The relationship between S-100 protein and functional activation of Schwann cell in peripheral nerve trauma

Objective To investigate the function of S-100 in Schwann cell during peripheral nerve traumatic degeneration. Methods Ninety-five SD rats were divided randomly into one normal group (8 rats) and 11 experimental groups (66 rats). Both hind-legs of each rat in experimental groups were randomly divided into test leg (with sciatic nerve transected) and control one (nerve uninjured). All test legs constituted a test group and all control legs constituted a control one. After operation, all rats were respectively sacrificed at 1 hour, 6 hour, 12 hour, 24 hour, 2 day, 3 day, 4 day, 8 day, 14 day, 21 day and 30 day. We analyzed the specimens of mid distal sciatic nerve, especially the morphological changes of the nerve, and the different expression levels of S-100 protein in Schwann cell. Results The test group showed Wallerian degeneration. The number of Schwann cell began to decrease at 24 hour, surprisingly be rare at day 3 and 4, then began to increase from day 8 and formed Bungner belt after 14 days. Schwann cell generally expressed S-100 at low level in all groups. The control group was not significantly different from the normal group; There existed statistical significance at 1 hour and day 21 in test group. Conclusion S-100 protein plays an important role in Schwann cell's reaction to peripheral nerve injury, especially in Schwann cell proliferation and the nerve regeneration. And it also reflects the functional activity of Schwann cell.