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Duan JJ, Cai J, Gao L, Yu SC. ALDEFLUOR activity, ALDH isoforms, and their clinical significance in cancers. J Enzyme Inhib Med Chem 2023; 38:2166035. [PMID: 36651035 PMCID: PMC9858439 DOI: 10.1080/14756366.2023.2166035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
High aldehyde dehydrogenase (ALDH) activity is a metabolic feature of adult stem cells and various cancer stem cells (CSCs). The ALDEFLUOR system is currently the most commonly used method for evaluating ALDH enzyme activity in viable cells. This system is applied extensively in the isolation of normal stem cells and CSCs from heterogeneous cell populations. For many years, ALDH1A1 has been considered the most important subtype among the 19 ALDH family members in determining ALDEFLUOR activity. However, in recent years, studies of many types of normal and tumour tissues have demonstrated that other ALDH subtypes can also significantly influence ALDEFLUOR activity. In this article, we briefly review the relationships between various members of the ALDH family and ALDEFLUOR activity. The clinical significance of these ALDH isoforms in different cancers and possible directions for future studies are also summarised.
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Affiliation(s)
- Jiang-Jie Duan
- Department of Stem Cell and Regenerative Medicine, Southwest Hospital; Third Military Medical University (Army Medical University), Chongqing, China,International Joint Research Center for Precision Biotherapy, Ministry of Science and Technology, Chongqing, China,Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Chongqing, China,Ministry of Education, Key Laboratory of Cancer Immunopathology, Chongqing, China
| | - Jiao Cai
- Department of Stem Cell and Regenerative Medicine, Southwest Hospital; Third Military Medical University (Army Medical University), Chongqing, China,International Joint Research Center for Precision Biotherapy, Ministry of Science and Technology, Chongqing, China,Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Chongqing, China,Ministry of Education, Key Laboratory of Cancer Immunopathology, Chongqing, China
| | - Lei Gao
- Department of Hematology, Xinqiao Hospital; Third Medical University (Army Medical University), Chongqing, China
| | - Shi-Cang Yu
- Department of Stem Cell and Regenerative Medicine, Southwest Hospital; Third Military Medical University (Army Medical University), Chongqing, China,International Joint Research Center for Precision Biotherapy, Ministry of Science and Technology, Chongqing, China,Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Chongqing, China,Ministry of Education, Key Laboratory of Cancer Immunopathology, Chongqing, China,Jin-feng Laboratory, Chongqing, China,CONTACT Shi-Cang Yu Department of Stem Cell and Regenerative Medicine, Third Military Medical University (Army Medical University), Chongqing400038, China
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2
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Non-cytochrome P450 enzymes involved in the oxidative metabolism of xenobiotics: Focus on the regulation of gene expression and enzyme activity. Pharmacol Ther 2021; 233:108020. [PMID: 34637840 DOI: 10.1016/j.pharmthera.2021.108020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 09/25/2021] [Accepted: 10/04/2021] [Indexed: 12/16/2022]
Abstract
Oxidative metabolism is one of the major biotransformation reactions that regulates the exposure of xenobiotics and their metabolites in the circulatory system and local tissues and organs, and influences their efficacy and toxicity. Although cytochrome (CY)P450s play critical roles in the oxidative reaction, extensive CYP450-independent oxidative metabolism also occurs in some xenobiotics, such as aldehyde oxidase, xanthine oxidoreductase, flavin-containing monooxygenase, monoamine oxidase, alcohol dehydrogenase, or aldehyde dehydrogenase-dependent oxidative metabolism. Drugs form a large portion of xenobiotics and are the primary target of this review. The common reaction mechanisms and roles of non-CYP450 enzymes in metabolism, factors affecting the expression and activity of non-CYP450 enzymes in terms of inhibition, induction, regulation, and species differences in pharmaceutical research and development have been summarized. These non-CYP450 enzymes are detoxifying enzymes, although sometimes they mediate severe toxicity. Synthetic or natural chemicals serve as inhibitors for these non-CYP450 enzymes. However, pharmacokinetic-based drug interactions through these inhibitors have rarely been reported in vivo. Although multiple mechanisms participate in the basal expression and regulation of non-CYP450 enzymes, only a limited number of inducers upregulate their expression. Therefore, these enzymes are considered non-inducible or less inducible. Overall, this review focuses on the potential xenobiotic factors that contribute to variations in gene expression levels and the activities of non-CYP450 enzymes.
