ABSTRACT

CD147 is a widely expressed matrix metalloproteinase inducer involved in the regulation of cell migration. The high glycosylation and ability to undergo oligomerization have been linked to CD147 function, yet there is limited understanding on the molecular mechanisms behind these processes. The current study demonstrates that the expression of Golgi α1,2-mannosidase I is key to maintaining the cell surface organization of CD147 during cell migration. Using an in vitro model of stratified human corneal epithelial wound healing, we show that CD147 is clustered within lateral plasma membranes at the leading edge of adjacent migrating cells. This localization correlates with a surge in matrix metalloproteinase activity and an increase in the expression of α1,2-mannosidase subtype IC (MAN1C1). Global inhibition of α1,2-mannosidase I activity with deoxymannojirimycin markedly attenuates the glycosylation of CD147 and disrupts its surface distribution at the leading edge, concomitantly reducing the expression of matrix metalloproteinase-9. Likewise, treatment with deoxymannojirimycin or siRNA-mediated knockdown of MAN1C1 impairs the ability of the carbohydrate-binding protein galectin-3 to stimulate CD147 clustering in unwounded cells. We conclude that the mannose-trimming activity of α1,2-mannosidase I coordinates the clustering and compartmentalization of CD147 that follows an epithelial injury.

摘要

CD147是广泛表达的基质金属蛋白酶诱导剂，参与细胞迁移的调控。高糖基化和进行寡聚的能力与CD147的功能有关，但是对这些过程背后的分子机制的理解还很有限。当前的研究表明高尔基α1,2-甘露糖苷酶I的表达是细胞迁移过程中维持CD147细胞表面组织的关键。使用分层的人类角膜上皮伤口愈合的体外模型，我们显示CD147聚集在相邻迁移细胞前沿的侧质膜内。这种定位与基质金属蛋白酶活性的激增和α1,2-甘露糖苷酶亚型IC（MAN1C1）的表达增加有关。全局抑制α1，具有脱氧甘露糖霉素的2-甘露糖苷酶I活性显着减弱了CD147的糖基化并破坏了其在前缘的表面分布，因此降低了基质金属蛋白酶-9的表达。同样，用脱氧甘露糖霉素或siRNA介导的MAN1C1敲低处理会损害碳水化合物结合蛋白galectin-3刺激未受伤细胞中CD147聚集的能力。我们得出结论，α1,2-甘露糖苷酶I的甘露糖修饰活性协调了上皮损伤后CD147的聚集和区室化。用脱氧甘露糖霉素或siRNA介导的敲除MAN1C1进行的治疗会削弱碳水化合物结合蛋白galectin-3刺激未受伤细胞中CD147聚集的能力。我们得出结论，α1,2-甘露糖苷酶I的甘露糖修饰活性协调了上皮损伤后CD147的聚集和区室化。用脱氧甘露糖霉素或siRNA介导的敲除MAN1C1进行的治疗会削弱碳水化合物结合蛋白galectin-3刺激未受伤细胞中CD147聚集的能力。我们得出结论，α1,2-甘露糖苷酶I的甘露糖修饰活性协调了上皮损伤后CD147的聚集和区室化。