title: An AT1-receptor antagonist and an angiotensin-converting enzyme inhibitor protect against hypoxia-induced apoptosis in human aortic endothelial cells through upregulation of endothelial cell nitric oxide synthase activity.
abstract: The protective effects and roles of AT1-receptor antagonists (AT1-RA) or angiotensin-converting enzyme inhibitors (ACEI) on vascular endothelial cell (EC) injury during hypoxia are not entirely known. Therefore, we investigated these effects and mechanisms in human aortic (HA) EC. DNA fragmentation, Lactate dehydrogenase (LDH) release, and caspase-3 activity were measured in cultured HAEC after exposure to hypoxia in the presence or absence of an AT1-RA (candesartan, CS) and/or an ACEI (temocaprilat, TC). Next, we investigated endothelial cell nitric oxide synthase (ecNOS) and inducible (i) NOS to determine the role of the bradykinin(BK)-NO pathway in the protective effect on ACEI and AT1-RA in the setting of hypoxia-induced apoptosis. Exposure to hypoxia increased DNA fragmentation in HAEC associated with the activation of caspase-3, but did not affect LDH release. In addition, hypoxia induced ecNOS mRNA but not mRNA iNOS. CS and/or TC reduced apoptosis induced by hypoxia in a dose-dependent manner, and significantly increased BK and ecNOS expression. This effect was attenuated by the kinin B2 receptor antagonist, HOE 140, and the NOS inhibitor, N-nitro-L-arginine methylester (L-NMMA). Hypoxia activates the pathway leading to apoptosis by enhancing caspase-3 activity. Both CS and TC can ameliorate hypoxia-induced apoptosis in HAEC through inhibiting caspase-3 activation by enhancing ecNOS activity, via the accumulation of BK.
authors.affiliation: First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Hiroki
authors.initials: H
authors.lastname: Manabe
authors.forename: Jun
authors.initials: J
authors.lastname: Ochiai
authors.forename: Noriko
authors.initials: N
authors.lastname: Fujita
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Takagi
authors.forename: Manabu
authors.initials: M
authors.lastname: Uemura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Naito
authors.forename: Norimasa
authors.initials: N
authors.lastname: Yoshida
authors.forename: Shigenori
authors.initials: S
authors.lastname: Oka
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yoshikawa
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D001011:Aorta; D017209:Apoptosis / Q000187:drug effects*; D001562:Benzimidazoles / Q000494:pharmacology*; D001713:Biphenyl Compounds; D001920:Bradykinin / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D009336:Necrosis; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D011725:Pyridines / Q000494:pharmacology; D013777:Tetrazoles / Q000494:pharmacology*; D013841:Thiazepines / Q000494:pharmacology*; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D001562:Benzimidazoles; D001713:Biphenyl Compounds; D007093:Imidazoles; D011725:Pyridines; D013777:Tetrazoles; D013841:Thiazepines; C073402:PD 123319; D019323:omega-N-Methylarginine; C069156:temocaprilat; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; C081643:candesartan; D001920:Bradykinin