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3
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Di L, Balesano A, Jordan S, Shi SM. The Role of Alcohol Dehydrogenase in Drug Metabolism: Beyond Ethanol Oxidation. AAPS JOURNAL 2021; 23:20. [DOI: 10.1208/s12248-020-00536-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/17/2020] [Indexed: 02/08/2023]
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4
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Moody DE. The inhibition of first-pass metabolism of ethanol by H2-receptor antagonists: a tabulated review. Expert Opin Drug Saf 2018; 17:917-934. [PMID: 30117350 DOI: 10.1080/14740338.2018.1512969] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- David E. Moody
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
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5
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Dixit VA, Lal LA, Agrawal SR. Recent advances in the prediction of non‐
CYP450
‐mediated drug metabolism. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2017. [DOI: 10.1002/wcms.1323] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Vaibhav A. Dixit
- Department of Pharmaceutical Chemistry, School of Pharmacy & Technology Management (SPTM)Shri Vile Parle Kelavani Mandal's (SVKM's), Narsee Monjee Institute of Management Studies (NMIMS)ShirpurIndia
| | - L. Arun Lal
- Department of Pharmaceutical Chemistry, School of Pharmacy & Technology Management (SPTM)Shri Vile Parle Kelavani Mandal's (SVKM's), Narsee Monjee Institute of Management Studies (NMIMS)ShirpurIndia
| | - Simran R. Agrawal
- Department of Pharmaceutical Chemistry, School of Pharmacy & Technology Management (SPTM)Shri Vile Parle Kelavani Mandal's (SVKM's), Narsee Monjee Institute of Management Studies (NMIMS)ShirpurIndia
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6
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Chi YC, Lee SL, Lai CL, Lee YP, Lee SP, Chiang CP, Yin SJ. Ethanol oxidation and the inhibition by drugs in human liver, stomach and small intestine: Quantitative assessment with numerical organ modeling of alcohol dehydrogenase isozymes. Chem Biol Interact 2016; 258:134-41. [PMID: 27544634 DOI: 10.1016/j.cbi.2016.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 08/04/2016] [Accepted: 08/15/2016] [Indexed: 12/31/2022]
Abstract
Alcohol dehydrogenase (ADH) is the principal enzyme responsible for metabolism of ethanol. Human ADH constitutes a complex isozyme family with striking variations in kinetic function and tissue distribution. Liver and gastrointestinal tract are the major sites for first-pass metabolism (FPM). Their relative contributions to alcohol FPM and degrees of the inhibitions by aspirin and its metabolite salicylate, acetaminophen and cimetidine remain controversial. To address this issue, mathematical organ modeling of ethanol-oxidizing activities in target tissues and that of the ethanol-drug interactions were constructed by linear combination of the corresponding numerical rate equations of tissue constituent ADH isozymes with the documented isozyme protein contents, kinetic parameters for ethanol oxidation and the drug inhibitions of ADH isozymes/allozymes that were determined in 0.1 M sodium phosphate at pH 7.5 and 25 °C containing 0.5 mM NAD(+). The organ simulations reveal that the ADH activities in mucosae of the stomach, duodenum and jejunum with ADH1C*1/*1 genotype are less than 1%, respectively, that of the ADH1B*1/*1-ADH1C*1/*1 liver at 1-200 mM ethanol, indicating that liver is major site of the FPM. The apparent hepatic KM and Vmax for ethanol oxidation are simulated to be 0.093 ± 0.019 mM and 4.0 ± 0.1 mmol/min, respectively. At 95% clearance in liver, the logarithmic average sinusoidal ethanol concentration is determined to be 0.80 mM in accordance with the flow-limited gradient perfusion model. The organ simulations indicate that higher therapeutic acetaminophen (0.5 mM) inhibits 16% of ADH1B*1/*1 hepatic ADH activity at 2-20 mM ethanol and that therapeutic salicylate (1.5 mM) inhibits 30-31% of the ADH1B*2/*2 activity, suggesting potential significant inhibitions of ethanol FPM in these allelotypes. The result provides systematic evaluations and predictions by computer simulation on potential ethanol FPM in target tissues and hepatic ethanol-drug interactions in the context of tissue ADH isozymes.
