RESUMEN

This study is to elucidate the effect of the LINC00663/EBF1/NR2F1 axis on inflammation and angiogenesis in bladder cancer (BC) and related molecular mechanisms. After transfection, functional experiments were conducted to test cell proliferation and invasion, tube formation ability, and content of inflammatory factors, Snail, E-cadherin, and VEGFA. Meanwhile, the relationships among LINC00663, EBF1, and NR2F1 were predicted and verified. In addition, xenograft experiments in nude mice were performed to observe the oncogenicity of 5637 BC cells in vivo. In BC tissues and cells, LINC00663 and NR2F1 were upregulated. Silencing NR2F1 or LINC00663 repressed cell proliferation and invasion, weakened vascular mimicry in vitro, decreased inflammatory factor, Snail, and VEGFA levels, and increased expression of E-cadherin. LINC00663 positively regulated NR2F1 expression through EBF1. Additionally, in vivo experiments showed that NR2F1 upregulation reversed the suppression effects of LINC00663 silencing on tumour growth, inflammation, and angiogenesis. Silencing LINC00663 decreased NR2F1 expression by mediating EBF1, thereby inhibiting BC inflammation and angiogenesis.

Asunto(s)

Factor de Transcripción COUP I , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Inflamación , Neovascularización Patológica , ARN Largo no Codificante , Transactivadores , Neoplasias de la Vejiga Urinaria , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/metabolismo , Neoplasias de la Vejiga Urinaria/patología , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Animales , Ratones , Línea Celular Tumoral , Factor de Transcripción COUP I/metabolismo , Factor de Transcripción COUP I/genética , Inflamación/metabolismo , Inflamación/genética , Inflamación/patología , Transactivadores/metabolismo , Transactivadores/genética , Femenino , Masculino , Ratones Desnudos , Silenciador del Gen , Movimiento Celular , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Angiogénesis

RESUMEN

Tendons, which transmit force from muscles to bones, are highly prone to injury. Understanding the mechanisms driving tendon fate would impact efforts to improve tendon healing, yet this knowledge is limited. To find direct regulators of tendon progenitor emergence, we performed a zebrafish high-throughput chemical screen. We established forskolin as a tenogenic inducer across vertebrates, functioning through Creb1a, which is required and sufficient for tendon fate. Putative enhancers containing cyclic AMP (cAMP) response elements (CREs) in humans, mice, and fish drove specific expression in zebrafish cranial and fin tendons. Analysis of these genomic regions identified motifs for early B cell factor (Ebf/EBF) transcription factors. Mutation of CRE or Ebf/EBF motifs significantly disrupted enhancer activity and specificity in tendons. Zebrafish ebf1a/ebf3a mutants displayed defects in tendon formation. Notably, Creb1a/CREB1 and Ebf1a/Ebf3a/EBF1 overexpression facilitated tenogenic induction in zebrafish and human pluripotent stem cells. Together, our work identifies the functional conservation of two transcription factors in promoting tendon fate.

RESUMEN

Immunotherapy has limited response rates in colorectal cancer (CRC) due to an immunosuppressive tumor microenvironment (TME). Combining transcriptome sequencing, clinical specimens, and functional experiments, we identified a unique group of CAF subpopulations (COX4I2 + ) with inhibited mitochondrial respiration and enhanced glycolysis. Through bioinformatics predictions and luciferase reporter assays, we determined that EBF1 can upstreamly regulate COX4I2 transcription. COX4I2 + CAFs functionally and phenotypically resemble myofibroblasts, are important for the formation of the fibrotic TME, and are capable of activating the M2 phenotype of macrophages. In vitro experiments demonstrated that COX4I2 + CAFs promote immunosuppressive TME by blocking CD8 + T cell infiltration and inducing CD8 + T cell dysfunction. Using multiple independent cohorts, we also found a strong correlation between the immunotherapy response rate of CRC patients and COX4I2 expression in their tumors. Our results identify a CAF subpopulation characterized by activation of the EBF1-COX4I2 axis, and this group of CAFs can be targeted to improve cancer immunotherapy outcomes.

