Publications by authors named "Tommy B Andersson"

87 Publications

Short- and long-term effects of body weight loss following calorie restriction and gastric bypass on CYP3A-activity - a non-randomized three-armed controlled trial.

Clin Transl Sci 2021 Aug 26. Epub 2021 Aug 26.

Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway.

It remains uncertain whether pharmacokinetic changes following Roux-en-Y gastric bypass (RYGB) can be attributed to surgery-induced gastrointestinal alterations per se and/or the subsequent weight loss. The aim was to compare short- and long-term effects of RYGB and calorie restriction on CYP3A-activity, and cross-sectionally compare CYP3A-activity with normal weight to overweight controls using midazolam as probe drug. This three-armed controlled trial included patients with severe obesity preparing for RYGB (n = 41) or diet-induced (n = 41) weight-loss, and controls (n = 18). Both weight-loss groups underwent a 3-week low-energy-diet (<1200 kcal/day) followed by a 6-week very-low-energy-diet or RYGB (both <800 kcal/day). Patients were followed for 2 years, with four pharmacokinetic investigations using semisimultaneous oral and intravenous dosing to determine changes in midazolam absolute bioavailability and clearance, within and between groups. The RYGB and diet groups showed similar weight-loss at week 9 (13 ± 2.4% vs. 11 ± 3.6%), but differed substantially after 2 years (-30 ± 7.0% vs. -3.1 ± 6.3%). At baseline, mean absolute bioavailability and clearance of midazolam were similar in the RYGB and diet groups, but higher compared with controls. On average, absolute bioavailability was unaltered at week 9, but decreased by 40 ± 7.5% in the RYGB group and 32 ± 6.1% in the diet group at year 2 compared with baseline, with no between-group difference. No difference in clearance was observed over time, nor between groups. In conclusion, neither RYGB per se nor weight loss impacted absolute bioavailability or clearance of midazolam short term. Long term, absolute bioavailability was similarly decreased in both groups despite different weight loss, suggesting that the recovered CYP3A-activity is not only dependent on weight-loss through RYGB.
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http://dx.doi.org/10.1111/cts.13142DOI Listing
August 2021

In Vitro Assessment of the Drug-Drug Interaction Potential of Verinurad and Its Metabolites as Substrates and Inhibitors of Metabolizing Enzymes and Drug Transporters.

J Pharmacol Exp Ther 2021 Aug 1;378(2):108-123. Epub 2021 Jun 1.

Early Research and Development Cardiovascular Renal and Metabolism, AstraZeneca Biopharmaceuticals R&D Gothenburg, Mölndal, Sweden (V.S.G, A.V., T.B.A, C.H.); CVRM Late Clinical, AstraZeneca Biopharmaceuticals R&D Gothenburg, Mölndal, Sweden (F.E.); Ardea Biosciences, San Diego, CA, USA (C.A.L.); Clinical Pharmacology & Safety Sciences & AstraZeneca Biopharmaceuticals R&D Gothenburg, Mölndal, Sweden (S.J.).

Verinurad is a selective uric acid transporter 1 (URAT1) inhibitor in development for the treatment of chronic kidney disease and heart failure. In humans, two major acyl glucuronide metabolites have been identified: direct glucuronide M1 and -oxide glucuronide M8. Using in vitro systems recommended by regulatory agencies, we evaluated the interactions of verinurad, M1, and M8 with major drug-metabolizing enzymes and transporters and the potential for clinically relevant drug-drug interactions (DDIs). The IC for inhibition of CYP2C8, CYP2C9, and CYP3A4/5 for verinurad was ≥14.5 µM, and maximum free plasma concentration (I)/IC was <0.02 at the anticipated therapeutic C and therefore not considered a DDI risk. Verinurad was not an inducer of CYP1A2, CYP2B6, or CYP3A4/5. Verinurad was identified as a substrate of the hepatic uptake transporter organic anion-transporting polypeptide (OATP) 1B3. Since verinurad hepatic uptake involved both active and passive transport, there is a low risk of clinically relevant DDIs with OATP, and further study is warranted. Verinurad was a substrate of the efflux transporters P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), and renal transporter organic anion transporter 1 (OAT1), although it is not considered a DDI risk in vivo because of dose-proportional pharmacokinetics (P-gp and BCRP) and limited renal excretion of verinurad (OAT1). M1 and M8 were substrates of multidrug resistance-associated protein (MRP) 2 and MRP4 and inhibitors of MRP2. Apart from verinurad being a substrate of OATP1B3 in vitro, the potential for clinically relevant DDIs involving verinurad and its metabolites as victims or perpetrators of metabolizing enzymes or drug transporters is considered low. SIGNIFICANCE STATEMENT: Drug transporters and metabolizing enzymes have an important role in the absorption and disposition of a drug and its metabolites. Using in vitro systems recommended by regulatory agencies, we determined that, apart from verinurad being a substrate of organic anion-transporting polypeptide 1B3, the potential for clinically relevant drug-drug interactions involving verinurad and its metabolites M1 and M8 as victims or perpetrators of metabolizing enzymes or drug transporters is considered low.
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http://dx.doi.org/10.1124/jpet.121.000549DOI Listing
August 2021

Evaluation of 1β-Hydroxylation of Deoxycholic Acid as a Non-Invasive Urinary Biomarker of CYP3A Activity in the Assessment of Inhibition-Based Drug-Drug Interaction in Healthy Volunteers.

J Pers Med 2021 May 24;11(6). Epub 2021 May 24.

Department of Pharmaceutical Medicine, African Institute of Biomedical Science and Technology (AiBST), Block C, Wilkins Hospital Complex, Harare, Zimbabwe.

In this study, we aimed to evaluate the utility of endogenous 1β-hydroxy-deoxycholic acid/total deoxycholic acid ratio (1β-OH-DCA/ToDCA) in spot urine as a surrogate marker of cytochrome P450 3A (CYP3A) activity in the assessment inhibition-based drug-drug interactions in healthy volunteers. This was accomplished through an open-label, three-treatment parallel-arm study in healthy male volunteers from Zimbabwe. Each group received itraconazole (ITZ; 100 mg once daily; = 10), fluconazole (FKZ; 50 mg once daily; = 9), or alprazolam (APZ; 1 mg once daily; = 8) orally. Midazolam (MDZ), dosed orally and intravenously, was used as a comparator to validate the exploratory measures of CYP3A activity and the effects of known inhibitors. Urinary metabolic ratios of 1β-OH-DCA/ToDCA before and after CYP3A inhibitor treatment showed a similar magnitude of inhibitory effects of the three treatments as that measured by oral MDZ clearance. The maximum inhibition effect of a 75% reduction in the 1β-OH-DCA/ToDCA ratio compared to the baseline was achieved in the ITZ group following six once-daily doses of 100 mg. The correlations of the two markers for CYP3A inhibitor treatment were significant (r = 0.53, < 0.01). The half-life of urinary endogenous 1β-OH-DCA/ToDCA was estimated as four days. These results suggested that 1β-OH-DCA/ToDCA in spot urine is a promising convenient, non-invasive, sensitive, and relatively quickly responsive endogenous biomarker that can be used for CYP3A inhibition-based drug-drug interaction in clinical studies.
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http://dx.doi.org/10.3390/jpm11060457DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8224742PMC
May 2021

Influence of Proteome Profiles and Intracellular Drug Exposure on Differences in CYP Activity in Donor-Matched Human Liver Microsomes and Hepatocytes.

