| 1. |
- Ahlin, Gustav, et al.
(författare)
-
Structural requirements for drug inhibition of the liver specific human organic cation transport protein 1
- 2008
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 51:19, s. 5932-5942
-
Tidskriftsartikel (refereegranskat)abstract
- The liver-specific organic cation transport protein (OCT1; SLC22A1) transports several cationic drugs including the antidiabetic drug metformin and the anticancer agents oxaliplatin and imatinib. In this study, we explored the chemical space of registered oral drugs with the aim of studying the inhibition pattern of OCT1 and of developing predictive computational models of OCT1 inhibition. In total, 191 structurally diverse compounds were examined in HEK293-OCT1 cells. The assay identified 47 novel inhibitors and confirmed 15 previously known inhibitors. The enrichment of OCT1 inhibitors was seen in several drug classes including antidepressants. High lipophilicity and a positive net charge were found to be the key physicochemical properties for OCT1 inhibition, whereas a high molecular dipole moment and many hydrogen bonds were negatively correlated to OCT1 inhibition. The data were used to generate OPLS-DA models for OCT1 inhibitors; the final model correctly predicted 82% of the inhibitors and 88% of the noninhibitors of the test set.
|
|
| 2. |
- Artursson, Per, et al.
(författare)
-
Absorption Prediction
- 2004
-
Ingår i: Profiling in Drug Discovery for Lead Selection. - : AAPS Press, Arlington VA.
-
Bokkapitel (refereegranskat)
|
|
| 3. |
|
|
| 4. |
- Chen, Eugene C., et al.
(författare)
-
High Throughput Screening of a Prescription Drug Library for Inhibitors of Organic Cation Transporter 3, OCT3
- 2022
-
Ingår i: Pharmaceutical research. - : Springer. - 0724-8741 .- 1573-904X. ; 39:7, s. 1599-1613
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction The organic cation transporter 3 (OCT3, SLC22A3) is ubiquitously expressed and interacts with a wide array of compounds including endogenous molecules, environmental toxins and prescription drugs. Understudied as a determinant of pharmacokinetics and pharmacodynamics, OCT3 has the potential to be a major determinant of drug absorption and disposition and to be a target for drug-drug interactions (DDIs).Goal The goal of the current study was to identify prescription drug inhibitors of OCT3.Methods We screened a compound library consisting of 2556 prescription drugs, bioactive molecules, and natural products using a high throughput assay in HEK-293 cells stably expressing OCT3.Results We identified 210 compounds that at 20 mu M inhibit 50% or more of OCT3-mediated uptake of 4-Di-1-ASP (2 mu M). Of these, nine were predicted to inhibit the transporter at clinically relevant unbound plasma concentrations. A Structure-Activity Relationship (SAR) model included molecular descriptors that could discriminate between inhibitors and non-inhibitors of OCT3 and was used to identify additional OCT3 inhibitors. Proteomics of human brain microvessels (BMVs) indicated that OCT3 is the highest expressed OCT in the human blood-brain barrier (BBB).Conclusions This study represents the largest screen to identify prescription drug inhibitors of OCT3. Several are sufficiently potent to inhibit the transporter at therapeutic unbound plasma levels, potentially leading to DDIs or off-target pharmacologic effects.
|
|
| 5. |
- Chu, X., et al.
(författare)
-
Intracellular Drug Concentrations and Transporters : Measurement, Modeling, and Implications for the Liver
- 2013
-
Ingår i: Clinical Pharmacology and Therapeutics. - : Springer Science and Business Media LLC. - 0009-9236 .- 1532-6535. ; 94:1, s. 126-141
-
Forskningsöversikt (refereegranskat)abstract
- Intracellular concentrations of drugs and metabolites are often important determinants of efficacy, toxicity, and drug interactions. Hepatic drug distribution can be affected by many factors, including physicochemical properties, uptake/efflux transporters, protein binding, organelle sequestration, and metabolism.This white paper highlights determinants of hepatocyte drug/metabolite concentrations and provides an update on model systems, methods, and modeling/simulation approaches used to quantitatively assess hepatocellular concentrations of molecules. The critical scientific gaps and future research directions in this field are discussed.
|
|
| 6. |
- Galetin, Aleksandra, et al.
(författare)
-
Membrane transporters in drug development and as determinants of precision medicine
- 2024
-
Ingår i: NATURE REVIEWS DRUG DISCOVERY. - 1474-1776 .- 1474-1784.
-
Forskningsöversikt (refereegranskat)abstract
- The effect of membrane transporters on drug disposition, efficacy and safety is now well recognized. Since the initial publication from the International Transporter Consortium, significant progress has been made in understanding the roles and functions of transporters, as well as in the development of tools and models to assess and predict transporter-mediated activity, toxicity and drug-drug interactions (DDIs). Notable advances include an increased understanding of the effects of intrinsic and extrinsic factors on transporter activity, the application of physiologically based pharmacokinetic modelling in predicting transporter-mediated drug disposition, the identification of endogenous biomarkers to assess transporter-mediated DDIs and the determination of the cryogenic electron microscopy structures of SLC and ABC transporters. This article provides an overview of these key developments, highlighting unanswered questions, regulatory considerations and future directions. Significant progress has been made in understanding the influence of membrane transporters in drug disposition and response. Here, the International Transporter Consortium provides an update on the current status of membrane transporters in drug development and regulatory requirements, discusses recent scientific advances in the field and highlights future directions and unanswered questions.
|
|
| 7. |
- Giacomini, K. M., et al.
(författare)
-
New and Emerging Research on Solute Carrier and ATP Binding Cassette Transporters in Drug Discovery and Development: Outlook from the International Transporter Consortium
- 2022
-
Ingår i: Clinical Pharmacology & Therapeutics. - : Wiley. - 0009-9236 .- 1532-6535. ; 112:3, s. 540-561
-
Tidskriftsartikel (refereegranskat)abstract
- Enabled by a plethora of new technologies, research in membrane transporters has exploded in the past decade. The goal of this state-of-the-art article is to describe recent advances in research on membrane transporters that are particularly relevant to drug discovery and development. This review covers advances in basic, translational, and clinical research that has led to an increased understanding of membrane transporters at all levels. At the basic level, we describe the available crystal structures of membrane transporters in both the solute carrier (SLC) and ATP binding cassette superfamilies, which has been enabled by the development of cryogenic electron microscopy methods. Next, we describe new research on lysosomal and mitochondrial transporters as well as recently deorphaned transporters in the SLC superfamily. The translational section includes a summary of proteomic research, which has led to a quantitative understanding of transporter levels in various cell types and tissues and new methods to modulate transporter function, such as allosteric modulators and targeted protein degraders of transporters. The section ends with a review of the effect of the gut microbiome on modulation of transporter function followed by a presentation of 3D cell cultures, which may enable in vivo predictions of transporter function. In the clinical section, we describe new genomic and pharmacogenomic research, highlighting important polymorphisms in transporters that are clinically relevant to many drugs. Finally, we describe new clinical tools, which are becoming increasingly available to enable precision medicine, with the application of tissue-derived small extracellular vesicles and real-world biomarkers.
|
|
| 8. |
- Guo, Yingying, et al.
