| 1. |
- Ahlin, Gustav, 1977-, et al.
(författare)
-
Endogenous Gene and Protein Expression of Drug Transporting Proteins in Cell Lines Routinely used in Drug Discovery Programs
- 2009
-
Ingår i: Drug Metabolism And Disposition. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0090-9556 .- 1521-009X. ; 37:12, s. 2275-2283
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the gene and protein expression profiles of important drug transporting proteins in human cell lines commonly used for studies of drug transport mechanisms. Human cell lines used to transiently or stably express single transporters (HeLa, HEK293) and leukaemia cell lines used to study drug resistance by ABC-transporters (HL-60, K562) were investigated, and compared with organotypic cell lines (HepG2, Saos-2, Caco-2 and Caco-2 TC7). For gene expression studies, real-time PCR was used, while monospecific polyclonal antibodies were generated and used to investigate protein expression by immunohistochemistry. Thirty-six transporters were studied for gene expression and nine for protein expression. The antibodies were validated using expression patterns in human tissues. Finally, the function of one ubiquitously expressed transporter, MCT1; SLC16A1 was investigated using 14C-lactic acid as a substrate. In general, the adherent cell lines (HeLa, HEK293) displayed low transporter expression and the expression patterns were barely affected by transfection. The leukaemia cell lines (K562, HL-60) and Saos-2 also had low endogenous transporter expression, while the organotypic cell lines (HepG2 and Caco-2) showed higher expression of some transporters. Comparison of gene and protein expression profiles gave poor correlations, but better agreement was obtained for antibodies with a good validation score, indicating that antibody quality was a significant variable. Importantly, the monocarboxylic acid transporting protein MCT1 was significantly expressed in all, and functional in most of the cell lines, indicating that MCT1 may be a confounding factor when the transport of small anionic drugs is investigated.
|
|
| 2. |
- Darwich, Adam S., et al.
(författare)
-
IMI - Oral biopharmaceutics tools project - Evaluation of bottom-up PBPK prediction success part 3 : Identifying gaps in system parameters by analysing In Silico performance across different compound classes
- 2017
-
Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 96, s. 626-642
-
Tidskriftsartikel (refereegranskat)abstract
- Three Physiologically Based Pharmacokinetic software packages (GI-Sim, Simcyp (R) Simulator, and GastroPlus (TM)) were evaluated as part of the Innovative Medicine Initiative Oral Biopharmaceutics Tools project (OrBiTo) during a blinded "bottom-up" anticipation of human pharmacokinetics. After data analysis of the predicted vs. measured pharmacokinetics parameters, it was found that oral bioavailability (F-oral) was underpredicted for compounds with low permeability, suggesting improper estimates of intestinal surface area, colonic absorption and/or lack of intestinal transporter information. Foralwas also underpredicted for acidic compounds, suggesting overestimation of impact of ionisation on permeation, lack of information on intestinal transporters, or underestimation of solubilisation of weak acids due to less than optimal intestinal model pH settings or underestimation of bile micelle contribution. F-oral was overpredicted for weak bases, suggesting inadequate models for precipitation or lack of in vitro precipitation information to build informed models. Relative bioavailability was underpredicted for both high logP compounds as well as poorly water-soluble compounds, suggesting inadequate models for solubility/dissolution, underperforming bile enhancement models and/or lack of biorelevant solubility measurements. These results indicate areas for improvement in model software, modelling approaches, and generation of applicable input data. However, caution is required when interpreting the impact of drug-specific properties in this exercise, as the availability of input parameters was heterogeneous and highly variable, and the modellers generally used the data "as is" in this blinded bottom-up prediction approach.
|
|
| 3. |
- Desbans, Coraline, et al.
