Plasmalogens Activate AKT/mTOR Signaling to Attenuate Reactive Oxygen Species Production in Spinal Cord Injury.

Background: Plasmalogens, the primary phospholipids in the brain, possess intrinsic antioxidant properties and are crucial components of the myelin sheath surrounding neuronal axons. While their neuroprotective effects have been demonstrated in Alzheimer's disease, their potential benefits in spinal cord injury remain unexplored. This study investigates the reparative effects of plasmalogens on spinal cord injury and the underlying mechanisms.

Methods: In vitro, we developed dorsal root ganglion (DRG) and RAW 264.7 cell models under high-reactive oxygen species (ROS) conditions to assess ROS levels, neuronal damage, and inflammatory microenvironment changes before and after plasmalogen application. In vivo, we used a complete mouse spinal cord transection model to evaluate changes in ROS levels, neuronal demyelination, and apoptosis following plasmalogen treatment. Additionally, we assessed sensory and motor function recovery and investigated the regulatory effects of plasmalogens on the AKT/mTOR signaling pathway.

Results: In high-ROS cell models, plasmalogens protected DRG neurons (TUJ-1) from axonal damage and modulated the proinflammatory/anti-inflammatory balance in RAW 264.7 cells. In vivo, plasmalogens significantly reduced ROS levels, improved the immune microenvironment, decreased the proinflammatory (iNOS)/anti-inflammatory (ARG-1) ratio, lowered neuronal (TUJ-1) apoptosis (Caspase-3, BAX), and reduced axonal degeneration while promoting myelin (MBP) regeneration, indicating a neuroprotective effect. These findings are linked to the activation of the AKT/mTOR signaling pathway.

Conclusion: Plasmalogens reduce ROS levels and regulate inflammation-induced damage, contributing to neuroprotection. This study reveals that plasmalogens promote remyelination, reduce axonal degeneration and neuronal apoptosis, and-used here for the first time in spinal cord injury repair- may protect neurons by reducing ROS levels and activating the AKT/mTOR signaling pathway.