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BioRxiv : the Preprint Server For... Jun 2024related dilated cardiomyopathy ( -DCM) is one of the most severe forms of DCM. The incomplete understanding of the molecular disease mechanisms results in lacking...
related dilated cardiomyopathy ( -DCM) is one of the most severe forms of DCM. The incomplete understanding of the molecular disease mechanisms results in lacking treatment options, leading to high mortality amongst patients. Here, using an inducible, cardiomyocyte-specific lamin A/C depletion mouse model, we conducted a comprehensive transcriptomic study, combining both bulk and single nucleus RNA sequencing, and spanning -DCM disease progression, to identify potential disease drivers. Our refined analysis pipeline identified 496 genes already misregulated early in disease. The expression of these genes was largely driven by disease specific cardiomyocyte sub-populations and involved biological processes mediating cellular response to DNA damage, cytosolic pattern recognition, and innate immunity. Indeed, DNA damage in -DCM hearts was significantly increased early in disease and correlated with reduced cardiomyocyte lamin A levels. Activation of cytosolic pattern recognition in cardiomyocytes was independent of cGAS, which is rarely expressed in cardiomyocytes, but likely occurred downstream of other pattern recognition sensors such as IFI16. Altered gene expression in cardiac fibroblasts and immune cell infiltration further contributed to tissue-wide changes in gene expression. Our transcriptomic analysis further predicted significant alterations in cell-cell communication between cardiomyocytes, fibroblasts, and immune cells, mediated through early changes in the extracellular matrix (ECM) in the -DCM hearts. Taken together, our work suggests a model in which nuclear damage in cardiomyocytes leads to activation of DNA damage responses, cytosolic pattern recognition pathway, and other signaling pathways that activate inflammation, immune cell recruitment, and transcriptional changes in cardiac fibroblasts, which collectively drive -DCM pathogenesis.
PubMed: 38915720
DOI: 10.1101/2024.06.11.598511 -
BioRxiv : the Preprint Server For... Jun 2024-Related Dilated Cardiomyopathy (DCM) is an autosomal-dominant genetic condition with cardiomyocyte and conduction system dysfunction often resulting in heart failure...
-Related Dilated Cardiomyopathy: Single-Cell Transcriptomics during Patient-derived iPSC Differentiation Support Cell type and Lineage-specific Dysregulation of Gene Expression and Development for Cardiomyocytes and Epicardium-Derived Cells with Lamin A/C Haploinsufficiency.
-Related Dilated Cardiomyopathy (DCM) is an autosomal-dominant genetic condition with cardiomyocyte and conduction system dysfunction often resulting in heart failure or sudden death. The condition is caused by mutation in the Lamin A/C ( ) gene encoding Type-A nuclear lamin proteins involved in nuclear integrity, epigenetic regulation of gene expression, and differentiation. Molecular mechanisms of disease are not completely understood, and there are no definitive treatments to reverse progression or prevent mortality. We investigated possible mechanisms of -Related DCM using induced pluripotent stem cells derived from a family with a heterozygous splice-site mutation. We differentiated one mutant iPSC line derived from an affected female (Patient) and two non-mutant iPSC lines derived from her unaffected sister (Control) and conducted single-cell RNA sequencing for 12 samples (4 Patient and 8 Control) across seven time points: Day 0, 2, 4, 9, 16, 19, and 30. Our bioinformatics workflow identified 125,554 cells in raw data and 110,521 (88%) high-quality cells in sequentially processed data. Unsupervised clustering, cell annotation, and trajectory inference found complex heterogeneity: ten main cell types; many possible subtypes; and lineage bifurcation for Cardiac Progenitors to Cardiomyocytes (CM) and Epicardium-Derived Cells (EPDC). Data integration and comparative analyses of Patient and Control cells found cell type and lineage differentially expressed genes (DEG) with enrichment to support pathway dysregulation. Top DEG and enriched pathways included: 10 genes and RNA polymerase II transcription in Pluripotent cells (PP); and TGF Beta/BMP signaling, sarcomere gene subsets and cardiogenesis, and EMT in CM; and epigenetic regulation and and mTORC1 signaling in EPDC. Top DEG also included: and other X-linked genes, six imprinted genes: , , , , , , and enriched gene sets in metabolism, proliferation, and homeostasis. We confirmed Lamin A/C haploinsufficiency by allelic expression and Western blot. Our complex Patient-derived iPSC model for Lamin A/C haploinsufficiency in PP, CM, and EPDC provided support for dysregulation of genes and pathways, many previously associated with Lamin A/C defects, such as epigenetic gene expression, signaling, and differentiation. Our findings support disruption of epigenomic developmental programs as proposed in other disease models. We recognized other factors influencing epigenetics and differentiation; thus, our approach needs improvement to further investigate this mechanism in an iPSC-derived model.
