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Screening of cellular activity for inhibitors of histone lysine modifiers is most frequently performed indirectly by analyzing changes in the total levels of histone marks targeted by lysine methylases/demethylases. However, inhibition of histone lysine modifiers often leads to local rather than total changes in histone marks. Also, because histone modifications can be modulated by more than one cellular enzyme, it is not always clear whether changes in histone marks are a direct or indirect consequence of the inhibitor treatment applied. Direct assessment of target occupation can provide a useful tool to quantify the fraction of an epigenetic modifier that is bound to a pharmacological inhibitor (target engagement). Here, we developed and used a novel chemoprobe-based immunoassay to quantify target engagement in cells. Quantification of the fraction of free KDM1A was made possible, in an immune-based assay, by coupling a biotinylated chemoprobe to a warhead capable of selectively and irreversibly binding to the free active form of KDM1A. The results obtained confirmed that this approach is able to determine the degree of target engagement in a dose-dependent manner. Furthermore, the assay can be also used on tissue extracts to analyze the in vivo pharmacokinetics and pharmacodynamics relationship of KDM1A inhibitors, as has been exemplified with ORY-1001 (iadademstat), a potent and irreversible inhibitor of KDM1A. The principle of this assay may be applied to other targets, and the KDM1A probe may be employed in chemoproteomic analyses.
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Inibidores Enzimáticos , Histona Desmetilases/antagonistas & inibidores , Histona Desmetilases/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/farmacologia , Humanos , Células THP-1RESUMO
Rapid and reliable diagnosis of endometrial cancer (EC) in uterine aspirates is highly desirable. Current sensitivity and failure rate of histological diagnosis limit the success of this method and subsequent hysteroscopy is often necessary. Using quantitative reverse transcriptase-polymerase chain reaction on RNA from uterine aspirates samples, we measured the expression level of 20 previously identified genes involved in EC pathology, created five algorithms based on combinations of five genes and evaluated their ability to diagnose EC. The algorithms were tested in a prospective, double-blind, multicenter study. We enlisted 514 patients who presented with abnormal uterine bleeding. EC was diagnosed in 60 of the 514 patients (12%). Molecular analysis was performed on the remnants of aspirates and results were compared to the final histological diagnoses obtained through biopsies acquired by aspiration or guided by hysteroscopy, or from the specimens resected by hysterectomy. Algorithm 5 was the best performing molecular diagnostic classifier in the case-control and validation study. The molecular test had a sensitivity of 81%, specificity of 96%, positive predictive value (PPV) of 75% and negative predictive value (NPV) of 97%. A combination of the molecular and histological diagnosis had a sensitivity of 91%, specificity of 97%, PPV of 79% and NPV of 99% and the cases that could be diagnosed on uterine aspirate rose from 76 to 93% when combined with the molecular test. Incorporation of the molecular diagnosis increases the reliability of a negative diagnosis, reduces the need for hysteroscopies and helps to identify additional cases.
