tbuckley/cabot-search huggingface dataset:
The sterol element binding protein 1c (SREBP1c) preserves cellular metabolism and immunosuppressive function of regulatory t cells
Authors: F Bonacina, C Procaccini, S Pedretti, G Stucchi, A Moregola, J Bogie, G Matarese, N Mitro, G D Norata
Journal: Cardiovascular Research (2024)

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Cariplo Foundation PRIN (Italian Ministry of University and Research) Aim Balance of cellular metabolism is increasingly recognized as a hallmark of physiologic cellular functions; this also extends to cells of the immune system. Here, we aimed at investigating the role of SREBP1c, a key protein regulating intracellular fatty acid (FA) metabolism, on the metabolism and function of Treg, that play a key role in immune tolerance maintenance. Material and Methods A detailed immunophenotyping through flow cytometry and metabolic profiling (metabolomics and seahorse analysis) of isolated Tregulatory (CD4+CD25+, nTreg) and in vitro induced Treg (iTreg) cells were performed together with in vitro and in vivo assays of Treg function from SREBP1c KO and WT littermates. RNAseq and lipidomics was performed on iTreg. Results Srebp1c deficiency reduced suppressive (-21%,p&amp;lt;0,01) and increased migratory function (+40%,p&amp;lt;0,05) of nTreg and iTreg, tested by in vitro assays. In vivo, Srebp1c KO mice presented reduced circulating and tissues’ level of Treg compared to WT mice (-66%,p&amp;lt;0,01) and nTreg from Srebp1c KO mice worsened Experimental Autoimmune Encephalomyelitis progression compared to WT nTreg. We addressed impaired Treg function to metabolic alteration due to Srebp1c deficiency: KO iTreg showed an increased glycolytic potential with preserved mitochondrial function coupled to accumulation of glycolytic metabolites and lactate (+20%,p&amp;lt;0,01) and reduced energy charge (-40%,p&amp;lt;0.01). We associated the switch to anaerobic glycolysis in KO Treg to an impaired lipid metabolism, as suggested by impaired abundance of lipid species (TG, LPC and PC); this was confirmed by RNAseq showing a downregulation of lipid metabolism’s pathways and upregulation of glycolysis. In parallel, tolerogenic response was impaired, a phenotype associated to a reduced transcription and activation of Foxp3, the master regulator of Treg function. Conclusion By restrain glycolysis and preserving lipid metabolism, our data have identified SREBP1c as a checkpoint crucial for the immunometabolic suppressive response of Tregs.
Generation of isogenic allelic series of LMNA-mutated hiPSC lines using the novel and highly-efficient targeting platform, STRAIGHT-IN
Authors: V Meraviglia, A Blanch-Asensio, R Davis, C L Mummery, M Bellin
Journal: Cardiovascular Research (2024)

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Netherlands Organisation for Health Research and Development ZonMW Background Human induced pluripotent stem cells (hiPSCs) have demonstrated enormous potential for advancing in vitro disease modelling and genetically modified hiPSCs carrying disease-associated variants are particularly useful tools for this purpose. Until now, strategies for efficient and rapid integration of large DNA payloads (&amp;gt;10 kb) into specific genomic regions are still limited, thus precluding efficient and rapid targeting of hiPSC lines. Purpose and Methods To overcome this, the STRAIGHT-IN platform (Serine and Tyrosine Recombinase Assisted Integration of Genes for High-Throughput INvestigation) was developed that combined different classes of site-specific recombinases with CRISPR-Cas9 mediated homologous recombination and allowed stringent site-specific replacement of large genomic fragments in hiPSCs. Here, we use STRAIGHT-IN to simultaneously generate a library of genetically matched hiPSC lines carrying multiple heterozygous mutations in LMNA gene. Mutations in LMNA, encoding Lamin A/C protein, have been associated with 5-10% cases of dilated cardiomyopathy (DCM) with conduction defects. Results Through detailed online searches of the LMNA database and literature, we identified and selected 11 LMNA mutations to insert into a wild-type hiPSC line based on the following criteria: (i) mutations associated with cardiac abnormalities, in terms of structural (DCM/heart failure) and arrhythmic phenotypes; (ii) mutations with known familiar/pedigree-relationship; (iii) different types of mutations (missense and nonsense). We then applied the workflow of STRAIGHT-IN consisting of: (1) replacing the entire LMNA genomic locus (33 kb) on one allele with a Landing Pad (LP) cassette containing Serine Recombinase (Bxb1) recognition sites; (2) reintroducing LMNA gene into the LP cassette through integration of Bxb1-Donor plasmids carrying the LMNA variants of interest via Bxb1 expression; (3) expressing a tyrosine recombinase (Cre) to excise the majority of the auxiliary exogenous DNA sequences. Conclusions STRAIGHT-IN allows simultaneous generation of a panel of 11 isogenic hiPSC lines carrying selected LMNA mutations rapidly (5-6 weeks), efficiently and cost-effectively, thus facilitating the production of specific mutated hiPSC lines for disease modelling and personalized medicine applications.
