The non-provitamin A carotenoid, lutein, inhibits NF-kappaB-dependent gene expression through redox-based regulation of the phosphatidylinositol 3-kinase/PTEN/Akt and NF-kappaB-inducing kinase pathways: role of H(2)O(2) in NF-kappaB activation.
Reactive oxygen species (ROS) have been implicated in the regulation of NF-kappaB activation, which plays an important role in inflammation and cell survival. However, the molecular mechanisms of ROS in NF-kappaB activation remain poorly defined. We found that the non-provitamin A carotenoid, lutein, decreased intracellular H(2)O(2) accumulation by scavenging superoxide and H(2)O(2) and the NF-kappaB-regulated inflammatory genes, iNOS, TNF-alpha, IL-1beta, and cyclooxygenase-2, in lipopolysaccharide (LPS)-stimulated macrophages. Lutein inhibited LPS-induced NF-kappaB activation, which highly correlated with its inhibitory effect on LPS-induced IkappaB kinase (IKK) activation, IkappaB degradation, nuclear translocation of NF-kappaB, and binding of NF-kappaB to the kappaB motif of the iNOS promoter. This compound inhibited LPS- and H(2)O(2)-induced increases in phosphatidylinositol 3-kinase (PI3K) activity, PTEN inactivation, NF-kappaB-inducing kinase (NIK), and Akt phosphorylation, which are all upstream of IKK activation, but did not affect the interaction between Toll-like receptor 4 and MyD88 and the activation of mitogen-activated protein kinases. The NADPH oxidase inhibitor apocynin and gp91(phox) deletion reduced the LPS-induced NF-kappaB signaling pathway as lutein did. Moreover, lutein treatment and gp91(phox) deletion decreased the expressional levels of the inflammatory genes in vivo and protected mice from LPS-induced lethality. Our data suggest that H(2)O(2) modulates IKK-dependent NF-kappaB activation by promoting the redox-sensitive activation of the PI3K/PTEN/Akt and NIK/IKK pathways. These findings further provide new insights into the pathophysiological role of intracellular H(2)O(2) in the NF-kappaB signal pathway and inflammatory process.
Kim
Ji-Hee
JH
Vascular System Research Center and Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chunchon, Kangwon-do 200-701, Korea.
Na
Hee-Jun
HJ
Kim
Chun-Ki
CK
Kim
Ji-Yoon
JY
Ha
Kwon-Soo
KS
Lee
Hansoo
H
Chung
Hun-Taeg
HT
Kwon
Ho Jeong
HJ
Kwon
Young-Guen
YG
Kim
Young-Myeong
YM
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001483:Base Sequence; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D014975:Lutein / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000502:physiology; D010084:Oxidation-Reduction; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000893:Anti-Inflammatory Agents; D017931:DNA Primers; D016328:NF-kappa B; D006861:Hydrogen Peroxide; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C487757:Pten protein, mouse; D014975:Lutein