Figure 7. Malat1 knockdown promotes profibrotic differentiation of macrophages.

(A) Wide-type mice were i.t. instilled with 50 μl saline or 1.5 U/kg bleomycin (BLM) in 50 μl saline. Three weeks after bleomycin administration, BAL cells were collected and resident and recruited alveolar macrophages were sorted as described in Methods. Levels of Malat1 were determined by real-time PCR. n = 3, 3 mice for each group; mean ± SE. (B and C) BMDMs were transfected with 20 nM control (con) GapmeR or Malat1 GapmeR. Forty-eight hours after transfection, the cells were treated for 48 hours with BALFs from mice that were treated i.t. with saline or 1.5 U/kg bleomycin for 3 weeks. Levels of the indicated genes were determined by real-time PCR. n = 4; mean ± SD. (D and E) BMDMs were transfected with 20 nM con GapmeR or Malat1 GapmeR. Forty-eight hours after transfection, the cells were pretreated with vehicle, 2 mM 2-DG (D), or 50 μM UK-5099 (E) for 1 hour, followed by treatment with BALFs from mice that were treated i.t. with saline or 1.5 U/kg bleomycin for 3 weeks. Levels of the indicated profibrotic markers were determined by real-time PCR and normalized to the group of cells treated with con GapmeR and saline BALF. n = 3; mean ± SD. *P < 0.05; **P < 0.01; ***P < 0.001 by 1-way ANOVA with Bonferroni’s post hoc test (A–E). Representative of 2 independent experiments.