152 research outputs found
Deletion of AU-rich elements within the Bcl2 3'UTR reduces protein expression and B cell survival in vivo.
Post-transcriptional mRNA regulation by RNA binding proteins (RBPs) associated with AU-rich elements (AREs) present in the 3' untranslated region (3'UTR) of specific mRNAs modulates transcript stability and translation in eukaryotic cells. Here we have functionally characterised the importance of the AREs present within the Bcl2 3'UTR in order to maintain Bcl2 expression. Gene targeting deletion of 300 nucleotides of the Bcl2 3'UTR rich in AREs diminishes Bcl2 mRNA stability and protein levels in primary B cells, decreasing cell lifespan. Generation of chimeric mice indicates that Bcl2-ARE∆/∆ B cells have an intrinsic competitive disadvantage compared to wild type cells. Biochemical assays and predictions using a bioinformatics approach show that several RBPs bind to the Bcl2 AREs, including AUF1 and HuR proteins. Altogether, association of RBPs to Bcl2 AREs contributes to Bcl2 protein expression by stabilizing Bcl2 mRNA and promotes B cell maintenance
Role of Peroxisome Proliferator-Activated Receptor Alpha in the Control of Cyclooxygenase 2 and Vascular Endothelial Growth Factor: Involvement in Tumor Growth
A growing body of evidence indicates that PPAR (peroxisome proliferator-activated receptor) α agonists might have therapeutic usefulness in antitumoral therapy by decreasing abnormal cell growth, and reducing tumoral angiogenesis. Most of the anti-inflammatory and antineoplastic properties of PPAR ligands are due to their inhibitory effects on transcription of a variety of genes involved in inflammation, cell growth and angiogenesis. Cyclooxygenase (COX)-2 and vascular endothelial growth factor (VEGF) are crucial agents in inflammatory and angiogenic processes. They also have been significantly associated to cell proliferation, tumor growth, and metastasis, promoting tumor-associated angiogenesis. Aberrant expression of VEGF and COX-2 has been observed in a variety of tumors, pointing to these proteins as important therapeutic targets in the treatment of pathological angiogenesis and tumor growth. This review summarizes the current understanding of the role of PPARα and its ligands in the regulation of COX-2 and VEGF gene expression in the context of tumor progression
Tia1 dependent regulation of mRNA subcellular location and translation controls p53 expression in B cells.
Post-transcriptional regulation of cellular mRNA is essential for protein synthesis. Here we describe the importance of mRNA translational repression and mRNA subcellular location for protein expression during B lymphocyte activation and the DNA damage response. Cytoplasmic RNA granules are formed upon cell activation with mitogens, including stress granules that contain the RNA binding protein Tia1. Tia1 binds to a subset of transcripts involved in cell stress, including p53 mRNA, and controls translational silencing and RNA granule localization. DNA damage promotes mRNA relocation and translation in part due to dissociation of Tia1 from its mRNA targets. Upon DNA damage, p53 mRNA is released from stress granules and associates with polyribosomes to increase protein synthesis in a CAP-independent manner. Global analysis of cellular mRNA abundance and translation indicates that this is an extended ATM-dependent mechanism to increase protein expression of key modulators of the DNA damage response.Sequestering mRNA in cytoplasmic stress granules is a mechanism for translational repression. Here the authors find that p53 mRNA, present in stress granules in activated B lymphocytes, is released upon DNA damage and is translated in a CAP-independent manner
Evidencias arqueológicas de desplomes paramentales traumáticos en las Termas Marítimas de Baelo Claudia. Reflexiones arqueosismológicas
Durante los años 2011 a 2013 se han localizado, identificado y excavado parcialmente los restos de un nuevo complejo termal en la ciudad hispanorromana de Baelo Claudia (Tarifa, Cádiz), situado en el suburbium occidental de la ciudad, junto a la línea de costa. Denominadas Termas Marítimas, construidas en la primera mitad del s. II d.C. y abandonadas en época de Diocleciano/Constantino han sido excavadas estratigráficamente con detalle, habiéndose detectado la existencia de fases anteriores (que se remontan al s. II a.C.) y una continuidad de uso del ambiente en época tardorromana y moderna, vinculada con la explotación de los recursos marinos. Especialmente singular ha sido la constatación del desplome traumático de parte de los paramentos de las habitaciones del edificio en dos momentos concretos: por un lado en la Antigüedad Tardía (500 d.C. circa), ya que una unidad muraria de una de las habitaciones (H-3), anexa a la natatio, se localizó completamente derrumbada sobre el suelo, conexionada; y por otro, el desplome del muro oeste de la natatio y el oriental de la cisterna, estructuras de más de seis metros de longitud y cuatro de altura mínima conservada, desplomadas sobre los niveles de abandono del asentamiento en época bajomedieval o moderna (ss. XIV-XV d.C.). Se trata en ambas ocasiones de colapsos estructurales no habituales en circunstancias normales en los procesos de sedimentación arqueológica, por lo que es muy probable que su desplome se pueda vincular con eventos sísmicos u otras causas naturales similare
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RNA-binding proteins ZFP36L1 and ZFP36L2 promote cell quiescence.
