NLRP3 and major depressive disorder: By contrast, downregulation of Kir4.1 in astrocytes activates the NLRP3 inflammasome through the NMDAR/calpain-1 signaling pathway in lipopolysaccharide (LPS)-treated mouse [52], while the NLRP3 inflammasome facilitates the conversion of proIL-1β into IL-1β [53], which creates a vicious cycle, finally leading to depression-like behaviors.