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Tominaga S, Yoshioka H, Yokota S, Tsukiboshi Y, Suzui M, Nagai M, Hara H, Maeda T, Miura N. Copper-induced diurnal hepatic toxicity is associated with Cry2 and Per1 in mice. Environ Health Prev Med 2023; 28:78. [PMID: 38092388 PMCID: PMC10739358 DOI: 10.1265/ehpm.23-00205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/07/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND This study aimed to investigate diurnal variations in copper-induced hepatic toxicity and the molecular mechanisms underlying this chronotoxicity. METHODS Male C57BL/6J mice were intraperitoneally injected with copper chloride (CuCl2) at zeitgeber time 2 (ZT2) or 14 (ZT14), twice per week for 5 or 8 weeks. Seventy-two hours after the final CuCl2 injection, the mice were euthanized, and plasma samples were collected. The livers and kidneys were collected and weighed. In vitro experiments were performed to assess cell viability and fluctuations in clock gene expression levels in Hepa1-6 cells after CuCl2 treatment. We examined copper homeostasis- and apoptosis-related genes under clock genes overexpression. RESULTS Repeated CuCl2 administration for 8 weeks resulted in more severe toxicity at ZT14 compared to ZT2. CuCl2 administration at ZT14 elevated plasma aspartate aminotransferase, hepatic tumor necrosis factor-α, and interleukin-6 for 5 weeks, whereas the toxic effects of CuCl2 administration at ZT2 were weaker. Moreover, CuCl2 treatment inhibited Hepa1-6 cell viability in a dose-dependent manner. We observed increased expression of three clock genes (Ciart, Cry2, and Per1) after CuCl2 treatment. Among them, overexpression of Cry2 and Per1 accelerated CuCl2-induced inhibition of Hepa1-6 cell viability. Moreover, we found that the overexpression of Cry2 and Per1 regulates cleaved caspase-3 by modulating the copper transporter genes ATP7B and CTR1. CONCLUSION These results suggest that CuCl2-induced diurnal toxicity is associated with Cry2 and Per1 expression through the regulation of copper transporter genes in mice.
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Affiliation(s)
- Sarah Tominaga
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyamaku, Nagoya, Aichi 463-8521, Japan
- Department of Neurotoxicology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan
| | - Hiroki Yoshioka
- Faculty of Pharmacy, Gifu University of Medical Science, 4-3-3 Nijigaoka, Kani, Gifu 509-0293, Japan
| | - Satoshi Yokota
- Division of Cellular and Molecular Toxicology, Center for Biological Safety and Research, National Institute of Health Sciences, 3-25-26 Tono-machi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Yosuke Tsukiboshi
- Faculty of Pharmacy, Gifu University of Medical Science, 4-3-3 Nijigaoka, Kani, Gifu 509-0293, Japan
| | - Masumi Suzui
- Department of Neurotoxicology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan
| | - Makoto Nagai
- Graduate School of Health and Medicine, Gifu University of Medical Science, 795-1 Nagamine Ichihiraga, Seki, Gifu 501-3892, Japan
| | - Hirokazu Hara
- Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, Gifu 501-1196, Japan
| | - Tohru Maeda
- College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyamaku, Nagoya, Aichi 463-8521, Japan
| | - Nobuhiko Miura
- Department of Health Science, Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama, Kanagawa 245-2006, Japan
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Yu F, Liu Y, Zhang R, Zhu L, Zhang T, Shi Y. Recent advances in circadian-regulated pharmacokinetics and its implications for chronotherapy. Biochem Pharmacol 2022; 203:115185. [PMID: 35902039 DOI: 10.1016/j.bcp.2022.115185] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 11/02/2022]
Abstract
Dependence of pharmacokinetics and drug effects (efficacy and toxicity) on dosing time has long been recognized. However, significant progress has only recently been made in our understanding of circadian rhythms and their regulation on drug pharmacokinetics, efficacy and toxicity. This review will cover the relevant literature and a series of publications from our work summarizing the effects of circadian rhythms on drug pharmacokinetics, and propose that the influence of circadian rhythms on pharmacokinetics are ultimately translated into therapeutic effects and side effects of drugs. Evidence suggests that daily rhythmicity in expression of drug-metabolizing enzymes and transporters necessary for drug ADME (absorption, distribution, metabolism and excretion) are key factors determining circadian pharmacokinetics. Newly discovered mechanisms for circadian control of the enzymes and transporters are covered. We also discuss how the rhythms of drug-processing proteins are translated into circadian pharmacokinetics and drug chronoefficacy/chronotoxicity, which has direct implications for chronotherapy. More importantly, we will present perspectives on the challenges that are still needed for a breakthrough in translational research. In addition, knowledge of the circadian influence on drug disposition has provided new possibilities for novel pharmacological strategies. Careful application of pharmacokinetics-based chronotherapy strategies can improve efficacy and reduce toxicity. Circadian rhythm-mediated metabolic and transport strategies can also be implemented to design drugs.
