Polyphyllin VI Induces Caspase-1-Mediated Pyroptosis via the Induction of ROS/NF-κB/NLRP3/GSDMD Signal Axis in Non-Small Cell Lung Cancer

Abstract

Trillium tschonoskii Maxim (TTM), a traditional Chinese medicine, has been demonstrated to have a potent anti-tumor effect. Recently, polyphyllin VI (PPVI), a main saponin isolated from TTM, was reported by us to significantly suppress the proliferation of non-small cell lung cancer (NSCLC) via the induction of apoptosis and autophagy in vitro and in vivo. In this study, we further found that the NLRP3 inflammasome was activated in PPVI administrated A549-bearing athymic nude mice. As is known to us, pyroptosis is an inflammatory form of caspase-1-dependent programmed cell death that plays an important role in cancer. By using A549 and H1299 cells, the in vitro effect and action mechanism by which PPVI induces activation of the NLRP3 inflammasome in NSCLC were investigated. The anti-proliferative effect of PPVI in A549 and H1299 cells was firstly measured and validated by MTT assay. The activation of the NLRP3 inflammasome was detected by using Hoechst33324/PI staining, flow cytometry analysis and real-time live cell imaging methods. We found that PPVI significantly increased the percentage of cells with PI signal in A549 and H1299, and the dynamic change in cell morphology and the process of cell death of A549 cells indicated that PPVI induced an apoptosis-to-pyroptosis switch, and, ultimately, lytic cell death. In addition, belnacasan (VX-765), an inhibitor of caspase-1, could remarkably decrease the pyroptotic cell death of PPVI-treated A549 and H1299 cells. Moreover, by detecting the expression of NLRP3, ASC, caspase-1, IL-1β, IL-18 and GSDMD in A549 and h1299 cells using Western blotting, immunofluorescence imaging and flow cytometric analysis, measuring the caspase-1 activity using colorimetric assay, and quantifying the cytokines level of IL-1β and IL-18 using ELISA, the NLRP3 inflammasome was found to be activated in a dose manner, while VX-765 and necrosulfonamide (NSA), an inhibitor of GSDMD, could inhibit PPVI-induced activation of the NLRP3 inflammasome. Furthermore, the mechanism study found that PPVI could activate the NF-κB signaling pathway via increasing reactive oxygen Cancers 2020, 12, 193 2 of 27 species (ROS) levels in A549 and H1299 cells, and N-acetyl-L-cysteine (NAC), a scavenger of ROS, remarkably inhibited the cell death, and the activation of NF-κB and the NLRP3 inflammasome in PPVI-treated A549 and H1299 cells. Taken together, these data suggested that PPVI-induced, caspase-1-mediated pyroptosis via the induction of the ROS/NF-κB/NLRP3/GSDMD signal axis in NSCLC, which further clarified the mechanism of PPVI in the inhibition of NSCLC, and thereby provided a possibility for PPVI to serve as a novel therapeutic agent for NSCLC in the future.

Tanshinone II A enhances pyroptosis and represses cell proliferation of HeLa cells by regulating miR-145/GSDMD signaling pathway

“…As a critical form of cell death, pyroptosis has been reported to be involved in many physiological processes, such as regulation of tumor immune microenvironment [35], treatment of acute myeloid leukemia [36] and act as an innate immune effector against intracellular bacteria [37]. There are various researches showing an association between pyroptosis and tumor proliferation [38][39][40]. In this study, we found that tanshinone II A enhanced cell proliferation and inhibited apoptosis by up-regulating GSDMD expression on HeLa cells, especially at high concentrations.…”

<p>Polyphyllin VI Induces Apoptosis and Autophagy via Reactive Oxygen Species Mediated JNK and P38 Activation in Glioma</p>

“…ROS play a crucial role in tumorigenesis, with accumulating evidence suggesting that excessive production of ROS directly causes DNA damage and leads to apoptosis. 38,39 Consequently, targeting ROS has been considered a promising strategy for anti-tumor therapy, since it can stimulate or inhibit different cell signaling pathways to induce apoptosis and autophagy thereby inhibit tumor growth. 40,41 Additionally, high levels of ROS can induce cell cycle arrest.…”

α-Cyperone Confers Antidepressant-Like Effects in Mice via Neuroplasticity Enhancement by SIRT3/ROS Mediated NLRP3 Inflammasome Deactivation

“…Activated Caspase-1 promotes the secretion of IL-1β, IL-18 and GSDMD, consequently leading to the impairments of neuroplasticity ( Qi et al, 2018 ; Shao et al, 2018 ). ROS is a crucial activator in triggering NLRP3 inflammasome activation directly or indirectly by acting on NF-κB ( Teng et al, 2020 ). SIRT3, a NAD+-dependent deacetylase that mainly located in mitochondria, modulates signal pathways to control ROS generation ( Teng et al, 2020 ).…”

“…ROS is a crucial activator in triggering NLRP3 inflammasome activation directly or indirectly by acting on NF-κB ( Teng et al, 2020 ). SIRT3, a NAD+-dependent deacetylase that mainly located in mitochondria, modulates signal pathways to control ROS generation ( Teng et al, 2020 ). SIRT3 maintains the ROS homeostasis by targeting mitochondrial enzymes such as superoxide dismutase 2 (SOD2), which transforms harmful superoxide radicals into nontoxic oxygen or hydrogen peroxide ( Zheng et al, 2018 ).…”