Astrocytes in Atp1a2-deficient heterozygous mice exhibit hyperactivity after induction of cortical spreading depression

Research Project

Project/Area Number	18K07373
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 51030:Pathophysiologic neuroscience-related
Research Institution	Jichi Medical University
Principal Investigator	SUGIMOTO Hiroki 自治医科大学, 医学部, 助教 (70515866)
Project Period (FY)	2018-04-01 – 2022-03-31
Project Status	Completed (Fiscal Year 2021)
Budget Amount *help	¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000) Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000) Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords	片頭痛 / マウス / カルシウムイメージング / G-CaMP7 / 家族性片麻痺性片頭痛２型 / ナトリウムポンプ / G-CaMP / CSD
Outline of Final Research Achievements	The ATP1A2 coding a2 subunit of Na,K-ATPase, which is predominantly located in astrocytes, is a causative gene of familial hemiplegic migraine type 2 (FHM2). FHM2 model mice (Atp1a2tmCKwk/+) are susceptible to cortical spreading depression (CSD), which is profoundly related to migraine aura and headache. However, astrocytic properties during CSD have not been examined in FHM2 model mice. Using Atp1a2tmCKwk/+ crossed with transgenic mice expressing G-CaMP7 in cortical neurons and astrocytes (Atp1a2+/-), we analyzed the changes in Ca2+concentrations during CSD. The propagation speed of Ca2+ waves and the percentages of astrocytes with elevated Ca2+concentrations in Atp1a2+/- were higher than those in wild-type mice. Increased percentages of astrocytes with elevated Ca2+ concentrations in Atp1a2+/- may contribute to FHM2 pathophysiology.
Academic Significance and Societal Importance of the Research Achievements	Naポンプα2サブユニットの変異は、家族性片麻痺性片頭痛２型（FHM2）の原因であり、同遺伝子欠損マウスで明らかにした大脳皮質アストロサイトの活動異常は、FHM2の病態解明に大いに役立つと考えられる。さらにアストロサイトの活動異常は、２型以外のFHMでも見られており、FHMの共通基盤としてアストロサイトの活動異常が存在することを示唆する。