TRAIL-Dependent Resolution of Pulmonary Fibrosis

Figure 5

TRAIL expression is required for the optimal resolution of lung fibrosis in vivo. (a) Mice received bleomycin and were killed at days 14, 21, and 42 after challenge and ELISA was used to determine the concentration of TRAIL in whole lung samples. As a control, whole lung samples from naïve mice were subjected to the same analysis. (b) Mice were treated with Clod Lipo one day (D−1) prior to bleomycin, and ELISA was used to determine the whole lung levels of TRAIL. (c) Bleomycin-challenged mice were analyzed at days 14, 21, and 42 after challenge. Another group of mice were injected with IgG control or anti-Gr-1 mAb on day 21 and analyzed at day 42. Quantitative PCR analysis was used to determine TRAIL and peroxiredoxin 6 transcript expression in whole lung RNA samples. (d) Purified Gr-1⁺ myeloid cells were adoptively transferred into bleomycin-challenged mice at day 5 or 14 after bleomycin. At day 21, ELISA was used to determine TRAIL levels in all groups of mice. (e) Mice were injected by intraperitoneal injection with anti-TRAIL mAb from days 14 to 21 after bleomycin, and quantitative PCR was used to determine whole lung transcript expression of procollagen 1 and procollagen 3. Data are mean ± SEM, n = 5–10 mice/group, compared with the appropriate control group. All statistics were performed using unpaired parametric t-tests; and .

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