Integrin-mediated force application induces a conformational change in latent TGF-β1 that leads to the release of active form growth factor from extracellular matrix (ECM). Mechanical activation is currently understood as an acute process depends on contractile cells. However, we show ECM remodeling, preceding step, mechanically primes akin loading mechanical spring. Cell-based assays and unique strain devices were used produce cell-derived controlled organization prestrain. Mechanically...

Members of the Rho GTPase family play a central role in orchestration cytoskeletal rearrangements, which are prime importance endothelial cell physiology. To explore their this specialized type, we used bacterial toxin cytotoxic necrotizing factor 1 (CNF1) as activator. Punctate filamentous actin structures appeared along ventral plasma membrane cells and were identified core podosomes by distinctive vinculin ring around F-actin. Rho, Rac, Cdc42 all targets CNF1, but only constitutively...

T cells express multiple isotypes of protein kinase C (PKC) and although it is well accepted that PKCs have an important role in cell activation, little known about the function individual PKC isotypes. To address this issue, mutationally active PKC-α, -ε, or -ζ been transfected into consequences for activation determined. p21 plays essential activation. Accordingly, effects constitutively were compared to activated p21. The data indicate PKC-ε and, a lesser extent PKC-α but not -ζ, can...

The involvement of Src, Cdc42, RhoA and PKC in the regulation podosome assembly has been identified various cell models. In endothelial cells, ectopic expression constitutively active mutants Src or but not RhoA, induced formation podosomes. Short-term exposure to phorbol-12-myristate-13-acetate (PMA) appearance podosomes rosettes after initial disruption stress fibres. Molecular analysis PMA-induced revealed that their composition was identical described other Pharmacological inhibition...

Cytoskeletal rearrangements are central to endothelial cell physiology and controlled by soluble factors, matrix proteins, cell-cell interactions, mechanical forces. We previously reported that aortic cells can rearrange their cytoskeletons into complex actin-based structures called podosomes when a constitutively active mutant of Cdc42 is expressed. now report transforming growth factor beta (TGF-beta) promotes podosome formation in primary cells. TGF-beta-induced assembled together large...

The actin cytoskeleton of mature osteoclasts (OCs) adhering to nonmineralized substrates is organized in a belt podosomes reminiscent the sealing zone (SZ) found bone resorbing OCs. In this study, we demonstrate that composed two functionally different actin-based domains: podosome cores linked with CD44, which are involved cell adhesion, and diffuse cloud associated beta3 integrin, adhesion contraction. Wiskott Aldrich Syndrome Protein (WASp) Interacting (WIP)-/- OCs were devoid podosomes,...

Podosomes are specialized plasma-membrane actin-based microdomains that combine adhesive and proteolytic activities to spatially restrict sites of matrix degradation in vitro assays, but the physiological relevance these observations remain unknown. Inducible rings podosomes (podosome rosettes) form cultured aortic cells exposed inflammatory cytokine TGFbeta. In an attempt prove existence living tissues, we developed ex vivo endothelium observation model. This system enabled us visualize...

Invadosomes are F-actin structures capable of degrading the matrix through activation metalloproteases. As fibrillar type I collagen promotes pro-matrix metalloproteinase 2 by membrane 1 metalloproteinase, we aimed at investigating functional relationships between organization and invadosome induction. We found that induced linear structures, distributed along fibrils, on endothelial cells, macrophages, fibroblasts, tumor cells. These share features with conventional invadosomes, as they...

Fibrillin-1 is an extracellular matrix protein that assembles into microfibrils which provide critical functions in large blood vessels and other tissues. Mutations the fibrillin-1 gene are associated with cardiovascular, ocular, skeletal abnormalities Marfan syndrome. Here, we reveal for angiogenesis compromised by a typical mutation. In mouse retina vascularization model, present at angiogenic front where it colocalizes microfibril-associated glycoprotein-1, MAGP1. Fbn1C1041G/+ mice, model...

The serine/threonine kinase Akt (also known as protein B) (Akt/PKB) is activated upon T-cell antigen receptor (TCR) engagement or expression of an active form phosphatidylinositide (PI) 3-kinase in T lymphocytes. Here we report that the small GTPase Rac1 implicated this pathway, connecting with lipid kinase. We show Jurkat cells, forms Cdc42, but not Rho, stimulate increase Akt/PKB activity. TCR-induced activation inhibited either by PI inhibitors (LY294002 and wortmannin) overexpression a...

Abstract Background information Podosomes are actin‐based structures involved in cell adhesion, migration, invasion and extracellular matrix degradation. They have been described large vessel endothelial cells, but nothing is known concerning microvascular cells. Here, we focussed on liver sinusoidal cells (LSECs), fenestrated that play major roles physiology. Liver fibrosis induces a dedifferentiation of LSECs leading notably to loss fenestrae. Because associated with increased stiffness,...

During angiogenic sprouting, endothelial tip cells emerge from existing vessels in a process that requires vascular basement membrane degradation. Here, we show F-actin/cortactin/P-Src-based matrix-degrading microdomains called podosomes contribute to this step. In vitro, VEGF-A/Notch signaling regulates the formation of functional cells. Using retinal neovascularization model, demonstrate assemble during physiological angiogenesis vivo. retina, are also part an interconnected network...

Vascular development is an orchestrated process of vessel formation from pre-existing vessels via sprouting and intussusceptive angiogenesis as well vascular remodeling to generate the mature vasculature. Bone morphogenetic protein (BMP) signaling intracellular SMAD1 SMAD5 effectors regulates in early mouse embryo, but its role other processes beds remains incompletely understood. Here, we investigate function SMAD1/5 during postnatal retinal using inducible, endothelium-specific deletion...

The purpose of this study was to investigate the role Fat4 and Dachsous1 signaling in lymphatic vasculature.Phenotypic analysis vasculature performed mice lacking functional or Dachsous1. overall architecture is unaltered, yet both genes are specifically required for valve morphogenesis. Valve endothelial cells (Prox1high [prospero homeobox protein 1] cells) disoriented failed form proper leaflets. Using Lifeact-GFP (green fluorescent protein) mice, we revealed that display prominent actin...

Tumor cells exposed to a physiological matrix of type I collagen fibers form elongated collagenolytic invadopodia, which differ from dotty-like invadopodia forming on the gelatin substratum model. The related scaffold proteins, TKS5 and TKS4, are key components mechanism assembly. molecular events through TKS proteins direct formation poorly defined. Using coimmunoprecipitation experiments, identification bound by mass spectrometry, in vitro pull-down we found an interaction between FGD1,...

The two isoforms of p190 RhoGAP (p190A and p190B) are important regulators RhoGTPase activity in mammalian cells. Both proteins ubiquitously expressed, involved the same signalling pathways interact with identified binding partners. In search isoform functional specificity, we knocked down expression each protein using siRNA examined resulting phenotypic changes human umbilical vein endothelial cells (HUVECs). We provide evidence that p190B plays a crucial role regulation MT1-MMP...

Podosomes are dynamic actin-rich adhesion plasma membrane microdomains endowed with extracellular matrix-degrading activities. In aortic endothelial cells, podosomes induced by transforming growth factor β (TGF-β), but how this occurs is largely unknown. It thought that, in play a role vessel remodeling and/or breaching anatomical barriers. We demonstrate here bovine that the Cdc42-specific guanine exchange (GEF) Fgd1 expressed and regulated TGF-β to induce Cdc42-dependent podosome assembly....