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Fujii J, Osaki T, Bo T. Ascorbate Is a Primary Antioxidant in Mammals. Molecules 2022; 27:6187. [PMID: 36234722 PMCID: PMC9572970 DOI: 10.3390/molecules27196187] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/18/2022] [Accepted: 09/19/2022] [Indexed: 11/19/2022] Open
Abstract
Ascorbate (vitamin C in primates) functions as a cofactor for a number of enzymatic reactions represented by prolyl hydroxylases and as an antioxidant due to its ability to donate electrons, which is mostly accomplished through non-enzymatic reaction in mammals. Ascorbate directly reacts with radical species and is converted to ascorbyl radical followed by dehydroascorbate. Ambiguities in physiological relevance of ascorbate observed during in vivo situations could be attributed in part to presence of other redox systems and the pro-oxidant properties of ascorbate. Most mammals are able to synthesize ascorbate from glucose, which is also considered to be an obstacle to verify its action. In addition to animals with natural deficiency in the ascorbate synthesis, such as guinea pigs and ODS rats, three strains of mice with genetic removal of the responsive genes (GULO, RGN, or AKR1A) for the ascorbate synthesis have been established and are being used to investigate the physiological roles of ascorbate. Studies using these mice, along with ascorbate transporter (SVCT)-deficient mice, largely support its ability in protection against oxidative insults. While combined actions of ascorbate in regulating epigenetics and antioxidation appear to effectively prevent cancer development, pharmacological doses of ascorbate and dehydroascorbate may exert tumoricidal activity through redox-dependent mechanisms.
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Affiliation(s)
- Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Tsukasa Osaki
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Tomoki Bo
- Laboratory Animal Center, Institute for Promotion of Medical Science Research, Yamagata University Faculty of Medicine, Yamagata 990-9585, Japan
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Zhang L, Zhu T, He F, Li X. Senescence marker protein 30 (SMP30) protects against high glucose-induced apoptosis, oxidative stress and inflammatory response in retinal ganglion cells by enhancing Nrf2 activation via regulation of Akt/GSK-3β pathway. Int Immunopharmacol 2021; 101:108238. [PMID: 34688152 DOI: 10.1016/j.intimp.2021.108238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/23/2021] [Accepted: 10/05/2021] [Indexed: 11/26/2022]
Abstract
Senescence marker protein 30 (SMP30) is an aging-related protein that participates in the regulation of tissue damage under various pathological conditions. However, the role of SMP30 in mediating high glucose (HG)-induced injury of retinal ganglion cells (RGCs) has not been fully determined. We found that SMP30 expression declined during HG stimulation in RGCs. Cellular functional studies showed that the up-regulation of SMP30 dramatically prohibited HG-evoked apoptosis, oxidative stress and inflammatory response in RGCs. Mechanism research reported that SMP30 overexpression led to the enhancement of nuclear factor erythroid 2-related factor (Nrf2) activation in HG-stimulated RGCs. Moreover, SMP30 overexpression enhanced the phosphorylation of Akt and glucogen synthase kinase-3β (GSK-3β), and the suppression of Akt markedly abolished SMP30-mediated Nrf2 activation in HG-stimulated RGCs. Additionally, the suppression of Nrf2 substantially reversed SMP30-overexpression-induced anti-HG injury effects in RGCs. Overall, these findings suggest that SMP30 protects against HG injury of RGCs by potentiating Nrf2 through regulation of the Akt/GSK-3β pathway. Our work underscores that SMP30/Akt/GSK-3β/Nrf2 may exert a vital role in mediating the injury of RGCs during diabetic retinopathy.
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Affiliation(s)
- Le Zhang
- Department of Ophthalmology, Shaanxi Provincial People's Hospital, Xi'an 710068, Shaanxi Province, China; Department of Ophthalmology, Northwest Woman's and Children's Hospital, Xi'an 710061, Shaanxi Province, China
| | - Tao Zhu
- Department of Ophthalmology, Shaanxi Provincial People's Hospital, Xi'an 710068, Shaanxi Province, China
| | - Fang He
- The 8th Medical Center of the PLA General Hospital, Beijing 100091, China
| | - Xueying Li
- Department of Ophthalmology, Shaanxi Provincial People's Hospital, Xi'an 710068, Shaanxi Province, China.
