scholarly journals Structural analysis of receptors and actin polarity in platelet protrusions

2021 ◽  
Vol 118 (37) ◽  
pp. e2105004118
Author(s):  
Simona Sorrentino ◽  
Jose Javier Conesa ◽  
Ana Cuervo ◽  
Roberto Melero ◽  
Bruno Martins ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Structural Analysis ◽  
Structural Information ◽  
Three Dimensional ◽  
Cell Spreading ◽  
Membrane Receptors ◽  
Structural Class ◽  
Matrix Interactions ◽  
Contractile Forces ◽  
Extracellular Matrix Interactions

During activation the platelet cytoskeleton is reorganized, inducing adhesion to the extracellular matrix and cell spreading. These processes are critical for wound healing and clot formation. Initially, this task relies on the formation of strong cellular–extracellular matrix interactions, exposed in subendothelial lesions. Despite the medical relevance of these processes, there is a lack of high-resolution structural information on the platelet cytoskeleton controlling cell spreading and adhesion. Here, we present in situ structural analysis of membrane receptors and the underlying cytoskeleton in platelet protrusions by applying cryoelectron tomography to intact platelets. We utilized three-dimensional averaging procedures to study receptors at the plasma membrane. Analysis of substrate interaction-free receptors yielded one main structural class resolved to 26 Å, resembling the αIIbβ3 integrin folded conformation. Furthermore, structural analysis of the actin network in pseudopodia indicates a nonuniform polarity of filaments. This organization would allow generation of the contractile forces required for integrin-mediated cell adhesion.

A rhabdomyosarcoma hydrogel model to unveil cell-extracellular matrix interactions

2021 ◽  
Author(s):  
Mattia Saggioro ◽  
Stefania D'Agostino ◽  
Anna Gallo ◽  
Sara Crotti ◽  
Sara D'Aronco ◽  
...  
Keyword(s):  
Cell Culture ◽  
Extracellular Matrix ◽  
Three Dimensional ◽  
3D Culture ◽  
3D Cell Culture ◽  
Culture Systems ◽  
Matrix Interactions ◽  
In Vitro Systems ◽  
Extracellular Matrix Interactions

Three-dimensional (3D) culture systems are progressively getting attention given their potential in overcoming limitations of the classical 2D in vitro systems. Among different supports for 3D cell culture, hydrogels (HGs)...

ROS stimulate reorganization of mesangial cell-collagen gels by tyrosine kinase signaling

1999 ◽  
Vol 276 (2) ◽  
pp. F278-F287 ◽  
Author(s):  
Roy Zent ◽  
Menachem Ailenberg ◽  
Gregory P. Downey ◽  
Melvin Silverman
Keyword(s):  
Extracellular Matrix ◽  
Tyrosine Phosphorylation ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Three Dimensional ◽  
Collagen Gel ◽  
Kinase Signaling ◽  
Matrix Interactions ◽  
Three Dimensional Culture ◽  
Extracellular Matrix Interactions

Reactive oxygen species (ROS) initiate multiple pathological and physiological cellular responses, including tyrosine phosphorylation of proteins. In this study, we investigated the effects of ROS on cell-extracellular matrix interactions utilizing the floating three-dimensional collagen gel assay. Exposure of mesangial cells grown in three-dimensional culture to H2O2, 3-amino-1,2,4-triazole (a catalase inhibitor), or puromycin is associated with gel reorganization accompanied by tyrosine phosphorylation of multiple proteins, including focal adhesion kinase (FAK). Neutrophils cocultured with mesangial cells in three-dimensional culture also induce mesangial cell-collagen gel reorganization and initiate tyrosine phosphorylation of a similar set of proteins. Collectively, these results show that ROS of either endogenous or exogenous origin can modulate mesangial cell-extracellular matrix interactions through initiation of a phosphotyrosine kinase signaling cascade. Consequently, ROS may play a role as signaling molecules that regulate mesangial cell-extracellular matrix interactions in both physiological and pathological conditions.

SHCA PHOSPHOTYROSINE DERIVED SIGNALING IS REQUIRED FOR THE MAINTENANCE OF CARDIAC FUNCTION

2008 ◽  
Vol 31 (4) ◽  
pp. 23
Author(s):  
Rachel Vanderlaan ◽  
Rod Hardy ◽  
Golam Kabir ◽  
Peter Back ◽  
A J Pawson
Keyword(s):  
Extracellular Matrix ◽  
Cardiac Function ◽  
Tyrosine Kinases ◽  
Sh2 Domain ◽  
Scaffolding Protein ◽  
Restricted Domain ◽  
Downstream Signaling ◽  
Matrix Interactions ◽  
Extracellular Matrix Interactions ◽  
Ptb Domain