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Neoplasias do Endométrio/diagnóstico , Neoplasias Uterinas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia/métodos , Estudos de Casos e Controles , Método Duplo-Cego , Neoplasias do Endométrio/patologia , Feminino , Humanos , Histerectomia/métodos , Histeroscopia/métodos , Pessoa de Meia-Idade , Patologia Molecular/métodos , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Hemorragia Uterina/diagnóstico , Hemorragia Uterina/patologia , Neoplasias Uterinas/genética , Neoplasias Uterinas/patologia , Adulto JovemRESUMO
Lysine specific demethylase 1 (LSD1; also known as KDM1A), is an epigenetic modulator that modifies the histone methylation status. KDM1A forms a part of protein complexes that regulate the expression of genes involved in the onset and progression of diseases such as cancer, central nervous system (CNS) disorders, viral infections, and others. Vafidemstat (ORY-2001) is a clinical stage inhibitor of KDM1A in development for the treatment of neurodegenerative and psychiatric diseases. However, the role of ORY-2001 targeting KDM1A in neuroinflammation remains to be explored. Here, we investigated the effect of ORY-2001 on immune-mediated and virus-induced encephalomyelitis, two experimental models of multiple sclerosis and neuronal damage. Oral administration of ORY-2001 ameliorated clinical signs, reduced lymphocyte egress and infiltration of immune cells into the spinal cord, and prevented demyelination. Interestingly, ORY-2001 was more effective and/or faster acting than a sphingosine 1-phosphate receptor antagonist in the effector phase of the disease and reduced the inflammatory gene expression signature characteristic ofEAE in the CNS of mice more potently. In addition, ORY-2001 induced gene expression changes concordant with a potential neuroprotective function in the brain and spinal cord and reduced neuronal glutamate excitotoxicity-derived damage in explants. These results pointed to ORY-2001 as a promising CNS epigenetic drug able to target neuroinflammatory and neurodegenerative diseases and provided preclinical support for the subsequent design of early-stage clinical trials.
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Endometrial cancer (EC) is the most frequent of the invasive tumors of the female genital tract. Although usually detected in its initial stages, a 20% of the patients present with advanced disease. To date, no characterized molecular marker has been validated for the diagnosis of EC. In addition, new methods for prognosis and classification of EC are needed to combat this deadly disease. We thus aimed to identify new molecular markers of EC and to evaluate their validity on endometrial aspirates. Gene expression screening on 52 carcinoma samples and series of real-time quantitative PCR validation on 19 paired carcinomas and normal tissue samples and on 50 carcinoma and noncarcinoma uterine aspirates were performed to identify and validate potential biomarkers of EC. Candidate markers were further confirmed at the protein level by immunohistochemistry and Western blot. We identified ACAA1, AP1M2, CGN, DDR1, EPS8L2, FASTKD1, GMIP, IKBKE, P2RX4, P4HB, PHKG2, PPFIBP2, PPP1R16A, RASSF7, RNF183, SIRT6, TJP3, EFEMP2, SOCS2 and DCN as differentially expressed in ECs. Furthermore, the differential expression of these biomarkers in primary endometrial tumors is correlated to their expression level in corresponding uterine fluid samples. Finally, these biomarkers significantly identified EC with area under the receiver-operating-characteristic values ranging from 0.74 to 0.95 in uterine aspirates. Interestingly, analogous values were found among initial stages. We present the discovery of molecular biomarkers of EC and describe their utility in uterine aspirates. These findings represent the basis for the development of a highly sensitive and specific minimally invasive method for screening ECs.
Assuntos
Biomarcadores Tumorais/análise , Neoplasias do Endométrio/genética , Perfilação da Expressão Gênica , Líquidos Corporais/química , Neoplasias do Endométrio/metabolismo , Feminino , Humanos , Reprodutibilidade dos TestesRESUMO
Lysine-specific demethylase 1 (LSD1 or KDM1A) is a chromatin modifying enzyme playing a key role in the cell cycle and cell differentiation and proliferation through the demethylation of histones and nonhistone substrates. In addition to its enzymatic activity, LSD1 plays a fundamental scaffolding role as part of transcription silencing complexes such as rest co-repressor (CoREST) and nucleosome remodeling and deacetylase (NuRD). A host of classical amine oxidase inhibitors such as tranylcypromine, pargyline, and phenelzine together with LSD1 tool compounds such as SP-2509 and GSK-LSD1 have been extensively utilized in LSD1 mechanistic cancer studies. Additionally, several optimized new chemical entities have reached clinical trials in oncology such as ORY-1001 (iadademstat), GSK2879552, SP-2577 (seclidemstat), IMG-7289 (bomedemstat), INCB059872, and CC-90011 (pulrodemstat). Despite this, no single study exists that characterizes them all under the same experimental conditions, preventing a clear interpretation of published results. Herein, we characterize the whole LSD1 small molecule compound class as inhibitors of LSD1 catalytic activity, disruptors of SNAIL/GFI1 (SNAG)-scaffolding protein-protein interactions, inducers of cell differentiation, and potential anticancer treatments for hematological and solid tumors to yield an updated, unified perspective of this field. Our results highlight significant differences in potency and selectivity among the clinical compounds with iadademstat being the most potent and reveal that most of the tool compounds have very low activity and selectivity, suggesting some conclusions derived from their use should be taken with caution.
