Adrenomedullin inhibits angiotensin II-induced oxidative stress via Csk-mediated inhibition of Src activity.
We have demonstrated that adrenomedullin (AM) protects against angiotensin II (ANG II)-induced cardiovascular damage through the attenuation of increased oxidative stress observed in AM-deficient mice. However, the mechanism(s) that underlie this activity remain unclear. To address this question, we investigated the effect of AM on ANG II-stimulated reactive oxygen species (ROS) production in cultured rat aortic vascular smooth muscle cells (VSMCs). ANG II markedly increased ROS production through activation of NADPH oxidase. This effect was significantly attenuated by AM in a concentration-dependent manner. This effect was mimicked by dibutyl-cAMP and blocked by pretreatment with N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide hydrochloride (H-89), a protein kinase A inhibitor, and CGRP(8-37), an AM/CGRP receptor antagonist. This inhibitory effect of AM was also lost following the expression of a constitutively active Src. Moreover, AM intersected ANG II signaling by inducing COOH-terminal Src kinase (Csk) activation that, in turn, inhibits Src activation. These data, for the first time, demonstrate that AM attenuates the ANG II-induced increase in ROS in VSMCs via activation of Csk, thereby inhibiting Src activity.
Liu
Jing
J
Departments of Endocrinology and Nephrology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
Shimosawa
Tatsuo
T
Matsui
Hiromitsu
H
Meng
Fanyin
F
Supowit
Scott C
SC
DiPette
Donald J
DJ
Ando
Katsuyuki
K
Fujita
Toshiro
T
D053607:Adrenomedullin / Q000494:pharmacology*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001013:Aorta, Thoracic / Q000166:cytology; D000081247:CSK Tyrosine-Protein Kinase; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014443:Tyrosine / Q000378:metabolism; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D019061:src-Family Kinases / Q000378:metabolism
D000975:Antioxidants; D010446:Peptide Fragments; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; C058636:calcitonin gene-related peptide (8-37); D053607:Adrenomedullin; D014443:Tyrosine; D000242:Cyclic AMP; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D015740:Calcitonin Gene-Related Peptide