Expression of osteopontin in human endometrium throughout menstrual cycle

摘要

Objective:To analyze mRNA and protein expression of osteopontin(OPN) in human endometrium throughout menstrual cycle.Methods:Immunohistochemical method was used to determine the level and the location of OPN in normal cycling endometrium of 50 women. Western Blot analysis was also used to detect the existence of OPN at proliferative and secretory phases in six samples. The levels of OPN mRNA in 18 samples were measured by RT-PCR. Results:The OPN mainly expressed in human endometrial glandular epithelium but not in stromal cells. The expression was highest at mid and late secretory phases and menstruous phase as well. No expression was found in early and mid proliferative endometria. Two subtypes of OPN proteins (40 kDa-75 kDa) were detected by Western blot analysis in homogenized endometria at secretory phase.The level of OPN mRNA in secretory phase endometrium was significantly higher than that in proliferative phase. Conclusions:OPN was only found in endometrial glandular epithelial cells, and the OPN and its mRNA showed a pronounced cycle-dependent expression in human endometrium, higher expression at mid and late secretory phases and menstruous phase. It's probably involved in embryonic implantation and endometrial shedding.