(författare)
-
Accurate prediction of variability in CLint and Fm via 3A4 is only obtained by assessing a series of individual cryopreserved human hepatocyte batches
- 2010
-
Ingår i: Drug metabolism reviews (Softcover ed.). - New York : Informa Healthcare. - 0360-2532 .- 1097-9883. ; 42:Suppl. 1, s. 274-274
-
Tidskriftsartikel (refereegranskat)abstract
- Multiple in-vitro and in-vivo methods are currently assessed and under discussion to predict human clearance and pharmacokinetics from preclinical studies. A combination of high fm with a high fraction metabolism via a single pathway, e.g. via CYP3A4 (fmCYP3A4), has been recognized as a high risk factor for Drug Drug Interactions (DDI) in the clinical setting[1],[2],[3],[4] . Thus, an early predictive tool to allow for appropriate modeling of this potential risk for DDI is highly warranted. Hepatocytes, capable of both phase I and phase II reactions, are an attractive system to study fraction metabolized (fm) via a single pathway. In the present study, intrinsic clearance (CLint) was determined in cryopreserved human hepatocytes in suspension for a set of five compounds with known and variable fm via CYP3A4 (amitriptyline, loratadine, methylprednisolone, midazolam, and tacrolimus) in the absence or presence of ketoconazole. In order to get an insight into the influence of inter-individual variability, twelve batches of cryopreserved human hepatocytes with either high, moderate or low CYP3A4-dependent activity towards midazolam (MDZ) were chosen. Clint values were determined as substrate depletion under shaking conditions (900rpm) using an elliptic shaker as previously reported[5]. For all compounds, the mean CLint for individual donors in absence of ketoconazole correlated very well with literature data on the mean of individual donors1,2,3, and/or pools of donors5. Average fmCYP3A4 for midazolam was 83%, tacrolimus 64%, methylprednisolone 55%, amitriptyline 28%, and loratadine 19% are also well within the literature data2,3,4. Interestingly, the results obtained for a homogenous subpopulation regarding MDZ CLint and percent inhibition by ketoconazole, were not directly related to the ketoconazole sensitive CLint for the other CYP3A4 substrates tested. The variability in CYP3A4 contribution for compounds having multiple metabolic pathways cannot be predicted by the fm3A4 for MDZ. This suggests that an overall prediction of CLint or fm via CYP3A4 for compounds partially metabolized by this enzyme is not possible. Thus, the individual differences in CLint for a given compound and fmCYPi can only be well covered by assessing a series of individual cryopreserved human hepatocyte batches.[1] Lu, C., Miwa, G. T., Prakash, S. R., Gan, L-S. and Balani, S. K. (2007), Drug Metabolism And Disposition, 35: 1, 79–85[2] Lu, C., Hatsis,P., Berg,C., Lee, F. W. and Balani, S. K. (2008), Drug Metabolism And Disposition, 36: 7, 1255–1260[3] Lu, C., Hatsis,P., Berg,C., Lee, F. W. and Balani, S. K. (2008), Drug Metabolism And Disposition, 36: 7, 1261–1266[4] Emoto, C., Murase, S. and Iwasaki, K.(2006), Xenobiotica, 36: 8, 671 — 683[5] Simon ,S., Blanchard, N., Alexandre, E., Hewitt, N. J., Bachellier, P., Heyd, B., Coassolo, P., Schuler, F., Richert, L., (2009) ‘MV-HUF Copenhagen’
|
|
| 4. |
|
|
| 5. |
- Emeh, Prosper, et al.
(författare)
-
Experiences and Translatability of In Vitro and In Vivo Models to Evaluate Caprate as a Permeation Enhancer
- 2024
-
Ingår i: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 21:1, s. 313-324
-
Tidskriftsartikel (refereegranskat)abstract
- Transient permeation enhancers (PEs) have been widely used to improve the oral absorption of macromolecules. During pharmaceutical development, the correct selection of the macromolecule, PE, and the combination needs to be made to maximize oral bioavailability and ensure successful clinical development. Various in vitro and in vivo methods have been investigated to optimize this selection. In vitro methods are generally preferred by the pharmaceutical industry to reduce the use of animals according to the "replacement, reduction, and refinement" principle commonly termed "3Rs," and in vitro methods typically have a higher throughput. This paper compares two in vitro methods that are commonly used within the pharmaceutical industry, being Caco-2 and an Ussing chamber, to two in vivo models, being in situ intestinal instillation to rats and in vivo administration via an endoscope to pigs. All studies use solution formulation of sodium caprate, which has been widely used as a PE, and two macromolecules, being FITC-dextran 4000 Da and MEDI7219, a GLP-1 receptor agonist peptide. The paper shares our experiences of using these models and the challenges with the in vitro models in mimicking the processes occurring in vivo. The paper highlights the need to consider these differences when translating data generated using these in vitro models for evaluating macromolecules, PE, and combinations thereof for enabling oral delivery.
|
|
| 6. |
- Hayeshi, Rose, et al.
