RESUMEN
Genome instability relies on preserving the chromatin structure, with any histone imbalances threating DNA integrity. Histone synthesis occurs in the cytoplasm, followed by a maturation process before their nuclear translocation. This maturation involves protein folding and the establishment of post-translational modifications. Disruptions in this pathway hinder chromatin assembly and contribute to genome instability. JMJD1B, a histone demethylase, not only regulates gene expression but also ensures a proper supply of histones H3 and H4 for the chromatin assembly. Reduced JMJD1B levels lead to the cytoplasmic accumulation of histones, causing defects in the chromatin assembly and resulting in DNA damage. To investigate the role of JMJD1B in regulating genome stability and the malignancy of melanoma tumors, we used a JMJD1B/KDM3B knockout in B16F10 mouse melanoma cells to perform tumorigenic and genome instability assays. Additionally, we analyzed the transcriptomic data of human cutaneous melanoma tumors. Our results show the enhanced tumorigenic properties of JMJD1B knockout melanoma cells both in vitro and in vivo. The γH2AX staining, Micrococcal Nuclease sensitivity, and comet assays demonstrated increased DNA damage and genome instability. The JMJD1B expression in human melanoma tumors correlates with a lower mutational burden and fewer oncogenic driver mutations. Our findings highlight JMJD1B's role in maintaining genome integrity by ensuring a proper histone supply to the nucleus, expanding its function beyond gene expression regulation. JMJD1B emerges as a crucial player in preserving genome stability and the development of melanoma, with a potential role as a safeguard against oncogenic mutations.
Asunto(s)
Daño del ADN , Inestabilidad Genómica , Histonas , Histona Demetilasas con Dominio de Jumonji , Melanoma , Neoplasias Cutáneas , Animales , Humanos , Ratones , Línea Celular Tumoral , Daño del ADN/genética , Regulación Neoplásica de la Expresión Génica , Histonas/metabolismo , Histona Demetilasas con Dominio de Jumonji/metabolismo , Histona Demetilasas con Dominio de Jumonji/genética , Melanoma/genética , Melanoma/patología , Melanoma/metabolismo , Melanoma Experimental/genética , Melanoma Experimental/patología , Melanoma Experimental/metabolismo , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/metabolismoRESUMEN
Autism spectrum disorders (ASD) are complex neurodevelopmental conditions characterized by impairments in social communication, repetitive behaviors, and restricted interests. Epigenetic modifications serve as critical regulators of gene expression playing a crucial role in controlling brain function and behavior. Lysine (K)-specific demethylase 6B (KDM6B), a stress-inducible H3K27me3 demethylase, has emerged as one of the highest ASD risk genes, but the precise effects of KDM6B mutations on neuronal activity and behavioral function remain elusive. Here we show the impact of KDM6B mosaic brain knockout on the manifestation of different autistic-like phenotypes including repetitive behaviors, social interaction, and significant cognitive deficits. Moreover, KDM6B mosaic knockout display abnormalities in hippocampal excitatory synaptic transmission decreasing NMDA receptor mediated synaptic transmission and plasticity. Understanding the intricate interplay between epigenetic modifications and neuronal function may provide novel insights into the pathophysiology of ASD and potentially inform the development of targeted therapeutic interventions.
