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European Journal of Pharmacology Jun 2024Fenofibrate, a PPAR-α agonist clinically used to lower serum lipid levels, reduces cardiac remodeling and improves cardiac function. However, its mechanism of action is...
Fenofibrate, a PPAR-α agonist clinically used to lower serum lipid levels, reduces cardiac remodeling and improves cardiac function. However, its mechanism of action is not completely elucidated. In this study we examined the effect of fenofibrate on mitochondria in a rat model of renovascular hypertension, focusing on mediators controlling mitochondrial dynamics and autophagy. Rats with two-kidney one-clip (2K1C) hypertension were treated with fenofibrate 150 mg/kg/day (2K1C-FFB) or vehicle (2K1C-VEH) for 8 weeks. Systolic blood pressure and cardiac functional were in-vivo assessed, while cardiomyocyte size and protein expression of mediators of cardiac hypertrophy and mitochondrial dynamics were ex-vivo examined by histological and Western blot analyses. Fenofibrate treatment counteracted the development of hypertension and the increase of left ventricular mass, relative wall thickness and cross-sectional area of cardiomyocytes. Furthermore, fenofibrate re-balanced the expression Mfn2, Drp1 and Parkin, regulators of fusion, fission, mitophagy respectively. Regarding autophagy, the LC3-II/LC3-I ratio was increased in 2K1C-VEH and 2K1C-FFB, whereas the autophagy was increased only in 2K1C-FFB. In cultured H9C2 cardiomyoblasts, fenofibrate reversed the Ang II-induced mRNA up-regulation of hypertrophy markers Nppa and Myh7, accumulation of reactive oxygen species and depolarization of the mitochondrial membrane exerting protection mediated by up-regulation of the Uncoupling protein 2. Our results indicate that fenofibrate acts directly on cardiomyocytes and counteracts the pressure overload-induced cardiac maladaptive remodeling. This study reveals a so far hidden mechanism involving mitochondrial dynamics in the beneficial effects of fenofibrate, support its repurposing for the treatment of cardiac hypertrophy and provide new potential targets for its pharmacological function.
PubMed: 38909934
DOI: 10.1016/j.ejphar.2024.176767 -
Biomedical Engineering Online Jun 2024Left ventricular enlargement (LVE) is a common manifestation of cardiac remodeling that is closely associated with cardiac dysfunction, heart failure (HF), and...
BACKGROUND
Left ventricular enlargement (LVE) is a common manifestation of cardiac remodeling that is closely associated with cardiac dysfunction, heart failure (HF), and arrhythmias. This study aimed to propose a machine learning (ML)-based strategy to identify LVE in HF patients by means of pulse wave signals.
METHOD
We constructed two high-quality pulse wave datasets comprising a non-LVE group and an LVE group based on the 264 HF patients. Fourier series calculations were employed to determine if significant frequency differences existed between the two datasets, thereby ensuring their validity. Then, the ML-based identification was undertaken by means of classification and regression models: a weighted random forest model was employed for binary classification of the datasets, and a densely connected convolutional network was utilized to directly estimate the left ventricular diastolic diameter index (LVDdI) through regression. Finally, the accuracy of the two models was validated by comparing their results with clinical measurements, using accuracy and the area under the receiver operating characteristic curve (AUC-ROC) to assess their capability for identifying LVE patients.
RESULTS
The classification model exhibited superior performance with an accuracy of 0.91 and an AUC-ROC of 0.93. The regression model achieved an accuracy of 0.88 and an AUC-ROC of 0.89, indicating that both models can quickly and accurately identify LVE in HF patients.
CONCLUSION
The proposed ML methods are verified to achieve effective classification and regression with good performance for identifying LVE in HF patients based on pulse wave signals. This study thus demonstrates the feasibility and potential of the ML-based strategy for clinical practice while offering an effective and robust tool for diagnosing and intervening ventricular remodeling.