Mol Pharm 2021 04 19;18(4):1792-1805. Epub 2021 Mar 19.

Department of Pharmacy and Science for Life Laboratory, Uppsala University, 752 37 Uppsala, Sweden.

Human liver microsomes (HLM) and human hepatocytes (HH) are important systems for studies of intrinsic drug clearance (CL) in the liver. However, the CL 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 (Kp) effects on the CL 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 CL. 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 CL with CYP amounts and Kp could only partly explain the discordance in absolute values of CL 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.
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http://dx.doi.org/10.1021/acs.molpharmaceut.1c00053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8041379PMC
April 2021

Primary Human Hepatocyte Spheroid Model as a 3D In Vitro Platform for Metabolism Studies.

J Pharm Sci 2021 01 26;110(1):422-431. Epub 2020 Oct 26.

DMPK, Research and Early Development Cardiovascular Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca Gothenburg, Sweden.

3D cultures of primary human hepatocytes (PHH) are emerging as a more in vivo-like culture system than previously available hepatic models. This work describes the characterisation of drug metabolism in 3D PHH spheroids. Spheroids were formed from three different donors of PHH and the expression and activities of important cytochrome P450 enzymes (CYP1A2, 2B6, 2C9, 2D6, and 3A4) were maintained for up to 21 days after seeding. The activity of CYP2B6 and 3A4 decreased, while the activity of CYP2C9 and 2D6 increased over time (P < 0.05). For six test compounds, that are metabolised by multiple enzymes, intrinsic clearance (CL) values were comparable to standard in vitro hepatic models and successfully predicted in vivo CL within 3-fold from observed values for low clearance compounds. Remarkably, the metabolic turnover of these low clearance compounds was reproducibly measured using only 1-3 spheroids, each composed of 2000 cells. Importantly, metabolites identified in the spheroid cultures reproduced the major metabolites observed in vivo, both primary and secondary metabolites were captured. In summary, the 3D PHH spheroid model shows promise to be used in drug discovery projects to study drug metabolism, including unknown mechanisms, over an extended period of time.
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http://dx.doi.org/10.1016/j.xphs.2020.10.043DOI Listing
January 2021

A Tribute to Professor Per Artursson - Scientist, Explorer, Mentor, Innovator, and Giant in Pharmaceutical Research.

J Pharm Sci 2021 01 21;110(1):2-11. Epub 2020 Oct 21.

Department of Pharmacy, Uppsala University, Uppsala, Sweden. Electronic address:

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.
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http://dx.doi.org/10.1016/j.xphs.2020.10.031DOI Listing
January 2021

Correlation of Body Weight and Composition With Hepatic Activities of Cytochrome P450 Enzymes.

J Pharm Sci 2021 01 19;110(1):432-437. Epub 2020 Oct 19.

Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway. Electronic address:

Obesity is associated with comorbidities of which pharmacological treatment is needed. Physiological changes associated with obesity may influence the pharmacokinetics of drugs, but the effect of body weight on drug metabolism capacity remains uncertain. The aim of this study was to investigate ex vivo activities of hepatic drug metabolizing CYP enzymes in patients covering a wide range of body weight. Liver biopsies from 36 individuals with a body mass index (BMI) ranging from 18 to 63 kg/m were obtained. Individual hepatic microsomes were prepared and activities of CYP3A, CYP2B6, CYP2C8, CYP2D6, CYP2C9, CYP2C19 and CYP1A2 were determined. The unbound intrinsic clearance (CL) values for CYP3A correlated negatively with body weight (r = -0.43, p < 0.01), waist circumference (r = -0.47, p < 0.01), hip circumference (r = -0.51, p < 0.01), fat percent (r = -0.41, p < 0.05), fat mass (r = -0.48, p < 0.01) and BMI (r = -0.46, p < 0.01). Linear regression analysis showed that CL values for CYP3A decreased with 5% with each 10% increase in body weight (r = 0.12, β = -0.558, p < 0.05). There were no correlations between body weight measures and CL values for the other CYP enzymes investigated. These results indicate reduced hepatic metabolizing capacity of CYP3A substrates in patients with increasing body weight.
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http://dx.doi.org/10.1016/j.xphs.2020.10.027DOI Listing
January 2021

Proteomics-Informed Prediction of Rosuvastatin Plasma Profiles in Patients With a Wide Range of Body Weight.

Clin Pharmacol Ther 2021 03 18;109(3):762-771. Epub 2020 Oct 18.

Department of Pharmacy and Science for Life Laboratory, Uppsala University, Uppsala, Sweden.

Rosuvastatin is a frequently used probe to study transporter-mediated hepatic uptake. Pharmacokinetic models have therefore been developed to predict transporter impact on rosuvastatin disposition in vivo. However, the interindividual differences in transporter concentrations were not considered in these models, and the predicted transporter impact was compared with historical in vivo data. In this study, we investigated the influence of interindividual transporter concentrations on the hepatic uptake clearance of rosuvastatin in 54 patients covering a wide range of body weight. The 54 patients were given an oral dose of rosuvastatin the day before undergoing gastric bypass or cholecystectomy, and pharmacokinetic (PK) parameters were established from each patient's individual time-concentration profiles. Liver biopsies were sampled from each patient and their individual hepatic transporter concentrations were quantified. We combined the transporter concentrations with in vitro uptake kinetics determined in HEK293-transfected cells, and developed a semimechanistic model with a bottom-up approach to predict the plasma concentration profiles of the single dose of rosuvastatin in each patient. The predicted PK parameters were evaluated against the measured in vivo plasma PKs from the same 54 patients. The developed model predicted the rosuvastatin PKs within two-fold error for rosuvastatin area under the plasma concentration versus time curve (AUC; 78% of the patients; average fold error (AFE): 0.96), peak plasma concentration (C ; 76%; AFE: 1.05), and terminal half-life (t ; 98%; AFE: 0.89), and captured differences in the rosuvastatin PKs in patients with the OATP1B1 521T
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http://dx.doi.org/10.1002/cpt.2056DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7984432PMC
March 2021

Clinically Relevant Cytochrome P450 3A4 Induction Mechanisms and Drug Screening in Three-Dimensional Spheroid Cultures of Primary Human Hepatocytes.

