Regulación de la función plaquetaria por la acetilación de proteínas no histonas

La activación plaquetaria es un proceso complejo en el que participan diversos mecanismos de transmisión de señales no completamente comprendidos. Recientemente se ha empezado a poner de manifiesto el papel jugado por la acetilación enzimática de proteínas no histonas como mecanismo de transmisión de señales. Sin embargo, no se tiene conocimiento sobre la existencia de estos procesos en las plaquetas o sus implicaciones funcionales. Por todo ello hipotetizamos en primer lugar que la regulación de la acetilación/deacetilación de proteínas plaquetarias podría constituir un nuevo mecanismo de transmisión de señales implicado en la regulación de la función plaquetaria. Por, otro lado, la presencia de factores de transcripción en la plaqueta es un hecho inesperado. Entre ellos, el STAT3 el cual se ha sugerido que puede estar ligado a la transmisión de señales a través del receptor del colágeno GPVI. Sin embargo estos estudios no han tenido en cuenta la importante vía de amplificación que constituye la síntesis de tromboxano A2 (TXA2) en las plaquetas. Hipotetizamos en segundo lugar que STAT3 podría estar implicado en las vías de señalización plaquetaria inducidas por TXA2. Nuestro objetivo fue estudiar: (1) la presencia de proteínas acetiladas (acetiloma) en las plaquetas humanas, (1.1) la regulación de la acetilación de la α-tubulina en las plaquetas, (2) la posible implicación de la acetilación/deacetilación de proteínas en distintas respuestas plaquetarias (2.1) la presencia de distintas deacetilasas (HDAC clásicas y Sirtuinas) en las plaquetas, (3) los mecanismos de transmisión de señales regulados por procesos de acetilación/deacetilación de proteínas, (4) la acetilación de proteínas plaquetarias por la aspirina (AAS), (5) la participación de STAT3 en la transmisión de señales inducida por el TXA2. Concluimos que el proceso enzimático de la acetilación/deacetilación de proteínas no histonas en las plaquetas, es un nuevo regulador de la función plaquetaria y que constituye un importante mecanismo de transmisión de señales en las plaquetas. Las plaquetas humanas presentan un acetiloma característico, regulado por diversas actividades deacetilasas, y variable con la agregación plaquetaria. La acetilación/deacetilación de proteínas no histonas tiene importantes consecuencias en las repuestas funcionales de las plaquetas como son la agregación plaquetaria, liberación de gránulos y movimientos de Ca2+. Nuestros resultados demuestran que tanto la HDAC6 como la SIRT2 juegan un papel importante en la reactividad plaquetaria. La HDAC6 participa en la regulación de la función plaquetaria a través del control de la acetilación de la α-tubulina, mientras que la SIRT2 actuaría a nivel de la cinasa AKT. Nuestros resultados sugieren que la acetilación inducida por el AAS de proteínas distintas de COX-1 podría ser un nuevo mecanismo de acción al producir la acetilación de diversas proteínas, como la α-tubulina. Un factor de transcripción como es STAT3, participa en la regulación de la función plaquetaria, formando parte de los mecanismos de transmisión de señales a través del receptor del TXA2

Heart Disease Characterization and Myocardial Strain Analysis in Patients with PACS1 Neurodevelopmental Disorder