Topics: Humans; Heart Failure; Machine Learning; Female; Male; Pulse Wave Analysis; Middle Aged; Aged; Signal Processing, Computer-Assisted; Hypertrophy, Left Ventricular
PubMed: 38909231
DOI: 10.1186/s12938-024-01257-5 -
Medicina 2024Fabry disease (FD) is an X-linked lysosomal storage disorder affecting glycosphingolipid metabolism. Most FD patients have cardiac involvement, mainly manifested as left... (Observational Study)
Observational Study
INTRODUCTION
Fabry disease (FD) is an X-linked lysosomal storage disorder affecting glycosphingolipid metabolism. Most FD patients have cardiac involvement, mainly manifested as left ventricular hypertrophy (LVH), leading to early death due to complications (arrhythmias, valvular disease, vascular involvement). Early initiation of enzyme replacement therapy (ERT) before fibrosis development has been associated with better cardiac outcomes in terms of left ventricular mass index (LVMI) and functional parameters.
METHODS
A retrospective observational study was conducted in patients with FD treated with agalsidase alfa for at least 2 years. The primary objectives were: [a] to assess the annual rate of change in LVMI; [b] to define the overall incidence of stability, regression or progression of LVMI.
RESULTS
Forty-nine patients were included in the final analysis, with a median follow-up of 7 years. The overall change in LVMI was 0.38 g/m2.73/year, without significant influence of baseline LVH, gender, age at ERT initiation, LV ejection fraction, body mass index, renal disease, and classical cardiovascular risk factors. Long-term ERT with agalsidase alfa was associated with stabilization of LVMI in 98% of patients with FD and was independent of the same covariables.
CONCLUSION
Our results are in line with previous literature of comparable FD populations and probably represent the first study of its kind in Argentina. We here highlight the importance of cardiac morphometric stability as a positive outcome of ERT.
Topics: Humans; Fabry Disease; Male; Female; Retrospective Studies; alpha-Galactosidase; Hypertrophy, Left Ventricular; Adult; Enzyme Replacement Therapy; Middle Aged; Isoenzymes; Recombinant Proteins; Treatment Outcome; Follow-Up Studies; Time Factors
PubMed: 38907966
DOI: No ID Found -
Medicina 2024The different structural modifications that have been described in the heart of the high-performance athlete depend on factors such as age, gender, type of sport, and... (Comparative Study)
Comparative Study
INTRODUCTION
The different structural modifications that have been described in the heart of the high-performance athlete depend on factors such as age, gender, type of sport, and the intensity and time dedicated to training.
OBJECTIVES
Evaluation of elite athletes through echocardiography for the description of cardiac structure and function, and the comparison between athletes with cardiorespiratory endurance and the rest of the athletes.
METHODS
We performed the echocardiographic examination in 224 elite athletes, 96 women and 128 men aged 15 to 38 years (21.7 ± 5.3 years) and they were divided into 2 groups: "Endurance Group" (cardiorespiratory endurance) and "Non-Endurance Group" which included the rest of the sports. Univariate comparison between the two groups was performed by measuring 14 echocardiographic variables.
RESULTS
In men, statistically significant higher values were identified in the endurance group for interventricular septum, left ventricular posterior wall, relative wall thickness (RWT), left ventricular mass index and left atrial dimension. In women, the endurance group had significantly lower heart rate values, and significantly higher left ventricular diastolic dimension with normal RWT.
CONCLUSIONS
Most of the echocardiographic variables showed higher sample means in the endurance athletes. In the subgroup of men from the Endurance Group, eccentric hypertrophy prevailed with a greater increase in wall thickness, as well as in the diameter of the left atrium, while in women the variables indicated eccentric hypertrophy at the expense of an increase in left ventricle diameter, without increased wall thickness.
Topics: Humans; Male; Female; Adult; Physical Endurance; Young Adult; Echocardiography; Adolescent; Athletes; Adaptation, Physiological; Heart Rate; Sex Factors; Heart Ventricles
PubMed: 38907955
DOI: No ID Found -
SAGE Open Medical Case Reports 2024Midventricular obstruction (MVO) is a rare form of hypertrophic cardiomyopathy (HCM). While surgical treatment for HCM is among the most technically challenging cardiac...
