The effect of different iron compounds on transferrin receptor expression in term human cytotrophoblast cells

1992 ◽  
Vol 35 (1) ◽  
pp. 55-63 ◽  
Author(s):  
J. S. Starreveld ◽  
A. M. Abdoel ◽  
J. P. v. Dijk ◽  
M. J. Kroos ◽  
H. G. v. Eijk
1997 ◽  
Vol 9 (6) ◽  
pp. 609 ◽  
Author(s):  
Martha L. Kennedy ◽  
Gordon C. Douglas ◽  
Barry F. King

Transferrin receptor expression has been examined in primary cultures of morphologically differentiated placental syncytiotrophoblast cells. More than 90% of the cells were multinucleated. Incubation of syncytiotrophoblast for 4 days in the presence of iron salts had no effect on receptor expression assessed by measuring the binding of 125I-labelled transferrin. However, incubation of cells in the presence of human diferric transferrin (10-100 µM) led to a 50% decrease in surface and intracellular receptor expression. This down-regulation was not accompanied by a signicant decrease in receptor synthesis. In contrast to syncytiotrophoblast, expression of intracellular transferrin receptors in non-differentiated cytotrophoblast cells decreased when cells were cultured with iron salts; this was accompanied by decreased receptor synthesis. Addition of diferric transferrin to cytotrophoblast cells led to a 50% reduction in surface and intracellular receptor expression, similar to that seen in the syncytiotrophoblast. This reduction was accompanied by a decrease in receptor synthesis. In contrast to that of most cell types, the expression and distribution of trophoblast transferrin receptors were not altered by insulin, epidermal growth factor or hydrocortisone. These characteristics of syncytiotrophoblast transferrin receptor expression may assist in ensuring a supply of iron to the fetus regardless of the maternal iron status.


1986 ◽  
Vol 6 (12) ◽  
pp. 4244-4250
Author(s):  
L M Neckers ◽  
S Bauer ◽  
R C McGlennen ◽  
J B Trepel ◽  
K Rao ◽  
...  

Transferrin receptor expression is essential for the proliferation of both normal and malignant T cells. While transferrin receptor expression in normal T cells is tightly coupled to interleukin-2 receptor expression, transferrin receptor expression in malignant cells is usually constitutive and is released from this constraint. Temporally, the appearance of these membrane receptors is preceded by changes in the expression of the proto-oncogenes c-myc and c-myb. In addition, although an increase in the level of intracellular free calcium occurs early in the sequence of T-cell activation, the activation events dependent on this calcium flux have not been resolved. In the present study we report that diltiazem, an ion channel-blocking agent that inhibits calcium influx, arrested the growth in vitro of both normal and malignant human T cells in the G1 phase of the cell cycle. However, diltiazem did not inhibit the expression of c-myc or interleukin-2 receptor mRNA and protein in normal mitogen-activated T cells or the constitutive expression of c-myc and c-myb mRNA in malignant T cells (T acute lymphoblastic leukemia cells). In contrast, diltiazem prevented the induction of transferrin receptor (mRNA and protein) in normal T cells and caused a progressive loss of transferrin receptor (mRNA and protein) in malignant T cells. These data demonstrate that diltiazem can dissociate several growth-related processes normally occurring in G1 and thereby disrupt the biochemical cascade leading to cell proliferation.


Neurology ◽  
2004 ◽  
Vol 62 (9) ◽  
pp. 1563-1567 ◽  
Author(s):  
J. R. Connor ◽  
X. S. Wang ◽  
S. M. Patton ◽  
S. L. Menzies ◽  
J. C. Troncoso ◽  
...  

2000 ◽  
Vol 267 (23) ◽  
pp. 6762-6774 ◽  
Author(s):  
Nadia M. Sposi ◽  
Luciano Cianetti ◽  
Elena Tritarelli ◽  
Elvira Pelosi ◽  
Stefania Militi ◽  
...  

Blood ◽  
1986 ◽  
Vol 67 (6) ◽  
pp. 1631-1638 ◽  
Author(s):  
KM Shannon ◽  
JW Larrick ◽  
SA Fulcher ◽  
KB Burck ◽  
J Pacely ◽  
...  

Abstract The relative requirements of colonies derived from erythroid (BFU-E) and myeloid (CFU-c) progenitors for transferrin were examined using monoclonal antibodies directed against the transferrin molecule (TF-6) or its cell surface receptor (TFR-A12, TFR1–2B). Growth of erythroid bursts was profoundly reduced at concentrations of all three antibodies that had no effect on CFU-c-derived colonies. When TFR1–2B was layered over cultures established one to seven days previously, further burst development was inhibited, and degeneration of early erythroid colonies was observed. Addition of erythropoietin augmented transferrin receptor expression on cells harvested after 1 to 2 weeks in culture and analyzed by flow cytometry. Recombinant human erythropoietin gave results comparable to those obtained in experiments using human urinary erythropoietin. Analysis of erythroblasts plucked directly from culture plates confirmed the presence of transferrin receptors on BFU-E-derived colonies. Thymidine incorporation was maximal early in the second week of culture and coincided with high transferrin receptor expression. These data demonstrate that transferrin must be available into the second week of culture to support the growth and differentiation of BFU- E-derived erythroid bursts, that the generation of erythroid colonies from BFU-E is more dependent on transferrin than myeloid colony formation from CFU-c, and that erythropoietin modulates the expression of transferrin receptors on growing bursts.


2017 ◽  
Vol 37 (3) ◽  
pp. 1529-1536 ◽  
Author(s):  
Aya Sugyo ◽  
Atsushi B. Tsuji ◽  
Hitomi Sudo ◽  
Fumiko Nomura ◽  
Hirokazu Satoh ◽  
...  

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