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BACKGROUND: Vafidemstat, an inhibitor of the histone lysine-specific demethylase KDM1A, corrects cognition deficits and behavior alterations in rodent models. Here, we report the results from the first-in-human trial of vafidemstat in healthy young and older adult volunteers. A total of 110 volunteers participated: 87 were treated with vafidemstat and 23 with placebo. OBJECTIVES: The study aimed to determine the safety and tolerability of vafidemstat, to characterize its pharmacokinetic and pharmacodynamic profiles, to assess its central nervous system (CNS) exposure, and to acquire the necessary data to select the appropriate doses for long-term treatment of patients with CNS disease in phase II trials. METHODS: This single-center, randomized, double-blind, placebo-controlled phase I trial included a single and 5-day repeated dose-escalation and open-label CNS penetration substudy. Primary outcomes were safety and tolerability; secondary outcomes included analysis of the pharmacokinetics and pharmacodynamics, including chemoprobe-based immune analysis of KDM1A target engagement (TE) in peripheral blood mononuclear cells (PBMCs) and platelet monoamine oxidase B (MAOB) inhibition. CNS and cognitive function were also evaluated. RESULTS: No severe adverse events (AEs) were reported in the dose-escalation stage. AEs were reported at all dose levels; none were dose dependent, and no significant differences were observed between active treatment and placebo. Biochemistry, urinalysis, vital signs, electrocardiogram, and hematology did not change significantly with dose escalation, with the exception of a transient reduction of platelet counts in an extra dose level incorporated for that purpose. Vafidemstat exhibits rapid oral absorption, approximate dose-proportional exposures, and moderate systemic accumulation after 5 days of treatment. The cerebrospinal fluid-to-plasma unbound ratio demonstrated CNS penetration. Vafidemstat bound KDM1A in PBMCs in a dose-dependent manner. No MAOB inhibition was detected. Vafidemstat did not affect the CNS or cognitive function. CONCLUSIONS: Vafidemstat displayed good safety and tolerability. This phase I trial confirmed KDM1A TE and CNS penetration and permitted characterization of platelet dynamics and selection of phase IIa doses. TRIAL REGISTRATION: EUDRACT No. 2015-003721-33, filed 30 October 2015.
Assuntos
Histona Desmetilases/antagonistas & inibidores , Oxidiazóis/farmacocinética , Oxidiazóis/uso terapêutico , Área Sob a Curva , Sistema Nervoso Central/efeitos dos fármacos , Método Duplo-Cego , Feminino , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Masculino , Inibidores da Monoaminoxidase/farmacocinética , Inibidores da Monoaminoxidase/farmacologiaRESUMO
BACKGROUND: Microarrays strategies, which allow for the characterization of thousands of alternative splice forms in a single test, can be applied to identify differential alternative splicing events. In this study, a novel splice array approach was developed, including the design of a high-density oligonucleotide array, a labeling procedure, and an algorithm to identify splice events. RESULTS: The array consisted of exon probes and thermodynamically balanced junction probes. Suboptimal probes were tagged and considered in the final analysis. An unbiased labeling protocol was developed using random primers. The algorithm used to distinguish changes in expression from changes in splicing was calibrated using internal non-spliced control sequences. The performance of this splice array was validated with artificial constructs for CDC6, VEGF, and PCBP4 isoforms. The platform was then applied to the analysis of differential splice forms in lung cancer samples compared to matched normal lung tissue. Overexpression of splice isoforms was identified for genes encoding CEACAM1, FHL-1, MLPH, and SUSD2. None of these splicing isoforms had been previously associated with lung cancer. CONCLUSIONS: This methodology enables the detection of alternative splicing events in complex biological samples, providing a powerful tool to identify novel diagnostic and prognostic biomarkers for cancer and other pathologies.
