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Schreiber H, Cohen G, Zahavi M, Wiener I, Biron-Shental T, Chowers M, Kovo M. Adverse obstetric outcomes in cases of meconium-stained amniotic fluid complicated with intrapartum fever. Arch Gynecol Obstet 2024; 310:1951-1957. [PMID: 39093332 DOI: 10.1007/s00404-024-07673-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Accepted: 07/23/2024] [Indexed: 08/04/2024]
Abstract
PURPOSE Meconium-stained amniotic fluid (MSAF) often signifies colonization of the amniotic sac by microorganisms. This study investigated additional adverse obstetric outcomes associated with MSAF in deliveries complicated by maternal intrapartum fever (IF). METHODS This retrospective study included all singleton pregnancies from 2014 to 2020, with intrapartum maternal fever ≥ 38 °C during a trial of labor. In accordance with departmental protocol, all patients received intravenous antibiotic therapy consisting of ampicillin and gentamicin in the absence of allergies to these medications. Subsequent antibiotic therapy was adjusted based on the culture results. Antibiotic treatment was discontinued postpartum after 48 h without fever. Swab cultures were obtained immediately postpartum from both the maternal and fetal sides of the placenta. Maternal and fetal outcomes, along with positive placental cultures, were compared between participants with MSAF&IF and those with clear amniotic fluid &IF (control group). RESULTS In comparison to the control group (n = 1089), the MSAF&IF group (n = 264) exhibited significantly higher rates of cesarean delivery (CD) (p = 0.001), CD due to non-reassuring fetal heart rate (p = 0.001), and cord pH ≤ 7.1 (p = 0.004). Positive swab cultures from the placental maternal and fetal sides were more prevalent among the MSAF&IF group (23.1% vs. 17.6%, p = 0.041 and 29.2% vs. 22.9%, p = 0.032, respectively). Placental cultures yielding gastrointestinal pathogens and extended spectrum beta-lactamase were notably more common in the MSAF&IF group compared to controls (p = 0.023). However, there was no significant difference between groups regarding the rate of group B streptococcus positive placental cultures. CONCLUSIONS Women experiencing IF and MSAF during labor face an elevated risk of CD compared to those with IF alone. The presence of MSAF heightens the risk of positive placental cultures, particularly with gastrointestinal and extended spectrum beta-lactamase pathogens.
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Affiliation(s)
- Hanoch Schreiber
- Department of Obstetrics and Gynecology, Meir Medical Center, 59 Tchernichovsky St., 44281, Kfar Saba, Israel.
- School of Medicine, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel.
| | - Gal Cohen
- Department of Obstetrics and Gynecology, Meir Medical Center, 59 Tchernichovsky St., 44281, Kfar Saba, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Maya Zahavi
- Department of Obstetrics and Gynecology, Meir Medical Center, 59 Tchernichovsky St., 44281, Kfar Saba, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Izaac Wiener
- Department of Obstetrics and Gynecology, Meir Medical Center, 59 Tchernichovsky St., 44281, Kfar Saba, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Tal Biron-Shental
- Department of Obstetrics and Gynecology, Meir Medical Center, 59 Tchernichovsky St., 44281, Kfar Saba, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Michal Chowers
- Infectious Diseases Unit, Meir Medical Center, Kfar Saba, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Michal Kovo
- Department of Obstetrics and Gynecology, Meir Medical Center, 59 Tchernichovsky St., 44281, Kfar Saba, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel
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2
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Gallo DM, Romero R, Bosco M, Gotsch F, Jaiman S, Jung E, Suksai M, Ramón Y Cajal CL, Yoon BH, Chaiworapongsa T. Meconium-stained amniotic fluid. Am J Obstet Gynecol 2023; 228:S1158-S1178. [PMID: 37012128 PMCID: PMC10291742 DOI: 10.1016/j.ajog.2022.11.1283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/09/2022] [Accepted: 11/09/2022] [Indexed: 04/04/2023]
Abstract
Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard. The condition has been attributed to the passage of fetal colonic content (meconium), intraamniotic bleeding with the presence of heme catabolic products, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reaching approximately 27% in post-term gestation. Green-stained amniotic fluid during labor has been associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures as well as cerebral palsy. Hypoxia is widely considered a mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, as patients with these conditions have a higher rate of clinical chorioamnionitis and neonatal sepsis. The precise mechanisms linking intraamniotic inflammation to green-stained amniotic fluid have not been determined, but the effects of oxidative stress in heme catabolism have been implicated. Two randomized clinical trials suggest that antibiotic administration decreases the rate of clinical chorioamnionitis in patients with meconium-stained amniotic fluid. A serious complication of meconium-stained amniotic fluid is meconium aspiration syndrome. This condition develops in 5% of cases presenting with meconium-stained amniotic fluid and is a severe complication typical of term newborns. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Histologic examination of the fetal membranes for meconium has been invoked in medical legal litigation to time the occurrence of fetal injury. However, inferences have been largely based on the results of in vitro experiments, and extrapolation of such findings to the clinical setting warrants caution. Fetal defecation throughout gestation appears to be a physiologic phenomenon based on ultrasound as well as in observations in animals.
