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. 2016 Sep 22;11(9):e0162008. doi: 10.1371/journal.pone.0162008

Fig 2. Metalloproteinases cleave CD13 from the surface of FLS.

Fig 2

Five different protease inhibitors were added to FLS cultures covering all classes of proteases. (A) The only inhibitor to decrease shedding of CD13 into the supernatant of the cultures was GM6001. (B) No significant decreases were seen in cell lysate CD13 concentrations. Cultures were incubated with serum free media containing protease inhibitors for 48 hours: Pepstatin A (aspartic) 10μM, Aprotinin (serine) 100nM, Leupeptin (serine/cysteine) 10μM, GM6001 (metalloproteinase) 25μM, and E-64 (cysteine) 10μM. (C) TIMP-2 (0.6μg/ml) inhibited the secretion of CD13 from RA FLS while TIMP-1(0.6μg/ml) did not. We used FLS from 3 different RA patients. Secretion was measured by ELISA and optical density (OD) of the samples was measured. (n = 3) mean of % change ± SEM *p≤0.05 ***p≤0.0001