(författare)
-
Advancing Predictions of Tissue and Intracellular Drug Concentrations Using In Vitro, Imaging and Physiologically Based Pharmacokinetic Modeling Approaches
- 2018
-
Ingår i: Clinical Pharmacology and Therapeutics. - : John Wiley & Sons. - 0009-9236 .- 1532-6535. ; 104:5, s. 865-889
-
Forskningsöversikt (refereegranskat)abstract
- This white paper examines recent progress, applications, and challenges in predicting unbound and total tissue and intra/subcellular drug concentrations using in vitro and preclinical models, imaging techniques, and physiologically based pharmacokinetic (PBPK) modeling. Published examples, regulatory submissions, and case studies illustrate the application of different types of data in drug development to support modeling and decision making for compounds with transporter-mediated disposition, and likely disconnects between tissue and systemic drug exposure. The goals of this article are to illustrate current best practices and outline practical strategies for selecting appropriate in vitro and in vivo experimental methods to estimate or predict tissue and plasma concentrations, and to use these data in the application of PBPK modeling for human pharmacokinetic (PK), efficacy, and safety assessment in drug development.
|
|
| 9. |
- Hesselson, Stephanie E, et al.
(författare)
-
Genetic variation in the proximal promoter of ABC and SLC superfamilies : liver and kidney specific expression and promoter activity predict variation
- 2009
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 4:9, s. e6942-
-
Tidskriftsartikel (refereegranskat)abstract
- Membrane transporters play crucial roles in the cellular uptake and efflux of an array of small molecules including nutrients, environmental toxins, and many clinically used drugs. We hypothesized that common genetic variation in the proximal promoter regions of transporter genes contribute to observed variation in drug response. A total of 579 polymorphisms were identified in the proximal promoters (-250 to +50 bp) and flanking 5' sequence of 107 transporters in the ATP Binding Cassette (ABC) and Solute Carrier (SLC) superfamilies in 272 DNA samples from ethnically diverse populations. Many transporter promoters contained multiple common polymorphisms. Using a sliding window analysis, we observed that, on average, nucleotide diversity (pi) was lowest at approximately 300 bp upstream of the transcription start site, suggesting that this region may harbor important functional elements. The proximal promoters of transporters that were highly expressed in the liver had greater nucleotide diversity than those that were highly expressed in the kidney consistent with greater negative selective pressure on the promoters of kidney transporters. Twenty-one promoters were evaluated for activity using reporter assays. Greater nucleotide diversity was observed in promoters with strong activity compared to promoters with weak activity, suggesting that weak promoters are under more negative selective pressure than promoters with high activity. Collectively, these results suggest that the proximal promoter region of membrane transporters is rich in variation and that variants in these regions may play a role in interindividual variation in drug disposition and response.
|
|
| 10. |
- Karlgren, M., et al.
(författare)
-
CHAPTER 7: OATPs: The SLCO Family of Organic Anion Transporting Polypeptide Transporters
- 2021
-
Ingår i: The Medicinal Chemist’s Guide to Solving ADMET Challenges. Patrick Schnider (red.). - : Royal Society of Chemistry. - 2041-3203. - 9781788012270 ; , s. 143-159
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The organic anion transporting polypeptides (OATP/SLCO) belong to the solute carrier (SLC) transporter superfamily and primarily mediate cellular uptake of anionic substrates in diverse tissues, including the liver, small intestines, kidneys and blood-brain barrier. This chapter summarizes current knowledge about the function of OATP transporters, their preclinical characterization, and the structural determinants of OATP-mediated drug transport and drug-drug interactions with a focus on the liver-specific transporters OATP1B1 and OATP1B3. © The Royal Society of Chemistry 2021.
|
|
| 11. |
- Kido, Yasuto, et al.
(författare)
-
Profiling of a prescription drug library for potential renal drug-drug interactions mediated by the organic cation transporter 2
- 2011
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 54:13, s. 4548-4558
-
Tidskriftsartikel (refereegranskat)abstract
- Drug-drug interactions (DDIs) are major causes of serious adverse drug reactions. Most DDIs have a pharmacokinetic basis in which one drug reduces the elimination of a second drug, leading to potentially toxic drug levels. As a major organ of drug elimination, the kidney represents an important site for DDIs. Here, we screened a prescription drug library against the renal organic cation transporter OCT2/SLC22A2, which mediates the first step in the renal secretion of many cationic drugs. Of the 910 compounds screened, 244 inhibited OCT2. Computational analyses revealed key properties of inhibitors versus noninhibitors, which included overall molecular charge. Four of six potential clinical inhibitors were transporter-selective in follow-up screens against additional transporters: OCT1/SLC22A1, MATE1/SLC47A1, and MATE2-K/SLC47A2. Two compounds showed different kinetics of interaction with the common polymorphism OCT2-A270S, suggesting a role of genetics in modulating renal DDIs.
|
|
| 12. |
- Koziolek, M., et al.
(författare)
-
Challenges in Permeability Assessment for Oral Drug Product Development
- 2023
-
Ingår i: Pharmaceutics. - : MDPI. - 1999-4923. ; 15:10
-
Tidskriftsartikel (refereegranskat)abstract
- Drug permeation across the intestinal epithelium is a prerequisite for successful oral drug delivery. The increased interest in oral administration of peptides, as well as poorly soluble and poorly permeable compounds such as drugs for targeted protein degradation, have made permeability a key parameter in oral drug product development. This review describes the various in vitro, in silico and in vivo methodologies that are applied to determine drug permeability in the human gastrointestinal tract and identifies how they are applied in the different stages of drug development. The various methods used to predict, estimate or measure permeability values, ranging from in silico and in vitro methods all the way to studies in animals and humans, are discussed with regard to their advantages, limitations and applications. A special focus is put on novel techniques such as computational approaches, gut-on-chip models and human tissue-based models, where significant progress has been made in the last few years. In addition, the impact of permeability estimations on PK predictions in PBPK modeling, the degree to which excipients can affect drug permeability in clinical studies and the requirements for colonic drug absorption are addressed.
|
|
| 13. |
- Larsson, Charlotta, et al.