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Affiliation(s)
- Dahiana M Gallo
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI; Department of Gynecology and Obstetrics, Universidad Del Valle, Cali, Colombia
| | - Roberto Romero
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI; Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI.
| | - Mariachiara Bosco
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Francesca Gotsch
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Sunil Jaiman
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Pathology, Wayne State University School of Medicine, Detroit, MI
| | - Eunjung Jung
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Manaphat Suksai
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Carlos López Ramón Y Cajal
- Unit of Prenatal Diagnosis, Service of Obstetrics and Gynecology, Álvaro Cunqueiro Hospital, Vigo, Spain
| | - Bo Hyun Yoon
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Tinnakorn Chaiworapongsa
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
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3
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Banerjee B, Olajide OJ, Bortolussi G, Muro AF. Activation of Alternative Bilirubin Clearance Pathways Partially Reduces Hyperbilirubinemia in a Mouse Model Lacking Functional Ugt1a1 Activity. Int J Mol Sci 2022; 23:ijms231810703. [PMID: 36142606 PMCID: PMC9505366 DOI: 10.3390/ijms231810703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/08/2022] [Accepted: 09/11/2022] [Indexed: 11/21/2022] Open
Abstract
Bilirubin is a heme catabolite and Ugt1a1 is the only enzyme involved in the biological elimination of bilirubin. Partially functional or non-functional Ugt1a1 may result in neuronal damage and death due to the accumulation of unconjugated bilirubin in the brain. The understanding of the role of alternative bilirubin detoxification mechanisms that can reduce bilirubin toxicity risk is crucial for developing novel therapeutic strategies. To provide a proof-of-principle showing whether activation of alternative detoxification pathways could lead to life-compatible bilirubin levels in the absence of Ugt1a1 activity, we used Ugt1−/− hyperbilirubinemic mice devoid of bilirubin glucuronidation activity. We treated adult Ugt1−/− mice with TCPOBOP, a strong agonist of the constitutive androstane receptor (CAR). TCPOBOP treatment decreased plasma and liver tissue bilirubin levels by about 38%, and resulted in the transcriptional activation of a vast array of genes involved in bilirubin transport and metabolism. However, brain bilirubin level was unaltered. We observed ~40% degradation of bilirubin in the liver microsomes from TCPOBOP treated Ugt1−/− mice. Our findings suggest that, in the absence of Ugt1a1, the activation of alternative bilirubin clearance pathways can partially improve hyperbilirubinemic conditions. This therapeutic approach may only be considered in a combinatorial manner along with other treatments.
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4
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Bianco A, Dvořák A, Capková N, Gironde C, Tiribelli C, Furger C, Vitek L, Bellarosa C. The Extent of Intracellular Accumulation of Bilirubin Determines Its Anti- or Pro-Oxidant Effect. Int J Mol Sci 2020; 21:ijms21218101. [PMID: 33143041 PMCID: PMC7663266 DOI: 10.3390/ijms21218101] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/26/2020] [Accepted: 10/28/2020] [Indexed: 12/14/2022] Open
Abstract
Background: Severe hyperbilirubinemia can cause permanent neurological damage in particular in neonates, whereas mildly elevated serum bilirubin protects from various oxidative stress-mediated diseases. The present work aimed to establish the intracellular unconjugated bilirubin concentrations (iUCB) thresholds differentiating between anti- and pro-oxidant effects. Methods: Hepatic (HepG2), heart endothelial (H5V), kidney tubular (HK2) and neuronal (SH-SY5Y) cell lines were exposed to increasing concentration of bilirubin. iUCB, cytotoxicity, intracellular reactive oxygen species (ROS) concentrations, and antioxidant capacity (50% efficacy concentration (EC50)) were determined. Results: Exposure of SH-SY5Y to UCB concentration > 3.6 µM (iUCB of 25 ng/mg) and >15 µM in H5V and HK2 cells (iUCB of 40 ng/mg) increased intracellular ROS production (p < 0.05). EC50 of the antioxidant activity was 21 µM (iUCB between 5.4 and 21 ng/mg) in HepG2 cells, 0.68 µM (iUCB between 3.3 and 7.5 ng/mg) in SH-SY5Y cells, 2.4 µM (iUCB between 3 and 6.7 ng/mg) in HK2 cells, and 4 µM (iUCB between 4.7 and 7.5 ng/mg) in H5V cells. Conclusions: In all the cell lines studied, iUCB of around 7 ng/mg protein had antioxidant activities, while iUCB > 25 ng/mg protein resulted in a prooxidant and cytotoxic effects. UCB metabolism was found to be cell-specific resulting in different iUCB.
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Affiliation(s)
- Annalisa Bianco
- Italian Liver Foundation (FIF), Bldg Q—AREA Science Park Basovizza, SS14 Km 163,5, 34149 Trieste, Italy; (A.B.); (C.T.)
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy
| | - Aleš Dvořák
- Institute of Medical Biochemistry and Laboratory Diagnostics, Faculty General Hospital and 1st Faculty of Medicine, Charles University, 121 08 Prague 2, Czech Republic; (A.D.); (N.C.); (L.V.)
| | - Nikola Capková
- Institute of Medical Biochemistry and Laboratory Diagnostics, Faculty General Hospital and 1st Faculty of Medicine, Charles University, 121 08 Prague 2, Czech Republic; (A.D.); (N.C.); (L.V.)
| | - Camille Gironde
- AOP/MH2F Team, LAAS-CNRS, 7 avenue de l’Europe, 31400 Toulouse, France; (C.G.); (C.F.)
| | - Claudio Tiribelli
- Italian Liver Foundation (FIF), Bldg Q—AREA Science Park Basovizza, SS14 Km 163,5, 34149 Trieste, Italy; (A.B.); (C.T.)
| | - Christophe Furger
- AOP/MH2F Team, LAAS-CNRS, 7 avenue de l’Europe, 31400 Toulouse, France; (C.G.); (C.F.)
| | - Libor Vitek
- Institute of Medical Biochemistry and Laboratory Diagnostics, Faculty General Hospital and 1st Faculty of Medicine, Charles University, 121 08 Prague 2, Czech Republic; (A.D.); (N.C.); (L.V.)
- 4 Department of Internal Medicine, Faculty General Hospital and 1 Faculty of Medicine, Charles University, 121 08 Prague 2, Czech Republic
| | - Cristina Bellarosa
- Italian Liver Foundation (FIF), Bldg Q—AREA Science Park Basovizza, SS14 Km 163,5, 34149 Trieste, Italy; (A.B.); (C.T.)
