Nfluence on thrombin-cleaved OPN levels.

The -443TT and -66GG
Nfluence on thrombin-cleaved OPN levels. The -443TT and -66GG, which PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/14960617 showed a protective role against susceptibility to OA, had markedly lower thrombin-cleaved OPN levels. Our data confirmed the positive correlation between thrombin-cleaved OPN levels in SF and OA severity. We suggest that thrombin-cleaved OPN may serve as a biochemical marker for determining disease severity and could be predictive of prognosis 1-(Cyclopropylsulfonyl)-1,4-diazepane with respect to the progression of knee OA. Since previous studies showed that the alleles at polymorphic sites in the OPN gene influence the OPN level by influencing the level of promoter activity and characterizing their ability to bind transcription factors, we here postulated that the influence of OPN polymorphisms on risk and severity of OA is very likely due to its effect on the synthesis of the active OPN protein. Some limitations of this study need to be addressed. First, there was a large proportion of obese patients in this study. As obesity is an important risk factor for OA, not only as a mechanical factor but also due to the related increase in cytokines, which contribute to OA development. Thus, there PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/10714611 might have been enrollment bias in the recruitment of patients with primary OA into this study. Second, we enrolled a Chinese cohort of patients with knee OA only, so, whether the positive roles of OPN gene polymorphisms we found in this study exist in other types of OA, or in other ethnic populations, remains unknown. Third, we did not perform functional analyses to further disclose the mechanism under which the OPN gene polymorphisms affect the susceptibility to and severity of OA.Abbreviations BMI: body mass index; CV: coefficient of variation; ELISA: enzyme-linked immunosorbent assay; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; KL: Kellgren-Lawrence; NSCLC: non-small cell lung cancer; OA: osteoarthritis; OPN: osteopontin; OR: odds ratio; PBS: phosphate-buffered saline; RA: rheumatoid arthritis; SF: synovial fluid; SP: specificity protein. Authors' contributions YJ: study design, manuscript writing; MY, CZ and QL: OPN genotyping and clinical data collection. All authors have read and approved the manuscript for publication. Competing interests The authors declare that they have no competing interests. Acknowledgements We thank Dr. Li Zhen and Xuwei Hou for their help in Methyl 3-amino-2,4-dichloro-5-fluorobenzoate statistical analyses. This study was supported by the National Natural Science Foundation of China (30770543). Received: 29 July 2012 Revised: 18 November 2012 Accepted: 20 December 2012 Published: 5 January 2013 References 1. Hunter DJ, Wilson DR: Imaging the role of biomechanics in osteoarthritis. Rheum Dis Clin North Am 2009, 35:465-483. 2. Coulibaly Y, Diakite AA, Keita M, Diakite I, Dembele M, Diallo G: Epidemiology and therapy of osteoarthritis in children. Mali Med 2009, 24:7-10. 3. Abramson SB: Inflammation in osteoarthritis. J Rheumatol Suppl 2004, 70:70-76. 4. Bonnet CS, Walsh DA: Osteoarthritis, angiogenesis and inflammation. Rheumatology (Oxford) 2005, 44:7-16. 5. Benito MJ, Veale DJ, FitzGerald O, van den Berg WB, Bresnihan B: Synovial tissue inflammation in early and late osteoarthritis. Ann Rheum Dis 2005, 64:1263-1267. 6. Esser S, Bailey A: Effects of exercise and physical activity on knee osteoarthritis. Curr Pain Headache Rep 2011, 15:423-430. 7. Bae JY, Park KS, Seon JK, Kwak DS, Jeon I, Song EK: Biomechanical analysis of the effects of medial meniscectomy on degenerative osteoarthritis. Med Biol Eng Comput 2012, 50:53-60. 8.