RESUMEN
Nuclear pore complexes (NPCs) mediate transport across the nuclear envelope. In yeast, they also interact with active genes, attracting or retaining them at the nuclear periphery. In higher eukaryotes, some NPC components (nucleoporins) are also found in the nucleoplasm, with a so far unknown function. We have functionally characterized nucleoporin-chromatin interactions specifically at the NPC or within the nucleoplasm in Drosophila. We analyzed genomic interactions of full-length nucleoporins Nup98, Nup50, and Nup62 and nucleoplasmic and NPC-tethered forms of Nup98. We found that nucleoporins predominantly interacted with transcriptionally active genes inside the nucleoplasm, in particular those involved in developmental regulation and the cell cycle. A smaller set of nonactive genes interacted with the NPC. Genes strongly interacting with nucleoplasmic Nup98 were downregulated upon Nup98 depletion and activated on nucleoplasmic Nup98 overexpression. Thus, nucleoporins stimulate developmental and cell-cycle gene expression away from the NPC by interacting with these genes inside the nucleoplasm.
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Ciclo Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Regulación de la Expresión Génica , Proteínas de Complejo Poro Nuclear/metabolismo , Animales , Núcleo Celular/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Laminas/metabolismo , Proteínas de Complejo Poro Nuclear/genética , Transcripción GenéticaRESUMEN
Elucidating genetic aberrations in pediatric acute myeloid leukemia (AML) provides insight in biology and may impact on risk-group stratification and clinical outcome. This study aimed to detect such aberrations in a selected series of samples without known (cyto)genetic aberration using molecular profiling. A cohort of 161 patients was selected from various study groups: DCOG, BFM, SJCRH, NOPHO and AEIOP. Samples were analyzed using RNA sequencing (n=152), whole exome (n=135) and/or whole genome sequencing (n=100). In 70 of 156 patients (45%), of whom RNA sequencing or whole genome sequencing was available, rearrangements were detected, 22 of which were novel; five involving ERG rearrangements and four NPM1 rearrangements. ERG rearrangements showed self-renewal capacity in vitro, and a distinct gene expression pattern. Gene set enrichment analysis of this cluster showed upregulation of gene sets derived from Ewing sarcoma, which was confirmed comparing gene expression profiles of AML and Ewing sarcoma. Furthermore, NPM1-rearranged cases showed cytoplasmic NPM1 localization and revealed HOXA/B gene overexpression, as described for NPM1 mutated cases. Single-gene mutations as identified in adult AML were rare. Patients had a median of 24 coding mutations (range, 7-159). Novel recurrent mutations were detected in UBTF (n=10), a regulator of RNA transcription. In 75% of patients an aberration with a prognostic impact could be detected. Therefore, we suggest these techniques need to become standard of care in diagnostics.
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Leucemia Mieloide Aguda , Sarcoma de Ewing , Niño , Adulto , Humanos , Nucleofosmina , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Mutación , Transcriptoma , PronósticoRESUMEN
The redox state of the neural progenitors regulates physiological processes such as neuronal differentiation and dendritic and axonal growth. The relevance of endoplasmic reticulum (ER)-associated oxidoreductases in these processes is largely unexplored. We describe a severe neurological disorder caused by bi-allelic loss-of-function variants in thioredoxin (TRX)-related transmembrane-2 (TMX2); these variants were detected by exome sequencing in 14 affected individuals from ten unrelated families presenting with congenital microcephaly, cortical polymicrogyria, and other migration disorders. TMX2 encodes one of the five TMX proteins of the protein disulfide isomerase family, hitherto not linked to human developmental brain disease. Our mechanistic studies on protein function show that TMX2 localizes to the ER mitochondria-associated membranes (MAMs), is involved in posttranslational modification and protein folding, and undergoes physical interaction with the MAM-associated and ER folding chaperone calnexin and ER calcium pump SERCA2. These interactions are functionally relevant because TMX2-deficient fibroblasts show decreased mitochondrial respiratory reserve capacity and compensatory increased glycolytic activity. Intriguingly, under basal conditions TMX2 occurs in both reduced and oxidized monomeric form, while it forms a stable dimer under treatment with hydrogen peroxide, recently recognized as a signaling molecule in neural morphogenesis and axonal pathfinding. Exogenous expression of the pathogenic TMX2 variants or of variants with an in vitro mutagenized TRX domain induces a constitutive TMX2 polymerization, mimicking an increased oxidative state. Altogether these data uncover TMX2 as a sensor in the MAM-regulated redox signaling pathway and identify it as a key adaptive regulator of neuronal proliferation, migration, and organization in the developing brain.