Assuntos
Processamento Alternativo/genética , Variação Genética , Neoplasias Pulmonares/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Algoritmos , Clonagem Molecular , Cor , Regulação Neoplásica da Expressão Gênica , Humanos , Hibridização de Ácido Nucleico , RNA Mensageiro/genética , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/genéticaRESUMO
The histone demethylase lysine-specific demethylase 1 (LSD1 or KDM1A) has emerged as a candidate therapeutic target in acute myeloid leukaemia (AML); tranylcypromine-derivative inhibitors induce loss of clonogenic activity and promote differentiation, in particular in the MLL-translocated molecular subtype of AML. In AML, the use of drugs in combination often delivers superior clinical activity. To identify genes and cellular pathways that collaborate with LSD1 to maintain the leukaemic phenotype, and which could be targeted by combination therapies, we performed a genome-wide CRISPR-Cas9 dropout screen. We identified multiple components of the amino acid sensing arm of mTORC1 signalling-RRAGA, MLST8, WDR24 and LAMTOR2-as cellular sensitizers to LSD1 inhibition. Knockdown of mTORC1 components, or mTORC1 pharmacologic inhibition, in combination with LSD1 inhibition enhanced differentiation in both cell line and primary cell settings, in vitro and in vivo, and substantially reduced the frequency of clonogenic primary human AML cells in a modelled minimal residual disease setting. Synergistic upregulation of a set of transcription factor genes associated with terminal monocytic lineage differentiation was observed. Thus, dual mTORC1 and LSD1 inhibition represents a candidate combination approach for enhanced differentiation in MLL-translocated AML which could be evaluated in early phase clinical trials.
Assuntos
Everolimo/farmacologia , Histona Desmetilases/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Proteína de Leucina Linfoide-Mieloide/genética , Translocação Genética , Tranilcipromina/farmacologia , Animais , Antidepressivos/farmacologia , Antineoplásicos/farmacologia , Apoptose , Proliferação de Células , Quimioterapia Combinada , Feminino , Regulação Leucêmica da Expressão Gênica , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PURPOSE: Iadademstat is a novel, highly potent, and selective inhibitor of LSD1 (KDM1A), with preclinical in vitro and in vivo antileukemic activity. This study aimed to determine safety and tolerability of iadademstat as monotherapy in patients with relapsed/refractory acute myeloid leukemia (R/R AML). METHODS: This phase I, nonrandomized, open-label, dose-escalation (DE), and extension-cohort (EC) trial included patients with R/R AML and evaluated the safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary antileukemic activity of this orally bioavailable first-in-class lysine-specific demethylase 1 inhibitor. RESULTS: Twenty-seven patients were treated with iadademstat on days 1 to 5 (5-220 µg/m2/d) of each week in 28-day cycles in a DE phase that resulted in a recommended dose of 140 µg/m2/d of iadademstat as a single agent. This dose was chosen to treat all patients (n = 14) in an EC enriched with patients with MLL/KMT2A-rearranged AML. Most adverse events (AEs) were as expected in R/R AML and included myelosuppression and nonhematologic AEs, such as infections, asthenia, mucositis, and diarrhea. PK data demonstrated a dose-dependent increase in plasma exposure, and PD data confirmed a potent time- and exposure-dependent induction of differentiation biomarkers. Reductions in blood and bone marrow blast percentages were observed, together with induction of blast cell differentiation, in particular, in patients with MLL translocations. One complete remission with incomplete count recovery was observed in the DE arm. CONCLUSION: Iadademstat exhibits a good safety profile together with signs of clinical and biologic activity as a single agent in patients with R/R AML. A phase II trial of iadademstat in combination with azacitidine is ongoing (EudraCT No.: 2018-000482-36).