Neurodevelopmental disorder; Congenital heart disease; Myocardial strain analysisTrastorn del neurodesenvolupament; Malaltia cardíaca congènita; Anàlisi de la tensió miocàrdicaTrastorno del neurodesarrollo; Enfermedad cardíaca congénita; Análisis de la tensión miocárdicaBackground: PACS1 neurodevelopmental disorder (PACS1-NDD) (MIM# 615009) is a rare autosomal dominant disease characterized by neurodevelopmental delay, dysmorphic facial features, and congenital malformations. Heart disease (HD) is frequently present in individuals with PACS1-NDD, but a compressive review of these anomalies and an evaluation of cardiac function in a cohort of patients are lacking. Methods: (i) Cardiac evaluation in 11 PACS1-NDD patients was conducted using conventional echocardiography. (ii) Heart function was assessed by tissue Doppler imaging, and two-dimensional speckle tracking was performed in seven patients and matched controls. (iii) This systematic review focused on determining HD prevalence in individuals with PACS1-NDD. Results: In our cohort, 7 of 11 patients presented HD. (Among them, three cases of ascending aortic dilatation (AAD) were detected and one mitral valve prolapse (MVP).) None of the patients showed echocardiographic pathological values, and the left global longitudinal strain was not significantly different between patients and controls (patients −24.26 ± 5.89% vs. controls −20.19 ± 1.75%, p = 0.3176). In the literature review, almost 42% (42/100) of individuals with PACS1-NDD reportedly experienced HD. Septal defects were the most common malformation, followed by patent ductus arteriosus. Conclusions: Our results show a high prevalence of HD in PACS1-NDD patients; in this way, AAD and MVP are reported for the first time in this syndrome. Furthermore, a detailed cardiac function evaluation in our cohort did not reveal evidence of cardiac dysfunction in individuals with PACS1-NDD. Cardiology evaluation should be included for all individuals with Schuurs-Hoeijmakers syndrome.This work was supported by the Spanish Ministry of Health-ISCIII Fondo de Investigación Sanitaria (FIS) (Ref. PI19/01860, to F.J.R. and J.P.) and the Diputación General de Aragón-FEDER: European Social Fund (Grupo de Referencia B32_17R/B32_20R, to J.P.). A.L.-P. was supported by a Miguel Servet ISC-III Research Contract (CP22/00105), and M.G.-S. and C.L.-C. were, respectively, supported by predoctoral fellowships from the Diputación General de Aragón and the Spanish Ministry of Health-ISCIII (FI20/00290)

More than one HMG-CoA Lyase: The classical mitochondrial enzyme plus the peroxisomal and the cytosolic ones

There are three human enzymes with HMG-CoA lyase activity that are able to synthesize ketone bodies in different subcellular compartments. The mitochondrial HMG-CoA lyase was the first to be described, and catalyzes the cleavage of 3-hydroxy-3-methylglutaryl CoA to acetoacetate and acetyl-CoA, the common final step in ketogenesis and leucine catabolism. This protein is mainly expressed in the liver and its function is metabolic, since it produces ketone bodies as energetic fuels when glucose levels are low. Another isoform is encoded by the same gene for the mitochondrial HMG-CoA lyase (HMGCL), but it is located in peroxisomes. The last HMG-CoA lyase to be described is encoded by a different gene, HMGCLL1, and is located in the cytosolic side of the endoplasmic reticulum membrane. Some activity assays and tissue distribution of this enzyme have shown the brain and lung as key tissues for studying its function. Although the roles of the peroxisomal and cytosolic HMG-CoA lyases remain unknown, recent studies highlight the role of ketone bodies in metabolic remodeling, homeostasis, and signaling, providing new insights into the molecular and cellular function of these enzymes

Heart disease characterization and myocardial strain analysis in patients with PACS1 Neurodevelopmental Disorder

Background: PACS1 neurodevelopmental disorder (PACS1-NDD) (MIM# 615009) is a rare autosomal dominant disease characterized by neurodevelopmental delay, dysmorphic facial features, and congenital malformations. Heart disease (HD) is frequently present in individuals with PACS1-NDD, but a compressive review of these anomalies and an evaluation of cardiac function in a cohort of patients are lacking. Methods: (i) Cardiac evaluation in 11 PACS1-NDD patients was conducted using conventional echocardiography. (ii) Heart function was assessed by tissue Doppler imaging, and two-dimensional speckle tracking was performed in seven patients and matched controls. (iii) This systematic review focused on determining HD prevalence in individuals with PACS1-NDD. Results: In our cohort, 7 of 11 patients presented HD. (Among them, three cases of ascending aortic dilatation (AAD) were detected and one mitral valve prolapse (MVP).) None of the patients showed echocardiographic pathological values, and the left global longitudinal strain was not significantly different between patients and controls (patients −24.26 ± 5.89% vs. controls −20.19 ± 1.75%, p = 0.3176). In the literature review, almost 42% (42/100) of individuals with PACS1-NDD reportedly experienced HD. Septal defects were the most common malformation, followed by patent ductus arteriosus. Conclusions: Our results show a high prevalence of HD in PACS1-NDD patients; in this way, AAD and MVP are reported for the first time in this syndrome. Furthermore, a detailed cardiac function evaluation in our cohort did not reveal evidence of cardiac dysfunction in individuals with PACS1-NDD. Cardiology evaluation should be included for all individuals with Schuurs-Hoeijmakers syndrome

Things are not always what they seem: From Cornelia de Lange to KBG phenotype in a girl with genetic variants in NIPBL and ANKRD11.