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Affiliation(s)
- Fangjun Yu
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yuanyuan Liu
- School of Fundamental Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Rong Zhang
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Lijun Zhu
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Tianpeng Zhang
- Institute of Molecular Rhythm and Metabolism, Guangzhou University of Chinese Medicine, Guangzhou, China.
| | - Yafei Shi
- School of Fundamental Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.
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Ozturk N, Ozturk Civelek D, Sancar S, Kaptan E, Pala Kara Z, Okyar A. Dosing-time dependent testicular toxicity of everolimus in mice. Eur J Pharm Sci 2021; 165:105926. [PMID: 34242751 DOI: 10.1016/j.ejps.2021.105926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 06/13/2021] [Accepted: 07/04/2021] [Indexed: 11/19/2022]
Abstract
The circadian timing system controls many biological functions in mammals including drug metabolism and detoxification, cell cycle events, and thus may affect pharmacokinetics, target organ toxicity and efficacy of medicines. Selective mTOR (mammalian target of rapamycin) inhibitor everolimus is an immunosuppressant and anticancer drug that is effective against several cancers. The aim of this study was to investigate dosing-time dependent testicular toxicity of subacute everolimus administration in mice. C57BL/6 J male mice were synchronized with Light-Dark (12h:12 h) cycle, with Light-onset at Zeitgeber Time (ZT)-0. Everolimus (5 mg/kg/day) was administered orally to mice at ZT1rest-span or ZT13activity-span for 4 weeks. Body weight loss, clinical signs, changes in testicular weights, testis histology, spermatogenesis and proliferative activity of germinal epithelium of seminiferous tubules were examined. Steady-state everolimus concentrations in testes were determined with validated HPLC method. Everolimus toxicity was less severe following dosing at ZT13 compared to ZT1, as shown with least body weight loss (p<0.001), least reductions in testes weights (p<0.001) and least histopathological findings. Everolimus-induced histological changes on testes included vacuolisation and atrophy of germinal epithelium, and loss of germinal cell attachment. The severity of everolimus-induced histological toxicity on testes was significantly more evident in mice treated at ZT1 than ZT13 (p<0.001). Spermatogenic cell population significantly decreased when everolimus administered at ZT1 compared to ZT13 (p<0.001). Proliferative activity of germinal epithelium was significantly decreased due to treatment at ZT1 compared to ZT13 (p<0.001). Everolimus concentrations in testes indicated a pronounced circadian variation, which was greater in mice treated at ZT1 compared to ZT13 (p<0.05). Our study revealed dosing-time dependent testicular toxicity of everolimus in mice, which was greater in severity when everolimus administered at early rest-span (daytime-ZT1) than early activity-span (nighttime-ZT13). These findings support the concept of everolimus chronotherapy for minimizing reproductive toxicity and increasing the tolerability of everolimus, as a clinical advantage.
