An Epilepsy-Causing Mutation Leads to Co-Translational Misfolding of the Kv7.2 Channel

BACKGROUND: The amino acid sequence of proteins generally carries all the necessary information for acquisition of native conformations, but the vectorial nature of translation can additionally determine the folding outcome. Such consideration is particularly relevant in human diseases associated to inherited mutations leading to structural instability, aggregation, and degradation. Mutations in the KCNQ2 gene associated with human epilepsy have been suggested to cause misfolding of the encoded Kv7.2 channel. Although the effect on folding of mutations in some domains has been studied, little is known of the way pathogenic variants located in the calcium responsive domain (CRD) affect folding. Here, we explore how a Kv7.2 mutation (W344R) located in helix A of the CRD and associated with hereditary epilepsy interferes with channel function. RESULTS: We report that the epilepsy W344R mutation within the IQ motif of CRD decreases channel function, but contrary to other mutations at this site, it does not impair the interaction with Calmodulin (CaM) in vitro, as monitored by multiple in vitro binding assays. We find negligible impact of the mutation on the structure of the complex by molecular dynamic computations. In silico studies revealed two orientations of the side chain, which are differentially populated by WT and W344R variants. Binding to CaM is impaired when the mutated protein is produced in cellulo but not in vitro, suggesting that this mutation impedes proper folding during translation within the cell by forcing the nascent chain to follow a folding route that leads to a non-native configuration, and thereby generating non-functional ion channels that fail to traffic to proper neuronal compartments. CONCLUSIONS: Our data suggest that the key pathogenic mechanism of Kv7.2 W344R mutation involves the failure to adopt a configuration that can be recognized by CaM in vivo but not in vitroThe Government of the Autonomous Community of the Basque Country (IT1165-19 and KK-2020/00110) and the Spanish Ministry of Science and Innovation (RTI2018-097839-B-100 to A.V. and FIS2016-76617-P to A.B.) and FEDER funds and the US National Institute of Neurological Disorders (NINDS) and Stroke Research Project Grant (R01NS083402 to H.J.C.) provided financial support for this work. E.N. and A.M-M. are supported by predoctoral contracts from the Basque Government administered by University of the Basque Country. C.M. was supported by the Basque Government through a Basque Excellence Research Centre (BERC) grant administered by Fundación Biofisika Bizkaia (FBB). J.U. was partially supported by BERC funds. O.R.B. was supported by the Basque Government through a BERC grant administered by Donostia International Physics Center. J.Z. and H.J.C. was supported by the NINDS Research Project Grant #R01NS083402 (PI: H.J.C.)

Guía de práctica clínica SENPE/SEGHNP/SEFH sobre nutrición parenteral pediátrica

Introduction: Parenteral nutrition (PN) in childhood is a treatment whose characteristics are highly variable depending on the age and pathology of the patient. Material and methods: The Standardization and Protocols Group of the Spanish Society for Parenteral and Enteral Nutrition (SENPE) is an interdisciplinary group formed by members of the SENPE, the Spanish Society of Gastroenterology, Hepatology and Pediatric Nutrition (SEGHNP) and the Spanish Society of Hospital Pharmacy (SEFH) that intends to update this issue. For this, a detailed review of the literature has been carried out, looking for the evidences that allow us to elaborate a Clinical Practice Guide following the criteria of the Oxford Center for Evidence-Based Medicine. Results: This manuscript summarizes the recommendations regarding indications, access routes, requirements, modifications in special situations, components of the mixtures, prescription and standardization, preparation, administration, monitoring, complications and home NP. The complete document is published as a monographic number. Conclusions: This guide is intended to support the prescription of pediatric PN. It provides the basis for rational decisions in the context of the existing evidence. No guidelines can take into account all of the often compelling individual clinical circumstances.Introducción: la nutrición parenteral (NP) en la infancia es un tratamiento cuyas características son muy variables en función de la edad y la patología que presente el paciente. Material y métodos: el grupo de Estandarización y Protocolos de la Sociedad Española de Nutrición Parenteral y Enteral (SENPE) es un grupo interdisciplinar formado por miembros de la SENPE, Sociedad Española de Gastroenterología, Hepatología y Nutrición Pediátrica (SEGHNP) y Sociedad Española de Farmacia Hospitalaria (SEFH) que pretende poner al día este tema. Para ello, se ha realizado una revisión pormenorizada de la literatura buscando las evidencias que nos permiten elaborar una Guía de Práctica Clínica siguiendo los criterios del Oxford Centre for Evidence-Based Medicine. Resultados: este manuscrito expone de forma resumida las recomendaciones en cuanto a indicaciones, vías de acceso, requerimientos, modificaciones en situaciones especiales, componentes de las mezclas, prescripción y estandarización, preparación, administración, monitorización, complicaciones y NP domiciliaria. El documento completo se publica como número monográfico. Conclusiones: esta guía pretende servir de apoyo para la prescripción de la NP pediátrica. Constituye la base para tomar decisiones en el contexto de la evidencia existente. Ninguna guía puede tener en cuenta todas las circunstancias clínicas individuale

