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Scientific Reports Jun 2024Plekhm2 is a protein regulating endosomal trafficking and lysosomal distribution. We recently linked a recessive inherited mutation in PLEKHM2 to a familial form of...
Plekhm2 is a protein regulating endosomal trafficking and lysosomal distribution. We recently linked a recessive inherited mutation in PLEKHM2 to a familial form of dilated cardiomyopathy and left ventricular non-compaction. These patients' primary fibroblasts exhibited abnormal lysosomal distribution and autophagy impairment. We therefore hypothesized that loss of PLEKHM2 impairs cardiac function via autophagy derangement. Here, we characterized the roles of Plekhm2 in the heart using global Plekhm2 knockout (PLK2-KO) mice and cultured cardiac cells. Compared to littermate controls (WT), young PLK2-KO mice exhibited no difference in heart function or autophagy markers but demonstrated higher basal AKT phosphorylation. Older PLK2-KO mice had body and heart growth retardation and increased LC3II protein levels. PLK2-KO mice were more vulnerable to fasting and, interestingly, impaired autophagy was noted in vitro, in Plekhm2-deficient cardiofibroblasts but not in cardiomyocytes. PLK2-KO hearts appeared to be less sensitive to pathological hypertrophy induced by angiotensin-II compared to WT. Our findings suggest a role of Plekhm2 in murine cardiac autophagy. Plekhm2 deficiency impaired autophagy in cardiofibroblasts, but the autophagy in cardiomyocytes is not critically dependent on Plekhm2. The absence of Plekhm2 in mice appears to promote compensatory mechanism(s) enabling the heart to manage angiotensin-II-induced stress without detrimental consequences.
Topics: Animals; Autophagy; Mice, Knockout; Fibroblasts; Mice; Myocytes, Cardiac; Protein Serine-Threonine Kinases; Myocardium; Cells, Cultured; Phosphorylation
PubMed: 38942823
DOI: 10.1038/s41598-024-65670-5 -
JACC. Advances Nov 2023
PubMed: 38938713
DOI: 10.1016/j.jacadv.2023.100650 -
Frontiers in Cardiovascular Medicine 2024This case report details the identification of a novel likely pathogenic splicing variant in the TTN gene, associated with dilated cardiomyopathy (DCM), in a 42-year-old...
This case report details the identification of a novel likely pathogenic splicing variant in the TTN gene, associated with dilated cardiomyopathy (DCM), in a 42-year-old male patient presenting with early-onset heart failure and reduced ejection fraction. DCM is a nonischemic heart condition characterized by left biventricular dilation and systolic dysfunction, with approximately one-third of cases being familial and often linked to genetic mutations. The TTN gene, encoding the largest human protein essential for muscle contraction and sarcomere structure, is implicated in about 25% of DCM cases through mutations, especially truncating variants. Our investigation revealed a previously unreported G > C mutation at the splice acceptor site in intron 356 of TTN, confirmed by Sanger sequencing and not found in population databases, suggesting a novel contribution to the understanding of DCM etiology. The case emphasizes the critical role of the TTN gene in cardiac function and the genetic complexity underlying DCM. A comprehensive literature review highlighted the prevalence and significance of splice variants in the TTN gene, particularly those affecting the titin A-band, which is known for its role in muscle contraction and stability. This variant's identification underscores the importance of genetic screening in patients with DCM, offering insights into the disease's familial transmission and potential therapeutic targets. Our findings contribute to the expanding knowledge of genetic factors in DCM, demonstrating the necessity of integrating genetic diagnostics in cardiovascular medicine. This case supports the growing evidence linking splicing mutations in specific regions of the TTN gene to DCM development and underscores the importance of genetic counseling and testing in managing heart disease.
PubMed: 38938651
DOI: 10.3389/fcvm.2024.1387063 -
Children (Basel, Switzerland) Jun 2024Our knowledge regarding the epidemiology of pediatric cardiomyopathy is based on large national population studies reporting an annual incidence of 1 case per 100,000...
BACKGROUND
Our knowledge regarding the epidemiology of pediatric cardiomyopathy is based on large national population studies reporting an annual incidence of 1 case per 100,000 children, with a higher incidence observed in infancy and among selected populations. The aim here is to document the epidemiology of pediatric cardiomyopathy in a Mediterranean population.
METHODS
Children younger than 18 years of age living on the Mediterranean island of Crete, Greece, who have been evaluated since the establishment of tertiary pediatric cardiology services (2002-2022) were included in this retrospective study.
