scholarly journals Two sites on P-selectin (the lectin and epidermal growth factor-like domains) are involved in the adhesion of monocytes to thrombin-activated endothelial cells

1994 ◽  
Vol 303 (2) ◽  
pp. 619-624 ◽  
Author(s):  
J F Murphy ◽  
J L McGregor
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mononuclear Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Activated Platelets ◽  
Epidermal Growth

P-selectin, also known as GMP-140, PADGEM or CD62, is expressed on the surface of thrombin-activated platelets and endothelial cells (EC). It is a member of the selectin family of adhesion molecules that regulate leucocyte interactions with the blood vessel wall. In this study we have found that peptides derived from both the lectin (residues 19-34 and 51-61) and epidermal growth factor (EGF)-like (residues 127-139) domains inhibit the adhesion of peripheral blood mononuclear cells (PBMC), elutriated monocytes and a monocytic cell line (U937) to thrombin-activated EC. This inhibition occurred in a concentration-dependent manner and the peptide most active at the lowest concentrations was the one derived from the EGF-like motif (127-139). The scrambled forms of these peptides, identical in amino acid composition to the authentic peptides but with altered sequences, were not inhibitory. Thrombin-activated platelets supported adhesion of U937 cells and this adhesion was dramatically inhibited by the two peptides derived from the lectin-like domain (residues 19-34 and 51-61). All three peptides, when conjugated to BSA and coated on plastic plates, mediated U937 cell adhesion. This study shows, for the first time, that two sites on P-selectin, the lectin and EGF-like domains, are involved in the adhesion of monocytes to thrombin-activated EC.

Activated epidermal growth factor receptor (ErbB1) protects the heart against stress-induced injury in mice

2003 ◽  
Vol 285 (2) ◽  
pp. R455-R462 ◽  
Author(s):  
Miguel Pareja ◽  
Olga Sánchez ◽  
Jordi Lorita ◽  
Maria Soley ◽  
Ignasi Ramírez
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mononuclear Cells ◽  
Egf Receptor ◽  
Kinase Inhibitor ◽  
Growth Factor Receptor ◽  
Dependent Manner ◽  
Epidermal Growth ◽  
Heart Injury ◽  
Exogenous Ligands

Acute, high-intensity stress induces necrotic lesions in the heart. We found that restraint-and-cold (4°C) exposure (RCE) raises plasma lactate dehydrogenase (LDH), creatine kinase (CK), and transaminase activity in a time-dependent manner, with a peak value 7 h after stimulus cessation. At 24 h, signs of necrotic lesions were observed in paraffin sections stained with hematoxylineosin: focal accumulation of mononuclear cells in subendocardial areas of the left ventricle wall and focal hemorrhage in papillary muscles. In contrast, intermale fighting (IF) did not increase plasma CK activity, although LDH and transaminase activities did increase. In IF, no histological evidence of heart injury was observed. Because IF, but not RCE, increased plasma epidermal growth factor (EGF) concentration by ∼1,000-fold, we hypothesized that EGF receptor (ErbB1) activation may protect the heart against stress-induced injury. To examine this hypothesis, we injected the ErbB1 tyrosine kinase inhibitor tyrphostin AG-1478 (25 mg/kg ip) immediately before mice were exposed to IF. After 3 h, plasma activities of LDH-1 and CK increased. Plasma enzyme activities were as low in control mice (injected with vehicle alone) as in nonfighting mice. In the last experiment, we injected EGF (0.25 mg/kg ip) 20 min before exposing mice to RCE. After 7 h, plasma LDH-1 and CK activities were significantly lower in these animals than in mice injected with vehicle. The effect required ErbB1 activation, because simultaneous administration of AG-1478 completely abolished the effect of exogenous EGF. We conclude that activated ErbB1, by endogenous or exogenous ligands, may protect the heart against stress-induced injury.

scholarly journals Tri-iodothyronine induces proliferation in cultured bovine thyroid cells: evidence for the involvement of epidermal growth factor-associated tyrosine kinase activity

2000 ◽  
Vol 166 (1) ◽  
pp. 173-182 ◽  
Author(s):  
M Di Fulvio ◽  
AH Coleoni ◽  
CG Pellizas ◽  
AM Masini-Repiso
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Western Blot ◽  
Blot Analysis ◽  
Thymidine Incorporation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Thyroid Cells ◽  
Epidermal Growth ◽  
Bovine Thyroid