Surface Expression and Subunit Specific Control of Steady Protein Levels by the Kv7.2 Helix A-B Linker

12 p.Kv7.2 and Kv7.3 are the main components of the neuronal voltage-dependent M-current, which is a subthreshold potassium conductance that exerts an important control on neuronal excitability. Despite their predominantly intracellular distribution, these channels must reach the plasma membrane in order to control neuronal activity. Thus, we analyzed the amino acid sequence of Kv7.2 to identify intrinsic signals that may control its surface expression. Removal of the interlinker connecting helix A and helix B of the intracellular C-terminus produces a large increase in the number of functional channels at the plasma membrane. Moreover, elimination of this linker increased the steady-state amount of protein, which was not associated with a decrease of protein degradation. The magnitude of this increase was inversely correlated with the number of helix A - helix B linkers present in the tetrameric channel assemblies. In contrast to the remarkable effect on the amount of Kv7.2 protein, removal of the Kv7.2 linker had no detectable impact on the steady-state levels of Kv7.3 protein.This work was supported by grants from the VII European framework program managed by the Fondo de Investigaciones Sanitarias (PI071316), from the Spanish Ministry of Education (BFU2009-07581 and SAF2006-1450), the Spanish Ion Channel Initiative Consolider project (CSD2008-00005), and the Basque Government (SAIOTEK SA-2006/00023). A. Alaimo was partially funded by Fundacion Biofisica Bizkaia. PA and JFO held a FPI fellowship from the Spanish Ministry of Science and Innovation (BES-2008-002314). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

Pivoting between Calmodulin Lobes Triggered by Calcium in the Kv7.2/Calmodulin Complex

Kv7.2 (KCNQ2) is the principal molecular component of the slow voltage gated M-channel, which strongly influences neuronal excitability. Calmodulin (CaM) binds to two intracellular C-terminal segments of Kv7.2 channels, helices A and B, and it is required for exit from the endoplasmic reticulum. However, the molecular mechanisms by which CaM controls channel trafficking are currently unknown. Here we used two complementary approaches to explore the molecular events underlying the association between CaM and Kv7.2 and their regulation by Ca2+. First, we performed a fluorometric assay using dansylated calmodulin (D-CaM) to characterize the interaction of its individual lobes to the Kv7.2 CaM binding site (Q2AB). Second, we explored the association of Q2AB with CaM by NMR spectroscopy, using N-15-labeled CaM as a reporter. The combined data highlight the interdependency of the N- and C-lobes of CaM in the interaction with Q2AB, suggesting that when CaM binds Ca2+ the binding interface pivots between the N-lobe whose interactions are dominated by helix B and the C-lobe where the predominant interaction is with helix A. In addition, Ca2+ makes CaM binding to Q2AB more difficult and, reciprocally, the channel weakens the association of CaM with Ca2+.This work was supported by grants from the Spanish Ministry of Education (BFU2012-39883 and BFU2009-07581), the Spanish Ion Channel Initiative Consolider project (CSD2008-00005), and the Basque Government (SAIOTEK SA-2006/00023 and 304211ENA9). A. Alaimo and C. Malo were partially funded by Fundacion Biofisica Bizkaia. J. Fernandez-Orth held a FPI fellowship from the Spanish Ministry of Science and Innovation (BES-2008-002314). A. Alberdi holds a JAE-predoctoral CSIC fellowship cofinanced with European Social Funds. G. Bernardo-Seisdedos holds a fellowship from the Basque Country Government (BFI-2011-159). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Targeted immunotherapy against distinct cancer-associated fibroblasts overcomes treatment resistance in refractory HER2+ breast tumors

