[Eur. J. Immunol. 2013. 43, 2126–2137] show that the NLRP3 inflammasome contributes to oxidative DNA damage. In addition, activation of the NLRP3 inflammasome modulates a number of pathways involved in DNA damage repair, cell cycle, and apoptosis, suggesting a novel role for the NLRP3 inflammasome in DNA damage responses following cellular stress. From microbes to radiation and other carcinogens, the environment in which we live can seem like a veritable minefield. Fortunately, the cells and molecules of the innate immune system have evolved, along with cell-intrinsic processes, to respond swiftly in defense of our cellular and genomic integrity. These multilayered and redundant mechanisms combat

the potentially deleterious effects of diverse environmental stresses by promoting either resolution or cell buy Selumetinib death in an attempt to return to homeostasis. An important component of the innate immune system is the NLRP3 inflammasome. Following detection of cellular damage,

the cytoplasmic nucleotide-binding domain leucine-rich repeat containing (NLR) molecule NLRP3 forms a multiprotein complex, along with the adaptor molecule ASC and the cysteine protease caspase-1 [1]. This process culminates in the activation of caspase-1 and the subsequent maturation and secretion of the proinflammatory cytokines, IL-1β and IL-18 [2-5]. Interestingly, oligomerization and activation of the NLRP3 inflammasome can be induced by a heterogeneous collection of pathogen- and damage-associated molecular patterns (PAMPs and DAMPs, respectively), although the means KPT-330 purchase by which this occurs is unclear. It has been proposed that these inflammasome activating signals actually

work indirectly via a common downstream ligand, such as reactive oxygen species (ROS) [6, 7] generated following mitochondrial damage [8, 9]. Cellular cation fluxes, including a potassium efflux and a calcium influx, have also been shown to be critical DNA ligase for activation of the NLRP3 inflammasome [10, 11]. In addition to its role in immune surveillance, dysregulation of the NLRP3 inflammasome has been reported to contribute to the pathogenesis of a number of human diseases that have an underlying component of chronic inflammation, such as type 2 diabetes mellitus, atherosclerosis, and inflammatory bowel disease [12]. As well, mutations within the gene encoding NLRP3 have been associated with the autoinflammatory cryopyrin-associated periodic syndromes [13]. Such widespread effects underscore the complexity of pathways through which the well-studied NLRP3 inflammasome functions, and emerging literature on the subject indicates there is much left to learn. In this issue of the European Journal of Immunology, Licandro et al. [14] explore noncanonical roles for the NLRP3 inflammasome, i.e. proinflammatory cytokine-independent effects under conditions of cellular stress.