Ultrasensitive Proteomics of Trace Cardiac Tissues with Anchor-Nanoparticles.

Pathological cardiac hypertrophy is a complex process that often leads to heart failure. Label-free proteomics has emerged as an important platform to reveal protein variations and to elucidate the mechanisms of cardiac hypertrophy. Endomyocardial biopsy is a minimally invasive technique for sampling cardiac tissue, but it yields only limited amounts of an ethically permissible specimen. After regular pathological examination, the remaining trace samples pose significant challenges for effective protein extraction and mass spectrometry analysis. Herein, we developed trace cardiac tissue proteomics based on the anchor-nanoparticles (TCPA) method. We identified an average of 6666 protein groups using ∼50 µg of myocardial interventricular septum samples by TCPA. We then applied TCPA to acquire proteomics from patients' cardiac samples both diagnosed as hypertrophic hearts and myocarditis controls and identified significant alterations in pathways such as regulation of actin cytoskeleton, oxidative phosphorylation, and cGMP-PKG signaling pathway. Moreover, we found multiple lipid metabolic pathways to be dysregulated in transthyretin cardiac amyloidosis compared to other types of cardiac hypertrophy. TCPA offers a new technique for studying pathological cardiac hypertrophy and can serve as a platform toolbox for proteomic research in other cardiac diseases.

Imaging cardiac hypertrophy in hypertrophic cardiomyopathy and its differential diagnosis.

PURPOSE OF REVIEW: The aim of this study was to review imaging of myocardial hypertrophy in hypertrophic cardiomyopathy (HCM) and its phenocopies. The introduction of cardiac myosin inhibitors in HCM has emphasized the need for careful evaluation of the underlying cause of myocardial hypertrophy. RECENT FINDINGS: Advances in imaging of myocardial hypertrophy have focused on improving precision, diagnosis, and predicting prognosis. From improved assessment of myocardial mass and function, to assessing myocardial fibrosis without the use of gadolinium, imaging continues to be the primary tool in understanding myocardial hypertrophy and its downstream effects. Advances in differentiating athlete's heart from HCM are noted, and the increasing rate of diagnosis in cardiac amyloidosis using noninvasive approaches is especially highlighted due to the implications on treatment approach. Finally, recent data on Fabry disease are shared as well as differentiating other phenocopies from HCM. SUMMARY: Imaging hypertrophy in HCM and ruling out other phenocopies is central to the care of patients with HCM. This space will continue to rapidly evolve, as disease-modifying therapies are under investigation and being advanced to the clinic.

Long Noncoding RNA Cardiac Physiological Hypertrophy-Associated Regulator Induces Cardiac Physiological Hypertrophy and Promotes Functional Recovery After Myocardial Ischemia-Reperfusion Injury.

BACKGROUND: The benefits of exercise training in the cardiovascular system have been well accepted; however, the underlying mechanism remains to be explored. Here, we report the initial functional characterization of an exercise-induced cardiac physiological hypertrophy-associated novel long noncoding RNA (lncRNA). METHODS: Using lncRNA microarray profiling, we identified lncRNAs in contributing the modulation of exercise-induced cardiac growth that we termed cardiac physiological hypertrophy-associated regulator (CPhar). Mice with adeno-associated virus serotype 9 driving CPhar overexpression and knockdown were used in in vivo experiments. Swim training was used to induce physiological cardiac hypertrophy in mice, and ischemia reperfusion injury surgery was conducted to investigate the protective effects of CPhar in mice. To investigate the mechanisms of CPhar's function, we performed various analyses including quantitative reverse transcription polymerase chain reaction, Western blot, histology, cardiac function (by echocardiography), functional rescue experiments, mass spectrometry, in vitro RNA transcription, RNA pulldown, RNA immunoprecipitation, chromatin immunoprecipitation assay, luciferase reporter assay, and coimmunoprecipitation assays. RESULTS: We screened the lncRNAs in contributing the modulation of exercise-induced cardiac growth through lncRNA microarray profiling and found that CPhar was increased with exercise and was necessary for exercise-induced physiological cardiac growth. The gain and loss of function of CPhar regulated the expression of proliferation markers, hypertrophy, and apoptosis in cultured neonatal mouse cardiomyocytes. Overexpression of CPhar prevented myocardial ischemia reperfusion injury and cardiac dysfunction in vivo. We identified DDX17 (DEAD-Box Helicase 17) as a binding partner of CPhar in regulating CPhar downstream factor ATF7 (activating transcription factor 7) by sequestering C/EBPß (CCAAT/enhancer binding protein beta). CONCLUSIONS: Our study of this lncRNA CPhar provides new insights into the regulation of exercise-induced cardiac physiological growth, demonstrating the cardioprotective role of CPhar in the heart, and expanding our mechanistic understanding of lncRNA function, as well.

