1
|
Imbabi T, Hassan A, Ahmed-Farid O, El-Garhy O, Sabeq I, Moustafa M, Mohammadein A, Hassan N, Osman A, Sitohy M. Supplementing rabbit diets with butylated hydroxyanisole affects oxidative stress, growth performance, and meat quality. Animal 2021; 15:100339. [PMID: 34425485 DOI: 10.1016/j.animal.2021.100339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/18/2021] [Accepted: 07/22/2021] [Indexed: 11/19/2022] Open
Abstract
Butylated hydroxyanisole (BHA) is a synthetic antioxidant analogous of vitamin E. It is used as a preservative to prevent free radical-mediated oxidation in high-fat foods, and this study's objective was to investigate the effects of BHA on oxidative stress and apoptosis in addition to delineating its efficacy as a growth-promoting feed additive. 60 weaned male rabbits (V-line) were randomly divided into four equal groups: BHA0.0 (control), BHA50, BHA100, and BHA150, administered basal diets with 0.0, 50, 100, and 150 mg BHA/kg of feed for 60 days. Animals were examined for growth performance, markers of oxidative stress and apoptosis, and meat characteristics. Compared to the control group, rabbits receiving BHA-supplemented diets exhibited increases in BW and average daily gain (P < 0.01), where BHA50 and BHA100 groups showed increased muscle content of methionine aspartic acid, serine, and glutamine (P < 0.05). These two groups also exhibited elevated catalase and superoxide dismutase activities and diminished malondialdehyde levels in the liver. Butylated hydroxyanisole upregulated fatty acid synthase gene (FASN), especially in BHA100 animals. Bcl-2-associated X/B-celllymphoma-2 (Bax/Bcl-2) ratio significantly increased in animals receiving higher doses of BHA, and the weight of the liver significantly increased following BHA treatment. Supplementing growing rabbits with lower doses of dietary BHA may promote growth performance and meat quality via maintaining the redox balance. Hence, the 50-100 mg/kg may be recommended as a safe and still effective feed additive as well as an oxidative stress attenuator.
Collapse
Affiliation(s)
- T Imbabi
- Animal Production Department, Faculty of Agriculture, Benha University, Moshtohor 13736, Egypt
| | - A Hassan
- Department of Biotechnology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - O Ahmed-Farid
- Department of Physiology, National Organization for Drug Control and Research, Giza 12553, Egypt
| | - O El-Garhy
- Animal Production Department, Faculty of Agriculture, Benha University, Moshtohor 13736, Egypt
| | - I Sabeq
- Department of Food Hygiene, Faculty of Veterinary Medicine, Benha University, Moshtohor 13736, Egypt
| | - M Moustafa
- Genetics and Genetic Engineering Department, Faculty of Agriculture, Benha University, Moshtohor 13736, Egypt(1)
| | - A Mohammadein
- Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - N Hassan
- Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - A Osman
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt.
| | - M Sitohy
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt
| |
Collapse
|
2
|
Atia A, Alrawaiq NS, Abdullah A. Tocotrienols Activate Nrf2 Nuclear Translocation and Increase the Antioxidant- Related Hepatoprotective Mechanism in Mice Liver. Curr Pharm Biotechnol 2021; 22:1085-1098. [PMID: 32988349 DOI: 10.2174/1389201021666200928095950] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/26/2020] [Accepted: 09/01/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND The most common preparation of tocotrienols is the Tocotrienol-Rich Fraction (TRF). This study aimed to investigate whether TRF induced liver Nrf2 nuclear translocation and influenced the expression of Nrf2-regulated genes. METHODS In the Nrf2 induction study, mice were divided into control, 2000 mg/kg TRF and diethyl maleate treated groups. After acute treatment, mice were sacrificed at specific time points. Liver nuclear extracts were prepared and Nrf2 nuclear translocation was detected through Western blotting. To determine the effect of increasing doses of TRF on the extent of liver nuclear Nrf2 translocation and its implication on the expression levels of several Nrf2-regulated genes, mice were divided into 5 groups (control, 200, 500 and 1000 mg/kg TRF, and butylated hydroxyanisole-treated groups). After 14 days, mice were sacrificed and liver RNA was extracted for qPCR assay. RESULTS 2000 mg/kg TRF administration initiated Nrf2 nuclear translocation within 30 min, reached a maximum level of around 1 h and dropped to half-maximal levels by 24 h. Incremental doses of TRF resulted in dose-dependent increases in liver Nrf2 nuclear levels, along with concomitant dosedependent increases in the expressions of Nrf2-regulated genes. CONCLUSION TRF activated the liver Nrf2 pathway resulting in increased expression of Nrf2-regulated cytoprotective genes.
Collapse
Affiliation(s)
- Ahmed Atia
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Nadia S Alrawaiq
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Azman Abdullah
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| |
Collapse
|
3
|
Zheng Z, Chen Y, Huang J, Deng H, Tang X, Wang XJ. Mkp-1 is required for chemopreventive activity of butylated hydroxyanisole and resveratrol against colitis-associated colon tumorigenesis. Food Chem Toxicol 2019; 127:72-80. [PMID: 30844440 DOI: 10.1016/j.fct.2019.02.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 02/04/2019] [Accepted: 02/27/2019] [Indexed: 02/07/2023]
Abstract
Many dietary compounds show promising protective activity against colon cancer by activating nuclear factor-erythroid 2 related factor 2 (Nrf2). Recently, we reported that mitogen-activated protein kinase phosphatase 1 (Mkp-1) exhibits crosstalk with the Nrf2 signaling pathway, protecting against intestinal inflammation. Here, we present evidence that Mkp-1 is required for the chemopreventive action of the Nrf2 activators butylated hydroxyanisole (BHA) and resveratrol (RSV). In an azoxymethane/dextran sulfate sodium model of colitis-associated tumorigenesis, Mkp-1-/- mice exhibited a phenotype similar to Nrf2-/- mice with significantly more tumors than WT mice. Tumors from Mkp-1-/- mice exhibited higher levels of macrophage infiltration than those from WT mice. This was accompanied by increased expression of nitrotyrosine and p53BP1, markers of oxidative stress and DNA damage, respectively. Moreover, dietary suppression of tumorigenesis using BHA (0.5%) or RSV (300 ppm) supplementation was achieved in WT but not in Mkp-1-/- mice. In adenomas from WT mice, the expression of Mkp-1 was markedly lower than in adjacent normal tissue, concomitant with the down-regulation of Nrf2 and its target genes. Our data revealed that Mkp-1 is required in the protective role of Nrf2 signaling against colitis-associated tumorigenesis.
Collapse
Affiliation(s)
- Zhaohong Zheng
- Department of Pharmacology and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, PR China
| | - Yeru Chen
- Department of Pharmacology and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, PR China
| | - Jianan Huang
- Chu Kochen Honors College, Zhejiang University School of Medicine, Hangzhou, 310058, PR China; Department of Biochemistry, Department of Thoracic Surgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, PR China
| | - Hong Deng
- Department of Pathology, Zhejiang University School of Medicine, Hangzhou, 310058, PR China
| | - Xiuwen Tang
- Department of Biochemistry, Department of Thoracic Surgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, PR China
| | - Xiu Jun Wang
- Department of Pharmacology and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, PR China.
| |
Collapse
|
4
|
Abstract
Significance: Obesity and type 2 diabetes mellitus are increasing globally. There is also increasing associated complications, such as non-alcoholic fatty liver disease (NAFLD) and vascular complications of diabetes. There is currently no licensed treatment for NAFLD and no recent treatments for diabetic complications. New approaches are required, particularly those addressing mechanism-based risk factors for health decline and disease progression. Recent Advances: Dicarbonyl stress is the abnormal accumulation of reactive dicarbonyl metabolites such as methylglyoxal (MG) leading to cell and tissue dysfunction. It is a potential driver of obesity, diabetes, and related complications that are unaddressed by current treatments. Increased formation of MG is linked to increased glyceroneogenesis and hyperglycemia in obesity and diabetes and also down-regulation of glyoxalase 1 (Glo1)-which provides the main enzymatic detoxification of MG. Glo1 functional genomics studies suggest that increasing Glo1 expression and activity alleviates dicarbonyl stress; slows development of obesity, related insulin resistance; and prevents development of diabetic nephropathy and other microvascular complications of diabetes. A new therapeutic approach constitutes small-molecule inducers of Glo1 expression-Glo1 inducers-exploiting a regulatory antioxidant response element in the GLO1 gene. A prototype Glo1 inducer, trans-resveratrol (tRES)-hesperetin (HESP) combination, in corrected insulin resistance, improved glycemic control and vascular inflammation in healthy overweight and obese subjects in clinical trial. Critical Issues: tRES and HESP synergize pharmacologically, and HESP likely overcomes the low bioavailability of tRES by inhibition of intestinal glucuronosyltransferases. Future Directions: Glo1 inducers may now be evaluated in Phase 2 clinical trials for treatment of NAFLD and vascular complications of diabetes.
Collapse
Affiliation(s)
- Naila Rabbani
- 1 Clinical Sciences Research Laboratories, Warwick Medical School, University of Warwick, University Hospital , Coventry, United Kingdom .,2 Warwick Systems Biology Centre, Senate House, University of Warwick , Coventry, United Kingdom
| | - Paul J Thornalley
- 1 Clinical Sciences Research Laboratories, Warwick Medical School, University of Warwick, University Hospital , Coventry, United Kingdom .,2 Warwick Systems Biology Centre, Senate House, University of Warwick , Coventry, United Kingdom
| |
Collapse
|
5
|
Keleku-Lukwete N, Suzuki M, Yamamoto M. An Overview of the Advantages of KEAP1-NRF2 System Activation During Inflammatory Disease Treatment. Antioxid Redox Signal 2018; 29:1746-1755. [PMID: 28899203 DOI: 10.1089/ars.2017.7358] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inflammation can be defined as a protective immune response against harmful exogenous and endogenous stimuli. Nevertheless, prolonged or autoimmune inflammatory responses are likely to cause pathological states that are associated with a production of inflammation-associated molecules along with reactive oxygen species (ROS). Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2 (KEAP1-NRF2) signaling provides a cell protection mechanism against oxidative insults when endogenous stress defense mechanisms are imbalanced. Understanding the roles of the KEAP1-NRF2 system in inflammation caused by various types of stimuli may aid in the development of new therapies. Recent Advances: There have been tremendous advances in understanding the mechanism by which the KEAP1-NRF2 pathway abrogates inflammation. In addition to the well-established ROS-dependent pathway, recent studies have provided evidence of the direct repression of the transcription of pro-inflammatory cytokine genes, such as IL1b and IL6 (encoding Interleukin-1β and Interleukin-6, respectively). Further, the expanding functions of NRF2 have elicited interest in the development of therapeutic modalities for inflammatory diseases, including multiple sclerosis and sickle cell disease. Critical Issues and Future Directions: Despite progress in the understanding of molecular mechanisms supporting the roles that NRF2 plays during inflammation, the relationship between NRF2 and other transcription factors and mediators of inflammation still remains ambiguous. Further studies are required to address the effects of functional polymorphisms in KEAP1 and NRF2 that modify susceptibility to specific disease-related inflammation. Comprehensive analyses in the future should explore tissue- or cell-type specific NRF2 activation to elaborate effects of NRF2 induction. Antioxid. Redox Signal. 00, 000-000.
