Figure 5

Effects of human marrow stromal cells on lipopolysaccharide-induced activation of microglia. Microglia were stimulated with 1 mg/μl lipopolysaccharide (LPS), and cultures were treated with human marrow stromal cells (hMSCs) in co-cultures and transwell cultures, and hMSC conditioned medium (CM) (400× magnifications). Cells were fixed after 12 hours of stimulation with LPS. Microglial cells were immunostained with an antibody against the F4/80 antigen, and hMSCs were stained with anti-HuNu antibody. In normal control cultures, the majority of microglial cells were small and round. Upon stimulation with LPS, most of the microglial cells showed an enlarged shape. MSCs in co-cultures and transwell cultures dramatically inhibited microglial activation, whereas hMSC CM has no significant effect on the microglial activation.