Search results for "eta1"
showing 10 items of 133 documents
Modulation of proliferation and lymphokine secretion of murine CD4+ T cells and cloned Th1 cells by proteins of the extracellular matrix.
1997
In this study we investigated the co-stimulatory signaling capacity of diverse proteins of the extracellular matrix (ECM) for murine resting CD4+ T cells and Th1 clone cells, activated by immobilized anti-CD3 mAb. ECM proteins used in various concentrations had no effect on IL-2 production or proliferation of highly purified CD4+ T cell populations. When the preparation of CD4+ T cells contained contaminating accessory cells, IL-2 secretion and proliferation was enhanced in the presence of co-immobilized collagens or fibronectin. However, the level of proliferation attainable by added irradiated splenocytes was not reached. Using Th1 cell clone M4, enhanced production of IL-2 in the presenc…
Chemokine stromal cell-derived factor-1alpha modulates VLA-4 integrin-dependent adhesion to fibronectin and VCAM-1 on bone marrow hematopoietic proge…
2001
Stromal cell-derived factor-1alpha (SDF-1alpha) is a potent chemoattractant for hematopoietic progenitor cells (HPC), suggesting that it could play an important role during their migration within or to the bone marrow (BM). The integrin VLA-4 mediates HPC adhesion to BM stroma by interacting with CS-1/fibronectin and VCAM-1. It is required during hematopoiesis and homing of HPC to the BM. As HPC migration in response to SDF-1alpha might require dynamic regulation of integrin function, we investigated if SDF-1alpha could modulate VLA-4 function on BM CD34(hi) cells.CD34(hi) BM cells and hematopoietic cell lines were tested for the effect of SDF-1alpha on VLA-4-dependent adhesion to CS-1/fibr…
Differential inhibition of renal cancer cell invasion mediated by fibronectin, collagen IV and laminin.
2000
Invasion of tumor cells into the extracellular matrix is an essential step in the formation of metastases in renal cancer. Cell adhesion molecules such as beta(1)-integrins, which bind to the RGD sequence (arginine-glycine-asparagine) and CD44 are involved in this process. We examined the invasion of a renal carcinoma cell line (CCF-RC1) into the extracellular matrix compounds fibronectin, collagen IV and laminin and the effect of TGFbeta and IFNgamma on this process. The inhibitory effect of an antibody against the beta(1)-subunit of integrins (CD29), as well as a pentapeptide including the RGD sequence, was also evaluated. A micro-chemotaxis chamber, including a polycarbonate membrane wit…
Genetic abrogation of the fibronectin-α5β1 integrin interaction in articular cartilage aggravates osteoarthritis in mice.
2018
The balance between synthesis and degradation of the cartilage extracellular matrix is severely altered in osteoarthritis, where degradation predominates. One reason for this imbalance is believed to be due to the ligation of the α5β1 integrin, the classic fibronectin (FN) receptor, with soluble FN fragments instead of insoluble FN fibrils, which induces matrix metalloproteinase (MMP) expression. Our objective was to determine whether the lack of α5β1-FN binding influences cartilage morphogenesis in vivo and whether non-ligated α5β1 protects or aggravates the course of osteoarthritis in mice. We engineered mice (Col2a-Cre;Fn1RGE/fl), whose chondrocytes express an α5β1 binding-deficient FN, …
L-asparaginase inhibits invasive and angiogenic activity and induces autophagy in ovarian cancer
2012
Recent work identified L-asparaginase (L-ASP) as a putative therapeutic target for ovarian cancer. We suggest that L-ASP, a dysregulator of glycosylation, would interrupt the local microenvironment, affecting the ovarian cancer cell-endothelial cell interaction and thus angiogenesis without cytotoxic effects. Ovarian cancer cell lines and human microvascular endothelial cells (HMVEC) were exposed to L-ASP at physiologically attainable concentrations and subjected to analyses of endothelial tube formation, invasion, adhesion and the assessment of sialylated proteins involved in matrix-associated and heterotypic cell adhesion. Marked reduction in HMVEC tube formation in vitro, HMVEC and ovari…
Spleen Tyrosine Kinase (SYK) in the Progression of Peritoneal Fibrosis Through Activation of the TGF-β1/Smad3 Signaling Pathway.
2019
BACKGROUND Long-term exposure to hypertonic and high glucose in peritoneal dialysis fluid can result in peritoneal fibrosis. Spleen tyrosine kinase (SYK) has a role in inflammation and fibrosis. This study aimed to investigate the role of SYK in an in vivo rat model of peritoneal fibrosis and in rat peritoneal mesothelial cells (PMCs) in vitro and to investigate the underlying mechanisms. MATERIAL AND METHODS Sprague-Dawley rats (N=24) were randomized into the sham control group (N=6); the peritoneal fibrosis group (N=6) treated with intraperitoneal chlorhexidine digluconate; the SYK inhibitor group (N=6), treated with chlorhexidine digluconate and fostamatinib; and the TGF-s inhibitor grou…
Permeability changes of integrin-containing multivesicular structures triggered by picornavirus entry.
2014
Cellular uptake of clustered α2β1-integrin induces the formation of membrane compartments that subsequently mature into a multivesicular body (MVB). Enhanced internalization mediated by clustered integrins was observed upon infection by the picornavirus echovirus 1 (EVI). We elucidated the structural features of virus-induced MVBs (vMVBs) in comparison to antibody-induced control MVBs (mock infection) by means of high-pressure cryo fixation of cells followed by immuno electron tomography during early entry of the virus. Three-dimensional tomograms revealed a marked increase in the size and complexity of these vMVBs and the intraluminal vesicles (ILVs) at 2 and 3.5 hours post infection (p.i.…
Increased Expression of Integrin and Receptor Tyrosine Kinase Genes During Autograft Fusion in the SpongeGeodia cydonium
1999
Recently cDNAs coding for cell surface molecules have been isolated from sponges. The molecules for alpha-integrin, galectin, and receptor tyrosine kinase (RTK), obtained from the marine sponge, Geodia cydonium, have been described earlier. In the present study also the cDNA for one putative beta-integrin has been identified from G. cydonium. The deduced aa sequence comprises the characteristic signatures, found in other metazoan beta-integrin molecules; the estimated size is 95,215 Da. To obtain first insights into the molecular events which proceed during autograft fusion, the expressions of these genes were determined on transcriptional and translational level. The cDNAs as well as antib…
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.
Lactate adversely affects the in vitro formation of endothelial cell tubular structures through the action of TGF-beta1.
2006
When lactate accumulation in a tumor microenvironment reaches an average concentration of 10-20 mM, it tends to reflect a high degree of malignancy. However, the hypothesis that tumor-derived lactate has a number of partially adverse biological effects on malignant and tumor-associated host cells requires further evidence. The present study attempted to evaluate the impact of lactate on the process of angiogenesis, in particular on the formation of tubular structures. The endothelial cell (EC) network in desmoplastic breast tumors is primarily located in areas of reactive fibroblastic stroma. We employed a fibroblast-endothelial cell co-culture model as in vitro angiogenesis system normally…