Dynamic gene expression in Schwann cell for regulating myelination

To obtain the dynamic gene expression of myelinating Schwann cells, we have employed gene expression profiling microarray as a discovery platform to analyze the gene expression of Schwann cells in different stages of myelination in an DRG neuron and SC co-culture myelinating model. Rat Schwann cells and dorsal root ganglion (DRG) neurons were cocultured and induced myelination in DMEM medium containing 15% FBS, 50 ng/ml NGF and 50 μg/ml L-ascorbic acid for 21d. During the co-cultivation, myelinating SCs at different stages dissected by Laser microdissection (LMD) in myelination model (i.e. co-culture 1d, 3d, 7d, 14d, 21d), the Schwann cells without co-culture as control samples (i.e. co-culture 0d). The results from Euclidean distance matrix, principal component analysis, and hierarchical clustering indicated that 2 nodal transitions in temporal gene expressions could segregate 3 distinct transcriptional phases within the period of DRG/SC co-culture 21 days. The 3 phases were designated as “premyelination”, “myelination”, and “mature phase”, respectively, by referring to morphological observation of post co-culture changes and gene ontology (GO) analysis. Dynamic gene expression of myelinating Schwann cells were measured at co-culture 0d, 1d, 3d, 7d, 14d, 21d. Three independent experiments were performed at each time using different donors for each experiment.