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Affiliation(s)
- Narin Ozturk
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Beyazit-Istanbul, Turkey
| | - Dilek Ozturk Civelek
- Department of Pharmacology, Faculty of Pharmacy, Bezmialem Vakif University, Fatih-Istanbul, Turkey
| | - Serap Sancar
- Department of Biology, Faculty of Science, Istanbul University, Vezneciler-Istanbul, Turkey
| | - Engin Kaptan
- Department of Biology, Faculty of Science, Istanbul University, Vezneciler-Istanbul, Turkey
| | - Zeliha Pala Kara
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Beyazit-Istanbul, Turkey
| | - Alper Okyar
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Beyazit-Istanbul, Turkey.
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Yang Z, Lin Y, Gao L, Zhou Z, Wang S, Dong D, Wu B. Circadian clock regulates metabolism and toxicity of Fuzi(lateral root of Aconitum carmichaeli Debx) in mice. Phytomedicine 2020; 67:153161. [PMID: 31911401 DOI: 10.1016/j.phymed.2019.153161] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/18/2019] [Accepted: 12/24/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Therapeutic applications of Fuzi (lateral root of Aconitum carmichaeli Debx) are seriously concerned with its toxic effects. Strategies and approaches to reducing toxicity are of great interest. PURPOSE We aimed to characterize the diurnal rhythm of Fuzi toxicity, and to determine the role of metabolism and pharmacokinetics in generating toxicity rhythmicity. METHODS Toxicity was determined based on assessment of heart injury and animal survival after dosing mice with Fuzi decoction at different circadian time points. Circadian clock control of pharmacokinetics and toxicity was investigated using Bmal1-deficient (Bmal1-/-) mice. RESULTS Fuzi exhibited a diurnal rhythmicity in cardiotoxicity (reflected by plasma CK-MB and LDH levels). The highest level of toxicity was observed at ZT10 (5 PM), while the lowest level of toxicity occurred at ZT22 (5 AM). Also, a higher mortality rate was observed at ZT10 and lower mortality rates at other times of the day. ZT10 dosing of Fuzi generated higher systemic exposures of three toxic alkaloid ingredients aconitine (AC), hypaconitine (HA) and mesaconitine (MA) compared to ZT22. This was accompanied by reduced the formation of the metabolites (N-deethyl-AC, didemethyl-HA and 2‑hydroxyl‑MA) at ZT10. Bmal1 ablation resulted in an increased level of Fuzi toxicity at ZT22, while having no influences when drug was dosed at ZT10. As a consequence, circadian time-dependent toxicity of Fuzi was lost in Bmal1-deficient mice. In addition, Bmal1 ablation increased the plasma concentrations of AC, HA and MA in mice after oral gavage of Fuzi, and reduced formation of their metabolites (N-deethyl-AC, didemethyl-HA and 2‑hydroxyl‑MA). Moreover, Fuzi metabolism in wild-type liver microsomes was more extensive at ZT22 than at ZT10. Bmal1 ablation abrogated circadian time-dependency of hepatic Fuzi metabolism. CONCLUSIONS Fuzi chronotoxicity in mice was attributed to time-varying hepatic metabolism and systemic exposure regulated by circadian clock. The findings may have implications in reducing Fuzi toxicity with a chronotherapeutic approach.
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Affiliation(s)
- Zemin Yang
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Yanke Lin
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Lu Gao
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Ziyue Zhou
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Shuai Wang
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Dong Dong
- School of Medicine, Jinan University, Guangzhou, China.
| | - Baojian Wu
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632, China.
