心筋特異的(プロ)レニン受容体欠損により発症する心筋症の病態解明と標的治療の開発

• Project/Area Number: 22790724
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Circulatory organs internal medicine
• Research Institution: Keio University
• Principal Investigator: 木内 謙一郎 Keio University, 医学部, 助教 (50528578)
• Project Period (FY): 2010
• Project Status: Completed (Fiscal Year 2011)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2011: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2010: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• Keywords: (プロ)レニン受容体 / レニン・アンジオテンシン系 / オートファジー

Research Abstract

【目的】2002年にヒト腎臓からクローニングされた(プロ)レニン受容体[(P)RR]の遺伝子配列はV-ATPaseのVo sectorと局在を共にする蛋白であるATP6AP2と同一であり、アミノ酸配列は(P)RRの膜貫通ドメインを含むC末端側がATP6AP2であった。しかし、V-ATPaseはオルガネラの酸性環境の維持に必須であることが知られている一方で、ATP6AP2の生理的な役割は不明であった。
【方法】我々はFloxed(P)RR transgenic mouse由来の胎児線維芽細胞と心筋細胞特異的発現Cre発現マウスとの交配によって得た心筋特異的欠損モデルマウスを用いて(P)RR/ATP6AP2の生理的な役割を検討した。
【研究実績の概要】Floxed(P)RRマウスより採取した胎児線維芽細胞にCreアデノウイルスベクターを感染させ(P)RRを欠損させたところ、Vo sector選択的にサブユニットのタンパク発現の減少を認め、オルガネラの酸性環境が障害されていた。心筋特異的(P)RR欠損マウスは、生後約3週間で拡張型心筋症様の心不全を発症し死亡した。心筋組織において核周囲の著明な空胞変性と線維化を認め、これらの空胞はMulti-vesicular bodyやautophagosomeから構成され、後期エンドソーム/ライソソームのマーカーであるRab7、Lamp-2が陽性であった。更に心臓組織のLC3-IIやp62のタンパク発現亢進を認め、autophagosomeの増加が示唆された。オルガネラの酸性化障害が同様な細胞変化を起こすかを検討するため、BafilomycinおよびChloroquineをラット初代培養心筋細胞に投与したところ、両薬剤ともにRab7陽性の空胞形成が認められた。以上よりオルガネラの酸性化障害が後期エンドソーム/ライソソームの蓄積をもたらしていると考えられた。

