Journal: Journal of immunology (Baltimore, Md. : 1950)
Article Title: Tissue Inhibitor of Metalloproteinase-1 (TIMP-1) Promotes PMN Pericellular Proteolysis by Anchoring Matrix Metalloproteinase-8 and -9 to PMN Surfaces
doi: 10.4049/jimmunol.1801466
Figure Lengend Snippet: In A, PAF- and fMLP-activated PMNs from Mmp-9−/− and Timp-1−/− mice were incubated with or without 50–400 nM exogenous murine proMmp-9, and then immunostained with rabbit anti-Mmp-9 IgG, or non-immune rabbit IgG followed by goat anti-rabbit F(ab)2-conjugated to Alexa 488. In B, PAF- and fMLP-activated PMNs from Mmp-8−/− and Timp-1−/− mice were incubated with or without 50–400 nM exogenous murine proMmp-8, and then immunostained with rabbit anti-Mmp-8 IgG, or non-immune rabbit IgG followed by goat- anti-rabbit F(ab)2-conjugated to Alexa 488. In A-B, the antibodies used detect both the pro and active forms of the Mmps. Data are mean + SEM; n = 150–200 cells per group. Data were analyzed using a One-Way ANOVA followed by pair-wise testing with two-tailed Student’s t-tests. Asterisk indicates P < 0.001 compared with cells incubated without exogenous murine proMmp-9 or proMmp-8. In C, Timp-1−/− PMNs were incubated at 4°C with: 1) no exogenous proteins for 2 h; 2) no exogenous proteins for 1 h and then 200 nM proMmp-9 for 1 h; 3) 200 nM Timp-1 for 1 h and then with proMmp-9 for 1 h; 4) 200 nM Timp-2 for 1 h, and then with proMmp-9 for 1 h. Unbound proteins were removed after each incubation step by washing PMN twice in buffer. Non-permeabilized PMNs were then immunostained with Alexa 488 for surface-bound pro and active Mmp-9. Data are mean + SEM; n = 150–200 cells per group. Data were analyzed using a One-Way ANOVA followed by pair-wise testing with two-tailed Student’s t-tests. Asterisk indicates P < 0.001 compared with all other groups. In D, Timp-1−/− PMN were incubated at 4°C with: 1) no exogenous proteins for 2 h; 2) no exogenous proteins for 1 h and then 200 nM proMmp-8 for 1 h; 3) 200 nM Timp-1 for 1 h and then proMmp-8 for 1 h; 4) 200 nM Timp-2 for 1 h and then proMmp-8 for 1 h; 5) 200 nM myeloperoxidase for 1 h and then 200 nM proMmp-8 for 1 h. Unbound proteins were removed after each incubation step by washing PMN twice in PBS. Non-permeabilized PMNs were then immunostained with Alexa 488 for surface-bound pro and active Mmp-8. Data are mean + SEM; n = 150–200 cells per group. Data were analyzed using a One-Way ANOVA followed by pair-wise testing with two-tailed Student’s t-tests. Asterisk indicates P < 0.001 compared with all other groups. In A-D, the results shown are representative of at least 3 independent experiments. In E-F, equal numbers of PAF- and fMLP-activated PMNs from Timp-1−/− mice were incubated at 4°C with: 1) no exogenous proteins for 2 h; 2) no exogenous proteins for 1 h and 200 nM proMmp-9 or proMmp-8 alone for 1 h; 3) 200 nM Timp-1 for 1 h and then 200 nM proMmp-9 or proMmp-8 for 1 h; 4) 200 nM Timp-2 for 1 h and then 200 nM proMmp-9 or proMmp-8 for 1 h; The cells were fixed and then incubated at 37°C with: 1) gelatin conjugated to quenched FITC for 18 h (in E); or 2) type-I collagen conjugated to quenched FITC for 18 h (in F). In E-F, Mmp-mediated cleavage of each substrate in the presence of amino-phenyl mercuric acetate was quantified in cell-free supernatant samples using fluorimetry, as described in Methods. The data are expressed as mean + SEM % cleavage of the substrate in cells incubated without exogenous proteins; n=4–5 separate experiments. Data were analyzed using a Kruskal-Wallis One-Way ANOVA followed by pair-wise testing with Mann-Whitney U tests. Asterisks indicate P < 0.05 compared with all other groups.
Article Snippet: The PMNs were then incubated at 4°C for 60 min with or without 500 nM purified murine hemopexin protein (Sino Biological, Wayne, PA), and then incubated at 4°C for 60 min with or without 400 nM proMmp-8 (R&D Systems, Minneapolis, MN) or 400 nM proMmp-9 (R&D Systems, Minneapolis, MN).
Techniques: Incubation, Two Tailed Test, MANN-WHITNEY