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Zhou C, Yu F, Zeng P, Zhang T, Huang H, Chen W, Wu B. Circadian sensitivity to the cardiac glycoside oleandrin is associated with diurnal intestinal P-glycoprotein expression. Biochem Pharmacol 2019; 169:113622. [PMID: 31472126 DOI: 10.1016/j.bcp.2019.08.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 08/26/2019] [Indexed: 12/21/2022]
Abstract
The cardiac glycoside oleandrin is a main active constituent of the botanical anti-cancer drug candidate PBI-05204, an extract of Nerium oleander. Here, we aimed to determine the circadian sensitivity of mice to oleandrin, and to investigate the role of intestinal P-gp in generating rhythmic drug toxicity. Toxicity and pharmacokinetic experiments were performed with wild-type, Bmal1iKO (intestine-specific Bmal1 knockout) and Bmal1fl/fl (control littermates of Bmal1iKO) mice. The cardiac toxicity (reflected by plasma CK-MB, LDH and cTn-I levels) varied significantly with the times of drug dosing in wild-type mice (a lower toxicity at ZT10 and more severe at ZT2/22). Dosing at ZT2 generated a higher drug exposure than ZT10, supporting a lower toxicity at ZT10. Intracellular accumulation of oleandrin (2.5-10 μM) was reduced in MDCKⅡ-MDR1 than in parental cells. MDR1 overexpression decreased the cell sensitivity to oleandrin toxicity. The net flux ratio (MDCKⅡ-MDR1 versus parental cells) was 2.9 for oleandrin. These data indicated oleandrin as a P-gp substrate. Both mdr1a mRNA and P-gp protein oscillated with the times of the day in small intestine of Bmal1fl/fl mice. Intestinal ablation of Bmal1 down-regulated mdr1a mRNA and P-gp protein, and abrogated their rhythms. Likewise, Bmal1 silencing led to down-regulated mdr1a mRNA and to a loss of its rhythmicity in serum-shocked CT26 cells. Based on luciferase reporter assays, Bmal1 regulated rhythmic mdr1a transcription through the clock output genes Hlf and E4bp4. Intestinal ablation of Bmal1 exacerbated oleandrin toxicity and enhanced drug exposure. Moreover, time dependency of toxicity and drug exposure were lost in Bmal1iKO mice. In conclusion, diurnal intestinal P-gp is a critical factor influencing daily oleandrin exposure and toxicity. Our findings have implications in minimizing oleandrin (and possibly Nerium oleander) toxicity and improving drug efficacy via dosing time optimization.
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Affiliation(s)
- Cui Zhou
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, Guangzhou, China; College of Chemistry and Biology Engineering, Yichun University, Jiangxi, China
| | - Fangjun Yu
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, Guangzhou, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Peng Zeng
- School of Food and Pharmaceutical Engineering, Zhaoqing University, Zhaoqing, Guangdong, China
| | - Tianpeng Zhang
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, Guangzhou, China
| | - Hao Huang
- College of Chemistry and Biology Engineering, Yichun University, Jiangxi, China
| | - Wenying Chen
- The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Baojian Wu
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, Guangzhou, China; International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou 510632, China.
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Lin Y, Zhou Z, Yang Z, Gao L, Wang S, Yu P, Wu B. Circadian Cyp3a11 metabolism contributes to chronotoxicity of hypaconitine in mice. Chem Biol Interact 2019; 308:288-293. [PMID: 31150629 DOI: 10.1016/j.cbi.2019.05.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 04/18/2019] [Accepted: 05/13/2019] [Indexed: 01/10/2023]
Abstract
Hypaconitine is an active and highly toxic constituent derived from Aconitum species. Here we aimed to determine the chronotoxicity of hypaconitine in mice, and to investigate a potential role of metabolism in hypaconitine chronotoxicity. Cardiac toxicity was assessed by measuring CK (creatine kinase) and LDH (lactate dehydrogenase) levels after hypaconitine administration to wild-type and Bmal1-/- (a clock disrupted model) mice at different times of day. The mRNA and protein levels of Cyp3a11 in mouse livers were determined by qPCR and western blotting, respectively. In vitro metabolism was assessed using liver microsomes. Pharmacokinetic study of hypaconitine was performed with wild-type mice. We observed injection time-dependent toxicity (i.e., a more severe toxicity during the light phase than the dark phase) for hypaconitine in mice. The chronotoxicity was attributed to a difference in systemic exposure of hypaconitine caused by time of day-dependent metabolism. Furthermore, circadian metabolism of hypaconitine was accounted for by the diurnal expression of Cyp3a11, a major enzyme for hypaconitine detoxification in the liver. Moreover, Bmal1 ablation in mice abolished the daily rhythm of Cyp3a11 expression and abrogated the time-dependency of hypaconitine toxicity. In conclusion, circadian Cyp3a11 metabolism contributed to chronotoxicity of hypaconitine in mice. This metabolism-based chronotoxicity would facilitate the formulation of best timing for drug administration.
