Modelos de toxicidad inducidos por microsatélites CAG y caracterización de dianas terapéuticas en C. elegans

[ES] El equilibrio de la homeostasis de proteínas es esencial para asegurar la funcionalidad celular. La expresión de proteínas propensas a plegarse mal induce la formación de agregados tóxicos que alteran el correcto funcionamiento de estos sistemas de control, lo que conduce a un desequilibrio de la homeostasis de proteínas, y por consiguiente a una afectación patológica. Varias enfermedades neurodegenerativas, como la enfermedad de Huntington (EH), Parkinson, Alzheimer, entre otras, tienen en común esta marca patológica molecular. Especialmente, la EH pertenece a un grupo de patologías producidas por proteínas que contienen expansiones de poliQs (varias ataxias espinocerebelosas, la atrofia muscular bulbar y espinal y la atrofia dentatorubro-pálidoluisiana), que hacen que estos péptidos sean propensos a la agregación, y causen los problemas que hemos descrito. A pesar de que estas enfermedades son genéticas, y se conoce su causa molecular, se cree que la presencia de variantes alélicas en otros genes puede exacerbar o ralentizar la agregación de proteínas con poliQs. Por tanto, la identificación de estos genes permitirá profundizar en los mecanismos moduladores de la dinámica de agregación de poliQs e identificar dianas terapéuticas frente a la toxicidad de poliQs. También es ampliamente conocido que el ARN que porta tripletes CAG tiene carácter patogénico. En este trabajo hemos desarrollado modelos, empleando C. elegans, que muestran signos indirectos de que están expresando transcritos CAG patogénicos, puesto que los tejidos diana están alterados. Usamos uno de estos modelos, que perturba la función de las neuronas GABAérgicas del gusano, para realizar un cribado de 85 compuestos farmacológicos, que nos llevó a identificar cuatro compuestos que reducían los defectos motores en estos animales. Además de poliQs y transcritos CAG, también se producen péptidos derivados de una traducción no canónica, conocida como traducción RAN. En relación a esto, hemos profundizado en la identificación y modelización de estos péptidos en C. elegans mediante la expresión de expansiones CAG fusionadas a proteínas fluorescentes para su detección in vivo. Además hemos empleado otros modelos ya existentes, para caracterizar potenciales dianas terapéuticas, como AMPK, la cual puede ser activada por diferentes sustancias. Sin embargo, algunas sustancias, como la metformina o el salicilato, son pleiotrópicas. Por tanto, hemos caracterizado la activación sinérgica de AMPK, mediante metformina y salicilato, para reducir el estrés por agregados de poliQs, con lo que podríamos evitar que otras dianas resulten activadas. Por último, hemos demostrado que este tratamiento sinérgico reduce la toxicidad inducida por la α -sinucleína implicada en la enfermedad de Parkinson. Por otro lado, hemos caracterizado en C. elegans un nuevo alelo que potencia la la agregación de poliQs, vlt10, en el gen unc-1. Nuestros resultados sugieren que la mutación unc-1(vlt10) perturba la sinapsis eléctrica entre las neuronas sensoriales IL2 y ASJ, induciendo un exceso de señalización hormonal que requiere la función de la sulfotransferasa SSU-1. También hemos demostrado que la diana de esta señal es un receptor nuclear llamado NHR-1. En este mismo capítulo, hemos identificado otra ruta de señalización hormonal, mediada por otro receptor nuclear (DAF-12), que tiene un papel protector. Se desconoce qué hormona modula la actividad de NHR-1. Sin embargo, hemos identificado que algunos de los genes regulados por NHR-1 están relacionados con el metabolismo lipídico. Además, hemos observado que la disrupción de unc-1 induce la acumulación de lípidos en los gusanos, pero a la vez estos animales contienen menos ácidos grasos totales. Esto sugiere que las grasas juegan un papel fundamental en la modulación de la agregación de poliQs, y quizás señala posibles dianas terapéuticas contra enfermedades causadas[CA] L'equilibri de l'homeòstasi de proteïnes és essencial per a assegurar la funcionalitat cel·lular. L'expressió de proteïnes propenses a plegar-se malament indueix la formació d'agregats tòxics i altera el correcte funcionament dels sistemes de control, cosa que condueix a un desequilibri de l'homeòstasi de proteïnes, i per consegüent a una afectació patològica. Diverses malalties neurodegeneratives, com la malaltia de Huntington (MH), Parkinson i Alzheimer, entre altres, tenen en comú aquesta signatura patològica. Especialment, la MH pertany a un grup de patologies produïdes per proteïnes que contenen expansions de poliQs (s'inclouen diverses atàxies espinocerebel·loses 1, 2, 3, 6, 7 i 17, l'atròfia muscular bulbar i espinal, i l'atròfia dentatorúbrica-pàl·lidaluisiana), que fan que aquests pèptids siguen propensos a l'agregació, i causen els problemes que hem descrit. Malgrat que aquestes malalties són genètiques i es coneix la seva causa molecular, es creu que la presència de variants al·lèliques en gens pot incrementar o alentir l'agregació de proteïnes amb poliQs. Per tant, la identificació de gens modificadors permet aprofundir en els mecanismes moduladors de la dinàmica d'agregació de poliQs ens permet trobar dianes terapèutiques enfront de la toxicitat de poliQs. També és àmpliament conegut que l'ARN que contenen expansions CAG té caràcter patogènic. Per tant, hem desenvolupat models, utilitzant C. elegans, en els quals es mostren signes indirectes que expressen transcrits patogènics, ja que els teixits diana revelen una funcionalitat alterada. Utilitzant aquests models, que alteren la funció de les neurones GABAèrgiques del cuc, hem realitzat un cribratge de 85 compostos farmacològics, que ens va portar a identificar quatre compostos que reduïen els defectes motors en aquests animals. A més de poliQs i l'ARN que conté