PDGF (alpha)-receptor is unresponsive to PDGF-AA in aortic smooth muscle cells from the NG2 knockout mouse

1999 ◽  
Vol 112 (6) ◽  
pp. 905-915 ◽  
Author(s):  
K.A. Grako ◽  
T. Ochiya ◽  
D. Barritt ◽  
A. Nishiyama ◽  
W.B. Stallcup

A line of null mice has been produced which fails to express the transmembrane chondroitin sulfate proteoglycan NG2. Homozygous NG2 null mice do not exhibit gross phenotypic differences from wild-type mice, suggesting that detailed analyses are required to detect subtle alterations caused by the absence of NG2. Accordingly, dissociated cultures of aortic smooth muscle cells from null mice were compared to parallel cultures from wild-type mice for their ability to proliferate and migrate in response to specific growth factors. Both null and wild-type smooth muscle cells exhibited identical abilities to proliferate and migrate in response to PDGF-BB. In contrast, only the wild-type cells responded to PDGF-AA in both types of assays. NG2 null cells failed to proliferate or migrate in response to PDGF-AA, implying a defect in the signaling cascade normally initiated by activation of the PDGF (alpha)-receptor. In agreement with this idea, activation of the extracellular signal-regulated kinase (ERK) in response to PDGF-AA treatment occured only in wild-type cells. Failure to observe autophosphorylation of the PDGF (alpha)-receptor in PDGF-AA-treated null cells indicates that the absence of NG2 causes a defect in signal transduction at the level of (alpha)-receptor activation.

FEBS Letters ◽  
1992 ◽  
Vol 311 (3) ◽  
pp. 195-198 ◽  
Author(s):  
Takaaki Yoshimasa ◽  
Kazuwa Nakao ◽  
Shin-ichi Suga ◽  
Ichiro Kishimoto ◽  
Yoshiaki Kiso ◽  
...  

2008 ◽  
Vol 99 (4) ◽  
pp. 709-714 ◽  
Author(s):  
Weng-Cheng Chang ◽  
Ya-Mei Yu ◽  
Su-Yin Chiang ◽  
Chiung-Yao Tseng

Proliferation of intimal vascular smooth muscle cells is an important component in the development of atherosclerosis. Ellagic acid is a phenolic compound present in fruits (raspberries, blueberries, strawberries) and walnuts. The present study investigated the effect of ellagic acid on the oxidised LDL (ox-LDL)-induced proliferation of rat aortic smooth muscle cells (RASMC). The study found that ellagic acid significantly inhibited ox-LDL-induced proliferation of RASMC and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2.Furthermore, ellagic acid also blocked the ox-LDL-induced (inducible) cell-cycle progression and down regulation of the expression of proliferating cell nuclear antigen (PCNA) in RASMC. Therefore, ellagic acid reduced the amount of ox-LDL-induced proliferation of RASMC via inactivation of the ERK pathway and suppression of PCNA expression. These results may significantly advance the understanding of the role that antioxidants play in the prevention of atherosclerosis.


2018 ◽  
Vol 88 (5-6) ◽  
pp. 309-318
Author(s):  
Hae Seong Song ◽  
Jung-Eun Kwon ◽  
Hyun Jin Baek ◽  
Chang Won Kim ◽  
Hyelin Jeon ◽  
...  

Abstract. Sorghum bicolor L. Moench is widely grown all over the world for food and feed. The effects of sorghum extracts on general inflammation have been previously studied, but its anti-vascular inflammatory effects are unknown. Therefore, this study investigated the anti-vascular inflammation effects of sorghum extract (SBE) and fermented extract of sorghum (fSBE) on human aortic smooth muscle cells (HASMCs). After the cytotoxicity test of the sorghum extract, a series of experiments were conducted. The inhibition effects of SBE and fSBE on the inflammatory response and adhesion molecule expression were measured using treatment with tumor necrosis factor-α (TNF-α), a crucial promoter for the development of atherosclerotic lesions, on HASMCs. After TNF-α (10 ng/mL) treatment for 2 h, then SBE and fSBE (100 and 200 μg/mL) were applied for 12h. Western blotting analysis showed that the expression of vascular cell adhesion molecule-1 (VCAM-1) (2.4-fold) and cyclooxygenase-2 (COX-2) (6.7-fold) decreased, and heme oxygenase-1 (HO-1) (3.5-fold) increased compared to the TNF-α control when treated with 200 μg/mL fSBE (P<0.05). In addition, the fSBE significantly increased the expression of HO-1 and significantly decreased the expression of VCAM-1 and COX-2 compared to the TNF-α control in mRNA level (P<0.05). These reasons of results might be due to the increased concentrations of procyanidin B1 (about 6-fold) and C1 (about 30-fold) produced through fermentation with Aspergillus oryzae NK for 48 h, at 37 °C. Overall, the results demonstrated that fSBE enhanced the inhibition of the inflammatory response and adherent molecule expression in HASMCs.


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