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Encefalopatías/patología , Encéfalo/anomalías , Discapacidades del Desarrollo/patología , Proteínas de la Membrana/metabolismo , Mitocondrias/metabolismo , Tiorredoxinas/metabolismo , Adolescente , Adulto , Encefalopatías/genética , Encefalopatías/metabolismo , Niño , Preescolar , Estudios de Cohortes , Discapacidades del Desarrollo/genética , Discapacidades del Desarrollo/metabolismo , Femenino , Fibroblastos/metabolismo , Fibroblastos/patología , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Proteínas de la Membrana/genética , Mitocondrias/patología , Oxidación-Reducción , Pronóstico , Piel/metabolismo , Piel/patología , Tiorredoxinas/genética , TranscriptomaRESUMEN
OBJECTIVE: Examine the associations of training volume and longest endurance run with (half-)marathon performance and running-related injuries (RRIs) in recreational runners. MATERIALS AND METHODS: During the preparation for and directly after the running event, 556 participants of a half marathon and 441 participants of a marathon completed three questionnaires on RRIs, average weekly training volume and the longest endurance run. With finish time, decline in pace during the running event and RRIs as dependent variables, linear and logistic regression analyses were performed to test the associations with weekly training volume and the longest endurance run. RESULTS: In half-marathon runners, a high training volume (>32 km/wk) (ß -4.19, 95% CI: -6.52;-1.85) and a long endurance run (>21 km) (ß -3.87, 95% CI: -6.31;--1.44) were associated with a faster finish time, while a high training volume (ß -1.81, 95% CI: -3.49;-0.12) and a long endurance run (ß -1.89, 95% CI: -3.65;-0.12) were also related to less decline in pace. In marathon runners, a low training volume (<40 km/wk) was related to a slower finish time (ß 6.33, 95% CI: 0.18;12.48) and a high training volume (>65 km/wk) to a faster finish time (ß -14.09, 95% CI: -22.47;-5.72), while a longest endurance run of <25 km was associated with a slower finish time (ß 13.44, 95% CI: 5.34;21.55). No associations between training characteristics and RRIs were identified. CONCLUSIONS: Preparation for a (half-)marathon with a relatively high training volume and long endurance runs associates with a faster finish time, but does not seem related to an increased injury risk.
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Traumatismos en Atletas/epidemiología , Rendimiento Atlético/estadística & datos numéricos , Carrera de Maratón/lesiones , Carrera de Maratón/estadística & datos numéricos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Encuestas y CuestionariosRESUMEN
[This corrects the article DOI: 10.1371/journal.pgen.1006809.].
RESUMEN
Integrator is an RNA polymerase II (RNAPII)-associated complex that was recently identified to have a broad role in both RNA processing and transcription regulation. Importantly, its role in human development and disease is so far largely unexplored. Here, we provide evidence that biallelic Integrator Complex Subunit 1 (INTS1) and Subunit 8 (INTS8) gene mutations are associated with rare recessive human neurodevelopmental syndromes. Three unrelated individuals of Dutch ancestry showed the same homozygous truncating INTS1 mutation. Three siblings harboured compound heterozygous INTS8 mutations. Shared features by these six individuals are severe neurodevelopmental delay and a distinctive appearance. The INTS8 family in addition presented with neuronal migration defects (periventricular nodular heterotopia). We show that the first INTS8 mutation, a nine base-pair deletion, leads to a protein that disrupts INT complex stability, while the second missense mutation introduces an alternative splice site leading to an unstable messenger. Cells from patients with INTS8 mutations show increased levels of unprocessed UsnRNA, compatible with the INT function in the 3'-end maturation of UsnRNA, and display significant disruptions in gene expression and RNA processing. Finally, the introduction of the INTS8 deletion mutation in P19 cells using genome editing alters gene expression throughout the course of retinoic acid-induced neural differentiation. Altogether, our results confirm the essential role of Integrator to transcriptome integrity and point to the requirement of the Integrator complex in human brain development.