Asunto(s)

Fibroblastos Asociados al Cáncer , Neoplasias Colorrectales , Miofibroblastos , Transducción de Señal , Transactivadores , Microambiente Tumoral , Microambiente Tumoral/inmunología , Humanos , Fibroblastos Asociados al Cáncer/metabolismo , Fibroblastos Asociados al Cáncer/inmunología , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/genética , Transactivadores/metabolismo , Transactivadores/genética , Miofibroblastos/inmunología , Miofibroblastos/metabolismo , Animales , Línea Celular Tumoral , Fenotipo , Linfocitos T CD8-positivos/inmunología , Ratones , Regulación Neoplásica de la Expresión Génica , Inmunoterapia/métodos

RESUMEN

During lymphocyte development, a diverse repertoire of lymphocyte antigen receptors is produced to battle against pathogens, which is the basis of adaptive immunity. The diversity of the lymphocyte antigen receptors arises primarily from recombination-activated gene (RAG) protein-mediated V(D)J rearrangement in early lymphocytes. Furthermore, transcription factors (TFs), such as early B cell factor 1 (EBF1), paired box gene 5 (PAX5), and proto-oncogene myelocytomatosis oncogene (MYC), play critical roles in regulating recombination and maintaining normal B cell development. Therefore, the aberrant expression of these TFs may lead to hematologic neoplasms.

Asunto(s)

Neoplasias Hematológicas , Neoplasias , Factor de Transcripción PAX5 , Proteínas Proto-Oncogénicas c-myc , Transactivadores , Humanos , Linfocitos B , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Neoplasias/metabolismo , Factor de Transcripción PAX5/genética , Factor de Transcripción PAX5/metabolismo , Receptores de Antígenos/metabolismo , Transactivadores/genética , Transactivadores/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo

RESUMEN

The gaseous phytohormone ethylene plays a crucial role in plant growth, development, and stress responses. In the ethylene signal transduction cascade, the F-box proteins EIN3-BINDING F-BOX 1 (EBF1) and EBF2 are identified as key negative regulators governing ethylene sensitivity. The translation and processing of EBF1/2 mRNAs are tightly controlled, and their 3' untranslated regions (UTRs) are critical in these regulations. However, despite their significance, the exact mechanisms modulating the processing of EBF1/2 mRNAs remain poorly understood. In this work, we identified the gene DCP1-ASSOCIATED NYN ENDORIBONUCLEASE 1 (DNE1), which encodes an endoribonuclease and is induced by ethylene treatment, as a positive regulator of ethylene response. The loss of function mutant dne1-2 showed mild ethylene insensitivity, highlighting the importance of DNE1 in ethylene signaling. We also found that DNE1 colocalizes with ETHYLENE INSENSITIVE 2 (EIN2), the core factor manipulating the translation of EBF1/2, and targets the P-body in response to ethylene. Further analysis revealed that DNE1 negatively regulates the abundance of EBF1/2 mRNAs by recognizing and cleaving their 3'UTRs, and it also represses their translation. Moreover, the dne1 mutant displays hypersensitivity to 1,4-dithiothreitol (DTT)-induced ER stress and oxidative stress, indicating the function of DNE1 in stress responses. This study sheds light on the essential role of DNE1 as a modulator of ethylene signaling through regulation of EBF1/2 mRNA processing. Our findings contribute to the understanding of the intricate regulatory process of ethylene signaling and provide insights into the significance of ribonuclease in stress responses.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Proteínas F-Box , Arabidopsis/metabolismo , Factores de Transcripción/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Endorribonucleasas/genética , Endorribonucleasas/metabolismo , Proteínas Nucleares/genética , Etilenos/farmacología , Etilenos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas F-Box/genética

RESUMEN

B lineage priming by pioneer transcription factor EBF1 requires the function of an intrinsically disordered region (IDR). Here, we examine the role of regularly spaced tyrosines in the IDR as potential determinants of IDR function and activity of EBF1. We found that four Y > A mutations in EBF1 reduced the formation of condensates in vitro and subdiffractive clusters in vivo. Notably, Y > A mutant EBF1 was inefficient in promoting B cell differentiation and showed impaired chromatin binding, recruitment of BRG1, and activation of specific target genes. Thus, regularly spaced tyrosines in the IDR contribute to the biophysical and functional properties of EBF1.

