-
Oxidative Medicine and Cellular... 2023Microglia are activated following cerebral ischemic insult. P-glycoprotein (P-gp) is an efflux transporter on microvascular endothelial cells and upregulated after...
Microglia are activated following cerebral ischemic insult. P-glycoprotein (P-gp) is an efflux transporter on microvascular endothelial cells and upregulated after cerebral ischemia. This study evaluated the effects and possible mechanisms of P-gp on microglial polarization/activation in mice after ischemic stroke. P-gp-specific siRNA and adeno-associated virus (p-AAV) were used to silence and overexpress P-gp, respectively. Middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R) were performed in mice and cerebral microvascular endothelial cells (bEnd.3) , respectively. OGD/R-injured bEnd.3 cells were cocultured with mouse microglial cells (BV2) in Transwell. Influences on acute ischemic stroke outcome, the expression of inflammatory cytokines, and chemokines and chemokines receptors, microglial polarization, glucocorticoid receptor (GR) nuclear translocation, and GR-mediated mRNA decay (GMD) activation were evaluated via reverse transcription real-time polymerase chain reaction, western blot, or immunofluorescence. Silencing P-gp markedly alleviated experimental ischemia injury as indicated by reduced cerebral infarct size, improved neurological deficits, and reduced the expression of interleukin-6 (IL-6) and IL-12 expression. Silencing P-gp also mitigated proinflammatory microglial polarization and the expression of C-C motif chemokine ligand 2 (CCL2) and its receptor CCR2 expression, whereas promoted anti-inflammatory microglia polarization. Additionally, P-gp silencing promoted GR nuclear translocation and the expression of GMD relative proteins in endothelial cells. Conversely, overexpressing P-gp via p-AAV transfection offset all these effects. Furthermore, silencing endothelial GR counteracted all effects mediated by silencing or overexpressing P-gp. Elevated P-gp expression aggravated inflammatory response and brain damage after ischemic stroke by augmenting proinflammatory microglial polarization in association with increased endothelial CCL2 release due to GMD inhibition by P-gp.
Topics: Animals; Mice; ATP Binding Cassette Transporter, Subfamily B, Member 1; Brain Injuries; Brain Ischemia; Chemokines; Endothelial Cells; Infarction, Middle Cerebral Artery; Ischemia; Ischemic Stroke; Microglia; Reperfusion Injury
PubMed: 38144707
DOI: 10.1155/2023/6916819 -
British Journal of Pharmacology Nov 2021P-glycoprotein (P-gp) exhibits a broad substrate specificity and affects pharmacokinetics, especially intestinal absorption. However, prediction, in vivo, of...
BACKGROUND AND PURPOSE
P-glycoprotein (P-gp) exhibits a broad substrate specificity and affects pharmacokinetics, especially intestinal absorption. However, prediction, in vivo, of P-gp-mediated drug-drug interaction (DDI) and non-linear absorption at the preclinical stage, is challenging. Here we evaluate the use of human MDR1 mouse artificial chromosome (hMDR1-MAC) mice carrying human P-gp and lacking their own murine P-gp to quantitatively predict human P-gp-mediated DDI and non-linear absorption.
EXPERIMENTAL APPROACH
The P-gp substrates (aliskiren, betrixaban, celiprolol, digoxin, fexofenadine and talinolol) were administered orally to wild-type, Mdr1a/b-knockout (KO) and hMDR1-MAC mice, and their plasma concentrations were measured. We calculated the ratio of area under the curve (AUCR) in mice (AUC /AUC or AUC /AUC ) estimated as attributable to complete P-gp inhibition and the human AUCR with and without P-gp inhibitor administration. The correlations of AUCR with AUCR and AUCR were investigated. For aliskiren, betrixaban and celiprolol, the K and V values for P-gp in hMDR1-MAC mice and humans were optimized from different dosing studies using GastroPlus. The correlations of K and V for P-gp between human and hMDR1-MAC mice were investigated.
KEY RESULTS
A better correlation between AUCR and AUCR (R = 0.88) was observed. Moreover, good relationships of K (R = 1.00) and V (R = 0.98) for P-gp between humans and hMDR1-MAC mice were observed.
