1
|
Induction by Phenobarbital of Phase I and II Xenobiotic-Metabolizing Enzymes in Bovine Liver: An Overall Catalytic and Immunochemical Characterization. Int J Mol Sci 2022; 23:ijms23073564. [PMID: 35408925 PMCID: PMC8998613 DOI: 10.3390/ijms23073564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/14/2022] [Accepted: 03/21/2022] [Indexed: 12/15/2022] Open
Abstract
In cattle, phenobarbital (PB) upregulates target drug-metabolizing enzyme (DME) mRNA levels. However, few data about PB's post-transcriptional effects are actually available. This work provides the first, and an almost complete, characterization of PB-dependent changes in DME catalytic activities in bovine liver using common probe substrates and confirmatory immunoblotting investigations. As expected, PB increased the total cytochrome P450 (CYP) content and the extent of metyrapone binding; moreover, an augmentation of protein amounts and related enzyme activities was observed for known PB targets such as CYP2B, 2C, and 3A, but also CYP2E1. However, contradictory results were obtained for CYP1A, while a decreased catalytic activity was observed for flavin-containing monooxygenases 1 and 3. The barbiturate had no effect on the chosen hydrolytic and conjugative DMEs. For the first time, we also measured the 26S proteasome activity, and the increase observed in PB-treated cattle would suggest this post-translational event might contribute to cattle DME regulation. Overall, this study increased the knowledge of cattle hepatic drug metabolism, and further confirmed the presence of species differences in DME expression and activity between cattle, humans, and rodents. This reinforced the need for an extensive characterization and understanding of comparative molecular mechanisms involved in expression, regulation, and function of DMEs.
Collapse
|
2
|
SMOLENSKY MH, REINBERG AE, FISCHER FM. Working Time Society consensus statements: Circadian time structure impacts vulnerability to xenobiotics-relevance to industrial toxicology and nonstandard work schedules. INDUSTRIAL HEALTH 2019; 57:158-174. [PMID: 30700669 PMCID: PMC6449632 DOI: 10.2486/indhealth.sw-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/27/2018] [Indexed: 05/13/2023]
Abstract
The circadian time structure (CTS) has long been the subject of research in occupational medicine, but not to industrial toxicology, including methods of setting threshold limit values (TLVs) and employee biological monitoring. Numerous animal and human investigations document vulnerability to chemical, contagion, and other xenobiotics varies according to the circadian time of encounter. Permanent and rotating nightshift personnel are exposed to industrial contaminants in the same or higher concentration as dayshift personnel, and because of incomplete CTS adjustment to night work, contact with contaminants occurs during a different biological time than day workers. Thus, the amount of protection afforded by certain TLVs, especially for employees of high-risk settings who work night and other nonstandard shift schedules, might be inadequate. The CTS seems additionally germane to procedures of employee biological monitoring in that high-amplitude 24 h rhythms in biomarkers indicative of xenobiotic exposure may result in misjudgment of health risks when data are not gathered in sufficient frequency over time and properly interpreted. Biological reference values time-qualified for their rhythmic variation, currently of interest to laboratory medicine practice, are seemingly important to industrial medicine as circadian time and work-shift specific biological exposure indices to improve surveillance of personnel, particularly those working nonstandard shift schedules.
