Modulation of telomere protection by the PI3K/AKT pathway

Telomeres and the insulin/PI3K pathway are considered hallmarks of aging and cancer. Here, we describe a role for PI3K/AKT in the regulation of TRF1, an essential component of the shelterin complex. PI3K and AKT chemical inhibitors reduce TRF1 telomeric foci and lead to increased telomeric DNA damage and fragility. We identify the PI3Kα isoform as responsible for this TRF1 inhibition. TRF1 is phosphorylated at different residues by AKT and these modifications regulate TRF1 protein stability and TRF1 binding to telomeric DNA in vitro and are important for in vivo TRF1 telomere location and cell viability. Patient-derived breast cancer PDX mouse models that effectively respond to a PI3Kα specific inhibitor, BYL719, show decreased TRF1 levels and increased DNA damage. These findings functionally connect two of the major pathways for cancer and aging, telomeres and the PI3K pathway, and pinpoint PI3K and AKT as novel targets for chemical modulation of telomere protection.We are indebted to D. Megias for microscopy analysis, to D. Calvo for protein purification as well as to J. Muñoz and F. García for LC/MS/MS analysis. The research was funded by project SAF2013-45111-R of Societal Changes Program of the Spanish Ministry of Economics and Competitiveness (MINECO) co-financed through the European Fund of Regional Development (FEDER), Fundación Botín, Banco Santander (Santander Universities Global Division) and Worldwide Cancer Research (WCR 16-1177).S

Therapeutic effects of telomerase in mice with pulmonary fibrosis induced by damage to the lungs and short telomeres

Pulmonary fibrosis is a fatal lung disease characterized by fibrotic foci and inflammatory infiltrates. Short telomeres can impair tissue regeneration and are found both in hereditary and sporadic cases. We show here that telomerase expression using AAV9 vectors shows therapeutic effects in a mouse model of pulmonary fibrosis owing to a low-dose bleomycin insult and short telomeres. AAV9 preferentially targets regenerative alveolar type II cells (ATII). AAV9-Tert-treated mice show improved lung function and lower inflammation and fibrosis at 1-3 weeks after viral treatment, and improvement or disappearance of the fibrosis at 8 weeks after treatment. AAV9-Tert treatment leads to longer telomeres and increased proliferation of ATII cells, as well as lower DNA damage, apoptosis, and senescence. Transcriptome analysis of ATII cells confirms downregulation of fibrosis and inflammation pathways. We provide a proof-of-principle that telomerase activation may represent an effective treatment for pulmonary fibrosis provoked or associated with short telomeres.We are indebted to D Megias for microscopy analysis, to J Mun˜ oz and F Garcı´a for hydroxiproline analysis as well as to CNIO Histopathological Unit. The research was funded by project SAF2013- 45111-R of Societal Changes Programme of the Spanish Ministry of Economics and Competitiveness (MINECO) co-financed through the European Fund of Regional Development (FEDER), Fundacio´n Botı´n and Banco Santander (Santander Universities Global Division) and Roche Extending the Innova- tion Network Program (EIN) Academia Partnering Programme.S

Differential Epigenetic Compatibility of qnr Antibiotic Resistance Determinants with the Chromosome of Escherichia coli

Environmental bacteria harbor a plethora of genes that, upon their horizontal transfer to new hosts, may confer resistance to antibiotics, although the number of such determinants actually acquired by pathogenic bacteria is very low. The founder effect, fitness costs and ecological connectivity all influence the chances of resistance transfer being successful. We examined the importance of these bottlenecks using the family of quinolone resistance determinants Qnr. The results indicate the epigenetic compatibility of a determinant with the host genome to be of great importance in the acquisition and spread of resistance. A plasmid carrying the widely distributed QnrA determinant was stable in Escherichia coli, whereas the SmQnr determinant was unstable despite both proteins having very similar tertiary structures. This indicates that the fitness costs associated with the acquisition of antibiotic resistance may not derive from a non-specific metabolic burden, but from the acquired gene causing specific changes in bacterial metabolic and regulatory networks. The observed stabilization of the plasmid encoding SmQnr by chromosomal mutations, including a mutant lacking the global regulator H-NS, reinforces this idea. Since quinolones are synthetic antibiotics, and since the origin of QnrA is the environmental bacterium Shewanella algae, the role of QnrA in this organism is unlikely to be that of conferring resistance. Its evolution toward this may have occurred through mutations or because of an environmental change (exaptation). The present results indicate that the chromosomally encoded Qnr determinants of S. algae can confer quinolone resistance upon their transfer to E. coli without the need of any further mutation. These results suggest that exaptation is important in the evolution of antibiotic resistance

