Epidermal growth factor inhibits glycylsarcosine transport and hPepT1 expression in a human intestinal cell line
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Epidermal growth factor inhibits glycylsarcosine transport and hPepT1 expression in a human intestinal cell line. / Nielsen, C U; Amstrup, J; Steffansen, B; Frokjaer, S; Brodin, Birger.
In: American Journal of Physiology: Gastrointestinal and Liver Physiology, Vol. 281, No. 1, 2001, p. G191-9.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Epidermal growth factor inhibits glycylsarcosine transport and hPepT1 expression in a human intestinal cell line
AU - Nielsen, C U
AU - Amstrup, J
AU - Steffansen, B
AU - Frokjaer, S
AU - Brodin, Birger
PY - 2001
Y1 - 2001
N2 - The human intestinal cell line Caco-2 was used as a model system to study the effects of epidermal growth factor (EGF) on peptide transport. EGF decreased apical-to-basolateral fluxes of [(14)C]glycylsarcosine ([(14)C]Gly-Sar) up to 50.2 +/- 3.6% (n = 6) of control values. Kinetic analysis of the fluxes showed that maximal flux (V(max)) of transepithelial transport decreased from 3.00 +/- 0.17 nmol x cm(-2) x min(-1) in control cells to 0.50 +/- 0.07 nmol x cm(-2) x min(-1) in cells treated with 5 ng/ml EGF (n = 6, P <0.01). The apparent Michaelis-Menten constant (K(m)) was 2.71 +/- 0.31 mM (n = 6) in control cells and 1.89 +/- 0.28 mM (n = 6, not significantly different from control) in EGF-treated cells. Similarly, apical uptake of [(14)C]Gly-Sar decreased in cells treated with EGF, with an ED(50) value of 0.36 +/- 0.06 ng/ml (n = 6) EGF and a maximal inhibition of 80 +/- 0.02% (n = 6). V(max) decreased from 2.61 +/- 0.4 to 1.06 +/- 0.1 nmol x cm(-2) x min(-1) (n = 3, P <0.05), whereas K(m) remained constant. Basolateral Gly-Sar uptake showed no changes in V(max) or K(m) after EGF treatment (n = 3). RT-PCR showed a decrease in hPepT1 mRNA (using glucose-6-phosphate dehydrogenase mRNA as control) in cells treated with EGF. Western blotting indicated a decrease in hPepT1 protein in cell lysates. We conclude that EGF treatment decreases Gly-Sar transport in Caco-2 cells by decreasing the number of peptide transporter molecules in the apical membrane.
AB - The human intestinal cell line Caco-2 was used as a model system to study the effects of epidermal growth factor (EGF) on peptide transport. EGF decreased apical-to-basolateral fluxes of [(14)C]glycylsarcosine ([(14)C]Gly-Sar) up to 50.2 +/- 3.6% (n = 6) of control values. Kinetic analysis of the fluxes showed that maximal flux (V(max)) of transepithelial transport decreased from 3.00 +/- 0.17 nmol x cm(-2) x min(-1) in control cells to 0.50 +/- 0.07 nmol x cm(-2) x min(-1) in cells treated with 5 ng/ml EGF (n = 6, P <0.01). The apparent Michaelis-Menten constant (K(m)) was 2.71 +/- 0.31 mM (n = 6) in control cells and 1.89 +/- 0.28 mM (n = 6, not significantly different from control) in EGF-treated cells. Similarly, apical uptake of [(14)C]Gly-Sar decreased in cells treated with EGF, with an ED(50) value of 0.36 +/- 0.06 ng/ml (n = 6) EGF and a maximal inhibition of 80 +/- 0.02% (n = 6). V(max) decreased from 2.61 +/- 0.4 to 1.06 +/- 0.1 nmol x cm(-2) x min(-1) (n = 3, P <0.05), whereas K(m) remained constant. Basolateral Gly-Sar uptake showed no changes in V(max) or K(m) after EGF treatment (n = 3). RT-PCR showed a decrease in hPepT1 mRNA (using glucose-6-phosphate dehydrogenase mRNA as control) in cells treated with EGF. Western blotting indicated a decrease in hPepT1 protein in cell lysates. We conclude that EGF treatment decreases Gly-Sar transport in Caco-2 cells by decreasing the number of peptide transporter molecules in the apical membrane.
KW - Biological Transport
KW - Caco-2 Cells
KW - Carbon Radioisotopes
KW - Carrier Proteins
KW - Dipeptides
KW - Dose-Response Relationship, Drug
KW - Epidermal Growth Factor
KW - Gene Expression
KW - Humans
KW - Immunohistochemistry
KW - Intestinal Mucosa
KW - Microscopy, Confocal
KW - RNA, Messenger
KW - Symporters
M3 - Journal article
C2 - 11408272
VL - 281
SP - G191-9
JO - American Journal of Physiology: Gastrointestinal and Liver Physiology
JF - American Journal of Physiology: Gastrointestinal and Liver Physiology
SN - 0193-1857
IS - 1
ER -
ID: 37899733