Clin Pharmacol Ther 2020 10 22;108(4):844-855. Epub 2020 May 22.

Department of Physiology and Pharmacology, Section of Pharmacogenetics, Karolinska Institutet, Stockholm, Sweden.

Cytochrome P450 (CYP) 3A4 induction is an important cause of drug-drug interactions, making early identification of drug candidates with CYP3A4 induction liability in drug development a prerequisite. Here, we present three-dimensional (3D) spheroid cultures of primary human hepatocytes (PHHs) as a novel CYP3A4 induction screening model. Screening of 25 drugs (12 known CYP3A4 inducers in vivo and 13 negative controls) at physiologically relevant concentrations revealed a 100% sensitivity and 100% specificity of the system. Three of the in vivo CYP3A4 inducers displayed much higher CYP3A4 induction capacity in 3D spheroid cultures as compared with in two-dimensional (2D) monolayer cultures. Among those, we identified AZD1208, a proviral integration site for Moloney murine leukemia virus (PIM) kinase inhibitor terminated in phase I of development due to unexpected CYP3A4 autoinduction, as a CYP3A4 inducer only active in 3D spheroids but not in 2D monolayer cultures. Gene knockdown experiments revealed that AZD1208 requires pregnane X receptor (PXR) to induce CYP3A4. Rifampicin requires solely PXR to induce CYP3A4 and CYP2B6, while phenobarbital-mediated induction of these CYPs did not show absolute dependency on either PXR or constitutive androstane receptor (CAR), suggesting its ability to switch nuclear receptor activation. Mechanistic studies into AZD1208 uncovered an involvement of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway in CYP3A4 induction that is sensitive to the culture format used, as revealed by its inhibition of ERK1/2 Tyrosine 204 phosphorylation and sensitivity to epidermal growth factor (EGF) pressure. In line, we also identified lapatinib, a dual epidermal growth factor receptor/human epidermal growth factor receptor 2 (EGFR/HER2) inhibitor, as another CYP3A4 inducer only active in 3D spheroid culture. Our findings offer insights into the pathways involved in CYP3A4 induction and suggest PHH spheroids for preclinical CYP3A4 induction screening.
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http://dx.doi.org/10.1002/cpt.1860DOI Listing
October 2020

Human Pluripotent Stem Cell-Derived Hepatocytes Show Higher Transcriptional Correlation with Adult Liver Tissue than with Fetal Liver Tissue.

ACS Omega 2020 Mar 2;5(10):4816-4827. Epub 2020 Mar 2.

School of Bioscience, Systems Biology Research Center, University of Skövde, 541 28 Skövde, Sweden.

Human pluripotent stem cell-derived hepatocytes (hPSC-HEP) display many properties of mature hepatocytes, including expression of important genes of the drug metabolizing machinery, glycogen storage, and production of multiple serum proteins. To this date, hPSC-HEP do not, however, fully recapitulate the complete functionality of in vivo mature hepatocytes. In this study, we applied versatile bioinformatic algorithms, including functional annotation and pathway enrichment analyses, transcription factor binding-site enrichment, and similarity and correlation analyses, to datasets collected from different stages during hPSC-HEP differentiation and compared these to developmental stages and tissues from fetal and adult human liver. Our results demonstrate a high level of similarity between the in vitro differentiation of hPSC-HEP and in vivo hepatogenesis. Importantly, the transcriptional correlation of hPSC-HEP with adult liver (AL) tissues was higher than with fetal liver (FL) tissues (0.83 and 0.70, respectively). Functional data revealed mature features of hPSC-HEP including cytochrome P450 enzymes activities and albumin secretion. Moreover, hPSC-HEP showed expression of many genes involved in drug absorption, distribution, metabolism, and excretion. Despite the high similarities observed, we identified differences of specific pathways and regulatory players by analyzing the gene expression between hPSC-HEP and AL. These findings will aid future intervention and improvement of in vitro hepatocyte differentiation protocol in order to generate hepatocytes displaying the complete functionality of mature hepatocytes. Finally, on the transcriptional level, our results show stronger correlation and higher similarity of hPSC-HEP to AL than to FL. In addition, potential targets for further functional improvement of hPSC-HEP were also identified.
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http://dx.doi.org/10.1021/acsomega.9b03514DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7081255PMC
March 2020

Biology-inspired microphysiological systems to advance patient benefit and animal welfare in drug development

ALTEX 2020 28;37(3):365-394. Epub 2020 Feb 28.

National Center for Toxicological Research, FDA, Silver Spring, MD, USA.

The first microfluidic microphysiological systems (MPS) entered the academic scene more than 15 years ago and were considered an enabling technology to human (patho)biology in vitro and, therefore, provide alternative approaches to laboratory animals in pharmaceutical drug development and academic research. Nowadays, the field generates more than a thousand scientific publications per year. Despite the MPS hype in academia and by platform providers, which says this technology is about to reshape the entire in vitro culture landscape in basic and applied research, MPS approaches have neither been widely adopted by the pharmaceutical industry yet nor reached regulated drug authorization processes at all. Here, 46 leading experts from all stakeholders - academia, MPS supplier industry, pharmaceutical and consumer products industries, and leading regulatory agencies - worldwide have analyzed existing challenges and hurdles along the MPS-based assay life cycle in a second workshop of this kind in June 2019. They identified that the level of qualification of MPS-based assays for a given context of use and a communication gap between stakeholders are the major challenges for industrial adoption by end-users. Finally, a regulatory acceptance dilemma exists against that background. This t4 report elaborates on these findings in detail and summarizes solutions how to overcome the roadblocks. It provides recommendations and a roadmap towards regulatory accepted MPS-based models and assays for patients' benefit and further laboratory animal reduction in drug development. Finally, experts highlighted the potential of MPS-based human disease models to feedback into laboratory animal replacement in basic life science research.
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http://dx.doi.org/10.14573/altex.2001241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7863570PMC
July 2021

A Comparative Analysis of Cytochrome P450 Activities in Paired Liver and Small Intestinal Samples from Patients with Obesity.

Drug Metab Dispos 2020 01 4;48(1):8-17. Epub 2019 Nov 4.

Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway (V.K., I.R., A.Å., H.C.); Department of Transplantation Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway (V.K., A.Å.); Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca Gothenburg, Gothenburg, Sweden (A.P., C.W., S.A., T.B.A.); Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway (M.K.K.); Department of Health Sciences, OsloMet-Oslo Metropolitan University, Oslo, Norway (M.K.K.); Department of Pharmacy, Uppsala University, Uppsala, Sweden (C.W., P.A.); The Morbid Obesity Centre, Vestfold Hospital Trust, Tønsberg, Norway (P.C.A., J.H.); Department of Surgery, Vestfold Hospital Trust, Tønsberg, Norway (P.C.A.); Department of Endocrinology, Morbid Obesity and Preventive Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway (J.H.); Late-Stage Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca Gothenburg, Gothenburg, Sweden (C.K.); Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden (C.K.); and Department of Physiology and Pharmacology, Section of Pharmacogenetics, Karolinska Institutet, Stockholm, Sweden (T.B.A.).

