scholarly journals The Atrial Phenotype of the Inherited Primary Arrhythmia Syndromes

2019 ◽  
Vol 8 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Giulio Conte ◽  
Ulrich Schotten ◽  
Angelo Auricchio
Keyword(s):  
Ventricular Arrhythmias ◽  
Clinical Characteristics ◽  
Current Knowledge ◽  
Polymorphic Ventricular Tachycardia ◽  
Causative Role ◽  
Atrial Arrhythmias ◽  
The Past ◽  
Molecular Features ◽  
Cardiac Channelopathy

Over the past two decades, our understanding of inherited primary arrhythmia syndromes has been enriched by studies that have aimed to define the clinical characteristics and the genetic, cellular and molecular features predisposing patients to an enhanced risk of ventricular arrhythmias. In contrast, very little is known about the causative role of inherited cardiac channelopathies on atrial conduction abnormalities possibly leading to different atrial tachyarrhythmias. The diagnostic and therapeutic management of patients with an inherited cardiac channelopathy presenting with atrial arrhythmias remains highly challenging and is in urgent need of improvement. This review will assess the current knowledge on atrial electrical abnormalities affecting patients with different forms of inherited primary arrhythmia syndromes, including long and short QT syndromes, early repolarisation syndrome, catecholaminergic polymorphic ventricular tachycardia and Brugada syndrome.

scholarly journals The role of calcium homeostasis remodeling in inherited cardiac arrhythmia syndromes

2021 ◽  
Author(s):  
Shanna Hamilton ◽  
Roland Veress ◽  
Andriy Belevych ◽  
Dmitry Terentyev
Keyword(s):  
Cardiac Arrhythmia ◽  
Cardiac Death ◽  
Ventricular Arrhythmias ◽  
Polymorphic Ventricular Tachycardia ◽  
Genetic Mutations ◽  
Strong Basis ◽  
Functional Changes ◽  
Intracellular Ca ◽  
Qt Syndrome

AbstractSudden cardiac death due to malignant ventricular arrhythmias remains the major cause of mortality in the postindustrial world. Defective intracellular Ca2+ homeostasis has been well established as a key contributing factor to the enhanced propensity for arrhythmia in acquired cardiac disease, such as heart failure or diabetic cardiomyopathy. More recent advances provide a strong basis to the emerging view that hereditary cardiac arrhythmia syndromes are accompanied by maladaptive remodeling of Ca2+ homeostasis which substantially increases arrhythmic risk. This brief review will focus on functional changes in elements of Ca2+ handling machinery in cardiomyocytes that occur secondary to genetic mutations associated with catecholaminergic polymorphic ventricular tachycardia, and long QT syndrome.

scholarly journals Thyroid Hormone Plays an Important Role in Cardiac Function: From Bench to Bedside

2021 ◽  
Vol 12 ◽  
Author(s):  
Hiroyuki Yamakawa ◽  
Tomoko S. Kato ◽  
Jaeduk Yoshimura Noh ◽  
Shinsuke Yuasa ◽  
Akio Kawamura ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Cardiac Function ◽  
Cardiovascular System ◽  
Antiarrhythmic Agent ◽  
Current Knowledge ◽  
Cardiac Contractility ◽  
The Body ◽  
The Past ◽  
Systolic And Diastolic Function

Thyroid hormones (THs) are synthesized in the thyroid gland, and they circulate in the blood to regulate cells, tissues, and organs in the body. In particular, they exert several effects on the cardiovascular system. It is well known that THs raise the heart rate and cardiac contractility, improve the systolic and diastolic function of the heart, and decrease systemic vascular resistance. In the past 30 years, some researchers have studied the molecular pathways that mediate the role of TH in the cardiovascular system, to better understand its mechanisms of action. Two types of mechanisms, which are genomic and non-genomic pathways, underlie the effects of THs on cardiomyocytes. In this review, we summarize the current knowledge of the action of THs in the cardiac function, the clinical manifestation and parameters of their hemodynamics, and treatment principles for patients with hyperthyroid- or hypothyroid-associated heart disease. We also describe the cardiovascular drugs that induce thyroid dysfunction and explain the mechanism underlying the thyroid toxicity of amiodarone, which is considered the most effective antiarrhythmic agent. Finally, we discuss the recent reports on the involvement of thyroid hormones in the regulation of myocardial regeneration and metabolism in the adult heart.

scholarly journals Incidence and Clinical Management of Atrial Arrhythmias in Patients with Catecholaminergic Polymorphic Ventricular Tachycardia