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Discapacidades del Desarrollo/genética , Eliminación de Gen , Mutación Missense , Subunidades de Proteína/genética , ARN Mensajero/metabolismo , Adulto , Empalme Alternativo , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Encéfalo/patología , Células Cultivadas , Niño , Discapacidades del Desarrollo/diagnóstico , Femenino , Fibroblastos/metabolismo , Células HEK293 , Células HeLa , Heterocigoto , Humanos , Masculino , Mutación , Linaje , Subunidades de Proteína/metabolismo , ARN Mensajero/genética , Síndrome , Transcriptoma , Proteína Wnt1RESUMEN
Genetic abnormalities and early treatment response are the main prognostic factors in acute myeloid leukemia (AML). Acute megakaryoblastic leukemia (AMKL) is a rare subtype of AML. Deep sequencing has identified CBFA2T3/GLIS2 and NUP98/KDM5A as recurrent aberrations, occurring in similar frequencies as RBM15/MKL1 and KMT2A-rearrangements. We studied whether these cytogenetic aberrations can be used for risk group stratification. To assess frequencies and outcome parameters of recurrent cytogenetic aberrations in AMKL, samples and clinical data of patients treated by the Associazione Italiana Ematologia Oncologia Pediatrica, Berlin-Frankfurt-Munster Study Group, Children's Oncology Group, Dutch Childhood Oncology Group, and the Saint Louis Hôpital were collected, enabling us to screen 153 newly diagnosed pediatric AMKL cases for the aforementioned aberrations and to study their clinical characteristics and outcome. CBFA2T3/GLIS2 was identified in 16% of the cases; RBM15/MKL1, in 12%; NUP98/KDM5A and KMT2A rearrangements, in 9% each; and monosomy 7, in 6%. These aberrations were mutually exclusive. RBM15/MKL1-rearranged patients were significantly younger. No significant differences in sex and white blood cell count were found. NUP98/KDM5A, CBFA2T3/GLIS2, KMT2A-rearranged lesions and monosomy 7 (NCK-7) independently predicted a poor outcome, compared with RBM15/MKL1-rearranged patients and those with AMKL not carrying these molecular lesions. NCK-7-patients (n = 61) showed a 4-year probability of overall survival of 35 ± 6% vs 70 ± 5% in the RBM15/MKL1-other groups (n = 92, P < .0001) and 4-year probability of event-free survival of 33 ± 6% vs 62 ± 5% (P = .0013), the 4-year cumulative incidence of relapse being 42 ± 7% and 19 ± 4% (P = .003), respectively. We conclude that these genetic aberrations may be used for risk group stratification of pediatric AMKL and for treatment tailoring.
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Aberraciones Cromosómicas , Cromosomas Humanos/genética , Reordenamiento Génico , Leucemia Megacarioblástica Aguda/genética , Proteínas de Neoplasias/genética , Adolescente , Niño , Preescolar , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Lactante , Leucemia Megacarioblástica Aguda/mortalidad , Masculino , Factores de RiesgoRESUMEN
Pediatric acute myeloid leukemia (AML) is a heterogeneous disease, characterized by different collaborating karyotypic and molecular abnormalities, which are used in risk group stratification. In â¼20% of the pediatric AML cases a specific genetic aberration is still unknown. Minimally differentiated myeloid leukemia or FAB-type M0 is a rare morphological subtype of AML. The translocation t(10;17)(p15;q21) is described to be recurrent in minimally differentiated AML, but the involved genes and location of the breakpoints have so far not been identified. In this study, we show that this translocation results in an in-frame translocation fusing exon 12 of the tumor suppressor gene ZMYND11 to exon 3 of the chromatin protein MBTD1, encoding a protein of 1,054 amino acids, while the reciprocal fusion product is predicted to lack a productive start codon. Gene expression profiling of the leukemic cells showed high HOXA expression. ZMYND11, also known as BS69, is a tumor suppressor that specifically recognizes H3K36me3, which is linked to aberrant HOXA expression in leukemogenesis. Aberrant expression of the genes involved in this fusion may thus contribute to the HOXA-phenotype observed with gene expression profiling.