The liver and small intestine restrict oral bioavailability of drugs and constitute the main sites of pharmacokinetic drug-drug interactions. Hence, detailed data on hepatic and intestinal activities of drug metabolizing enzymes is important for modeling drug disposition and optimizing pharmacotherapy in different patient populations. The aim of this study was to determine the activities of seven cytochrome P450 (P450) enzymes in paired liver and small intestinal samples from patients with obesity. Biopsies were obtained from 20 patients who underwent Roux-en-Y gastric bypass surgery following a 3-week low-energy diet. Individual hepatic and intestinal microsomes were prepared and specific probe substrates in combined incubations were used for determination of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A activities. The activities of CYP2C8, CYP2C9, CYP2D6, and CYP3A were quantified in both human liver microsomes (HLM) and human intestinal microsomes (HIM), while the activities of CYP1A2, CYP2B6, and CYP2C19 were only quantifiable in HLM. Considerable interindividual variability was present in both HLM (9- to 23-fold) and HIM (5- to 55-fold). The median metabolic HLM/HIM ratios varied from 1.5 for CYP3A to 252 for CYP2C8. The activities of CYP2C9 in paired HLM and HIM were positively correlated ( = 0.74, < 0.001), while no interorgan correlations were found for activities of CYP2C8, CYP2D6, and CYP3A ( > 0.05). Small intestinal CYP3A activities were higher in females compared with males ( < 0.05). Hepatic CYP2B6 activity correlated negatively with body mass index ( = -0.72, < 0.001). These data may be useful for further in vitro-in vivo predictions of drug disposition in patients with obesity. SIGNIFICANCE STATEMENT: Hepatic and intestinal drug metabolism is the key determinant of oral drug bioavailability. In this study, paired liver and jejunum samples were obtained from 20 patients with obesity undergoing gastric bypass surgery following a 3-week low-energy diet. We determined the hepatic and small intestinal activities of clinically important P450 enzymes and provide detailed enzyme kinetic data relevant for predicting in vivo disposition of P450 substrates in this patient population.
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http://dx.doi.org/10.1124/dmd.119.087940DOI Listing
January 2020

Global variability analysis of mRNA and protein concentrations across and within human tissues.

NAR Genom Bioinform 2020 Mar 30;2(1):lqz010. Epub 2019 Oct 30.

Department of Pharmacy and Science for Life Laboratory, Uppsala University, Uppsala SE-75123, Sweden.

Genes and proteins show variable expression patterns throughout the human body. However, it is not clear whether relative differences in mRNA concentrations are retained on the protein level. Furthermore, inter-individual protein concentration variability within single tissue types has not been comprehensively explored. Here, we used the Gini index for in-depth concentration variability analysis of publicly available transcriptomics and proteomics data, and of an in-house proteomics dataset of human liver and jejunum from 38 donors. We found that the transfer of concentration variability from mRNA to protein is limited, that established 'reference genes' for data normalization vary markedly at the protein level, that protein concentrations cover a wide variability spectrum within single tissue types, and that concentration variability analysis can be a convenient starting point for identifying disease-associated proteins and novel biomarkers. Our results emphasize the importance of considering individual concentration levels, as opposed to population averages, for personalized systems biology analysis.
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http://dx.doi.org/10.1093/nargab/lqz010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7671341PMC
March 2020

The TM6SF2 E167K genetic variant induces lipid biosynthesis and reduces apolipoprotein B secretion in human hepatic 3D spheroids.

Sci Rep 2019 08 12;9(1):11585. Epub 2019 Aug 12.

Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden.

There is a high unmet need for developing treatments for nonalcoholic fatty liver disease (NAFLD), for which there are no approved drugs today. Here, we used a human in vitro disease model to understand mechanisms linked to genetic risk variants associated with NAFLD. The model is based on 3D spheroids from primary human hepatocytes from five different donors. Across these donors, we observed highly reproducible differences in the extent of steatosis induction, demonstrating that inter-donor variability is reflected in the in vitro model. Importantly, our data indicates that the genetic variant TM6SF2 E167K, previously associated with increased risk for NAFLD, induces increased hepatocyte fat content by reducing APOB particle secretion. Finally, differences in gene expression pathways involved in cholesterol, fatty acid and glucose metabolism between wild type and TM6SF2 E167K mutation carriers (N = 125) were confirmed in the in vitro model. Our data suggest that the 3D in vitro spheroids can be used to investigate the mechanisms underlying the association of human genetic variants associated with NAFLD. This model may also be suitable to discover new treatments against NAFLD.
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http://dx.doi.org/10.1038/s41598-019-47737-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6690969PMC
August 2019

Validation of in vitro methods for human cytochrome P450 enzyme induction: Outcome of a multi-laboratory study.

Toxicol In Vitro 2019 Oct 31;60:212-228. Epub 2019 May 31.

European Commission, Joint Research Centre (JRC), Ispra, Italy. Electronic address:

CYP enzyme induction is a sensitive biomarker for phenotypic metabolic competence of in vitro test systems; it is a key event associated with thyroid disruption, and a biomarker for toxicologically relevant nuclear receptor-mediated pathways. This paper summarises the results of a multi-laboratory validation study of two in vitro methods that assess the potential of chemicals to induce cytochrome P450 (CYP) enzyme activity, in particular CYP1A2, CYP2B6, and CYP3A4. The methods are based on the use of cryopreserved primary human hepatocytes (PHH) and human HepaRG cells. The validation study was coordinated by the European Union Reference Laboratory for Alternatives to Animal Testing of the European Commission's Joint Research Centre and involved a ring trial among six laboratories. The reproducibility was assessed within and between laboratories using a validation set of 13 selected chemicals (known human inducers and non-inducers) tested under blind conditions. The ability of the two methods to predict human CYP induction potential was assessed. Chemical space analysis confirmed that the selected chemicals are broadly representative of a diverse range of chemicals. The two methods were found to be reliable and relevant in vitro tools for the assessment of human CYP induction, with the HepaRG method being better suited for routine testing. Recommendations for the practical application of the two methods are proposed.
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http://dx.doi.org/10.1016/j.tiv.2019.05.019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6718736PMC
October 2019

Critical differences in drug metabolic properties of human hepatic cellular models, including primary human hepatocytes, stem cell derived hepatocytes, and hepatoma cell lines.