expansions de CAG, es produeixen pèptids derivats d'una traducció no canònica, coneguda com a traducció RAN. En relació amb això, hem aprofundit en la identificació i modelització d'aquests pèptids en C. elegans mitjançant l'expressió d'expansions CAG fusionades a proteïnes fluorescents per a la seva detecció in vivo. A més hem emprat models ja generats, per a caracteritzar potencials dianes terapèutiques, com AMPK puga ser activat per diversos fàrmacs. No obstant això, alguns activadors, com la metformina o el salicilat, són substàncies pleiotròpiques. Per tant, hem caracteritzat l'activació sinèrgic de AMPK, mitjançant metformina i salicilat, per a reduir l'estrés induït per agregats de poliQs i s'evita l'activació de dianes no desitjades. I finalment, hem demostrat que aquest tractament sinèrgic podria ser utilitzat per a reduir proteïnes tòxiques com la α-sinucleína, causant de la malaltia de Parkinson. D'altra banda, hem caracteritzat un nou modulador de l'agregació de poliQs, vlt10, en el gen unc-1, que produeix un augment d'agregació de poliQs. Els nostres resultats suggereixen que la mutació unc-1(vlt10) pertorba la sinapsi elèctrica entre les neurones sensorials IL2 i ASJ, induint un excés de senyalització hormonal que requereix la funció de la sulfotransferasa SSU-1. També hem demostrat que la diana d'aquest senyal és un receptor nuclear anomenat NHR-1. En el mateix capítol, hem identificat una altra ruta de senyalització hormonal, mitjançada per un altre receptor nuclear (DAF-12), que té un paper protector. Es desconeix l'hormona que modula l'activitat de NHR-1. No obstant això, hem identificat que alguns del genes regulats per NHR-1 estan relacionats amb el metabolisme lipídic. els resultats han sigut confirmats. També hem observat que la disrupció de unc-1 indueix l'acumulació de lípids en els cucs, però simultàniament aquests animals contenen menys àcids grassos totals. Això suggereix que els greixos juguen un paper fonamental en la modulació de l'agregació de poliQs, i potser assenyala[EN] The balance of protein homeostasis is essential to ensure cellular functionality. The expression of proteins that are prone to misfolding induces the formation of toxic aggregates, which leads to an imbalance in protein homeostasis and pathological consequences. Several neurodegenerative diseases, such as Huntington disease (HD), Parkinson, Alzheimer, among others, have this molecular pathological mark in common. HD belongs to a group of pathologies produced by proteins that contain expansions of polyQs (several spinocerebellar ataxias 1, 2, 3, 6, 7 and 17, bulbar and spinal muscular atrophy and the dentatorubral-pallidoluysian atrophy), which make these peptides prone to aggregation, and cause the problems described above. Although these diseases are genetic, and their molecular cause is known, it is believed that the presence of allelic variants in other genes can exacerbate or slow the polyQ aggregation. Therefore, the identification of these genes will allow delving into the modulating mechanisms of the polyQ aggregation dynamics and find therapeutic targets against the polyQ toxicity. In addition, RNA that contains CAG triplets is pathogenic. In this work we have developed models using C. elegans that show indirect signs of pathogenic transcript expression since altered functionality was observed in target tissues. We use a model, which disturbs the function of the worm's GABAergic neurons, to screen for 85 pharmacological compounds, which led us to identify four compounds that reduced motor defects in these animals. In addition to polyQs and CAG transcripts, also are produced peptides derived from a non-canonical translation, known as RAN translation. In this regard, we have delved into the identification and modelling of these peptides in C. elegans through the expression of CAG expansions fused to fluorescent proteins to investigate them in vivo. Furthermore, we have used models previously generated to characterize potential therapeutic targets, such as AMPK. This enzyme can be activated using different compounds. However, some activators, such as metformin or salicylate, are pleiotropic substances. Therefore, in the second chapter of this thesis, we have characterised the synergistic activation of AMPK, using metformin and salicylate, to reduce the stress induced by polyQ aggregates and prevent possible unwanted targets from being activated. Finally, we have shown that this synergistic treatment could be used to reduce α-synuclein toxicity, which is involved in Parkinson disease. On the other hand, we have characterised a new allele that enhances polyQ aggregation, vlt10, in the unc-1 gene. Our results suggest that the unc-1(vlt10) mutation disturbs the electrical synapse between sensory neurons IL2 and ASJ, inducing an excess of hormonal signalling that requires the function of the sulfotransferase SSU-1. We have also shown that the target of this signal is the nuclear receptor NHR-1. In the same chapter, we have identified another hormonal signalling pathway, mediated by another nuclear receptor (DAF-12), which has a protective role. It is unknown which hormone modulates the activity of NHR-1. However, we have identified several genes that regulate lipid metabolism and whose expression could be modulated by NHR-1. In addition, we have observed that the disruption of unc-1 induces the accumulation of lipids in worms, but at the same time these animals contain less total fatty acids. Thus, our results suggest that the metabolism of fats play a key role in modulating polyQs aggregation, highlighting potential therapeutic targets against diseases caused by aggregation-prone proteins.Gómez Escribano, AP. (2021). Modelos de toxicidad inducidos por microsatélites CAG y caracterización de dianas terapéuticas en C. elegans [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/166783TESI

