1,238 research outputs found
Extracellular cysteine disulfide bond break at Cys122 disrupts PIP2-dependent Kir2.1 channel function and leads to arrhythmias in Andersen-Tawil Syndrome
S
Extracellular Kir2.1C122Y Mutant Upsets Kir2.1-PIP2 Bonds and Is Arrhythmogenic in Andersen-Tawil Syndrome.
BACKGROUND
Andersen-Tawil syndrome type 1 is a rare heritable disease caused by mutations in the gene coding the strong inwardly rectifying K+ channel Kir2.1. The extracellular Cys (cysteine)122-to-Cys154 disulfide bond in the channel structure is crucial for proper folding but has not been associated with correct channel function at the membrane. We evaluated whether a human mutation at the Cys122-to-Cys154 disulfide bridge leads to Kir2.1 channel dysfunction and arrhythmias by reorganizing the overall Kir2.1 channel structure and destabilizing its open state.
METHODS
We identified a Kir2.1 loss-of-function mutation (c.366 A>T; p.Cys122Tyr) in an ATS1 family. To investigate its pathophysiological implications, we generated an AAV9-mediated cardiac-specific mouse model expressing the Kir2.1C122Y variant. We employed a multidisciplinary approach, integrating patch clamping and intracardiac stimulation, molecular biology techniques, molecular dynamics, and bioluminescence resonance energy transfer experiments.
RESULTS
Kir2.1C122Y mice recapitulated the ECG features of ATS1 independently of sex, including corrected QT prolongation, conduction defects, and increased arrhythmia susceptibility. Isolated Kir2.1C122Y cardiomyocytes showed significantly reduced inwardly rectifier K+ (IK1) and inward Na+ (INa) current densities independently of normal trafficking. Molecular dynamics predicted that the C122Y mutation provoked a conformational change over the 2000-ns simulation, characterized by a greater loss of hydrogen bonds between Kir2.1 and phosphatidylinositol 4,5-bisphosphate than wild type (WT). Therefore, the phosphatidylinositol 4,5-bisphosphate-binding pocket was destabilized, resulting in a lower conductance state compared with WT. Accordingly, on inside-out patch clamping, the C122Y mutation significantly blunted Kir2.1 sensitivity to increasing phosphatidylinositol 4,5-bisphosphate concentrations. In addition, the Kir2.1C122Y mutation resulted in channelosome degradation, demonstrating temporal instability of both Kir2.1 and NaV1.5 proteins.
CONCLUSIONS
The extracellular Cys122-to-Cys154 disulfide bond in the tridimensional Kir2.1 channel structure is essential for the channel function. We demonstrate that breaking disulfide bonds in the extracellular domain disrupts phosphatidylinositol 4,5-bisphosphate-dependent regulation, leading to channel dysfunction and defects in Kir2.1 energetic stability. The mutation also alters functional expression of the NaV1.5 channel and ultimately leads to conduction disturbances and life-threatening arrhythmia characteristic of Andersen-Tawil syndrome type 1.The authors thank the Centro Nacional de Investigaciones Cardiovasculares (CNIC)
Viral Vectors Unit for producing the adeno-associated virus serotype 9. Confocal experiments were conducted at the CNIC Microscopy and Dynamic Imaging Unit. The
authors thank the CNIC Bioinformatics Unit for generating the in silico homology
modeling simulations, F-function analysis, and helpful discussions. The authors also
thank the Centro de SupercomputaciĂłn de Galicia for the use of the Finis Terrae III
supercomputer to perform molecular dynamics studies. The CNIC was supported
by the Instituto de Salud Carlos III, the Ministerio de Ciencia, InnovaciĂłn y Universidades, and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence
(grant CEX2020-001041-S funded by MICIU/AEI/10.13039/501100011033).
