The role of post-transcriptional regulation in chemokine gene expression in inflammation and allergy.

The aim of this review is to discuss recent advances in the understanding of the regulation of chemokine expression occurring during chronic inflammatory conditions, such as allergic diseases. The focus will be on current data, which suggest that post-transcriptional regulation plays a larger role in chemokine gene regulation than previously recognised. In particular, a growing body of data indicates that mechanisms controlling mRNA stability may be relevant in determining, or maintaining, the increased levels of chemokine gene expression in this context. Such regulatory pathways may be important targets of novel anti-inflammatory strategies

The human glucocorticoid receptor as an RNA-binding protein: global analysis of glucocorticoid receptor-associated transcripts and identification of a target RNA motif.

Posttranscriptional regulation is emerging as a key factor in glucocorticoid (GC)-mediated gene regulation. We investigated the role of the human GC receptor (GR) as an RNA-binding protein and its effect on mRNA turnover in human airway epithelial cells. Cell treatment with the potent GC budesonide accelerated the decay of CCL2 mRNA (t(1/2) = 8 ± 1 min versus 62 ± 17 min in DMSO-treated cells) and CCL7 mRNA (t(1/2) = 15 ± 4 min versus 114 ± 37 min), but not that of CCL5 mRNA (t(1/2)=231 ± 8 min versus 266 ± 5 min) in the BEAS-2B cell line. This effect was inhibited by preincubation with an anti-GR Ab, indicating that GR itself plays a role in the turnover of these transcripts. Coimmunoprecipitation and biotin pulldown experiments showed that GR associates with CCL2 and CCL7 mRNAs, but not CCL5 mRNA. These methods confirmed CCL2 mRNA targeting by GR in human primary airway epithelial cells. Association of the GR was localized to the 5' untranslated region of CCL2 mRNA and further mapped to nt 44-60. The collection of transcripts associated with GR, identified by immunoprecipitation of GR-mRNA complexes followed by microarray analysis, revealed 479 transcripts that associated with GR. Computational analysis of the primary sequence and secondary structures of these transcripts yielded a GC-rich motif, which was shown to bind to GR in vitro. This motif was used to predict binding of GR to an additional 7889 transcripts. These results indicate that cytoplasmic GR interacts with a subset of mRNA through specific sequences and can regulate turnover rates, suggesting a novel posttranscriptional role for GR as an RNA-binding protein

APRENDER A ENSINAR: A CONSTITUIÇÃO DA IDENTIDADE DO PROFESSOR NA EDUCAÇÃO PRIMÁRIA E INFANTIL

El estudio acerca de la construcción de la identidad del profesor en los últimos 20 años ha mostrado la importancia de la formación y de las primeras experiencias docentes para el proceso de aprender a ser profesor. Las evidencias recogidas mediante el análisis de 23 microetnografías y 13 grupos focales, en que han participado un total de 88 profesores, siete de ellos especialistas en Educación Física, nos ha permitido explorar los componentes macro, meso y microsistemas en que los profesores interactúan y dan sentido a su aprender a enseñar. La discusión y contextualización de las experiencias de los docentes en relación a: (a) el ingreso a la formación, (b) la experiencia de la formación inicial y permanente, (c) el concepto de conocimiento y aprendizaje y (d) cómo han aprendido a enseñar, pone de manifiesto la complejidad de ser docente en los días actuales y nos posibilita elaborar recomendaciones para la mejora de la formación y de la inserción en las escuelas. Studies on the construction of teacher identity in the past 20 years showed the importance of professional development and early teaching experiences for the process of learning how to be a teacher. Evidence was collected by conducting 23 micro-ethnographies and 13 focus groups, in which a total of 88 teachers participated, seven of whom were specialists in Physical Education. It allowed us to explore the components of the ‘macro’, ‘meso’ and ‘micro’ systems in which teachers interact and ascribe meaning to their learning of how to become teachers, and to how they have been constructed as teachers. The complexity involved in learning to be a teacher today was shown by discussion and contextualization of teachers’ experiences regarding: (a) starting their development; (b) experience with initial and continued training; (c) the notion of knowledge and learning; and (d) how they have been learning to teach, allowing us to make recommendations to improve teachers’ training and their placement in schools.O estudo sobre a construção da identidade do professor nos últimos vinte anos destacou a importância da formação e das primeiras experiências docentes para o processo de aprender a ser professor. As evidências identificadas por meio da análise de 23 microetnografías e de 13 grupos focais, nos quais participaram um total de 88 professores, sete deles especialistas em Educação Física, nos permitiram explorar os componentes dos macro, meso e microsistemas em que os professores interagem e atribuem sentido ao seu aprender a ensinar e a como eles têm se constituído como professores. A discussão e a contextualização das experiências dos professores em relação a: (a) a entrada em formação, (b) a experiência da formação inicial e continuada, (c) o conceito de conhecimento e aprendizagem e (d) como eles têm aprendido a ensinar colocam em evidência a complexidade que implica ser docente hoje e nos possibilita elaborar recomendações para a melhoraria da formação e da inserção nas escolas