RESULTS
A total of 40 children were included, corresponding to an average annual incidence of pediatric cardiomyopathy of 1.59 cases (95% CI: 1.4-2.3) and a prevalence of 26 cases per 100,000 children. In decreasing order of frequency, most cases corresponded to dilated (50%), followed by hypertrophic (42.5%), arrhythmogenic (5%), and restrictive (2.5%) cardiomyopathy. An etiology was identified in 40%, including a genetic diagnosis in 22.5%.
CONCLUSIONS
The incidence of pediatric cardiomyopathy in the Mediterranean island of Crete is higher compared with that reported previously for other Caucasian populations. Further study is needed to investigate the exact prevalence and specific genetic factors associated with the epidemiology of pediatric cardiomyopathy in Mediterranean populations.
PubMed: 38929311
DOI: 10.3390/children11060732 -
International Journal of Molecular... Jun 2024The prevalence of dilated cardiomyopathy (DCM) is increasing globally, highlighting the need for innovative therapeutic approaches to prevent its onset. In this study,...
The prevalence of dilated cardiomyopathy (DCM) is increasing globally, highlighting the need for innovative therapeutic approaches to prevent its onset. In this study, we examined the energetic and epigenetic distinctions between dilated and non-dilated human myocardium-derived mesenchymal stem/stromal cells (hmMSCs) and assessed the effects of class I and II HDAC inhibitors (HDACi) on these cells and their cardiomyogenic differentiation. Cells were isolated from myocardium biopsies using explant outgrowth methods. Mitochondrial and histone deacetylase activities, ATP levels, cardiac transcription factors, and structural proteins were assessed using flow cytometry, PCR, chemiluminescence, Western blotting, and immunohistochemistry. The data suggest that the tested HDAC inhibitors improved acetylation and enhanced the energetic status of both types of cells, with significant effects observed in dilated myocardium-derived hmMSCs. Additionally, the HDAC inhibitors activated the cardiac transcription factors Nkx2-5, HOPX, GATA4, and Mef2C, and upregulated structural proteins such as cardiac troponin T and alpha cardiac actin at both the protein and gene levels. In conclusion, our findings suggest that HDACi may serve as potential modulators of the energetic status and cardiomyogenic differentiation of human heart hmMSCs. This avenue of exploration could broaden the search for novel therapeutic interventions for dilated cardiomyopathy, ultimately leading to improvements in heart function.
Topics: Humans; Histone Deacetylase Inhibitors; Mesenchymal Stem Cells; Cardiomyopathy, Dilated; Cell Differentiation; Myocardium; Histone Deacetylases; Myocytes, Cardiac; MEF2 Transcription Factors; Homeobox Protein Nkx-2.5; Acetylation; Transcription Factors; Cells, Cultured
PubMed: 38928463
DOI: 10.3390/ijms25126758 -
Genes Jun 2024Cardiomyopathies (CMs), one of the main causes of sudden death among the young population, are a heterogeneous group of myocardial diseases, usually with a genetic...
Cardiomyopathies (CMs), one of the main causes of sudden death among the young population, are a heterogeneous group of myocardial diseases, usually with a genetic cause. Next-Generation Sequencing (NGS) has expanded the genes studied for CMs; however, the yield is still around 50%. The systematic study of Copy Number Variants (CNVs) could contribute to improving our diagnostic capacity. These alterations have already been described as responsible for cardiomyopathies in some cases; however, their impact has been rarely assessed. We analyzed the clinical significance of CNVs in cardiomyopathies by studying 11,647 affected patients, many more than those considered in previously published studies. We evaluated the yield of the systematic study of CNVs in a production context using NGS and a novel CNV detection software tool v2.0 that has demonstrated great efficacy, maximizing sensitivity and avoiding false positives. We obtained a CNV analysis yield of 0.8% that fluctuated depending on the type of cardiomyopathy studied (0.29% HCM, 1.41% DCM, 1.88% ARVC, 1.8% LVNC, 1.45% RCM), and we present the frequency of occurrence for 18 genes that agglutinate the 95 pathogenic/likely pathogenic CNVs detected. We conclude the importance of including in diagnostic tests a systematic study of these genetic alterations for the different cardiomyopathies.
