Effects of MCP-1 on proliferation activity of astrocytes derived from SJL and G1H+/− mice. Cultured astrocytes derived from SJL (gray columns) and G1H+/− (black columns) mice are stimulated with recombinant murine MCP-1 (rmMCP-1) at concentrations of 0, 1, 10 and 50 ng/mL for 48 h, and the proliferation activity determined by a CCK8 kit is compared (a). The G1H+/− astrocytes are also stimulated with 10 ng/mL rmMCP-1 in the presence (black columns) or absence (gray columns) of treatment with 10 μM CCR2 antagonist, and the proliferation activity is compared (d). Two-way ANOVA provides P < 0.05 (a, d). Posthoc Bonferroni correction provides *P < 0.001 as compared to the MCP-1-unstimulated SJL cell group, #P < 0.05 and §P < 0.01 as compared to the MCP-1-unstimulated G1H+/− group, and ¶P < 0.05 and †P < 0.01 as compared to the CCR2 antagonist-untreated, rmMCP-1 concentration-matched G1H+/− groups. Morphological changes of cultured astrocytes stimulated with 10 ng/mL rmMCP-1 are compared between the SJL and G1H+/− groups by phase-contrast images (b) and CCR2 immunocytochemistry detected by the immunofluorescence method using a secondary antibody conjugated with Cy3 (red) and DAPI (blue) as a nuclear marker (c). Scale bars indicate 50 μm (b, c).