Management approach for recurrent spontaneous pneumothorax in consecutive pregnancies based on clinical and radiographic findings

OBJECTIVE: To describe management and clinical features observed in a patient's seven spontaneous pneumothoraces that developed during two consecutive pregnancies involving both hemithoraces. MATERIALS AND METHODS: A 21 year old former smoker developed three spontaneous left pneumothoraces in the index pregnancy, having already experienced four right pneumothorax events in a prior pregnancy at age 19. RESULTS: Chest tubes were required in several (but not all) hospitalizations during these two pregnancies. Following her fourth right pneumothorax, thoracoscopic excision of right apical lung blebs and mechanical pleurodesis was performed. The series of left pneumothoraces culminated in mini-thoracotomy and thoracoscopically directed mechanical pleurodesis. For both pregnancies unassisted vaginal delivery was performed with no adverse perinatal sequelae. With the exception of multiple pneumothoraces, there were no additional pregnancy complications. CONCLUSION: Spontaneous pneumothorax in pregnancy is believed to be a rare phenomenon, yet the exact incidence is unknown. Here we present the first known case of multiple spontaneous pneumothoraces in two consecutive pregnancies involving both hemithoraces. Clinical management coordinated with obstetrics and surgical teams facilitated a satisfactory outcome for both pregnancies. The diagnosis of pneumothorax should be contemplated in any pregnant patient with dyspnea and chest pain, followed by radiographic confirmation

Cómo aprendemos los docentes de universidad. Implicaciones para la formación docente

Este artículo se basa en un proyecto de investigación coordinado sobre cómo aprenden los docentes, sus implicaciones educativas y los retos para afrontar el cambio social. Desde un posicionamiento basado en la investigación inclusiva y la utilización de métodos visuales se crearon 65 cartografías sobre los escenarios o contextos de aprendizaje de docentes de educación infantil, primaria, secundaria y superior (en este caso los investigadores del proyecto). También, se compartieron las explicaciones y reflexiones sobre las cartografías realizadas dando cuenta de los tránsitos y experiencias de aprendizaje. En este artículo, presentamos los resultados y las conclusiones sobre cómo aprendemos los docentes de educación superior, centrados en los autores de este texto. Destacamos las posibilidades de la experiencia cartográfica para la investigación educativa y la consideración de que el aprendizaje del profesorado no solo tiene lugar en contextos formales e institucionales, sino a lo largo y ancho de la vida. Elaboramos conclusiones sobre las características del aprendizaje del profesorado actual y sobre la importancia de tener en cuenta su carácter contextual, biográfico, corporeizado y socioafectivo en la formación inicial y permanente de los docentes. También avanzamos algunas implicaciones para repensar la formación docente al considerar las relaciones entre las experiencias de vida y el aprendizaje, la importancia de conectar las instituciones educativas con la sociedad, la reflexión sobre la práctica educativa y los principales desafíos educativos. Todo ello con la finalidad de promover la transformación de los centros educativos en instituciones de aprendizaje con sentido

Diverse Genetic Regulon of the Virulence-Associated Transcriptional Regulator MucR in Brucella abortus 2308

The Ros-type regulator MucR is one of the few transcriptional regulators that have been linked to virulence in Brucella. Here, we show that a Brucella abortus in-frame mucR deletion strain exhibits a pronounced growth defect during in vitro cultivation and, more importantly, that the mucR mutant is attenuated in cultured macrophages and in mice. The genetic basis for the attenuation of Brucella mucR mutants has not been defined previously, but in the present study the genes regulated by MucR in B. abortus have been elucidated using microarray analysis and real-time reverse transcription-PCR (RT-PCR). In B. abortus 2308, MucR regulates a wide variety of genes whose products may function in establishing and maintaining cell envelope integrity, polysaccharide biosynthesis, iron homeostasis, genome plasticity, and transcriptional regulation. Particularly notable among the MucR-regulated genes identified is arsR6 (nolR), which encodes a transcriptional regulator previously linked to virulence in Brucella melitensis 16 M. Importantly, electrophoretic mobility shift assays (EMSAs) determined that a recombinant MucR protein binds directly to the promoter regions of several genes repressed by MucR (including arsR6 [nolR]), and in Brucella, as in other alphaproteobacteria, MucR binds to its own promoter to repress expression of the gene that encodes it. Overall, these studies have uncovered the diverse genetic regulon of MucR in Brucella, and in doing so this work has begun to define the MucR-controlled genetic circuitry whose misregulation contributes to the virulence defect of Brucella mucR mutants

The association of Alu repeats with the generation of potential AU-rich elements (ARE) at 3' untranslated regions.

