scholarly journals Cell focal adhesion clustering leads to decreased and homogenized basal strains

2019 ◽  
Author(s):  
Julie Kohn ◽  
Tamer Abdalrahman ◽  
Kevin L Sack ◽  
Cynthia Reinhart-King ◽  
Thomas Franz
Keyword(s):  
Endothelial Cell ◽  
Focal Adhesion ◽  
Apical Cell ◽  
Focal Adhesions ◽  
Cell Strain ◽  
Model Cell ◽  
Subendothelial Matrix ◽  
Cell Strains ◽  
The Impact ◽  
Substrate Model

The subendothelial matrix of the artery is a complex mechanical environment where endothelial cells respond to and affect changes upon the underlying substrate. Our recent work has demonstrated that endothelial cell strain heterogeneity increases on a more heterogeneous underlying subendothelial matrix, and these cells display increased focal adhesion presence on stiffer substrate areas. However, the impact of these grouped focal adhesions on endothelial cell strains has not been explored. Here, we use finite element modeling to investigate the effects of micro-scale stiffness heterogeneities and focal adhesion location and stiffness on endothelial cell strains. Shear stress applied to the apical cell layer demonstrated a minimal effect on cell strain values while substrate stretch had a greater effect on cell strain in the cell-substrate model. The addition of focal adhesions into the computational model (cell-FA-substrate model) predicted a decrease and homogenization of the cell strains. For simulations including focal adhesions, stiffer and more distributed adhesions caused increased and more heterogeneous endothelial cell strains. Overall, our data indicate that cells may group focal adhesions to minimize and homogenize their basal strains.

Smooth muscle cell rigidity and extracellular matrix organization influence endothelial cell spreading and adhesion formation in coculture

2007 ◽  
Vol 293 (3) ◽  
pp. H1978-H1986 ◽  
Author(s):  
Charles S. Wallace ◽  
Sophie A. Strike ◽  
George A. Truskey
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Endothelial Cell ◽  
Focal Adhesion ◽  
Adhesion Formation ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Tissue Engineered Blood Vessels ◽  
Focal Adhesion Formation ◽  
Fibrillar Adhesion

Efforts to develop functional tissue-engineered blood vessels have focused on improving the strength and mechanical properties of the vessel wall, while the functional status of the endothelium within these vessels has received less attention. Endothelial cell (EC) function is influenced by interactions between its basal surface and the underlying extracellular matrix. In this study, we utilized a coculture model of a tissue-engineered blood vessel to evaluate EC attachment, spreading, and adhesion formation to the extracellular matrix on the surface of quiescent smooth muscle cells (SMCs). ECs attached to and spread on SMCs primarily through the α5β1-integrin complex, whereas ECs used either α5β1- or αvβ3-integrin to spread on fibronectin (FN) adsorbed to plastic. ECs in coculture lacked focal adhesions, but EC α5β1-integrin bound to fibrillar FN on the SMC surface, promoting rapid fibrillar adhesion formation. As assessed by both Western blot analysis and quantitative real-time RT-PCR, coculture suppressed the expression of focal adhesion proteins and mRNA, whereas tensin protein and mRNA expression were elevated. When attached to polyacrylamide gels with similar elastic moduli as SMCs, focal adhesion formation and the rate of cell spreading increased relative to ECs in coculture. Thus, the elastic properties are only one factor contributing to EC spreading and focal adhesion formation in coculture. The results suggest that the softness of the SMCs and the fibrillar organization of FN inhibit focal adhesions and reduce cell spreading while promoting fibrillar adhesion formation. These changes in the type of adhesions may alter EC signaling pathways in tissue-engineered blood vessels.

scholarly journals STIM1 Controls the Focal Adhesion Dynamics and Cell Migration by Regulating SOCE in Osteosarcoma

2021 ◽  
Vol 23 (1) ◽  
pp. 162
Author(s):  
Yu-Shan Lin ◽  
Yi-Hsin Lin ◽  
MyHang Nguyen Thi ◽  
Shih-Chuan Hsiao ◽  
Wen-Tai Chiu
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Cancer Metastasis ◽  
Focal Adhesions ◽  
Dominant Negative ◽  
Osteosarcoma Cell ◽  
Wild Type ◽  
Calpain Activity ◽  
The Impact ◽  
Constitutively Active