Biochem Pharmacol 2018 09 25;155:124-140. Epub 2018 Jun 25.

Drug Metabolism and Pharmacokinetics, Cardiovascular and Metabolic Diseases, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden; Department of Physiology and Pharmacology, Section of Pharmacogenetics, Karolinska Institutet, Stockholm, Sweden.

Primary human hepatocytes (PHH), HepaRG™, HepG2, and two sources of induced pluripotent stem cell (iPSC) derived hepatocytes were characterized regarding gene expression and function of key hepatic proteins, important for the metabolic fate of drugs. The gene expression PCA analysis showed a distance between the two iPSC derived hepatocytes as well as the HepG2 and HepaRG™ cells to the three PHH donors and PHH pool, which were clustered more closely together. Correlation-based hierarchical analysis clustered HepG2 close to the stem cell derived hepatocytes both when the expression of 91 genes related to liver function or only cytochrome P450 (P450) genes were analyzed indicating the non-liver feature and a similar low P450 profile in these cell models. The specific P450 activities and the metabolic pattern of well-characterized drug substances in the cell models demonstrated that iPSC derived hepatocytes had modest levels of CYP3A and CYP2C9, while CYP1A2, 2B6, 2C8, 2C9, 2C19, and 2D6 were barely detectable. High expression of several extrahepatic P450s such as CYP1A1 and 1B1 detected in the stem cell derived hepatocytes may have significant effects on metabolite profiles. However, one of the iPSC derived hepatocytes demonstrated significant combined P450 and conjugating enzyme activity of certain drugs. HepaRG™ cells showed many metabolic properties similar to PHHs and will in many respects be a good model in studies of metabolic pathways and induction of drug metabolism whereas there is still ground to cover before iPSC derived hepatocytes will be seen as a substitute to PHH in drug metabolism studies.
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http://dx.doi.org/10.1016/j.bcp.2018.06.026DOI Listing
September 2018

Impact of body weight, low energy diet and gastric bypass on drug bioavailability, cardiovascular risk factors and metabolic biomarkers: protocol for an open, non-randomised, three-armed single centre study (COCKTAIL).

BMJ Open 2018 05 29;8(5):e021878. Epub 2018 May 29.

Cardiovascular, Renal and Metabolism Translational Medicine Unit, Early Clinical Development, IMED Biotech Unit, AstraZeneca Gothenburg, Gothenburg, Sweden.

Introduction: Roux-en-Y gastric bypass (GBP) is associated with changes in cardiometabolic risk factors and bioavailability of drugs, but whether these changes are induced by calorie restriction, the weight loss or surgery per se, remains uncertain. The COCKTAIL study was designed to disentangle the short-term (6 weeks) metabolic and pharmacokinetic effects of GBP and a very low energy diet (VLED) by inducing a similar weight loss in the two groups.

Methods And Analysis: This open, non-randomised, three-armed, single-centre study is performed at a tertiary care centre in Norway. It aims to compare the short-term (6 weeks) and long-term (2 years) effects of GBP and VLED on, first, bioavailability and pharmacokinetics (24 hours) of probe drugs and biomarkers and, second, their effects on metabolism, cardiometabolic risk factors and biomarkers. The primary outcomes will be measured as changes in: (1) all six probe drugs by absolute bioavailability area under the curve (AUC/AUC) of midazolam (CYP3A4 probe), systemic exposure (AUC) of digoxin and rosuvastatin and drug:metabolite ratios for omeprazole, losartan and caffeine, levels of endogenous CYP3A biomarkers and genotypic variation, changes in the expression and activity data of the drug-metabolising, drug transport and drug regulatory proteins in biopsies from various organs and (2) body composition, cardiometabolic risk factors and metabolic biomarkers.

Ethics And Dissemination: The COCKTAIL protocol was reviewed and approved by the Regional Committee for Medical and Health Research Ethics (Ref: 2013/2379/REK sørøst A). The results will be disseminated to academic and health professional audiences and the public via presentations at conferences, publications in peer-reviewed journals and press releases and provided to all participants.

Trial Registration Number: NCT02386917.
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http://dx.doi.org/10.1136/bmjopen-2018-021878DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5988193PMC
May 2018

Human hepatocytes and cytochrome P450-selective inhibitors predict variability in human drug exposure more accurately than human recombinant P450s.

Br J Pharmacol 2018 06 19;175(11):2116-2129. Epub 2018 Apr 19.

Cardiovascular, Renal and Metabolism, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Gothenburg, Sweden.

Background And Purpose: Drugs metabolically eliminated by several enzymes are less vulnerable to variable compound exposure in patients due to drug-drug interactions (DDI) or if a polymorphic enzyme is involved in their elimination. Therefore, it is vital in drug discovery to accurately and efficiently estimate and optimize the metabolic elimination profile.

Experimental Approach: CYP3A and/or CYP2D6 substrates with well described variability in vivo in humans due to CYP3A DDI and CYP2D6 polymorphism were selected for assessment of fraction metabolized by each enzyme (fm ) in two in vitro systems: (i) human recombinant P450s (hrP450s) and (ii) human hepatocytes combined with selective P450 inhibitors. Increases in compound exposure in poor versus extensive CYP2D6 metabolizers and by the strong CYP3A inhibitor ketoconazole were mathematically modelled and predicted changes in exposure were compared with in vivo data.

Key Results: Predicted changes in exposure were within twofold of reported in vivo values using fm estimated in human hepatocytes and there was a strong linear correlation between predicted and observed changes in exposure (r  = 0.83 for CYP3A, r  = 0.82 for CYP2D6). Predictions using fm in hrP450s were not as accurate (r  = 0.55 for CYP3A, r  = 0.20 for CYP2D6).

Conclusions And Implications: The results suggest that variability in human drug exposure due to DDI and enzyme polymorphism can be accurately predicted using fm from human hepatocytes and CYP-selective inhibitors. This approach can be efficiently applied in drug discovery to aid optimization of candidate drugs with a favourable metabolic elimination profile and limited variability in patients.
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http://dx.doi.org/10.1111/bph.14203DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5980217PMC
June 2018

Cytochrome P450 Induction and Xeno-Sensing Receptors Pregnane X Receptor, Constitutive Androstane Receptor, Aryl Hydrocarbon Receptor and Peroxisome Proliferator-Activated Receptor α at the Crossroads of Toxicokinetics and Toxicodynamics.

Basic Clin Pharmacol Toxicol 2018 Sep 29;123 Suppl 5:42-50. Epub 2018 Apr 29.

Research Unit of Biomedicine, Pharmacology and Toxicology, Faculty of Medicine, University of Oulu, Oulu, Finland.