- Correspondence:
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5
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Ghavami A, Ziaei R, Foshati S, Hojati Kermani MA, Zare M, Amani R. Benefits and harms of ginseng supplementation on liver function? A systematic review and meta-analysis. Complement Ther Clin Pract 2020; 39:101173. [DOI: 10.1016/j.ctcp.2020.101173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/27/2020] [Accepted: 04/07/2020] [Indexed: 02/06/2023]
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6
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Nitti M, Furfaro AL, Mann GE. Heme Oxygenase Dependent Bilirubin Generation in Vascular Cells: A Role in Preventing Endothelial Dysfunction in Local Tissue Microenvironment? Front Physiol 2020; 11:23. [PMID: 32082188 PMCID: PMC7000760 DOI: 10.3389/fphys.2020.00023] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/13/2020] [Indexed: 12/22/2022] Open
Abstract
Among antioxidants in the human body, bilirubin has been recognized over the past 20 years to afford protection against different chronic conditions, including inflammation and cardiovascular disease. Moderate increases in plasma concentration and cellular bilirubin generation from metabolism of heme via heme oxygenase (HMOX) in virtually all tissues can modulate endothelial and vascular function and exert antioxidant and anti-inflammatory roles. This review aims to provide an up-to-date and critical overview of the molecular mechanisms by which bilirubin derived from plasma or from HMOX1 activation in vascular cells affects endothelial function. Understanding the molecular actions of bilirubin may critically improve the management not only of key cardiovascular diseases, but also provide insights into a broad spectrum of pathologies driven by endothelial dysfunction. In this context, therapeutic interventions aimed at mildly increasing serum bilirubin as well as bilirubin generated endogenously by endothelial HMOX1 should be considered.
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Affiliation(s)
- Mariapaola Nitti
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Anna Lisa Furfaro
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Giovanni E Mann
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
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7
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Kwon J, Park JS, Kang M, Choi S, Park J, Kim GT, Lee C, Cha S, Rhee HW, Shim SH. Bright ligand-activatable fluorescent protein for high-quality multicolor live-cell super-resolution microscopy. Nat Commun 2020; 11:273. [PMID: 31937765 PMCID: PMC6959352 DOI: 10.1038/s41467-019-14067-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 12/17/2019] [Indexed: 11/09/2022] Open
Abstract
We introduce UnaG as a green-to-dark photoswitching fluorescent protein capable of high-quality super-resolution imaging with photon numbers equivalent to the brightest photoswitchable red protein. UnaG only fluoresces upon binding of a fluorogenic metabolite, bilirubin, enabling UV-free reversible photoswitching with easily controllable kinetics and low background under Epi illumination. The on- and off-switching rates are controlled by the concentration of the ligand and the excitation light intensity, respectively, where the dissolved oxygen also promotes the off-switching. The photo-oxidation reaction mechanism of bilirubin in UnaG suggests that the lack of ligand-protein covalent bond allows the oxidized ligand to detach from the protein, emptying the binding cavity for rebinding to a fresh ligand molecule. We demonstrate super-resolution single-molecule localization imaging of various subcellular structures genetically encoded with UnaG, which enables facile labeling and simultaneous multicolor imaging of live cells. UnaG has the promise of becoming a default protein for high-performance super-resolution imaging. Photoconvertible proteins occupy two color channels thereby limiting multicolour localisation microscopy applications. Here the authors present UnaG, a new green-to-dark photoswitching fluorescent protein for super-resolution imaging, whose activation is based on a noncovalent binding with bilirubin.
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Affiliation(s)
- Jiwoong Kwon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul, 02841, Republic of Korea
| | - Jong-Seok Park
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.,SK Biopharmaceuticals Co., Ltd.,, Daejeon, 34124, Republic of Korea
| | - Minsu Kang
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul, 02841, Republic of Korea.,Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
| | - Soobin Choi
- Department of Chemistry, Hankuk University of Foreign Studies, Yongin, 17035, Republic of Korea
| | - Jumi Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Gyeong Tae Kim
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Changwook Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sangwon Cha
- Department of Chemistry, Hankuk University of Foreign Studies, Yongin, 17035, Republic of Korea
| | - Hyun-Woo Rhee
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea. .,Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.
| | - Sang-Hee Shim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul, 02841, Republic of Korea. .,Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea.
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8
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Experimental models assessing bilirubin neurotoxicity. Pediatr Res 2020; 87:17-25. [PMID: 31493769 DOI: 10.1038/s41390-019-0570-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/29/2019] [Accepted: 08/16/2019] [Indexed: 02/08/2023]
Abstract
The molecular and cellular events leading to bilirubin-induced neurotoxicity, the mechanisms regulating liver and intestine expression in neonates, and alternative pathways of bilirubin catabolism remain incompletely defined. To answer these questions, researchers have developed a number of model systems to closely recapitulate the main characteristics of the disease, ranging from tissue cultures to engineered mouse models. In the present review we describe in vitro, ex vivo, and in vivo models developed to study bilirubin metabolism and neurotoxicity, with a special focus on the use of engineered animal models. In addition, we discussed the most recent studies related to potential therapeutic approaches to treat neonatal hyperbilirubinemia, ranging from anti-inflammatory drugs, activation of nuclear receptor pathways, blockade of bilirubin catabolism, and stimulation of alternative bilirubin-disposal pathways.
