Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Cell Rep ; 42(12): 113538, 2023 12 26.
Artículo en Inglés | MEDLINE | ID: mdl-38096051

RESUMEN

A unique signature of neurons is the high expression of the longest genes in the genome. These genes have essential neuronal functions, and disruption of their expression has been implicated in neurological disorders. DNA topoisomerases resolve DNA topological constraints and facilitate neuronal long gene expression. Conversely, the Rett syndrome protein, methyl-CpG-binding protein 2 (MeCP2), can transcriptionally repress long genes. How these factors regulate long genes is not well understood, and whether they interact is not known. Here, we identify and map a functional interaction between MeCP2 and topoisomerase IIß (TOP2ß) in mouse neurons. We profile neuronal TOP2ß activity genome wide, detecting enrichment at regulatory regions and gene bodies of long genes, including MeCP2-regulated genes. We show that loss and overexpression of MeCP2 alter TOP2ß activity at MeCP2-regulated genes. These findings uncover a mechanism of TOP2ß inhibition by MeCP2 in neurons and implicate TOP2ß dysregulation in disorders caused by MeCP2 disruption.


Asunto(s)
Proteína 2 de Unión a Metil-CpG , Síndrome de Rett , Animales , Ratones , Proteína 2 de Unión a Metil-CpG/genética , Proteína 2 de Unión a Metil-CpG/metabolismo , Neuronas/metabolismo , Síndrome de Rett/genética
2.
bioRxiv ; 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37961702

RESUMEN

Protein kinases are disease drivers whose therapeutic targeting traditionally centers on inhibition of enzymatic activity. Here chemically induced proximity is leveraged to convert kinase inhibitors into context-specific activators of therapeutic genes. Bivalent molecules that link ligands of the transcription factor B-cell lymphoma 6 (BCL6) to ATP-competitive inhibitors of cyclin-dependent kinases (CDKs) were developed to re-localize CDK to BCL6-bound loci on chromatin and direct phosphorylation of RNA Pol II. The resulting BCL6-target proapoptotic gene expression translated into killing of diffuse large B-cell lymphoma (DLBCL) cells at 72 h with EC50s of 0.9 - 10 nM and highly specific ablation of the BCL6-regulated germinal center response in mice. The molecules exhibited 10,000-fold lower cytotoxicity in normal lymphocytes and are well tolerated in mice. Genomic and proteomic evidence corroborated a gain-of-function mechanism where, instead of global enzyme inhibition, a fraction of total kinase activity is borrowed and re-localized to BCL6-bound loci. The strategy demonstrates how kinase inhibitors can be used to context-specifically activate transcription, accessing new therapeutic space.

3.
Mol Cell ; 83(9): 1412-1428.e7, 2023 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-37098340

RESUMEN

During postnatal development, the DNA methyltransferase DNMT3A deposits high levels of non-CG cytosine methylation in neurons. This methylation is critical for transcriptional regulation, and loss of this mark is implicated in DNMT3A-associated neurodevelopmental disorders (NDDs). Here, we show in mice that genome topology and gene expression converge to shape histone H3 lysine 36 dimethylation (H3K36me2) profiles, which in turn recruit DNMT3A and pattern neuronal non-CG methylation. We show that NSD1, an H3K36 methyltransferase mutated in NDD, is required for the patterning of megabase-scale H3K36me2 and non-CG methylation in neurons. We find that brain-specific deletion of NSD1 causes altered DNA methylation that overlaps with DNMT3A disorder models to drive convergent dysregulation of key neuronal genes that may underlie shared phenotypes in NSD1- and DNMT3A-associated NDDs. Our findings indicate that H3K36me2 deposited by NSD1 is important for neuronal non-CG DNA methylation and suggest that the H3K36me2-DNMT3A-non-CG-methylation pathway is likely disrupted in NSD1-associated NDDs.


Asunto(s)
Metilación de ADN , Histonas , Animales , Ratones , Histonas/genética , Histonas/metabolismo , Lisina/metabolismo , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Neuronas/metabolismo
4.
bioRxiv ; 2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-36824816