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Affiliation(s)
- Yu-Chou Chi
- Graduate Institute of Life Sciences, National Defense Medical Center, 161 Minchuan East Road Section 6, Taipei 11490, Taiwan
| | - Shou-Lun Lee
- Department of Biological Science and Technology, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan
| | - Ching-Long Lai
- Department of Nursing, Chang Gung University of Science and Technology, 261 Wenhwa 1st Road, Kweishan Township, Taoyuan 33303, Taiwan
| | - Yung-Pin Lee
- Department of Biochemistry, National Defense Medical Center, 161 Minchuan East Road Section 6, Taipei 11490, Taiwan
| | - Shiao-Pieng Lee
- Department of Dentistry, Tri-Service General Hospital, National Defense Medical Center, 325 Chenggong Road Section 2, Taipei 11490, Taiwan
| | - Chien-Ping Chiang
- Department of Dermatology, Tri-Service General Hospital, National Defense Medical Center, 325 Chenggong Road Section 2, Taipei 11490, Taiwan
| | - Shih-Jiun Yin
- Graduate Institute of Life Sciences, National Defense Medical Center, 161 Minchuan East Road Section 6, Taipei 11490, Taiwan; Department of Biochemistry, National Defense Medical Center, 161 Minchuan East Road Section 6, Taipei 11490, Taiwan.
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7
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Inhibition of human alcohol and aldehyde dehydrogenases by aspirin and salicylate: assessment of the effects on first-pass metabolism of ethanol. Biochem Pharmacol 2015; 95:71-9. [PMID: 25772736 DOI: 10.1016/j.bcp.2015.03.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/05/2015] [Indexed: 12/14/2022]
Abstract
Previous studies have reported that aspirin significantly reduced the first-pass metabolism (FPM) of ethanol in humans thereby increasing adverse effects of alcohol. The underlying causes, however, remain poorly understood. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), principal enzymes responsible for metabolism of ethanol, are complex enzyme families that exhibit functional polymorphisms among ethnic groups and distinct tissue distributions. We investigated the inhibition profiles by aspirin and its major metabolite salicylate of ethanol oxidation by recombinant human ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, ADH1C2, ADH2, and ADH4, and acetaldehyde oxidation by ALDH1A1 and ALDH2, at pH 7.5 and 0.5 mM NAD(+). Competitive inhibition pattern was found to be a predominant type among the ADHs and ALDHs studied, although noncompetitive and uncompetitive inhibitions were also detected in a few cases. The inhibition constants of salicylate for the ADHs and ALDHs were considerably lower than that of aspirin with the exception of ADH1A that can be ascribed to a substitution of Ala-93 at the bottom of substrate pocket as revealed by molecular docking experiments. Kinetic inhibition equation-based simulations show at higher therapeutic levels of blood plasma salicylate (1.5 mM) that the decrease of activities at 2-10 mM ethanol for ADH1A/ADH2 and ADH1B2/ADH1B3 are predicted to be 75-86% and 31-52%, respectively, and that the activity decline for ALDH1A1 and ALDH2 at 10-50 μM acetaldehyde to be 62-73%. Our findings suggest that salicylate may substantially inhibit hepatic FPM of alcohol at both the ADH and ALDH steps when concurrent intaking aspirin.
