Tyrosine Phosphorylation of Caveolin 1 by Oxidative Stress Is Reversible and Dependent on the c-src Tyrosine Kinase but Not Mitogen-Activated Protein Kinase Pathways in Placental Artery Endothelial Cells

Acute H 2 O 2 exposure to placental artery endothelial cells induced an array of tyrosine-phosphorylated proteins, including caveolin 1 (CAV1) rapid and transient tyr 14 phosphorylated in a time- and concentration-dependent manner. Basal tyr 14 phosphorylated CAV1 was primarily located at the edges of cells and associated with actin filaments. Phosphorylated CAV1 was markedly increased and diffused with the disorganization of actin filaments at 20 min, disappeared at 120 min treatment with 0.2 mM H 2 O 2 . Treatment with H 2 O 2 also disorganized actin filaments and changed cell shape in a time-dependent manner. Pretreatment with antioxidants catalase completely, whereas the other tested superoxide dismutase, N-acetyl- l -cysteine and sodium formate partially attenuated H 2 O 2 -induced CAV1 phosphorylation in a concentration-dependent manner. Acute treatment with H 2 O 2 activated multiple signaling pathways, including the mitogen-activated protein kinases (MAPK) members (MAPK3/1-ERK2/1, MAPK8/9-JNK1/2, and MAPK11-p38 mapk ) and the c-src tyrosine kinase (CSK). Pharmacological studies demonstrated that, among these pathways, only the blockade of CSK activation abolished H 2 O 2 -induced CAV1 phosphorylation. Additionally, H 2 O 2 -induced CAV1 phosphorylation was reversible rapidly (