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9
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Li X, Yu D, Jie H, Zhou H, Ye H, Ma G, Wan L, Li C, Shi H, Yin S. Cytochrome P450 1A2 Is Incapable of Oxidizing Bilirubin Under Physiological Conditions. Front Pharmacol 2019; 10:1220. [PMID: 31680983 PMCID: PMC6813656 DOI: 10.3389/fphar.2019.01220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 09/23/2019] [Indexed: 12/31/2022] Open
Abstract
Background: Bilirubin (BR) is metabolized mainly by uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1) through glucuronidation in the liver. Some studies have shown that several subtypes of cytochrome P450 (CYP) enzymes, including CYP1A2, are upregulated by inducers and proposed to be alternative BR degradation enzymes. However, no information is available on the BR degradation ability of CYP in normal rats without manipulation by CYP inducers. Methods: Quantitative real-time polymerase chain reaction (QRT-PCR), western blot, immunofluorescence, and confocal microscopy were used to find expression of CYP1A2 in the brain and the liver. BR metabolites in microsomal fractions during development were examined by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (LC-MS/MS). Results: In the present study, we observed that CYP1A2 mRNA levels increased at postnatal days (P)14 and P30 with respect to the level at P7 both in liver and brain, this increment was especially pronounced in the brain at P14. The expression of CYP1A2 in the brainstem (BS) was higher than that in the cerebellum (CLL) and cortex (COR). Meanwhile, the CYP1A2 protein level was significantly higher in the COR than in the brainstem and CLL at P14. The levels of BR and its metabolites (m/z values 301, 315, 333 and biliverdin) were statistically unaltered by incubation with liver and brain microsomal fractions. Conclusion: Our results indicated that the region-specific expression of CYP1A2 increased during development, but CYP family enzymes were physiologically incapable of metabolizing BR. The ability of CYPs to oxidize BR may be triggered by CYP inducers.
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Affiliation(s)
- Xinyi Li
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Dongzhen Yu
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Huiqun Jie
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Huiqun Zhou
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Haibo Ye
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Guo Ma
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University, Shanghai, China
| | - Lili Wan
- Department of Pharmacy, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Chunyan Li
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Haibo Shi
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Shankai Yin
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
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10
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Bock KW. Human AHR functions in vascular tissue: Pro- and anti-inflammatory responses of AHR agonists in atherosclerosis. Biochem Pharmacol 2018; 159:116-120. [PMID: 30508524 DOI: 10.1016/j.bcp.2018.11.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/29/2018] [Indexed: 02/07/2023]
Abstract
Despite decades of intense research physiologic aryl hydrocarbon receptor (AHR) functions have not been elucidated. Challenges include marked species differences and dependence on cell type and cellular context. A previous commentary on human AHR functions in skin and intestine has been extended to vascular tissue. Similar functions appear to be operating in vascular tissue including microbial defense, modulation of stem/progenitor cells as well as control of immunity and inflammation. However, AHR functions are Janus faced: Detrimental AHR functions in vascular tissue are well documented, e.g., upon exposure to polycyclic aromatic hydrocarbons in cigarette smoke leading to oxidative stress and generation of oxidized LDL. Modified LDL particles accumulate in macrophages and smooth muscle-derived pro-inflammatory foam cells, the hallmark of atherosclerosis. On the other hand, numerous anti-inflammatory AHR agonists have been identified including bilirubin and quercetin. Mechanisms as to how AHR produces pro- and anti-inflammatory responses in the vascular system need further investigation.
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Affiliation(s)
- Karl Walter Bock
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Wilhelmstrasse 56, D-72074 Tübingen, Germany.
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11
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Burkina V, Rasmussen MK, Oliinychenko Y, Zamaratskaia G. Porcine cytochrome 2A19 and 2E1. Basic Clin Pharmacol Toxicol 2018; 124:32-39. [PMID: 30171805 PMCID: PMC7379952 DOI: 10.1111/bcpt.13121] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/24/2018] [Indexed: 12/21/2022]
Abstract
Cytochrome P450 (CYP) is a major group of enzymes, which conduct Phase I metabolism. Among commonly used animal models, the pig has been suggested as the most suitable model for investigating drug metabolism in human beings. Moreover, porcine CYP2A19 and CYP2E1 are responsible for the biotransformation of both endogenous and exogenous compounds such as 3‐methylindole (skatole), sex hormones and food compounds. However, little is known about the regulation of porcine CYP2A19 and CYP2E1. In this MiniReview, we summarise the current knowledge about the regulation of porcine CYP2A19 and CYP2E1 by environmental, biological and dietary factors. Finally, we reflect on the need for further research, to clarify the interaction between active feed components and the porcine CYP system.
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Affiliation(s)
- Viktoriia Burkina
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in Ceske Budejovice, Vodnany, Czech Republic.,Department of Molecular Science, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | | | - Galia Zamaratskaia
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in Ceske Budejovice, Vodnany, Czech Republic.,Department of Molecular Science, Swedish University of Agricultural Sciences, Uppsala, Sweden
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12
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Bock KW. From TCDD-mediated toxicity to searches of physiologic AHR functions. Biochem Pharmacol 2018; 155:419-424. [PMID: 30055148 DOI: 10.1016/j.bcp.2018.07.032] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 07/23/2018] [Indexed: 12/18/2022]
Abstract
TCDD-mediated toxicity of human individuals together with animal studies led to identification of the aryl hydrocarbon receptor (AHR). It was characterized as multifunctional ligand-activated transcription factor and environmental sensor. Comparison of human toxic responses and animal models provide hints to physiologic AHR functions including chemical and microbial defense, homeostasis of stem/progenitor cells and modulation of the immune system in barrier organs such as skin and the gastrointestinal tract. Extrapolation from animals to humans is difficult due to marked species differences and dependence of AHR function on the cellular context. Nevertheless, therapeutic possibilities of AHR agonists and antagonists are in development. The AHR remains challenging and fascinating.
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Affiliation(s)
- Karl Walter Bock
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Wilhelmstrasse 56, D-72074 Tübingen, Germany.