This work was supported by the National heart, Lung and Blood Institute under
National Institutes of Health (NIH) grant R01HL163943; the La Caixa Banking
Foundation project code HR18-00304 (grant LCF/PR/HR19/52160013); grants
PI-FIS-2020, PI20/01220, PI-FIS-2023, and PI23/01039 from the Instituto de Salud Carlos III and cofunded by the Fondo Europeo de Desarrollo Regional
(FEDER) and the European Union, respectively; grants PID2020-116935RB-I00
and BFU2016-75144-R funded by MICIU/AEI/10.13039/501100011033; the
FundaciĂłn La MaratĂł de TV3 (736/C/2020) amb el suport de la FundaciĂł La MaratĂł
de TV3; the CIBER (Centro de Investigación Biomédica en Red) de Enfermedades
Cardiovasculares (grant CB16/11/00458); the European Unionâs Horizon 2020
grant agreement GA-965286; and the Program S2022/BMD7229-CM ARCADIACM funded by the Comunidad de Madrid to J. Jalife; grant PID2021-126423OB-C22
(to M. MartĂn-MartĂnez) funded by MICIU/AEI/10.13039/501100011033; and European Regional Development Fund (ERDF) grant PID2022-137214OB-C22 (to
M. Gutierrez-RodrĂguez) funded by MICIU/AEI/10.13039/501100011033. The
imaging studies were performed in the TRIMA@CNIC (Infraestructura de Imagen
Traslacional Avanzada del CNIC) node of the ICTS ReDIB (Infraestructuras CientĂficas y TĂ©cnicas Singulares: Red Distribuida de Imagen BiomĂ©dica) grant ICTS-2018-
04-CNIC-16 funded by MICIU/AEI/10.13039/501100011033 and ERDF, and
project EQC2018-005070-P funded by MICIU/AEI/10.13039/501100011033
and FEDER. A.I. Moreno-Manuel holds an formaciĂłn profesional universitaria (FPU)
contract (FPU20/01569) from the Ministerio de Universidades. J.M. Ruiz Robles
holds an FPU contract (FPU22/03253) from the Ministerio de Universidades.
L.K. Gutiérrez holds an FPI contract (PRE2018-083530) from the Ministerio de
EconomĂa y Competitividad de España cofunded by the Fondo Social Europeo, attached to project SEV-2015-0505-18-2. I. MartĂnez-Carrascoso holds a PFIS (Contratos predoctorales de formaciĂłn en investigaciĂłn en salud) contract (FI21/00243)
funded by Instituto de Salud Carlos III and the Fondo Social Europeo Plus cofunded
by the European Union. M.L. Vera-Pedrosa held contract PEJD-2019-PRE/BMD15982 funded by the ConsejerĂa de EducaciĂłn e InvestigaciĂłn de la Comunidad de
Madrid y Fondo Social Europeo.S
Pulmonary Arterial Hypertension Affects the Rat Gut Microbiome
We have analysed whether pulmonary arterial hypertension (PAH) alters the rat faecal microbiota.
Wistar rats were injected with the VEGF receptor antagonist SU5416 (20 mg/kg s.c.) and followed
for 2 weeks kept in hypoxia (10% O2, PAH) or injected with vehicle and kept in normoxia (controls).
Faecal samples were obtained and microbiome composition was determined by 16S rRNA gene
sequencing and bioinformatic analysis. No effect of PAH on the global microbiome was found (α- or
ÎČ-diversity). However, PAH-exposed rats showed gut dysbiosis as indicated by a taxonomy-based
analysis. Specifically, PAH rats had a three-fold increase in Firmicutes-to-Bacteroidetes ratio. Within
the Firmicutes phylum, there were no large changes in the relative abundance of the bacterial families
in PAH. Among Bacteroidetes, all families were less abundant in PAH. A clear separation was observed
between the control and PAH clusters based on short chain fatty acid producing bacterial genera.
