Figure 4
MCP-1 secretion from microglia under stimulation of soluble Aβ and self-promoted microglial recruitment.
(a) Microglial cells are cultured in wells containing sAβ42 and discernibly expressed five cytokines (MCP-1, MIP-1b, IL-ra1, IL-6 and IL-8) are measured among tested twenty-seven human cytokines from extracted solutions. (b) Highest levels of a cytokine, MCP-1 are measured when microglia are cultured under sAβ42 in monomers and oligomers at 2.3 pg.mL−1. (c) Microglial cells are cultured in the presence of gradients of cytokine-neutralizing antibody (Ab) combined with sAβ42 or cytokines and reduction of recruitment index is measured in the presence of neutralizing antibody against MCP-1 and sAβ42 at 23 pg.mL−1 but not 23 ng.mL−1. (d) MCP-1 is validated to be a potent chemoattractant for microglia and the recruitment is inhibited by immune-neutralization of MCP-1. However, MIP-1a and MIP-1b have no microglial chemoattractant activity in this assay. (Student's t-test. *P < 0.01 for oligomers with respect to no sAβ42). nwell = 3, ncell ≈ 2,000 in ‘(a)’, ‘(b)’ and nplatform = 4, ncell ≈ 2,500 in ‘(c)’, ‘(d)’ for each condition. Data represent mean ± s.e.m.