Asunto(s)
Trastorno del Espectro Autista , Histona Demetilasas con Dominio de Jumonji , Ratones Noqueados , Transmisión Sináptica , Animales , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Transmisión Sináptica/genética , Trastorno del Espectro Autista/genética , Ratones , Encéfalo/metabolismo , Plasticidad Neuronal/genética , Conducta Animal , Hipocampo/metabolismo , Epigénesis Genética , Masculino , Sinapsis/metabolismoRESUMEN
BACKGROUND: Aberrant gluconeogenesis is considered among primary drivers of hyperglycemia under insulin resistant conditions, with multiple studies pointing towards epigenetic dysregulation. Here we examine the role of miR-721 and effect of epigenetic modulator laccaic acid on the regulation of gluconeogenesis under high fat diet induced insulin resistance. RESULTS: Reanalysis of miRNA profiling data of high-fat diet-induced insulin-resistant mice model, GEO dataset (GSE94799) revealed a significant upregulation of miR-721, which was further validated in invivo insulin resistance in mice and invitro insulin resistance in Hepa 1-6 cells. Interestingly, miR-721 mimic increased glucose production in Hepa 1-6 cells via activation of FOXO1 regulated gluconeogenic program. Concomitantly, inhibition of miR-721 reduced glucose production in palmitate induced insulin resistant Hepa 1-6 cells by blunting the FOXO1 induced gluconeogenesis. Intriguingly, at epigenetic level, enrichment of the transcriptional activation mark H3K36me2 got decreased around the FOXO1 promoter. Additionally, identifying targets of miR-721 using miRDB.org showed H3K36me2 demethylase KDM2A as a potential target. Notably, miR-721 inhibitor enhanced KDM2A expression which correlated with H3K36me2 enrichment around FOXO1 promoter and the downstream activation of the gluconeogenic pathway. Furthermore, inhibition of miR-721 in high-fat diet-induced insulin-resistant mice resulted in restoration of KDM2A levels, concomitantly reducing FOXO1, PCK1, and G6PC expression, attenuating gluconeogenesis, hyperglycemia, and improving glucose tolerance. Interestingly, the epigenetic modulator laccaic acid also reduced the hepatic miR-721 expression and improved KDM2A expression, supporting our earlier report that laccaic acid attenuates insulin resistance by reducing gluconeogenesis. CONCLUSION: Our study unveils the role of miR-721 in regulating gluconeogenesis through KDM2A and FOXO1 under insulin resistance, pointing towards significant clinical and therapeutic implications for metabolic disorders. Moreover, the promising impact of laccaic acid highlights its potential as a valuable intervention in managing insulin resistance-associated metabolic diseases.
Asunto(s)
Gluconeogénesis , Resistencia a la Insulina , Histona Demetilasas con Dominio de Jumonji , MicroARNs , Animales , Masculino , Ratones , Dieta Alta en Grasa , Epigénesis Genética , Proteína Forkhead Box O1/metabolismo , Proteína Forkhead Box O1/genética , Gluconeogénesis/genética , Gluconeogénesis/fisiología , Resistencia a la Insulina/fisiología , Histona Demetilasas con Dominio de Jumonji/metabolismo , Histona Demetilasas con Dominio de Jumonji/genética , Ratones Endogámicos C57BL , MicroARNs/metabolismo , MicroARNs/genéticaRESUMEN
BACKGROUND: Valproic acid/sodium valproate (VPA), a well-known anti-epileptic agent, inhibits histone deacetylases, induces histone hyperacetylation, promotes DNA demethylation, and affects the histone methylation status in some cell models. Histone methylation profiles have been described as potential markers for cervical cancer prognosis. However, histone methylation markers that can be studied in a cervical cancer cell line, like HeLa cells, have not been investigated following treatment with VPA. METHODS: In this study, the effect of 0.5 mM and 2.0 mM VPA for 24 h on H3K4me2/me3, H3K9me/me2 and H3K27me/me3 signals as well as on KMT2D, EZH2, and KDM3A gene expression was investigated using confocal microscopy, Western blotting, and RT-PCR. Histone methylation changes were also investigated by Fourier-transform infrared spectroscopy (FTIR). RESULTS: We found that VPA induces increased levels of H3K4me2/me3 and H3K9me, which are indicative of chromatin activation. Particularly, H3K4me2 markers appeared intensified close to the nuclear periphery, which may suggest their implication in increased transcriptional memory. The abundance of H3K4me2/me3 in the presence of VPA was associated with increased methyltransferase KMT2D gene expression. VPA induced hypomethylation of H3K9me2, which is associated with gene silencing, and concomitant with the demethylase KDM3A, it increased gene expression. Although VPA induces increased H3K27me/me3 levels, it is suggested that the role of the methyltransferase EZH2 in this context could be affected by interactions with this drug. CONCLUSION: Histone FTIR spectra were not affected by VPA under present experimental conditions. Whether our epigenetic results are consistent with VPA affecting the aggressive tumorous state of HeLa cells, further investigation is required.