RESUMEN

During postnatal development the DNA methyltransferase DNMT3A deposits high levels of non-CG cytosine methylation in neurons. This unique methylation is critical for transcriptional regulation in the mature mammalian brain, and loss of this mark is implicated in DNMT3A-associated neurodevelopmental disorders (NDDs). The mechanisms determining genomic non-CG methylation profiles are not well defined however, and it is unknown if this pathway is disrupted in additional NDDs. Here we show that genome topology and gene expression converge to shape histone H3 lysine 36 dimethylation (H3K36me2) profiles, which in turn recruit DNMT3A and pattern neuronal non-CG methylation. We show that NSD1, the H3K36 methyltransferase mutated in the NDD, Sotos syndrome, is required for megabase-scale patterning of H3K36me2 and non-CG methylation in neurons. We find that brain-specific deletion of NSD1 causes alterations in DNA methylation that overlap with models of DNMT3A disorders and define convergent disruption in the expression of key neuronal genes in these models that may contribute to shared phenotypes in NSD1- and DNMT3A-associated NDD. Our findings indicate that H3K36me2 deposited by NSD1 is an important determinant of neuronal non-CG DNA methylation and implicates disruption of this methylation in Sotos syndrome. Highlights: Topology-associated DNA methylation and gene expression independently contribute to neuronal gene body and enhancer non-CG DNA methylation patterns.Topology-associated H3K36me2 patterns and local enrichment of H3K4 methylation impact deposition of non-CG methylation by DNMT3A. Disruption of NSD1 in vivo leads to alterations in H3K36me2, DNA methylation, and gene expression that overlap with models of DNMT3A disorders.

5.
Am J Pathol ; 191(11): 2009-2022, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34364880

RESUMEN

Myelodysplastic syndromes (MDS) are clonal neoplasms of the hematopoietic stem cell that result in aberrant differentiation of hematopoietic lineages caused by a wide range of underlying genetic, epigenetic, and other causes. Despite the myriad origins, a recognizable MDS phenotype has been associated with miRNA aberrant expression. A model of aberrant myeloid maturation that mimics MDS was generated using a stable knockdown of miR-378-3p. This model exhibited a transcriptional profile indicating aberrant maturation and function, immunophenotypic and morphologic dysplasia, and aberrant growth that characterizes MDS. Moreover, aberrant signal transduction in response to stimulation specific to the stage of myeloid maturation as indicated by CyTOF mass cytometry was similar to that found in samples from patients with MDS. The aberrant signaling, immunophenotypic changes, cellular growth, and colony formation ability seen in this myeloid model could be reversed with azacytidine, albeit without significant improvement of neutrophil function.


Asunto(s)
MicroARNs/genética , Síndromes Mielodisplásicos/genética , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Técnicas de Silenciamiento del Gen , Células HL-60 , Humanos , Masculino , Persona de Mediana Edad
6.
Cell Rep ; 33(8): 108416, 2020 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-33238114

RESUMEN

Mutations in DNA methyltransferase 3A (DNMT3A) have been detected in autism and related disorders, but how these mutations disrupt nervous system function is unknown. Here, we define the effects of DNMT3A mutations associated with neurodevelopmental disease. We show that diverse mutations affect different aspects of protein activity but lead to shared deficiencies in neuronal DNA methylation. Heterozygous DNMT3A knockout mice mimicking DNMT3A disruption in disease display growth and behavioral alterations consistent with human phenotypes. Strikingly, in these mice, we detect global disruption of neuron-enriched non-CG DNA methylation, a binding site for the Rett syndrome protein MeCP2. Loss of this methylation leads to enhancer and gene dysregulation that overlaps with models of Rett syndrome and autism. These findings define the effects of DNMT3A haploinsufficiency in the brain and uncover disruption of the non-CG methylation pathway as a convergence point across neurodevelopmental disorders.


Asunto(s)
ADN Metiltransferasa 3A/metabolismo , Epigenómica/métodos , Trastornos del Neurodesarrollo/genética , Animales , Haploinsuficiencia , Humanos , Ratones
7.
J Neuroendocrinol ; 32(10): e12904, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33000549

RESUMEN

Neural progestin receptors (PR) function in reproduction, neural development, neuroprotection, learning, memory and the anxiety response. In the absence of progestins, PR can be activated by dopamine (DA) in the rodent hypothalamus to elicit female sexual behaviour. The present study investigated mechanisms of DA activation of PR by testing the hypothesis that proteins from DA-treated hypothalami interact with PR in the absence of progestins. Ovariectomised, oestradiol-primed mice were infused with a D1-receptor agonist, SKF38393 (SKF), into the third ventricle 30 minutes prior to death. Proteins from SKF-treated hypothalami were pulled-down with glutathione S-transferase-tagged mouse PR-A or PR-B and the interactomes were analysed by mass spectrometry. The largest functional group to interact with PR-A in a DA-dependent manner was synaptic proteins. To test the hypothesis that DA activation of PR regulates synaptic proteins, we developed oestradiol-induced PR-expressing hypothalamic-like neurones derived from human-induced pluripotent stem cells (hiPSCs). Similar to progesterone (P4), SKF treatment of hiPSCs increased synapsin1/2 expression. This SKF-dependent effect was blocked by the PR antagonist RU486, suggesting that PR are necessary for this DA-induced increase. The second largest DA-dependent PR-A protein interactome comprised metabolic regulators involved in glucose metabolism, lipid synthesis and mitochondrial energy production. Interestingly, hypothalamic proteins interacted with PR-A, but not PR-B, in an SKF-dependent manner, suggesting that DA promotes the interaction of multiple hypothalamic proteins with PR-A. These in vivo and in vitro results indicate novel mechanisms by which DA can differentially activate PR isoforms in the absence of P4 and provide a better understanding of ligand-independent PR activation in reproductive, metabolic and mental health disorders in women.


