Impact of blood factors on endothelial cell metabolism and function in two diverse heart failure models.

Role of blood-based factors in development and progression of heart failure (HF) is poorly characterized. Blood contains factors released during pathophysiological states that may impact cellular function and provide mechanistic insights to HF management. We tested effects of blood from two distinct HF models on cardiac metabolism and identified possible cellular targets of the effects. Blood plasma was obtained from daunorubicin- and myocardial infarction-induced HF rabbits (Dauno-HF and MI-HF) and their controls (Dauno-Control and MI-Control). Effects of plasma on bioenergetics of myocardial tissue from healthy mice and cellular cardiac components were assessed using high-resolution respirometry and Seahorse flux analyzer. Since endothelial cell respiration was profoundly affected by HF plasma, effects of plasma on endothelial cell barrier function and death were further evaluated. Western-blotting and electron microscopy were performed to evaluate mitochondrial proteins and morphology. Brief exposure to HF plasma decreased cardiac tissue respiration. Endothelial cell respiration was most impacted by exposure to HF plasma. Endothelial cell monolayer integrity was decreased by incubation with Dauno-HF plasma. Apoptosis and necrosis were increased in cells incubated with Dauno-HF plasma for 24 h. Down-regulation of voltage-dependent anion-selective channel (VDAC)-1, translocase of outer membrane 20 (Tom20), and mitochondrial fission factor (MFF) in cells exposed to Dauno-HF plasma and mitochondrial signal transducer and activator of transcription 3 (Stat3) and MFF in cells exposed to MI-HF plasma were observed. Mitochondrial structure was disrupted in cells exposed to HF plasma. These findings indicate that endothelial cells and mitochondrial structure and function may be primary target where HF pathology manifests and accelerates. High-throughput blood-based screening of HF may provide innovative ways to advance disease diagnosis and management.

Cardiac features of Noonan syndrome in Japanese patients.

BACKGROUND: Cardiovascular disease is one of the most important problems in long-term follow-up for Noonan syndrome. We examined cardiovascular issues and clinical manifestations, with a focus on the cardiovascular disease and prognosis of patients with Noonan syndrome. METHODS: This single-centre study evaluated patients who were clinically and genetically diagnosed with Noonan syndrome. RESULTS: Forty-three patients diagnosed with Noonan syndrome were analysed. The most prevalent responsible mutation was found in PTPN11 (25/43). The second and third most prevalent causative genes were SOS1 (6/43) and RIT1 (5/43), respectively, and 67.4% of genetically diagnosed patients with Noonan syndrome had structural cardiovascular abnormalities. Pulmonary valve stenosis was prevalent in patients with mutations in PTPN11 (8/25), SOS1 (4/6), and RIT1 (4/5). Hypertrophic cardiomyopathy was found in two of three patients with mutations in RAF1. There was no difference in the cardiovascular events or cardiovascular disease prevalence in patients with or without PTPN11 mutations. The proportion of RIT1 mutation-positive patients who underwent intervention due to cardiovascular disease was significantly higher than that of patients with PTPN11 mutations. Patients who underwent any intervention for pulmonary valve stenosis exhibited significantly higher pulmonary flow velocity than patients who did not undergo intervention, when they visited our hospital for the first time. All patients who underwent intervention for pulmonary valve stenosis had a pulmonary flow velocity of more than 3.0 m/s at first visit. CONCLUSIONS: These findings suggest that genetic information can provide a clinical prognosis for cardiovascular disease and may be part of genotype-based follow-up in Noonan syndrome.

Electrocardiographic Changes with Age in Japanese Patients with Noonan Syndrome.

