Abstract:

BACKGROUND: Osteonectin is a unique matricellular glycoprotein that is expressed by many different types of cells. As an important component of matricellular matrix, osteonectin contributes to developing and remodeling of bone, tumorigenesis, cell turnover and differentiation.
OBJECTIVE: To review and summarize the structure and functions of osteonectin, and to assess the role of osteonectin comprehensively.
METHODS: The relevant articles between 2000 and 2010 were retried from PubMed (http://www.ncbi.nlm.nih.gov/PubMed) and Wanfang (http://www.wanfangdata.com.cn) using the key words of “osteonectin, SPARC, matricellular protein, fracture healing, tumorigenesis” by the first author. A total 59 literatures were retrieved, and 27 met the inclusion criteria were further analyzed.
CONCLUSION: As a widely expressed matricellular protein, osteonctin not only served as structural protein of extracellular matrix, but also served as regulatory protein for many materials. Osteonctin plays an important role in many biological functions via binding to Ca2+ and collagen, but the study is still at the preliminary step and the mechanism remains unclear. On the other hand, it is reported that osteonctin was abnormal expressed in pathologic state, but the perspective study still limited in animal experiment and in vitro cell experiment, thus, it is far from clinical application. However, osteonctin has breakthrough in treating bone union and tumor with the deepening of studies.