PubMed: 38915555
DOI: 10.1101/2024.06.12.598335 -
Frontiers in Medicine 2024Systemic lupus erythematosus (SLE) is frequently accompanied by various complications, with cardiovascular diseases being particularly concerning due to their high...
BACKGROUND
Systemic lupus erythematosus (SLE) is frequently accompanied by various complications, with cardiovascular diseases being particularly concerning due to their high mortality rate. Although there is clinical evidence suggesting a potential correlation between SLE and heart failure (HF), the underlying shared mechanism is not fully understood. Therefore, it is imperative to explore the potential mechanisms and shared therapeutic targets between SLE and HF.
METHODS
The SLE and HF datasets were downloaded from the NCBI Gene Expression Omnibus database. Differentially expressed genes (DEGs) in both SLE and HF were performed using "limma" R package. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genes (KEGG) analyses were conducted to analyze the enriched functions and pathways of DEGs in both SLE and HF datasets. Protein-Protein Interaction network (PPI) and the molecular complex detection (MCODE) plugins in the Cytoscape software were performed to identify the shared hub genes between SLE and HF datasets. R package "limma" was utilized to validate the expression of hub genes based on SLE (GSE122459) and HF (GSE196656) datasets. CIBERSORT algorithm was utilized to analyze the immune cell infiltration of SLE and HF samples based on SLE (GSE112087) and HF (GSE116250) datasets. A weighted gene co-expression network analysis (WGCNA) network was established to further validate the hub genes based on HF dataset (GSE116250). Molecular biology techniques were conducted to validate the hub genes.
RESULTS
999 shared DGEs were identified between SLE and HF datasets, which were mainly enriched in pathways related to Th17 cell differentiation. 5 shared hub genes among the common DGEs between SLE and HF datasets were screened and validated, including HSP90AB1, NEDD8, RPLP0, UBB, and UBC. Additionally, 5 hub genes were identified in the central part of the MEbrown module, showing the strongest correlation with dilated cardiomyopathy. HSP90AB1 and UBC were upregulated in failing hearts compared to non-failing hearts, while UBB, NEDD8, and RPLP0 did not show significant changes.
CONCLUSION
HSP90AB1 and UBC are closely related to the co-pathogenesis of SLE and HF mediated by immune cell infiltration. They serve as promising molecular markers and potential therapeutic targets for the treatment of SLE combined with HF.
PubMed: 38912340
DOI: 10.3389/fmed.2024.1402010 -
Circulation. Heart Failure Jun 2024The mechanism of cardiac reverse remodeling (CRR) mediated by the left ventricular assist device remains unclear. This study aims to identify the specific cell type...
BACKGROUND
The mechanism of cardiac reverse remodeling (CRR) mediated by the left ventricular assist device remains unclear. This study aims to identify the specific cell type responsible for CRR and develop the therapeutic target that promotes CRR.
METHODS
The nuclei were extracted from the left ventricular tissue of 4 normal controls, 4 CRR patients, and 4 no cardiac reverse remodeling patients and then subjected to single-nucleus RNA sequencing for identifying key cell types responsible for CRR. Gene overexpression in transverse aortic constriction and dilated cardiomyopathy heart failure mouse model (C57BL/6J background) and pathological staining were performed to validate the results of single-nucleus RNA sequencing.