Topics: Humans; DNA Copy Number Variations; Cardiomyopathies; High-Throughput Nucleotide Sequencing; Male; Female; Adult; Clinical Relevance
PubMed: 38927710
DOI: 10.3390/genes15060774 -
Biomolecules Jun 2024Dilated cardiomyopathy (DCM) is a common cause of heart failure (HF) and heart transplantation (HTx), with genetic factors playing a significant role. In recent years,... (Review)
Review
Dilated cardiomyopathy (DCM) is a common cause of heart failure (HF) and heart transplantation (HTx), with genetic factors playing a significant role. In recent years, the RNA-binding protein motif 20 (), which affects the gene splicing of various proteins with different cellular functions, was identified as the first DCM gene with regulatory properties. Variants of have been associated with severe forms of DCM. The aim of this critical systematic review was to analyse cardiomyopathy clinical features and outcomes. According to PRISMA guidelines, a search was run in the PubMed, Scopus and Web of Science electronic databases using the following keywords: ""; "cardiomyopathy"; "arrhythmias"; "heart failure". A total of 181 records were screened, of which 27 studies were potentially relevant to the topic. Through the application of inclusion and exclusion criteria, eight papers reporting 398 patients with pathogenic variants were analysed. The mean age at presentation was 41 years. Familiarity with cardiomyopathy was available in 59% of cases, with 55% of probands reporting a positive family history. Imaging data indicated a mild reduction of left ventricular ejection fraction (mean LVEF 40%), while tissue characterization was reported in 24.3% of cases, showing late gadolinium enhancement in 33% of patients. Composite outcomes of sustained monomorphic ventricular tachycardia or ventricular fibrillation occurred in 19.4% of patients, with 12% undergoing HTx. There were no gender differences in arrhythmic outcomes, while 96.4% of patients who underwent HTx were male. In conclusion, cardiomyopathy exhibits a severe phenotypic expression, both in terms of arrhythmic burden and HF progression.
Topics: Humans; RNA-Binding Proteins; Cardiomyopathy, Dilated; Male; Female; Adult
PubMed: 38927106
DOI: 10.3390/biom14060702 -
Molecular Genetics & Genomic Medicine Jun 2024Dilated cardiomyopathy (DCM) is characterized by dilatation of the left ventricle, systolic dysfunction, and normal or reduced thickness of the left ventricular wall. It...
BACKGROUND
Dilated cardiomyopathy (DCM) is characterized by dilatation of the left ventricle, systolic dysfunction, and normal or reduced thickness of the left ventricular wall. It is a leading cause of heart failure and cardiac death at a young age. Cases with neonatal onset DCM were correlated with severe clinical presentation and poor prognosis. A monogenic molecular etiology accounts for nearly half of cases.
FAMILY DESCRIPTION
Here, we report a family with three deceased offspring at the age of 1 year old. The autopsy of the first deceased infant revealed a DCM. The second infant presented a DCM phenotype with a severely reduced Left Ventricular Ejection Fraction (LVEF) of 10%. Similarly, the third infant showed a severe DCM phenotype with LVEF of 30% as well, in addition to eccentric mitral insufficiency.
RESULTS
Exome sequencing was performed for the trio (the second deceased infant and her parents). Data analysis following the autosomal dominant and recessive patterns of inheritance was carried out along with a mitochondrial pathways-based analysis. We identified a homozygous frameshift variant in the TNNI3 gene (c.204delG; p.(Arg69AlafsTer8)). This variant has been recently reported in the ClinVar database in association with cardiac phenotypes as pathogenic or likely pathogenic and classified as pathogenic according to ACMG.
CONCLUSION
Genetic counseling was provided for the family and a prenatal diagnosis of choronic villus was proposed in the absence of pre-implantation genetic diagnosis possibilities. Our study expands the case series of early-onset DCM patients with a protein-truncating variant in the TNNI3 gene by reporting three affected infant siblings.
Topics: Humans; Cardiomyopathy, Dilated; Frameshift Mutation; Female; Homozygote; Pedigree; Consanguinity; Male; Infant; Phenotype; Troponin I
PubMed: 38924380
DOI: 10.1002/mgg3.2486 -
Journal of Anaesthesiology, Clinical... 2024
PubMed: 38919428
DOI: 10.4103/joacp.joacp_287_22 -
Cureus May 2024Peripherally inserted central catheter (PICC) placement under real-time ultrasound guidance has emerged as a favorable procedure in children as a method to efficiently...
Peripherally inserted central catheter (PICC) placement under real-time ultrasound guidance has emerged as a favorable procedure in children as a method to efficiently obtain central access. Nevertheless, small infants with hemodynamic instability are at high risk of complications and extra precautions are necessary. We present a case of an inadvertent arterial placement of a PICC in a two-month-old infant with dilated cardiomyopathy and decompensated heart failure. Differentiation of arteries and veins under ultrasonographic evaluation may sometimes be difficult when the applied tourniquet pressure exceeds the patient's arterial blood pressure. In particular, arterial flow can be easily compromised by applying tourniquet pressure in small children with low blood pressure. A thorough understanding of the upper extremity vascular anatomy, basic scanning techniques, and meticulous preparation especially in small infants with hemodynamic instability are essential for maintaining the safety and efficacy of this procedure.
PubMed: 38916025
DOI: 10.7759/cureus.61053