This study aims to investigate the role of apoptosis and autophagy under endoplasmic reticulum (ER) stress in a lithium-treated SCI model.

We established a rat thoracic 10 (T10) spinal cord contusion model and observed its therapeutic effect by intraperitoneal (IP) injection of lithium. Histological and behavioral recovery with or without lithium injection were evaluated after rat spinal cord injury. In addition, we employed an oxygen-glucose deprivation (OGD)-PC12 cell model to study the effects of lithium on OGD-PC12 cell apoptosis, autophagy and ER stress.

We found that lithium administration to SCI rats reduced neuronal apoptosis and autophagy, restored rat locomotor function by reducing ER stress via IRE1 and PERK/eIF2α pathways. In vitro experiments confirmed that upon lithium treatment, OGD-PC12 cells resisted ER stress caused by thapsigargin (TG) via the IRE1 and PERK/eIF2α signaling pathways.

Lithium attenuated neuronal apoptosis and autophagy, and facilitates the recovery after spinal cord injury through ameliorating ER stress, providing a new therapeutic mechanism for lithium to treat SCI.