Shed-Apovs Promote Myelin Regeneration In Refractory Facial Nerve Injury

To investigate the therapeutic effect of apoptotic vesicles derived from stem cells from exfoliated deciduous teeth (SHED-apoVs) on refractory facial nerve injury (FNI) in rats and explore possible molecular mechanism. Intractable peripheral facial nerve injury models were established in male SD rats. SHED-apoVs or apoptotic vesicles derived from adipose-derived stem cells (ADSC-apoVs) were injected into refractory FNI rats. Two weeks later, HE, Nissl, Masson and TEM were used to detect histological changes in rats. In vitro, Schwann cells injured by oxygen and glucose deprivation were treated with SHED-apoVs. CCK8, cell scratch assays and western blotting were used to detect Schwann cell function. Histology showed reduced pons neurons, decreased buccal muscle fibers, and increased facial nerve fiber lysis in FNI rats. After SHED-apoVs treatment, the facial nerve exhibited a thickened outer membrane with enhanced integrity, along with a reduction in nerve fiber necrosis, dissolution, and intimal rupture in FNI rats. Furthermore, the organization of nerve fibers within the bundle improved, and the myelin sheath contours surrounding the axons became more distinct. Moreover, SHED-apoVs treatment significantly increased the number of pons neuron and the proportion of buccal muscle fibers. In addition, SHED-apoVs enhanced the activity and migration of injured Schwann cell, upregulated the expression of βⅢ-Tubulin, NGF, and MBP. Notably, SHED-apoVs demonstrated superior therapeutic efficacy compared to ADSC-apoVs at equivalent doses. SHED-apoVs could effectively ameliorate refractory facial nerve injury by promoting myelin regeneration.