Urine Proteomics Profiling and Functional Characterization of Knee Osteoarthritis Using iTRAQ Technology

Abstract

AbstractOsteoarthritis (OA) is a degenerative chronic disease affecting the whole joint structures. With the increment in life expectancy and aging population, OA has become one of the largest socioeconomic burdens, associated with pain and loss of joint function. However, early laboratory tests of OA are still lacking. Therefore, new diagnostic tests for this disease are urgently needed. In this study, to gain an insight into the pathogenesis and the potential biomarkers of OA, we implemented a comparative urine proteomics study on OA patients and health people using iTRAQ-based mass spectrometry technology. Western blotting was used to validate the relative changes in urine protein levels for four of the identified proteins. We constructed a comprehensive urine proteome profile of the OA patients and identified 102 proteins differently changed in abundance. Forty-six proteins were upregulated and 56 proteins were significantly downregulated in OA patients. Furthermore, the proteins, COL-4, MMP9, adiponectin, and BBOX1 were validated through Western blots, which can serve as valuable candidate biomarkers and help to illustrate the pathogenesis of OA. These findings may provide clues for promising biomarkers for the early diagnosis and also offer a theoretical basis for the early treatment of OA.