Targeting E3 Ubiquitin Ligase WWP1 Prevents Cardiac Hypertrophy Through Destabilizing DVL2 via Inhibition of K27-Linked Ubiquitination.

BACKGROUND: Without adequate treatment, pathological cardiac hypertrophy induced by sustained pressure overload eventually leads to heart failure. WWP1 (WW domain-containing E3 ubiquitin protein ligase 1) is an important regulator of aging-related pathologies, including cancer and cardiovascular diseases. However, the role of WWP1 in pressure overload-induced cardiac remodeling and heart failure is yet to be determined. METHODS: To examine the correlation of WWP1 with hypertrophy, we analyzed WWP1 expression in patients with heart failure and mice subjected to transverse aortic constriction (TAC) by Western blotting and immunohistochemical staining. TAC surgery was performed on WWP1 knockout mice to assess the role of WWP1 in cardiac hypertrophy, heart function was examined by echocardiography, and related cellular and molecular markers were examined. Mass spectrometry and coimmunoprecipitation assays were conducted to identify the proteins that interacted with WWP1. Pulse-chase assay, ubiquitination assay, reporter gene assay, and an in vivo mouse model via AAV9 (adeno-associated virus serotype 9) were used to explore the mechanisms by which WWP1 regulates cardiac remodeling. AAV9 carrying cardiac troponin T (cTnT) promoter-driven small hairpin RNA targeting WWP1 (AAV9-cTnT-shWWP1) was administered to investigate its rescue role in TAC-induced cardiac dysfunction. RESULTS: The WWP1 level was significantly increased in the hypertrophic hearts from patients with heart failure and mice subjected to TAC. The results of echocardiography and histology demonstrated that WWP1 knockout protected the heart from TAC-induced hypertrophy. There was a direct interaction between WWP1 and DVL2 (disheveled segment polarity protein 2). DVL2 was stabilized by WWP1-mediated K27-linked polyubiquitination. The role of WWP1 in pressure overload-induced cardiac hypertrophy was mediated by the DVL2/CaMKII/HDAC4/MEF2C signaling pathway. Therapeutic targeting WWP1 almost abolished TAC induced heart dysfunction, suggesting WWP1 as a potential target for treating cardiac hypertrophy and failure. CONCLUSIONS: We identified WWP1 as a key therapeutic target for pressure overload induced cardiac remodeling. We also found a novel mechanism regulated by WWP1. WWP1 promotes atypical K27-linked ubiquitin multichain assembly on DVL2 and exacerbates cardiac hypertrophy by the DVL2/CaMKII/HDAC4/MEF2C pathway.

HINT1 (Histidine Triad Nucleotide-Binding Protein 1) Attenuates Cardiac Hypertrophy Via Suppressing HOXA5 (Homeobox A5) Expression.