Ventricular hyperinnervation in a mouse model of catecholaminergic polymorphic ventricular tachycardia
Authors: M O'reilly, T De Waal, S Casini, C A Remme
Journal: Cardiovascular Research (2024)

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): European Society of Cardiology Basic Research Fellowship. Dutch Heart Foundation Dekker Grant Background Inherited arrhythmia syndromes are a leading cause of sudden cardiac death in young and otherwise healthy patients. They are often caused by mutations in genes that encode ion channels or transporters, leading to conditions such as Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). CPVT is caused by mutations in RYR2 (encoding ryanodine receptor 2, RyR2). In arrhythmia research, investigation into the effects of these mutations have exclusively been performed in cardiac cells. However, RyR2 is also present in neuronal tissue, including intracardiac neurons [1] (which modulate cardiac function). Moreover, patients often present with clinical signs of autonomic nervous system (ANS) dysfunction, and treatment strategies frequently target the ANS. Aim Our novel research line aims to investigate the neuronal phenotype induced by RyR2 mutations, using a CPVT mouse model to assess functional alterations as well as broader autonomic remodelling. Results Using immunocytochemistry, we reveal for the first time that RyR2 is also expressed in mouse stellate ganglia (crucial autonomic modulators of cardiac function). Through analysis of published RNA sequencing datasets, we find that RYR2 is more abundantly expressed in both stellate ganglion and intracardiac neurons than characteristic neuronal markers such as CHAT, SYN1 and SCN8A [2,3]. Functional patch clamp investigation of isolated stellate ganglion neurons have revealed two distinct populations based on their patterns of action potential (AP) firing, identifying both phasic-firing and tonic-firing type neurons. Investigation of an established CPVT mouse model (RyR2-R2474S) has thus far not revealed any differences in the AP firing frequency of isolated stellate ganglion neurons during sustained depolarising stimuli of various amplitudes. Assessment of calcium homeostasis and neurotransmitter release is currently ongoing. We have furthermore investigated broader autonomic remodelling using immunohistochemistry in mouse heart cryosections. Neuronal innervation density was assessed by staining 10 µm sections of mid-ventricular myocardium for the sympathetic neuron marker tyrosine hydroxylase (TH). Quantification of the TH-positive area revealed a significant increase in the percentage of sympathetic neuronal innervation in ventricular tissue of CPVT mice (5.7% wild-type vs 7.2% RyR2-R2474S, p=0.0253, N=6). Conclusions The neurons that modulate heart function (stellate ganglion and intracardiac neurons) abundantly express RyR2. The RyR2-R2474S mutation leads to significant sympathetic hyper-innervation of ventricular myocardium, which may have important consequences for neurotransmitter release and hence cardiac (electrical) function and arrhythmogenesis.