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Proteínas Portadoras/genética , Proteínas Cromosómicas no Histona/genética , Leucemia Mieloide Aguda/genética , Proteínas de Fusión Oncogénica/genética , Translocación Genética , Secuencia de Aminoácidos , Secuencia de Bases , Proteínas de Ciclo Celular , Diferenciación Celular , Niño , Cromosomas Humanos Par 11 , Proteínas Co-Represoras , Proteínas de Unión al ADN , Humanos , Masculino , Datos de Secuencia Molecular , Proteínas de Complejo Poro Nuclear/genética , Proteínas de Complejo Poro Nuclear/metabolismoRESUMEN
Genetic alterations causing constitutive tyrosine kinase activation are observed in a broad spectrum of cancers. Thus far, these mutant kinases have been localized to the plasma membrane or cytoplasm, where they engage proliferation and survival pathways. We report that the NUP214-ABL1 fusion is unique among these because of its requisite localization to the nuclear pore complex for its transforming potential. We show that NUP214-ABL1 displays attenuated transforming capacity as compared to BCR-ABL1 and that NUP214-ABL1 preferentially transforms T cells, which is in agreement with its unique occurrence in T cell acute lymphoblastic leukemia. Furthermore, NUP214-ABL1 differs from BCR-ABL1 in subcellular localization, initiation of kinase activity, and signaling and lacks phosphorylation on its activation loop. In addition to delineating an unusual mechanism for kinase activation, this study provides new insights into the spectrum of chromosomal translocations involving nucleoporins by indicating that the nuclear pore context itself may play a central role in transformation.
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Transformación Celular Neoplásica/metabolismo , Poro Nuclear/enzimología , Proteínas de Fusión Oncogénica/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Animales , Línea Celular , Activación Enzimática , Humanos , Ratones , Proteínas de Complejo Poro Nuclear/metabolismoRESUMEN
BACKGROUND: One of the most important application spectrums of transcriptomic data is cancer phenotype classification. Many characteristics of transcriptomic data, such as redundant features and technical artifacts, make over-fitting commonplace. Promising classification results often fail to generalize across datasets with different sources, platforms, or preprocessing. Recently a novel differential network rank conservation (DIRAC) algorithm to characterize cancer phenotypes using transcriptomic data. DIRAC is a member of a family of algorithms that have shown useful for disease classification based on the relative expression of genes. Combining the robustness of this family's simple decision rules with known biological relationships, this systems approach identifies interpretable, yet highly discriminate networks. While DIRAC has been briefly employed for several classification problems in the original paper, the potentials of DIRAC in cancer phenotype classification, and especially robustness against artifacts in transcriptomic data have not been fully characterized yet. RESULTS: In this study we thoroughly investigate the potentials of DIRAC by applying it to multiple datasets, and examine the variations in classification performances when datasets are (i) treated and untreated for batch effect; (ii) preprocessed with different techniques. We also propose the first DIRAC-based classifier to integrate multiple networks. We show that the DIRAC-based classifier is very robust in the examined scenarios. To our surprise, the trained DIRAC-based classifier even translated well to a dataset with different biological characteristics in the presence of substantial batch effects that, as shown here, plagued the standard expression value based classifier. In addition, the DIRAC-based classifier, because of the integrated biological information, also suggests pathways to target in specific subtypes, which may enhance the establishment of personalized therapy in diseases such as pediatric AML. In order to better comprehend the prediction power of the DIRAC-based classifier in general, we also performed classifications using publicly available datasets from breast and lung cancer. Furthermore, multiple well-known classification algorithms were utilized to create an ideal test bed for comparing the DIRAC-based classifier with the standard gene expression value based classifier. We observed that the DIRAC-based classifier greatly outperforms its rival. CONCLUSIONS: Based on our experiments with multiple datasets, we propose that DIRAC is a promising solution to the lack of generalizability in classification efforts that uses transcriptomic data. We believe that superior performances presented in this study may motivate other to initiate a new aline of research to explore the untapped power of DIRAC in a broad range of cancer types.
