Figure 6. p38α regulates TTP expression and activity in TAMs.

A, EG7 TAM RNA from WT or p38α^ΔH tumor bearing mice was analyzed by qRT-PCR. Expression values from individual mice combined from 3 experiments (n ≥ 13) were normalized to GAPDH and the mean WT within each experiment and are depicted as mean indicated by black lines. Error bars, SEM.

B and G, mRNA stability measured by qRT-PCR as in Figure 4Din EG7 TAMs from WT (Mapk14^flox/flox) and p38α^ΔH animals (B) and in unstimulated (−) or SB203580 (SB) treated WT EG7 TAMs (G). SB treatment was started concomitant to Actinomycin D imposed transcriptional blockade. Data represent values from individual mice normalized to GAPDH from either 3–5 (n ≥ 10, B) or 1 out of 2 (n ≥ 7, G) experiments, respectively. Black lines indicate the mean per group. Error bars, SEM. C, cytokine expression analyzed by flow cytometry of EG7 TAMs (gated on CD11b⁺) isolated from WT or p38α^ΔH mice. Values from individual mice are percent of CD11b⁺ cells (n = 6) representing 1 out of 2 experiments with the mean depicted as black line. Error bars, SEM. D, cytokine production evaluated by intracellular flow cytometry in lethally irradiated mice reconstituted with a mixture of WT (CD45.1) and p38α^ΔH (CD45.2) bone marrow (n = 4). Depicted values represent % positive cells of CD11b⁺ TAMs gated for CD45.1 or CD45.2 as shown (left panel). Error bars, SEM. E, EG7 tumor mass 12days post transplantation of EG7 cells into WT or p38α^ΔH animals. Values from individual mice combined from 3 experiments are shown with the black line representing the mean. Error bars, SEM. F, qRT-PCR analysis of TTP and TTP family members in EG7 TAMs from WT and p38α^ΔH mice. Data represent expression values from individual mice (n ≥ 14) normalized to GAPDH and the corresponding mean WT from 3 independent experiments. The mean is shown as black line. Error bars, SEM. H, mRNA decay measured in WT and TTP^ΔM EG7 TAMs with and without SB treatment as in G. Values of individual mice are depicted as % of mRNA stability after SB treatment relative to the corresponding stability in untreated WT or TTP^ΔM TAMs. Values were normalized to GAPDH and the corresponding untreated TAM sample (n ≥ 9) and were combined from 2 experiments. The black line represents the mean. Error bars, SEM.