P2-006 Profiles of Receptors for Specialized Lipid Mediators on Synoviocyte from Osteoarthritis

【Background】 As specialized pro-resolving mediators (SPM) derived from fatty acids are detectable in synovial fluids in osteoarthritis (OA), they appear to take some roles for disease pathogenesis. Receptors for SPMs have been found, such as leukotriene B4 receptor (BLT1), formyl peptide receptor 2 (FPR2), and chemokine like receptor 1 (CMKLR1). 【Purpose】 To identify the significance of receptors for SPMs on the cells in synovial tissue from OA joints. 【Methods】 Expression of BLT1, FPR2 and CMKLR1 on synoviocytes from OA patients (45.5% women, mean age 69 years, mean BMI 27.9 kg/m(2)) and macrophage were analysed by flow cytometry and quantitative PCR. 【Results】 FPR2 and CMKLR1 are found on synoviocyte, in which mean expression by flow cytometry were 8.5% and 6.2%, respectively, but BLT1 was less than 2.0%, although all of them decreased by keeping incubation. LPS treatment increased rather FPR2, but not so much CMKLR1, on synoviocytes and macrophage. 【Conclusion】 There are FPR2 or CMKLR1 positive cells in synovial tissues, and especially FPR2 seems to have a certain function under inflammatory conditions.