2021 ◽  
Author(s):  
Gurukripa Kowlgi ◽  
John Giudicessi ◽  
Walid Barake ◽  
Konstantinos Siontis ◽  
Johan Bos ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Ventricular Arrhythmias ◽  
Catecholaminergic Polymorphic Ventricular Tachycardia ◽  
Polymorphic Ventricular Tachycardia ◽  
Atrial Arrhythmias ◽  
Single Center ◽  
Ablation Therapy ◽  
Inappropriate Shocks ◽  
Drug Intolerance

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic arrhythmia syndrome characterized by adrenergically-triggered ventricular arrhythmias, syncope, and sudden cardiac death. Several small studies suggest that atrial arrhythmias (AAs) are common in patients with CPVT. Objective: To determine the incidence and type of AAs observed within a large, single-center cohort of CPVT cases as well as the efficacy and durability of AA-directed management. Methods: In this retrospective study, the electronic medical record of 129 patients (52% female; average age at diagnosis 20.8  15.3 years) with CPVT (95% with a putative CPVT1-causative RYR2 variant) between 01/2000 and 09/2019 were reviewed for electrocardiographic evidence of AAs. Clinical features and efficacy of pharmacologic and ablation therapy were assessed. Results: Overall, 10/129 (7.8%) CPVT patients, all RYR2 variant-positive, had evidence of an AA (atrial fibrillation/flutter in 6, atrial tachycardia in 3, and supraventricular tachycardia in 1). The median age at AA diagnosis was 23 (14.2-35.5) years. 8/10 of patients experienced symptoms attributed to their AA, including inappropriate shocks. All patients were trialed on anti-arrhythmics, including -blockers, and/or flecainide. Owing to drug failure (1/10), drug intolerance (1/10), or patient preference (2/10); 4/10 patients received an ablation. Over a median follow-up of 23.5 (4.5-63) months, no AA recurrences were observed. Conclusion: Compared to prior studies, the incidence of AAs in this large, single-center referral cohort of CPVT patients was substantially lower (7.8% vs. 26%-35%). Although larger multi-center studies are needed to confirm, this study suggests that ablation is efficacious and durable in CPVT-associated AAs.

scholarly journals Tight junction proteins in gastrointestinal and liver disease

Gut ◽  
2018 ◽  
Vol 68 (3) ◽  
pp. 547-561 ◽  
Author(s):  
Mirjam B Zeisel ◽  
Punita Dhawan ◽  
Thomas F Baumert
Keyword(s):  
Liver Disease ◽  
Tight Junction ◽  
Functional Role ◽  
Epithelial To Mesenchymal Transition ◽  
Current Knowledge ◽  
Regulation Of Gene Expression ◽  
Causative Role ◽  
Mesenchymal Transition ◽  
Disease Biology

Over the past two decades a growing body of evidence has demonstrated an important role of tight junction (TJ) proteins in the physiology and disease biology of GI and liver disease. On one side, TJ proteins exert their functional role as integral proteins of TJs in forming barriers in the gut and the liver. Furthermore, TJ proteins can also be expressed outside TJs where they play important functional roles in signalling, trafficking and regulation of gene expression. A hallmark of TJ proteins in disease biology is their functional role in epithelial-to-mesenchymal transition. A causative role of TJ proteins has been established in the pathogenesis of colorectal cancer and gastric cancer. Among the best characterised roles of TJ proteins in liver disease biology is their function as cell entry receptors for HCV—one of the most common causes of hepatocellular carcinoma. At the same time TJ proteins are emerging as targets for novel therapeutic approaches for GI and liver disease. Here we review our current knowledge of the role of TJ proteins in the pathogenesis of GI and liver disease biology and discuss their potential as therapeutic targets.

scholarly journals MiRNAs in the Peri-Implantation Period: Contribution to Embryo–Maternal Communication in Pigs

2020 ◽  
Vol 21 (6) ◽  
pp. 2229 ◽  
Author(s):  
Monika M. Kaczmarek ◽  
Joanna Najmula ◽  
Maria M. Guzewska ◽  
Emilia Przygrodzka
Keyword(s):  
Current Knowledge ◽  
Mammalian Species ◽  
Embryo Implantation ◽  
Cell Communication ◽  
Large Family ◽  
Protein Coding ◽  
The Past ◽  
Domestic Livestock ◽  
Implantation Period

