Cellular expression of src-suppressed C kinase substrate (SSeCKS) in the peripheral nervous system and sensory organs

Abstract

Src-suppressed C kinase substrate (SSeCKS) is expressed in a variety of cells and plays an important role in cell differentiation, migration and shaping via remodeling of the actin-based cytoskeleton. In the present study, the cellular distribution of SSeCKS was studied in the peripheral nervous system and sensory organs of mice by in situ hybridization and immunohistochemistry. In the dorsal root ganglia and trigeminal ganglia, small- and medium-sized neurons expressed SSeCKS, whereas large-sized neurons showed negative or faintly positive reactions. Definite positive signals of SSeCKS mRNA and protein in the sensory ganglia were also found in some satellite cells which frequently enveloped ganglion cells without SSeCKS expression. In autonomic ganglia (celiac ganglia, pelvic ganglia, and intestinal myenteric nerve plexus), SSeCKS immunoreactivity was confined to satellite cells, and not detectable in neuronal somata. No significant immunoreactivity for SSeCKS appeared in most sensory organs, including the retina, organ of Corti, taste buds, and olfactory mucosa. In contrast, the vomeronasal organ displayed intense and selective expression of SSeCKS in the sensory epithelium, where only supporting cells were immunolabeled. SSeCKS-immunoreactive Schwann cells were widely distributed in nerve bundles including the vomeronasal nerve, olfactory nerve, and dorsal root. These findings suggest that SSeCKS might be involved in regulation and homeostasis of the peripheral nervous system and of the vomeronasal organ among sensory organs.