Moreover, acetate was reduced in the serum of PAH rats. In conclusion, faecal microbiota composition is
altered as a result of PAH. This misbalanced bacterial ecosystem might in turn play a pathophysiological
role in PAH by altering the immunologic, hormonal and metabolic homeostasis.This study is supported by grants from Mineco (SAF2014-55399-R, SAF2014-55523-R,
SAF2016-77222 and SAF2017-84494-C2-1R), Instituto de Salud Carlos III (PI15/01100), with funds from the
European Union (Fondo Europeo de Desarrollo Regional FEDER). M.C., G.M-P. and S.E-R. are funded by
Universidad Complutense, Fondo de GarantĂa Juvenil (Comunidad de Madrid) and Ciberes grant with funds
from FundaciĂłn Contra la HipertensiĂłn Pulmonar, a FPU grant from Ministerio de EducaciĂłn, respectively.
J.L.I.G is a CNIC IPP COFUND Fellow and has received funding from the People Programme (Marie Curie
Actions) of the FP7/2007-2013 under REA grant agreement n° 600396. The CNIC is supported by MEIC-AEI and
the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (MEIC award SEV-2015-0505)
Yeasts associated with the production of distilled alcoholic beverages
Distilled alcoholic beverages are produced firstly by fermenting sugars emanating from cereal starches (in the case of whiskies), sucrose-rich plants (in the case of rums), fructooligosaccharide-rich plants (in the case of tequila) or from fruits (in the case of brandies). Traditionally, such fermentations were conducted in a spontaneous fashion, relying on indigenous microbiota, including wild yeasts. In modern practices, selected strains of Saccharomyces cerevisiae are employed to produce high levels of ethanol together with numerous secondary metabolites (eg. higher alcohols, esters, carbonyls etc.) which greatly influence the final flavour and aroma characteristics of spirits following distillation of the fermented wash. Therefore, distillers, like winemakers, must carefully choose their yeast strain which will be very important in providing the alcohol content and the sensory profiles of spirit beverages. This Chapter discusses yeast and fermentation aspects associated with the production of selected distilled spirits and highlights similarities and differences with the production of wine
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in âs=13âTeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of âs=13ââTeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139ââfbâ1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015â2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at â s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fbâ1 of â s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Predictores de riesgo en una cohorte española con cardiolaminopatĂas. Registro REDLAMINA
[Abstract]
Introduction and objectives.
According to sudden cardiac death guidelines, an implantable cardioverter-defibrillator (ICD) should be considered in patients with LMNA-related dilated cardiomyopathy (DCM) and â„ 2 risk factors: male sex, left ventricular ejection fraction (LVEF) < 45%, nonsustained ventricular tachycardia (NSVT), and nonmissense genetic variants. In this study we aimed to describe the clinical characteristics of carriers of LMNA genetic variants among individuals from a Spanish cardiac-laminopathies cohort (REDLAMINA registry) and to assess previously reported risk criteria.
Methods.
The relationship between risk factors and cardiovascular events was evaluated in a cohort of 140 carriers (age â„ 16 years) of pathogenic LMNA variants (54 probands, 86 relatives). We considered: a) major arrhythmic events (MAE) if there was appropriate ICD discharge or sudden cardiac death; b) heart failure death if there was heart transplant or death due to heart failure.
Results.
We identified 11 novel and 21 previously reported LMNA-related DCM variants. LVEF < 45% (P = .001) and NSVT (P < .001) were related to MAE, but not sex or type of genetic variant. The only factor independently related to heart failure death was LVEF < 45% (P < .001).
Conclusions.
In the REDLAMINA registry cohort, the only predictors independently associated with MAE were NSVT and LVEF < 45%. Therefore, female carriers of missense variants with either NSVT or LVEF < 45% should not be considered a low-risk group. It is important to individualize risk stratification in carriers of LMNA missense variants, because not all have the same prognosis.[Resumen]
IntroducciĂłn y objetivos.
SegĂșn las guĂas de muerte sĂșbita, se debe considerar un desfibrilador automĂĄtico implantable (DAI) para los pacientes con miocardiopatĂa dilatada debida a variantes en el gen de la lamina (LMNA) con al menos 2 factores: varones, fracciĂłn de eyecciĂłn del ventrĂculo izquierdo (FEVI) < 45%, taquicardia ventricular no sostenida (TVNS) y variantes no missense. Nuestro objetivo es describir las caracterĂsticas clĂnicas de una cohorte española de pacientes con cardiolaminopatĂas (registro REDLAMINA) y evaluar los criterios de riesgo vigentes.
