Oleic acid prevents apoptotic cell death induced by trans10, cis12 isomer of conjugated linoleic acid via p38 MAP kinase dependent pathway.
Our previous study indicated that oleic acid prevented apoptotic cell death induced by trans10, cis12 (t10, c12)-conjugated linoleic acid in rat hepatoma dRLh-84 cells. The intracellular mechanism of action oleic acid is still unknown. Here, we showed that p38 mitogen-activated protein kinase (MAPK) inhibition using its specific inhibitor SB203580 cancelled the ameliorative effect of oleic acid on the cytotoxicity of t10, c12-conjugated linoleic acid. In addition, SubG1 cell population analysis showed that p38 MAPK played an essential role in the prevention of apoptotic cell death by oleic acid. In fact, p38 phosphorylation level was upregulated in cells treated with oleic acid irrespective of t10, c12-conjugated linoleic acid stimulation. Interestingly, t10, c12-conjugated linoleic acid increased intracellular triglyceride accumulation. However, oleic acid completely inhibited this effect. These observations indicated the involvement of blockade of a p38 MAPK pathway in the ameliorative effect of oleic acid on apoptosis induced by t10, c12-conjugated linoleic acid.
Department of Biochemistry and Applied BioScience, Faculty of Agriculture, Miyazaki University, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan. myamasaki@cc.miyazaki-u.ac.jp
Masao
M
Yamasaki
Hirofumi
H
Tachibana
Arisa
A
Yamada
Yukari
Y
Ochi
Harishkumar
H
Madhyastha
Kazuo
K
Nishiyama
Koji
K
Yamada
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D044243:Linoleic Acids, Conjugated / Q000633:toxicity*; D050356:Lipid Metabolism / Q000187:drug effects; D019301:Oleic Acid / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D044243:Linoleic Acids, Conjugated; D047428:Protein Kinase Inhibitors; C496197:trans-10,cis-12-conjugated linoleic acid; D019301:Oleic Acid; D048051:p38 Mitogen-Activated Protein Kinases