Asunto(s)

Linfocitos B , Regulación de la Expresión Génica , Linaje de la Célula/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Heterocromatina/metabolismo

RESUMEN

Functions of the SKP1-CUL1-F box (SCF) ubiquitin E3 ligases are essential in plants. The F box proteins (FBPs) are substrate receptors that recruit substrates and assemble an active SCF complex, but the regulatory mechanism underlying the FBPs binding to CUL1 to activate the SCF cycle is not fully understood. We show that Arabidopsis csn1-10 is defective in SCFEBF1-mediated PIF3 degradation during de-etiolation, due to impaired association of EBF1 with CUL1 in csn1-10. EBF1 preferentially associates with un-neddylated CUL1 that is deficient in csn1-10 and the EBF1-CUL1 binding is rescued by the neddylation inhibitor MLN4924. Furthermore, we identify a subset of FBPs with impaired binding to CUL1 in csn1-10, indicating their assembly to form SCF complexes may depend on COP9 signalosome (CSN)-mediated deneddylation of CUL1. This study reports that a key role of CSN-mediated CULLIN deneddylation is to gate the binding of the FBP-substrate module to CUL1, thus initiating the SCF cycle of substrate ubiquitination.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Proteínas F-Box , Proteínas Cullin/metabolismo , Arabidopsis/metabolismo , Núcleo Celular/metabolismo , Proteínas F-Box/metabolismo , Ubiquitina/metabolismo , Complejo del Señalosoma COP9/metabolismo , Proteínas Ligasas SKP Cullina F-box/metabolismo , Proteínas de Arabidopsis/metabolismo

RESUMEN

Nerve injury-induced alternations of gene expression in primary sensory neurons of the dorsal root ganglion (DRG) are molecular basis of neuropathic pain genesis. Transcription factors regulate gene expression. In this study, we examined whether early B cell factor 1 (EBF1), a transcription factor, in the DRG, participated in neuropathic pain caused by chronic constriction injury (CCI) of the sciatic nerve. EBF1 was distributed exclusively in the neuronal nucleus and coexpressed with cytoplasmic/membrane Kv1.2 in individual DRG neurons. The expression of Ebf1 mRNA and protein was time-dependently downregulated in the ipsilateral lumbar (L) 3/4 DRGs after unilateral CCI. Rescuing this downregulation through microinjection of the adeno-associated virus 5 expressing full-length Ebf1 mRNA into the ipsilateral L3/4 DRGs reversed the CCI-induced decrease of DRG Kv1.2 expression and alleviated the development and maintenance of mechanical, heat and cold hypersensitivities. Conversely, mimicking the downregulation of DRG EBF1 through microinjection of AAV5-expressing Ebf1 shRNA into unilateral L3/4 DRGs produced a reduction of Kv1.2 expression in the ipsilateral L3/4 DRGs, spontaneous pain, and the enhanced responses to mechanical, heat and cold stimuli in naive mice. Mechanistically, EBF1 not only bound to the Kcna2 gene (encoding Kv1.2) promoter but also directly activated its activity. CCI decreased the EBF1 binding to the Kcna2 promoter in the ipsilateral L3/4 DRGs. Our findings suggest that DRG EBF1 downregulation contributes to neuropathic pain likely by losing its binding to Kcna2 promoter and subsequently silencing Kv1.2 expression in primary sensory neurons. Exogenous EBF1 administration may mitigate neuropathic pain by rescuing DRG Kv1.2 expression.

Asunto(s)

Neuralgia , Factores de Transcripción , Animales , Ratones , Regulación de la Expresión Génica , Hiperalgesia/genética , Neuralgia/genética , ARN Mensajero/metabolismo , Células Receptoras Sensoriales , Factores de Transcripción/genética , Canal de Potasio Kv.1.2/metabolismo

RESUMEN

Reciprocal interactions between non-myocytes and cardiomyocytes regulate cardiac growth and differentiation. Here, we report that the transcription factor Ebf1 is highly expressed in non-myocytes and potently regulates heart development. Ebf1-deficient hearts display myocardial hypercellularity and reduced cardiomyocyte size, ventricular conduction system hypoplasia, and conduction system disease. Growth abnormalities in Ebf1 knockout hearts are observed as early as embryonic day 13.5. Transcriptional profiling of Ebf1-deficient embryonic cardiac non-myocytes demonstrates dysregulation of Polycomb repressive complex 2 targets, and ATAC-Seq reveals altered chromatin accessibility near many of these same genes. Gene set enrichment analysis of differentially expressed genes in cardiomyocytes isolated from E13.5 hearts of wild-type and mutant mice reveals significant enrichment of MYC targets and, consistent with this finding, we observe increased abundance of MYC in mutant hearts. EBF1-deficient non-myocytes, but not wild-type non-myocytes, are sufficient to induce excessive accumulation of MYC in co-cultured wild-type cardiomyocytes. Finally, we demonstrate that BMP signaling induces Ebf1 expression in embryonic heart cultures and controls a gene program enriched in EBF1 targets. These data reveal a previously unreported non-cell-autonomous pathway controlling cardiac growth and differentiation.