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8
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Neuman MG, Cohen L, Zakhari S, Nanau RM, Mueller S, Schneider M, Parry C, Isip R, Seitz HK. Alcoholic liver disease: a synopsis of the Charles Lieber's Memorial Symposia 2009-2012. Alcohol Alcohol 2014; 49:373-80. [PMID: 24816574 DOI: 10.1093/alcalc/agu021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This paper is based upon the 'Charles Lieber Satellite Symposia' organized by Manuela G. Neuman at each of the 2009-2012 Research Society on Alcoholism (RSA) Annual Meetings. The presentations represent a broad spectrum dealing with alcoholic liver disease (ALD). In addition, a literature search (2008-2013) in the discussed area was performed in order to obtain updated data. The presentations are focused on genetic polymorphisms of ethanol metabolizing enzymes and the role of cytochrome P4502E1 (CYP2E1) in ALD. In addition, alcohol-mediated hepatocarcinogenesis, immune response to alcohol and fibrogenesis in alcoholic hepatitis as well as its co-morbidities with chronic viral hepatitis infections in the presence or absence of human deficiency virus are discussed. Finally, emphasis was led on alcohol and drug interactions as well as liver transplantation for end-stage ALD.
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Affiliation(s)
- Manuela G Neuman
- In Vitro Drug Safety and Biotechnology, University of Toronto, Toronto, ON, Canada Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Lawrence Cohen
- Division of Gastroenterology, Sunnybrook Health Sciences Centre, Department of Medicine, Medicine, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Samir Zakhari
- Division of Metabolism and Health Effects, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Radu M Nanau
- In Vitro Drug Safety and Biotechnology, University of Toronto, Toronto, ON, Canada Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Sebastian Mueller
- Centre of Alcohol Research, University of Heidelberg and Department of Medicine (Gastroenterology and Hepatology), Salem Medical Centre, Heidelberg, Germany
| | - Michelle Schneider
- Alcohol and Drug Abuse Research Unit, Medical Research Council, Stellenbosch University, Cape Town, South Africa
| | - Charles Parry
- Alcohol and Drug Abuse Research Unit, Medical Research Council, Stellenbosch University, Cape Town, South Africa Department of Psychiatry, Stellenbosch University, Cape Town, South Africa
| | - Romina Isip
- In Vitro Drug Safety and Biotechnology, University of Toronto, Toronto, ON, Canada Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Helmut K Seitz
- Centre of Alcohol Research, University of Heidelberg and Department of Medicine (Gastroenterology and Hepatology), Salem Medical Centre, Heidelberg, Germany
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Wang HL, Zhou PY, Liu P, Zhang Y. ALDH2 and ADH1 genetic polymorphisms may contribute to the risk of gastric cancer: a meta-analysis. PLoS One 2014; 9:e88779. [PMID: 24633362 PMCID: PMC3954547 DOI: 10.1371/journal.pone.0088779] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 01/13/2014] [Indexed: 01/11/2023] Open
Abstract
AIM We conducted a meta-analysis of case-control studies to determine whether ALDH2, ADH1 and ADH2 genetic polymorphisms contribute to the pathogenesis of gastric cancer. METHODS The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before November 1st, 2013 without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. We calculated crude odds ratios (ORs) with their 95% confidence intervals (95%CI) to evaluate their relationships under five genetic models. Seven case-control studies with a total of 2,563 gastric cancer patients and 4,192 healthy controls met the inclusion criteria. Nine common polymorphisms were evaluated, including rs671, rs16941667 and rs886205 in the ALDH2 gene, rs1230025, rs13123099, rs698 and rs1693482 in the ADH1 gene, and rs1229984 and rs17033 in the ADH2 gene. RESULTS The results of our meta-analysis suggested that ALDH2 genetic polymorphisms might be strongly correlated with an increased risk of gastric cancer (allele model: OR = 1.21, 95%CI: 1.11 ∼ 1.32, P<0.001; dominant model: OR = 1.23, 95%CI: 1.09 ∼ 1.39, P = 0.001; respectively), especially for rs671 polymorphism. Furthermore, we observed significant associations between ADH1 genetic polymorphisms and an increased risk of gastric cancer (allele model: OR = 1.21, 95%CI: 1.08 ∼ 1.36, P = 0.001; dominant model: OR = 10.52, 95%CI: 3.04 ∼ 36.41, P<0.001; respectively), especially for rs1230025 polymorphism. Nevertheless, no positive relationships were found between ADH2 genetic polymorphisms and gastric cancer risk (all P>0.05). CONCLUSION The current meta-analysis suggests that ALDH2 and ADH1 genetic polymorphisms may play crucial roles in the pathogenesis of gastric cancer. However, ADH2 genetic polymorphisms may not be important dominants of susceptibility to gastric cancer.
