bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deletion of nephrocystin 4 exacerbates cardiac function and survival rate in a mouse model of cardio-renal syndrome
Authors: Sato J , Otaki Y , Watanabe T , Ono H , Yamaguchi R , Tachibana S , Kobayashi Y , Aono T , Goto J , Takahashi H , Arimoto T , Ochi H , Konta T , Watanabe M 
Published: October 2024

Abstract

Background
Cardiorenal syndrome (CRS), characterized by cardiac and renal dysfunction, is an increasing health problem associated with high mortality rate. Nephrocystin 4 (NPHP4) gene is the major cause of end-stage renal disease in children. We have reported NPHP4 single nucleotide polymorphism is the genetic risk for CRS and subsequent cardiovascular events in general population. However, the functional role of Nphp4 in the development of CRS has never been examined yet.

Methods and Results
We generated systemic Nphp4 knockout (KO) mice deleting exon 3 to 8 using CRISPR-Cas9 system. RNA sequence analysis of heart and kidney tissues demonstrated that gene-sets related to mitochondrial function were significantly downregulated in Nphp4 KO mice compared to their wild-type (WT) littermates. Nphp4 KO mice showed less cardiac hypertrophy, however, exacerbated cardiac function and survival compared to WT mice in a CRS model induced by thoracic transverse aortic constriction. Nphp4 located in endosome and cell membrane in H9C2 cardiomyocytes. Immunoprecipitation confirmed protein interaction between Nphp4 and HECT-type E3 ligase Itch. Furthermore, we found that Itch targeted Lats2 and insulin-like growth factor-1 receptor in cardiomyocytes. Knockdown of Nphp4 activated Hippo signaling and worsened mitochondrial function in H9C2 cardiomyocytes through the inhibition of Itch-dependent Lats2 degradation. Knockdown of Nphp4 inhibited insulin-like growth factor-1 signaling through the disturbance of Itch-mediated endosome function.

Conclusions
Deletion of Nphp4 impaired compensatory cardiac hypertrophy and exacerbated cardiac function and survival in a mouse CRS model through mitochondrial dysfunction. Nphp4 mediated Hippo signaling and insulin-like growth factor-1 signaling through the interaction with Itch. NPHP4 could be the novel therapeutic target in CRS.figure1figure2
Intact DNA repair in differentiated cardiomyocytes is essential for maintaining cardiac function in response to pressure overload in mice
Authors: De Boer M , Hoeijmakers J H J , Duncker D J 
Published: October 2024

Abstract

Introduction
DNA in every cell is continuously damaged and DNA repair mechanisms are essential for protection against DNA damage-induced aging-related diseases. For example, deficient repair of endogenously generated DNA damage in mice with cardiomyocyte-restricted inactivation of Xpg, is associated with progressive heart failure.

Purpose
Here we tested the hypothesis that unrepaired DNA damage in differentiated cardiomyocytes increases cardiac vulnerability in response to hemodynamic overload.

Methods
To increase the burden of spontaneous DNA damage, we generated mice with cardiomyocyte-restricted inactivation of DNA repair endonuclease XPG. At 8 weeks of age, αMHC-Xpgc/- and control (Ctrl) mice were subjected to pressure overload by transverse aortic constriction (TAC). Eight weeks after TAC, left ventricular (LV) function was assessed using echocardiography and hemodynamic measurements, followed by molecular and histological analyses.

Results
Cardiomyocyte-restricted inactivation of Xpg resulted in systolic as well as diastolic LV dysfunction (Table). TAC-induced LV hypertrophy is similar in both groups (Ctrl 38%; αMHC-Xpgc/- 34%). In Ctrl mice, LV hypertrophy was accompanied by minimal LV dilation and modest changes in systolic and diastolic LV function. Conversely, TAC in αMHC-Xpgc/- produced severe LV dysfunction and resulted in overt congestive heart failure, demonstrated by aggravation of LV dilation, and marked increases in LV end-diastolic pressure, left atrial weight and lung fluid weight, which was accompanied by further increases in the expression levels of the hypertrophic marker genes atrial natriuretic peptide and beta-myosin heavy chain (Table). Moreover, lectin staining revealed a decrease in capillary density and TUNEL staining revealed further elevated levels of myocardial apoptosis. In addition, a significant increase of myocardial collagen content was observed.

