade de Anticorpos , Bacteriófagos/imunologia , Escherichia coli/genética , Escherichia coli/imunologia , Feminino , Furões/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Imunoglobulina G/imunologia , Interferon gama/biossíntese , Camundongos , Infecções por Orthomyxoviridae/prevenção & controle , RNA Bacteriano/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Células Th1/metabolismoRESUMO
The emergence of bacterial drug resistance highlights the need for new antibacterial targets. The role of protein kinases in signal transduction and cell regulation is ubiquitous. In spite of this the development of small molecule inhibitors of bacterial protein kinases has been slow, and no inhibitor has yet been successfully introduced to clinical use. In this review we focus on recent developments in inhibitors of the Histidine kinase family and pay particular attention to work on inhibiting the YycG Histidine kinase. We also highlight exciting new work in developing inhibitors for the eukaryote-like protein kinases of Mycobacterium tuberculosis including attempts to develop multi-target inhibitors.