(författare)
-
Cardiovascular complications following cesarean section and vaginal delivery : a national population-based study
- 2022
-
Ingår i: The Journal of Maternal-Fetal & Neonatal Medicine. - : Taylor & Francis. - 1476-7058 .- 1476-4954. ; 35:25, s. 8072-8079
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Rates of cesarean section are rising in both developed and developing countries and while pregnancy and cesarean section are established as risk factors for thromboembolism and stroke, large population-based investigations focusing on all types of cardiovascular complication after delivery is missing. The aim was to analyze the risk of severe cardiovascular complications in the post-partum period following delivery by cesarean section. We also had a control group of vaginal deliveries and a reference group with nulliparas.Materials and Methods: This Swedish population-based study used three national registers between 2005 and 2017 and comprised a total of 1 165 684 individuals. Unselected register data was cross-linked and cardiovascular adverse events were identified by ICD diagnosis codes. 140 128 women (209 391 deliveries) were included in the cesarean group and 614 355 women (973 429 deliveries) in the vaginal control group. The reference group comprised 411 201 age-matched nulliparous women. The primary analysis was the risk of severe cardiovascular complications within 42 days of cesarean section or vaginal delivery. The secondary analysis evaluated risk factors for cardiovascular complications.Results: In the cesarean section group, 410 (0.20%) had a serious cardiovascular event within 42 days after delivery, and in the vaginal control group the number was 857 (0.09%). The risk of having an adverse cardiovascular event was significantly greater in the cesarean group (OR 2.23, CI 1.98 to 2.51) for all types of cardiovascular events. Risk factors were high BMI, preeclampsia, greater maternal age, tobacco use and acute cesarean delivery.Conclusions: The absolute numbers on severe maternal morbidity after delivery are low. However, since almost half of the world’s population are affected and the frequency of elective cesarean section continues to rise, a doubling of the risk for a severe cardiovascular event within 42 days of delivery is important to consider globally.
|
|
| 14. |
- Mateus, André, et al.
(författare)
-
A High-Throughput Cell-Based Method to Predict the Unbound Drug Fraction in the Brain
- 2014
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 57:7, s. 3005-3010
-
Tidskriftsartikel (refereegranskat)abstract
- Optimization of drug efficacy in the brain requires understanding of the local exposure to unbound drug at the site of action. This relies on measurements of the unbound drug fraction (f(u,brain)), which currently requires access to brain tissue. Here, we present a novel methodology using homogenates of cultured cells for rapid estimation of f(u,brain). In our setup, drug binding to human embryonic kidney cell (HEK293) homogenate was measured in a small-scale dialysis apparatus. To increase throughput, we combined drugs into cassettes for simultaneous measurement of multiple compounds. Our method estimated f(u,brain) with an average error of 1.9-fold. We propose that our simple method can be used as an inexpensive, easily available and high-throughput alternative to brain tissues excised from laboratory animals. Thereby, estimates of unbound drug exposure can now implemented at a much earlier stage of the drug discovery process, when molecular property changes are easier to make.
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
- Mateus, André, et al.
(författare)
-
Intracellular drug bioavailability : a new predictor of system dependent drug disposition
- 2017
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7, s. 1-12
-
Tidskriftsartikel (refereegranskat)abstract
- Intracellular drug exposure is influenced by cell-and tissue-dependent expression of drug-transporting proteins and metabolizing enzymes. Here, we introduce the concept of intracellular bioavailability (F-ic) as the fraction of extracellular drug available to bind intracellular targets, and we assess how Fic is affected by cellular drug disposition processes. We first investigated the impact of two essential drug transporters separately, one influx transporter (OATP1B1; SLCO1B1) and one efflux transporter (P-gp; ABCB1), in cells overexpressing these proteins. We showed that OATP1B1 increased Fic of its substrates, while P-gp decreased Fic. We then investigated the impact of the concerted action of multiple transporters and metabolizing enzymes in freshly-isolated human hepatocytes in culture configurations with different levels of expression and activity of these proteins. We observed that Fic was up to 35-fold lower in the configuration with high expression of drug-eliminating transporters and enzymes. We conclude that Fic provides a measurement of the net impact of all cellular drug disposition processes on intracellular bioavailable drug levels. Importantly, no prior knowledge of the involved drug distribution pathways is required, allowing for high-throughput determination of drug access to intracellular targets in highly defined cell systems (e.g., single-transporter transfectants) or in complex ones (including primary human cells).
|
|
| 18. |
- Mateus, André, 1986-
(författare)
-
Intracellular unbound drug concentrations : Methodology and application for understanding cellular drug exposure
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Most known drug targets and metabolizing enzymes are located inside cells. Interactions with these proteins are determined by intracellular unbound drug concentrations. Assessing intracellular drug exposure is technically challenging, but essential for predicting pharmacokinetic, pharmacological, and toxicological profiles of new drugs.This thesis aims at establishing and applying a straightforward methodology to measure intracellular unbound drug concentrations. This was achieved by separately measuring cellular drug binding (fu,cell), and total intracellular drug accumulation (Kp). This allowed the calculation of intracellular drug bioavailability (Fic), which represents the fraction of the concentration added to the cells that is unbound in the cell interior.The methodology was initially developed in HEK293 cells, where the Fic of 189 drug-like compounds was measured. Binding to HEK293 cells was governed by compound lipophilicity and was correlated with binding to more complex systems, such as hepatocytes and brain. Due to negligible expression of drug transporters, Fic in this cell line was consistent with pH-dependent subcellular sequestration of lipophilic cations in low pH compartments.The methodology was then applied to study the effects of drug transporters on Fic. The uptake transporter OATP1B1 increased the Fic of its substrates in a concentration-dependent manner. In contrast, the Fic of P-gp substrates was decreased when P-gp was present. In human hepatocytes, the methodology allowed the determination of Fic without prior knowledge of transporter mechanisms or metabolic activity.Finally, the methodology was applied to measure the impact of Fic on target binding and cellular drug response. Intracellular concentrations of active metabolites of pro-drugs targeting the intracellular target thymidylate synthase were in agreement with the level of binding to this target. Further, high Fic was generally required for kinase and protease inhibitors to be active in cellular assays.In conclusion, the methodology can be used to predict if new drug candidates reach their intracellular targets in sufficient amounts. Furthermore, the methodology can improve in vitro predictions of drug clearance and drug-drug interactions, by measuring the drug available for intracellular enzymes. Finally, this work can be expanded to other xenobiotics, e.g., to predict their intracellular toxicity.
|
|
| 19. |
- Mateus, André, 1986-, et al.
