Noncanonical Il-1ß maturation in microglia impairs cognition in chronic kidney disease via neuronal IL1R signaling

While cognitive impairment is common in peripheral diseases such as chronic kidney disease (CKD), mechanistic insights and effective therapies are lacking. Here, we show that microglial potassium (K+) dyshomeostasis induces noncanonical IL-1ß maturation and neuronal dysfunction via IL-1R signaling in CKD. Despite inflammasome activation in the brain, microglial caspase-1 deficiency does not improve inflammation and cognition in CKD mice. Noncanonical IL-1ß maturation in microglia is mediated by the cathepsin C–caspase-8 pathway. Restoring K+ homeostasis in microglia or genetically inhibiting neuronal IL-1R1 signaling abolishes CKD-induced cognitive impairment. Microglial K+ dyshomeostasis and noncanonical microglial IL-1ß maturation may therefore be druggable targets in some forms of cognitive impairment. These insights identify a new intercellular microglia–neuron crosstalk and identify potential therapeutic targets to combat inflammasome-induced neuronal dysfunction. Overall design: We performed single nuclei RNAseq in order to investigate gene expression profiling in brain cells of the cortex in chronic kidney disease versus control/sham mice.