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Affiliation(s)
- He-Ling Wang
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, P. R. China
- * E-mail:
| | - Ping-Yi Zhou
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, P. R. China
| | - Peng Liu
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, P. R. China
| | - Yu Zhang
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, P. R. China
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Abstract
Concomitant use of alcohol and medications may lead to potentially serious medical conditions. Increasing prescription medication abuse in today's society necessitates a deeper understanding of the mechanisms involved in alcohol-medication interactions in order to help prevent adverse events. Interactions of medications with alcohol result in altered bioavailability of the medication or alcohol (pharmacokinetic interactions) or modification of the effects at receptor or ion channel sites to alter behavioral or physical outcome (pharmacodynamic interactions). The nature of pharmacokinetic or pharmacodynamic interactions involved in alcohol-medication interactions may differ between acute and chronic alcohol use and be influenced by race, gender, or environmental or genetic factors. This review focuses on the mechanisms underlying pharmacokinetic and pharmacodynamic interactions between alcohol and medications and provides examples for such interactions from replicated research studies. In conclusion, further translational research is needed to address several gaps in our current knowledge of alcohol-medication interactions, including those under various pathologic conditions.
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Affiliation(s)
- Bankole A Johnson
- Department of Psychiatry and Brain Science Research Consortium at the University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Chamindi Seneviratne
- Department of Psychiatry, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
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11
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Inhibition of human alcohol and aldehyde dehydrogenases by acetaminophen: Assessment of the effects on first-pass metabolism of ethanol. Alcohol 2013; 47:559-65. [PMID: 24169088 DOI: 10.1016/j.alcohol.2013.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 09/03/2013] [Accepted: 09/04/2013] [Indexed: 12/13/2022]
Abstract
Acetaminophen is one of the most widely used over-the-counter analgesic, antipyretic medications. Use of acetaminophen and alcohol are commonly associated. Previous studies showed that acetaminophen might affect bioavailability of ethanol by inhibiting gastric alcohol dehydrogenase (ADH). However, potential inhibitions by acetaminophen of first-pass metabolism (FPM) of ethanol, catalyzed by the human ADH family and by relevant aldehyde dehydrogenase (ALDH) isozymes, remain undefined. ADH and ALDH both exhibit racially distinct allozymes and tissue-specific distribution of isozymes, and are principal enzymes responsible for ethanol metabolism in humans. In this study, we investigated acetaminophen inhibition of ethanol oxidation with recombinant human ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, ADH1C2, ADH2, and ADH4, and inhibition of acetaldehyde oxidation with recombinant human ALDH1A1 and ALDH2. The investigations were done at near physiological pH 7.5 and with a cytoplasmic coenzyme concentration of 0.5 mM NAD(+). Acetaminophen acted as a noncompetitive inhibitor for ADH enzymes, with the slope inhibition constants (Kis) ranging from 0.90 mM (ADH2) to 20 mM (ADH1A), and the intercept inhibition constants (Kii) ranging from 1.4 mM (ADH1C allozymes) to 19 mM (ADH1A). Acetaminophen exhibited noncompetitive inhibition for ALDH2 (Kis = 3.0 mM and Kii = 2.2 mM), but competitive inhibition for ALDH1A1 (Kis = 0.96 mM). The metabolic interactions between acetaminophen and ethanol/acetaldehyde were assessed by computer simulation using inhibition equations and the determined kinetic constants. At therapeutic to subtoxic plasma levels of acetaminophen (i.e., 0.2-0.5 mM) and physiologically relevant concentrations of ethanol (10 mM) and acetaldehyde (10 μm) in target tissues, acetaminophen could inhibit ADH1C allozymes (12-26%) and ADH2 (14-28%) in the liver and small intestine, ADH4 (15-31%) in the stomach, and ALDH1A1 (16-33%) and ALDH2 (8.3-19%) in all 3 tissues. The results suggest that inhibition by acetaminophen of hepatic and gastrointestinal FPM of ethanol through ADH and ALDH pathways might become significant at higher, subtoxic levels of acetaminophen.
