Calcineurin expression and activity is regulated by the intracellular redox status and under hypertension in human neutrophils

Calcineurin (protein phosphatase 2B) (CN) comprises a family of serine/threonine phosphatases that play a pivotal role in signal transduction cascades in a variety of cells, including neutrophils. Angiotensin II (Ang II) increases both activity and de novo synthesis of CN in human neutrophils. This study focuses on the role that intracellular redox status plays in the induction of CN activity by Ang II. Both de novo synthesis of CN and activity increase promoted by Ang II were downregulated when cells were treated with l-buthionine-(S,R)-sulfoximine, an inhibitor of synthesis of the antioxidant glutathione. We have also investigated the effect of pyrrolidine dithiocarbamate and phenazine methosulfate, which are antioxidant and oxidant compounds, respectively, and concluded that the intracellular redox status of neutrophils is highly critical for Ang II-induced increase of CN expression and activity. Results obtained in neutrophils from hypertensive patients were very similar to those obtained in these cells on treatment with Ang II. We have also addressed the possible functional implication of CN activation in the development of hypertension. Present findings indicate that downregulation of hemoxygenase-1 expression in neutrophils from hypertensive subjects is likely mediated by CN, which acts by hindering translocation to the nucleus of the transcription factor NRF2. These data support and extend our previous results and those from other authors on modulation of CN expression and activity levels by the intracellular redox status.

Canales, sifones y almenaras: el impacto ambiental de las infraestructuras del Canal de Isabel II (Madrid)

El presente artículo tiene como finalidad, valorar el impacto ambiental de las conducciones del Canal de Isabel II en el contexto del paisaje. Partimos de la idea según la cual, las infraestructuras del Canal de Isabel II, y más que formar parte del paisaje por el que se extienden, son el propio paisaje. Nuestra zona de estudio es el noroeste de la Comunidad de Madrid (síntesis de la interacción de los propios agentes naturales, de la ocupación humana y de los usos del suelo), área a la que nos aproximarnos a través de la investigación de la integración paisajística, entendida ésta como una estrategia de intervención en el territorio, que tiene como objetivo principal orientar las transformaciones del paisaje o corregir las ya realizadas, para conseguir su adaptación al propio paisaje. En definitiva, nos encontramos ante la necesidad de ajustar un objeto o actuación territorial a las características fisonómicas de un paisaje dado, o de algunos de sus componentes, así como a su carácter y a sus contenidos semánticos.