Identificación de nuevos sistemas de transporte de nitrato-nitrito en la levadura Hansenula polymorpha. Caracterización de NAR1 y CHL1

Esta tesis doctoral está dedicada fundamentalmente a la identificación y caracterización de transportadores de nitrato/nitrito de la levadura H. polymorpha. El uso de las herramientas bioinformáticas nos ha permitido identificar dos proteínas denominadas Nar1 y Chl1 que comparten similitud de secuencia con los respectivos transportadores de nitrito y nitrato descritos en otros organismos. Los resultados del presente trabajo indican que Nar1 es una proteína ubicada en la membrana plasmática que regula la concentración intracelular de nitrito mediante su excreción. De esta forma, las células toman el nitrato del medio principalmente a través del transportador de nitrato y nitrito de alta afinidad, Ynt1. Una vez en el citoplasma, el nitrato se reduce a nitrito, cuyo excedente es devuelto al medio extracelular a través de Nar1, y de otro(s) sistema(s). Pensamos que esto mantiene el nitrito intracelular por debajo de los niveles tóxicos. A su vez, demostramos que los niveles de Ynt1 están regulados por el nitrito presente en el medio de cultivo. Por otra parte, los resultados obtenidos indican que la proteína Chl1 participa en la excreción de aminoácidos, cuando la concentración intracelular del amonio alcanza cotas tóxicas. La acumulación de fuentes reducidas en el interior de las células afectadas en Chl1 disminuyen el grado de activación de la vía calcineurina disminuyendo a su vez los niveles de expresión de los genes de la vía de asimilación de nitrato. En conjunto, estos resultados nos han permitido conocer nuevos elementos que participan en la asimilación de nitrato, si bien ninguno de ellos parece mediar directamente el transporte de nitrato o nitrito al interior de la célul

Lung Transplant Improves Survival and Quality of Life Regardless of Telomere Dysfunction

Trasplante de pulmón; Fibrosis pulmonar; Trastornos de los telómerosTrasplantament pulmonar; Fibrosi pulmonar; Trastorns dels telòmersLung transplantation; Pulmonary fibrosis; Telomere disordersIntroduction: Fibrotic interstitial lung diseases (ILDs) are the first indication for lung transplantation (LT). Telomere dysfunction has been associated with poor post-transplant outcomes. The aim of the study was to evaluate the morbi-mortality and quality of life in fibrotic ILDs after lung transplant depending on telomere biology. Methods: Fibrotic ILD patients that underwent lung transplant were allocated to two arms; with or without telomere dysfunction at diagnosis based on the telomere length and telomerase related gene mutations revealed by whole-exome sequencing. Post-transplant evaluation included: (1) short and long-term mortality and complications and (2) quality of life. Results: Fifty-five percent of patients that underwent LT carried rare coding mutations in telomerase-related genes. Patients with telomere shortening more frequently needed extracorporeal circulation and presented a higher rate of early post-transplant hematological complications, longer stay in the intensive care unit (ICU), and a higher number of long-term hospital admissions. However, post-transplant 1-year survival was higher than 80% regardless of telomere dysfunction, with improvement in the quality of life and oxygen therapy withdrawal. Conclusions: Post-transplant morbidity is higher in patients with telomere dysfunction and differs according to elapsed time from transplantation. However, lung transplant improves survival and quality of life and the associated complications are manageable.This study was funded by Instituto de Salud Carlos III through project PI18/00367 (Co-funded by European Regional Development Fund, ERDF, a way to build Europe), Spanish Society of Respiratory (SEPAR), Barcelona Respiratory Network (BRN), and Fundació Ramón Pla Armengol. RP laboratory was funded by grants PI20-00335 (Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Spain supported by FEDER funds). MM-M was funded by grants PI18/00367 (Fondo de Investigaciones Sanitarias, ISCIII, Spain, supported by FEDER funds), AC19/00006 (Projects of International Programs, ISCIII, Spain, supported by FEDER funds), Cohorte FPI CIBERES-ISCIII, Barcelona Respiratory Network-Fundation Ramon Pla Armengol, Spanish Society of Respiratory (SEPAR), and Catalan Society of Respiratory (SOCAP-FUCAP). CF was funded by Ministerio de Ciencia e Innovación (grant RTC-2017-6471-1; AEI/FEDER, UE), and by Cabildo Insular de Tenerife (CGIEU0000219140)

Genomic epidemiology of the primary methicillin-resistant Staphylococcus aureus clones causing invasive infections in Paraguayan children

