Hypertrophied Hearts Research Articles

Ketone body oxidation increases cardiac endothelial cell proliferation

Blood vessel formation is dependent on metabolic adaption in endothelial cells. Glucose and fatty acids are essential substrates for ATP and biomass production; however, the metabolism of other substrates remains poorly understood. Ketone bodies are important nutrients for cardiomyocytes during starvation or consumption of carbohydrate‐restrictive diets. This raises the question whether cardiac endothelial cells would not only transport ketone bodies but also consume some of these to achieve their metabolic needs. Here, we report that cardiac endothelial cells are able to oxidize ketone bodies and that this enhances cell proliferation, migration, and vessel sprouting. Mechanistically, this requires succinyl‐CoA:3‐oxoacid‐CoA transferase, a key enzyme of ketone body oxidation. Targeted metabolite profiling revealed that carbon from ketone bodies got incorporated into tricarboxylic acid cycle intermediates as well as other metabolites fueling biomass production. Elevation of ketone body levels by a high‐fat, low‐carbohydrate ketogenic diet transiently increased endothelial cell proliferation in mouse hearts. Notably, in a mouse model of heart hypertrophy, ketogenic diet prevented blood vessel rarefication. This suggests a potential beneficial role of dietary intervention in heart diseases.

The Chinese herbal medicine Fufang Zhenzhu Tiaozhi protects against diabetic cardiomyopathy by alleviating cardiac lipotoxicity-induced oxidative stress and NLRP3-dependent inflammasome activation

BackgroundFufang Zhenzhu Tiao Zhi (FTZ) formula is a Chinese herbal preparation used in the clinical treatment of disorders of glucolipid metabolism. Given its effective actions on the regulation of lipid dysfunction and its anti-inflammatory and antioxidative effects, we designed this study to investigate the cardioprotective effect and possible mechanism of FTZ in diabetic cardiomyopathy (DCM) mice. MethodsFTZ was administered to diabetic mice by oral gavage daily at a dose of 1.2 g/kg or 2.4 g/kg bodyweight for 8 weeks. Doppler echocardiography, H&E, and WGA staining were used to evaluate cardiac function and structure in the mice. The levels of proinflammatory cytokines and lipids in serum were detected with corresponding commercial kits. Immunofluorescence staining and flow cytometry were used to detect oxidation damage and pyroptosis in myocardial cells. RT–PCR and western blotting were used to analyze the protein and mRNA expression levels of NLRP3 inflammasome-related genes. ResultsOur study indicated that FTZ improved cardiac function, attenuated heart hypertrophy, improved serum lipid and proinflammatory cytokine levels, and restrained oxidative stress and NLRP3 inflammasome-induced inflammatory activities in diabetic mouse hearts. The in vitro data suggested that FTZ suppressed intercellular lipid accumulation as well as palmitic acid (PA)-induced oxidative stress and NLRP3 inflammasome-dependent pyroptosis in cardiomyocytes. ConclusionOur present findings indicate that FTZ inhibits DCM by inhibiting both oxidative stress and NLRP3 inflammasome activation induced by cardiac lipotoxicity.

SPARC, a Novel Regulator of Vascular Cell Function in Pulmonary Hypertension.

Pulmonary hypertension (PH) is a life-threatening disease, characterized by excessive pulmonary vascular remodeling, leading to elevated pulmonary arterial pressure and right heart hypertrophy. PH can be caused by chronic hypoxia, leading to hyper-proliferation of pulmonary arterial smooth muscle cells (PASMCs) and apoptosis-resistant pulmonary microvascular endothelial cells (PMVECs). On reexposure to normoxia, chronic hypoxia-induced PH in mice is reversible. In this study, the authors aim to identify novel candidate genes involved in pulmonary vascular remodeling specifically in the pulmonary vasculature. After microarray analysis, the authors assessed the role of SPARC (secreted protein acidic and rich in cysteine) in PH using lung tissue from idiopathic pulmonary arterial hypertension (IPAH) patients, as well as from chronically hypoxic mice. In vitro studies were conducted in primary human PASMCs and PMVECs. In vivo function of SPARC was proven in chronic hypoxia-induced PH in mice by using an adeno-associated virus-mediated Sparc knockdown approach. C57BL/6J mice were exposed to normoxia, chronic hypoxia, or chronic hypoxia with subsequent reexposure to normoxia for different time points. Microarray analysis of the pulmonary vascular compartment after laser microdissection identified Sparc as one of the genes downregulated at all reoxygenation time points investigated. Intriguingly, SPARC was vice versa upregulated in lungs during development of hypoxia-induced PH in mice as well as in IPAH, although SPARC plasma levels were not elevated in PH. TGF-β1 (transforming growth factor β1) or HIF2A (hypoxia-inducible factor 2A) signaling pathways induced SPARC expression in human PASMCs. In loss of function studies, SPARC silencing enhanced apoptosis and reduced proliferation. In gain of function studies, elevated SPARC levels induced PASMCs, but not PMVECs, proliferation. Coculture and conditioned medium experiments revealed that PMVECs-secreted SPARC acts as a paracrine factor triggering PASMCs proliferation. Contrary to the authors' expectations, in vivo congenital Sparc knockout mice were not protected from hypoxia-induced PH, most probably because of counter-regulatory proproliferative signaling. However, adeno-associated virus-mediated Sparc knockdown in adult mice significantly improved hemodynamic and cardiac function in PH mice. This study provides evidence for the involvement of SPARC in the pathogenesis of human PH and chronic hypoxia-induced PH in mice, most likely by affecting vascular cell function.

