Shuttling and function of MMP28 during EMT and collective migration

项目总结 基质金属蛋白酶(MMPs)是一类以基质重塑为主要特征的蛋白酶家族。 几种癌症和慢性炎症性疾病中的活动性。然而，MMPs也存在于细胞内。 包括几种细胞类型的核的隔室。MMP28是家庭中最后一个被确认的成员，它 参与伤口修复、中枢神经系统发育和免疫系统成熟。此外, MMP28的错误调控与几种癌症有关。MMP28活性可诱导上皮细胞向上皮细胞转化 间充质转化(EMT)和人肺泡上皮中的迁移 细胞核。关于基质金属蛋白酶的核活动或基质金属蛋白酶是如何穿梭的，人们知之甚少。 不同的细胞隔间。在非洲爪哇的胚胎中，MMP28在头部的胎盘中表达， 位于非常能动的神经脊(NC)细胞的侧面，后来持续存在于鳃上的胎盘 在迁移的颅骨NC细胞流之间。有趣的是，我们的初步结果显示，MMP28 在邻近的NC细胞的核中检测到由颅骨安慰剂分泌的。MMP28击倒实验 证明核MMP28活性是触发EMT和NC集体细胞迁移的关键 体内和体外。MMP28这种非正则/核活动的发现是 MMP场。然而，目前仍不清楚NC中的MMP28功能是否仅限于这种核活动 以及MMP28是否也有更传统的活动。此外，MMP28的作用机制 被NC细胞内化并最终穿梭到细胞核尚不清楚。在本申请中，我们建议 为了解决这些问题，i)评估MMP28如何调节EMT和NC细胞的迁移，并产生影响 胎盘和NC细胞的协调集体迁移；ii)揭示控制机制 MMP28从胞外室向胞核转运。该项目具有很强的潜力 揭示MMPs功能的新方面，以及它们在控制正常和 病态的情况。

PROJECT SUMMARY Matrix Metalloproteinase (MMPs) constitute a family of proteases primarily known for their matrix remodeling activity in several cancers and chronic inflammatory diseases. However, MMPs are also found in intracellular compartments including the nucleus of several cell types. MMP28 is the last identified member of the family, it is involved in wound repair, central nervous system development, and immune system maturation. In addition, MMP28 mis-regulation has been linked to several cancers. MMP28 activity can induce epithelial-to- mesenchymal transition (EMT) and migration in human alveolar epithelium where it has been described in the cell nucleus. Very little is known about the nuclear activity of MMPs or how MMPs are shuttling through different cellular compartments. In Xenopus laevis embryos, MMP28 is expressed in cranial placodes which are located lateral to the very motile neural crest (NC) cells, and later persists in the epibranchial placodes between the migrating streams of cranial NC cells. Interestingly, our preliminary results show that MMP28 secreted by cranial placodes is detected in the nuclei of neighboring NC cells. MMP28 knockdown experiments demonstrate that nuclear MMP28 activity is essential to trigger EMT and NC collective cell migration both in vivo and in vitro. The discovery of this non-canonical/nuclear activity of MMP28 is paradigm shifting in the MMP field. However, it is still unclear whether MMP28 function in the NC is restricted to this nuclear activity and whether MMP28 has a more conventional activity as well. Furthermore, the mechanisms by which MMP28 is internalized by NC cells and eventually shuttles to the nucleus are not known. In this application we propose to address these questions by, i) assessing how MMP28 modulates EMT and NC cells migration, and impacts the coordinated collective migration of both placode and NC cells; ii) uncovering the mechanisms controlling MMP28 trafficking from the extracellular compartment into the nucleus. The project has the strong potential to reveal novel aspects of MMPs functions, and their roles in the control of migratory cell behaviour in normal and pathological situations.