Histological analysis of novel transforming mechanisms in adipocytes

2021 Fiscal Year Final Research Report

• Project/Area Number: 17K08508
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: General anatomy (including histology/embryology)
• Research Institution: Yamagata University
• Principal Investigator: Nakano Tomoyuki 山形大学, 医学部, 准教授 (00333948)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Keywords: 脂肪組織 / ベージュ化 / ジアシルグリセロールキナーゼ / 高脂肪食 / 寒冷暴露

Outline of Final Research Achievements

Diacylglycerol kinase (DGK) is an enzyme that converts DG to phosphatidic acid. DG is known as an intermediate product for triglyceride synthesis, but also is known as a lipidic second messenger. Thus, DG serves as a hub between energy metabolism and intracellular signaling. DGKe resides in the endoplasmic reticulum (ER). Since ER is known as a central site for lipid synthesis, current study focused on DGKe using its knock out mice. Two animal experiments were conducted in this project. One experiment revealed that beige adipogenesis was induced in the epididymal white adipose tissue（WAT） of DGKe-KO mice under long term High fat diet（HFD）） feeding. The other experiment showed that DGKe-KO mice was susceptible to cold exposure. To compensate body heat loss, beige adipogenesis was induced in inguinal WAT. Present projected concluded that stress conditions in adipose tissue such as HFD feeding and cold exposure, DGKe-deletion confers susceptibility to adipose tissue remodeling.

Free Research Field

解剖学一般

Academic Significance and Societal Importance of the Research Achievements

白色脂肪組織中に褐色脂肪細胞が誘導される褐色化は、肥満治療の観点で注目を集めているが、脂肪細胞の形質転換メカニズムという基礎的な、解剖学的に興味深い現象である。本研究プロジェクトの結果から、高エネルギー条件や寒冷環境において、DGKe欠損によるDG代謝の低下が褐色化を促進するという新規メカニズムが明らかとなった。特に、高エネルギー条件においては、DGKeと同じく小胞体に局在するシクロオキシゲナーゼ2依存的に褐色化が生じることは、小胞体における脂質代謝が褐色化に影響を与える点で興味深い知見である。