The observation of phenotypic changes of Schwann cells after rat sciatic nerve injury.

To describe the phenotypic changes of Schwann cells during nerve regeneration, we made two different neurorrhaphy models after rat sciatic nerves injury, the epineurium neurorrhaphy and small gap bridging suture. Then, at selected time points after surgery (1d, 3d, 5d, 7d, 2 weeks, 3 weeks), the materials were drawn for detecting the expression of GFAP, Sox2, Krox20 by immunofluorescence. GFAP is expressed in non-myelin-forming Schwann cells and Krox20 is a marker for myelin-forming cells in the adult nerve. Sox2 is a marker for neural stem and progenitor cells. Our findings showed the rule of phenotypic changes of Schwann cells during nerve regeneration. Furthermore, the difference in the phenotypic changes of Schwann cells between two operation methods indicated that the small gap changes the regenerated microenvironment and may be one of the reasons that small gap bridging suture is superior to the epineurium suture.