Upregulated Expression of TRIM32 Is Involved in Schwann Cell Differentiation, Migration and Neurite Outgrowth After Sciatic Nerve Crush.

Abstract

Tripartite motif containing 32 (TRIM32), a member of the tripartite motif (TRIM) family, plays an indispensable role in myoblast proliferation. It also regulates neuron and skeletal muscle stem cell differentiation. Although it is of great importance, we know little about the roles of TRIM32 during peripheral nervous system injury. Here, we examined the dynamic changes of TRIM32 in acute sciatic nerve crush (SNC) model. After crush, TRIM32 rapidly increased and reached the climax at 1week but then gradually declined to the normal level at 4weeks post-injury. Meanwhile, we observed similar changes of Oct-6. What is more, we found co-localization of TRIM32 with S100 and Oct-6 in 1-week-injured tissues using double immunofluorescent staining. In further vitro experiments, enhancive expression of TRIM32 was detected during the process of cyclic adenosine monophosphate (cAMP)-induced Schwann cell differentiation and nerve growth factor (NGF)-induced PC12 cell neurite outgrowth. More interestingly, specific si-TRIM32-transfected RSC96 cells exhibited obvious reduction in the ability of migration. Taken together, we inferred that upregulated TRIM32 was not only involved in the differentiation and migration of Schwann cells but the neurite elongation after SNC.