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Inibidores Enzimáticos/uso terapêutico , Histona Desmetilases/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RecidivaRESUMO
Transcription disequilibria are characteristic of many neurodegenerative diseases. The activity-evoked transcription of immediate early genes (IEGs), important for neuronal plasticity, memory and behavior, is altered in CNS diseases and governed by epigenetic modulation. KDM1A, a histone 3 lysine 4 demethylase that forms part of transcription regulation complexes, has been implicated in the control of IEG transcription. Here we report the development of vafidemstat (ORY-2001), a brain penetrant inhibitor of KDM1A and MAOB. ORY-2001 efficiently inhibits brain KDM1A at doses suitable for long term treatment, and corrects memory deficit as assessed in the novel object recognition testing in the Senescence Accelerated Mouse Prone 8 (SAMP8) model for accelerated aging and Alzheimer's disease. Comparison with a selective KDM1A or MAOB inhibitor reveals that KDM1A inhibition is key for efficacy. ORY-2001 further corrects behavior alterations including aggression and social interaction deficits in SAMP8 mice and social avoidance in the rat rearing isolation model. ORY-2001 increases the responsiveness of IEGs, induces genes required for cognitive function and reduces a neuroinflammatory signature in SAMP8 mice. Multiple genes modulated by ORY-2001 are differentially expressed in Late Onset Alzheimer's Disease. Most strikingly, the amplifier of inflammation S100A9 is highly expressed in LOAD and in the hippocampus of SAMP8 mice, and down-regulated by ORY-2001. ORY-2001 is currently in multiple Phase IIa studies.
Assuntos
Inibidores Enzimáticos/farmacologia , Histona Desmetilases/antagonistas & inibidores , Transtornos da Memória/tratamento farmacológico , Inibidores da Monoaminoxidase/farmacologia , Oxidiazóis/farmacologia , Envelhecimento/efeitos dos fármacos , Envelhecimento/psicologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/psicologia , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Modelos Animais de Doenças , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Epigênese Genética/efeitos dos fármacos , Feminino , Expressão Gênica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Inibidores da Monoaminoxidase/química , Inibidores da Monoaminoxidase/farmacocinética , Oxidiazóis/química , Oxidiazóis/farmacocinética , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Integration and exploration of data obtained from genome wide monitoring technologies has become a major challenge for many bioinformaticists and biologists due to its heterogeneity and high dimensionality. A widely accepted approach to solve these issues has been the creation and use of controlled vocabularies (ontologies). Ontologies allow for the formalization of domain knowledge, which in turn enables generalization in the creation of querying interfaces as well as in the integration of heterogeneous data, providing both human and machine readable interfaces. RESULTS: We designed and implemented a software tool that allows investigators to create their own semantic model of an organism and to use it to dynamically integrate expression data obtained from DNA microarrays and other probe based technologies. The software provides tools to use the semantic model to postulate and validate of hypotheses on the spatial and temporal expression and function of genes. In order to illustrate the software's use and features, we used it to build a semantic model of rice (Oryza sativa) and integrated experimental data into it. CONCLUSION: In this paper we describe the development and features of a flexible software application for dynamic gene expression data annotation, integration, and exploration called Orymold. Orymold is freely available for non-commercial users from http://www.oryzon.com/media/orymold.html.