Little information is available on age-related electrocardiographic changes in patients with Noonan syndrome. This single-center study evaluated the electrocardiograms of patients with Noonan syndrome. We divided the patients (n = 112; electrocardiograms, 256) into four groups according to age: G1 (1 month-1 year), G2 (1-6 years), G3 (6-12 years), and G4 (>12 years). Typical Noonan syndrome-related electrocardiographic features such as left-axis deviation, abnormal Q wave, wide QRS complex, and small R wave in precordial leads were detected. A high percentage of QRS axis abnormalities was found in all groups. Significant differences in right-axis deviation (RAD) were noted among the groups: 56.5% of G1 patients showed RAD compared with 33.3% of G2, 21.1% of G3, and 19.2% of G4 patients. The small R was also significantly different among the groups: 32.6% of G1 patients showed a small R wave compared with 14.9% of G2, 8.5% of G3, and 15.4% of G4 patients. Of the 53 patients with Noonan syndrome aged 1 month to 2 years, 18 had T-positive V1 with a higher prevalence of pulmonary stenosis and cardiac interventions. QRS axis abnormalities, small R in V6, and T-positive V1 could help diagnose Noonan syndrome in infants or young children.

Assessment of the left ventricular volume of tetralogy of Fallot by electrocardiogram.

BACKGROUND: Sufficient left ventricular volume is required for patients with tetralogy of Fallot (TOF) who are going to have biventricular repair. In this study, we investigated the utility of the electrocardiogram to evaluate left ventricular volume in patients with TOF. METHOD: Patients whose left ventricular (LV) end-diastolic volume was lower than 80% of normal were defined as having a small LV. Seven patients with TOF who had to undergo Blalock-Taussig shunt surgery because of a small LV were assigned to group S. Twenty patients with TOF who had sufficient LV volume were assigned to group G. The amplitudes of the Q wave of V5-7 leads (QV5-QV7), the S wave of V1 lead, and the R wave of the II, III, aVf, and V5-7 leads of the electrocardiogram were evaluated. RESULTS: The amplitude of QV5 was 0 mV in all cases in group S, which was significantly smaller than that in group G (0 vs 0.01 mV, P = 0.028). The frequency of absent QV5 was significantly higher in group S than in group G (100% vs 50%, P = 0.026). Absent QV5 showed 100% sensitivity, 50% specificity, and a negative predictive value of 100% for a small LV. CONCLUSIONS: In TOF, the amplitude of the septal Q wave reflects LV volume. In particular, the absence of QV5 suggests a small LV end-diastolic volume, which is lower than 80% of normal.

Progressive Left Ventricular Outflow Tract Stenosis in a Noonan Syndrome Patient With Severe Hypertrophic Cardiomyopathy During Growth Hormone Treatment.

Short stature is a main problem in Noonan syndrome (NS). Recombinant human growth hormone (GH) has been used to safely improve the growth rate in NS patients with short stature. However, there is little information about GH therapy for NS associated with hypertrophic obstructive cardiomyopathy. We present the case of a seven-year-old NS patient with severe hypertrophic obstructive cardiomyopathy. The patient received GH therapy for six months, at which time progressive left ventricular outflow tract stenosis was apparent.

A Case of NAA10-related Syndrome With Prolonged QTc Treated With a Subcutaneous Implantable Cardioverter Defibrillator After Ventricular Fibrillation.

NAA10 is an enzyme involved in the N-terminal acetylation of proteins. NAA10-related syndrome is caused by a pathogenic variant of NAA10 on X chromosome, resulting in several phenotypes, including mental retardation, hypotonia, growth retardation, and various external malformations, with varying degrees of severity. With regard to cardiac diseases, hypertrophic cardiomyopathy is a possible complication. Some mutations are also associated with long QT syndrome. Herein, we describe the case of a 7-year-old boy with a novel NAA10 mutation who experienced cardiopulmonary arrest possibly due to long QT syndrome and was implanted with a subcutaneous implantable cardioverter defibrillator.

