1. Triclabendazole Induces Pyroptosis by Activating Caspase-3 to Cleave GSDME in Breast Cancer Cells
Yu-Hui Zhang, Hai-Yan Lin, Gang Wu, Liang Yan, Yong Sun, Shan-Shan Shi, Tim Forouzanfar, Xue-Feng Ma, Jun Fan, Yi Liu, Dan Hou Front Pharmacol . 2021 Jul 8;12:670081. doi: 10.3389/fphar.2021.670081.
Pyroptosis is a form of programmed cell death, in which gasdermin E (GSDME) plays an important role in cancer cells, which can be induced by activated caspase-3 on apoptotic stimulation. Triclabendazole is a new type of imidazole in fluke resistance and has been approved by the FDA for the treatment of fascioliasis and its functions partially acting through apoptosis-related mechanisms. However, it remains unclear whether triclabendazole has obvious anti-cancer effects on breast cancer cells. In this study, to test the function of triclabendazole on breast cancer, we treated breast cancer cells with triclabendazole and found that triclabendazole induced lytic cell death in MCF-7 and MDA-MB-231, and the dying cells became swollen with evident large bubbles, a typical sign of pyroptosis. Triclabendazole activates apoptosis by regulating the apoptoic protein levels including Bax, Bcl-2, and enhanced cleavage of caspase-8/9/3/7 and PARP. In addition, enhanced cleavage of GSDME was also observed, which indicates the secondary necrosis/pyroptosis is further induced by active caspase-3. Consistent with this, triclabendazole-induced GSDME-N-terminal fragment cleavage and pyroptosis were reduced by caspase-3-specific inhibitor (Ac-DEVD-CHO) treatment. Moreover, triclabendazole induced reactive oxygen species (ROS) elevation and increased JNK phosphorylation and lytic cell death, which could be rescued by the ROS scavenger (NAC), suggesting that triclabendazole-induced GSDME-dependent pyroptosis is related to the ROS/JNK/Bax-mitochondrial apoptotic pathway. Besides, we showed that triclabendazole significantly reduced the tumor volume by promoting the cleavage of caspase-3, PARP, and GSDME in the xenograft model. Altogether, our results revealed that triclabendazole induces GSDME-dependent pyroptosis by caspase-3 activation at least partly through augmenting the ROS/JNK/Bax-mitochondrial apoptotic pathway, providing insights into this on-the-market drug in its potential new application in cancer treatment.
2. Caspase-3 and gasdermin E detection in peri-implantitis
Qifeng Jiang, Ying Wang, Zhiwei Jiang, Qianming Chen, Guoli Yang, Wei Dai, Chaozhen Chen, Qin Shao Biochim Biophys Acta Mol Basis Dis . 2021 Nov 1;1867(11):166217. doi: 10.1016/j.bbadis.2021.166217.
Peri-implantitis could lead to progressive bone loss and implant failure; however, the mechanism of peri-implantitis remains unclear. Based on emerging evidence, pyroptosis, a novel proinflammatory programmed death, contributes to different oral infectious diseases. In the present study, we investigated the involvement of cleaved caspase-3 and gasdermin E (GSDME) in peri-implantitis and established a pyroptosis model in vitro. By collecting and examining the inflamed biopsies around peri-implantitis, we found that the pyroptosis-related markers (caspase-3, GSDME, and IL-1β) were enhanced relative to levels in control individuals. Furthermore, human gingival epithelium cells (HGECs) induced by tumor necrosis factor-α (TNF-α) exhibited pyroptosis morphological changes (cell swelling and balloon-shaped bubbles) and upregulated expression of pyroptosis-related markers. Pretreated with Ac-DEVD-CHO (a caspase-3 inhibitor) or GSDME small interference RNA (siRNA) were found to attenuate pyroptosis in HGECs. In conclusion, our findings revealed a high expression of caspase-3 and GSDME in the inflamed biopsies of peri-implantitis and confirmed that the caspase-3/GSDME pathway mediates TNF-α-triggered pyroptosis in human gingival epithelium cells, which provides a new target for peri-implantitis treatment.
3. Mild hypothermia protects hippocampal neurons from oxygen-glucose deprivation injury through inhibiting caspase-3 activation
Hui Lin, Tao Yu, Longyuan Jiang, Chaotao Zeng, Tianen Zhou, Zhengfei Yang, Juanhua Liu Cryobiology . 2018 Feb;80:55-61. doi: 10.1016/j.cryobiol.2017.12.004.
Mild hypothermia (MH) is thought to be one of the most effective therapeutic methods to treat hypoxic-ischemic encephalopathy (HIE) after cardiac arrest (CA). However, its precise mechanisms remain unclear. In this research, hippocampal neurons were cultured and treated with mild hypothermia and Ac-DEVD-CHO after oxygen-glucose deprivation (OGD). The activity of caspase-3 was detected, in order to find the precise concentration of Ac-DEVD-CHO with the same protective role in OGD injury as MH treatment. Western blot and immunofluorescence staining were conducted to analyze the effects of MH and Ac-DEVD-CHO on the expressions of caspase-3, caspase-8, and PARP. The neuronal morphology was observed with an optical microscope. The lactic acid dehydrogenase (LDH) release rate, neuronal viability, and apoptotic rate were also detected. We found that MH (32 °C) and Ac-DEVD-CHO (5.96 μMol/L) had equal effects on blocking the activation of caspase-3 and the OGD-induced cleavage of PARP, but neither had any effect on the activation of caspase-8, which goes on to activate caspase-3 in the apoptotic pathway. Meanwhile, both MH and Ac-DEVD-CHO had similar effects in protecting cell morphology, reducing LDH release, and inhibiting OGD-induced apoptosis in neurons. They also similarly improved neuronal viability after OGD. In conclusion, caspase-3 serves as a key intervention point of the key modulation site or regulatory region in MH treatment that protects neuronal apoptosis against OGD injury. Inhibiting the expression of caspase-3 had a protective effect against OGD injury in MH treatment, and caspase-3 activation could be applied to evaluate the neuroprotective effectiveness of MH on HIE.