Pregnane X receptor (PXR), constitutive androstane receptor (CAR), aryl hydrocarbon receptor (AHR) and peroxisome proliferator-activated receptor α (PPARα) are ligand-activated transcription factors that regulate expression of many xenobiotic-metabolizing enzymes including several cytochrome P450 (CYP) enzymes. Many xenobiotics induce CYP enzymes through these intracellular receptors and consequently affect toxicokinetics and possible metabolic activation of the receptor ligands and other xenobiotics utilizing similar metabolic pathways. However, it is now apparent that the xenobiotic receptors regulate also many endogenous functions and signalling pathways, and xenobiotic exposure thus may dysregulate an array of fundamental cell functions. This MiniReview surveys and discusses the multifaceted roles of xenobiotic receptors, for which CYP induction may serve as the first alert and possibly a biomarker for exposure to xenobiotics. With the current emergence of the adverse outcome pathway (AOP) concept, these receptors are being and will be assigned as molecular initiating events or key events in numerous discrete toxicity pathways.
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http://dx.doi.org/10.1111/bcpt.13004DOI Listing
September 2018

Publisher Correction: Functional coupling of human pancreatic islets and liver spheroids on-a-chip: Towards a novel human ex vivo type 2 diabetes model.

Sci Rep 2018 01 23;8(1):1672. Epub 2018 Jan 23.

DMPK, Cardiovascular and Metabolic Diseases, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.
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http://dx.doi.org/10.1038/s41598-018-20340-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5780393PMC
January 2018

Functional coupling of human pancreatic islets and liver spheroids on-a-chip: Towards a novel human ex vivo type 2 diabetes model.

Sci Rep 2017 11 6;7(1):14620. Epub 2017 Nov 6.

DMPK, Cardiovascular and Metabolic Diseases, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

Human in vitro physiological models studying disease and drug treatment effects are urgently needed as more relevant tools to identify new drug targets and therapies. We have developed a human microfluidic two-organ-chip model to study pancreatic islet-liver cross-talk based on insulin and glucose regulation. We have established a robust co-culture of human pancreatic islet microtissues and liver spheroids maintaining functional responses up to 15 days in an insulin-free medium. Functional coupling, demonstrated by insulin released from the islet microtissues in response to a glucose load applied in glucose tolerance tests on different days, promoted glucose uptake by the liver spheroids. Co-cultures maintained postprandial glucose concentrations in the circulation whereas glucose levels remained elevated in both single cultures. Thus, insulin secreted into the circulation stimulated glucose uptake by the liver spheroids, while the latter, in the absence of insulin, did not consume glucose as efficiently. As the glucose concentration fell, insulin secretion subsided, demonstrating a functional feedback loop between the liver and the insulin-secreting islet microtissues. Finally, inter-laboratory validation verified robustness and reproducibility. Further development of this model using tools inducing impaired glucose regulation should provide a unique in vitro system emulating human type 2 diabetes mellitus.
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http://dx.doi.org/10.1038/s41598-017-14815-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5668271PMC
November 2017

Variability in Mass Spectrometry-based Quantification of Clinically Relevant Drug Transporters and Drug Metabolizing Enzymes.

Mol Pharm 2017 09 16;14(9):3142-3151. Epub 2017 Aug 16.

Department of Pharmacy, Uppsala University , Uppsala 75123, Sweden.

Many different methods are used for mass-spectrometry-based protein quantification in pharmacokinetics and systems pharmacology. It has not been established to what extent the results from these various methods are comparable. Here, we compared six different mass spectrometry-based proteomics methods by measuring the expression of clinically relevant drug transporters and metabolizing enzymes in human liver. Mean protein concentrations were in general quantified to similar levels by methods using whole tissue lysates. Methods using subcellular membrane fractionation gave incomplete enrichment of the proteins. When the enriched proteins were adjusted to levels in whole tissue lysates, they were on average 4-fold lower than those quantified directly in whole tissue lysates. The differences in protein levels were propagated into differences in predictions of hepatic clearance. In conclusion, caution is needed when comparing and applying quantitative proteomics data obtained with different methods, especially since membrane fractionation is common practice for protein quantification used in drug clearance predictions.
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http://dx.doi.org/10.1021/acs.molpharmaceut.7b00364DOI Listing
September 2017

Comparative transcriptomics of hepatic differentiation of human pluripotent stem cells and adult human liver tissue.

Physiol Genomics 2017 Aug 10;49(8):430-446. Epub 2017 Jul 10.

School of Bioscience, Systems Biology Research Center, University of Skövde, Skövde, Sweden.

Hepatocytes derived from human pluripotent stem cells (hPSC-HEP) have the potential to replace presently used hepatocyte sources applied in liver disease treatment and models of drug discovery and development. Established hepatocyte differentiation protocols are effective and generate hepatocytes, which recapitulate some key features of their in vivo counterparts. However, generating mature hPSC-HEP remains a challenge. In this study, we applied transcriptomics to investigate the progress of in vitro hepatic differentiation of hPSCs at the developmental stages, definitive endoderm, hepatoblasts, early hPSC-HEP, and mature hPSC-HEP, to identify functional targets that enhance efficient hepatocyte differentiation. Using functional annotation, pathway and protein interaction network analyses, we observed the grouping of differentially expressed genes in specific clusters representing typical developmental stages of hepatic differentiation. In addition, we identified hub proteins and modules that were involved in the cell cycle process at early differentiation stages. We also identified hub proteins that differed in expression levels between hPSC-HEP and the liver tissue controls. Moreover, we identified a module of genes that were expressed at higher levels in the liver tissue samples than in the hPSC-HEP. Considering that hub proteins and modules generally are essential and have important roles in the protein-protein interactions, further investigation of these genes and their regulators may contribute to a better understanding of the differentiation process. This may suggest novel target pathways and molecules for improvement of hPSC-HEP functionality, having the potential to finally bring this technology to a wider use.
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http://dx.doi.org/10.1152/physiolgenomics.00007.2017DOI Listing
August 2017

Evolution of Novel 3D Culture Systems for Studies of Human Liver Function and Assessments of the Hepatotoxicity of Drugs and Drug Candidates.

Basic Clin Pharmacol Toxicol 2017 Oct 3;121(4):234-238. Epub 2017 Jul 3.

Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Mölndal, Sweden.

The pharmaceutical industry urgently needs reliable pre-clinical models to evaluate the efficacy and safety of new chemical entities before they enter the clinical trials. Development of in vitro model systems that emulate the functions of the human liver organ has been an elusive task. Cell lines exhibit a low drug-metabolizing capacity and primary liver cells rapidly dedifferentiate in culture, which restrict their usefulness substantially. Recently, the development of hepatocyte spheroid cultures has shown promising results. The proteome and transcriptome in the spheroids were similar to the liver tissue, and hepatotoxicity of selected substances was detected at in vivo-relevant concentrations.
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http://dx.doi.org/10.1111/bcpt.12804DOI Listing
October 2017

Transcriptional, Functional, and Mechanistic Comparisons of Stem Cell-Derived Hepatocytes, HepaRG Cells, and Three-Dimensional Human Hepatocyte Spheroids as Predictive In Vitro Systems for Drug-Induced Liver Injury.