The dysregulation of store-operated Ca2+ entry (SOCE) promotes cancer progression by changing Ca2+ levels in the cytosol or endoplasmic reticulum. Stromal interaction molecule 1 (STIM1), a component of SOCE, is upregulated in several types of cancer and responsible for cancer cell migration, invasion, and metastasis. To explore the impact of STIM1-mediated SOCE on the turnover of focal adhesion (FA) and cell migration, we overexpressed the wild-type and constitutively active or dominant negative variants of STIM1 in an osteosarcoma cell line. In this study, we hypothesized that STIM1-mediated Ca2+ elevation may increase cell migration. We found that constitutively active STIM1 dramatically increased the Ca2+ influx, calpain activity, and turnover of FA proteins, such as the focal adhesion kinase (FAK), paxillin, and vinculin, which impede the cell migration ability. In contrast, dominant negative STIM1 decreased the turnover of FA proteins as its wild-type variant compared to the cells without STIM1 overexpression while promoting cell migration. These unexpected results suggest that cancer cells need an appropriate amount of Ca2+ to control the assembly and disassembly of focal adhesions by regulating calpain activity. On the other hand, overloaded Ca2+ results in excessive calpain activity, which is not beneficial for cancer metastasis.

Hic-5 promotes endothelial cell migration to lysophosphatidic acid

2007 ◽  
Vol 293 (1) ◽  
pp. H193-H203 ◽  
Author(s):  
C. Avraamides ◽  
M. E. Bromberg ◽  
J. P. Gaughan ◽  
S. M. Thomas ◽  
A. Y. Tsygankov ◽  
...  
Keyword(s):  
Cell Migration ◽  
Endothelial Cell ◽  
Focal Adhesion ◽  
Lysophosphatidic Acid ◽  
Fluorescent Protein ◽  
Focal Adhesions ◽  
Endothelial Cell Migration ◽  
Erk Phosphorylation ◽  
Green Fluorescent

Endothelial cell migration is critical for proper blood vessel development. Signals from growth factors and matrix proteins are integrated through focal adhesion proteins to alter cell migration. Hydrogen peroxide-inducible clone 5 (Hic-5), a paxillin family member, is enriched in the focal adhesions in bovine pulmonary artery endothelial (BPAE) cells, which migrate to lysophosphatidic acid (LPA) on denatured collagen. In this study, we investigate the role of Hic-5 in LPA-stimulated endothelial cell migration. LPA recruits Hic-5 to the focal adhesions and to the pseudopodia in BPAE cells plated on collagen, suggesting that recruitment of Hic-5 to focal adhesions is associated with endothelial cell migration. Knockdown of endogenous Hic-5 significantly decreases migration toward LPA, confirming involvement of Hic-5 in migration. To address the role of Hic-5 in endothelial cell migration, we exogenously expressed wild-type (WT) Hic-5 and green fluorescent protein Hic-5 C369A/C372A (LIM3 mutant) constructs in BPAE cells. WT Hic-5 expression increases chemotaxis of BPAE cells to LPA, whereas migration toward LPA of the green fluorescent protein Hic-5 C369A/C372A-expressing cells is similar to that shown in vector control cells. Additionally, ERK phosphorylation is enhanced in the presence of LPA in WT Hic-5 cells. A pharmacological inhibitor of MEK activity inhibits LPA-stimulated WT Hic-5 cell migration and ERK phosphorylation, suggesting Hic-5 enhances migration via MEK activation of ERK. Together, these studies indicate that Hic-5, a focal adhesion protein in endothelial cells, is recruited to the pseudopodia in the presence of LPA and enhances migration.

scholarly journals EVL is a novel focal adhesion protein involved in the regulation of cytoskeletal dynamics and vascular permeability

