Subcellular distribution and cytokine- and chemokine-regulated secretion of leukolysin/MT6-MMP/MMP-25 in neutrophils
Subcellular distribution and cytokine- and chemokine-regulated secretion of leukolysin/MT6-MMP/MMP-25 in neutrophils
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DOI：
10.1074/jbc.m007997200
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发表时间：
2001-06-15
影响因子：
4.8
通讯作者：
Pei, DQ
中科院分区：
文献类型：
--
作者：
Kang, TB;Yi, J;Pei, DQ
白细胞溶血素最初从人类白细胞中分离出来，是膜型基质金属蛋白酶 (MT-MMP) 亚家族的第六个成员，具有潜在的糖基磷脂酰肌醇 (GPI) 锚。为了了解其生物学功能，我们筛选了白细胞亚群，并将白细胞溶血素在 mRNA 水平上的表达定位于中性粒细胞。针对来自其铰链区的合成肽产生的多克隆和单特异性抗血清可识别中性粒细胞裂解物中 56 kDa 的主要蛋白质种类和 38 至 45 kDa 之间的几种次要形式。在静息中性粒细胞中，溶细胞素分布在特定颗粒（类似于 10%）、明胶酶颗粒（类似于 40%）、分泌囊泡（类似于30%）和质膜（类似于 20%），这种模式与中性粒细胞 MMP-8 和 MMP-9 不同。与其膜定位和报道的 GPI 锚一致，白细胞溶血素分配到 Triton X-114 的去污剂相中，并可通过糖基磷脂酰肌醇特异性磷脂酶 C 从完整的静息中性粒细胞中释放。佛波醇肉豆蔻酸酯乙酸酯刺激中性粒细胞从特定颗粒和明胶酶颗粒中排出 100% 的白细胞溶血素，并从分泌囊泡中排出约 50% 的白细胞溶血素。和质膜，表明白细胞溶血素可以通过生理信号作为可溶性酶动员到细胞外环境。事实上，白细胞介素 8（一种中性粒细胞趋化剂）通过对蛋白酶抑制剂混合物（包括抑肽酶、BB-94、胃酶抑素和 E64）具有抗性的过程，引发了大约 85% 的细胞白细胞溶血素的释放。最后，纯化的重组白细胞溶血素可以降解细胞外基质的成分。这些结果不仅确立了白细胞溶血素作为第一个中性粒细胞特异性 MT-MMP，而且还暗示其在先天免疫反应或组织损伤期间作为细胞因子/趋化因子调节的效应物。
Leukolysin, originally isolated from human leukocytes, is the sixth member of the membrane-type matrix metalloproteinase (MT-MMP) subfamily with a potential glycosylphosphatidylinositol (GPI) anchor. To understand its biological functions, we screened subpopulations of leukocytes and localized the expression of leukolysin at the mRNA level to neutrophils. Polyclonal and mono-specific antisera raised against a synthetic peptide from its hinge region recognized a major protein species at 56 kDa and several minor forms between 38 and 45 kDa in neutrophil lysates, In resting neutrophils, leukolysin is distributed among specific granules (similar to 10%), gelatinase granules (similar to 40%), secretory vesicles (similar to 30%), and the plasma membrane (similar to 20%), a pattern distinct from that of neutrophil MMP-8 and MMP-9. Consistent with its membrane localization and its reported GPI anchor, leukolysin partitions into the detergent phase of Triton X-114 and can be released from intact resting neutrophils by glycosylphosphatidylinositol-specific phospholipase C. Phorbol myristate acetate stimulates neutrophils to discharge 100% of leukolysin from specific and gelatinase granules and similar to 50% from the secretory vesicles and plasma membrane, suggesting that leukolysin can be mobilized by physiological signals to the extracellular milieu as a soluble enzyme. Indeed, interleukin 8, a neutrophil chemoattractant, triggered a release of similar to 85% of cellular leukolysins by a process resistant to a mixture of proteinase inhibitors, including aprotinin, BB-94, pepstatin, and E64. Finally, purified recombinant leukolysin can degrade components of the extracellular matrix. These results not only establish leukolysin as the first neutrophil-specific MT-MMP but also implicate it as a cytokine/chemokine-regulated effector during innate immune responses or tissue injury.