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Algoritmos , Biología Computacional/métodos , Perfilación de la Expresión Génica/métodos , Redes Reguladoras de Genes , Leucemia Mieloide Aguda/clasificación , Leucemia Mieloide Aguda/genética , Niño , Bases de Datos Factuales , HumanosRESUMEN
IKAROS family zinc finger 1/IKZF1 is a transcription factor important in lymphoid differentiation, and a known tumor suppressor in acute lymphoid leukemia. Recent studies suggest that IKZF1 is also involved in myeloid differentiation. To investigate whether IKZF1 deletions also play a role in pediatric acute myeloid leukemia, we screened a panel of pediatric acute myeloid leukemia samples for deletions of the IKZF1 locus using multiplex ligation-dependent probe amplification and for mutations using direct sequencing. Three patients were identified with a single amino acid variant without change of IKZF1 length. No frame-shift mutations were found. Out of 11 patients with an IKZF1 deletion, 8 samples revealed a complete loss of chromosome 7, and 3 cases a focal deletion of 0.1-0.9Mb. These deletions included the complete IKZF1 gene (n=2) or exons 1-4 (n=1), all leading to a loss of IKZF1 function. Interestingly, differentially expressed genes in monosomy 7 cases (n=8) when compared to non-deleted samples (n=247) significantly correlated with gene expression changes in focal IKZF1-deleted cases (n=3). Genes with increased expression included genes involved in myeloid cell self-renewal and cell cycle, and a significant portion of GATA target genes and GATA factors. Together, these results suggest that loss of IKZF1 is recurrent in pediatric acute myeloid leukemia and might be a determinant of oncogenesis in acute myeloid leukemia with monosomy 7.
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Eliminación de Gen , Factor de Transcripción Ikaros/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidad , Proteínas de Neoplasias/genética , Adolescente , Niño , Preescolar , Deleción Cromosómica , Cromosomas Humanos Par 7/genética , Supervivencia sin Enfermedad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Tasa de SupervivenciaRESUMEN
The nuclear lamina binds chromatin in vitro and is thought to function in its organization, but genes that interact with it are unknown. Using an in vivo approach, we identified approximately 500 Drosophila melanogaster genes that interact with B-type lamin (Lam). These genes are transcriptionally silent and late replicating, lack active histone marks and are widely spaced. These factors collectively predict lamin binding behavior, indicating that the nuclear lamina integrates variant and invariant chromatin features. Consistently, proximity of genomic regions to the nuclear lamina is partly conserved between cell types, and induction of gene expression or active histone marks reduces Lam binding. Lam target genes cluster in the genome, and these clusters are coordinately expressed during development. This genome-wide analysis gives clear insight into the nature and dynamic behavior of the genome at the nuclear lamina, and implies that intergenic DNA functions in the global organization of chromatin in the nucleus.
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Drosophila melanogaster/genética , Genoma de los Insectos , Lámina Nuclear/genética , Animales , Técnicas de Cultivo de Célula , Células Cultivadas , Inmunoprecipitación de Cromatina , Cromosomas , Análisis por Conglomerados , Drosophila melanogaster/citología , Drosophila melanogaster/metabolismo , Electroporación , Perfilación de la Expresión Génica , Hibridación Fluorescente in Situ , Laminas/genética , Laminas/metabolismo , Modelos Genéticos , Plásmidos , Unión ProteicaRESUMEN
Acute myeloid leukemia with t(6;9)(p22;q34) is listed as a distinct entity in the 2008 World Health Organization classification, but little is known about the clinical implications of t(6;9)-positive myeloid leukemia in children. This international multicenter study presents the clinical and genetic characteristics of 62 pediatric patients with t(6;9)/DEK-NUP214-rearranged myeloid leukemia; 54 diagnosed as having acute myeloid leukemia, representing <1% of all childhood acute myeloid leukemia, and eight as having myelodysplastic syndrome. The t(6;9)/DEK-NUP214 was associated with relatively late onset (median age 10.4 years), male predominance (sex ratio 1.7), French-American-British M2 classification (54%), myelodysplasia (100%), and FLT3-ITD (42%). Outcome was substantially better than previously reported with a 5-year event-free survival of 32%, 5-year overall survival of 53%, and a 5-year cumulative incidence of relapse of 57%. Hematopoietic stem cell transplantation in first complete remission improved the 5-year event-free survival compared with chemotherapy alone (68% versus 18%; P<0.01) but not the overall survival (68% versus 54%; P=0.48). The presence of FLT3-ITD had a non-significant negative effect on 5-year overall survival compared with non-mutated cases (22% versus 62%; P=0.13). Gene expression profiling showed a unique signature characterized by significantly higher expression of EYA3, SESN1, PRDM2/RIZ, and HIST2H4 genes. In conclusion, t(6;9)/DEK-NUP214 represents a unique subtype of acute myeloid leukemia with a high risk of relapse, high frequency of FLT3-ITD, and a specific gene expression signature.