(författare)
-
Comparison of drug transporter gene expression and functionality in Caco-2 cells from 10 different laboratories
- 2008
-
Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 35:5, s. 383-396
-
Tidskriftsartikel (refereegranskat)abstract
- Caco-2 cells, widely used to study carrier mediated uptake and efflux mechanisms, are known to have different properties when cultured under different conditions. In this study, Caco-2 cells from 10 different laboratories were compared in terms of mRNA expression levels of 72 drug and nutrient transporters, and 17 other target genes, including drug metabolising enzymes, using real-time PCR. The rank order of the top five expressed genes was: HPT1>GLUT3>GLUT5>GST1A>OATP-B. Rank correlation showed that for most of the samples, the gene ranking was not significantly different. Functionality of transporters and the permeability of passive transport markers metoprolol (transcellular) and atenolol (paracellular) were also compared. MDR1 and PepT1 function was investigated using talinolol and Gly-Sar transport, respectively. Sulfobromophthalein (BSP) was used as a marker for MRP2 and OATP-B functionality. Atenolol permeability was more variable across laboratories than metoprolol permeability. Talinolol efflux was observed by all the laboratories, whereas only five laboratories observed significant apical uptake of Gly-Sar. Three laboratories observed significant efflux of BSP. MDR1 expression significantly correlated to the efflux ratio and net active efflux of talinolol. PepT1 mRNA levels showed significant correlation to the uptake ratio and net active uptake of Gly-Sar. MRP2 and OATP-B showed no correlation to BSP transport parameters. Heterogeneity in transporter activity may thus be due to differences in transporter expression as shown for PepT1 and MDR1 which in turn is determined by the culture conditions. Absolute expression of genes was variable indicating that small differences in culture conditions have a significant impact on gene expression, although the overall expression patterns were similar.
|
|
| 7. |
- Hilgendorf, Constanze, et al.
(författare)
-
Expression of thirty-six drug transporter genes in human intestine, liver, kidney, and organotypic cell lines
- 2007
-
Ingår i: Drug Metabolism And Disposition. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0090-9556 .- 1521-009X. ; 35:8, s. 1333-1340
-
Tidskriftsartikel (refereegranskat)abstract
- This study was designed to quantitatively assess the mRNA expression of 36 important drug transporters in human jejunum, colon, liver, and kidney. Expression of these transporters in human organs was compared with expression in commonly used cell lines (Caco-2, HepG2, and Caki-1) originating from these organs to assess their value as in vitro transporter system models, and was also compared with data obtained from the literature on expression in rat tissues to assess species differences. Transporters that were highly expressed in the intestine included HPT1, PEPT1, BCRP, MRP2, and MDR1, whereas, in the liver, OCT1, MRP2, OATP-C, NTCP and BSEP were the main transporters. In the kidney, OAT1 was expressed at the highest levels, followed by OAT3, OAT4, MCT5, MDR1, MRP2, OCT2, and OCTN2. The best agreement between human tissue and the representative cell line was observed for human jejunum and Caco-2 cells. Expression in liver and kidney ortholog cell lines was not correlated with that in the associated tissue. Comparisons with rat transporter gene expression revealed significant species differences. Our results allowed a comprehensive quantitative comparison of drug transporter expression in human intestine, liver, and kidney. We suggest that it would be beneficial for predictive pharmacokinetic research to focus on the most highly expressed transporters. We hope that our comparison of rat and human tissue will help to explain the observed species differences in in vivo models, increase understanding of the impact of active transport processes on pharmacokinetics and distribution, and improve the quality of predictions from animal studies to humans.
|
|
| 8. |
- Karlsson, Fredrik, 1984, et al.
