Paraquat Induces Apoptosis through a Mitochondria-Dependent Pathway in RAW264.7 Cells

Abstract

Paraquat dichloride (N,N-dimethyl-4-4′-bipiridinium, PQ) is an extremely toxic chemical that is widely used in herbicides. PQ generates reactive oxygen species (ROS) and causes multiple organ failure. In particular, PQ has been reported to be an immunotoxic agrochemical compound. PQ was shown to decrease the number of macrophages in rats and suppress monocyte phagocytic activity in mice. However, the effect of PQ on macrophage cell viability remains unclear. In this study, we evaluated the cytotoxic effect of PQ on the mouse macrophage cell line, RAW264.7 and its possible mechanism of action. RAW264.7 cells were treated with PQ (0, 75, and 150 μM), and cellular apoptosis, mitochondrial membrane potential (MMP), and intracellular ROS levels were determined. Morphological changes to the cell nucleus and cellular apoptosis were also evaluated by DAPI and Annexin V staining, respectively. In this study, PQ induced apoptotic cell death by dose-dependently decreasing MMP. Additionally, PQ increased the cleaved form of caspase-3, an apoptotic marker. In conclusion, PQ induces apoptosis in RAW264.7 cells through a ROS-mediated mitochondrial pathway. Thus, our study improves our knowledge of PQ-induced toxicity, and may give us a greater understanding of how PQ affects the immune system.

An engineered cell line lacking OGG1 and MUTYH glycosylases implicates the accumulation of genomic 8-oxoguanine as the basis for paraquat mutagenicity

“…Previous studies have shown that cells deficient in Ogg1 and Mutyh are sensitive to oxidants, in part because of the negative effects of oxidative stress on cell-cycle progression [3]. These observations are in accord with studies showing that increased levels of ROS are associated with cell death [22, 42, 43], as well as DNA damage [44]. There should be a substantial increase in ROS levels when cells are severely repair-deficient.…”

“…Previous studies have documented the ability of PQ to redox cycle resulting in generation of ROS and extensive mitochondrial damage [17–19]. Among the different ROS, the superoxide anion radical, has been observed and reported [2, 19–22]; H 2 O 2 has also been observed being induced in a dose-dependent manner [22, 42, 43]. ROS-dependent cell death was also reported in other cultured mammalian cells, such as human promyelocytic leukemia HL-60 cells [22], RAW264.7 cells [42], and human neutrophils [43].…”

Assessment of the Cytotoxic and Apoptotic Eἀects of Chaetominine in a Human Leukemia Cell Line

“…Changes in mitochondrial membrane potential (MMP) were evaluated using the JC-1 Mitochondrial Potential Assay Kit (Beyotime). Mitochondrial depolarization occurring in the early stage of apoptosis was evidenced by a fluorescence emission shift from green (JC-1 monomer) to red (J-aggregate), and the results showed potential-dependent accumulations in mitochondria ( Jang et al ., 2015 ). K562 cells were seeded in a 6-well plate at 2×10 5 cells per well and then treated with chaetominine (0, 25, 50 or 100 nM) for 24 h or 48 h. Approximately 10 5 cells were harvested, incubated in dye-containing medium, and washed twice in staining buffer.…”

Herbicide exposure induces apoptosis, inflammation, immune modulation and suppression of cell survival mechanism in murine model

“…Both in vivo and in vitro reports with PQ induced caspase-3 activation in brain cells are consistent with our ndings. 51 Moreover, the AKT/PI3K pathway plays a central role in integrating various cellular stimuli with a broad range of cellular functions. AKT further regulates an array of downstream targets involving cell survival, cell growth and cell proliferation, including members of the Bcl-2 family.…”