Phosphoinositide 3-Kinase C2alpha controls cardiac contractility through regulation of beta2-adrenergic receptor recycling
Authors: S Cnudde, T Brand, J Fender, L Prever, A Murabito, M Russo, F Gulluni, K Lorenz, E Hirsch, A Ghigo
Journal: Cardiovascular Research (2024)

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Doctoral fellowship Introduction Phosphoinositide 3-kinase C2α (PI3KC2α) is a ubiquitously expressed class II PI3K isoform, which has been previously shown to be involved in the control of vesicular trafficking. However, its role in the myocardium has not been investigated. The primary aim of this study is to elucidate the mechanism by which mechanism PI3KC2α controls cardiac pathophysiology. Methods Cardiomyocyte-specific PI3KC2α knockout (PI3KC2α KO) animals were generated by crossing mice expressing a tamoxifen-inducible Cre recombinase under the control of the αMHC promoter with PI3KC2αflox/flox mice. Zebrafish embryos were injected with a PI3KC2α (PI3KC2α morphants) or a control morpholino (control morphants) at 1-cell stage. HEK293 with stable overexpression of GFP-tagged β2-AR were generated and transfected with either scramble or PI3KC2α siRNAs. Results Our findings indicate that PI3KC2α KO mice display a reduced cardiac contractility compared to wildtype animals. Similarly, PI3KC2α morphants zebrafish exhibit lower heart rate and fractional shortening compared to controls, both at baseline and after isoproterenol (ISO) stimulation. A similar unresponsiveness to ISO was found in vivo in PI3KC2α KO mice where chronic treatment with the β-adrenergic receptor (β-AR) agonist failed to induce the classical β-AR-mediated remodeling, characterized by an increase of the left ventricular mass and of cardiomyocyte area. These findings suggest that PI3KC2α plays a critical role in the regulation of β-AR signaling. In agreement, cAMP levels failed to increase in response to ISO treatment in PI3KC2α morphants. Furthermore, silencing of PI3KC2α in HEK293-GFP-β2-AR cells resulted in an increased GFP-β2-AR internalization compared to control cells, both at baseline and after ISO stimulation. Interestingly, preliminary findings indicate that overexpression of constitutively active Rab11Q70L induced a redistribution of GFP-β2-AR at the plasma membrane in PI3KC2α-silenced cells. Conclusion Overall, we identify a key role for PI3KC2α in the control of cardiac contractility through the regulation of β2-AR trafficking to the plasma membrane through a Rab11-dependent mechanism.
FABP4 as potential indicator for GDM-induced fetal endothelial dysfunction
Authors: M L Villar Ballesteros, H Brendel, P Carstens, D Effenberger, J Mittag, S Giebe, P D Taylor, H Morawietz
Journal: Cardiovascular Research (2024)

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): DFG project no. 288034826—International Research Training Group (IRTG) 2251 Background Gestational diabetes mellitus (GDM) is linked to an elevated risk of developing cardiovascular diseases (CVD) both for the mother and the baby in later life. Previous studies have identified fatty acid-binding protein 4 (FABP4) as a prime candidate involved in the pathophysiology of GDM. FABP4 is known to promote an inflammatory response and vascular permeability, induce oxidative stress in endothelial cells (ECs), and impair the nitric oxide signaling pathway, thereby promoting endothelial dysfunction. Indeed, women with GDM exhibit elevated blood levels of FABP4, suggesting its potential as a biomarker for endothelial dysfunction and cardiovascular risk assessment in GDM. However, the role that FABP4 plays in the fetal endothelial function remains poorly understood. Purpose Thus, our aim is to understand the role of FABP4 in fetal endothelial dysfunction and its regulation to mitigate the impact of GDM on the vasculature. Methods Fetoplacental vessels and primary human umbilical vein endothelial cells (HUVECs) were isolated from placentas and umbilical cords obtained from both normoglycemic (NG) and GDM pregnancies. We also obtained the clinical data from the mothers and collected the cord blood. Total mRNA from HUVECs was used for bulk RNA sequencing to compare gene expression, while gene expression analysis in the vessels was conducted using RT-qPCR. Additionally, NG HUVECs were pooled and cultured under high laminar flow conditions (30 dyn/cm²) or subjected to various treatments, including insulin (5nM), glucose (25mM), simvastatin (10nm), or VEGF-A stimulation. Subsequent RT-qPCRs were performed to analyze the gene expression of several genes of interest. Results The bulk RNA sequencing data analysis revealed FABP4 as an overexpressed gene in GDM HUVECs compared to NG. Furthermore, the analysis of data through Gene Set Enrichment Analysis provided a list of different gene sets that are enriched in GDM samples. Among these gene sets are pathways or processes implicated in endothelial dysfunction, such as angiogenesis, PI3K/AKT/mTOR signaling, reactive oxygen species pathway, or inflammatory response. In vitro experiments provided evidence for an elevated FABP4 mRNA expression after VEGF treatment of HUVECs. Conversely, both simvastatin treatment and exposure to laminar flow reduced FABP4 mRNA expression and increased eNOS expression, suggesting a potential inhibitory effect of nitric oxide on FABP4. Conclusion We provided evidence that FABP4 could be involved in fetal GDM-induced endothelial dysfunction. Shear stress and statins might protect the endothelium against the negative impact of FABP4.