Address correspondence to Fátima Rodríguez, [email protected] Staphylococcus aureus (MRSA) is one of the major human pathogens. It could carry numerous resistance genes and virulence factors in its genome, some of which are related to the severity of the infection. An observational, descriptive, cross-sectional study was designed to molecularly analyze MRSA isolates that cause invasive infections in Paraguayan children from 2009 to 2013. Ten representative MRSA isolates of the main clonal complex identified were analyzed with short-read paired-end sequencing and assessed for the virulome, resistome, and phylogenetic relationships. All the genetically linked MRSA isolates were recovered from diverse clinical sources, patients, and hospitals at broad gap periods. The pan-genomic analysis of these clones revealed three major and different clonal complexes (CC30, CC5, and CC8), each composed of clones closely related to each other. The CC30 genomes prove to be a successful clone, strongly installed and disseminated throughout our country, and closely related to other CC30 public genomes from the region and the world. The CC5 shows the highest genetic variability, and the CC8 carried the complete arginine catabolic mobile element (ACME), closely related to the USA300-NAE-ACME+, identified as the major cause of CA-MRSA infections in North America. Multiple virulence and resistance genes were identified for the first time in this study, highlighting the complex virulence profiles of MRSA circulating in the country. This study opens a wide range of new possibilities for future projects and trials to improve the existing knowledge on the epidemiology of MRSA circulating in Paraguay.Consejo Nacional de Ciencia y TecnologíaPrograma Paraguayo para el Desarrollo de la Ciencia y Tecnología. Financiamiento para la vinculación de científicos y tecnólogo

Lung Transplant Improves Survival and Quality of Life Regardless of Telomere Dysfunction

Introduction: Fibrotic interstitial lung diseases (ILDs) are the first indication for lung transplantation (LT). Telomere dysfunction has been associated with poor post-transplant outcomes. The aim of the study was to evaluate the morbi-mortality and quality of life in fibrotic ILDs after lung transplant depending on telomere biology. Methods: Fibrotic ILD patients that underwent lung transplant were allocated to two arms; with or without telomere dysfunction at diagnosis based on the telomere length and telomerase related gene mutations revealed by whole-exome sequencing. Post-transplant evaluation included: (1) short and long-term mortality and complications and (2) quality of life. Results: Fifty-five percent of patients that underwent LT carried rare coding mutations in telomerase-related genes. Patients with telomere shortening more frequently needed extracorporeal circulation and presented a higher rate of early post-transplant hematological complications, longer stay in the intensive care unit (ICU), and a higher number of long-term hospital admissions. However, post-transplant 1-year survival was higher than 80% regardless of telomere dysfunction, with improvement in the quality of life and oxygen therapy withdrawal. Conclusions: Post-transplant morbidity is higher in patients with telomere dysfunction and differs according to elapsed time from transplantation. However, lung transplant improves survival and quality of life and the associated complications are manageable

Transactive Response DNA-Binding Protein (TARDBP/TDP-43) Regulates Cell Permissivity to HIV-1 Infection by Acting on HDAC6