Multiview motion tracking based on a cartesian robot to monitor Caenorhabditis elegans in standard Petri dishes

[EN] Data from manual healthspan assays of the nematode Caenorhabditis elegans (C. elegans) can be complex to quantify. The first attempts to quantify motor performance were done manually, using the so-called thrashing or body bends assay. Some laboratories have automated these approaches using methods that help substantially to quantify these characteristic movements in small well plates. Even so, it is sometimes difficult to find differences in motor behaviour between strains, and/or between treated vs untreated worms. For this reason, we present here a new automated method that increases the resolution flexibility, in order to capture more movement details in large standard Petri dishes, in such way that those movements are less restricted. This method is based on a Cartesian robot, which enables high-resolution images capture in standard Petri dishes. Several cameras mounted strategically on the robot and working with different fields of view, capture the required C. elegans visual information. We have performed a locomotion-based healthspan experiment with several mutant strains, and we have been able to detect statistically significant differences between two strains that show very similar movement patterns.This work was supported by the research agency of the Spanish Ministry of Science and Innovation under Grant RTI2018-094312-B-I00 (European FEDER funds).Puchalt-Rodríguez, JC.; González-Rojo, JF.; Gómez-Escribano, AP.; Vázquez-Manrique, RP.; Sánchez Salmerón, AJ. (2022). Multiview motion tracking based on a cartesian robot to monitor Caenorhabditis elegans in standard Petri dishes. Scientific Reports. 12(1):1-11. https://doi.org/10.1038/s41598-022-05823-611112

