Signal transduction of betacellulin in growth and migration of vascular smooth muscle cells

2004 ◽  
Vol 287 (3) ◽  
pp. C807-C813 ◽  
Author(s):  
Mizuo Mifune ◽  
Haruhiko Ohtsu ◽  
Hiroyuki Suzuki ◽  
Gerald D. Frank ◽  
Tadashi Inagami ◽  
...  

Epidermal growth factor (EGF) family ligands have been implicated in cardiovascular diseases because of their enhanced expression in vascular lesions and their promoting effects on growth and migration of vascular smooth muscle cells (VSMCs). Betacellulin (BTC), a novel EGF family ligand, has been shown to be expressed in atherosclerotic lesions and to be a potent growth factor of VSMCs. However, the molecular mechanisms downstream of BTC involved in mediating vascular remodeling remain largely unknown. Therefore, the aim of this study was to examine the effects of BTC on signal transduction, growth, and migration in VSMCs. We found that BTC stimulated phosphorylation of EGF receptor (EGFR) at Tyr1068, which was completely blocked by an EGFR kinase inhibitor, AG-1478. BTC also phosphorylated ErbB2 at Tyr877, Tyr1112, and Tyr1248 and induced association of ErbB2 with EGFR, suggesting their heterodimerization in VSMCs. In postreceptor signal transduction, BTC stimulated phosphorylation of extracellular signal-regulated kinase (ERK)1/2, Akt, and p38 mitogen-activated protein kinase (MAPK). Moreover, BTC stimulated proliferation and migration of VSMCs. ERK and Akt inhibitors suppressed migration markedly and proliferation partially, whereas the p38 inhibitor suppressed migration partially but not proliferation. In addition, we found the presence of endogenous BTC in conditioned medium of VSMCs and an increase of BTC on angiotensin II stimulation. In summary, BTC promotes growth and migration of VSMCs through activation of EGFR, ErbB2, and downstream serine/threonine kinases. Together with the expression and processing of endogenous BTC in VSMCs, our results suggest a critical involvement of BTC in vascular remodeling.

1993 ◽  
Vol 290 (3) ◽  
pp. 649-653 ◽  
Author(s):  
Y Homma ◽  
H Sakamoto ◽  
M Tsunoda ◽  
M Aoki ◽  
T Takenawa ◽  
...  

In order to examine the mechanisms underlying smooth-muscle cell proliferation, we investigated effect of platelet-derived growth factor (PDGF) dimers on proliferation of rabbit vascular smooth-muscle cells (VSMCs) and also involvement of phospholipase C (PLC) isoforms in the signal transduction. PDGF-BB and -AB, but not -AA, stimulated cell proliferation and intracellular production of inositol trisphosphate. Northern and Western analyses demonstrated that VSMCs mainly expressed PLC-gamma 2 and PLC-delta 1 among four PLC isoforms tested. A number of cellular proteins, including PLC-gamma 2, but not PLC-delta 1, were phosphorylated on a tyrosine residue by the stimulation of either PDGF-BB or -AB. These results suggest a functional association of PDGF receptor and PLC-gamma 2 that might be responsible for PDGF-dependent VSMC growth. In addition, the expression of PLC-gamma 2 was extremely low in the primary VSMC cultures and was induced during further cultivation of the primary cultures, indicating that an acquisition of PDGF-signal-transducing components, including PLC-gamma 2, may be an important step for proliferation of smooth-muscle cells.


2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Jie Su ◽  
Han-Ting Xu ◽  
Jing-Jing Yu ◽  
Jian-Li Gao ◽  
Jing Lei ◽  
...  

Objectives. Preliminary researches showed that luteolin was used to treat hypertension. However, it is still unclear whether luteolin has effect on the hypertensive complication such as vascular remodeling. The present study was designed to investigate the effect of luteolin on the hypertensive vascular remodeling and its molecular mechanism.Method and Results. We evaluated the effect of luteolin on aorta thickening of hypertension in spontaneous hypertensive rats (SHRs) and found that luteolin could significantly decrease the blood pressure and media thickness of aortain vivo. Luteolin could inhibit angiotensin II- (Ang II-) induced proliferation and migration of vascular smooth muscle cells (VSMCs). Dichlorofluorescein diacetate (DCFH-DA) staining result showed that luteolin reduced Ang II-stimulated ROS production in VSMCs. Furthermore, western blot and gelatin zymography results showed that luteolin treatment leaded to a decrease in ERK1/2, p-ERK1/2, p-p38, MMP2, and proliferating cell nuclear antigen (PCNA) protein level.Conclusion. These data support that luteolin can ameliorate hypertensive vascular remodeling by inhibiting the proliferation and migration of Ang II-induced VSMCs. Its mechanism is mediated by the regulation of MAPK signaling pathway and the production of ROS.


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