Drug Metabolism and Disposition最新文献

{"title":"<b>Impact of Genetic Polymorphisms and Drug-Drug Interactions Mediated by Carboxylesterase1 on Remimazolam Deactivation</b>.","authors":"Zhuo Wang, Zachary McCalla, Li Lin, Dominic Tornichio, Yaw Agyemang, John A Bastulli, Xiaochun Susan Zhang, Hao-Jie Zhu, Xinwen Wang","doi":"10.1124/dmd.124.001916","DOIUrl":"https://doi.org/10.1124/dmd.124.001916","url":null,"abstract":"<p><p>Remimazolam (Byfavo^®), a recent FDA-approved ester-linked benzodiazepine, offers advantages in sedation, such as rapid onset and predictable duration, making it suitable for broad anesthesia applications. Its favorable pharmacological profile is primarily attributed to rapid hydrolysis, the primary metabolism pathway for its deactivation. Thus, understanding remimazolam hydrolysis determinants is essential for optimizing its clinical use. This study aimed to identify the enzyme(s) and tissue(s) responsible for remimazolam hydrolysis and to evaluate the influence of genetic polymorphisms and drug-drug interactions (DDIs) on its hydrolysis in the human liver. An initial incubation study with remimazolam and phosphate buffer saline (PBS), human serum, and the S9 fractions of human liver and intestine demonstrated that remimazolam was exclusively hydrolyzed by human liver S9 fractions. Subsequent incubation studies utilizing a Carboxylesterase inhibitor (Bis-para-nitrophenylphosphate, BNPP), recombinant human Carboxylesterase1 (CES1) and Carboxylesterase 2 (CES2) confirmed that remimazolam is specifically hydrolyzed by CES1 in human liver. Furthermore, <i>in vitro</i> studies with wild-type <i>CES1</i> and <i>CES1</i> variants transfected cells revealed that certain genetic polymorphisms significantly impair remimazolam deactivation. Notably, the impact of <i>CES1 G143E</i> was verified using individual human liver samples. Moreover, our evaluation of the DDIs between remimazolam and several other substrates/inhibitors of CES1-including simvastatin, enalapril, clopidogrel and sacubitril- found that clopidogrel significantly inhibited remimazolam hydrolysis at clinically relevant concentrations, with CES1 genetic variants potentially influencing the interactions. In summary, <i>CES1</i> genetic variants and its interacting drugs are crucial factors contributing to interindividual variability in remimazolam hepatic hydrolysis, holding the potential to serve as biomarkers for optimizing remimazolam use. <b>Significance Statement</b> This investigation demonstrates that remimazolam is deactivated by CES1 in the human liver, with CES1 genetic variants and DDIs significantly influencing its metabolism. These findings emphasize the need to consider CES1 genetic variability and potential DDIs in remimazolam use, especially in personalized pharmacotherapy to achieve optimal anesthetic outcomes.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142582170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Candesartan Has No Clinically Meaningful Effect on the Plasma Concentrations of CYP2C8 Substrate Repaglinide in Humans.","authors":"Mikael O W Piha, Kristiina Cajanus, Marica T Engström, Mikko Neuvonen, Troels K Bergmann, Mikko Niemi, Janne T Backman, Anne M Filppula, Aleksi Tornio","doi":"10.1124/dmd.124.001798","DOIUrl":"https://doi.org/10.1124/dmd.124.001798","url":null,"abstract":"<p><p>In vitro evidence show that the acyl-<i>β</i>-D-glucuronide metabolite of candesartan inhibits cytochrome P450 (CYP) 2C8 with an inhibition constant of 7.12 µM. We investigated the effect of candesartan on the plasma concentrations and glucose-lowering effect of repaglinide, a sensitive clinical CYP2C8 index substrate. In a randomized crossover study, ten healthy volunteers ingested 8 mg of candesartan or placebo daily for three days, and on day 3, they also ingested 0.25 mg of repaglinide one hour after candesartan or placebo. We measured the plasma concentrations of repaglinide, candesartan, and candesartan acyl-<i>β</i>-D-glucuronide, and blood glucose concentrations for up to nine hours after repaglinide intake. Candesartan had no effect on the area under the plasma concentration-time curve and peak plasma concentration of repaglinide compared to placebo, with ratios of geometric means of 1.02 [<i>P</i> = 0.809; 90% confidence interval (CI) 0.90-1.15] and 1.13 (<i>P</i> = 0.346; 90% CI 0.90-1.43), respectively. Other pharmacokinetic variables and blood glucose concentrations were neither affected. Candesartan acyl-<i>β</i>-D-glucuronide was detectable in seven subjects, in whom the