A large keratan sulfate proteoglycan present in human cervical mucous appears to be involved in the reorganization of the cervical extracellular matrix at term

OBJECTIVE: To elucidate the function of keratan sulfate proteoglycan (KS-PG ) in the human uterine cervix, we analyzed its distribution with respect to physiologic conditions. METHODS: Immunohistochemistry iva used to localize KS bearing proteoglycans (InAb 5D4) and decorin (mAb 6B6) in the lower uterine segment. Proteins pr esent in cervical mucous were labeled with biotin, glycosaminoglycan chains were digested enzymatically, and the samples were analyzed by Western blot . RESULTS: Decorin was detected throughout the extracellular matrix, in tissu es from menstruating nonpregnant women, in early pregnancy, from women who had cesarean at term, at postpartum hysterectomy, and from postmenopausal w omen. In menstruating nonpregnant women, in early pregnancy (first trimeste r), and in postmenopausal women, KS-PG was detectable only in epithelial, m ucous-producing cells. Interestingly, in samples obtained either at the tim e of cesarean at term (lower uterine segment) or after postpartal hysterect omy, KS-PG was detectable throughout the extracellular matrix, indicating t hat the expression of KS-PG is associated with reorganization of the tissue . Biochemical analysis of the KS present in mucous revealed a core protein in the range of 220 kDa, suggesting an identity with the large KS-PG descri bed previously. CONCLUSION: At parturition, a large KS-PG, which is virtually exclusively p resent in the cervical mucous of either early or nonpregnant women, was det ected in the extracellular matrix. This finding indicates that cervical rip ening is accompanied not only by quantitative but also by qualitative chang es in the composition of the extracellular matrix. Copyright (C) 2001 by th e Society for Gynecologic Investigation.