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Genômica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Oryza/genética , Software , Vocabulário Controlado , Bases de Dados Genéticas , Expressão Gênica , Processamento de Imagem Assistida por Computador/métodos , Reprodutibilidade dos Testes , Semântica , Interface Usuário-ComputadorRESUMO
The assessment of the target engagement, defined as the interaction of a drug with the protein it was designed for, is a basic requirement for the interpretation of the biological activity of any compound in drug development or in basic research projects. In epigenetics, target engagement is most often assessed by the analysis of proxy markers instead of measuring the union of the compound to the target. Downstream biological readouts that have been analyzed include the histone mark modulation or gene expression changes. KDM1A is a lysine demethylase that removes methyl groups from mono- and dimethylated H3K4, a modification associated with the silencing of gene expression. Modulation of the proxy markers is dependent on the cell type and function of the genetic make-up of the cells investigated, which can make interpretation and cross-case comparison quite difficult. To circumvent these problems, a versatile protocol is presented to assess the dose effects and dynamics of the direct KDM1A target engagement. The assay described makes use of a KDM1A chemoprobe to capture and quantify uninhibited enzyme, can be broadly applied to cells or tissue samples without the need for genetic modification, has an excellent window of detection, and can be used both for basic research and analysis of clinical samples.
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Histona Desmetilases/genética , Imunoensaio/métodos , Animais , HumanosRESUMO
BACKGROUND: The Senegalese sole, Solea senegalensis, is a highly prized flatfish of growing commercial interest for aquaculture in Southern Europe. However, despite the industrial production of Senegalese sole being hampered primarily by lack of information on the physiological mechanisms involved in reproduction, growth and immunity, very limited genomic information is available on this species. RESULTS: Sequencing of a S. senegalensis multi-tissue normalized cDNA library, from adult tissues (brain, stomach, intestine, liver, ovary, and testis), larval stages (pre-metamorphosis, metamorphosis), juvenile stages (post-metamorphosis, abnormal fish), and undifferentiated gonads, generated 10,185 expressed sequence tags (ESTs). Clones were sequenced from the 3'-end to identify isoform specific sequences. Assembly of the entire EST collection into contigs gave 5,208 unique sequences of which 1,769 (34%) had matches in GenBank, thus showing a low level of redundancy. The sequence of the 5,208 unigenes was used to design and validate an oligonucleotide microarray representing 5,087 unique Senegalese sole transcripts. Finally, a novel interactive bioinformatic platform, Soleamold, was developed for the Senegalese sole EST collection as well as microarray and ISH data. CONCLUSION: New genomic resources have been developed for S. senegalensis, an economically important fish in aquaculture, which include a collection of expressed genes, an oligonucleotide microarray, and a publicly available bioinformatic platform that can be used to study gene expression in this species. These resources will help elucidate transcriptional regulation in wild and captive Senegalese sole for optimization of its production under intensive culture conditions.
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Linguados/genética , Genoma/genética , Genômica/métodos , Animais , Sequência de Bases , Biologia Computacional/métodos , Etiquetas de Sequências Expressas , Biblioteca Gênica , Análise de Sequência com Séries de Oligonucleotídeos/métodosRESUMO
The lysine-specific demethylase KDM1A is a key regulator of stem cell potential in acute myeloid leukemia (AML). ORY-1001 is a highly potent and selective KDM1A inhibitor that induces H3K4me2 accumulation on KDM1A target genes, blast differentiation, and reduction of leukemic stem cell capacity in AML. ORY-1001 exhibits potent synergy with standard-of-care drugs and selective epigenetic inhibitors, reduces growth of an AML xenograft model, and extends survival in a mouse PDX (patient-derived xenograft) model of T cell acute leukemia. Surrogate pharmacodynamic biomarkers developed based on expression changes in leukemia cell lines were translated to samples from patients treated with ORY-1001. ORY-1001 is a selective KDM1A inhibitor in clinical trials and is currently being evaluated in patients with leukemia and solid tumors.
