Regulation of tie receptor expression on human endothelial cells by protein kinase C-mediated release of soluble tie
Regulation of tie receptor expression on human endothelial cells by protein kinase C-mediated release of soluble tie
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DOI：
10.1182/blood.v90.2.706.706_706_715
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发表时间：
1997-07-15
期刊：
影响因子：
20.3
通讯作者：
Ratzkin, B
中科院分区：
文献类型：
--
作者：
Yabkowitz, R;Meyer, S;Ratzkin, B
细胞表面受体酪氨酸激酶 (RTK) 的表达和活性可以通过几种不同的途径进行调节，包括胞外结构域作为可溶性受体的蛋白水解释放。我们研究了tie受体表达的调节，tie受体是一种仅限于造血和内皮谱系细胞的孤儿RTK，在原代人内皮细胞和稳定转染的中国仓鼠卵巢（CHO）细胞系上的表达，Tie在细胞中表达为135和125 kD的双联体； 135-kD 条带代表含有唾液酸和 N 连接寡糖残基的成熟细胞表面受体，而 125kD 条带代表细胞内未成熟受体库，佛波醇 12-肉豆蔻酸酯 13-乙酸酯 (PMA) 对细胞表面的连接表达具有显着影响。 PMA 处理 15 分钟内，135 kD 条带从细胞表面消失，并伴随细胞上清液中出现 100 kD 条带。在整个 PMA 处理期间，100-kD 条带在培养基中持续积累，在此期间，通过荧光激活细胞分选 (FAGS) 在细胞表面上或通过免疫印迹分析在细胞裂解物中检测不到成熟的连接受体。使用特异性抗体，这种 100-kD 的物质被证明是含有胞外结构域的可溶性连接受体的可溶形式，可溶性连接的 PMA 依赖性释放是通过蛋白激酶 C (PKC) 的激活介导的；在存在 PKC 抑制剂（无活性 PMA 类似物）或通过长期 PMA 治疗下调 PKC 后，可溶性 Tie 不会释放。这些结果表明，内皮细胞上的 Tie 受体表达受到 PKC 激活后可溶性细胞外片段释放的调节。调节 c-kit、肿瘤坏死因子 (TNF) 和集落刺激因子 (CSF) 受体表达的平行途径表明，细胞外受体片段的释放代表了细胞调节对生长因子和细胞因子反应的另一种机制。 (C) 1997 年，美国血液学会。
The expression and activity of receptor tyrosine kinases (RTK) at the cell surface can be modulated by several different pathways including the proteolytic release of the extracellular domain as a soluble receptor. We investigated the regulation of tie receptor expression, an orphan RTK restricted to cells of hematopoietic and endothelial lineages, on primary human endothelial cells and a stably transfected Chinese hamster ovary (CHO) cell line, Tie was expressed in cells as a doublet of 135 and 125 kD; the 135-kD band represented mature cell surface receptor containing sialic acid and N-linked oligosaccharide residues, whereas the 125kD band represented an intracellular pool of immature receptor, Phorbol 12-myristate 13-acetate (PMA) had dramatic effects on tie expression at the cell surface. Within 15 minutes of PMA treatment, the 135-kD band disappeared from the cell surface and was accompanied by the appearance of a 100-kD band in cell supernatants. The 100-kD band continued to accumulate in the media throughout the duration of PMA treatment during which mature tie receptor was undetectable on the cell surface by fluorescence-activated cell sorting (FAGS) or in cell lysates by immunoblot analysis. Using specific antibodies, this 100-kD species was shown to be a soluble form of the tie receptor containing the extracellular domain, PMA-dependent release of soluble tie was mediated through the activation of protein kinase C (PKC); soluble tie was not released in the presence of PKC inhibitors, an inactive PMA analog, or following the downregulation of PKC through chronic PMA treatment, These results indicate that tie receptor expression on endothelial cells is regulated by the release of a soluble extracellular fragment following activation of PKC. Parallel pathways regulating c-kit, tumor necrosis factor (TNF), and colony stimulating factor (CSF) receptor expression suggest that the release of extracellular receptor fragments represents an alternative mechanism through which cells modulate responses to growth factors and cytokines. (C) 1997 by The American Society of Hematology.