Asunto(s)
Dopamina/farmacología , Proteínas del Tejido Nervioso/metabolismo , Receptores de Progesterona/metabolismo , Animales , Femenino , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Ratones , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Progesterona/farmacología , Unión Proteica/efectos de los fármacos , Isoformas de Proteínas/efectos de los fármacos , Isoformas de Proteínas/metabolismo , Receptores de Progesterona/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
8.
eNeuro ; 4(5)2017.
Artículo en Inglés | MEDLINE | ID: mdl-28955722

RESUMEN

Progestins bind to the progestin receptor (PR) isoforms, PR-A and PR-B, in brain to influence development, female reproduction, anxiety, and stress. Hormone-activated PRs associate with multiple proteins to form functional complexes. In the present study, proteins from female mouse hypothalamus that associate with PR were isolated using affinity pull-down assays with glutathione S-transferase-tagged mouse PR-A and PR-B. Using complementary proteomics approaches, reverse phase protein array (RPPA) and mass spectrometry, we identified hypothalamic proteins that interact with PR in a ligand-dependent and isoform-specific manner and were confirmed by Western blot. Synaptic proteins, including synapsin-I and synapsin-II, interacted with agonist-bound PR isoforms, suggesting that both isoforms function in synaptic plasticity. In further support, synaptogyrin-III and synapsin-III associated with PR-A and PR-B, respectively. PR also interacted with kinases, including c-Src, mTOR, and MAPK1, confirming phosphorylation as an integral process in rapid effects of PR in the brain. Consistent with a role in transcriptional regulation, PR associated with transcription factors and coactivators in a ligand-specific and isoform-dependent manner. Interestingly, both PR isoforms associated with a key regulator of energy homeostasis, FoxO1, suggesting a novel role for PR in energy metabolism. Because many identified proteins in this PR interactome are synaptic proteins, we tested the hypothesis that progestins function in synaptic plasticity. Indeed, progesterone enhanced synaptic density, by increasing synapsin-I-positive synapses, in rat primary cortical neuronal cultures. This novel combination of RPPA and mass spectrometry allowed identification of PR action in synaptic remodeling and energy homeostasis and reveals unique roles for progestins in brain function and disease.


Asunto(s)
Hipotálamo/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Receptores de Progesterona/metabolismo , Sinapsis/metabolismo , Animales , Células Cultivadas , Corteza Cerebral/citología , Embrión de Mamíferos , Estradiol/farmacología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Glutatión Transferasa/metabolismo , Ligandos , Ratones , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Ovariectomía , Unión Proteica , Isoformas de Proteínas/metabolismo , Receptores de Progesterona/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Transcripción Genética
9.
eNeuro ; 3(4)2016.
Artículo en Inglés | MEDLINE | ID: mdl-27679811

RESUMEN

Estrogens and leptins act in the hypothalamus to maintain reproduction and energy homeostasis. Neurogenesis in the adult mammalian hypothalamus has been implicated in the regulation of energy homeostasis. Recently, high-fat diet (HFD) and estradiol (E2) have been shown to alter cell proliferation and the number of newborn leptin-responsive neurons in the hypothalamus of adult female mice. The current study tested the hypothesis that new cells expressing estrogen receptor α (ERα) are generated in the arcuate nucleus (ARC) and the ventromedial nucleus of the hypothalamus (VMH) of the adult female mouse, hypothalamic regions that are critical in energy homeostasis. Adult mice were ovariectomized and implanted with capsules containing E2 or oil. Within each hormone group, mice were fed an HFD or standard chow for 6 weeks and treated with BrdU to label new cells. Newborn cells that respond to estrogens were identified in the ARC and VMH, of which a subpopulation was leptin sensitive, indicating that the subpopulation consists of neurons. Moreover, there was an interaction between diet and hormone with an effect on the number of these newborn ERα-expressing neurons that respond to leptin. Regardless of hormone treatment, HFD increased the number of ERα-expressing cells in the ARC and VMH. E2 decreased hypothalamic fibroblast growth factor 10 (Fgf10) gene expression in HFD mice, suggesting a role for Fgf10 in E2 effects on neurogenesis. These findings of newly created estrogen-responsive neurons in the adult brain provide a novel mechanism by which estrogens can act in the hypothalamus to regulate energy homeostasis in females.