Asunto(s)

Regulación de la Expresión Génica , Factores de Transcripción , Animales , Ratones , Diferenciación Celular/genética , Miocardio/metabolismo , Miocitos Cardíacos/metabolismo , Factores de Transcripción/metabolismo

RESUMEN

Gene aberrations of B-cell regulators and growth signal components such as the JAK-STAT pathway are frequently found in B-cell acute lymphoblastic leukemia (B-ALL). EBF1 is a B-cell regulator that regulates the expression of PAX5 and co-operates with PAX5 to regulate B-cell differentiation. Here, we analyzed the function of the fusion protein of EBF1 and JAK2, EBF1-JAK2 (E-J). E-J caused constitutive activation of JAK-STAT and MAPK pathways and induced autonomous cell growth in a cytokine-dependent cell line. E-J did not affect the transcriptional activity of EBF1 but inhibited that of PAX5. Both the physical interaction of E-J with PAX5 and kinase activity of E-J were required for E-J to inhibit PAX5 function, although the detailed mechanism of inhibition remains unclear. Importantly, gene set enrichment analysis using the results of our previous RNA-seq data of 323 primary BCR-ABL1-negative ALL samples demonstrated repression of the transcriptional target genes of PAX5 in E-J-positive ALL cells, which suggests that E-J also inhibited PAX5 function in ALL cells. Our results shed new light on the mechanisms of differentiation block by kinase fusion proteins.

Asunto(s)

Quinasas Janus , Factores de Transcripción STAT , Humanos , Quinasas Janus/metabolismo , Factores de Transcripción STAT/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Línea Celular , Factor de Transcripción PAX5/genética , Factor de Transcripción PAX5/metabolismo , Transactivadores/genética , Transactivadores/metabolismo , Janus Quinasa 2/genética , Janus Quinasa 2/metabolismo

RESUMEN

Acute lung injury is a critical acute respiratory distress syndrome (ARDS) with high morbidity and mortality. MicroRNAs (miRNAs) have been demonstrated to play important roles regulating acute lung injury development. In this study, we found that the expression of miR-598 was significantly upregulated in the lung tissues of mice with lipopolysaccharide (LPS)-induced acute lung injury. Both loss-of-function and gain-of-function studies were performed to evaluate the function of miR-598 in acute lung injury. The results showed that inhibition of miR-598 attenuated inflammatory response, oxidative stress, and lung injury in mice treated with LPS, while overexpression of miR-598 exacerbated the LPS-induced acute lung injury. Mechanistically, transcription factor Early B-cell Factor-1 (Ebf1) was predicted and validated as a downstream target of miR-598. Overexpression of Ebf1 attenuated LPS-induced production of inflammatory cytokine TNF-α and IL-6, ameliorated LPS-induced oxidative stress, promoted proliferation, and inhibited apoptosis in murine lung epithelial-15 (MLE-15) cells. Moreover, we demonstrated that Ebf1 knockdown abolished the protective effect of miR-598 inhibition in LPS-treated MLE-15 cells. In summary, miR-598 inhibition ameliorates LPS-induced acute lung injury in mice through upregulating Ebf1 expression, which might provide potential therapeutic treatment for acute lung injury.

Asunto(s)

Lesión Pulmonar Aguda , MicroARNs , Animales , Ratones , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/genética , Lesión Pulmonar Aguda/prevención & control , Apoptosis , Citocinas , Lipopolisacáridos/efectos adversos , MicroARNs/genética , MicroARNs/metabolismo , FN-kappa B/metabolismo , Transactivadores