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13
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Tomankova V, Anzenbacher P, Anzenbacherova E. Effects of obesity on liver cytochromes P450 in various animal models. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2017; 161:144-151. [DOI: 10.5507/bp.2017.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 05/11/2017] [Indexed: 01/24/2023] Open
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14
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Amin HK, El-Araby AM, Eid S, Nasr T, Bondock S, Leheta O, Dawoud ME. A Thiazole Analogue Exhibits an Anti-Proliferative Effect in Different Human Carcinoma Cell Lines and Its Mechanism Based on Molecular Modeling. ACTA ACUST UNITED AC 2017. [DOI: 10.4236/abc.2017.71005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Gazzin S, Vitek L, Watchko J, Shapiro SM, Tiribelli C. A Novel Perspective on the Biology of Bilirubin in Health and Disease. Trends Mol Med 2016; 22:758-768. [PMID: 27515064 DOI: 10.1016/j.molmed.2016.07.004] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 07/14/2016] [Indexed: 01/02/2023]
Abstract
Unconjugated bilirubin (UCB) is known to be one of the most potent endogenous antioxidant substances. While hyperbilirubinemia has long been recognized as an ominous sign of liver dysfunction, recent data strongly indicate that mildly elevated bilirubin (BLB) levels can be protective against an array of diseases associated with increased oxidative stress. These clinical observations are supported by new discoveries relating to the role of BLB in immunosuppression and inhibition of protein phosphorylation, resulting in the modulation of intracellular signaling pathways in vascular biology and cancer, among others. Collectively, the evidence suggests that targeting BLB metabolism could be considered a potential therapeutic approach to ameliorate a variety of conditions.
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Affiliation(s)
- Silvia Gazzin
- Liver Research Center, Italian Liver Foundation, SS14, Km 163.5, Trieste, Italy
| | - Libor Vitek
- 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
| | - Jon Watchko
- Division of Newborn Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Steven M Shapiro
- Division of Neurology, Department of Pediatrics, Children's Mercy Hospital & Clinics, Kansas City, MO, USA; University of Missouri-Kansas City, Kansas City, MO, USA; Department of Neurology, University of Kansas, Kansas City, KS, USA; Department of Pediatrics, University of Kansas, Kansas City, KS, USA
| | - Claudio Tiribelli
- Liver Research Center, Italian Liver Foundation, SS14, Km 163.5, Trieste, Italy; Department of Medical Sciences, University of Trieste, Trieste, Italy.
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16
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Hu H, Yu T, Arpiainen S, Lang MA, Hakkola J, Abu-Bakar A. Tumour suppressor protein p53 regulates the stress activated bilirubin oxidase cytochrome P450 2A6. Toxicol Appl Pharmacol 2015; 289:30-9. [PMID: 26343999 DOI: 10.1016/j.taap.2015.08.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 08/31/2015] [Accepted: 08/31/2015] [Indexed: 12/20/2022]
Abstract
Human cytochrome P450 (CYP) 2A6 enzyme has been proposed to play a role in cellular defence against chemical-induced oxidative stress. The encoding gene is regulated by various stress activated transcription factors. This paper demonstrates that p53 is a novel transcriptional regulator of the gene. Sequence analysis of the CYP2A6 promoter revealed six putative p53 binding sites in a 3kb proximate promoter region. The site closest to transcription start site (TSS) is highly homologous with the p53 consensus sequence. Transfection with various stepwise deletions of CYP2A6-5'-Luc constructs--down to -160bp from the TSS--showed p53 responsiveness in p53 overexpressed C3A cells. However, a further deletion from -160 to -74bp, including the putative p53 binding site, totally abolished the p53 responsiveness. Electrophoretic mobility shift assay with a probe containing the putative binding site showed specific binding of p53. A point mutation at the binding site abolished both the binding and responsiveness of the recombinant gene to p53. Up-regulation of the endogenous p53 with benzo[α]pyrene--a well-known p53 activator--increased the expression of the p53 responsive positive control and the CYP2A6-5'-Luc construct containing the intact p53 binding site but not the mutated CYP2A6-5'-Luc construct. Finally, inducibility of the native CYP2A6 gene by benzo[α]pyrene was demonstrated by dose-dependent increases in CYP2A6 mRNA and protein levels along with increased p53 levels in the nucleus. Collectively, the results indicate that p53 protein is a regulator of the CYP2A6 gene in C3A cells and further support the putative cytoprotective role of CYP2A6.
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Affiliation(s)
- Hao Hu
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland, Australia.
| | - Ting Yu
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland, Australia.
| | - Satu Arpiainen
- Institute of Biomedicine, Department of Pharmacology and Toxicology and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.
| | - Matti A Lang
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland, Australia.
| | - Jukka Hakkola
- Institute of Biomedicine, Department of Pharmacology and Toxicology and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.
| | - A'edah Abu-Bakar
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland, Australia.
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17
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Pelkonen O. Drug Metabolism - FromIn VitrotoIn Vivo, From Simple to Complex. Basic Clin Pharmacol Toxicol 2015; 117:147-55. [DOI: 10.1111/bcpt.12429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 06/09/2015] [Indexed: 11/26/2022]
Affiliation(s)
- Olavi Pelkonen
- Centre of Biomedical Research; Department of Pharmacology and Toxicology; University of Oulu; Oulu Finland
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18
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Abramovitz A, McQueen A, Martinez RE, Williams BJ, Sumner W. Electronic cigarettes: The nicotyrine hypothesis. Med Hypotheses 2015; 85:305-10. [PMID: 26100465 DOI: 10.1016/j.mehy.2015.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 05/26/2015] [Accepted: 06/02/2015] [Indexed: 01/03/2023]
Abstract
There are conflicting reports about the efficacy of electronic cigarettes (e-cigs) as nicotine delivery devices and smoking cessation products. In addition, smokers' responses to some nicotine dependence questions often change as they transition to exclusive e-cig use. Nicotyrine may explain these observations. Nicotyrine forms by the gradual oxidation of nicotine in e-liquids exposed to air. E-cigs aerosolize nicotyrine along with nicotine. Nicotyrine inhibits the cytochrome P450 2A family of enzymes (CYP2A) in airways and liver. These enzymes metabolize nicotine to cotinine, and then cotinine to trans 3-hydroxycotinine. In humans, nicotine is metabolized primarily by hepatic CYP2A6. We propose that e-cig users (vapers) achieve measurable serum nicotine levels when they inhale nicotine and nicotyrine together, because nicotyrine reversibly inhibits nicotine metabolism by CYP2A13 in airways. Consuming nicotyrine by any route should irreversibly inhibit hepatic CYP2A6. When CYP2A6 is substantially inhibited, nicotine clearance is delayed and nicotine withdrawal symptoms are attenuated. Small, relatively infrequent nicotine doses can then sustain satisfying nicotine levels. This theory has numerous implications for e-cig research and tobacco control. Behavioral and pharmacokinetic e-cig studies should be interpreted with attention to likely levels of nicotyrine delivery: e-cig studies may need to routinely measure nicotyrine exposure, assess CYP2A6 activity, confirm nicotine delivery, or deliberately compare unoxidized and oxidized e-liquids. The risks of nicotyrine exposure include impaired clearance of all CYP2A substrates and any effects of the metabolic products of nicotyrine. CYP2A inhibitors like nicotyrine may be useful for future smoking cessation therapy.