MicroRNAs (miRNAs) constitute a large family of noncoding RNAs, approximately 22 nucleotides long, which function as guide molecules in RNA silencing. Targeting most protein-coding transcripts, miRNAs are involved in nearly all developmental and pathophysiological processes in animals. To date, the regulatory roles of miRNAs in reproduction, such as fertilization, embryo development, implantation, and placenta formation, among others, have been demonstrated in numerous mammalian species, including domestic livestock such as pigs. Over the past years, it appeared that understanding the functions of miRNAs in mammalian reproduction can substantially improve our understanding of the biological challenges of successful reproductive performance. This review describes the current knowledge on miRNAs, specifically in relation to the peri-implantation period when the majority of embryonic mortality occurs in pigs. To present a broader picture of crucial peri-implantation events, we focus on the role of miRNA-processing machinery and miRNA–mRNA infarctions during the maternal recognition of pregnancy, leading to maintenance of the corpus luteum function and further embryo implantation. Furthermore, we summarize the current knowledge on cell-to-cell communication involving extracellular vesicles at the embryo–maternal interface in pigs. Finally, we discuss the potential of circulating miRNAs to serve as indicators of ongoing embryo–maternal crosstalk.

scholarly journals On transposons and totipotency

2020 ◽  
Vol 375 (1795) ◽  
pp. 20190339 ◽  
Author(s):  
Maria-Elena Torres-Padilla
Keyword(s):  
Large Scale ◽  
Current Knowledge ◽  
Regulation Of Gene Expression ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Host Genome ◽  
The Past ◽  
Stage Of Development ◽  
Mammalian Genomes

Our perception of the role of the previously considered ‘selfish’ or ‘junk’ DNA has been dramatically altered in the past 20 years or so. A large proportion of this non-coding part of mammalian genomes is repetitive in nature, classified as either satellites or transposons. While repetitive elements can be termed selfish in terms of their amplification, such events have surely been co-opted by the host, suggesting by itself a likely altruistic function for the organism at the subject of such natural selection. Indeed numerous examples of transposons regulating the functional output of the host genome have been documented. Transposons provide a powerful framework for large-scale relatively rapid concerted regulatory activities with the ability to drive evolution. Mammalian totipotency has emerged as one key stage of development in which transposon-mediated regulation of gene expression has taken centre stage in the past few years. During this period, large-scale (epigenetic) reprogramming must be accomplished in order to activate the host genome. In mice and men, one particular element murine endogenous retrovirus with leucine tRNA primer (MERVL) (and its counterpart human ERVL (HERVL)) appears to have acquired roles as a key driving force in this process. Here, I will discuss and interpret the current knowledge and its implications regarding the role of transposons, particularly of long interspersed nuclear elements (LINE-1s) and endogenous retroviruses (ERVs), in the regulation of totipotency. This article is part of a discussion meeting issue ‘Crossroads between transposons and gene regulation’.

Ventricular arrhythmias

2019 ◽  
pp. 221-240
Author(s):  
Martin Borggrefe ◽  
Erol Tülümen ◽  
Josep Brugada
Keyword(s):  
Heart Disease ◽  
Ventricular Arrhythmias ◽  
Arrhythmogenic Right Ventricular Cardiomyopathy ◽  
Atrioventricular Node ◽  
Structural Heart Disease ◽  
Polymorphic Ventricular Tachycardia ◽  
European Society Of Cardiology ◽  
Ventricular Tachycardias ◽  
Current Guidelines

Ventricular arrhythmias are abnormal rhythms that originate from below the atrioventricular node. They include premature ventricular complexes, ventricular tachycardias, and ventricular fibrillation. Ventricular arrhythmias may occur in patients with structural heart disease (ischaemic heart disease, cardiomyopathies such as dilated cardiomyopathy, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, etc.) or in patients with a structurally normal heart (genetic arrhythmia syndromes such as long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, or as idiopathic ventricular tachycardias). Symptoms depend on the frequency, duration, and haemodynamic effects of the arrhythmia. They may be asymptomatic or may cause symptoms, such as palpitations, shortness of breath, chest discomfort, dizziness, or syncope, or may present with cardiac arrest. This chapter is focused on the role of antiarrhythmic drugs in the management of ventricular arrhythmias. The recommendations are based on the current guidelines of the European Society of Cardiology for the management of patients with ventricular arrhythmias.

scholarly journals Molecular Crosstalking among Noncoding RNAs: A New Network Layer of Genome Regulation in Cancer

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Marco Ragusa ◽  
Cristina Barbagallo ◽  
Duilia Brex ◽  
Angela Caponnetto ◽  
Matilde Cirnigliaro ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Structural Integrity ◽  
Current Knowledge ◽  
Noncoding Rnas ◽  
Special Focus ◽  
Cellular Mechanisms ◽  
Protein Coding ◽  
The Past ◽  
Higher Eukaryotes