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Sharma D, Goel HC, Chauhan S. Radioprotective potential of Lagenaria siceraria extract against radiation-induced gastrointestinal injury. Appl Physiol Nutr Metab 2016; 41:1248-1254. [DOI: 10.1139/apnm-2016-0136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The cucurbits (prebiotics) were investigated as novel agents for radio-modification against gastrointestinal injury. The cell-cycle fractions and DNA damage were monitored in HCT-15 cells. A cucurbit extract was added to culture medium 2 h before irradiation (6 Gy) and was substituted by fresh medium at 4 h post-irradiation. The whole extract of the fruits of Lagenaria siceraria, Luffa cylindrica, or Cucurbita pepo extract enhanced G2 fractions (42%, 34%, and 37%, respectively) as compared with control (20%) and irradiated control (31%). With cucurbits, the comet tail length remained shorter (L. siceraria, 28 μm; L. cylindrica, 34.2 μm; C. pepo, 36.75 μm) than irradiated control (41.75 μm). For in vivo studies, L. siceraria extract (2 mg/kg body weight) was administered orally to mice at 2 h before and 4 and 24 h after whole-body irradiation (10 Gy). L. siceraria treatment restored the glutathione contents to 48.8 μmol/gm as compared with control (27.6 μmol/gm) and irradiated control (19.6 μmol/gm). Irradiation reduced the villi height from 379 to 350 μm and width from 54 to 27 μm. L. siceraria administration countered the radiation effects (length, 366 μm; width, 30 μm, respectively) and improved the villi morphology and tight junction integrity. This study reveals the therapeutic potential of cucurbits against radiation-induced gastrointestinal injury.
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Affiliation(s)
- Dhara Sharma
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
| | - Harish Chandra Goel
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
| | - Sonal Chauhan
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
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Hellweg CE. The Nuclear Factor κB pathway: A link to the immune system in the radiation response. Cancer Lett 2015; 368:275-89. [DOI: 10.1016/j.canlet.2015.02.019] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 02/08/2015] [Accepted: 02/10/2015] [Indexed: 01/01/2023]
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Jung KJ, Lee EK, Kim SJ, Song CW, Maruyama N, Ishigami A, Kim ND, Im DS, Yu BP, Chung HY. Anti-inflammatory activity of SMP30 modulates NF-κB through protein tyrosine kinase/phosphatase balance. J Mol Med (Berl) 2014; 93:343-56. [PMID: 25394676 DOI: 10.1007/s00109-014-1219-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 09/25/2014] [Accepted: 10/23/2014] [Indexed: 10/24/2022]
Abstract
UNLABELLED Recent studies on senescence marker protein-30 (SMP30) have shown that it has an important functional role in the aging process, but its precise participation in cellular works has not been fully determined. We hypothesize that SMP30 plays crucial roles in signaling processes by modulating the balance of protein tyrosine kinase (PTK)/protein tyrosine phosphatase (PTP) and in activating proinflammatory NF-κB. An experimental paradigm of gain and loss of SMP30 function was established using SMP30-overexpressed YPEN-1 cells (herein referred to as "SMP30(+) cells") and SMP30 (Y/-) knockout mouse kidneys. The resulting data show that SMP30 expression suppressed oxidative stress-induced PTK/PTP dysregulation and PP1/2A inactivation in SMP30(+) cells, leading to the suppression of NF-κB activation. In the kidneys of SMP30 (Y/-) mice, SMP30 deficiency was found to induce NF-κB activation via the upstream signaling of NIK/IKK and MAPKs and to upregulate downstream NF-κB-responsive gene expression. In this study, we also demonstrate for the first time that SMP30 deficiency induced PTK activity in SMP30 (Y/-) kidneys, thereby significantly increasing the tyrosine phosphorylation of a catalytic subunit of PP2A (PP2Ac-Tyr307). Based on these findings, we propose that SMP30 involves NF-κB regulation through the PTK/PTP balance and that the age-related decrease of SMP30 causes NF-κB activation, which contributes to an exacerbation of the inflammatory process during aging. KEY MESSAGES SMP30-deficient mice induced a shorter lifespan and redox changes. Overexpression of SMP30 prevented oxidative stress insults. The depletion of SMP30 increased redox-related PTK/PTP imbalance and PP1/PP2A inactivation. The depletion of SMP30 caused an elevation of NF-κB-responsive inflammatory markers. SMP30 may be a potent inhibitory protein against oxidative stress and chronic inflammation.