Elevated MCU Expression by CaMKIIδB Limits Pathological Cardiac Remodeling.

Calcium (Ca2+) is a key regulator of energy metabolism. Impaired Ca2+ homeostasis damages mitochondria, causing cardiomyocyte death, pathological hypertrophy, and heart failure. This study investigates the regulation and the role of the mitochondrial Ca2+ uniporter (MCU) in chronic stress-induced pathological cardiac remodeling. MCU knockout or transgenic mice were infused with isoproterenol (ISO; 10 mg/kg per day, 4 weeks). Cardiac hypertrophy and remodeling were evaluated by echocardiography and histology. Primary cultured rodent adult cardiomyocytes were treated with ISO (1 nmol/L, 48 hours). Intracellular Ca2+ handling and cell death pathways were monitored. Adenovirus-mediated gene manipulations were used in vitro. Chronic administration of the β-adrenergic receptor agonist ISO increased the levels of the MCU and the MCU complex in cardiac mitochondria, raising mitochondrial Ca2+ concentrations, in vivo and in vitro. ISO also upregulated MCU without affecting its regulatory proteins in adult cardiomyocytes. It is interesting that ISO-induced cardiac hypertrophy, fibrosis, contractile dysfunction, and cardiomyocyte death were exacerbated in global MCU knockout mice. Cardiomyocytes from knockout mice or overexpressing a dominant negative MCU exhibited defective intracellular Ca2+ handling and activation of multiple cell death pathways. Conversely, cardiac-specific overexpression of MCU maintained intracellular Ca2+ homeostasis and contractility, suppressed cell death, and prevented ISO-induced heart hypertrophy. ISO upregulated MCU expression through activation of Ca2+/calmodulin kinase II δB (CaMKIIδB) and promotion of its nuclear translocation via calcineurin-mediated dephosphorylation at serine 332. Nuclear CaMKIIδB phosphorylated CREB (cAMP-response element binding protein), which bound the Mcu promoter to enhance Mcu gene transcription. The β-adrenergic receptor/CaMKIIδB/CREB pathway upregulates Mcu gene expression in the heart. MCU upregulation is a compensatory mechanism that counteracts stress-induced pathological cardiac remodeling by preserving Ca2+ homeostasis and cardiomyocyte viability.

Cardiomyocyte BRAF and type 1 RAF inhibitors promote cardiomyocyte and cardiac hypertrophy in mice in vivo.

The extracellular signal-regulated kinase 1/2 (ERK1/2) cascade promotes cardiomyocyte hypertrophy and is cardioprotective, with the three RAF kinases forming a node for signal integration. Our aims were to determine if BRAF is relevant for human heart failure, whether BRAF promotes cardiomyocyte hypertrophy, and if Type 1 RAF inhibitors developed for cancer (that paradoxically activate ERK1/2 at low concentrations: the ‘RAF paradox') may have the same effect. BRAF was up-regulated in heart samples from patients with heart failure compared with normal controls. We assessed the effects of activated BRAF in the heart using mice with tamoxifen-activated Cre for cardiomyocyte-specific knock-in of the activating V600E mutation into the endogenous gene. We used echocardiography to measure cardiac dimensions/function. Cardiomyocyte BRAFV600E induced cardiac hypertrophy within 10 d, resulting in increased ejection fraction and fractional shortening over 6 weeks. This was associated with increased cardiomyocyte size without significant fibrosis, consistent with compensated hypertrophy. The experimental Type 1 RAF inhibitor, SB590885, and/or encorafenib (a RAF inhibitor used clinically) increased ERK1/2 phosphorylation in cardiomyocytes, and promoted hypertrophy, consistent with a ‘RAF paradox' effect. Both promoted cardiac hypertrophy in mouse hearts in vivo, with increased cardiomyocyte size and no overt fibrosis. In conclusion, BRAF potentially plays an important role in human failing hearts, activation of BRAF is sufficient to induce hypertrophy, and Type 1 RAF inhibitors promote hypertrophy via the ‘RAF paradox'. Cardiac hypertrophy resulting from these interventions was not associated with pathological features, suggesting that Type 1 RAF inhibitors may be useful to boost cardiomyocyte function.