La NAA10 est une enzyme qui intervient dans l'acétylation N-terminale des protéines. Le syndrome lié au gène NAA10 est causé par un variant pathogène du NAA10 sur le chromosome X qui entraîne plusieurs phénotypes, comme une déficience intellectuelle, une hypotonie, un retard de croissance ou différentes malformations externes, et ce, à divers degrés de sévérité. En ce qui concerne les maladies cardiaques, une cardiomyopathie hypertrophique est une complication possible. Certaines mutations sont également associées au syndrome du QT long. Nous décrivons ici le cas d'un garçon âgé de sept ans qui présente une nouvelle mutation du gène NAA10 et qui a fait un arrêt cardiorespiratoire, possiblement en raison d'un syndrome du QT long. L'enfant a reçu un défibrillateur cardiaque implantable sous-cutané.

Transient phrenic nerve palsy induced by cardiac catheterisation in an infant.

We report on a 7-month-old male with transient phrenic nerve palsy induced by diagnostic cardiac catheterisation. The phrenic nerve palsy, which is a rare complication, was due to extravascular bleeding from a branch of the internal mammary artery.

Cardiac features in a patient with erythrokeratodermia cardiomyopathy syndrome.

Patients with erythrokeratodermia cardiomyopathy syndrome exhibit congenital, generalised erythrokeratoderma and dilated cardiomyopathy during early childhood. We report a case of erythrokeratodermia cardiomyopathy syndrome in a 15-year-old male patient and focus this report on cardiac features that were present.

A retrospective study of perioperative clinical seizures and epilepsy in children after operation for CHD.

This study investigated the incidence and risk factors of perioperative clinical seizure and epilepsy in children after operation for CHD. We included 777 consecutive children who underwent operation from January 2013 to December 2016 at Kanagawa Children's Medical Center, Kanagawa, Japan. Perinatal, perioperative, and follow-up medical data were collected. Elastic net regression and mediation analysis were performed to investigate risk factors of perioperative clinical seizure and epilepsy. Anatomic CHD classification was performed based on the preoperative echocardiograms; cardiac surgery was evaluated using Risk Adjustment in Congenital Heart Surgery 1. Twenty-three (3.0%) and 15 (1.9%) patients experienced perioperative clinical seizure and epilepsy, respectively. Partial regression coefficient with epilepsy as the objective variable for anatomical CHD classification, Risk Adjustment in Congenital Heart Surgery 1, and the number of surgeries was 0.367, 0.014, and 0.142, respectively. The proportion of indirect effects on epilepsy via perioperative clinical seizure was 22.0, 21.0, and 33.0%, respectively. The 15 patients with epilepsy included eight cases with cerebral infarction, two cases with cerebral haemorrhage, and three cases with hypoxic-ischaemic encephalopathy; white matter integrity was not found. Anatomical complexity of CHD, high-risk cardiac surgery, and multiple cardiac surgeries were identified as potential risk factors for developing epilepsy, with a low rate of indirect involvement via perioperative clinical seizure and a high rate of direct involvement independently of perioperative clinical seizure. Unlike white matter integrity, stroke and hypoxic-ischaemic encephalopathy were identified as potential factors for developing epilepsy.

Correlation of exercise-induced peripheral venous hypertension with exercise intolerance in patients with Fontan circulation.

Owing to the absence of a sub-pulmonary ventricle, the central venous pressure rises in patients with Fontan circulation. During exercise, central venous pressure may rise further to increase the systemic ventricular preload and cardiac output. We performed a single-centre prospective trial of cardiopulmonary exercise test while monitoring peripheral venous pressure which strongly correlates with central venous pressure. The objective of this study was to test the hypothesis that peripheral venous pressure at peak exercise inversely correlates with exercise capacity in patients with Fontan circulation. Seventeen patients following Fontan operation performed cardiopulmonary exercise test while monitoring peripheral venous pressure. Peak oxygen uptake, heart rate reserve, peak oxygen pulse (divided by body surface area), and peripheral venous pressure at peak exercise were measured. Correlations of peripheral venous pressure at peak exercise with the peak oxygen uptake, heart rate reserve, and peak oxygen pulse were evaluated. The peripheral venous pressure at peak exercise inversely correlated with the peak oxygen uptake (R = -0.66, p < 0.01), heart rate reserve (R = -0.6, p < 0.05), and peak oxygen pulse (R = -0.48, p < 0.05). Exercise-induced peripheral venous hypertension correlates with exercise intolerance in patients with Fontan circulation. Peak oxygen uptake is a useful index for evaluating the status of congestion in the daily life of patients with Fontan circulation.

