MaR1 and NGF combine to inhibit autophagy through the GSK-3β/β-catenin pathway to promote sciatic nerve repair.

Abstract

<h4>Background</h4>Peripheral nerve injury (PNI) is a public health problem that can lead to sensory and motor deficits as well as neuropathic pain and secondary lesions. We explored the effects of the combination of MaR1 and NGF on sciatic nerve regeneration, reduction of neuropathic pain, and anti-inflammation, and further elucidated the associated molecular mechanisms.<h4>Methods</h4>After treatment of PC12 (adrenal pheochromocytoma cells) cells with NGF, MaR1 and H₂O₂, changes in proliferation were detected by CCK8; cell migration ability was detected by Transwell; reactive oxygen species (ROS) and apoptosis were detected by flow cytometry; and the mRNA expression of the inflammatory factors IL-1β, IL-6, and TNF-α was detected by qRT-PCR. Western blot detected the protein expression of β-catenin, P62, GSK-3β, LC3B, NF200, S100, MBP; Immunofluorescence analysis of LC3B expression; During recovery experiments, observe changes following treatment with GSK-3β activators and the autophagy agonist rapamycin. PNI model was constructed using 6-week-old male SD rats, NGF, MaR1 or saline was injected locally, and the drug was administered 3 times on alternate days after surgery, sciatic nerve function index analysis and muscle atrophy test were performed after surgery; the gastrocnemius muscle wet weight ratio and HE staining were observed after the samples were taken after surgery, and NF200, S100, MBP, β-catenin, and P62 were detected by Western blot, GSK-3β, LC3B levels; the expression of NF200, β-catenin, P62, GSK-3β, LC3B was detected by immunohistochemistry.<h4>Results</h4>NGF and MaR1 were non-toxic and the combination of NGF and MaR1 increased the proliferation and migration of PC12 cells, reduced H₂O₂ induced ROS production, inhibited apoptosis, and had a significant anti-inflammatory effect. In vivo studies showed that MaR1 and NGF combined could more effectively promote nerve repair and recovery of sensory and motor functions in SD rats, and reduce gastrocnemius muscle atrophy.The combination of MaR1 and NGF inhibited autophagy through GSK-3β/β-catenin signaling pathway to regulate the growth and repair of sciatic nerve. And the GSK-3β agonist DIF-3 and the autophagy activator rapamycin antagonize this effect.<h4>Conclusion</h4>The combination of MaR1 and NGF promotes sciatic nerve repair and motor function recovery and reduces local inflammation by inhibiting autophagy through the GSK-3β/β-catenin pathway.