PEA-15 mediates cytoplasmic sequestration of ERK MAP kinase.

The ERK 1/2 MAP kinase pathway controls cell growth and survival and modulates integrin function. Here, we report that PEA-15, a protein variably expressed in multiple cell types, blocks ERK-dependent transcription and proliferation by binding ERKs and preventing their localization in the nucleus. PEA-15 contains a nuclear export sequence required for its capacity to anchor ERK in the cytoplasm. Genetic deletion of PEA-15 results in increased ERK nuclear localization with consequent increased cFos transcription and cell proliferation. Thus, PEA-15 can redirect the biological outcome of MAP kinase signaling by regulating the subcellular localization of ERK MAP kinase.

Transforming growth factor alpha acts as a gliatrophin for mouse and human astrocytes.

Astrocyte death has been implicated in several neuropathological diseases, but the identification of molecules susceptible of promoting astrocyte survival has been elusive. We investigated whether transforming growth factor alpha (TGFalpha), an erbB1/EGFR ligand, which promotes glioma progression and affects astrocyte metabolism at embryonic and adult stages, regulates astrocyte survival. Primary serum-free astrocyte cultures from post-natal mouse and fetal human cortices were used. Transforming growth factor alpha protected both species of astrocytes from staurosporine-induced apoptosis. In serum-free medium, mouse astrocytes did not survive beyond 2 months while TGFalpha-treated astrocytes survived up to 12 months. Transforming growth factor alpha also promoted long-term survival of human astrocytes. We additionally extended TGFalpha proliferative effects to human astrocytes. After 3 days of permanent application, TGFalpha induced a major downregulation of both erbB1 and erbB2. This downregulation did not impair the functional activation of the receptors, as ascertained by their tyrosine phosphorylation and the continuous stimulation of both ERK/MAPK and PI3K/Akt pathways up to 7 days, the longest time examined. The full cellular effects of TGFalpha required activation of both transduction pathways. Enhanced proliferation and survival thus define TGFalpha as a gliatrophin for mammalian astrocytes. These results demonstrate that in normal, non-transformed astrocytes, sustained and functional erbBs activation is achieved without bypassing ligand-induced receptors downregulation.

[Evaluation of the appropriateness of stays in a third level hospital]. / Evaluación de la adecuación de las estancias en un hospital de tercer nivel.

BACKGROUND: Appropriateness Evaluation Protocol (AEP) has proved to be a useful tool for reviewing the utilisation of hospital resources. The aim of this article is to determine the proportion of inappropriate admissions and stays, as well as their causes, in patients hospitalised in the Hospital Clínico Universitario de Valladolid (HCUV). MATERIAL AND METHODS: A retrospective, analytical, observational, cohort study. The period of study was one year (2004). A sample of 1,630 admissions was gathered. Case definition, variables of interest and the model of data gathering were carried out in accordance with the AEP. The principal variables were analysed by means of a basal analysis and the possible relations between them. RESULTS: Fifty-four percent of the admissions showed at least one day of inappropriate stay, with the global rate of inappropriateness being 34.17%. Amongst the causes responsible for inappropriateness, 68.9% of admissions showed at least one criterion falling under the responsibility of the doctor or the hospital, and 51.3% were due to delays in the development of study or treatment. CONCLUSIONS: The utilisation of methods of identification of inappropriate use such as AEP show applications both in planning and in hospital management, by making it possible to identify hospital problems causing delays, principally problems of an organisational type, making it possible to develop interventions aimed at reducing inappropriate use.

Knock-out of the neural death effector domain protein PEA-15 demonstrates that its expression protects astrocytes from TNFalpha-induced apoptosis.

Apoptosis is a very general phenomenon, but only a few reports concern astrocytes. Indeed, astrocytes express receptors for tumor necrosis factor (TNF) alpha, a cytokine demonstrated on many cells and tissues to mediate apoptosis after recruitment of adaptor proteins containing a death effector domain (DED). PEA-15 is a DED-containing protein prominently expressed in the CNS and particularly abundant in astrocytes. This led us to investigate if PEA-15 expression could be involved in astrocytic protection against deleterious effects of TNF. In vitro assays evidence that PEA-15 may bind to DED-containing protein FADD and caspase-8 known to be apical adaptors of the TNF apoptotic signaling. After generation of PEA-15 null mutant mice, our results demonstrate that PEA-15 expression increases astrocyte survival after exposure to TNF.

Inhibition of eicosanoid and PAF formation by dexamethasone in rat inflammatory polymorphonuclear neutrophils may implicate lipocortin 's'.

In polymorphonuclear neutrophils, phospholipase A2 activity is the rate-limiting step for platelet-activating factor (PAF) formation and for the biosynthesis of arachidonic acid derivatives, leukotrienes and prostaglandins. Glucocorticosteroids inhibit phospholipase A2 activity by inducing in target cells the synthesis and release of phospholipase A2 inhibitory proteins named 'lipocortins'. Here, we report that rat pleural inflammatory polymorphonuclear neutrophils, treated with dexamethasone, decrease their production of eicosanoids and PAF. Evidence is presented which may implicate lipocortin 's' in these inhibitions since (i) phospholipase A2 inhibitory proteins are found in the supernatant of dexamethasone-treated cells, (ii) this supernatant inhibits the formation of lipid mediators in untreated cells, inhibition being reversed either by incubating the supernatant with a monoclonal antibody against rat lipocortin or by boiling it and (iii) a 36 kDa lipocortin from mice lungs mimics the effects of dexamethasone when added exogenously on untreated cells. Our results favour the hypothesis that the newly formed lipocortin 's' could be responsible for the antiphospholipase A2 activity of glucocorticosteroids.