peak concentration of repaglinide was 1.32-fold higher in the candesartan phase than in the placebo phase (<i>P</i> = 0.041; 90% CI 1.07-1.62). Systemic concentrations of candesartan acyl-<i>β</i>-D-glucuronide were very low compared to its CYP2C8 inhibition constant (ratio << 0.1). Furthermore, in a cohort of 93 cancer patients, no indication of decreased paclitaxel clearance was found in four patients using candesartan concomitantly. In conclusion, candesartan therapy is unlikely to inhibit CYP2C8-mediated metabolism of other drugs to any clinically significant extent. <b>Significance Statement</b> The findings of this study suggest that candesartan is unlikely to cause drug-drug interactions via inhibition of CYP2C8. Even though candesartan acyl-<i>β</i>-D-glucuronide has been shown to inhibit CYP2C8 in vitro, it shows no clinically relevant CYP2C8 inhibition in humans due to low systemic concentrations.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142564223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterotropic Allosteric Modulation of CYP3A4 In Vitro by Progesterone: Evidence for Improvement in Prediction of Time Dependent Inhibition for Macrolides.","authors":"Luc R A Rougee, Pooja V Hegde, Kaitlin Shin, Trent L Abraham, Alec Bell, Stephen D Hall","doi":"10.1124/dmd.124.001820","DOIUrl":"https://doi.org/10.1124/dmd.124.001820","url":null,"abstract":"<p><p>Predictions of drug-drug interactions resulting from time-dependent inhibition (TDI) of CYP3A4 have consistently overestimated or mis-predicted (i.e. false positives) the interaction that is observed in vivo. Recent findings demonstrated that the presence of the allosteric modulator progesterone (PGS) in the in vitro assay could alter the in vitro kinetics of CYP3A4 TDI with inhibitors that interact with the heme moiety, such as metabolic-intermediate complex (MIC) forming inhibitors. The impact of the presence of 100 µM PGS on the TDI of molecules in the class of macrolides typically associated with MIC formation was investigated. Presence of PGS resulted in varied responses across the inhibitors tested. The TDI signal was eliminated for five inhibitors, and unaltered in the case of one, fidaxomicin. The remaining molecules erythromycin, clarithromycin, and troleandomycin, were observed to have a decrease in both potency and maximum inactivation rate ranging from 1.7-fold to 6.7-fold. These changes in TDI kinetics led to a >90% decrease in inactivation efficiency. In order to determine in vitro conditions that could reproduce in vivo inhibition, varied concentrations of PGS were incubated with clarithromycin and erythromycin. Resulting in vitro TDI kinetics were incorporated into dynamic physiologically-based pharmacokinetic (PBPK) models to predict clinically observed interactions. The results suggested that a concentration of ~45 µM PGS would result in TDI kinetic values that could reproduce in vivo observations and could potentially improve predictions for CYP3A4 TDI. <b>Significance Statement</b> The impact of the allosteric heterotropic modulator progesterone on the CYP3A4 time-dependent inhibition kinetics was quantified for a set of metabolic-intermediate complex forming mechanism-based inhibitors. We identify the in vitro conditions that optimally predict time-dependent inhibition for in vivo drug-drug interactions through dynamic physiologically-based pharmacokinetic modeling. The optimized assay conditions improve in vitro to in vivo translation and prediction of time-dependent inhibition.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142544348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<b>Uncovering the Impact of COVID-19 Mediated Bidirectional Dysregulation of CYP3A4 on Systemic and Pulmonary Drug Concentrations Using Physiologically Based Pharmacokinetic Modeling</b>.","authors":"Chukwunonso K Nwabufo","doi":"10.1124/dmd.124.001893","DOIUrl":"https://doi.org/10.1124/dmd.124.001893","url":null,"abstract":"<p><p>Several clinical studies have shown that COVID-19 increases the systemic concentration of drugs in hospitalized COVID-19 patients. However, it is unclear how COVID-19-mediated bidirectional dysregulation of hepatic and pulmonary CYP3A4 impacts drug concentrations, especially in the lung tissue which is most affected by the disease. Herein, PBPK modeling was used to demonstrate the differences in systemic and pulmonary concentrations of four respiratory infectious disease drugs when CYP3A4 is concurrently downregulated in the liver and upregulated in the lung based on existing