Angiotensin II Stimulates Platelet-Derived Growth Factor-B Chain Expression in Newborn Rat Vascular Smooth Muscle Cells and Neointimal Cells Through Ras, Extracellular Signal-Regulated Protein Kinase, and c-Jun N-Terminal Protein Kinase Mechanisms

• Published in: Circulation research Vol. 85; no. 7; pp. 565 - 574
• Main Authors: Deguchi, Jun-o, Makuuchi, Masatoshi, Nakaoka, Takashi, Collins, Tucker, Takuwa, Yoh
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD American Heart Association, Inc 01-10-1999; Lippincott; Lippincott Williams & Wilkins Ovid Technologies
• Subjects: Aging - metabolism; Angiotensin II - pharmacology; Animals; Animals, Newborn - physiology; Biological and medical sciences; Blood vessels and receptors; Calcium-Calmodulin-Dependent Protein Kinases - physiology; Cells, Cultured; DNA - biosynthesis; DNA-Binding Proteins - metabolism; Early Growth Response Protein 1; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes, ras - physiology; Immediate-Early Proteins; JNK Mitogen-Activated Protein Kinases; Male; Mitogen-Activated Protein Kinases; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - physiology; Platelet-Derived Growth Factor - genetics; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins c-sis; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, Angiotensin - genetics; RNA, Messenger - metabolism; Transcription Factors - metabolism; Tunica Intima - cytology; Tunica Intima - physiology; Vertebrates: cardiovascular system; Rat; Enzyme; Transferases; Rodentia; Smooth muscle; MAP kinase; Peptide chain; Gene expression; Artery; Signal transduction; Renin angiotensin system; Vertebrata; Mammalia; Protein kinase; Blood vessel; Newborn animal; Aorta; Circulatory system; Angiotensin II; Platelet derived growth factor
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/01.res.85.7.565

Platelet-derived growth factors (PDGFs) have been implicated in the pathogenesis of vascular proliferative disorders. Vascular smooth muscle cells (VSMCs) are one of the cell types that produce PDGF-B chain in proliferative lesions, although the mechanism of regulation of PDGF-B chain production in these cells is not well understood. In the present study, we demonstrate that angiotensin II (Ang II), which is also implicated in vascular stenosis after angioplasty and atherosclerosis, markedly stimulates PDGF-B chain mRNA expression in cultured newborn rat medial VSMCs and neointimal VSMCs via an AT1, but not in adult rat VSMCs. In newborn rat VSMCs, Ang II activates extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal protein kinase (JNK), and p38 mitogen-activated protein kinase. The mitogen-activated protein/ERK (MEK) inhibitor PD98059, but not the p38 inhibitor SB203580, abrogates Ang II-induced PDGF-B mRNA expression. Transient transfection analysis using a PDGF-B promoter-luciferase gene reporter construct reveals that Ang II induces transcriptional activation of PDGF-B chain gene, which is abolished by the expression of a dominant negative form of either ERK or JNK, but not of p38. The expression of a dominant negative form of Ras abolishes the stimulatory effects of Ang II on ERK activity and PDGF-B mRNA expression. In adult rat VSMCs, Ang II activates ERK and JNK, but weakly induces Egr-1, a transcription factor implicated in PDGF-B chain gene expression, compared with newborn VSMCs. These data indicate that Ang II activates PDGF-B chain gene expression in VSMCs through mechanisms involving Ras-ERK and JNK.