Drug Metab Dispos 2017 04 30;45(4):419-429. Epub 2017 Jan 30.

Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (C.C.B., V.M.L., S.U.V., T.B.A., M.I.-S.); Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Mölndal, Sweden (H.P., T.B.A.); and CXR Biosciences Ltd., Dundee, United Kingdom (R.D.).

Reliable and versatile hepatic in vitro systems for the prediction of drug pharmacokinetics and toxicity are essential constituents of preclinical safety assessment pipelines for new medicines. Here, we compared three emerging cell systems-hepatocytes derived from induced pluripotent stem cells, HepaRG cells, and three-dimensional primary human hepatocyte (PHH) spheroids-at transcriptional and functional levels in a multicenter study to evaluate their potential as predictive models for drug-induced hepatotoxicity. Transcriptomic analyses revealed widespread gene expression differences between the three cell models, with 8148 of 17,462 analyzed genes (47%) being differentially expressed. Expression levels of genes involved in the metabolism of endogenous as well as xenobiotic compounds were significantly elevated in PHH spheroids, whereas genes involved in cell division and endocytosis were significantly upregulated in HepaRG cells and hepatocytes derived from induced pluripotent stem cells, respectively. Consequently, PHH spheroids were more sensitive to a panel of drugs with distinctly different toxicity mechanisms, an effect that was amplified by long-term exposure using repeated treatments. Importantly, toxicogenomic analyses revealed that transcriptomic changes in PHH spheroids were in compliance with cholestatic, carcinogenic, or steatogenic in vivo toxicity mechanisms at clinically relevant drug concentrations. Combined, the data reveal important phenotypic differences between the three cell systems and suggest that PHH spheroids can be used for functional investigations of drug-induced liver injury in vivo in humans.
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http://dx.doi.org/10.1124/dmd.116.074369DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5363699PMC
April 2017

Managing the Risk of CYP3A Induction in Drug Development: A Strategic Approach.

Drug Metab Dispos 2017 01 24;45(1):35-41. Epub 2016 Oct 24.

Oncology Innovative Medicines and Early Development Biotech Unit (B.C.J.) and Drug Safety and Metabolism (H.R.), AstraZeneca, Cambridge, United Kingdom; Quantitative Clinical Pharmacology (S.J.), and Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit (K.P.K., T.B.A.), AstraZeneca, Mölndal, Sweden; Quantitative Clinical Pharmacology, AstraZeneca, Hertfordshire, United Kingdom (C.L.); Quantitative Clinical Pharmacology, AstraZeneca, Waltham, Massachusetts (K.V.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (T.B.A.).

Induction of cytochrome P450 (P450) can impact the efficacy and safety of drug molecules upon multiple dosing with coadministered drugs. This strategy is focused on CYP3A since the majority of clinically relevant cases of P450 induction are related to these enzymes. However, the in vitro evaluation of induction is applicable to other P450 enzymes; however, the in vivo relevance cannot be assessed because the scarcity of relevant clinical data. In the preclinical phase, compounds are screened using pregnane X receptor reporter gene assay, and if necessary structure-activity relationships (SAR) are developed. When projects progress toward the clinical phase, induction studies in a hepatocyte-derived model using HepaRG cells will generate enough robust data to assess the compound's induction liability in vivo. The sensitive CYP3A biomarker 4β-hydroxycholesterol is built into the early clinical phase I studies for all candidates since rare cases of in vivo induction have been found without any induction alerts from the currently used in vitro methods. Using this model, the AstraZeneca induction strategy integrates in vitro assays and in vivo studies to make a comprehensive assessment of the induction potential of new chemical entities. Convincing data that support the validity of both the in vitro models and the use of the biomarker can be found in the scientific literature. However, regulatory authorities recommend the use of primary human hepatocytes and do not advise the use of sensitive biomarkers. Therefore, primary human hepatocytes and midazolam studies will be conducted during the clinical program as required for regulatory submission.
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http://dx.doi.org/10.1124/dmd.116.072025DOI Listing
January 2017

Massive rearrangements of cellular MicroRNA signatures are key drivers of hepatocyte dedifferentiation.

Hepatology 2016 11 30;64(5):1743-1756. Epub 2016 Sep 30.

Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.

Hepatocytes are dynamic cells that, upon injury, can alternate between nondividing differentiated and dedifferentiated proliferating states in vivo. However, in two-dimensional cultures, primary human hepatocytes (PHHs) rapidly dedifferentiate, resulting in loss of hepatic functions that significantly limits their usefulness as an in vitro model of liver biology, liver diseases, as well as drug metabolism and toxicity. Thus, understanding the underlying mechanisms and stalling of the dedifferentiation process would be highly beneficial to establish more-accurate and relevant long-term in vitro hepatocyte models. Here, we present comprehensive analyses of whole proteome and transcriptome dynamics during the initiation of dedifferentiation during the first 24 hours of culture. We report that early major rearrangements of the noncoding transcriptome, hallmarked by increased expression of small nucleolar RNAs, long noncoding RNAs, microRNAs (miRNAs), and ribosomal genes, precede most changes in coding genes during dedifferentiation of PHHs, and we speculated that these modulations could drive the hepatic dedifferentiation process. To functionally test this hypothesis, we globally inhibited the miRNA machinery using two established chemically distinct compounds, acriflavine and poly-l-lysine. These inhibition experiments resulted in a significantly impaired miRNA response and, most important, in a pronounced reduction in the down-regulation of hepatic genes with importance for liver function. Thus, we provide strong evidence for the importance of noncoding RNAs, in particular, miRNAs, in hepatic dedifferentiation, which can aid the development of more-efficient differentiation protocols for stem-cell-derived hepatocytes and broaden our understanding of the dynamic properties of hepatocytes with respect to liver regeneration.

Conclusion: miRNAs are important drivers of hepatic dedifferentiation, and our results provide valuable information regarding the mechanisms behind liver regeneration and possibilities to inhibit dedifferentiation in vitro. (Hepatology 2016;64:1743-1756).
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http://dx.doi.org/10.1002/hep.28780DOI Listing
November 2016

Novel 3D Culture Systems for Studies of Human Liver Function and Assessments of the Hepatotoxicity of Drugs and Drug Candidates.

Chem Res Toxicol 2016 12 23;29(12):1936-1955. Epub 2016 Sep 23.

Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet , SE-17177 Stockholm, Sweden.

