Rat kidney proximal tubule cells in defined medium: The roles of cholera toxin, extracellular calcium and serum in cell growth and expression of γ-glutamyltransferase

1989 ◽  
Vol 25 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Paul B. Hatzinger ◽  
James L. Stevens
Keyword(s):  
Cell Growth ◽  
Proximal Tubule ◽  
Cholera Toxin ◽  
Rat Kidney ◽  
Defined Medium ◽  
Extracellular Calcium ◽  
Proximal Tubule Cells ◽  
Kidney Proximal Tubule ◽  
Tubule Cells

scholarly journals Regulation of P-Glycoprotein in Renal Proximal Tubule Epithelial Cells by LPS and TNF-α

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Suzanne Heemskerk ◽  
Janny G. P. Peters ◽  
Jochem Louisse ◽  
Seil Sagar ◽  
Frans G. M. Russel ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Proximal Tubule ◽  
De Novo ◽  
Rat Kidney ◽  
Renal Proximal Tubule ◽  
Proximal Tubule Cells ◽  
Kidney Proximal Tubule ◽  
P Glycoprotein ◽  
Gene And Protein Expression ◽  
Tubule Cells

During endotoxemia, the ATP-dependent drug efflux pump P-glycoprotein (Abcb1/P-gp) is upregulated in kidney proximal tubule epithelial cells. The signaling pathway through which lipopolysaccharide (LPS) or tumor necrosis factor-α(TNF-α) regulates P-gp expression and activity was investigated further in the present study. Exposure of rat kidney proximal tubule cells to TNF-αalone or TNF-αand LPS increased P-gp gene and protein expression levels and efflux activity, suggesting de novo P-gp synthesis. Upon exposure to TNF-αin combination with LPS, P-gp activity in renal proximal tubule cells is increased under influence of nitric oxide (NO) produced by inducible NO synthase. Upon exposure to TNF-αalone, P-gp upregulation seems to involve TLR4 activation and nuclear factor kappaB (NF-κB) translocation, a pathway that is likely independent of NO. These findings indicate that at least two pathways regulate P-gp expression in the kidney during endotoxemia.

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