Downregulation of PTEN Promotes Autophagy via Concurrent Reduction in Apoptosis in Cardiac Hypertrophy in PPAR α-/- Mice.

Cardiac hypertrophy is characterized by an increase in the size of the cardiomyocytes which is initially triggered as an adaptive response but ultimately becomes maladaptive with chronic exposure to different hypertrophic stimuli. Prolonged cardiac hypertrophy is often associated with mitochondrial dysfunctions and cardiomyocyte cell death. Peroxisome proliferator activated receptor alpha (PPAR α), which is critical for mitochondrial biogenesis and fatty acid oxidation, is down regulated in hypertrophied cardiomyocytes. Yet, the role of PPAR α in cardiomyocyte death is largely unknown. To assess the role of PPAR α in chronic hypertrophy, isoproterenol, a β-adrenergic receptor agonist was administered in PPAR α knock out (PPAR α−/−) mice for 2 weeks and hypertrophy associated changes in cardiac tissues were observed. Echocardiographic analysis ensured the development of cardiac hypertrophy and compromised hemodynamics in PPAR α−/− mice. Proteomic analysis using high resolution mass spectrometer identified about 1,200 proteins enriched in heart tissue. Proteins were classified according to biological pathway and molecular functions. We observed an unexpected down regulation of apoptotic markers, Annexin V and p53 in hypertrophied heart tissue. Further validation revealed a significant down regulation of apoptosis regulator, PTEN, along with other apoptosis markers like p53, Caspase 9 and c-PARP. The autophagy markers Atg3, Atg5, Atg7, p62, Beclin1 and LC3 A/B were up regulated in PPAR α−/− mice indicating an increase in autophagy. Similar observations were made in a high cholesterol diet fed PPAR α−/−mice. The results were further validated in vitro using NRVMs and H9C2 cell line by blocking PPAR α that resulted in enhanced autophagosome formation upon hypertrophic stimulation. The results demonstrate that in the absence of PPAR α apoptotic pathway is inhibited while autophagy is enhanced. The data suggest that PPAR α signaling might act as a molecular switch between apoptosis and autophagy thereby playing a critical role in adaptive process in cardiac hypertrophy.

Consumption of combined fructose and sucrose diet exacerbates oxidative stress, hypertrophy and CaMKIIδ oxidation in hearts from rats with metabolic syndrome.

The prevalence of the metabolic syndrome (MetS) and its cardiac comorbidities as cardiac hypertrophy (CH) have increased considerably due to the high consumption of carbohydrates, such as sucrose and/or fructose. We compared the effects of sucrose (S), fructose (F) and their combination (S + F) on the development of MetS in weaned male Wistar rats and established the relationship between the consumption of these sugars and the degree of cardiac CH development, oxidative stress (OS) and Calcium/calmodulin-dependent protein kinase type II subunit delta oxidation (ox-CaMKIIδ). 12weeks after the beginning of treatments with S, F or S + F, arterial pressure was measured and 8weeks later (to complete 20weeks) the animals were sacrificed and blood samples, visceral adipose tissue and hearts were obtained. Biochemical parameters were determined in serum and cardiac tissue to evaluate the development of MetS and OS. To evaluate CH, atrial natriuretic peptide (ANP), CaMKIIδ and ox-CaMKIIδ were determined by western blot and histological studies were performed in cardiac tissue. Our data showed that chronic consumption of S + F exacerbates MetS-induced CH which is related with a higher OS and ox-CaMKIIδ.

