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Xu J, Li D, Lu Y, Zheng TY. Aβ monomers protect lens epithelial cells against oxidative stress by upregulating CDC25B. Free Radic Biol Med 2021; 175:161-170. [PMID: 34478836 DOI: 10.1016/j.freeradbiomed.2021.08.242] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 12/30/2022]
Abstract
Our previous studies showed high β-amyloid (Aβ) expression levels in the nuclei of the lens epithelial cells (LECs) of healthy subjects and revealed that Aβ monomers could protect LECs from oxidative damage. Here, we further explored the mechanism by which Aβ monomers act as transcription factors to regulate the oxidative stress of LECs through high-throughput studies. First, we compared the Aβ-binding sites in the lens epithelia (LE) of age-related cataract patients with those in the LE of healthy donors via chromatin immunoprecipitation-sequencing (ChIP-seq), and we identified comparable numbers (1648 and 1445, respectively) of Aβ peaks. Then, the KEGG tool was used for gene function enrichment analysis of these genes, which were more highly enriched in healthy LE. Combining the literature review with these KEGG analysis results, in the current study, we chose four target genes related to oxidative stress, namely, CDC25B, SOS2, CTNNA1 and Cox6a1. Then, ChIP-PCR assays, dual-luciferase reporter assays, real-time PCR and Western blotting were performed to validate the regulatory effects of Aβ on these targets. Our data suggested that Aβ monomers could upregulate the mRNA and protein expression levels of CDC25B in LECs. We also confirmed that Aβ monomers could activate the Akt/Nrf2 pathway in a CDC25B-dependent manner by knockdown experiments in cultured LECs. Furthermore, we performed functional verification of the CDC25B-mediated protective effects of Aβ monomers against oxidative stress. We observed that Aβ monomers significantly improved the antioxidant capacity (the GSH level, SOD activity and total antioxidant capacity) and decreased the oxidative stress (the ROS and MDA levels) of LECs, while CDC25B knockdown decreased the antioxidant effects of Aβ, disrupting redox homeostasis. Therefore, we propose that Aβ monomers activate the Akt/Nrf2 pathway by upregulating CDC25B expression, increase various downstream antioxidant enzyme levels, maintain peroxidation-antioxidant homeostasis in LECs, and prevent the cell damage caused by oxidative stress.
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Affiliation(s)
- Jie Xu
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd., Shanghai 200031, China; Eye Institute, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd., Shanghai 200031, China; Key Laboratory of Myopia, Ministry of Health, 83 Fenyang Rd., Shanghai 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, 83 Fenyang Rd., Shanghai 200031, China
| | - Dan Li
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd., Shanghai 200031, China; Eye Institute, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd., Shanghai 200031, China; Key Laboratory of Myopia, Ministry of Health, 83 Fenyang Rd., Shanghai 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, 83 Fenyang Rd., Shanghai 200031, China
| | - Yi Lu
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd., Shanghai 200031, China; Eye Institute, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd., Shanghai 200031, China; Key Laboratory of Myopia, Ministry of Health, 83 Fenyang Rd., Shanghai 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, 83 Fenyang Rd., Shanghai 200031, China.
| | - Tian-Yu Zheng
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd., Shanghai 200031, China; Eye Institute, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd., Shanghai 200031, China; Key Laboratory of Myopia, Ministry of Health, 83 Fenyang Rd., Shanghai 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, 83 Fenyang Rd., Shanghai 200031, China.
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Yamamoto N, Takeda S, Hatsusaka N, Hiramatsu N, Nagai N, Deguchi S, Nakazawa Y, Takata T, Kodera S, Hirata A, Kubo E, Sasaki H. Effect of a Lens Protein in Low-Temperature Culture of Novel Immortalized Human Lens Epithelial Cells (iHLEC-NY2). Cells 2020; 9:cells9122670. [PMID: 33322631 PMCID: PMC7764252 DOI: 10.3390/cells9122670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/27/2020] [Accepted: 12/11/2020] [Indexed: 11/24/2022] Open
Abstract
The prevalence of nuclear cataracts was observed to be significantly higher among residents of tropical and subtropical regions compared to those of temperate and subarctic regions. We hypothesized that elevated environmental temperatures may pose a risk of nuclear cataract development. The results of our in silico simulation revealed that in temperate and tropical regions, the human lens temperature ranges from 35.0 °C to 37.5 °C depending on the environmental temperature. The medium temperature changes during the replacement regularly in the cell culture experiment were carefully monitored using a sensor connected to a thermometer and showed a decrease of 1.9 °C, 3.0 °C, 1.7 °C, and 0.1 °C, after 5 min when setting the temperature of the heat plate device at 35.0 °C, 37.5 °C, 40.0 °C, and 42.5 °C, respectively. In the newly created immortalized human lens epithelial cell line clone NY2 (iHLEC-NY2), the amounts of RNA synthesis of αA crystallin, protein expression, and amyloid β (Aβ)1-40 secreted into the medium were increased at the culture temperature of 37.5 °C compared to 35.0 °C. In short-term culture experiments, the secretion of Aβ1-40 observed in cataracts was increased at 37.5 °C compared to 35.0 °C, suggesting that the long-term exposure to a high-temperature environment may increase the risk of cataracts.
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Affiliation(s)
- Naoki Yamamoto
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan; (N.Y.); (S.T.); (N.H.); (E.K.)
