Autoimmune diseases are heterogeneous pathologies with difficult diagnosis and few therapeutic options. In the last decade, several omics studies have provided significant insights into the molecular ...mechanisms of these diseases. Nevertheless, data from different cohorts and pathologies are stored independently in public repositories and a unified resource is imperative to assist researchers in this field.
Here, we present Autoimmune Diseases Explorer ( https://adex.genyo.es ), a database that integrates 82 curated transcriptomics and methylation studies covering 5609 samples for some of the most common autoimmune diseases. The database provides, in an easy-to-use environment, advanced data analysis and statistical methods for exploring omics datasets, including meta-analysis, differential expression or pathway analysis.
This is the first omics database focused on autoimmune diseases. This resource incorporates homogeneously processed data to facilitate integrative analyses among studies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The identification of novel biomarkers for early breast cancer detection would be a great advance. Because of their role in tumorigenesis and stability in body fluids, microRNAs (miRNAs) are emerging ...as a promising diagnostic tool. Our aim was to identify miRNAs deregulated in breast tumors and evaluate the potential of circulating miRNAs in breast cancer detection.
We conducted miRNA expression profiling of 1919 human miRNAs in paraffin-embedded tissue from 122 breast tumors and 11 healthy breast tissue samples. Differential expression analysis was performed, and a microarray classifier was generated. The most relevant miRNAs were analyzed in plasma from 26 healthy individuals and 83 patients with breast cancer (36 before and 47 after treatment) and validated in 116 healthy individuals and 114 patients before treatment.
We identified a large number of miRNAs deregulated in breast cancer and generated a 25-miRNA microarray classifier that discriminated breast tumors with high diagnostic sensitivity and specificity. Ten miRNAs were selected for further investigation, of which 4 (miR-505-5p, miR-125b-5p, miR-21-5p, and miR-96-5p) were significantly overexpressed in pretreated patients with breast cancer compared with healthy individuals in 2 different series of plasma. MiR-505-5p and miR-96-5p were the most valuable biomarkers (area under the curve 0.72). Moreover, the expression levels of miR-3656, miR-505-5p, and miR-21-5p were decreased in a group of treated patients.
Circulating miRNAs reflect the presence of breast tumors. The identification of deregulated miRNAs in plasma of patients with breast cancer supports the use of circulating miRNAs as a method for early breast cancer detection.
Reprogramming of differentiated cells into pluripotent cells can occur in vivo, but the mechanisms involved remain to be elucidated. Senescence is a cellular response to damage, characterized by ...abundant production of cytokines and other secreted factors that, together with the recruitment of inflammatory cells, result in tissue remodeling. Here, we show that in vivo expression of the reprogramming factors OCT4, SOX2, KLF4, and cMYC (OSKM) in mice leads to senescence and reprogramming, both coexisting in close proximity. Genetic and pharmacological analyses indicate that OSKM-induced senescence requires the Ink4a/Arf locus and, through the production of the cytokine interleukin-6, creates a permissive tissue environment for in vivo reprogramming. Biological conditions linked to senescence, such as tissue injury or aging, favor in vivo reprogramming by OSKM. These observations may be relevant for tissue repair.
Pulmonary fibrosis is a fatal lung disease characterized by fibrotic foci and inflammatory infiltrates. Short telomeres can impair tissue regeneration and are found both in hereditary and sporadic ...cases. We show here that telomerase expression using AAV9 vectors shows therapeutic effects in a mouse model of pulmonary fibrosis owing to a low-dose bleomycin insult and short telomeres. AAV9 preferentially targets regenerative alveolar type II cells (ATII). AAV9-
-treated mice show improved lung function and lower inflammation and fibrosis at 1-3 weeks after viral treatment, and improvement or disappearance of the fibrosis at 8 weeks after treatment. AAV9-
treatment leads to longer telomeres and increased proliferation of ATII cells, as well as lower DNA damage, apoptosis, and senescence. Transcriptome analysis of ATII cells confirms downregulation of fibrosis and inflammation pathways. We provide a proof-of-principle that telomerase activation may represent an effective treatment for pulmonary fibrosis provoked or associated with short telomeres.
Cohesin exists in two variants carrying either STAG/SA1 or SA2. Here we have addressed their specific contributions to the unique spatial organization of the mouse embryonic stem cell genome, which ...ensures super-enhancer-dependent transcription of pluripotency factors and repression of lineage-specification genes within Polycomb domains. We find that cohesin-SA2 facilitates Polycomb domain compaction through Polycomb repressing complex 1 (PRC1) recruitment and promotes the establishment of long-range interaction networks between distant Polycomb-bound promoters that are important for gene repression. Cohesin-SA1, in contrast, disrupts these networks, while preserving topologically associating domain (TAD) borders. The diverse effects of both complexes on genome topology may reflect two modes of action of cohesin. One, likely involving loop extrusion, establishes overall genome arrangement in TADs together with CTCF and prevents excessive segregation of same-class compartment regions. The other is required for organization of local transcriptional hubs such as Polycomb domains and super-enhancers, which define cell identity.