(författare)
-
Prediction of intracellular exposure bridges the gap between target- and cell-based drug discovery
- 2017
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 114:30, s. E6231-E6239
-
Tidskriftsartikel (refereegranskat)abstract
- Inadequate target exposure is a major cause of high attrition in drug discovery. Here, we show that a label-free method for quantifying the intracellular bioavailability (F-ic) of drug molecules predicts drug access to intracellular targets and hence, pharmacological effect. We determined F-ic in multiple cellular assays and cell types representing different targets from a number of therapeutic areas, including cancer, inflammation, and dementia. Both cytosolic targets and targets localized in subcellular compartments were investigated. F-ic gives insights on membrane-permeable compounds in terms of cellular potency and intracellular target engagement, compared with biochemical potency measurements alone. Knowledge of the amount of drug that is locally available to bind intracellular targets provides a powerful tool for compound selection in early drug discovery.
|
|
| 20. |
- Mateus, André, et al.
(författare)
-
Rapid Measurement of Intracellular Unbound Drug Concentrations
- 2013
-
Ingår i: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 10:6, s. 2467-2478
-
Tidskriftsartikel (refereegranskat)abstract
- Intracellular unbound drug concentrations determine affinity to targets in the cell interior. However, due to difficulties in measuring them, they are often overlooked in pharmacology. Here we present a simple experimental technique for the determination of unbound intracellular drug concentrations in cultured cells that is based on parallel measurements of cellular drug binding and steady-state intracellular drug concentrations. Binding in HEK293 cells was highly correlated with binding in liver-derived systems, whereas binding in plasma did not compare well with cellular binding. Compound lipophilicity increased drug binding, while negative charge and aromatic functional groups decreased binding. Intracellular accumulation of unbound drug was consistent with pH dependent subcellular sequestration, as confirmed by modeling and by inhibition of subcellular pH gradients. The approach developed here can be used to measure intracellular unbound drug concentrations in more complex systems, for example, cell lines with controlled expression of transporters and enzymes or primary cells.
|
|
| 21. |
- Matsson, Pär, et al.
(författare)
-
A Global Drug Inhibition Pattern for the Human ATP-Binding Cassette Transporter Breast Cancer Resistance Protein (ABCG2)
- 2007
-
Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0022-3565 .- 1521-0103. ; 323:1, s. 19-30
-
Tidskriftsartikel (refereegranskat)abstract
- In this article, we explore the entire structural space of registered drugs to obtain a global model for the inhibition of the drug efflux transporter breast cancer resistance protein (BCRP; ABCG2). For this purpose, the inhibitory effect of 123 structurally diverse drugs and drug-like compounds on mitoxantrone efflux was studied in Saos-2 cells transfected with human wild-type (Arg482) BCRP. The search for BCRP inhibitors throughout the drug-like chemical space resulted in the identification of 29 previously unknown inhibitors. The frequency of BCRP inhibition was 3 times higher for compounds reported to interact with other ATP-binding cassette (ABC) transporters than for compounds without reported ABC transporter affinity. An easily interpreted computational model capable of discriminating inhibitors from noninhibitors using only two molecular descriptors, octanol-water partition coefficient at pH 7.4 and molecular polarizability, was constructed. The discriminating power of this two-descriptor model was 93% for the training set and 79% for the test set, respectively. The results were supported by a global pharmacophore model and are in agreement with a two-step mechanism for the inhibition of BCRP, where both the drug's capacity to insert into the cell membrane and to interact with the inhibitory binding site of the transporter are important.
|
|
| 22. |
- Matsson, Pär, et al.
(författare)
-
A Tribute to Professor Per Artursson - Scientist, Explorer, Mentor, Innovator, and Giant in Pharmaceutical Research
- 2021
-
Ingår i: Journal of Pharmaceutical Sciences. - : Elsevier. - 0022-3549 .- 1520-6017. ; 110:1, s. 2-11
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This issue of the Journal of Pharmaceutical Sciences is dedicated to Professor Per Artursson and the groundbreaking contributions he has made and continues to make in the Pharmaceutical Sciences. Per is one of the most cited researchers in his field, with more than 30,000 citations and an h-index of 95 as of September 2020. Importantly, these citations are distributed over the numerous fields he has explored, clearly showing the high impact the research has had on the discipline. We provide a short portrait of Per, with emphasis on his personality, driving forces and the inspirational sources that shaped his career as a world-leading scientist in the field. He is a curious scientist who deftly moves between disciplines and has continued to innovate, expand boundaries, and profoundly impact the pharmaceutical sciences throughout his career. He has developed new tools and provided insights that have significantly contributed to today’s molecular and mechanistic approaches to research in the fields of intestinal absorption, cellular disposition, and exposure-efficacy relationships of pharmaceutical drugs. We want to celebrate these important contributions in this special issue of the Journal of Pharmaceutical Sciences in Per’s honor.
|
|
| 23. |
|
|
| 24. |
- Matsson, Pär, 1978-
(författare)
-
ATP-Binding Cassette Efflux Transporters and Passive Membrane Permeability in Drug Absorption and Disposition
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Transport into and across the cells of the human body is a prerequisite for the pharmacological action of drugs. Passive membrane permeability and active transport mechanisms are major determinants of the intestinal absorption of drugs, as well as of the distribution to target tissues and the subsequent metabolism and excretion from the body. In this thesis, the role of ATP-binding cassette (ABC) transporters and passive permeability on drug absorption and disposition was investigated. Particular emphasis was placed on defining the molecular properties important for these transport mechanisms. The influence of different transport pathways on predictions of intestinal drug absorption was investigated using experimental models of different complexity. Experimental models that include the paracellular pathway gave improved predictions of intestinal drug absorption, especially for incompletely absorbed drugs. Further, the inhibition of the ABC transporters breast cancer resistance protein (BCRP/ABCG2) and multidrug-resistance associated protein 2 (MRP2/ABCC2) was experimentally investigated using structurally diverse datasets that were representative of orally administered drugs. A large number of previously unknown inhibitors were identified among registered drugs, but their clinical relevance for drug-drug interactions and drug-induced toxicity remains to be determined. The majority of the inhibitors affected all three major ABC transporters BCRP, MRP2 and P-glycoprotein (P gp/ABCB1), and these multi-specific inhibitors were found to be enriched in highly lipophilic weak bases. To summarize, the present work has led to an increased knowledge of the molecular features of importance for ABC transporter inhibition and passive membrane permeability. Previously unknown ABC transporter inhibitors were identified and predictive computational models were developed for the different drug transport mechanisms. These could be valuable tools to assist in the prioritization of experimental efforts in early drug discovery.
|
|
| 25. |
- Matsson, Pär, et al.