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12
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Lai CL, Yao CT, Chau GY, Yang LF, Kuo TY, Chiang CP, Yin SJ. Dominance of the inactive Asian variant over activity and protein contents of mitochondrial aldehyde dehydrogenase 2 in human liver. Alcohol Clin Exp Res 2013; 38:44-50. [PMID: 23909789 DOI: 10.1111/acer.12215] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Accepted: 05/09/2013] [Indexed: 01/09/2023]
Abstract
BACKGROUND It has been well documented that a variant allele of mitochondrial aldehyde dehydrogenase 2 (ALDH2), ALDH2*2, commonly occurs in East Asians but rarely in other ethnic populations. This unique allelic variation significantly influences drinking behavior and susceptibility to development of alcoholism. Previous structural, functional, and cellular studies indicate that the resulting variant polypeptide subunit K (Lys-487) exerts dominance of null activity and shorter half-life over the tetrameric enzyme molecules in distinct manners. However, the in vivo evidence for the proposed dominance mechanisms remains lacking. METHODS To address this question, we investigated 33 surgical liver samples identified to be normal homozygous ALDH2*1/*1 (n = 17), heterozygous ALDH2*1/*2 (n = 13), and variant homozygous ALDH2*2/*2 (n = 3). The ALDH2 activity was determined at a sufficient low acetaldehyde concentration (3 μM) and the isozyme protein amount by immunotitration using purified class-specific antibodies. RESULTS The tissue ALDH2 activity in heterozygotes was 17% that of the ALDH2*1/*1 genotype (p < 0.001), whereas the activity of ALDH2*2/*2 was too low to be precisely determined. The protein amounts of tissue ALDH2 in variant homozygotes and heterozygotes were similar but only 30 to 40% that of normal homozygotes (p < 0.01). Linear regression analyses show that ALDH2 activities were significantly correlated with the protein contents in normal homozygotes and heterozygotes, respectively (p < 0.005). The specific activity of ALDH2 per enzyme protein in ALDH2*1/*2 was 38% that of ALDH2*1/*1 (p < 0.001). CONCLUSIONS These results are in good agreement with those predicted by the model studies, thus providing in vivo evidence for differential impairments of hepatic acetaldehyde oxidation with alcohol metabolism in individuals carrying ALDH2*1/*2 and ALDH2*2/*2 genotypes.
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Affiliation(s)
- Ching-Long Lai
- Department of Nursing , Chang Gung University of Science and Technology, Taoyuan, Taiwan
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13
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Bell CC, Santoyo Castelazo A, Yang EL, Maggs JL, Jenkins RE, Tugwood J, O’Neill PM, Naisbitt DJ, Park BK. Oxidative Bioactivation of Abacavir in Subcellular Fractions of Human Antigen Presenting Cells. Chem Res Toxicol 2013; 26:1064-72. [DOI: 10.1021/tx400041v] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Catherine C. Bell
- MRC Centre
for Drug Safety Science,
Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, United Kingdom
| | - Anahi Santoyo Castelazo
- MRC Centre
for Drug Safety Science,
Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, United Kingdom
| | - Emma L. Yang
- MRC Centre
for Drug Safety Science,
Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, United Kingdom
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United
Kingdom
| | - James L. Maggs
- MRC Centre
for Drug Safety Science,
Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, United Kingdom
| | - Rosalind E. Jenkins
- MRC Centre
for Drug Safety Science,
Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, United Kingdom
| | - Jonathan Tugwood
- Paterson Institute
for Cancer
Research, The University of Manchester,
Manchester M20 4BX, United Kingdom
| | - Paul M. O’Neill
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United
Kingdom
| | - Dean J. Naisbitt
- MRC Centre
for Drug Safety Science,
Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, United Kingdom
| | - B. Kevin Park
- MRC Centre
for Drug Safety Science,
Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GE, United Kingdom
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