Collapse
Affiliation(s)
- Nadine Keleku-Lukwete
- 1 Department of Medical Biochemistry, Tohoku University Graduate School of Medicine , Sendai, Japan
| | - Mikiko Suzuki
- 2 Center for Radioisotope Sciences, Tohoku University Graduate School of Medicine , Sendai, Japan
| | - Masayuki Yamamoto
- 1 Department of Medical Biochemistry, Tohoku University Graduate School of Medicine , Sendai, Japan
| |
Collapse
|
6
|
Rowan S, Bejarano E, Taylor A. Mechanistic targeting of advanced glycation end-products in age-related diseases. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3631-3643. [PMID: 30279139 DOI: 10.1016/j.bbadis.2018.08.036] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 08/02/2018] [Accepted: 08/27/2018] [Indexed: 02/06/2023]
Abstract
Glycative stress, caused by the accumulation of cytotoxic and irreversibly-formed sugar-derived advanced glycation end-products (AGEs), contributes to morbidity associated with aging, age-related diseases, and metabolic diseases. In this review, we summarize pathways leading to formation of AGEs, largely from sugars and glycolytic intermediates, and discuss detoxification of AGE precursors, including the glyoxalase system and DJ-1/Park7 deglycase. Disease pathogenesis downstream of AGE accumulation can be cell autonomous due to aggregation of glycated proteins and impaired protein function, which occurs in ocular cataracts. Extracellular AGEs also activate RAGE signaling, leading to oxidative stress, inflammation, and leukostasis in diabetic complications such as diabetic retinopathy. Pharmaceutical agents have been tested in animal models and clinically to diminish glycative burden. We summarize existing strategies and point out several new directions to diminish glycative stress including: plant-derived polyphenols as AGE inhibitors and glyoxalase inducers; improved dietary patterns, particularly Mediterranean and low glycemic diets; and enhancing proteolytic capacities of the ubiquitin-proteasome and autophagy pathways that are involved in cellular clearing of AGEs.
Collapse
Affiliation(s)
- Sheldon Rowan
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Tufts University, 711 Washington St, Boston, MA 02111, USA
| | - Eloy Bejarano
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Tufts University, 711 Washington St, Boston, MA 02111, USA
| | - Allen Taylor
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Tufts University, 711 Washington St, Boston, MA 02111, USA.
| |
Collapse
|
7
|
Luo L, Chen Y, Wang H, Wang S, Liu K, Li X, Wang XJ, Tang X. Mkp-1 protects mice against toxin-induced liver damage by promoting the Nrf2 cytoprotective response. Free Radic Biol Med 2018; 115:361-370. [PMID: 29241671 DOI: 10.1016/j.freeradbiomed.2017.12.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 11/14/2017] [Accepted: 12/07/2017] [Indexed: 12/30/2022]
Abstract
The present study was undertaken to investigate the possible protective effect of mitogen-activated protein kinase phosphatase 1 (Mkp-1) on toxin-induced hepatic injury. Here, we uncovered a positive feedback loop between Mkp-1, a dual threonine/tyrosine phosphatase, and nuclear factor erythroid 2-related factor 2 (Nrf2), a crucial regulator of the defense system in the liver. Mkp-1-/- mice exhibited decreased protein levels of Nrf2, phase II gene products, and reduced glutathione (GSH) in the liver. Induction of detoxifying enzymes by the Nrf2 activator butylated hydroxyanisole (BHA) or sulforaphane, was attenuated in the liver and small intestines of Mkp-1-/- mice, indicating that the Nrf2 signaling pathway is impaired as a result of Mkp-1 deficiency. Mkp-1-/- mice suffered more severe liver injury after a single exposure to hepatotoxin carbon tetrachloride (CCl4) than their wild-type (WT) counterparts. BHA partially rescued the CCl4-induced liver damage in WT mice, but not in Mkp-1-/- mice, suggesting the requirement of Mkp-1 in the activation of Nrf2 signaling against the liver injury. Mechanistically, Mkp-1 upregulated Nrf2 through a direct interaction with the Neh2 domain in the transcription factor, while Nrf2 enhanced the expression of Mkp-1 mRNA by binding to the ARE site at -1719 to -1710bp in the Mkp-1 promoter. Our results reveal novel role of Mkp-1 in the maintenance of redox homeostasis in the liver. Thus, strategies aimed at augmenting Mkp-1 expression may be beneficial in protecting the liver and may provide novel therapeutic approaches to toxin-induced liver injury.
Collapse
Affiliation(s)
- Lin Luo
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, PR China
| | - Yeru Chen
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, PR China
| | - Hongyan Wang
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, PR China; Department of Biochemistry, Zhejiang University School of Medicine, Hangzhou 310058, PR China
| | - Shengcun Wang
- Department of Biochemistry, Zhejiang University School of Medicine, Hangzhou 310058, PR China
| | - Kaihua Liu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, PR China
| | - Xin Li
- Department of Biochemistry, Zhejiang University School of Medicine, Hangzhou 310058, PR China
| | - Xiu Jun Wang
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, PR China.
| | - Xiuwen Tang
- Department of Biochemistry, Zhejiang University School of Medicine, Hangzhou 310058, PR China.
| |
Collapse
|
8
|
Liu Y, Kurita A, Nakashima S, Zhu B, Munemasa S, Nakamura T, Murata Y, Nakamura Y. 3,4-Dihydroxyphenylacetic acid is a potential aldehyde dehydrogenase inducer in murine hepatoma Hepa1c1c7 cells. Biosci Biotechnol Biochem 2017; 81:1978-1983. [DOI: 10.1080/09168451.2017.1361809] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Abstract
3,4-Dihydroxyphenylacetic acid (DOPAC) is one of the major colonic microflora-produced catabolites of quercetin glycosides, such as quercetin 4′-glucoside derived from onion. Here, we investigated whether DOPAC modulates the aldehyde dehydrogenase (ALDH) activity and protects the cells from the acetaldehyde-induced cytotoxicity in vitro. DOPAC was shown to enhance not only the total ALDH activity, but also the gene expression of ALDH1A1, ALDH2 and ALDH3A1 in a concentration-dependent manner. DOPAC simultaneously stimulated the nuclear translocation of NFE2-related factor 2 and aryl hydrocarbon receptor. The pretreatment of DOPAC completely protected the cells from the acetaldehyde-induced cytotoxicity. The present study suggested that DOPAC acts as a potential ALDH inducer to prevent the alcohol-induced abnormal reaction.
Collapse
Affiliation(s)
- Yujia Liu
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, China
| | - Ayuki Kurita
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Sayaka Nakashima
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Beiwei Zhu
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, China
| | - Shintaro Munemasa
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Toshiyuki Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Yoshiyuki Murata
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Yoshimasa Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| |
Collapse
|
9
|
Shintyapina AB, Vavilin VA, Safronova OG, Lyakhovich VV. The gene expression profile of a drug metabolism system and signal transduction pathways in the liver of mice treated with tert-butylhydroquinone or 3-(3'-tert-butyl-4'-hydroxyphenyl)propylthiosulfonate of sodium. PLoS One 2017; 12:e0176939. [PMID: 28467491 PMCID: PMC5415222 DOI: 10.1371/journal.pone.0176939] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 04/19/2017] [Indexed: 11/25/2022] Open
Abstract
Tert-butylhydroquinone (tBHQ) is a highly effective phenolic antioxidant used in edible oils and fats in foods as well as in medicines and cosmetics. TBHQ has been shown to have both chemoprotective and carcinogenic effects. Furthermore, it has potential anti-inflammatory, antiatherogenic, and neuroprotective activities. TBHQ induces phase II detoxification enzymes via the Keap1/Nrf2/ARE mechanism, which contributes to its chemopreventive functions. Nonetheless, there is growing evidence that biological effects of tBHQ may be mediated by Nrf2-independent mechanisms related to various signaling cascades. Here, we studied changes in gene expression of phase I, II, and III drug metabolizing enzymes/transporters as well as protein levels and activities of cytochromes P450 (CYPs) elicited by tBHQ and its structural homolog TS-13 in the mouse liver. Next, we carried out gene expression analysis to identify signal transduction pathways modulated by the antioxidants. Mice received 100 mg/kg tBHQ or TS-13 per day or only vehicle. The liver was collected at 12 hours and after 7 days of the treatment. Protein and total RNA were extracted. Gene expression was analyzed using Mouse Drug Metabolism and Signal Transduction PathwayFinder RT2Profiler™PCR Arrays. A western blot analysis was used to measure protein levels and a fluorometric assay was employed to study activities of CYPs. Genes that were affected more than 1.5-fold by tBHQ or TS-13 treatment compared with vehicle were identified. Analysis of the gene expression data revealed changes in various genes that are important for drug metabolism, cellular defense mechanisms, inflammation, apoptosis, and cell cycle regulation. Novel target genes were identified, including xenobiotic metabolism genes encoding CYPs, phase II/III drug metabolizing enzymes/transporters. For Cyp1a2 and Cyp2b, we observed an increase in protein levels and activities during tBHQ or TS-13 treatment. Changes were found in the gene expression regulated by NFκB, androgen, retinoic acid, PI3K/AKT, Wnt, Hedgehog and other pathways.
Collapse
Affiliation(s)
| | - Valentin A. Vavilin
- Institute of Molecular Biology and Biophysics, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | | | - Vyacheslav V. Lyakhovich
- Institute of Molecular Biology and Biophysics, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| |
Collapse
|
10
|
Luo L, Chen Y, Wu D, Shou J, Wang S, Ye J, Tang X, Wang XJ. Butylated hydroxyanisole induces distinct expression patterns of Nrf2 and detoxification enzymes in the liver and small intestine of C57BL/6 mice. Toxicol Appl Pharmacol 2015; 288:339-48. [PMID: 26291391 DOI: 10.1016/j.taap.2015.08.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 12/11/2022]
Abstract
Butylated hydroxyanisole (BHA) is widely used as an antioxidant and preservative in food, food packaging and medicines. Its chemopreventive properties are attributing to its ability to activate the transcription factor NF-E2 p45-related factor 2 (Nrf2), which directs central genetic programs of detoxification and protection against oxidative stress. This study was to investigate the histological changes of Nrf2 and its regulated phase II enzymes Nqo1, AKR1B8, and Ho-1 in wild-type (WT) and Nrf2(-/-) mice induced by BHA. The mice were given a 200mg/kg oral dose of BHA daily for three days. Immunohistochemistry revealed that, in the liver from WT mice, BHA increased Nqo1 staining in hepatocytes, predominately in the pericentral region. In contrast, the induction of AKR1B8 appeared mostly in hepatocytes in the periportal region. The basal and inducible Ho-1 was located almost exclusively in Kupffer cells. In the small intestine from WT mice, the inducible expression patterns of Nqo1 and AKR1B8 were nearly identical to that of Nrf2, with more intense staining in the villus than that the crypt. Conversely, Keap1 was more highly expressed in the crypt, where the proliferative cells reside. Our study demonstrates that BHA elicited differential expression patterns of phase II-detoxifying enzymes in the liver and small intestine from WT but not Nrf2(-/-) mice, demonstrating a cell type specific response to BHA in vivo.