Strain-volume loops for assessment of diastolic function in hypertrophic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background Diastolic function assessment in patients with hypertrophic hearts and preserved ejection fraction (EF) is a rather challenging task, necessitating the introduction of new parameters. Strain-volume loops (SVLs), based on simultaneous frame-by-frame strain and volume changes’ recordings acquired by means of three-dimensional (3D) speckle tracking imaging, is an innovative tool which has been applied in various substrates. The ability of SVLs to assess diastolic function in hypertrophic cardiomyopathy (HCM) has not been investigated until now. Purpose Aim of this study was to investigate potential correlations between SVLs, traditional diastolic function indices and phenotypic features of HCM (thickness, obstruction and fibrosis) that may also reflect myocardial "stiffness". Methods We included 40 HCM patients (54.1 ± 14.3 years, 82.5% male, maximum wall thickness 19.3 ± 4.8mm) who have consecutively undergone 3D-speckle tracking echocardiography (panel A) and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Values of 3D strain were plotted vs. volume for each frame to build an SVL. Peak of radial, longitudinal and circumferential systolic strain (Rsp, Lsp, and Csp, respectively), systolic slopes of the loops (RsSl, LsSl, CsSl), strain to end-diastolic volume (EDV) ratios (Rs/V, Ls/V, Cs/V) as well as the extent of systolic-diastolic uncoupling (difference between systolic and diastolic strain for the same volume) were computed for the analysis. Left atrial volume index (LAVI), E/E’ and tricuspid regurgitation velocity (TRvel) were measured to define diastolic dysfunction (DD) stage. Burden of fibrosis was evaluated by LGE extent in CMR slices. Results All HCM patients had preserved EF (60.5 ± 5,7%), while 16 (40%) had LV outflow tract obstruction (LVOTO > 30 mm Hg at rest). Mean LV mass index was 78.9 ± 14.5 g (evaluated by 3D echocardiography). LGE was observed in 23 patients (57.5%) occupying 5.2 ± 4.5% of LV mass. Concerning SVLs the following values were recorded for radial (Rsp 30.8 ± 9.8%, RsSl 0.4 ± 0.13 and Rs/V 0.25 ± 0.09), longitudinal (Lsp -9.4 ± 3.7%, LsSl 0.12 ± 0.06 and Ls/V 0.08 ± 0.04) and circumferential deformation (Csp -14.2 ± 3.5%, CsSl 0.18 ± 0.05 and Cs/V 0.11 ± 0.03). Traditional isolated diastolic indices (E/E’, LAVI, TRvel and DD stage) did not present significant correlations with SVL parameters or HCM phenotypic features. However, potentially "stiffer" hearts (combination of increased LVMI and fibrosis) presented a leftward transition of longitudinal SVLs, which also became wider (greater uncoupling) (panel B). Conclusions Traditional diastolic indices show modest only correlations with SVLs or HCM phenotypic characteristics, necessitating new approaches to DD of HCM patients. SVLs seem to be a promising-innovative tool for indirect assessment of myocardial "stiffness" and diastolic function. Abstract Figure.

A Novel Compound, Tanshinol Borneol Ester, Ameliorates Pressure Overload-Induced Cardiac Hypertrophy by Inhibiting Oxidative Stress via the mTOR/β-TrCP/NRF2 Pathway.

Tanshinol borneol ester (DBZ) exerts anti-atherosclerotic and anti-inflammatory effects. However, its effects on cardiac hypertrophy are not well understood. In this work, we investigated the treatment effects and potential mechanisms of DBZ on the hypertrophic heart under oxidative stress and endoplasmic reticulum (ER) stress. A hypertrophic model was established in rats using transverse-aortic constriction (TAC) surgery and in neonatal rat cardiomyocytes (NRCMs) using angiotensin II (Ang II). Our results revealed that DBZ remarkably inhibited oxidative stress and ER stress, blocked autophagy flow, and decreased apoptosis in vivo and in vitro through nuclear NRF2 accumulation, and enhanced NRF2 stability via regulating the mTOR/β-TrcP/NRF2 signal pathway. Thus, DBZ may serve as a promising therapeutic for stress-induced cardiac hypertrophy.

A human cell atlas of the pressure-induced hypertrophic heart

Pathological cardiac hypertrophy is a leading cause of heart failure, but knowledge of the full repertoire of cardiac cells and their gene expression profiles in the human hypertrophic heart is missing. Here, by using large-scale single-nucleus transcriptomics, we present the transcriptional response of human cardiomyocytes to pressure overload caused by aortic valve stenosis and describe major alterations in cardiac cellular crosstalk. Hypertrophied cardiomyocytes had reduced input from endothelial cells and fibroblasts. Genes encoding Eph receptor tyrosine kinases, particularly EPHB1, were significantly downregulated in cardiomyocytes of the hypertrophied heart. Consequently, EPHB1 activation by its ligand ephrin (EFN)B2, which is mainly expressed by endothelial cells, was reduced. EFNB2 inhibited cardiomyocyte hypertrophy in vitro, while silencing its expression in endothelial cells induced hypertrophy in co-cultured cardiomyocytes. Our human cell atlas of the hypertrophied heart highlights the importance of intercellular crosstalk in disease pathogenesis and provides a valuable resource.