RESUMEN

Nerve injury to peripheral somatosensory system causes refractory neuropathic pain. Maladaptive changes of gene expression in primary sensory neurons are considered molecular basis of this disorder. Long non-coding RNAs (lncRNAs) are key regulators of gene transcription; however, their significance in neuropathic pain remains largely elusive.Here, we reported a novel lncRNA, named sensory neuron-specific lncRNA (SS-lncRNA), for its expression exclusively in dorsal root ganglion (DRG) and trigeminal ganglion. SS-lncRNA was predominantly expressed in small DRG neurons and significantly downregulated due to a reduction of early B cell transcription factor 1 in injured DRG after nerve injury. Rescuing this downregulation reversed a decrease of the calcium-activated potassium channel subfamily N member 1 (KCNN1) in injured DRG and alleviated nerve injury-induced nociceptive hypersensitivity. Conversely, DRG downregulation of SS-lncRNA reduced the expression of KCNN1, decreased total potassium currents and afterhyperpolarization currents and increased excitability in DRG neurons and produced neuropathic pain symptoms.Mechanistically, downregulated SS-lncRNA resulted in the reductions of its binding to Kcnn1 promoter and heterogeneous nuclear ribonucleoprotein M (hnRNPM), consequent recruitment of less hnRNPM to the Kcnn1 promoter and silence of Kcnn1 gene transcription in injured DRG.These findings indicate that SS-lncRNA may relieve neuropathic pain through hnRNPM-mediated KCNN1 rescue in injured DRG and offer a novel therapeutic strategy specific for this disorder.

Asunto(s)

Neuralgia , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , Células Receptoras Sensoriales/metabolismo , Neuralgia/terapia , Canales de Potasio de Pequeña Conductancia Activados por el Calcio/genética

RESUMEN

Although the incidence and death rates of gastric cancer (GC) are decreasing, approximately one million new cases and 800,000 GC-related deaths were reported worldwide in 2018. Currently, the oncogenesis of GC remains unclear, and the demand for novel treatment options are unmet. Here, we explored the role of aldo-keto reductase family 1 member B (AKR1B1) in the progression of GC. The proliferation, migration, and invasion of GC cells were evaluated by CCK-8 assay, wound healing assay, and transwell assay, respectively. The interaction between EBF transcription factor 1 (EBF1) and the promoter region of AKR1B1 was determined by luciferase reporter assay and chromatin immunoprecipitation (ChIP). Gene expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting assay. The expression of AKR1B1 was elevated in GC cells, resulting in increased cell proliferation, migration, and invasion. Meanwhile, EBF1 was a negative regulator of AKR1B1; its overexpression suppressed AKR1B1 expression and GC progression. Furthermore, knockdown of ZNF521 induced EBF1 expression, thus suppressing AKR1B1 expression and resulting in attenuated GC growth and invasiveness. Notably, knockdown of ZNF521 attenuated GC progression and was rescued by overexpression of AKR1B1. Our current study revealed a novel ZNF521/EBF1/AKR1B1 axis in GC and elaborated its important role in promoting GC progression, providing potential therapeutic targets for anti-GC treatments.

Asunto(s)

MicroARNs , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Línea Celular Tumoral , Factores de Transcripción/genética , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Movimiento Celular/genética , Invasividad Neoplásica/genética , Transactivadores/metabolismo , Aldehído Reductasa/genética , Aldehído Reductasa/metabolismo

RESUMEN

OBJECTIVE: Class 3 semaphorins are reduced in the synovial tissue of RA patients and these proteins are involved in the pathogenesis of the disease. The aim of this study was to identify the transcription factors involved in the expression of class 3 semaphorins in the synovium of RA patients. METHODS: Protein and mRNA expression in synovial tissue from RA and individuals at risk (IAR) patients, human umbilical vein endothelial cells (HUVEC) and RA fibroblast-like synoviocytes (FLS) was determined by ELISA, immunoblotting and quantitative PCR. TCF-3, EBF-1 and HOXA5 expression was knocked down using siRNA. Cell viability, migration and invasion were determined using MTT, calcein, wound closure and invasion assays, respectively. RESULTS: mRNA expression of all class 3 semaphorins was significantly lower in the synovium of RA compared with IAR patients. In silico analysis suggested TCF-3, EBF-1 and HOXA5 as transcription factors involved in the expression of these semaphorins. TCF-3, EBF-1 and HOXA5 silencing significantly reduced the expression of several class 3 semaphorin members in FLS and HUVEC. Importantly, HOXA5 expression was significantly reduced in the synovium of RA compared with IAR patients and was negatively correlated with clinical disease parameters. Additionally, TNF-α down-regulated the HOXA5 expression in FLS and HUVEC. Finally, HOXA5 silencing enhanced the migratory and invasive capacities of FLS and the viability of HUVEC. CONCLUSION: HOXA5 expression is reduced during the progression of RA and could be a novel therapeutic strategy for modulating the hyperplasia of the synovium, through the regulation of class 3 semaphorins expression.