(författare)
-
Cell permeability beyond the rule of 5
- 2016
-
Ingår i: Advanced Drug Delivery Reviews. - : Elsevier BV. - 0169-409X .- 1872-8294. ; 101, s. 42-61
-
Forskningsöversikt (refereegranskat)abstract
- Drug discovery for difficult targets that have large and flat binding sites is often better suited to compounds beyond the "rule of 5" (bRo5). However, such compounds carry higher pharmacokinetic risks, such as low solubility and permeability, and increased efflux and metabolism. Interestingly, recent drug approvals and studies suggest that cell permeable and orally bioavailable drugs can be discovered far into bRo5 space. Tactics such as reduction or shielding of polarity by N-methylation, bulky side chains and intramolecular hydrogen bonds may be used to increase cell permeability in this space, but often results in decreased solubility. Conformationally flexible compounds can, however, combine high permeability and solubility, properties that are keys for cell permeability and intestinal absorption. Recent developments in computational conformational analysis will aid design of such compounds and hence prediction of cell permeability. Transporter mediated efflux occurs for most investigated drugs in bRo5 space, however it is commonly overcome by high local intestinal concentrations on oral administration. In contrast, there is little data to support significant impact of transporter-mediated intestinal absorption in bRo5 space. Current knowledge of compound properties that govern transporter effects of bRo5 drugs is limited and requires further fundamental and comprehensive studies.
|
|
| 26. |
- Matsson, Pär, 1978, et al.
(författare)
-
CHAPTER 6: OATs and OCTs: The SLC22 Family of Organic Anion and Cation Transporters
- 2021
-
Ingår i: The Medicinal Chemist’s Guide to Solving ADMET Challenges. Patrick Schnider (red.). - : Royal Society of Chemistry. - 2041-3203. - 9781788012270 ; , s. 128-142
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The SLC22 transporters belong to the solute carrier (SLC) transporter superfamily and have diverse functions and expression patterns that include the cellular uptake of organic cations, anions and zwitterions in the liver and kidneys. Important members from a pharmacokinetic perspective include the organic anion transporters 1-3 (OAT1-3) and the organic cation transporters 1 and 2 (OCT1 and OCT2). This chapter summarizes current knowledge about the function of OATs and OCTs, their preclinical characterization and the structural determinants of OAT- and OCT-mediated drug transport and drug-drug interactions. © The Royal Society of Chemistry 2021.
|
|
| 27. |
|
|
| 28. |
- Matsson, Pär, et al.
(författare)
-
Computational modeling to predict the functions and impact of drug transporters
- 2015
-
Ingår i: In silico pharmacology. - : Springer Science and Business Media LLC. - 2193-9616. ; 3:1
-
Tidskriftsartikel (refereegranskat)abstract
- Transport proteins are important mediators of cellular drug influx and efflux and play crucial roles in drug distribution, disposition and clearance. Drug-drug interactions have increasingly been found to occur at the transporter level and, hence, computational tools for studying drug-transporter interactions have gained in interest. In this short review, we present the most important transport proteins for drug influx and efflux. Computational tools for predicting and understanding the substrate and inhibitor interactions with these membrane-bound proteins are discussed. We have primarily focused on ligand-based and structure-based modeling, for which the state-of-the-art and future challenges are also discussed.
|
|
| 29. |
- Matsson, Pär, et al.
(författare)
-
Computational Prospecting for Drug-Transporter Interactions
- 2013
-
Ingår i: Clinical Pharmacology and Therapeutics. - : Springer Science and Business Media LLC. - 0009-9236 .- 1532-6535. ; 94:1, s. 30-32
-
Tidskriftsartikel (refereegranskat)abstract
- Membrane transporters are recognized as important determinants of drug disposition, action, and adverse events, yet our understanding of the molecular determinants of drug-transporter interactions is limited. Here, we discuss how computational analysis of transporter amino acid sequence, transporter structure, and ligand chemistry can be used to explore transporter function at the molecular level and to predict interactions with drug molecules.
|
|
| 30. |
- Matsson, Pär, et al.
(författare)
-
Discovery of regulatory elements in human ATP-binding cassette transporters through expression quantitative trait mapping
- 2012
-
Ingår i: The Pharmacogenomics Journal. - : Springer Science and Business Media LLC. - 1470-269X .- 1473-1150. ; 12, s. 214-226
-
Tidskriftsartikel (refereegranskat)abstract
- ATP-binding cassette (ABC) membrane transporters determine the disposition of many drugs, metabolites and endogenous compounds. Coding region variation in ABC transporters is the cause of many genetic disorders, but much less is known about the genetic basis and functional outcome of ABC transporter expression level variation. We used genotype and mRNA transcript level data from human lymphoblastoid cell lines to assess population and gender differences in ABC transporter expression, and to guide the discovery of genomic regions involved in transcriptional regulation. Nineteen of 49 ABC genes were differentially expressed between individuals of African, Asian and European descent, suggesting an important influence of race on expression level of ABC transporters. Twenty-four significant associations were found between transporter transcript levels and proximally located genetic variants. Several of the associations were experimentally validated in reporter assays. Through influencing ABC expression levels, these single-nucleotide polymorphisms may affect disease susceptibility and response to drugs.
|
|
| 31. |
|
|
| 32. |
|
|
| 33. |
- Matsson, Pär, et al.
(författare)
-
How Big Is Too Big for Cell Permeability?
- 2017
-
Ingår i: Journal of Medicinal Chemistry. - : AMER CHEMICAL SOC. - 0022-2623 .- 1520-4804. ; 60:5, s. 1662-1664
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding how to design cell permeable ligands for intracellular targets that have difficult binding sites, such as protein protein interactions, would open vast opportunities for drug discovery. Interestingly, libraries of cyclic peptides displayed a steep drop-off in membrane permeability at molecular weights above 1000 Da and it appears likely that this cutoff constitutes an upper size limit also for more druglike compounds. However, chemical space from 500 to 1000 Da remains virtually unexplored and represents a vast opportunity for those prepared to venture into new territories of drug discovery.
|
|
| 34. |
- Matsson, Pär, et al.
