Effect of vasoconstrictor coupling factor 6 on gene expression profile in human vascular endothelial cells: enhanced release of asymmetric dimethylarginine.
BACKGROUND
Coupling factor 6 (CF6), a component of ATP synthase, inhibits phospholipase A2 and induces vasoconstriction. However, because arachidonic acid acts in the widespread fields of vascular biology, CF6 might exert profound effects in addition to vasoconstriction. We investigated the effect of CF6 on the gene expression profile in human umbilical vein endothelial cells.


RESULTS
The increased gene expression after 24-h exposure to CF6 at 10 mol/l, assessed by cDNA microarray (n = 3), included neuregulin-1 (1.84 +/- 0.07 fold compared with control, P < 0.05) and relaxin-1 (1.74 +/- 0.20, P < 0.05), both relating to congestive heart failure, urokinase type plasminogen activator receptor (1.77 +/- 0.24, P = 0.06) and estrogen receptor beta (1.74 +/- 0.36, P = 0.08), both relating to vascular inflammation and cell infiltration, and protein arginine methyltransferase (PRMT-1; 1.73 +/- 0.20, P < 0.05). Out of these genes, the enzyme relating to the synthesis (PRMT-1) of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), was further examined concomitantly with the degradation enzyme, dimethylarginine dimethylaminohydrolase 2 (DDAH-2). The ratio of PRMT-1 to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA, measured by real-time quantitative reverse transcription-polymerase chain reaction, was increased by 9 +/- 2% (n = 10, P < 0.01) at 48 h after CF6 at 10 mol/l, whereas the ratio of DDAH-2 to GAPDH was decreased by 12 +/- 2% (n = 8, P < 0.01). DDAH-2 protein and activity were decreased by 28 +/- 5% (n = 5, P < 0.01) and 19 +/- 2% (n = 6, P < 0.01) by CF6, respectively. ADMA release was enhanced by 20 +/- 8% and NOS activity was decreased by 13 +/- 1% (both n = 8, P < 0.05) by CF6.


CONCLUSIONS
CF6 changes the gene expression profile to be proatherogenic and functions as a novel stimulator for ADMA release by enhancing its synthesis and suppressing its degradation.
Second Department of Internal Medicine, Hirosaki University School of Medicine, Osaka, Japan.
Makoto
M
Tanaka
Tomohiro
T
Osanai
Reiichi
R
Murakami
Satoko
S
Sasaki
Hirofumi
H
Tomita
Naotaka
N
Maeda
Kei
K
Satoh
Koji
K
Magota
Ken
K
Okumura
D000581:Amidohydrolases / Q000378:metabolism; D001120:Arginine / Q000031:analogs & derivatives* / Q000378:metabolism; D015153:Blotting, Western; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects*; D020869:Gene Expression Profiling; D006801:Humans; D025261:Mitochondrial Proton-Translocating ATPases / Q000378:metabolism / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010086:Oxidative Phosphorylation Coupling Factors / Q000378:metabolism / Q000494:pharmacology*; D011484:Protein-Arginine N-Methyltransferases / Q000378:metabolism; D014471:Umbilical Veins
D010086:Oxidative Phosphorylation Coupling Factors; C018524:N,N-dimethylarginine; D001120:Arginine; D019001:Nitric Oxide Synthase; D011484:Protein-Arginine N-Methyltransferases; D000581:Amidohydrolases; C059999:dimethylargininase; C000628217:F(6) ATPase; D025261:Mitochondrial Proton-Translocating ATPases