Identification of miRNAs induced by low-dose methylmercury exposure and their roles in inflammatory responses using human aortic endothelial cells.

Rika MATSUYAMA; Athira NANDAKUMAR; Munekazu YAMAKUCHI; Saekhol BAKRI; Shiroh TANOUE; Mayumi TSUJI; Megumi YAMAMOTO; Teruto HASHIGUCHI; Chihaya KORIYAMA

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Identification of miRNAs induced by low-dose methylmercury exposure and their roles in inflammatory responses using human aortic endothelial cells.

Author: Rika MATSUYAMA ¹ ; Athira NANDAKUMAR ¹ ; Munekazu YAMAKUCHI ² ; Saekhol BAKRI ¹ ; Shiroh TANOUE ¹ ; Mayumi TSUJI ³ ; Megumi YAMAMOTO ⁴ ; Teruto HASHIGUCHI ² ; Chihaya KORIYAMA ¹
Author Information

1. Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences.
2. Department of Laboratory and Vascular Medicine, Kagoshima University Graduate School of Medical and Dental Sciences.
3. Department of Environment Health, University of Occupational and Environmental Health.
4. Department of Environment and Public Health, National Institute for Minamata Disease.
Publication Type:Journal Article
Keywords: Cyclooxygenase-2; Human aortic endothelial cells; Inflammation; Methylmercury; MicroRNAs
MeSH: Methylmercury Compounds/adverse effects*; Humans; MicroRNAs/genetics*; Endothelial Cells/metabolism*; Inflammation/genetics*; Cell Line; Aorta/drug effects*; Biomarkers/metabolism*
From:Environmental Health and Preventive Medicine 2025;30():93-93
CountryJapan
Language:English
Abstract: BACKGROUND:Exposure to methylmercury (MeHg) is predominantly attributed to consumption of marine products. However, the general population is exposed to low MeHg levels, which can induce chronic inflammation. Although some MeHg-related microRNAs (miRNAs) have been reported, their functions remain elusive. The objective of this study was to identify the miRNAs induced by low-level MeHg exposure in a human endothelial cell line (HAECs). This study aimed to determine the specific miRNAs induced by low-level MeHg exposure using a HAECs as a potential novel and sensitive biomarker. The roles of miRNAs in inflammatory processes have been examined.
METHODS:Using HAECs, a miRNA microarray assay was performed to identify miRNAs with altered expression upon exposure to a non-cytotoxic MeHg level (0.1 and 1.5 µM). The expression patterns of interleukin-6 and -8, cyclooxygenase 2 (COX-2), RelB, and prostaglandin E₂ (PGE₂) were examined after transfection of the identified miRNAs with mimics/inhibitors.
RESULTS:Although the microarray assay identified six MeHg-specific miRNAs, miR-3613-5p, upregulated by 0.1 and 1.5 µM MeHg exposures, demonstrated the best reproducibility in HAECs. Transfection with the miR-3613-5p mimic enhanced the MeHg-induced inflammatory responses, including PGE₂ and COX-2 protein levels, whereas the miR-3613-5p inhibitor suppressed these inflammatory responses.
CONCLUSION:This study observed that miR-3613-5p is induced by low-dose MeHg exposure, plays a crucial role in the inflammatory process, and could serve as a novel and sensitive biomarker for low-level MeHg exposure.