Effect of celastrol on pulmonary hypertension associated to bronchopulmonary dysplasia

Bronchopulmonary dysplasia is a common pathology of premature newborns caused by oxidative stress and mechanical ventilation, resulting in hypoalveolization and impaired angiogenesis. It can be complicated by pulmonary hypertension (HTP-DBP) with excess mortality. Celastrol has anti-inflammatory and antioxidant properties and we addressed its potential therapeutic interest in HTP-DBP. Different concentrations of celastrol were used in a murine model of hyperoxic HTP-DBP (14 days with 90% O2) and we evaluated hemodynamic parameters with echocardiography and lung remodeling with histological methods. Pulmonary arterial (PA) reactivity was addressed with myograph. Cytoplasmic calcium (Ca2 + i) response to endothelin-1 (ET-1) was evaluated in human fetal PA smooth muscle cells (fPASMC) with spectrophotometry in normoxic (21% O2) and hyperoxic conditions (48 h with 60% O2). Inflammation was addressed with IL6 ELISA assay in fPASMC. Celastrol reduces mortality at doses of 1 and 0.5 mg/kg/d compared to the hyperoxic control group. At 1 mg/kg/d, it normalizes PAAT (PA acceleration time) ( P < 0.001) and reduces vascular hyperreactivity to phenylephrine ( P < 0.001) with no effect on the alteration of the response to acetylcholine induced by hyperoxia. At doses of 0.1, 0.5 and 1 mg/kg/d, it decreases right heart hypertrophy and vascular remodeling (wall thickness) but has no effect on alveolization and vascular density (vWF staining). Finally, although celastrol (0.1 and 0.3 μM) decreases the increased Ca2 + i response to ET-1 in hyperoxia in fPASMC, expression of ET-1 receptors (Western blotting and qPCR for ET-A and ET-B) was unchanged. However, celastrol 0.5 μM decreases ET-1 concentration measured with an ELISA assay in human umbilical arterial endothelial cells. An increased concentration of IL6 was also observed in fPASMC in hyperoxia and was decreased by celastrol 0.5 μM. Celastrol has a preventive dose-dependent effect on some hallmarks of HTP induced by hyperoxia and could thus be considered as an interesting new potential therapeutic option for HTP-DBP.

Peroxiredoxin-5 Knockdown Accelerates Pressure Overload-Induced Cardiac Hypertrophy in Mice.

A recent study showed that peroxiredoxins (Prxs) play an important role in the development of pathological cardiac hypertrophy. However, the involvement of Prx5 in cardiac hypertrophy remains unclear. Therefore, this study is aimed at investigating the role and mechanisms of Prx5 in pathological cardiac hypertrophy and dysfunction. Transverse aortic constriction (TAC) surgery was performed to establish a pressure overload-induced cardiac hypertrophy model. In this study, we found that Prx5 expression was upregulated in hypertrophic hearts and cardiomyocytes. In addition, Prx5 knockdown accelerated pressure overload-induced cardiac hypertrophy and dysfunction in mice by activating oxidative stress and cardiomyocyte apoptosis. Importantly, heart deterioration caused by Prx5 knockdown was related to mitogen-activated protein kinase (MAPK) pathway activation. These findings suggest that Prx5 could be a novel target for treating cardiac hypertrophy and heart failure.

Ero1α-Dependent ERp44 Dissociation From RyR2 Contributes to Cardiac Arrhythmia.

Oxidative stress in cardiac disease promotes proarrhythmic disturbances in Ca2+ homeostasis, impairing luminal Ca2+ regulation of the sarcoplasmic reticulum (SR) Ca2+ release channel, the RyR2 (ryanodine receptor), and increasing channel activity. However, exact mechanisms underlying redox-mediated increase of RyR2 function in cardiac disease remain elusive. We tested whether the oxidoreductase family of proteins that dynamically regulate the oxidative environment within the SR are involved in this process. A rat model of hypertrophy induced by thoracic aortic banding (TAB) was used for ex vivo whole heart optical mapping and for Ca2+ and reactive oxygen species imaging in isolated ventricular myocytes (VMs). The SR-targeted reactive oxygen species biosensor ERroGFP showed increased intra-SR oxidation in TAB VMs that was associated with increased expression of Ero1α (endoplasmic reticulum oxidoreductase 1 alpha). Pharmacological (EN460) or genetic Ero1α inhibition normalized SR redox state, increased Ca2+ transient amplitude and SR Ca2+ content, and reduced proarrhythmic spontaneous Ca2+ waves in TAB VMs under β-adrenergic stimulation (isoproterenol). Ero1α overexpression in Sham VMs had opposite effects. Ero1α inhibition attenuated Ca2+-dependent ventricular tachyarrhythmias in TAB hearts challenged with isoproterenol. Experiments in TAB VMs and human embryonic kidney 293 cells expressing human RyR2 revealed that an Ero1α-mediated increase in SR Ca2+-channel activity involves dissociation of intraluminal protein ERp44 (endoplasmic reticulum protein 44) from the RyR2 complex. Site-directed mutagenesis and molecular dynamics simulations demonstrated a novel redox-sensitive association of ERp44 with RyR2 mediated by intraluminal cysteine 4806. ERp44-RyR2 association in TAB VMs was restored by Ero1α inhibition, but not by reducing agent dithiothreitol, as hypo-oxidation precludes formation of covalent bond between RyR2 and ERp44. A novel axis of intraluminal interaction between RyR2, ERp44, and Ero1α has been identified. Ero1α inhibition exhibits promising therapeutic potential by stabilizing RyR2-ERp44 complex, thereby reducing spontaneous Ca2+ release and Ca2+-dependent tachyarrhythmias in hypertrophic hearts, without causing hypo-oxidative stress in the SR.

