المنشورات البحثية

Found 37 publicacions matching the indicated search criteria.
Tomás-Daza L, Rovirosa L, López-Martí P, Nieto-Aliseda A, Serra F, Planas-Riverola A, Molina O, McDonald R, Ghevaert C, Cuatrecasas E, Costa D, Camós M, Bueno C, Menéndez P, Valencia A, Javierre BM

Low input capture Hi-C (liCHi-C) identifies promoter-enhancer interactions at high-resolution.

Nature Commununications 17 Jan 2023, 14 (1) 268. Epub 17 Jan 2023
Long-range interactions between regulatory elements and promoters are key in gene transcriptional control; however, their study requires large amounts of starting material, which is not compatible with clinical scenarios nor the study of rare cell populations. Here we introduce low input capture Hi-C (liCHi-C) as a cost-effective, flexible method to map and robustly compare promoter interactomes at high resolution. As proof of its broad applicability, we implement liCHi-C to study normal and malignant human hematopoietic hierarchy in clinical samples. We demonstrate that the dynamic promoter architecture identifies developmental trajectories and orchestrates transcriptional transitions during cell-state commitment. Moreover, liCHi-C enables the identification of disease-relevant cell types, genes and pathways potentially deregulated by non-coding alterations at distal regulatory elements. Finally, we show that liCHi-C can be harnessed to uncover genome-wide structural variants, resolve their breakpoints and infer their pathogenic effects. Collectively, our optimized liCHi-C method expands the study of 3D chromatin organization to unique, low-abundance cell populations, and offers an opportunity to uncover factors and regulatory networks involved in disease pathogenesis.
More information
Azagra A, Meler A, de Barrios O, Tomás-Daza L, Collazo O, Monterde B, Obiols M, Rovirosa L, Vila-Casadesús M, Cabrera-Pasadas M, Gusi-Vives M, Graf T, Varela I, Sardina JL, Javierre BM, Parra M

The HDAC7-TET2 epigenetic axis is essential during early B lymphocyte development.

Nucleic Acids Res 29 Jul 2022, . Epub 29 Jul 2022
Correct B cell identity at each stage of cellular differentiation during B lymphocyte development is critically dependent on a tightly controlled epigenomic landscape. We previously identified HDAC7 as an essential regulator of early B cell development and its absence leads to a drastic block at the pro-B to pre-B cell transition. More recently, we demonstrated that HDAC7 loss in pro-B-ALL in infants associates with a worse prognosis. Here we delineate the molecular mechanisms by which HDAC7 modulates early B cell development. We find that HDAC7 deficiency drives global chromatin de-condensation, histone marks deposition and deregulates other epigenetic regulators and mobile elements. Specifically, the absence of HDAC7 induces TET2 expression, which promotes DNA 5-hydroxymethylation and chromatin de-condensation. HDAC7 deficiency also results in the aberrant expression of microRNAs and LINE-1 transposable elements. These findings shed light on the mechanisms by which HDAC7 loss or misregulation may lead to B cell-based hematological malignancies.
More information
P. Kobialka, H. Sabata, O. Vilalta, L. Gouveia, A. Angulo, L. Muixí, J. Zanoncello, O. Muñoz, Nagore G Olaciregui, Lucia Fanlo, Anna Esteve-Codina , Cinzia Lavarino, Biola M Javierre, Veronica Celis, Carlota Rovira, Susana López-Fernández, Eulàlia Baselga, Jaume Mora, Sandra D Castillo, Mariona Graupera

The onset of PI3K-related vascular malformations occurs during angiogenesis and is prevented by the AKT inhibitor miransertib

Embo Molecular Medicine 13 Jun 2022, . Epub 13 Jun 2022
Low-flow vascular malformations are congenital overgrowths composed of abnormal blood vessels potentially causing pain, bleeding and obstruction of different organs. These diseases are caused by oncogenic mutations in the endothelium, which result in overactivation of the PI3K/AKT pathway. Lack of robust in vivo preclinical data has prevented the development and translation into clinical trials of specific molecular therapies for these diseases. Here, we demonstrate that the Pik3caH1047R activating mutation in endothelial cells triggers a transcriptome rewiring that leads to enhanced cell proliferation. We describe a new reproducible preclinical in vivo model of PI3K-driven vascular malformations using the postnatal mouse retina. We show that active angiogenesis is required for the pathogenesis of vascular malformations caused by activating Pik3ca mutations. Using this model, we demonstrate that the AKT inhibitor miransertib both prevents and induces the regression of PI3K-driven vascular malformations. We confirmed the efficacy of miransertib in isolated human endothelial cells with genotypes spanning most of human low-flow vascular malformations.
More information
Llabata P, Torres-Diz M, Gomez A, Tomas-Daza L, Romero OA, Grego-Bessa J, Llinas-Arias P, Valencia A, Esteller M, Javierre BM, Zhang X, Sanchez-Cespedes M

MAX mutant small-cell lung cancers exhibit impaired activities of MGA-dependent noncanonical polycomb repressive complex.