Transcriptome Analysis Reveals Differential Gene Expression between the Closing Ductus Arteriosus and the Patent Ductus Arteriosus in Humans.

The ductus arteriosus (DA) immediately starts closing after birth. This dynamic process involves DA-specific properties, including highly differentiated smooth muscle, sparse elastic fibers, and intimal thickening (IT). Although several studies have demonstrated DA-specific gene expressions using animal tissues and human fetuses, the transcriptional profiles of the closing DA and the patent DA remain largely unknown. We performed transcriptome analysis using four human DA samples. The three closing DA samples exhibited typical DA morphology, but the patent DA exhibited aorta-like elastic lamellae and poorly formed IT. A cluster analysis revealed that samples were clearly divided into two major clusters, the closing DA and patent DA clusters, and showed distinct gene expression profiles in IT and the tunica media of the closing DA samples. Cardiac neural crest-related genes such as JAG1 were highly expressed in the tunica media and IT of the closing DA samples compared to the patent DA sample. Abundant protein expressions of jagged 1 and the differentiated smooth muscle marker calponin were observed in the closing DA samples but not in the patent DA sample. Second heart field-related genes such as ISL1 were enriched in the patent DA sample. These data indicate that the patent DA may have different cell lineages compared to the closing DA.

Excessive EP4 Signaling in Smooth Muscle Cells Induces Abdominal Aortic Aneurysm by Amplifying Inflammation.

OBJECTIVE: Excessive prostaglandin E2 production is a hallmark of abdominal aortic aneurysm (AAA). Enhanced expression of prostaglandin E2 receptor EP4 (prostaglandin E receptor 4) in vascular smooth muscle cells (VSMCs) has been demonstrated in human AAAs. Although moderate expression of EP4 contributes to vascular homeostasis, the roles of excessive EP4 in vascular pathology remain uncertain. We aimed to investigate whether EP4 overexpression in VSMCs exacerbates AAAs. Approach and Results: We constructed mice with EP4 overexpressed selectively in VSMCs under an SM22α promoter (EP4-Tg). Most EP4-Tg mice died within 2 weeks of Ang II (angiotensin II) infusion due to AAA, while nontransgenic mice given Ang II displayed no overt phenotype. EP4-Tg developed much larger AAAs than nontransgenic mice after periaortic CaCl2 application. In contrast, EP4fl/+;SM22-Cre;ApoE-/- and EP4fl/+;SM22-Cre mice, which are EP4 heterozygous knockout in VSMCs, rarely exhibited AAA after Ang II or CaCl2 treatment, respectively. In Ang II-infused EP4-Tg aorta, Ly6Chi inflammatory monocyte/macrophage infiltration and MMP-9 (matrix metalloprotease-9) activation were enhanced. An unbiased analysis revealed that EP4 stimulation positively regulated the genes binding cytokine receptors in VSMCs, in which IL (interleukin)-6 was the most strongly upregulated. In VSMCs of EP4-Tg and human AAAs, EP4 stimulation caused marked IL-6 production via TAK1 (transforming growth factor-ß-activated kinase 1), NF-κB (nuclear factor-kappa B), JNK (c-Jun N-terminal kinase), and p38. Inhibition of IL-6 prevented Ang II-induced AAA formation in EP4-Tg. In addition, EP4 stimulation decreased elastin/collagen cross-linking protein LOX (lysyl oxidase) in both human and mouse VSMCs. CONCLUSIONS: Dysregulated EP4 overexpression in VSMCs promotes inflammatory monocyte/macrophage infiltration and attenuates elastin/collagen fiber formation, leading to AAA exacerbation.

