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The p53/p21 pathway is activated in response to cell stress. However, its role in acute lung injury has not been elucidated. Acute lung injury is associated with disruption of the alveolo-capillary barrier leading to acute respiratory distress syndrome (ARDS). Mechanical ventilation may be necessary to support gas exchange in patients with ARDS, however, high positive airway pressures can cause regional overdistension of alveolar units and aggravate lung injury. Here, we report that acute lung injury and alveolar overstretching activate the p53/p21 pathway to maintain homeostasis and avoid massive cell apoptosis. A systematic pooling of transcriptomic data from animal models of lung injury demonstrates the enrichment of specific p53- and p21-dependent gene signatures and a validated senescence profile. In a clinically relevant, murine model of acid aspiration and mechanical ventilation, we observed changes in the nuclear envelope and the underlying chromatin, DNA damage and activation of the Tp53/p21 pathway. Absence of Cdkn1a decreased the senescent response, but worsened lung injury due to increased cell apoptosis. Conversely, treatment with lopinavir and/or ritonavir led to Cdkn1a overexpression and ameliorated cell apoptosis and lung injury. The activation of these mechanisms was associated with early markers of senescence, including expression of senescence-related genes and increases in senescence-associated heterochromatin foci in alveolar cells. Autopsy samples from lungs of patients with ARDS revealed increased senescence-associated heterochromatin foci. Collectively, these results suggest that acute lung injury activates p53/p21 as an antiapoptotic mechanism to ameliorate damage, but with the side effect of induction of senescence., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The epithelial-mesenchymal transition (EMT) is considered a key step in tumor progression, where the invasive cancer cells change from epithelial to mesenchymal phenotype. During this process, a decrease or loss in adhesion molecules expression and an increase in migration molecules expression are observed. The aim of this work was to determine the expression and cellular distribution of syndecan-1 and -2 (migration molecules) and E-cadherin and beta-catenin (adhesion molecules) in different stages of prostate cancer progression. A quantitative immunohistochemical study of these molecules was carried out in tissue samples from benign prostatic hyperplasia and prostate carcinoma, with low and high Gleason score, obtained from biopsies archives of the Clinic Hospital of the University of Chile and Dipreca Hospital. Polyclonal specific antibodies and amplification system of estreptavidin-biotin peroxidase and diaminobenzidine were used. Syndecan-1 was uniformly expressed in basolateral membranes of normal epithelium, changing to a granular cytoplasmatic expression pattern in carcinomas. Syndecan-2 was observed mainly in a cytoplasmatic granular pattern, with high immunostaining intensity in areas of low Gleason score. E-cadherin was detected in basolateral membrane of normal epithelia showing decreased expression in high Gleason score samples. beta-Catenin was found in cell membranes of normal epithelia changing its distribution toward the nucleus and cytoplasm in carcinoma samples. We concluded that changes in expression and cell distribution of E-cadherin and beta-catenin correlated with the progression degree of prostate adenocarcinoma, suggesting a role of these molecules as markers of progression and prognosis. Furthermore, changes in the pattern expression of syndecan-1 and -2 indicate that both molecules may be involved in the EMT and tumor progression of prostate cancer., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

Absence of gradients and Nernstian equilibrium stripping (AGNES) is an emerging electroanalytical technique designed to measure free metal ion concentration. The practical implementation of AGNES requires a critical selection of the deposition time, which can be drastically reduced if the contribution of the complexes is properly taken into account. The resin titration (RT) is a competition method based on the sorption of metal ions on a complexing resin. The competitor here considered is the resin Chelex 100 whose sorbing properties towards Pb(II) are well known. The RT is a consolidated technique especially suitable to perform an intercomparison with AGNES, due to its independent physicochemical nature. Two different ligands for Pb(II) complexation have been analyzed here: nitrilotriacetic acid (NTA) and pyridinedicarboxylic acid (PDCA). The complex PbNTA is practically inert in the diffusion layer, so, for ordinary deposition potentials, its contribution is almost negligible; however, at potentials more negative than -0.8 V vs. Ag/AgCl the complex dissociates on the electrodic surface giving rise to a second wave in techniques such as normal pulse polarography. The complex Pb-PDCA is partially labile, so that its contribution can be estimated from an expression of the lability degree of the complex. These new strategies allow us to reduce the deposition time. The free Pb(II) concentrations obtained by AGNES and by RT are in full agreement for both systems here considered. The main advantage of the use of AGNES in these systems lies in the reduction of the time of the experiment, while RT can be applied to non-amalgamating elements and offers the possibility of simultaneous determinations.

Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) is a recently suggested electroanalytical technique designed for the determination of the free concentration of heavy metals (such as Zn, Cd or Pb) which is here developed and applied to seawater samples. A key improvement for the implementation of AGNES with complex matrices is the development of a new blank, called the shifted blank (presented in this work for the first time), which can be applied to the same sample where the measurement is intended. The careful selection of the required parameters for the determination of the free Zn concentration (or activity) at the nanomolar level is described in detail. The methodology has been validated with a synthetic solution containing Zn and nitrilotriacetic acid (NTA) and then applied, as a first case, to two coastal seawater samples taken close to Barcelona and Tarragona (Catalonia, North-Eastern Spain) finding values in the range of 1-3nM, representing around 25% of total Zn. This technique can, in the near future, be crucial in helping to elucidate the role of the free zinc(II) concentration in natural waters.