title: Gossypol induces pyroptosis in mouse macrophages via a non-canonical inflammasome pathway.
abstract: Gossypol, a polyphenolic compound isolated from cottonseeds, has been reported to possess many pharmacological activities, but whether it can influence inflammasome activation remains unclear. In this study, we found that in mouse macrophages, gossypol induced cell death characterized by rapid membrane rupture and robust release of HMGB1 and pro-caspase-11 comparable to ATP treatment, suggesting an induction of pyroptotic cell death. Unlike ATP, gossypol induced much low levels of mature interleukin-1β (IL-1β) secretion from mouse peritoneal macrophages primed with LPS, although it caused pro-IL-1β release similar to that of ATP. Consistent with this, activated caspase-1 responsible for pro-IL-1β maturation was undetectable in gossypol-treated peritoneal macrophages. Besides, RAW 264.7 cells lacking ASC expression and caspase-1 activation also underwent pyroptotic cell death upon gossypol treatment. In further support of pyroptosis induction, both pan-caspase inhibitor and caspase-1 subfamily inhibitor, but not caspase-3 inhibitor, could sharply suppress gossypol-induced cell death. Other canonical pyroptotic inhibitors, including potassium chloride and N-acetyl-l-cysteine, could suppress ATP-induced pyroptosis but failed to inhibit or even enhanced gossypol-induced cell death, whereas nonspecific pore-formation inhibitor glycine could attenuate this process, suggesting involvement of a non-canonical pathway. Of note, gossypol treatment eliminated thioglycollate-induced macrophages in the peritoneal cavity with recruitment of other leukocytes. Moreover, gossypol administration markedly decreased the survival of mice in a bacterial sepsis model. Collectively, these results suggested that gossypol induced pyroptosis in mouse macrophages via a non-canonical inflammasome pathway, which raises a concern for its in vivo cytotoxicity to macrophages.
authors.affiliation: Department of Immunobiology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors.forename: Qiu-Ru
authors.initials: QR
authors.lastname: Lin
authors.affiliation: Department of Immunobiology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors.forename: Chen-Guang
authors.initials: CG
authors.lastname: Li
authors.affiliation: Department of Fetal Medicine, The First Affiliated Hospital of Jinan University, Guangzhou 510632, China.
authors.forename: Qing-Bing
authors.initials: QB
authors.lastname: Zha
authors.affiliation: Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors.forename: Li-Hui
authors.initials: LH
authors.lastname: Xu
authors.affiliation: Department of Immunobiology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Pan
authors.affiliation: Department of Immunobiology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors.forename: Gao-Xiang
authors.initials: GX
authors.lastname: Zhao
authors.affiliation: Department of Immunobiology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China. Electronic address: dongyun1967@aliyun.com.
authors.forename: Dong-Yun
authors.initials: DY
authors.lastname: Ouyang
authors.affiliation: Department of Immunobiology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China. Electronic address: thexh@jnu.edu.cn.
authors.forename: Xian-Hui
authors.initials: XH
authors.lastname: He
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D006072:Gossypol / Q000633:toxicity*; D058847:Inflammasomes / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D000069292:Pyroptosis / Q000187:drug effects* / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology
chemical_list: D058847:Inflammasomes; D006072:Gossypol
keywords: Gossypol; HMGB1; Inflammasome; Interleukin-1β; Pyroptosis