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Chen C, Cai H, Shen J, Zhang X, Peng W, Li C, Lv H, Wen T. Exploration of a hypoxia-immune-related microenvironment gene signature and prediction model for hepatitis C-induced early-stage fibrosis. J Transl Med 2024; 22:116. [PMID: 38287425 PMCID: PMC10826039 DOI: 10.1186/s12967-024-04912-6] [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: 08/26/2023] [Accepted: 01/19/2024] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND Liver fibrosis contributes to significant morbidity and mortality in Western nations, primarily attributed to chronic hepatitis C virus (HCV) infection. Hypoxia and immune status have been reported to be significantly correlated with the progression of liver fibrosis. The current research aimed to investigate the gene signature related to the hypoxia-immune-related microenvironment and identify potential targets for liver fibrosis. METHOD Sequencing data obtained from GEO were employed to assess the hypoxia and immune status of the discovery set utilizing UMAP and ESTIMATE methods. The prognostic genes were screened utilizing the LASSO model. The infiltration level of 22 types of immune cells was quantified utilizing CIBERSORT, and a prognosis-predictive model was established based on the selected genes. The model was also verified using qRT-PCR with surgical resection samples and liver failure samples RNA-sequencing data. RESULTS Elevated hypoxia and immune status were linked to an unfavorable prognosis in HCV-induced early-stage liver fibrosis. Increased plasma and resting NK cell infiltration were identified as a risk factor for liver fibrosis progression. Additionally, CYP1A2, CBS, GSTZ1, FOXA1, WDR72 and UHMK1 were determined as hypoxia-immune-related protective genes. The combined model effectively predicted patient prognosis. Furthermore, the preliminary validation of clinical samples supported most of the conclusions drawn from this study. CONCLUSION The prognosis-predictive model developed using six hypoxia-immune-related genes effectively predicts the prognosis and progression of liver fibrosis. The current study opens new avenues for the future prediction and treatment of liver fibrosis.
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Affiliation(s)
- Chuwen Chen
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Si Chuan University, Chengdu, 610041, China
| | - Haozheng Cai
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Si Chuan University, Chengdu, 610041, China
| | - Junyi Shen
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Si Chuan University, Chengdu, 610041, China
| | - Xiaoyun Zhang
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Si Chuan University, Chengdu, 610041, China
| | - Wei Peng
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Si Chuan University, Chengdu, 610041, China
| | - Chuan Li
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Si Chuan University, Chengdu, 610041, China
| | - Haopeng Lv
- Department of General Surgery, ChengDu Shi Xinjin Qu Renmin Yiyuan: People's Hospital of Xinjin District, Chengdu, China
| | - Tianfu Wen
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Si Chuan University, Chengdu, 610041, China.
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Duo D, Duan Y, Zhu J, Bai X, Yang J, Liu G, Wang Q, Li X. New strategy for rational use of antihypertensive drugs in clinical practice in high-altitude hypoxic environments. Drug Metab Rev 2023; 55:388-404. [PMID: 37606301 DOI: 10.1080/03602532.2023.2250930] [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: 03/30/2023] [Accepted: 08/15/2023] [Indexed: 08/23/2023]
Abstract
High-altitude hypoxic environments have critical implications on cardiovascular system function as well as blood pressure regulation. Such environments place patients with hypertension at risk by activating the sympathetic nervous system, which leads to an increase in blood pressure. In addition, the high-altitude hypoxic environment alters the in vivo metabolism and antihypertensive effects of antihypertensive drugs, which changes the activity and expression of drug-metabolizing enzymes and drug transporters. The present study reviewed the pharmacodynamics and pharmacokinetics of antihypertensive drugs and its effects on patients with hypertension in a high-altitude hypoxic environment. It also proposes a new strategy for the rational use of antihypertensive drugs in clinical practice in high-altitude hypoxic environments. The increase in blood pressure on exposure to a high-altitude hypoxic environment was mainly dependent on increased sympathetic nervous system activity. Blood pressure also increased proportionally to altitude, whilst ambulatory blood pressure increased more than conventional blood pressure, especially at night. High-altitude hypoxia can reduce the activities and expression of drug-metabolizing enzymes, such as CYP1A1, CYP1A2, CYP3A1, and CYP2E1, while increasing those of CYP2D1, CYP2D6, and CYP3A6. Drug transporter changes were related to tissue type, hypoxic degree, and hypoxic exposure time. Furthermore, the effects of high-altitude hypoxia on drug-metabolism enzymes and transporters altered drug pharmacokinetics, causing changes in pharmacodynamic responses. These findings suggest that high-altitude hypoxic environments affect the blood pressure, pharmacokinetics, and pharmacodynamics of antihypertensive drugs. The optimal hypertension treatment plan and safe and effective medication strategy should be formulated considering high-altitude hypoxic environments.
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Affiliation(s)
- Delong Duo
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
- Qinghai Provincial People's Hospital, Xining, China
| | - Yabin Duan
- Qinghai University Affiliated Hospital, Xining, China
| | - Junbo Zhu
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Xue Bai
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Jianxin Yang
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Guiqin Liu
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Qian Wang
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Xiangyang Li
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
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Bai X, Liu G, Yang J, Zhu J, Li X. Gut Microbiota as the Potential Mechanism to Mediate Drug Metabolism Under High-Altitude Hypoxia. Curr Drug Metab 2022; 23:8-20. [PMID: 35088664 DOI: 10.2174/1389200223666220128141038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/25/2021] [Accepted: 12/30/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND The characteristics of pharmacokinetics and the activity and expression of drug-metabolizing enzymes and transporters significantly change under a high-altitude hypoxic environment. Gut microbiota is an important factor affecting the metabolism of drugs through direct or indirect effects, changing the bioavailability, biological activity, or toxicity of drugs and further affecting the efficacy and safety of drugs in vivo. A high-altitude hypoxic environment significantly changes the structure and diversity of gut microbiota, which may play a key role in drug metabolism under a high-altitude hypoxic environment. METHODS An investigation was carried out by reviewing published studies to determine the role of gut microbiota in the regulation of drug-metabolizing enzymes and transporters. Data and information on expression change in gut microbiota, drug-metabolizing enzymes and transporters under a high-altitude hypoxic environment were explored and proposed. RESULTS High-altitude hypoxia is an important environmental factor that can adjust the structure of the gut microbiota and change the diversity of intestinal microbes. It was speculated that the gut microbiota could regulate drug-metabolizing enzymes through two potential mechanisms, the first being through direct regulation of the metabolism of drugs in vivo and the second being indirect, i.e., through the regulation of drug-metabolizing enzymes and transporters, thereby affecting the activity of drugs. CONCLUSION This article reviews the effects of high-altitude hypoxia on the gut microbiota and the effects of these changes on drug metabolism.
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Affiliation(s)
- Xue Bai
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
| | - Guiqin Liu
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
| | - Jianxin Yang
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Junbo Zhu
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
| | - Xiangyang Li
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
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Duan Y, Bai X, Yang J, Zhou Y, Gu W, Liu G, Wang Q, Zhu J, La L, Li X. Exposure to High-Altitude Environment is Associated with Drug Transporters Change: miR-873-5p-Mediated Alteration of Function and Expression Levels of Drug Transporters under Hypoxia. Drug Metab Dispos 2021; 50:174-186. [PMID: 34844996 DOI: 10.1124/dmd.121.000681] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/12/2021] [Indexed: 11/22/2022] Open
Abstract
Hypoxia is the main characteristic of a high-altitude environment, affect ing drug metabolism. However, so far, the mechanism of miRNA involved in the regulation of drug metabolism and transporters under high-altitude hypoxia is still unclear. This study aims to investigate the function s and expression levels of multidrug resistance protein 1 ( MDR1 ), m ultidrug resistance-associated protein 2 ( MRP2 ), breast cancer resistance protein ( BCRP ) , peptide transport 1 (PEPT1), and organic anion-transporting polypeptides 2B1 (OATP2B1) in rats and Caco-2 cells after exposure to high - altitude hypoxia. The protein and mRNA expression of MDR1 , MRP2, BCRP, PEPT1, and OATP2B1 were determined by Western blot and qPCR. The function s of MDR1 , MRP2, BCRP, PEPT1, and OATP2B1 were evaluated by determining the effective intestinal permeability and a bsorption rate constants of their specific substrates in rats under high-altitude hypoxia , and uptake and transport studies were performed on Caco-2 cells . To screen the miRNA associated with hypoxia, Caco-2 cells were examined by high throughput sequencing . We observed that the miR-873-5p was significantly decreased under hypoxia and might target MDR1 and pregnane X receptor ( PXR). To clarify whether miR-873-5p regulates MDR1 and pregnane X receptor (PXR) under hypoxia, Caco-2 cells were transfected with mimics or inhibitors of miR-873-5p and negative control (NC). The function and expression of drug transporters were found to be significantly increased in rats and Caco-2 cells under hypoxia. We found that miR-873-5p regulated MDR1 and PXR expression. Herein, it is shown that miRNA may affect the expression of drug transporter and nuclear receptor under hypoxia. Significance Statement This study explores if alterations to the microRNAs, induced by high-altitude hypoxia, can be translated to altered drug transporters. Among miRNAs, which show a significant change in a hypoxic environment, miR-873-5p can act on the MDR1 gene; however, there are multiple miRNAs that can act on the PXR. We speculate that the miRNA-PXR-Drug transporter axis is important in the physiological disposition of drugs. The results of this study are anticipated to be helpful for rational pharmaceutical use in high - altitude environments .