Conclusion
Cardiomyocyte-restricted loss of DNA repair protein XPG increases cardiac vulnerability to develop heart failure in response to pressure overload. These findings underscore the importance of genomic stability for maintenance of cardiac function, not only during basal conditions, but also in response to a pathological stimulus.
MRPL44 haploinsufficient mouse spontaneously develops hypertrophic cardiomyopathy and shows systolic dysfunction after aldosterone treatment
Authors: Okamoto R , Ye Z , Ito R , Moriwaki K , Ito H , Kimena L , Ichikawa M , Dohi K 
Published: October 2024

Abstract

Introduction
It has been recently reported there are big differences in pathophysiological and molecular phenotypes in mouse and human hypertrophic cardiomyopathy. These differences are observed all in terms of myocyte redox, mitochondrial number and respiration, mitochondrial reactive oxygen species generation and Ca2+ handling. Therefore we should search for molecules to be able to induce similar phenotype and molecular signaling both in mice and human. Mitochondrial ribosomal large subunit 44 (MRPL44) knockout mice were embryonic lethal, for which mutations are known to cause mitochondrial infantile cardiomyopathy and hypertrophic cardiomyopathy.

Purpose
Our purpose is to investigate the effect of MRPL44 haploinsufficiency in mice.

Methods
MRPL44 haploinsufficient (MRPL44+/-) mice were generated. Mineralocorticoid receptor-associated hypertension mice were induced in MRPL44+/- and wild-type (WT, MRPL44+/+) mice with subcutaneous infusion of aldosterone(Aldo) and 8% NaCl food for 4 weeks after uninephrectomy. Systolic blood pressure was measured by tail cuffs every week. WB, qPCR, cardiac echo, and histological examinations were performed. RNA sequencing analysis, electron microscopy examinations and mitochondrial activity assay were performed to find differences between MRPL44+/- and MRPL44+/+ mice.

Results
MRPL44 haploinsufficient mice spontaneously developed left ventricular hypertrophy in 6 weeks old. Heart rate, blood pressure, and cardiac systolic function were normal in MRPL44 haploinsufficient mice. MRPL44 was decreased about to 70% in MRPL44 haploinsufficient mice and mitochondrial arrangement were impaired in electron microscopic analysis. After Aldo treatment, blood pressure elevation were similar, however, MRPL44 haploinsufficient mice developed left ventricular systolic dysfunction and dilation compared with MRPL44+/+ mice. WB showed mitochondrial electron transport chain protein complex IV expression was significantly decreased. Furthermore, mitochondrial activity assay showed MRPL44 haploinsufficient mice had a significant reduction in complex IV activity, whereas complex I and II activity were similar to MRPL44+/+ mice. RNA sequencing analysis showed the significant changes in the expression of ribosomal subunits coded by nucleus in addition to mitochondrial ribosomal subunits. These results indicate MRPL44 plays an important role in the cardiac function of mitochondrial electron transport chain protein complexes via the expression of ribosomal protein subunits coded by both nucleus and mitochondria.

Conclusions
MRPL44 haploinsufficient mice spontaneously develop left ventricular hypertrophy and shows systolic dysfunction after aldosterone treatment accompanied with oxidative phosphorylation enzyme dysfunction.
Assessing boundary conditions in CFD for transvalvular pressure gradient calculation in cardiac hemodynamics
Authors: Wu F , Feng S , Wang H , He X , Wang S , He G , Pan X 
Published: October 2024

Abstract

Background
Computational fluid dynamics (CFD), which has the advantages of providing detailed pressure distribution, has been widely used for cardiac function assessment and heart disease diagnosis. However, the results are usually influenced by the boundary conditions. Particularly, the transvalvular pressure gradient, which serves as a crucial indicator for mitral stenosis and the efficacy of mitral valve surgery, can easily be miscalculated. Here, we assess the effects of widely used boundary conditions on the transvalvular pressure gradient computed based on the Bernoulli equation and the line probe, respectively.