clinical data on COVID-19 - CYP3A4 interactions at varying severity levels including outpatients, non-ICU, and ICU patients. The study showed that hepatic metabolism is the primary determinant of both systemic and pulmonary drug concentrations despite the concurrent bidirectional dysregulation of liver and lung CYP3A4. ICU patients had the most systemic and pulmonary drug exposure with a percentage increase in AUC_plasma of approximately 44%, 56%, 114%, and 196% for clarithromycin, nirmatrelvir, dexamethasone, and itraconazole, respectively, relative to the healthy group. Within the ICU cohort, clarithromycin exhibited its highest exposure in lung tissue mass with a fold change of 1189, while nirmatrelvir and dexamethasone showed their highest exposure in the plasma compartment, with fold changes of about 126 and 5, respectively, compared to the maximum therapeutic concentrations for their target pathogens. Itraconazole was significantly under-exposed in the lung fluid compartment potentially explaining its limited efficacy for the treatment of COVID-19. These findings underscore the importance of optimizing dosing regimens in at risk ICU patients to enhance both efficacy and safety profiles. <b>Significance Statement</b> This study investigated whether COVID-19-mediated concurrent hepatic downregulation and pulmonary upregulation of CYP3A4 leads to differences in the systemic and pulmonary concentrations of four respiratory medicines. The study demonstrated that intercompartmental differences in drug concentrations were driven by only hepatic CYP3A4 expression. This work suggests that ICU patients with significant COVID-19 - CYP3A4 interactions may be at risk of clinically relevant COVID-19-drug interactions, highlighting the need for optimizing dosing regimens in this patient group to improve safety and efficacy.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142544346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of human alcohol dehydrogenase 4 and aldehyde dehydrogenase 2 as enzymes involved in the formation of 5-carboxylpirfenidone, a major metabolite of pirfenidone.","authors":"Rei Sato, Tatsuki Fukami, Kazuya Shimomura, Yongjie Zhang, Masataka Nakano, Miki Nakajima","doi":"10.1124/dmd.124.001917","DOIUrl":"https://doi.org/10.1124/dmd.124.001917","url":null,"abstract":"<p><p>Pirfenidone (PIR) is used to treatment of idiopathic pulmonary fibrosis. After oral administration, it is metabolized by cytochrome P450 1A2 to 5-hydroxylpirfenidone (5-OH PIR) and further oxidized to 5-carboxylpirfenidone (5-COOH PIR), a major metabolite excreted in the urine (90% of the dose). This study aimed to identify enzymes that catalyze the formation of 5-COOH PIR from 5-OH PIR in the human liver. 5-COOH PIR was formed from 5-OH PIR in the presence of NAD⁺ by human liver microsomes (HLM) more than by human liver cytosol (HLC), with the concomitant formation of the aldehyde form (5-CHO PIR) as an intermediate metabolite. By purifying enzymes from HLM, alcohol dehydrogenases (ADHs) were identified as candidate enzymes catalyzing 5-CHO PIR formation, although ADHs are localized in the cytoplasm. Among constructed recombinant ADH1-5 expressed in HEK293T cells, only ADH4 efficiently catalyzed 5-CHO PIR formation from 5-OH PIR with a <i>K</i> _m value (29.0 {plus minus} 4.9 µM), which was close to that by HLM (59.1 {plus minus} 4.6 µM). In contrast to commercially available HLC, in-house prepared HLC clearly showed substantial 5-CHO PIR formation, and ADH4 protein levels were significantly (<i>rs</i> = 0.772, <i>P</i> < 0.0001) correlated with 5-CHO PIR formation in 25 in-house prepared HLC samples. Some components of the commercially available HLC may inhibit ADH4 activity. Disulfiram, an inhibitor of aldehyde dehydrogenases (ALDH), decreased 5-COOH PIR formation and increased 5-CHO PIR formation from 5-OH PIR in HLM. ALDH2 knockdown in HepG2 cells by siRNA decreased 5-COOH PIR formation by 61%. <b>Significance Statement</b> This study clarified that 5-COOH PIR formation from 5-OH PIR proceeds via a two-step oxidation reaction catalyzed by ADH4 and disulfiram-sensitive enzymes, including ALDH2. Inter-individual differences in the expression levels or functions of these enzymes could cause variations in the pharmacokinetics of PIR.