Expression of purinergic receptor P2Y4 in Schwann cell following nerve regeneration

Data from the present study suggested a potential role of P2Y4 receptors in functional modulation of SCs in the regeneration of RLN.

Right RLN of fifty Sprague-Dawley rats was cut and immediately repaired with PLGA/chitosan nerve conduit. Immunofluorescence, real-time qPCR and Western blot were used to detect the expression alterations of P2Y4 receptor.

Emerging evidences suggested an important role of purinergic receptor P2Y4 in nerve system. The present study aims to investigate the localization and possible function of P2Y4 receptor in recurrent laryngeal nerve (RLN) following regeneration.

Weak immunostaining signals of P2Y4 receptor were located on the plasmalemma of Schwann cell (SC) with regular arrangement of axons in normal RLN. On the post-injury 4th day, the sprouting axons regrowed along the degenerated SCs intensively expressing P2Y4 receptor. On the post-injury 7th day, the regenerating axons existed in multicellular cords of P2Y4 receptor-positive SCs occupying the nerve gap. On the post-injury 14th day, the axons grew along the bands of P2Y4 receptor-positive SCs exhibiting the regularly parallel distribution. On the post-injury 30th day, mild immunostaining signals of P2Y4 receptor still existed on SC surface, and the regenerated axons were located inside the remodeled endoneurium tube. In accordance with immunofluorescence findings, the transcription and protein expression levels of P2Y4 were significantly increased after the injury and the peak value appeared on the post-injury 7th day, compared to control group (P < 0.05).