Endothelial cell ER stress and Ca^<2+> signaling pathway

• Project/Area Number: 14570652
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Circulatory organs internal medicine
• Research Institution: Hamamatsu University School of Medicine
• Principal Investigator: WATANABE Hirosi Hamamatsu University School of Medicine, Clinical Pharmacology and Ther apeutics, Professor, 医学部, 教授 (50262803)
• Co-Investigator(Kenkyū-buntansha): KATOH Hideki Hamamatsu University School of Medicine, Internal Medicine III, Assistant Prof., 医学部, 助手 (80314029) ; SATOH Hirosi Hamamatsu University School of Medicine, Internal Medicine III, Assistant Prof., 医学部附属病院, 助手 (30293632)
• Project Period (FY): 2002 – 2004
• Project Status: Completed (Fiscal Year 2004)
• Budget Amount: ¥3,400,000 (Direct Cost: ¥3,400,000); Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000); Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000); Fiscal Year 2002: ¥2,400,000 (Direct Cost: ¥2,400,000)
• Keywords: apoptosis / endothelial cell / calcium / ER stress / caspase / Akt / PI3キナーゼ

Research Abstract

Apoptosis of endothelial cells (ECs) is now regarded to be an initial step inducing atherosclerosis. Recent studies have reported that the depletion of endoplasmic reticulum (ER) Ca^<2+> stores plays an important role in apoptosis. Caspase-12 is a key signal to lead ER stress-induced apoptosis. However, it is not known whether the depletion of ER Ca^<2+> is linked to caspase-12 signaling in ECs. Here we have investigated the interaction of Ca^<2+> signaling and caspase-12 cleavage in apoptosis of cultured porcine aortic ECs. Cytosolic Ca^<2+> concentration ([Ca^<2+>]i) was measured using fura-2/AM. Apoptosis was assessed by DNA ladder formation, and cleavage of caspase-12 by Western blotting. Thapsigargin (6μM), an inhibitor of the ER-associated Ca^<2+>-ATPase, increased [Ca^<2+>]i (F340/F380 ratio 0.717±0.137 to 6.133±0.710 : p<0.001) and induced persistent ER calcium depletion, cleavage of caspase-12 and apoptosis. Bradykinin (10 nM) increased [Ca^<2+>]i (F340/F380 ratio 0.717±0.053 to 6.133±0.528 : p<0.001) but induced neither cleavage of caspase-12 nor apoptosis. However, when ECs were treated with BAPTA/AM (100μM), BK caused the Ca^<2+> depletion of ER and apoptosis without the cleavage of caspase-12. Moreover non-selective caspase inhibitor, zVAD-fmk (100μM), inhibited apoptosis and cleavage of caspase-12 in TG-stimulated ECs, and calpain inhibitor, MDL 28170 (120μM), inhibited cleavage of caspase-12 but not inhibited apoptosis. These results suggested that the increase of [Ca^<2+>]i did not play an important role in inducing apoptosis in ECs, and ER Ca^<2+> depletion induced apoptosis, which is independent from caspase-12 linked signaling pathway.

Research Products

• [Journal Article] Modification of sarcoplasmic reticulum (SR) Ca^<2+> release by FK506 induces defective excitationcontraction coupling only when SR Ca^<2+> recycling is disturbed (2005)
  • Author(s): Yoshihara S, Satoh H, Saotome M, Katoh H, Terada H, Watanabe H, Hayashi H
  • Journal Title: Can.J.Physiol.Pharmacol. 83 Pages: 357-366
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Akt and Ca^<2+> signaling in endothelial cells. (2004)
  • Author(s): Ozeki M, Watanabe H, Luo JH, Nakano T, Takeuchi K, Kureishi Y, Ito M, Nakano T, Ohashi K, Hayashi H.
  • Journal Title: Molecular and Cellular Biochemistry 259 Pages: 169-176
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Nitric oxide : inhibitory effects on endothelial cell calcium signaling, prostaglandin I_2 production and nitric oxide synthase expression. (2004)
  • Author(s): Takeuchi K, Watanabe H, Tran QK, Ozeki M, Sumi D, Hayashi T, Iguchi A, Ignarro LJ, Ohashi K, Hayashi H
  • Journal Title: Cardiovascular Research 62 Pages: 194-201
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Akt and Ca^<2+> signaling in endothelial cells (2004)
  • Author(s): Ozeki M, Watanabe H, Luo JH, Nakano T, Takeuchi K, Kureishi Y, Ito M, Nakano T, Ohashi K, Hayashi H.
  • Journal Title: Molecular and Cellular Biochemistry 259 Pages: 169-176
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Nitric oxide : inhibitory effects on endothelial cell calcium signaling, prostaglandin I_2 production and nitric oxide synthase expression (2004)
  • Author(s): Takeuchi K, Watanabe H, Tran QK, Ozeki M, Sumi D, Hayashi T, Iguchi A, Ignarro LJ, Ohashi K, Hayashi H
  • Journal Title: Cardiovascular Research 62 Pages: 194-201
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Akt and Ca^<2+> signaling in endothelial cells. (2004)
  • Author(s): Ozeki M, Watanabe H, Luo JH, Nakan o T, Takeuchi K, Kureishi Y, Ito M, Na kano T, Ohashi K, Hayashi H.
  • Journal Title: MOLECULAR AND CELLULAR BIOCHEMISTRY 259 Pages: 169-176
• [Journal Article] Nitric oxide : inhibitory effects on endothelial cell calcium signaling, prostaglandin 12 production and nitric oxide synthase expression. (2004)
  • Author(s): Takeuchi K, Watanabe H, Tran QK, Ozeki M, Sumi D, Hayashi T, Iguchi A, Ignarro LJ, Ohashi K, Hayashi H
  • Journal Title: CARDIOVASCULAR RESEARCH 62 Pages: 194-201
• [Journal Article] Effects of cytochrome P450 inhibitors on agonistinduced Ca^<2+> responses and production of NO and PGI_2 in vascular endothelial cells (2003)
  • Author(s): Takeuchi K, Watanabe H, Tran QK, Ozeki M, Uehara A, Katoh H, Satoh H, Terada H, Ohashi K, Hayashi H
  • Journal Title: Molecular and Cellular Biochemistry 248 Pages: 129-134
  • Description: 「研究成果報告書概要(和文)」より