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142544347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmacokinetics and ADME Profiling of Tanimilast Following an Intravenous ¹⁴C-Microtracer co-administered with an Inhaled Dose in Healthy Male Individuals.","authors":"Michele Bassi, Veronica Puviani, Debora Santoro, Sonia Biondaro, Aida Emirova, Mirco Govoni","doi":"10.1124/dmd.124.001895","DOIUrl":"https://doi.org/10.1124/dmd.124.001895","url":null,"abstract":"<p><p>Tanimilast is an inhaled phosphodiesterase-4 inhibitor currently in phase 3 clinical development for treating chronic obstructive pulmonary disease (COPD) and asthma. This trial aimed to characterize the pharmacokinetics, mass balance, and metabolite profiling of tanimilast. Eight healthy male volunteers received a single dose of non-radiolabeled tanimilast via powder inhaler (NEXThaler^® (3200μg)), followed by a concomitant intravenous (IV) infusion of a microtracer ([¹⁴C]-tanimilast: 18.5μg and 500nCi). Plasma, whole blood, urine, and feces samples were collected up to 240 hours post-dose to quantify non-radiolabeled tanimilast, [¹⁴C]-tanimilast, and total-[¹⁴C]. The inhaled absolute bioavailability of tanimilast was found to be approximately 50%. Following IV administration of [¹⁴C]-tanimilast, plasma clearance was 22 L/h, the steady-state volume of distribution was 201 L, and the half-life was shorter compared to inhaled administration (14 vs. 39 hours, respectively), suggesting that plasma elimination is limited by the absorption rate from the lungs. 79% (71% in feces; 8% in urine) of the IV dose was recovered in excreta as total-[¹⁴C]. [¹⁴C]-tanimilast was the major radioactive compound in plasma, while no recovery was observed in urine and only 0.3% was recovered in feces, indicating predominant elimination through metabolic route. Importantly, as far as no metabolites accounting for more than 10% of the circulating drug-related exposure in plasma or the administered dose in excreta were detected, no further qualification is required according to regulatory guidelines. This study design successfully characterized the absorption, distribution, and elimination of tanimilast, providing key pharmacokinetic parameters to support its clinical development and regulatory application. <b>Significance Statement</b> This trial investigates PK and ADME profile of tanimilast, an inhaled PDE4 inhibitor for COPD and asthma. Eight male volunteers received a dose of non-radiolabeled tanimilast via NEXThaler^® and a microtracer IV dose. Results show pivotal PK results for the characterization of tanimilast, excretion route and quantification of significant metabolites, facilitating streamlined clinical development and regulatory approval.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142544349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absolute Membrane Protein Abundance of P-gp, BCRP and MRPs in Term Human Placenta Tissue and Commonly Used Cell Systems: Application in PBPK Modeling of Placental Drug Disposition.","authors":"Zubida M Al-Majdoub, Jolien J M Freriksen, Angela Colbers, Jeroen van den Heuvel, Jan Koenderink, Khaled Abduljalil, Brahim Achour, Jill Barber, Rick Greupink, Amin Rostami-Hodjegan","doi":"10.1124/dmd.124.001824","DOIUrl":"https://doi.org/10.1124/dmd.124.001824","url":null,"abstract":"<p><p>The placenta acts as a barrier, excluding noxious substances whilst actively transferring nutrients to the fetus, mediated by various transporters. This study quantified the expression of key placental transporters in term human placenta (n=5) and BeWo, BeWo b30, and JEG-3 placenta cell lines. Combining these results with pregnancy physiologically-based pharmacokinetic (PBPK) modeling, we demonstrate the utility of proteomic analysis for predicting placental drug disposition and fetal exposure. Using targeted proteomics with QconCAT standards, we found significant expression of P-gp, BCRP, MRP2, MRP4, and MRP6 in the human placenta (0.05 - 0.25 pmol/mg membrane protein) with only regional differences observed for P-gp. Unexpectedly, both P-gp and BCRP were below the limit of quantification in the regularly used BeWo cells, indicating that this cell line may not be suitable for the study of placental P-gp and BCRP-mediated transport. In cellular and vesicular overexpression systems, P-gp and BCRP were detectable as expected. Vesicle batches showed consistent P-gp expression correlating with functional activity (N-methyl-quinidine (NMQ) transport). However, BCRP activity (Estrone 3-sulfate (E1S) transport) did not consistently align with expression levels. Incorporating in vitro transporter kinetic data, along with placental transporter abundance, into a PBPK model enabled the evaluation of fetal exposure. Simulation with a hypothetical drug indicated that