Asunto(s)

Artritis Reumatoide , Semaforinas , Sinoviocitos , Humanos , Semaforinas/genética , Células Cultivadas , Membrana Sinovial/metabolismo , Artritis Reumatoide/tratamiento farmacológico , Sinoviocitos/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana/patología , Factores de Transcripción/metabolismo , ARN Mensajero/metabolismo , Fibroblastos/metabolismo , Proliferación Celular , Proteínas de Homeodominio/metabolismo , Proteínas de Homeodominio/uso terapéutico

RESUMEN

Brassinosteroids (BRs) are a group of plant steroid hormones that play important roles in a wide range of developmental and physiological processes in plants. Transcription factors BRASSINOZALE-RESISTANT1 (BZR1) and its homologs are key components of BR signaling and integrate a wide range of internal and environmental signals to coordinate plant growth and development. Although several E3 ligases have been reported to regulate the stability of BZR1, the molecular mechanism of BZR1 degradation remains unclear. Here, we reveal how a newly identified molecular mechanism underlying EBF1 directly regulates BZR1 protein stability via the 26S proteasome pathway, repressing BR function on regulating Arabidopsis apical hook development and hypocotyl elongation. BZR1 directly binds to the EBF1 gene promotor to reduce EBF1 expression. Furthermore, the genetic analysis shows that BZR1, EIN3 and PIF4 interdependently regulate plant apical hook development. Taken together, our data demonstrates that EBF1 is a negative regulator of the BR signaling pathway.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Proteínas F-Box , Brasinoesteroides/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas F-Box/genética

RESUMEN

Caveolin-1 (CAV1) is implicated in the pathophysiology of diabetes and obesity. Previously, we demonstrated an association between the CAV1 rs1997623 C > A variant and metabolic syndrome (MetS). Here, we decipher the functional role of rs1997623 in CAV1 gene regulation. A cohort of 38 patients participated in this study. The quantitative MetS scores (siMS) of the participants were computed. CAV1 transcript and protein expression were tested in subcutaneous adipose tissue using RT-PCR and immunohistochemistry. Chromatin immunoprecipitation assays were performed using primary preadipocytes isolated from individuals with different CAV1 rs1997623 genotypes (AA, AC, and CC). The regulatory region flanking the variant was cloned into a luciferase reporter plasmid and expressed in human preadipocytes. Additional knockdown and overexpression assays were carried out. We show a significant correlation between siMS and CAV1 transcript levels and protein levels in human adipose tissue collected from an Arab cohort. We found that the CAV1 rs1997623 A allele generates a transcriptionally active locus and a new transcription factor binding site for early B-cell factor 1 (EBF1), which enhanced CAV1 expression. Our in vivo and in vitro combined study implicates, for the first time, EBF1 in regulating CAV1 expression in individuals harboring the rs1997623 C > A variant.

Asunto(s)

Caveolina 1 , Síndrome Metabólico , Polimorfismo de Nucleótido Simple , Transactivadores , Humanos , Tejido Adiposo/metabolismo , Alelos , Sitios de Unión , Caveolina 1/genética , Genotipo , Síndrome Metabólico/metabolismo , Transactivadores/metabolismo

RESUMEN

The establishment of de novo chromatin accessibility in lymphoid progenitors requires the "pioneering" function of transcription factor (TF) early B cell factor 1 (EBF1), which binds to naïve chromatin and induces accessibility by recruiting the BRG1 chromatin remodeler subunit. However, it remains unclear whether the function of EBF1 is continuously required for stabilizing local chromatin accessibility. To this end, we replaced EBF1 by EBF1-FKBPF36V in pro-B cells, allowing the rapid degradation by adding the degradation TAG13 (dTAG13) dimerizer. EBF1 degradation results in a loss of genome-wide EBF1 occupancy and EBF1-targeted BRG1 binding. Chromatin accessibility was rapidly diminished at EBF1-binding sites with a preference for sites whose occupancy requires the pioneering activity of the C-terminal domain of EBF1. Diminished chromatin accessibility correlated with altered gene expression. Thus, continuous activity of EBF1 is required for the stable maintenance of the transcriptional and epigenetic state of pro-B cells.

