Subcellular distribution pattern of Nogo-A in cortical neurons

Objective To investigate the content of Nogo-A protein in different developmental stages of primary cultured neurons, as well as the distribution pattern of Nogo-A in neuronal specialized regions. Methods In 1d, 3d, 7d, 14 d of in vitro cultured cortical neurons, four components containing cytoplasm, membrane, nucleus and cytoskeleton were extracted respectively. The expression level of Nogo-A in different components at different time points was exam ined with Western blot. Immunofluorescence staining study was performed to check the distribution of Nogo- A in dendrites, axons, synapses and growth cone.Results In the whole developmental period, Nogo-A was highly expressed in the cell membrane and organelle membrane fractions, followed by cytoplasm. 80 k Da fragment of Nogo-A degradation was visible in the nucleus at 1-7 d, which was the critical stages of dendritic development. Distribution data showed that Nogo-A largely positioned in the cytoplasm, dendrites and axons of neurons, especially enriched in growth cones and synaptic regions. Conclusion Nogo-A is primarily expressed in the special regions of neurons that are closely related with neurite outgrowth. Fragment of Nogo-A in nuclear of early development may be involved in the regulation of dendritic growth.