[Advanced oxidation protein products-induced tumor necrosis factor alpha secretion in monocytes via reactive oxygen species generation].
OBJECTIVE
To investigate the effect of advanced oxidation protein products (AOPP) on the secretion of tumor necrosis factor alpha eTNFalphae in monocytes and its possible mechanism.


METHODS
Human monocyte cell line THP-1 and peripheral blood monocytes were incubated with AOPP-bovine serum albumin(BSA) prepared by incubation of BSA with hypochlorous acid. TNFalpha in the supernatant of the culture medium of THP-1 cells was measured by enzyme-linked immunosorbent assay and the production of reactive oxygen species (ROS) evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2,7-dichlorefluorescin using Wallac 1420 multilabel counter. The intracellular signal was observed by pre-treatment of the cells with antioxidant pyrrolidine dithiocarbamate, NADPH oxidase inhibitor apocynin or p38 phosphorylation inhibitor SB203580.


RESULTS
AOPP-BSA induced TNF-alpha secretion and ROS production in monocytes. Pretreatment of the cells with pyrrolidine dithiocarbamate scavenged most of ROS and almost completely blocked TNF-alpha secretion induced by AOPP-BSA. Inhibition of NADPH oxidase by apocynin and p38 phosphorylation by SB203580 could both effectively block AOPP-BSA-induced TNF-alpha secretion.


CONCLUSIONS
AOPP-BSA induced TNF-alpha secretion in monocytes, and the intracellular signaling involves ROS produced by activated NADPH oxidase and subsequent p38 phosphorylation.
Zhang
Zhi-hui
ZH
Department of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. zhangzhihui@126.com
Liu
Shang-xi
SX
Hou
Fan-fan
FF
Tian
Jian-wei
JW
Wang
Li
L
Liu
Zhi-qiang
ZQ
Chen
Yuan
Y
D001798:Blood Proteins / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D009000:Monocytes / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D001798:Blood Proteins; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D019255:NADPH Oxidases; D048051:p38 Mitogen-Activated Protein Kinases