Collapse
Affiliation(s)
- Michael H. SMOLENSKY
- Department of Biomedical Engineering, Cockrell School of
Engineering, The University of Texas at Austin, USA
| | | | - Frida Marina FISCHER
- Department of Environmental Health, School of Public Health,
University of São Paulo, Brazil
| |
Collapse
|
3
|
Rudeck J, Bert B, Marx-Stoelting P, Schönfelder G, Vogl S. Liver lobe and strain differences in the activity of murine cytochrome P450 enzymes. Toxicology 2018; 404-405:76-85. [PMID: 29879457 DOI: 10.1016/j.tox.2018.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/17/2018] [Accepted: 06/02/2018] [Indexed: 12/19/2022]
Abstract
The cytochrome P450 (CYP) enzyme superfamily is the most important enzyme system for phase I biotransformation. For toxico- and pharmacokinetic studies, use of liver-based microsomes, including those of mice, is state-of-the-art to study CYP-dependent metabolism. However, reproducibility and interpretation of these data is still very variable, partly because current testing guidelines do not cover details on organ sampling and potential liver lobe differences. Hence, we analyzed CYP activity, CYP protein content, mRNA expression of CYP1A, CYP2C, CYP2D and CYP3A isozymes, and cytochrome P450 reductase (CPR) activity of the four different liver lobes and processus papillaris of male C57BL/6J mice in comparison to whole liver. Additionally, we used whole liver of Balb/cJ and 129S1/SvImJ for strain comparison. Our data show significant differences in CYP activity, being most prominent in lobus sinister lateralis and lobus medialis, and lowest in processus papillaris. These differences were not caused by varying Cyp gene expression or CYP protein level, but partly correspond with lobe specific CPR activities. We also observed significant strain differences in CYP mRNA expression and activities with overall high activities in 129S1/SvImJ mice and low activities in Balb/cJ mice compared to C57BL/6J mice. In addition, strain specific differences in CYP2C and CYP2D activity seem to be reflected in strain dependent differences in CPR activity. In summary, our results indicate that in mice CYP activity and gene expression are strain dependent and may vary highly between liver lobes. To ensure reproducibility and comparability of different probes and studies, this should be taken into account when liver samples are collected for the analysis of CYP-dependent metabolism.
Collapse
Affiliation(s)
- Juliane Rudeck
- German Federal Institute for Risk Assessment, German Centre for the Protection of Laboratory Animals (Bf3R), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
| | - Bettina Bert
- German Federal Institute for Risk Assessment, German Centre for the Protection of Laboratory Animals (Bf3R), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
| | - Philip Marx-Stoelting
- German Federal Institute for Risk Assessment, German Centre for the Protection of Laboratory Animals (Bf3R), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
| | - Gilbert Schönfelder
- German Federal Institute for Risk Assessment, German Centre for the Protection of Laboratory Animals (Bf3R), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; Charité - Universitätsmedizin Berlin, Cooperate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Clinical Pharmacology and Toxicology, Charitéplatz 1, 10117 Berlin, Germany.
| | - Silvia Vogl
- German Federal Institute for Risk Assessment, German Centre for the Protection of Laboratory Animals (Bf3R), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
| |
Collapse
|
4
|
Chernoff N, Hill DJ, Chorus I, Diggs DL, Huang H, King D, Lang JR, Le TT, Schmid JE, Travlos GS, Whitley EM, Wilson RE, Wood CR. Cylindrospermopsin toxicity in mice following a 90-d oral exposure. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2018; 81:549-566. [PMID: 29693504 PMCID: PMC6764423 DOI: 10.1080/15287394.2018.1460787] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 02/26/2018] [Indexed: 05/19/2023]
Abstract
Cylindrospermopsin (CYN) is a toxin associated with numerous species of freshwater cyanobacteria throughout the world. It is postulated to have caused an episode of serious illnesses in Australia through treated drinking water, as well as lethal effects in livestock exposed to water from farm ponds. Toxicity included effects indicative of both hepatic and renal dysfunction. In humans, symptoms progressed from initial hepatomegaly, vomiting, and malaise to acidosis and hypokalemia, bloody diarrhea, and hyperemia in mucous membranes. Laboratory animal studies predominantly involved the intraperitoneal (i.p.) route of administration and confirmed this pattern of toxicity with changes in liver enzyme activities and histopathology consistent with hepatic injury and adverse renal effects. The aim of this study was designed to assess subchronic oral exposure (90 d) of purified CYN from 75 to 300 µg/kg/d in mouse. At the end of the dosing period, examinations of animals noted (1) elevated organ to body weight ratios of liver and kidney at all dose levels, (2) treatment-related increases in serum alanine aminotransferase (ALT) activity, (3) decreased blood urea nitrogen (BUN) and cholesterol concentrations in males, and (4) elevated monocyte counts in both genders. Histopathological alterations included hepatocellular hypertrophy and cord disruption in the liver, as well as renal cellular hypertrophy, tubule dilation, and cortical tubule lesions that were more prominent in males. A series of genes were differentially expressed including Bax (apoptosis), Rpl6 (tissue regeneration), Fabp4 (fatty acid metabolism), and Proc (blood coagulation). Males were more sensitive to many renal end points suggestive of toxicity. At the end of exposure, toxicity was noted at all dose levels, and the 75 µg/kg group exhibited significant effects in liver and kidney/body weight ratios, reduced BUN, increased serum monocytes, and multiple signs of histopathology indicating that a no-observed-adverse-effect level could not be determined for any dose level.