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Affiliation(s)
- Yabin Duan
- Department of Clinical Pharmacy,, Qinghai University Affiliated Hospital, China
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Liu TT, Zhong JJ. Impact of oxygen supply on production of a novel ganoderic acid in Saccharomyces cerevisiae fermentation. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Kurata Y, Muraki S, Hirota T, Araki H, Ieiri I. Reduced theophylline clearance due to hepatic congestion secondary to right heart failure - A population pharmacokinetic study. Drug Metab Pharmacokinet 2021; 41:100403. [PMID: 34619548 DOI: 10.1016/j.dmpk.2021.100403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 12/28/2022]
Abstract
Theophylline, a beneficial drug with bronchodilatory and anti-inflammatory effects, is used for the treatment of respiratory diseases. Pulmonary (PC) and hepatic congestion (HC) are secondary to the development of left- and right-sided heart failure (HF), respectively. This study aimed to evaluate the effects of PC and HC on theophylline clearance (CL) by population pharmacokinetic (PPK) analysis with consideration of the severity of HF assessed by the New York Heart Association (NYHA) functional classification. We obtained 710 minimum steady-state concentrations from 201 Japanese bronchial asthma patients with and without HF. PPK analysis was performed by NONMEM. In the analysis, the left ventricular ejection fraction, smoking (SMK), clarithromycin (CAM), sex, and age were also considered as covariates. The final model of apparent theophylline clearance (CL/F) was as follows: CL/F (L/hr/kg) = 0.0465 × 1.40SMK × 0.870CAM × 0.863HC(+)NYHA II × 0.634HC(+)NYHA III × 0.586HC(-)NYHA IV × 0.467HC(+)NYHA IV. SMK is a well-known factor that markedly enhances theophylline clearance through the induction of CYP1A enzymes, while CAM has been reported to inhibit CYP3A4. The final model indicates that HF patients with HC show reduced clearance of theophylline depending on the severity of HF. In this study, no effects of PC were observed.
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Affiliation(s)
- Yasuo Kurata
- Department of Pharmacy, Fukuoka City Hospital, Fukuoka City Hospital Organization, Local Incorporated Administrative Agency, Fukuoka, Japan.
| | - Shota Muraki
- Department of Clinical Pharmacokinetics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Takeshi Hirota
- Department of Clinical Pharmacokinetics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan; Department of Pharmacy, Kyushu University Hospital, Fukuoka, Japan
| | - Hiroshi Araki
- Department of Pharmacy, Fukuoka City Hospital, Fukuoka City Hospital Organization, Local Incorporated Administrative Agency, Fukuoka, Japan
| | - Ichiro Ieiri
- Department of Clinical Pharmacokinetics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan; Department of Pharmacy, Kyushu University Hospital, Fukuoka, Japan
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Nakano N, Sakata N, Katsu Y, Nochise D, Sato E, Takahashi Y, Yamaguchi S, Haga Y, Ikeno S, Motizuki M, Sano K, Yamasaki K, Miyazawa K, Itoh S. Dissociation of the AhR/ARNT complex by TGF-β/Smad signaling represses CYP1A1 gene expression and inhibits benze[a]pyrene-mediated cytotoxicity. J Biol Chem 2020; 295:9033-9051. [PMID: 32409577 PMCID: PMC7335805 DOI: 10.1074/jbc.ra120.013596] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/11/2020] [Indexed: 12/22/2022] Open
Abstract
Cytochrome P450 1A1 (CYP1A1) catalyzes the metabolic activation of polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene (B[a]P) and is transcriptionally regulated by the aryl hydrocarbon receptor (AhR)/AhR nuclear translocator (ARNT) complex upon exposure to PAHs. Accordingly, inhibition of CYP1A1 expression reduces production of carcinogens from PAHs. Although transcription of the CYP1A1 gene is known to be repressed by transforming growth factor-β (TGF-β), how TGF-β signaling is involved in the suppression of CYP1A1 gene expression has yet to be clarified. In this study, using mammalian cell lines, along with shRNA-mediated gene silencing, CRISPR/Cas9-based genome editing, and reporter gene and quantitative RT-PCR assays, we found that TGF-β signaling dissociates the B[a]P-mediated AhR/ARNT heteromeric complex. Among the examined Smads, Smad family member 3 (Smad3) strongly interacted with both AhR and ARNT via its MH2 domain. Moreover, hypoxia-inducible factor 1α (HIF-1α), which is stabilized upon TGF-β stimulation, also inhibited AhR/ARNT complex formation in the presence of B[a]P. Thus, TGF-β signaling negatively regulated the transcription of the CYP1A1 gene in at least two different ways. Of note, TGF-β abrogated DNA damage in B[a]P-exposed cells. We therefore conclude that TGF-β may protect cells against carcinogenesis because it inhibits CYP1A1-mediated metabolic activation of PAHs as part of its anti-tumorigenic activities.
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Affiliation(s)
- Naoko Nakano
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Nobuo Sakata
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Yuki Katsu
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Daiki Nochise
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Erika Sato
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Yuta Takahashi
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Saori Yamaguchi
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Yoko Haga
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Souichi Ikeno
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Mitsuyoshi Motizuki
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Keigo Sano
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Kohei Yamasaki
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Keiji Miyazawa
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Susumu Itoh
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan.
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8
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Long N, Tang H, Lin L, Li J, Guo L, Sun F, Dai M. Effects of infection of MRSA on the expression and activity of renal cytochrome P450s in mice. J Toxicol Sci 2019; 44:299-307. [PMID: 30944282 DOI: 10.2131/jts.44.299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) leads to serious infections, but it is not known whether it changes the expression of kidney drug metabolizing enzymes during infection. The mice were infected with different doses of MRSA and the oxidative stress and inflammation levels in the kidney were examined. The mRNA expression and activity of cytochrome P450 enzyme was analysed. Mice infected with high levels of MRSA showed a decrease in renal antioxidant capability and an elevated level of oxidative metabolites, which was accompanied by the release of inflammatory cytokines. The levels of interleukin 1β, tumour necrosis factor alpha, and macrophage inflammatory protein-1α were significantly increased along with the levels of nitric oxide and malondialdehyde. On day 7, mRNA expression of Cyp1a2, 2d22, and 3a11 were decreased by the high level of MRSA, but the low level of MRSA increased their expressions. Cyp2e1 mRNA expression was increased by MRSA in the kidney of mice. High dose of MRSA infection increased the oxidative stress and inflammatory response in mouse kidney, leading to the decrease in the expression of renal drug-metabolizing enzymes and no recovery within 7 days.