The transactive response DNA-binding protein (TARDBP/TDP-43) influences the processing of diverse transcripts, including that of histone deacetylase 6 (HDAC6). Here, we assessed TDP-43 activity in terms of regulating CD4+ T-cell permissivity to HIV-1 infection. We observed that overexpression of wt-TDP-43 increased both mRNA and protein levels of HDAC6, resulting in impaired HIV-1 infection independently of the viral envelope glycoprotein complex (Env) tropism. Consistently, using an HIV-1 Env-mediated cell-to-cell fusion model, the overexpression of TDP-43 levels negatively affected viral Env fusion capacity. Silencing of endogenous TDP-43 significantly decreased HDAC6 levels and increased the fusogenic and infection activities of the HIV-1 Env. Using pseudovirus bearing primary viral Envs from HIV-1 individuals, overexpression of wt-TDP-43 strongly reduced the infection activity of Envs from viremic non-progressors (VNP) and rapid progressors (RP) patients down to the levels of the inefficient HIV-1 Envs observed in long-term non-progressor elite controllers (LTNP-EC). On the contrary, silencing endogenous TDP-43 significantly favored the infectivity of primary Envs from VNP and RP individuals, and notably increased the infection of those from LTNP-EC. Taken together, our results indicate that TDP-43 shapes cell permissivity to HIV-1 infection, affecting viral Env fusion and infection capacities by altering the HDAC6 levels and associated tubulin-deacetylase anti-HIV-1 activity.This work is supported by the Spanish AIDS network “Red Temática Cooperativa de Investigación en SIDA” RD12/0017/0002, RD12/0017/0028, RD12/0017/0034, RD16/0025/0011, RDCIII16/0002/0005 and RD16/0025/0041 as part of the Plan Nacional R + D+I and co-funded by the Spanish “Instituto de Salud Carlos III (ISCIII)-Subdirección General de Evaluación y el Fondo Europeo de Desarrollo Regional (FEDER)”. J.B. is a researcher from “Fundació Institut de Recerca en Ciències de la Salut Germans Trias i Pujol” supported by the Health Department of the Catalonian Government/Generalitat de Catalunya and ISCIII grant numbers PI17/01318 and PI20/00093 (to J.B.). Work in CC Lab was supported by grants SAF (2010-17226) and (2016-77894-R) from MINECO (Spain), FIS (PI 13/02269, ISCIII) and PI20/00093. Work in CF Lab was supported by the Cabildo Insular de Tenerife (grants CGIEU0000219140 and “Apuestas científicas del ITER para colaborar en la lucha contra la COVID-19”); the agreement with the Instituto Tecnológico y de Energías Renovables (ITER) to strengthen scientific and technological education, training research, development and innovation in Genomics, Personalized Medicine and Biotechnology (grant number OA17/008). A.V.-F.’s Lab is supported by the European Regional Development Fund (ERDF), RTI2018-093747-B-100 (“Ministerio de Ciencia e Innovación”, Spain), “Ministerio de Ciencia, Innovación y Universidades” (Spain), ProID2020010093 (“Agencia Canaria de Investigación, Innovación y Sociedad de la Información” and European Social Fund), UNLL10-3E-783 (ERDF and “Fundación CajaCanarias”) and “SEGAI-ULL”. S.P-Y is funded by “Fundación Doctor Manuel Morales” (La Palma, Spain) and “Contrato Predoctoral Ministerio-ULL Formación de Doctores” (2019 Program) (“Ministerio de Ciencia, Innovación y Universidades”, Spain). R.C.-R. is funded by RD16/0025/0011 and ProID2020010093 (“Agencia Canaria de Investigación, Innovación y Sociedad de la Información” and European Social Fund). J.G.-L. is funded by the “Juan de la Cierva de Incorporación” Spanish Program (IJC2019-038902-I) (“Ayudas Juan de la Cierva de incorporación; Agencia Estatal de Investigación. Ministerio de Ciencia e Innovación”).S

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

PKCα-Mediated Downregulation of RhoA Activity in Depolarized Vascular Smooth Muscle: Synergistic Vasorelaxant Effect of PKCα and ROCK Inhibition

[Background/Aims] Protein kinase C (PKC)- and RhoA/Rho-associated kinase (ROCK) play important roles in arterial sustained contraction. Although depolarization-elicited RhoA/ROCK activation is accepted, the role of PKC in depolarized vascular smooth muscle cells (VSMCs) is a subject of controversy. Our aim was to study the role of PKC in arterial contraction and its interaction with RhoA/ROCK.[Methods] Mass spectrometry was used to identify the PKC isoenzymes. PKCα levels and RhoA activity were analyzed by western blot and G-LISA, respectively, and isometric force was measured in arterial rings.[Results] In depolarized VSMCs RhoA and PKCα were translocated to the plasma membrane, where they colocalize and coimmunoprecipitate. Interestingly, depolarization-induced RhoA activation was downregulated by PKCα, effect reverted by PKCα inhibition. Phorbol 12,13-dibutyrate (PDBu) induced the translocation of PKCα to the plasma membrane, increased the level of RhoA in the cytosol and reduced RhoA/ROCK activity. These effects were reverted when PKC was inhibited. Pharmacological or siRNA inhibition of PKCα synergistically potentiated the vasorelaxant effect of RhoA/ROCK inhibition.[Conclusion] The present study provides the first evidence that RhoA activity is downregulated by PKCα in depolarized and PDBu treated freshly isolated VSMCs and arteries, with an important physiological role on arterial contractility.This work was supported by the "Red de Investigación Cardiovascular, RIC, RD12/0042/0041" of the Instituto de Salud Carlos III and by Ministerio de Economía y Competitividad and FEDER (SAF2013-46806-R and SAF2017-89474-R). WPeer reviewe

PKCα-Mediated Downregulation of RhoA Activity in Depolarized Vascular Smooth Muscle: Synergistic Vasorelaxant Effect of PKCα and ROCK Inhibition

