Biological activities of ovine and bovine placental prolactin family proteins

牛催乳素相关蛋白-I（PRP 1）是催乳素（PRL）家族的一个非经典成员。然而，它的功能仍然未知。PRL被组织蛋白酶D和基质金属蛋白酶（MMP）切割后，在人和啮齿类动物中产生具有抗血管生成特性的N-末端16 kDa片段（16 K-PRL）。我们研究了牛PRP 1类似活性的可能性。PRP 1（通常为33 kDa）被组织蛋白酶（CTS）、基质金属蛋白酶和牛子叶条件培养基（BCCM）切割，主要产生26 kDa的N-末端片段。两种特异性酶家族，CTS和MMPs切割完整的PRP 1，BCCM也含有PRP 1切割活性。使用牛脑血管内皮细胞在细胞增殖试验中检查切割的PRP 1的生物活性。切割的PRP 1在体外刺激内皮细胞的增殖。切割的PRP 1的内皮细胞增殖活性可能在特定的牛胎盘血管生成中共享。

Bovine prolactin-related protein-I (PRP1) is a non-classical member of prolactin (PRL) family proteins. However, its function is still unknown. PRL, when cleaved by cathepsin D and matrix metalloproteinases (MMPs), resulted in N-terminal 16 kDa fragments (16K-PRL) that have antiangiogenetic properties in human and rodents. We examined the possibility of similar activity of bovine PRP1. PRP1 (normally 33 kDa) was cleaved by cathepsins (CTSs), MMPs, and bovine cotyledonary-conditioned medium (BCCM), and generated mainly 26 kDa N-terminal fragments. Two specific enzyme families, CTSs and MMPs cleaved intact PRP1, and BCCM also contained PRP1 cleavage activity. Bioactivity of cleaved PRP1 was examined in a cell proliferation assay using bovine brain vascular endothelial cells. The cleaved PRP1 stimulated the proliferation of endothelial cells in vitro. The endothelial cell proliferation activity of cleaved PRP1 may be shared in specific bovine placentomal angiogenesis.