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Affiliation(s)
- Nana Long
- School of Laboratory Medicine, Chengdu Medical College, China.,Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-origin Food, Chengdu Medical College, China
| | - Huaqiao Tang
- School of Laboratory Medicine, Chengdu Medical College, China.,Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-origin Food, Chengdu Medical College, China
| | - Lin Lin
- School of Laboratory Medicine, Chengdu Medical College, China.,Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-origin Food, Chengdu Medical College, China
| | - Jianlong Li
- School of Laboratory Medicine, Chengdu Medical College, China.,Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-origin Food, Chengdu Medical College, China
| | - Lijuan Guo
- School of Laboratory Medicine, Chengdu Medical College, China.,Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-origin Food, Chengdu Medical College, China
| | - Fenghui Sun
- School of Laboratory Medicine, Chengdu Medical College, China.,Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-origin Food, Chengdu Medical College, China
| | - Min Dai
- School of Laboratory Medicine, Chengdu Medical College, China.,Sichuan Provincial Engineering Laboratory for Prevention and Control Technology of Veterinary Drug Residue in Animal-origin Food, Chengdu Medical College, China
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Kwapiszewska G, Johansen AKZ, Gomez-Arroyo J, Voelkel NF. Role of the Aryl Hydrocarbon Receptor/ARNT/Cytochrome P450 System in Pulmonary Vascular Diseases. Circ Res 2019; 125:356-366. [PMID: 31242807 DOI: 10.1161/circresaha.119.315054] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
RATIONALE CYPs (cytochrome p450) are critically involved in the metabolism of xenobiotics and toxins. Given that pulmonary hypertension is strongly associated with environmental exposure, we hypothesize that CYPs play a role in the development and maintenance of pathological vascular remodeling. OBJECTIVE We sought to identify key CYPs that could link drug or hormone metabolism to the development of pulmonary hypertension. METHODS AND RESULTS We searched in Medline (PubMed) database, as well as http://www.clinicaltrials.gov, for CYPs associated with many key aspects of pulmonary arterial hypertension including, but not limited to, severe pulmonary hypertension, estrogen metabolism, inflammation mechanisms, quasi-malignant cell growth, drug susceptibility, and metabolism of the pulmonary arterial hypertension-specific drugs. CONCLUSIONS We postulate a hypothesis where the AhR (aryl hydrocarbon receptor) mediates aberrant cell growth via expression of different CYPs associated with estrogen metabolism and inflammation.
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Affiliation(s)
- Grazyna Kwapiszewska
- From the Ludwig Boltzmann Institute for Lung Vascular Research, Medical University of Graz, Austria (G.K.)
| | - Anne Katrine Z Johansen
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, OH (A.K.Z.J.)
| | - Jose Gomez-Arroyo
- Division of Pulmonary and Critical Care Medicine, University of Cincinnati College of Medicine, OH (J.G.-A.)
- Division of Pulmonary Biology, Perinatal Institute of Cincinnati Children's Hospital Research Foundation, OH (J.G.-A.)
| | - Norbert F Voelkel
- Department of Pulmonary Medicine, Amsterdam University Medical Centers, the Netherlands (N.F.V.)
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Valencia-Cervantes J, Huerta-Yepez S, Aquino-Jarquín G, Rodríguez-Enríquez S, Martínez-Fong D, Arias-Montaño JA, Dávila-Borja VM. Hypoxia increases chemoresistance in human medulloblastoma DAOY cells via hypoxia‑inducible factor 1α‑mediated downregulation of the CYP2B6, CYP3A4 and CYP3A5 enzymes and inhibition of cell proliferation. Oncol Rep 2018; 41:178-190. [PMID: 30320358 PMCID: PMC6278548 DOI: 10.3892/or.2018.6790] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 09/17/2018] [Indexed: 02/06/2023] Open
Abstract
Medulloblastomas are among the most frequently diagnosed pediatric solid tumors, and drug resistance remains as the principal cause of treatment failure. Hypoxia and the subsequent activation of hypoxia-inducible factor 1α (HIF-1α) are considered key factors in modulating drug antitumor effectiveness, but the underlying mechanisms in medulloblastomas have not yet been clearly understood. The aim of the present study was to determine whether hypoxia induces resistance to cyclophosphamide (CPA) and ifosfamide (IFA) in DAOY medulloblastoma cells, whether the mechanism is dependent on HIF-1α, and whether involves the modulation of the expression of cytochromes P450 (CYP)2B6, 3A4 and 3A5 and the control of cell proliferation. Monolayer cultures of DAOY medulloblastoma cells were exposed for 24 h to moderate (1% O2) or severe (0.1% O2) hypoxia, and protein expression was evaluated by immunoblotting. Cytotoxicity was studied with the MTT assay and by Annexin V/PI staining and flow cytometry. Cell proliferation was determined by the trypan-blue exclusion assay and cell cycle by propidium iodide staining and flow cytometry. Hypoxia decreased CPA and IFA cytotoxicity in medulloblastoma cells, which correlated with a reduction in the protein levels of CYP2B6, CYP3A4 and CYP3A5 and inhibition of cell proliferation. These responses were dependent on hypoxia-induced HIF-1α activation, as evidenced by chemical inhibition of its transcriptional activity with 2-methoxyestradiol (2-ME), which enhanced the cytotoxic activity of CPA and IFA and increased apoptosis. Our results indicate that by stimulating HIF-1α activity, hypoxia downregulates the expression of CYP2B6, CYP3A4 and CYP3A5, that in turn leads to decreased conversion of CPA and IFA into their active forms and thus to diminished cytotoxicity. These results support that the combination of HIF-1α inhibitors and canonical antineoplastic agents provides a potential therapeutic alternative against medulloblastoma.
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Affiliation(s)
- Jesús Valencia-Cervantes
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City 07360, Mexico
| | - Sara Huerta-Yepez
- Oncology Disease Research Unit, Children's Hospital of Mexico 'Federico Gomez', Mexico City 06720, Mexico
| | - Guillermo Aquino-Jarquín
- Laboratory of Research on Genomics, Genetics and Bioinformatics, Haemato‑Oncology Building, Children's Hospital of Mexico 'Federico Gomez', Mexico City 06720, Mexico
| | - Sara Rodríguez-Enríquez
- Department of Biochemistry,National Institute of Cardiology 'Ignacio Chavez', Mexico City 14080, Mexico
| | - Daniel Martínez-Fong
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City 07360, Mexico
| | - José-Antonio Arias-Montaño
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City 07360, Mexico
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Dean A, Gregorc T, Docherty CK, Harvey KY, Nilsen M, Morrell NW, MacLean MR. Role of the Aryl Hydrocarbon Receptor in Sugen 5416-induced Experimental Pulmonary Hypertension. Am J Respir Cell Mol Biol 2018; 58:320-330. [PMID: 28956952 DOI: 10.1165/rcmb.2017-0260oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Rats dosed with the vascular endothelial growth factor inhibitor Sugen 5416 (Su), subjected to hypoxia, and then restored to normoxia have become a widely used model of pulmonary arterial hypertension (PAH). However, the mechanism by which Su exacerbates pulmonary hypertension is unclear. We investigated Su activation of the aryl hydrocarbon receptor (AhR) in human pulmonary artery smooth muscle cells (hPASMCs) and blood outgrowth endothelial cells (BOECs) from female patients with PAH. We also examined the effect of AhR on aromatase and estrogen levels in the lung. Protein and mRNA analyses demonstrated that CYP1A1 was very highly induced in the lungs of Su/hypoxic (Su/Hx) rats. The AhR antagonist CH223191 (8 mg/kg/day) reversed the development of PAH in this model in vivo and normalized lung CYP1A1 expression. Increased lung aromatase and estrogen levels in Su/Hx rats were also normalized by CH223191, as was AhR nuclear translocator (ARNT [HIF-1β]), which is shared by HIF-1α and AhR. Su reduced HIF-1α expression in hPASMCs. Su induced proliferation in BOECs and increased apoptosis in human pulmonary microvascular ECs and also induced translocation of AhR to the nucleus in hPASMCs. Under normoxic conditions, hPASMCs did not proliferate to Su. However, when grown in hypoxia (1%), Su induced hPASMC proliferation. In combination with hypoxia, Su is proliferative in hPASMCs and BOECs from patients with PAH, and Su/Hx-induced PAH in rats may be facilitated by AhR-induced CYP1A1, ARNT, and aromatase. Inhibition of AhR may be a novel approach to the treatment of pulmonary hypertension.