CONCLUSIONS AND IMPLICATIONS
These results suggest that P-gp-mediated DDI and non-linear absorption can be predicted using hMDR1-MAC mice. These mice are a useful in vivo tool for quantitatively predicting P-gp-mediated disposition in drug discovery and development.
Topics: ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Animals; Drug Interactions; Intestinal Absorption; Mice; Pharmaceutical Preparations
PubMed: 34232502
DOI: 10.1111/bph.15612 -
Fluids and Barriers of the CNS Oct 2023Loss of P-glycoprotein (P-gp) at the blood-brain barrier contributes to amyloid-β (Aβ) brain accumulation in Alzheimer's disease (AD). Using transgenic human amyloid...
BACKGROUND
Loss of P-glycoprotein (P-gp) at the blood-brain barrier contributes to amyloid-β (Aβ) brain accumulation in Alzheimer's disease (AD). Using transgenic human amyloid precursor protein (hAPP)-overexpressing mice (Tg2576), we previously showed that Aβ triggers P-gp loss by activating the ubiquitin-proteasome pathway, which leads to P-gp degradation. Furthermore, we showed that inhibiting the ubiquitin-activating enzyme (E1) prevents P-gp loss and lowers Aβ accumulation in the brain of hAPP mice. Based on these data, we hypothesized that repurposing the FDA-approved proteasome inhibitor, bortezomib (Velcade; BTZ), protects blood-brain barrier P-gp from degradation in hAPP mice in vivo.
METHODS
We treated hAPP mice with the proteasome inhibitor BTZ or a combination of BTZ with the P-gp inhibitor cyclosporin A (CSA) for 2 weeks. Vehicle-treated wild-type (WT) mice were used as a reference for normal P-gp protein expression and transport activity. In addition, we used the opioid receptor agonist loperamide as a P-gp substrate in tail flick assays to indirectly assess P-gp transport activity at the blood-brain barrier in vivo. We also determined P-gp protein expression by Western blotting, measured P-gp transport activity levels in isolated brain capillaries with live cell confocal imaging and assessed Aβ plasma and brain levels with ELISA.
RESULTS
We found that 2-week BTZ treatment of hAPP mice restored P-gp protein expression and transport activity in brain capillaries to levels found in WT mice. We also observed that hAPP mice displayed significant loperamide-induced central antinociception compared to WT mice indicating impaired P-gp transport activity at the blood-brain barrier of hAPP mice in vivo. Furthermore, BTZ treatment prevented loperamide-induced antinociception suggesting BTZ protected P-gp loss in hAPP mice. Further, BTZ-treated hAPP mice had lower Aβ40 and Aβ42 brain levels compared to vehicle-treated hAPP mice.
CONCLUSIONS
Our data indicate that BTZ protects P-gp from proteasomal degradation in hAPP mice, which helps to reduce Aβ brain levels. Our data suggest that the proteasome system could be exploited for a novel therapeutic strategy in AD, particularly since increasing Aβ transport across the blood-brain barrier may prove an effective treatment for patients.
Topics: Humans; Mice; Animals; Alzheimer Disease; Blood-Brain Barrier; Proteasome Endopeptidase Complex; Loperamide; Proteasome Inhibitors; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Brain; Mice, Transgenic; ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily B
PubMed: 37803468
DOI: 10.1186/s12987-023-00470-z -
British Journal of Clinical Pharmacology Jul 2022P-glycoprotein (P-gp) and CYP3A4-interacting drugs influence plasma levels of non-vitamin K antagonist oral anticoagulants (NOACs). However, the clinical relevance is... (Meta-Analysis)
Meta-Analysis Review
Impact of P-glycoprotein and/or CYP3A4-interacting drugs on effectiveness and safety of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: A meta-analysis.
AIMS
P-glycoprotein (P-gp) and CYP3A4-interacting drugs influence plasma levels of non-vitamin K antagonist oral anticoagulants (NOACs). However, the clinical relevance is questioned. Therefore, the impact of pharmacokinetically-interacting drugs on the effectiveness and safety of NOACs in patients with atrial fibrillation (AF) was investigated.
METHODS
A meta-analysis was performed based on randomized controlled trials and observational studies retrieved from Pubmed and Embase that investigated the impact of concomitantly used P-gp/CYP3A4-interacting drugs on the risk-benefit profile of NOACs in AF patients.