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Diferenciação Celular/efeitos dos fármacos , Histona Desmetilases/efeitos dos fármacos , Leucemia Mieloide Aguda/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral/metabolismo , Modelos Animais de Doenças , Histona Desmetilases/antagonistas & inibidores , Histona Desmetilases/genética , Humanos , Leucemia Mieloide Aguda/genética , Camundongos , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismoRESUMO
BACKGROUND: Alzheimer's and Parkinson's disease represent the two most common neurodegenerative disorders, affecting an increasing number of patients worldwide. Population ageing and lack of effective therapies and biomarkers strongly contribute to the socio-economical impact of these conditions. Message and Conclusion: The aim of the review is to present a summary of the discoveries made on the epigenetics of Alzheimer's and Parkinson's disease, with a special focus on the recent advances towards the identification of new targeted therapies and biomarkers. Data supporting broad spectrum and selective small-molecule inhibition of enzymes controlling DNA methylation and histone modifications are discussed in the context of Alzheimer's and Parkinson's disease. The results obtained from studies performed on patients samples are also mentioned, to provide a picture of the efforts made toward identification of epigenetic-based biomarkers. Finally, given the importance of non-coding RNAs in neurodegeneration, their contribution to Alzheimer's and Parkinson's disease will be examined, together with a brief summary of the available miRNA-based biomarker signatures for these two conditions.
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Doença de Alzheimer/terapia , Biomarcadores/metabolismo , Epigênese Genética , Terapia de Alvo Molecular , Doença de Parkinson/terapia , Doença de Alzheimer/genética , Animais , Metilação de DNA , Humanos , Doença de Parkinson/genéticaRESUMO
The nitrogen-fixing endophyte Azoarcus sp. strain BH72 infects roots of Kallar grass and rice inter- and intra-cellularly and can spread systemically into shoots without causing symptoms of plant disease. Although cellulose or its breakdown products do not support growth, this strain expresses an endoglucanase, which might be involved in infection. Sequence analysis of eglA places the secreted 34-kDa protein into the glycosyl hydrolases family 5, with highest relatedness (40% identity) to endoglucanases of the phytopathogenic bacteria Xanthomonas campestris and Ralstonia solanacearum. Transcriptional regulation studied by eglA:: gusA fusion was not significantly affected by cellulose or its breakdown products or by microaerobiosis. Strongest induction (threefold) was obtained in bacteria grown in close vicinity to rice roots. Visible sites of expression were the emergence points of lateral roots and root tips, which are the primary regions of ingress into the root. To study the role in endophytic colonization, eglA was inactivated by transposon mutagenesis. Systemic spreading of the eglA mutant and of a pilAB mutant into the rice shoot could no longer be detected by polymerase chain reaction. Microscopic inspection of infection revealed that the intracellular colonization of root epidermis cells was significantly reduced in the eglA- mutant BHE6 compared with the wild type and partially restored in the complementation mutant BHRE2 expressing eglA. This provides evidence that Azoarcus sp. endoglucanase is an important determinant for successful endophytic colonization of rice roots, suggesting an active bacterial colonization process.
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Azoarcus/enzimologia , Azoarcus/fisiologia , Celulase/metabolismo , Oryza/microbiologia , Raízes de Plantas/microbiologia , Azoarcus/classificação , Azoarcus/citologia , Celulase/genética , Celulose/metabolismo , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano , Mutação/genética , Nitrogenase/genética , Oryza/anatomia & histologia , Raízes de Plantas/citologia , Raízes de Plantas/ultraestrutura , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Plântula/microbiologia , Análise de Sequência de DNARESUMO
The covalent modification of histones is closely associated with regulation of gene transcription. Chromatin modifications have been suggested to represent an epigenetic code that is dynamically 'written' and 'erased' by specialized proteins, and 'read', or interpreted, by proteins that translate the code into gene expression changes. Initially thought to be an irreversible process, histone methylation is now known to be reversed by demethylases, FAD dependent amineoxidases and by iron(II)-alpha-ketoglutarate dependent deoxygenases of the Jumonji family. Altered histone demethylase activities have been associated with human disease, including cancer. The first wave of novel investigational drugs directed against KDM1A has recently entered the clinic, and the first specific inhibitor targeting a Jumonji KDM is advancing in preclinical regulatory studies.