Collapse
Affiliation(s)
- N Chernoff
- a National Health and Environmental Effects Research Laboratory , US Environmental Protection Agency, Office of Research and Development , Research Triangle Park , NC , USA
| | - D J Hill
- a National Health and Environmental Effects Research Laboratory , US Environmental Protection Agency, Office of Research and Development , Research Triangle Park , NC , USA
| | - I Chorus
- b Division of Drinking-Water and Swimming-Pool Hygiene , Umweltbundesamt , Berlin , Germany
| | - D L Diggs
- c NHEERL , Oak Ridge Institute for Science and Education Internship/Research Participation Program at the US Environmental Protection Agency , Research Triangle Park , NC , USA
| | - H Huang
- d North Carolina State University , Raleigh , NC , USA
| | - D King
- e Cellular and Molecular Pathology Branch , National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - J R Lang
- c NHEERL , Oak Ridge Institute for Science and Education Internship/Research Participation Program at the US Environmental Protection Agency , Research Triangle Park , NC , USA
| | - T-T Le
- c NHEERL , Oak Ridge Institute for Science and Education Internship/Research Participation Program at the US Environmental Protection Agency , Research Triangle Park , NC , USA
| | - J E Schmid
- a National Health and Environmental Effects Research Laboratory , US Environmental Protection Agency, Office of Research and Development , Research Triangle Park , NC , USA
| | - G S Travlos
- e Cellular and Molecular Pathology Branch , National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - E M Whitley
- f Pathogenesis , LLC , Gainesville , FL , USA
| | - R E Wilson
- e Cellular and Molecular Pathology Branch , National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - C R Wood
- a National Health and Environmental Effects Research Laboratory , US Environmental Protection Agency, Office of Research and Development , Research Triangle Park , NC , USA
| |
Collapse
|
5
|
Parfett C, Williams A, Zheng J, Zhou G. Gene batteries and synexpression groups applied in a multivariate statistical approach to dose–response analysis of toxicogenomic data. Regul Toxicol Pharmacol 2013; 67:63-74. [DOI: 10.1016/j.yrtph.2013.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/26/2013] [Indexed: 12/28/2022]
|
6
|
Jackson AF, Williams A, Moffat I, Phillips SL, Recio L, Waters MD, Lambert IB, Yauk CL. Preparation of archival formalin-fixed paraffin-embedded mouse liver samples for use with the Agilent gene expression microarray platform. J Pharmacol Toxicol Methods 2013; 68:260-268. [PMID: 23458726 DOI: 10.1016/j.vascn.2013.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 02/14/2013] [Accepted: 02/17/2013] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Tissue samples are routinely formalin-fixed and paraffin-embedded (FFPE) for long term preservation. Gene expression analysis of archival FFPE tissues may advance knowledge of the molecular perturbations contributing to disease. However, formalin causes extensive degradation of RNA. METHODS We compared RNA quality/yield from FFPE samples using six commercial FFPE RNA extraction kits. In addition we compared four DNA microarray protocols for the Agilent 8×60K platform using 16year old FFPE mouse liver samples treated with phenobarbital or vehicle. RESULTS Despite low quality RNA, archival phenobarbital samples exhibited strong induction of the positive control genes Cyp2b9 and Cyp2b10 by quantitative real-time PCR (qPCR). We tested one- and two-color microarray designs and evaluated the effects of increasing the amount of hybridized cDNA. Canonical gene responders to phenobarbital were measurably induced under each experimental condition. Increasing the amount of labeled cDNA did not improve the overall signal intensity. One-color experiments yielded larger fold changes than two-color and the number of differentially expressed genes varied between protocols. Gene expression changes were validated by qPCR and literature searches. Individual protocols exhibited high rates of false positives; however, pathway analysis revealed that nine of the top ten canonical pathways were consistent across experiments. Genes that were differentially expressed in more than one experiment were more likely to be validated. Thus, we recommend that experiments on FFPE samples be done in duplicate to reduce false positives. DISCUSSION In this analysis of archival FFPE samples we were able to identify pathways that are consistent with phenobarbital's mechanism of action. Therefore, we conclude that FFPE samples can be used for meaningful microarray gene expression analyses.
