- 作者：Yaser Abdallah ; Dragan Gligorievski ; Sascha A. Kasseckert ; Lukas Dieterich ; Matthias Schä ; fer ; Christoph R. Kuhlmann ; Thomas Noll ; Heinrich Sauer ; H.Michael Piper ; Claudia Schä ; fer
- 关键词：PARP ; Hypoxia ; Endothelial cell ; Proloferation ; Calcium ; ROS
- 刊名：Cardiovascular Research
- 出版年：2007
- 期刊代码：48_00086363
- 类别：med
- 出版时间：1 February 2007
- 卷：73
- 期：3
- 页码：568-574
- 文件大小：654 K
The autonomous proliferative response of endothelial cells to hypoxia has been shown to be dependent on activation of NAD(P)H oxidase, on the cytosolic Ca2+ load, and, consequently, on nuclear translocation of extracellular signal-regulated kinase (ERK)1/2 during transient hypoxia. The aim of the present study was to investigate whether poly(ADP-ribose) polymerase (PARP) is a downstream signal of NAD(P)H oxidase, mediating cytosolic Ca2+ load and hence nuclear translocation of ERK1/2 and endothelial cell proliferation.
Methods
Porcine aortic endothelial cells were incubated under hypoxic conditions for 40 min. Cytosolic [Ca2+] and reactive oxygen species (ROS) formation were measured in fura-2- and DCF-loaded cells, respectively. PARP activation was detected by immunocytochemistry, and endothelial cell proliferation was determined 24 h after 60 min of transient hypoxia.
Results
Inhibition of NAD(P)H oxidase with antisense oligonucleotide against the p22phox subunit, MEK/ERK signalling with UO 126 (30 μM), or PARP with PJ 34 (10 μM) leads to a marked reduction in hypoxia-induced cytosolic Ca2+ load and activation of PARP. Hypoxia-induced translocation of ERK1/2 and endothelial cell proliferation were also prevented when NAD(P)H oxidase or PARP were inhibited; however, hypoxic ROS formation was not affected in the presence of PARP inhibitor.
Conclusion
PARP represents a downstream effector of NADP(H) oxidase and acts as a necessary intermediate step for the hypoxic proliferative response of endothelial cells.