Expression of syndecan-1 in female reproductive tract tissues and cultured keratinocytes.

The syndecans form a family of cell surface heparan sulphate proteoglycans, which participate in cell-matrix interaction and growth factor binding. The expression of syndecan-1 was studied in tissues of the female reproductive tract with respect to the menstrual cycle, and in cultured vaginal and ectocervical keratinocytes. Immunohistochemical localization of syndecan-1 showed a clear biphasic pattern, with intense staining in the basal cell layer of vaginal and ectocervical epithelium in the proliferative phase, and minimal staining in the secretory phase. Low concentrations of syndecan-1 protein and mRNA were expressed in endometrium throughout the cycle. In cultured keratinocytes isolated from vaginal and ectocervical epithelium, the addition of physiological amounts of 17 beta-oestradiol or progesterone, alone or in combination, failed to produce significant changes in syndecan-1 expression. The cyclic changes of syndecan-1 localization in stratified epithelia of vagina and ectocervix observed in this study may be a result of growth factor action rather than a direct sex steroid regulation.