Regulation of P-Glycoprotein in Renal Proximal Tubule Epithelial Cells by LPS and TNF-α
Figure 4
Role of TNF receptors and toll-like receptor 4 in modulation of P-gp activity in GERP cells. (a) TNFR1, TNFR2 and TLR4 mRNA expression was analyzed in GERP cells (control; lane 1 and 2) exposed for 24 hours to TNF-α (lanes 3 and 4) using PCR. For TNFR1 and TNFR2 two different primer sets were used, for TLR4 only one primer set was used. MilliQ (MQ) was used as a negative control. For both experiments the expression of the housekeeping gene -actin was performed as a control for the performed PCR reaction. ((b) ) P-gp transport activity in GERP cells after exposure to 10 ng/mL TNF-α in combination with 10 mg/mL of the TNFR1 inhibitor H398 for 24 hours compared to control (cells exposed to culture medium). ((c) ) P-gp transport activity in GERP cells after exposure to 10 ng/mL TNF-α in combination with 5 ng/mL of the antibody against human TLR4 for 24 hours compared to control. Data are expressed as mean SEM. Significantly different compared to control (: ) or to TNF-α (; ). Treatment with H398 or anti-TLR4 alone showed no significant difference compared to control.