BACKGROUND: Cardiac hypertrophy is an important prepathology of, and will ultimately lead to, heart failure. However, the mechanisms underlying pathological cardiac hypertrophy remain largely unknown. This study aims to elucidate the effects and mechanisms of HINT1 (histidine triad nucleotide-binding protein 1) in cardiac hypertrophy and heart failure. METHODS: HINT1 was downregulated in human hypertrophic heart samples compared with nonhypertrophic samples by mass spectrometry analysis. Hint1 knockout mice were challenged with transverse aortic constriction surgery. Cardiac-specific overexpression of HINT1 mice by intravenous injection of adeno-associated virus 9 (AAV9)-encoding Hint1 under the cTnT (cardiac troponin T) promoter were subjected to transverse aortic construction. Unbiased transcriptional analyses were used to identify the downstream targets of HINT1. AAV9 bearing shRNA against Hoxa5 (homeobox A5) was administrated to investigate whether the effects of HINT1 on cardiac hypertrophy were HOXA5-dependent. RNA sequencing analysis was performed to recapitulate possible changes in transcriptome profile.Coimmunoprecipitation assays and cellular fractionation analyses were conducted to examine the mechanism by which HINT1 regulates the expression of HOXA5. RESULTS: The reduction of HINT1 expression was observed in the hearts of hypertrophic patients and pressure overloaded-induced hypertrophic mice, respectively. In Hint1-deficient mice, cardiac hypertrophy deteriorated after transverse aortic construction. Conversely, cardiac-specific overexpression of HINT1 alleviated cardiac hypertrophy and dysfunction. Unbiased profiler polymerase chain reaction array showed HOXA5 is 1 target for HINT1, and the cardioprotective role of HINT1 was abolished by HOXA5 knockdown in vivo. Hoxa5 was identified to affect hypertrophy through the TGF-ß (transforming growth factor ß) signal pathway. Mechanically, HINT1 inhibited PKCß1 (protein kinase C ß type 1) membrane translocation and phosphorylation via direct interaction, attenuating the MEK/ERK/YY1 (mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/yin yang 1) signal pathway, downregulating HOXA5 expression, and eventually attenuating cardiac hypertrophy. CONCLUSIONS: HINT1 protects against cardiac hypertrophy through suppressing HOXA5 expression. These findings indicate that HINT1 may be a potential target for therapeutic interventions in cardiac hypertrophy and heart failure.

Adaptation to exercise-induced stress is not dependent on cardiomyocyte α1A-adrenergic receptors.

The 'fight or flight' response to physiological stress involves sympathetic nervous system activation, catecholamine release and adrenergic receptor stimulation. In the heart, this induces positive inotropy, previously attributed to the ß1-adrenergic receptor subtype. However, the role of the α1A-adrenergic receptor, which has been suggested to be protective in cardiac pathology, has not been investigated in the setting of physiological stress. To explore this, we developed a tamoxifen-inducible, cardiomyocyte-specific α1A-adrenergic receptor knock-down mouse model, challenged mice to four weeks of endurance swim training and assessed cardiac outcomes. With 4-OH tamoxifen treatment, expression of the α1A-adrenergic receptor was knocked down by 80-89%, without any compensatory changes in the expression of other adrenergic receptors, or changes to baseline cardiac structure and function. Swim training caused eccentric hypertrophy, regardless of genotype, demonstrated by an increase in heart weight/tibia length ratio (30% and 22% in vehicle- and tamoxifen-treated animals, respectively) and an increase in left ventricular end diastolic volume (30% and 24% in vehicle- and tamoxifen-treated animals, respectively) without any change in the wall thickness/chamber radius ratio. Consistent with physiological hypertrophy, there was no increase in fetal gene program (Myh7, Nppa, Nppb or Acta1) expression. In response to exercise-induced volume overload, stroke volume (39% and 30% in vehicle- and tamoxifen-treated animals, respectively), cardiac output/tibia length ratio (41% in vehicle-treated animals) and stroke work (61% and 33% in vehicle- and tamoxifen-treated animals, respectively) increased, regardless of genotype. These findings demonstrate that cardiomyocyte α1A-adrenergic receptors are not necessary for cardiac adaptation to endurance exercise stress and their acute ablation is not deleterious.