Collapse
Affiliation(s)
- Lin Luo
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, PR China; Department of Pharmacology, University of Nantong, Nantong, PR China
| | - Yeru Chen
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Deqi Wu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Jiafeng Shou
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Shengcun Wang
- Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Jie Ye
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Xiuwen Tang
- Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058, PR China.
| | - Xiu Jun Wang
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, PR China.
| |
Collapse
|
11
|
Huang Y, Li W, Su ZY, Kong ANT. The complexity of the Nrf2 pathway: beyond the antioxidant response. J Nutr Biochem 2015; 26:1401-13. [PMID: 26419687 DOI: 10.1016/j.jnutbio.2015.08.001] [Citation(s) in RCA: 292] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 08/03/2015] [Indexed: 12/11/2022]
Abstract
The NF-E2-related factor 2 (Nrf2)-mediated signalling pathway provides living organisms an efficient and pivotal line of defensive to counteract environmental insults and endogenous stressors. Nrf2 coordinates the basal and inducible expression of antioxidant and Phase II detoxification enzymes to adapt to different stress conditions. The stability and cellular distribution of Nrf2 is tightly controlled by its inhibitory binding protein Kelch-like ECH-associated protein 1. Nrf2 signalling is also regulated by posttranslational, transcriptional, translational and epigenetic mechanisms, as well as by other protein partners, including p62, p21 and IQ motif-containing GTPase activating protein 1. Many studies have demonstrated that Nrf2 is a promising target for preventing carcinogenesis and other chronic diseases, including cardiovascular diseases, neurodegenerative diseases and pulmonary injury. However, constitutive activation of Nrf2 in advanced cancer cells may confer drug resistance. Here, we review the molecular mechanisms of Nrf2 signalling, the diverse classes of Nrf2 activators, including bioactive nutrients and other chemicals, and the cellular functions and disease relevance of Nrf2 and discuss the dual role of Nrf2 in different contexts.
Collapse
Affiliation(s)
- Ying Huang
- Department of Pharmaceutics, Earnest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Wenji Li
- Department of Pharmaceutics, Earnest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Zheng-yuan Su
- Department of Pharmaceutics, Earnest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Ah-Ng Tony Kong
- Department of Pharmaceutics, Earnest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
| |
Collapse
|
12
|
Abstract
Plant-based Ayurvedic medicine has been practiced in India for thousands of years for the treatment of a variety of disorders. They are rich sources of bioactive compounds potentially useful for prevention and treatment of cancer. Withania somnifera (commonly known as Ashwagandha in Ayurvedic medicine) is a widely used medicinal plant whose anticancer value was recognized after isolation of steroidal compounds withanolides from the leaves of this shrub. Withaferin A is the first member of withanolides to be isolated, and it is the most abundant withanolide present in W. somnifera. Its cancer-protective role has now been established using chemically induced and oncogene-driven rodent cancer models. The present review summarizes the key preclinical studies demonstrating anticancer effects of withaferin along with its molecular targets and mechanisms related to its anticancer effects. Anticancer potential of other withanolides is also discussed.
Collapse
|
13
|
Shirai M, Matsuoka M, Makino T, Kai K, Teranishi M, Takasaki W. Hepatic glutathione contributes to attenuation of thioacetamide-induced hepatic necrosis due to suppression of oxidative stress in diet-induced obese mice. J Toxicol Sci 2015; 40:509-21. [PMID: 26165648 DOI: 10.2131/jts.40.509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We previously reported that hepatic necrosis induced by thioacetamide (TA), a hepatotoxicant, was attenuated in mice fed a high-fat diet (HFD mice) in comparison with mice fed a normal rodent diet (ND mice). In this study, we focused on investigation of the mechanism of the attenuation. Hepatic content of thiobarbituric acid reactive substances (TBARS), an oxidative stress marker, significantly increased in ND mice at 24 and 48 hr after TA administration in comparison to that in vehicle-treated ND mice. At these time points, severe hepatic necrosis was observed in ND mice. Treatment with an established antioxidant, butylated hydroxyanisole, attenuated the TA-induced hepatic necrosis in ND mice. In contrast, in HFD mice, hepatic TBARS content did not increase, and hepatic necrosis was attenuated in comparison with ND mice at 24 and 48 hr after TA dosing. Metabolomics analysis regarding hepatic glutathione, a biological antioxidant, revealed decreased glutathione and changes in the amount of glutathione metabolism-related metabolites, such as increased ophtalmate and decreased cysteine, and this indicated activation of glutathione synthesis and usage in HFD mice. Finally, after treatment with L-buthionine-S,R-sulfoxinine, an inhibitor of glutathione synthesis, TA-induced hepatic necrosis was enhanced and hepatic TBARS contents increased after TA dosing in HFD mice. These results suggested that activated synthesis and usage of hepatic GSH, which suppresses hepatic oxidative stress, is one of the factors that attenuate TA-induced hepatic necrosis in HFD mice.
Collapse
Affiliation(s)
- Makoto Shirai
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd
| | | | | | | | | | | |
Collapse
|
14
|
CUI XUELIAN, JIN TIEFENG, WANG XIAOYAN, JIN GUANG, LI ZHUHU, LIN LIJUAN. NAD(P)H:quinone oxidoreductase-1 overexpression predicts poor prognosis in small cell lung cancer. Oncol Rep 2014; 32:2589-95. [DOI: 10.3892/or.2014.3494] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 08/06/2014] [Indexed: 11/05/2022] Open
|
15
|
Chen H, Fu J, Chen H, Hu Y, Soroka DN, Prigge J, Schmidt EE, Yan F, Major MB, Chen X, Sang S. Ginger compound [6]-shogaol and its cysteine-conjugated metabolite (M2) activate Nrf2 in colon epithelial cells in vitro and in vivo. Chem Res Toxicol 2014; 27:1575-85. [PMID: 25148906 PMCID: PMC4176387 DOI: 10.1021/tx500211x] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 12/20/2022]
Abstract
In this study, we identified Nrf2 as a molecular target of [6]-shogaol (6S), a bioactive compound isolated from ginger, in colon epithelial cells in vitro and in vivo. Following 6S treatment of HCT-116 cells, the intracellular GSH/GSSG ratio was initially diminished but was then elevated above the basal level. Intracellular reactive oxygen species (ROS) correlated inversely with the GSH/GSSG ratio. Further analysis using gene microarray showed that 6S upregulated the expression of Nrf2 target genes (AKR1B10, FTL, GGTLA4, and HMOX1) in HCT-116 cells. Western blotting confirmed upregulation, phosphorylation, and nuclear translocation of Nrf2 protein followed by Keap1 decrease and upregulation of Nrf2 target genes (AKR1B10, FTL, GGTLA4, HMOX1, and MT1) and glutathione synthesis genes (GCLC and GCLM). Pretreatment of cells with a specific inhibitor of p38 (SB202190), PI3K (LY294002), or MEK1 (PD098059) attenuated these effects of 6S. Using ultra-high-performance liquid chromatography-tandem mass spectrometry, we found that 6S modified multiple cysteine residues of Keap1 protein. In vivo 6S treatment induced Nrf2 nuclear translocation and significantly upregulated the expression of MT1, HMOX1, and GCLC in the colon of wild-type mice but not Nrf2(-/-) mice. Similar to 6S, a cysteine-conjugated metabolite of 6S (M2), which was previously found to be a carrier of 6S in vitro and in vivo, also activated Nrf2. Our data demonstrated that 6S and its cysteine-conjugated metabolite M2 activate Nrf2 in colon epithelial cells in vitro and in vivo through Keap1-dependent and -independent mechanisms.
Collapse
Affiliation(s)
- Huadong Chen
- Center
for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North
Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States
| | - Junsheng Fu
- Center
for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North
Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States
| | - Hao Chen
- Cancer
Research Program, Julius L. Chambers Biomedical/Biotechnology Research
Institute, North Carolina Central University, 700 George Street, Durham, North Carolina 27707, United States
| | - Yuhui Hu
- Cancer
Research Program, Julius L. Chambers Biomedical/Biotechnology Research
Institute, North Carolina Central University, 700 George Street, Durham, North Carolina 27707, United States
| | - Dominique N. Soroka
- Center
for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North
Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States
| | - Justin
R. Prigge
- Department
of Immunology and Infectious Diseases, Montana
State University, Bozeman, Montana 59717, United States
| | - Edward E. Schmidt
- Department
of Immunology and Infectious Diseases, Montana
State University, Bozeman, Montana 59717, United States
| | - Feng Yan
- Department
of Cell Biology and Physiology, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Michael B. Major
- Department
of Cell Biology and Physiology, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Xiaoxin Chen
- Cancer
Research Program, Julius L. Chambers Biomedical/Biotechnology Research
Institute, North Carolina Central University, 700 George Street, Durham, North Carolina 27707, United States
| | - Shengmin Sang
- Center
for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North
Carolina Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States
| |
Collapse
|
16
|
Deng H, Kerppola TK. Visualization of the Drosophila dKeap1-CncC interaction on chromatin illumines cooperative, xenobiotic-specific gene activation. Development 2014; 141:3277-88. [PMID: 25063457 DOI: 10.1242/dev.110528] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Interactions among transcription factors control their physiological functions by regulating their binding specificities and transcriptional activities. We implement a strategy to visualize directly the genomic loci that are bound by multi-protein complexes in single cells in Drosophila. This method is based on bimolecular fluorescence complementation (BiFC) analysis of protein interactions on polytene chromosomes. Drosophila Keap1 (dKeap1)-CncC complexes localized to the nucleus and bound chromatin loci that were not bound preferentially by dKeap1 or CncC when they were expressed separately. dKeap1 and CncC binding at these loci was enhanced by phenobarbital, but not by tert-butylhydroquinone (tBHQ) or paraquat. Endogenous dKeap1 and CncC activated transcription of the Jheh (Jheh1, Jheh2, Jheh3) and dKeap1 genes at these loci, whereas CncC alone activated other xenobiotic response genes. Ectopic dKeap1 expression increased CncC binding at the Jheh and dKeap1 gene loci and activated their transcription, whereas dKeap1 inhibited CncC binding at other xenobiotic response gene loci and suppressed their transcription. The combinatorial chromatin-binding specificities and transcriptional activities of dKeap1-CncC complexes mediated the selective activation of different sets of genes by different xenobiotic compounds, in part through feed-forward activation of dKeap1 transcription.
