Figure 5.

The expression profiles of TAM receptors and Gas6 mRNA are regulated in response to microglial activation, and activation is reduced in the presence of exogenous rhGas6. a–c, Purified rat microglia were incubated with or without 1 μg/ml LPS for 48 h, and mRNA was measured using qPCR. a, Levels of mRNA of both CDllb and TNFα, markers of microglial activation, increased in response to LPS treatment (**p < 0.01). b, Expression of both Axl and Mer mRNA increased in response to LPS-induced activation of microglia (**p < 0.01). c, In contrast, expression profiles of both Tyro3 and Gas6 mRNA in LPS-activated microglia were not significantly different from control cells (p > 0.05). d, Purified rat microglia were cultured in the presence or absence of rhGas6 for 3 h before activation was induced with LPS (1 ng/ml). Cells were harvested after 5 h of LPS treatment and RNA collected. Levels of TNFα mRNA, used as a surrogate marker for microglial activation, were measured by qPCR. There was a significant reduction in TNFα expression in rhGas6 treated microglia compared with microglia not treated with rhGas6 (**p < 0.01, ***p < 0.001).