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Affiliation(s)
- Afshan Dean
- 1 Research Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; and
| | - Teja Gregorc
- 1 Research Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; and
| | - Craig K Docherty
- 1 Research Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; and
| | - Katie Y Harvey
- 1 Research Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; and
| | - Margaret Nilsen
- 1 Research Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; and
| | - Nicholas W Morrell
- 2 Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Margaret R MacLean
- 1 Research Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; and
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12
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Wang R, Sun Y, Yin Q, Xie H, Li W, Wang C, Guo J, Hao Y, Tao R, Jia Z. The effects of metronidazole on Cytochrome P450 Activity and Expression in rats after acute exposure to high altitude of 4300m. Biomed Pharmacother 2017; 85:296-302. [DOI: 10.1016/j.biopha.2016.11.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 10/14/2016] [Accepted: 11/08/2016] [Indexed: 11/28/2022] Open
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13
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Li X, Wang X, Li Y, Zhu J, Su X, Yao X, Fan X, Duan Y. The activity, protein, and mRNA expression of CYP2E1 and CYP3A1 in rats after exposure to acute and chronic high altitude hypoxia. High Alt Med Biol 2015; 15:491-6. [PMID: 25330250 DOI: 10.1089/ham.2014.1026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The effects of exposure to acute and chronic high altitude hypoxia on the activity and expression of CYP2E1 and CYP3A1 were examined in rats. Rats were divided into low altitude (LA, 400 m), acute moderate altitude hypoxia (AMH, 2800 m), chronic moderate altitude hypoxia (CMH, 2800 m), acute high altitude hypoxia (AHH, 4300 m), and chronic high altitude hypoxia groups (CHH, 4300 m). Probe drugs were administrated orally to all five groups. Then the serum concentration of probe drug and its metabolite was determined by RP-HPLC. The activity of CYP2E1 and CYP3A1 was evaluated using the ratio of the metabolite to chlorzoxazone and testosterone, respectively. ELISA and real-time PCR were used to analyze the protein and mRNA expression of CYP2E1 and CYP3A1 in liver microsomes, respectively. Chronic high altitude hypoxia caused significant decreases in the activity and protein and mRNA expression of rat CYP2E1 and CYP3A1 in vivo. Acute high altitude hypoxia was not found to change the activity, protein or mRNA expression of rat CYP2E1 or CYP3A1. This study showed significant changes in the activity and protein and mRNA expression of CYP2E1 or CYP3A1 in rats after exposure to chronic high altitude hypoxia.
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Affiliation(s)
- Xiangyang Li
- 1 Department of Pharmacy, Qinghai University Medical College , Xining, China
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14
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Feere DA, Velenosi TJ, Urquhart BL. Effect of erythropoietin on hepatic cytochrome P450 expression and function in an adenine-fed rat model of chronic kidney disease. Br J Pharmacol 2015; 172:201-13. [PMID: 25219905 PMCID: PMC4280978 DOI: 10.1111/bph.12932] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 09/04/2014] [Accepted: 09/08/2014] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND AND PURPOSE Erythropoietin (EPO) is used to treat anaemia associated with chronic kidney disease (CKD). Hypoxia is associated with anaemia and is known to cause a decrease in cytochrome P450 (P450) expression. As EPO production is regulated by hypoxia, we investigated the role of EPO on P450 expression and function. EXPERIMENTAL APPROACH Male Wistar rats were subjected to a 0.7% adenine diet for 4 weeks to induce CKD. The diet continued for an additional 2 weeks while rats received EPO by i.p. injection every other day. Following euthanasia, hepatic P450 mRNA and protein expression were determined. Hepatic enzyme activity of selected P450s was determined and chromatin immunoprecipitation was used to characterize binding of nuclear receptors involved in the transcriptional regulation of CYP2C and CYP3A. KEY RESULTS EPO administration decreased hepatic mRNA and protein expression of CYP3A2 (P < 0.05), but not CYP2C11. Similarly, EPO administration decreased CYP3A2 protein expression by 81% (P < 0.001). A 32% decrease (P < 0.05) in hepatic CYP3A enzymatic activity (Vmax ) was observed for the formation of 6βOH-testosterone in the EPO-treated group. Decreases in RNA pol II recruitment (P < 0.01), hepatocyte nuclear factor 4α binding (P < 0.05) and pregnane X receptor binding (P < 0.01) to the promoter region of CYP3A were also observed in EPO-treated rats. CONCLUSIONS AND IMPLICATIONS Our data show that EPO decreases the expression and function of CYP3A, but not CYP2C in rat liver.
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MESH Headings
- Adenine
- Animals
- Constitutive Androstane Receptor
- Cytochrome P-450 Enzyme System/genetics
- Cytochrome P-450 Enzyme System/metabolism
- Diet
- Disease Models, Animal
- Erythropoietin/pharmacology
- Hepatocyte Nuclear Factor 4/genetics
- Hepatocyte Nuclear Factor 4/metabolism
- Kidney/pathology
- Liver/drug effects
- Liver/metabolism
- Male
- Microsomes, Liver/drug effects
- Microsomes, Liver/enzymology
- Pregnane X Receptor
- RNA Polymerase II/genetics
- RNA Polymerase II/metabolism
- RNA, Messenger/metabolism
- Rats, Wistar
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Recombinant Proteins/pharmacology
- Renal Insufficiency, Chronic/metabolism
- Renal Insufficiency, Chronic/pathology
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Affiliation(s)
- D A Feere
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
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15
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Li X, Wang X, Li Y, Yuan M, Zhu J, Su X, Yao X, Fan X, Duan Y. Effect of exposure to acute and chronic high-altitude hypoxia on the activity and expression of CYP1A2, CYP2D6, CYP2C9, CYP2C19 and NAT2 in rats. Pharmacology 2014; 93:76-83. [PMID: 24557547 DOI: 10.1159/000358128] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 12/19/2013] [Indexed: 11/19/2022]
Abstract
We investigated the effect of exposure to acute and chronic high-altitude hypoxia (AHH and CHH) on the activity and expression of CYP1A2, CYP2D6, CYP2C9, CYP2C19 and NAT2 in rats. The rats were divided into plain (400 m), acute middle-altitude hypoxia (2,800 m), chronic middle-altitude hypoxia (2,800 m), AHH (4,300 m) and CHH (4,300 m). After probe drugs had been orally administered to the rats of the 5 groups, the serum or urine concentration of the probe drug and its metabolite was determined by reversed-phase HPLC. The activity of cytochrome P450 isozyme and NAT2 was evaluated by the ratio of the metabolite to the probe drug. The ELISA and real-time PCR were used to analyze the protein and mRNA expression of cytochrome P450 isozyme and NAT2, respectively. AHH and CHH caused significant decreases in the activity and protein and mRNA expression of rat CYP1A2 in vivo. AHH downregulates the activity and mRNA expression of rat NAT2 in vivo, and CHH upregulates the activity and protein and mRNA expression of rat CYP2D6. AHH and CHH did not change the expression of CYP2C9 and CYP2C19 in rats. This study found significant changes in the activity and protein and mRNA expression of CYP1A2, CYP2D6 and NAT2 in rats in the special environment of high-altitude hypoxia.
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Affiliation(s)
- Xiangyang Li
- Department of Pharmacy, Qinghai University Medical College, Xining, China
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16
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Gola S, Keshri GK, Gupta A. Hepatic metabolism of ibuprofen in rats under acute hypobaric hypoxia. ACTA ACUST UNITED AC 2013; 65:751-8. [DOI: 10.1016/j.etp.2012.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 09/04/2012] [Accepted: 11/08/2012] [Indexed: 01/09/2023]
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17
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Cotton RB, Shah LP, Poole SD, Ehinger NJ, Brown N, Shelton EL, Slaughter JC, Baldwin HS, Paria BC, Reese J. Cimetidine-associated patent ductus arteriosus is mediated via a cytochrome P450 mechanism independent of H2 receptor antagonism. J Mol Cell Cardiol 2013; 59:86-94. [PMID: 23454087 DOI: 10.1016/j.yjmcc.2013.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 02/02/2013] [Accepted: 02/18/2013] [Indexed: 01/13/2023]
Abstract
Persistent patency of the ductus arteriosus (PDA) is a common problem in preterm infants. The antacid cimetidine is a potent antagonist of the H2 histamine receptor but it also inhibits certain cytochrome P450 enzymes (CYPs), which may affect DA patency. We examined whether cimetidine contributes to PDA and is mediated by CYP inhibition rather than H2 blockade. Analysis of a clinical trial to prevent lung injury in premature infants revealed a significant association between cimetidine treatment and PDA. Cimetidine and ranitidine, both CYP inhibitors as well as H2 blockers, caused relaxation of the term and preterm mouse DA. CYP enzymes that are inhibited by cimetidine were expressed in DA subendothelial smooth muscle. The selective CYP3A inhibitor ketoconazole induced greater DA relaxation than cimetidine, whereas famotidine and other H2 antagonists with less CYP inhibitory effects caused less dilation. Histamine receptors were developmentally regulated and localized in DA smooth muscle. However, cimetidine caused DA relaxation in histamine-deficient mice, consistent with CYP inhibition, not H2 antagonism, as the mechanism for PDA. Oxygen-induced DA constriction was inhibited by both cimetidine and famotidine. These studies show that antacids and other compounds with CYP inhibitory properties pose a significant and previously unrecognized risk for PDA in critically ill newborn infants.