A peptide of the amino-terminus of GRK2 induces hypertrophy and yet elicits cardioprotection after pressure overload.

G protein-coupled receptor (GPCR) kinase 2 (GRK2) expression and activity are elevated early on in response to several forms of cardiovascular stress and are a hallmark of heart failure. Interestingly, though, in addition to its well-characterized role in regulating GPCRs, mounting evidence suggests a GRK2 "interactome" that underlies a great diversity in its functional roles. Several such GRK2 interacting partners are important for adaptive and maladaptive myocyte growth; therefore, an understanding of domain-specific interactions with signaling and regulatory molecules could lead to novel targets for heart failure therapy. Herein, we subjected transgenic mice with cardiac restricted expression of a short, amino terminal fragment of GRK2 (ßARKnt) to pressure overload and found that unlike their littermate controls or previous GRK2 fragments, they exhibited an increased left ventricular wall thickness and mass prior to cardiac stress that underwent proportional hypertrophic growth to controls after acute pressure overload. Importantly, despite this enlarged heart, ßARKnt mice did not undergo the expected transition to heart failure observed in controls. Further, ßARKnt expression limited adverse left ventricular remodeling and increased cell survival signaling. Proteomic analysis to identify ßARKnt binding partners that may underlie the improved cardiovascular phenotype uncovered a selective functional interaction of both endogenous GRK2 and ßARKnt with AKT substrate of 160 kDa (AS160). AS160 has emerged as a key downstream regulator of insulin signaling, integrating physiological and metabolic cues to couple energy demand to membrane recruitment of Glut4. Our preliminary data indicate that in ßARKnt mice, cardiomyocyte insulin signaling is improved during stress, with a coordinate increase in spare respiratory activity and ATP production without metabolite switching. Surprisingly, these studies also revealed a significant decrease in gonadal fat weight, equivalent to human abdominal fat, in male ßARKnt mice at baseline and following cardiac stress. These data suggest that the enhanced AS160-mediated signaling in the ßARKnt mice may ameliorate pathological cardiac remodeling through direct modulation of insulin signaling within cardiomyocytes, and translate these to beneficial effects on systemic metabolism.

Scoparone alleviates Ang II-induced pathological myocardial hypertrophy in mice by inhibiting oxidative stress.

Long-term poorly controlled myocardial hypertrophy often leads to heart failure and sudden death. Activation of ras-related C3 botulinum toxin substrate 1 (RAC1) by angiotensin II (Ang II) plays a pivotal role in myocardial hypertrophy. Previous studies have demonstrated that scoparone (SCO) has beneficial effects on hypertension and extracellular matrix remodelling. However, the function of SCO on Ang II-mediated myocardial hypertrophy remains unknown. In our study, a mouse model of myocardial hypertrophy was established by Ang II infusion (2 mg/kg/day) for 4 weeks, and SCO (60 mg/kg bodyweight) was administered by gavage daily. In vitro experiments were also performed. Our results showed that SCO could alleviate Ang II infusion-induced cardiac hypertrophy and fibrosis in mice. In vitro, SCO treatment blocks Ang II-induced cardiomyocyte hypertrophy, cardiac fibroblast collagen synthesis and differentiation to myofibroblasts. Meanwhile, we found that SCO treatment blocked Ang II-induced oxidative stress in cardiomyocytes and cardiac fibroblasts by inhibiting RAC1-GTP and total RAC1 in vivo and in vitro. Furthermore, reactive oxygen species (ROS) burst by overexpression of RAC1 completely abolished SCO-mediated protection in cardiomyocytes and cardiac fibroblasts in vitro. In conclusion, SCO, an antioxidant, may attenuate Ang II-induced myocardial hypertrophy by suppressing of RAC1 mediated oxidative stress.

Role of metabolomics in identifying cardiac hypertrophy: an overview of the past 20 years of development and future perspective.

