Persistent SOX10 expression in terminal glial cells of human cutaneous sensory corpuscles throughout life.

Cutaneous sensory corpuscles contain specialized non-myelinating terminal glial cells essential in mechanosensing. SOX10 is a transcription factor critically involved in Schwann-cell differentiation and myelination, but its expression in terminal glial cells of human sensory corpuscles has not been systematically investigated. The aim of this study was to analyze the expression of SOX10 in human Meissner and Pacinian corpuscles throughout development, adulthood, and aging. Samples of glabrous digital skin were obtained from human fetal, perinatal, and postnatal specimens ranging from 11 weeks of estimated gestational age to 90 years of age. Immunohistochemistry, double immunohistochemistry, and immunofluorescence were performed to determine the cellular localization of SOX10. S100 protein was used to identify terminal glial cells, whereas myelin basic protein (MBP) was employed to assess myelin formation. Nuclear SOX10 immunoreactivity was detected from the earliest stages of development in both Meissner and Pacinian corpuscles. In Meissner corpuscles, SOX10 expression appeared earlier than S100 protein expression. Throughout life, SOX10-positive nuclei were consistently localized within terminal glial cells identified by S100 immunoreactivity. In contrast, terminal glial cells of both corpuscle types lacked MBP immunoreactivity at all developmental and postnatal stages examined. Quantitative analysis demonstrated that virtually all Meissner corpuscles were SOX10-positive. The proportion of Meissner corpuscles containing SOX10-positive cells remained relatively stable throughout life, with no significant age-related differences. Human terminal glial cells of cutaneous sensory corpuscles maintain SOX10 expression throughout life despite the absence of detectable myelin. These findings identify SOX10 as a persistent marker of terminal glial cells in human cutaneous sensory corpuscles and suggest that maintenance of Schwann-cell transcriptional programs occurs independently of myelin formation.