Fig. 7.

Sirpα promoted the stabilization and relocation of HIF1α. The macrophages collected from adductor muscles of WT mice were pre-treated with 30 ng/ml IL-4 for 48 h to elevate the level of Sirpα and then incubated under hypoxic conditions for 0 to 168 h. A The growth factors secreted by the pre-conditioned macrophages were checked using ELISA. B The level of HIF1α in the macrophages’ nuclei at various times post-hypoxic pre-conditioning. C The level of Sirpα in the macrophages at various times post-hypoxic pre-conditioning. D–F Lentiviruses were used to overexpress Sirpα in 30 ng/ml IL-4 pre-conditioned macrophages. Then macrophages were incubated under hypoxic conditions for 0 to 168 h with or without the presence of CD47. The level of HIF1α in the Sirpα overexpressed macrophages nuclei without the presence of CD47 at various times post-hypoxic pre-conditioning (D). The level of HIF1α in the Sirpα overexpressed macrophages nuclei with CD47 at various times post-hypoxic pre-conditioning, Lentiviruses control-treated macrophages were used as a control (E). The nucleus relocation of HIF1α in the macrophages was checked by immunofluorescence (F, n = 4, 168 h post-hypoxic pre-conditioning, scale bar: 50 µm), Cont: Lentiviruses control-treated macrophage without the presence of CD47, Cont CD47: Lentiviruses control-treated macrophage with the presence of CD47, Sirpα: Sirpα overexpressed macrophage without the presence of CD47, Sirpα CD47: Sirpα overexpressed macrophage with the presence of CD47. Data is analyzed using one-way ANOVA followed by Tukey multiple range test and expressed as mean ± SD of n = 3, unless specified. ***p < 0.001, and ****p < 0.0001. ns, non-significant. IC, isotype control