CALL FOR PAPERS Regulation of Cardiovascular Functions by Eicosanoids and Other Lipid Mediators ANG II stimulates phospholipase D through PKC activation in VSMC: implications in adhesion, spreading, and hypertrophy

Parmentier, Jean-Hugues, Zoran Pavicevic, and Kafait U. Malik. ANG II stimulates phospholipase D through PKC activation in VSMC: implications in adhesion, spreading, and hypertrophy. Am J Physiol Heart Circ Physiol 290: H46–H54, 2006. First published August 19, 2005; doi:10.1152/ajpheart.00769.2005.—ANG II stimulates phospholipase D (PLD) activity and growth of vascular smooth muscle cells (VSMC). The atypical protein kinase C(PKC ) plays a central role in the regulation of cell survival and proliferation. This study was conducted to determine the relationship between ANG II-induced activation of PKC and PLD and their implication in VSMC adhesion, spreading, and hypertrophy. ANG II stimulated PKC activity with maximal activation at 30 s followed by a decline in its activity to 45% above basal at 5 min. Inhibition of PKC activity with a myristoylated pseudosubstrate peptide or overexpression of a kinase-inactive form of PKC decreased ANG II-induced PLD activity. Moreover, depletion of PKC with selective antisense oligonucleotides also decreased ANG II-induced PLD activity. Interaction between PLD2 and PKC in VSMC was detected by coimmunoprecipitation. ANG II-induced PLD activity was inhibited by the primary alcohol n-butanol but not the tertiary alcohol t-butanol. The functional significance of PKC and PLD2 in VSMC adhesion, spreading, and hypertrophy was investigated. Inhibition of PKC and PLD2 activity or expression attenuated VSMC adhesion to collagen I and ANG II-induced cell spreading and hypertrophy. These results demonstrate that ANG II-induced PLD activation is regulated by PKC and suggest a crucial role of PKC -dependent PLD2 in VSMC functions such as adhesion, spreading, and hypertrophy, which are associated with the pathogenesis of atherosclerosis and malignant hypertension.