The liver is an organ with critical importance for drug treatment as the disposition and response to a given drug is often determined by its hepatic metabolism. Patient-specific factors can entail increased susceptibility to drug-induced liver injury, which constitutes a major risk for drug development programs causing attrition of promising drug candidates or costly withdrawals in postmarketing stages. Hitherto, mainly animal studies and 2D hepatocyte systems have been used for the examination of human drug metabolism and toxicity. Yet, these models are far from satisfactory due to extensive species differences and because hepatocytes in 2D cultures rapidly dedifferentiate resulting in the loss of their hepatic phenotype and functionality. With the increasing comprehension that 3D cell culture systems more accurately reflect in vivo physiology, in the recent decade more and more research has focused on the development and optimization of various 3D culture strategies in an attempt to preserve liver properties in vitro. In this contribution, we critically review these developments, which have resulted in an arsenal of different static and perfused 3D models. These systems include sandwich-cultured hepatocytes, spheroid culture platforms, and various microfluidic liver or multiorgan biochips. Importantly, in many of these models hepatocytes maintain their phenotype for prolonged times, which allows probing the potential of newly developed chemical entities to cause chronic hepatotoxicity. Moreover, some platforms permit the investigation of drug action in specific genetic backgrounds or diseased hepatocytes, thereby significantly expanding the repertoire of tools to detect drug-induced liver injuries. It is concluded that the development of 3D liver models has hitherto been fruitful and that systems are now at hand whose sensitivity and specificity in detecting hepatotoxicity are superior to those of classical 2D culture systems. For the future, we highlight the need to develop more integrated coculture model systems to emulate immunotoxicities that arise due to complex interactions between hepatocytes and immune cells.
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http://dx.doi.org/10.1021/acs.chemrestox.6b00150DOI Listing
December 2016

CYP3A Specifically Catalyzes 1β-Hydroxylation of Deoxycholic Acid: Characterization and Enzymatic Synthesis of a Potential Novel Urinary Biomarker for CYP3A Activity.

Drug Metab Dispos 2016 09 11;44(9):1480-9. Epub 2016 Jul 11.

Cardiovascular and Metabolic Diseases, Drug Metabolism and Pharmacokinetics (M.A.H., X.-Q.L., T.B.A.) and Respiratory, Inflammation and Autoimmune Disease, Medicinal Chemistry (G.G.), Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Mölndal, Sweden; Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden (U.D.); Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (T.B.A.)

The endogenous bile acid metabolite 1β-hydroxy-deoxycholic acid (1β-OH-DCA) excreted in human urine may be used as a sensitive CYP3A biomarker in drug development reflecting in vivo CYP3A activity. An efficient and stereospecific enzymatic synthesis of 1β-OH-DCA was developed using a Bacillus megaterium (BM3) cytochrome P450 (P450) mutant, and its structure was confirmed by nuclear magnetic resonance (NMR) spectroscopy. A [(2)H4]-labeled analog of 1β-OH-DCA was also prepared. The major hydroxylated metabolite of deoxycholic acid (DCA) in human liver microsomal incubations was identified as 1β-OH-DCA by comparison with the synthesized reference analyzed by UPLC-HRMS. Its formation was strongly inhibited by CYP3A inhibitor ketoconazole. Screening of 21 recombinant human cytochrome P450 (P450) enzymes showed that, with the exception of extrahepatic CYP46A1, the most abundant liver P450 subfamily CYP3A, including CYP3A4, 3A5, and 3A7, specifically catalyzed 1β-OH-DCA formation. This indicated that 1β-hydroxylation of DCA may be a useful marker reaction for CYP3A activity in vitro. The metabolic pathways of DCA and 1β-OH-DCA in human hepatocytes were predominantly via glycine and, to a lesser extent, via taurine and sulfate conjugation. The potential utility of 1β-hydroxylation of DCA as a urinary CYP3A biomarker was illustrated by comparing the ratio of 1β-OH-DCA:DCA in a pooled spot urine sample from six healthy control subjects to a sample from one patient treated with carbamazepine, a potent CYP3A inducer; 1β-OH-DCA:DCA was considerably higher in the patient versus controls (ratio 2.8 vs. 0.4). Our results highlight the potential of 1β-OH-DCA as a urinary biomarker in clinical CYP3A DDI studies.
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http://dx.doi.org/10.1124/dmd.116.070805DOI Listing
September 2016

Bile canaliculi formation and biliary transport in 3D sandwich-cultured hepatocytes in dependence of the extracellular matrix composition.

Arch Toxicol 2016 Oct 21;90(10):2497-511. Epub 2016 Jun 21.

Department of General-, Visceral- and Transplantation Surgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.

Primary human hepatocytes (PHH) are still considered as gold standard for investigation of in vitro metabolism and hepatotoxicity in pharmaceutical research. It has been shown that the three-dimensional (3D) cultivation of PHH in a sandwich configuration between two layers of extracellular matrix (ECM) enables the hepatocytes to adhere three dimensionally leading to formation of in vivo like cell-cell contacts and cell-matrix interactions. The aim of the present study was to investigate the influence of different ECM compositions on morphology, cellular arrangement and bile canaliculi formation as well as bile excretion processes in PHH sandwich cultures systematically. Freshly isolated PHH were cultured for 6 days between two ECM layers made of collagen and/or Matrigel in four different combinations. The cultures were investigated by phase contrast microscopy and immunofluorescence analysis with respect to cell-cell connections, repolarization as well as bile canaliculi formation. The influence of the ECM composition on cell activity and viability was measured using the XTT assay and a fluorescent dead or alive assay. Finally, the bile canalicular transport was analyzed by live cell imaging to monitor the secretion and accumulation of the fluorescent substance CDF in bile canaliculi. Using collagen and Matrigel in different compositions in sandwich cultures of hepatocytes, we observed differences in morphology, cellular arrangement and cell activity of PHH in dependence of the ECM composition. Sandwich-cultured hepatocytes with an underlay of collagen seem to represent the best in vivo tissue architecture in terms of formation of trabecular cell arrangement. Cultures overlaid with collagen were characterized by the formation of abundant bile canaliculi, while the bile canaliculi network in hepatocytes cultured on a layer of Matrigel and overlaid with collagen showed the most branched and stable canalicular network. All cultures showed a time-dependent leakage of CDF from the bile canaliculi into the culture supernatant with variations in dependence on the used matrix combination. In conclusion, the results of this study show that the choice of ECM has an impact on the morphology, cell assembly and bile canaliculi formation in PHH sandwich cultures. The morphology and the multicellular arrangement were essentially influenced by the underlaying matrix, while bile excretion and leakage of sandwich-cultured hepatocytes were mainly influenced by the overlay matrix. Leaking and damaged bile canaliculi could be a limitation of the investigated sandwich culture models in long-term excretion studies.
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http://dx.doi.org/10.1007/s00204-016-1758-zDOI Listing
October 2016
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