Deciphering Common Long QT Syndrome Using CRISPR/Cas9 in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Cardiac Channelopathies: Clinical Diagnosis and Promising Therapeutics

Cardiac channelopathies, also known as primary electrical heart diseases, are inherited genetic abnormalities of cardiomyocyte electrical behavior. Notable for their absence of structural heart diseases, they include a diverse group of diseases such as long QT syndrome, short QT syndrome, Brugada syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, and idiopathic ventricular fibrillation, and carry the risk of malignant arrhythmias leading to sudden cardiac death. The genetic and molecular foundations of these diseases are diverse and complex, with evolving research highlighting the multifactorial nature of their pathophysiology and the intricate interplay of various genes in the manifestation of arrhythmias. While advances in diagnostic techniques, such as genetic testing and electrophysiological studies, have improved the identification and management of these conditions, the relationship between specific genetic mutations and sudden cardiac death remains incompletely understood. This review provides an overview of the molecular and genetic mechanisms underlying those inherited arrhythmias, exploring both well-established and emerging data. Additionally, it discusses current diagnostic approaches and management strategies, aiming to enhance the understanding of these conditions and contribute to better sudden cardiac death prevention.

When HERG-caused LQT2 encounters antisense oligonucleotide: is exon 6 skipping therapy plausible?

The unique in-frame exon 6 of the HERG gene as a potential target for antisense oligonucleotide-mediated exon skipping therapy.

CRISPR-Cas9 in Cardiovascular Medicine: Unlocking New Potential for Treatment

Cardiovascular diseases (CVDs) remain a significant global health challenge, with many current treatments addressing symptoms rather than the genetic roots of these conditions. The advent of CRISPR-Cas9 technology has revolutionized genome editing, offering a transformative approach to targeting disease-causing mutations directly. This article examines the potential of CRISPR-Cas9 in the treatment of various CVDs, including atherosclerosis, arrhythmias, cardiomyopathies, hypertension, and Duchenne muscular dystrophy (DMD). The technology's ability to correct single-gene mutations with high precision and efficiency positions it as a groundbreaking tool in cardiovascular therapy. Recent developments have extended the capabilities of CRISPR-Cas9 to include mitochondrial genome editing, a critical advancement for addressing mitochondrial dysfunctions often linked to cardiovascular disorders. Despite its promise, significant challenges remain, including off-target effects, ethical concerns, and limitations in delivery methods, which hinder its translation into clinical practice. This article also explores the ethical and regulatory considerations surrounding gene editing technologies, emphasizing the implications of somatic versus germline modifications. Future research efforts should aim to enhance the accuracy of CRISPR-Cas9, improve delivery systems for targeted tissues, and ensure the safety and efficacy of treatments in the long term. Overcoming these obstacles could enable CRISPR-Cas9 to not only treat but also potentially cure genetically driven cardiovascular diseases, heralding a new era in precision medicine for cardiovascular health.

Cardiomyopathy: pathogenesis and therapeutic interventions

Cardiomyopathy is a group of disease characterized by structural and functional damage to the myocardium. The etiologies of cardiomyopathies are diverse, spanning from genetic mutations impacting fundamental myocardial functions to systemic disorders that result in widespread cardiac damage. Many specific gene mutations cause primary cardiomyopathy. Environmental factors and metabolic disorders may also lead to the occurrence of cardiomyopathy. This review provides an in-depth analysis of the current understanding of the pathogenesis of various cardiomyopathies, highlighting the molecular and cellular mechanisms that contribute to their development and progression. The current therapeutic interventions for cardiomyopathies range from pharmacological interventions to mechanical support and heart transplantation. Gene therapy and cell therapy, propelled by ongoing advancements in overarching strategies and methodologies, has also emerged as a pivotal clinical intervention for a variety of diseases. The increasing number of causal gene of cardiomyopathies have been identified in recent studies. Therefore, gene therapy targeting causal genes holds promise in offering therapeutic advantages to individuals diagnosed with cardiomyopathies. Acting as a more precise approach to gene therapy, they are gradually emerging as a substitute for traditional gene therapy. This article reviews pathogenesis and therapeutic interventions for different cardiomyopathies.

