Project description:Hippo effectors YAP/TAZ act as on-off mechanosensing switches by sensing modifications in extracellular matrix (ECM) composition and mechanics. The regulation of their activity has been described so far through a hierarchical model in which elements of Hippo pathway are under the control of Focal Adhesions (FAs). Here we unveiled the molecular mechanism by which cell spreading and RhoA GTPase control FA formation through YAP to stabilize the anchorage of actin cytoskeleton to cell membrane. This mechanism required YAP co-transcriptional function and involved the activation of genes encoding for integrins and FA docking proteins. Tuning YAP transcriptional activity led to the modification of cell mechanics, force development, adhesion strength, determined cell shaping, migration and differentiation. These results provide new insights into the mechanism of YAP mechanosensing activity and qualify Hippo effector as the key determinant of cell mechanics in response to ECM cues.
Project description:YAP transcriptional regulator controls cell mechanics by activating genes involved in cell-matrix interaction following extracellular matrix (ECM) remodelling and stiffening. YAP is needed for cardiogenesis in mouse but is repressed in adult cardiomyocytes. The protein is reactivated following ischemic insults, although the timing and mechanisms underlying YAP depletion during heart development and the reason for its reactivation are unclear. Here, we combine pluripotent stem cell (PSC) cardiac differentiation, mouse embryo development and human heart tissue analysis to demonstrate that the fine-tuning of cell mechanics, as controlled by YAP multiphasic activation through TEAD transcription, is crucial for mesoderm commitment and cardiac progenitor specification. Finally, by adopting induced PSC models of dilated cardiomyopathy, we prove that YAP-TEAD reactivation in diseased cardiomyocytes empowers calcium handling apparatus and increases cell contractility. Given YAP prompt activation following myocardial infarction, we unveil a novel role for mechanosensing in connecting ECM remodelling to cardiomyocyte function in pathological heart.
Project description:YAP transcriptional regulator controls cell mechanics by activating genes involved in cell-matrix interaction following extracellular matrix (ECM) remodelling and stiffening. YAP is needed for cardiogenesis in mouse but is repressed in adult cardiomyocytes. The protein is reactivated following ischemic insults, although the timing and mechanisms underlying YAP depletion during heart development and the reason for its reactivation are unclear. Here, we combine pluripotent stem cell (PSC) cardiac differentiation, mouse embryo development and human heart tissue analysis to demonstrate that the fine-tuning of cell mechanics, as controlled by YAP multiphasic activation through TEAD transcription, is crucial for mesoderm commitment and cardiac progenitor specification. Finally, by adopting induced PSC models of dilated cardiomyopathy, we prove that YAP-TEAD reactivation in diseased cardiomyocytes empowers calcium handling apparatus and increases cell contractility. Given YAP prompt activation following myocardial infarction, we unveil a novel role for mechanosensing in connecting ECM remodelling to cardiomyocyte function in pathological heart.
Project description:The goal of this study was to identify transcripts, which are differentially regulatulated in the presence and absence of Focal Adhesion Kinase. As Focal Adhesion Kinase activity can depend upon cell density (Snijder et al. Nature 2009), biological replicates where cells, were seeded very sparsely or confluently, were used. Focal Adhesion Kinase Knockout (ATCC CRL-2644) and Rescue Cells (Sieg et al. 1998, clone DA2) were seeded at two different concentrations. Replicas refer to biological replicates, performed on different days. Only one single technical replicate has been done per biological replicate.
Project description:The goal of this study was to identify transcripts, which are differentially regulatulated in the presence and absence of Focal Adhesion Kinase. As Focal Adhesion Kinase activity can depend upon cell density (Snijder et al. Nature 2009), biological replicates where cells, were seeded very sparsely or confluently, were used.
Project description:Targeted therapy is effective in many tumor types including lung cancer, the leading cause of cancer mortality. Paradigm defining examples are targeted therapies directed against non-small cell lung cancer (NSCLC) subtypes with oncogenic alterations in EGFR, ALK and KRAS. The success of targeted therapy is limited by drug-tolerant persister cells (DTPs) which withstand and adapt to treatment and comprise the residual disease state that is typical during treatment with clinical targeted therapies. Here, we integrate studies in patient-derived and immunocompetent lung cancer models and clinical specimens obtained from patients on targeted therapy to uncover a focal adhesion kinase (FAK)-YAP signaling axis that promotes residual disease during oncogenic EGFR-, ALK-, and KRAS-targeted therapies. FAK-YAP signaling inhibition combined with the primary targeted therapy suppressed residual drug-tolerant cells and enhanced tumor responses. This study unveils a FAK-YAP signaling module that promotes residual disease in lung cancer and mechanism-based therapeutic strategies to improve tumor response.
Project description:Targeted therapy is effective in many tumor types including lung cancer, the leading cause of cancer mortality. Paradigm defining examples are targeted therapies directed against non-small cell lung cancer (NSCLC) subtypes with oncogenic alterations in EGFR, ALK and KRAS. The success of targeted therapy is limited by drug-tolerant persister cells (DTPs) which withstand and adapt to treatment and comprise the residual disease state that is typical during treatment with clinical targeted therapies. Here, we integrate studies in patient-derived and immunocompetent lung cancer models and clinical specimens obtained from patients on targeted therapy to uncover a focal adhesion kinase (FAK)-YAP signaling axis that promotes residual disease during oncogenic EGFR-, ALK-, and KRAS-targeted therapies. FAK-YAP signaling inhibition combined with the primary targeted therapy suppressed residual drug-tolerant cells and enhanced tumor responses. This study unveils a FAK-YAP signaling module that promotes residual disease in lung cancer and mechanism-based therapeutic strategies to improve tumor response.
Project description:Cellular senescence is a phenotype characterized by cessation of cell division, which can be caused by exhaustive replication or environmental stress. It is involved in age-related pathophysiological conditions and affects both the cellular cytoskeleton and the prime cellular mechanosensors, focal adhesion complexes. While the size of focal adhesions increases during senescence, it is unknown if and how this is accompanied by a remodeling of the internal focal adhesion structure. Our study uses metal-induced energy transfer to study the axial dimension of focal adhesion proteins from oxidative-stress-induced senescent cells with nanometer precision, and compares these to unstressed cells. We influenced cytoskeletal tension and the functioning of mechanosensitive ion channels using drugs and studied the combined effect of senescence and drug intervention on the focal adhesion structure. We find that H 2 O 2 induced restructuring of the focal adhesion complex indicates a loss of tension and altered talin complexation. Mass spectroscopy-based proteomics confirmed the differential regulation of several cytoskeletal proteins induced by H 2 O 2 treatment.