BACKGROUND: A significant portion (about 8% in the human genome) of mammalian mRNA sequences contains AU (Adenine and Uracil) rich elements or AREs at their 3' untranslated regions (UTR). These mRNA sequences are usually stable. However, an increasing number of observations have been made of unstable species, possibly depending on certain elements such as Alu repeats. ARE motifs are repeats of the tetramer AUUU and a monomer A at the end of the repeats ((AUUU)(n)A). The importance of AREs in biology is that they make certain mRNA unstable. Proto-oncogene, such as c-fos, c-myc, and c-jun in humans, are associated with AREs. Although it has been known that the increased number of ARE motifs caused the decrease of the half-life of mRNA containing ARE repeats, the exact mechanism is as of yet unknown. We analyzed the occurrences of AREs and Alu and propose a possible mechanism for how human mRNA could acquire and keep AREs at its 3' UTR originating from Alu repeats. RESULTS: Interspersed in the human genome, Alu repeats occupy 5% of the 3' UTR of mRNA sequences. Alu has poly-adenine (poly-A) regions at its end, which lead to poly-thymine (poly-T) regions at the end of its complementary Alu. It has been found that AREs are present at the poly-T regions. From the 3' UTR of the NCBI's reference mRNA sequence database, we found nearly 40% (38.5%) of ARE (Class I) were associated with Alu sequences (Table 1) within one mismatch allowance in ARE sequences. Other ARE classes had statistically significant associations as well. This is far from a random occurrence given their limited quantity. At each ARE class, random distribution was simulated 1,000 times, and it was shown that there is a special relationship between ARE patterns and the Alu repeats. CONCLUSION: AREs are mediating sequence elements affecting the stabilization or degradation of mRNA at the 3' untranslated regions. However, AREs' mechanism and origins are unknown. We report that Alu is a source of ARE. We found that half of the longest AREs were derived from the poly-T regions of the complementary Alu

pp32 (ANP32A) Expression Inhibits Pancreatic Cancer Cell Growth and Induces Gemcitabine Resistance by Disrupting HuR Binding to mRNAs

The expression of protein phosphatase 32 (PP32, ANP32A) is low in poorly differentiated pancreatic cancers and is linked to the levels of HuR (ELAV1), a predictive marker for gemcitabine response. In pancreatic cancer cells, exogenous overexpression of pp32 inhibited cell growth, supporting its long-recognized role as a tumor suppressor in pancreatic cancer. In chemotherapeutic sensitivity screening assays, cells overexpressing pp32 were selectively resistant to the nucleoside analogs gemcitabine and cytarabine (ARA-C), but were sensitized to 5-fluorouracil; conversely, silencing pp32 in pancreatic cancer cells enhanced gemcitabine sensitivity. The cytoplasmic levels of pp32 increased after cancer cells are treated with certain stressors, including gemcitabine. pp32 overexpression reduced the association of HuR with the mRNA encoding the gemcitabine-metabolizing enzyme deoxycytidine kinase (dCK), causing a significant reduction in dCK protein levels. Similarly, ectopic pp32 expression caused a reduction in HuR binding of mRNAs encoding tumor-promoting proteins (e.g., VEGF and HuR), while silencing pp32 dramatically enhanced the binding of these mRNA targets. Low pp32 nuclear expression correlated with high-grade tumors and the presence of lymph node metastasis, as compared to patients' tumors with high nuclear pp32 expression. Although pp32 expression levels did not enhance the predictive power of cytoplasmic HuR status, nuclear pp32 levels and cytoplasmic HuR levels associated significantly in patient samples. Thus, we provide novel evidence that the tumor suppressor function of pp32 can be attributed to its ability to disrupt HuR binding to target mRNAs encoding key proteins for cancer cell survival and drug efficacy

SRT1720 improves survival and healthspan of obese mice

Sirt1 is an NAD+-dependent deacetylase that extends lifespan in lower organisms and improves metabolism and delays the onset of age-related diseases in mammals. Here we show that SRT1720, a synthetic compound that was identified for its ability to activate Sirt1 in vitro, extends both mean and maximum lifespan of adult mice fed a high-fat diet. This lifespan extension is accompanied by health benefits including reduced liver steatosis, increased insulin sensitivity, enhanced locomotor activity and normalization of gene expression profiles and markers of inflammation and apoptosis, all in the absence of any observable toxicity. Using a conditional SIRT1 knockout mouse and specific gene knockdowns we show SRT1720 affects mitochondrial respiration in a Sirt1- and PGC-1α-dependent manner. These findings indicate that SRT1720 has long-term benefits and demonstrate for the first time the feasibility of designing novel molecules that are safe and effective in promoting longevity and preventing multiple age-related diseases in mammals