[Copper treatment alters the barrier functions of human intestinal Caco-2 cells].
OBJECTIVE
To investigate the effects of copper on permeability and P-glycoprotein (P-gp) of Caco-2 cell monolayers.


METHODS
The differentiated Caco-2 cell model was used in this study. Permeability of cell monolayers was reflected by monitoring transepithelial electrical resistance (TEER); distribution of tight junctional protein ZO-1 was measured by immunofluorescent staining; F actin was measured by fluorescence staining; and Activity of P-gp was reflected by changes of transcellular transport and accumulation of Rho-123 in Caco-2 cells.


RESULTS
Apical treatment with copper (30 - 100 micromol/L, Hanks' buffered salt solution, up to 3 hours) induced a time- and concentration-dependent increase in permeability reflected by progressive decrease of TEER of Caco-2 cell monolayers, accompanied by deorganization of F actin, but without significant effects on tight junctional protein ZO-1; at a dose without any adverse effects on viability and permeability of Caco-2 monolayers, copper treatment (300 micromol/L, complete medium, 24 hours) decreased Papp(BL-->AP) from 7.37 +/- 0.20 x 10(-6) cm/s (controls) to (6.43 +/- 0.27) x 10(-6) cm/s, the increased Papp(AP-->BL) from (1.23 +/- 0.05) x 10(-7) cm/s (controls) to (3.41 +/- 0.08) x 10(-7) cm/s, and enhanced the intracellular Rho-123 from (0.31 +/- 0.01) nmol/filter (controls) to (0.50 +/- 0.03) nmol/filter.


CONCLUSIONS
Copper might alter the barrier functions of Caco-2 cells through increasing the permeability and inhibiting P-gp of Caco-2 cells.
Liu
Zhi-wei
ZW
Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China.
Chen
Jia-lin
JL
Chen
Bing-heng
BH
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D001692:Biological Transport; D018938:Caco-2 Cells; D002463:Cell Membrane Permeability / Q000187:drug effects*; D003300:Copper / Q000633:toxicity*; D006801:Humans
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D003300:Copper