Kyaw Moe, Yoshizumi Masanori, Tsuchiya Koichiro, Kagami Shoji, Izawa Yuki, Fujita Yoshiko, Ali Nermin, Kanematsu Yasuhisa, Toida Kazunori, Ishimura Kazunori, Tamaki Toshiaki
Department of Pharmacology, The University of Tokushima School of Medicine, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
Mol Pharmacol. 2004 Apr;65(4):832-41. doi: 10.1124/mol.65.4.832.
Angiotensin II (Ang II) plays an important role in several cardiovascular diseases associated with vascular smooth muscle cell (VSMC) growth and migration. Src activity is known to be required for the migration of a number of cell types. p130Cas was reported to be essential for cell migration and actin filament reorganization. Mitogen-activated protein (MAP) kinases were also reported to be critical regulatory factors for growth and migration of VSMC. However, precise intracellular mechanisms involving c-Src, p130Cas, and MAP kinases in Ang II-stimulated migration of VSMC have not been well elucidated. Here we demonstrated that Ang II rapidly and significantly stimulated tyrosine phosphorylation of Src and Cas and their association in rat aortic smooth muscle cells (RASMC). Ang II-stimulated tyrosine phosphorylation of Src and Cas and activation of ERK1/2 and JNK, but not p38, were potently inhibited by Src family tyrosine kinase inhibitors, herbimycin A (HA) and PP2. Ang II-stimulated Src and Cas association, tyrosine phosphorylation of Cas, and activation of ERK1/2 and JNK were suppressed in kinase-inactive Src (KI Src)-overexpressed RASMC. Ang II-stimulated JNK activation but not ERK1/2 activation was blocked in substrate domain-deleted Cas (DeltaSD Cas)-overexpressed RASMC. In addition, HA, PP2, ERK1/2 inhibitor, 2'-amino-3'-methoxyflavone (PD98059) and JNK inhibitor, and anthra[1,9-cd]pyrazol-6(2H)-one (SP600125) significantly inhibited Ang II-stimulated migration of RASMC. Ang II-induced colocalization of Src and Cas and migration were inhibited in both KI Src- and DeltaSD Cas-overexpressed RASMC. These findings suggest that Src and Cas are essentially but differentially involved in Ang II-stimulated migration of VSMC through the activation of ERK1/2 and JNK.
血管紧张素II（Ang II）在与血管平滑肌细胞（VSMC）生长和迁移相关的多种心血管疾病中起重要作用。已知Src活性是多种细胞类型迁移所必需的。据报道，p130Cas对细胞迁移和肌动蛋白丝重组至关重要。有报道称丝裂原活化蛋白（MAP）激酶也是VSMC生长和迁移的关键调节因子。然而，在Ang II刺激的VSMC迁移中，涉及c-Src、p130Cas和MAP激酶的精确细胞内机制尚未得到充分阐明。在这里，我们证明Ang II在大鼠主动脉平滑肌细胞（RASMC）中迅速且显著地刺激Src和Cas的酪氨酸磷酸化及其结合。Src家族酪氨酸激酶抑制剂赫司特霉素A（HA）和PP2可有效抑制Ang II刺激的Src和Cas的酪氨酸磷酸化以及ERK1/2和JNK的激活，但不抑制p38的激活。在过表达激酶失活Src（KI Src）的RASMC中，Ang II刺激的Src和Cas结合、Cas的酪氨酸磷酸化以及ERK1/2和JNK的激活均受到抑制。在过表达底物结构域缺失Cas（DeltaSD Cas）的RASMC中，Ang II刺激的JNK激活被阻断，但ERK1/2激活未被阻断。此外，HA、PP2、ERK1/2抑制剂2'-氨基-3'-甲氧基黄酮（PD98059）和JNK抑制剂蒽[1,9-cd]吡唑-6(2H)-酮（SP600125）显著抑制Ang II刺激下RASMC的迁移。在过表达KI Src和DeltaSD Cas的RASMC中，Ang II诱导的Src和Cas共定位及迁移均受到抑制。这些发现表明，Src和Cas通过激活ERK1/2和JNK，在Ang II刺激的VSMC迁移中起重要但不同的作用。
