Effect of the oxidized-LDL on the migration of smooth muscle cells

• Main Authors: Cheng Ching Chen, 陳建志
• Other Authors: Ming T. Lin
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/13880242305667923266

碩士 === 國立成功大學 === 生物化學研究所 === 82 === Recent study showed that ox-LDL could stimulate migration of smooth muscle cells. It has been proposed that protease is required to digest the extracellular matrix before cell migration. Therefore, it can be reasonably expected that the proteolytic activity of smooth muscle cells may be regulated by ox-LDL. The ox-LDL is also known to stimulate the biosynthesis of plasminogen activator inhibitor PAI in the endothelial cells. Experiments were designed to study the regulation of proteolytic balance by ox-LDL in smooth muscle cells. The treatment of smooth muscle cells with ox-LDL resulted in a decrease in its ability to digest the labeled extracellular matrix, suggesting that the protease activity of smooth muscle cells was inhibited by ox-LDL. In vitro assay of smooth muscle migration by Boyden chamber also showed that ox-LDL inhibited both PDGF-BB-stimulated and non-PDGF-BB-stimulated cell migration in a dose-dependent manner. Ox-LDL induced PAI-1 activity and protein synthesis by 1.7-fold and 1.2- fold, respectively. The increase in PAI-1 protein synthesis was ascribed to elevated levels of PAI-1 mRNA, however, the increase of PAI-1 activity was more than the increase of PAI-1 protein synthesis. The increase of PAI-1 activity was most likely associated with conversion of latent PAI-1 to active PAI-1. The biosynthesis of t-PA antigen and the activation of collagenase inhibitor were not affected by the treatment with ox-LDL. Our experiments indicated that ox-LDL inhibited smooth muscle cells migration was mainly due to the increase of PAI-1 activity.