(författare)
-
Utility of in vitro systems and preclinical data for the prediction of human intestinal first-pass metabolism during drug discovery and preclinical development
- 2013
-
Ingår i: Drug Metabolism and Disposition. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-009X .- 0090-9556. ; 41:12, s. 2033-2046
-
Tidskriftsartikel (refereegranskat)abstract
- A growing awareness of the risks associated with extensive intestinal metabolism has triggered an interest in developing robust methods for its quantitative assessment. This study explored the utility of intestinal S9 fractions, human liver microsomes, and recombinant cytochromes P450 to quantify CYP3A-mediated intestinal extraction in humans for a selection of marketed drugs that are predominantly metabolized by CYP3A4. A simple competing rates model is used to estimate the fraction of drug escaping gut wall metabolism (f g ) from in vitro intrinsic clearance in humans. The f g values extrapolated from the three in vitro systems used in this study, together with literature-derived f g from human intestinal microsomes, were validated against f g extracted from human in vivo pharmacokinetic (PK) profiles using a generic whole-body physiologically-based pharmacokinetic (PBPK) model. The utility of the rat as a model for human CYP3A-mediated intestinal meta bolism was also evaluated. Human f g from PBPK compares well with that from the grapefruit juice method, justifying its use for the evaluation of human in vitro systems. Predictive performance of all human in vitro systems was comparable [root mean square error (RMSE) = 0.22-0.27; n = 10]. Rat f g derived from in vivo PK profiles using PBPK has the lowest RMSE (0.19; n = 11) for the prediction of human f g for the selected compounds, most of which have a fraction absorbed close to 1. On the basis of these evaluations, the combined use of f g from human in vitro systems and rats is recommended for the estimation of CYP3A4-mediated intestinal metabolism in lead optimization and preclinical development phases.
|
|
| 9. |
- Margolskee, Alison, et al.
(författare)
-
IMI - Oral biopharmaceutics tools project - Evaluation of bottom-up PBPK prediction success part 2 : An introduction to the simulation exercise and overview of results
- 2017
-
Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 96, s. 610-625
-
Tidskriftsartikel (refereegranskat)abstract
- Orally administered drugs are subject to a number of barriers impacting bioavailability (F-oral), causing challenges during drug and formulation development. Physiologically-based pharmacokinetic (PBPK) modelling can help during drug and formulation development by providing quantitative predictions through a systems approach. The performance of three available PBPK software packages (GI-Sim, Simcyp (R), and GastroPlus (TM)) were evaluated by comparing simulated and observed pharmacokinetic (PK) parameters. Since the availability of input parameters was heterogeneous and highly variable, caution is required when interpreting the results of this exercise. Additionally, this prospective simulation exercise may not be representative of prospective modelling in industry, as API information was limited to sparse details. 43 active pharmaceutical ingredients (APIs) from the OrBiTo database were selected for the exercise. Over 4000 simulation output files were generated, representing over 2550 study arm-institution-software combinations and approximately 600 human clinical study arms simulated with overlap. 84% of the simulated study arms represented administration of immediate release formulations, 11% prolonged or delayed release, and 5% intravenous (i.v.). Higher percentages of i.v. predicted area under the curve (AUC) were within two-fold of observed (52.9%) compared to per oral (p.o.) (37.2%), however, F-oral and relative AUC (F-rel) between p.o. formulations and solutions were generally well predicted (64.7% and 75.0%). Predictive performance declined progressing from i.v. to solution and immediate release tablet, indicating the compounding error with each layer of complexity. Overall performance was comparable to previous large-scale evaluations. A general overprediction of AUC was observed with average fold error (AFE) of 1.56 over all simulations. AFE ranged from 0.0361 to 64.0 across the 43 APIs, with 25 showing overpredictions. Discrepancies between software packages were observed for a few APIs, the largest being 606, 171, and 81.7-fold differences in AFE between SimCYP and GI-Sim, however average performance was relatively consistent across the three software platforms.
|
|
| 10. |
- Nilsson, Anna, et al.
