The role of Gαq in regulating NLRP3 inflammasome activation.

Background: G proteins are a class of important signal transducers in mammalians. G proteins can corpoarated with G proteincoupled receptors (GPCRs) and transmit signals from extracellular stimuli into intracellular response, which will regulate a series of biological functions. G-proteins are heterotrimeric proteins composed of Gα, Gβ, and Gγ subunits. Based on structural and functional similarity of their α-subunits, G proteins are typically grouped into four classes (Gi, Gs, Gq/11, and G12/13). The Gq/11 subfamily consists of Gq, G11, G14, and G15/16 proteins. Gαq is the α-subunit of Gq protein and encoded by GNAQ. Our previous studies revealed that Gαq play an important role in regulating T cell survival and T cell differentiation. Inflammasomes are multiprotein complexes that play a critical role in modulating innate inflammatory response. NLRP3 inflammasome is currently the most extensively studied inflammasome.

Methods: We found that Gαq suppressed NLRP3 inflammasome activation in macrophage, Gαq also suppressed NLRP3 inflammasome activation in a LPS-induced sepsis mouse model. Gαq can locate to mitochondria and Gαq was required for the maintenance of mitochondrial homeostasis. Gαq regulated NLRP3 inflammasome activation by modulating mitochondrial reactive oxygen species (mtROS).

Results: We found that Gαq suppressed NLRP3 inflammasome activation in macrophage, Gαq also suppressed NLRP3 inflammasome activation in a LPS-induced sepsis mouse model. Gαq can locate to mitochondria and Gαq was required for the maintenance of mitochondrial homeostasis. Gαq regulated NLRP3 inflammasome activation by modulating mitochondrial reactive oxygen species (mtROS).

Conclusion: Our results indicate that Gαq regulates NLRP3 inflammasome activation by modulating mitochondrial ROS production. Our research provides new mechanistic insight into the activation of NLRP3 inflammasome. As it has been proved that NLRP3 inflammasome plays an important role in the pathogenesis many diseases such as Alzheimer's disease, cancer, and inflammatory bowel disease, Gαq might become a novel drug target for these diseases in future.