RESULTS
Fifteen studies were included, investigating 21 711 and 306 421 NOAC-treated AF patients with and without P-gp/CYP3A4 inhibitor use respectively, while only 1 study included P-gp/CYP3A4 inducers. In NOAC-treated AF patients, concomitant use of P-gp/CYP3A4 inhibitors was associated with significantly higher major bleeding (relative risk [RR] 1.10, 95% confidence interval [CI; 1.01-1.19]) and all-cause mortality risks (RR 1.14, 95%CI [1.05-1.23]) compared to not using P-gp/CYP3A4 inhibitors, while the risks of stroke/systemic embolism (RR 0.88, 95%CI [0.77-1.01]), intracranial bleeding (RR 0.89, 95%CI [0.68-1.15]) and gastrointestinal bleeding (RR 1.09, 95%CI [0.91-1.30]) were not significantly different. Concomitant use of amiodarone with NOACs was associated with lower thromboembolic (RR 0.75, 95%CI [0.61-0.92]), similar major bleeding (RR 0.92, 95%CI [0.80-1.07]) but higher mortality risks (RR 1.21, 95%CI [1.05-1.39]). Coadministration of verapamil or diltiazem was associated with higher major bleeding risks (RR 1.64, 95%CI [1.31-2.06]), but comparable thromboembolic (RR 1.10, 95%CI [0.75-1.61]) and mortality risks (RR 1.01, 95%CI [0.77-1.33]).
CONCLUSION
Given the higher bleeding and mortality risks in NOAC-treated AF patients concomitantly using P-gp/CYP3A4 inhibitors, close monitoring is warranted.
Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Administration, Oral; Anticoagulants; Atrial Fibrillation; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inhibitors; Gastrointestinal Hemorrhage; Humans; Stroke; Thromboembolism
PubMed: 35132677
DOI: 10.1111/bcp.15265 -
Molecular Oncology Jan 2023Chemotherapy resistance is a persistent clinical problem in relapsed high-risk neuroblastomas. We tested a panel of 15 drugs for sensitization of neuroblastoma cells to...
Chemotherapy resistance is a persistent clinical problem in relapsed high-risk neuroblastomas. We tested a panel of 15 drugs for sensitization of neuroblastoma cells to the conventional chemotherapeutic vincristine, identifying tariquidar, an inhibitor of the transmembrane pump P-glycoprotein (P-gp/ABCB1), and the ERBB family inhibitor afatinib as the top resistance breakers. Both compounds were efficient in sensitizing neuroblastoma cells to vincristine in trypan blue exclusion assays and in inducing apoptotic cell death. The evaluation of ERBB signaling revealed no functional inhibition, that is, dephosphorylation of the downstream pathways upon afatinib treatment but direct off-target interference with P-gp function. Depletion of ABCB1, but not ERRB4, sensitized cells to vincristine treatment. P-gp inhibition substantially broke vincristine resistance in vitro and in vivo (zebrafish embryo xenograft). The analysis of gene expression datasets of more than 50 different neuroblastoma cell lines (primary and relapsed) and more than 160 neuroblastoma patient samples from the pediatric precision medicine platform INFORM (Individualized Therapy For Relapsed Malignancies in Childhood) confirmed a pivotal role of P-gp specifically in neuroblastoma resistance at relapse, while the ERBB family appears to play a minor part.