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Affiliation(s)
- Robert B Cotton
- Department of Pediatrics, Vanderbilt University School of Medicine and the Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, TN 37232, USA
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18
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du Souich P, Fradette C. The effect and clinical consequences of hypoxia on cytochrome P450, membrane carrier proteins activity and expression. Expert Opin Drug Metab Toxicol 2011; 7:1083-100. [DOI: 10.1517/17425255.2011.586630] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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19
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Aggarwal NT, Pfister SL, Gauthier KM, Chawengsub Y, Baker JE, Campbell WB. Chronic hypoxia enhances 15-lipoxygenase-mediated vasorelaxation in rabbit arteries. Am J Physiol Heart Circ Physiol 2008; 296:H678-88. [PMID: 19112096 DOI: 10.1152/ajpheart.00777.2008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
15-Lipoxygenase (15-LO-1) metabolizes arachidonic acid (AA) to 11,12,15-trihydroxyeicosatrienoic acids (THETAs) and 15-hydroxy-11,12-epoxyeicosatrienoic acids (HEETA) that dilate rabbit arteries. Increased endothelial 15-LO-1 expression enhances arterial relaxations to agonists. We tested the effect of hypoxia on 15-LO-1 expression, THETA and HEETA synthesis, and relaxations in rabbit arteries. The incubation of rabbit aortic endothelial cells and isolated aortas in 0.7% O(2) increased 15-LO-1 expression. Rabbits were housed in a hypoxic atmosphere of 12% O(2) for 5 days. 15-LO-1 expression increased in the endothelium of the arteries of rabbits in 12% O(2) compared with room air. THETA and HEETA synthesis was also enhanced in aortas and mesenteric arteries. AA hyperpolarized the smooth muscle cells in indomethacin- and phenylephrine-treated mesenteric arteries of hypoxic rabbits from -29.4 +/- 1 to -50.1 +/- 3 mV. The hyperpolarization to AA was less in arteries of normoxic rabbits (from -26.0 +/- 2 to -37 +/- 2 mV). This AA-induced hyperpolarization was inhibited by the 15-LO inhibitor BW-755C. Nitric oxide and prostaglandin-independent maximum relaxations to acetylcholine (79.7 +/- 2%) and AA (38.3 +/- 4%) were enhanced in mesenteric arteries from hypoxic rabbits compared with the normoxic rabbits (49.7 +/- 6% and 19.9 +/- 2%, respectively). These relaxations were inhibited by BW-755C and nordihydroguaiaretic acid. Therefore, hypoxia increased the relaxations to agonists in the rabbit mesenteric arteries by enhancing endothelial 15-LO-1 expression and synthesis of the hyperpolarizing factors THETA and HEETA.
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Affiliation(s)
- Nitin T Aggarwal
- Dept. of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA
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20
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Horiuchi I, Nozawa T, Fujii N, Inoue H, Honda M, Shimizu T, Taguchi M, Hashimoto Y. Pharmacokinetics of R- and S-Carvedilol in Routinely Treated Japanese Patients with Heart Failure. Biol Pharm Bull 2008; 31:976-80. [DOI: 10.1248/bpb.31.976] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Isao Horiuchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Takashi Nozawa
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Nozomu Fujii
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Hiroshi Inoue
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Mutsuko Honda
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Takako Shimizu
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Masato Taguchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Yukiya Hashimoto
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
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21
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Zhang N, Walker MK. Crosstalk between the aryl hydrocarbon receptor and hypoxia on the constitutive expression of cytochrome P4501A1 mRNA. Cardiovasc Toxicol 2007; 7:282-90. [PMID: 17968679 DOI: 10.1007/s12012-007-9007-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Accepted: 10/17/2007] [Indexed: 01/09/2023]
Abstract
Endothelial cells are a target of halogenated aromatic hydrocarbon toxicity following aryl hydrocarbon receptor (AHR) activation. Further, evidence suggests that AHR has a physiological function in endothelial cells in the absence of exogenous ligands. Understanding these "normal" functions of AHR may help to reveal the mechanisms that contribute to the toxicity of xenobiotic ligands. Thus, this study focused on the crosstalk between hypoxia and AHR in the absence of exogenous ligands. Constitutive CYP1A1 mRNA was measured by real time PCR in human pulmonary microvascular endothelial cells exposed to hypoxia (1 or 2.5% O2), 25 nM AHR siRNA, 25 nM hypoxia-inducible factor (HIF)-2alpha siRNA, or their combinations. Hypoxia significantly induced known hypoxia-regulated genes, and this induction was highly attenuated by HIF-2alpha siRNA, suggesting that HIF-2alpha is a primary mediator of hypoxic responses in these cells. Hypoxia also significantly reduced CYP1A1 mRNA and this reduction was also attenuated by HIF-2alpha siRNA. As expected, AHR siRNA significantly reduced constitutive CYP1A1 mRNA. While the combination of hypoxia plus AHR siRNA reduced CYP1A1 mRNA more than either treatment alone, the reduction was less than additive, suggesting that hypoxia and AHR deficiency may share a common pathway in reducing CYP1A1 expression. Finally, hypoxia significantly reduced AHR mRNA and this reduction was completely prevented by HIF-2alpha siRNA. In conclusion, constitutive CYP1A1 mRNA expression is dependent on AHR and is reduced by hypoxia via a HIF-2alpha-dependent mechanism, which may be mediated by a HIF-2alpha-dependent reduction of AHR expression.
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Affiliation(s)
- Nan Zhang
- College of Pharmacy, University of New Mexico Health Sciences Center, 2703 Frontier NE, Albuquerque, NM 87131-5691, USA
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22
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Fradette C, Batonga J, Teng S, Piquette-Miller M, du Souich P. Animal models of acute moderate hypoxia are associated with a down-regulation of CYP1A1, 1A2, 2B4, 2C5, and 2C16 and up-regulation of CYP3A6 and P-glycoprotein in liver. Drug Metab Dispos 2007; 35:765-71. [PMID: 17303624 DOI: 10.1124/dmd.106.013508] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In humans, indirect evidence suggests that hypoxia reduces the rate of biotransformation of drugs cleared by cytochrome P450 (P450) subfamilies CYP1A, 2B, and 2C. The aim of this study was to assess whether acute moderate hypoxia modulates the expression of CYP2B4, 2C5, and 2C16 in vivo, and to determine whether the changes in hepatic P450 are conveyed by serum mediators. Moreover, because hypoxia increases the expression of P-glycoprotein in vitro, we examined whether in vivo acute moderate hypoxia modulates the expression of several membrane transporters in the liver. Rabbits and rats were exposed to a fractional concentration of oxygen of 8% for 48 h to generate a stable arterial partial pressure of O2 of 34 +/- 1 mm Hg. Compared with rabbits breathing room air, hypoxia in rabbits reduced the amount of CYP1A1, 1A2, 2B4, 2C5, and 2C16 proteins and increased the expression of CYP3A6. Sera of rabbits with hypoxia were fractionated by size exclusion chromatography, the fractions were tested for their ability to modify the expression of P450 isoforms, and serum mediators were identified through neutralization experiments. The serum mediators responsible for the down-regulation of P450 isoforms were interferon-gamma, interleukin-1beta (IL-1beta), and IL-2. In vivo, in rats, hypoxia increased the mRNA and protein expression of P-glycoprotein but did not affect the mRNA of breast cancer resistance protein and organic anion-transporting polypeptide 2. It is concluded that in vivo, hypoxia down-regulates rabbit hepatic CYP1A1, 1A2, 2B4, 2C5, and 2C16 and up-regulates CYP3A6. CYP3A11 and P-glycoprotein were up-regulated in the livers of hypoxic rats.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Acute Disease
- Animals
- Aryl Hydrocarbon Hydroxylases/genetics
- Aryl Hydrocarbon Hydroxylases/metabolism
- Cell Hypoxia
- Cells, Cultured
- Chromatography, High Pressure Liquid
- Cytochrome P-450 CYP1A1/genetics
- Cytochrome P-450 CYP1A1/metabolism
- Cytochrome P-450 CYP3A
- Down-Regulation/drug effects
- Hepatocytes/cytology
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Hypoxia/physiopathology
- Immunoblotting
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Liver/drug effects
- Liver/enzymology
- Liver/metabolism
- Male
- Models, Animal
- Oxygen/metabolism
- Oxygen/pharmacology
- Oxygen Consumption
- Pregnane X Receptor
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rabbits
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Up-Regulation/drug effects
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Affiliation(s)
- Caroline Fradette
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Québec, Canada
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23
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24
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Renton KW. Regulation of drug metabolism and disposition during inflammation and infection. Expert Opin Drug Metab Toxicol 2006; 1:629-40. [PMID: 16863429 DOI: 10.1517/17425255.1.4.629] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The expression and activity of cytochrome P450 (CYP) is altered during periods of infectious disease or when an inflammatory response is activated. Most of the major forms of CYP are affected in this manner and this leads to a decrease in the capacity of the liver and other organs to handle drugs, chemicals and some endogenous compounds. The loss in drug metabolism is predominantly an effect resulting from the production of cytokines and the modulation of the transcription factors that control the expression of specific CYP forms. In clinical medicine numerous examples have been reported indicating the occurrence of compromised drug clearance and changes to pharmacokinetics during disease states with an inflammatory component or during infections. For any drug that is metabolised by CYP and has a narrow therapeutic index, there is a significant risk in placing patients in a position where an infection or inflammatory response might lead to aberrant drug handling and an adverse drug response.
