Chernousov M A, Scherer S S, Stahl R C, Carey D J
Henry Hood M.D. Research Program, Weis Center for Research, Pennsylvania State College of Medicine, Danville 17822-2613, USA.
J Neurosci Res. 1999 May 1;56(3):284-94. doi: 10.1002/(SICI)1097-4547(19990501)56:3<284::AID-JNR8>3.0.CO;2-Q.
Previously we reported that cultured rat Schwann cells secrete p200, a collagen-like heparin-binding adhesive glycoprotein with a restricted pattern of expression. Here we report that p200 is secreted as a stable trimer, but only after treatment of Schwann cells with ascorbic acid, and was deposited in the fibrillar extracellular matrix. Heparin and heparitinase treatment inhibited incorporation of p200 into extracellular matrix, suggesting the involvement of Schwann cell heparan sulfate proteoglycans in this process. Pepsin digestion revealed that p200 secreted by ascorbate-treated cells contains a collagenous domain of approximately 140 kDa. Immunofluorescent staining of rat embryos at different ages showed that p200 first appeared between embryonic days 15 and 18, and was confined to peripheral nerves. Staining of adult peripheral nerve was negative, but p200 expression was induced in adult sciatic nerve following nerve transection. These data suggest that p200 carries out unique functions during peripheral nerve development and regeneration and that its expression by Schwann cells is regulated by axon-Schwann cell interaction.
此前我们报道，培养的大鼠雪旺细胞分泌p200，这是一种具有受限表达模式的胶原样肝素结合黏附糖蛋白。在此我们报道，p200以稳定的三聚体形式分泌，但仅在雪旺细胞用抗坏血酸处理后才会如此，并且会沉积在纤维状细胞外基质中。肝素和硫酸乙酰肝素酶处理抑制了p200掺入细胞外基质，提示雪旺细胞硫酸乙酰肝素蛋白聚糖参与了这一过程。胃蛋白酶消化显示，经抗坏血酸处理的细胞分泌的p200含有一个约140 kDa的胶原结构域。对不同年龄大鼠胚胎的免疫荧光染色显示，p200最早出现在胚胎第15至18天之间，且局限于周围神经。成年周围神经的染色为阴性，但在成年坐骨神经横断后可诱导p200表达。这些数据表明，p200在周围神经发育和再生过程中发挥独特功能，且雪旺细胞对其表达受轴突-雪旺细胞相互作用调控。
