Figure 3.

Macrophages isolated from prostaglandin E₂ receptor 2 (EP2) knockout mice show attenuated migration ability. A, The effect of EP2 deficiency on the number of monocytes was examined in various tissues. Representative flow cytometric analyses of CD115⁺/Ly6c⁺ monocytes, as indicated in the red boxes, in the bone marrow, spleen, and peripheral blood before and after myocardial infarction (MI) are shown. B, The number of monocytes examined in different tissues of wild‐type (WT) and EP2‐null (EP2^−/−) mice before and after MI was quantified and statistically analyzed. Before MI, n=5 to 6 animals per group. After MI, n=5 to 9 animals per group. Statistical analysis was performed using an unpaired t test or a nonparametric test. C and D, The mobilization ability of macrophages isolated from WT and EP2^−/− mice was examined. C, Representative images showing the macrophages, as presented by 4,6‐diamidino‐2‐phenylindole staining, which migrated in response to different levels of monocyte chemoattractant protein 1 (MCP‐1). The experiment was repeated 4 times. D, The mobilization ability of macrophages was quantified as cell migration index. Statistical analysis was performed using 2‐way ANOVA with Sidak's test. Bar=50 µm. n.s. indicates not significant. **P=0.0040 and ****P<0.0001 at MCP‐1 concentrations of 3 and 30 ng/mL, respectively.