Collapse
Affiliation(s)
- Huai Deng
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0650, USA
| | - Tom K Kerppola
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0650, USA
| |
Collapse
|
17
|
Li C, Xu X, Wang XJ, Pan Y. Imine resveratrol analogues: molecular design, Nrf2 activation and SAR analysis. PLoS One 2014; 9:e101455. [PMID: 25028928 PMCID: PMC4100753 DOI: 10.1371/journal.pone.0101455] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/06/2014] [Indexed: 12/13/2022] Open
Abstract
Resveratrol is a natural phenol with protective effects against cancer and inflammation-related diseases. Its mechanism of action involves the activation of nuclear factor E2 p45-related factor 2 (Nrf2), which plays a key role in regulation of genes driven by antioxidant response element (ARE). Inspired by the effect of resveratrol, here we synthesized a series of imine resveratrol analogs (IRAs), evaluated their abilities to activate Nrf2 by using cell based ARE-reporter assay. After the first-round screening, preliminary and quantitative structure-activity relationship (SAR) was analyzed, and the structural features determining Nrf2 activation ability were proposed. Two novel IRAs were designed and subsequently synthesized, namely 2-methoxyl-3,6-dihydroxyl-IRA and 2,3,6-trihydroxyl-IRA. They were proved to be the most potent Nrf2 activators among the IRAs.
Collapse
Affiliation(s)
- Chang Li
- Department of Chemistry, Zhejiang University, Hangzhou, P. R. China
| | - Xiaofei Xu
- Department of Chemistry, Zhejiang University, Hangzhou, P. R. China
| | - Xiu Jun Wang
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, P. R. China
- * E-mail: (YP); (XJW)
| | - Yuanjiang Pan
- Department of Chemistry, Zhejiang University, Hangzhou, P. R. China
- * E-mail: (YP); (XJW)
| |
Collapse
|
18
|
Ma Y, Kong J, Yan G, Ren X, Jin D, Jin T, Lin L, Lin Z. NQO1 overexpression is associated with poor prognosis in squamous cell carcinoma of the uterine cervix. BMC Cancer 2014; 14:414. [PMID: 24912939 PMCID: PMC4058702 DOI: 10.1186/1471-2407-14-414] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 05/16/2014] [Indexed: 12/16/2022] Open
Abstract
Background NQO1 (NAD(P)H: quinone oxidoreductase-1), located on chromosome 16q22, functions primarily to protect normal cells from oxidant stress and electrophilic attack. Recent studies have revealed that NQO1 is expressed at a high level in most human solid tumors including those of the colon, breast, pancreas, ovaries and thyroid, and it has also been detected following the induction of cell cycle progression and proliferation of melanoma cells. In this study, we aimed to investigate the clinicopathological significance of upregulated NQO1 protein expression in squamous cell carcinomas (SCCs) of the uterine cervix. Methods The localization of the NQO1 protein was determined in the SiHa cervical squamous cancer cell line using immunofluorescence (IF) staining, and immunohistochemical (IHC) staining performed on paraffin-embedded cervical SCC specimens from 177 patients. For comparison, 94 cervical intraepithelial neoplasia (CIN) and 25 normal cervical epithelia samples were also included. QRT-PCR was performed on RNA from fresh tissues to detect NQO1 mRNA expression levels, and HPV infection status was genotyped using oligonucleotide microarray. Disease-free survival (DFS) and 5-year overall survival (OS) rates for all cervical SCC patients were calculated using the Kaplan–Meier method, and univariate and multivariate analysis was performed using the Cox proportional hazards regression model. Results The NQO1 protein showed a mainly cytoplasmic staining pattern in cervical cancer cells, and only three cases of cervical SCC showed a nuclear staining pattern. The strongly positive rate of NQO1 protein expression was significantly higher in cervical SCCs and CINs than in normal cervical epithelia. High-level NQO1 expression was closely associated with poor differentiation, late-stage, lymph node metastasis and high-risk for HPV infection. Additionally, high-level NQO1 expression was associated with lower DFS and 5-year OS rates, particularly for patients with early-stage cervical SCCs. Furthermore, Cox analysis revealed that NQO1 expression emerged as a significant independent hazard factor for DFS rate in patients with cervical SCC. Conclusions NQO1 overexpression might be an independent biomarker for prognostic evaluation of cervical SCCs.
Collapse
Affiliation(s)
| | | | | | | | | | - Tiefeng Jin
- Department of Pathology & Cancer Research Center, Yanbian University Medical College, Yanji, China.
| | | | | |
Collapse
|
19
|
Brignull LM, Czimmerer Z, Saidi H, Daniel B, Villela I, Bartlett NW, Johnston SL, Meira LB, Nagy L, Nohturfft A. Reprogramming of lysosomal gene expression by interleukin-4 and Stat6. BMC Genomics 2013; 14:853. [PMID: 24314139 PMCID: PMC3880092 DOI: 10.1186/1471-2164-14-853] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 11/26/2013] [Indexed: 01/05/2023] Open
Abstract
Background Lysosomes play important roles in multiple aspects of physiology, but the problem of how the transcription of lysosomal genes is coordinated remains incompletely understood. The goal of this study was to illuminate the physiological contexts in which lysosomal genes are coordinately regulated and to identify transcription factors involved in this control. Results As transcription factors and their target genes are often co-regulated, we performed meta-analyses of array-based expression data to identify regulators whose mRNA profiles are highly correlated with those of a core set of lysosomal genes. Among the ~50 transcription factors that rank highest by this measure, 65% are involved in differentiation or development, and 22% have been implicated in interferon signaling. The most strongly correlated candidate was Stat6, a factor commonly activated by interleukin-4 (IL-4) or IL-13. Publicly available chromatin immunoprecipitation (ChIP) data from alternatively activated mouse macrophages show that lysosomal genes are overrepresented among Stat6-bound targets. Quantification of RNA from wild-type and Stat6-deficient cells indicates that Stat6 promotes the expression of over 100 lysosomal genes, including hydrolases, subunits of the vacuolar H+ ATPase and trafficking factors. While IL-4 inhibits and activates different sets of lysosomal genes, Stat6 mediates only the activating effects of IL-4, by promoting increased expression and by neutralizing undefined inhibitory signals induced by IL-4. Conclusions The current data establish Stat6 as a broadly acting regulator of lysosomal gene expression in mouse macrophages. Other regulators whose expression correlates with lysosomal genes suggest that lysosome function is frequently re-programmed during differentiation, development and interferon signaling.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Axel Nohturfft
- Division of Biomedical Sciences, Molecular and Metabolic Signaling Centre, St, George's University of London, Cranmer Terrace, London SW17 0RE, UK.
| |
Collapse
|
20
|
Ignea C, Dorobanţu CM, Mintoff CP, Branza-Nichita N, Ladomery MR, Kefalas P, Chedea VS. Modulation of the antioxidant/pro-oxidant balance, cytotoxicity and antiviral actions of grape seed extracts. Food Chem 2013; 141:3967-76. [DOI: 10.1016/j.foodchem.2013.06.094] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/10/2013] [Accepted: 06/20/2013] [Indexed: 12/22/2022]
|
21
|
Osada J. The use of transcriptomics to unveil the role of nutrients in Mammalian liver. ISRN NUTRITION 2013; 2013:403792. [PMID: 24967258 PMCID: PMC4045299 DOI: 10.5402/2013/403792] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 08/04/2013] [Indexed: 01/03/2023]
Abstract
Liver is the organ primarily responding to diet, and it is crucial in determining plasma carbohydrate, protein, and lipid levels. In addition, it is mainly responsible for transformation of xenobiotics. For these reasons, it has been a target of transcriptomic analyses. In this review, we have covered the works dealing with the response of mammalian liver to different nutritional stimuli such as fasting/feeding, caloric restriction, dietary carbohydrate, cholesterol, fat, protein, bile acid, salt, vitamin, and oligoelement contents. Quality of fats or proteins has been equally addressed, and has the influence of minor dietary components. Other compounds, not purely nutritional as those represented by alcohol and food additives, have been included due to their relevance in processed food. The influence has been studied not only on mRNA but also on miRNA. The wide scope of the technology clearly reflects that any simple intervention has profound changes in many metabolic parameters and that there is a synergy in response when more compounds are included in the intervention. Standardized arrays to systematically test the same genes in all studies and analyzing data to establish patterns of response are required, particularly for RNA sequencing. Moreover, RNA is a valuable, easy-screening ally but always requires further confirmation.
Collapse
Affiliation(s)
- Jesús Osada
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón, Universidad de Zaragoza, 50013 Zaragoza, Spain ; CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain
| |
Collapse
|
22
|
Ushida Y, Talalay P. Sulforaphane Accelerates Acetaldehyde Metabolism by Inducing Aldehyde Dehydrogenases: Relevance to Ethanol Intolerance. Alcohol Alcohol 2013; 48:526-34. [DOI: 10.1093/alcalc/agt063] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
|
23
|
Novel hematopoietic target genes in the NRF2-mediated transcriptional pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:120305. [PMID: 23766848 PMCID: PMC3677633 DOI: 10.1155/2013/120305] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 04/16/2013] [Accepted: 04/29/2013] [Indexed: 12/18/2022]
Abstract
Nuclear factor- (erythroid-derived 2) like 2 (NFE2L2, NRF2) is a key transcriptional activator of the antioxidant response pathway and is closely related to erythroid transcription factor NFE2. Under oxidative stress, NRF2 heterodimerizes with small Maf proteins and binds cis-acting enhancer sequences found near oxidative stress response genes. Using the dietary isothiocyanate sulforaphane (SFN) to activate NRF2, chromatin immunoprecipitation sequencing (ChIP-seq) identified several hundred novel NRF2-mediated targets beyond its role in oxidative stress. Activated NRF2 bound the antioxidant response element (ARE) in promoters of several known and novel target genes involved in iron homeostasis and heme metabolism, including known targets FTL and FTH1, as well as novel binding in the globin locus control region. Five novel NRF2 target genes were chosen for followup: AMBP, ABCB6, FECH, HRG-1 (SLC48A1), and TBXAS1. SFN-induced gene expression in erythroid K562 and lymphoid cells were compared for each target gene. NRF2 silencing showed reduced expression in lymphoid, lung, and hepatic cells. Furthermore, stable knockdown of NRF2 negative regulator KEAP1 in K562 cells resulted in increased NQO1, AMBP, and TBXAS1 expression. NFE2 binding sites in K562 cells revealed similar binding profiles as lymphoid NRF2 sites in all potential NRF2 candidates supporting a role for NRF2 in heme metabolism and erythropoiesis.