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Affiliation(s)
- Kenneth W Renton
- Dalhousie University, Department of Pharmacology, Faculty of Medicine, Halifax, Nova Scotia, B3H 4H7, Canada.
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25
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Taherzadeh M, Fradette C, Bleau AM, Jomphe C, Trudeau LE, du Souich P. The 21-aminosteroid U74389G prevents the down-regulation and decrease in activity of CYP1A1, 1A2 and 3A6 induced by an inflammatory reaction. Biochem Pharmacol 2006; 71:366-76. [PMID: 16332358 DOI: 10.1016/j.bcp.2005.10.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Revised: 10/21/2005] [Accepted: 10/21/2005] [Indexed: 11/16/2022]
Abstract
In vivo, the 21-aminosteroid U74389G prevents the decrease in cytochrome P450 (P450) activity produced by a turpentine-induced inflammatory reaction (TIIR). To investigate the underlying mechanism of action, four groups of rabbits were used, controls receiving or not U74389G, and rabbits with the inflammatory reaction receiving or not U74389G. Hepatocytes were isolated 48h later and incubated for 4 and 24h with the serum of the rabbits. In vivo, the TIIR diminished CYP1A1/2 and 3A6 expression, and enhanced hepatic malondialdehyde (MDA) and nitric oxide (NO*) concentrations (p<0.05). U74389G prevented the increase in MDA, as well as the decrease in CYP1A1/2 amounts and activity, but increased CYP3A6 expression by 40% (p<0.05). In vitro, compared with serum from control rabbits (S(CONT)), incubation of serum from rabbits with TIIR (S(TIIR)) for 4 and 24h with hepatocytes from rabbits with TIIR (H(TIIR)) reduced CYP1A2 and CYP3A6 activity (p<0.05) and increased the formation of NO* and MDA. In rabbits with TIIR pretreated with U74389G, the S(TIIR+U) failed to reduce CYP1A2 activity or to increase MDA, although increased NO* and further reduced CYP3A6 activity. On the other hand, in hepatocytes harvested from rabbits with TIIR pretreated with U74389G, S(TIIR) did not decrease CYP1A2 activity and did not enhance MDA, but still increased NO*. In vitro, the reduction of CYP1A2 and CYP3A6 activity by S(TIIR) is not associated to NF-kappaB activation. In conclusion, U74389G prevents CYP1A1/2 down-regulation and decrease in activity by a double mechanism: hindering the release of serum mediators and by averting intracellular events, effect possibly associated with its antioxidant activity. On the other hand, U74389G up-regulates CYP3A6 but inhibits its catalytic activity.
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Affiliation(s)
- Mehrzad Taherzadeh
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Que., Canada
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26
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Callahan SM, Boquet MP, Ming X, Brunner LJ, Croyle MA. Impact of transgene expression on drug metabolism following systemic adenoviral vector administration. J Gene Med 2006; 8:566-76. [PMID: 16508909 DOI: 10.1002/jgm.884] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Systemic administration of a first-generation adenovirus expressing E. coli beta-galactosidase (AdlacZ) alters expression and function of two hepatic drug-metabolizing enzymes, cytochrome P450 (CYP) 3A2 and 2C11, for 14 days. The objective of these studies was to determine how the transgene cassette influences CYP expression and function. METHODS Sprague-Dawley rats were given 5.7 x 10(12) viral particles (vp)/kg of either: AdlacZ, Ad expressing murine erythropoietin (Epo), Ad without a transgene (Null), or phosphate-buffered saline (Vehicle). Hepatic CYP protein expression, activity, mRNA and alanine aminotransferase (ALT) levels were analyzed 0.25, 1, 4, and 14 days following a single intravenous injection. RESULTS Administration of Epo did not alter CYP3A2 activity, but induced RNA levels by a factor of 2 at 4 and 14 days (P< or =0.01). This vector suppressed CYP2C11 activity levels by 45% at 1 day (P< or =0.05) and RNA levels throughout the study period (P< or =0.05). The Null vector suppressed CYP3A2 activity by 36, 63, 34, and 45% at 0.25, 1, 4 and 14 days, respectively (P< or =0.05). CYP2C11 activity was suppressed 1 day after administration (41%) and RNA levels were suppressed at 6 h (53%) and 1 day (36%, P< or =0.05). In contrast, AdlacZ suppressed both CYP3A2 and 2C11 at all time points. CONCLUSIONS The immunogenic and biological nature of the transgene cassette can influence changes in CYP3A2, but not the 2C11 isoform. The shift in transcription and translation of protein for maintenance of physiologic homeostasis to production of viral proteins and transgene product and their associated toxicity during viral infection may explain our observations.
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Affiliation(s)
- Shellie M Callahan
- College of Pharmacy, Division of Pharmaceutics, The University of Texas at Austin, Austin, TX 78712-1074, USA
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27
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Vengellur A, Phillips JM, Hogenesch JB, LaPres JJ. Gene expression profiling of hypoxia signaling in human hepatocellular carcinoma cells. Physiol Genomics 2005; 22:308-18. [PMID: 15942021 DOI: 10.1152/physiolgenomics.00045.2004] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cellular, local, and organismal responses to low O2 availability occur during processes such as anaerobic metabolism and wound healing and pathological conditions such as stroke and cancer. These responses include increases in glycolytic activity, vascularization, breathing, and red blood cell production. These responses are mediated in part by the hypoxia-inducible factors (HIFs), which receive information on O2 levels from a group of iron- and O2-dependent hydroxylases. Hypoxia mimics, such as cobalt chloride, nickel chloride, and deferoxamine, act to simulate hypoxia by altering the iron status of these hydroxylases. To determine whether these mimics are appropriate substitutes for the lower O2 tension evoked naturally, we compared transcriptional responses of a Hep3B cell line using high-density oligonucleotide arrays. A battery of core genes was identified that was shared by all four treatments (hypoxia, cobalt, nickel, and deferoxamine) including glycolytic enzymes, cell cycle regulators, and apoptotic genes. Importantly, cobalt, nickel, and deferoxamine influenced transcription of distinct sets of genes that were not affected by cellular hypoxia. These global responses to hypoxia indicate a balancing act between adaptation and programmed cell death and suggest caution in the use of hypoxia mimics as substitutes for the low O2 tension that occurs in vivo.
