Figure 1.

p38α in macrophages regulates production of proinflammatory cytokines in a stimulus‐ and time‐dependent manner.

(A) RNA was isolated from naïve BMDM from male WT and p38αCKO (CKO) mice (n = 3), and Mapk14 mRNA abundance was assayed using quantitative RT‐PCR, with the housekeeping gene B2m as a normalizer, and then normalized further to the average expression in WT as equal to 1. BMDMs were stimulated with 100 ng/ml LPS or 50 µg/ml MTB for the indicated lengths of time (minutes). (B) Cells were lysed at the indicated time points (minutes) and subjected to immunoblotting for phosphorylated p38 (p‐p38), total p38α, and GAPDH (as a loading control). (C–F) The production of the TNF‐α (C and D) and IL‐6 (E and F) at the indicated time points (4 and 24 h) in the cell supernatants was quantified by ELISA. Significance of differences was determined by t‐test (A) and 2‐way ANOVA, followed by Sidak's post hoc comparison tests for individual time points, comparing WT with CKO. Symbols indicate a significant difference between WT and CKO, as follows: *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. The absence of a symbol indicates a lack of significant difference.