The effects of the tri-iodothyronine (T(3)) secreted by thyroid cells on the growth of the thyrocyte are poorly known. In this study we analyzed the effects of T(3) on the proliferation of bovine thyroid follicles in primary culture previously depleted of endogenous T(3). Cellular deoxiribonucleic acid (DNA) synthesis, determined by [(3)H]thymidine incorporation, was stimulated by T(3) (0.1-5.0 nM) for 24 h in a concentration-dependent fashion with a maximal effect at 1.0 nM T(3) (P<0.01). This T(3) action was time-dependent when assayed from 12 to 72 h. The induction of mitogenic activity was corroborated by the increase in proliferating cell nuclear antigen (PCNA) measured by Western blot analysis. PCNA increased after treatment with T(3) (0.1-5.0 nM) in a concentration-dependent manner. Since T(3) modifies the activity of growth factors whose actions are mainly mediated by tyrosine kinase (TK) activation in diverse cellular types, we assayed the effects of genistein, a general TK inhibitor, and tyrphostin A25, a specific epidermal growth factor (EGF)-receptor (EGFR)-dependent TK activity inhibitor, on the proliferative effects of T(3). The T(3)-induced [(3)H]thymidine incorporation was inhibited by both agents in a concentration-dependent manner. A significant increase in the total TK activity measured in cellular protein extracts was induced by 0.5 and 1.0 nM T(3) (P<0.001). Tyrosine phosphorylation of the EGFR was also stimulated by T(3) (P<0.001) with no change in the EGFR expression as determined by Western blot analysis. Both, the T(3)-stimulated [(3)H]thymidine incorporation and the TK activity were inhibited by a anti-mouse EGF antibody. These results lead us to propose that T(3) could operate as a proliferative agent in bovine thyroid cells through a mechanism involving an autocrine/paracrine EGF/EGFR-dependent regulation.

Mechanical stresses induce paracrine β-2 microglobulin from cardiomyocytes to activate cardiac fibroblasts through epidermal growth factor receptor

2018 ◽  
Vol 132 (16) ◽  
pp. 1855-1874 ◽  
Author(s):  
Yang Li ◽  
Xiaoyi Zhang ◽  
Lu Li ◽  
Xiang Wang ◽  
Zhidan Chen ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cardiac Dysfunction ◽  
Cardiac Fibroblasts ◽  
Growth Factor Receptor ◽  
Pressure Overload ◽  
Dependent Manner ◽  
Epidermal Growth ◽  
High Level

By employing a proteomic analysis on supernatant of mechanically stretched cardiomyocytes, we found that stretch induced a significantly high level of β-2 microglobulin (β2M), a non-glycosylated protein, which is related to inflammatory diseases but rarely known in cardiovascular diseases. The present data showed that serum β2M level was increased in patients with hypertension and further increased in patients with chronic heart failure (HF) as compared with control group, and the high level of serum β2M level correlated to cardiac dysfunction in these patients. In pressure overload mice model by transverse aortic constriction (TAC), β2M levels in serum and heart tissue increased progressively in a time-dependent manner. Exogenous β2M showed pro-fibrotic effects in cultured cardiac fibroblasts but few effects in cardiomyocytes. Adeno-associated virus 9 (AAV9)-mediated knockdown of β2M significantly reduced cardiac β2M level and inhibited myocardial fibrosis and cardiac dysfunction but not cardiac hypertrophy at 4 weeks after TAC. In vitro, mechanical stretch induced the rapid secretion of β2M mainly from cardiomyocytes by activation of extracellular-regulated protein kinase (ERK). Conditional medium (CM) from mechanically stretched cardiomyocytes activated cultured cardiac fibroblasts, and the effect was partly abolished by CM from β2M-knockdown cardiomyocytes. In vivo, knockdown of β2M inhibited the increase in phosphorylation of epidermal growth factor receptor (EGFR) induced by TAC. In cultured cardiac fibroblasts, inhibition of EGFR significantly attenuated the β2M-induced the activation of EGFR and pro-fibrotic responses. The present study suggests that β2M is a paracrine pro-fibrotic mediator and associated with cardiac dysfunction in response to pressure overload.

