scholarly journals Epidermal growth factor modifies the expression and function of extracellular matrix adhesion receptors expressed by peritoneal mesothelial cells from patients on CAPD

1999 ◽  
Vol 14 (5) ◽  
pp. 1208-1216 ◽  
Author(s):  
D Leavesley
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mesothelial Cells ◽  
Adhesion Receptors ◽  
Peritoneal Mesothelial Cells ◽  
Matrix Adhesion ◽  
Epidermal Growth ◽  
And Function

L-Cysteine Improves Growth of Human Peritoneal Mesothelial Cells In Vitro

1996 ◽  
Vol 16 (6) ◽  
pp. 599-606 ◽  
Author(s):  
Stephen D. Bird ◽  
Michael Legge ◽  
Robert J. Walker
Keyword(s):  
Growth Factor ◽  
Cell Growth ◽  
Epidermal Growth Factor ◽  
Culture Medium ◽  
Cell Attachment ◽  
Mesothelial Cells ◽  
Cell Protein ◽  
Peritoneal Mesothelial Cells ◽  
Human Peritoneal Mesothelial Cells ◽  
Epidermal Growth

Objective To improve the growth characteristics of human peritoneal mesothelial cells (HPMC). Design The effect of commonly used agents, L-cysteine and epidermal growth factor (EGF), added individually (“single”) or mixed with hydrocortisone and apo-transferrin (“admixture”) in the culture medium (M199) on cultured HPMC, was investigated. Methods: Growth agents were added to M199 medium along with 2% fetal bovine serum and L-glutamine. Growth was determined by the analysis of thymidine ([methyl-3H] thymidine) incorporation into deoxyribonucleic acid, total cell protein, and by cell counts. Morphology was assessed by phase contrast light microscopy and scanning electron microscopy. Results HPMC exposed to L-cysteine 0.25 x 10–3 mol/L (30 μg/mL) exhibited significantly improved attachment and growth. Attached cells appeared flat and well spread out shortly after seeding, and produced a tight polygonal monolayer in 14 days, in contrast to the growth of HPMC in control M199 medium, which failed to reach confluence. After an initial lag period in cell growth, EGF (0.01 μg/mL) produced a greater increase in cell growth than L-cysteine did; however, this was associated with changes in HPMC morphology. During the growth period (14 days), EGF-stimulated HPMC appeared distorted and irregular compared to L-cysteine-treated cells, which had the characteristic tight “cobblestone” appearance. Conclusion L-cysteine improved cell attachment with preservation of the characteristic morphology of HPMC. Epidermal growth factor improved cell growth but produced changes in morphology. The addition of L-cysteine to the culture medium has an important cell growth enhancement role due to the improved cell attachment and cell viability.

Interaction of epidermal growth factor with receptors on human and porcine thyroid membranes

1984 ◽  
Vol 102 (1) ◽  
pp. 57-61 ◽  
Author(s):  
H. Humphries ◽  
S. MacNeil ◽  
D. S. Munro ◽  
S. Tomlinson
Keyword(s):  
Enzyme Activity ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Sites ◽  
Affinity Constant ◽  
Maximal Inhibition ◽  
High Affinity ◽  
Epidermal Growth ◽  
And Function ◽  
Bovine Tsh

ABSTRACT Recent evidence suggests that epidermal growth factor (EGF) may play an important role in the regulation of thyroid growth and function. We have examined the interaction of murine EGF (mEGF) with human and porcine thyroid membranes and compared this with the binding of bovine TSH (bTSH) using 125I-labelled hormones as tracers. The characteristics of the binding of mEGF were found to be similar for human and porcine thyroid membranes. Epidermal growth factor bound with high affinity (affinity constant = 1·4 × 109 l/mol); the density of binding sites was low compared with the TSH receptor. At 37 °C, the binding of 125I-labelled EGF was maximal at 1 h and was saturable in the presence of unlabelled EGF; half-maximal inhibition was at 1 ng EGF/tube (0·5 nmol/l) using 0·5 mg membrane protein/tube. Unlabelled bTSH had no effect on the binding of labelled EGF. Similarly, unlabelled EGF did not affect the binding of labelled TSH; hence it was concluded that mEGF and bTSH bound to independent sites. Epidermal growth factor had no effect on adenylate cyclase activity in membranes prepared from human non-toxic goitre; increasing concentrations of EGF did not affect basal, TSH-stimulated or fluoride-stimulated enzyme activity. J. Endocr. (1984) 102, 57–61