RESULTS
Ten cell types were identified among 126 156 nuclei. Cardiomyocytes in CRR patients expressed higher levels of than the other 2 groups. The macrophages in CRR patients expressed more anti-inflammatory genes and functioned in angiogenesis. Endothelial cells that elevated in no cardiac reverse remodeling patients were involved in the inflammatory response. Echocardiography showed that overexpressing through cardiomyocyte-specific adeno-associated virus 9 demonstrated an ability to improve heart function and morphology. Pathological staining showed that overexpressing could reduce fibrosis and cardiomyocyte size in the heart failure mouse model.
CONCLUSIONS
The present results of single-nucleus RNA sequencing and heart failure mouse model indicated that could mediate CRR and supported the development of therapeutics for overexpressing in promoting CRR.
PubMed: 38910562
DOI: 10.1161/CIRCHEARTFAILURE.123.011504 -
Circulation Journal : Official Journal... Jun 2024The incidence and prognostic predictors of heart failure (HF) without left ventricular systolic dysfunction (LVSD) in hypertrophic cardiomyopathy (HCM), particularly...
BACKGROUND
The incidence and prognostic predictors of heart failure (HF) without left ventricular systolic dysfunction (LVSD) in hypertrophic cardiomyopathy (HCM), particularly their differences in terms of developing LVSD (progression to end-stage) or sudden cardiac death (SCD), are not fully elucidated.Methods and Results: This study included 330 consecutive HCM patients with left ventricular ejection fraction (LVEF) ≥50%. HF hospitalization without LVSD and development of LVSD were evaluated as main outcomes. During a median follow-up of 7.3 years, the incidence of HF hospitalization without LVSD was 18.8%, which was higher than the incidence of developing LVSD (10.9%) or SCD (8.8%). Among patients who developed LVSD, only 19.4% experienced HF hospitalization without LVSD before developing LVSD. Multivariable analysis showed that predictors for HF hospitalization without LVSD (higher age, atrial fibrillation, history of HF hospitalization, and higher B-type natriuretic peptide concentrations) were different from those of developing LVSD (male sex, lower LVEF, lower left ventricular outflow tract gradient, and higher tricuspid regurgitation pressure gradient). Known risk factors for SCD did not predict either HF without LVSD or developing LVSD.
CONCLUSIONS
In HCM with LVEF ≥50%, HF hospitalization without LVSD was more frequently observed than development of LVSD or SCD during mid-term follow-up. The overlap between HF without LVSD and developing LVSD was small (19.4%), and these 2 HF events had different predictors.
PubMed: 38910134
DOI: 10.1253/circj.CJ-24-0049 -
Frontiers in Genetics 2024Previous studies have shown that Alzheimer's disease (AD) can cause myocardial damage. However, whether there is a causal association between AD and non-ischemic...
The causal effect of Alzheimer's disease and family history of Alzheimer's disease on non-ischemic cardiomyopathy and left ventricular structure and function: a Mendelian randomization study.
BACKGROUND
Previous studies have shown that Alzheimer's disease (AD) can cause myocardial damage. However, whether there is a causal association between AD and non-ischemic cardiomyopathy (NICM) remains unclear. Using a comprehensive two-sample Mendelian randomization (MR) method, we aimed to determine whether AD and family history of AD (FHAD) affect left ventricular (LV) structure and function and lead to NICM, including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM).
METHODS
The summary statistics for exposures [AD, paternal history of AD (PH-AD), and maternal history of AD (MH-AD)] and outcomes (NICM, HCM, DCM, and LV traits) were obtained from the large European genome-wide association studies. The causal effects were estimated using inverse variance weighted, MR-Egger, and weighted median methods. Sensitivity analyses were conducted, including Cochran's Q test, MR-Egger intercept test, MR pleiotropy residual sum and outlier, MR Steiger test, leave-one-out analysis, and the funnel plot.
