Down--regulation of perlecan expression contributes to the inhibition of rat cardiac microvascular endothelial cell proliferation induced by hypoxia
Li Yuzhen, Liu Xiuhua, Cai Lirong
Department of Pathophysiology,Institute of Basic Medical Science,PLA General Hospital.Beijing 100853
Abstract
Exposure of endothelial cells (ECs) to hypoxia leads to a decrease in EC proliferation. However, the mechanism by which hypoxia inhibits EC proliferation is unclear. Perlecan has been reported to play an important role in regulating EC proliferation. We hypothesized that perlecan was involved in the hypoxia-induced inhibition of EC proliferation. To test this hypothesis, rat cardiac microvascular ECs were cultured under normoxic or hypoxic conditions for 12 h and harvested for determination of perlecan mRNA expression using real-time reverse transcription-polymerase chain reaction (RT-PCR). The results showed that exposure of ECs to hypoxia for 12 h induced a decrease in perlecan mRNA expression (61.72%, P<0.05). Concomitantly, the down-regulation of endogenous perlecan induced by hypoxia or the neutralization of endogenous perlecan with anti-perlecan antibody significantly inhibited EC proliferation and responsiveness to basic fibroblast growth factor (bFGF), and decreased focal adhesion kinase (FAK) expression and extracellular signal-regulated kinase 1/2 (ERK1/2) activation. These data indicate that down-regulation of perlecan expression contributes to hypoxia-induced inhibition of rat cardiac microvascular EC proliferation by suppressing FAK-mediated and ERK1/2-dependent growth signals.
Key words: Hypoxia;Endothelial cell;Cell proliferation;perlecan
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Citing This Article:
Li Yuzhen, Liu Xiuhua, Cai Lirong. Down--regulation of perlecan expression contributes to the inhibition of rat cardiac microvascular endothelial cell proliferation induced by hypoxia. Acta Physiol Sin 2007; 59 (2): 221-226 (in Chinese with English abstract).