Research Products

• [Journal Article] The (pro)renin receptor/ATP6AP2 is essential for vacuolar H+-ATPase assembly in murine cardiomyocytes (2010)
  • Author(s): Kinouchi K, et al.
  • Journal Title: Circ Res. Volume: 107 Pages: 30-34
  • Peer Reviewed
• [Journal Article] Effects of telmisartan on arterial stiffness assessed by the cardio-ankle vascular index in hypertensive patients. (2010)
  • Author(s): Kinouchi K, et al.
  • Journal Title: Kidney Blood Press Res. Volume: 33 Pages: 304-312
  • Peer Reviewed
• [Journal Article] Aliskiren inhibits intracellular angiotensin II levels without affecting (pro)renin receptor signals in human podocytes. (2010)
  • Author(s): Sakoda M, et al.
  • Journal Title: Am J Hypertens Volume: 23 Pages: 575-580
  • Peer Reviewed
• [Journal Article] Renoprotective effects of mineralocorticoid receptor blockade in heminephrectomized (pro)renin receptor transgenic rats. (2010)
  • Author(s): Mizuguchi Y, et al.
  • Journal Title: Clin Exp Pharmacol Physiol. Volume: 37 Pages: 569-573
  • Peer Reviewed
• [Journal Article] Add-on blockade of (pro)renin receptor in imidapril-treated diabetic SHRsp. (2010)
  • Author(s): Seki Y, et al.
  • Journal Title: Front Biosci. Volume: 2 Pages: 972-979
  • Peer Reviewed
• [Journal Article] New approaches to blockade of the renin-angiotensin-aldosterone system : characteristics and usefulness of the direct renin inhibitor aliskiren. (2010)
  • Author(s): Ichihara A, et al.
  • Journal Title: J Pharmacol Sci. Volume: 113 Pages: 296-300
  • Peer Reviewed
• [Journal Article] Blood pressure-independent effect of candesartan on cardio-ankle vascular index in hypertensive patients with metabolic syndrome. (2010)
  • Author(s): Bokuda K, et al.
  • Journal Title: Vasc Health Risk Manag. Volume: 6 Pages: 571-578
  • Peer Reviewed
• [Journal Article] Involvement of activated prorenin in the pathogenesis of slowly progressive nephropathy in the non-clipped kidney of two kidney, one-clip hypertension. (2010)
  • Author(s): Ryuzaki M, et al.
  • Journal Title: Hypertens Res. Volume: 34 Pages: 301-307
  • Peer Reviewed
• [Presentation] 細胞内酸性環境を維持する(プロ)レニン受容体の生理的な機能 (2011)
  • Author(s): 木内謙一郎
  • Organizer: 第40回日本心脈管作動物質学会
  • Place of Presentation: 高松
• [Presentation] Cardiomyocyte-specific Ablation of (Pro)renin Receptor Caused Fulminant Heart Failure Due To Disruption of Intracellular Acidification (2010)
  • Author(s): Kinouchi K, et al.
  • Organizer: AHA Scientific Sessions
  • Place of Presentation: Chicago, USA
  • Year and Date: 2010-11-16
• [Presentation] 心筋細胞特異的(プロ)レニン受容体ノックアウトマウスの解析 (2010)
  • Author(s): 木内謙一郎
  • Organizer: 第33回日本高血圧学会総会
  • Place of Presentation: 福岡
  • Year and Date: 2010-10-16
• [Presentation] (Pro)renin receptor is essential for cell survival in murine cardiomyocytes. (2010)
  • Author(s): Kinouchi K, et al.
  • Organizer: 64^<th> Annual High Blood Pressure Research Conference of the American Heart Association.
  • Place of Presentation: Washington, USA
  • Year and Date: 2010-10-14
• [Presentation] ATP6AP2/(Pro)renin receptor is essential for assembly of the V-ATPase in murine cardiomyocytes. (2010)
  • Author(s): Kinouchi K, et al.
  • Organizer: The 23^<rd> Scientific Meeting of the International Society of Hypertension.
  • Place of Presentation: Vancouver, Canada
  • Year and Date: 2010-09-29
• [Presentation] Comparative effects of telmisartan-based therapy and calcium channel blockers-based therapy on cardio-ankle vascular index in hypertensive patients (2010)
  • Author(s): Kinouchi K, et al.
  • Organizer: The 23^<rd> Scientific Meeting of the International Society of Hypertension.
  • Place of Presentation: Vancouver, Canada
  • Year and Date: 2010-09-29
• [Presentation] 細胞内小器官における(プロ)レニン受容体の生理機能の解明 (2010)
  • Author(s): 木内謙一郎
  • Organizer: 第53回日本腎臓学会学術総会
  • Place of Presentation: 神戸
  • Year and Date: 2010-06-18
• [Presentation] Physiological levels of prorenin and (pro)renin receptor influence the ZO-1 mRNA expression in human podocytes. (2010)
  • Author(s): Kinouchi K, et al.
  • Organizer: The 8^<th> International Podocytes Conference Bristol.
  • Place of Presentation: Bristol, UK
  • Year and Date: 2010-06-08
• [Presentation] Safety and benefits of a tablet combining losartan and hydrochlorothiazide in Japanese diabetic patients with hypertension. (2010)
  • Author(s): Kinouchi K, et al.
  • Organizer: The 12^<th> Asian Pacific Congress of Nephrology.
  • Place of Presentation: Seoul, Korea
  • Year and Date: 2010-06-06
• [Presentation] Effects of telmisartan on arterial stiffness assessed by the cardio-ankle vascular index in hypertensive patients. (2010)
  • Author(s): Kinouchi K, et al.
  • Organizer: The 12^<th> Asian Pacific Congress of Nephrology.
  • Place of Presentation: Seoul, Korea
  • Year and Date: 2010-05-06