Figure 9.

ACM from HN-deficient astrocytes has reduced capacity to modulate microglia. Rat astrocytes were transfected with HNr-specific siRNAs or scrambled RNA for 24 h. After 24 h, siRNA-containing media was replaced with fresh culture medium. Forty-eight hours later, ACM was collected and transferred onto cultured microglia (see schematic; A). The microglia were incubated with ACM for 24 h. The knockdown efficiencies of two different siRNAs in astrocytes were assessed by confirming reduced protein level using immune dot blot analysis for HNr (B). C, Gene expression profiles of PPARγ, LPL, and IL-1β by SYBR real-time RT-PCR in microglia treated for 24 h with ACM collected from astrocytes treated with siRNA targeting HNr or scrambled siRNA. Data are mean ± SEM and assessed for difference between scrambled siRNA and HNr. For scrambled versus HNr: scrambled ACM (n = 3), HNr knockdown ACM (n = 5), two-tailed unpaired t test, PPARγ; *p = 0.0357, LPL; *p = 0.0430, t values (t = 2.558), IL-1β; *p = 0.0024, t values (t = 5.007).