Purpose
This study aims to determine the effects of boundary conditions on the transvalvular pressure gradient in CFD.

Methods
We constructed cardiac models including left atrium, left ventricle, aorta from CT and mitral valve from transesophageal echocardiography data (Figure 1). The intraventricular flow fields were computed using CFD tool with four different boundary conditions (BC) at the same cardiac output. BC1 involved specifying the total flow rate of the aorta, with zero pressure at the entrance of the pulmonary veins. BC2 maintained equal flow rates at the entrances of the pulmonary veins. BC3 followed Murray's law, where the flow rate ratio in the pulmonary veins is proportional to the 1.5 power of the area ratio. BC4 followed Poiseuille's law, where the flow rate ratio is proportional to the square of the area ratio. The results encompassed the mean transvalvular pressure gradient and peak transvalvular pressure gradient obtained through the Bernoulli equation and the line probe methods, respectively.

Results
Figures 2(A-D) present the contours of transvalvular pressure under peak flow velocity conditions and the isosurfaces of vorticity within the ventricle. The results show that the pressure within the atrium is notably lower in the BC2, leading to a 63% underestimation in the mean transvalvular pressure gradient and a 22.9% deviation in the peak transvalvular pressure gradient (Figure 2 F). The transvalvular pressure gradient for BC1, BC3, and BC4 do not exceed 10%. The results reveal that the pressure distribution and vorticity within the ventricle are consistent, primarily due to the influence of the mitral valve.

Conclusion
When evaluating transvalvular pressure gradient using CFD, it is crucial to specify appropriate boundary conditions. Using inappropriate boundary conditions may lead to underestimation of the transvalvular pressure gradient, thereby affecting further diagnostic decisions. In research studies, it is recommended to allocate flow in different branch vessels according to Murray's law, where the flow in different branch vessels is proportional to the 1.5 power of the vessel cross-sectional area.Modelling flow chartTransvalvular pressure gradient
Cancer ameliorates cardiac dysfunction and suppresses fibrosis in a mouse model for Duchenne muscular dystrophy
Authors: Achlaug L , Awwad L , Langier-Goncalves I , Goldenberg T , Aronheim A 
Published: October 2024

Abstract

The interplay between heart failure and cancer represents a double-edged sword. Whereas cardiac remodeling promotes cancer progression, tumor growth suppresses cardiac hypertrophy and reduces fibrosis deposition. Whether these two opposing interactions are connected awaits to be determined. In addition, it is not known whether cancer affects solely the heart, or if other organs are affected as well. To explore the dual interaction between heart failure and cancer, we studied the human genetic disease Duchenne Muscular Dystrophy (DMD) using the MDX mouse model. We analyzed fibrosis and cardiac function as well as molecular parameters by multiple methods in the heart, diaphragm, lungs, skeletal muscles, and tumors derived from MDX and control mice. Surprisingly, cardiac dysfunction in MDX mice failed to promote murine cancer cell growth. In contrast, tumor-bearing MDX mice displayed reduced fibrosis in the heart , skeletal and diaphragm muscles, resulting in improved cardiac function. The latter is at least partially mediated via M2 macrophage recruitment to the heart and diaphragm muscles. Remarkably, an analysis of of cytokines in the blood of tumor-bearing and non-tumor-bearing MDX mice initially revealed several potential factors. These factors hold promise in significantly reducing fibrosis within our model. Administering these factors simultaneously to MDX mice led to decreased fibrosis in the heart, diaphragm, and skeletal muscles, along with an improvement in cardiac function. Collectively, our data support the notion that the effect of heart failure on tumor promotion is independent of the improved cardiac function in tumor-bearing mice. Reduced fibrosis in tumor-bearing MDX mice stems from the suppression of new fibrosis synthesis and the removal of existing fibrosis. These findings offer potential therapeutic strategies for DMD patients, fibrotic diseases, and cardiac dysfunction.Tumor growth suppresses fibrosisGraphical representation
Genome-wide association study of CMR image-based aortic stiffness in 45,789 individuals identifies loci linked with cardiovascular diseases
Authors: Paliwal N , Henry A , Finan C , Davies R , Hughes A , Williams B , Malarstig A , Lumbers R T , Hingorani A D 
Published: October 2024

Abstract

Background
The use of artificial intelligence on large-scale cardiac magnetic resonance (CMR) imaging data has enabled detailed characterisation of cardiac shape and function for use in genome-wide association studies (GWAS), leading to improved understanding of genetic aetiology of cardiovascular diseases (CVDs). Aortic stiffness is associated with increased risk of cardiovascular events in observational studies. Here, we present a novel CMR-based pressure-independent measure of aortic stiffness, identify genetic associations and explore links with CVDs.

