Pannexin-1 is required for ATP release during apoptosis but not for inflammasome activation

Y Qu, S Misaghi, K Newton, LL Gilmour… - The Journal of …, 2011 - journals.aai.org
Y Qu, S Misaghi, K Newton, LL Gilmour, S Louie, JE Cupp, GR Dubyak, D Hackos, VM Dixit
The Journal of Immunology, 2011journals.aai.org
Apoptotic cell death is important for embryonic development, immune cell homeostasis, and
pathogen elimination. Innate immune cells also undergo a very rapid form of cell death
termed pyroptosis after activating the protease caspase-1. The hemichannel pannexin-1 has
been implicated in both processes. In this study, we describe the characterization of
pannexin-1–deficient mice. LPS-primed bone marrow-derived macrophages lacking
pannexin-1 activated caspase-1 and secreted its substrates IL-1β and IL-18 normally after …
Abstract
Apoptotic cell death is important for embryonic development, immune cell homeostasis, and pathogen elimination. Innate immune cells also undergo a very rapid form of cell death termed pyroptosis after activating the protease caspase-1. The hemichannel pannexin-1 has been implicated in both processes. In this study, we describe the characterization of pannexin-1–deficient mice. LPS-primed bone marrow-derived macrophages lacking pannexin-1 activated caspase-1 and secreted its substrates IL-1β and IL-18 normally after stimulation with ATP, nigericin, alum, silica, flagellin, or cytoplasmic DNA, indicating that pannexin-1 is dispensable for assembly of caspase-1–activating inflammasome complexes. Instead, thymocytes lacking pannexin-1, but not the P2X7R purinergic receptor, were defective in their uptake of the nucleic acid dye YO-PRO-1 during early apoptosis. Cell death was not delayed but, unlike their wild-type counterparts, Panx1−/− thymocytes failed to recruit wild-type peritoneal macrophages in a Transwell migration assay. These data are consistent with pannexin-1 liberating ATP and other yet to be defined “find me” signals necessary for macrophage recruitment to apoptotic cells.
journals.aai.org