(författare)
-
Identification of novel specific and general inhibitors of the three major human ATP-binding cassette transporters P-gp, BCRP and MRP2 among registered drugs
- 2009
-
Ingår i: Pharmaceutical research. - : Springer Science and Business Media LLC. - 0724-8741 .- 1573-904X. ; 26:8, s. 1816-1831
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To study the inhibition patterns of the three major human ABC transporters P-gp (ABCB1), BCRP (ABCG2) and MRP2 (ABCC2), using a dataset of 122 structurally diverse drugs. METHODS: Inhibition was investigated in cellular and vesicular systems over-expressing single transporters. Computational models discriminating either single or general inhibitors from non-inhibitors were developed using multivariate statistics. RESULTS: Specific (n = 23) and overlapping (n = 19) inhibitors of the three ABC transporters were identified. GF120918 and Ko143 were verified to specifically inhibit P-gp/BCRP and BCRP in defined concentration intervals, whereas the MRP inhibitor MK571 was revealed to inhibit all three transporters within one log unit of concentration. Virtual docking experiments showed that MK571 binds to the ATP catalytic site, which could contribute to its multi-specific inhibition profile. A computational model predicting general ABC inhibition correctly classified 80% of both ABC transporter inhibitors and non-inhibitors in an external test set. CONCLUSIONS: The inhibitor specificities of P-gp, BCRP and MRP2 were shown to be highly overlapping. General ABC inhibitors were more lipophilic and aromatic than specific inhibitors and non-inhibitors. The identified specific inhibitors can be used to delineate transport processes in complex experimental systems, whereas the multi-specific inhibitors are useful in primary ABC transporter screening in drug discovery settings.
|
|
| 35. |
- Matsson, Pär, et al.
(författare)
-
Quantifying the impact of transporters on cellular drug permeability.
- 2015
-
Ingår i: TIPS - Trends in Pharmacological Sciences. - : Elsevier BV. - 0165-6147 .- 1873-3735. ; 35:5, s. 255-262
-
Tidskriftsartikel (refereegranskat)abstract
- The conventional model of drug permeability has recently been challenged. An alternative model proposes that transporter-mediated flux is the sole mechanism of cellular drug permeation, instead of existing in parallel with passive transmembrane diffusion. We examined a central assumption of this alternative hypothesis; namely, that transporters can give rise to experimental observations that would typically be explained with passive transmembrane diffusion. Using systems-biology simulations based on available transporter kinetics and proteomic expression data, we found that such observations are possible in the absence of transmembrane diffusion, but only under very specific conditions that rarely or never occur for known human drug transporters.
|
|
| 36. |
|
|
| 37. |
|
|
| 38. |
- Over, Bjorn, et al.
(författare)
-
Impact of Stereospecific Intramolecular Hydrogen Bonding on Cell Permeability and Physicochemical Properties
- 2014
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 57:6, s. 2746-2754
-
Tidskriftsartikel (refereegranskat)abstract
- Profiling of eight stereoisomeric T. cruzi growth inhibitors revealed vastly different in vitro properties such as solubility, lipophilicity, pK(a), and cell permeability for two sets of four stereoisomers. Using computational chemistry and NMR spectroscopy, we identified the formation of an intramolecular NH -> NR3 hydrogen bond in the set of stereoisomers displaying lower solubility, higher lipophilicity, and higher cell permeability. The intramolecular hydrogen bond resulted in a significant pKa difference that accounts for the other structure property relationships. Application of this knowledge could be of particular value to maintain the delicate balance of size, solubility, and lipophilicity required for cell penetration and oral administration for chemical probes or therapeutics with properties at, or beyond, Lipinski's rule of 5.
|
|
| 39. |
- Over, Bjorn, et al.
(författare)
-
Structural and conformational determinants of macrocycle cell permeability
- 2016
-
Ingår i: Nature Chemical Biology. - New York : Nature Publishing Group. - 1552-4450 .- 1552-4469. ; 12:12, s. 1065-1074
-
Tidskriftsartikel (refereegranskat)abstract
- Macrocycles are of increasing interest as chemical probes and drugs for intractable targets like protein-protein interactions, but the determinants of their cell permeability and oral absorption are poorly understood. To enable rational design of cell-permeable macrocycles, we generated an extensive data set under consistent experimental conditions for more than 200 nonpeptidic, de novo-designed macrocycles from the Broad Institute's diversity-oriented screening collection. This revealed how specific functional groups, substituents and molecular properties impact cell permeability. Analysis of energy-minimized structures for stereo- and regioisomeric sets provided fundamental insight into how dynamic, intramolecular interactions in the 3D conformations of macrocycles may be linked to physicochemical properties and permeability. Combined use of quantitative structure-permeability modeling and the procedure for conformational analysis now, for the first time, provides chemists with a rational approach to design cell-permeable non-peptidic macrocycles with potential for oral absorption.
|
|
| 40. |
- Pedersen, Jenny M., 1979-, et al.
(författare)
-
Early Identification of Clinically Relevant Drug Interactions with the Human Bile Salt Export Pump (BSEP; ABCB11)
- 2013
-
Ingår i: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 136:2, s. 328-343
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A comprehensive analysis was performed to investigate how inhibition of the human bile salt export pump (BSEP/ABCB11) relates to clinically observed drug induced liver injury (DILI). Inhibition of taurocholate (TA) transport was investigated in BSEP membrane vesicles for a dataset of 250 compounds, and 86 BSEP inhibitors were identified. Structure-activity modeling identified BSEP inhibition to correlate strongly with compound lipophilicity, while positive molecular charge was associated with a lack of inhibition. All approved drugs in the dataset (n=182) were categorized according to DILI warnings in drug labels issued by the FDA and a strong correlation between BSEP inhibition and DILI was identified. As many as 38 of the 61 identified BSEP inhibitors were associated with severe DILI, including nine drugs not previously linked to BSEP inhibition. Further, among the tested compounds, every second drug associated with severe DILI was a BSEP inhibitor. Finally, sandwich cultured human hepatocytes (SCHH) were used to investigate the relationship between BSEP inhibition, TA transport and clinically observed DILI in detail. BSEP inhibitors associated with severe DILI greatly reduced the TA canalicular efflux while BSEP inhibitors with less severe or no DILI resulted in weak or no reduction of TA efflux in SCHH. This distinction illustrates the usefulness of SCHH in refined analysis of BSEP inhibition. In conclusion, BSEP inhibition in membrane vesicles was found to correlate to DILI severity, and altered disposition of TA in SCHH was shown to separate BSEP inhibitors associated with severe DILI from those with no or mild DILI.
|
|
| 41. |
- Pedersen, Jenny, et al.
