Upregulation of tumor necrosis factor-alpha expression by trans10-cis12 conjugated linoleic acid enhances phagocytosis of RAW macrophages via a peroxisome proliferator-activated receptor gamma-dependent pathway.
The aim of this study was to examine whether tumor necrosis factor (TNF)-alpha expression in the phagocytic activity of RAW macrophages by trans10-cis12 (10t-12c) conjugated linoleic acid (CLA) is associated with peroxisome proliferator-activated receptor gamma (PPARgamma) activation. 10t-12c CLA induced the TNF-alpha expression in RAW macrophages. Phagocytic activity of naive RAW macrophages was increased either by recombinant mouse (rm) TNF-alpha or by culture supernatant from 10t-12c CLA-treated RAW macrophages. This phagocytic activity was inhibited by addition of anti-rmTNF-alpha polyclonal antibody (pAb). 10t-12c CLA also increased the level of PPARgamma protein and mRNA in RAW macrophages. When naive RAW macrophages were incubated with the culture supernatant from RAW macrophages treated with 10t-12c CLA plus GW 9662, a PPARgamma antagonist, their phagocytic activity was significantly inhibited. In addition, GW 9662 antagonized the effect of 10t-12c CLA in stimulating TNF-alpha expression. These results suggest that 10t-12c CLA modulates the phagocytic activity of RAW macrophages by upregulating TNF-alpha expression via a PPARgamma-dependent pathway.
Song
Deok-Ho
DH
Laboratory of Veterinary Internal Medicine, Department of Veterinary Medicine, College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
Kang
Ji-Houn
JH
Lee
Geun-Shik
GS
Jeung
Eui-Bae
EB
Yang
Mhan-Pyo
MP
D000813:Anilides / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D008264:Macrophages / Q000502:physiology*; D051379:Mice; D047495:PPAR gamma / Q000037:antagonists & inhibitors / Q000502:physiology*; D010587:Phagocytosis / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*; D015854:Up-Regulation
C457499:2-chloro-5-nitrobenzanilide; D000813:Anilides; D044243:Linoleic Acids, Conjugated; D047495:PPAR gamma; D014409:Tumor Necrosis Factor-alpha; C496197:trans-10,cis-12-conjugated linoleic acid