Proc Natl Acad Sci U S A 14 Sep 2021, 118 (37) .
The MYC axis is disrupted in cancer, predominantly through activation of the MYC family oncogenes but also through inactivation of the MYC partner MAX or of the MAX partner MGA. MGA and MAX are also members of the polycomb repressive complex, ncPRC1.6. Here, we use genetically modified MAX-deficient small-cell lung cancer (SCLC) cells and carry out genome-wide and proteomics analyses to study the tumor suppressor function of MAX. We find that MAX mutant SCLCs have ASCL1 or NEUROD1 or combined ASCL1/NEUROD1 characteristics and lack MYC transcriptional activity. MAX restitution triggers prodifferentiation expression profiles that shift when MAX and oncogenic MYC are coexpressed. Although ncPRC1.6 can be formed, the lack of MAX restricts global MGA occupancy, selectively driving its recruitment toward E2F6-binding motifs. Conversely, MAX restitution enhances MGA occupancy to repress genes involved in different functions, including stem cell and DNA repair/replication. Collectively, these findings reveal that MAX mutant SCLCs have either ASCL1 or NEUROD1 or combined characteristics and are MYC independent and exhibit deficient ncPRC1.6-mediated gene repression.
More information
Watt S, Vasquez L, Walter K, Mann AL, Kundu K, Chen L, Sims Y, Ecker S, Burden F, Farrow S, Farr B, Iotchkova V, Elding H, Mead D, Tardaguila M, Ponstingl H, Richardson D, Datta A, Flicek P, Clarke L, Downes K, Pastinen T, Fraser P, Frontini M, Javierre BM, Spivakov M, Soranzo N

Genetic perturbation of PU.1 binding and chromatin looping at neutrophil enhancers associates with autoimmune disease.

Nat Commun 16 Apr 2021, 12 (1) 2298.
Neutrophils play fundamental roles in innate immune response, shape adaptive immunity, and are a potentially causal cell type underpinning genetic associations with immune system traits and diseases. Here, we profile the binding of myeloid master regulator PU.1 in primary neutrophils across nearly a hundred volunteers. We show that variants associated with differential PU.1 binding underlie genetically-driven differences in cell count and susceptibility to autoimmune and inflammatory diseases. We integrate these results with other multi-individual genomic readouts, revealing coordinated effects of PU.1 binding variants on the local chromatin state, enhancer-promoter contacts and downstream gene expression, and providing a functional interpretation for 27 genes underlying immune traits. Collectively, these results demonstrate the functional role of PU.1 and its target enhancers in neutrophil transcriptional control and immune disease susceptibility.
More information
Watt S., Vasquez L., Walter K, Mann AL, Kundu K, Chen L, Yan Y, Ecker S, Burden F, Farrow S, Farr B, Lotchkova V, Elding H, Mead D, Tardaguila M, Ponstingl H, Richardson D, Datta A, Flicek P, Clarke L, Downes K, Pastinen T, Fraser P, Frontini M, Javierre BM, Spivakov M, Soranzo N

Variation in PU.1 binding and chromatin looping at neutrophil enhancers influences autoimmune disease susceptibility

Nat Commun (Under revision) 2020, .
Neutrophils play fundamental roles in innate inflammatory response, shape adaptive immunity1, and have been identified as a potentially causal cell type underpinning genetic associations with immune system traits and diseases2,3 The majority of these variants are non-coding and the underlying mechanisms are not fully understood. Here, we profiled the binding of one of the principal myeloid transcriptional regulators, PU.1, in primary neutrophils across nearly a hundred volunteers, and elucidate the coordinated genetic effects of PU.1 binding variation, local chromatin state, promoter-enhancer interactions, and gene expression. We show that PU.1 binding and the associated chain of molecular changes underlie genetically-driven differences in cell count and autoimmune disease susceptibility. Our results advance interpretation for genetic loci associated with neutrophil biology and immune disease.
Azagra A, Marina-Zárate E, Ramiro AR, Javierre BM, Parra M

From Loops to Looks: Transcription Factors and Chromatin Organization Shaping Terminal B Cell Differentiation.