Asunto(s)

Cromatina , Células Precursoras de Linfocitos B , Cromatina/genética , Epigenómica , Sitios de Unión , Recuento de Células

RESUMEN

Unlike animals, plant development is plastic and sensitive to environmental changes. For example, Arabidopsis thaliana seedlings display distinct growth patterns when they are grown under different light or temperature conditions. Moreover, endogenous plant hormone such as ethylene also impacts seedling morphology. Ethylene induces hypocotyl elongation in light-grown seedlings but strongly inhibits hypocotyl elongation in etiolated (dark-grown) seedlings. Another characteristic ethylene response in etiolated seedlings is the formation of exaggerated apical hooks. Although it is well known that high ambient temperature promotes hypocotyl elongation in light-grown seedlings (thermomorphogenesis), ethylene suppresses thermomorphogenesis. On another side, high ambient temperature also inhibits the ethylene-responsive hypocotyl shortening and exaggerated hook formation in etiolated seedlings. Therefore, the simplest phytohormone ethylene exhibits almost the most complicated responses, depending on temperature and/or light conditions. In this review, we will focus on two topics related to the main theme of this special issue (response to high temperature): (1) how does high temperature suppress ethylene-induced seedling morphology in dark-grown seedlings, and (2) how does ethylene inhibit high temperature-induced seedling growth in light-grown seedlings. Controlling ethylene biosynthesis through antisense technology was the hallmark event in plant genetic engineering in 1990, we assume that manipulations on plant ethylene signaling in agricultural plants may pave the way for coping with climate change in future.

RESUMEN

Transcription factor EBF1 (early B cell factor 1) acts as a key regulator of B cell specification. The transcriptional network in which EBF1 operates has been extensively studied; however, the regulation of EBF1 function remains poorly defined. By mass spectrometric analysis of proteins associated with endogenous EBF1 in pro-B cells, we identified the nuclear import receptor Transportin-3 (Tnpo3) and found that it interacts with the immunoglobulin-like fold domain of EBF1. We delineated glutamic acid 271 of EBF1 as a critical residue for the association with Tnpo3. EBF1E271A showed normal nuclear localization; however, it had an impaired B cell programming ability in conditions of Notch signaling, as determined by retroviral transduction of Ebf1 -/- progenitors. By RNA-seq analysis of EBF1E271A-expressing progenitors, we found an up-regulation of T lineage determinants and down-regulation of early B genes, although similar chromatin binding of EBF1E271A and EBF1wt was detected in pro-B cells expressing activated Notch1. B lineage-specific inactivation of Tnpo3 in mice resulted in a block of early B cell differentiation, accompanied by a down-regulation of B lineage genes and up-regulation of T and NK lineage genes. Taken together, our observations suggest that Tnpo3 ensures B cell programming by EBF1 in nonpermissive conditions.

Asunto(s)

Ácido Glutámico , Transactivadores , beta Carioferinas , Animales , Ratones , beta Carioferinas/metabolismo , Linaje de la Célula/genética , Cromatina , Inmunoglobulinas/genética , Inmunoglobulinas/metabolismo , Carioferinas/genética , Receptores Notch/metabolismo , Transactivadores/metabolismo , Factores de Transcripción/metabolismo

RESUMEN

Early B cell factor 1 (EBF1) is a transcriptional factor with a variety of roles in cell differentiation and metabolism. However, the functional roles of EBF1 in tumorigenesis remain elusive. Here, we demonstrate that EBF1 is highly expressed in triple-negative breast cancer (TNBC). Furthermore, EBF1 has a pivotal role in the tumorigenicity and progression of TNBC. Moreover, we found that depletion of EBF1 induces extensive cell mitophagy and inhibits tumor growth. Genome-wide mapping of the EBF1 transcriptional regulatory network revealed that EBF1 drives TNBC tumorigenicity by assembling a transcriptional complex with HIF1α that fine-tunes the expression of HIF1α targets via suppression of p300 activity. EBF1 therefore holds HIF1α activity in check to avert extensive mitophagy-induced cell death. Our findings reveal a key function for EBF1 as a master regulator of mitochondria homeostasis in TNBC and indicate that targeting this pathway may offer alternative treatment strategies for this aggressive subtype of breast cancer.

Asunto(s)

Subunidad alfa del Factor 1 Inducible por Hipoxia , Transactivadores , Neoplasias de la Mama Triple Negativas , Carcinogénesis/genética , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Transducción de Señal , Transactivadores/genética , Transactivadores/metabolismo , Neoplasias de la Mama Triple Negativas/metabolismo , Neoplasias de la Mama Triple Negativas/patología