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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 -
Cells May 2024During mammalian heart development, the clustered genes encoding peptide hormones, Natriuretic Peptide A (; ANP) and B (; BNP), are transcriptionally co-regulated and... (Review)
Review
During mammalian heart development, the clustered genes encoding peptide hormones, Natriuretic Peptide A (; ANP) and B (; BNP), are transcriptionally co-regulated and co-expressed predominately in the atrial and ventricular trabecular cardiomyocytes. After birth, expression of and a natural antisense transcript becomes restricted to the atrial cardiomyocytes. Both and are induced by cardiac stress and serve as markers for cardiovascular dysfunction or injury. gene products are extensively used as diagnostic and prognostic biomarkers for various cardiovascular disorders. Membrane-localized guanylyl cyclase receptors on many cell types throughout the body mediate the signaling of the natriuretic peptide ligands through the generation of intracellular cGMP, which interacts with and modulates the activity of cGMP-activated kinase and other enzymes and ion channels. The natriuretic peptide system plays a fundamental role in cardio-renal homeostasis, and its potent diuretic and vasodilatory effects provide compensatory mechanisms in cardiac pathophysiological conditions and heart failure. In addition, both peptides, but also CNP, have important intracardiac actions during heart development and homeostasis independent of the systemic functions. Exploration of the intracardiac functions may provide new leads for the therapeutic utility of natriuretic peptide-mediated signaling in heart diseases and rhythm disorders. Here, we review recent insights into the regulation of expression and intracardiac functions of and during heart development, homeostasis, and disease.
Topics: Humans; Homeostasis; Animals; Natriuretic Peptides; Heart; Heart Diseases
PubMed: 38891063
DOI: 10.3390/cells13110931 -
European Heart Journal. Case Reports Apr 2024Desmoplakin cardiomyopathy has been recently classified as a non-dilated left ventricular cardiomyopathy, which is characterized by inflammatory-like episodes followed...
BACKGROUND
Desmoplakin cardiomyopathy has been recently classified as a non-dilated left ventricular cardiomyopathy, which is characterized by inflammatory-like episodes followed by left ventricular fibrosis/dysfunction and ventricular arrhythmias. Specific management is unclear.
CASE SUMMARY
We report a detailed case of a 46-year-old Caucasian woman presenting with repeated sudden cardiac arrests who was diagnosed with a new variant in the desmoplakin gene. Because the initial 18F-fluorodeoxyglucose positron emission tomography scan showed significant hypermetabolism, she was treated with immunosuppressors, with only minimal improvement on imaging.
DISCUSSION
Desmoplakin cardiomyopathy should be considered in the differential diagnosis of inflammatory cardiomyopathies. Little is known about the use of immunosuppressive treatments, but it could be reasonable for some selected patients.
PubMed: 38887779
DOI: 10.1093/ehjcr/ytae160 -
ERJ Open Research May 2024Worldwide, 1-2% of children are born premature and at risk for developing bronchopulmonary dysplasia (BPD). Preterm-born adults are at risk for early cardiovascular...
BACKGROUND
Worldwide, 1-2% of children are born premature and at risk for developing bronchopulmonary dysplasia (BPD). Preterm-born adults are at risk for early cardiovascular disease. The role of BPD is unclear. This study aims to examine cardiorespiratory function during submaximal exercise in young adult survivors of extreme prematurity, with or without BPD.
METHODS
40 preterm-born young adults, 20 with BPD (median gestational age 27 weeks, interquartile range (IQR) 26-28 weeks) and 20 without BPD (median gestational age 28 weeks, IQR 27-29 weeks) were prospectively compared to age-matched at term-born adults (median gestational age 39 weeks, IQR 38-40 weeks). Participants underwent exercise testing and cardiovascular magnetic resonance with submaximal exercise.
RESULTS
Resting heart rate in BPD subjects was higher than in at term-born subjects (69±10 mL 61±7 mL, p=0.01). Peak oxygen uptake during maximal cardiopulmonary exercise testing was decreased in BPD subjects (91±18% 106±17% of predicted, p=0.01). In BPD subjects, cardiac stroke volume change with exercise was impaired compared to at term-born subjects (11±13% 25±10%; p<0.001). With exercise, left ventricular end-diastolic volume decreased more in preterm-born subjects with without BPD (-10±8% -3±8%; p=0.01) and compared to at term-born subjects (0±5%; p<0.001). Exploratory data analysis revealed that exercise stroke volume and end-diastolic volume change were inversely correlated with oxygen dependency in those born prematurely.
CONCLUSIONS
In preterm-born young adults, particularly those with BPD, resting cardiac function, exercise performance and cardiac response to exercise is impaired compared to controls. Exercise cardiovascular magnetic resonance may reveal an important predisposition for heart disease later in life.