10.
eNeuro ; 2(4)2015.
Artículo en Inglés | MEDLINE | ID: mdl-26465008

RESUMEN

Estrogens act in brain to profoundly influence neurogenesis, sexual differentiation, neuroprotection, cognition, energy homeostasis, and female reproductive behavior and physiology through a variety of mechanisms, including the induction of progestin receptors (PRs). PRs are expressed as two isoforms, PR-A and PR-B, that have distinct functions in physiology and behavior. Because these PR isoforms cannot be distinguished using cellular resolution techniques, the present study used isoform-specific null mutant mice that lack PR-A or PR-B for the first time to investigate whether 17ß-estradiol benzoate (EB) regulates the differential expression of the PR isoforms in the ventromedial nucleus of the hypothalamus (VMN), arcuate nucleus, and medial preoptic area, brain regions that are rich in EB-induced PRs. Interestingly, EB induced more PR-A than PR-B in all three brain regions, suggesting that PR-A is the predominant isoform in these regions. Given that steroid receptor coactivator (SRC)-1 and SRC-2 are important in estrogen receptor (ER)-dependent transcription in brain, including PR induction, we tested whether the expression of these coactivators was correlated with PR isoform expression. The majority of EB-induced PR cells expressed both SRC-1 and SRC-2 in the three brain regions of all genotypes. Interestingly, the intensity of PR-A immunoreactivity correlated with SRC-2 expression in the VMN, providing a potential mechanism for selective ER-mediated transactivation of PR-A over PR-B in a brain region-specific manner. In summary, these novel findings indicate that estrogens differentially regulate PR-A and PR-B expression in the female hypothalamus, and provide a mechanism by which steroid action in brain can selectively modulate behavior and physiology.

11.
J Neurosci ; 30(7): 2571-81, 2010 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-20164342

RESUMEN

During development, early-life stress, such as abuse or trauma, induces long-lasting changes that are linked to adult anxiety and depressive behavior. It has been postulated that altered expression of corticotropin-releasing hormone (CRH) can at least partially account for the various effects of stress on behavior. In accord with this hypothesis, evidence from pharmacological and genetic studies has indicated the capacity of differing levels of CRH activity in different brain areas to produce behavioral changes. Furthermore, stress during early life or adulthood causes an increase in CRH release in a variety of neural sites. To evaluate the temporal and spatial specificity of the effect of early-life CRH exposure on adult behavior, the tetracycline-off system was used to produce mice with forebrain-restricted inducible expression of CRH. After transient elevation of CRH during development only, behavioral testing in adult mice revealed a persistent anxiogenic and despair-like phenotype. These behavioral changes were not associated with alterations in adult circadian or stress-induced corticosterone release but were associated with changes in CRH receptor type 1 expression. Furthermore, the despair-like changes were normalized with antidepressant treatment. Overall, these studies suggest that forebrain-restricted CRH signaling during development can permanently alter stress adaptation leading to increases in maladaptive behavior in adulthood.


Asunto(s)
Ansiedad/etiología , Hormona Liberadora de Corticotropina/metabolismo , Depresión/etiología , Regulación del Desarrollo de la Expresión Génica/fisiología , Prosencéfalo/metabolismo , Adaptación Ocular/efectos de los fármacos , Adaptación Ocular/genética , Factores de Edad , Análisis de Varianza , Animales , Animales Recién Nacidos , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Ansiedad/tratamiento farmacológico , Ansiedad/genética , Conducta Animal/fisiología , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/genética , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Ritmo Circadiano/efectos de los fármacos , Ritmo Circadiano/genética , Hormona Liberadora de Corticotropina/genética , Depresión/tratamiento farmacológico , Depresión/genética , Modelos Animales de Enfermedad , Doxiciclina/administración & dosificación , Embrión de Mamíferos , Conducta Exploratoria/efectos de los fármacos , Conducta Exploratoria/fisiología , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica/genética , Hormona del Crecimiento/metabolismo , Suspensión Trasera/métodos , Sistema Hipotálamo-Hipofisario/crecimiento & desarrollo , Sistema Hipotálamo-Hipofisario/metabolismo , Imipramina/farmacología , Imipramina/uso terapéutico , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación/genética , Sistema Hipófiso-Suprarrenal/crecimiento & desarrollo , Sistema Hipófiso-Suprarrenal/metabolismo , Prosencéfalo/embriología , Prosencéfalo/crecimiento & desarrollo , Radioinmunoensayo/métodos , Tiempo de Reacción/genética , Receptores de Hormona Liberadora de Corticotropina/genética , Receptores de Hormona Liberadora de Corticotropina/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...