(författare)
-
Mass Spectrometry Imaging proves differential absorption profiles of well-characterised permeability markers along the crypt-villus axis
- 2017
-
Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge about the region-specific absorption profiles from the gastrointestinal tract of orally administered drugs is a critical factor guiding dosage form selection in drug development. We have used a novel approach to study three well-characterized permeability and absorption marker drugs in the intestine. Propranolol and metoprolol (highly permeable compounds) and atenolol (low-moderate permeability compound) were orally co-administered to rats. The site of drug absorption was revealed by high spatial resolution matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) and complemented by quantitative measurement of drug concentration in tissue homogenates. MALDI-MSI identified endogenous molecular markers that illustrated the villi structures and confirmed the different absorption sites assigned to histological landmarks for the three drugs. Propranolol and metoprolol showed a rapid absorption and shorter transit distance in contrast to atenolol, which was absorbed more slowly from more distal sites. This study provides novel insights into site specific absorption for each of the compounds along the crypt-villus axis, as well as confirming a proximal-distal absorption gradient along the intestine. The combined analytical approach allowed the quantification and spatial resolution of drug distribution in the intestine and provided experimental evidence for the suggested absorption behaviour of low and highly permeable compounds.
|
|
| 11. |
- 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.
|
|
| 12. |
- 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.
|
|
| 13. |
- Schophuizen, Carolien M. S., et al.
(författare)
-
Cationic uremic toxins affect human renal proximal tubule cell functioning through interaction with the organic cation transporter
- 2013
-
Ingår i: Pflügers Archiv. - : Springer Science and Business Media LLC. - 0031-6768. ; 465:12, s. 1701-1714
-
Tidskriftsartikel (refereegranskat)abstract
- Several organic cations, such as guanidino compounds and polyamines, have been found to accumulate in plasma of patients with kidney failure due to inadequate renal clearance. Here, we studied the interaction of cationic uremic toxins with renal organic cation transport in a conditionally immortalized human proximal tubule epithelial cell line (ciPTEC). Transporter activity was measured and validated in cell suspensions by studying uptake of the fluorescent substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium-iodide (ASP(+)). Subsequently, the inhibitory potencies of the cationic uremic toxins, cadaverine, putrescine, spermine and spermidine (polyamines), acrolein (polyamine breakdown product), guanidine, and methylguanidine (guanidino compounds) were determined. Concentration-dependent inhibition of ASP(+) uptake by TPA, cimetidine, quinidine, and metformin confirmed functional endogenous organic cation transporter 2 (OCT2) expression in ciPTEC. All uremic toxins tested inhibited ASP(+) uptake, of which acrolein required the lowest concentration to provoke a half-maximal inhibition (IC50 = 44 +/- 2 mu M). A Dixon plot was constructed for acrolein using three independent inhibition curves with 10, 20, or 30 mu M ASP(+), which demonstrated competitive or mixed type of interaction (K (i) = 93 +/- 16 mu M). Exposing the cells to a mixture of cationic uremic toxins resulted in a more potent and biphasic inhibitory response curve, indicating complex interactions between the toxins and ASP(+) uptake. In conclusion, ciPTEC proves a suitable model to study cationic xenobiotic interactions. Inhibition of cellular uptake transport was demonstrated for several uremic toxins, which might indicate a possible role in kidney disease progression during uremia.
|
|
| 14. |
- Sjögren, Erik, et al.
(författare)
-
Excised segments of rat small intestine in Ussing chamber studies : A comparison of native and stripped tissue viability and permeability to drugs
- 2016
-
Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 505:1-2, s. 361-368
-
Tidskriftsartikel (refereegranskat)abstract
- Excised rat intestinal tissue mounted in an Ussing chamber can be used for intestinal permeability assessments in drug development. The outer layer of the intestine, the serosa and part of the muscle layer, is traditionally removed since it is considered a barrier to the diffusion of nutrients and oxygen as well as to that of pharmaceutical substances. However, the procedure for removing the serosal-muscle layer, i.e. stripping, is a technically challenging process in the pre-experimental preparation of the tissue which may result in tissue damage and reduced viability of the segment. In this study, the viability of stripped and native (non-stripped) rat small intestine tissue segments mounted in Ussing chambers was monitored and the apparent permeability of the tissue to a set of test compounds across both tissue preparations was determined. Electrical measurements, in particular the potential difference (PD) across the intestinal membrane, were used to evaluate the viability. In this study, there were no differences in initial PD (health status of the tissue) or PD over time (viability throughout the experiment) between native and stripped rat jejunum segments. Overall, there were also no significant differences in permeability between stripped and native rat intestinal tissue for the compounds in this study. Based on these results, we propose that stripping can be excluded from the preparation procedures for rat jejunal tissue for permeability studies when using the Ussing chamber technique.
|
|