Metabolomic analysis of serum and myocardium in compensated heart failure after myocardial infarction.

AIMS: To determine the metabolic adaptations to compensated heart failure using a reproducible model of myocardial infarction and an unbiased metabolic screen. To address the limitations in sample availability and model variability observed in preclinical and clinical metabolic investigations of heart failure. MAIN METHODS: Metabolomic analysis was performed on serum and myocardial tissue from rabbits after myocardial infarction (MI) was induced by cryo-injury of the left ventricular free wall. Rabbits followed for 12 weeks after MI exhibited left ventricular dilation and depressed systolic function as determined by echocardiography. Serum and tissue from the viable left ventricular free wall, interventricular septum and right ventricle were analyzed using a gas chromatography time of flight mass spectrometry-based untargeted metabolomics assay for primary metabolites. KEY FINDINGS: Unique results included: a two- three-fold increase in taurine levels in all three ventricular regions of MI rabbits and similarly, the three regions had increased inosine levels compared to sham controls. Reduced myocardial levels of myo-inositol in the myocardium of MI animals point to altered phospholipid metabolism and membrane receptor function in heart failure. Metabolite profiles also provide evidence for responses to oxidative stress and an impairment in TCA cycle energy production in the failing heart. SIGNIFICANCE: Our results revealed metabolic changes during compensated cardiac dysfunction and suggest potential targets for altering the progression of heart failure.

Tissue-type plasminogen activator contributes to remodeling of the rat ductus arteriosus.

AIMS: The ductus arteriosus (DA) closes after birth to adapt to the robust changes in hemodynamics, which require intimal thickening (IT) to occur. The smooth muscle cells of the DA have been reported to play important roles in IT formation. However, the roles of the endothelial cells (ECs) have not been fully investigated. We herein focused on tissue-type plasminogen activator (t-PA), which is a DA EC dominant gene, and investigated its contribution to IT formation in the DA. METHODS AND RESULTS: ECs from the DA and aorta were isolated from fetal rats using fluorescence-activated cell sorting. RT-PCR showed that the t-PA mRNA expression level was 2.7-fold higher in DA ECs than in aortic ECs from full-term rat fetuses (gestational day 21). A strong immunoreaction for t-PA was detected in pre-term and full-term rat DA ECs. t-PA-mediated plasminogen-plasmin conversion activates gelatinase matrix metalloproteinases (MMPs). Gelatin zymography revealed that plasminogen supplementation significantly promoted activation of the elastolytic enzyme MMP-2 in rat DA ECs. In situ zymography demonstrated that marked gelatinase activity was observed at the site of disruption in the internal elastic laminae (IEL) in full-term rat DA. In a three-dimensional vascular model, EC-mediated plasminogen-plasmin conversion augmented the IEL disruption. In vivo administration of plasminogen to pre-term rat fetuses (gestational day 19), in which IT is poorly formed, promoted IEL disruption accompanied by gelatinase activation and enhanced IT formation in the DA. Additionally, experiments using five human DA tissues demonstrated that the t-PA expression level was 3.7-fold higher in the IT area than in the tunica media. t-PA protein expression and gelatinase activity were also detected in the IT area of the human DAs. CONCLUSION: t-PA expressed in ECs may help to form IT of the DA via activation of MMP-2 and disruption of IEL.

Modulation of caveolins, integrins and plasma membrane repair proteins in anthracycline-induced heart failure in rabbits.