PubMed: 38887679
DOI: 10.1183/23120541.00501-2023 -
Journal of Korean Medical Science Jun 2024Heart failure with preserved ejection fraction (HFpEF) is prevalent and associated with a poor prognosis, imposing a significant burden on society. Arterial stiffness is... (Review)
Review
Heart failure with preserved ejection fraction (HFpEF) is prevalent and associated with a poor prognosis, imposing a significant burden on society. Arterial stiffness is increasingly recognized as a crucial factor in the pathophysiology of HFpEF, affecting diagnosis, management, and prognosis. As a hallmark of vascular aging, arterial stiffness contributes to increased afterload on the left ventricle (LV), leading to diastolic dysfunction, a key feature of HFpEF. Elevated arterial stiffness is linked with common cardiovascular risk factors in HFpEF, such as hypertension, diabetes and obesity, exacerbating the progression of disease. Studies have demonstrated that patients with HFpEF exhibit significantly higher levels of arterial stiffness compared to those without HFpEF, highlighting the value of arterial stiffness measurements as both diagnostic and prognostic tools. Moreover, interventions aimed at reducing arterial stiffness, whether through pharmacological therapies or lifestyle modifications, have shown potential in improving LV diastolic function and patient outcomes. Despite these advancements, the precise mechanisms by which arterial stiffness contributes to HFpEF are still not fully understood, necessitating the need for further research.
Topics: Vascular Stiffness; Humans; Heart Failure; Stroke Volume; Risk Factors; Ventricular Function, Left; Prognosis
PubMed: 38887204
DOI: 10.3346/jkms.2024.39.e195 -
ESC Heart Failure Jun 2024Anthracycline chemotherapy (AC) for breast cancer can cause cancer therapy-related cardiac dysfunction (CTRCD) with resultant heart failure, traditionally defined as a...
AIMS
Anthracycline chemotherapy (AC) for breast cancer can cause cancer therapy-related cardiac dysfunction (CTRCD) with resultant heart failure, traditionally defined as a reduction in left ventricular (LV) ejection fraction on echocardiography. In recent years, global longitudinal systolic strain (GLS) has been used to identify subclinical cardiac dysfunction prior to development of overt CTRCD. Recent harmonized guidelines have incorporated GLS into definitions for CTRCD to identify cardiac dysfunction and inform decisions regarding cardioprotective strategies.
METHODS AND RESULTS
We evaluated subclinical dysfunction in breast cancer patients treated with AC and determined the echocardiographic and patient factors associated with significant GLS changes. One hundred fourteen HER2 negative patients treated with AC were prospectively recruited and underwent serial echocardiograms (LVEF and LVGLS) at three time points (prior to AC, 3 months, and 1 year). CTRCD was defined as an asymptomatic reduction in LVEF of 10% or symptomatic drop of 5% to LVEF <53%. Subclinical LV dysfunction was defined as a reduction of ≥10% in GLS compared with baseline, recognizing that this cut off identified an 'at risk cohort' rather than patients with established CTRCD. No participant demonstrated CTRCD by reduction in LVEF. Forty-three patients (38%) demonstrated a ≥10% relative reduction in GLS at 12 months; 20/43 (47%) had a reduced absolute GLS to <16%, and were older, had hypertension, increased LV mass, lower baseline e' velocity and GLS. GLS ≥20.5% at baseline yielded a sensitivity of 79% and specificity of 87% for a normal GLS (i.e., ≥16%) at 1 year despite a ≥10% reduction from baseline.
CONCLUSIONS
We present a stepwise evaluation for subclinical LV dysfunction using both a relative reduction in GLS combined with an absolute reduction in GLS. We believe our findings may re-stratify patients with a high baseline GLS into a lower risk group despite transient relative GLS decrements ≥10%.
PubMed: 38887181
DOI: 10.1002/ehf2.14884 -
BMJ Open Diabetes Research & Care Jun 2024Oxidative stress is known to affect left ventricular functions negatively. There is a strong bidirectional connection between diabetes mellitus (DM) and oxidative... (Observational Study)
Observational Study
INTRODUCTION
Oxidative stress is known to affect left ventricular functions negatively. There is a strong bidirectional connection between diabetes mellitus (DM) and oxidative stress. In parallel, left ventricular dysfunction is observed more frequently, even in patients with DM without other risk factors. In this context, the objective of this study is to comparatively investigate the potential relationship between oxidative stress and subclinical left ventricular dysfunction (SCLVD) assessed by Myocardial Performance Index (MPI) in patients with and without DM.
RESEARCH DESIGN AND METHODS
The sample of this observational cross-sectional single-center study consisted of 151 patients who were evaluated for oxidative stress and SCLVD by tissue Doppler echocardiography. Patients' total oxidant status (TOS), total antioxidant status (TAS), and Oxidative Stress Index (OSI) values were calculated. The effects of oxidative stress and DM on MPI were analyzed.