RESULTS
Genetically predicted AD was associated with a lower risk of NICM [odds ratio (OR) 0.9306, 95% confidence interval (CI) 0.8825-0.9813, = 0.0078], DCM (OR 0.8666, 95% CI 0.7752-0.9689, = 0.0119), and LV remodeling index (OR 0.9969, 95% CI 0.9940-0.9998, = 0.0337). Moreover, genetically predicted PH-AD was associated with a decreased risk of NICM (OR 0.8924, 95% CI 0.8332-0.9557, = 0.0011). MH-AD was also strongly associated with a decreased risk of NICM (OR 0.8958, 95% CI 0.8449-0.9498, = 0.0002). Different methods of sensitivity analysis demonstrated the robustness of the results.
CONCLUSION
Our study revealed that AD and FHAD were associated with a decreased risk of NICM, providing a new genetic perspective on the pathogenesis of NICM.
PubMed: 38903751
DOI: 10.3389/fgene.2024.1379865 -
Kidney & Blood Pressure Research Jun 2024A hereditary condition primarily affecting the kidneys and heart has newly been identified: the RRAGD-associated Autosomal Dominant Kidney Hypomagnesemia with... (Review)
Review
BACKGROUND
A hereditary condition primarily affecting the kidneys and heart has newly been identified: the RRAGD-associated Autosomal Dominant Kidney Hypomagnesemia with Cardiomyopathy (ADKH-RRAGD). This disorder is characterized by renal loss of magnesium and potassium, coupled with varying degrees of cardiac dysfunction. These range from arrhythmias to severe dilated cardiomyopathy, which may require heart transplantation. Mutations associated with RRAGD significantly disrupt the non-canonical branch of the mTORC1 pathway. This disruption hinders the the nuclear translocation and transcriptional activity of the transcription factor EB (TFEB) a crucial regulator of lysosomal and autophagic function.
SUMMARY
All identified RRAGD variants compromise kidney function, leading to hypomagnesemia and hypokalemia of various severity. The renal phenotype for most of the variants (i.e. S76L, I221K, P119R, P119L), typically manifests in the second decade of life occasionally preceded by childhood symptoms of dilated cardiomyopathy. In contrast, the P88L variant is associated to dilated cardiomyopathy manifesting in adulthood. To date, the T97P variant has not been linked to cardiac involvement. The most severe manifestations of ADKH-RRAGD, particularly concerning electrolyte imbalance and heart dysfunction requiring transplantation in childhood appear to be associated with the S76L, I221K, P119R variants.
KEY MESSAGES
This review aims to provide an overview of the clinical presentation for ADKH-RRAGD, aiming to enhance o awareness, promote early diagnosis and facilitate proper treatment. It also reports on the limited experience in patient management with diuretics, magnesium and potassium supplements, metformin, or calcineurin- and SGLT2-inhibitors.
PubMed: 38901414
DOI: 10.1159/000539889 -
Diagnostics (Basel, Switzerland) Jun 2024Non-ischemic dilated cardiomyopathy (DCM) represents a significant cause of heart failure, defined as the presence of left ventricular (LV) dilatation and systolic... (Review)
Review
Non-ischemic dilated cardiomyopathy (DCM) represents a significant cause of heart failure, defined as the presence of left ventricular (LV) dilatation and systolic dysfunction unexplained solely by abnormal loading conditions or coronary artery disease. Cardiac resynchronization therapy (CRT) has emerged as a cornerstone in the management of heart failure, particularly in patients with DCM. However, identifying patients who will benefit the most from CRT remains challenging. Speckle tracking echocardiography (STE) has garnered attention as a non-invasive imaging modality that allows for the quantitative assessment of myocardial mechanics, offering insights into LV function beyond traditional echocardiographic parameters. This comprehensive review explores the role of STE in guiding patient selection and optimizing outcomes in CRT for DCM. By assessing parameters such as LV strain, strain rate, and dyssynchrony, STE enables a more precise evaluation of myocardial function and mechanical dyssynchrony, aiding in the identification of patients who are most likely to benefit from CRT. Furthermore, STE provides valuable prognostic information and facilitates post-CRT optimization by guiding lead placement and assessing response to therapy. Through an integration of STE with CRT, clinicians can enhance patient selection, improve procedural success rates, and ultimately, optimize clinical outcomes in patients with DCM. This review underscores the pivotal role of STE in advancing personalized management strategies for DCM patients undergoing CRT.