2021 ◽  
Vol 11 (4) ◽  
pp. 204589402110490
Author(s):  
Joseph B. Mascarenhas ◽  
Amir A. Gaber ◽  
Tania M. Larrinaga ◽  
Rachel Mayfield ◽  
Stefanie Novak ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Actin Cytoskeleton ◽  
Focal Adhesion Kinase ◽  
Vascular Permeability ◽  
Focal Adhesion ◽  
Regulatory Protein ◽  
Focal Adhesions ◽  
Adhesion Protein ◽  
Cytoskeletal Responses ◽  
Focal Adhesion Protein

Increases in lung vascular permeability is a cardinal feature of inflammatory disease and represents an imbalance in vascular contractile forces and barrier-restorative forces, with both forces highly dependent upon the actin cytoskeleton. The current study investigates the role of Ena-VASP-like (EVL), a member of the Ena-VASP family known to regulate the actin cytoskeleton, in regulating vascular permeability responses and lung endothelial cell barrier integrity. Utilizing changes in transendothelial electricial resistance (TEER) to measure endothelial cell barrier responses, we demonstrate that EVL expression regulates endothelial cell responses to both sphingosine-1-phospate (S1P), a vascular barrier-enhancing agonist, and to thrombin, a barrier-disrupting stimulus. Total internal reflection fluorescence demonstrates that EVL is present in endothelial cell focal adhesions and impacts focal adhesion size, distribution, and the number of focal adhesions generated in response to S1P and thrombin challenge, with the focal adhesion kinase (FAK) a key contributor in S1P-stimulated EVL-transduced endothelial cell but a limited role in thrombin-induced focal adhesion rearrangements. In summary, these data indicate that EVL is a focal adhesion protein intimately involved in regulation of cytoskeletal responses to endothelial cell barrier-altering stimuli. Keywords: cytoskeleton, vascular barrier, sphingosine-1-phosphate, thrombin, focal adhesion kinase (FAK), Ena-VASP like protein (EVL), cytoskeletal regulatory protein

scholarly journals Staurosporine induces endothelial cell apoptosis via focal adhesion kinase dephosphorylation and focal adhesion disassembly independent of focal adhesion kinase proteolysis

2002 ◽  
Vol 367 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Jahangir KABIR ◽  
Melvin LOBO ◽  
Ian ZACHARY
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Cell Apoptosis ◽  
Focal Adhesions ◽  
Cell Types ◽  
Protein Synthesis Inhibitor ◽  
Endothelial Cell Apoptosis ◽  
Synthesis Inhibitor

The survival of endothelial cells is dependent on interactions between the matrix and integrins mediated through focal adhesions. Focal adhesion kinase (FAK) is thought to play a key role in maintaining focal adhesion function and cell survival, whereas caspase-mediated FAK proteolysis is implicated in focal adhesion disassembly during apoptosis. We examined the relationship between changes in FAK phosphorylation and proteolysis during apoptosis of primary porcine aortic endothelial cells (PAEC) induced by staurosporine, a widely used apoptogenic agent in diverse cell types. Staurosporine-induced PAEC apoptosis was detected after 1h and was preceded by disruption and loss of FAK localization to focal adhesions within a few minutes, whereas staurosporine-induced cleavage of FAK occurred only after 8—24h. Staurosporine induced a very rapid dephosphorylation of FAK at Tyr861 and Tyr397 and caused dissociation of phosphorylated FAK from focal adhesions as early as 30s. The effect of staurosporine was very potent with striking inhibition of Tyr861 and Tyr397 phosphorylation and focal adhesion disruption occurring in the range 10—100nM. Selective inhibition of a known target of staurosporine, protein kinase C, using GF109203X, and of phosphoinositide 3′-kinase using wortmannin, did not reduce FAK tyrosine phosphorylation at Tyr861 and Tyr397, or cause disruption of focal adhesions. Cycloheximide, the protein synthesis inhibitor, induced PAEC apoptosis more slowly than staurosporine, but did not induce FAK dephosphorylation or rapid focal adhesion disruption, and instead caused a slower loss of focal adhesions and a marked increase in FAK proteolysis. These studies show that FAK dephosphorylation and focal adhesion disassembly are very early events mediating the onset of staurosporine-induced endothelial cell apoptosis and are dissociated from FAK proteolysis. Cycloheximide induces apoptosis through a pathway involving FAK proteolysis without dephosphorylation.

