MDR MRP transporters

• Multidrug resistance type I P-glycoproteins (P-gp) and multidrug resistance associated proteins MRP are members of the superfamiliy of ABC (ATP-binding cassette) transporters. These transporters contribute towards detoxifications of a spectrum of xenobiotics by mediating energy-dependent transport from the cell. Rodent as well as human liver and human hepatocytes in serum-free culture exhibit high P-gp expression which is concentrated on the canalicular hepatocyte membrane. In primary hepatocytes maintained in serum-free culture, accumulation of immunodetectable P-glycoprotein and mdr1b mRNA occurred in a time-dependent manner. Epidermal growth factor and insulin-like growth factor markedly enhanced timedependent accumulation of P-gp, mRNA and increased the efflux of the substrate rhodamine 123 which indicates that an increase in functional transporters occurs under EGF. In primary hepatocytes treated with the cytokine tumor necrosis factor alpha (TNFa) expression of mdr1b mRNA and immunodetectable P-gp was induced. Treatment of cells with antioxidants markedly suppressed mdr1b mRNA and protein expression supporting the notation that reactive oxygen species participate in regulation of basal mdr1b gene expression during hepatocyte culture. Primary AII cells exhibited low levels of mdr-1b mRNA, that increased over time and after oxygen radical production induced by paraquat. Normal human bronchial cells in culture expressed immuno-reactive MDR1 P-gp and MRP protein that was active in the fluorescence assay. We observe inter-individual variation in MRP in both mRNA and the immunoreactive protein. Model compounds of oxygen radical production, such as paraquat and hydrogen peroxide, modulate the regulation of MRP-1 and MDR in normal bronchial cell as well as in lung tumor cell lines. This effect could be counteracted by ascorbate. The mRNA level drastically increases when explant cultures are continued for a long time. Actual experiments aim to determine whether this RNA signal is transcribed into functionally active protein and whether MRP expression is controlled by external factors.

Hirsch-Ernst K, Ziemann Ch, Schmitz-Salue Ch, Foth H, Kahl GF (1995) Modulation of PGlycoprotein and mdr1bmRNA Expression by growth factors in primary rat hepatocyte culture. Biochem Biophys Research Comm 2, 15, 179   185

Hirsch-Ernst KI, Ziermann C, Foth H, Kozian D, Schmitz-Salue C, Kahl GF (1998) Induction of mdr 1b mRNA and P-glycoprotein expression by tumor necrosis factor alpha in primary rat hepatocyte cultures. J Cell Physiol 176, 506   515

Lehmann T, Khler Ch, Weidauer E, Taege Ch, Foth H Expression of MRP1 and related transporters in human lung cells in culture. Toxicology revision submitted

• Abstracts

Hirsch-Ernst KI, Ziemann C, Schmitz-Salue C, Foth H, Kahl GF (1995) Regulation of P-glycoprotein expression by tumor-necrosis factor alpha (TNF-a) in primary hepatocyte culture. Conference  Novel Strategies Against Resistant Cancers  of the American Association for Cancer Research, November 17   21, 1995, Fort Myers, Florida, USA

Hirsch-Ernst KI, Ziemann C, Foth H, Kahl GF (1996) Chemosensitizing agents delay development of intracellular steady-state levels of the mdr1 substrate rhodamine 123. Naunyn-Schmiedeberg s Arch Pharmacol 353, Suppl, R 46

Hirsch-Ernst KI, Ziemann C, Schmitz-Salue C, Foth H, Kahl GF (1996) Functional characterization of growth factor dependent mdr1 expression in rodent hepatocyte cultures using rhodamine 123. Biol Chem, Vol 377, Special Suppl, p27

Hirsch-Ernst KI, Ziemann C, Foth H, Kahl GF (1996) Induction of P-glycoprotein and mdr1b mRNA expression by tumor-necrosis factor alpha (TNF-a) in primary hepatocyte cultures. Naunyn- Schmiedeberg s Arch Pharmacol 354, Suppl, R 19

Ziemann C, Hirsch-Ernst KI, Foth H, Kahl GF (1997) Modulation of p-glycoprotein expression and mdr1 transport activity by reactive oxygen species in primary rat hepatocyte cultures. Naunyn- Schmiedeberg s Arch of Pharmacol 355, Suppl, R 143