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Molecular Basis of the Schuurs–Hoeijmakers Syndrome: What We Know about the Gene and the PACS-1 Protein and Novel Therapeutic Approaches

The Schuurs–Hoeijmakers syndrome (SHMS) or PACS1 Neurodevelopment Disorder (PACS1-NDD) is a rare autosomal dominant disease caused by mutations in the PACS1 gene. To date, only 87 patients have been reported and, surprisingly, most of them carry the same variant (c.607C>T; p.R203W). The most relevant clinical features of the syndrome include neurodevelopment delay, seizures or a recognizable facial phenotype. Moreover, some of these characteristics overlap with other syndromes, such as the PACS2 or Wdr37 syndromes. The encoded protein phosphofurin acid cluster sorting 1 (PACS-1) is able to bind to different client proteins and direct them to their subcellular final locations. Therefore, although its main function is protein trafficking, it could perform other roles related to its client proteins. In patients with PACS1-NDD, a gain-of-function or a dominant negative mechanism for the mutated protein has been suggested. This, together with the fact that most of the patients carry the same genetic variant, makes it a good candidate for novel therapeutic approaches directed to decreasing the toxic effect of the mutated protein. Some of these strategies include the use of antisense oligonucleotides (ASOs) or targeting of its client proteins

A Novel Intragenic Duplication in the HDAC8 Gene Underlying a Case of Cornelia de Lange Syndrome

Cornelia de Lange syndrome; Genetic disorder; Intragenic duplicationSíndrome de Cornelia de Lange; Trastorno genético; Duplicación intragénicaSíndrome de Cornelia de Lange; Trastorn genètic; Duplicació intragènicaCornelia de Lange syndrome (CdLS) is a multisystemic genetic disorder characterized by distinctive facial features, growth retardation, and intellectual disability, as well as various systemic conditions. It is caused by genetic variants in genes related to the cohesin complex. Single-nucleotide variations are the best-known genetic cause of CdLS; however, copy number variants (CNVs) clearly underlie a substantial proportion of cases of the syndrome. The NIPBL gene was thought to be the locus within which clinically relevant CNVs contributed to CdLS. However, in the last few years, pathogenic CNVs have been identified in other genes such as HDAC8, RAD21, and SMC1A. Here, we studied an affected girl presenting with a classic CdLS phenotype heterozygous for a de novo ~32 kbp intragenic duplication affecting exon 10 of HDAC8. Molecular analyses revealed an alteration in the physiological splicing that included a 96 bp insertion between exons 9 and 10 of the main transcript of HDAC8. The aberrant transcript was predicted to generate a truncated protein whose accessibility to the active center was restricted, showing reduced ease of substrate entry into the mutated enzyme. Lastly, we conclude that the duplication is responsible for the patient’s phenotype, highlighting the contribution of CNVs as a molecular cause underlying CdLS.This work was supported by the Spanish Ministry of Health-ISCIII Fondo de Investigación Sanitaria (FIS) (Ref. PI19/01860, to F.J.R. and J.P.) and Diputación General de Aragón-FEDER: European Social Fund (Grupo de Referencia B32_17R/B32_20R, to J.P.). A.L.-P. is supported by a “Juan de la Cierva-Incorporación” postdoctoral grant from MICIU (Spanish Ministry of Science and Universities), M.G.-S. is supported by a Predoctoral Fellowship from the Diputación General de Aragón, and C.L.-C. is supported by a Predoctoral Fellowship from the MH-ISCIII. This work was also supported by Spanish government grants RTI2018-094434-B-I00 (MCIU/AEI/FEDER, UE) and DTS20-00024 (ISCIII) to P.G.-P., as well as funds from the European JPIAMR network “EPIC-Alliance” to P.G.-P. The computational support of the “Centro de Computación Científica CCC-UAM” is gratefully recognized. This work was also partially supported by Spanish Instituto de Salud Carlos III, Fondo de Investigaciones Sanitarias co-funded with ERDF funds, Grant No. FIS PI20/01767) to A.P. and by Spanish Instituto de Salud Carlos III, Fondo de Investigaciones Sanitarias co-funded with ERDF funds, Grant No. FIS PI18/000687 to E.F.T