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Affiliation(s)
- Aaron Abramovitz
- School of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Amy McQueen
- School of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Raul E Martinez
- School of Engineering & Applied Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Brent J Williams
- School of Engineering & Applied Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Walton Sumner
- School of Medicine, Washington University in St. Louis, St. Louis, MO, USA.
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19
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Ng JC, Juhasz A, Smith E, Naidu R. Assessing the bioavailability and bioaccessibility of metals and metalloids. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:8802-8825. [PMID: 23764979 DOI: 10.1007/s11356-013-1820-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 05/13/2013] [Indexed: 06/02/2023]
Abstract
Bioavailability (BA) determines the potential harm of a contaminant that exerts on the receptor. However, environmental guidelines for site contamination assessment are often set assuming the contaminant is 100 % bioavailable. This conservative approach to assessing site risk may result in the unnecessary and expensive remediation of a contaminated site. The National Environmental Protection Measures in Australia has undergone a statutory 5-year review that recommended that contaminant bioavailability and bioaccessibility (BAC) measures be adopted as part of the contaminated site risk assessment process by the National Environment Protection Council. We undertook a critical review of the current bioavailability and bioaccessibility approaches, methods and their respective limitations. The 'gold' standard to estimate the portion of a contaminant that reaches the system circulatory system (BA) of its receptor is to determine BA in an in vivo system. Various animal models have been utilised for this purpose. Because of animal ethics issues, and the expenses associated with performing in vivo studies, several in vitro methods have been developed to determine BAC as a surrogate model for the estimation of BA. However, few in vitro BAC studies have been calibrated against a reliable animal model, such as immature swine. In this review, we have identified suitable methods for assessing arsenic and lead BAC and proposed a decision tree for the determination of contaminant bioavailability and bioaccessibility for health risk assessment.
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Affiliation(s)
- Jack C Ng
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), Brisbane, Queensland, 4108, Australia,
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20
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Bock KW. Roles of human UDP-glucuronosyltransferases in clearance and homeostasis of endogenous substrates, and functional implications. Biochem Pharmacol 2015; 96:77-82. [PMID: 25937523 DOI: 10.1016/j.bcp.2015.04.020] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 04/24/2015] [Indexed: 11/19/2022]
Abstract
Human UDP-glucuronosyltransferases (UGTs) are major phase II enzymes in the drug metabolism system. Despite major advances in characterization of UGT gene family members, their role in clearance and homeostasis of endogenous substrates is insufficiently understood. Endobiotic substrates including bilirubin, serotonin, eicosanoids, steroid hormones, bile acids, thyroxine and fat-soluble vitamins A and D are discussed. Species- and tissue/cell-dependent regulation of UGT expression by ligand-activated transcription factors is often involved in endobiotic homeostasis. However, roles of particular UGTs are often difficult to delineate since they function together with other enzymes and transporters. Better knowledge of endobiotic UGT substrates and consequences of their conjugation may help to understand evolutionary conserved UGT functions.
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Affiliation(s)
- Karl Walter Bock
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology. University of Tübingen, Wilhelmstrasse 56, D-72074 Tübingen, Germany.
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21
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De-Oliveira ACAX, Poça KS, Totino PRR, Paumgartten FJR. Modulation of cytochrome P450 2A5 activity by lipopolysaccharide: low-dose effects and non-monotonic dose-response relationship. PLoS One 2015; 10:e0117842. [PMID: 25635819 PMCID: PMC4311977 DOI: 10.1371/journal.pone.0117842] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 01/03/2015] [Indexed: 12/23/2022] Open
Abstract
Mouse cytochrome P450 (CYP) 2A5 is induced by inflammatory conditions and infectious diseases that down-regulate the expression and activity of most other CYP isoforms. Enhanced oxidative stress and nuclear factor (erythroid 2-related factor) 2 (Nrf2) transcription factor activation have been hypothesised to mediate up-regulation of CYP2A5 expression in the murine liver. The unique and complex regulation of CYP2A5, however, is far from being thoroughly elucidated. Sepsis and high doses of bacterial lipopolysaccharide (LPS) elicit oxidative stress in the liver, but depression, not induction, of CYP2A5 has been observed in studies of mice treated with LPS. The foregoing facts prompted us to evaluate the response of CYP2A5 liver activity in female DBA-2 mice over a broad range of LPS doses (0, 0.025, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, and 20 mg/kg). Cytokine levels (interleukin [IL]-2, IL-4, IL-6, IL-10, IL-17A, interferon gamma, tumour necrosis factor alpha) and nitric oxide (NO) were measured in the blood serum. Activities of CYP1A (EROD) and CYP2B (BROD) in the liver were also determined for comparative purposes. LPS depressed CYP2A5 at low doses (0.025–2.0 mg/kg) but not at doses (>2 mg/kg) that increased pro-inflammatory cytokines and NO serum levels, and depressed CYP1A and CYP2B activities. Blockade of pro-inflammatory cytokines and the overproduction of NO induced by co-treatment with pentoxifylline and LPS and iNOS inhibition with aminoguanidine both extended down-regulation of CYP2A5 to the high dose range while not affecting LPS-induced depression of CYP1A and CYP2B. Overall, the results suggested that NO plays a role in the reversal of the low-dose LPS-induced depression of CYP2A5 observed when mice were challenged with higher doses of LPS.