Hirsch-Ernst KI, Ziemann C, Kahl GF, Foth H (1998) Modulation of mdr1b mRNA and P-glycoprotein expression by cytokines in primary rat hepatocyte cultures. International Falk Workshop, January 29   30, 1998, Halle/Saale

 Ziemann C, Foth H, Kahl GF, Hirsch-Ernst KI (1998) Modulation der mdr1b mRNA Expression durch reaktive Sauerstoffspezies und durch den Cyclooxgenase-2 Inhibitor NS-398 in Primrkulturen von Rattenhepatozyten. Z Gastroenterol 36, 057

 Khler C, Weidauer E, Runge DM, Lehmann T, Rhrdanz E, Tran Thi QH, Kahl R, Foth H (2000) Oxidative stress alters expression of P-glycoprotein and multidrug resistance-associated protein, but not antioxidant enzymes in lung tumor cell lines. Naunyn-Schmiedeberg s Arch Pharmacol 361, Suppl, R 163

 Lehmann T, Weidauer E, Rhrdanz E, Tran Thi QH, Kahl R, Foth H (2000) Influence of paraquat and hydrogen peroxide to antioxidant enzymes (cat, MnSOD) and mdr1b in rat alveolar type II pneumocytes. Naunyn-Schmiedeberg s Arch Pharmacol 361, Suppl, R 142

 Runge D, Runge DM, Khler C, Lehmann T, Jger D, May U, Foth H, Dorko H, Strom SC, Michalopoulos GK, Fleig WE (2000) Expression of membrane transporter and cytochrome P450 proteins in serum-free long-term human hepatocyte cultures. FASEB J 4, Vol 14, A183, Experimental Biology Meeting, San Diego, 15.04.   18.04.

 Runge DM, Runge D, Foth H, Strom SC, Michalopoulos GK (2000) EGF-receptor and Met: crosstalk between the two growth factor receptors mediated by STAT proteins in human hepatocytes. FASEB J 4, Vol 14, A722, Experimental Biology Meeting, San Diego, 15.04.   18.04.

 Runge D, Runge DM, Khler C, Lehmann T, Jger D, May U, Foth H, Dorko H, Strom SC, Michalopoulos GK, Fleig WE (2000) Expression of membrane transporter and cytochrome P450 proteins in serum-free long-term human hepatocyte cultures. FASEB J 4, Vol 14, A183, Experimental Biology Meeting, San Diego, 15.04.   18.04.

 Köhler C, Weidauer E, Runge DM, Lehmann T, Rhrdanz E, Tran Thi QH, Kahl R, Foth H (2000) Oxidative stress alters expression of P-glycoprotein and multidrug resistance-associated protein, but not antioxidant enzymes in lung tumor cell lines. Naunyn-Schmiedeberg s Arch Pharmacol 361, Suppl, R 163

 Lehmann T, Weidauer E, Rhrdanz E, Tran Thi QH, Kahl R, Foth H (2000) Influence of paraquat and hydrogen peroxide to antioxidant enzymes (cat, MNSOD) and mdr1b in rat alveolar type II pneumocytes. Naunyn-Schmiedeberg s Arch Pharmacol 361, Suppl, R 142

Köhler C, Runge DM, Foth H, May U, Fleig WE, Strom SC, Michaolopoulos GK, Runge D (2000) Regulation of P-Glycoprotein and MRP (multidrug resistance-associated protein) by cytochrome P450 inducers in serum-free cultures of human hepatocytes. Falk Workshop 27.-28.01., Köln

Rennicke A, Lehmann T, Mller SP, Foth H (2001) Expression of multidrug-resistance transporters in hepatocytes and lung cells treated with Ubiquinone (CoQ10) nanodispersion and hydrogen peroxide. Naunyn-Schmiedberg s Arch Pharmacol 363, Suppl, R 161

Lehmann T, Khler C, Weidauer E, Foth H (2001) Expression of multidrug-resistance (MRP) associated protein in normal human lung. Naunyn-Schmiedeberg s Arch Pharmacol 363, Suppl, R161