Midventricular obstruction (MVO) is a rare form of hypertrophic cardiomyopathy (HCM). While surgical treatment for HCM is among the most technically challenging cardiac operations for acquired disease, surgery for MVO is rarely reported. A 38-year-old man was admitted to our hospital with a cough and dyspnea. Transthoracic and transesophageal echography and computed tomography revealed extensive left ventricular hypertrophy, extending from the anteroseptal wall to the apex, and marked papillary muscle hypertrophy. We underwent septal myectomy via aortotomy (Morrow procedure) and apical surgery. Extended myectomy provides the best exposure to the hypertrophied septum and improves the functional status of patients.
PubMed: 38903183
DOI: 10.1177/2050313X241263704 -
BioRxiv : the Preprint Server For... Apr 2024Hypertrophic cardiomyopathy (HCM) is associated with phenotypic variability. To gain insights into transcriptional regulation of cardiac phenotype, single-nucleus linked...
Hypertrophic cardiomyopathy (HCM) is associated with phenotypic variability. To gain insights into transcriptional regulation of cardiac phenotype, single-nucleus linked RNA-/ATAC-seq was performed in 5-week-old control mouse-hearts (WT) and two HCM-models (R92W-TnT, R403Q-MyHC) that exhibit differences in heart size/function and fibrosis; mutant data was compared to WT. Analysis of 23,304 nuclei from mutant hearts, and 17,669 nuclei from WT, revealed similar dysregulation of gene expression, activation of AP-1 TFs (FOS, JUN) and the SWI/SNF complex in both mutant ventricular-myocytes. In contrast, marked differences were observed between mutants, for gene expression/TF enrichment, in fibroblasts, macrophages, endothelial cells. Cellchat predicted activation of pro-hypertrophic IGF-signaling in both mutant ventricular-myocytes, and profibrotic TGFβ-signaling only in mutant-TnT fibroblasts. In summary, our bioinformatics analyses suggest that activation of IGF-signaling, AP-1 TFs and the SWI/SNF chromatin remodeler complex promotes myocyte hypertrophy in early-stage HCM. Selective activation of TGFβ-signaling in mutant-TnT fibroblasts contributes to genotype-specific differences in cardiac fibrosis.
PubMed: 38903075
DOI: 10.1101/2024.04.24.589078 -
Kidney International Reports Jun 2024Fluid and salt overload in patients on dialysis result in high blood pressure (BP), left ventricular hypertrophy (LVH) and hemodynamic instability, resulting in...
INTRODUCTION
Fluid and salt overload in patients on dialysis result in high blood pressure (BP), left ventricular hypertrophy (LVH) and hemodynamic instability, resulting in cardiovascular morbidity.
METHODS
Analysis of 910 pediatric patients on maintenance hemodialysis/hemodiafiltration (HD/HDF), prospectively followed-up with 2758 observations recorded every 6-months in the International Pediatric Hemodialysis Network (IPHN).
RESULTS
Uncontrolled hypertension was present in 55% of observations, with 27% of patients exhibiting persistently elevated predialysis BP. Systolic and diastolic age- and height-standardized BP (BP-SDS) were independently associated with the number of antihypertensive medications (odds ratio [OR] = 1.47, 95% confidence interval 1.39-1.56, 1.36 [1.23-1.36]) and interdialytic weight gain (IDWG; 1.19 [1.14-1.22], 1.09 [1.06-1.11]; all < 0.0001). IDWG was related to urine output (OR = 0.27 [0.23-0.32]) and dialysate sodium (dNa; 1.06 [1.01-1.10]; all < 0.0001). The prevalence of masked hypertension was 24%, and HD versus HDF use was an independent risk factor of elevated age- and height-standardized mean arterial pressure (MAP-SDS) (OR = 2.28 [1.18-4.41], = 0.01). Of the 1135 echocardiograms, 51% demonstrated LVH. Modifiable risk factors included predialysis systolic BP-SDS (OR = 1.06 [1.04-1.09], < 0.0001), blood hemoglobin (0.97 [0.95-0.99], = 0.004), HD versus HDF modality (1.09 [1.02-1.18], = 0.01), and IDWG (1.02 [1.02-1.03], = 0.04). In addition, HD modality increased the risk of LVH progression (OR = 1.23 [1.03-1.48], = 0.02). Intradialytic hypotension (IDH) was prevalent in patients progressing to LVH and independently associated with predialysis BP-SDS below 25th percentile, lower number of antihypertensives, HD versus HDF modality, ultrafiltration (UF) rate, and urine output, but not with dNa.