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Affiliation(s)
- Ana C. A. X. De-Oliveira
- Laboratory of Environmental Toxicology, Department of Biological Sciences, National School of Public Health, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, 21040–361, Brazil
- * E-mail:
| | - Kátia S. Poça
- Laboratory of Environmental Toxicology, Department of Biological Sciences, National School of Public Health, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, 21040–361, Brazil
| | - Paulo R. R. Totino
- Laboratory of Malaria Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, 21040–361, Brazil
| | - Francisco J. R. Paumgartten
- Laboratory of Environmental Toxicology, Department of Biological Sciences, National School of Public Health, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, 21040–361, Brazil
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22
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Muhsain SNF, Lang MA, Abu-Bakar A. Mitochondrial targeting of bilirubin regulatory enzymes: An adaptive response to oxidative stress. Toxicol Appl Pharmacol 2015; 282:77-89. [DOI: 10.1016/j.taap.2014.11.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/15/2014] [Accepted: 11/21/2014] [Indexed: 12/20/2022]
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23
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Role of brain cytochrome P450 mono-oxygenases in bilirubin oxidation-specific induction and activity. Arch Toxicol 2014; 90:279-90. [DOI: 10.1007/s00204-014-1394-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 10/16/2014] [Indexed: 01/24/2023]
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24
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Konstandi M, Johnson EO, Lang MA. Consequences of psychophysiological stress on cytochrome P450-catalyzed drug metabolism. Neurosci Biobehav Rev 2014; 45:149-67. [DOI: 10.1016/j.neubiorev.2014.05.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/17/2014] [Accepted: 05/18/2014] [Indexed: 12/11/2022]
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25
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Bock KW. Homeostatic control of xeno- and endobiotics in the drug-metabolizing enzyme system. Biochem Pharmacol 2014; 90:1-6. [DOI: 10.1016/j.bcp.2014.04.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/14/2014] [Accepted: 04/14/2014] [Indexed: 10/25/2022]
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26
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Niittynen M, Simanainen U, Pohjanvirta R, Sankari S, Tuomisto JT. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) increases bilirubin formation but hampers quantitative hepatic conversion of biliverdin to bilirubin in rats with wild-type AH receptor. Basic Clin Pharmacol Toxicol 2014; 114:497-509. [PMID: 24418412 DOI: 10.1111/bcpt.12191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 12/30/2013] [Indexed: 11/29/2022]
Abstract
In haem degradation, haem oxygenase-1 (HO-1) first cleaves haem to biliverdin, which is reduced to bilirubin by biliverdin IXα reductase (BVR-A). The environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes hepatic accumulation of biliverdin in moderately TCDD-resistant line B (Kuopio) rats. Using line B and two TCDD-sensitive rat strains, the present study set out to probe the dose-response and biochemical mechanisms of this accumulation. At 28 days after exposure to 3-300 μg/kg TCDD in line B rats, already the lowest dose of TCDD tested, 3 μg/kg, affected serum bilirubin conjugates, and after doses ≥100 μg/kg, the liver content of bilirubin, biliverdin and their conjugates (collectively 'bile pigments') as well as HO-1 was elevated. BVR-A activity and serum bile acids were increased only by the doses of 100 and 300 μg/kg TCDD, respectively. Biliverdin conjugates correlated best with biliverdin suggesting it to be their immediate precursor. TCDD (100 μg/kg, 10 days) increased hepatic bilirubin and biliverdin levels also in TCDD-sensitive Long-Evans (Turku/AB; L-E) rats. Hepatic bilirubin and bile acids, but not biliverdin, were increased in feed-restricted L-E control rats. In TCDD-sensitive line C (Kuopio) rats, 10 μg/kg of TCDD increased the body-weight-normalized biliary excretion of bilirubin. Altogether, the results suggest that at acutely toxic doses, TCDD induces the formation of bilirubin in rats. However, concurrently, TCDD seems to hamper the quantitative conversion of biliverdin to bilirubin in line B and L-E rats' liver. Biliverdin conjugates are most likely formed as secondary products of biliverdin.
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Affiliation(s)
- Marjo Niittynen
- Department of Environmental Health, National Institute for Health and Welfare, Kuopio, Finland
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27
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Huang CC, Monte A, Cook JM, Kabir MS, Peterson KP. Zebrafish heart failure models for the evaluation of chemical probes and drugs. Assay Drug Dev Technol 2013; 11:561-72. [PMID: 24351044 PMCID: PMC3870487 DOI: 10.1089/adt.2013.548] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Heart failure is a complex disease that involves genetic, environmental, and physiological factors. As a result, current medication and treatment for heart failure produces limited efficacy, and better medication is in demand. Although mammalian models exist, simple and low-cost models will be more beneficial for drug discovery and mechanistic studies of heart failure. We previously reported that aristolochic acid (AA) caused cardiac defects in zebrafish embryos that resemble heart failure. Here, we showed that cardiac troponin T and atrial natriuretic peptide were expressed at significantly higher levels in AA-treated embryos, presumably due to cardiac hypertrophy. In addition, several human heart failure drugs could moderately attenuate the AA-induced heart failure by 10%-40%, further verifying the model for drug discovery. We then developed a drug screening assay using the AA-treated zebrafish embryos and identified three compounds. Mitogen-activated protein kinase kinase inhibitor (MEK-I), an inhibitor for the MEK-1/2 known to be involved in cardiac hypertrophy and heart failure, showed nearly 60% heart failure attenuation. C25, a chalcone derivative, and A11, a phenolic compound, showed around 80% and 90% attenuation, respectively. Time course experiments revealed that, to obtain 50% efficacy, these compounds were required within different hours of AA treatment. Furthermore, quantitative polymerase chain reaction showed that C25, not MEK-I or A11, strongly suppressed inflammation. Finally, C25 and MEK-I, but not A11, could also rescue the doxorubicin-induced heart failure in zebrafish embryos. In summary, we have established two tractable heart failure models for drug discovery and three potential drugs have been identified that seem to attenuate heart failure by different mechanisms.