(författare)
-
Prediction and identification of drug interactions with the human ATP-binding cassette transporter multidrug-resistance associated protein 2 (MRP2; ABCC2)
- 2008
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 51:11, s. 3275-3287
-
Tidskriftsartikel (refereegranskat)abstract
- The chemical space of registered oral drugs was explored for inhibitors of the human multidrug-resistance associated protein 2 (MRP2, ABCC2), using a data set of 191 structurally diverse drugs and drug-like compounds. The data set included a new reference set of 75 compounds, for studies of hepatic drug interactions with transport proteins, CYP enzymes, and compounds associated with liver toxicity. The inhibition of MRP2-mediated transport of estradiol-17 beta-D-glucuronide was studied in inverted membrane vesicles from Sf9 cells overexpressing human MRP2. A total of 27 previously unknown MRP2 inhibitors were identified, and the results indicate an overlapping but narrower inhibitor space for MRP2 compared with the two other major ABC efflux transporters P-gp (ABCB1) and BCRP (ABCG2). In addition, 13 compounds were shown to stimulate the transport of cstradiol-17 beta-D-glucuronide. The experimental results were used to develop a computational model able to discriminate inhibitors from noninhibitors according to their molecular structure, resulting in a predictive power of 86% for the training set and 72% for the test set. The inhibitors were in general larger and more lipophilic and presented a higher aromaticity than the noninhibitors. The developed computational model is applicable in an early stage of the drug discovery process and is proposed as a tool for prediction of MRP2-mediated hepatic drug interactions and toxicity.
|
|
| 42. |
- Schlessinger, Avner, et al.
(författare)
-
Comparison of human solute carriers
- 2010
-
Ingår i: Protein Science. - : Wiley. - 0961-8368 .- 1469-896X. ; 19:3, s. 412-428
-
Tidskriftsartikel (refereegranskat)abstract
- Solute carriers are eukaryotic membrane proteins that control the uptake and efflux of solutes, including essential cellular compounds, environmental toxins, and therapeutic drugs. Solute carriers can share similar structural features despite weak sequence similarities. Identification of sequence relationships among solute carriers is needed to enhance our ability to model individual carriers and to elucidate the molecular mechanisms of their substrate specificity and transport. Here, we describe a comprehensive comparison of solute carriers. We link the proteins using sensitive profile-profile alignments and two classification approaches, including similarity networks. The clusters are analyzed in view of substrate type, transport mode, organism conservation, and tissue specificity. Solute carrier families with similar substrates generally cluster together, despite exhibiting relatively weak sequence similarities. In contrast, some families cluster together with no apparent reason, revealing unexplored relationships. We demonstrate computationally and experimentally the functional overlap between representative members of these families. Finally, we identify four putative solute carriers in the human genome. The solute carriers include a biomedically important group of membrane proteins that is diverse in sequence and structure. The proposed classification of solute carriers, combined with experiment, reveals new relationships among the individual families and identifies new solute carriers. The classification scheme will inform future attempts directed at modeling the structures of the solute carriers, a prerequisite for describing the substrate specificities of the individual families.
|
|
| 43. |
- Schlessinger, Avner, et al.
(författare)
-
Molecular Modeling of Drug-Transporter Interactions-An International Transporter Consortium Perspective
- 2018
-
Ingår i: Clinical Pharmacology and Therapeutics. - : John Wiley & Sons. - 0009-9236 .- 1532-6535. ; 104:5, s. 818-835
-
Forskningsöversikt (refereegranskat)abstract
- Membrane transporters play diverse roles in the pharmacokinetics and pharmacodynamics of small-molecule drugs. Understanding the mechanisms of drug-transporter interactions at the molecular level is, therefore, essential for the design of drugs with optimal therapeutic effects. This white paper examines recent progress, applications, and challenges of molecular modeling of membrane transporters, including modeling techniques that are centered on the structures of transporter ligands, and those focusing on the structures of the transporters. The goals of this article are to illustrate current best practices and future opportunities in using molecular modeling techniques to understand and predict transporter-mediated effects on drug disposition and efficacy. Membrane transporters from the solute carrier (SLC) and ATP-binding cassette (ABC) superfamilies regulate the cellular uptake, efflux, and homeostasis of many essential nutrients and significantly impact the pharmacokinetics of drugs(1-4); further, they may provide targets for novel therapeutics as well as facilitate prodrug approaches.(5,6) Because of their often broad substrate selectivity they are also implicated in many undesirable and sometimes life-threatening drug-drug interactions (DDIs).(5,6)
|
|
| 44. |
- Sebastiano, Matteo Rossi, et al.
(författare)
-
Impact of Dynamically Exposed Polarity on Permeability and Solubility of Chameleonic Drugs Beyond the Rule of 5
- 2018
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 61:9, s. 4189-4202
-
Tidskriftsartikel (refereegranskat)abstract
- Conformational flexibility has been proposed to significantly affect drug properties outside rule-of-5 (Ro5) chemical space. Here, we investigated the influence of dynamically exposed polarity on cell permeability and aqueous solubility for a structurally diverse set of drugs and clinical candidates far beyond the Ro5, all of which populated multiple distinct conformations as revealed by X-ray crystallography. Efflux-inhibited (passive) Caco-2 cell permeability correlated strongly with the compounds’ minimum solvent-accessible 3D polar surface areas (PSA), whereas aqueous solubility depended less on the specific 3D conformation. Inspection of the crystal structures highlighted flexibly linked aromatic side chains and dynamically forming intramolecular hydrogen bonds as particularly effective in providing “chameleonic” properties that allow compounds to display both high cell permeability and aqueous solubility. These structural features, in combination with permeability predictions based on the correlation to solvent-accessible 3D PSA, should inspire drug design in the challenging chemical space far beyond the Ro5.
|
|
| 45. |
- Simoff, Ivailo, et al.
(författare)
-
Complete Knockout of Endogenous Mdr1 (Abcb1) in MDCK Cells by CRISPR-Cas9
- 2016
-
Ingår i: Journal of Pharmaceutical Sciences. - 0022-3549 .- 1520-6017. ; 105:2, s. 1017-1021
-
Tidskriftsartikel (refereegranskat)abstract
- Madin-Darby canine kidney II cells transfected with one or several transport proteins are commonly used models to study drug transport. In these cells, however, endogenous transporters such as canine Mdr1/P-glycoprotein (Abcb1) complicate the interpretation of transport studies. The aim of this investigation was to establish a Madin-Darby canine kidney II cell line using CRISPR-Cas9 gene-editing technology to knock out endogenous canine Mdr1 (cMdr1) expression. CRISPR-Cas9-mediated Abcb1 homozygous disruption occurred at frequencies of around 20% and resulted in several genotypes. We selected 1 clonal cell line, cMdr1 KO Cl2, for further examination. Consistent with an on-target effect of CRISPR-Cas9 in specific regions of the endogenous canine Abcb1 gene, we obtained a cell clone with Abcb1 gene alterations and without any cMdr1 expression, as confirmed by genome sequencing and quantitative protein analysis. Functional studies of these cells, using digoxin and other prototypic MDR1 substrates, showed close to identical transport in the apical-to-basolateral and basolateral-to-apical directions, resulting in efflux ratios indistinguishable from unity.
|
|
| 46. |
- Treyer, Andrea, et al.