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Benzoatos/administração & dosagem , Ciclopropanos/administração & dosagem , Histona Desmetilases/antagonistas & inibidores , Animais , Benzoatos/química , Ciclopropanos/química , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Histona Desmetilases/química , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/enzimologiaRESUMO
Histone methylation and demethylation are important processes associated with the regulation of gene transcription, and alterations in histone methylation status have been linked to a large number of human diseases. Initially thought to be an irreversible process, histone methylation is now known to be reversed by two families of proteins containing over 30 members that act to remove methyl groups from specific lysine residues present in the tails of histone H3 and histone H4. A rapidly growing number of reports have implicated the FAD-dependent lysine specific demethylase (KDM1) family in cancer, and several small-molecule inhibitors are in development for the treatment of cancer. An additional role has emerged for KDM1 in brain function, offering additional opportunities for the development of novel therapeutic strategies in neurodegenerative disease. A decade after the identification of KDM1A as a histone demethylase, the first selective inhibitors have now reached the clinic.
Assuntos
Epigênese Genética , Histona Desmetilases/genética , Neoplasias/genética , Doenças Neurodegenerativas/genética , Sequência de Aminoácidos , Animais , Terapia Genética , Histona Desmetilases/química , Histona Desmetilases/metabolismo , Humanos , Dados de Sequência Molecular , Neoplasias/terapia , Doenças Neurodegenerativas/terapiaRESUMO
DNA microarray technology is based on the principle of hybridization between 2 complementary strands of nucleic acids, one being fixed into a solid membrane, the other being the sample to analyze. This has resulted in a very powerful method to examine differential gene expression between samples, and has been widely used in the study of tumors. The application of DNA microarray technology to the study of the nervous system has to consider several properties of the nervous tissue: composition of various neuronal types, as well as astrocytes, oligodendrocytes, and microglia; regional and area differences; developmental and age-dependent variations; and functional and pathological status. Moreover, human samples are usually obtained postmortem following variable agonal periods and postmortem delays between death and tissue preservation, which are accompanied by variable RNA degradation. Yet human postmortem nervous tissue stored in brain banks offers a unique opportunity to facilitate material for the study of diseases of the nervous system and to gain direct understanding on the mechanisms of disease. This review analyzes the application of DNA microarray technology to current practice using brain-banked tissues in order to recognize and minimize sub-optimal processing of brain samples and to correct pitfalls due to inadequate procedures. Also discussed are RNA preservation and RNA degradation effects on expression pattern assessments, analysis of individual versus pooled samples, array normalization, types of DNA chip platforms, whole genomic analysis versus specialized chips, and microgenomics. Minimizing RNA degradation and improving detection of resistant RNA in postmortem brain has been considered in detail in order to improve the efficiency and reliability of DNA microarray technology employed in the study of human postmortem nervous tissue.
Assuntos
Encéfalo/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , RNA/metabolismo , Bancos de Tecidos , Animais , Cadáver , Genômica , Humanos , Hipóxia/metabolismo , NeurobiologiaRESUMO
The generation of cortical interneuron subtypes is controlled by genetic programs that are activated in the ventral forebrain and unfold during the prolonged period of inhibitory neuron development. The LIM-homeodomain protein LHX6 is critical for the development of all cortical interneurons originating in the medial ganglionic eminence, but the molecular mechanisms that operate downstream of LHX6 to control the terminal differentiation of somatostatin- and parvalbumin-expressing interneurons within the cortex remain unknown. Here, we provide evidence that the nuclear matrix and genome organizer protein SATB1 is induced by neuronal activity and functions downstream of Lhx6 to control the transition of tangentially migrating immature interneurons into the terminally differentiated Somatostatin (SST)-expressing subtype. Our experiments provide a molecular framework for understanding the genetic and epigenetic mechanisms by which specified but immature cortical interneurons acquire the subtype-defining molecular and morphophysiological characteristics that allow them to integrate and function within cortical circuits.