The Current State of Realistic Heart Models for Disease Modelling and Cardiotoxicity

One of the many unresolved obstacles in the field of cardiovascular research is an uncompromising in vitro cardiac model. While primary cell sources from animal models offer both advantages and disadvantages, efforts over the past half-century have aimed to reduce their use. Additionally, obtaining a sufficient quantity of human primary cardiomyocytes faces ethical and legal challenges. As the practically unlimited source of human cardiomyocytes from induced pluripotent stem cells (hiPSC-CM) is now mostly resolved, there are great efforts to improve their quality and applicability by overcoming their intrinsic limitations. The greatest bottleneck in the field is the in vitro ageing of hiPSC-CMs to reach a maturity status that closely resembles that of the adult heart, thereby allowing for more appropriate drug developmental procedures as there is a clear correlation between ageing and developing cardiovascular diseases. Here, we review the current state-of-the-art techniques in the most realistic heart models used in disease modelling and toxicity evaluations from hiPSC-CM maturation through heart-on-a-chip platforms and in silico models to the in vitro models of certain cardiovascular diseases.

A causal relationship between appendicular lean mass and atrial fibrillation: A two sample Mendelian randomization study

BACKGROUND AND AIM

The relationship between appendicular lean mass (ALM) and most cardiovascular events has been established, but the direct association between ALM and atrial fibrillation (AF) remains uncertain.

METHODS AND RESULTS

Herein, we identified 494 single-nucleotide polymorphisms (SNPs) strongly associated with ALM as instrumental variables (P < 5E-8) based on a genome-wide association study (GWAS) with 450,243 European participants. Then, we employed five Mendelian randomization (MR) analysis methods to investigate the causal relationship between ALM and AF. All results indicated a causal relationship between ALM and AF, among Inverse variance weighted (P = 8.44E-15, odds ratio [OR]: 1.16, 95 % confidence interval [CI]: 1.114-1.198). Furthermore, we performed a sensitivity analysis, which revealed no evidence of pleiotropy (egger_intercept = 0.000089, P = 0.965) or heterogeneity (MR Egger, Q Value = 0.980; Inverse variance weighted, Q Value = 0.927). The leave-one-out method demonstrates that individual SNPs have no driven impact on the whole causal relationship. Multivariable MR analysis indicates that, after excluding the influence of hypertension and coronary heart disease, a causal relationship between ALM and AF still exists (P = 7.74E-40, OR 95 %CI: 1.389 (1.323-1.458)). Importantly, the Radial MR framework analysis and Robust Adjusted Profile Score (RAPS) further exhibit the robustness of this causal relationship.

CONCLUSION

A strong association between ALM and AF was confirmed, and high ALM is a risk factor for AF.

Gene and stem cell therapy for inherited cardiac arrhythmias

Inherited cardiac arrhythmias are a group of genetic diseases predisposing to sudden cardiac arrest, mainly resulting from variants in genes encoding cardiac ion channels or proteins involved in their regulation. Currently available therapeutic options (pharmacotherapy, ablative therapy and device-based therapy) can not preclude the occurrence of arrhythmia events and/or provide complete protection. With growing understanding of the genetic background and molecular mechanisms of inherited cardiac arrhythmias, advancing insight of stem cell technology, and development of vectors and delivery strategies, gene therapy and stem cell therapy may be promising approaches for treatment of inherited cardiac arrhythmias. Recent years have witnessed impressive progress in the basic science aspects and there is a clear and urgent need to be translated into the clinical management of arrhythmic events. In this review, we present a succinct overview of gene and cell therapy strategies, and summarize the current status of gene and cell therapy. Finally, we discuss future directions for implementation of gene and cell therapy in the therapy of inherited cardiac arrhythmias.