Collapse
|
24
|
Su ZY, Shu L, Khor TO, Lee JH, Fuentes F, Tony Kong AN. A perspective on dietary phytochemicals and cancer chemoprevention: oxidative stress, nrf2, and epigenomics. Top Curr Chem (Cham) 2013; 329:133-62. [PMID: 22836898 PMCID: PMC3924422 DOI: 10.1007/128_2012_340] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Oxidative stress is caused by an imbalance of reactive oxygen species (ROS)/reactive nitrogen species (RNS) and the antioxidative stress defense systems in cells. ROS/RNS or carcinogen metabolites can attack intracellular proteins, lipids, and nucleic acids, which can result in genetic mutations, carcinogenesis, and other diseases. Nrf2 plays a critical role in the regulation of many antioxidative stress/antioxidant and detoxification enzyme genes, such as glutathione S-transferases (GSTs), NAD(P)H:quinone oxidoreductase 1 (NQO1), UDP-glucuronyl transferases (UGTs), and heme oxygenase-1 (HO-1), directly via the antioxidant response element (ARE). Recently, many studies have shown that dietary phytochemicals possess cancer chemopreventive potential through the induction of Nrf2-mediated antioxidant/detoxification enzymes and anti-inflammatory signaling pathways to protect organisms against cellular damage caused by oxidative stress. In addition, carcinogenesis can be caused by epigenetic alterations such as DNA methylation and histone modifications in tumor-suppressor genes and oncogenes. Interestingly, recent studies have shown that several naturally occurring dietary phytochemicals can epigenetically modify the chromatin, including reactivating Nrf2 via demethylation of CpG islands and the inhibition of histone deacetylases (HDACs) and/or histone acetyltransferases (HATs). The advancement and development of dietary phytochemicals in cancer chemoprevention research requires the integration of the known, and as-yet-unknown, compounds with the Nrf2-mediated antioxidant, detoxification, and anti-inflammatory systems and their in vitro and in vivo epigenetic mechanisms; human clinical efficacy studies must also be performed.
Collapse
Affiliation(s)
- Zheng-Yuan Su
- Department of Pharmaceutics, Center for Cancer Prevention Research, Ernest-Mario School of Pharmacy, Rutgers, the State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Limin Shu
- Department of Pharmaceutics, Center for Cancer Prevention Research, Ernest-Mario School of Pharmacy, Rutgers, the State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Tin Oo Khor
- Department of Pharmaceutics, Center for Cancer Prevention Research, Ernest-Mario School of Pharmacy, Rutgers, the State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Jong Hun Lee
- Department of Pharmaceutics, Center for Cancer Prevention Research, Ernest-Mario School of Pharmacy, Rutgers, the State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Francisco Fuentes
- Department of Pharmaceutics, Center for Cancer Prevention Research, Ernest-Mario School of Pharmacy, Rutgers, the State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA, Departamento de Agricultura del Desierto y Biotecnología, Universidad Arturo Prat, Casilla 121, Iquique, Chile
| | - Ah-Ng Tony Kong
- Department of Pharmaceutics, Center for Cancer Prevention Research, Ernest-Mario School of Pharmacy, Rutgers, the State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
| |
Collapse
|
25
|
Lee JH, Khor TO, Shu L, Su ZY, Fuentes F, Kong ANT. Dietary phytochemicals and cancer prevention: Nrf2 signaling, epigenetics, and cell death mechanisms in blocking cancer initiation and progression. Pharmacol Ther 2012; 137:153-71. [PMID: 23041058 DOI: 10.1016/j.pharmthera.2012.09.008] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 09/17/2012] [Indexed: 02/06/2023]
Abstract
Reactive metabolites from carcinogens and oxidative stress can drive genetic mutations, genomic instability, neoplastic transformation, and ultimately carcinogenesis. Numerous dietary phytochemicals in vegetables/fruits have been shown to possess cancer chemopreventive effects in both preclinical animal models and human epidemiological studies. These phytochemicals could prevent the initiation of carcinogenesis via either direct scavenging of reactive oxygen species/reactive nitrogen species (ROS/RNS) or, more importantly, the induction of cellular defense detoxifying/antioxidant enzymes. These defense enzymes mediated by Nrf2-antioxidative stress and anti-inflammatory signaling pathways can contribute to cellular protection against ROS/RNS and reactive metabolites of carcinogens. In addition, these compounds would kill initiated/transformed cancer cells in vitro and in in vivo xenografts via diverse anti-cancer mechanisms. These mechanisms include the activation of signaling kinases (e.g., JNK), caspases and the mitochondria damage/cytochrome c pathways. Phytochemicals may also have anti-cancer effects by inhibiting the IKK/NF-κB pathway, inhibiting STAT3, and causing cell cycle arrest. In addition, other mechanisms may include epigenetic alterations (e.g., inhibition of HDACs, miRNAs, and the modification of the CpG methylation of cancer-related genes). In this review, we will discuss: the current advances in the study of Nrf2 signaling; Nrf2-deficient tumor mouse models; the epigenetic control of Nrf2 in tumorigenesis and chemoprevention; Nrf2-mediated cancer chemoprevention by naturally occurring dietary phytochemicals; and the mutation or hyper-expression of the Nrf2-Keap1 signaling pathway in advanced tumor cells. The future development of dietary phytochemicals for chemoprevention must integrate in vitro signaling mechanisms, relevant biomarkers of human diseases, and combinations of different phytochemicals and/or non-toxic therapeutic drugs, including NSAIDs.
Collapse
Affiliation(s)
- Jong Hun Lee
- Center for Cancer Prevention Research, Department of Pharmaceutics, Ernest-Mario School of Pharmacy, Rutgers, the State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | | | | | | | | | | |
Collapse
|
26
|
Chorley BN, Campbell MR, Wang X, Karaca M, Sambandan D, Bangura F, Xue P, Pi J, Kleeberger SR, Bell DA. Identification of novel NRF2-regulated genes by ChIP-Seq: influence on retinoid X receptor alpha. Nucleic Acids Res 2012; 40:7416-29. [PMID: 22581777 PMCID: PMC3424561 DOI: 10.1093/nar/gks409] [Citation(s) in RCA: 414] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 04/18/2012] [Accepted: 04/19/2012] [Indexed: 12/14/2022] Open
Abstract
Cellular oxidative and electrophilic stress triggers a protective response in mammals regulated by NRF2 (nuclear factor (erythroid-derived) 2-like; NFE2L2) binding to deoxyribonucleic acid-regulatory sequences near stress-responsive genes. Studies using Nrf2-deficient mice suggest that hundreds of genes may be regulated by NRF2. To identify human NRF2-regulated genes, we conducted chromatin immunoprecipitation (ChIP)-sequencing experiments in lymphoid cells treated with the dietary isothiocyanate, sulforaphane (SFN) and carried out follow-up biological experiments on candidates. We found 242 high confidence, NRF2-bound genomic regions and 96% of these regions contained NRF2-regulatory sequence motifs. The majority of binding sites were near potential novel members of the NRF2 pathway. Validation of selected candidate genes using parallel ChIP techniques and in NRF2-silenced cell lines indicated that the expression of about two-thirds of the candidates are likely to be directly NRF2-dependent including retinoid X receptor alpha (RXRA). NRF2 regulation of RXRA has implications for response to retinoid treatments and adipogenesis. In mouse, 3T3-L1 cells' SFN treatment affected Rxra expression early in adipogenesis, and knockdown of Nrf2-delayed Rxra expression, both leading to impaired adipogenesis.
Collapse
Affiliation(s)
- Brian N. Chorley
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Michelle R. Campbell
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Xuting Wang
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Mehmet Karaca
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Deepa Sambandan
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Fatu Bangura
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Peng Xue
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Jingbo Pi
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Steven R. Kleeberger
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Douglas A. Bell
- Environmental Genomics Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, The Hamner Institutes and Environmental Genetics Section, Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| |
Collapse
|
27
|
Abstract
Diquat is an herbicide that generates superoxide anions through redox cycling. Nuclear factor erythroid-derived 2- like 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the protective effect of Nrf2 against diquat-induced toxicity, wild-type, Nrf2-null and Kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2 activity were treated with diquat dibromide (125 mg/kg, i.p.). Blood and tissues were collected at 1, 2, 4 and 6 hours after treatment. Administration of diquat resulted in lipid peroxidation and lethality in wild-type mice, which were more in Nrf2-null mice and less in Keap1-KD mice. Diquat produced liver injury in Nrf2-null mice, as evidenced by increased serum ALT activity and extensive hepatic necrosis, but not in wild-type and Keap1-KD mice. Diquat produced more severe lung injury in Nrf2-null than in wild-type mice, as evidenced by increased lung weight and alveolar collapse. In contrast, Keap1-KD mice had attenuated lung edema and no histopathological alterations. To further investigate the mechanism of the protective effects of Nrf2, lung and liver glutathione (GSH) concentrations were quantified. Diquat decreased GSH in lung and liver in wild-type mice, and the decrease was more in Nrf2-null mice, and less in Keap1-KD mice. After diquat treatment, the mRNA of the GSH synthesis enzyme Gclc was increased in Keap1-KD, but not in Nrf2-null mice. Collectively, Nrf2 plays an important role in preventing diquat-induced liver and lung injury, and this protective effect results from Nrf2-regulated elevation of cellular GSH and expression of GSH synthetic genes.
Collapse
Affiliation(s)
- Kai Connie Wu
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | | | | |
Collapse
|
28
|
Transcriptional control of glyoxalase 1 by Nrf2 provides a stress-responsive defence against dicarbonyl glycation. Biochem J 2012; 443:213-22. [PMID: 22188542 DOI: 10.1042/bj20111648] [Citation(s) in RCA: 227] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abnormal cellular accumulation of the dicarbonyl metabolite MG (methylglyoxal) occurs on exposure to high glucose concentrations, inflammation, cell aging and senescence. It is associated with increased MG-adduct content of protein and DNA linked to increased DNA strand breaks and mutagenesis, mitochondrial dysfunction and ROS (reactive oxygen species) formation and cell detachment from the extracellular matrix. MG-mediated damage is countered by glutathione-dependent metabolism by Glo1 (glyoxalase 1). It is not known, however, whether Glo1 has stress-responsive up-regulation to counter periods of high MG concentration or dicarbonyl stress. We identified a functional ARE (antioxidant-response element) in the 5'-untranslated region of exon 1 of the mammalian Glo1 gene. Transcription factor Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2) binds to this ARE, increasing basal and inducible expression of Glo1. Activators of Nrf2 induced increased Glo1 mRNA, protein and activity. Increased expression of Glo1 decreased cellular and extracellular concentrations of MG, MG-derived protein adducts, mutagenesis and cell detachment. Hepatic, brain, heart, kidney and lung Glo1 mRNA and protein were decreased in Nrf2-/- mice, and urinary excretion of MG protein and nucleotide adducts were increased approximately 2-fold. We conclude that dicarbonyl stress is countered by up-regulation of Glo1 in the Nrf2 stress-responsive system, protecting protein and DNA from increased damage and preserving cell function.