MĂ©todos.
Se evaluĂł la relaciĂłn entre factores de riesgo y eventos cardiovasculares en una cohorte de 140 portadores de variantes en LMNA (54 probandos, 86 familiares, edad â„ 16 años). Se considerĂł: a) evento arrĂtmico mayor (EAM) si hubo descarga apropiada del DAI o muerte sĂșbita, y b) muerte por insuficiencia cardiaca, incluidos los trasplantes.
Resultados.
Se identificaron 11 variantes nuevas y 21 previamente publicadas. La FEVI < 45% (p = 0,001) y la TVNS (p < 0,001) se relacionaron con los EAM, pero no el sexo o el tipo de variante (missense frente a no missense). La FEVI < 45% (p < 0,001) fue el Ășnico factor relacionado con la muerte por insuficiencia cardiaca.
Conclusiones.
En el registro REDLAMINA, los Ășnicos 2 predictores asociados con EAM fueron la TVNS y la FEVI < 45%. No se deberĂa considerar grupo de bajo riesgo a las portadoras de variantes missense con TVNS o FEVI < 45%. Es importante individualizar la estratificaciĂłn del riesgo de los portadores de variantes missense en LMNA, porque no todas tienen el mismo pronĂłstico.This study received a grant from the Proyecto de investigaciĂłn de la SecciĂłn de Insuficiencia Cardiaca 2017 from the Spanish Society of Cardiology and grants from the Instituto de Salud Carlos III (ISCIII) [PI14/0967, PI15/01551, AC16/0014] and ERA-CVD Joint Transnational Call 2016 (Genprovic). Grants from the ISCIII and the Ministerio de EconomĂa y Competitividad de España (Spanish Department of Economy and Competitiveness) are supported by the Plan Estatal de I+D+i 2013-2016: Fondo Europeo de Desarrollo Regional (FEDER) âUna forma de hacer Europaâ
Natural History of MYH7-Related Dilated Cardiomyopathy
BACKGROUND: Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVE: We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS: We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 ± 19.2 years) recruited from 29 international centers. RESULTS: At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% ± 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of â€35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS: MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare
A modern network approach to revisiting the positive and negative affective schedule (PANAS) construct validity
Introduction: The factor structure of the Positive and Negative Affective Schedule (PANAS) is still a topic of debate. There are several reasons why using Exploratory Graph Analysis (EGA) for scale validation is advantageous and can help understand and resolve conflicting results in the factor analytic literature. Objective: The main objective of the present study was to advance the knowledge regarding the factor structure underlying the PANAS scores by utilizing the different functionalities of the EGA method. EGA was used to (1) estimate the dimensionality of the PANAS scores, (2) establish the stability of the dimensionality estimate and of the item assignments into the dimensions, and (3) assess the impact of potential redundancies across item pairs on the dimensionality and structure of the PANAS scores. Method: This assessment was carried out across two studies that included two large samples of participants. Results and Conclusion: In sum, the results are consistent with a two-factor oblique structure.Fil: Flores Kanter, Pablo Ezequiel. Universidad Empresarial Siglo XXI; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Garrido, Luis Eduardo. Pontificia Universidad CatĂłlica Madre y Maestra; RepĂșblica DominicanaFil: Moretti, Luciana SofĂa. Universidad Empresarial Siglo XXI; Argentina. Pontificia Universidad CatĂłlica Madre y Maestra; RepĂșblica Dominicana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Medrano, Leonardo. Universidad Empresarial Siglo XXI; Argentina. Pontificia Universidad CatĂłlica Madre y Maestra; RepĂșblica Dominicana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
PrĂĄticas e significados de saĂșde bucal: um estudo qualitativo com mĂŁes de crianças atendidas na Universidade Federal de Santa Catarina
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