Asunto(s)
Metilación de ADN , Histonas , Neoplasias del Cuello Uterino , Ácido Valproico , Femenino , Humanos , Células HeLa , Histonas/metabolismo , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Lisina/metabolismo , Metiltransferasas , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/genética , Ácido Valproico/farmacología , Ácido Valproico/uso terapéuticoRESUMEN
Histone lysine methylation plays a key role in gene activation and repression. The trimethylation of histone H3 on lysine-27 (H3K27me3) is a critical epigenetic event that is controlled by Jumonji domain-containing protein-3 (JMJD3). JMJD3 is a histone demethylase that specifically removes methyl groups. Previous studies have suggested that JMJD3 has a dual role in cancer cells. JMJD3 stimulates the expression of proliferative-related genes and increases tumor cell growth, propagation, and migration in various cancers, including neural, prostate, ovary, skin, esophagus, leukemia, hepatic, head and neck, renal, lymphoma, and lung. In contrast, JMJD3 can suppress the propagation of tumor cells, and enhance their apoptosis in colorectal, breast, and pancreatic cancers. In this review, we summarized the recent advances of JMJD3 function in cancer cells.
Asunto(s)
Lisina , Neoplasias , Apoptosis , Femenino , Histonas/genética , Histonas/metabolismo , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Lisina/metabolismo , Masculino , Metilación , Neoplasias/genéticaRESUMEN
Metformin has been tested as an anti-cancer therapy with potential to improve conventional chemotherapy. However, in some cases, metformin fails to sensitize tumors to chemotherapy. Here we test if the presence of P53 could predict the activity of metformin as an adjuvant for cisplatin-based therapy in non-small cell lung cancer (NSCLC). A549, HCC 827 (TP53 WT), H1299, and H358 (TP53 null) cell lines were used in this study. A549 cells were pre-treated with a sub-lethal dose of cisplatin to induce chemoresistance. The effects of metformin were tested both in vitro and in vivo and related to the ability of cells to accumulate Jarid1b, a histone demethylase involved in cisplatin resistance in different cancers. Metformin sensitized A549 and HCC 827 cells (but not H1299 and H358 cells) to cisplatin in a P53-dependent manner, changing its subcellular localization to the mitochondria. Treatment with a sub-lethal dose of cisplatin increased Jarid1b expression, yet downregulated P53 levels, protecting A549Res cells from metformin-induced chemosensitization to cisplatin and favored a glycolytic phenotype. Treatment with FL3, a synthetic flavagline, sensitized A549Res cells to cisplatin. In conclusion, metformin could potentially be used as an adjuvant for cisplatin-based therapy in NSCLC cells if wild type P53 is present.
Asunto(s)
Antineoplásicos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/genética , Cisplatino/farmacología , Histona Demetilasas con Dominio de Jumonji/genética , Metformina/farmacología , Proteínas Nucleares/genética , Proteínas Represoras/genética , Proteína p53 Supresora de Tumor/genética , Células A549 , Animales , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Sinergismo Farmacológico , Regulación Neoplásica de la Expresión Génica , Humanos , Histona Demetilasas con Dominio de Jumonji/metabolismo , Masculino , Ratones , Ratones Endogámicos NOD , Proteínas Nucleares/metabolismo , Proteínas Represoras/metabolismo , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
BACKGROUND: Maintaining a proper supply of soluble histones throughout the cell cycle is important to ensure chromatin and genome stability. Following their synthesis, histones undergo a series of maturation steps to prepare them for deposition onto chromatin. RESULTS: Here, we identify the lysine demethylase JMJD1B as a novel player in the maturation cascade that contributes to regulate histone provision. We find that depletion of JMJD1B increases the protein levels of the histone chaperone tNASP leading to an accumulation of newly synthesized histones H3 and H4 at early steps of the histone maturation cascade, which perturbs chromatin assembly. Furthermore, we find a high rate of JMJD1B mutations in cancer patients, and a correlation with genomic instability. CONCLUSIONS: Our data support a role for JMJD1B in fine-tuning histone supply to maintain genome integrity, opening novel avenues for cancer therapeutics.