PRMT7 ablation in cardiomyocytes causes cardiac hypertrophy and fibrosis through β-catenin dysregulation.

Angiotensin II (AngII) has potent cardiac hypertrophic effects mediated through activation of hypertrophic signaling like Wnt/β-Catenin signaling. In the current study, we examined the role of protein arginine methyltransferase 7 (PRMT7) in cardiac function. PRMT7 was greatly decreased in hypertrophic hearts chronically infused with AngII and cardiomyocytes treated with AngII. PRMT7 depletion in rat cardiomyocytes resulted in hypertrophic responses. Consistently, mice lacking PRMT7 exhibited the cardiac hypertrophy and fibrosis. PRMT7 overexpression abrogated the cellular hypertrophy elicited by AngII, while PRMT7 depletion exacerbated the hypertrophic response caused by AngII. Similar with AngII treatment, the cardiac transcriptome analysis of PRMT7-deficient hearts revealed the alteration in gene expression profile related to Wnt signaling pathway. Inhibition of PRMT7 by gene deletion or an inhibitor treatment enhanced the activity of β-catenin. PRMT7 deficiency decreases symmetric dimethylation of β-catenin. Mechanistic studies reveal that methylation of arginine residue 93 in β-catenin decreases the activity of β-catenin. Taken together, our data suggest that PRMT7 is important for normal cardiac function through suppression of β-catenin activity.

To detect potential pathways and target genes in infantile Pompe patients using computational analysis.

Introduction: Pompe disease (PD) is a disease caused by pathogenic variations in the GAA gene known as glycogen storage disease type II, characterized by heart hypertrophy, respiratory failure, and muscle hypotonia, leading to premature death if not treated early. The only treatment option, enzyme replacement therapy (ERT), significantly improves the prognosis for some patients while failing to help others. In this study, the determination of key genes involved in the response to ERT and potential molecular mechanisms were investigated. Methods: Gene Expression Omnibus (GEO) data, accession number GSE38680, containing samples of biceps and quadriceps muscles was used. Expression array data were analyzed using BRB-Array Tools. Biceps group patients did not receive ERT, while quadriceps received treatment with rhGAA at 0, 12, and 52 weeks. Differentially expressed genes (DEGs) were deeply analyzed by DAVID, GO, KEGG and STRING online analyses, respectively. Results: A total of 1727 genes in the biceps group and 1198 genes in the quadriceps group are expressed differently. It was observed that DEGs were enriched in the group that responded poorly to ERT in the 52nd week. Genes frequently changed in the weak response group; the expression of 530 genes increased and 1245 genes decreased compared to 0 and 12 weeks. The GO analysis demonstrated that the DEGs were mainly involved in vascular smooth muscle contraction, lysosomes, autophagy, regulation of actin cytoskeleton, inflammatory response, and the WNT signaling pathway. We also discovered that the WNT signaling pathway is highly correlated with DEGs. Several DEGs, such as WNT11, WNT5A, CTNNB1, M6PR, MYL12A, VCL, TLN, FYN, YES1, and BCL2, may be important in elucidating the mechanisms underlying poor response to ERT. Conclusion: Early diagnosis and treatment of PD are very important for the clinic of the disease. As a result, it suggests that the enriched genes and new pathways emerging as a result of the analysis may help identify the group that responds poorly to treatment and the outcome of the treatment. Obtained genes and pathways in neonatal screening will guide diagnosis and treatment.

Calorie restriction changes lipidomic profiles and maintains mitochondrial function and redox balance during isoproterenol-induced cardiac hypertrophy.