Roles of epidermal growth factor and Na+/H+ exchanger-1 in esophageal epithelial defense against acid-induced injury

2006 ◽  
Vol 290 (4) ◽  
pp. G665-G673 ◽  
Author(s):  
Yasuhiro Fujiwara ◽  
Kazuhide Higuchi ◽  
Takashi Takashima ◽  
Masaki Hamaguchi ◽  
Tsuyoshi Hayakawa ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Epithelial Cells ◽  
Acid Reflux ◽  
Dependent Manner ◽  
Egf Receptors ◽  
Epithelial Proliferation ◽  
Epidermal Growth ◽  
Esophageal Epithelial Cells ◽  
Chronic Esophagitis

Epidermal growth factor (EGF) is predominantly secreted by salivary glands and activates Na+/H+ exchanger-1 (NHE-1), which regulates intracellular pH (pHi). We investigated the roles of EGF and NHE-1 in esophageal epithelial defense against acid using human esophageal epithelial cell lines and a rat chronic esophagitis model. Esophageal epithelial cells were incubated with acidified medium in the absence or presence of EGF. Cell viability and changes in pHi were measured. Chronic acid reflux esophagitis was induced in rats with and without sialoadenectomy. Esophageal lesion index, epithelial proliferation, and expression of EGF receptors and NHE-1 were examined. EGF protected esophageal epithelial cells against acid in a dose-dependent manner, and the cytoprotective effect of EGF was completely blocked by treatment with NHE-1 inhibitors. Tyrosine kinase, calmodulin, and PKC inhibitors significantly inhibited cytoprotection by EGF, whereas MEK, phosphatidylinositol 3-kinase, and PKA inhibitors had no effect. EGF significantly increased pHi recovery after NH4Cl pulse acidification, and this increase in pHi recovery was significantly blocked by inhibitors of calmodulin and PKC. Sialoadenectomy led to an increase in the severity of chronic esophagitis but affected neither epithelial proliferation nor expression of EGF receptors. Expression of NHE-1 mRNA was increased in esophagitis and upregulated in rats with sialoadenectomy. The increasing severity of esophagitis in rats with sialoadenectomy was prevented by exogenous administration of EGF. In conclusion, EGF protects esophageal epithelial cells against acid through NHE activation via Ca2+/calmodulin and the PKC pathway. Deficiency in endogenous EGF is associated with increased severity of esophagitis. EGF and NHE-1 play crucial roles in esophageal epithelial defense against acid.

Epidermal growth factor induces intracellular Ca2 oscillations in microvascular endothelial cells

2003 ◽  
Vol 194 (2) ◽  
pp. 139-150 ◽  
Author(s):  
Francesco Moccia ◽  
Roberto Berra-Romani ◽  
Simona Tritto ◽  
Silvia Signorelli ◽  
Vanni Taglietti ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Microvascular Endothelial Cells ◽  
Epidermal Growth ◽  
Microvascular Endothelial

scholarly journals Sorting to Synaptic-like Microvesicles from Early and Late Endosomes Requires Overlapping but Not Identical Targeting Signals

2000 ◽  
Vol 11 (5) ◽  
pp. 1801-1814 ◽  
Author(s):  
Anastasiya D. Blagoveshchenskaya ◽  
Daniel F. Cutler
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Pc12 Cells ◽  
Protein Complex ◽  
Adaptor Protein ◽  
Neuroendocrine Cells ◽  
Dependent Manner ◽  
Late Endosomes ◽  
Early Endosomes ◽  
Epidermal Growth

In PC12 neuroendocrine cells, synaptic-like microvesicles (SLMV) are thought to be formed by two pathways. One pathway sorts the proteins to SLMV directly from the plasma membrane (or a specialized domain thereof) in an adaptor protein complex 2-dependent, brefeldin A (BFA)-insensitive manner. Another pathway operates via an endosomal intermediate, involves adaptor protein complex 3, and is BFA sensitive. We have previously shown that when expressed in PC12 cells, HRP-P-selectin chimeras are directed to SLMV mostly via the endosomal, BFA-sensitive route. We have now found that two endosomal intermediates are involved in targeting of HRP-P-selectin chimeras to SLMV. The first intermediate is the early, transferrin-positive, epidermal growth factor-positive endosome, from which exit to SLMV is controlled by the targeting determinants YGVF and KCPL, located within the cytoplasmic domain of P-selectin. The second intermediate is the late, transferrin-negative, epidermal growth factor-positive late endosome, from where HRP-P-selectin chimeras are sorted to SLMV in a YGVF- and DPSP-dependent manner. Both sorting steps, early endosomes to SLMV and late endosomes to SLMV, are affected by BFA. In addition, analysis of double mutants with alanine substitutions of KCPL and YGVF or KCPL and DPSP indicated that chimeras pass sequentially through these intermediates en route both to lysosomes and to SLMV. We conclude that a third site of formation for SLMV, the late endosomes, exists in PC12 cells.

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