estimating fetal exposure relies on the intrinsic clearances of relevant transporters. To minimize interlaboratory discrepancies, expression data was generated using consistent proteomic methodologies in the same lab. Integration of this data in pregnancy-PBPK modeling offers a promising tool to investigate maternal, placental and fetal drug exposure. <b>Significance Statement</b> This study quantified the expression of key transporters in human placenta and various placental cell lines, revealing significant expression variations. By integrating these data with PBPK modeling, the study highlights the importance of transporter abundance data in understanding and predicting placental drug disposition.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142460475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<b>Utility of common <i>in vitro</i> systems for predicting circulating metabolites</b>.","authors":"Elyse C Freiberger, Michael P Thompson, Xiaomei Zhang, Essence B Underwood, Thomas L Lynch, Gary J Jenkins, David S Wagner","doi":"10.1124/dmd.124.001732","DOIUrl":"https://doi.org/10.1124/dmd.124.001732","url":null,"abstract":"<p><p><i>In vitro</i> systems such as cultured hepatocytes are used early in drug development as a proxy for <i>in vivo</i> data to predict metabolites in human and the potential pre-clinical species. These data support preclinical species selection for toxicology studies as well as provide early evidence for potential active and reactive metabolites that can be generated in human. While <i>in vivo</i> data would be best to select preclinical species for a given compound, only <i>in vitro</i> systems are available when selecting tox species. However, as with any <i>in vitro</i> system, the correlation to actual <i>in vivo</i> results can be variable. Understanding the predictivity of a given <i>in vitro</i> assay for <i>in vivo</i> metabolism would help drug development teams appreciate the significance of early cross-species metabolite profiles relative to the eventual clinical outcomes. In a retrospective analysis of historic metabolite profiling data from Abbott/AbbVie, <i>in vitro</i> systems predicted ~50% of circulating metabolites present <i>in vivo</i>, across preclinical species and human, with no correlation between apparent exposures <i>in vitro</i> vs <i>in vivo</i> A direct comparison of five common <i>in vitro</i> systems using commercial compounds with known metabolism resulted in suspension hepatocytes and co-cultured hepatocytes slightly outperforming the other systems in successfully generating major human circulating metabolites. Current <i>in vitro</i> systems have value early in development when <i>in vivo</i> studies are not feasible and are required for regulatory filings to support pre-clinical toxicology species selection but should not be treated as wholly representative of a given drug's <i>in vivo</i> metabolism. <b>Significance Statement</b> This is a comprehensive assessment of historic metabolism data quantitating the success rate of <i>in vitro</i> to <i>in vivo</i> predictivity. Reliability of <i>in vitro</i> systems for metabolite profiling is important for early drug development, and understanding predictivity will help give appropriate context to the data. New data were also generated to compare common <i>in vitro</i> liver models to determine whether any could be definitively identified as more predictive of human circulating metabolites than others.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142460474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isoform-level expression of the constitutive androstane receptor (CAR or NR1I3) transcription factor better predicts the mRNA expression of the cytochrome P450s in human liver samples.","authors":"Joseph M Collins, Danxin Wang","doi":"10.1124/dmd.124.001923","DOIUrl":"https://doi.org/10.1124/dmd.124.001923","url":null,"abstract":"<p><p>Many factors cause inter-person variability in the activity and expression of liver cytochrome P450 (CYP) drug-metabolizing enzymes, leading to variable drug exposure and treatment outcomes. Several liver-enriched transcription factors (TFs) are associated with CYP expression, with estrogen receptor alpha (ESR1) and constitutive androstane receptor (CAR or NR1I3) being the two top factors. ESR1 and NR1I3 undergo extensive alternative splicing that results in numerous splice isoforms, but how these splice isoforms associate with CYP expression is unknown. Here, we quantified 18 NR1I3 splice isoforms and the three most abundant ESR1 