ABSTRACT
Objective To investigate the role of white matter astrocytes and their specific protein S100A4 in sensory neurite outgrowth in vitro.Methods White matter astrocyte cultures expressing S100A4 were prepared. Dissociated adult dorsal root ganglion(DRG)cells were placed on the top of the astrocytes and co-cultured for 6,12, 18,24 hours.Small interfering S100A4 RNA was used to eliminate S100A4 expression.The growth of DRG cell neu- rites on S100A4-sileneed and S100A4-expressing astrocytes was compared.Results 12,18 and 24 hours after the co-culture with S100A4-expressing or S100A4-silenced astroeytes,neurite growth from the DRG cells was observed. Neurite outgrowth was significantly greater in S100A4 siRNA treated cultures compared to control siRNA treated white matter astrocyte cultures.Conclusion These findings suggest that white matter astroeytes are able to support axonal regeneration and,furthermore,that administration of small interfering S100A4 RNA provides strong additional support for axon regeneration.