Sodek J, Batista Da Silva A Paes, Zohar R
CIHR Group in Matrix Dynamics, Faculty of Dentistry, University of Toronto, ON, Canada.
J Dent Res. 2006 May;85(5):404-15. doi: 10.1177/154405910608500503.
Protection of mucosal tissues of the oral cavity, intestines, respiratory tract, and urogenital tract from the constant challenge of pathogens is achieved by the combined barrier function of the lining epithelia and specialized immune cells. Recent studies have indicated that osteopontin (OPN) has a pivotal role in the development of immune responses and in the tissue destruction and the subsequent repair processes associated with inflammatory diseases. While expression of OPN is increased in immune cells--including neutrophils, macrophages, T- and B-lymphocytes--and in epithelial, endothelial, and fibroblastic cells of inflamed tissues, deciphering the specific functions of OPN has been difficult. In part, this is due to the broad range of biological activities of OPN that are mediated by multiple receptors which recognize several signaling motifs whose activities are influenced by post-translational modifications and proteolytic processing of OPN. Understanding the role of OPN in mucosal inflammation is further complicated by its contributions to the barrier function of the lining epithelia and the complexity of the specialized mucosal immune system. In an attempt to provide some insights into the involvement of OPN in mucosal diseases, this review summarizes current knowledge of the biological activities of OPN involved in the development of inflammatory responses and in wound healing, and indicates how these activities may affect the protection of mucosal tissues.
口腔、肠道、呼吸道和泌尿生殖道的黏膜组织通过内衬上皮和特殊免疫细胞的联合屏障功能，抵御病原体的持续侵袭。最近的研究表明，骨桥蛋白（OPN）在免疫反应的发展、与炎症性疾病相关的组织破坏及后续修复过程中起关键作用。虽然在免疫细胞（包括中性粒细胞、巨噬细胞、T淋巴细胞和B淋巴细胞）以及炎症组织的上皮细胞、内皮细胞和成纤维细胞中，OPN的表达均增加，但解析OPN的具体功能却颇具难度。部分原因在于，OPN具有广泛的生物学活性，由多种受体介导，这些受体识别多个信号基序，而这些基序的活性受OPN翻译后修饰和蛋白水解加工的影响。OPN对内衬上皮屏障功能的贡献以及特殊黏膜免疫系统的复杂性，进一步增加了理解OPN在黏膜炎症中作用的难度。为了深入了解OPN在黏膜疾病中的作用，本综述总结了目前关于OPN参与炎症反应发展和伤口愈合的生物学活性的知识，并指出这些活性如何影响黏膜组织的保护。
