Biology subjects

Schiattarella, G. G.

Publications and source records attributed to Schiattarella, G. G..

3 recordsLinked to original sources

bioRxiv2025

Isogenic monocytes improve the responsiveness of hiPSC cardiac spheroids to cardiac stressors

AimsHeart failure remains a leading cause of morbidity and mortality worldwide. Suitable in vitro models to accurately replicate the pathological environment in heart failure with reduced and preserved ejection fraction (HFrEF/HFpEF) are limited, hampering mechanistic studies and drug screening. In particular, these models rarely incorporate immune cells, which play a critical role in heart failure. To address these limitations, we developed an isogenic 3D induced pluripotent stem cell (iPSC)-derived cardiac spheroid model incorporating monocytes. Methods and resultsCardiac spheroids were assembled from three healthy female iPSC lines: three-cell-type (3CT) spheroids consisting of iPSC-derived cardiomyocytes, cardiac fibroblasts, and endothelial cells, and four-cell-type (4CT) spheroids additionally containing monocytes. After six days of culture, established spheroids were treated for 24 h with different known heart failure-associated triggers (glucose & tumour necrosis factor alpha (TNF) or ischaemia with/without reoxygenation). Differences between treated and control 3CT and 4CT spheroids were investigated at the cellular, molecular, and functional levels using confocal microscopy, RNA expression (qPCR and RNA sequencing), protein secretion using proximity extension assay technology (Olink), and functional analyses of beating rate, contraction, and relaxation. The results confirmed successful monocyte integration in 4CT spheroids, and only spheroids with monocytes (4CTs) exhibited changes in beating rate and relaxation duration upon stimulation, highlighting the necessity of incorporating immune cells to successfully mimic heart failure-associated functional changes. Along with a more pronounced global transcriptomic treatment response and inflammatory changes, additional transcriptomic alterations previously linked to heart failure in patients, as well as changes in metabolism, ion channels, and extracellular matrix pathways, were observed in 4CT compared with 3CT spheroids. ConclusionWe showed that immune cell incorporation enhances the functional and transcriptional responses of engineered cardiac tissue to relevant heart failure triggers in vitro and is essential for future studies to elucidate the cellular crosstalk and pathomechanisms. Translational perspectiveHeart failure continues to be a predominant cause of morbidity and mortality, necessitating the development of innovative therapeutic strategies, particularly in light of the rising prevalence of obesity and diabetes mellitus. We introduced an isogenic in vitro spheroid model comprising iPSC-derived cardiomyocytes, cardiac fibroblasts, endothelial cells, and monocytes to examine the effects of heart failure-associated triggers on cardiac tissue. Our findings indicate that spheroids incorporating monocytes exhibit a more pronounced response to heart failure-associated triggers and demonstrate greater differential transcriptional and functional responses than spheroids lacking immune cells. This model

cell biology↗

bioRxiv2025

Targeting Runx1 protects against heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a public health problem and an elusive illness for which there are few treatment options. HFpEF is a systemic condition with a broad phenotype including diastolic dysfunction, pulmonary oedema, exercise intolerance, and left ventricular (LV) hypertrophy, collectively resulting in enhanced morbidity and mortality. Master-regulator transcription factor RUNX1 has recently been identified as a mediator of pathological changes in many cardiac diseases, however its role in HFpEF was unknown. Here we show that inhibition of Runx1 limits adverse cardiac remodelling in a clinically relevant mouse model of HFpEF. Cardiomyocyte-specific tamoxifen-inducible Runx1-deficient mice with HFpEF are protected, with preservation of diastolic function, and attenuation of pulmonary oedema, exercise intolerance, and hypertrophy. Furthermore, targeting Runx1 in HFpEF by using gene transfer or small molecule inhibitors improves diastolic function, both in female and male mice. Overall, our research enhances our understanding of RUNX1 in cardiac disease and demonstrates a novel translational target for the treatment of HFpEF. Keywords: Heart failure with preserved ejection fraction, metabolic heart failure, diastolic dysfunction, hypertrophy, pulmonary oedema, exercise intolerance CLINICAL PERSPECTIVEHeart failure (HF) is a leading cause of death world-wide and traditionally divided into different subtypes according to cardiac ejection fraction (EF). In contrast to HF with reduced EF (HFrEF), there are limited treatment options for HF with preserved EF which is of considerable concern given that HFpEF is projected to become the dominant HF subtype in the future 1. RUNX1 has been demonstrated to play an important role in the development of many cardiac and non-cardiac diseases. As a result, the potential for RUNX1 inhibitors as therapeutic agents across various conditions has become increasingly evident. In this study we established the therapeutic potential of targeting RUNX1 in the context of HFpEF. Targeting RUNX1 in cardiomyocytes markedly attenuates the development of the HFpEF phenotype and therefore this novel translational therapeutic target has great potential to address one of the biggest challenges in cardiac research.

physiology↗

bioRxiv2024

Polycystin-1 loss of function increases susceptibility to atrial fibrillation through impaired DNA damage response

BackgroundThe increasing prevalence of atrial fibrillation (AF) and chronic kidney diseases highlights the need for a deeper comprehension of the molecular mechanisms linking them. Mutations in PKD1, the gene encoding Polycystin-1 (PKD1 or PC1), account for 85% of autosomal dominant polycystic kidney disease (ADPKD) cases. This disease often includes cardiac complications such as AF. In cardiomyocytes, PC1 deletion reduces hypertrophic response to pressure overload but promotes baseline ventricular dysfunction, while deletion in fibroblasts ameliorates post-myocardial infarction fibrosis. Despite its known cardiac impact, the role of PC1 in atrial cardiomyocytes and arrhythmias is less understood. Here, we sought to investigate the role of PC1 in AF. MethodsWe used intracardiac programmed stimulation and optical mapping to evaluate AF inducibility in two mouse models, Pkd1 R3277C, which recapitulates human ADPKD progression, and cardiomyocyte-specific Pkd1 deletion, and their respective controls. Isolated adult mouse atrial cardiomyocytes, human iPSC-derived atrial cardiomyocytes (hiPSC-aCM), and HL-1 cells served as in vitro cellular models. Molecular mechanisms were evaluated using optical mapping and molecular and biochemical approaches. ResultsLoss-of-function PC1 mutations significantly increased AF susceptibility in vivo and facilitated local reentry in ex vivo left atrial appendages. Comprehensive in vitro experiments supported a direct effect of PC1 in atrial cardiomyocytes. PC1-deficient monolayers exhibited increased arrhythmic events, escalating into reentrant spiral waves post-tachypacing. Transcriptomics analysis revealed PC1-dependent regulation of DNA repair, with PC1 deficiency leading to increased DNA damage under stress. PARP1 inhibitors or nicotinamide riboside, which counteract DNA damage-related metabolic consequences, reduced in vitro arrhythmias PC1-deficient monolayers. Overexpression of the C-terminus of PC1 had the opposite effects in DNA repair genes, suggesting its regulatory effects in atrial cardiomyocytes through retinoblastoma/E2F. Analyses of human atrial tissue from non-ADPKD AF patients showed reduced levels of mature PC1, suggesting a broader relevance of impaired PC1 in AF. ConclusionsImpaired PC1 increases in vivo AF inducibility under programmed electrical stimulation and promotes in vitro arrhythmias in hiPSC-aCM and HL-1 cells. Our findings indicate that PC1 protects against DNA damage to reduce AF susceptibility.

pathology↗