The role of natural anti-oxidants in gut microbiota alteration subsequent to high fat diet (HFD)
Authors: V Mollace, R Mollace, R Macri, F Scarano
Journal: Cardiovascular Research (2024)

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): PON-MIUR 000_78 Evidence exists that the gut microbiota contributes to the alterations of lipid metabolism associated with high-fat diet (HFD). Moreover, the gut microbiota has been found to modulate the metabolism and absorption of dietary lipids, thereby affecting the formation of lipoproteins occurring at the intestinal level as well as systemically, though the pathophysiological implication of altered microbiota composition in HFD and its role in the development of atherosclerotic vascular disease (ATVD) remain to be better clarified. Recently, evidence has been collected indicating that supplementation with natural polyphenols and fibres accounts for an improvement of HFD-associated intestinal dysbiosis, thereby leading to improved lipidaemic profile. This study aimed to investigate the protective effect of a bergamot polyphenolic extract (BPE) containing 48% polyphenols enriched with albedo and pulp-derived micronized fibres (BMF) in the gut microbiota of HFD-induced dyslipidaemia. In particular, rats that received an HFD over a period of four consecutive weeks showed a significant increase in plasma cholesterol, triglycerides and plasma glucose compared to a normal-fat diet (NFD) group. This effect was accompanied by body weight increase and alteration of lipoprotein size and concentration, followed by high levels of MDA, a biomarker of lipid peroxidation. Treatment with a combination of BPE plus BMF (50/50%) resulted in a significant reduction in alterations of the metabolic parameters found in HFD-fed rats, an effect associated with increased size of lipoproteins. Furthermore, the effect of BPE plus BMF treatment on metabolic balance and lipoprotein size re-arrangement was associated with reduced gut-derived lipopolysaccharide (LPS) levels, an effect subsequent to improved gut microbiota as expressed by modulation of the Gram-negative bacteria Proteobacteria, as well as Firmicutes and Bacteroidetes. This study suggests that nutraceutical supplementation of HFD-fed rats with BPE and BMP or with their combination product leads to restored gut microbiota, an effect associated with lipoprotein size re-arrangement and better lipidaemic and metabolic profiles.
Soluble guanylate cyclase stimulator as an emerging therapeutic option in the management of arrhythmias in heart failure rat model
Authors: B Szeiffova Bacova, A Martiskova, M Sykora, O Gawrys, N Tribulova, L Cervenka
Journal: Cardiovascular Research (2024)

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): This research was supported by VEGA grant no. 2/0002/20 and 2/0006/23, the Slovak Research and Development Agency under contract no. 21-0410, European Regional Development Fund: ITMS2014+: 313011AVG3. This research was also partially supported by the Ministry of Health of the Czech Republic within the project for the development of the research organization [grant number 00023001 (IKEM)—institutional support] and also supported by the project National Institute for Research of Metabolic and Cardiovascular Diseases (Program EXCELES, Project No. LX22NPO5104)—Funded by the European Union—Next Generation EU Heart failure (HF) is a complex clinical syndrome characterized by a decrease in the efficiency of the heart pump, leading to a decline in hemodynamic status and cardiac remodelling, that can contribute to the formation of a substrate for arrhythmias. Antiarrhythmic drug therapy is still suboptimal and current therapies are not efficacious enough. The purpose of the current study was therefore to examine the efficiency of nitric oxide (NO)/soluble guanylyl cyclase (sGC)/cyclic guanosine monophosphate (cGMP) stimulator. We used as an experimental model male hypertensive Ren-2 transgenic rats (TGR, n = 16), normotensive Hannover Sprague–Dawley rats (HSD, n = 17), and a rat model of HF