Typically, healthy cardiac tissue utilizes more fat than any other organ. Cardiac hypertrophy induces a metabolic shift leading to a preferential consumption of glucose over fatty acids to support the high energetic demand. Calorie restriction is a dietary procedure that induces health benefits and lifespan extension in many organisms. Given the beneficial effects of calorie restriction, we hypothesized that calorie restriction prevents cardiac hypertrophy, lipid content changes, mitochondrial and redox dysregulation. Strikingly, calorie restriction reversed isoproterenol-induced cardiac hypertrophy. Isolated mitochondria from hypertrophic hearts produced significantly higher levels of succinate-driven H2O2 production, which was blocked by calorie restriction. Cardiac hypertrophy lowered mitochondrial respiratory control ratios, and decreased superoxide dismutase and glutathione peroxidase levels. These effects were also prevented by calorie restriction. We performed lipidomic profiling to gain insights into how calorie restriction could interfere with the metabolic changes induced by cardiac hypertrophy. Calorie restriction protected against the consumption of several triglycerides (TGs) linked to unsaturated fatty acids. Also, this dietary procedure protected against the accumulation of TGs containing saturated fatty acids observed in hypertrophic samples. Cardiac hypertrophy induced an increase in ceramides, phosphoethanolamines, and acylcarnitines (12:0, 14:0, 16:0, and 18:0). These were all reversed by calorie restriction. Altogether, our data demonstrate that hypertrophy changes the cardiac lipidome, causes mitochondrial disturbances, and oxidative stress. These changes are prevented (at least partially) by calorie restriction intervention in vivo. This study uncovers the potential for calorie restriction to become a new therapeutic intervention against cardiac hypertrophy, and mechanisms in which it acts.

Arecoline induces cardiotoxicity by upregulating and activating cardiac hypertrophy-related pathways in Sprague–Dawley rats

Habitual chewing of the areca nut increases the risk of mortality owing to cardiovascular disease, but few reports have revealed the cardiotoxicity mechanism of the areca nut. Arecoline has been reported to be the primary toxic constituent in the areca nut. In order to study the acute cardiotoxicity of the areca nut in the development of pathologic heart hypertrophy, we induced heart injury in rats using arecoline. Arecoline at a low dosage (5 mg/kg/day) or a high dosage (50 mg/kg/day) was intraperitoneally injected to Sprague–Dawley rats for 21 days. The change of heart function and biochemical pathways were investigated with echocardiography and Western blot. The results were presented that heart functions were weakened by arecoline stimulation, and western blotting analysis revealed an elevation in BNP levels in the heart after arecoline exposure. Arecoline induced IL-6-mediated activation of the MEK5/ERK5 and JAK2/STAT3 pathways, as well as mitogen-activated protein kinase signaling cascades. Further, arecoline increased the calcineurin and NFATc3 levels in the heart. In summary, our results suggest that arecoline causes significantly cardiotoxicity and heart damage by inducing several hypertrophy-related signaling pathways, including IL-6-induced MEK5/ERK5, JAK2/STAT3, mitogen-activated protein kinases, and calcineurin signaling pathways. The study elucidated, for the first time, the possible cardiac hypertrophy mechanisms underlying the cardiotoxicity of the areca nut.

Gallic acid protects against isoproterenol-induced cardiotoxicity in rats.

Gallic acid (GA) is a polyphenolic agent with interesting pharmacological impacts on the cardiovascular system. The present study purposed to study the protective effects of GA at 25 and 50mg/kg against isoproterenol (ISO)-induced cardiac damage in ischemia/reperfusion (I/R) in rats. Male Wistar rats were randomly assigned into six groups: Control, Control treated with GA at 25mg/kg (GA25), Control treated with GA at 50mg/kg (GA50), Hypertrophic rats induced by ISO (ISO), Hypertrophic rats treated with GA at 25mg/kg (ISO+GA25), and Hypertrophic rats treated with GA at 50mg/kg (ISO+GA50). Heart isolation was performed to induce a cardiac I/R injury model. Cardiac hemodynamic parameters were recorded. Serum Lactate Dehydrogenase (LDH) and Creatine Kinase-MB (CK-MB) and cardiac Superoxide dismutases (SOD) levels were evaluated. The gene expression of Sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) was assessed. We found that GA at 50mg/kg was significantly increased cardiac function at post I/R period in ISO-induced hypertrophic hearts. Moreover, it suppressed cardiac hypertrophy, the serum LDH and CK-MB levels in ISO injected rats. Administration of GA at 50mg/kg was significantly increased SOD level and SERCA2a gene expression in the hypertrophic hearts. GA at 50mg/kg could improve cardiac performance possibly by increasing antioxidant defense enzymes, reducing cell damage, and enhancing SERCA2a gene expression in hypertrophic heart induced by ISO in I/R injury conditions.