Clinical Heterogeneity of Pulmonary Arterial Hypertension Associated With Variants in TBX4

Background: The knowledge of hereditary predisposition has changed our understanding of Pulmonary Arterial Hypertension. Genetic testing has been widely extended and the application of Pulmonary Arterial Hypertension specific gene panels has allowed its inclusion in the diagnostic workup and increase the diagnostic ratio compared to the traditional sequencing techniques. This is particularly important in the differential diagnosis between Pulmonary Arterial Hypertension and Pulmonary Venoocclusive Disease. Methods: Since November 2011, genetic testing is offered to all patients with idiopathic, hereditable and associated forms of Pulmonary Arterial Hypertension or Pulmonary Venoocclusive Disease included in the Spanish Registry of Pulmonary Arterial Hypertension. Herein, we present the clinical phenotype and prognosis of all Pulmonary Arterial Hypertension patients with disease-associated variants in TBX4. Results: Out of 579 adults and 45 children, we found in eight patients from seven families, disease-causing associated variants in TBX4. All adult patients had a moderate-severe reduction in diffusion capacity. However, we observed a wide spectrum of clinical presentations, including Pulmonary Venoocclusive Disease suspicion, interstitial lung disease, pulmonary vascular abnormalities and congenital heart disease. Conclusions: Genetic testing is now essential for a correct diagnosis work-up in Pulmonary Arterial Hypertension. TBX4-associated Pulmonary Arterial Hypertension has marked clinical heterogeneity. In this regard, a genetic study is extremely useful to obtain an accurate diagnosis and provide appropriate management.This project was founded by Project "Bases Gene´tico Moleculares de la Medicina de Precisio´n en la Hipertensio´n Arterial Pulmonar". Funder: Instituto Carlos III. Ministerio de Economı´a y Competitividad. https://www.isciii.es/Paginas/Inicio.aspx Award number: PI 18/01233 Grant Recipient: P E-

Persistent Pulmonary Hypertension in Corrected Valvular Heart Disease: Hemodynamic Insights and Long-Term Survival.

Background The determinants and consequences of pulmonary hypertension after successfully corrected valvular heart disease remain poorly understood. We aim to clarify the hemodynamic bases and risk factors for mortality in patients with this condition. Methods and Results We analyzed long-term follow-up data of 222 patients with pulmonary hypertension and valvular heart disease successfully corrected at least 1 year before enrollment who had undergone comprehensive hemodynamic and imaging characterization as per the SIOVAC (Sildenafil for Improving Outcomes After Valvular Correction) clinical trial. Median (interquartile range) mean pulmonary pressure was 37 mm Hg (32-44 mm Hg) and pulmonary artery wedge pressure was 23 mm Hg (18-26 mm Hg). Most patients were classified either as having combined precapillary and postcapillary or isolated postcapillary pulmonary hypertension. After a median follow-up of 4.5 years, 91 deaths accounted for 4.21 higher-than-expected mortality in the age-matched population. Risk factors for mortality were male sex, older age, diabetes mellitus, World Health Organization functional class III and higher pulmonary vascular resistance-either measured by catheterization or approximated from ultrasound data. Higher pulmonary vascular resistance was related to diabetes mellitus and smaller residual aortic and mitral valve areas. In turn, the latter correlated with prosthetic nominal size. Six-month changes in the composite clinical score and in the 6-minute walk test distance were related to survival. Conclusions Persistent valvular heart disease-pulmonary hypertension is an ominous disease that is almost universally associated with elevated pulmonary artery wedge pressure. Pulmonary vascular resistance is a major determinant of mortality in this condition and is related to diabetes mellitus and the residual effective area of the corrected valve. These findings have important implications for individualizing valve correction procedures. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00862043.This study was funded by the Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación, Spain, the European Union–European Regional Development Fund (EC07/90772 and PI19/00649), and the Consorcio de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV).S

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Association Between Preexisting Versus Newly Identified Atrial Fibrillation and Outcomes of Patients With Acute Pulmonary Embolism

