The physiological significance of eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) on lipid accumulation in rat liver under protein deprivation.

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07747
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Food science
• Research Institution: Nippon Medical School
• Principal Investigator: TOYOSHIMA Yuka (豊島由香) 日本医科大学, 先端医学研究所, 講師 (70516070)
• Research Collaborator: KATO Hisanori
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 肝臓 / タンパク質 / 中性脂肪 / 翻訳抑制因子 / 代謝

Outline of Final Research Achievements

We previously elucidated that protein deprivation increased 4E-BP1 level, leading to fatty liver in rats. In this study, we examined how the increase in 4E-BP1 contributes to lipid accumulation in rat liver under protein deprivation. Overexpression of 4E-BP1 in the liver did not change hepatic triglyceride (TG) level in rats, regardless of nutritional status, suggesting that the increase in 4E-BP1 by itself is insufficient to increase TG level in rat liver. We also found that 4E-BP1 is involved in the suppression of fatty acid oxidation, leading to the increase in TG level in rat liver under protein deprivation. These results suggest that 4E-BP1 could regulate not only translation but also lipid metabolism in rat liver.

Free Research Field

食品科学

Academic Significance and Societal Importance of the Research Achievements

これまで、翻訳抑制因子4E-BP1が糖・脂質代謝を調節しているかは不明であったが、本研究によって、4E-BP1がタンパク質翻訳調節だけでなく、脂質代謝調節を担うことを明らかにすることができた。さらに本研究を発展させれば、翻訳調節を介した新しい肝臓脂質蓄積機構の提唱につながると期待している。また、低栄養によって発症する脂肪肝を“改善”するだけでなく、“予防”するための新しい知見が得られ、我が国で増加の一途をたどっている脂肪肝の罹患率を減らすことに貢献できるとも期待している。