Collapse
|
29
|
Abdullah A, Kitteringham NR, Jenkins RE, Goldring C, Higgins L, Yamamoto M, Hayes J, Park BK. Analysis of the role of Nrf2 in the expression of liver proteins in mice using two-dimensional gel-based proteomics. Pharmacol Rep 2012; 64:680-97. [DOI: 10.1016/s1734-1140(12)70863-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 03/09/2012] [Indexed: 12/16/2022]
|
30
|
Di Domenico F, Foppoli C, Coccia R, Perluigi M. Antioxidants in cervical cancer: Chemopreventive and chemotherapeutic effects of polyphenols. Biochim Biophys Acta Mol Basis Dis 2012; 1822:737-47. [DOI: 10.1016/j.bbadis.2011.10.005] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Revised: 10/05/2011] [Accepted: 10/06/2011] [Indexed: 01/09/2023]
|
31
|
Scientific Opinion on the re-evaluation of butylated hydroxyanisole - BHA (E 320) as a food additive. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2392] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
32
|
Ohnuma T, Anan E, Hoashi R, Takeda Y, Nishiyama T, Ogura K, Hiratsuka A. Dietary Diacetylene Falcarindiol Induces Phase 2 Drug-Metabolizing Enzymes and Blocks Carbon Tetrachloride-Induced Hepatotoxicity in Mice through Suppression of Lipid Peroxidation. Biol Pharm Bull 2011; 34:371-8. [DOI: 10.1248/bpb.34.371] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Tomokazu Ohnuma
- Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Eisaburo Anan
- Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Rika Hoashi
- Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Yuika Takeda
- Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Takahito Nishiyama
- Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Kenichiro Ogura
- Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Akira Hiratsuka
- Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| |
Collapse
|
33
|
Hayes JD, McMahon M, Chowdhry S, Dinkova-Kostova AT. Cancer chemoprevention mechanisms mediated through the Keap1-Nrf2 pathway. Antioxid Redox Signal 2010; 13:1713-48. [PMID: 20446772 DOI: 10.1089/ars.2010.3221] [Citation(s) in RCA: 412] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The cap'n'collar (CNC) bZIP transcription factor Nrf2 controls expression of genes for antioxidant enzymes, metal-binding proteins, drug-metabolising enzymes, drug transporters, and molecular chaperones. Many chemicals that protect against carcinogenesis induce Nrf2-target genes. These compounds are all thiol-reactive and stimulate an adaptive response to redox stress in cells. Such agents induce the expression of genes that posses an antioxidant response element (ARE) in their regulatory regions. Under normal homeostatic conditions, Nrf2 activity is restricted through a Keap1-dependent ubiquitylation by Cul3-Rbx1, which targets the CNC-bZIP transcription factor for proteasomal degradation. However, as the substrate adaptor function of Keap1 is redox-sensitive, Nrf2 protein evades ubiquitylation by Cul3-Rbx1 when cells are treated with chemopreventive agents. As a consequence, Nrf2 accumulates in the nucleus where it heterodimerizes with small Maf proteins and transactivates genes regulated through an ARE. In this review, we describe synthetic compounds and phytochemicals from edible plants that induce Nrf2-target genes. We also discuss evidence for the existence of different classes of ARE (a 16-bp 5'-TMAnnRTGABnnnGCR-3' versus an 11-bp 5'-RTGABnnnGCR-3', with or without the embedded activator protein 1-binding site 5'-TGASTCA-3'), species differences in the ARE-gene battery, and the identity of critical Cys residues in Keap1 required for de-repression of Nrf2 by chemopreventive agents.
Collapse
Affiliation(s)
- John D Hayes
- Biomedical Research Institute, Ninewells Hospital, University of Dundee, Scotland, United Kingdom.
| | | | | | | |
Collapse
|
34
|
Abstract
The transcription factor NF-E2-related factor (NRF2) is a key regulator of several enzymatic pathways, including cytoprotective enzymes in highly metabolic organs. In this review, we summarize the ongoing research related to NRF2 activity in cancer development, focusing on in vivo studies using NRF2 knockout (KO) mice, which have helped in defining the crucial role of NRF2 in chemoprevention. The lower cancer protection observed in NRF2 KO mice under calorie restriction (CR) suggests that most of the beneficial effects of CR on the carcinogenesis process are likely mediated by NRF2. We propose that future interventions in cancer treatment would be carried out through the activation of NRF2 in somatic cells, which will lead to a delay or prevention of the onset of some forms of human cancers, and subsequently an extension of health- and lifespan.
Collapse
|
35
|
The Nrf2 system as a potential target for the development of indirect antioxidants. Molecules 2010; 15:7266-91. [PMID: 20966874 PMCID: PMC6259123 DOI: 10.3390/molecules15107266] [Citation(s) in RCA: 334] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Revised: 10/18/2010] [Accepted: 10/20/2010] [Indexed: 12/15/2022] Open
Abstract
Oxidative stress causes damage to multiple cellular components such as DNA, proteins, and lipids, and is implicated in various human diseases including cancer, neurodegeneration, inflammatory diseases, and aging. In response to oxidative attack, cells have developed an antioxidant defense system to maintain cellular redox homeostasis and to protect cells from damage. The thiol-containing small molecules (e.g. glutathione), reactive oxygen species-inactivating enzymes (e.g. glutathione peroxidase), and phase 2 detoxifying enzymes (e.g. NAD(P)H: quinine oxidoreductase 1 and glutathione-S-transferases) are members of this antioxidant system. NF-E2-related factor 2 (Nrf2) is a CNC-bZIP transcription factor which regulates the basal and inducible expression of a wide array of antioxidant genes. Following dissociation from the cytosolic protein Keap1, a scaffolding protein which binds Nrf2 and Cul3 ubiquitin ligase for proteasome degradation, Nrf2 rapidly accumulates in the nucleus and transactivates the antioxidant response element in the promoter region of many antioxidant genes. The critical role of Nrf2 has been demonstrated by various animal studies showing that mice with a targeted disruption of the nrf2 gene are prone to develop lesions in response to environmental toxicants/carcinogens, drugs, and inflammatory insults. In this review, we discuss the role of the Nrf2 system, with particular focus on Nrf2-controlled target genes and the potential pleiotropic effects of Nrf2 activation of indirect antioxidants.
Collapse
|
36
|
Buranrat B, Prawan A, Kukongviriyapan U, Kongpetch S, Kukongviriyapan V. Dicoumarol enhances gemcitabine-induced cytotoxicity in high NQO1-expressing cholangiocarcinoma cells. World J Gastroenterol 2010; 16:2362-70. [PMID: 20480521 PMCID: PMC2874140 DOI: 10.3748/wjg.v16.i19.2362] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate whether dicoumarol, a potent inhibitor of NAD(P)H quinone oxidoreductase-1 (NQO1), potentiates gemcitabine to induce cytotoxicity in cholangiocarcinoma cells (CCA) and the role of reactive oxygen generation in sensitizing the cells.
METHODS: Four human cell lines with different NQO1 activity were used; the human CCA cell lines, KKU-100, KKU-OCA17, KKU-M214, and Chang liver cells. NQO1 activity and mRNA expression were determined. The cells were pretreated with dicoumarol at relevant concentrations before treatment with gemcitabine. Cytotoxicity was determined by staining with fluorescent dyes. Oxidant formation was examined by assay of cellular glutathione levels and reactive oxygen species production by using dihydrofluorescein diacetate. Measurement of mitochondrial transmembrane potential was performed by using JC-1 fluorescent probe. Western blotting analysis was performed to determine levels of survival related proteins.
RESULTS: Dicoumarol markedly enhanced the cytotoxicity of gemcitabine in KKU-100 and KKU-OCA17, the high NQO1 activity and mRNA expressing cells, but not in the other cells with low NQO1 activity. Dicoumarol induced a marked decrease in cellular redox of glutathione in KKU-100 cells, in contrast to KKU-M214 cells. Dicoumarol at concentrations that inhibited NQO1 activity did not alter mitochondrial transmembrane potential and production of reactive oxygen species. Gemcitabine alone induced activation of NF-κB and Bcl-XL protein expression. However, gemcitabine and dicoumarol combination induced increased p53 and decreased Bcl-XL levels in KKU-100, but not in KKU-M214 cells.
CONCLUSION: NQO1 may be important in sensitizing cells to anticancer drugs and inhibition of NQO1 may be a strategy for the treatment of CCA.
Collapse
|
37
|
Targeting NRF2 signaling for cancer chemoprevention. Toxicol Appl Pharmacol 2009; 244:66-76. [PMID: 19732782 DOI: 10.1016/j.taap.2009.08.028] [Citation(s) in RCA: 229] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 08/13/2009] [Accepted: 08/26/2009] [Indexed: 02/06/2023]
Abstract
Modulation of the metabolism and disposition of carcinogens through induction of cytoprotective enzymes is one of several promising strategies to prevent cancer. Chemopreventive efficacies of inducers such as dithiolethiones and sulforaphane have been extensively studied in animals as well as in humans. The KEAP1-NRF2 system is a key, but not unilateral, molecular target for these chemopreventive agents. The transcription factor NRF2 (NF-E2-related factor 2) is a master regulator of the expression of a subset of genes, which produce proteins responsible for the detoxication of electrophiles and reactive oxygen species as well as the removal or repair of some of their damage products. It is believed that chemopreventive enzyme inducers affect the interaction between KEAP1 and NRF2 through either mediating conformational changes of the KEAP1 protein or activating phosphorylation cascades targeting the KEAP1-NRF2 complex. These events in turn affect NRF2 stability and trafficking. Recent advances elucidating the underlying structural biology of KEAP1-NRF2 signaling and identification of the gene clusters under the transcriptional control of NRF2 are facilitating understanding of the potential pleiotropic effects of NRF2 activators and discovery of novel classes of potent chemopreventive agents such as the triterpenoids. Although there is appropriately a concern regarding a deleterious role of the KEAP1-NRF2 system in cancer cell biology, especially as the pathway affects cell survival and drug resistance, the development and the use of NRF2 activators as chemopreventive agents still holds a great promise for protection of normal cells from a diversity of environmental stresses that contribute to the burden of cancer and other chronic, degenerative diseases.
