GsMTx4 Combined with Exercise Exerts Neuroprotective Effects by Regulating Neuronal Autophagy in Rats with Spinal Cord Injury

Abstract

A sharp increase in intramedullary pressure after spinal cord injury (SCI) can aggravate secondary injury and lead to severe neurological deficits. Unfortunately, effective treatment options are currently lacking. The mechanosensitive ion channel Piezo1 plays an important role in the pathological process of SCI by transducing mechanical stress. The Piezo1 inhibitor GsMTx4 has been shown to have neuroprotective effects and may hold therapeutic potential for SCI. Given that single drug treatment strategy has limited effect on functional recovery after SCI, we explored the efficacy of combining GsMTx4 with exercise training in treating SCI in rats and investigated the underlying mechanisms. We used the T10 SCI rat model, administered GsMTx4 immediately after injury, and performed 4 weeks of body weight supported treadmill training starting (BWSTT) 2 weeks post injury. Subsequently, HE and LFB staining were used to observe the morphology of spinal cord tissue, WB was used to detect autophagy and apoptosis-related proteins, biochemical detection of calcium ion concentration and CTSD activity, IHC detection of LAMP1 expression, immunofluorescence labeling of NeuN and ChAT-positive motor neurons, as well as MBP and GFAP, and BBB scores were used to evaluate rat motor function. We found that the combined treatment of GsMTx4 drug and exercise training was more effective than single treatment alone. The combined treatment reduced calcium ion concentration, improved lysosomal function, enhanced autophagic flux, reduced cell apoptosis, and significantly improved the motor function of rats. This combined treatment regimen may pave the way for developing more comprehensive treatment strategies for SCI in the future.

Graphical Abstract

Mechanism diagram. Piezo1 inhibitors combined with exercise exerts neuroprotective effects by regulating neuronal autophagy. Excessive mechanical stress following spinal cord injury (SCI) over activates the mechanosensitive Piezo1 channel in spinal neurons, leading to increased Ca²⁺ release and subsequent lysosomal dysfunction. This dysfunction decreases autophagic flux, potentially resulting in neuronal apoptosis, exacerbated glial scar formation, and demyelination. The application of Piezo1 inhibitors improves lysosomal function and enhances autophagic flux, thereby reducing cell apoptosis. Additionally, exercise training further amplifies the neuroprotective effects of Piezo1 inhibitors, contributing to overall neuronal recovery.