Kinetic Analysis of Human and Canine P-Glycoprotein-Mediated Drug Transport in MDR1-MDCK Cell Model: Approaches to Reduce False-Negative Substrate Classification

2013 ◽  
Vol 102 (9) ◽  
pp. 3436-3446 ◽  
Author(s):  
Jibin Li ◽  
Ying Wang ◽  
Ismael J. Hidalgo
Keyword(s):  
Kinetic Analysis ◽  
Mdck Cell ◽  
Drug Transport ◽  
Cell Model ◽  
False Negative ◽  
P Glycoprotein ◽  
Substrate Classification

scholarly journals Transfected MDCK Cell Line with Enhanced Expression of CYP3A4 and P-Glycoprotein as a Model To Study Their Role in Drug Transport and Metabolism

2012 ◽  
Vol 9 (7) ◽  
pp. 1877-1886 ◽  
Author(s):  
Deep Kwatra ◽  
Balasubramanyam Budda ◽  
Aswani Dutt Vadlapudi ◽  
Ramya Krishna Vadlapatla ◽  
Dhananjay Pal ◽  
...  
Keyword(s):  
Cell Line ◽  
Mdck Cell ◽  
Drug Transport ◽  
Mdck Cell Line ◽  
P Glycoprotein ◽  
Enhanced Expression

scholarly journals Inhibition of P-Glycoprotein–Mediated Drug Transport

Circulation ◽  
1999 ◽  
Vol 99 (4) ◽  
pp. 552-557 ◽  
Author(s):  
Martin F. Fromm ◽  
Richard B. Kim ◽  
C. Michael Stein ◽  
Grant R. Wilkinson ◽  
Dan M. Roden
Keyword(s):  
Drug Transport ◽  
P Glycoprotein

Exact kinetic analysis of passive transport across a polarized confluent MDCK cell monolayer modeled as a single barrier

2004 ◽  
Vol 93 (8) ◽  
pp. 2108-2123 ◽  
Author(s):  
Thuy Thanh Tran ◽  
Tracy Gales ◽  
Beverly Maleeff ◽  
Tanya Aldinger ◽  
Joseph W. Polli ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Mdck Cell ◽  
Cell Monolayer ◽  
Passive Transport

scholarly journals The Fluorescent Probe Bodipy-FL-Verapamil Is a Substrate for Both P-glycoprotein and Multidrug Resistance-related Protein (MRP)-1

2002 ◽  
Vol 50 (5) ◽  
pp. 731-734 ◽  
Author(s):  
Enrico Crivellato ◽  
Luigi Candussio ◽  
Anna M. Rosati ◽  
Fiora Bartoli-Klugmann ◽  
Franco Mallardi ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Drug Transport ◽  
Mrna Level ◽  
Fluorescent Microscopy ◽  
Flow Cytometric Analysis ◽  
Cell Types ◽  
Multidrug Resistant ◽  
Related Protein ◽  
P Glycoprotein ◽  
Multidrug Resistance Related Protein

Several fluorescent probes have been used in functional studies to analyze drug transport in multidrug-resistant cells by fluorescent microscopy. Because many of these molecules have some drawbacks, such as toxicity, nonspecific background, or accumulation in mitochondria, new fluorescent compounds have been proposed as more useful tools. Among these substances, Bodipy-FL-Verapamil, a fluorescent conjugate of the drug efflux blocker verapamil, has been used to study P-glycoprotein activity in different cell types. In this study we tested by fluorescent microscopy the accumulation of Bodipy-FL- Verapamil in cell lines that overexpress either P-glycoprotein (P-gp) or multidrug resistance-related protein 1 (MRP1). Expression of P-gp and MRP1 was evaluated at the mRNA level by RT-PCR technique and at the protein level by flow cytometric analysis using C219 and MRP-m6 monoclonal antibodies. Results indicate that Bodipy-FL-Verapamil is actually a substrate for both proteins. As a consequence, any conclusion about P-gp activity obtained by the use of Bodipy-FL-Verapamil as fluorescent tracer should be interpreted with caution.

Establishment and characterization of an MDCK cell line stably-transfected with chicken Abcb1 encoding P-glycoprotein

2016 ◽  
Vol 106 ◽  
pp. 37-44 ◽  
Author(s):  
Yong Sun ◽  
Tingting Guo ◽  
Dawei Guo ◽  
Li Guo ◽  
Li Chen ◽  
...  
Keyword(s):  
Cell Line ◽  
Mdck Cell ◽  
Mdck Cell Line ◽  
P Glycoprotein

scholarly journals ATP-dependent thermostabilization of human P-glycoprotein (ABCB1) is blocked by modulators

2019 ◽  
Vol 476 (24) ◽  
pp. 3737-3750 ◽  
Author(s):  
Sabrina Lusvarghi ◽  
Suresh V. Ambudkar
Keyword(s):  
Conformational Changes ◽  
Drug Transport ◽  
Atp Hydrolysis ◽  
Atp Binding ◽  
Dependent Manner ◽  
Deficient Mutant ◽  
Concentration Dependent Manner ◽  
Glycoprotein P ◽  
Binding Domains ◽  
P Glycoprotein