Collapse
|
38
|
Yates MS, Tran QT, Dolan PM, Osburn WO, Shin S, McCulloch CC, Silkworth JB, Taguchi K, Yamamoto M, Williams CR, Liby KT, Sporn MB, Sutter TR, Kensler TW. Genetic versus chemoprotective activation of Nrf2 signaling: overlapping yet distinct gene expression profiles between Keap1 knockout and triterpenoid-treated mice. Carcinogenesis 2009; 30:1024-31. [PMID: 19386581 DOI: 10.1093/carcin/bgp100] [Citation(s) in RCA: 212] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Loss of NF-E2-related factor 2 (Nrf2) signaling increases susceptibility to acute toxicity, inflammation and carcinogenesis in mice due to the inability to mount adaptive responses. In contrast, disruption of Keap1 (a cytoplasmic modifier of Nrf2 turnover) protects against these stresses in mice, although inactivating mutations in Keap1 have been identified recently in some human cancers. Global characterization of Nrf2 activation is important to exploit this pathway for chemoprevention in healthy, yet at-risk individuals and also to elucidate the consequences of hijacking the pathway in Keap1-mutant human cancers. Liver-targeted conditional Keap1-null, Albumin-Cre:Keap1((flox/-)) (CKO) mice provide a model of genetic activation of Nrf2 signaling. By coupling global gene expression analysis of CKO mice with analysis of pharmacologic activation using the synthetic oleanane triterpenoid 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im), we are able to gain insight into pathways affected by Nrf2 activation. CDDO-Im is an extremely potent activator of Nrf2 signaling. CKO mice were used to identify genes modulated by genetic activation of Nrf2 signaling. The CKO response was compared with hepatic global gene expression changes in wild-type mice treated with CDDO-Im at a maximal Nrf2 activating dose. The results show that genetic and pharmacologic activation of Nrf2 signaling modulates pathways beyond detoxication and cytoprotection, with the largest cluster of genes associated with lipid metabolism. Genetic activation of Nrf2 results in much larger numbers of detoxication and lipid metabolism gene changes. Additionally, analysis of pharmacologic activation suggests that Nrf2 is the primary mediator of CDDO-Im activity, though other cell-signaling targets are also modulated following an oral dose of 30 micromol/kg.
Collapse
Affiliation(s)
- Melinda S Yates
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Noyan-Ashraf MH, Sadeghinejad Z, Davies GF, Ross AR, Saucier D, Harkness TAA, Juurlink BHJ. Phase 2 protein inducers in the diet promote healthier aging. J Gerontol A Biol Sci Med Sci 2008; 63:1168-76. [PMID: 19038831 DOI: 10.1093/gerona/63.11.1168] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Oxidative stress drives many aging-associated problems. Because oxidative stress can be decreased by induction of phase 2 proteins, we hypothesized that incorporating the phase 2 protein inducer 2(3)-tert-butyl-4-hydroxyanisole (tBHA) into the diet would result in healthier aging. C57BL/6 mice were placed either on control mouse chow diet or on chow containing tBHA and were examined at 6, 12, and 18 months. Dietary tBHA resulted in the antioxidant response activation, decreased both oxidative stress and pro-inflammatory gene expression in tissues examined, counteracted the decrease in the transcription factors peroxisome proliferator-activated receptor-gamma and increase in CCAAT/enhancer binding protein-alpha levels seen in liver with aging, and was associated with mice having less weight gain, despite having no differences in food consumption, and better locomotor function. We conclude that simple changes in the diet such as incorporation of phase 2 protein inducers can have a profound influence on health and, thereby, the aging process.
Collapse
|
40
|
Nair S, Doh ST, Chan JY, Kong AN, Cai L. Regulatory potential for concerted modulation of Nrf2- and Nfkb1-mediated gene expression in inflammation and carcinogenesis. Br J Cancer 2008; 99:2070-82. [PMID: 19050705 PMCID: PMC2607222 DOI: 10.1038/sj.bjc.6604703] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Many studies have implicated nuclear factor E2-related factor 2 (Nrf2) and nuclear factor-kappaB1 (Nfkb1) in inflammation and cancer. However, the regulatory potential for crosstalk between these two important transcription factors in inflammation and carcinogenesis has not been explored. To delineate conserved transcription factor-binding site signatures, we performed bioinformatic analyses on the promoter regions of human and murine Nrf2 and Nfkb1. We performed multiple sequence alignment of Nrf2 and Nfkb1 genes in five mammalian species - human, chimpanzee, dog, mouse and rat - to explore conserved biological features. We constructed a canonical regulatory network for concerted modulation of Nrf2 and Nfkb1 involving several members of the mitogen-activated protein kinase (MAPK) family and present a putative model for concerted modulation of Nrf2 and Nfkb1 in inflammation/carcinogenesis. Our results reflect potential for putative crosstalk between Nrf2 and Nfkb1 modulated through the MAPK cascade that may influence inflammation-associated etiopathogenesis of cancer. Taken together, the elucidation of potential relationships between Nrf2 and Nfkb1 may help to better understand transcriptional regulation, as well as transcription factor networks, associated with the etiopathogenesis of inflammation and cancer.
Collapse
Affiliation(s)
- S Nair
- Department of Pharmaceutics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | | | | | | | | |
Collapse
|
41
|
The Nrf2 transcription factor protects from toxin-induced liver injury and fibrosis. J Transl Med 2008; 88:1068-78. [PMID: 18679376 DOI: 10.1038/labinvest.2008.75] [Citation(s) in RCA: 165] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The liver is frequently exposed to insults, including toxic chemicals and alcohol, viral infection or metabolic overload. Although it can fully regenerate after acute injury, chronic liver damage causes liver fibrosis and cirrhosis, which can result in complete liver failure. In this study, we demonstrate that the NF-E2-related factor 2 (Nrf2) transcription factor protects the liver from acute and chronic toxin-mediated damage. Repair of the liver injury that occurs after a single treatment with the hepatotoxin carbon tetrachloride (CCl(4)) was severely delayed in Nrf2-deficient mice. The defect in repair was accompanied by an enhanced and prolonged inflammatory and profibrotic response. After long-term CCl(4) treatment, liver fibrosis was strongly aggravated in the Nrf2 knockout mice and inflammation was enhanced. We demonstrate that these abnormalities are at least in part due to the reduced expression of known and novel Nrf2 target genes in hepatocytes, which encode enzymes involved in the detoxification of CCl(4) and its metabolites. These results suggest that activation of Nrf2 may be a novel strategy to prevent or ameliorate toxin-induced liver injury and fibrosis.
Collapse
|
42
|
Barve A, Khor TO, Nair S, Lin W, Yu S, Jain MR, Chan JY, Kong AN. Pharmacogenomic profile of soy isoflavone concentrate in the prostate of Nrf2 deficient and wild-type mice. J Pharm Sci 2008; 97:4528-45. [PMID: 18236473 DOI: 10.1002/jps.21311] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The involvement of Nrf2-a bZip transcription factor in soy isoflavones induced protection against oxidative stress and cancer has been reported. To gain better insight into the role of Nrf2 in prostate cancer chemoprevention by soy isoflavones, we examined the pharmacogenomics and gene expression profiles elicited by soy isoflavones in the prostates of C57BL/6J/Nrf2(-/-) and C57BL6J/Nrf2(+/+) wildtype. The profiles were analyzed using 45000 Affymetrix mouse genome 430-2.0 array and Genespring-7.2 software. The results obtained from microarray were further validated by real-time reverse transcription-PCR. Clusters of genes that were induced or suppressed more than twofold were identified as Nrf2 regulated soy isoflavone induced or suppressed genes. Classification based on their biological function revealed that genes mainly belonging to the categories of electron transport, phase II metabolizing enzymes, cell growth and differentiation, apoptosis, cell cycle, transcription factors, transport, mRNA processing, and carbohydrate homeostasis were either induced or suppressed by soy isoflavone and regulated by Nrf2. In addition, modulation of novel target genes such as LATS2 and GREB1 were identified to be mediated by Nrf2. Thus our current study provides a potential link between cancer chemopreventive properties of soy derived phytochemicals, the transcription factor Nrf2 and prevention of prostate cancer.
Collapse
Affiliation(s)
- Avantika Barve
- Graduate Program in Pharmaceutical Sciences, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Son TG, Camandola S, Mattson MP. Hormetic dietary phytochemicals. Neuromolecular Med 2008; 10:236-46. [PMID: 18543123 DOI: 10.1007/s12017-008-8037-y] [Citation(s) in RCA: 219] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 05/06/2008] [Indexed: 01/23/2023]
Abstract
Compelling evidence from epidemiological studies suggests beneficial roles of dietary phytochemicals in protecting against chronic disorders such as cancer, and inflammatory and cardiovascular diseases. Emerging findings suggest that several dietary phytochemicals also benefit the nervous system and, when consumed regularly, may reduce the risk of disorders such as Alzheimer's and Parkinson's diseases. The evidence supporting health benefits of vegetables and fruits provide a rationale for identification of the specific phytochemicals responsible, and for investigation of their molecular and cellular mechanisms of action. One general mechanism of action of phytochemicals that is emerging from recent studies is that they activate adaptive cellular stress response pathways. From an evolutionary perspective, the noxious properties of such phytochemicals play an important role in dissuading insects and other pests from eating the plants. However at the subtoxic doses ingested by humans that consume the plants, the phytochemicals induce mild cellular stress responses. This phenomenon has been widely observed in biology and medicine, and has been described as 'preconditioning' or 'hormesis.' Hormetic pathways activated by phytochemicals may involve kinases and transcription factors that induce the expression of genes that encode antioxidant enzymes, protein chaperones, phase-2 enzymes, neurotrophic factors, and other cytoprotective proteins. Specific examples of such pathways include the sirtuin-FOXO pathway, the NF-kappaB pathway, and the Nrf-2/ARE pathway. In this article, we describe the hormesis hypothesis of phytochemical actions with a focus on the Nrf2/ARE signaling pathway as a prototypical example of a neuroprotective mechanism of action of specific dietary phytochemicals.