Epidermal Growth Factor Modulates Thyroid Growth and Function in Culture*

Endocrinology ◽  
1983 ◽  
Vol 112 (5) ◽  
pp. 1680-1686 ◽  
Author(s):  
K. WESTERMARK ◽  
F. A. KARLSSON ◽  
B. WESTERMARK
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Epidermal Growth ◽  
And Function

Lack of effect of epidermal growth factor treatment in late-pregnant ewes on subsequent lactation

1991 ◽  
Vol 58 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Christine B. Gow ◽  
Debbi J. Singleton ◽  
Mervyn J. Silvapulle ◽  
G. Philip M. Moore
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mammary Gland Development ◽  
Epidermal Growth Factor Treatment ◽  
Epidermal Growth ◽  
And Function ◽  
And Control ◽  
Gland Development ◽  
Mean Concentration ◽  
Growth Factor Treatment

SummaryTwin-bearing ewes were treated with epidermal growth factor (EGF) to determine its effect on mammogenesis and resultant milk production and composition. The EGF was infused intravenously at a dose rate of O5 mg/d in 300 ml saline between days 117 and 139 of gestation; control animals received placebo infusions of saline. All animals then received continuous infusions of 300 ml/d saline on days 139–144. Following parturition 1–5 d later, ewes were milked by hand for 10 d and thereafter were machine-milked until day 16 of lactation. At this level of treatment, EGF was not detected in the circulation during infusion and feed intake was not affected. All ewes gave birth to healthy twin lambs. There were no effects of EGF on birth weights of lambs, live weights of ewes or lengths of gestation. An EGF immunoreactive material was detected in the mammary secretions of control ewes at a mean concentration of 2 μg/l on day 1 of lactation. Two ewes had detectable levels on day 2, but none was found in the milk thereafter. In the EGF-infused group, concentrations of EGF in colostrum were ñ 10 times higher than in the control ewes on day 1 of lactation and EGF was detected in mammary secretions on day 2 but not in subsequent milk samples. A range of 0·3–0·5% of the EGF infused appeared in mammary secretions over the first 2 d of lactation. No other differences were observed for colostrum composition, subsequent milk yield or composition between the two groups of ewes indicating that mammary gland development and function were unaffected. The levels of EGF observed in the mammary secretions of treated and control ewes indicate that the mammary glands accumulate and store EGF in the pre partum period.

scholarly journals Epidermal-growth-factor-stimulated phosphorylation of calpactin II in membrane vesicles shed from cultured A-431 cells

1989 ◽  
Vol 259 (2) ◽  
pp. 577-583 ◽  
Author(s):  
J Blay ◽  
K A Valentine-Braun ◽  
J K Northup ◽  
M D Hollenberg
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Membrane Vesicles ◽  
Receptor Internalization ◽  
Receptor Kinase ◽  
Kinase Substrate ◽  
Epidermal Growth ◽  
Shed Vesicles ◽  
And Function

Membrane vesicles shed from intact A-431 epidermoid carcinoma cells and harvested in the presence of Ca2+ contained epidermal-growth-factor (EGF) receptor/kinase substrates of apparent molecular masses 185, 85, 70, 55, 38 and 27 kDa. The 38 kDa substrate (p38) was recognized by an antibody that had been raised against the human placental EGF receptor/kinase substrate calpactin II (lipocortin I). The A-431 and placental substrates, isolated by immunoprecipitation after phosphorylation in situ, yielded identical phosphopeptide maps upon limited proteolytic digestion with each of five different enzymes. The A-431-cell vesicular p38 is therefore calpactin II. EGF treatment of the intact A-431 cells before inducing vesiculation was not necessary for the substrate to be present within the vesicles. Our data thus indicate that receptor internalization is not a prerequisite for receptor-mediated phosphorylation of calpactin II. The ability of the protein to function as a substrate for the receptor/kinase depended upon the continued presence of Ca2+ during the vesicle-isolation procedure. EGF-stimulated phosphorylation of calpactin II was much less pronounced in vesicles prepared from A-431 cells in the absence of Ca2+, although comparable amounts of the protein were detectable by immunoblotting. Calpactin II therefore appears to be sequestered in a Ca2+-modulated manner within shed vesicles, along with at least four other major targets for the EGF receptor/kinase. The vesicle preparation may be a useful model system in which to study the phosphorylation and function of potentially important membrane-associated substrates for the receptor.

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