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Proteínas Cromosómicas no Histona/genética , Cromosomas Humanos Par 6 , Cromosomas Humanos Par 9 , Leucemia Mieloide/genética , Proteínas de Complejo Poro Nuclear/genética , Proteínas de Fusión Oncogénica/genética , Proteínas Oncogénicas/genética , Translocación Genética , Adolescente , Médula Ósea/patología , Niño , Preescolar , Femenino , Perfilación de la Expresión Génica , Trasplante de Células Madre Hematopoyéticas , Humanos , Lactante , Recién Nacido , Leucemia Mieloide/diagnóstico , Leucemia Mieloide/mortalidad , Leucemia Mieloide/terapia , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/terapia , Masculino , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/mortalidad , Síndromes Mielodisplásicos/terapia , Proteínas de Unión a Poli-ADP-Ribosa , Recurrencia , Resultado del TratamientoRESUMEN
BICD2 is one of the two mammalian homologues of the Drosophila Bicaudal D, an evolutionarily conserved adaptor between microtubule motors and their cargo that was previously shown to link vesicles and mRNP complexes to the dynein motor. Here, we identified a G2-specific role for BICD2 in the relative positioning of the nucleus and centrosomes in dividing cells. By combining mass spectrometry, biochemical and cell biological approaches, we show that the nuclear pore complex (NPC) component RanBP2 directly binds to BICD2 and recruits it to NPCs specifically in G2 phase of the cell cycle. BICD2, in turn, recruits dynein-dynactin to NPCs and as such is needed to keep centrosomes closely tethered to the nucleus prior to mitotic entry. When dynein function is suppressed by RNA interference-mediated depletion or antibody microinjection, centrosomes and nuclei are actively pushed apart in late G2 and we show that this is due to the action of kinesin-1. Surprisingly, depletion of BICD2 inhibits both dynein and kinesin-1-dependent movements of the nucleus and cytoplasmic NPCs, demonstrating that BICD2 is needed not only for the dynein function at the nuclear pores but also for the antagonistic activity of kinesin-1. Our study demonstrates that the nucleus is subject to opposing activities of dynein and kinesin-1 motors and that BICD2 contributes to nuclear and centrosomal positioning prior to mitotic entry through regulation of both dynein and kinesin-1.
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Proteínas Portadoras/metabolismo , Núcleo Celular/metabolismo , Centrosoma/metabolismo , Dineínas/metabolismo , Cinesinas/metabolismo , Proteínas de la Membrana/metabolismo , Mitosis/fisiología , Poro Nuclear/metabolismo , Animales , Proteínas Portadoras/genética , Línea Celular , Núcleo Celular/ultraestructura , Complejo Dinactina , Humanos , Cinesinas/genética , Proteínas de la Membrana/genética , Ratones , Proteínas Asociadas a Microtúbulos/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas de Complejo Poro Nuclear/genética , Proteínas de Complejo Poro Nuclear/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Huso Acromático/metabolismo , Técnicas del Sistema de Dos HíbridosRESUMEN
Acute myeloid leukemia (AML) is a hematopoietic malignancy with poor prognosis and limited treatment options. Here we provide a comprehensive census of the bone marrow immune microenvironment in adult and pediatric patients with AML. We characterize unique inflammation signatures in a subset of AML patients, associated with inferior outcomes. We identify atypical B cells, a dysfunctional B-cell subtype enriched in patients with high-inflammation AML, as well as an increase in CD8+GZMK+ and regulatory T cells, accompanied by a reduction in T-cell clonal expansion. We derive an inflammation-associated gene score (iScore) that associates with poor survival outcomes in patients with AML. Addition of the iScore refines current risk stratifications for patients with AML and may enable identification of patients in need of more aggressive treatment. This work provides a framework for classifying patients with AML based on their immune microenvironment and a rationale for consideration of the inflammatory state in clinical settings.
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Leucemia Mieloide Aguda , Adulto , Humanos , Niño , Leucemia Mieloide Aguda/genética , Médula Ósea/patología , Linfocitos T Reguladores/patología , Inflamación/patología , Medición de Riesgo , Microambiente TumoralRESUMEN
Nucleoporins are the constituents of the nuclear pore complex, but they are also known to shuttle to the nuclear interior, the function of which is unclear. In a recent issue of Nature Cell Biology, Wang et al.'s mechanistic studies of leukemogenic fusion proteins that contain nucleoporins suggest that they have a direct role in transcription.
