| Research Abstract |
Ryudocan is a cell surface heparin sulfate proteoglycan, a member of the syndecan family, syndecan-4, that have anticoagulant property. We investigated the ryudocan expression in mouse ovarian tissues by in situ hybridization, and found that ryudocan is expressed in the granulosa cells type-4-5b follicles and, most intensely, in those of the atretic follicles. There is no relationship between ryudocan expression and age or sexual cycle stage. Compared with ryudocan expression, syndecan-1 and -3 are expressed more abundantly in postovulatory follicles and the corpora lutea, but less in the type 4-5b follicles and much less in the atretic follicles. Thus, ryudocan could be expressed in ovarian granulosa cells and secrete into follicular fluid to maintain its fluidity. It has been reported that ryudocan may play an important role in a variety of biological functions including regulation of blood coagulation, cell adhesion, and bFGF signaling. A little is known, however, regarding the regulation of its expression. We examined that hypoxia effect on ryudocan expression in the mouse LTA cells, and found that hypoxia treatment up-regulates the gene expression of ryudocan as well as VEGF. Thus, ryudocan would be induced by hypoxia stimuli in ischemic tissues, and function as a tissue-repairing molecule via biologic mediators such as heparin-binding growth factors including bFGF, VEGF, and midkine.
|