Background: ShcA, a scaffolding protein, generates signalspecificity by docking to activated tyrosine kinases through distinct phosphotyrosine recognition motifs, while mediating signal complexity through formation of diverse downstream phosphotyrosine complexes. Mammalian ShcA encodes 3 isoforms having a modular architecture of a PTB domain and SH2 domain, separated by a CH1 region containing tyrosine phosphorylation sites important in Ras-MAPK activation. Objective and Methods: ShcA has a necessary role in cardiovascular development^1,2. However, the role of ShcA in the adult myocardium is largely unknown, also unclear, is how ShcA uses its signaling modules to mediate downstream signaling. To this end, cre/loxP technology was employed to generate a conditional ShcA allele series. The myocardial specific ShcA KO (ShcA CKO) and myocardial restricted domain mutant KI mice were generated using cre expressed from the mlc2v locus^3 coupled with the ShcA floxed allele and in combination with the individual ShcA domain mutant KI alleles^2. Results: ShcACKO mice develop a dilated cardiomyopathy phenotype by 3 months of life, typified by depressed cardiac function and enlarged chamber dimensions. Isolated cardiomyocytes from ShcA CKO mice have preserved contractility indicating an uncoupling between global heart function and single myocyte contractile mechanics. Force-length experiments suggest that the loss of shcAmediates the uncoupling through deregulation of extracellular matrix interactions. Subsequent, analysis of the ShcA myocardial restricted domain mutant KImice suggests that ShcA requires PTB domain docking to upstream tyrosine kinases and subsequent phosphorylation of the CH1 tyrosines important for downstream signaling. Conclusion: ShcA is required for proper maintenance of cardiac function, possibly regulation of extracellular matrix interactions. References: 1. Lai KV, Pawson AJ. The ShcA phosphotyrosine docking protein sensitizescardiovascular signaling in the mouse embryo. Genes and Dev 2000;14:1132-45. 2. Hardy WR. et al. Combinatorial ShcA docking interactions supportdiversity in tissue morphogenesis. Science2007;317:251-6. 3.Minamisawa, s. et al. A post-transcriptional compensatory pathway inheterozygous ventricular myosin light chain 2-deficient mice results in lack ofgene dosage effect during normal cardiac growth or hypertrophy. J Biol Chem 1999;274:10066-70.

scholarly journals Macromolecular Interactions in Cartilage Extracellular Matrix Vary According to the Cartilage Type and Location

Cartilage ◽  
2021 ◽  
pp. 194760352110008
Author(s):  
Manula S. B. Rathnayake ◽  
Brooke L. Farrugia ◽  
Karyna Kulakova ◽  
Colet E. M. ter Voert ◽  
Gerjo J. V. M. van Osch ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Dry Weight ◽  
Extraction Methods ◽  
Auricular Cartilage ◽  
Nasal Cartilage ◽  
Sulfated Glycosaminoglycan ◽  
Cartilage Extracellular Matrix ◽  
Matrix Interactions ◽  
Anatomic Locations ◽  
Extracellular Matrix Interactions

Objective To investigate GAG-ECM (glycosaminoglycan–extracellular matrix) interactions in different cartilage types. To achieve this, we first aimed to determine protocols for consistent calculation of GAG content between cartilage types. Design Auricular cartilage containing both collagen and elastin was used to determine the effect of lyophilization on GAG depletion activity. Bovine articular, auricular, meniscal, and nasal cartilage plugs were treated using different reagents to selectively remove GAGs. Sulfated glycosaminoglycan (sGAG) remaining in the sample after treatment were measured, and sGAG loss was compared between cartilage types. Results The results indicate that dry weight of cartilage should be measured prior to cartilage treatment in order to provide a more accurate reference for normalization. Articular, meniscal, and nasal cartilage lost significant amounts of sGAG for all reagents used. However, only hyaluronidase was able to remove significant amount of sGAG from auricular cartilage. Furthermore, hyaluronidase was able to remove over 99% of sGAG from all cartilage types except auricular cartilage where it only removed around 76% of sGAG. The results indicate GAG-specific ECM binding for different cartilage types and locations. Conclusions In conclusion, lyophilization can be performed to determine native dry weight for normalization without affecting the degree of GAG treatment. To our knowledge, this is the first study to compare GAG-ECM interactions of different cartilage types using different GAG extraction methods. Degree of GAG depletion not only varied with cartilage type but also the same type from different anatomic locations. This suggests specific structure-function roles for GAG populations found in the tissues.

Cell-extracellular matrix interactions under in vivo conditions during interstitial cell migration in Hydra vulgaris

Development ◽  
1994 ◽  
Vol 120 (2) ◽  
pp. 425-432 ◽  
Author(s):  
X. Zhang ◽  
M.P. Sarras
Keyword(s):  
Extracellular Matrix ◽  
Cell Migration ◽  
Synthetic Peptide ◽  
Interstitial Cell ◽  
Extracellular Matrix Components ◽  
Matrix Interactions ◽  
Apical Half ◽  
Matrix Components ◽  
Extracellular Matrix Interactions

Interstitial cell (I-cell) migration in hydra is essential for establishment of the regional cell differentiation pattern in the organism. All previous in vivo studies have indicated that cell migration in hydra is a result of cell-cell interactions and chemotaxic gradients. Recently, in vitro cell adhesion studies indicated that isolated nematocytes could bind to substrata coated with isolated hydra mesoglea, fibronectin and type IV collagen. Under these conditions, nematocytes could be observed to migrate on some of these extracellular matrix components. By modifying previously described hydra grafting techniques, two procedures were developed to test specifically the role of extracellular matrix components during in vivo I-cell migration in hydra. In one approach, the extracellular matrix structure of the apical half of the hydra graft was perturbed using beta-aminopropionitrile and beta-xyloside. In the second approach, grafts were treated with fibronectin, RGDS synthetic peptide and antibody to fibronectin after grafting was performed. In both cases, I-cell migration from the basal half to the apical half of the grafts was quantitatively analyzed. Statistical analysis indicated that beta-aminopropionitrile, fibronectin, RGDS synthetic peptide and antibody to fibronectin all were inhibitory to I-cell migration as compared to their respective controls. beta-xyloside treatment had no effect on interstitial cell migration. These results indicate the potential importance of cell-extracellular matrix interactions during in vivo I-cell migration in hydra.

Sign in / Sign up

Export Citation Format

Share Document