Mesenchymal stem cells modulate the expression of IL-6 and TNF-α in microglia co-culture. Microglia (BV2 cells or primary microglia) and Mesenchymal stem cells (MSC) were seeded simultaneously into 24-well plates at a 1:0.2 ratio. Cells were left overnight in culture and stimulated with 1 μg/ml lipopolysaccharide (LPS). Culture supernatants were collected 24 hours later and expression of (a,b) interleukin (IL)-6 and (c,d) tumour necrosis factor (TNF)- α were analysed using the RayBio antibody array (a,c) or BD Cytokine Bead Array (b,d). Protein array results are expressed as mean relative protein level ± standard deviation from two independent experiments and cytokine bead array results are expressed in mean concentration (pg/ml) ± standard deviation from three independent experiments. *P < 0.001, versus BV2 cells; #P < 0.001, versus BV2 +μlPS.