surgically induced by aortocaval fistula (ACF) in rats of both strains (n = 27). After ACF induction were rats treated by sGC stimulator BAY41-8543 (3 mg/kg/day for 30 weeks) alone or combined with angiotensin-converting enzyme inhibitor (ACEi) Trandolapril (0.25 mg/kg/day for 30 weeks). Age of the animals at the end of the experiment was 40 weeks. Left ventricle tissue and plasma samples were used for further analyses. Treatment by sGC stimulator significantly decreased rats' mortality, and systolic blood pressure, and significantly increased levels of antioxidant enzyme superoxide dismutase 1, matrix metalloproteinase 2, total and phosphorylated connexin 43 as well as protein kinase C epsilon, implicated in remodelling of extracellular matrix and intercellular communication, in the left ventricle of TGR rats. Application of sGC stimulator slightly normalized elevated collagen deposition and hydroxyproline content in the left ventricular tissue of TGR rats. Unfortunately, we did not observe any effect of the sGC stimulator in the TGR ACF group. These results support the hypothesis that sGC stimulators might represent a class of drugs suitable for combating heart failure with partially anti-arrhythmic potential, but further studies are needed.
Exploring the regulation of circulating factors involved in aortic valve sclerosis onset
Authors: D Moschetta, M Chiesa, I Massaiu, V Valerio, V Rusconi, F Bertolini, V A Myasoedova, P Poggio
Journal: Cardiovascular Research (2024)

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Ministero della Salute - Ricerca Finalizzata Background Aortic valve sclerosis (AVSc), the first stage of calcific aortic valve stenosis (CAVS), has a prevalence of 25-30% in subjects older than 65 years. Being a clinically silent phase, it is characterized only by non-uniform leaflet thickening due to fibrosis and microcalcifications, without the obstruction of the blood flow with an increased local oxidative stress, inflammation, and endothelial-to-mesenchymal transition (EndMT). However, to date, AVSc is not considered a pathology but 10% of cases evolve a full-blown CAVS. Aim Our aim is to investigate which systemic process(es) are activated in AVSc, in order to better define these subjects. These evaluations will allow us to identify potential druggable targets. Methods We consecutively enrolled 157 healthy subjects and detected AVSc presence by echocardiography. Plasma and serum samples were collected to evaluate circulating microRNA (RNA-sequencing) and cytokines (Luminex), respectively. Functional analysis was performed to reveal systemic pathway regulation. Healthy human valve endothelial cells were employed to evaluate viability (MTT assay) and EndMT (morphological analysis and quantitative PCR) Results AVSc was present in 77 patients (49%) and the differential expression analysis revealed that 59 microRNAs were down-regulated, while 93 were up-regulated in these subjects compared to healthy ones (adjusted-p&amp;lt;0.05). The functional analysis revealed that the major enriched pathways in AVSc subjects were related to inflammation. Indeed, serum GROα and IL1β levels were higher in AVSc vs healthy (p&amp;lt;0.05). In vitro, chronic GROα treatment resulted in lower cell viability (100.0±17.4 vs 61.8±16.5% of vital cells; p&amp;lt;0.0001), while IL1β treatment induced a decrease in cell roundness and an increase in total area (0.40±0.18 vs 0.47±0.19AU, p&amp;lt;0.0001; and 0.75±0.73 vs 0.45±0.48AU, p&amp;lt;0.0001; respectively). Quantitative PCR revealed EndMT activation: SNAI1 (1.87±0.57 log2(foldchange), p&amp;lt;0.0001) and SNAI2 (2.19±0.46 log2(foldchange), p&amp;lt;0.0001) only after IL1β treatment. Conclusions Inflammation is the most regulated systemic pathway in AVSc subjects and its master regulator, IL1β, seems to be involved in the EndMT progression of valve endothelial cells, while GROα contributes to their death. These effects could be related to the early triggers of AVSc onset, leading to fibrosis and eventually calcification of aortic leaflets.