PubMed: 38893704
DOI: 10.3390/diagnostics14111178 -
Diagnostics (Basel, Switzerland) Jun 2024The benefit of prophylactic implantable cardioverter defibrillators (ICDs) in patients with severe systolic dysfunction of non-ischemic origin is still unclear, and the...
Right Bundle Branch Block Predicts Appropriate Implantable Cardioverter Defibrillator Therapies in Patients with Non-Ischemic Dilated Cardiomyopathy and a Prophylactic Implantable Cardioverter Defibrillator.
The benefit of prophylactic implantable cardioverter defibrillators (ICDs) in patients with severe systolic dysfunction of non-ischemic origin is still unclear, and the identification of patients at risk for sudden cardiac death remains a major challenge. We retrospectively reviewed all consecutive patients with non-ischemic dilated cardiomyopathy (NICM) who underwent prophylactic ICD implantation between 2008 and 2020 in two tertiary centers. Our main goal was to identify the predictors of appropriate ICD therapies (anti-tachycardia pacing [ATP] and/or shocks) in this cohort of patients. A total of 224 patients were included. After a median follow-up of 51 months, 61 patients (27.2%) required appropriate ICD therapies. Patients with appropriate ICD therapies were more frequently men (87% vs. 69%, = 0.006), of younger age (59 years, (53-65) vs. 64 years, (57-70); = 0.02), showed more right bundle branch blocks (RBBBs) (15% vs. 4%, = 0.007) and less left bundle branch blocks (LBBBs) (26% vs. 47%, = 0.005) in the ECG, and had higher left ventricular end-diastolic (100 mL/m, (90-117) vs. 86, (71-110); = 0.011) and systolic volumes (72 mL/m, (59-87) vs. 61, (47-81), = 0.05). In a multivariate competing-risks regression analysis, RBBB (HR 2.26, CI 95% 1.02-4.98, = 0.043) was identified as an independent predictor of appropriate ICD therapies. RBBBs may help to identify patients with NICM at high risk of ventricular arrhythmias and requiring ICD intervention.
PubMed: 38893699
DOI: 10.3390/diagnostics14111173 -
Journal of Clinical Medicine May 2024-related dilated cardiomyopathy (-DCM) caused by mutations in the lamin A/C gene () is one of the most common forms of hereditary DCM. Due to the high risk of mutation...
-related dilated cardiomyopathy (-DCM) caused by mutations in the lamin A/C gene () is one of the most common forms of hereditary DCM. Due to the high risk of mutation transmission to offspring and the high incidence of ventricular arrhythmia and sudden death even before the onset of heart failure symptoms, it is very important to identify -mutation carriers. However, many relatives of -DCM patients do not report to specialized centers for clinical or genetic screening. Therefore, an easily available tool to identify at-risk subjects is needed. We compared two cohorts of young, asymptomatic relatives of DCM patients who reported for screening: 29 mutation carriers and 43 individuals from the control group. Receiver operating characteristic (ROC) curves for potential indicators of mutation carriership status were analyzed. PR interval, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and high-sensitivity cardiac troponin T (hscTnT) serum levels were higher in the mutation carrier cohort. Neither group differed significantly with regard to creatinine concentration or left ventricular ejection fraction. The best mutation carriership discriminator was hscTnT level with an optimal cut-off value at 5.5 ng/L, for which sensitivity and specificity were 86% and 93%, respectively. The median hscTnT level was 11.0 ng/L in mutation carriers vs. <3.0 ng/L in the control group, < 0.001. Wherever access to genetic testing is limited, mutation carriership status can be assessed reliably using the hscTnT assay. Among young symptomless relatives of -DCM patients, a hscTnT level >5.5 ng/L strongly suggests mutation carriers.
PubMed: 38892874
DOI: 10.3390/jcm13113164