Topics: Animals; Humans; ATP Binding Cassette Transporter, Subfamily B, Member 1; Vincristine; Afatinib; Zebrafish; Drug Resistance, Neoplasm; Neuroblastoma; ATP Binding Cassette Transporter, Subfamily B; ErbB Receptors; Recurrence; Cell Line, Tumor
PubMed: 36181342
DOI: 10.1002/1878-0261.13318 -
International Journal of Molecular... Nov 2022ABC transporters play a critical role in both drug bioavailability and toxicity, and with the discovery of the P-glycoprotein (P-gp), this became even more evident, as... (Review)
Review
ABC transporters play a critical role in both drug bioavailability and toxicity, and with the discovery of the P-glycoprotein (P-gp), this became even more evident, as it plays an important role in preventing intracellular accumulation of toxic compounds. Over the past 30 years, intensive studies have been conducted to find new therapeutic molecules to reverse the phenomenon of multidrug resistance (MDR) ), that research has found is often associated with overexpression of P-gp, the most extensively studied drug efflux transporter; in MDR, therapeutic drugs are prevented from reaching their targets due to active efflux from the cell. The development of P-gp inhibitors is recognized as a good way to reverse this type of MDR, which has been the subject of extensive studies over the past few decades. Despite the progress made, no effective P-gp inhibitors to reverse multidrug resistance are yet on the market, mainly because of their toxic effects. Computational studies can accelerate this process, and in silico models such as QSAR models that predict the activity of compounds associated with P-gp (or analogous transporters) are of great value in the early stages of drug development, along with molecular modelling methods, which provide a way to explain how these molecules interact with the ABC transporter. This review highlights recent advances in computational P-gp research, spanning the last five years to 2022. Particular attention is given to the use of machine-learning approaches, drug-transporter interactions, and recent discoveries of potential P-gp inhibitors that could act as modulators of multidrug resistance.
Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Drug Resistance, Neoplasm; Drug Resistance, Multiple; ATP-Binding Cassette Transporters; Antineoplastic Agents
PubMed: 36499131
DOI: 10.3390/ijms232314804 -
Biomedicine & Pharmacotherapy =... Jul 2021P-glycoprotein, encoded by ATP-binding cassette transporters B1 gene (ABCB1), renders multidrug resistance (MDR) during cancer chemotherapy. Several synthetic small... (Review)
Review
P-glycoprotein, encoded by ATP-binding cassette transporters B1 gene (ABCB1), renders multidrug resistance (MDR) during cancer chemotherapy. Several synthetic small molecule inhibitors affect P-glycoprotein (P-gp) transport function in MDR tumor cells. However, inhibition of P-gp transport function adversely accumulates chemotherapeutic drugs in non-target normal tissues. Moreover, most small-molecule P-gp inhibitors failed in the clinical trials due to the low therapeutic window at the maximum tolerated dose. Therefore, downregulation of ABCB1-gene expression (P-gp) in tumor tissues seems to be a novel approach rather than inhibiting its transport function for the reversal of multidrug resistance (MDR). Several plant-derived phytochemicals modulate various signal transduction pathways and inhibit translocation of transcription factors, thereby reverses P-gp mediated MDR in tumor cells. Therefore, phytochemicals may be considered an alternative to synthetic small molecule P-gp inhibitors for the reversal of MDR in cancer cells. This review discussed the role of natural phytochemicals that modulate ABCB1 expression through various signal transduction pathways in MDR cancer cells. Therefore, modulating the cell signaling pathways by phytochemicals might play crucial roles in modulating ABCB1 gene expression and the reversal of MDR.
Topics: ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Animals; Drug Resistance, Multiple; Gene Expression; Humans; Phytochemicals; Signal Transduction
PubMed: 34243600
DOI: 10.1016/j.biopha.2021.111632 -
International Journal of Oncology Nov 2023Multidrug resistance (MDR) seriously limits the clinical application of chemotherapy. A mechanism underlying MDR is the overexpression of efflux transporters associated... (Review)
Review
Multidrug resistance (MDR) seriously limits the clinical application of chemotherapy. A mechanism underlying MDR is the overexpression of efflux transporters associated with chemotherapeutic drugs. P‑glycoprotein (P‑gp) is an ATP‑binding cassette (ABC) transporter, which promotes MDR by pumping out chemotherapeutic drugs and reducing their intracellular concentration. To date, overexpression of P‑gp has been detected in various types of chemoresistant cancer and inhibiting P‑gp‑related MDR has been suggested. The present review summarizes the mechanisms underlying MDR mediated by P‑gp in different tumors and evaluated the related signaling pathways, with the aim of improving understanding of the current status of P‑gp‑mediated chemotherapeutic resistance. This review focuses on the main mechanisms of inhibiting P‑gp‑mediated MDR, with the aim of providing a reference for the study of reversing P‑gp‑mediated MDR. The first mechanism involves decreasing the efflux activity of P‑gp by altering its conformation or hindering P‑gp‑chemotherapeutic drug binding. The second inhibitory mechanism involves inhibiting P‑gp expression to reduce efflux. The third inhibitory mechanism involves knocking out the ABCB1 gene. Potential strategies that can inhibit P‑gp include certain natural products, synthetic compounds and biological techniques. It is important to screen lead compounds or candidate techniques for P‑gp inhibition, and to identify inhibitors by targeting the relevant signaling pathways to overcome P‑gp‑mediated MDR.
