The roles of endogenous reactive oxygen species and nitric oxide in triptolide-induced apoptotic cell death in macrophages.
Triptolide, a major active component extracted from the root of Tripterygium wilfordii Hook f, has been shown to possess potent immunosuppressive and anti-inflammatory properties. In the present report, we reported that triptolide increased the generation of reactive oxygen species (ROS) and nitric oxide (NO) and induced apoptosis of RAW 264.7 cells in a dose-dependent manner (5-25 ng/ml). The antioxidant, reduced glutathione (GSH), significantly inhibited triptolide-induced apoptosis and inhibited the degradation of Bcl-2 protein, disruption of mitochondrial membrane potential, release of cytochrome c from mitochondria into the cytosol, activation of caspase-3, and cleavage of poly-(ADP-ribose)-polymerase. The inducible nitric oxide synthase-specific inhibitor 1400w blocked triptolide-induced apoptosis, but did not alter mitochondria disruption and caspase-3 activation. These results, for the first time, implicated that the increased endogenous ROS and NO co-mediated triptolide-induced apoptosis in macrophages. ROS initiated triptolide-induced apoptosis by the mitochondria signal pathway, while the apoptotic cell death mediated by NO was not via mitochondria collapse and caspase-3 activation. In addition, combining mathematical calculation and computer simulation based on our conventional experimental results, we set and validated the apoptotic model and provided more dynamic processes of triptolide-induced apoptotic cascade in macrophages.
Bao
Xiaofeng
X
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210093, China.
Cui
Jun
J
Wu
Yuanyuan
Y
Han
Xiaodong
X
Gao
Cheng
C
Hua
Zichun
Z
Shen
Pingping
P
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D004224:Diterpenes / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D004852:Epoxy Compounds / Q000494:pharmacology; D006801:Humans; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010616:Phenanthrenes / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020298:U937 Cells
D000894:Anti-Inflammatory Agents, Non-Steroidal; D018906:Antineoplastic Agents, Alkylating; D004224:Diterpenes; D004852:Epoxy Compounds; D009573:Nitrites; D010616:Phenanthrenes; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; C001899:triptolide; D009569:Nitric Oxide; D045304:Cytochromes c; D052247:Nitric Oxide Synthase Type II; D020169:Caspases