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RAN, L.

Publications and source records attributed to RAN, L..

2 recordsLinked to original sources

KCNN4 links PIEZO-dependent mechanotransduction to NLRP3 inflammasome activation

Immune cells sense the microenvironment to fine-tune their inflammatory responses. Patients with cryopyrin associated periodic syndrome (CAPS), caused by mutations in the NLRP3 gene, develop auto-inflammation triggered by non-antigenic, e.g. environmental cues. However, the underlying mechanisms are poorly understood. Here, we uncover that KCNN4, a calcium-activated potassium channel, links PIEZO-mediated mechanotransduction to NLRP3 inflammasome activation. Yoda1, a PIEZO1 agonist, lowers the threshold for NLRP3 inflammasome activation. PIEZO-mediated sensing of stiffness and shear stress increases NLRP3-dependent inflammation. Myeloid-specific deletion of PIEZO1/2 protects mice from gouty arthritis. Activation of PIEZO1 triggers calcium influx, which activates KCNN4 to evoke potassium efflux promoting NLRP3 inflammasome activation. Activation of PIEZO signaling is sufficient to activate the inflammasome in cells expressing CAPS-causing NLRP3 mutants via KCNN4. Finally, pharmacologic inhibition of KCNN4 alleviates auto-inflammation in CAPS patient cells and in CAPS-mimicking mice. Thus, PIEZO-dependent mechanical inputs augment inflammation in NLRP3-dependent diseases including CAPS. One Sentence SummaryPIEZO-mediated mechanotransduction stimulates KCNN4-dependent potassium efflux to potentiate NLRP3 inflammasome activation.

immunology↗

Defective endosome-TGN retrograde transport promotes NLRP3 inflammasome activation

Inflammasome complexes are pivotal in the innate immune response to pathogens and other danger signals1-4. The NLRP3 inflammasome is activated in response to a broad variety of cellular stressors. Most of the stimuli act in a potassium efflux-dependent manner but a primary and converging sensing mechanism by the NLRP3 receptor initiating inflammasome assembly remains ill-defined. Here we show that NLRP3 activators disrupt endosome-TGN retrograde transport (ETRT) and lead to localization of NLRP3 to endosomal vesicles. Genetic and pharmacologic perturbation of ETRT leads to accumulation of phosphoinositol-4-phosphate (PI4P) in endosomes to which NLRP3 is recruited. Disruption of ETRT potentiates NLRP3 inflammasome activation in murine and human macrophages in vitro. Mice with defects in ETRT in the myeloid compartment are more susceptible to LPS-induced sepsis showing enhanced mortality and IL-1{beta} serum levels as compared to control animals. Our study thus uncovers that changes in endocytic trafficking mediate NLRP3-dependent inflammatory responses.

immunology↗