Collapse
Affiliation(s)
- A Francina Jackson
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa K1A 0K9, Canada; Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Andrew Williams
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa K1A 0K9, Canada
| | - Ivy Moffat
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa K1A 0K9, Canada
| | | | - Leslie Recio
- ILS, Inc., P.O. Box 13501, Research Triangle Park, NC 27709, USA
| | - Michael D Waters
- ILS, Inc., P.O. Box 13501, Research Triangle Park, NC 27709, USA
| | - Iain B Lambert
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Carole L Yauk
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa K1A 0K9, Canada
| |
Collapse
|
7
|
Zancanella V, Giantin M, Lopparelli RM, Nebbia C, Dacasto M. Tissue distribution and phenobarbital induction of target SLC- and ABC- transporters in cattle. J Vet Pharmacol Ther 2012; 36:358-69. [PMID: 22897113 DOI: 10.1111/j.1365-2885.2012.01427.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 07/07/2012] [Indexed: 01/16/2023]
Abstract
In veterinary pharmaco-toxicological sciences, few data about uptake and efflux drug transporters (DTs) expression and regulation phenomena have been published. In this study, the tissue distribution and transcriptional modulation of solute carrier (SLC) and ATP-binding cassette (ABC) DTs were investigated in cattle orally administered with phenobarbital (PB) by using a quantitative real-time RT-PCR approach. The criterion for target gene selection was the PB-responsiveness in human and rodent model species. All target DTs were expressed in the liver. Only two of the seven PB-responsive target DTs (SLCO1B3 and SLC10A1) were not constitutively expressed in cattle extra-hepatic tissues. The greatest number of DTs (SLCO2B1, ABCB1, ABCC2, ABCG2) were expressed in intestine and testis, followed by, adrenal gland (SLCO2B1, ABCB1, ABCG2), lung (ABCB1, ABCG2), kidney, and skeletal muscle (ABCG2). PB administration never altered DTs mRNA levels, except for an increase in hepatic ABCC2 mRNA and a down-regulation of renal ABCG2. Altogether, these results confirm only to some extent data obtained in humans and laboratory species; clearly, they should be considered a preliminary step for further molecular investigations about species-differences in DT gene expression and regulation as well as in DT expression and function.
Collapse
Affiliation(s)
- V Zancanella
- Dipartimento di Biomedicina Comparata e Alimentazione, viale dell'Università 16, Padova, Italy
| | | | | | | | | |
Collapse
|
8
|
Zancanella V, Giantin M, Lopparelli RM, Nebbia C, Dacasto M. Constitutive expression and phenobarbital modulation of drug metabolizing enzymes and related nuclear receptors in cattle liver and extra-hepatic tissues. Xenobiotica 2012; 42:1096-109. [PMID: 22694178 DOI: 10.3109/00498254.2012.694493] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In humans and rodents, phenobarbital (PB) induces hepatic and extra-hepatic drug metabolizing enzymes (DMEs) through the activation of specific nuclear receptors (NRs). In contrast, few data about PB transcriptional effects in veterinary species are available. The constitutive expression and modulation of PB-responsive NR and DME genes, following an oral PB challenge, were investigated in cattle liver and extra-hepatic tissues (duodenum, kidney, lung, testis, adrenal and muscle). Likewise to humans and rodents, target genes were expressed to a lower extent compared to the liver with few exceptions. Phenobarbital significantly affected hepatic CYP2B22, 2C31, 2C87, 3A and UDP-glucuronosyltransferase 1A1-like, glutathione S-transferase A1-like and sulfotransferase 1A1-like (SULT1A1-like) mRNAs and apoprotein amounts; in extra-hepatic tissues, only duodenum showed a significant down-regulation of SULT1A1-like gene and apoprotein. Nuclear receptor mRNAs were never affected by PB. Presented data are the first evidence about the constitutive expression of foremost DME and NR genes in cattle extra-hepatic tissues, and the data obtained following a PB challenge are suggestive of species-differences in drug metabolism; altogether, these information are of value for the extrapolation of pharmacotoxicological data among species, the characterization of drug-drug interactions as well as the animal and consumer's risk caused by harmful residues formation.
Collapse
Affiliation(s)
- Vanessa Zancanella
- Dipartimento di Biomedicina Comparata e Alimentazione, Agripolis Legnaro, Padova, Italy
| | | | | | | | | |
Collapse
|