Fig. 4: sCSF1R_inh blocks murine microglia proliferation and attenuates pro-inflammatory signaling.

a Bright field images illustrate the impact of CSF1 stimulation on cell confluence in primary murine microglia cultures. Quantification with IncuCyte Zoom software demonstrates that sCSF1R_inh blocks CSF1-induced increases in cell coverage. Data points represent the average cell coverage per well and graphical columns represent the mean and standard deviation (n=6). Statistical significance was determined by a one-way ANOVA and p values are indicated by ****p < 0.0001. b Immunocytochemistry with an Iba1 antibody shows microglial morphology and number following CSF1 stimulation. Quantification with IncuCyte Zoom software further confirms that sCSF1R_inh abrogates CSF1-induced increases in Iba1 coverage. Data points represent the average Iba1 area per well and graphical columns represent the mean and standard deviation (n=3). Statistical significance was determined by a one-way ANOVA and p values are indicated by **p < 0.01 and ****p < 0.0001. c Ki67 immunostaining was utilized to visualize microglial proliferation following CSF1 stimulation. Ki67⁺ cells were quantified with IncuCyte Zoom software. Data points represent the average number of Ki67⁺ cells a per well (from nine images) and graphical columns represent the mean and standard deviation (n = 3). Statistical significance was determined by a one-way ANOVA and p values are indicated by ****p < 0.0001. d CSF1 (5 ng/mL) induced murine macrophage proliferation over the course of 24 h as measured by H3 incorporation and sCSF1R_inh blocked proliferation in a concentration-dependent manner. Data points and error bars represent the mean and standard deviation (n = 9); the IC₅₀ was calculated with Prism 6 (GraphPad Software). e CSF1 stimulation (100 ng/mL) induced MCP-1 release from primary murine microglia and sCSF1R_inh blocked MCP-1 production in a concentration-dependent manner (f) LPS (10 ng/mL) induced a significant increase in IL-12p40 production by primary murine microglia and sCSF1R_inh significantly reduced IL-12p40 in a concentration-dependent manner. Data points represent the protein concentration per well and graphical columns represent the mean and standard deviation. Statistical significance was determined by a one-way ANOVA and p values are indicated by **p < 0.01, ****p < 0.0001.