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Affiliation(s)
- A Vengellur
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824-1319, USA
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28
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Prandota J. Possible pathomechanisms of sudden infant death syndrome: key role of chronic hypoxia, infection/inflammation states, cytokine irregularities, and metabolic trauma in genetically predisposed infants. Am J Ther 2005; 11:517-46. [PMID: 15543094 DOI: 10.1097/01.mjt.0000140648.30948.bd] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Chronic hypoxia, viral infections/bacterial toxins, inflammation states, biochemical disorders, and genetic abnormalities are the most likely trigger of sudden infant death syndrome (SIDS). Autopsy studies have shown increased pulmonary density of macrophages and markedly more eosinophils in the lungs accompanied by increased T and B lymphocytes. The elevated levels of immunoglobulins, about 20% more muscle in the pulmonary arteries, increased airway smooth muscle cells, and increased fetal hemoglobin and erythropoietin are evidence of chronic hypoxia before death. Other abnormal findings included mucosal immune stimulation of the tracheal wall, duodenal mucosa, and palatine tonsils, and circulating interferon. Low normal or higher blood levels of cortisol often with petechiae on intrathoracic organs, depleted maternal IgG antibodies to endotoxin core (EndoCAb) and early IgM EndoCAb triggered, partial deletions of the C4 gene, and frequent IL-10-592*A polymorphism in SIDS victims as well as possible hypoxia-induced decreased production of antiinflammatory, antiimmune, and antifibrotic cytokine IL-10, may be responsible for the excessive reactions to otherwise harmless infections. In SIDS infants, during chronic hypoxia and times of infection/inflammation, several proinflammatory cytokines are released in large quantities, sometimes also representing a potential source of tissue damage if their production is not sufficiently well controlled, eg, by pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP). These proinflammatory cytokines down-regulate gene expression of major cytochrome P-450 and/or other enzymes with the specific effects on mRNA levels, protein expression, and enzyme activity, thus affecting metabolism of several endogenous lipophilic substances, such as steroids, lipid-soluble vitamins, prostaglandins, leukotrienes, thromboxanes, and exogenous substances. In SIDS victims, chronic hypoxia, TNF-alpha and other inflammatory cytokines, and arachidonic acid (AA) as well as n-3 polyunsaturated fatty acids (FA), stimulated and/or augmented superoxide generation by polymorphonuclear leukocytes, which contributed to tissue damage. Chronic hypoxia, increased amounts of nonheme iron in the liver and adrenals of these infants, enhanced activity of CYP2C9 regarded as the functional source of reactive oxygen species (ROS) in some endothelial cells, and nicotine accumulation in tissues also intensified production of ROS. These increased quantities of proinflammatory cytokines, ROS, AA, and nitric oxide (NO) also resulted in suppression of many CYP450 and other enzymes, eg, phosphoenolpyruvate carboxykinase (PEPCK), an enzyme important in the metabolism of FA during gluconeogenesis and glyceroneogenesis. PEPCK deficit found in SIDS infants (caused also by vitamin A deficiency) and eventually enhanced by PACAP lipolysis of adipocyte triglycerides resulted in an increased FA level in blood because of their impaired reesterification to triacylglycerol in adipocytes. In turn, the overproduction and release of FA into the blood of SIDS victims could lead to the metabolic syndrome and an early phase of type 2 diabetes. This is probably the reason for the secondary overexpression of the hepatic CYP2C8/9 content and activity reported in SIDS infants, which intensified AA metabolism. Pulmonary edema and petechial hemorrhages often present in SIDS victims may be the result of the vascular leak syndrome caused by IL-2 and IFN-alpha. Chronic hypoxia with the release of proinflammatory mediators IL-1alpha, IL-1beta and IL-6, and overloading of the cardiovascular and respiratory systems due to the narrowing airways and small pulmonary arteries of these children could also contribute to the development of these abnormalities. Moreover, chronic hypoxia of SIDS infants induced also production of hypoxia-inducible factor 1alpha (HIF-1alpha), which stimulated synthesis and release of different growth factors by vascular endothelial cells and intensified subclinical inflammatory reactions in the central nervous system, perhaps potentiated also by PACAP and VIP gene mutations. These processes could lead to the development of brainstem gliosis and disorders in the release of neuromediators important for physiologic sleep regulation. All these changes as well as eventual PACAP abnormalities could result in disturbed homeostatic control of the cardiovascular and respiratory responses of SIDS victims, which, combined with the nicotine effects and metabolic trauma, finally lead to death in these often genetically predisposed children.
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Affiliation(s)
- Joseph Prandota
- Faculty of Medicine and Dentistry, and Department of Social Pediatrics, Faculty of Public Health, University Medical School, Wroclaw, Poland.
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Nicoll-Griffith DA, Chauret N, Houle R, Day SH, D'Antoni M, Silva JM. USE OF A BENZYLOXY-SUBSTITUTED LACTONE CYCLOOXYGENASE-2 INHIBITOR AS A SELECTIVE FLUORESCENT PROBE FOR CYP3A ACTIVITY IN PRIMARY CULTURED RAT AND HUMAN HEPATOCYTES. Drug Metab Dispos 2004. [DOI: 10.1124/dmd.32.12.1509] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Levitchi M, Fradette C, Bleau AM, Michaud D, Kourylko O, Arcand M, du Souich P. Signal transduction pathways implicated in the decrease in CYP1A1, 1A2 and 3A6 activity produced by serum from rabbits and humans with an inflammatory reaction. Biochem Pharmacol 2004; 68:573-82. [PMID: 15242823 DOI: 10.1016/j.bcp.2004.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2003] [Accepted: 04/13/2004] [Indexed: 10/26/2022]
Abstract
Incubation of serum from rabbits with a turpentine-induced inflammatory reaction and from humans with an upper respiratory viral infection with hepatocytes from rabbits with a turpentine-induced inflammatory reaction for 4h reduces total cytochrome P450 content and activity of cytochrome P450 isoforms CYP1A1/1A2 and 3A6 without affecting the expression of these proteins. To document the signal transduction pathways implicated in the decrease in CYP1A1/1A2 and 3A6 activity, hepatocytes from rabbits with a turpentine-induced inflammatory reaction were incubated with serum from rabbits with a turpentine-induced inflammatory reaction, serum from individuals with a viral infection and interleukin-6 for 4h in presence of inhibitors of protein kinases. The sera-induced decrease in CYP1A1/1A2 and 3A6 activity was partially prevented by the inhibition of Janus-associated protein tyrosine kinase, double-stranded RNA-dependent protein kinase, protein kinase C, and p42/44 mitogen-activated protein kinase. The serum from rabbits with a turpentine-induced inflammatory reaction increased the phosphorylation of Erk1/2, effect prevented by PD98059 but not by bis-indolylmaleimide, a specific inhibitor of protein kinase C. The results demonstrated that the decrease in total cytochrome P450 content and in CYP1A1/1A2 and 3A6 activity by sera and interleukin-6 involves the activation of protein tyrosine kinases, p42/44 mitogen-activated protein kinase and protein kinase C. Indirect evidence supported that nitric oxide is implicated in the decrease in activity of these enzymes.
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Affiliation(s)
- Mihaela Levitchi
- Département de Pharmacologie, Faculté de Médecine, Université de Montréal, Montreal, Quebec, Canada H3C 3J7
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Fichtlscherer S, Dimmeler S, Breuer S, Busse R, Zeiher AM, Fleming I. Inhibition of Cytochrome P450 2C9 Improves Endothelium-Dependent, Nitric Oxide–Mediated Vasodilatation in Patients With Coronary Artery Disease. Circulation 2004; 109:178-83. [PMID: 14662709 DOI: 10.1161/01.cir.0000105763.51286.7f] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Nitric oxide (NO)– and prostacyclin-independent vasodilatation in several vascular beds has been linked to the activation of cytochrome P450 (CYP) epoxygenases expressed in endothelial cells. However, these enzymes, which generate vasodilator epoxyeicosatrienoic acids, may also produce oxygen-derived free radicals, which attenuate the bioavailability of NO. Here, we studied the involvement of CYP 2C9 in modulating endothelium-dependent and -independent changes in forearm blood flow (FBF) in healthy volunteers and in patients with manifest coronary artery disease.
Methods and Results—
The effects of sulfaphenazole, a selective inhibitor of CYP 2C9, on endothelium-dependent (acetylcholine) and endothelium-independent (sodium nitroprusside, SNP) FBF responses were measured by venous occlusion plethysmography in 5 healthy subjects and in 16 patients with angiographically documented stable coronary artery disease. Sulfaphenazole did not modify FBF responses to acetylcholine or SNP in healthy subjects. In contrast, sulfaphenazole markedly and dose-dependently enhanced the FBF response to acetylcholine without affecting the response to SNP. Vitamin C also increased the FBF response to acetylcholine, but this effect was further potentiated by sulfaphenazole. In the presence of
N
ω
-monomethyl-
l
-arginine, sulfaphenazole failed to significantly improve acetylcholine-induced vasodilatation. The oxidation of serum proteins was enhanced in patients with coronary artery disease, and this effect was significantly attenuated by sulfaphenazole.
