A novel mechanism of fatty liver by lipoprotein uptake

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02916
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 38050:Food sciences-related
• Research Institution: Meiji University
• Principal Investigator: Takenaka Asako 明治大学, 農学部, 専任教授 (40231401)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: protein deficiency / IGF-I / FGF21 / VLDL receptor

Outline of Final Research Achievements

The purpose of this study was to elucidate a new mechanism by which liver fat increases during protein deficiency. For this purpose, the following hypotheses were tested. “Increase in FGF21 during protein deficiency causes a decrease in muscle mass through a decrease in blood levels of IGF-I, resulting in the generation of excess energy. At the same time, VLDLR is highly expressed in the liver, and fat is accumulated in the liver by uptake of VLDL.” From the results of the research, we were able to clarify a new mechanism that "A decrease in the blood concentration of IGF-I during protein deficiency causes a decrease in muscle weight, and excess energy is taken up in the liver as sugar and accumulated as fat."

Free Research Field

nutritional biochemistry

Academic Significance and Societal Importance of the Research Achievements

タンパク質欠乏下において、体タンパク質合成の材料であるアミノ酸が不足していてもIGF-Iが存在すれば体タンパク質合成が活性化・維持されることを示した点、および肝臓VLDLR増加が必ずしも脂肪肝を引き起こさないことを示した点で、本研究は学術的意義のある成果を出すことができた。また、本研究で対象とするタンパク質欠乏時の肝臓脂肪増加は、筋肉量低下を伴う高齢者などにおける異所性脂肪蓄積のモデルとなる。異所性脂肪蓄積における筋肉量低下やIGF-I低下の意義を示すことで、その予防に貢献することが期待される。