Angiotensin II-induced vascular smooth muscle cell migration and growth are mediated by cytochrome P450 1B1-dependent superoxide generation.
Cytochrome P450 1B1, expressed in vascular smooth muscle cells, can metabolize arachidonic acid in vitro into several products including 12- and 20-hydroxyeicosatetraenoic acids that stimulate vascular smooth muscle cell growth. This study was conducted to determine whether cytochrome P450 1B1 contributes to angiotensin II-induced rat aortic smooth muscle cell migration, proliferation, and protein synthesis. Angiotensin II stimulated migration of these cells, measured by the wound healing approach, by 1.78-fold; and DNA synthesis, measured by [(3)H]thymidine incorporation, by 1.44-fold after 24 hours; and protein synthesis, measured by [(3)H]leucine incorporation, by 1.40-fold after 48 hours. Treatment of vascular smooth muscle cells with the cytochrome P450 1B1 inhibitor 2,4,3',5'-tetramethoxystilbene or transduction of these cells with adenovirus cytochrome P450 1B1 small hairpin RNA but not its scrambled control reduced the activity of this enzyme and abolished angiotensin II- and arachidonic acid-induced cell migration, as well as [(3)H]thymidine and [(3)H]leucine incorporation. Metabolism of arachidonic acid to 5-, 12-, 15-, and 20-hydoxyeicosatetraenoic acids in these cells was not altered, but angiotensin II- and arachidonic acid-induced reactive oxygen species production and extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase activity were inhibited by 2,4,3',5'-tetramethoxystilbene and cytochrome P450 1B1 small hairpin RNA (shRNA) and by Tempol, which inactivates reactive oxygen species. Tempol did not alter cytochrome P450 1B1 activity. These data suggest that angiotensin II-induced vascular smooth muscle cell migration and growth are mediated by reactive oxygen species generated from arachidonic acid by cytochrome P450 1B1 and activation of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase.
Yaghini
Fariborz A
FA
Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
Song
Chi Young
CY
Lavrentyev
Eduard N
EN
Ghafoor
Hafiz U B
HU
Fang
Xiao R
XR
Estes
Anne M
AM
Campbell
William B
WB
Malik
Kafait U
KU
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000166:cytology; D002465:Cell Movement / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D019362:Cytochrome P-450 CYP2B1 / Q000187:drug effects / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012084:Renin-Angiotensin System / Q000502:physiology; D012680:Sensitivity and Specificity; D013481:Superoxides / Q000378:metabolism*
D011506:Proteins; D017382:Reactive Oxygen Species; D013481:Superoxides; D000804:Angiotensin II; D004247:DNA; D019362:Cytochrome P-450 CYP2B1