The expression of PEA-15 (phosphoprotein enriched in astrocytes of 15 kDa) defines subpopulations of astrocytes and neurons throughout the adult mouse brain.

Phosphoprotein enriched in astrocytes of 15 kDa (PEA-15) is an abundant phosphoprotein in primary cultures of mouse brain astrocytes. Its capability to interact with members of the apoptotic and mitogen activated protein (MAP) kinase cascades endows PEA-15 with anti-apoptotic and anti-proliferative properties. We analyzed the in vivo cellular sources of PEA-15 in the normal adult mouse brain using a novel polyclonal antibody. Immunohistochemical assays revealed numerous PEA-15-immunoreactive cells throughout the brain of wild-type adult mice while no immunoreactive signal was observed in the brain of PEA-15 -/- mice. Cell morphology and double immunofluorescent staining showed that both astrocytes and neurons could be cellular sources of PEA-15. Closer examination revealed that in a given area only part of the astrocytes expressed the protein. The hippocampus was the most striking example of this heterogeneity, a spatial segregation restricting PEA-15 positive astrocytes to the CA1 and CA3 regions. A PEA-15 immunoreactive signal was also observed in a few cells within the subventricular zone and the rostral migratory stream. In vivo analysis of an eventual PEA-15 regulation in astrocytes was performed using a model of astrogliosis occurring along motor neurons degeneration, the transgenic mouse expressing the mutant G93A human superoxyde-dismutase-1, a model of amyotrophic lateral sclerosis. We observed a marked up-regulation of PEA-15 in reactive astrocytes that had developed throughout the ventral horn of the lumbar spinal cord of the transgenic mice. The heterogeneous cellular expression of the protein and its increased expression in pathological situations, combined with the known properties of PEA-15, suggest that PEA-15 expression is associated with a particular metabolic status of cells challenged with potentially apoptotic and/or proliferative signals.

Evaluación de la adecuación de las estancias en un hospital de tercer nivel / Evaluation of the appropriateness of stays in a third level hospital

FUNDAMENTO The Appropriateness Evaluation Protocol (AEP) se ha mostrado como una herramienta útil para la revisión de la utilización de los recursos hospitalarios. El objetivo de este trabajo es conocer la proporción de ingresos y estancias inadecuadas, así como sus causas, en pacientes hospitalizados en el Hospital Clínico Universitario de Valladolid (HCUV). MATERIAL Y MÉTODOS Estudio observacional analítico de cohortes retrospectivo. El período de estudio ha sido de un año (2004). Se seleccionó una muestra de 1.630 ingresos. La definición de caso, las variables de interés y el modelo de recogida de datos se han llevado a cabo conforme al AEP. Se han analizado las principales variables mediante un análisis basal y las posibles relaciones entre ellas. RESULTADOS El 54% de los ingresos presentaron al menos un día de estancia inadecuada, siendo la tasa de inadecuación global del 34,17%. Entre las causas responsables de la inadecuación, el 68,9% de los ingresos presentaron al menos un criterio englobado dentro de la responsabilidad del médico o del hospital, y el 51,3% debido a retrasos en el desarrollo del estudio o tratamiento. CONCLUSIONES La utilización de métodos de identificación del uso inapropiado como el AEP presenta aplicaciones tanto en planificación como en gestión hospitalaria, al permitir identificar problemas hospitalarios causantes de demoras, principalmente problemas de tipo organizativo, permitiendo el desarrollo de intervenciones encaminadas a la reducción del uso inapropiado

BACKGROUND The Appropriateness Evaluation Protocol (AEP) has proved to be a useful tool for reviewing the utilisation of hospital resources. The aim of this article is to determine the proportion of inappropriate admissions and stays, as well as their causes, in patients hospitalised in the Hospital Clínico Universitario de Valladolid (HCUV). MATERIAL AND METHODS A retrospective, analytical, observational, cohort study. The period of study was one year (2004). A sample of 1,630 admissions was gathered. Case definition, variables of interest and the model of data gathering were carried out in accordance with the AEP. The principal variables were analysed by means of a basal analysis and the possible relations between them. RESULTS Fifty-four percent of the admissions showed at least one day of inappropriate stay, with the global rate of inappropriateness being 34.17%. Amongst the causes responsible for inappropriateness, 68.9% of admissions showed at least one criterion falling under the responsibility of the doctor or the hospital, and 51.3% were due to delays in the development of study or treatment. CONCLUSIONS The utilisation of methods of identification of inappropriate use such as AEP show applications both in planning and in hospital management, by making it possible to identify hospital problems causing delays, principally problems of an organisational type, making it possible to develop interventions aimed at reducing inappropriate use