Evaluating face2gene as a tool to identify cornelia de lange syndrome by facial phenotypes

Characteristic or classic phenotype of Cornelia de Lange syndrome (CdLS) is associated with a recognisable facial pattern. However, the heterogeneity in causal genes and the presence of overlapping syndromes have made it increasingly difficult to diagnose only by clinical features. DeepGestalt technology, and its app Face2Gene, is having a growing impact on the diagnosis and management of genetic diseases by analysing the features of affected individuals. Here, we performed a phenotypic study on a cohort of 49 individuals harbouring causative variants in known CdLS genes in order to evaluate Face2Gene utility and sensitivity in the clinical diagnosis of CdLS. Based on the profile images of patients, a diagnosis of CdLS was within the top five predicted syndromes for 97.9% of our cases and even listed as first prediction for 83.7%. The age of patients did not seem to affect the prediction accuracy, whereas our results indicate a correlation between the clinical score and affected genes. Furthermore, each gene presents a different pattern recognition that may be used to develop new neural networks with the goal of separating different genetic subtypes in CdLS. Overall, we conclude that computer-assisted image analysis based on deep learning could support the clinical diagnosis of CdLS.Spanish Ministry of Science, Innovation and Universities/State Research Agency RTC-2017-6494-1; RTI2018-094434-B-I00 (MCIU/AEI/FEDER, UE) to P.G.-P.; Diputación General de Aragón - FEDER: European Social Fund [Grupo de Referencia B32_17R, to J.P.] as well as funds from the European JPIAMR-VRI network “CONNECT” to P.G.-P.; Medical Faculty of the University of Lübeck J09-2017 to I. P.; German Federal Ministry of Education and Research (BMBF

A Novel Intragenic Duplication in the HDAC8 Gene Underlying a Case of Cornelia de Lange Syndrome

Cornelia de Lange syndrome (CdLS) is a multisystemic genetic disorder characterized by distinctive facial features, growth retardation, and intellectual disability, as well as various systemic conditions. It is caused by genetic variants in genes related to the cohesin complex. Single-nucleotide variations are the best-known genetic cause of CdLS; however, copy number variants (CNVs) clearly underlie a substantial proportion of cases of the syndrome. The NIPBL gene was thought to be the locus within which clinically relevant CNVs contributed to CdLS. However, in the last few years, pathogenic CNVs have been identified in other genes such as HDAC8, RAD21, and SMC1A. Here, we studied an affected girl presenting with a classic CdLS phenotype heterozygous for a de novo ~32 kbp intragenic duplication affecting exon 10 of HDAC8. Molecular analyses revealed an alteration in the physiological splicing that included a 96 bp insertion between exons 9 and 10 of the main transcript of HDAC8. The aberrant transcript was predicted to generate a truncated protein whose accessibility to the active center was restricted, showing reduced ease of substrate entry into the mutated enzyme. Lastly, we conclude that the duplication is responsible for the patient’s phenotype, highlighting the contribution of CNVs as a molecular cause underlying CdLS

Evaluating Face2Gene as a Tool to Identify Cornelia de Lange Syndrome by Facial Phenotypes

Characteristic or classic phenotype of Cornelia de Lange syndrome (CdLS) is associated with a recognisable facial pattern. However, the heterogeneity in causal genes and the presence of overlapping syndromes have made it increasingly difficult to diagnose only by clinical features. DeepGestalt technology, and its app Face2Gene, is having a growing impact on the diagnosis and management of genetic diseases by analysing the features of affected individuals. Here, we performed a phenotypic study on a cohort of 49 individuals harbouring causative variants in known CdLS genes in order to evaluate Face2Gene utility and sensitivity in the clinical diagnosis of CdLS. Based on the profile images of patients, a diagnosis of CdLS was within the top five predicted syndromes for 97.9% of our cases and even listed as first prediction for 83.7%. The age of patients did not seem to affect the prediction accuracy, whereas our results indicate a correlation between the clinical score and affected genes. Furthermore, each gene presents a different pattern recognition that may be used to develop new neural networks with the goal of separating different genetic subtypes in CdLS. Overall, we conclude that computer-assisted image analysis based on deep learning could support the clinical diagnosis of CdL