Purpose
Identify genetic contributions to pressure-independent aortic stiffness and links to CVDs using large-scale GWAS analysis on the UK Biobank cohort.

Methods
A pre-trained neural network was used to segment CMR images of participants in the UK Biobank to quantify ascending aorta diameter, which together with contemporaneous systolic and diastolic blood pressure measurements (SBP, DBP, respectively) were used to calculate a pressure-independent measure of aortic stiffness (β0). The measurement assumes an exponential relationship between pressure and aortic diameter. We then performed a GWAS on β0 in 45,789 participants of European ancestry without CVDs. A multi-trait-based conditional & joint analysis (mtCOJO) was performed to estimate genetic effects independent of SBP, DBP and aortic area. We mapped the independent lead variants associated with aortic stiffness at P &lt; 5x10-8 to nearest gene, and characterised shared genetic association across CVDs using Open Targets Platform database.

Results
The GWAS identified 17 independent lead variants, including 6 that remained significant in the conditional analysis. Four of these lead variants, not previously reported in GWAS of other aortic traits, were located near CTD-2203A3.1, MCF2L, CFDP1 and CDH13 genes (red annotations in the Figure). MCF2L, CFDP1 and CDH13 have been associated with coronary artery disease, and CFDP1 with myocardial infarction and coronary atherosclerosis in previous studies.

Conclusion
A GWAS of CMR-derived aortic stiffness identified 4 loci distinct from other aortic traits that also associate with other CVDs, suggesting genetic links between aortic stiffness and CVDs. Further analyses are required to explore biological mechanisms underlying these genetic associations.Aortic Stiffness Manhattan Plot
Human epicardial adipose tissue secretome alters metabolomic profile and induces endothelial-to-mesenchymal transition in human lymphatic endothelial cells
Authors: Abe I , Takahashi M , Yamasaki H , Harada T , Takano M , Kondo H , Teshima Y , Takahashi N 
Published: October 2024

Abstract

Background
Cardiac lymphatic systems play an important role in maintaining myocardial fluid homeostasis during inflammation. We have recently reported the epicardial adipose tissue (EAT)-derived factor induces inflammation and fibrosis in atrial myocardium, which lead to atrial fibrillation (AF). However, the direct effect of EAT on the cardiac lymphatic endothelial cells (LECs) remains unknown.

Objective
To elucidate the effect of EAT on cardiac LECs, as one of the potential causes of AF.

Methods
Human EAT samples were collected from 18 consecutive patients with or without AF patients during cardiovascular surgery. They were categorized into the sinus rhythm (SR) group (n=9, 72.7±8.6 years) and the AF group (n=9, 73.3±7.4 years). Preadipocytes were extracted from EAT by homogenization and collagenase treatment, and cultured to confluence. After differentiation to mature adipocytes, cell culture supernatant was collected, and cultured with human LECs. Cell permeability was measured by using FITC-dextran assay. Tube forming ability was analyzed by seeding LECs on the extracellular matrix gels. Metabolomic profiling of LECs was performed by GC-MS system.

