Pericardial fluid (PF) has been suggested as a reservoir of molecular targets that can be modulated for efficient repair after myocardial infarction (MI). Here, we set out to address the content of this biofluid after MI, namely in terms of microRNAs (miRs) that are important modulators of the cardiac pathological response. PF was collected during coronary artery bypass grafting (CABG) from two MI cohorts, patients with non-ST-segment elevation MI (NSTEMI) and patients with ST-segment elevation MI (STEMI), and a control group composed of patients with stable angina and without previous history of MI. The PF miR content was analyzed by small RNA sequencing, and its biological effect was assessed on human cardiac fibroblasts. PF accumulates fibrotic and inflammatory molecules in STEMI patients, namely causing the soluble suppression of tumorigenicity 2 (ST-2), which inversely correlates with the left ventricle ejection fraction. Although the PF of the three patient groups induce similar levels of fibroblast-to-myofibroblast activation in vitro, RNA sequencing revealed that PF from STEMI patients is particularly enriched not only in pro-fibrotic miRs but also anti-fibrotic miRs. Among those, miR-22-3p was herein found to inhibit TGF-β-induced human cardiac fibroblast activation in vitro. PF constitutes an attractive source for screening diagnostic/prognostic miRs and for unveiling novel therapeutic targets in cardiac fibrosis.

Aging and chronic inflammation are associated with the development of heart failure with preserved ejection fraction (HFpEF). However, cellular senescence as a potential mechanistic link between both events and its pathophysiological and therapeutic role were yet unexplored. Here we show that ZSF1-obese rats, a model of cardiometabolic HFpEF, have exacerbated systemic inflammation and endothelial damage compared to ZSF1-lean littermates. In addition, ZSF1-obese rats accumulated immune and endothelial senescent cells in the peripheral blood and myocardium. Accordingly, the frequency of circulating senescent leukocytes associated with markers of disease severity in HFpEF patients. Notably, systemic treatment of ZSF1-obese rats with Navitoclax, a BCL-2 family inhibitor, reduced senescent cell burden, decreased circulating B-type natriuretic peptide levels, and attenuated inflammation, vascular remodeling and cardiac fibrosis. Our findings advance cellular senescence as a key mechanistic pathway leading to HFpEF and provide proof-of-concept evidence that senolytics are a promising treatment for this disease.

Cardiac fibroblasts (CFbs) determine the topological arrangement and the anisotropy of the heart tissue which maintains tissue integrity and function through the production and remodeling of the extracellular matrix (ECM). Under pathological conditions, CFbs can activate into myofibroblasts and promote maladaptive ECM remodeling that may lead to heart failure. Yes-Associated Protein (YAP) - a key player in cardiac fibrosis onset - has been implicated in CFb activation but its role in coordinating the supracellular organization of CFbs and in shaping the instructive properties of the ECM remains poorly understood. We addressed these questions by generating CFbs from wild-type (WT) and YAP knockout (KO) human embryonic stem cells. YAP depletion reduced the expression of cardiogenic markers and altered the transcriptomic profile of ECM- and contractility-related genes. We further demonstrated that YAP expression is required for CFbs monolayer alignment, and its absence resulted in reduced ECM deposition, decreased anisotropy, and diminished force generation. Pharmacological inhibition of cell contractility closely mirrored YAP KO phenotype, suggesting that YAP regulates both monolayer organization and ECM structure through its control over contractility. ECM cross-seeding experiments confirmed the role of ECM as a structural guide for cellular alignment. Moreover, cardiomyocytes cultured on KO CFb-derived ECM exhibited impaired sarcomere organization and altered calcium dynamics. Together, these findings demonstrate that YAP activity in CFbs governs the structural and functional properties of the ECM, influencing both fibroblast alignment and cardiomyocyte activity. Moreover, they underscore the critical role of YAP in maintaining the supracellular organization and mechanical integrity of cardiac tissue.

Bio–nano interactions have been extensively explored in nanomedicine to develop selective delivery strategies, reduce systemic toxicity, and minimize therapeutic dosing requirements. To enhance the delivery of nanocarriers to cancer cells and improve the therapeutic efficiency and clinical translation of nanomedicines, numerous nanomaterials with diverse and tunable properties have been developed. However, the limited clinical translation of nanoparticle-based therapies, largely due to issues associated with poor targeting and therapeutic delivery, requires a deeper understanding of the biological phenomena underlying cell–nanoparticle interactions. In this context, herein we investigate the molecular and cellular mechanobiology parameters that control such interactions. We demonstrate that the pharmacological inhibition or the genetic ablation of the key mechanosensitive component of the Hippo pathway, i.e., yes-associated protein, enhances nanoparticle internalization by 1.5-fold. Importantly, this phenomenon occurs independently of nanoparticle properties, such as size, or cell properties such as surface area, substrate adhesion, and stiffness. Our study reveals that the internalization of nanoparticles in target cells can be controlled by modulating cell mechanosensing pathways, potentially ultimately enhancing nanoparticle delivery and nanotherapy specificity.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and is associated with high cell plasticity, recurrence, and metastatic rate. During epithelial-to-mesenchymal transition (EMT), cancer cells display EMT plasticity, or partial-EMT features, which are required for breast cancer metastasis, such as collective migration. ERK3 has been implicated in promoting migration and invasion of breast cancer, but the mechanisms remain elusive. Here, we investigated ERK3 expression across patient-derived datasets of breast cancer and established its association with aggressive breast cancer phenotypes and poor clinical outcomes. Leveraging the hypothesis that ERK3 contributes to TNBC progression by supporting a partial-EMT state, we showed that ERK3 is essential in different steps of the metastatic process, especially by enabling collective migration but also by modulating cell-extracellular matrix adhesion, anchorage-independent growth, extravasation and colonization. In conclusion, our results demonstrate that ERK3 contributes to TNBC progression and potentially metastasis by promoting EMT plasticity and collective migration.

Cardiac fibroblasts (CFbs) determine the topological arrangement and the anisotropy of the heart tissue - essential features for maintaining tissue integrity and function - through the production and remodeling of the extracellular matrix (ECM). Under pathological conditions, CFbs can activate into myofibroblasts and promote maladaptive ECM remodeling that may lead to heart failure. Yes-Associated Protein (YAP) – a key player in cardiac fibrosis onset - has been implicated in CFb activation but its role in coordinating the supracellular organization of CFbs and in shaping the instructive properties of the ECM remains poorly understood. We addressed these questions by generating CFbs from wild-type (WT) and YAP knockout (KO) human embryonic stem cells. YAP depletion reduced the expression of cardiogenic markers and altered the transcriptomic profile of ECM- and contractility-related genes. We further demonstrated that YAP expression is required for CFbs monolayer alignment, and its absence resulted in reduced ECM deposition, decreased anisotropy, and diminished force generation. Pharmacological inhibition of cell contractility closely mirrored YAP KO phenotype, suggesting that YAP regulates both monolayer organization and ECM structure through its control over contractility. ECM cross-seeding experiments confirmed the role of ECM as a structural guide for cellular alignment. Moreover, cardiomyocytes cultured on KO CFb-derived ECM exhibited impaired sarcomere organization and altered calcium dynamics. Together, these findings demonstrate that YAP activity in CFbs governs the structural and functional properties of the ECM, influencing both fibroblast alignment and cardiomyocyte activity. Moreover, they underscore the critical role of YAP in maintaining the supracellular organization and mechanical integrity of cardiac tissue.