Association of VAV2 and VAV3 polymorphisms with cardiovascular risk factors

Hypertension, diabetes and obesity are cardiovascular risk factors closely associated to the development of renal and cardiovascular target organ damage. VAV2 and VAV3, members of the VAV family proto-oncogenes, are guanosine nucleotide exchange factors for the Rho and Rac GTPase family, which is related with cardiovascular homeostasis. We have analyzed the relationship between the presence of VAV2 rs602990 and VAV3 rs7528153 polymorphisms with cardiovascular risk factors and target organ damage (heart, vessels and kidney) in 411 subjects. Our results show that being carrier of the T allele in VAV2 rs602990 polymorphism is associated with an increased risk of obesity, reduced levels of ankle-brachial index and diastolic blood pressure and reduced retinal artery caliber. In addition, being carrier of T allele is associated with increased risk of target organ damage in males. On the other hand, being carrier of the T allele in VAV3 rs7528153 polymorphism is associated with a decreased susceptibility of developing a pathologic state composed by the presence of hypertension, diabetes, obesity or cardiovascular damage, and with an increased risk of developing altered basal glycaemia. This is the first report showing an association between VAV2 and VAV3 polymorphisms with cardiovascular risk factors and target organ damage

Effects of a Mediterranean Diet Intervention on Maternal Stress, Well-Being, and Sleep Quality throughout Gestation-The IMPACT-BCN Trial

Stress and anxiety are frequent occurrences among pregnant women. We aimed to evaluate the effects of a Mediterranean diet intervention during pregnancy on maternal stress, well-being, and sleep quality throughout gestation. In a randomized clinical trial, 1221 high-risk pregnant women were randomly allocated into three groups at 19-23 weeks' gestation: a Mediterranean diet intervention, a Mindfulness-Based Stress Reduction program, or usual care. All women who provided self-reported life-style questionnaires to measure their anxiety (State Trait Anxiety Inventory (STAI), Perceived Stress Scale (PSS)), well-being (WHO Five Well Being Index (WHO-5)), and sleep quality (Pittsburgh sleep quality index (PSQI)) at enrollment and at the end of the intervention (34-36 weeks) were included. In a random subgroup of 106 women, the levels of cortisol and related metabolites were also measured. At the end of the intervention (34-36 weeks), participants in the Mediterranean diet group had significantly lower perceived stress and anxiety scores (PSS mean (SE) 15.9 (0.4) vs. 17.0 (0.4), p = 0.035; STAI-anxiety mean (SE) 13.6 (0.4) vs. 15.8 (0.5), p = 0.004) and better sleep quality (PSQI mean 7.0 ± 0.2 SE vs. 7.9 ± 0.2 SE, p = 0.001) compared to usual care. As compared to usual care, women in the Mediterranean diet group also had a more significant increase in their 24 h urinary cortisone/cortisol ratio during gestation (mean 1.7 ± SE 0.1 vs. 1.3 ± SE 0.1, p < 0.001). A Mediterranean diet intervention during pregnancy is associated with a significant reduction in maternal anxiety and stress, and improvements in sleep quality throughout gestation. Keywords: Mediterranean diet; pregnancy; anxiety; well-being; sleep qualit

La universidad humanista

Esta obra, titulada La universidad humanista, es fruto de la colaboración entre dos instituciones centenarias: la Universidad de Santiago de Compostela, una de las universidades más antiguas de España que ofrece educación superior desde 1495 y la Universidad Autónoma del Estado de México, heredera del Instituto Científico y Literario Autónomo, fundado en 1828, a escasos siete años de que México naciera como entidad política independiente. Ambas instituciones, con un pasado muy diferente, se encuentran hermanadas por la misma vocación de futuro y las preocupaciones propias de las universidades del siglo XXI.Universidad Autónoma del Estado de México y Universidad de Santiago de Compostel

Carglumic acid enhances rapid ammonia detoxification in classical organic acidurias with a favourable risk-benefit profile: A retrospective observational study