Over the past few years, noncoding RNAs (ncRNAs) have been extensively studied because of the significant biological roles that they play in regulation of cellular mechanisms. ncRNAs are associated to higher eukaryotes complexity; accordingly, their dysfunction results in pathological phenotypes, including cancer. To date, most research efforts have been mainly focused on how ncRNAs could modulate the expression of protein-coding genes in pathological phenotypes. However, recent evidence has shown the existence of an unexpected interplay among ncRNAs that strongly influences cancer development and progression. ncRNAs can interact with and regulate each other through various molecular mechanisms generating a complex network including different species of RNAs (e.g., mRNAs, miRNAs, lncRNAs, and circRNAs). Such a hidden network of RNA-RNA competitive interactions pervades and modulates the physiological functioning of canonical protein-coding pathways involved in proliferation, differentiation, and metastasis in cancer. Moreover, the pivotal role of ncRNAs as keystones of network structural integrity makes them very attractive and promising targets for innovative RNA-based therapeutics. In this review we will discuss: (1) the current knowledge on complex crosstalk among ncRNAs, with a special focus on cancer; and (2) the main issues and criticisms concerning ncRNAs targeting in therapeutics.

scholarly journals A review of the pathogenesis of ankylosing spondylitis

2008 ◽  
Vol 24 (1) ◽  
pp. E2 ◽  
Author(s):  
Elias Dakwar ◽  
Jaypal Reddy ◽  
Fernando L. Vale ◽  
Juan S. Uribe
Keyword(s):  
Ankylosing Spondylitis ◽  
Strong Association ◽  
Critical Role ◽  
Axial Skeleton ◽  
Causative Role ◽  
Hla B27 ◽  
Pathogenic Role ◽  
The Past ◽  
New Findings

✓ Ankylosing spondylitis (AS) is a chronic, progressive inflammatory rheumatic disease involving primarily the sacroiliac joints and the axial skeleton. The main clinical features are back pain and progressive stiffness of the spine. Oligoarthritis of the hips and shoulders, enthesopathy, and anterior uveitis are common, and involvement of the heart and lungs is rare. The current understanding of the pathogenesis of this disorder is limited. Despite the strong association between human leukocyte antigen B27 (HLA-B27) and susceptibility to AS reported over the past 30 years, the exact pathogenic role of HLA-B27 in AS and other spondyloarthropathies has yet to be determined. The authors present a review of the literature pertaining to the pathogenesis of AS over the past several decades. Ankylosing spondylitis is a polygenic disorder, with HLA-B27 playing a critical causative role in its pathogenesis. Animal studies of the immunobiology of HLA-B27 have provided significant insight into the pathogenic role of HLA-B27. The search for the antigenic peptide to support the “arthritogenic peptide” hypothesis has been disappointing. Over the past decade there has been increasing interest in the critical role of the misfolding and unfolded protein response of the heavy chain HLA-B27 in the modulation of the inflammatory response. Although there have been significant new findings in the understanding of the pathogenesis of AS, the exact mechanisms have yet to be identified. There is considerable optimism that additional susceptibility genes, predisposing factors, and regulators of the inflammatory process will be identified that will provide avenues for future treatment.

Role of ryanodine receptor mutations in cardiac pathology: more questions than answers?

2006 ◽  
Vol 34 (5) ◽  
pp. 913-918 ◽  
Author(s):  
N.L. Thomas ◽  
C.H. George ◽  
F.A. Lai
Keyword(s):  
Ryanodine Receptor ◽  
Ventricular Arrhythmias ◽  
Striated Muscle ◽  
Polymorphic Ventricular Tachycardia ◽  
Wild Type ◽  
Cell Interior ◽  
Cardiac Pathology ◽  
Physiological Processes ◽  
The Common

The RyR (ryanodine receptor) mediates rapid Ca2+ efflux from the ER (endoplasmic reticulum) and is responsible for triggering numerous Ca2+-activated physiological processes. The most studied RyR-mediated process is excitation–contraction coupling in striated muscle, where plasma membrane excitation is transmitted to the cell interior and results in Ca2+ efflux that triggers myocyte contraction. Recently, single-residue mutations in the cardiac RyR (RyR2) have been identified in families that exhibit CPVT (catecholaminergic polymorphic ventricular tachycardia), a condition in which physical or emotional stress can trigger severe tachyarrhythmias that can lead to sudden cardiac death. The RyR2 mutations in CPVT are clustered in the N- and C-terminal domains, as well as in a central domain. Further, a critical signalling role for dysfunctional RyR2 has also been implicated in the generation of arrhythmias in the common condition of HF (heart failure). We have prepared cardiac RyR2 plasmids with various CPVT mutations to enable expression and analysis of Ca2+ release mediated by the wild-type and mutated RyR2. These studies suggest that the mutational locus may be important in the mechanism of Ca2+ channel dysfunction. Understanding the causes of aberrant Ca2+ release via RyR2 may assist in the development of effective treatments for the ventricular arrhythmias that often leads to sudden death in HF and in CPVT.

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