Regulation of reactive oxygen species-induced apoptosis and necrosis by caspase 3-like proteases

Abstract

Reactive oxygen species (ROS) and caspases have been implicated as potential mediators of cell death. However, their mechanistic relationship remains to be elucidated. Here we investigated the roles of caspases in apoptosis and necrosis induced by ROS, generated by the mixture of xanthine and xanthine oxidase (X/XO). A low concentration of XO (0.025 U/ml) induced DNA fragmentation with little cellular membrane damage 3 h after treatment, suggesting the induction of apoptosis. The same treatment induced membrane blebbing, a morphological change typical of apoptosis, 15 min after treatment. A high concentration of XO (0.1 U/ml) damaged cell membranes with little concomitance of DNA fragmention, suggesting the induction of necrosis. ROS also activated caspase 3-like proteases and caspase 3 itself together with the release of cytochrome c which might be the cause of caspase activation. Apoptosis induced by low concentrations of XO and necrosis induced by high concentrations of XO was inhibited by Z-DEVD-CH 2 F, an irreversible inhibitor of caspase 3. However, rapid induction of membrane blebbing was not inhibited by Z-DEVD-CH 2 F. These results suggest that both apoptosis and necrosis could be induced by ROS through the activation of caspase 3-like protease; however, caspase 3 activation is not needed for ROSinduced membrane blebbing.

Implication of mitochondria-derived reactive oxygen species, cytochrome C and caspase-3 in N-(4-Hydroxyphenyl)retinamide-induced apoptosis in cervical carcinoma cells

“…Alternatively, the di erence between the e cacy of the complex I and II inhibitors may be due to the fact that electrons channeled through complex II produce about four times more superoxide than those channeled through complex I (Forman and Boveris, 1982;Higuchi et al, 1998).…”

“…More recently, it has been shown that Bcl-2 maintains Delta psi by enhancing H + e ux in the presence of agents that induce Delta psi loss and thereby exerts its anti-apoptotic e ects (Shimizu et al, 1998). A question was raised about the requirement of MPT for apoptosis by recent reports, which demonstrated that MPT occurs later than cytochrome c release from mitochondria and caspase activation (Bossy-Wetzel et al, 1998;Higuchi et al, 1998).…”

“…Further, we have shown that 4HPR induced cytochrome c release, caspase-3 activation, and MPT and that all of these events occurred later than ROS generation and were suppressed by the antioxidant PDTC. It is possible that, in 4HPR-treated cells, ROS derived from MRC a ect the mitochondrial membrane such that cytochrome c is released into the cytosol and, consequently, caspase-3-like protease is activated and leads to execution of terminal events of apoptosis (Green and Reed, 1998;Higuchi et al, 1998). However, further studies are required to determine how 4HPR increases the generation of ROS in the mitochondria and whether the e ect of 4HPR on MPT is required for apoptosis induction or not.…”

Zonal necrosis prevented by transduction of the artificial anti-death FNK protein

“…17 In a previous study, PTD-FNK was demonstrated to reduce ischemic injury to hippocampal CA1 neurons after a transient forebrain ischemia, 18 which involves slow progressive neuronal degeneration, and an apoptotic pathway is suggested to contribute to the ischemic degeneration, to some extent. 19 The enhanced cytoprotective activity of FNK against oxidative stress and a calcium ionophore give rise to the possibility that FNK effectively protects cells from necrosis as well as apoptosis, because oxidative stress [20][21][22] and a disruption of calcium homeostasis [23][24][25] are known to induce necrosis. Carbon tetrachloride (CCl 4 ) has been used to induce necrosis in control experiments for studies on apoptosis [26][27][28][29] and is one of most typical model agents for studying the pathogenesis of liver injury.…”

The late increase in intracellular free radical oxygen species during apoptosis is associated with cytochrome c release, caspase activation, and mitochondrial dysfunction

“…33 The combination of X (1 mM) with different concentrations of XO (0.01 or 0.1 units) induced apoptosis in a dose-dependent manner, as determined by annexin V staining (Figure 5b). In contrast, X or XO alone had no effect compared to treatment with vehicle alone.…”