Cardiac hypertrophy (CH) is an augmentation of either the right ventricular or the left ventricular mass in order to compensate for the increase of work load on the heart. Metabolic abnormalities lead to histological changes of cardiac myocytes and turn into CH. The molecular mechanisms that lead to initiate CH have been of widespread concern, hence the development of the new field of research, metabolomics: one 'omics' approach that can reveal comprehensive information of the paradigm shift of metabolic pathways network in contrast to individual enzymatic reaction-based metabolites, have attempted and until now only 19 studies have been conducted using experimental animal and human specimens. Nuclear magnetic resonance spectroscopy and mass spectrometry-based metabolomics studies have found that CH is a metabolic disease and is mainly linked to the harmonic imbalance of glycolysis, citric acid cycle, amino acids and lipid metabolism. The current review will summarise the main outcomes of the above mentioned 19 studies that have expanded our understanding of the molecular mechanisms that may lead to CH and eventually to heart failure.

Behavioral and cognitive functioning in individuals with Cantú syndrome.

Cantú syndrome (CS) is caused by pathogenic variants in ABCC9 and KCNJ8 encoding the regulatory and pore-forming subunits of ATP-sensitive potassium (KATP ) channels. CS is characterized by congenital hypertrichosis, distinctive facial features, peripheral edema, and cardiac and neurodevelopmental abnormalities. Behavioral and cognitive issues have been self-reported by some CS individuals, but results of formal standardized investigations have not been published. To assess the cognitive profile, social functioning, and psychiatric symptoms in a large group of CS subjects systematically in a cross-sectional manner, we invited 35 individuals (1-69 years) with confirmed ABCC9 variants and their relatives to complete various commonly applied standardized age-related questionnaires, including the Kaufman brief intelligence test 2, the social responsiveness scale-2, and the Achenbach system of empirically based assessment. The majority of CS individuals demonstrated average verbal and nonverbal intelligence compared to the general population. Fifteen percent of cases showed social functioning strongly associated with a clinical diagnosis of autism spectrum disorder. Both externalizing and internalizing problems were also present in this cohort. In particular, anxiety, anxiety or attention deficit hyperactivity disorder, and autism spectrum behaviors were predominantly observed in the younger subjects in the cohort (≥25%), but this percentage decreased markedly in adults.

Beyond fitness tracking: The use of consumer-grade wearable data from normal volunteers in cardiovascular and lipidomics research.

The use of consumer-grade wearables for purposes beyond fitness tracking has not been comprehensively explored. We generated and analyzed multidimensional data from 233 normal volunteers, integrating wearable data, lifestyle questionnaires, cardiac imaging, sphingolipid profiling, and multiple clinical-grade cardiovascular and metabolic disease markers. We show that subjects can be stratified into distinct clusters based on daily activity patterns and that these clusters are marked by distinct demographic and behavioral patterns. While resting heart rates (RHRs) performed better than step counts in being associated with cardiovascular and metabolic disease markers, step counts identified relationships between physical activity and cardiac remodeling, suggesting that wearable data may play a role in reducing overdiagnosis of cardiac hypertrophy or dilatation in active individuals. Wearable-derived activity levels can be used to identify known and novel activity-modulated sphingolipids that are in turn associated with insulin sensitivity. Our findings demonstrate the potential for wearables in biomedical research and personalized health.

Engineered Circular RNA Sponges Act as miRNA Inhibitors to Attenuate Pressure Overload-Induced Cardiac Hypertrophy.