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Affiliation(s)
- Yanke Lin
- College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Ziyue Zhou
- College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Zemin Yang
- College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Lu Gao
- College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Shuai Wang
- College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Pei Yu
- College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China.
| | - Baojian Wu
- College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China.
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Yu F, Zhang T, Zhou C, Xu H, Guo L, Chen M, Wu B. The Circadian Clock Gene Bmal1 Controls Intestinal Exporter MRP2 and Drug Disposition. Theranostics 2019; 9:2754-2767. [PMID: 31244920 PMCID: PMC6568180 DOI: 10.7150/thno.33395] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 03/31/2019] [Indexed: 12/14/2022] Open
Abstract
The intestinal exporter MRP2 plays an important role in disposition and elimination of a wide range of drugs. Here, we aimed to clarify the impact of circadian clock on intestinal MRP2, and to determine the molecular mechanisms for generation of diurnal MRP2 expression. Methods: The regulatory effects of Bmal1 on intestinal MRP2 expression were assessed using intestine-specific Bmal1 knockout (Bmal1iKO ) mice and colon cancer cells. The relative mRNA and protein levels were determined by qPCR and Western blotting, respectively. Everted gut sac, cell viability and in situ intestinal perfusion experiments were performed to evaluate intestinal efflux of the MRP2 substrate methotrexate (MTX). Toxicity and pharmacokinetic experiments were performed with Bmal1iKO mice and control littermates (Bmal1fl/fl mice) after oral gavage of MTX. Transcriptional gene regulation was investigated using luciferase reporter, mobility shift and chromatin immunoprecipitation (ChIP) assays. Results: Bmal1iKO mice were generated by inter-crossing the mice carrying a Bmal1 exon 8 floxed allele (Bmal1fl/fl ) with Villin-Cre mice. Intestinal MRP2 expression exhibited a diurnal oscillation in Bmal1fl/fl mice with a zenith value at ZT6. Bmal1 ablation caused reductions in Mrp2 mRNA and protein levels [as well as in transport activity (measured by MTX)], and blunted their diurnal rhythms. Intestinal ablation of Bmal1 abrogated circadian time-dependency of MTX pharmacokinetics and toxicity. Bmal1/BMAL1 regulation of rhythmic Mrp2/MRP2 expression was also confirmed in the colon cancer CT26 and Caco-2 cells. Based on a combination of luciferase reporter, mobility shift and ChIP assays, we found that Dbp activated and E4bp4 repressed Mrp2 transcription via specific binding to a same D-box (-100/-89 bp) element in promoter region. Further, Bmal1 directly activated the transcription of Dbp and Rev-erbα through the E-boxes, whereas it negatively regulated E4bp4 via the transcriptional repressor Rev-erbα. Positive regulation of Mrp2 by Rev-erbα was also observed, and attained through modulation of E4bp4. Conclusion: Bmal1 coordinates temporal expressions of DBP (a MRP2 activator), REV-ERBα (an E4BP4 repressor) and E4BP4 (a MRP2 repressor), generating diurnal MRP2 expression.
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Affiliation(s)
- Fangjun Yu
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Tianpeng Zhang
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
- Integrated Chinese and Western Medicine Postdoctoral research station, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Cui Zhou
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Haiman Xu
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Lianxia Guo
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Min Chen
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
| | - Baojian Wu
- Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China
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