Collapse
Affiliation(s)
- Tae Gen Son
- Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | | | | |
Collapse
|
44
|
Anticarcinogenesis by dietary phytochemicals: Cytoprotection by Nrf2 in normal cells and cytotoxicity by modulation of transcription factors NF-κB and AP-1 in abnormal cancer cells. Food Chem Toxicol 2008; 46:1257-70. [DOI: 10.1016/j.fct.2007.09.082] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2007] [Revised: 08/20/2007] [Accepted: 09/03/2007] [Indexed: 01/09/2023]
|
45
|
Aleksunes LM, Manautou JE. Emerging role of Nrf2 in protecting against hepatic and gastrointestinal disease. Toxicol Pathol 2007; 35:459-73. [PMID: 17562481 DOI: 10.1080/01926230701311344] [Citation(s) in RCA: 228] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Transcription factor NF-E2-related factor 2 (Nrf2) belongs to the basic region-leucine zipper family and is activated in response to electrophiles and reactive oxygen species. Nrf2 coordinately regulates the constitutive and inducible transcription of a wide array of genes involved in drug metabolism, detoxification, and antioxidant defenses. During periods of oxidative stress, Nrf2 is released from sequestration in the cytoplasm and translocates to the nucleus. Nrf2 binds antioxidant response elements (AREs) in the regulatory regions of target genes and activates transcription. Genetically modified mice lacking Nrf2 serve as a useful tool for identifying new ARE-regulated genes and assessing the ability of Nrf2 to confer protection against a variety of pathologies in numerous organs including the liver, intestine, lung, skin, and nervous system. With regards to the liver and gastrointestinal tract, Nrf2 knockout mice are more susceptible to acetaminophen-induced hepatocellular injury, benzo[a]pyrene-induced tumor formation and Fas- and TNFalpha -mediated hepatocellular apoptosis. The higher sensitivity of Nrf2 knockout mice to chemical toxicity is due in part to reduced basal and inducible expression of detoxification enzymes. Nrf2 may also be important in protecting against liver fibrosis, gallstone development, and formation of aberrant crypt foci. Research of Nrf2 has opened up new opportunities in understanding how antioxidant defense pathways are regulated, how oxidative stress contributes to disease progression and may serve as a novel target for designing therapies to prevent and treat diseases in which oxidative stress is implicated.
Collapse
Affiliation(s)
- Lauren M Aleksunes
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269-3092, USA
| | | |
Collapse
|
46
|
Abstract
Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, causing nearly 600,000 deaths each year. Increased risk of HCC due to chronic infection with hepatitis B virus (HBV) and exposure to dietary aflatoxins is responsible for many of these deaths. Prevention strategies targeting HBV infection and aflatoxin exposure could dramatically impact the rates of HCC. Universal HBV vaccination programs have begun in some high-risk areas. Strategies to reduce aflatoxin contamination in food stores have also been implemented. However, complete elimination of aflatoxin contamination might not be possible. For this reason, chemoprevention strategies which alter aflatoxin disposition are a practical strategy to reduce the incidence of HCC in populations with high dietary aflatoxin exposure. The mechanisms of aflatoxin-induced hepatocarcinogenesis are well known. This knowledge provides the basis for evaluation of both exposures to aflatoxin, as well as modulation of aflatoxin disposition by chemopreventive agents. Products of aflatoxin DNA damage and toxicity as well as other metabolites can be used as biomarkers to evaluate modulation of aflatoxin disposition. Modulation of aflatoxin disposition can be achieved through induction of conjugating and cytoprotective enzymes. Many of these enzymes are regulated through Kelch ECH-associating protein 1 (Keap1)-NF-E2-related factor 2(Nrf2)-antioxidant response element (ARE) signaling, making this pathway an important molecular target for chemoprevention. Rodent studies have identified several classes of chemopreventive agents which induce cytoprotective genes. These inducers include phenolic antioxidants, dithiolethiones, isothiocyanates, and triterpenoids. Furthermore, clinical interventions have shown that inducers of Keap1-Nrf2- ARE signaling increase cytoprotective enzyme expression, resulting in modulation of aflatoxin disposition. Much work remains to be done in order to take promising chemopreventive agents from preclinical evaluation to application in at-risk populations. However, appropriately designed clinical trials will aid in this process, which can have profound impact on the incidence of HCC.
Collapse
Affiliation(s)
- Melinda Sue Yates
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | | |
Collapse
|
47
|
Ellis EM. Reactive carbonyls and oxidative stress: potential for therapeutic intervention. Pharmacol Ther 2007; 115:13-24. [PMID: 17570531 DOI: 10.1016/j.pharmthera.2007.03.015] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 03/27/2007] [Indexed: 12/17/2022]
Abstract
Reactive aldehydes and ketones are produced as a result of oxidative stress in several disease processes. Considerable evidence is now accumulating that these reactive carbonyl products are also involved in the progression of diseases, including neurodegenerative disorders, diabetes, atherosclerosis, diabetic complications, reperfusion after ischemic injury, hypertension, and inflammation. To counter carbonyl stress, cells possess enzymes that can decrease aldehyde load. These enzymes include aldehyde dehydrogenases (ALDH), aldo-keto reductases (AKR), carbonyl reductase (CBR), and glutathione S-transferases (GST). Some of these enzymes are inducible by chemoprotective compounds via Nrf2/ARE- or AhR/XRE-dependent mechanisms. This review describes the metabolism of reactive carbonyls and discusses the potential for manipulating levels of carbonyl-metabolizing enzymes through chemical intervention.
Collapse
Affiliation(s)
- Elizabeth M Ellis
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 204 George Street, Glasgow, G1 1XW, United Kingdom.
| |
Collapse
|
48
|
Nair S, Li W, Kong ANT. Natural dietary anti-cancer chemopreventive compounds: redox-mediated differential signaling mechanisms in cytoprotection of normal cells versus cytotoxicity in tumor cells. Acta Pharmacol Sin 2007; 28:459-72. [PMID: 17376285 DOI: 10.1111/j.1745-7254.2007.00549.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Many dietary phytochemicals exhibit health-beneficial effects including prevention of diseases such as cancer, as well as neurological, cardiovascular, inflammatory, and metabolic diseases. Evolutionarily, herbivorous and omnivorous animals have been ingesting plants. This interaction between "animal-plant" ecosystems has resulted in an elaborate system of detoxification and defense mechanisms evolved by animals including humans. Mammalian cells, including human cells, respond to these dietary phytochemicals by "non-classical receptor sensing" mechanisms of electrophilic chemical-stress typified by "thiol-modulated" cellular signaling events primarily leading to the gene expression of pharmacologically beneficial effects, but sometimes unwanted cytotoxicity also. Our laboratory has been studying two groups of dietary phytochemical cancer-chemopreventive compounds (isothiocyanates and polyphenols), which are effective in chemical-induced, as well as genetically-induced, animal carcinogenesis models. These compounds typically generate "cellular stress" and modulate gene expression of phase II detoxifying/antioxidant enzymes. Electrophiles, reactive oxygen species, and reactive nitrogen species are known to act as second messengers in the modulation of many cellular signaling pathways leading to gene expression changes and pharmacological responses. Redox-sensitive transcription factors such as nuclear factor-E2-related factor 2 (Nrf2), AP-1, NF-kappaB, to cite a few examples, sense and transduce changes in the cellular redox status and modulate gene expression responses to oxidative and electrophilic stresses, presumably via sulfhydryl modification of critical cysteine residues found on these proteins and/or other upstream redox-sensitive molecular targets. In the current review, we will explore dietary cancer chemopreventive phytochemicals, discuss the link between oxidative/electrophilic stresses and the redox circuitry, and consider different redox-sensitive transcription factors. We will also discuss the kelch-like erythroid Cap'n'Collar homologue-associated protein 1 (Keap1)-Nrf2 axis in redox signaling of induction of phase II detoxifying/antioxidant defense mechanisms, an important target and preventive strategy for normal cells against carcinogenesis, and the converse inhibition of cell growth/inflammatory signaling pathways that would confer therapeutic intervention in many types of cancers. Finally, we will summarize the Nrf2 paradigm in gene expression, the pharmacotoxicogenomic relevance of redox-sensitive Nrf2, and the redox regulation of cell death mechanisms.
Collapse
Affiliation(s)
- Sujit Nair
- Graduate Program in Pharmaceutical Sciences and Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers-The State University of New Jersey, Piscataway, NJ 08854, USA
| | | | | |
Collapse
|
49
|
Nair S, Xu C, Shen G, Hebbar V, Gopalakrishnan A, Hu R, Jain MR, Liew C, Chan JY, Kong AN. Toxicogenomics of endoplasmic reticulum stress inducer tunicamycin in the small intestine and liver of Nrf2 knockout and C57BL/6J mice. Toxicol Lett 2006; 168:21-39. [PMID: 17127020 PMCID: PMC1847389 DOI: 10.1016/j.toxlet.2006.10.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 10/24/2006] [Accepted: 10/24/2006] [Indexed: 01/06/2023]
Abstract
This objective of this study was to investigate the toxicogenomics and the spatial regulation of global gene expression profiles elicited by endoplasmic reticulum (ER) stress inducer tunicamycin (TM) in mouse small intestine and liver as well as to identify TM-modulated nuclear factor-E2-related factor 2 (Nrf2)-dependent genes. Gene expression profiles were analyzed using 45,000 Affymetrix mouse genome 430 2.0 array and GeneSpring 7.2 software. Microarray results were validated by quantitative real-time reverse transcription-PCR analyses. Clusters of genes that were either induced or suppressed more than two-fold by TM treatment compared with vehicle in C57BL/6J/Nrf2 (-/-; knockout) and C57BL/6J Nrf2 (+/+; wildtype) mice genotypes were identified. Amongst these, in small intestine and liver, 1291 and 750 genes, respectively, were identified as Nrf2-dependent and upregulated, and 1370 and 943 genes, respectively, as Nrf2-dependent and downregulated. Based on their biological functions, these genes can be categorized into molecular chaperones and heat shock proteins, ubiquitination/proteolysis, apoptosis/cell cycle, electron transport, detoxification, cell growth/differentiation, signaling molecules/interacting partners, kinases and phosphatases, transport, biosynthesis/metabolism, nuclear assembly and processing, and genes related to calcium and glucose homeostasis. Phase II detoxification/antioxidant genes as well as putative interacting partners of Nrf2 such as nuclear corepressors and coactivators, were also identified as Nrf2-dependent genes. The identification of TM-regulated and Nrf2-dependent genes in the unfolded protein response to ER stress not only provides potential novel insights into the gestalt biological effects of TM on the toxicogenomics and spatial regulation of global gene expression profiles in cancer pharmacology and toxicology, but also points to the pivotal role of Nrf2 in these biological processes.
Collapse
Affiliation(s)
- Sujit Nair
- Graduate Program in Pharmaceutical Science, Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ-08854, USA
| | - Changjiang Xu
- Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ-08854, USA
| | - Guoxiang Shen
- Graduate Program in Pharmaceutical Science, Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ-08854, USA
| | - Vidya Hebbar
- Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ-08854, USA
| | - Avantika Gopalakrishnan
- Graduate Program in Pharmaceutical Science, Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ-08854, USA
| | - Rong Hu
- Graduate Program in Pharmaceutical Science, Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ-08854, USA
| | - Mohit Raja Jain
- Department of Biochemistry and Molecular Biology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ-07103, USA
| | - Celine Liew
- Department of Pharmacy, National University of Singapore, 18, Science Drive 4, Singapore – 117543
| | - Jefferson Y. Chan
- Department of Pathology, University of California, D440 Medical Sciences, Irvine, California 92697, USA
| | - Ah-Ng Kong
- Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ-08854, USA
- To whom correspondence should be addressed (e-mail: )
| |
Collapse
|