Circular RNAs (circRNAs) sequester microRNAs (miRNAs) and repress their endogenous activity. We hypothesized that artificial circRNA sponges (circmiRs) can be constructed to target miRNAs therapeutically, with a low dosage requirement and extended half-lives compared to current alternatives. This could present a new treatment approach for critical global pathologies, including cardiovascular disease. Here, we constructed a circmiR sponge to target known cardiac pro-hypertrophic miR-132 and -212. Expressed circmiRs competitively inhibited miR-132 and -212 activity in luciferase rescue assays and showed greater stability than linear sponges. A design containing 12 bulged binding sites with 12 nucleotides spacing was determined to be optimal. Adeno-associated viruses (AAVs) were used to deliver circmiRs to cardiomyocytes in vivo in a transverse aortic constriction (TAC) mouse model of cardiac disease. Hypertrophic disease characteristics were attenuated, and cardiac function was preserved in treated mice, demonstrating the potential of circmiRs as novel therapeutic tools. Subsequently, group I permutated intron-exon sequences were used to directly synthesize exogenous circmiRs, which showed greater in vitro efficacy than the current gold standard antagomiRs in inhibiting miRNA function. Engineered circRNAs thus offer exciting potential as future therapeutics.

Serum microRNA-30d is a sensitive biomarker for angiotensin II-induced cardiovascular complications in rats.

We tested the hypothesis that angiotensin II (Ang II)-induced cardiovascular complications are distinguished from what catecholamine-induced by their serum circulating biomarkers in rats. Infusion of Ang II (1.68 mg/kg/day) significantly increased systolic and diastolic blood pressure assessed at week one or later, accompanied by an increase of heart/body weight ratio. Noradrenaline infusion (5.40 mg/kg/day) produced a similar degree of hypertension, but did not increase heart weight. Ang II-, but not noradrenaline-induced hypertension was associated with a drastic upregulation of serum microRNA-30d (miR-30d) by hundreds of times, accompanied by an increase of miR-30d levels in the atrium but not in the ventricle. Ang II, but not noradrenaline, significantly increased mRNA of brain natriuretic peptide (BNP) in the atrium. Studies using rat neonatal cardiomyocytes in vitro demonstrated that BNP caused an increase of miR-30d when applied for 6 h or longer in the culture medium. In vitro application of Ang II increased the cell size, although BNP and miR-30d were unable to mimic the effect of Ang II. We conclude that serum circulating microRNA-30d is a sensitive biomarker for Ang II-induced cardiovascular complications. It is also postulated that Ang II-induced cardiomyocyte hypertrophy could be independent of miR-30d/BNP signaling pathways.

Pachymic Acid Attenuated Doxorubicin-Induced Heart Failure by Suppressing miR-24 and Preserving Cardiac Junctophilin-2 in Rats.

Defects in cardiac contractility and heart failure (HF) are common following doxorubicin (DOX) administration. Different miRs play a role in HF, and their targeting was suggested as a promising therapy. We aimed to target miR-24, a suppressor upstream of junctophilin-2 (JP-2), which is required to affix the sarcoplasmic reticulum to T-tubules, and hence the release of Ca2+ in excitation-contraction coupling using pachymic acid (PA) and/or losartan (LN). HF was induced with DOX (3.5 mg/kg, i.p., six doses, twice weekly) in 24 rats. PA and LN (10 mg/kg, daily) were administered orally for four weeks starting the next day of the last DOX dose. Echocardiography, left ventricle (LV) biochemical and histological assessment and electron microscopy were conducted. DOX increased serum BNP, HW/TL, HW/BW, mitochondrial number/size and LV expression of miR-24 but decreased EF, cardiomyocyte fiber diameter, LV content of JP-2 and ryanodine receptors-2 (RyR2). Treatment with either PA or LN reversed these changes. Combined PA + LN attained better results than monotherapies. In conclusion, HF progression following DOX administration can be prevented or even delayed by targeting miR-24 and its downstream JP-2. Our results, therefore, suggest the possibility of using PA alone or as an adjuvant therapy with LN to attain better management of HF patients, especially those who developed tolerance toward LN.

Inhibition of the Notch1 pathway induces peripartum cardiomyopathy.