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Affiliation(s)
- Cheng-Chen Huang
- Department of Biology, University of Wisconsin–River Falls, River Falls, Wisconsin
| | - Aaron Monte
- Department of Chemistry and Biochemistry, University of Wisconsin–La Crosse, La Crosse, Wisconsin
| | - James M. Cook
- Department of Chemistry and Biochemistry, University of Wisconsin–Milwaukee, Milwaukee, Wisconsin
| | - Mohd Shahjahan Kabir
- Department of Chemistry and Biochemistry, University of Wisconsin–Milwaukee, Milwaukee, Wisconsin
| | - Karl P. Peterson
- Department of Chemistry, University of Wisconsin–River Falls, River Falls, Wisconsin
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28
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Cytochrome P450 2A5 and bilirubin: Mechanisms of gene regulation and cytoprotection. Toxicol Appl Pharmacol 2013; 270:129-38. [DOI: 10.1016/j.taap.2013.04.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 04/16/2013] [Accepted: 04/18/2013] [Indexed: 12/19/2022]
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29
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Cytochrome P450 enzymes in drug metabolism: regulation of gene expression, enzyme activities, and impact of genetic variation. Pharmacol Ther 2013; 138:103-41. [PMID: 23333322 DOI: 10.1016/j.pharmthera.2012.12.007] [Citation(s) in RCA: 2529] [Impact Index Per Article: 229.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 12/27/2012] [Indexed: 02/06/2023]
Abstract
Cytochromes P450 (CYP) are a major source of variability in drug pharmacokinetics and response. Of 57 putatively functional human CYPs only about a dozen enzymes, belonging to the CYP1, 2, and 3 families, are responsible for the biotransformation of most foreign substances including 70-80% of all drugs in clinical use. The highest expressed forms in liver are CYPs 3A4, 2C9, 2C8, 2E1, and 1A2, while 2A6, 2D6, 2B6, 2C19 and 3A5 are less abundant and CYPs 2J2, 1A1, and 1B1 are mainly expressed extrahepatically. Expression of each CYP is influenced by a unique combination of mechanisms and factors including genetic polymorphisms, induction by xenobiotics, regulation by cytokines, hormones and during disease states, as well as sex, age, and others. Multiallelic genetic polymorphisms, which strongly depend on ethnicity, play a major role for the function of CYPs 2D6, 2C19, 2C9, 2B6, 3A5 and 2A6, and lead to distinct pharmacogenetic phenotypes termed as poor, intermediate, extensive, and ultrarapid metabolizers. For these CYPs, the evidence for clinical significance regarding adverse drug reactions (ADRs), drug efficacy and dose requirement is rapidly growing. Polymorphisms in CYPs 1A1, 1A2, 2C8, 2E1, 2J2, and 3A4 are generally less predictive, but new data on CYP3A4 show that predictive variants exist and that additional variants in regulatory genes or in NADPH:cytochrome P450 oxidoreductase (POR) can have an influence. Here we review the recent progress on drug metabolism activity profiles, interindividual variability and regulation of expression, and the functional and clinical impact of genetic variation in drug metabolizing P450s.
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30
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Tanii H, Shitara Y, Torii M, Sekine S, Iwata H, Horie T. Induction of Cytochrome P450 2A6 by Bilirubin in Human Hepatocytes. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/pp.2013.42026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Lämsä V, Levonen AL, Sormunen R, Yamamoto M, Hakkola J. Heme and heme biosynthesis intermediates induce heme oxygenase-1 and cytochrome P450 2A5, enzymes with putative sequential roles in heme and bilirubin metabolism: different requirement for transcription factor nuclear factor erythroid- derived 2-like 2. Toxicol Sci 2012; 130:132-44. [PMID: 22859313 DOI: 10.1093/toxsci/kfs237] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cytochrome P450 2A5 (CYP2A5) oxidizes bilirubin to biliverdin and represents a putative candidate for maintaining bilirubin at safe but adequate antioxidant levels. Curiously, CYP2A5 is induced by both excessive heme and chemicals that inhibit heme synthesis. We hypothesized that heme homeostasis is a key modifier of Cyp2a5 expression via transcription factor nuclear factor erythroid-derived 2-like 2 (Nrf2) and characterized the coordination of CYP2A5 and heme oxygenase-1 (HMOX1) responses using wild-type and Nrf2(-/-) primary mouse hepatocytes. HMOX1 was rapidly elevated by exogenous hemin, thereby limiting the transactivation of Cyp2a5 until high heme (> 5µM) exposure. Nrf2 was mandatory for CYP2A5 but not for HMOX1 induction by heme. CYP2A5 was intensively and HMOX1 moderately elevated in heme synthesis blockades by succinylacetone and N-methyl protoporphyrin IX, and Nrf2 partially mediated the induction of CYP2A5. Immunoelectron microscopy revealed that CYP2A5 is targeted Nrf2 dependently both to the endoplasmic reticulum (ER) and mitochondria. However, excessive heme increased CYP2A5 predominantly in the ER. Phenobarbital, dibutyryl-cAMP, and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) overexpression stimulate heme biosynthesis and induce CYP2A5. Acute but not chronic CYP2A5 induction by phenobarbital required Nrf2, whereas CYP2A5 induction by dibutyryl-cAMP and PGC-1α was potentiated by Nrf2 knockout. Collectively, heme homeostasis is established as a crucial regulator of hepatic Cyp2a5 expression mediated via Nrf2 activation, whereas Nrf2 is redundant for Hmox1 induction by heme. Similar subcellular targeting and coordination of CYP2A5 and HMOX1 responses suggest favorable conditions for enhanced CYP2A5-mediated bilirubin maintenance in altered heme homeostasis that predisposes to oxidative stress.
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Affiliation(s)
- Virpi Lämsä
- Department of Pharmacology and Toxicology, Institute of Biomedicine, University of Oulu, 90014 Oulu, Finland
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