Topics: Humans; ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Transporters; Biological Products; Drug Resistance, Multiple
PubMed: 37654171
DOI: 10.3892/ijo.2023.5567 -
Journal of Neurochemistry Aug 2022P-glycoprotein (P-gp) is an efflux transporter at the blood-brain barrier (BBB) that hinders brain access of substrate drugs and clears endogenous molecules such as...
P-glycoprotein (P-gp) is an efflux transporter at the blood-brain barrier (BBB) that hinders brain access of substrate drugs and clears endogenous molecules such as amyloid beta (Aβ) from the brain. As biometals such as copper (Cu) modulate many neuronal signalling pathways linked to P-gp regulation, it was hypothesised that the bis(thiosemicarbazone) (BTSC) Cu-releasing complex, copper II glyoxal bis(4-methyl-3-thiosemicarbazone) (Cu [GTSM]), would enhance P-gp expression and function at the BBB, while copper II diacetyl bis(4-methyl-3-thiosemicarbazone) (Cu [ATSM]), which only releases Cu under hypoxic conditions, would not modulate P-gp expression. Following treatment with 25-250 nM Cu (BTSC)s for 8-48 h, expression of P-gp mRNA and protein in human brain endothelial (hCMEC/D3) cells was assessed by RT-qPCR and Western blot, respectively. P-gp function was assessed by measuring accumulation of the fluorescent P-gp substrate, rhodamine 123 and intracellular Cu levels were quantified by inductively coupled plasma mass spectrometry. Interestingly, Cu (ATSM) significantly enhanced P-gp expression and function 2-fold and 1.3-fold, respectively, whereas Cu (GTSM) reduced P-gp expression 0.5-fold and function by 200%. As both compounds increased intracellular Cu levels, the effect of different BTSC backbones, independent of Cu, on P-gp expression was assessed. However, only the Cu-ATSM complex enhanced P-gp expression and this was mediated partly through activation (1.4-fold) of the extracellular signal-regulated kinase 1 and 2, an outcome that was significantly attenuated in the presence of an inhibitor of the mitogen-activated protein kinase regulatory pathway. Our findings suggest that Cu (ATSM) and Cu (GTSM) have the potential to modulate the expression and function of P-gp at the BBB to impact brain drug delivery and clearance of Aβ.
Topics: ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Amyloid beta-Peptides; Brain; Copper; Endothelial Cells; Humans; Thiosemicarbazones
PubMed: 35304760
DOI: 10.1111/jnc.15609 -
Proceedings. Biological Sciences May 2022Pesticides remain one of the most effective ways of controlling agricultural and public health insects, but much is still unknown regarding how these compounds reach...
Pesticides remain one of the most effective ways of controlling agricultural and public health insects, but much is still unknown regarding how these compounds reach their targets. Specifically, the role of ABC transporters in pesticide absorption and excretion is poorly understood, especially compared to the detailed knowledge about mammalian systems. Here, we present a comprehensive characterization of pesticide transporters in the model insect . An RNAi screen was performed, which knocked down individual ABCs in specific epithelial tissues and examined the subsequent changes in sensitivity to the pesticides spinosad and fipronil. This implicated a novel ABC drug transporter, in spinosad transport, but also highlighted the P-glycoprotein orthologue as the most impactful ABC in terms of chemoprotection. Further characterization of the P-glycoprotein family was performed via transgenic overexpression and immunolocalization, finding that and play enigmatic roles in pesticide toxicology perhaps determined by their different subcellular localizations within the midgut. Lastly, transgenic lines expressing P-glycoprotein from the major malaria vector were used to establish a system for characterization of this transporter in non-model insects. This study provides the basis for establishing as a model for toxicology research on drug transporters.
Topics: ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP-Binding Cassette Transporters; Animals; Animals, Genetically Modified; Anopheles; Drosophila melanogaster; Insecticide Resistance; Insecticides; Malaria; Mammals; Mosquito Vectors; Pesticides
PubMed: 35582794
DOI: 10.1098/rspb.2022.0625