Increased expression and activity of cardiac and circulating cathepsin D and soluble fms-like tyrosine kinase-1 (sFlt-1) have been demonstrated to induce and promote peripartum cardiomyopathy (PPCM) via promoting cleavage of 23-kD prolactin (PRL) to 16-kD PRL and neutralizing vascular endothelial growth factor (VEGF), respectively. We hypothesized that activation of Hes1 is proposed to suppress cathepsin D via activating Stat3, leading to alleviated development of PPCM. In the present study, we aimed to investigate the role of Notch1/Hes1 pathway in PPCM. Pregnant mice between prenatal 3 days and postpartum 3 weeks were fed with LY-411575 (a notch inhibitor, 10 mg/kg/d). Ventricular function and pathology were evaluated by echocardiography and histological analysis. Western blotting analysis was used to examine the expression at the protein level. The results found that inhibition of Notch1 significantly promoted postpartum ventricular dilatation, myocardial hypertrophy and myocardial interstitial fibrosis and suppressed myocardial angiogenesis. Western blotting analysis showed that inhibition of Notch1 markedly increased cathepsin D and sFlt-1, reduced Hes1, phosphorylated Stat3 (p-Stat3), VEGFA and PDGFB, and promoted cleavage of 23k-D PRL to 16-kD PRL. Collectively, inhibition of Notch1/Hes1 pathway induced and promoted PPCM via increasing the expressions of cathepsin D and sFlt-1. Notch1/Hes1 was a promising target for prevention and therapeutic regimen of PPCM.

Up-regulation of miR-195 contributes to cardiac hypertrophy-induced arrhythmia by targeting calcium and potassium channels.

Previous studies have confirmed that miR-195 expression is increased in cardiac hypertrophy, and the bioinformatics website predicted by Targetscan software shows that miR-195 can directly target CACNB1, KCNJ2 and KCND3 to regulate Cavß1, Kir2.1 and Kv4.3 proteins expression. The purpose of this study is to confirm the role of miR-195 in arrhythmia caused by cardiac hypertrophy. The protein levels of Cavß1, Kir2.1 and Kv4.3 in myocardium of HF mice were decreased. After miR-195 was overexpressed in neonatal mice cardiomyocytes, the expression of ANP, BNP and ß-MHC was up-regulated, and miR-195 inhibitor reversed this phenomenon. Overexpression of miR-195 reduced the estimated cardiac function of EF% and FS% in wild-type (WT) mice. Transmission electron microscopy showed that the ultrastructure of cardiac tissues was damaged after miR-195 overexpression by lentivirus in mice. miR-195 overexpression increased the likelihood of arrhythmia induction and duration of arrhythmia in WT mice. Lenti-miR-195 inhibitor carried by lentivirus can reverse the decreased EF% and FS%, the increased incidence of arrhythmia and prolonged duration of arrhythmia induced by TAC in mice. After miR-195 treatment, the protein expressions of Cavß1, Kir2.1 and Kv4.3 were decreased in mice. The results were consistent at animal and cellular levels, respectively. Luciferase assay results showed that miR-195 may directly target CACNB1, KCNJ2 and KCND3 to regulate the expression of Cavß1, Kir2.1 and Kv4.3 proteins. MiR-195 is involved in arrhythmia caused by cardiac hypertrophy by inhibiting Cavß1, Kir2.1 and Kv4.3.

New formula for cardiothoracic ratio for the diagnosis of cardiomegaly on post-mortem CT.