RESULTS
There were 81 patients with DM (mean age: 46.17±10.33 years) and 70 healthy individuals (mean age: 45.72±9.04 years). Mean TOS and OSI values of the DM group were higher than healthy individuals (5.72±0.55 vs 5.31±0.50, p = <0.001; and 4.92±1.93 vs 1.79±0.39, p = <0.001; respectively). The mean TAS value of the DM group was significantly lower than the healthy group (1.21±0.40 vs 3.23±0.51, p = <0.001). There was a significant correlation between OSI and MPI mitral in the DM group (R 0.554, p = <0.001) but not in the healthy group (R -0.069, p=0.249).
CONCLUSIONS
Both oxidative stress and myocardial dysfunction were found to be more common in patients with DM. The study's findings indicated the negative effect of oxidative stress on myocardial functions. Accordingly, increased oxidative stress caused more significant deterioration in MPI in patients with DM compared with healthy individuals.
Topics: Humans; Oxidative Stress; Female; Male; Middle Aged; Ventricular Dysfunction, Left; Cross-Sectional Studies; Adult; Case-Control Studies; Antioxidants; Diabetes Mellitus; Biomarkers; Ventricular Function, Left; Echocardiography, Doppler; Diabetes Mellitus, Type 2; Prognosis; Follow-Up Studies
PubMed: 38886070
DOI: 10.1136/bmjdrc-2024-004153 -
JCI Insight Jun 2024Parasympathetic dysfunction after chronic myocardial infarction (MI) is known to predispose ventricular tachyarrhythmias (VT/VF). VT/VF after MI is more common in males...
Parasympathetic dysfunction after chronic myocardial infarction (MI) is known to predispose ventricular tachyarrhythmias (VT/VF). VT/VF after MI is more common in males than females. The mechanisms underlying the decreased vagal tone and the associated sex difference in the occurrence of VT/VF after MI remain elusive. In this study, using optogenetic approaches, we found that responses of glutamatergic vagal afferent neurons were impaired following chronic MI in male mice, leading to reduced reflex efferent parasympathetic function. Molecular analyses of vagal ganglia demonstrated reduced glutamate levels, accompanied by decreased mitochondrial function and impaired redox status in infarcted males vs. sham animals. Interestingly, infarcted females demonstrated reduced vagal sensory impairment, associated with greater vagal ganglia glutamate levels and decreased vagal mitochondrial dysfunction and oxidative stress compared to infarcted males. Treatment with 17β-estradiol mitigated this pathological remodeling and improved vagal neurotransmission in infarcted male mice. These data suggest that a decrease in efferent vagal tone following MI results from reduced glutamatergic afferent vagal signaling that may be due to impaired redox homeostasis in the vagal ganglia, which subsequently leads to pathological remodeling in a sex-dependent manner. Importantly, estrogen prevents pathological remodeling and improves parasympathetic function following MI.
PubMed: 38885308
DOI: 10.1172/jci.insight.181042 -
Journal of Thoracic Disease May 2024Little is known about the role of complement activation in acute pulmonary embolism (PE). We investigated whether complement activation is associated with the severity...
BACKGROUND
Little is known about the role of complement activation in acute pulmonary embolism (PE). We investigated whether complement activation is associated with the severity of acute PE, along with the associated prothrombotic state, systemic inflammation and neutrophil extracellular traps (NETs) formation.
METHODS
We studied 109 normotensive, non-cancer PE patients (aged 58.1±15.0 years). On admission prior to initiation of anticoagulation, plasma soluble complement components, i.e., C3a and sC5b-9, were measured with enzyme-linked immunosorbent assay (ELISA), along with thrombin generation, fibrinolysis proteins (plasminogen, antiplasmin, plasminogen activator inhibitor-1), factor VIII (FVIII) activity, and fibrin clot properties, including clot permeability (K, a measure of clot density) and clot lysis time (CLT). Moreover, we determined inflammatory markers and citrullinated histone H3, a specific marker of NETs formation.
RESULTS
Patients in the lower tertile of C3a (≤1.45 ng/mL, n=37) had lower simplified Pulmonary Embolism Severity Index (sPESI) values and were less likely to have right ventricular (RV) dysfunction compared to the remaining subjects. The former subgroup also had 13% lower FVIII activity, but not fibrinogen, interleukin-6, fibrinolysis proteins, and thrombin generation. Plasma C3a levels correlated inversely with K and positively with CLT indicating formation of denser and poorly lysable clots in subjects with elevated C3a. Despite a positive association between C3a and sC5b-9, the latter parameter was solely associated with higher FVIII, but not with other variables.
CONCLUSIONS
We showed that in acute PE enhanced complement activation characterizes patients with poorer short-term prognosis who display prothrombotic fibrin clot properties and elevated FVIII, which supports the involvement of complement proteins in acute thromboembolism.
PubMed: 38883666
DOI: 10.21037/jtd-24-171