P-glycoprotein (P-gp), an ATP-binding cassette transporter associated with multidrug resistance in cancer cells, is capable of effluxing a number of xenobiotics as well as anticancer drugs. The transport of molecules through the transmembrane (TM) region of P-gp involves orchestrated conformational changes between inward-open and inward-closed forms, the details of which are still being worked out. Here, we assessed how the binding of transport substrates or modulators in the TM region and the binding of ATP to the nucleotide-binding domains (NBDs) affect the thermostability of P-gp in a membrane environment. P-gp stability after exposure at high temperatures (37–80°C) was assessed by measuring ATPase activity and loss of monomeric P-gp. Our results show that P-gp is significantly thermostabilized (>22°C higher IT50) by the binding of ATP under non-hydrolyzing conditions (in the absence of Mg2+). By using an ATP-binding-deficient mutant (Y401A) and a hydrolysis-deficient mutant (E556Q/E1201Q), we show that thermostabilization of P-gp requires binding of ATP to both NBDs and their dimerization. Additionally, we found that transport substrates do not affect the thermal stability of P-gp either in the absence or presence of ATP; in contrast, inhibitors of P-gp including tariquidar and zosuquidar prevent ATP-dependent thermostabilization in a concentration-dependent manner, by stabilizing the inward-open conformation. Altogether, our data suggest that modulators, which bind in the TM regions, inhibit ATP hydrolysis and drug transport by preventing the ATP-dependent dimerization of the NBDs of P-gp.

Drug efflux mediated by the human multidrug resistance P-glycoprotein is inhibited by cell swelling

1994 ◽  
Vol 107 (12) ◽  
pp. 3281-3290
Author(s):  
A. Sardini ◽  
G.M. Mintenig ◽  
M.A. Valverde ◽  
F.V. Sepulveda ◽  
D.R. Gill ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Chloride Channels ◽  
Drug Transport ◽  
Atp Hydrolysis ◽  
Cell Swelling ◽  
Drug Efflux ◽  
Fluorescent Substrate ◽  
Membrane Stretch ◽  
P Glycoprotein ◽  
In Cells

P-glycoprotein (P-gp), the product of the human multidrug resistance (MDR1) gene, confers multidrug resistance on cells by acting as an ATP-dependent drug transporter. A method using confocal microscopy was developed to measure the transport activity of P-gp from the rate of movement of doxorubicin, a fluorescent substrate of P-gp, across the membrane of a single cell. Recent work has shown that expression of P-gp enhances the activation of chloride channels in response to cell swelling, suggesting that membrane stretch might switch P-gp from a drug-transporting mode to a mode in which it activates chloride channels. In agreement with this idea, we find that cell swelling inhibits drug efflux in cells expressing P-gp but is without effect on the slower background efflux in cells not expressing P-gp and in cells transiently transfected with a mutated MDR1 in which the ATP hydrolysis sites had been inactivated. The identification of a novel means for inhibiting P-gp-mediated drug transport may have implications for the reversal of multidrug resistance during chemotherapy.

scholarly journals Reversing the direction of drug transport mediated by the human multidrug transporter P-glycoprotein

2020 ◽  
Vol 117 (47) ◽  
pp. 29609-29617
Author(s):  
Andaleeb Sajid ◽  
Sabrina Lusvarghi ◽  
Megumi Murakami ◽  
Eduardo E. Chufan ◽  
Biebele Abel ◽  
...  
Keyword(s):  
Drug Transport ◽  
Atp Hydrolysis ◽  
Binding Pocket ◽  
Drug Binding ◽  
Drug Uptake ◽  
Cancer Drug ◽  
Binding Domains ◽  
Cancer Drug Resistance ◽  
P Glycoprotein ◽  
Cell Transforming

P-glycoprotein (P-gp), also known as ABCB1, is a cell membrane transporter that mediates the efflux of chemically dissimilar amphipathic drugs and confers resistance to chemotherapy in most cancers. Homologous transmembrane helices (TMHs) 6 and 12 of human P-gp connect the transmembrane domains with its nucleotide-binding domains, and several residues in these TMHs contribute to the drug-binding pocket. To investigate the role of these helices in the transport function of P-gp, we substituted a group of 14 conserved residues (seven in both TMHs 6 and 12) with alanine and generated a mutant termed 14A. Although the 14A mutant lost the ability to pump most of the substrates tested out of cancer cells, surprisingly, it acquired a new function. It was able to import four substrates, including rhodamine 123 (Rh123) and the taxol derivative flutax-1. Similar to the efflux function of wild-type P-gp, we found that uptake by the 14A mutant is ATP hydrolysis-, substrate concentration-, and time-dependent. Consistent with the uptake function, the mutant P-gp also hypersensitizes HeLa cells to Rh123 by 2- to 2.5-fold. Further mutagenesis identified residues from both TMHs 6 and 12 that synergistically form a switch in the central region of the two helices that governs whether a given substrate is pumped out of or into the cell. Transforming P-gp or an ABC drug exporter from an efflux transporter into a drug uptake pump would constitute a paradigm shift in efforts to overcome cancer drug resistance.

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