Ryudocan expression and its regulation

Ryudocan是一种细胞表面硫酸肝素蛋白多糖，属于Syndecan家族Syndecan-4，具有抗凝血特性。我们用原位杂交的方法研究了ryudocan在小鼠卵巢组织中的表达，发现ryudocan在颗粒细胞-4-5b型卵泡中表达，并且在闭锁卵泡中表达最强。Yyudocan的表达与年龄、性周期分期无关。与ryudocan表达相比，syndecan-1和-3在排卵后卵泡和黄体中表达更丰富，在4-5b型卵泡中表达较少，在闭锁卵泡中表达较少。因此，Yyudocan可以在卵巢颗粒细胞中表达并分泌到卵泡液中，以维持其流动性。已有研究表明，ryudocan可能在多种生物学功能中发挥重要作用，包括调节凝血、细胞黏附和bFGF信号转导。然而，人们对其表达的调控知之甚少。我们检测了低氧对小鼠LTA细胞Ryudocan表达的影响，发现低氧处理上调了Ryudocan和VEGF的基因表达。因此，yyudocan可以在缺血组织中受到低氧刺激的诱导，并通过生物介质发挥组织修复分子的作用，如肝素结合生长因子，包括bFGF，VEGF和Midkine。

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.