Results
RT-PCR analysis revealed that cell culture supernatant from mature adipocytes of AF patients significantly increased mRNA expression of mesenchymal marker, TAGLN/SM22a (p&lt;0.01) in human LECs, whereas mRNA expression of lymphatic endothelial markers, LYVE1 (p=0.0552) and PROX1 (p=0.0231) were decreased in human LECs, compared to those from mature adipocytes of SR patients. These data suggest cell culture supernatant from mature adipocytes of AF patients highly induce endothelial-to-mesenchymal transition (EndMT) of LECs. When assessing the endothelial barrier function by using FITC-dextran, cell culture supernatant from mature adipocytes of AF patients significantly decreased cell barrier function (p&lt;0.01) compared to those from mature adipocytes of SR patients. Furthermore, cell culture supernatant from mature adipocytes of AF patients significantly decreased the tube forming ability of LECs (p&lt;0.01) compared to those from mature adipocytes of SR patients. To assess the metabolomic changes in human LECs by EAT-secretome, we conducted the GC/MS analysis. Cell culture supernatant from mature adipocytes of AF patients significantly decreased several amino acids including branched-chain amino acid (BCAA; valine, leucine and isoleucine), compared to those from mature adipocytes of SR patients.

Conclusion
Our study with human EAT and LECs demonstrated that EAT-secretome from AF patients altered metabolomic profile in LECs, and highly caused EndMT in LECs, leading to impaired barrier function and the tube forming ability. Defects of lymphangiogenesis could be a therapeutic target for atrial cardiomyopathy.
Targeting the histone methyltransferase SETD7 rescues diabetes-induced impairment of angiogenic response by transcriptional repression of semaphorin 3G
Authors: Mohammed S A , Gorica E , Karsay G , Albiero M , Mengozzi A , Spinetti G , Fadini G P , Ruschitzka F , Costantino S , Paneni F 
Published: October 2024

Abstract

Background
Peripheral artery disease (PAD) is highly prevalent in patients with diabetes (DM) and associates with a high rate of limb amputation and poor prognosis. Surgical and catheter-based revascularization have failed to improve outcome in DM patients with PAD. Hence, a need exists to develop new treatment strategies able to promote blood vessel growth in this setting. Mono-methylation of histone 3 at lysine 4 (H3K4me1) - a specific epigenetic signature induced by the histone methyltransferase SETD7 - favours an open chromatin thus enabling gene transcription.

Purpose
To investigate whether SETD7-dependent epigenetic changes modulate angiogenic response in diabetes.

Methodology
Primary human aortic endothelial cells (HAECs) were exposed to normal glucose (NG, 5 mM) or high glucose (HG, 25 mM) concentrations for 48 hours. Unbiased gene expression profiling was performed by RNA sequencing (RNA-seq) followed by Ingenuity Pathway Analysis (IPA). In vitro assays, namely cell migration and tube formation were employed to study angiogenic properties in HAECs. SETD7 and H3K4me1 levels were investigated by Western blot and Chromatin immunoprecipitation (ChIP). Pharmacological blockade of SETD7 was achieved by using the highly selective inhibitor (R)-PFI-2. Mice with streptozotocin-induced diabetes were orally treated with (R)-PFI-2 or vehicle and underwent hindlimb ischemia by femoral artery ligation for 14 days. Blood flow recovery was analysed at 30 minutes, 7 and 14 days by laser Doppler imaging. Our experimental findings were also translated in gastrocnemius muscle samples from patients with and without diabetes.

Results
RNA-seq in HG-treated HAECs revealed a profound upregulation of the methyltransferase SETD7, an enzyme involved in mono-methylation of lysine 4 at histone 3 (H3K4me1). SETD7 upregulation in HG-treated HAECs was associated with increased H3K4me1 levels as well as with impaired endothelial cell migration and tube formation. Both SETD7 gene silencing and pharmacological inhibition by (R)PFI-2 rescued hyperglycemia-induced impairment of HAECs migration and tube formation, while SETD7 overexpression blunted the angiogenic response. RNA-seq and ChIP assays showed that SETD7-dependent H3K4me1 regulates the transcription of the angiogenesis inhibitor semaphorin-3G (SEMA-3G). Moreover, SEMA-3G overexpression blunted migration and tube formation in SETD7-depleted HAECs. In diabetic mice with hindlimb ischemia, treatment with (R)-PFI-2 improved limb vascularization and perfusion as compared to vehicle. Finally, SETD7/SEMA3G axis was upregulated in muscle specimens from T2D patients as compared to controls.

Conclusion
Targeting SETD7 represents a novel epigenetic-based therapy to boost neovascularization in diabetic patients with PAD.