| 研究課題/領域番号 |
20K11551
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| 研究機関 | お茶の水女子大学 |
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研究代表者 |
グホ サビン お茶の水女子大学, 理学部, 学部教育研究協力員 (30453179)
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| 研究分担者 |
宮本 泰則 お茶の水女子大学, ヒューマンライフイノベーション研究所, 教授 (50272737)
和気 秀文 順天堂大学, スポーツ健康科学部, 教授 (50274957)
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| 研究期間 (年度) |
2020-04-01 – 2024-03-31
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| キーワード | nanoplastics / oral exposure / heart rate / urine osmolality / area postrema / microglia morphology |
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| 研究実績の概要 |
Five weeks-old male Wistar rats (n=6 per group) were fed daily with 50 nm positively or negatively charged polystyrene nanoparticles (NPs) (12.5 mg/kg body weight) for two months. The analysis of their physical and biological parameters revealed a significant decrease in their heart rate and a substantial increase in their urine osmolality compared to control rats, suggesting that NPs exposure affects cardiovascular regulation and osmoregulation.
Immunofluorescence experiments performed with Iba-1 antibody to analyze microglial cells' morphology in the area postrema (AP), a blood-brain barrier-free cardiovascular center, revealed shorter branch length and fewer endpoints in rats exposed to NPs, suggesting that NPs exposure increased the reactivity of microglia in the AP.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
We confirmed the effects of chronic oral exposure to NPs on heart rate and urine osmolality found in FY2020 by repeating the experiment on a new batch of rats. We investigated microglial cell morphology in AP by immunofluorescence, confocal microscopy, and image analysis software on those rats. The whole process was time-consuming, but the data revealed an increased microglia reactivity in NP groups, suggesting an inflammatory condition in cardiovascular centers.
At the end of FY2021, we performed the exposure experiment on another batch of rats to collect brain tissues for future RNA extraction and further study the expression of inflammation-related genes.
Due to moving my laboratory to another university, we could not investigate the distribution of fluorescent NPs in the brain.
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| 今後の研究の推進方策 |
During FY2022
-1) the inflammatory status of the AP and other cardiovascular centers will be investigated at the molecular level. The expression of selected inflammatory markers and receptors, sensory and immune response receptors, and neuronal response-related genes in the blood-brain barrier-free areas will be investigated at a transcript level by using RT-qPCR on the total RNA extracted from the AP and other cardiovascular centers collected from the brain of rats chronically orally exposed to NPs in FY2021.
-2) the distribution of NPs will be assessed in AP and other cardiovascular centers of the brain. After an intravenous injection of F-NPs, the rat brain will be collected, frozen, sliced, and confocal microscopy will be used to observe F-NPs in various brain areas.
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| 次年度使用額が生じた理由 |
We could not perform the analysis of the distribution of fluorescent NP in the brain after intravenous injection during FY2021, therefore, the amount of money will be used to purchase the material needed for this experiment in FY2022 (ex. fluorescent NPs).
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