CONCLUSION
Uncontrolled hypertension and LVH are common in pediatric HD, despite intense pharmacologic therapy. The outcome may improve with use of HDF, and superior anemia and IDWG control; the latter via lowering dNa, without increasing the risk of IDH.
PubMed: 38899176
DOI: 10.1016/j.ekir.2024.03.016 -
BioRxiv : the Preprint Server For... Jun 2024Heart failure with preserved ejection fraction (HFpEF) is increasingly common but its pathogenesis is poorly understood. The ability to assess genetic and pharmacologic...
UNLABELLED
Heart failure with preserved ejection fraction (HFpEF) is increasingly common but its pathogenesis is poorly understood. The ability to assess genetic and pharmacologic interventions is hampered by the lack of robust preclinical mouse models of HFpEF. We have developed a novel "2-hit" model, which combines obesity and insulin resistance with chronic pressure overload to recapitulate clinical features of HFpEF. C57BL6/NJ mice fed a high fat diet for >10 weeks were administered an AAV8-driven vector resulting in constitutive overexpression of mouse . Control mice, HFD only, Renin only and HFD-Renin (aka "HFpEF") littermates underwent a battery of cardiac and extracardiac phenotyping. HFD-Renin mice demonstrated obesity and insulin resistance, a 2-3-fold increase in circulating renin levels that resulted in 30-40% increase in left ventricular hypertrophy, preserved systolic function, and diastolic dysfunction indicated by altered E/e', IVRT, and strain measurements; increased left atrial mass; elevated natriuretic peptides; and exercise intolerance. Transcriptomic and metabolomic profiling of HFD-Renin myocardium demonstrated upregulation of pro-fibrotic pathways and downregulation of metabolic pathways, in particular branched chain amino acid catabolism, similar to findings in human HFpEF. Treatment of these mice with the sodium-glucose cotransporter 2 inhibitor empagliflozin, an effective but incompletely understood HFpEF therapy, improved exercise tolerance, left heart enlargement, and insulin homeostasis. The HFD-Renin mouse model recapitulates key features of human HFpEF and will enable studies dissecting the contribution of individual pathogenic drivers to this complex syndrome. Addition of HFD-Renin mice to the preclinical HFpEF model platform allows for orthogonal studies to increase validity in assessment of interventions.
NEW & NOTEWORTHY
Heart failure with preserved ejection fraction (HFpEF) is a complex disease to study due to limited preclinical models. We rigorously characterize a new two-hit HFpEF mouse model, which allows for dissecting individual contributions and synergy of major pathogenic drivers, hypertension and diet-induced obesity. The results are consistent and reproducible in two independent laboratories. This high-fidelity pre-clinical model increases the available, orthogonal models needed to improve our understanding of the causes and assessment treatments for HFpEF.
PubMed: 38895483
DOI: 10.1101/2024.06.06.597821 -
International Journal of Molecular... Jun 2024Increased mitochondrial reactive oxygen species (ROS) formation is important for the development of right ventricular (RV) hypertrophy (RVH) and failure (RVF) during...
Does Cell-Type-Specific Silencing of Monoamine Oxidase B Interfere with the Development of Right Ventricle (RV) Hypertrophy or Right Ventricle Failure in Pulmonary Hypertension?