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Affiliation(s)
- Kyung Jin Jung
- Korea Institute of Toxicology, 141 Gajungro, Yuseong-gu, Daejeon, 305-343, Republic of Korea
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Yu R, Schellhorn HE. Recent applications of engineered animal antioxidant deficiency models in human nutrition and chronic disease. J Nutr 2013; 143:1-11. [PMID: 23173175 DOI: 10.3945/jn.112.168690] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Dietary antioxidants are essential nutrients that inhibit the oxidation of biologically important molecules and suppress the toxicity of reactive oxygen or nitrogen species. When the total antioxidant capacity is insufficient to quench these reactive species, oxidative damage occurs and contributes to the onset and progression of chronic diseases, such as neurodegenerative diseases, cardiovascular diseases, and cancer. However, epidemiological studies that examine the relationship between antioxidants and disease outcome can only identify correlative associations. Additionally, many antioxidants also have prooxidant effects. Thus, clinically relevant animal models of antioxidant function are essential for improving our understanding of the role of antioxidants in the pathogenesis of complex diseases as well as evaluating the therapeutic potential and risks of their supplementation. Recent progress in gene knockout mice and virus-based gene expression has potentiated these areas of study. Here, we review the current genetically modified animal models of dietary antioxidant function and their clinical relevance in chronic diseases. This review focuses on the 3 major antioxidants in the human body: vitamin C, vitamin E, and uric acid. We examine genetic models of vitamin C synthesis (guinea pig, Osteogenic Disorder Shionogi rat, Gulo(-/-) and SMP30(-/-) mouse mutants) and transport (Slc23a1(-/-) and Slc23a2(-/-) mouse mutants), vitamin E transport (Ttpa(-/-) mouse mutant), and uric acid synthesis (Uox(-/-) mouse mutant). The application of these models to current research goals is also discussed.
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Affiliation(s)
- Rosemary Yu
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
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Park HR, Jo SK. Lasting effects of an impairment of Th1-like immune response in γ-irradiated mice: A resemblance between irradiated mice and aged mice. Cell Immunol 2010; 267:1-8. [PMID: 21092942 DOI: 10.1016/j.cellimm.2010.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Revised: 10/11/2010] [Accepted: 10/15/2010] [Indexed: 11/30/2022]
Abstract
Although one of the several chronic effects of ionizing radiation is aging, there are no experimental data on radiation-induced immunological aging. The most interesting change in aging was a helper T (Th) 1/Th2 imbalance. We investigated chronic effect on immune responses after ionizing radiation and its effects in irradiated mice were compared with those of aged mice. The 2-month-old mice received a whole-body irradiation of 5Gy. At 6months after irradiation, we compared the immune functions of the irradiated mice with those of normal mice of the same age and with those of older. Interferon (IFN)-γ and antigen-specific immunoglobulin (Ig)G2a level were lower in the irradiated mice than in normal mice of same age, showing similar levels to those of old normal mice. In contrast, interleukin (IL)-4 and IL-5 and antigen-specific IgG1 level were increased in irradiated mice when compared with the same aged-normal mice. Next, we investigated the low expression of IL-12p70, IL-12 receptors and IL-18 receptors in irradiated and old mice. Also, the decrease of natural killer cell activity was intensified in the irradiated mice, showing lower than values to those of old mice. Interestingly, in irradiated mice, the absolute numbers and the percentages of natural killer (NK) cells was extremely decreased. But the absolute numbers of Th cells and cytotoxic T (Tc) cells in old mice were significantly decreased. In conclusion, an immunological imbalance by the whole-body irradiation of 5Gy induces to persist in the long term, resulting in the similar results with aging. Our results suggest that the downregulation of the Th1-like immune response shown in old mice rapidly occurred through exposure of ionizing radiation.
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Affiliation(s)
- Hae-Ran Park
- Radiation Biotechnology Research Division, Advanced Radiation Technology Institute, Jeongeup Campus of Korea Atomic Energy Research Institute (KAERI), 1266 Sinjeong-dong, Jeongeup-si Jeonbuk 580-185, Republic of Korea
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