NLRP3 and Parkinson disease: Therefore, using stereotactic injection of AAV-TREM2-shRNA to knock down TREM2 expression in the substantia nigra of the midbrain and intraperitoneal injection of MPTP to establish a chronic PD mouse model, we found that TREM2 knockdown significantly increased the expression of NLRP3 inflammasome and its downstream inflammatory factors IL-1β and IL-18 and the key pyroptosis factors GSDMD and GSDMD-N.