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Núcleo Celular/metabolismo , Proteínas de Complejo Poro Nuclear/metabolismo , Proteínas de Homeodominio/metabolismo , Modelos Biológicos , Proteínas de Complejo Poro Nuclear/química , Secuencias Repetitivas de Aminoácido , Saccharomyces cerevisiae/metabolismo , Transcripción GenéticaRESUMEN
In addition to its structural role in enclosing and protecting the genome, the nuclear envelope (NE) forms a highly adaptive communication interface between the cytoplasm and the nuclear interior in eukaryotic cells. The double membrane of the NE is perforated by nuclear pores lined with large multi-protein structures, called nuclear-pore complexes (NPCs), which selectively allow the bi-directional transport of ions and macromolecular cargo. In order to nucleate a pore, the inner and outer nuclear membrane have to fuse at the site of NPC insertion, a process requiring both lipid bilayers to be deformed into highly curved structures. How this curvature is achieved and which factors are involved in inducing and stabilizing membrane curvature at the nuclear pore remain largely unclear. In this review, we will summarize the molecular mechanisms thought to be involved in membrane curvature generation, with a particular emphasis on the role of lipids and lipid metabolism in shaping the nuclear pore membrane.
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Proteínas de Complejo Poro Nuclear , Poro Nuclear , Células Eucariotas/metabolismo , Membrana Dobles de Lípidos/metabolismo , Membrana Nuclear/metabolismo , Poro Nuclear/metabolismo , Proteínas de Complejo Poro Nuclear/metabolismoRESUMEN
SMPD4 is a neutral sphingomyelinase implicated in a specific type of congenital microcephaly. Although not intensively studied, SMPD4 deficiency has also been found to cause cell division defects. This suggests a role for SMPD4 in cell-cycle and differentiation. In order to explore this role, we used proximity ligation to identify the partners of SMPD4 in vivo in HEK293T cells. We found that these partners localize near the endoplasmic reticulum (ER) and the nuclear membrane. Using mass spectrometry, we could identify these partners and discovered that SMPD4 is closely associated with several nucleoporins, including NUP35, a nucleoporin directly involved in pore membrane curvature and pore insertion. This suggests that SMPD4 may play a role in this process.
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Microcefalia , Poro Nuclear , Esfingomielina Fosfodiesterasa , Células HEK293 , Humanos , Microcefalia/metabolismo , Membrana Nuclear/metabolismo , Poro Nuclear/metabolismo , Proteínas de Complejo Poro Nuclear/metabolismo , Esfingomielina Fosfodiesterasa/metabolismoAsunto(s)
Proteínas Portadoras/genética , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Leucemia Mieloide Aguda/genética , Masculino , Mutación , Proteínas RepresorasRESUMEN
BACKGROUND: NADPH oxidases play an essential role in reactive oxygen species (ROS)-based signaling in the heart. Previously, we have demonstrated that (peri)nuclear expression of the catalytic NADPH oxidase subunit NOX2 in stressed cardiomyocytes, e.g. under ischemia or high concentrations of homocysteine, is an important step in the induction of apoptosis in these cells. Here this ischemia-induced nuclear targeting and activation of NOX2 was specified in cardiomyocytes. METHODS: The effect of ischemia, mimicked by metabolic inhibition, on nuclear localization of NOX2 and the NADPH oxidase subunits p22(phox) and p47(phox), was analyzed in rat neonatal cardiomyoblasts (H9c2 cells) using Western blot, immuno-electron microscopy and digital-imaging microscopy. RESULTS: NOX2 expression significantly increased in nuclear fractions of ischemic H9c2 cells. In addition, in these cells NOX2 was found to colocalize in the nuclear envelope with nuclear pore complexes, p22(phox), p47(phox) and nitrotyrosine residues, a marker for the generation of ROS. Inhibition of NADPH oxidase activity, with apocynin and DPI, significantly reduced (peri)nuclear expression of nitrotyrosine. CONCLUSION: We for the first time show that NOX2, p22(phox) and p47(phox) are targeted to and produce ROS at the nuclear pore complex in ischemic cardiomyocytes.