Background/Aims: Protein kinase C (PKC)- and RhoA/Rho-associated kinase (ROCK) play important roles in arterial sustained contraction. Although depolarization-elicited RhoA/ROCK activation is accepted, the role of PKC in depolarized vascular smooth muscle cells (VSMCs) is a subject of controversy. Our aim was to study the role of PKC in arterial contraction and its interaction with RhoA/ROCK. Methods: Mass spectrometry was used to identify the PKC isoenzymes. PKCα levels and RhoA activity were analyzed by western blot and G-LISA, respectively, and isometric force was measured in arterial rings. Results: In depolarized VSMCs RhoA and PKCα were translocated to the plasma membrane, where they colocalize and coimmunoprecipitate. Interestingly, depolarization-induced RhoA activation was downregulated by PKCα, effect reverted by PKCα inhibition. Phorbol 12,13-dibutyrate (PDBu) induced the translocation of PKCα to the plasma membrane, increased the level of RhoA in the cytosol and reduced RhoA/ROCK activity. These effects were reverted when PKC was inhibited. Pharmacological or siRNA inhibition of PKCα synergistically potentiated the vasorelaxant effect of RhoA/ROCK inhibition. Conclusion: The present study provides the first evidence that RhoA activity is downregulated by PKCα in depolarized and PDBu treated freshly isolated VSMCs and arteries, with an important physiological role on arterial contractility

Relation of RhoA in Peripheral Blood Mononuclear Cells With Severity of Aneurysmal Subarachnoid Hemorrhage and Vasospasm.

Rho-kinase, an effector of RhoA, is associated with various cardiovascular diseases in circulating blood cells. However, the role of RhoA/Rho-kinase in peripheral blood mononuclear cells from patients with spontaneous aneurysmal subarachnoid hemorrhage (aSAH) has not yet been studied in relation to the severity of this disease. Therefore, we analyzed the expression and activity of RhoA as a possible biomarker in aSAH. Twenty-four patients with aSAH and 15 healthy subjects were examined. Peripheral blood mononuclear cells were collected, and RhoA activity and expression were determined by RhoA activation assay kit (G-LISA) and enzyme-linked immunosorbent assay tests, respectively. The severity of aSAH was determined from the World Federation of Neurological Surgeon scale, and vasospasm was evaluated using clinical symptoms, arteriography, and sonography. RhoA expression was significantly increased in peripheral blood mononuclear cells from patients on days 0, 2, and 4 after aSAH versus healthy subjects (P=0.036, 0.010, and 0.018, respectively, by U Mann-Whitney analysis). There was a significant correlation between RhoA expression and injury severity on days 2 and 4 (Spearman test, day 2: r=0.682, n=14, P=0.007; day 4: r=0.721, n=14, P=0.004). No significant correlation was observed on day 0 (day 0: r=0.131, n=6, P=0.805). Active RhoA was not significantly different in patients and healthy subjects on days 0, 2, and 4 (P=0.243, 0.222, and 0.600, respectively) nor did it increase significantly on days 0 and 2 in patients with vasospasm versus patients without vasospasm (P=0.064 and 0.519, respectively). In contrast, active RhoA was significantly higher on day 4 in patients who developed vasospasm versus patients without vasospasm (P=0.028). Our preliminary results indicate that RhoA expression and activity in peripheral blood mononuclear cells might be related with aSAH severity and cerebral vasospasm. RhoA is a potential biomarker of the risks associated with aSAH

Sensitivity of different RT-qPCR solutions for SARS-CoV-2 detection

OBJECTIVES: The ongoing COVID-19 pandemic continues to impose demands on diagnostic screening. In anticipation that the recurrence of outbreaks and the measures for lifting the lockdown worldwide may cause supply chain issues over the coming months, this study assessed the sensitivity of a number of one-step retrotranscription and quantitative polymerase chain reaction (RT-qPCR) solutions to detect SARS-CoV-2. METHODS: Six different RT-qPCR alternatives were evaluated for SARS-CoV-2/COVID-19 diagnosis based on standard RNA extractions. The one with best sensitivity was also assessed with direct nasopharyngeal swab viral transmission medium (VTM) heating; thus overcoming the RNA extraction step. RESULTS: A wide variability in the sensitivity of RT-qPCR solutions was found that was associated with a range of false negatives from 2% (0.3–7.9%) to 39.8% (30.2–50.2%). Direct preheating of VTM combined with the best solution provided a sensitivity of 72.5% (62.5–81.0%), in the range of some of the solutions based on standard RNA extractions. CONCLUSIONS: Sensitivity limitations of currently used RT-qPCR solutions were found. These results will help to calibrate the impact of false negative diagnoses of COVID-19, and to detect and control new SARS-CoV-2 outbreaks and community transmissions