BACKGROUND: Isovaleric aciduria (IVA), propionic aciduria (PA) and methylmalonic aciduria (MMA) are inherited organic acidurias (OAs) in which impaired organic acid metabolism induces hyperammonaemia arising partly from secondary deficiency of N-acetylglutamate (NAG) synthase. Rapid reduction in plasma ammonia is required to prevent neurological complications. This retrospective, multicentre, open-label, uncontrolled, phase IIIb study evaluated the efficacy and safety of carglumic acid, a synthetic structural analogue of NAG, for treating hyperammonaemia during OA decompensation. METHODS: Eligible patients had confirmed OA and hyperammonaemia (plasma NH3 > 60 μmol/L) in ≥1 decompensation episode treated with carglumic acid (dose discretionary, mean (SD) first dose 96.3 (73.8) mg/kg). The primary outcome was change in plasma ammonia from baseline to endpoint (last available ammonia measurement at ≤18 hours after the last carglumic acid administration, or on Day 15) for each episode. Secondary outcomes included clinical response and safety. RESULTS: The efficacy population (received ≥1 dose of study drug and had post-baseline measurements) comprised 41 patients (MMA: 21, PA: 16, IVA: 4) with 48 decompensation episodes (MMA: 25, PA: 19, IVA: 4). Mean baseline plasma ammonia concentration was 468.3 (±365.3) μmol/L in neonates (29 episodes) and 171.3 (±75.7) μmol/L in non-neonates (19 episodes). At endpoint the mean plasma NH3 concentration was 60.7 (±36.5) μmol/L in neonates and 55.2 (±21.8) μmol/L in non-neonates. Median time to normalise ammonaemia was 38.4 hours in neonates vs 28.3 hours in non-neonates and was similar between OA subgroups (MMA: 37.5 hours, PA: 36.0 hours, IVA: 40.5 hours). Median time to ammonia normalisation was 1.5 and 1.6 days in patients receiving and not receiving concomitant scavenger therapy, respectively. Although patients receiving carglumic acid with scavengers had a greater reduction in plasma ammonia, the endpoint ammonia levels were similar with or without scavenger therapy. Clinical symptoms improved with therapy. Twenty-five of 57 patients in the safety population (67 episodes) experienced AEs, most of which were not drug-related. Overall, carglumic acid seems to have a good safety profile for treating hyperammonaemia during OA decompensation. CONCLUSION: Carglumic acid when used with or without ammonia scavengers, is an effective treatment for restoration of normal plasma ammonia concentrations in hyperammonaemic episodes in OA patients

Dose‐dependent proteomic analysis of glioblastoma cancer stem cells upon treatment with γ‐secretase inhibitor

Notch signaling has been demonstrated to have a central role in glioblastoma (GBM) cancer stem cells (CSCs) and we have demonstrated recently that Notch pathway blockade by γ‐secretase inhibitor (GSI) depletes GBM CSCs and prevents tumor propagation both in vitro and in vivo. In order to understand the proteome alterations involved in this transformation, a dose‐dependent quantitative mass spectrometry (MS)‐based proteomic study has been performed based on the global proteome profiling and a target verification phase where both Immunoassay and a multiple reaction monitoring (MRM) assay are employed. The selection of putative protein candidates for confirmation poses a challenge due to the large number of identifications from the discovery phase. A multilevel filtering strategy together with literature mining is adopted to transmit the most confident candidates along the pipeline. Our results indicate that treating GBM CSCs with GSI induces a phenotype transformation towards non‐tumorigenic cells with decreased proliferation and increased differentiation, as well as elevated apoptosis. Suppressed glucose metabolism and attenuated NFR2‐mediated oxidative stress response are also suggested from our data, possibly due to their crosstalk with Notch Signaling. Overall, this quantitative proteomic‐based dose‐dependent work complements our current understanding of the altered signaling events occurring upon the treatment of GSI in GBM CSCs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88055/1/4529_ftp.pd

Function and Regulation of Vibrio campbellii Proteorhodopsin: Acquired Phototrophy in a Classical Organoheterotroph

Proteorhodopsins (PRs) are retinal-binding photoproteins that mediate light-driven proton translocation across prokaryotic cell membranes. Despite their abundance, wide distribution and contribution to the bioenergy budget of the marine photic zone, an understanding of PR function and physiological significance in situ has been hampered as the vast majority of PRs studied to date are from unculturable bacteria or culturable species that lack the tools for genetic manipulation. In this study, we describe the presence and function of a horizontally acquired PR and retinal biosynthesis gene cluster in the culturable and genetically tractable bioluminescent marine bacterium Vibrio campbellii. Pigmentation analysis, absorption spectroscopy and photoinduction assays using a heterologous over-expression system established the V. campbellii PR as a functional green light absorbing proton pump. In situ analyses comparing PR expression and function in wild type (WT) V. campbellii with an isogenic ΔpR deletion mutant revealed a marked absence of PR membrane localization, pigmentation and light-induced proton pumping in the ΔpR mutant. Comparative photoinduction assays demonstrated the distinct upregulation of pR expression in the presence of light and PR-mediated photophosphorylation in WT cells that resulted in the enhancement of cellular survival during respiratory stress. In addition, we demonstrate that the master regulator of adaptive stress response and stationary phase, RpoS1, positively regulates pR expression and PR holoprotein pigmentation. Taken together, the results demonstrate facultative phototrophy in a classical marine organoheterotrophic Vibrio species and provide a salient example of how this organism has exploited lateral gene transfer to further its adaptation to the photic zone