Background Atrial fibrillation (AF) may exist before or occur early in the course of pulmonary embolism (PE). We determined the PE outcomes based on the presence and timing of AF. Methods and Results Using the data from a multicenter PE registry, we identified 3 groups: (1) those with preexisting AF, (2) patients with new AF within 2 days from acute PE (incident AF), and (3) patients without AF. We assessed the 90-day and 1-year risk of mortality and stroke in patients with AF, compared with those without AF (reference group). Among 16 497 patients with PE, 792 had preexisting AF. These patients had increased odds of 90-day all-cause (odds ratio [OR], 2.81; 95% CI, 2.33-3.38) and PE-related mortality (OR, 2.38; 95% CI, 1.37-4.14) and increased 1-year hazard for ischemic stroke (hazard ratio, 5.48; 95% CI, 3.10-9.69) compared with those without AF. After multivariable adjustment, preexisting AF was associated with significantly increased odds of all-cause mortality (OR, 1.91; 95% CI, 1.57-2.32) but not PE-related mortality (OR, 1.50; 95% CI, 0.85-2.66). Among 16 497 patients with PE, 445 developed new incident AF within 2 days of acute PE. Incident AF was associated with increased odds of 90-day all-cause (OR, 2.28; 95% CI, 1.75-2.97) and PE-related (OR, 3.64; 95% CI, 2.01-6.59) mortality but not stroke. Findings were similar in multivariable analyses. Conclusions In patients with acute symptomatic PE, both preexisting AF and incident AF predict adverse clinical outcomes. The type of adverse outcomes may differ depending on the timing of AF onset.info:eu-repo/semantics/publishedVersio

Metformin intake associates with better cognitive function in patients with Huntington's disease.

Huntington's disease (HD) is an inherited, dominant neurodegenerative disorder caused by an abnormal expansion of CAG triplets in the huntingtin gene (htt). Despite extensive efforts to modify the progression of HD thus far only symptomatic treatment is available. Recent work suggests that treating invertebrate and mice HD models with metformin, a well-known AMPK activator which is used worldwide to treat type 2-diabetes, reduces mutant huntingtin from cells and alleviates many of the phenotypes associated to HD. Herein we report statistical analyses of a sample population of participants in the Enroll-HD database, a world-wide observational study on HD, to assess the effect of metformin intake in HD patients respect to cognitive status using linear models. This cross-sectional study shows for the first time that the use of metformin associates with better cognitive function in HD patients

Clinical heterogeneity of pulmonary arterial hypertension associated with variants in TBX4

Background The knowledge of hereditary predisposition has changed our understanding of Pulmonary Arterial Hypertension. Genetic testing has been widely extended and the application of Pulmonary Arterial Hypertension specific gene panels has allowed its inclusion in the diagnostic workup and increase the diagnostic ratio compared to the traditional sequencing techniques. This is particularly important in the differential diagnosis between Pulmonary Arterial Hypertension and Pulmonary Venoocclusive Disease. Methods Since November 2011, genetic testing is offered to all patients with idiopathic, hereditable and associated forms of Pulmonary Arterial Hypertension or Pulmonary Venoocclusive Disease included in the Spanish Registry of Pulmonary Arterial Hypertension. Herein, we present the clinical phenotype and prognosis of all Pulmonary Arterial Hypertension patients with disease-associated variants in TBX4. Results Out of 579 adults and 45 children, we found in eight patients from seven families, disease-causing associated variants in TBX4. All adult patients had a moderate-severe reduction in diffusion capacity. However, we observed a wide spectrum of clinical presentations, including Pulmonary Venoocclusive Disease suspicion, interstitial lung disease, pulmonary vascular abnormalities and congenital heart disease. Conclusions Genetic testing is now essential for a correct diagnosis work-up in Pulmonary Arterial Hypertension. TBX4-associated Pulmonary Arterial Hypertension has marked clinical heterogeneity. In this regard, a genetic study is extremely useful to obtain an accurate diagnosis and provide appropriate managementInstituto de Salud Carlos III | Ref. PI 18/0123

Cognitive results among the HD patients and controls ^a.

<p>Cognitive results among the HD patients and controls <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179283#t002fn001" target="_blank">^a</a>.</p