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•Cohesin variants have distinct effects on mESC chromatin architecture and transcription•Cohesin-SA1 preferentially contributes to TAD boundary strength•Cohesin-SA2 facilitates Polycomb domain compaction through PRC1 recruitment•Cohesin-SA1 impedes and cohesin-SA2 promotes aggregation of distal Polycomb domains
The unique chromatin architecture of mESCs ensures high transcription of pluripotency factors and repression of lineage-specification genes. Cuadrado et al. report that besides their differential contribution to genome organization in TADs, cohesin variants SA1 and SA2 have antagonistic effects on the establishment of long-range contacts between Polycomb-bound genes that are essential for repression.
Two variant cohesin complexes containing SMC1, SMC3, RAD21 and either SA1 (also known as STAG1) or SA2 (also known as STAG2) are present in all cell types. We report here their genomic distribution ...and specific contributions to genome organization in human cells. Although both variants are found at CCCTC-binding factor (CTCF) sites, a distinct population of the SA2-containing cohesin complexes (hereafter referred to as cohesin-SA2) localize to enhancers lacking CTCF, are linked to tissue-specific transcription and cannot be replaced by the SA1-containing cohesin complex (cohesin-SA1) when SA2 is absent, a condition that has been observed in several tumors. Downregulation of each of these variants has different consequences for gene expression and genome architecture. Our results suggest that cohesin-SA1 preferentially contributes to the stabilization of topologically associating domain boundaries together with CTCF, whereas cohesin-SA2 promotes cell-type-specific contacts between enhancers and promoters independently of CTCF. Loss of cohesin-SA2 rewires local chromatin contacts and alters gene expression. These findings provide insights into how cohesin mediates chromosome folding and establish a novel framework to address the consequences of mutations in cohesin genes in cancer.
The RNA polymerase II-associated protein 1 (RPAP1) is conserved across metazoa and required for stem cell differentiation in plants; however, very little is known about its mechanism of action or its ...role in mammalian cells. Here, we report that RPAP1 is essential for the expression of cell identity genes and for cell viability. Depletion of RPAP1 triggers cell de-differentiation, facilitates reprogramming toward pluripotency, and impairs differentiation. Mechanistically, we show that RPAP1 is essential for the interaction between RNA polymerase II (RNA Pol II) and Mediator, as well as for the recruitment of important regulators, such as the Mediator-specific RNA Pol II factor Gdown1 and the C-terminal domain (CTD) phosphatase RPAP2. In agreement, depletion of RPAP1 diminishes the loading of total and Ser5-phosphorylated RNA Pol II on many genes, with super-enhancer-driven genes among the most significantly downregulated. We conclude that Mediator/RPAP1/RNA Pol II is an ancient module, conserved from plants to mammals, critical for establishing and maintaining cell identity.
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•RPAP1 is an RNA Pol II regulator, conserved from plants to mammals•RPAP1 depletion erases cell identity gene expression, triggering de-differentiation•Mechanistically, RPAP1 is critical for the Mediator-RNA Pol II interaction•RPAP1 preferentially contributes to enhancer-driven gene transcription
Lynch et al. report a regulator of RNA Pol II called RPAP1, displaying functional conservation from plants to mammals. RPAP1 is required to establish and maintain cell identity. Mechanistically, RPAP1 is critical for the Mediator-RNA Pol II interaction, thereby preserving normal transcription at enhancer-driven genes.
NANOG is a pluripotency transcription factor in embryonic stem cells; however, its role in adult tissues remains largely unexplored. Here we show that mouse NANOG is selectively expressed in ...stratified epithelia, most notably in the oesophagus where the Nanog promoter is hypomethylated. Interestingly, inducible ubiquitous overexpression of NANOG in mice causes hyperplasia selectively in the oesophagus, in association with increased cell proliferation. NANOG transcriptionally activates the mitotic programme, including Aurora A kinase (Aurka), in stratified epithelia, and endogenous NANOG directly binds to the Aurka promoter in primary keratinocytes. Interestingly, overexpression of Nanog or Aurka in mice increased proliferation and aneuploidy in the oesophageal basal epithelium. Finally, inactivation of NANOG in cell lines from oesophageal or head and neck squamous cell carcinomas (ESCCs or HNSCCs, respectively) results in lower levels of AURKA and decreased proliferation, and NANOG and AURKA expression are positively correlated in HNSCCs. Together, these results indicate that NANOG has a lineage-restricted mitogenic function in stratified epithelia.
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