Trends Immunol. 7 Dec 2019, . Epub 7 Dec 2019
B lymphopoiesis is tightly regulated at the level of gene transcription. In recent years, investigators have shed light on the transcription factor networks and the epigenetic machinery involved at all differentiation steps of mammalian B cell development. During terminal differentiation, B cells undergo dramatic changes in gene transcriptional programs to generate germinal center B cells, plasma cells and memory B cells. Recent evidence indicates that mature B cell formation involves an essential contribution from 3D chromatin conformations through its interplay with transcription factors and epigenetic machinery. Here, we provide an up-to-date overview of the coordination between transcription factors, epigenetic changes, and chromatin architecture during terminal B cell differentiation, focusing on recent discoveries and technical advances for studying 3D chromatin structures.
More information
Bueno-Costa A, Piñeyro D, Soler M, Javierre BM, Raurell-Vila H, Subirana-Granés M, Pasquali L, Martinez-Climent JA, Esteller M

B-cell leukemia transdifferentiation to macrophage involves reconfiguration of DNA methylation for long-range regulation.

Leukemia 12 Nov 2019, . Epub 12 Nov 2019More information
Miguel-Escalada I, Bonàs-Guarch S, Cebola I, Ponsa-Cobas J, Mendieta-Esteban J, Atla G, Javierre BM, Rolando DMY, Farabella I, Morgan CC, García-Hurtado J, Beucher A, Morán I, Pasquali L, Ramos-Rodríguez M, Appel EVR, Linneberg A, Gjesing AP, Witte DR, Pedersen O, Grarup N, Ravassard P, Torrents D, Mercader JM, Piemonti L, Berney T, de Koning EJP, Kerr-Conte J, Pattou F, Fedko IO, Groop L, Prokopenko I, Hansen T, Marti-Renom MA, Fraser P, Ferrer J

Human pancreatic islet three-dimensional chromatin architecture provides insights into the genetics of type 2 diabetes.

Nat. Genet. Jul 2019, 51 (7) 1137-1148. Epub 28 Jun 2019
Genetic studies promise to provide insight into the molecular mechanisms underlying type 2 diabetes (T2D). Variants associated with T2D are often located in tissue-specific enhancer clusters or super-enhancers. So far, such domains have been defined through clustering of enhancers in linear genome maps rather than in three-dimensional (3D) space. Furthermore, their target genes are often unknown. We have created promoter capture Hi-C maps in human pancreatic islets. This linked diabetes-associated enhancers to their target genes, often located hundreds of kilobases away. It also revealed >1,300 groups of islet enhancers, super-enhancers and active promoters that form 3D hubs, some of which show coordinated glucose-dependent activity. We demonstrate that genetic variation in hubs impacts insulin secretion heritability, and show that hub annotations can be used for polygenic scores that predict T2D risk driven by islet regulatory variants. Human islet 3D chromatin architecture, therefore, provides a framework for interpretation of T2D genome-wide association study (GWAS) signals.
More information
Watt S, Vasquez L, Walter K, Mann AL, Kundu K, Chen Lu, Yan Y, Ecker S, Burden F, Farrow S, Farr B, Iotchkova V, Elding H, Mead D, Tardaguila M, Ponstingl H, Fraser P, Richardson D, Datta A, Flicek P, Clarke L, Downes K, Pastinen T, Fraser P, Frontini M, Javierre BM, Spivakov M, Soranzo N

Variation in PU.1 binding and chromatin looping at neutrophil enhancers influences autoimmune disease susceptibility

bioRxiv 29 Apr 2019, . Epub 29 Apr 2019
Neutrophils play fundamental roles in innate inflammatory response, shape adaptive immunity1, and have been identified as a potentially causal cell type underpinning genetic associations with immune system traits and diseases2,3 The majority of these variants are non-coding and the underlying mechanisms are not fully understood. Here, we profiled the binding of one of the principal myeloid transcriptional regulators, PU.1, in primary neutrophils across nearly a hundred volunteers, and elucidate the coordinated genetic effects of PU.1 binding variation, local chromatin state, promoter-enhancer interactions and gene expression. We show that PU.1 binding and the associated chain of molecular changes underlie genetically-driven differences in cell count and autoimmune disease susceptibility. Our results advance interpretation for genetic loci associated with neutrophil biology and immune disease.