Progression through the stages of lymphocyte development requires coordination of the cell cycle. Such coordination ensures genomic integrity while cells somatically rearrange their antigen receptor genes [in a process called variable-diversity-joining (VDJ) recombination] and, upon successful rearrangement, expands the pools of progenitor lymphocytes. Here we show that in developing B lymphocytes, the RNA-binding proteins (RBPs) ZFP36L1 and ZFP36L2 are critical for maintaining quiescence before precursor B cell receptor (pre-BCR) expression and for reestablishing quiescence after pre-BCR-induced expansion. These RBPs suppress an evolutionarily conserved posttranscriptional regulon consisting of messenger RNAs whose protein products cooperatively promote transition into the S phase of the cell cycle. This mechanism promotes VDJ recombination and effective selection of cells expressing immunoglobulin-μ at the pre-BCR checkpoint.This work was funded by the Biotechnology and Biological Sciences Research Council, a Medical Research Council CASE studentship with GSK, an MRC centenary award (A.G) and project grants from Bloodwise. DJH was supported by a Medical Research Council Clinician Scientist FellowshipThis is the author accepted manuscript. The final version is available from the American Association for the Advancement of Science via http://dx.doi.org/10.1126/science.aad597
Shared decision making in breast cancer treatment guidelines: Development of a quality assessment tool and a systematic review
Background: It is not clear whether clinical practice guidelines (CPGs) and consensus
statements (CSs) are adequately promoting shared decision making (SDM).
Objective: To evaluate the recommendations about SDM in CPGs and CSs concerning breast cancer (BC) treatment.
Search strategy: Following protocol registration (Prospero no.: CRD42018106643),
CPGs and CSs on BC treatment were identified, without language restrictions,
through systematic search of bibliographic databases (MEDLINE, EMBASE, Web of
Science, Scopus, CDSR) and online sources (12 guideline databases and 51 professional society websites) from January 2010 to December 2019.
Inclusion criteria: CPGs and CSs on BC treatment were selected whether published
in a journal or in an online document.
Data extraction and synthesis: A 31-item SDM quality assessment tool was developed and used to extract data in duplicate.
Main results: There were 167 relevant CPGs (139) and CSs (28); SDM was reported
in only 40% of the studies. SDM was reported more often in recent publications after
2015 (42/101 (41.6 %) vs 46/66 (69.7 %), P = .0003) but less often in medical journal
publications (44/101 (43.5 %) vs 17/66 (25.7 %), P = .009). In CPGs and CSs with
SDM, only 8/66 (12%) met one-fifth (6 of 31) of the quality items; only 14/66 (8%)
provided clear and precise SDM recommendations.
Discussion and conclusions: SDM descriptions and recommendations in CPGs and
CSs concerning BC treatment need improvement. SDM was more frequently reported in CPGs and CSs in recent years, but surprisingly it was less often covered in
medical journals, a feature that needs attention
MAPPING COMMUNITY INTEREST HABITATS IN THE COLUMBRETES ARCHIPELAGO, AN EXTRAORDINARY HOT SPOT OF BIODIVERSITY
The Columbretes Archipelago and their submerged surroundings are part of an unusual,
Pleistocene volcanic field located in the Western Mediterranean designated as a Site of
Community Importance (SCI) of the Natura 2000 Network. In the present study, 4 benthic
habitats of community interest (1110, 1170, 1180 and 8330) have been identified by analyzing
several sources of information. Generalized additive models (GAMs) have been used to model
the potential distribution of reefs (1170) and maërl beds (1110). Our results highlight the
diversity and extent of these habitats and allow comparisons to other marine SCIs of Spain. This
can be attributed to the variability of the environment of this site. The Columbretes Islands
combine a relatively shallow environment with volcanic structures, hydrothermalism with active
degassing, current-driven sedimentary lobes and the influence of inland flows. Understanding
high biodiversity spots is crucial as they offer natural laboratories to describe how ecosystems
respond to the effects of global change. The knowledge obtained will be of paramount
importance for the conservation of species and habitats. Furthermore, it will establish a
baseline for future monitoring and assist in the development of effective management plans
The RNA-binding protein PTBP1 is necessary for B cell selection in germinal centers.
Antibody affinity maturation occurs in germinal centers (GCs), where B cells cycle between the light zone (LZ) and the dark zone. In the LZ, GC B cells bearing immunoglobulins with the highest affinity for antigen receive positive selection signals from helper T cells, which promotes their rapid proliferation. Here we found that the RNA-binding protein PTBP1 was needed for the progression of GC B cells through late S phase of the cell cycle and for affinity maturation. PTBP1 was required for proper expression of the c-MYC-dependent gene program induced in GC B cells receiving T cell help and directly regulated the alternative splicing and abundance of transcripts that are increased during positive selection to promote proliferation
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