Biology subjects

Niro, F.

Publications and source records attributed to Niro, F..

4 recordsLinked to original sources

bioRxiv2024

Cardiac fibroblasts cellular anisotropy is determined by YAP-dependent cellular contractility and ECM production

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.

cell biology↗

bioRxiv2024

Regulation of cell-nanoparticle interactions through mechanobiology

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.

bioengineering↗

bioRxiv2024

An iPSC-derived bio-inspired scaffold modelling the structure and the effects of extracellular matrix in cardiac fibrosis

Cardiac fibrosis occurs following insults to the myocardium and is characterized by the abnormal accumulation of non-compliant extracellular matrix (ECM), which compromises cardiomyocyte contractile activity and eventually leads to heart failure. This phenomenon is driven by the differentiation of cardiac fibroblasts (cFbs) into myofibroblasts and results in changes in ECM biochemical, structural and mechanical properties. The lack of predictive in vitro models of heart fibrosis has so far hampered the search for innovative treatments. Here, we devised a single-step decellularization protocol to obtain and thoroughly characterize the biochemical and micro-mechanical properties of the ECM secreted by activated cFbs differentiated from human induced pluripotent stem cells (iPSCs). We activated iPSC-derived cFbs to the myofibroblast phenotype by tuning basic fibroblast growth factor (bFGF) and transforming growth factor beta 1 (TGF-{beta}1) signalling and confirmed that activated cells acquired key features of myofibroblast phenotype, like SMAD2/3 nuclear shuttling, the formation of aligned alpha-smooth muscle actin (-SMA)-rich stress fibres and increased focal adhesions (FAs) assembly. Next, we used Mass Spectrometry, nanoindentation, scanning electron and confocal microscopy to unveil the characteristic composition and the visco-elastic properties of the abundant, collagen-rich ECM deposited by cardiac myofibroblasts in vitro. Finally, we demonstrated that the fibrotic ECM activates mechanosensitive pathways in iPSC-derived cardiomyocytes, impacting on their shape, sarcomere alignment, phenotype, and calcium handling properties. We thus propose human bio-inspired decellularized matrices as animal-free, isogenic cardiomyocyte culture substrates recapitulating key pathophysiological changes occurring at the cellular level during cardiac fibrosis.

cell biology↗

bioRxiv2022

Generation and Maturation of Human iPSC-derived Cardiac Organoids in Long Term Culture

Cardiovascular diseases remain the leading cause of death worldwide; hence there is an increasing focus on developing physiologically relevant in vitro cardiovascular tissue models suitable for studying personalized medicine and pre-clinical tests. Despite recent advances, models that reproduce both tissue complexity and maturation are still limited. We have established a scaffold-free protocol to generate multicellular, beating and self-organized human cardiac organoids (hCO) in vitro from hiPSCs that can be cultured for long term. This is achieved by differentiation of hiPSC in 2D monolayer culture towards cardiovascular lineage, followed by further aggregation on low-attachment culture dishes in 3D. The generated human cardiac organoids (hCOs) containing multiple cell types that physiologically compose the heart, gradually self-organize and beat without external stimuli for more than 50 days. We have shown that 3D hCOs display improved cardiac specification, survival and maturation as compared to standard monolayer cardiac differentiation. We also confirmed the functionality of hCOs by their response to cardioactive drugs in long term culture. Furthermore, we demonstrated that hCOs can be used to study chemotherapy-induced cardiotoxicity. This study could help to develop more physiologically-relevant cardiac tissue models, and represent a powerful platform for future translational research in cardiovascular biology.

cell biology↗