Effect of Cassia fistula L. aqueous extract in maternal reproductive outcome, some serum indices and fetal anomaly frequency in rat.

Background: Cassia fistula was used traditionally as laxative in pregnant women. Nevertheless, its fetal and maternal effects in pregnancy have not been studied yet.Methods:Oral (Lethal Dose, 50%) LD50 was determined in mice. In addition, a control group, pregnant rats in other 5 experimental groups (n=12) received orally C. fistula aqueous extract (500, 1000 and 2000 mg/kg), tween80 (10%) and distilled water during pregnancy up to the delivery (21-23 days). Some serum indices were evaluated in maternal blood samples after delivery. Histopathologic and histomorphometric evaluations were performed on the selected slices of newborn rats.Results:Anthraquinone‎ content of the aqueous extract was 0.34% w/w. Oral LD50 was obtained more than 5000mg/kg. No abortions and newborn anomalies were observed in groups. The height and weight of the offspring were significantly reduced by the administration of 500, and 2000 mg/kg of extract compared to control. There was no significant change in maternal blood urea and creatinine. Higher concentration (2000mg/kg) led to ALT elevation. ALS levels decreased dose-dependency in treatment groups comparing to control. Histopathological findings showed significant lung vascular congestion, and hypertrophy of heart in group tween80, and significant hepatic parenchymal inflammation in tween80 and 2000mg/kg and 1000mg/kg groups. In all tissues of all groups, malpighian body area and bowman’s capsule space significantly increased compared to the control group.Conclusion: It seems C. fistula extract is safe in pregnancy. Because of confounding role of tween80 in histopathological finding, more research is necessary.

ECG in the clinical and prognostic evaluation of patients with pulmonary arterial hypertension: an underestimated value.

Background:Pulmonary arterial hypertension (PAH) is a rare disease leading to right ventricular (RV) failure and manifests in decreasing exercise tolerance. Our study aimed to assess the usefulness of electrocardiographic parameters reflecting right heart hypertrophy as predictors of clinical status in PAH.Methods:The retrospective analysis included 26 patients, mean 49 ± 17 years of age, diagnosed with PAH, and eligible to undergo cardiopulmonary exercise test (CPET). The relations between ECG values and parameters obtained in procedures such as six-minute walk test (6-MWT), echocardiography, right heart catheterization (RHC), and CPET were analyzed.Results:P-wave amplitude in lead II correlated positively with CPET parameter of respiratory response: minute ventilation to carbon dioxide production slope (VE/VCO2 slope; r = 0.436, p = 0.029) and echocardiographic estimated RA pressure (RAP; r = 0.504, p = 0.02). RV Sokolow-Lyon index (RVSLI) positively correlated with echocardiographic parameters reflecting RV function, overload, and afterload–tricuspid regurgitation pressure gradient (TRPG; r = 0.788, p < 0.001), RV free wall thickness (r = 0.738, p < 0.001), and mean pulmonary arterial pressure (mPAPECHO; r = 0.62, p = 0.0016), respectively, as well as VE/VCO2 slope (r = 0.593, p = 0.001) and mPAP assessed directly in RHC (mPAPRHC; r = 0.469, p = 0.0497). R-wave in lead aVR correlated positively with TRPG (r = 0.719, p < 0.001), mPAPECHO (r = 0.446, p = 0.033), and several hemodynamic criteria of PAH diagnosis: positively with mPAPRHC (r = 0.505, p = 0.033) and pulmonary vascular resistance (r = 0.554, p = 0.026) and negatively with pulmonary capillary wedge pressure (r = −0.646, p = 0.004). QRS duration correlated positively with estimated RAP (r = 0.589, p = 0.004), vena cava inferior diameter (r = 0.506, p = 0.016), and RA area (r = 0.679, p = 0.002) and negatively with parameters of exercise capacity: peak VO2 (r = −0.486, p = 0.012), CPET maximum load (r = − 0.439, p = 0.025), and 6-MWT distance (r = −0.430, p = 0.046). ROC curves to detect intermediate/high 1-year mortality risk (based on ESC criteria) indicate RVSLI (cut-off point: 1.57 mV, AUC: 0.771) and QRS duration (cut-off points: 0.09 s, AUC: 703 and 0.1 s, AUC: 0.759) as relevant predictors.Conclusion:Electrocardiography appears to be an important and underappreciated tool in PAH assessment. ECG corresponds with clinical parameters reflecting PAH severity.