(författare)
-
A Cell-Free Approach Based on Phospholipid Characterization for Determination of the Cell Specific Unbound Drug Fraction (f(u,cell))
- 2019
-
Ingår i: Pharmaceutical research. - : Springer Science and Business Media LLC. - 0724-8741 .- 1573-904X. ; 36:12
-
Tidskriftsartikel (refereegranskat)abstract
- PurposeThe intracellular fraction of unbound compound (f(u,cell)) is an important parameter for accurate prediction of drug binding to intracellular targets. f(u,cell) is the result of a passive distribution process of drug molecules partitioning into cellular structures. Initial observations in our laboratory showed an up to 10-fold difference in the f(u,cell) of a given drug for different cell types. We hypothesized that these differences could be explained by the phospholipid (PL) composition of the cells, since the PL cell membrane is the major sink of unspecific drug binding. Therefore, we determined the f(u,cell) of 19 drugs in cell types of different origin.MethodThe cells were characterized for their total PL content and we used mass spectrometric PL profiling to delineate the impact of each of the four major cellular PL subspecies: phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI). The cell-based experiments were compared to cell-free experiments that used beads covered by PL bilayers consisting of the most abundant PL subspecies.ResultsPC was found to give the largest contribution to the drug binding. Improved correlations between the cell-based and cell-free assays were obtained when affinities to all four major PL subspecies were considered. Together, our data indicate that f(u,cell) is influenced by PL composition of cells.ConclusionWe conclude that cellular PL composition varies between cell types and that cell-specific mixtures of PLs can replace cellular assays for determination of f(u,cell) as a rapid, small-scale assay covering a broad dynamic range.
|
|
| 47. |
|
|
| 48. |
- Treyer, Andrea, et al.
(författare)
-
Intracellular Drug Bioavailability : Effect of Neutral Lipids and Phospholipids
- 2018
-
Ingår i: Molecular Pharmaceutics. - : AMER CHEMICAL SOC. - 1543-8384 .- 1543-8392. ; 15:6, s. 2224-2233
-
Tidskriftsartikel (refereegranskat)abstract
- Intracellular unbound drug concentrations are the pharmacologically relevant concentrations for targets inside cells. Intracellular drug concentrations are determined by multiple processes, including the extent of drug binding to intracellular structures. The aim of this study was to evaluate the effect of neutral lipid (NL) and phospholipid (PL) levels on intracellular drug disposition. The NL and/or PL content of 3T3-L1 cells were enhanced, resulting in phenotypes (in terms of morphology and proteome) reminiscent of adipocytes (high NL and PL) or mild phospholipidosis (only high PL). Intracellular bioavailability (F-ic) was then determined for 23 drugs in these cellular models and in untreated wild-type cells. A higher PL content led to higher intracellular drug binding and a lower F-ic. The induction of NL did not further increase drug binding but led to altered F-ic due to increased lysosomal pH. Further, there was a good correlation between binding to beads coated with pure PL and intracellular drug binding. In conclusion, our results suggest that PL content is a major determinant of drug binding in cells and that PL beads may constitute a simple alternative to estimating this parameter. Further, the presence of massive amounts of intracellular NLs did not influence drug binding significantly.
|
|
| 49. |
- Unga, Johan, 1976, et al.
(författare)
-
Understanding polymer-lipid solid dispersions-The properties of incorporated lipids govern the crystallisation behaviour of PEG
- 2010
-
Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 386:1-2, s. 61-70
-
Tidskriftsartikel (refereegranskat)abstract
- A deeper insight into the crystallisation process of semi-crystalline polymers during formation of solid dispersions is crucial to improve control of product qualities in drug formulation. In this study we used PEG 4000 with 12 different lipids as a model system to study the effect that incorporated components may have on the crystallisation of the polymer. The lipids were melted with PEG 4000 and the crystallisation of the polymer studied with differential scanning calorimetry (DSC) and small angle X-ray diffraction (SAXD). PEG 4000 can crystallise into lamellar structures with either folded or fully extended polymer chains. All lipids increased the fraction of the folded form and lowered the crystallisation temperatures. Some lipids were incorporated to a high extent into the amorphous domains of the PEG lamellae and thereby swelling the structure, which also resulted in a high degree of chain folding. Partial least squares (PLS) modelling indicated that small hydrophilic lipids increased the folding of PEG and that large non-polar lipids retarded the unfolding during secondary crystallisation. This work shows that there is a large difference in the behaviour of PEG depending on lipid added. Differences are explained in terms of molecular properties for the lipids, demonstrated by the use of PLS modelling to describe the behaviour of PEG solid dispersions. (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 50. |
- Wegler, Christine, et al.
(författare)
-
Influence of Proteome Profiles and Intracellular Drug Exposure on Differences in CYP Activity in Donor-Matched Human Liver Microsomes and Hepatocytes
- 2021
-
Ingår i: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 18:4, s. 1792-1805
-
Tidskriftsartikel (refereegranskat)abstract
- Human liver microsomes (HLM) and human hepatocytes (HH) are important in vitro systems for studies of intrinsic drug clearance (CLint) in the liver. However, the CLint values are often in disagreement for these two systems. Here, we investigated these differences in a side-by-side comparison of drug metabolism in HLM and HH prepared from 15 matched donors. Protein expression and intracellular unbound drug concentration (Kpuu) effects on the CLint were investigated for five prototypical probe substrates (bupropion–CYP2B6, diclofenac–CYP2C9, omeprazole–CYP2C19, bufuralol–CYP2D6, and midazolam–CYP3A4). The samples were donor-matched to compensate for inter-individual variability but still showed systematic differences in CLint. Global proteomics analysis outlined differences in HLM from HH and homogenates of human liver (HL), indicating variable enrichment of ER-localized cytochrome P450 (CYP) enzymes in the HLM preparation. This suggests that the HLM may not equally and accurately capture metabolic capacity for all CYPs. Scaling CLint with CYP amounts and Kpuu could only partly explain the discordance in absolute values of CLint for the five substrates. Nevertheless, scaling with CYP amounts improved the agreement in rank order for the majority of the substrates. Other factors, such as contribution of additional enzymes and variability in the proportions of active and inactive CYP enzymes in HLM and HH, may have to be considered to avoid the use of empirical scaling factors for prediction of drug metabolism.
|
|
