Oxidized-1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine induces vascular endothelial superoxide production: implication of NADPH oxidase.
Modified low-density lipoprotein (LDL) induces reactive oxygen species (ROS) production by vascular cells. It is unknown if specific oxidized components in these LDL particles such as oxidized-1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (ox-PAPC) can stimulate ROS production. Bovine aortic endothelial cells (BAEC) were incubated with ox-PAPC (50 microg/ml). At 4 h, ox-PAPC significantly enhanced the rate of O2- production. Pretreatment of BAEC in glucose-free Dulbecco's modified Eagle's medium plus 10 mM 2-deoxyglucose (2-DOG), the latter being an antimetabolite that blocks NADPH production by the pentose shunt, significantly reduced the rate of O2- production. The intensity of NAD(P)H autofluorescence decreased by 28 +/- 12% in BAEC incubated with ox-PAPC compared to untreated cells, with a further decrease in the presence of 2-DOG. Ox-PAPC also increased Nox4 mRNA expression by 2.4-fold +/- 0.1 while pretreatment of BAEC with the small interfering RNA (siNox4) attenuated Nox4 RNA expression. Ox-PAPC further reduced the level of glutathione while pretreatment with apocynin (100 microM) restored the GSH level (control = 22.54 +/- 0.23, GSH = 18.06 +/- 0.98, apocynin = 22.55 +/- 0.60, ox-PAPC + apocynin = 21.17 +/- 0.36 nmol/10(6) cells). Treatment with ox-PAPC also increased MMP-2 mRNA expression accompanied by a 1.5-fold increase in MMP-2 activity. Ox-PAPC induced vascular endothelial OO2-(.) production that appears to be mediated largely by NADPH oxidase activity.
Rouhanizadeh
Mahsa
M
Department of Biomedical Engineering and Division of Cardiovascular Medicine, University of Southern California, Los Angeles, CA 90089-1451, USA.
Hwang
Juliana
J
Clempus
Roza E
RE
Marcu
Laura
L
Lassègue
Bernard
B
Sevanian
Alex
A
Hsiai
Tzung K
TK
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D015536:Down-Regulation; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis; D009249:NADP / Q000378:metabolism; D019255:NADPH Oxidases / Q000502:physiology*; D010713:Phosphatidylcholines / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D013481:Superoxides / Q000378:metabolism*; D015854:Up-Regulation
D010713:Phosphatidylcholines; C472349:oxidized-L-alpha-1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine; D013481:Superoxides; D009249:NADP; D019255:NADPH Oxidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9