Stem cells from human exfoliated deciduous teeth relieve pain via downregulation of c-Jun in a rat model of trigeminal neuralgia.

ABSTRACT

BACKGROUND: Stem cells from human exfoliated deciduous teeth (SHED) have excellent immunomodulatory and neuroprotective abilities. It is possible that systemic SHED transplantation could ameliorate trigeminal neuralgia. The phosphorylation of c-Jun contributes to the development of hyperalgesia and allodynia. OBJECTIVE: The present study aimed to evaluate whether systemic SHED transplantation could lead to analgesic effects by regulating peripheral c-Jun in the trigeminal ganglia (TG) in a rat model of trigeminal neuralgia. METHODS: Chronic constriction injury of the infraorbital nerve (CCI-ION) was performed to establish a rat pain model. SHED were obtained from discarded exfoliated deciduous teeth from children and transplanted by a single infusion through the tail vein. SHED were labelled with the PKH26 red fluorescent cell linker mini kit for tract distribution. The mechanical threshold was determined using von Frey filaments. The mRNA levels of c-Jun in the ipsilateral TG were quantified. The phosphorylation of c-Jun in the ipsilateral TG was assessed by immunohistochemistry and Western blotting. RESULTS: PKH26-labelled SHED were distributed to both sides of TG, lung, liver and spleen. Systemic SHED transplantation significantly elevated the mechanical thresholds in CCI-ION rats and blocked the upregulation of c-Jun mRNA levels in the TG caused by nerve ligation. The activation of c-Jun in the TG was blocked by SHED transplantation. CONCLUSIONS: These findings demonstrate that systemic SHED administration reverts trigeminal neuralgia via downregulation of c-Jun in the TG.