Asunto(s)
Inestabilidad Genómica , Histonas/metabolismo , Histona Demetilasas con Dominio de Jumonji/metabolismo , Procesamiento Proteico-Postraduccional , Células HeLa , Código de Histonas , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , MutaciónAsunto(s)
Metilación de ADN/inmunología , Epigénesis Genética/inmunología , Pénfigo/genética , Adulto , Estudios de Casos y Controles , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Haplotipos/inmunología , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Proteína del Locus del Complejo MDS1 y EV11/genética , Proteína del Locus del Complejo MDS1 y EV11/metabolismo , Masculino , Pénfigo/inmunología , Polimorfismo de Nucleótido Simple , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
The process of neuronal differentiation is associated with neurite elongation and membrane biogenesis, and phosphatidylcholine (PtdCho) is the major membrane phospholipid in mammalian cells. During neuroblast differentiation, the transcription of two genes involved in PtdCho biosynthesis are stimulated: Chka gene for choline kinase (CK) alpha isoform and Pcyt1a gene for CTP:phosphocholine cytidylyltransferase (CCT) alpha isoform. Here we show that CKα is essential for neuronal differentiation. In addition, we demonstrated that KDM2B regulates CKα expression and, as a consequence, neuronal differentiation. This factor is up-regulated in the course of the neuroblasts proliferative and undifferentiated state and down-regulated during differentiation induced by retinoic acid (RA). During proliferation, KDM2B binds to the Box2 located in the Chka promoter repressing its transcription. Interestingly, KDM2B knockdown enhances the levels of CKα expression in neuroblast cells and induces neuronal differentiation even in the absence of RA. These results suggest that KDM2B is required for the appropriate regulation of CKα during neuronal differentiation and to the maintaining of the undifferentiated stage of neuroblast cells.
Asunto(s)
Colina Quinasa/genética , Proteínas F-Box/metabolismo , Regulación Neoplásica de la Expresión Génica , Histona Demetilasas con Dominio de Jumonji/metabolismo , Neuroblastoma/genética , Tretinoina/metabolismo , Animales , Diferenciación Celular/genética , Línea Celular Tumoral , Colina Quinasa/metabolismo , Epigénesis Genética , Proteínas F-Box/genética , Estudios de Seguimiento , Técnicas de Silenciamiento del Gen , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , Ratones , Células-Madre Neurales/fisiología , Neuroblastoma/mortalidad , Neuroblastoma/patología , Pronóstico , Regiones Promotoras Genéticas/genética , ARN Interferente Pequeño/metabolismo , Regulación hacia ArribaRESUMEN
We have uncovered a role for Jumonji inhibitors in overcoming radioresistance through KDM5B inhibition. Pharmacological blockade of Jumonji demethylases with JIB-04 leads to specific accumulation of H3K4me3 at sites marked by γH2AX and impaired recruitment of DNA repair factors, preventing resolution of damage and resulting in robust sensitization to radiation therapy. In DNA-repair-proficient cancer cells, knockdown of the H3K4me3 demethylase KDM5B, but not other Jumonji enzymes, mimics pharmacological inhibition, and KDM5B overexpression rescues this phenotype and increases radioresistance. The H3K4me3 demethylase inhibitor PBIT also sensitizes cancer cells to radiation, while an H3K27me3 demethylase inhibitor does not. In vivo co-administration of radiation with JIB-04 significantly prolongs the survival of mice with tumors even long after cessation of treatment. In human patients, lung squamous cell carcinomas highly expressing KDM5B respond poorly to radiation. Thus, we propose the use of Jumonji KDM inhibitors as potent radiosensitizers.
