NPTX2 and Parkinson disease: To further explore the effects of the HOTAIR/miR-221-3p/ NPTX2 axis on autophagy in the PD mouse models, PD mice were initially injected with saline, MPTP, MPTP + LV-oe-NC + agomir-NC, MPTP + LV-oe-HOTAIR + agomir-NC and MPTP + LV-oe-HOTAIR + miR-221-3p agomir.