Fig. 4: Inhibiting SCD1 activity can modulate the responsiveness of microglia to inflammatory stimuli and suppress tumor cell proliferation.

A The heatmap showing the fatty acid concentrations detected by gas chromatography in microglia after the addition of 5 μM CAY10566. B GC/MS analysis of the SCD1 activity from control (DMSO) and CAY10566 (5 μM) treatment group; desaturation indices were determined by calculating the 16:1/16:0 and 18:1/18:0 ratios (n = 4). C Representative images showing that CAY10566 treatment in vitro can reduce lipid droplet formation in microglia. Bodipy (green) labels LDs, and DAPI (blue) marks the cell nuclei. Scale bar, 25 μm (n = 4). D Schematic diagram illustrating the experiment for investigating microglial inflammatory response. E Microglia were preconditioned with conditioned media from lung cancers for 12 h before 6 h stimulation with LPS (100 ng/mL) and IFN-γ (50 ng/mL). Expression levels of IL1β, IL6, and TNFα in microglia pre-treated with tumor-conditional medium or control were detected by RT-qPCR (n = 4). F Representative immunofluorescence staining image showing the proliferation of tumor cells in the mouse brains, with (blue) HuNu-labeled nuclei of tumor cells, (red) IBA1-labeled microglia, and (green) Ki67-labeled proliferating cells. Scale bar = 20 μm. G Representative EDU staining images showing the proliferation capacity of A549 cells co-cultured with microglia or the control group (n = 3). H Representative EDU staining images showing the proliferation capacity of A549-BrM cells co-cultured with microglia or the control group (n = 3). I Representative EDU staining images showing the proliferation capacity of NCI-H446 cells co-cultured with microglia or the control group (n = 3). J Representative EDU staining images showing the proliferation capacity of A549-BrM cells co-cultured with microglia treated with or without SCD1 inhibitors (n = 3). (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001).