isoforms in 260 liver samples derived from African Americans (AA, n=125) and European Americans (EA, n=135). Our results showed variable splice isoform populations in the liver for both NR1I3 and ESR1. Multiple linear regression analyses revealed that, compared to gene-level NR1I3, isoform-level NR1I3 expression better predicted the mRNA expression of most CYPs and three UDP-glucuronosyltransferases (UGTs), while ESR1 isoforms improved predictive models for the UGTs and CYP2D6, but not for most CYPs. Also, different NR1I3 isoforms were associated with different CYPs, and the associations varied depending on sample ancestry. Surprisingly, non-canonical NR1I3 isoforms having retained introns (introns 2 or 6) were abundantly expressed and associated with the expression of most CYPs and UGTs, whereas the reference isoform (NR1I3-205) only associated with CYP2D6. Moreover, NR1I3 isoform diversity increased during the differentiation of induced pluripotent stem cells to hepatocytes, paralleling increasing CYP expression. These results suggest that isoform-level TF expression may help to explain variation in CYP or UGT expression between individuals. <b>Significance Statement</b> We quantified 18 NR1I3 splice isoforms and three ESR1 splice isoforms in 260 liver samples derived from AA and EA donors and found variable NR1I3 and ESR1 splice isoform expression in the liver. Multiple linear regression analysis showed that, compared to gene-level expression, isoform-level expression of NR1I3 and ESR1 better predicted the mRNA expression of some CYPs and UGTs, highlighting the importance of isoform-level analyses to enhance our understanding of gene transcriptional regulatory networks controlling the expression of drug-metabolizing enzymes.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142460477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmentally Persistent Free Radicals stimulate CYP2E1-mediated generation of reactive oxygen species at the expense of substrate metabolism.","authors":"George F Cawley, J Patrick Connick, Marilyn K Eyer, Wayne L Backes","doi":"10.1124/dmd.124.001939","DOIUrl":"https://doi.org/10.1124/dmd.124.001939","url":null,"abstract":"<p><p>Environmentally persistent free radicals (EPFRs) are a recently recognized component of particulate matter that cause respiratory and cardiovascular toxicity. The mechanism of EPFR toxicity appears to be related to their ability to generate reactive oxygen species (ROS), causing oxidative damage. EPFRs were shown to affect P450 function, inducing the expression of some forms through the Ah receptor. However, another characteristic of EPFRs lies in their ability to inhibit P450 activities. CYP2E1 is one of the P450s that is inhibited by EPFR (MCP230) exposure. As CYP2E1 is also known to generate ROS, it is important to understand the ability of EPFRs to influence the function of this enzyme and to identify the mechanisms involved. CYP2E1 was shown to be inhibited by EPFRs, and to a lesser extent by non-EPFR particles. As EPFR-mediated inhibition was more robust at subsaturating NADPH-cytochrome P450 reductase (POR) concentrations, disruption of POR·CYP2E1 complex formation and electron transfer were examined. Surprisingly, neither complex formation nor electron transfer between POR and CYP2E1 were inhibited by EPFRs. Examination of ROS production showed that MCP230 generated a greater amount of ROS than the non-EPFR CuO-Si. When a POR/CYP2E1-containing reconstituted system was added to the pollutant-particle systems there was a synergistic stimulation of ROS production. The results indicate that EPFRs cause inhibition of CYP2E1-mediated substrate metabolism, yet do not alter electron transfer and actually stimulate ROS generation. Taken together, the results are consistent with EPFRs affecting CYP2E1 function by inhibiting substrate metabolism and increasing the generation of ROS. <b>Significance Statement</b> Environmentally persistent free radicals affect CYP2E1 function by inhibition of monooxygenase activity. This inhibition is not due to disruption of the POR·CYP2E1 complex or inhibition of electron transfer, but due to uncoupling of NADPH and oxygen consumption from substrate metabolism to the generation of ROS. These results show that EPFRs block the metabolism of foreign compounds, and also synergistically stimulate the formation of reactive oxygen species that lead to oxidative damage within the organism.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142460476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}