- Research Promotion and Support Headquarters, Fujita Health University, Aichi 470-1192, Japan;
| | - Shun Takeda
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan; (N.Y.); (S.T.); (N.H.); (E.K.)
| | - Natsuko Hatsusaka
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan; (N.Y.); (S.T.); (N.H.); (E.K.)
| | - Noriko Hiramatsu
- Research Promotion and Support Headquarters, Fujita Health University, Aichi 470-1192, Japan;
| | - Noriaki Nagai
- Faculty of Pharmacy, Kindai University, Osaka 577-8502, Japan; (N.N.); (S.D.)
| | - Saori Deguchi
- Faculty of Pharmacy, Kindai University, Osaka 577-8502, Japan; (N.N.); (S.D.)
| | - Yosuke Nakazawa
- Division of Hygienic Chemistry, Faculty of Pharmacy, Keio University, Tokyo 105-8512, Japan;
| | - Takumi Takata
- Radiation Biochemistry, Division of Radiation Life Science, Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka 590-0494, Japan;
| | - Sachiko Kodera
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Aichi 466-8555, Japan; (S.K.); (A.H.)
| | - Akimasa Hirata
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Aichi 466-8555, Japan; (S.K.); (A.H.)
- Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Aichi 466-8555, Japan
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan; (N.Y.); (S.T.); (N.H.); (E.K.)
| | - Hiroshi Sasaki
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan; (N.Y.); (S.T.); (N.H.); (E.K.)
- Correspondence: ; Tel.: +81-762-286-2211
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Mano Y, Otake H, Shibata T, Kubo E, Sasaki H, Nagai N. Enhancement of Amyloid β 1-43 Production in the Lens Epithelium of Japanese Type 2 Diabetic Patients. Biomedicines 2020; 8:biomedicines8040087. [PMID: 32294928 PMCID: PMC7235728 DOI: 10.3390/biomedicines8040087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/10/2020] [Accepted: 04/11/2020] [Indexed: 11/18/2022] Open
Abstract
We investigated whether the accumulation of amyloid β-protein (Aβ) is enhanced in the lenses of diabetic patients. Lens epithelium samples were collected from Japanese patients during cataract surgery, and the Aβ levels and gene expression of Aβ-producing and -degrading enzymes in the samples were measured by ELISA and real-time RT-PCR, respectively. The Aβ1–43 levels in lenses of non-diabetic patients were low (0.11 pmol/g protein), while the levels in lenses of diabetic patients were significantly (6-fold) higher. Moreover, the Aβ1–43/total-Aβ ratio in the lenses of diabetic patients was also significantly higher than non-diabetic patients (p < 0.05). In addition, the mRNA levels for Aβ-producing enzymes were also enhanced in the lenses of diabetic patients. In contrast to the results for Aβ-producing enzymes, the mRNAs for the Aβ-degrading enzymes in the lenses of diabetic patients were significantly lower than in non-diabetic patients (p < 0.05). Furthermore, Aβ1–43/total-Aβ ratio in lenses was found to increase with plasma glucose level. In conclusion, these results suggest that high glucose levels cause both an increase in Aβ production and a decrease in Aβ degradation, and these changes lead to the enhancement in Aβ1–43 accumulation in the lenses of diabetic patients. These findings are useful for developing therapies for diabetic cataracts and for developing anti-cataract drugs.
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Affiliation(s)
- Yu Mano
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan; (Y.M.); (H.O.)
| | - Hiroko Otake
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan; (Y.M.); (H.O.)
| | - Teppei Shibata
- Department of Ophthalmology, Kanazawa Medical University, 1-1 Daigaku Uchinada-machi, Kahoku-gun, Ishikawa 920-0293, Japan; (T.S.); (E.K.); (H.S.)
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, 1-1 Daigaku Uchinada-machi, Kahoku-gun, Ishikawa 920-0293, Japan; (T.S.); (E.K.); (H.S.)
| | - Hiroshi Sasaki
- Department of Ophthalmology, Kanazawa Medical University, 1-1 Daigaku Uchinada-machi, Kahoku-gun, Ishikawa 920-0293, Japan; (T.S.); (E.K.); (H.S.)
| | - Noriaki Nagai
- Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan; (Y.M.); (H.O.)
- Correspondence: ; Tel.: +81-6-4307-3638
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Hamada N, Azizova TV, Little MP. Glaucomagenesis following ionizing radiation exposure. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2019; 779:36-44. [PMID: 31097150 PMCID: PMC10654893 DOI: 10.1016/j.mrrev.2019.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 01/02/2019] [Accepted: 01/07/2019] [Indexed: 12/31/2022]
Abstract
Glaucoma is a group of optic neuropathies causing optic nerve damage and visual field defects, and is one of the leading causes of blindness. Nearly a century has passed since the first report of glaucoma manifested following ionizing radiation therapy of cancers. Nevertheless, associations between glaucoma and radiation exposures, a dose response relationship, and the mechanistic underpinnings remain incompletely understood. Here we review the current knowledge on manifestations and mechanisms of radiogenic glaucoma. There is some evidence that neovascular glaucoma is manifest relatively quickly, within a few years after high-dose and high dose-rate radiotherapeutic exposure, but little evidence of excess risks of glaucoma after exposure to much lower doses or dose rates. As such, glaucoma appears to have some of the characteristics of a tissue reaction effect, with a threshold of at least 5 Gy but possibly much higher.
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Affiliation(s)
- Nobuyuki Hamada
- Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwado-kita, Komae, Tokyo, 201-8511, Japan.
| | - Tamara V Azizova
- Clinical Department, Southern Urals Biophysics Institute, Ozyorskoe Shosse 19, Ozyorsk Chelyabinsk Region, 456780, Russia.
| | - Mark P Little
- Radiation Epidemiology Branch, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, MSC 9778, Bethesda, MD, 20892-9778, USA.
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