scholarly journals Mechanosensation and Mechanotransduction by Lymphatic Endothelial Cells Act as Important Regulators of Lymphatic Development and Function

2021 ◽  
Vol 22 (8) ◽  
pp. 3955
Author(s):  
László Bálint ◽  
Zoltán Jakus
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Mechanical Forces ◽  
Lymphatic Endothelial Cells ◽  
Lymphatic Development ◽  
And Function ◽  
The Impact

Our understanding of the function and development of the lymphatic system is expanding rapidly due to the identification of specific molecular markers and the availability of novel genetic approaches. In connection, it has been demonstrated that mechanical forces contribute to the endothelial cell fate commitment and play a critical role in influencing lymphatic endothelial cell shape and alignment by promoting sprouting, development, maturation of the lymphatic network, and coordinating lymphatic valve morphogenesis and the stabilization of lymphatic valves. However, the mechanosignaling and mechanotransduction pathways involved in these processes are poorly understood. Here, we provide an overview of the impact of mechanical forces on lymphatics and summarize the current understanding of the molecular mechanisms involved in the mechanosensation and mechanotransduction by lymphatic endothelial cells. We also discuss how these mechanosensitive pathways affect endothelial cell fate and regulate lymphatic development and function. A better understanding of these mechanisms may provide a deeper insight into the pathophysiology of various diseases associated with impaired lymphatic function, such as lymphedema and may eventually lead to the discovery of novel therapeutic targets for these conditions.

scholarly journals Performance Analysis of Indentation Punch on High Energy Lithium Pouch Cells and Simulated Model Improvement

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1971
Author(s):  
Lihua Ye ◽  
Muhammad Muzamal Ashfaq ◽  
Aiping Shi ◽  
Syyed Adnan Raheel Shah ◽  
Yefan Shi
Keyword(s):  
Short Circuit ◽  
Lithium Ion ◽  
Mechanical Deformation ◽  
High Energy ◽  
State Of Charge ◽  
Punch Test ◽  
Short Course ◽  
Model Cell ◽  
The Impact

In this research, the aim relates to the material characterization of high-energy lithium-ion pouch cells. The development of appropriate model cell behavior is intended to simulate two scenarios: the first is mechanical deformation during a crash and the second is an internal short circuit in lithium-ion cells during the actual effect scenarios. The punch test has been used as a benchmark to analyze the effects of different state of charge conditions on high-energy lithium-ion battery cells. This article explores the impact of three separate factors on the outcomes of mechanical punch indentation experiments. The first parameter analyzed was the degree of prediction brought about by experiments on high-energy cells with two different states of charge (greater and lesser), with four different sizes of indentation punch, from the cell’s reaction during the indentation effects on electrolyte. Second, the results of the loading position, middle versus side, are measured at quasi-static speeds. The third parameter was the effect on an electrolyte with a different state of charge. The repeatability of the experiments on punch loading was the last test function analyzed. The test results of a greater than 10% state of charge and less than 10% state of charge were compared to further refine and validate this modeling method. The different loading scenarios analyzed in this study also showed great predictability in the load-displacement reaction and the onset short circuit. A theoretical model of the cell was modified for use in comprehensive mechanical deformation. The overall conclusion found that the loading initiating the cell’s electrical short circuit is not instantaneously instigated and it is subsequently used to process the development of a precise and practical computational model that will reduce the chances of the internal short course during the crash.

scholarly journals Proline-rich tyrosine kinase 2 mediates transforming growth factor-beta-induced hepatic stellate cell activation and liver fibrosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jonghwa Kim ◽  
Wonseok Kang ◽  
So Hee Kang ◽  
Su Hyun Park ◽  
Ji Young Kim ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Tyrosine Kinase ◽  
Focal Adhesion ◽  
Transforming Growth Factor ◽  
Family Members ◽  
Type I ◽  
Tyrosine Kinase 2 ◽  
The Impact ◽  
Tgf Β1