The cardiothoracic ratio (CTR) is considered to be a reliable detector of cardiomegaly on computed tomography for livings, with a threshold of 0.5. Our study aimed to establish an adjusted CTR-based score to predict cardiac hypertrophy at PMCT. We selected adult's autopsy cases examined between 2009 and 2016. Two groups were considered, a normal heart weight group and an overweighed heart group. The CTR was measured on axial images. Logistic regression analysis was performed to investigate the discriminating power of the CTR between groups when adjusted to the confounding factors. Sixty-six cases with normal heart weight and 94 cases with overweighed heart were analyzed. The factors associated to the cardiac hypertrophy are CTR (p value 0.003, OR 3.57), BMI (p value 0.055, OR 1.09), age (p value < 0.001, OR 1.67), and gender (p value 0.002, OR 4.85). The area under the ROC curve (receiver operating characteristic curve) was 0.77 when using CTR alone and 0.88 when considering BMI, age, and gender. In conclusion, CTR alone cannot be used to discriminate between normal heart weight and overweighed heart at PMCT. A new formula has been developed, including age, gender, and BMI. Dilatation of the cardiac chambers, which is a subjective evaluation, influences the CTR measure and could be not related to a pre-existing cardiac hypertrophy. This new score formula allows to overpasses this subjective step. We proposed a cut-off value of the score of 32 for the diagnosis of cardiac hypertrophy. The Internet/smartphone application (http://calc.chuv.ch/CTR) facilitates its routine application.

First reported case of unrepaired tetralogy of Fallot complicated with coronavirus disease-19 (COVID-19).

The incidence of novel coronavirus disease-19 (nCoV-19) and its associated complications is higher in high-risk groups. In this article, we explain the symptoms and course of the disease and the treatment for an adult patient with CHD who has been infected with novel nCoV-19.

High-throughput single-molecule RNA imaging analysis reveals heterogeneous responses of cardiomyocytes to hemodynamic overload.

BACKGROUND: The heart responds to hemodynamic overload through cardiac hypertrophy and activation of the fetal gene program. However, these changes have not been thoroughly examined in individual cardiomyocytes, and the relation between cardiomyocyte size and fetal gene expression remains elusive. We established a method of high-throughput single-molecule RNA imaging analysis of in vivo cardiomyocytes and determined spatial and temporal changes during the development of heart failure. METHODS AND RESULTS: We applied three novel single-cell analysis methods, namely, single-cell quantitative PCR (sc-qPCR), single-cell RNA sequencing (scRNA-seq), and single-molecule fluorescence in situ hybridization (smFISH). Isolated cardiomyocytes and cross sections from pressure overloaded murine hearts after transverse aortic constriction (TAC) were analyzed at an early hypertrophy stage (2 weeks, TAC2W) and at a late heart failure stage (8 weeks, TAC8W). Expression of myosin heavy chain ß (Myh7), a representative fetal gene, was induced in some cardiomyocytes in TAC2W hearts and in more cardiomyocytes in TAC8W hearts. Expression levels of Myh7 varied considerably among cardiomyocytes. Myh7-expressing cardiomyocytes were significantly more abundant in the middle layer, compared with the inner or outer layers of TAC2W hearts, while such spatial differences were not observed in TAC8W hearts. Expression levels of Myh7 were inversely correlated with cardiomyocyte size and expression levels of mitochondria-related genes. CONCLUSIONS: We developed a new image-analysis pipeline to allow automated and unbiased quantification of gene expression at the single-cell level and determined the spatial and temporal regulation of heterogenous Myh7 expression in cardiomyocytes after pressure overload.

Molecular biomarkers in cardiac hypertrophy.

Cardiac hypertrophy is characterized by an increase in myocyte size in the absence of cell division. This condition is thought to be an adaptive response to cardiac wall stress resulting from the enhanced cardiac afterload. The pathogenesis of heart dysfunction, which is one of the primary causes of morbidity and mortality in elderly people, is often associated with myocardial remodelling caused by cardiac hypertrophy. In order to well understand the potential mechanisms, we described the molecules involved in the development and progression of myocardial hypertrophy. Increasing evidence has indicated that micro-RNAs are involved in the pathogenesis of cardiac hypertrophy. In addition, molecular biomarkers including vascular endothelial growth factor B, NAD-dependent deacetylase sirtuin-3, growth/differentiation factor 15 and glycoprotein 130, also play important roles in the development of myocardial hypertrophy. Knowing the regulatory mechanisms of these biomarkers in the heart may help identify new molecular targets for the treatment of cardiac hypertrophy.