Asunto(s)
Roturas del ADN de Doble Cadena , Histonas/metabolismo , Histona Demetilasas con Dominio de Jumonji/antagonistas & inhibidores , Tolerancia a Radiación , Aminopiridinas/farmacología , Animales , Benzazepinas/farmacología , Línea Celular Tumoral , Roturas del ADN de Doble Cadena/efectos de los fármacos , Reparación del ADN/efectos de los fármacos , Proteína Quinasa Activada por ADN/metabolismo , Proteínas de Unión al ADN/metabolismo , Desmetilación , Femenino , Humanos , Hidrazonas/farmacología , Histona Demetilasas con Dominio de Jumonji/metabolismo , Metilación/efectos de los fármacos , Ratones Desnudos , Proteínas Nucleares/metabolismo , Pirimidinas/farmacología , Recombinasa Rad51/metabolismo , Tolerancia a Radiación/efectos de los fármacos , Análisis de Supervivencia , Proteína 1 de Unión al Supresor Tumoral P53/metabolismoRESUMEN
AIMS: Jumonji Domain-Containing 1A (JMJD1A) protein promotes demethylation of histones, especially at lysin-9 of di-methylated histone H3 (H3K9me2) or mono-methylated (H3K9me1). Increased levels of H3 histone methylation at lysin-9 (H3K9) is related to tumor suppressor gene silencing. JMJD1A gene target Adrenomeduline (ADM) has shown to promote cell growth and tumorigenesis. JMJD1A and ADM expression, as well as H3K9 methylation level have been related with development risk and prognosis of several tumor types. METHODS AND RESULTS: We aimed to evaluate JMJD1A, ADM, H3K9me1 and H3K9me2expression in paraffin-embedded tissue microarrays from 84 oral and oropharyngeal squamous cell carcinoma samples through immunohistochemistry analysis. Our results showed that nuclear JMJD1A expression was related to lymph node metastasis risk. In addition, JMJD1A cytoplasmic expression was an independent risk marker for advanced tumor stages. H3K9me1 cytoplasmic expression was associated with reduced disease-specific death risk. Furthermore, high H3K9me2 nuclear expression was associated with worse specific-disease and disease-free survival. Finally, high ADM cytoplasmic expression was an independent marker of lymph node metastasis risk. CONCLUSION: JMJD1A, H3K9me1/2 and ADM expression may be predictor markers of progression and prognosis in oral and oropharynx cancer patients, as well as putative therapeutic targets.
Asunto(s)
Adrenomedulina/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/secundario , Histonas/metabolismo , Histona Demetilasas con Dominio de Jumonji/metabolismo , Neoplasias de la Boca/patología , Neoplasias Orofaríngeas/patología , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/cirugía , Epigénesis Genética , Femenino , Estudios de Seguimiento , Regulación Neoplásica de la Expresión Génica , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/metabolismo , Neoplasias de la Boca/cirugía , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/cirugía , Neoplasias Orofaríngeas/metabolismo , Neoplasias Orofaríngeas/cirugía , Pronóstico , Tasa de SupervivenciaRESUMEN
Novel bone regeneration approaches aim to obtain immature osteoblasts from somatic stem cells. Umbilical cord Wharton's jelly mesenchymal stem cells (WJ-MSCs) are an ideal source for cell therapy. Hence, the study of mechanisms involved in WJ-MSC osteoblastic differentiation is crucial to exploit their developmental capacity. Here, we have assessed epigenetic control of the Runt-related transcription factor 2 (RUNX2) osteogenic master regulator gene in WJ-MSC. We present evidence indicating that modulation of RUNX2 expression through preventing Jumonji AT-rich interactive domain 1B (JARID1B) histone demethylase activity is relevant to enhance WJ-MSC osteoblastic potential. Hence, JARID1B loss of function in WJ-MSC results in increased RUNX2/p57 expression. Our data highlight JARID1B activity as a novel target to modulate WJ-MSC osteoblastic differentiation with potential applications in bone tissue engineering. Stem Cells 2017;35:2430-2441.
Asunto(s)
Histona Demetilasas con Dominio de Jumonji/metabolismo , Células Madre Mesenquimatosas/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Epigenómica , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , Células Madre Mesenquimatosas/citología , Osteoblastos/citología , Osteoblastos/metabolismo , Cordón Umbilical/citología , Gelatina de Wharton/citologíaRESUMEN
As it has been established that demethylation of lysine 27 of histone H3 by the lysine-specific demethylase JMJD3 increases immune responses and thus elicits inflammation, we hypothesize that inhibition of JMJD3 may attenuate autoimmune disorders. We found that in vivo administration of GSK-J4, a selective inhibitor of JMJD3 and UTX, ameliorates the severity of experimental autoimmune encephalomyelitis (EAE). In vitro experiments revealed that the anti-inflammatory effect of GSK-J4 was exerted through an effect on dendritic cells (DCs), promoting a tolerogenic profile characterized by reduced expression of costimulatory molecules CD80/CD86, an increased expression of tolerogenic molecules CD103 and TGF-ß1, and reduced secretion of proinflammatory cytokines IL-6, IFN-γ, and TNF. Adoptive transfer of GSK-J4-treated DCs into EAE mice reduced the clinical manifestation of the disease and decreased the extent of inflammatory CD4+ T cells infiltrating the central nervous system. Notably, Treg generation, stability, and suppressive activity were all exacerbated by GSK-J4-treated DCs without affecting Th1 and Th17 cell production. Our data show that GSK-J4-mediated modulation of inflammation is achieved by a direct effect on DCs and that systemic treatment with GSK-J4 or adoptive transfer of GSK-J4-treated DCs ex vivo may be promising approaches for the treatment of inflammatory and autoimmune disorders.