AbstractHepatic fibrogenesis is characterized by activation of hepatic stellate cells (HSCs) and accumulation of extracellular matrix (ECM). The impact of ECM on TGF-β-mediated fibrogenic signaling pathway in HSCs has remained obscure. We studied the role of non-receptor tyrosine kinase focal adhesion kinase (FAK) family members in TGF-β-signaling in HSCs. We used a CCl4-induced liver fibrosis mice model to evaluate the effect of FAK family kinase inhibitors on liver fibrosis. RT-PCR and Western blot were used to measure the expression of its target genes; α-SMA, collagen, Nox4, TGF-β1, Smad7, and CTGF. Pharmacological inhibitors, siRNA-mediated knock-down, and plasmid-based overexpression were adopted to modulate the function and the expression level of proteins. Association of PYK2 activation with liver fibrosis was confirmed in liver samples from CCl4-treated mice and patients with significant fibrosis or cirrhosis. TGF-β treatment up-regulated expression of α-SMA, type I collagen, NOX4, CTGF, TGF-β1, and Smad7 in LX-2 cells. Inhibition of FAK family members suppressed TGF-β-mediated fibrogenic signaling. SiRNA experiments demonstrated that TGF-β1 and Smad7 were upregulated via Smad-dependent pathway through FAK activation. In addition, CTGF induction was Smad-independent and PYK2-dependent. Furthermore, RhoA activation was essential for TGF-β-mediated CTGF induction, evidenced by using ROCK inhibitor and dominant negative RhoA expression. We identified that TGF-β1-induced activation of PYK2-Src-RhoA triad leads to YAP/TAZ activation for CTGF induction in liver fibrosis. These findings provide new insights into the role of focal adhesion molecules in liver fibrogenesis, and targeting PYK2 may be an attractive target for developing novel therapeutic strategies for the treatment of liver fibrosis.

scholarly journals Candida albicans Expresses a Focal Adhesion Kinase-Like Protein That Undergoes Increased Tyrosine Phosphorylation upon Yeast Cell Adhesion to Vitronectin and the EA.hy 926 Human Endothelial Cell Line

2002 ◽  
Vol 70 (7) ◽  
pp. 3804-3815 ◽  
Author(s):  
Giorgio Santoni ◽  
Roberta Lucciarini ◽  
Consuelo Amantini ◽  
Jordan Jacobelli ◽  
Elisabetta Spreghini ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Candida Albicans ◽  
Cell Adhesion ◽  
Endothelial Cell ◽  
Yeast Cell ◽  
Focal Adhesion Kinase ◽  
Cell Line ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Human Endothelial Cell Line

ABSTRACT The signaling pathways triggered by adherence of Candida albicans to the host cells or extracellular matrix are poorly understood. We provide here evidence in C. albicans yeasts of a p105 focal adhesion kinase (Fak)-like protein (that we termed CaFak), antigenically related to the vertebrate p125Fak, and its involvement in integrin-like-mediated fungus adhesion to vitronectin (VN) and EA.hy 926 human endothelial cell line. Biochemical analysis with different anti-chicken Fak antibodies identified CaFak as a 105-kDa protein and immunofluorescence and cytofluorimetric analysis on permeabilized cells specifically stain C. albicans yeasts; moreover, confocal microscopy evidences CaFak as a cytosolic protein that colocalizes on the membrane with the integrin-like VN receptors upon yeast adhesion to VN. The protein tyrosine kinase (PTK) inhibitors genistein and herbimycin A strongly inhibited C. albicans yeast adhesion to VN and EA.hy 926 endothelial cells. Moreover, engagement of αvβ3 and αvβ5 integrin-like on C. albicans either by specific monoclonal antibodies or upon adhesion to VN or EA.hy 926 endothelial cells stimulates CaFak tyrosine phosphorylation that is blocked by PTK inhibitor. A role for CaFak in C. albicans yeast adhesion was also supported by the failure of VN to stimulate its tyrosine phosphorylation in a C. albicans mutant showing normal levels of CaFak and VNR-like integrins but displaying reduced adhesiveness to VN and EA.hy 926 endothelial cells. Our results suggest that C. albicans Fak-like protein is involved in the control of yeast cell adhesion to VN and endothelial cells.

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