Conclusions—
The CYP 2C9 inhibitor sulfaphenazole enhances endothelium-dependent vasodilator responses in patients with manifest coronary artery disease. This effect seems to be related to an increase in the bioavailability of NO, probably as a consequence of an attenuated generation of reactive oxygen species by CYP 2C9 in endothelial cells.
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Affiliation(s)
- Stephan Fichtlscherer
- Departments of Internal Medicine IV, Division of Cardiology, Johann W. Goethe-University, Frankfurt am Main, Germany
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Fradette C, Yamaguchi N, du Souich P. 5-Hydroxytryptamine is biotransformed by CYP2C9, 2C19 and 2B6 to hydroxylamine, which is converted into nitric oxide. Br J Pharmacol 2004; 141:407-14. [PMID: 14718257 PMCID: PMC1574215 DOI: 10.1038/sj.bjp.0705632] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
There is circumstantial evidence suggesting that 5-hydroxytryptamine (5-HT) could be biotransformed by enzymatic systems other than monoamino oxidase A, and that the isoforms of cytochrome P450 may be a source of nitric oxide. This study aimed to assess whether cytochrome P450 contributes to 5-HT biotransformation, and to provide evidence that 5-HT metabolism generates nitric oxide. Addition of 5-HT to cultured hepatocytes yielded 5-hydroxyindol acetic acid, a formation modulated by cytochrome P450 enzyme inducers and inhibitors. Recombinant human CYP2B6, 2C9 and 2C19 biotransformed 5-HT in 5-hydroxyindol acetic acid, but not CYP1A2, 2D6 or 3A4. Cultured hepatocytes with 5-HT generated nitric oxide, the amount of which was altered by cytochrome P450 enzyme inducers and inhibitors. In the presence of CYP2B6, 2C9 and 2C19, 5-HT relaxed precontracted isolated aortic rings, with or without endothelium, an effect prevented by the addition of methylene blue and an inhibitor of catalase, but not by myoglobin. In the absence of catalase, hydroxylamine was always assayed as a byproduct of 5-HT metabolism. In conclusion, CYP2B6, 2C9 and 2C19 biotransform 5-HT, yielding hydroxylamine, which is converted to nitric oxide in the presence of catalase. British Journal of Pharmacology (2004) 141, 407-414. doi:10.1038/sj.bjp.0705632
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Affiliation(s)
- Caroline Fradette
- Department of Pharmacology, Faculty of Medicine, University of Montréal, P.O. Box 6128, Stat. Centre-Ville, Montréal, Québec, Canada H3C 3J7
| | - Nobuharu Yamaguchi
- Faculty of Pharmacy, University of Montréal, P.O. Box 6128, Stat. Centre-Ville, Montréal, Québec, Canada H3C 3J7
| | - Patrick du Souich
- Department of Pharmacology, Faculty of Medicine, University of Montréal, P.O. Box 6128, Stat. Centre-Ville, Montréal, Québec, Canada H3C 3J7
- Author for correspondence:
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Mastyugin V, Mezentsev A, Zhang WX, Ashkar S, Dunn MW, Laniado-Schwartzman M. Promoter activity and regulation of the corneal CYP4B1 gene by hypoxia. J Cell Biochem 2004; 91:1218-38. [PMID: 15048876 DOI: 10.1002/jcb.20018] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hypoxic injury to the ocular surface provokes an inflammatory response that is mediated, in part, by corneal epithelial-derived 12-hydroxyeicosanoids. Recent studies indicate that a cytochrome P450 (CYP) monooxygenase, identified as CYP4B1, is involved in the production of these eicosanoids which exhibit potent inflammatory and angiogenic properties. We have isolated and cloned a corneal epithelial CYP4B1 full-length cDNA and demonstrated that the CYP4B1 mRNA is induced by hypoxia in vitro and in vivo. To further understand the molecular regulation that underlies the synthesis of these potent inflammatory eicosanoids in response to hypoxic injury, we isolated and cloned the CYP4B1 promoter region. GenomeWalker libraries constructed from rabbit corneal epithelial genomic DNA were used as templates for primary and nested PCR amplifications with gene- and adaptor-specific primers. A 3.41-kb DNA fragment of the 5'-flanking region of the CYP4B1 promoter was isolated, cloned, sequenced, and analyzed by computer software for the presence of known cis-acting elements. Analysis of the promoter sequence revealed the presence of consensus DNA binding sequences for factors known to activate gene transcription in response to hypoxia including HIF-1, NFkappaB, and AP-1. Transient transfection of luciferase reporter (pGL3-Basic) vectors containing different lengths of the CYP4B1 promoter fragment demonstrated hypoxia-induced transcription in rabbit corneal epithelial (RCE) cells. Electrophoretic mobility shift assay (EMSA) revealed a marked induction of nuclear binding activity for the labeled HIF-1 probe from the CYP4B1 promoter in nuclear extracts of cells exposed to hypoxia. This binding activity was due to sequence-specific binding to the HIF-1 oligonucleotide probe as shown by competition with excess unlabeled probe for the HIF-1 but not with unlabeled NFkappaB probe. The nuclear binding activity of AP-1 and NFkappaB probes from the CYP4B1 promoter was also enhanced in response to hypoxia suggesting that these transcription factors contribute to the hypoxic induction of CYP4B1 expression. The results of this study provide the first molecular mechanistic explanation for the induction of CYP4B1 and, thereby, the production of inflammatory eicosanoids in response to hypoxic injury. Further studies are needed to fully evaluate the molecular regulation of this gene during inflammation.
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Affiliation(s)
- Vladimir Mastyugin
- Department of Pharmacology, New York Medical College, Valhalla, New York 10595, USA
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Fradette C, Souich PD. Hypoxia-inducible factor-1 and activator protein-1 modulate the upregulation of CYP3A6 induced by hypoxia. Br J Pharmacol 2003; 140:1146-54. [PMID: 14559859 PMCID: PMC1574128 DOI: 10.1038/sj.bjp.0705543] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
1. Moderate hypoxia in vivo and serum from rabbits subjected to moderate hypoxia (SHYPO) in vitro reduce CYP1A1 and 1A2 p450 isoforms and upregulate CYP3A6. The aim of this project was to investigate the signal transduction pathways implicated in the upregulation of CYP3A6 expression by hypoxia. 2. Hypoxia in vivo and SHYPO in vitro increased the expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and c-jun, as well as CYP3A6. By electrophoresis mobility shift assay, it was shown that HIF-1 and activator protein-1 (AP-1) bind to CYP3A6 oligonucleotide probe after exposure to hypoxia in vivo and SHYPO in vitro. The effects of hypoxia in vivo or SHYPO in vitro were reproduced by CoCl2 and lead acetate, activators of HIF-1 and AP-1, respectively. 2. PD98059, a p42/44 MAPK inhibitor, prevented the increase of CYP3A6 and c-jun, but did not impede the increase of HIF-1alpha and binding to CYP3A6 oligonucleotide probe. Genistein, an inhibitor of protein tyrosine kinases (PTKs), prevented the increase in HIF-1alpha, c-jun and CYP3A6, as well as HIF-1 and AP-1 binding to CYP3A6 oligonucleotide probe. Moreover, hypoxia in vivo induced constitutive androstane receptor (CAR) as well as CAR binding to the CYP3A6 oligonucleotide probe, but not the pregnane X receptor. 4. In conclusion, hypoxia in vivo and SHYPO induce the expression of CYP3A6. The in vitro induction of CYP3A6 by SHYPO is PTK- and p42/44 MAPK-dependent. The present data support the hypothesis that HIF-1 and AP-1 are part of the signalling pathway leading to CYP3A6 induction by hypoxia.
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Affiliation(s)
- Caroline Fradette
- Department of Pharmacology, Faculty of Medicine, University of Montréal, PO Box 6128, Stat. Centre-Ville, Montréal, Québec, Canada H3C 3J7
| | - Patrick du Souich
- Department of Pharmacology, Faculty of Medicine, University of Montréal, PO Box 6128, Stat. Centre-Ville, Montréal, Québec, Canada H3C 3J7
- Author for correspondence:
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