Asunto(s)
Benzazepinas/farmacología , Células Dendríticas/efectos de los fármacos , Encefalomielitis Autoinmune Experimental/prevención & control , Histona Demetilasas con Dominio de Jumonji/antagonistas & inhibidores , Pirimidinas/farmacología , Traslado Adoptivo , Animales , Antígenos CD/inmunología , Antígenos CD/metabolismo , Antígeno B7-1/inmunología , Antígeno B7-1/metabolismo , Antígeno B7-2/inmunología , Antígeno B7-2/metabolismo , Western Blotting , Linfocitos T CD4-Positivos/inmunología , Citocinas/genética , Citocinas/inmunología , Citocinas/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Encefalomielitis Autoinmune Experimental/genética , Encefalomielitis Autoinmune Experimental/inmunología , Expresión Génica/efectos de los fármacos , Tolerancia Inmunológica/genética , Tolerancia Inmunológica/inmunología , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/metabolismo , Cadenas alfa de Integrinas/inmunología , Cadenas alfa de Integrinas/metabolismo , Histona Demetilasas con Dominio de Jumonji/inmunología , Histona Demetilasas con Dominio de Jumonji/metabolismo , Ratones Endogámicos C57BL , Ratones Transgénicos , Fenotipo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Crecimiento Transformador beta1/inmunología , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
One of the earliest manifestations of neural induction is onset of expression of the neural marker Sox2, mediated by the activation of the enhancers N1 and N2. By using loss and gain of function, we find that Sox2 expression requires the activity of JmjD2A and the Msk1 kinase, which can respectively demethylate the repressive H3K9me3 mark and phosphorylate the activating H3S10 (H3S10ph) mark. Bimolecular fluorescence complementation reveals that the adaptor protein 14-3-3, known to bind to H3S10ph, interacts with JMJD2A and may be involved in its recruitment to regulatory regions of the Sox2 gene. Chromatin immunoprecipitation reveals dynamic binding of JMJD2A to the Sox2 promoter and N-1 enhancer at the time of neural plate induction. Finally, we show a clear temporal antagonism on the occupancy of H3K9me3 and H3S10ph modifications at the promoter of the Sox2 locus before and after the neural plate induction. Taken together, our results propose a series of epigenetic events necessary for the early activation of the Sox2 gene in neural progenitor cells.
Asunto(s)
Histona Demetilasas con Dominio de Jumonji/metabolismo , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Proteínas 14-3-3/metabolismo , Animales , Embrión de Pollo , Desarrollo Embrionario/genética , Elementos de Facilitación Genéticos/genética , Epigenómica , Regulación del Desarrollo de la Expresión Génica/genética , Placa Neural/metabolismo , Células-Madre Neurales/metabolismo , Fosforilación , Regiones Promotoras Genéticas , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Factores de Transcripción/metabolismoRESUMEN
Transcription factor Runx2 controls bone development and osteoblast differentiation by regulating expression of a significant number of bone-related target genes. Here, we report that transcriptional activation and repression of the Runx2 gene via its osteoblast-specific P1 promoter (encoding mRNA for the Runx2/p57 isoform) is accompanied by selective deposition and elimination of histone marks during differentiation of mesenchymal cells to the osteogenic and myoblastic lineages. These epigenetic profiles are mediated by key components of the Trithorax/COMPASS-like and Polycomb group complexes together with histone arginine methylases like PRMT5 and lysine demethylases like JARID1B/KDM5B. Importantly, knockdown of the H3K4me2/3 demethylase JARID1B, but not of the demethylases UTX and NO66, prevents repression of the Runx2 P1 promoter during myogenic differentiation of mesenchymal cells. The epigenetically forced expression of Runx2/p57 and osteocalcin, a classical bone-related target gene, under myoblastic-differentiation is accompanied by enrichment of the H3K4me3 and H3K27ac marks at the Runx2 P1 promoter region. Our results identify JARID1B as a key component of a potent epigenetic switch that controls mesenchymal cell fate into myogenic and osteogenic lineages.