Infl ammasome is a large protein complex activated upon cellular stress or microbial infection,which triggers maturation of pro-inflammatory cytokines interleukin-1βand interleukin-18 through caspase-1 activation.Nod-like receptor family protein 3(NLRP3)is the most character-ized infl ammasome activated by various stimuli.However,the mechanism of its activation is unclear and its exact cellular localization is still unknown.We examined the potential co-localization of NLRP3 infl ammasome with mi-tochondria and seven other organelles under adenosine triphosphate,nigericin or monosodium urate stimulation in mouse peritoneal macrophages using confocal micros-copy approach.Our results revealed that the activated endogenous apoptosis-associated speck-like protein containing a CARD(ASC)pyroptosome forms in the cyto-plasm and co-localizes with NLRP3 and caspase-1,but not with any of the organelles screened.This study indicates that the ASC pyroptosome universally localizes within the cytoplasm rather than with any specifi c organelles.
Yan WangChen YangKairui MaoShuzhen ChenGuangxun MengBing Sun