Increased mitochondrial reactive oxygen species (ROS) formation is important for the development of right ventricular (RV) hypertrophy (RVH) and failure (RVF) during pulmonary hypertension (PH). ROS molecules are produced in different compartments within the cell, with mitochondria known to produce the strongest ROS signal. Among ROS-forming mitochondrial proteins, outer-mitochondrial-membrane-located monoamine oxidases (MAOs, type A or B) are capable of degrading neurotransmitters, thereby producing large amounts of ROS. In mice, MAO-B is the dominant isoform, which is present in almost all cell types within the heart. We analyzed the effect of an inducible cardiomyocyte-specific knockout of MAO-B (cmMAO-B KO) for the development of RVH and RVF in mice. Right ventricular hypertrophy was induced by pulmonary artery banding (PAB). RV dimensions and function were measured through echocardiography. ROS production (dihydroethidium staining), protein kinase activity (PamStation device), and systemic hemodynamics (in vivo catheterization) were assessed. A significant decrease in ROS formation was measured in cmMAO-B KO mice during PAB compared to Cre-negative littermates, which was associated with reduced activity of protein kinases involved in hypertrophic growth. In contrast to littermates in which the RV was dilated and hypertrophied following PAB, RV dimensions were unaffected in response to PAB in cmMAO-B KO mice, and no decline in RV systolic function otherwise seen in littermates during PAB was measured in cmMAO-B KO mice. In conclusion, cmMAO-B KO mice are protected against RV dilatation, hypertrophy, and dysfunction following RV pressure overload compared to littermates. These results support the hypothesis that cmMAO-B is a key player in causing RV hypertrophy and failure during PH.
Topics: Animals; Hypertrophy, Right Ventricular; Monoamine Oxidase; Hypertension, Pulmonary; Mice; Mice, Knockout; Reactive Oxygen Species; Myocytes, Cardiac; Heart Failure; Male; Disease Models, Animal; Heart Ventricles; Ventricular Dysfunction, Right
PubMed: 38892401
DOI: 10.3390/ijms25116212 -
International Journal of Molecular... May 2024The association between vitamin D deficiency and cardiovascular disease remains a controversial issue. This study aimed to further elucidate the role of vitamin D...
Ablation of Vitamin D Signaling in Cardiomyocytes Leads to Functional Impairment and Stimulation of Pro-Inflammatory and Pro-Fibrotic Gene Regulatory Networks in a Left Ventricular Hypertrophy Model in Mice.
The association between vitamin D deficiency and cardiovascular disease remains a controversial issue. This study aimed to further elucidate the role of vitamin D signaling in the development of left ventricular (LV) hypertrophy and dysfunction. To ablate the vitamin D receptor (VDR) specifically in cardiomyocytes, VDR mice were crossed with Mlcv2-Cre mice. To induce LV hypertrophy experimentally by increasing cardiac afterload, transverse aortic constriction (TAC) was employed. Sham or TAC surgery was performed in 4-month-old, male, wild-type, VDR, Mlcv2-Cre, and cardiomyocyte-specific VDR knockout (VDR) mice. As expected, TAC induced profound LV hypertrophy and dysfunction, evidenced by echocardiography, aortic and cardiac catheterization, cardiac histology, and LV expression profiling 4 weeks post-surgery. Sham-operated mice showed no differences between genotypes. However, TAC VDR mice, while having comparable cardiomyocyte size and LV fibrosis to TAC VDR controls, exhibited reduced fractional shortening and ejection fraction as measured by echocardiography. Spatial transcriptomics of heart cryosections revealed more pronounced pro-inflammatory and pro-fibrotic gene regulatory networks in the stressed cardiac tissue niches of TAC VDR compared to VDR mice. Hence, our study supports the notion that vitamin D signaling in cardiomyocytes plays a protective role in the stressed heart.
Topics: Animals; Myocytes, Cardiac; Mice; Hypertrophy, Left Ventricular; Receptors, Calcitriol; Vitamin D; Gene Regulatory Networks; Fibrosis; Signal Transduction; Male; Disease Models, Animal; Mice, Knockout; Inflammation
PubMed: 38892126
DOI: 10.3390/ijms25115929