Search results for "Collagen receptor"
showing 10 items of 36 documents
Novel α2β1 integrin inhibitors reveal that integrin binding to collagen under shear stress conditions does not require receptor preactivation.
2012
The interaction between α2β1 integrin (GPIa/IIa, VLA-2) and vascular collagen is one of the initiating events in thrombus formation. Here, we describe two structurally similar sulfonamide derivatives, BTT-3033 and BTT-3034, and show that, under static conditions, they have an almost identical effect on α2-expressing CHO cell adhesion to collagen I, but only BTT-3033 blocks platelet attachment under flow (90 dynes/cm(2)). Differential scanning fluorimetry showed that both molecules bind to the α2I domain of the recombinant α2 subunit. To further study integrin binding mechanism(s) of the two sulfonamides, we created an α2 Y285F mutant containing a substitution near the metal ion-dependent ad…
Absence of regular alpha2(I) collagen chains in colon carcinoma biopsy fragments.
1998
The extracellular matrix (ECM) is known to play an active role in numerous biological processes such as differentiation, apoptosis and cancer. Extensive alterations of epithelial basement membranes and of interstitial ECM are known to occur during the progression of most invasive carcinomas. Collagen, which represents the major component of the interstitial ECM, is primarily involved in the stromal changes at the site of tumor cell invasion. We have previously described the occurrence in breast and colon cancer ECM of an oncofetal form of collagen, characterized by an acidic chain distinct from those of type I and III collagen. In the present paper, we bring evidence that alpha2(I) collagen…
Type V collagen and protein kinase C η down-regulation in 8701-BC breast cancer cells
2011
We previously reported that ductal infiltrating carcinomas (d.i.c.) of the human breast display profound modifications of the stromal architecture, associated with anomalous collagen composition. Among the major alterations observed in the interstitial collagen, the relative increase of type V collagen content was detected. When type V collagen was used as an "in vitro" substrate for 8701-BC d.i.c. cells, it appeared able to restrain cell growth, inhibit cell motility and invasion "in vitro", and modify the expression levels of genes coding for apoptosis factors, caspases and stress response proteins. In the present paper we demonstrate that type V collagen induces the down-regulation of pr…
Mammary-derived growth inhibitor (MDGI) interacts with integrin α-subunits and suppresses integrin activity and invasion
2010
The majority of mortality associated with cancer is due to formation of metastases from the primary tumor. Adhesion mediated by different integrin heterodimers has an important role during cell migration and invasion. Protein interactions with the β1-integrin cytoplasmic tail are known to influence integrin affinity for extracellular ligands, but regulating binding partners for the α-subunit cytoplasmic tails have remained elusive. In this study, we show that mammary-derived growth inhibitor (MDGI) (also known as FABP-3 or H-FABP) binds directly to the cytoplasmic tail of integrin α-subunits and its expression inhibits integrin activity. In breast cancer cell lines, MDGI expression correlat…
Distinct Recognition of Collagen Subtypes by α1β1 and α2β1Integrins
2000
Two integrin-type collagen receptors, α1β1 and α2β1, are structurally very similar. However, cells can concomitantly express the both receptors and they might have independent functions. Here, Chinese hamster ovary (CHO) cells, which lack endogenous collagen receptors, were transfected with either α1 or α2 integrin cDNA. Cells were allowed to adhere to various collagen types and their integrin function was tested by observing the progression of cell spreading. The cells expressing α1β1 integrin could spread on collagen types I, III, IV, and V but not on type II, while α2β1 integrin could mediate cell spreading on collagen types I-V. Type XIII is a transmembrane collagen and its interaction …
P056 Crohn’s Disease associated fibrosis modulates the expression of collagen receptors
2021
Abstract Background Crohn’s Disease (CD) patients often develop stenotic complications as immunomodulatory treatments do not prevent the fibrogenic response in the affected tissues, where a dysregulated activation of stromal cells provokes an excessive deposition of extracellular matrix (ECM). Recent evidences support the notion that local cells can sense the consequent alterations in tissue structure and rigidity through receptors that respond to some ECM components, and this may perpetuate the fibrogenic process even in the absence of inflammation. We aim to analyse the relevance of these signalling pathways in the fibrotic process associated to CD. Methods We obtained fibrotic ileal tiss…
Competitive binding of Rab21 and p120RasGAP to integrins regulates receptor traffic and migration
2011
P120RasGAP competes with Rab21 for binding to the cytoplasmic domain of integrin α-subunits, thereby promoting receptor escape from early endosomes and recycling to the plasma membrane.
EGFL7 ligates αvβ3 integrin to enhance vessel formation
2013
Angiogenesis, defined as blood vessel formation from a preexisting vasculature, is governed by multiple signal cascades including integrin receptors, in particular integrin αVβ3. Here we identify the endothelial cell (EC)-secreted factor epidermal growth factor-like protein 7 (EGFL7) as a novel specific ligand of integrin αVβ3, thus providing mechanistic insight into its proangiogenic actions in vitro and in vivo. Specifically, EGFL7 attaches to the extracellular matrix and by its interaction with integrin αVβ3 increases the motility of EC, which allows EC to move on a sticky underground during vessel remodeling. We provide evidence that the deregulation of EGFL7 in zebrafish embryos leads …
Calpains promote α2β1 integrin turnover in nonrecycling integrin pathway
2012
A novel virus- and integrin clustering–specific pathway diverts integrin from its normal endo/exocytic traffic to a nonrecycling degradative endosomal route. Clustering of α2β1 integrin causes redistribution of the integrin to perinuclear endosomes, leading to enhanced integrin turnover promoted by calpains.
Integrins α5β1, αvβ1, and αvβ6 Collaborate in Squamous Carcinoma Cell Spreading and Migration on Fibronectin
2000
Abstract The expression of αvβ6 fibronectin/tenascin receptor integrin is induced in malignant transformation of oral epithelium. In this study, we demonstrate the contribution of αvβ6 as well as other fibronectin receptor integrins in squamous cell carcinoma (SCC) cell adhesion and migration. Of 11 SCC cell lines isolated from the head and neck area, 8 (73%) expressed αvβ6 integrin on the cell surface. Three cell lines were chosen for further functional experiments: 1 with relatively high, 1 with moderate, and 1 with minimal surface expression of αvβ6 integrin. In addition to αvβ6, all 3 cell lines expressed α5β1 and αvβ1 fibronectin receptor integrins. Function-blocking experiments with i…