Anthracyclines are chemotherapeutic drugs known to induce heart failure in a dose-dependent manner. Mechanisms involved in anthracycline cardiotoxicity are an area of relevant investigation. Caveolins bind, organize and regulate receptors and signaling molecules within cell membranes. Caveolin-3 (Cav-3), integrins and related membrane repair proteins can function as cardioprotective proteins. Expression of these proteins in anthracycline-induced heart failure has not been evaluated. We tested the hypothesis that daunorubicin alters cardioprotective protein expression in the heart. Rabbits were administered daunorubicin (3 mg/kg, IV) weekly, for three weeks or nine weeks. Nine weeks but not three weeks of daunorubicin resulted in progressive reduced left ventricular function. Cav-3 expression in the heart was unchanged at three weeks of daunorubicin and increased in nine week treated rabbits when compared to control hearts. Electron microscopy showed caveolae in the heart were increased and mitochondrial number and size were decreased after nine weeks of daunorubicin. Activated beta-1 (ß1) integrin and the membrane repair protein MG53 were increased after nine weeks of daunorubicin vs. controls with no change at the three week time point. The results suggest a potential pathophysiological role for Cav3, integrins and membrane repair in daunorubicin-induced heart failure.

Pathology and molecular mechanisms of coarctation of the aorta and its association with the ductus arteriosus.

Coarctation of the aorta (CoA) is defined as a congenital stenosis of the thoracic aorta and is one of the most common congenital cardiovascular diseases. Despite successful surgical treatment for CoA, arterial abnormalities, including refractory hypertension, aortic aneurysm, and proatherogenic phenotypic changes, frequently affect patients' quality of life. Emerging evidence from morphological and molecular biological investigations suggest that the area of CoA is characterized by phenotypic modulation of smooth muscle cells, intimal thickening, and impaired elastic fiber formation. These changes extend to the pre-and post-stenotic aorta and impair arterial elasticity. The aim of this review is to present current findings on the pathology and molecular mechanisms of vascular remodeling due to CoA. In particular, we will discuss the association between CoA and the ductus arteriosus since the most common site for the stenosis is in the proximity of the ductus arteriosus.

Chylothorax associated with child abuse.

We report a case of right chylothorax associated with physical abuse in a 10-month-old boy who presented with respiratory decompensation. Chylothorax was improved by thoracic drainage and nutrition management, such as fasting followed by medium-chain triglyceride milk. Chest computed tomography on admission showed bilateral old rib fractures. Accordingly, physical abuse was suspected. Chylothorax of unknown cause in infancy, especially in those with coexisting rib fractures, must be scrutinized for child abuse.

Decreased serum osmolality promotes ductus arteriosus constriction.

AIMS: At birth, dynamic changes occur in serum components and haemodynamics, such as closure of the ductus arteriosus (DA). A previous study demonstrated that, in full-term human neonates, serum osmolality decreased transiently after birth, but recovered over the next few days. However, the significance of this transient decrease in osmolality has never been addressed. The objective of the present study was to examine the role of changes in serum osmolality after birth in DA closure. METHODS AND RESULTS: We found that rats exhibited a similar transient hypoosmolality after birth. Hypotonic stimulation induced constriction of DA rings and increased Ca(2+) transient in DA smooth muscle cells, but not in the aorta. The hypoosmotic sensor transient receptor potential melastatin 3 (TRPM3) was highly expressed in the rat DA, and TRPM3 silencing abolished the Ca(2+) response to hypoosmolality. Pregnenolone sulfate stimulation of TRPM3 induced rat DA constriction ex vivo and in vivo. Furthermore, hypertonic fluid injection impaired rat DA closure. In humans, neonatal serum hypoosmolality was observed in relatively mature preterm infants (≥28 weeks). In extremely preterm infants (<28 weeks), however, this hypoosmolality was absent. Instead, a rapid increase in osmolality occurred thereafter. Such an increase was greater, in particular, among patent DA (PDA) patients. CONCLUSIONS: A transient decrease in serum osmolality may promote DA closure during the first few days of life. Adjusting serum osmolality to proper levels might help to prevent the onset of PDA, improving the therapeutic outcome in extremely preterm infants.