About 50% of human epidermal growth factor receptor 2 (HER2)+ breast cancer patients do not benefit from HER2-targeted therapy and almost 20% of them relapse after treatment. Here, we conduct a detailed analysis of two independent cohorts of HER2+ breast cancer patients treated with trastuzumab to elucidate the mechanisms of resistance to anti-HER2 monoclonal antibodies. In addition, we develop a fully humanized immunocompetent model of HER2+ breast cancer recapitulating ex vivo the biological processes that associate with patients' response to treatment. Thanks to these two approaches, we uncover a population of TGF-beta-activated cancer-associated fibroblasts (CAF) specific from tumors resistant to therapy. The presence of this cellular subset related to previously described myofibroblastic (CAF-S1) and podoplanin+ CAF subtypes in breast cancer associates with low IL2 activity. Correspondingly, we find that stroma-targeted stimulation of IL2 pathway in unresponsive tumors restores trastuzumab anti-cancer efficiency. Overall, our study underscores the therapeutic potential of exploiting the tumor microenvironment to identify and overcome mechanisms of resistance to anti-cancer treatment

Les competències transversals als graus dels Estudis d'Economia i Empresa de la UOC : guia d'aplicació, febrer 2013

Competencias transversales en los Estudios de Economía y Empresa de la UOC. Guía de aplicación.Competències transversals en els Estudis d'Economia i Empresa de la UOC. Guia d'aplicació.Transversal skills in the Economics and Business studies of the UOC. Practical guide

Les competències transversals als graus dels Estudis d'Economia i Empresa de la UOC : guia d'aplicació, febrer 2013

Competencias transversales en los Estudios de Economía y Empresa de la UOC. Guía de aplicación.Competències transversals en els Estudis d'Economia i Empresa de la UOC. Guia d'aplicació.Transversal skills in the Economics and Business studies of the UOC. Practical guide

Le désenchantement de la carte. Récit d’aventures

Competencias transversales en los Estudios de Economía y Empresa de la UOC. Guía de aplicación.Competències transversals en els Estudis d'Economia i Empresa de la UOC. Guia d'aplicació.Transversal skills in the Economics and Business studies of the UOC. Practical guide

Las competencias transversales en los grados de los Estudios de Economía y Empresa de la UOC : guía de aplicación, febrero 2013

Competencias transversales en los Estudios de Economía y Empresa de la UOC. Guía de aplicación.Competències transversals en els Estudis d'Economia i Empresa de la UOC. Guia d'aplicació.Transversal skills in the Economics and Business studies of the UOC. Practical guide

Pseudomonas aeruginosa antibiotic susceptibility profiles, genomic epidemiology and resistance mechanisms: a nation-wide five-year time lapse analysisResearch in context

Summary: Background: Pseudomonas aeruginosa healthcare-associated infections are one of the top antimicrobial resistance threats world-wide. In order to analyze the current trends, we performed a Spanish nation-wide high-resolution analysis of the susceptibility profiles, the genomic epidemiology and the resistome of P. aeruginosa over a five-year time lapse. Methods: A total of 3.180 nonduplicated P. aeruginosa clinical isolates from two Spanish nation-wide surveys performed in October 2017 and 2022 were analyzed. MICs of 13 antipseudomonals were determined by ISO-EUCAST. Multidrug resistance (MDR)/extensively drug resistance (XDR)/difficult to treat resistance (DTR)/pandrug resistance (PDR) profiles were defined following established criteria. All XDR/DTR isolates were subjected to whole genome sequencing (WGS). Findings: A decrease in resistance to all tested antibiotics, including older and newer antimicrobials, was observed in 2022 vs 2017. Likewise, a major reduction of XDR (15.2% vs 5.9%) and DTR (4.2 vs 2.1%) profiles was evidenced, and even more patent among ICU isolates [XDR (26.0% vs 6.0%) and DTR (8.9% vs 2.6%)] (p < 0.001). The prevalence of Extended-spectrum β-lactamase/carbapenemase production was slightly lower in 2022 (2.1%. vs 3.1%, p = 0.064). However, there was a significant increase in the proportion of carbapenemase production among carbapenem-resistant strains (29.4% vs 18.1%, p = 0.0246). While ST175 was still the most frequent clone among XDR, a slight reduction in its prevalence was noted (35.9% vs 45.5%, p = 0.106) as opposed to ST235 which increased significantly (24.3% vs 12.3%, p = 0.0062). Interpretation: While the generalized decrease in P. aeruginosa resistance, linked to a major reduction in the prevalence of XDR strains, is encouraging, the negative counterpart is the increase in the proportion of XDR strains producing carbapenemases, associated to the significant advance of the concerning world-wide disseminated hypervirulent high-risk clone ST235. Continued high-resolution surveillance, integrating phenotypic and genomic data, is necessary for understanding resistance trends and analyzing the impact of national plans on antimicrobial resistance. Funding: MSD and the Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea—NextGenerationEU